Month: March 2024

We used a nested design and selected three clustered sites within a 1.5 km radius circle and repeated this design across the region . The sites exist along a landscape gradient of semi-natural habitat density and agricultural land use density within a 1.5 km radius. Organic farms sites were all certified organic and used less intensive practices than paired nearby conventional farms that used more intensive practices . Many farms grew a single crop variety, most commonly Brussel’s sprouts, strawberry, broccoli, or lettuce. Farms with multiple crop varieties included a mix of vegetables , beans, squash, tomatoes, herbs, and strawberries. Within each farm pair, we chose monitoring sites in the center of fields planted in annual crops with similar proximity to natural habitat. We used one detector for each site and placed detectors within fields and at the edge of woodland patches .We sampled bats at all sites with passive acoustic bat detectors from mid-June to early September 2014. Bat detectors were mounted on t-posts and microphones were elevated on 3 m PVC poles attached to the t-posts. We monitored bat activity levels and species richness at all sites. We did not compare feeding buzzes due to high subjectivity in distinguishing between a bat inspecting research equipment, a novel structure in their environment, and pursuing insect prey . We sampled each site for 6–7 nights during one sampling period from sunset to sunrise to account for high variability of bat activity across nights; the three sites clustered within each landscape were sampled simultaneously to reduce variability and increase sampling efficiency . Recorded calls were processed using Kaleidoscope V2.3.0 to filter noise files and split files to a max duration of 5 s,fodder system which we defined as a bat pass and used in subsequent analyses.

Files were automatically classified using Sonobat V3.1 West and then manually vetted by a team of trained technicians. To account for potential bias among technicians, we worked as a team until our classification decisions were at least 90% in agreement and used a decision key to finalize call identifications. Remaining calls that could not be positively identified to species were classified by characteristic frequency into three phonic groups, with species that comprise each phonic group listed in parenthesis: 50 kHz , 40 kHz , and 30 kHz . To account for differences in how bats perceive their environment, we grouped a subset of the species recorded in the study region based on their echolocation call structure, characteristic frequency, and foraging ecology into two functional guilds: clutter-adapted and open space bats. Of the 12 species recorded in the study region, two were classified as clutter-adapted bats and four were classified as open-space bats . These groups include the most common species in the study region and represent 97% of recorded calls. We used guidelines described in Schnitzler and Kalko and Buchalski et al. and echolocation call parameters described by the Humboldt State Bat Lab to partition species into functional guilds. Species in the open-space guild have call characteristic frequencies < 30 kHz and > 6 ms in duration, which experience less environmental attenuation and are therefore suited for foraging in uncluttered, open areas. Species in the clutter-adapted guild have calls with characteristic frequencies of > 45 kHz and duration < 6 ms. Bats in the clutter-adapted guild are able to forage in highly cluttered forest habitat by using short duration, high frequency calls to distinguish insect echoes from echoes produced by background clutter .We designed bucket style light traps with 12 W black light bulbs and clear plastic vanes and a brewer’s funnel with a mesh collecting bag containing a 2cm2 piece of pesticide strip .

Light traps were deployed simultaneously with acoustic detectors and were programmed to turn on at civil sunset for three hours during the first two nights that the detectors were deployed. Light traps were placed 10 m from bat detectors to prevent potential high-frequency interference from light traps from being recorded by bat detectors, either within fields or along linear habitat edges. Insects were later sorted and identified to order. We measured the length of each insect to estimate biomass using relationships described for terrestrial California insects in Sabo et al. .We surveyed local vegetation within concentric circles centered on acoustic monitoring sites. Within a 25 m radius, we measured the number of weed morphospecies and visually estimated the total number of flowers within the crop field. Within a 50 m radius, we measured the number of crop varieties, average crop height, and the percent of different ground cover types. For the percent of ground cover types, we focused on cover classes exceeding 5% of ground cover, and included bare ground, crops, non-crop herbaceous vegetation, and woody vegetation. Within both a 50 m and 100 m radius, we measured the number of trees > 30 cm circumference and the number of tree species. For all farms, we estimated the percent of field margins in insectaries , the percent cover of insectaries in crop fields, and the percent of weedy field margins. We gathered information about pesticide application on each farm . Most growers applied broad spectrum insecticides and/or fungicides, although a few smaller, organic operations reported that they had not applied pesticides in years. Some of these pesticides were widely used by organic and conventional growers; only conventional growers used organophosphates. For each farm, we categorized frequency of pesticide applications according to these categories: 1=pesticides applied every 1–10 days; 2=pesticides applied every 11–30 days; 3=pesticides applied less than once a month; 4=pesticides applied less than once a year.

We also gathered information about distance to habitat features that are important for bats, and that we could not standardize across the trio of clustered sites. We used Google Earth to calculate the shortest distance to water and distance to the nearest linear habitat element, such as a treeline, hedgerow, or forest edge .We created land cover maps from the National Agricultural Imagery Project 2014 using manual likelihood classification in ArcMap V10.3.1 . We categorized agriculture and semi-natural habitat, and smoothed and resampled maps to a resolution of 7 m2 to reflect ground-truthed land cover classes. We then calculated the land use density of agriculture and semi-natural habitat within a 1.5 km radius, an ecologically relevant scale for bats and insects .We used total bat activity, clutter-adapted bat activity, open-space bat activity, diversity, and species richness as response variables. Bat activity is a measure of relative abundance calculated for each site over a minimum of six nights of sampling, and thus not true count data. Therefore, we opted to log transform the average number of bat passes per night to meet assumptions of normality with a Gaussian error distribution,fodder system for sale instead of using the Poisson error distribution recommended for count data . We used the Chao1 species richness estimator to assess the completeness of species inventories and to compare species richness across site types . We calculated estimated species richness and diversity using all calls identified to species and the 40k phonic group with the package “vegan” in R software, version 3.3.1 To compare response variables between organic farms, conventional farms, and natural sites, we used a randomized block ANOVA, with sites blocked by landscape cluster, and conducted multiple comparison tests using Tukey contrasts as implemented in the “multcomp’’ package in R . We checked that assumptions of normality and homogeneity of variance were met using the Shapiro-Wilk test and the Brown-Forsyth test in the “HH” package in R . To compare community composition between organic farms, conventional farms, and natural sites, we used a one-way Analysis of Similarity test. We used the Bray-Curtis index to characterize species dissimilarity between habitat types using the “vegan” package in R . We used linear mixed models to compare differences in responses to local, on-farm management practices. We selected predictor variables that represent agroecological farming practices and/or practices characteristic of intensive agriculture that growers could potentially manipulate. We included the percent of weedy field margins, number of crop varieties , average height of herbaceous vegetation , distance from a linear element, and percent woody vegetation . We did not include the percent of field margins planted in insectaries or the percent of field planted in insectaries as covariates because many farms did not utilize either of these practices. Selected predictor variables were not strongly correlated , although they were somewhat correlated with a number of other farm characteristics . In addition, we included distance to water as a fixed effect and landscape cluster as a random effect to account for variation in the surrounding landscape, and to avoid spatial autocorrelation problems.

We used standardized model residuals obtained by the top model for total bat activity to create a variogram and verify spatial independence . We performed model selection using the dredge function in the package “MuMIn” after testing for normality . We log-transformed total bat activity, clutter-adapted bat activity, and crop diversity, and used a square root transformation for open-space bat activity to meet assumptions of normality. We tested all possible combinations of explanatory variables and selected the top model if the corrected Akaike’s Information Criterion score was at least two points less than the next best model . When the top models had similar AICc scores , we selected the top models within two points of the lowest AICc score and adopted a model averaging approach to obtain estimated coefficients and the relative importance of predictor variables from the top model set. We visually inspected the relationships between predictors in top models and responses, and noted an outlier site for crop diversity and weed morphospecies, with most sites ranging from 1 to 10 crop varieties, and one site with 39 crop varieties. We decided to remove the outlier after exploring its leverage on LMMs and Pearson correlation coefficients. The effect of the outlier was minimal in most cases, but it changed the significance of the effect of crop diversity on open-space bat activity, and the strength and significance of the relationship between crop diversity and weed morphospecies within 25 m. We asked if the same local management practices and farm characteristics that predicted bat activity would also predict the biomass of insect orders that are known to be consumed by bats and were commonly collected in light trap samples . We tested LMMs that contained the same set of predictors as bat models to assess if variables that predicted bat activity operated on bats via changes in abundance of insect prey. All models contained a random effect of landscape cluster. To meet assumptions of normality, we used a square root transformation for Diptera biomass, and a log transformation for Lepidoptera and Coleoptera biomass. We assessed Pearson correlations between bat activity and insect biomass for these common prey orders. We used LMMs to test for an interaction between local practices that significantly predicted bat responses and semi-natural habitat density using LMMs. We built a set of candidate models using the top model from model averaging and added an interaction with semi-natural habitat density , and compared models using AICc scores.Across 648 detector nights, we recorded 36,294 bat calls. Of these, we were able to confirm identification to species for 14,969 calls, and remaining calls were identified to phonic group. A total of 12 different species were recorded , and of those, Tadarida brasiliensis and Myotis yumanensis were the most common across all sites. Three recorded species are listed as species of special concern in California: Lasiurus blossevellii , Corynorhinus townsendii , and Antrozous pallidus . The species inventory appears to be complete for natural habitat, but not for farms, according to rarefaction analysis . We recorded fewer, high quality calls on farms compared to natural habitat. Bat calls recorded on farms had less noise interference than recordings from natural habitat, allowing us identify a greater number of species from fewer calls, resulting in steeper species accumulation curves that did not reach an asymptote.Categorical comparisons of lower- and higher-intensity agricultural systems have documented mixed effects on bat activity, diversity and species richness, and provide limited insight on the effects of specific, agricultural management practices.

Mineral phosphate solubilization by bacteria is often correlated with the release of organic anions and corresponding free protons, which lowers the pH in the surrounding soil water solution, and thereby induces chelation of the metal complexes Rodr g e and raga, 1999. If MPS bacterial populations are affected by biochar, this could have a significant impact on P availability from biosolid-derived biochars and plant P uptake. The abilities of the native soil bacteria to solubilize mineral phosphate in treatments prepared with biosoild-derrived biochars generated at 4 HTT’s were quantified using spectrophotometric assays and indicator media. Also, biochar could impact phytoremediation processes utilized in efforts to reduce concentrations of heavy metals and organochlorines pesticides in contaminated soils. Biochar has been shown to enhance root development in arsenic contaminated soils and influence sorption of heavy metals in soils . Some ferns have the ability to remove heavy metals from soils by translocating them into their biomass. Root development in contaminated soils can also stimulate the growth of soil microorganisms by release of root exudates that serve as substrates. Many soil microorganisms degrade organic pollutants, such as organochlorine pesticides. Also, survival of the accumulator plants is essential for successful soil remediation. In this study root-colonizing strains were isolated from soils contaminated with dichlorodiphenyltrichloroethane and arsenic and assayed for ACC deaminase activity and auxin production, microbial traits that play a major role in assisting survival of plants stressed by heavy metals . These PGPR activities were quantified across isolated cultures and mixed consortia taken from the rhizospheres of 2 fern species in contaminated soils amended with biochars prepared at 2 HTT’s. The ferns incl ded a New Zealand native species, Blechnum novaezelandiae,vertical hydroponic nft system and a species originally from China, Pteris cretica, which has been demonstrated to be an arsenic-hyperaccumulating species .

The main objective of these studies were to determine if PGPR communities were affected by different biochar materials and if this effect could be related to plant development in the given treatment soils. Changes in the expression of enzymes brought about by biochar will shed light on the physiochemical processes in the soil environment that shape the structure and function of microbial communities in the rhizosphere. Current strategies for sustainable soil management entail the use of methods that selectively enrich indigenous plant growth promoting bacteria , or carrier materials, such as biochar, that deliver beneficial soil inoculants to plant root zones. Many PGPR have the capacity to produce exogenous plant growth hormones, an activity that has been correlated with increasedtotal root length, branched root architecture, and root hair formation . Enterobacter cloacae UW5 serves as a well-studied strain for production of plant growth hormone, indole-3-acetic acid by the indole pyruvate pathway. Indole-3-pyruvate-decarboxylase is an enzyme essential for IAA generation via this pathway and the expression of the ipdC gene is induced by tryptophan . Another significant PGPR trait is the ability of some microorganisms to produce 1-aminocyclopropane-1-carboxylic acid deaminase. Under conditions of abiotic stress plants generate ethylene, which can accumulate in the rhizosphere and, in turn, elicit a stunting response in the plant, drastically reducing crop yields . Diverse soil bacteria have the enzyme ACC deaminase, which allows them to utilize the precursor to ethylene, ACC, as a nitrogen source, degrading the ACC into ammonia and α-ketobutyrate . PGPR with ACC deaminase activity have been shown to improve plant growth during flooding and drought conditions and in soils affected by salinity or heavy metals . ACC deaminase has been best studied in Pseudomonas putida UW4, and the expression of the gene encoding this enzyme is induced in the presence of ACC . The activities of each of these enzymes were determined to be essential to plant-growth-promotion by the given strains . Hence, any interference of biochar with the expression of these genes could result in loss of benefit associated with inoculum harboring these traits.

