Nature Agriculture

The field of research and development of parasiticides provides perhaps the most blatant concrete examples of the One Health approach in parasitology, spanning across human and veterinary medicine. The possibly most renowned case in point in this respect is represented by the “wonder drug” ivermectin. Discovered in the late 1970s and initially developed for veterinary use as a broad-spectrum endectocide targeting gastro-intestinal nematodes and several ectoparasitic arthropods, ivermectin has then been largely employed in human medicine for the control of onchocerciasis, lymphatic filariasis , certain soil-transmitted helminthiases and scabies . This drug still represents the mainstay of two global campaigns aiming to eliminate onchocerciasis and LF, by the means of Mass Drug Administration , made possible through donations of the active ingredient by Merck & Co., Inc.. Recently, the use of ivermectin was proposed for MDAs in both humans and livestock as a complementary strategy to control malaria mosquito vectors .

Another successful example of an anthelmintic employed in both human and veterinary medicine is that of praziquantel. Also discovered in the 1970s, it is used to control cestodes and trematodes in dogs, cats, horses and sometimes even cattle , and it represents the only currently available option for the control of schistosomiasis in humans . Over the years, praziquantel has indeed been used for MDA-based preventative chemotherapy campaigns targeting school aged children in schistosomiasis-endemic areas in Africa . However, risks of emergence and/or spreading of resistance or reduced efficacy in human parasites addressed towards ivermectin  and praziquantel , together with the need for effective drugs and/or vaccines against NTDs and malaria, have paved the way for initiatives aiming to fill the void in R&D pipelines against these diseases. Indeed, from the early 2000s onwards, several “Product Development Partnerships” started being established, under the model of “Public–Private Partnerships” . These include, among others, the Drugs for Neglected Diseases initiative , Medicines for Malaria Venture  and the Global Health Innovation Technology , focused on drug and/or vaccine development; the Foundation for Innovative Diagnostics  devoted to diagnostics; the Program for Appropriate Technology in Health  dedicated to vaccine R&D, primary health care and advocacy; and the Innovative Vector Control Consortium , developing vector control tools .

Such PDPs are non-profit entities that collaborate with human pharmaceutical and biotech firms to support them in the development of solutions to address NTDs and malaria. Within this framework, the substantial funding provided by multilateral, bilateral and philanthropic donors , allows for the “de-risking” of R&D projects that would otherwise be prohibitive for industry alone, due to the limited return on investment that they may generate . The execution of the London Declaration on NTDs in 2012, which gathered initially the world’s 13 leading pharmaceutical companies, generated a major momentum in the fight against NTDs, catalysing an investment of more US$785 million to support R&D programmes . For example, DNDi’s target conditions include several parasitic NTDs that are endemic to the African continent such as leishmaniasis, sleeping sickness , LF and onchocerciasis . With respect to the latter condition, DNDi’s efforts are currently focused on evaluating emodepside, an anthelminthic veterinary drug used to control nematodes in cats and dogs, for the development of an oral macrofilaricidal treatment for onchocerciasis in humans, to be delivered as a tablet . Following successful Phase I studies in healthy volunteers, this project will soon undergo a Phase II proof-of-concept clinical trial in Ghana, aiming to assess the safety and efficacy of emodepside for people living with onchocerciasis . In the veterinary field, the Global Alliance for Livestock Veterinary Medicine was established in 2004 as a PDP supporting veterinary pharmaceutical companies developing drugs, vaccines and diagnostic tools for livestock diseases of poor smallholder farmers in sub-Saharan Africa and South Asia .

Some of GALVmed’s target diseases include NZDs such as porcine cysticercosis and animalAfrican trypanosomiasis and the zoonotic arthropod-borne RVF . In the case of porcine cysticercosis, GALVmed bolstered the commercial development of a dual approach based on the fifirst licensed cysticercosis vaccine for pigs , administered concurrently with a therapeutic drug , used to eliminate parasitic larvae, according to a “therapeutic-prevention” strategy . Following successful trials in Nepal, Tanzania, Uganda and Zambia, both products are now undergoing registration in several African countries . Given the zoonotic nature of cysticercosis, this initiative is expected to bring also public health benefits to the communities administering these products to their pigs. The examples of dewormers such as ivermectin and praziquantel show that opportunities do exist with regards to translating or even “repurposing5” drug discovery and development from human to veterinary health applications, and vice versa, in the area of parasitic infections.

A generalized regression neural network is another type of ANNs that has successfully been used for modeling and predicting different tissue culture processes . Although there exist no reports using GRNN for the modeling and optimization of disinfection process, we previously showed that GRNN has a higher predictive performance than RBF, MLP, and the adaptive neuro-fuzzy inference system for cannabis micropropagation . Therefore, in the current study, we used GRNN-GA to model and optimize cannabis seed disinfection. Mature seed germination can sometimes be more difficult than immature seed germination due to the increase in the seed coat’s impermeability and the accumulation of inhibitors during seed maturation . Hence, dormancy breaking plays a critical role relating to the speed and frequency of seed germination due to morpho-physiological dormancy.