In previous work soil-microbial enzymatic activity was shown to be increased or decreased in the presence of biochar . Thus, it is important to better understand the influence of biochar on beneficial PGPR enzyme activity. Several methods were employed to analyze the expression of genes involved in ACC deaminase activity and IAA biosynthesis. Spectrophotometric assays provided initial insight into the PGPR activity of these strains as influenced by biochar in culturing media. The assays for PGPR traits among the native soil microbial communities indicated whether biochar amendment is influencing the microbial communities, possibly shaping the communities to select for more or less plant beneficial strains. For the most part, microorganisms isolated and mixed consortia cultured from the amended soils showed similar MPS bacteria proportions and activities to that of the unamended soil. However, the soils amended with BS250 had significantly lower percentages of MPS bacteria or MPS activity in mixed consortia. Of the amendment chemical properties analysed by Wang et al.the BS250 had notably higher volatile matter/ ratio and lower pH than did the other amendments. These properties may have had an influence on the soil MPS bacteria. In the case of the PGPR activities assayed in the phytoremediation study, bacteria with ACC deaminase were present in all rhizospheres and did not correlate significantly to the soil treatments. However, the W550 treatment had a positive influence on bacteria that produce IAA in the B. novae-zelandiae rhizosphere. This species of fern was found growing in the area from which the contaminated soil was extracted. The P. cretica fern species is not native to this area. Soil microbial communities may have been better adapted to the B. novae-zelandiae rhizosphere and this may exhibit a greater indication of response to biochar amendment. In other work using the same soil and biochars, microbial dehydrogense activity was significantly increased in the presence of W350 and even more so by W550 . This could indicate the benefit of using an indigenous plant species for phytoremediation of contaminated soils involving biochar.

The results of this research indicated that the biochar amendments did not affect population sizes of bacteria harboring the plant-growth promoting traits tested. During the course of this research, several PGPR strains were isolated and characterized based on PGPR activity. The use of these strains offers New Zealand organic farmers biological fertilizers composed of native species. Enzymes and their substrates could adsorb to char surfaces or be regulated by signaling molecules that interact with biochar. Recent studies generated concern over this phenomenon and showed that biochar had an effect on plant gene regulation and also interfered with microbial signaling . Figure 4.1 demonstrates that levels of indole production and ACC deaminase activity assayed from cells grown in the presence of 2% Pine600 biochar were not significantly different than those for cells grown in biochar-free medium. However,nft hydroponic system the spectrophotometric assay measures only the accumulation of these compounds in culturing medium. Hence, more sophisticated assays were developed to better monitor the expression of genes essential for these beneficial traits in aims to better resolve responses to biochar. In the in vitro gene expression studies conducted here, we did not see a biochar-induced change in the promoter activity or expression of genes involved in IAA production or ACC deaminase. The RFP reporters provided a qualitative assessment that promoter activities were positively regulated in the presence of biochar. Furthermore, the RT-qPCR provided quantitative verification that gene expression was not significantly impacted by the presence of 2% or 5% biochar. It appears that precursor compounds, such as tryptophan, were not irreversibly adsorbed to the biochars, which would have resulted in lower bacterial gene expression in the presence of biochar. This addresses the concern that biochar may interfere with PGPR activities and lower the efficacy of beneficial soil inoculants.Hunger in Africa has been central to discourses in aid organizations, NGOs, multilateral and unilateral government agencies, and billion-dollar multinational agribusiness entities for decades. Claims of concern for malnutrition on the continent are infused in initiatives for a range of issues, from economic policy to public health interventions. This phenomenon can perhaps be attributed to the visceral and immediate accessibility of the issue. The idea of hunger conjures a primal sense of urgency in the mind and hearts of donors and, as such, does not require the same degree of unpacking and validation as other equally-complex sociopolitical issues. That is, less effort is required to convey the gravity of starvation, the need to feed oneself palpable. However, that the importance of an issue is easily understood does not necessarily equate to correspondingly easy solutions. Despite this observation, many proposed hunger reduction strategies are packaged in consumable pithy slogans and oversimplified action plans, though the task requires thoughtful consideration for a number of interrelated factors, the most important of which is attaining of thorough understanding of root causes for the persistence of hunger. The continent became a more formalized “zone for agriculturalist expansion” in the last decade , as the recipient of grand gestures such as the Bill and Melinda Gates Foundation pledging to contribute 3.2 billion USD to African hunger efforts from 2006- 2011, alone .

The Bill and Melinda Gates Foundation’s Alliance for a Green Revolution in Africa as well as agrochemical company, Monsanto, feature prominently in contemporaneous campaigns that fly a banner of hunger alleviation. The surge of interest in food policy coalesced in the formation of the US-led G8 New Alliance for Food Security and Nutrition. Launched in 2012, the Alliance includes 21 African nations, 27 multinational organizations, and is fueled by corporate and AGRA donor interests. Rallying behind the premise that populations are merely undernourished because there is not enough food, the entities address caloric and nutritional deficiencies by promoting the adoption of proprietary genetically-modified and proprietary “improved” or high-yielding seed varieties, engineered to increase production of certain food staples. Thorough consideration for local nutrition ecologies, particularly ways in which trade relations can be threatened by a drastic change in agricultural output, is lacking. Thus, trials of improved and genetically-modified crops have met unsuccessful results, demonstrating that adoption of high-performing seed, alone, is insufficient. Continued implementation of failed approaches heightens risk for future populations, for it carries the potential of exacerbating the very poverty from which hunger results, while siphoning off funds that could be better used for infrastructural development and other more practical projects. Regarding GM and otherwise enhanced seed, there exists a disproportionate volume of critical research in two areas: prospective threats to environmental biodiversity and heirloom seed populations, and health risks associated with the consumption of modified foods and farm worker exposure to glyphosate. In response, multiple pro-GMO publications focus on countering those claims. Much of the research that professes the environmental and public safety of modified food crops are published by very institutions that own and produce said seed, a clear conflict of interest. Owners of the rights to proprietary seeds do not readily share their products for third party study so there is little opportunity for transparency, cross-referencing, or long term trials in controlled environments. Thus, many public health and bio-safety reports are ambiguous and inconclusive. The following paper will not directly address either of these two concerns. It is observed that proponents of Monsanto, for example, while comfortable debating human and environmental safety, fall relatively silent on the issue of financial concerns regarding the sale and use of proprietary plant species. Royalty payments and loan programs often go unmentioned, even as they threaten to burden peasant farmers or further strain government budgets. The issue of payments also implies that only certain groups will have opportunities to participate, and surplus distribution costs are not factored into foreign initiatives. Perhaps failure to address these matters is simply indicative of a failure to consider them. Or, conversely, perhaps it indicates the difficulty of providing a sound argument for proprietary seeds initiatives if evaluated strictly through the scope of financial responsibility. This paper will assess some of the glaring economic concerns related to the adoption of genetically-modified and improved seed on the continent. It will point to dilemmas which must be investigated in order for one to confidently propose the adoption of new seed varieties as a viable solution to hunger in East and Southern Africa. It will assess these matters independent of concerns related to super weeds and allergens, more narrowly focusing on implied costs, vulnerability, debt accumulation, and soft commodity trade as it relates to GM and hybrid seed adoption in Southern African Development Community member states. It is understood that undernourishment causes social problems that are antithetical to progress, but it is also true that hunger and malnutrition are the result of systemic inefficiencies.

Taken together, our results indicate sex-dependent protective effects associated with elevated tissue levels of ω-3 fatty acids in reducing the number of infiltrating immune cells into the lung, lower pro-inflammatory cytokine levels and reduced overall histopathology of the lung. The results identified herein model a long-term dietary intake of high ω-3 PUFA and reduced intake of ω-6 PUFA that achieves an ideal ω-6:ω-3 PUFA ratio throughout the body as reviewed before . This was achieved through the use of the Fat-1 transgenic mouse model; these mice express the Fat-1 gene from C. elegans encoding an ω-3 FA desaturase, converting ω-6 PUFA to ω-3 PUFA, leading to tissue ω-6:ω-3 PUFA ratios of ∼1:1 . This model is advantageous because it overcomes several issues that limit diet- and supplementation based experimental strategies; current clinical and preclinical studies have no standardization in terms of dose, duration, or source and quality of ω-3 PUFA, and each of these factors has implications on outcomes . These inconsistencies are considered leading factors for discrepancies in ω-3 PUFA study outcomes . The Fat-1 mouse thus provides a preclinical model for assessing how elevated tissue levels of ω-3 PUFA and reduced ω-6 PUFA can influence health outcomes by minimizing variation based on supplementation, intake and absorption and distribution of ω-3 rich fatty acids. Using this model, we have found genotype and sex-specific differences in infiltrating cells , proinflammatory cytokines and lung histopathology . The decreases in infiltrating PMNs and cytokines were consistent with each other within the Fat-1 male sex. Among the swine farm workers, sex-specific differences in lung function and TLR gene polymorphisms, which is a toll like receptor activated by swine farm dust, have been reported before . Gao et al. found that lung function is worse in males with the TLR9 gene polymorphism as compared to those males without the polymorphism,stackable planters and females with the TLR2 gene polymorphism exhibit better functioning lungs as compared to those females without the polymorphism in swine farm full-time workers .

Another study by Senthilselvan et al. found increased plasma levels of TNF-α in males without any TLR4 gene polymorphisms , and in females with the TLR4 gene polymorphism following 5 hours of swine farm exposure in naïve healthy subjects . We are not the first ones to report sex-specific differences in Fat-1 mice; a recent study investigating the role of elevated tissue levels of ω-3 fatty acids in obesity-associated post-traumatic osteoarthritis also reported sex-specific differences in Fat-1 transgenic mice . It appears that such sex-dependent differences are disease model-specific where one sex in the Fat-1 transgenic background exhibits a greater response than the other sex. Another study reported on sex-and age-specific differences of Resolvin D1 levels in the retina. This study found sex-dependent differences in retinal levels of RvD1 in aged mice as compared to young mice , with aged male mice showing a larger decrease in RvD1 levels . Sexdependent changes in the expression of genes involved in fatty acid synthesis, steroids and drug metabolizing enzymes have been identified before . Some of those genes encode for enzymes involved in the metabolism of ω-3 and ω-6 PUFA, thus identifying sex-dependent differences can inform pharmacokinetics, bio-availability and treatment options related to ω-3 and ω-6 PUFA-derived lipid mediators. The sEH inhibitor TPPU was used in this study as an indicator that to the inflammation resolving epoxide metabolites of ω-3 lipids might be a partial explanation for their beneficial effect. It is attractive to consider sEH inhibitors or mimics of ω-3 fatty acid epoxides as a prophylactic or therapeutic agent . Such mimics and sEH inhibitors are in clinical development by several companies but none are available on the market . However, there are a number of sEH inhibitors from natural sources that are commercially available such as Maca . Male sex in the Fat-1 transgenic mouse had lesser number of aggregates as compared to their corresponding WT controls, which was further reduced in the presence of TPPU .

While we observed a similar trend for the female mice these differences did not reach significance. Lymphoid aggregates, which can be composed of T cells, B cells and dendritic cells play different roles in different disease models such as COPD and tuberculosis. For example, in a chronic cigarette smoke-induced murine COPD model, lymphoid aggregates are associated with adverse outcomes and thus pathological, whereas in a tuberculosis model induced by the Mycobacterium tuberculosis, it is found to be a host defense mechanism . To our knowledge sex-differences in lymphoid aggregate formation in the lung has not been fully explored. A recent study found that females are more susceptible to lymphoid aggregate formation as compared to males, and this was further confirmed by ovariectomy in a smoke-induced COPD model . This is consistent with the previous reports indicating that women are more susceptible to develop COPD than men . Overall, our results are consistent with the previously published literature on the effects of agricultural dust in males; and the improved histopathological effects seen in the male sex are novel. We observed an elevated alveolar cellularity , in wild-type female mice as compared to male mice. A study investigated the differences in alveolar macrophage proteome between males and females, and found several proteins associated with inflammation and interact with estrogen receptor to be expressed higher in females than males . Another study looking at sex-related differences in lung inflammation showed a higher baseline for lung histology score and number of infiltrating cells into the lungs in females compared to males in sham-operated controls . Both studies are consistent with the histological finding we observed in female wild-type mouse lungs. Because males responded TPPU treatment better, this might be related to differences in fatty acid metabolism between males and females given fatty acid epoxides regulate alveolar cell influx, as shown in a study demonstrating that pharmacological modulation of fatty acid epoxides affect inflammatory cell influx to the lungs . In addition, SPMs also modulate macrophage chemotaxis, trans-endothelial migration and cytokine release from macrophages as reviewed by Haworth and Levy . More studies are needed to dissect differences in fatty acid metabolism between males and females. It is well accepted that sex-specific differences that result in different biological responses between males and females stem from sex hormones. These differences affect storage and distribution of lipids thereby affect free fatty acid availability between sexes.

Stable isotope studies report that ARA and DHA contribute more to blood lipids in women than in men and that there are differences in the conversion rate of fatty acids, for example conversion of ALA to omega-3 fatty acids is higher in women than in men . Also, preclinical studies show that reproductive hormones affect the enzymes involved in the biosynthesis of fatty acids. Another study found that sex-related differences in COPD might be related in part to the increased production of leukotoxin-diol by goblet cell P450 and sEH activities . Overall,stacking pots our results suggest a mechanism that 1) availability of free fatty acids from the elevated tissue levels of ω-3 acids in Fat-1 mice are sex-dependent and 2) females have different conversion rates of fatty acids as compared to males and this might lead to changes in gene expression of chemokines and cytokines, thereby affecting alveolar macrophage recruitment into the lung and thus creating sex-dependent host defense mechanism within the Fat-1 genotype. In addition to dietary strategies aimed at promoting the healthful benefits of ω-3 PUFA, therapeutic strategies leveraging the endogenous repair SPM pathways to promote inflammation resolution and repair hold great clinical promise. For example, many investigations have identified positive outcomes in ameliorating lung inflammation/disease via therapeutic administration of SPM , including our own previous studies identifying beneficial effects of the DHA-derived SPM maresin-1 in reducing the lung inflammatory effects of acute and repetitive organic dust exposure . While SPM can potently inhibit inflammation while promoting tissue repair, these bioactive metabolites are quickly deactivated by subsequent metabolism . Thus, another therapeutic strategy to leverage these endogenous inflammation resolution pathways is to combine ω-3 PUFA supplementation with pharmacologic inhibition of enzymes responsible for the deactivation of SPM. One such strategy has been the use of inhibitors of the sEH enzyme to prevent the deactivation of the cytochrome P450 family of SPM, thereby potentiating their protective effects . Previous studies have found enhanced protective effects of ω-3 PUFA when used in combination with inhibitors of sEH such as TPPU . This enzyme deactivates the epoxide SPM into less active diol forms – DiHDPA. A recent study in a model of metabolic disease identified that a sEH inhibitor enhanced the protective effects identified in Fat-1 mice vs. WT mice , while previous studies also identify beneficial effects of sEH inhibition in murine models of acute lung injury , pulmonary fibrosis , asthma , and COPD . Corroborating these previous reports, when we utilized TPPU in the experiments described herein, we found that addition of TPPU lowered all outcomes examined in the DE-exposed animals, suggesting that TPPU not only enhanced the effects of ω-3 fatty acids as in Fat-1 + DE + TPPU animals, but also showed efficacy independent of the Fat-1 genotype. In addition, we observed a better response in the Fat-1 male sex receiving the TPPU treatment and three-weeks DE exposure. Consistent with our results sex-specific differences have been reported in sEH null mice and sEH activity in other mouse disease models . While our results support a beneficial effect of maintaining a low omega6:omega3 ratio in response to agricultural dust, omega- 6 PUFAs and their metabolites also modulate inflammation and participate in inflammation resolution and tissue homeostasis.

The SPMs derived from arachidonic acid, such as LXA4 and metabolites generated by the P450 pathway have been repeatedly shown to have anti-inflammatory effects . Most surprisingly, the ARA metabolites generated by the COX-2 pathway, such as PGE2 have protective effects in the lung despite their infamous proinflammatory notion, as shown in asthma and allergicairway inflammation . Airway epithelial cells are the major source of PGE2 production in the lung, and PGE2 protects against airway hyperresponsiveness to allergens by inhibiting leukotriene and thromboxane synthesis that cause bronchoconstriction and by reducing eosinophil recruitment, both of which are antiinflammatory effects of PGE2. Similarly, in asthma, it has been shown that the homeostatic balance between the COX and LOX pathways metabolizing ARA are altered due to damaged epithelium in asthmatic airways. Given this, it has been proposed that the dysregulation of these pathways leads to an imbalance between PGE2 and PGD2/LT which is in part responsible for increased bronchoconstriction. Other roles attributed to PGE2 in the lung include inflammatory cell recruitment, eosinophil degranulation, bronchodilation, T-cell recruitment and differentiation and adhesion molecule expression as reviewed before . With regards to sex-related differences in response to environmental stimuli, a study examined changes in gene expression in the lung associated with inflammation and immunity after ozone exposure . This study found increased lung histological scores and increased infiltrating PMN in the female sex as compared to males after ozone exposure. Among control mice exposed to filtered air alone, females displayed about 5% difference in gene expression of genes related to chemokines and cytokines as compared to males. These genes included Cxcl2 and Ccl19 , Myd88 , and C4b , all of which were associated with immune cell adhesion and recruitment. Considering the sex- and genotype-dependent differences in our model, we examined changes in gene expression as well. Since the most significant changes we observed in our model was in the male sex , we focused our gene expression studies to male sex. NanoString gene expression analysis identified differentially regulated pathways consistent with our previous results indicating that immune cell activation, cell proliferation, wound healing and transport pathways were altered following 3-weeks DE exposure. In an In-depth analysis both using STRING database proteinprotein interaction and NanoString advanced analyses, we also identified changes in NFκBIA, response to macrophage colony stimulating factor, immune clearance, and neutrophil aggregation between the two genotypes . In addition, TPPU treatment affected distinct cellular processes such as T-cell differentiation in WT mice and regulation of neutrophil activation in the Fat-1 genotype. This observed effect of TPPU is consistent with a previous report showing modulation of the Th1/Th17 response while elevating regulatory T-cells by TPPU in an arthritis model .

To complement experimental work in nanoparticle therapies, mechanistic mathematical modeling and computer simulation can be used to better understand experimental results and provide quantitative guidance for more efficient design of nanotherapeutics. Optimizing carrier and drug penetration into the tumor tissue is critical to maximize the therapeutic effect. Toward this goal, I developed a mathematical model of nanoparticle diffusion and uptake in a spheroid approximation of a solid tumor segment without capillaries. Our model differs from other models that can be found in the literature by taking into account the effect of shape and size on the diffusion constant of nanoparticles. Our model also builds on the previous models by incorporating the rate of endocytosis and how it is affected by size, shape, and surface modification of nanoparticles. As the model nanoparticle, I used the nucleoprotein components of the tobacco mosaic virus . Virus-based plant nanoparticles, such as TMV, provide a unique platform for nanomedical engineering because their dimensions are known and tunable on the molecular level, which cannot readily be accomplished with synthetic nanoparticles. Native TMV particles form a cylindrical structure measuring 300 × 18 nm with a 4 nmwide hollow interior channel. TMV is composed of single-stranded RNA wrapped inside a hollow nanotube formed by 2130 identical coat proteins. TMV offers a programmable scaffold for both genetic engineering and chemical bio-conjugation to impart new functionalities, e.g. therapeutic payloads. TMV virion formation can be initiated by self-assembly of coat proteins from an RNA hairpin forming sequence. This origin of assembly site is the only sequence required to promote a bidirectional coat protein self-assembly along the template RNA. This principle has been exploited to produce TMV nanotubes with diverse shapes such as kinked nanoboomerangs or branched tetrapods.This RNA-templated self-assembly principle has also been used to produce TMV-like nanotubes with distinct longitudinal domains as well as materials of defined aspect ratio.In previous studies,nft channel we have shown that bio-distribution and tumor homing is a function of the carrier’s aspect ratio.

With higher aspect ratio, particles avoid clearance by the mononuclear phagocyte system, resulting in increased tumor homing.Nevertheless, a balance must be established between immune evasion, tumor homing, and tissue penetration. While higher aspect-ratio materials have enhanced tumor homing, the higher molecular weight particles have slower diffusion rates. The TMV platform technology provides a high precision platform with which to specify aspect ratio and surface chemistries that affect tissue penetration in tumorspheroids. I chose to study TMV diffusion in a spheroidal cell-culture system with different sizes and cell densities. This 3D cellular system mimics a small segment of a solid tumor between capillaries and bridges the gap between 2D tissue culture and in vivo mouse models for screening therapeutics. In tumor tissue, the combination of leaky vasculature and deficient lymphatic clearance leads to diffusion as the driving mode of nanoparticle transport and penetration into the tumor tissue.For this study, I focused on ‘stealth’ TMV formulations with reduced cell uptake rates produced by coating the particle surface with polyethylene glycol . Targeted TMV formulations with molecular specificity and increased cellular uptake rates were simulated by displaying the integrin specific peptide ligand RGD on their surface. PEG and RGD are surface modifiers frequently used in nanoparticle engineering to promote immune invasion and targeted endocytosis, respectively. These coatings serve as good model systems whose results can be translated to other nanoparticle formulations.I developed a mathematical model of TMV diffusion and uptake in a spheroid tumor model to evaluate the effect of particle aspect ratio . The input to this model was a bolus injection of a known TMV mass in the medium surrounding the tumor . The rate of diffusion in the interstitial space is much slower than in the surrounding medium so that the distribution of TMV in the surrounding medium is uniform . In addition, the volume of the surrounding medium is much greater than the volume of the spheroid so that the changes in TMV concentration in the surrounding medium are negligible Supporting Equations 6.1.

The tumor cell density within the spheroid segment is uniform and considered as a continuum. The rates of cell proliferation and death are assumed negligible relative to the other TMV rate processes so that the viable cell volume remains constant. From the interstitial space, I assume that TMV is taken up irreversibly by tumor cells at a constant rate that is dependent on the aspect ratio and surface chemistry of TMV nanorods . Furthermore, the TMV does not interact with extracellular matrix components and cannot bind to them. The model parameter values known from direct measurement are the mass of TMV injected, the volume of the surrounding medium , and the radius of the spheroid . The parameters that must be estimated indirectly are the cellular uptake rate coefficient and the diffusion coefficient . For each experiment, these coefficients are constants. This implies that free receptors are always available at the cell surface so that k is constant in any experiment. For different experiments, however, their values change depending on their surface area, shape and cell density within the spheroid . The uptake rate coefficient is directly proportional to the total cell surface area as indicated by the cell density, where k = k0. The diffusion coefficient is a complex function of the cell shape and cell density. Our tumor micro-environment system consists of a spheroidal cancer cell-culture whose diameter can vary between a few hundred micrometers to 1 mm, which corresponds to the heterogeneous spacing of capillary distribution within the tumor . Modeling the diffusion of nanoparticles in the tumor tissue and quantifying the time scales as a function of capillary and cell density could inform dosing and administration schedules. The physiological barriers and diffusion rates of nanoparticles also depend on nanoparticle shape, size and surface chemistry. The simulated effects of spheroid radius, cell density, and aspect ratio on the TMV concentration distributions without cellular uptake are shown in Figures 6.2, 6.3 and 6.4, respectively. The parameters used in each of these figures are summarized in Table 6.1. These results and their significance are discussed in the following sections.The spheroid segment radius represents the distance between capillaries.

The intercapillary distance is highly regulated by a fine balance between angiogenic factors that promote or inhibit vessel growth, as well as the oxygen and nutrient consumption by the surrounding cells.In healthy tissue, particle diffusion from the vessels to the cytoplasmic membrane of surrounding cells does not exceed 100 μm. In the tumor micro-environment, however,hydroponic nft the oxygen consumption is lowered and the tolerance of cancer cells to hypoxic conditions is increased. Tumors with a high rate of oxygen consumption have a higher microvascular density and, therefore, a smaller intercapillary distance. On the other hand, tumors with a low rate of oxygen consumption have a lower microvascular density and, therefore, a higher intercapillary distance.This phenomenon is currently being investigated for nanoparticle-based antiangiogenic tumor therapy.By reducing the oxygen supply to the tumor site, anti-angiogenic tumor therapies aim to prevent the growth and aggressiveness of the tumor. To quantify the effect of different intercapillary distances within the tumor micro-environment, I simulated the diffusion of TMV in a spheroid system without cellular uptake for a range of radii in the absence of cellular uptake . Within the tumor cell spheroid, the simulated concentration distributions at various times of TMV with different spheroid radii are shown in two and three dimensions. This poor tumor penetration correlates with increasing risks of survival of cancer cells and promotes drug resistance.When the tumor cell density increases, the cytotoxicity of chemotherapeutic drugs such as vincristine, bleomycin, and doxorubicin is impaired.Increasing the cancer cell density within the spheroid decreases the void volume through which nanoparticles can diffuse as represented by a smaller diffusion coefficient. With high cell density, the limitation of TMV nanoparticle penetration is a major barrier to chemotherapeutic drug delivery in the deep tissue, which also correlates with increasing risks of survival of cancer cells and promotes drug resistance.While smaller aspect-ratio rod-shaped nanoparticles have higher diffusion and accumulates more easily in the deep tumor tissue, the higher aspect-ratio nanoparticles have enhanced margination toward blood-vessel walls, increased transport across tissue membranes, and reduced clearance by phagocytosis.In other words, a “one-size-fits-all” nanoparticle does not exist and a compromise must be made to optimize the diffusion and accumulation of nanoparticles within the tumor without impairing their ability to extravasate , cross tissue membranes, and evade the immune system. With complementary data, this model can provide a basis for predicting the aspect ratio that promotes optimal accumulation of nanoparticles injected intravenously.Perhaps, a better approach would be to inject intravenously a cocktail of TMV nanoparticles with various aspect ratios. In this scenario, the lowest aspect-ratio TMV are less likely to reach the tumor site, but the fraction that do penetrate the tumor can diffuse more readily than the higher aspect ratio TMV in the deep tumor tissue. In the meantime, the higher aspect ratio nanoparticles can reach the tumor site more readily, but only accumulate in the peripheral tissue of the tumor. The net result would be to improve overall drug distribution and maximize efficacy. The simulations presented above do not include TMV uptake by cells so that the effects on diffusion are not obfuscated. While targeted nanoparticle formulations can increase delivery, endocytotic clearance of targeted nanoparticle can reduce drug distribution and tumor cell access.