Although there are no reports on the effects of scarification on cannabis seed germination, the positive impact of dormancy breaking by scarification has previously been suggested in several plants, such as Limodorum , Salvia stenophylla , and legumes . Based on this evidence, studying the effect of scarification on cannabis seed germination can pave the way for devising an in vitro seed germination protocol with high speed and germination frequency. The current study uses GRNN-GA to model and optimize cannabis seed disinfection, and investigates the effect of scarification on seed germination. By combining these procedures, a superior in vitro cannabis seed germination protocol that limits contamination while allowing high germination rates in a short timeframe was established. In vitro seed germination of cannabis has great potential to improve the efficiency of elite cultivar selection, pheno-hunting, phenotyping, and to support various in vitro culture methods as initial explant materials .

In orthodox seeds, germination typically initiates with the passive uptake of water by the dry mature seed, and terminates with radicle protrusion through the seed envelope . Different abiotic factors affect seed germination,mainly through regulating the signaling and metabolism pathways of abscisic acid and gibberellic acid . Although cannabis seeds easily germinate within several days under greenhouse or fifield conditions, in vitro cannabis seed germination tends to be more difficult, with lower germination rates spread over a longer period of time. The cause of this difference is unknown, but is likely related to the disinfection protocol that may stress the developing embryo or potentially eliminate microbes that play a role in the germination process. As such, optimizing sterilization and scarification protocols can be considered the two most important procedures for successful in vitro seed germination . The surface sterilization of initial source material, including seeds, is a prerequisite for the success of the culture . Therefore, it is vital to optimize the sterilization protocol while allowing it to remain simple, cheap, environmentally friendly, and efficient .

Although various disinfectants and immersion times can be employed to sterilize the explants, each species and even explant type necessitates a particular sterilization protocol . The hybrid of machine learning—optimization algorithm procedures offer promising computational methodology that is well suited to model and optimize in vitro culture systems such as sterilization . Based on our results, GRNN-GA accurately predicted and optimized the in vitro surface sterilization of cannabis seed. According to the optimization process through GRNN-GA, 4.6% sodium hypochlorite along with 0.008% hydrogen peroxide for 16.81 min would result in no contamination. Similar to our results, previous studies showed that sodium hypochlorite was more successful than hydrogen peroxide in controlling contamination . Additionally, the results of the validation experiment confirmed no differences between the optimized predicted and observed results, showing the robustness of GRNN-GA.

In line with our results, previous studies showed that GRNN-GA can be considered a reliable computational method with high prediction performance for the modeling and optimizing of in vitro culture systems . While the optimized seed disinfection protocol resulted in 0% contamination, germination was still slow and sporadic. The second experiment was performed to evaluate the effect of scarification on the speed and frequency of in vitro seed germination. One possible explanation for this difference is the presence of different microbes that aid in the digestion of the seed coat or micropyle plug, thereby facilitating higher rates of imbibition, and thus, higher/quicker field germination rates.

Genetic modifications through the use of the modern recombinant DNA technology may play an important role in improvement of the crop only when it complements and integrates with other fields of science and not done in isolation . Moreover, to be cost-effective, the technology outputs must be tested and evaluated in whole-plant and within relevant cropping systems under prevailing environments as well as under predicted climatic changes in the 21st century . Connor et al., in their recently revised Crop Ecology text book , have rightly commented on the current research efforts targeted towards genetically transferring the quite complex C4 photosynthetic syndrome to C3 rice, where significant financial support was recently devoted to, by saying: “What a pity that cassava does not share the world-food limelight with rice. 

This species has the most, and best studied, intermediate photosynthetic types, and beneficial growth and yield responses have been demonstrated in them . The pathway to success ought to be shorter for this crop. It would be exciting to see progress in the search for this current ‘holy grail’ of biotechnology during the lifetime of this book.” Quote. Research institutions and donors agencies concerned with agricultural research and development must be aware of the high potential of cassava as food, feed, and industrial crop and its role in the face of global climate change. The author wishes to express his gratitude to Colombian farmers for their hospitality during conducting some of this research. Without the collaboration of the many former field laborers, secretaries, research associates, students and colleagues, who are now dispersed across countries, the achievements highlighted here would have never been obtained. The invaluable courtesy copies of books documenting important research on crop ecology by David Connor, Robert Loomis and Kenneth Cassman, and on climate change by Mary Beth Kirkham, and Cynthia Rosenzweig, article reprints from Andy Jarvis, Julian Ramirez-Villegas and David Rosenthal were appreciated.