To assess the effect of cell uptake on TMV distribution throughout the spheroid, I evaluated the cell uptake rates of TMV in cancer cells experimentally: fluorescently-labeled, RGDtargeted TMV formulations were obtained as described by Pitek et al.310 A fluorescence assay was developed to quantify TMV particle uptake cancer cells over time . I chose triple negative breast cancer cells as our model cell line for their relatively highexpression of v3 integrins.I determined that the targeted TMV formulation exhibits a cell uptake rate of 130 particles/h/cell. With this experimental value, we can extrapolate cell uptake rates of PEGylated and RGD-targeted TL, TM, and TS particles .These data and resulting cell uptake rates are summarized in Table 6.2. While RGD-targeted formulations are readily taken up by the cells, PEGylated formulations show negligible cell interactions. The PEGylated formulations with TS and TM aspect ratios have comparable effects on uptake. The targeted formulations with TL and TM have comparable effects on uptake, but the uptake with TS increases significantly . The experimental data shows that TMV-PEG formulations exhibit low uptake with time. The TMV-RGD formulations, however, display a biphasic behavior: rapid cell uptake within the first 3 h followed by a plateau region with little to no cellular uptake, most likely indicating saturation. This behavior is typical of particle internalization mediated by cell surface receptors.The rate of cellular uptake of TMV reported in this study is much smaller than the rates reported for synthetic nanoparticles. Doiron et al.320 reported that spherical polystyrene nanoparticles with diameters ranging from 20 nm to 500 nm had uptake rates ranging from 6.6×107 particles/h/cell to 12,000 particles/h/cell respectively within the first 3 h of incubation. In addition Huang et al.reported rod-shaped gold nanocrystals displaying RGD peptideson their surface had a rate of internalization in A549 lung carcinoma cells equivalent to 4500 particles/cell/h within the first 2 h of incubation at 37°C. However, the same nanoparticles coated with single-chain variable fragment peptide to target the epidermal growth factor receptor were internalized at a slower rate of 1,250 particles/cell/h. This demonstrates that the rate of cellular uptake is dependent on nanoparticle shape, surface chemistry, as well as the nature of the molecular receptor targeted. Using the evaluated cellular uptake of TMV formulations , I simulated TMV diffusion in a spheroid cell system with different rate coefficients of cell uptake and aspect ratios . This prevents deep tissue penetration because cell uptake occurs at a rate much higher than diffusion. Coating TMV with RGD peptides to target integrin receptors further decreases the TMV concentration within the spheroid. Active targeting of receptors overexpressed on cancer cells is commonly used to promote tissue specificity and accumulation. However, it is counterproductive for tissue penetration.For TM , the TMV concentration reached the center of the tumor within 3 h. At steady state, its concentration at the center was 4% of the concentration in the surrounding medium. For TS , the TMV concentration reached the center of the tumor within 3 h, but its steady-state concentration at the center was 12% of the concentration in the surrounding medium.

Each ferritin complex can sequester up to 4500 Fe2+ ions and convert them to Fe3+ to prevent oxidative stress in the cytosol, nucleus, and mitochondria. Ferritin has been investigated as an imaging reagent and vaccine platform as well as a nanocarrier.It has already been used to deliver cisplatin,doxorubicin,and curcumin,and the contrast agents gadolinium and Mn. There are few examples of proteinaceous nanocarriers used in agriculture, but nanocarriers based on maize storage proteins are being tested for the delivery of pesticides that protect soybean crops from defoliator parasites.The number of proteinaceous nanocarriers reaching the market will continue to grow as we learn more from nature and expand our bioengineering tools and processing capabilities, including the use of genome editing and directed evolution.Furthermore, rather than harnessing protein complexes from nature, advances in de novo protein design will allow us to select customized proteins with shapes that may be difficult to obtain via the directed evolution of natural proteins.Modular building concepts have been established to achieve the defined folding and programmed assembly of proteins into complex architectures.Accordingly, some synthetically designed protein-based nanoparticles have entered translational development. For example, the start-up company Tychon Bioscience is developing prosthetic antigen receptors that modulate protein dimerization to produce self-assembling nanoscale ring structures for applications in cancer immunotherapy. The entirety of my dissertation relied on the use of virus-based nanocarriers and their application in medicine and agriculture; they present many advantages over the other nanocarrier platforms,blueberry grow bag as described below and in all chapters of my dissertation. Viruses have evolved to deliver their genetic payload to host cells and can therefore be regarded as nature’s nanocarrier systems.

The structure of a virus capsid is genetically programmed so replication yields millions of identical particles, a level of monodispersity that cannot yet be achieved with synthetic nanoparticles. Viruses are proteinaceous structures, and are therefore similar to the protein cages discussed above in terms of biocompatibility. The capsids are highly symmetrical structures that come in various shapes and sizes, and they are amenable to both chemical and genetic modification to impart new functionalities, including the encapsulation or conjugation of active ingredients Given the natural function of viruses, it is unsurprising that one of the first applications of virus-based nanocarriers was the delivery of nucleic acids. Mammalian viruses such as Adenoassociated virus are established as gene delivery vectors.The first AAV-based gene therapy vector was approved by the EMA in 2012 for the treatment of lipoprotein lipase deficiency, but was not approved by the FDA, and UniQure subsequently announced its withdrawal from the European market in 2017 following the treatment of only 31 patients.The FDA has since approved two AAV-based vectors, namely Luxturna in 2017 for the treatment of patients with RPE65 mutation-associated retinal dystrophy, and Zolgensma in 2019 for the treatment of young infants with spinal muscular atrophy. One of the major drawbacks of AAV therapies is their high cost: Luxturna treatment is estimated to cost $850,000, whereas Zolgensma was priced at $2.125 million by Novartis as a one-time cure. In addition to AAV nanocarriers , other mammalian viruses have been developed for gene delivery including adenoviruses , herpesviruses , and lentiviruses and are undergoing clinical trials , whereas retroviruses and alphaviruses remain at the preclinical development stage.As an alternative to mammalian viruses, several plant viruses and bacteriophages have also been repurposed as nanocarriers or vaccines because they are non-infectious to humans and can be manufactured on a large scale as viral nanoparticles or virus-like particles .

For example, based on the immunostimulatory nature of VNPs/VLPs, several have been developed as in situ cancer vaccines, including Cowpea mosaic virus bacteriophage M13,Potato virus X ,Tobacco mosaic virus ,and Papaya mosaic virus.The CPMV system has already demonstrated efficacy in canine trials.The development of plant viruses or bacteriophages as vaccine candidates for infectious diseases, autoimmune disorders and cancer has been extensively reviewed.One of the key applications of VNP/VLP vaccine candidates is the display of heterologous epitopes.This protects the epitope from degradation, ensures delivery to antigen-presenting cells, provides an inbuilt adjuvant, and also generates cross stimulatory virus-based antigens to boost humoral and cellular immunity.Several VNPs/VLPs presenting heterologous epitopes have been tested in human clinical trials and veterinary tests.The use of VNPs and VLPs as nanocarriers for active ingredients can be achieved by passive infusion through pores in the capsid, encapsulation during assembly, as well as chemical conjugation and/or genetic fusion of active ingredients to the outer or inner surfaces. For example, doxorubicin has been conjugated to TMV,infused into Cucumber mosaic virus and Red clover necrotic mosaic virus ,and passively complexed with PVX.Virusbased nanocarriers have also been used to deliver bortezomib,cisplatin,5-fluorouracil,hygromycin,mitoxantrone,phenanthriplatin,and paclitaxel.Examples of protein delivery include TRAIL,40 TPA,and Herceptin. Filamentous phages have been developed to deliver antibiotics such as chloramphenicol and neomycin to prevent the growth of Escherichia coli, Streptococcus pyogenes, and Staphylococcus aureus.Finally, siRNA has been delivered using bacteriophage MS2 and Cowpea chlorotic mosaic virus ,and mRNA for the in situ expression of green fluorescent protein has been successfully encapsulated into CCMV and TMV, followed by the release of the mRNA cargo into the cytosol of mammalian cells and its subsequent translation.Plant VNPs have also been proposed as pesticide carriers because they are already part of the natural soil ecosystem and are harmless to humans and domestic animals.

Compared to synthetic nanocarriers, plant viruses are highly mobile in soil and can deliver pesticides to the roots, where many pests are concentrated. TMGMV was approved by the EPA in 2007 as a bioherbicide for the treatment of the invasive tropical soda apple weed in the state of Florida, thus paving the way for the development of nanocarriers based on plant viruses.Since then, RCNMV has been proposed for the delivery of abamectin to crops.The higher stability and superior soil mobility of abamectin encapsulated in RCNMV increased the efficacy of the nematicide in tomato seedlings infested with root knot nematodes compared to the free chemical. Similarly, TMGMV loaded with the anthelmintic drug crystal violet was highly toxic towards the nematode Caenorhabditis elegans in vitro. Rational design and size and shape engineering in plant virus-based carriers may enable multi-level targeting of different soil zones.Nanocarriers have revolutionized the medical, veterinary, and agricultural sectors through their ability to deliver active ingredients in a targeted and controlled manner to appropriate sites, such as cancer cells or plant roots, thereby maximizing efficacy while minimizing off-target effects. Based on the current landscape of research articles, patents, clinical trials, and approved nanocarriers, I have revealed a growth trend which predicts that more formulations will be commercially available over time, allowing the targeted delivery of small molecules, peptides and proteins, as well as nucleic acids to combat pests, pathogens and diseases in animals and plants. I observed a shift away from the development of nanocarriers for small-molecule reagents and toward the delivery of peptides, proteins and nucleic acids. Advances in bioengineering have also encouraged the development of bio-inspired nanocarriers that are friendly to the environment. Several challenges must be addressed to streamline the translation of nanocarriers from the bench to the market. In medicine, nanocarriers could greatly benefit from the incorporation of targeting ligands, aptamers, antibodies, or antibody fragments to promote their binding to receptors overexpressed on target cells or in the surrounding extracellular matrix. Additional targeted nanocarriers must undergo clinical trials before we can conclude that active targeting achieves greater therapeutic efficacy. In parallel,blueberry grow bag size the development of veterinary nanocarriers has intensified with the growing public interest in animal welfare and food safety and security. Companion animals with cancer have benefited the most from nanocarriers, whereas livestock require low-cost and prolonged treatments, such as the delivery of antibiotics. The future of veterinary nanocarriers will depend on our ability to manufacture products at a relatively low cost. Finally, precision agriculture is required to meet the growing demand for food. Nanocarriers provide the opportunity to increase crop yields in an environmentally friendly manner by delivering fertilizers and pesticides directly to plants while minimizing leaching. However, the translation of nanocarriers for agricultural applications is restricted by the lack of well-structured regulations for commercial approval. More research is therefore required to determine the fate and toxicity of nanocarriers applied in the field.Plant parasites are a major burden to the global agricultural industry.

Among them, the United States Department of Agriculture has highlighted several species of insects and worms as the most common and devastating parasites; they either directly injure crops by feeding on them or indirectly cause injury through the transmission of bacteria, viruses, and fungi. Specifically, crops infested by parasitic worms, including across the United States, results in an estimated $157 billion loss each year in crop production worldwide.In particular, endoparasitic plant nematodes feed on the crop roots, causing distinctive root swellings commonly referred to as galls. Gall formation impairs the root conduction of water and growth nutrients into the rest of the plant, resulting in lower crop yields. In addition, galls often promote crack damages in the roots and increase the plant vulnerability to secondary infections.The root-knot Meloidogyne spp, the potato cyst Globodera spp, and the soybean cyst Heterodera glycines are the most damaging and widely spread plant parasitic nematodes. Combined they can infect more than 3000 plant species, including bananas, corn, cotton, potatoes, lettuce, and tomatoes.While crop nematode infestation is relatively easy to diagnose , treatment options are limited. In most countries, crop rotation is frequently employed to selectively control plant parasitic nematode infestations.Nonetheless, the wide host-range of root-knot nematodes limits the choice of alternate crops to a few species yielding little to no revenue. Genetically modified crops resistant to nematodes are an economically and environmentally viable alternative.Unfortunately, genetic resistance to plant parasitic nematodes is selective to specific nematode species, limited to a few crops, and takes years to engineer.While these aforementioned control strategies can reduce the burden of plant parasitic nematodes on most crops, their efficacy and economic benefits are no match to the use of nematicides.The first generation of nematicides rely on highly toxic and volatile fumigants, such as methyl bromide, but their use has declined due to environmental and health concerns.Alternatively, non-fumigant nematicides, such as organophosphates, carbamates, and bio-nematicides, have been employed.Their efficacy, however, is limited by their ability to diffuse through soil, which is dependent on the amount of organic matter, moisture, and the soil structure . To be effective, non-fumigant nematicides must persist long enough and in concentrations equivalent to the nematode-lethal dose at the root level. Extended persistence in such doses increases the risk of chemical contamination of crops, soil, and groundwater. Therefore, there is a critical need to resolve soil mobility issues of nematicides to enhance their agrochemical efficacy, reduce their indiscriminate use, and ensure their safe application. To attack the problem at its roots, nanotechnology has led to the development of smart delivery systems that can be tailored to deliver pesticides in a controlled and targeted manner,similar to nanomedicine in humans.Nanomaterials used as carriers have advantages over commonly used pesticides, such as enhanced biodegradability, thermal stability, permeability, dispersibility, wettability, and stiffness.When pesticide-loaded nanoparticles are spread uniformly over the soil surface, their large surface areas increase their affinity to the target pest and reduce the dose of pesticide required to effectively eradicate the infestation.In addition, encapsulation of nematicides in nanoparticles protect the active compound from premature biodegradation and photolysis while isolating the toxic nature of the nematicide from the end-user. Liposomal formulations, as well as synthetic and natural polymer-based nanoparticle formulations have been employed as pesticide-delivery systems While synthetic nanomaterials overcome the various challenges associated with the use of nematicides, it still remains uncertain whether their high cost of manufacturing makes them economically viable.In this study, I turn toward using plant viral nanoparticles as an economically and environmentally viable alternative to synthetic nanoparticles. In addition, VNPs are exceptionally robust to the harsh environment of crop fields, yet they are biodegradable. From a human health perspective, VNPs are bio-compatible and non-infectious, making them safe to use on industrial crops. From an engineering perspective, VNPs are self-assembling systems that form highly symmetrical, monodisperse structures, amenable to both chemical and genetic modifications to impart new functionalities.Since plant viruses have naturally evolved to protect and efficiently deliver their payload , they can be regarded as naturally occurring nanocarriers. At first glance, applying VNPs onto crops might seem counterintuitive since their natural hosts for infections are plants. However, Cao et al. recently introduced the concept by utilizing the red clover necrotic mosaic virus to manage plant parasitic nematode infestation.

In Central and Northern Europe, where the cultural response to environmental stress involved the direct consumption of milk, this appears to buffer environmental stress and may have fueled the patterns of human growth and body size observed in the late Holocene. The trends observed in this paper may be a direct or indirect consequence of shifts in energy allocation to somatic growth associated with the digestion of lactose but may otherwise be influenced by patterns of disease load during growth, changes in weaning patterns, population density, migration, or genetic drift. A life-history framework may help to understand how the interaction of such factors influences somatic investment . We note that there are other regions where LP genetic variants are found in high frequencies, including the Mongolian Steppe , and convergent evolution of MCM6 in East Africa with what may be a stronger directional selection among the Maasai . At present, we do not have data of sufficient resolution to investigate whether ancient selection and dairying fueled phenotypic change in these regions. However, our results suggest that the transition to agriculture may have had regionally specific influences on human populations that can be elucidated through analyses of long-term diachronic trends in human-culture-environment interactions. Long-term trends are best investigated through broadscale integration of bio-archaeological and phenotypic data with aDNA, paleoecology, and archaeological data that account for the spatiotemporal complexity of Holocene cultural and dietary transitions.Waterborne zoonotic pathogens pose a public health risk due to their consistent point and non-point sources,plastic pot which can significantly impair the ecological quality of aquatic systems. Pathogens enter streams and rivers in a variety of processes including overland flow and groundwater fltration.

Viruses, bacteria, and parasites persist for varying amounts of time, especially within streambed sediments, leading to long-term disease transmission. Of particular concern is the protozoal parasite, Cryptosporidium, which can remain infective for weeks to months under cool and moist conditions, with the infectious state largely resistant to chlorination. Te 50% infectious dose for livestock-derived Cryptosporidium, specifcally C. parvum, for healthy humans ranges between 10–1,000 oocysts. Monitoring programs assess the microbiological quality of waters to minimize health risk associated with pathogenic microorganisms. However, as it is still unfeasible to experimentally monitor pathogen levels at the high spatiotemporal resolution ofen needed to assess risk, sampling is often complemented with a model. Both environmental and hydrological processes control the residence time and persistence of pathogens within a stream network. Current models consider stream flow conditions, but it is imperative to incorporate the wide variety of processes that control the transport and retention of Cryptosporidium in a dynamic stream environment. Commonly, hyporheic exchange – the two-way exchange of water with the underlying sediments induced by pressure variations associated with stream flow over stream channel topography – is ignored in surface water modeling of pathogen and microbial transport in streams. However, as the size and specific gravity of Cryptosporidium are low, it is mainly removed from the water column by hyporheic exchange and to a lesser extent by sedimentation via association with larger and denser suspended aggregates. Microbial interaction with the streambed and other stream transient storage areas has been greatly underestimated by only assuming gravitational settling without considering the key mechanism of hyporheic exchange.

Hyporheic exchange of particles differs from solutes because of strong particle deposition during porewater transport. Even though the settling velocities of fine particles are low, gravitational settling can be more important within porewaters, where porewater velocities are extremely small. Filtration in the bed leads to pathogen immobilization. However, filtered microbes and fne sediment are often remobilized, corresponding to reversible fltration. This slow release of microbes after initial deposition has been observed in streams. If models do not consider hyporheic exchange within the hyporheic region then pathogens will not be conceptualized as being in the nearbed or hyporheic region to experience these additional immobilization processes, thus underestimating pathogen immobilization and retention in streams. This underestimation of pathogen accumulation during base flow can lead to inaccurate predictions for pathogen resuspension during storm events, when the majority of pathogens are transmitted downstream. Te main objectives of this modeling study was to improve storm flow predictions of potential resuspended Cryptosporidium oocysts by appropriately characterizing the transport and retention of Cryptosporidium during base flow conditions through incorporating hyporheic exchange and immobilization processes, calculating residence times of Cryptosporidium in surface water and accumulation in immobile zones, such as streambed sediments, to estimate long-term persistence, and estimating Cryptosporidium accumulation during base flow conditions that can potentially be resuspended during a storm event. We apply a previously developed mobile-immobile model for microbes to Cryptosporidium, which accounts for hyporheic exchange and transport through pore water, reversible ifltration within the streambed, and inactivation of microbes, to accurately predict the long-term persistence of pathogenic microorganisms within stream storage areas.

The mobile-immobile model framework is convenient for river transport as the water column can be considered mobile and material retained in streambed sediments or slow-moving surface waters is comparatively immobile. This model framework, in contrast to previous work, was developed for microbial transport in streams to incorporate detailed measurements of transport and retention processes at multiple scales, which allows the use of lab-scale measurements to parameterize key transport and retention processes and apply them to reach-scale modeling. We used the model to assess the transport, retention, and inactivation of Cryptosporidium within stream environments, specifically under representative conditions of California’s Central Valley, where pathogen exposure can be at higher risk due to agricultural and wildlife non-point sources. Comparison of modeling results with and without immobilization processes provided novel insights into the significance of hyporheic exchange and subsequent immobilization processes on pathogen retention and long-term persistence within streams. This study provides new understanding of pathogen transport and retention dynamics in streams to help improve future risk assessment.Te study site is California’s Central Valley and the Sierra Nevada foothills , draining ~23,000 sq. miles of the western slope of the Sierra Nevada mountains down to the floor of the Central Valley. These streams originate in snow-fed lakes and streams surrounded by United States Forest Service and National Park lands where cattle and other livestock are grazed and descend through rolling foothills to the low-lying Central Valley, with food crop agriculture and animal feeding operations supported by a network of man-made canals. This site thus has potential inputs of fecal organisms from grazed allotments in the higher elevations and in animal feeding operations along the lower reaches and canals,grow bag in addition to inputs from wildlife such as striped skunks, coyotes, California ground squirrels, and yellow-bellied marmot. California’s Central Valley has a Mediterranean seasonal climate, with highly seasonal water inputs, with precipitation primarily in the winter and spring. Following the spring snow melt period, most of the Central Valley is relatively dry with occasional summertime precipitation at higher elevations.Approximately 1.7×105Cryptosporidium oocysts/animal/day are shed from a California adult beef cow and 6×105 oocysts/animal/day from California beef calf. An average beef herd size is approximately 100 adult cows and 150 calves, which equates to 1.1×108 oocysts/day/livestock operation. Cryptosporidium species include C. bovis, C. ryanae, and the more infectious C. parvum.

Oocysts deposited on the terrestrial portion of a watershed from beef cattle only reach streams through overland flow run of and direct deposition of feces. Oocysts remain trapped in the fecal matrix or are eluted and reach streams via groundwater or overland flow, with loads dependent on storm intensity, soil structure and infiltration rates. The high risk fecal pats are those deposited directly into the stream, less than 1–5% of total fecal loads, depending on cattle access to the stream via lack of fencing. Thus, a reasonable estimate of Cryptosporidium that could potentially reach a stream in the region, estimating that 20 beef lots may impact a single stream, from a combination of direct deposition, overland flow, and groundwater inputs is approximately 1–5% of the oocysts shed. Dairy lots are assumed to have minimal release of Cryptosporidium oocysts as the operations are confined and run of into stream is not permitted. Other non-point sources include wildlife, where the highest loads come from the California ground squirrel , averaging 1.13×105 C. parvum oocysts/animal/day. Ground squirrel populations result in loading rates of 9×105 oocysts/hectare/day for low density populations with 8 to 94 adults/hectare in California. Therefore, non-point sources could potentially be a large source of Cryptosporidium to streams, even larger than beef herds and dairy lots combined. To account for these variable inputs, the highest figure from beef herds was assumed to represent an upper boundary of the oocysts load, given the uncertainty in the number of oocysts shed by beef lots, the limited oocysts that may be released from dairy lots, and the additional contribution of non-point sources in the watershed from wildlife excretions.Stochastic theory predicts that the slowest mechanism will control the long-term tailing behavior and model parameterization of a tracer concentration vs. time surface water profile. This concept can link multiple scales of transport, as previously demonstrated by combining lab scale and field reach-scale studies on solute, particle, and microbial transport and retention in streams. We apply this scaling concept to this study by using the column Cryptosporidium model parameters from a published study to characterize the pathogen transport and retention within the immobile zone of the reach scale mobile-immobile model framework. Specifically, Cryptosporidium breakthrough curves in a sand column showed power-law behavior, with a particle immobilization rate within the immobile zone, ΛIMM =0.2 s−1 and a power-law slope of the pathogen residence time distribution within the immobile zone, βIMM =0.35 . We assume Cryptosporidium release under summer base flow conditions with an average flow of 60L/s and an average velocity, v, of 5 cm/s. This velocity within an agricultural stream was associated with a dispersion, D, of 0.095 m2 /s, an exchange rate between the mobile and immobile zone, Λ, of 6×10−2 s−1 , and a power-law slope within the immobile zone, β =0.7. These parameters are reasonable and are within the range of hydrologic model parameters for solute transport within streams during base flow conditions. Inactivation rates of Cryptosporidium in the mobile zone and immobile zone are estimated for summer conditions with water temperatures of approximately 20°C as 0.088/ day and 0.011/day, respectively. A summary of all parameters used within the model simulations is shown in Table 1. The model simulations were run with the 1-month scenario detailed in the previous section. The 1-month duration of the release was chosen as an arbitrary reference duration to assess the permanence of oocysts in the stream even after the release has stopped. A total count of Cryptosporidium oocysts immobilized and inactivated were determined at each sampling distance and at different time points of interest . A model output breakthrough curve with and without inactivation was produced. These model outputs were integrated to the different time points of interest using the trapezoidal method to determine a total number of oocysts that passed by the sampling point within the surface water with and without inactivation. The difference between with and without inactivation was used to calculate the number of oocysts inactivated vs. immobilized within the stream at each time point of interest. The # of oocysts immobilized at each downstream distance was estimated as the difference between the previous sampling point . The values for % Cryptosporidium immobilized were calculated by dividing the total # immobilized by the known model input of Cryptosporidium oocysts .Model simulations for a 1-month input of Cryptosporidium to an agricultural stream show in-stream pathogen counts at 100, 300, 500, and 700m downstream of the input . Cryptosporidium transmission is presented under two scenarios with only hyporheic exchange and inactivation and with hyporheic exchange, inactivation, and additional immobilization processes in transient storage areas . For scenario 1, a decrease in maximum in-stream concentrations from 2.1×10−2 #/mL at 100m to 2.0×10−2 #/mL at 700m downstream of the input demonstrates how hyporheic exchange delays downstream transport, but does not greatly reduce the maximum in-stream concentration. As described previously, a safe water supply is considered to have less than 10−5 oocysts/mL. This value assumes a typical human consumption of 2L/day and a safety/error factor of 300 to 1,000, which is typical for public health standards. In-stream concentrations remained above 10−5 oocysts/ mL for 1269 and 2357 hours for sites 100 and 700 m downstream of the input, respectively.