I am grateful for the waiving of the required pagecharges by the Editors of OJSS.Thanks to Farah El-Sharkawy Navarro for the editorial and the WWWnet search assistance. With nearly 60% of its population under the age of 25 years, Africa is the “youngest” continent on earth . Currently hosting a total of 1.37 billion people , corresponding to almost a double of Europe’s 750 million, the continent is expected to reach the size of 2.5 billion inhabitants by 2050 and of approximately 4 billion by 2100 . By then, one person in every three worldwide will be from the African continent. This exponential growth is expected to be accompanied by an equally significant increase in the continent’s need in animal source foods. Indeed, Africa’s demand for meat, milk and eggs will almost quadruple by 2050 , with annual growth rates of consumption estimated at 2.3% for milk and 2.8% for meat . Currently, however, not only Africa is overall a net food importer , but it is also the most food insecure region in the world, the only one in which the absolute number of undernourished people has increased in the past 30 years , and where that of stunted children under five is still rising . Presently, nearly 60% of Africans are moderately or severely food insecure, with more than 90% of them residing in sub-Saharan Africa . At thesame time, overweight rates are also increasing , highlighting the continent’s need for nutritious foods. Yet, Africa harbours 60% of the world’s uncultivated arable land , with one-quarter of the world’s cultivable land being in sub-Saharan Africa but only producing 10% of the global agricultural output .

Therefore, the continent’s rising demand for animal protein could be potentially met, at least partly, through enhanced local agricultural production, made possible by improving the productivity of farming processes , as envisaged by the African Union’s Comprehensive Africa Agriculture Development Programme  and New Alliance for food security and nutrition . This agricultural transformation process may also include possible access by livestock keepers to wild areas hardly attended or inhabited thus far, to make room for livestock rearing and grazing . By creating new human–animal–environment interfaces, such an expansion may however bring health risks, as pathogens from wildlife could spill over onto domestic animals and people . Moreover, the ongoing climatic changes and global warming may also compound this scenario.

The data for the physiological/psychological evaluation was indicated by mean ± standard deviation.We asked the stimulation group open-ended questions about their image of soil scent after they had smelled the soil. All the subjects gave a reply except for one. Eight subjects imagined landscapes and experiences related to soil scent, and one subject had no image. Two participants replied as to whether they liked the soil scent or not .In this study, we compared subjects which were presented with the scent of soil and those which were not . Consequently, although the control group showed no physiological changes, the stimulation group showed a significant decrease in heart rate . This frequency is influenced by the dominant sympathetic nerve and vagus nerve, thus leading to either excitability or inhibitory.

For this reason, periodic activity of the brain stem and higher order cerebral cortex that synchronize with signals from arteries and veins and changes in blood pressure influence behavior, emotions, circadian rhythm, which increase through hyperactivity of sympathetic nerve functions, and decrease through hyperactivity of parasympathetic nerve functions . In this study, the heart rate of the stimulation group decreased, but there was no significant difference between HF that is a parasympathetic nerve index of heart rate fluctuation and LF/HF that is a sympathetic nerve index. Thus, we conclude that neither the parasympathetic nerves nor the sympathetic nerves function independently. In the open-ended questions about what kind of image subjects associated with the soil scent, some of the answers included “insect collecting” in the mountains, a forest, and horticultural therapy. The sense of smell enters the limbic system which is responsible for processing memory and creating emotion and reaches the hypothalamus that is also an autonomic nerve center.

Accordingly, the emotional response from an individual who is stimulated by a scent can cause physiological changes in brain waves and various autonomic nerve functions. The heart rate is adjusted by the autonomic nervous system or endocrine system, and can change according to the subject’s posture, and physical and mental activities . Therefore, for the heart rate that showed significant difference, we performed a Pearson’s correlation analysis among the degrees of changes at the points of Stim and Post 15 against Pre, and the degree of changes at the point of Post against Pre in VAS and POMS, and examined the psychological factors related to heart rate . As a result, the degree to which the heart rate decreased after smelling soil scent had a significant negative correlationwith the factors “feel relaxed” and “feel soothed” as indicated by the increase in the VAS scores. Therefore, in this study, we found that the healing effects and autobiographical memories induced from smelling the soil may lead to hyperactivity of parasympathetic nerve functions or suppression of sympathetic nerve functions which may influence the heart rate.Water and soil are important natural resources that play a prominent role in domestic activities and agricultural development in most African cities, the pressure on the use of these resources is constantly increasing due to the exponential increase of the population orchestrated by rural exodus. In this situation, the design of food stuff supply is modified in urban and peri-urban areas of Yaounde in Cameroon .

Vegetables are valued by the population; therefore vegetable farming is not only a source of food supply but also a source of employment in agricultural sector . This activity is mainly located in swampy lowlands, slopes, roadsides with heavy pressure on space . Vegetable farming reveals an interaction among the categories of actors, spaces types, crops species, the products obtained and the average incomes generated . It thus constitutes one of the main economic activities on which the population depends. This type of agriculture is demanding in terms of soil fertility management and water supply. There is a significant investment in crop techniques, fertilizers used, and pesticides treatments to meet the ever-increasing demand throughout the year. The increasing demand for vegetable produces leads to an intensification of their production aiming to high yields, which may negatively impact the preservation of water and soil resources . This study aimed at having a better knowledge of the characteristics of the vegetable farming in Yaounde, Cameroon.Steeper slopes occur locally whereas flatter tracts of land are found on small plateaus. The average annual rainfall among to 1600 mm and occurs in a bimodal configuration such that the first and second cropping seasons, separated by a 4-month dry season, last from mid-March to early July and from late August through mid-November respectively .