The model is estimated using the sample of children ages 24 to 59 months living in rural areas. In these and in all other models standard errors are clustered at the treaty basin level. In the next-to-last two rows we report the F-statistic of the first stage for the “own dam” coefficient and for the “upstream dam” coefficient . The instruments for irrigation dams appear sufficiently strong to avoid bias from weak instruments. However the instruments for all “own dams” are small, and the bias that could result from this should be kept in mind when interpreting the results. I also run the Sargan-Hansen test to check that the instruments are relevant. The null hypothesis here is that the instruments are valid, i.e. they are uncorrelated with the error term and correctly excluded from the second stage. The p-values of the tests are when we estimate the model using irrigation dams only and and when including all types of dams. These p-values confirm that the instruments are relevant. We first analyze how dams with some irrigation purpose have affected the nutritional status of children in the 6-digit river basin where the dam is located and downstream. The first column of table 1.4 shows estimates from models which include controls for demographics and rainfall. The IV estimate indicates a large and significant decrease in the nutritional status of children in the 6-digit river basin where a dam is located and an increase in downstream 6-digit river basins. An additional dam reduces child height-for-age z-score in the 6-digit river basin basin where it is located by point of standard deviation and increases the probability of being stunted by points. In contrast an additional dam increases height-for-age z-score in downstream 6-digit river basins by points and reduces stunting by .03 points,french flower bucket but this last coefficient is small and insignificant.

These effects are large given that average height-for-age and stunting are -1.91 and 47 per cent respectively. The ratio of the effect of an additional dam in the 6-digit river basin where it is located to the mean are 18 per cent for height-for-age and 34 per cent for stunting. The same ratio for downstream 6-digit river basins are 8 per cent for height-for-age and 6 per cent for stunting. Columns and show estimates conditional on children’s gender, a dummy for twin birth, mother’s age, mother’s years of education, a dummy for a child living in a female headed household, the number of household members and the number of children in the household less than 5 years old. The coefficient on “own dam” drops by less of a standard error while the coefficient on “upstream dam” increases slightly. Columns and further control for rainfall during the survey year and the two years prior to the survey year. This has little effect on the coefficient estimates. Next we turn to the impact of all types of dams on weight-for-age and malnourishment. We find that dams with some irrigation purpose have, on average, little effect onweight-for-age in the 6-digit river basin where they are built but increase the incidence of malnourishment by points or 49 percent. However an additional irrigation dam increases weight-for-age in downstream 6-digit river basins by .10 to .20 points on average but this has no effect on the incidence of malnourishment. Lastly we analyze the impact of all types of dams taken together on child nutrition. We find that the impact of dams on weight-for-age are small and not precisely estimated. However we find that while an additional dam has no effect on height-for-age, on average, it increases the proportion of children who are stunted by .08 points or 17 percent. Moreover we find that an additional dam increases height-for-age and reduces stunting in downstream 6- digit river basins by .15 and .08 points respectively . It is important to know the overall net effect of dam construction on the nutritional status of children. We focus on the results for irrigation dams to carry out this analysis, results for all dams show a similar pattern.These impacts are small compared to standard errors of the point estimates or sample standard errors suggesting that dam construction has little aggregate effect on height-for-age and and weight-for-age z-score.

Turning to stunting and malnutrition, we find that dam construction has increased stunting in the average river basin by .025 points and malnutrition by .012, effects that are small compared to standard errors of the point estimates and sample standard errors. Taken together our findings show that while dam construction in Sub-Saharan Africa has had little aggregate effects, it clearly generates losers and winners. This suggests the scope for more effective policy making in order to capture the benefits from dam construction while compensating those who may lose. As most poor regions, rural African economies are characterized by limited access to insurance against risk. The inability to cope against shock may interact with the increased variance of agricultural production from dam construction to reduce household’s income and food security. We investigate this in Table 1.5 by examining how dam construction reduces or exacerbates the impact of rainfall shocks on child nutrition. We use rainfall deviation from its mean between 1970 and 2002 as a measure of rainfall shock, and we consider two types of intensity of rainfall shocks: the number of instances during the survey year and the two years prior to the survey year when rainfall was at least.3 point .6 point of standard deviation below the mean. So these rainfall shocks can take any value between 0 and 3. In columns to rainfall shock is the number of times rainfall was at least .3 point of standard deviation below the mean, while columns to show results where the rainfall shock is the number of times during which rainfall was at least .6 point of standard deviation below the mean. We find that dams amplify the impact of rainfall shocks both in the basin where they are built and in downstream river basins . We also find that dams amplify the effect of rainfall shocks more in the 6-digit river basin where they are built than in downstream basins, but these differences are significant only for larger shocks. In this section we analyze whether the effect of dams are more pronounced along certain demographic characteristics.

It is particularly important to know whether the construction of dams affect more significantly vulnerable children and poor households. Because the DHS do not collect measures of income or consumption we use demographic characteristics to proxy for a household’s likelihood to be poor or vulnerable: a dummy for whether the household is female headed and mother’s years of education. We also investigate whether the impact of dams is different for boys and girls. These regressions have 31037 observations each. All models control for child gender, a dummy for twin child, mother’s age, mother’s education, a dummy for female headed household, the number of household members and children under 5 years, rainfall during the survey year and the two years prior to the survey year. The results reported in Table 1.6 consistently show that girls, female headed households and children of more educated mothers benefit more from a dam in an upstream river basin. For children living in river basins where a dam is located we don’t find, across different measures of child nutritional status, any systematic difference in the effect of the dam by demographic characteristics: for height-for-age the “own dam” effect are lower for girls, male headed households,bucket flower and less educated mothers; while for weight-for-age these effects are larger. The framework presented in Section 2 highlights improved access to food as an important channel in the causal link between dam construction and the nutritional channel of children. The relevance of this channel is confirmed by Strobl and Strobl who find that large dams in Africa increased crop productivity in downstream regions while cropland within the vicinity of the dam tends to experience productivity losses. However the construction of a new dam may be accompanied or substituted for the provision of other public goods that may affect children’s nutritional status. We examine this possibility in Table 1.7. Table 1.7 shows estimation of model where the dependent variables are measures of access to health services, tap water and electricity. The model is estimated following an IV strategy using the same instruments described above. Columns to show that dam construction improves access to health services and electricity in the basin where the dam is built. However columns to show that access to health services, tap water and electricity are affected little by the construction of an irrigation dam.

Put together with the findings in Strobl and Strobl, the results in Table 1.7 also point to the importance of improved access to food as the main mechanism between dam construction and the nutritional status of children in Africa. Rural-urban and rural-rural population movements are central mechanisms in the process of structural transformation and economic development. As the Agricultural sector shrinks, workers leave rural areas for manufacturing and services jobs in cities. Moreover differences in agricultural development and economic activity between rural areas may prompt a process of labor reallocation between these regions. What is the effect of these population flows on rural economic activity and welfare? Despite a large empirical literature on the effects of rural out-migration on individuals and households, little empirical evidence exists on their consequences at a macro or meso level. Exceptions include papers that focus on a specific aspect related to migration such as remittances and investigate how they affect village-level investment and economic growth. An under-investigated question in this literature is how rural out-migration influences rural labor market outcomes. This analysis is related to papers that examine the effect of international emigration on domestic labor markets. Lucas shows that migration of mine workers to South Africa increased wages in both Malawi and Mozambique – the two largest source of foreign mine workers in South Africa – suggesting that out-migration may contract the labor market at origin. However Mishra is the first paper to provide evidence of a causal link between emigration and wages in source countries. The analysis presented in this paper is the first attempt to measure the effect of internal migration on wages in sending regions. I focus on a specific internal migration process, rural out-migration, because it accounts for a large share of a country’s internal migration and is particularly relevant for understanding rural economic development. Moreover given the magnitude of internal labor flows relative to international labor flows, it is surprising that the literature overlooked the effects of rural out-migration on rural labor markets. By way of comparison Mishra estimates that, in 2000, the number of Mexican emigrants living in the US was about 16%. In other words, in 2000, for every 100 Mexicans living in Mexico, 16 were residing in the US. I find much larger rural emigration shocks in Brazil. My analysis shows that between 1980 and 2000, for every 100 individuals residing in rural areas, 95 had already migrated out to cities or other rural areas outside their state of original residence. The empirical framework developed in this paper builds on Card and Lemieux, Borjas and Mishra. As in Mishra, this paper investigates how emigration affects the wages of those who stay behind. The empirical strategy in Mishra follows the framework in Borjas to investigate how an emigration shock of Mexican workers to the US in a specific skill group defined by education and experience affects the wages of workers of that skill group who remained in Mexico. In this paper, I use a cohort analysis similar to the approach in Card and Lemieux to examine how rural out-migration of a given cohort affects the wages of rural workers in that cohort. This cohort analysis is motivated by several considerations. First, rural workers in Brazil present little differentiation by educational attainment. In 2000, less than 13% of individuals included in my sample – individuals residing in rural areas and aged 20 to 54 years in 1991 – had completed secondary education with the majority having less than a complete primary education. Second, occupations in rural areas are characterized by many routine activities with a high level of learning-by-doing which may reward more experience than education.

Growers’ reactions to the updated waiver, especially the 2010 Draft Order, were diverse and abundant. Interestingly, many farmers and agricultural stakeholders highlighted their disappointment in how the negotiations were handled above all else, emphasizing the process itself more than individual mandates. A letter from the Santa Barbara Farm Bureau lamented the new approach, stating that its members supported the 2004 Ag Waiver because it “focused on collaboration” and was “based on a good faith effort from both the agricultural community as well as [the Regional] Board,” however, they were “extremely disappointed” by the stakeholder participation process for the updated waiver, calling it a “failed” attempt due to staff members’ “reluctance to collaborate”. Another stakeholder organization, the Salinas River Channel Coalition , shared similar sentiments: “The SRCC have been involved for many years with water quality solutions in the Central Coast. The first Ag Waiver process was about improvement of water quality, but this current process has become nothing more than regulation to develop fines and fees.” The SRCC also added that the new Regional Board staff did not show they wanted to understand the agricultural industry, nor did they have “a desire to continue the proactive cooperation and educational approach which was used to develop the last Agricultural Waiver”. While the Clean Water Act has achieved significant results in water quality standards,procona florida container and the Federal Insecticide, Fungicide and Rodenticide Act endeavors to prevent chemicals from causing unreasonable harm to the environment and human health, pesticides continue to contaminate America’s waters.

In California’s Central Coast, two pesticides in particular have been identified as the primary sources of water column toxicity and targeted for regulation. Because agricultural operations in the Central Coast have historically relied on diazinon and chlorpyrifos for use on several crops, the region has been a testing ground for important research on the effects of these two organophosphate pesticides. Impacts of chlorpyrifos and diazinon on regional ambient and sediment toxicity are well-documented in the literature . However, less researched have been the policy implications of their use and discharge into waterbodies. This chapter fills several critical gaps. Identifying challenges and successes of applied pesticide control policy offers valuable information and recommendations to water quality regulatory agencies charged with controlling agricultural pollution in the region and beyond. Several studies have reviewed policy tools aimed at agricultural non-point source pollution , including a comprehensive policy analysis specific to California’s Central Coast region , yet even the authors of that study cite a dearth of case studies of implemented policy approaches. This case study analyzes several specific pesticide-related provisions of the 2012 Agricultural Waiver. Of particular interest is why and how two pesticides—chlorpyrifos and diazinon—rose to the top of the policy agenda during the recent regulatory process over a long list of other chemicals used in the region, and what intended and unintended consequences have resulted from this regulatory spotlighting. This study utilizes a blend of historical and social scientific methods to comprehensively evaluate rich datasets relevant to issues of agricultural pesticide use, pollution, chemical switching and environmental governance.

Integrating information from policy documents, meeting minutes, interviews, survey responses, water quality data, monitoring and enforcement data, organic crop production data, and Pesticide Use Records from County Agricultural Commissioner offices and the California Department of Pesticide Regulation, this chapter advances the conversations on pesticide and water quality policy at the regional level and offers insights into larger systemic issues of regulatory spotlighting a limited number of pesticides.Chlorpyrifos and diazinon are both broad-spectrum organophosphate insecticides used throughout the U.S. and California for the control of invertebrate pests . Historically, both were widely applied for home pest control. But in 2000, due to mounting evidence of human health risks, the U.S. Consequently, the overall use of diazinon and chlorpyrifos in California urban areas has dramatically declined , and both pesticides are now used almost exclusively for agricultural pest control. In the Central Coast region, chlorpyrifos is primarily used on broccoli and cauliflower to control soil maggots and on wine grapes to target vine mealybug and ants. From 2006 to 2010, the Salinas Valley, Imperial Valley, Santa Maria Valley and Pajaro Valley regions used only 10% of statewide chlorpyrifos, but they had the highest frequencies of chlorpyrifos detections and exceedances . All of these regions except the Imperial Valley are located within the Central Coast. Diazinon is predominantly applied to head lettuce, leaf lettuce and spinach to kill a variety of insect pests, including green peach aphid , potato aphid , pea leafminer seed corn maggot , spring tails and cutworms . In 2001, diazinon was one of the only registered options for these pests . Diazinon use in the Salinas Valley, “the salad bowl of the world,” nearly tripled from 1997 to 2004 , before it began its steady decline. Seasonal use of chlorpyrifos and diazinon fluctuates with the cropping cycles . Because two or three vegetable crops per growing season are common in the region for brassicas and leafy greens, chlorpyrifos and diazinion use often peaks several times a year.

Between 2011 and 2014, over 20 waterbodies in the Central Coast Region were listed as impaired for chlorpyrifos and/or diazinon and/or unknown toxicity. These water bodies included the Lower Salinas River Watershed and several more in the Pajaro River Watershed and Santa Maria River Watershed . While the use and target species vary between chlorpyrifos and diazinon, the mechanisms of toxicity and associated risks of organophosphates are similar. Several studies suggest that even low-level contact with these neurotoxicants can have serious health implications. The EPA determined that the amount of chlorpyrifos and diazinon that can be consumed in drinking water at which no adverse health impacts would occur for adults is 0.02 mg/L and 0.0006 mg/L and respectively. Exposure has been associated with neurobehavioral deficiencies, including attention deficit and hyperactivity disorder in children . A study conducted in the Salinas Valley of Latina mothers and newborns found that exposure to the pesticides in utero can cause serious health effects to babies, whom are less able to detoxifyorganophosphates . Another recent study links exposure of organophosphates to lung damage in children . Despite the long list of serious human and environmental health implications posed by diazinon and chlopyrifos, one advantage of using these pesticides over others is their relatively shorter half-lives. The half-life of chlorpyrifos and diazinon in the water column ranges from 30-138 days depending on field conditions .In the U.S., a number of major federal and state laws govern pesticides. The Federal Insecticide, Fungicide and Rodenticide Act was passed in 1947 with the original goal of protecting consumers from ineffective products. Through a series of amendments, the Act’s function has evolved to include protecting human health and the environment from unreasonable adverse effects of pesticides. One such amendment that fundamentally changed EPA’s regulation of pesticides towards a health-based focus was the 1996 Food Quality Protection Act . The FQPA was the first to mandate the evaluation of a pesticide’s sensitivity to children, procona London container infants and fetuses as well as the aggregate risk of multiple exposures. Since its passage, the EPA has taken action under the FQPA targeting chlorpyrifos and diazinon for review due to their potential risk to children. Between 2000-2004, the Agency reviewed the two pesticides through a comprehensive Interim Registration Eligibility Decision and Registration Eligibility Decision . During the review, an agreement was made with the technical registrants of chlorpyrifos and diazinon to terminate the registration and begin a phase out for nearly all residential uses of both chemicals. As an extra measure to mitigate health risks, the EPA also required that all use of chlorpyrifos products be discontinued on tomatoes, and restricted its use on apples, citrus and tree nuts. The diazinon RED required more extensive mitigation measures for diazinon use on agricultural crops, including canceling or restricting agricultural uses for more than 20 crops, eliminating all aerial application except for lettuce crops, and limited overall use of the chemical. The agreement also began the process of developing special dormant spray label restrictions for diazinon and chlorpyrifos products. By 2006, product labels were amended to include restricted use during the rainy season, increasing buffer zones, prohibiting certain applications, requiring recommendations from pest control advisors and mandating certain best management practices. In 2012, after initiating a new registration review of chlorpyrifos, the EPA expanded the size of required buffers around sensitive sites, like schools.

Chlorpyrifos and diazinon are also regulated under several sections of the 1972 U.S. Clean Water Act . Water monitoring data collected during the IRED review process highlighted areas where more regulation was needed and where efforts to curb water pollution were already underway. Based on the detection of diazinon and chlorpyrifos in effluent from publically owned treatment facilities, National Pollution Discharge Elimination System permits were amended to include more monitoring and in many cases effluent restrictions. Many states had already begun listing water bodies impaired by chlorpyrifos and diazinon, and begun the process of setting Total Maximum Daily Loads for these waters. In California’s Central Coast, over 20 water bodies have been listed as impaired by chlorpyrifos and/or diazinon: the Pajaro River, Pajaro River Estuary, Llagas Creek, Santa Maria Watershed, Lower Salinas River, Arroyo Paredon, Moss Landing Harbor, Old Salinas River, Tembladero Slough, Blanco Drain, Salinas Reclamation Canal, Espinosa Lake, Chualar Creek, Quail Creek, Espinosa Slough, Alisal Slough, Natividad Creek, San Lorenzo River, Zayante Creek, Arana Gulch, Branciforte Creek, and San Antonio Creek. Additionally, the review process brought attention to several cases of toxic amounts of diazinon and chlorpyrifos in drinking water, forcing regulators to take action under the CWA and Safe Water Drinking Act. The two pesticides have also been identified as impacting several endangered species: California’s red-legged frog, Pacific salmon and steel head species, the Delta smelt and tidewater goby. Under the Endangered Species Act, the EPA has assessed the risks of the chemicals on each of these species and mandated specific practices for their protection. Mandates have included designating critical habitats, vegetative buffers, no spray zones, wind speed restrictions and fish mortality incident reporting requirements. In addition to federal laws, states may also have their own pesticide and water quality regulation programs. For example, in California, the 1969 Porter-Cologne Act gave all nine Regional Water Quality Control Boards broad authority to grant waste discharge requirements for all dischargers in their jurisdiction, as well as the authority to waive those requirements. However, in 1999, with evidence of increased water pollution, the state repealed the Regional Board’s authority to issue waivers, requiring them to, at the very least, attach conditions to waivers and to review these conditions every five years . To comply, each Regional Board has issued individual “Conditional Waivers of Waste Discharge Requirements” . In some cases, like in California’s Central Coast, a Conditional Waiver can act as the primary means for achieving TMDL requirements, raising important policy implications since Waivers have not historically allocated numeric loads to dischargers. California is the only state in the country where a permit and license are needed to apply pesticides. County Agricultural Commissioner offices collect the licensing information and pesticide use records and report these data to the state regulatory agency, the California Department of Pesticide Regulation . In addition to collecting information, the CDPR, as authorized by the California’s Food and Agricultural Code, has the power to reduce pesticide use. In 2015, the CDPR exercised that authority, restricting agricultural uses of chlorpyrifos by requiring applicators to obtain an additional permit from their County Agricultural Commissioner’s office. Yet another means of restricting pesticides is through litigation. For example, in 2015, in response to a lawsuit filed by Earthjustice on behalf of Pesticide Action Network and the Natural Resource Defense Council , the 9th Circuit Court of Appeals ordered the U.S. EPA to file status reports on chlorpyrifos. As discussed in previous chapters, two Conditional Agricultural Waivers have been adopted in the Central Coast Region—one in 2004 and an updated version eight years later, on March 15, 2012. In addition to controlling farm discharges from entering waterbodies, one of the major goals of the Agricultural Waiver is to collect monitoring data. Water quality data are not only used to assess the state of the regions’ waters, but also to assess and select appropriate BMPs, help characterize agricultural pollution problems, and identify pollution hotspots. In the 2012 Ag Waiver, BMP and monitoring requirements vary by tier .

The first employs a within-case method of process tracing to assess the factors that acted as drivers or limitations to the policy process. Part two, uses six evaluative criteria to assess the effectiveness of specific outcomes, such as water quality improvements and the value of monitoring data. The 1972 Clean Water Act employs a technology-based standards approach, whereby any discharger must obtain a permit that contains the limits on what an individual or industry can discharge into a given water body as well as details their monitoring and reporting requirements, all these provisions are defined and enforced by the National Pollution Discharge Elimination System permit system . This approach aims to control pollutants at the point of discharge by setting uniform discharge limitations based on the best available technology pertaining to a particular industrial category. The U.S. EPA grants states the primary responsibility of issuing NPDES permits, and monitoring and enforcing performance. When the technology-based approach does not adequately control pollution, an additional control tool, water quality-based standards, is implemented. The EPA and states use a calculation, Total Maximum Daily Load , to determine the maximum amount of a pollutant that a waterbody can receive while still meeting water quality standards. Water quality standards are set by designating a “beneficial use” for each waterbody as well as the criteria to protect the designated use of that water. The TMDL calculation is a multi-step process: first, the state lists each impaired waterbody within its jurisdiction, called the “303 list”; second,plastic planter pot using the state’s already-established “beneficial use” categories, a numeric TMDL is calculated for each waterbody; finally, a portion of the load is allocated to each discharger.

The fundamental problem of TMDLs, especially in waters polluted with non-point sources, is that they must be translated into specific numeric discharge limitations for each source of pollution . Because non-point source pollution , such as agricultural runoff, is inherently diffuse, the task of monitoring dispersed and dynamic discharges and connecting them back to their sources to identify what operation is polluting and to what extent is both expensive and complicated. However, efforts by the EPA are underway to make water quality modeling, specifically targeted at regulators implementing TMDLs and water quality standards, more easily accessible and affordable . Similar to the Clean Water Act, California’s Porter-Cologne Act gives broad authority to nine Regional Water Quality Control Boards to regulate water quality at a sub-state, localized scale. Regional Boards are responsible for water quality protection, permitting, inspection, and enforcement actions.The Regional Board issues permits on the condition that beneficial uses are protected and water quality objectives will be met. The Regional Boards also have the right to waive Waste Discharge Requirements for individuals or groups, including agriculture, if it is in the public interest . For agricultural discharges, Regional Boards have historically granted waivers rather than force growers to comply with WDRs. In October of 1999, with water quality high on the political agenda, Senate Bill 390 was passed, mandating that Regional Boards attach conditions to waivers and review them every five years .Such monitoring requirements must be adequate to verify the effectiveness of the Waiver’s conditions . In effect, the Conditional Waivers function similarly to Waste Discharge Requirements: the discharger needs to meet conditions specified in the Waiver/Permit. Each Regional Board has taken a different approach to controlling runoff from agricultural lands within their jurisdiction , but almost all have issued Conditional Waivers. In 2004, the Central Coast Region was the first to adopt a Conditional Agricultural Waiver .

The conditions attached to the 2004 Waiver required growers to enroll in the Agricultural Waiver program, complete 15 hours of water quality education, prepare a farm plan, implement water quality improvement practices, and complete individual or cooperative water quality monitoring. The 2004 Agricultural Waiver expired in July 2009, but the Order was extended five times from 2009 until 2012. After nearly three years of continued negotiation, on March 15, 2012 the Central Coast Regional Board adopted a new Conditional Agricultural Waiver, Order No. R3-2012-0011. The updated 2012 Ag Waiver places farms in one of three tiers, based on their risk to water quality . Bigger and more polluting farms are held to tougher standards. For most of the Tier 1 and 2 farms, the 2012 requirements are similar to those in the 2004 Waiver: water quality education, water quality management plans, implementation of management practices, and either cooperative or independent surface receiving water monitoring and reporting. For Tier 3 farms and a subset of Tier 2 farms, additional conditions are added, including submitting an annual compliance form, conducting individual discharge monitoring and reporting, and implementing vegetative buffers. Soon after the 2012 adoption, the State Board received petitions from five parties, representing both the agricultural community and environmental organizations, requesting a “stay” on specific provisions of the new waiver. The agricultural community argued that the Ag Waiver was too harsh, and environmentalists contended it did not go far enough . The State Board asked the Central Coast Regional Board to review and estimate the costs of the provisions of concern and further explain the environmental and public benefits that the updated Waiver would accrue from compliance . The State Board rewrote sections of the Agricultural Waiver, and released a final version in September 2013. Unsatisfied with the State Board’s revisions, a coalition of environmental groups, together with an elderly woman who could not drink water from her tap because it was contaminated with agricultural waste, filed a lawsuit in Sacramento’s Superior Court challenging the 2012 Central Coast Agricultural Waiver and the changes made by the State Board. The coalition claimed the State Board changes “cripple the already weak order,” and as it’s currently written, the Ag Waiver is “so weak, it did not comply with state law” .

In his ruling on August 11, 2015, Superior Court Judge Frawley agreed that the Central Coast’s Conditional Agricultural Waiver was doing an inadequate job of protecting regional water quality and needed to develop more stringent conditions.A more contextualized story of adopting the 2004 and 2012 Ag Waivers is laden with complex and contentious trade-offs, negotiations, lobbying efforts, alliance building, scientific findings, and difficult to foresee “focusing events” . This study pays special attention to assessing the effectiveness of the monitoring program and significance of data collected under the Conditional Agricultural Waiver. Monitoring data are arguably the most pressing concern for non-point source pollution control plans. This Central Coast case illustrates a common trend in non-point source pollution control and what Sunstein would mark as “regulatory failure due to information limitation.” The current monitoring data on agricultural water discharges are inadequate to allocate TMDLs and therefore implement and enforce water quality standards. In the absence of sufficient data, the Ag Waiver regulatory program cannot comply with state and federal law,30 litre plant pots and water protections are further delayed . In an attempt to comply with water quality standards, the Central Coast Regional Board has endeavored to ratchet up monitoring efforts. For example, the updated 2012 Agricultural Waiver program modestly expanded the amount of information it requires of Tier 3 growers to include some individual monitoring. Unfortunately, many are skeptical that this more “robust” monitoring program will, in practice, amount to much more in terms of useful information than the previous monitoring program, especially given the small number of growers in Tier 3. This study fills a gap in research on where monitoring efforts have succeeded and failed in the Central Coast’s agricultural NPS pollution control policies and in reaching TMDL goals. There is also a growing need to identify realistic tools for water quality agencies charged with the difficult task of regulating agricultural NPS pollution. While this study will tailor recommendations specifically to the Central Coast Region, other states and localities facing similar difficulties can utilize results from this research to better manage agricultural pollution with their jurisdiction.Though a general causal hypothesis can be made that certain independent variables have a causal effect on policy-making, process tracing allows the researcher to narrow down the list of potential influential causes as well as uncover independent variables that otherwise would have been left out . Process tracing can also identify whether or not these influential variables have a positive or negative effect on the policy outcome. Such a research design is an iterative, cyclical process—a broad hypothesis can be refined as more data are gathered. King, Keohane, and Verba explain that this type of “exploratory investigation”—selecting on the basis of variance in dependent and independent variables—generates a more precise hypothesis than that which can be made at the beginning. Process tracing requires an in-depth understanding of causal mechanisms in the policy making process in each case, relying on data from newspapers and magazine articles, websites, meeting minutes, policy documents, government reports, public comments, monitoring and enforcement data, and other archival documents.

Key informants for this part of the current research include Regional Water Board staff, university extension specialists, agricultural organizations, growers, water quality agencies, and stakeholders involved in water quality efforts. Interviews were conducted in a semi-structured manner and key informants were identified using “snowball” sampling—starting with a few identified stakeholders who then share names of additional significant individuals to interview. In this study, data from interviews are used to help contextualize events, perspectives, language or definitions and reaffirm information identified during the document analysis. Just as water quality was rising on the agenda, circumstances changed and priorities shifted. In September 2006, two years after passing the first Agricultural Waiver, an E. coli outbreak traced to the Salinas Valley killed three people and sickened more than 200 . Due to public concern, large supermarket chains including Safeway and Costco Wholesale Corporation, demanded that growers have more stringent food safety requirements . Subsequently, food safety auditors began requiring a “scorched-earth” policy including minimizing any vegetative habitat around farms that could attract wildlife. One farmer stated that the “Western Growers Association said they wouldn’t buy anything from farms with vegetative buffer strips.” Because maintaining vegetation on a field’s edge protects water quality from discharging into nearby waterbodies, calling for its removal could threaten efforts to address water pollution on the Central Coast . The E. coli “focusing event” forced the Regional Board to rethink this key provision , which was already under discussion in drafts of the updated Agricultural Waiver. Mandating vegetative buffer strips for all farms would, quite literally, compete with food safety requirements, which require farms to clear vegetation. The contradictory food safety requirement versus water quality requirement left growers confused about which policies to follow. A representative from the Farm Bureau voiced frustration on behalf of the agricultural community, “ever since E. coli there has been a series of complex overlay of regulations” . Two additional issues related to buffer implementation concerned growers: the cost and the science driving the policy. Growers worried about the price not only of installing, irrigating and maintaining the new vegetation around their farms, but also the lost revenue from taking cropland out of production and replacing it with vegetation. Moreover, some agricultural stakeholders contended that the science driving this mandate was inadequate. The improved water quality from vegetative buffers, including pollutant, nutrient and sediment retention, infiltration, sediment deposition, and absorption are well documented in the literature . However, regional agronomic research demonstrating the effectiveness of vegetative buffers is limited to only a few studies, and their results are mixed, especially in regards to the most effective width-size and vegetation . Buffer width became a cornerstone of debate since the jury was still out on exactly how wide a buffer should be to improve water quality. The results of a meta-analysis of over 80 scientific articles on vegetated buffers and sediment trapping efficacy concluded that while wider buffers provide a longer “residence” time for runoff water and thus, are more effective in reducing sediment, sediment trapping efficacy does not improve significantly when buffer width was increased beyond 10 meters . In other words, beyond 10 meters, the law of diminishing returns takes effect. The analysis by Liu and colleagues also concludes that buffer width alone only explains about one-third of retention effectiveness, and other factors, such as soil, slope and vegetation play an equally important role. Because of these competing interests, the vegetative buffer requirement was substantially weakened throughout the Agricultural Waiver deliberation process.

John Eperjesi has shown that this vision espoused by the character Cedarquist is largely based on two contemporary figures, Charles Conant and Albert Beveridge. Although Western writers had dreamed of making a fortune in the China market since the days of Marco Polo, it was Conant who popularized the idea that new overseas markets were the only solution to economic recessions at home. The late nineteenth century saw a fall in profits from manufacturing and a rise in financialization, not unlike the late twentieth century.Thus the closing of Cedarquist’s U.S. factories prompt him to look to China. Like Karl Marx, Conant argued against classical economists that supply and demand could not remain in balance, and that overproduction crises, or recessions, were not an aberration but a structural and repeating feature of capitalist markets. Conant proposed that what he called the problem of “oversaving” on the part of Americans could be counteracted by controlling foreign markets through Imperialism, which would not involve the political difficulties of direct rule as in “Colonialism.”Furthermore, while many celebrated the China market, the Senator Albert Beveridge did so with Cedarquist-like rhetorical flourish. In a speech in 1900, while Norris was writing The Octopus, Beveridge argued: “The Pacific is our Ocean. More and more Europe will manufacture the most it needs,black plastic nursery pots secure from its colonies the most it consumes. Where shall we turn for consumers of our surplus? Geography answers the question. China is our natural customer” . The China market has been called a myth not because there was no market, but because the idea of the market involved a complex narrative of world-historical developments in China and the West, and so structured plans in excess of actual conditions.

In Beveridge’s rhetoric, the myth emerges as a historical narrative grounding the United States’s destiny in the inevitable unfolding of natural processes. The problem of overproduction turns out not to be overproduction at all, but the lack of population increase. Food is not to be produced to feed the population, but ideally the population would be grown to meet the supply of food. As in many places in the text that enter into elevated language such as this, the word wheat is capitalized to indicate its divinity.Wheat is the “concrete example” that stands in for all American goods, due to its seemingly-natural production on the farm—growth—and consumption as food—digestion. Food is the key commodity of the coming twentieth-century where population must be made to depend on the global market. Whereas Cedarquist laments that the European population does not increase to meet U.S. supply, a suitable population does exist in China. Together with the standard Malthusian argument of an ever-expanding number of bodies who have overrun a limited food supply, there is also a decline in the quality of Chinese food, and so the danger is to each individual body. The supposed inability of the Chinese to feed themselves, and specifically the deficiency of their rice crops, is a boon to American agribusiness. Norris did not invent this idea, which reflects one competing view of Chinese agriculture among Americans at the time, which will be taken up in detail in the following chapter. Briefly, one common view of nineteenth-century Americans had been that China was the preeminent traditional agrarian society, but around the turn of the century, however, as China’s position in the world continued to decline and the U.S.’s continued to rise, the agrarian hierarchy was also reversed, and soon American agricultural experts such as Lossing Buck began traveling to China to teach. Indeed there was a crisis in Chinese rural economy at the time, though Norris does not find the cause in European or American interventions, nor even in domestic political failings.

He reverses the causality so that Empire will deliver food to Asia rather than famine, and moreover applies the naturalist trope of degeneracy to Chinese agricultural production. Chinese agriculture does not have an economic problem of production or circulation, the two great “watchwords” of American development, but instead a biological problem, the degeneration of the species itself. As we will see below, agriculture is understood in The Octopus to be propelled by a vital force, the nutritive quality perhaps, that is passing away in the Orient, replaced by the younger vigor of the wheat. The sublime hunger of the Chinese can never actually be relieved, so California wheat production can continue to expand indefinitely, without ever again saturating the market. Cedarquist predicts how such market “effects” will continue to help them in Europe, yet somehow not hurt them in China: “When in feeding China you have decreased the European shipments, the effect is instantaneous. Prices go up in Europe without having the least effect upon the prices in China” . China remains insulated, unaffected by changes in the rest of the world. It is simultaneously the key to international business success, and forever outside of the world market, playing a supplementary and ultimately mystical role. As the text continues, the mathematical sublime established in the Chinese population is transferred to American wheat, which itself becomes infinite: “We hold the key, we have the wheat,—infinitely more than we ourselves can eat” . The sublime quality of the wheat has actually begun with its infinite consumption in China, and then has been logically extended to an infinite production in the U.S. Here we see most clearly how the myth of the China market is the condition of possibility for imagining an infinitely expanding agricultural commodity production. This is how the qualities of the hungry Chinese body, discussed in more detail below, play into the transformation of the meaning of the land in the American West at the “close” of the frontier. The key to China’s role in the novel is that it is not simply a new market, but one where the “laws” of markets cease to apply; it is the limit point of capitalism beyond the horizon.

Norris uses the adjective “vague” throughout the novel to indicate a character’s intentions when his or her reason and common sense are overwhelmed by emotional excitation. This can happen either in business dreams, as here, or also in feelings of romantic love. The novel continuously oscillates between the precise calculation of grain rates, land values, and train schedules, and the “vague” stirrings of personal ambition, revenge, and love. This language encapsulates the tension between the realistic and the romantic that we saw earlier. In this passage, we see that the same word sums up the Orient, another object of ambition and love. Whereas Cedarquist has just given a pseudo-scientific account of nutrition and population figures to argue for the China trade, it is the fact that he cannot prove any of it that makes it so desirable; it must remain mysterious. By flowing over the water to China,greenhouse pot the wheat itself becomes water. By evading the Trust, they become a trust. As many commentators have noted, The Octopus constantly invokes the popular hostility for the middleman in late-nineteenth century American agrarianism while ultimately suggesting that all capitalist enterprise, even farming, operates on the same principles. This sense of geography as destiny follows from Frederick Jackson Turner’s thesis on the historical end of the frontier in the American West, widely influential from Norris’s time well into the twentieth century. In “The Significance of the Frontier in American History,” a paper delivered to the American Historical Association in 1893, Turner argued that the frontier had been the decisive factor in shaping the course of U.S. history, and that the end of the frontier meant the closing of the first period of that history. The Octopus is addressed to Turner’s thesis in a double sense: the advent of industrial agriculture proves that California is no longer a frontier, while the interest in China expands the westward push beyond the continent. As Turner put it, “Up to our own day American history has been in a large degree the history of the colonization of the Great West. The existence of an area of free land, its continuous recession, and the advance of American settlement westward, explain American development” . Here colonization is understood as overtaking and ruling “free” land. Many commentators at the time and since have seen the frontier thesis as underlining the importance of expansion across the Pacific. What separates the actions around the Spanish American War, the era that U.S. politicians openly debated imperialism as a policy, from the earlier settler colonial policies on the continent and Hawaii is first that these areas of Asia are not imagined as empty “free land,” and second that they are occupied for their strategic geographical positions, specifically for access to the China market.

For Frank Norris, moreover, the end of the frontier can be pinpointed to the specific moment of U.S. military action in China, when U.S. troops joined with an international force to put down the Boxer Rebellion in 1900. In a significant essay that has received little attention from critics, “The Frontier Gone at Last,” he wrote that “[u]ntil the day when the first United States marine landed in China we had always imagined that out yonder somewhere in the West was the borderland where civilization disintegrated and merged into the untamed” . Once the marines have landed, that is, Americans can no longer imagine that there is a frontier to the west. The frontier is by definition untamed, uncivilized, whereas China is understood to be a civilization of ancient provenance—in The Octopus, as we have seen, it is in fact the first empire, ancestor of the present U.S. Thus moving into this area is no longer frontier expansion, but meeting, in Turner’s words, “other growing peoples [to be] conquered” . Finally, “the day” when the marines landed and the frontier vanished took place while Norris was writing the novel, which perhaps partly accounts for Cedarquist’s oracular style. Norris’s conception of the U.S. encounter with China as the historical as well as geographical end to the frontier is what links the land dispute plot to the dream of the China market. When the ranchers read the circulars advertising land that is virtually free, they are still operating with a frontier mentality. Their leader, Magnus Derrick, in particular is presented as a veteran of the gold rush, a 49’er, who has shifted to ranching as a new form of prospecting. When the railroad comes to charge the current market value, however, the frontier has been closed. Although commentators on the novel have tended to analyze either the environmental meaning of new agriculture, or the representation of China and the Chinese, but not both, the structural connection between these two foci needs to be emphasized. As Cedarquist explains to the group, there can be no going back to the economics of the frontier, but they must compete in an industrial capitalist market. The only way profits can be guaranteed in this new world is through the China market, and in order to secure this ideologically, Asia must be seen as having been America’s destiny all along. Thus, I follow William Conlogue’s argument that The Octopus should not be understood as pastoral, the term that is most often used to describe the representation of the land in American literature. In the U.S. context, the pastoral is used slightly differently than its classical meaning in the Western tradition, in which is the countryside is imagined by urban cultural elites. Instead, Leo Marx famously argued that Americans’ attitudes toward rural space betrayed a contradiction, both idealizing the scene of natural purity and simultaneously displaying enthusiasm for industrialization. Literary writers displayed this tension by producing a compromise formation captured in Marx’s paradoxical term “complex pastoral,” which is somewhat analogous to the classical pastoral’s position as the cultivated middle space between the city and the wasteland. The Octopus is one of his key examples, not only because the railroad is the paradigmatic “machine in the garden” but more specifically because of the novel’s vivid depictions of industrial agriculture as the sexual union of machines and the soil. Whereas Marx establishes the complex pastoral as a trope that repeats across the full range of fiction and nonfiction genres, for Walter Benn Michaels The Octopus represents something more specific,which is the “central problem for naturalism, the irruption in nature of the powerfully unnatural” .