Author: naturehydro

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The heart rate is determined by the firing frequency of the sinus node

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 .

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Income inequality was the highest among farmers with farmland located far from homestead

The vegetation of the area is extremely variable ranging from drier lowland coastal forest to transitional rainforests, sub-montane, montane and upper montane forest types, as well as the afromontane grasslands on the Lukwangule plateau. All these ecosystems are rich in endemic species making them of high conservation priority. However, land degradation in the area is rampant due to existence of unsustainable anthropologic activities . The mountains also serve as a water catchment and water source for populations living downstream in Morogoro rural and Municipality as well as other residents in the Dar es Salaam City and the Ruvu/Wami River Catchments. Thus, we purposefully selected the study area not only for its importance as a water catchment, but also as an enormous biodiversity hotspot which is encountered by the challenge of increasing human activities that threaten biodiversity and environmental integrity.

The study used the multi-stage sampling procedure to select the study villages and sample households. The third stage entailed the selection of sample households from each stratum using the proportionate probability sampling procedure. The purpose of using wealth ranks, apart from understanding the perceptions of communities in the study area about poverty and wealth gained from the wealth ranking exercise, was to ensure that the sample drawn and quantitative analyses represent the full range of livelihoodcircumstances in the study area, rather than being accidentally clustered around the mode of range. The distribution of sample size by hamlets is given in Table 1. The study used both primary and secondary data. Prior to commencement of fieldwork, we hired six enumerators to assist during data collection. These were trained on how to administer questionnaires and use other research tools . They were also reminded about the research ethics they should comply with. The actual fieldwork started with a reconnaissance survey to get an overview and understanding of the study area and applicability of the questionnaire. During the reconnaissance survey the household questionnaire was pre-test to a small number of respondents before the actual fieldwork to check for their relevance to the study area and objectives. This was followed by the main survey which used different research tools and techniques, including structured questionnaires, interviews with key informants and Focus Group Discussions .

The FGDs were attended by at least 10 participants per village representing different socioeconomic groups that existed in the area, including the rich, poor, youth and women, men, abled and disabled people. In addition, direct observation served as a complementary tool. In selecting the key informants for interview the snowball technique was used. The technique is particularly suitable when the population of interest is hard to reach and compiling a list of the population poses difficulties for the researcher . It begins with a convenience number of initial subject which serves as “seeds,” through which wave 1 subject is identified; wave 1 subject, in turn, identifies wave 2 subjects; and the number of interviewees consequently expands wave by wave-like a snowball growing in size as it rolls down a hill .The results of qualitative analysis poverty using the wealth ranking results were complemented with quantitative analysis of income inequality and drivers of income inequality using the Gini coefficient and Lorenz curves, as well as, the coefficient of variation measure adapted from Adams . The percentile shares quantify the proportions of total outcome that go to different groups defined in terms of their relative ranks in the distribution . The approach provides more details about the processes that cause the various distribution changes which may either increase or decrease the Gini coefficient . The percentile shares approach is more useful in cases where time series data is used but it also compliments the analysis of income inequality using cross-sectional data. The approach addresses the interpretation limitation inherent in specific values of the Gini coefficient .

As mentioned earlier, the Gini index is a widely used and favoured measure of income inequality over other alternatives because this index can be applied to both time series and cross-sectional data simultaneously . The value of the Gini Index ranges from 0 to 1. With the value 1,the Gini coefficient represents perfect unequal distribution of income, while with the value 0, it represents perfect equality of income . Links with the Lorenz curve make the Gini coefficient an attractive statistic for the decomposition by income components, as the Lorenz curve graphically represents the Gini coefficient. The concentration coefficient of each income component with respect to total income is obtained from a concentration curve . However, it should be noted here that, the Gini coefficient cannot be used to rank distributions if the Lorenz curves intersect. According to Litchfield , there are alternative ways to decompose the Gini, however the component terms of total inequality are not always intuitively or mathematically appealing.

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Chemosit and Kipsonoi rivers traverses through different land use types

Soil pH was determined using a pH meter. In this case, six distinct land use activities were identified along based on their dominant land uses and characteristics. Generally there is a variation in land use activities from upstream to downstream. Upstream is dominated by indigenous forest characterized by dense network of trees and bushes with little human disturbance. From the edge of the forests towards midstream, the land opens up to a rich upland agricultural area of extensive and intensive farming characterized by tea plantation and few human settlements. Moving downstream, grazing and mixed agricultural farming predominate with more permanently settled small scale farmers and urban set-up with high population and economic activities.Upstream riparian vegetation was least disturbed with native vegetation present on both sides of the river, intact canopy and with continuous woody vegetation along the riparian zone, dense ground cover and river banks in natural condition.

Midstream riparian vegetation is in poor condition characterized by isolated woody vegetation, limited ground cover and disturbed banks. In addition there is a high disturbance of the riparian zone by stock or through the intrusion of exotic species, although some native species remain. Valley vegetation is clearly agriculture with native vegetation clearly disturbed and with a high percentage of introduced species present. Downstream riparian vegetation is severely disturbed on both sides as indicated by reduced and absence of riparian vegetation.During the study period, significant differences were observed in Water pH and Total Nitrogen between sampling sites. Tukey’s test showed that the mean water pH at upstream sampling site differed significantly from that recorded at downstream of Chemosit river. Along Kipsonoi river, the mean water pH differed significantly between midstream and Downstream sampling sites. In both rivers, the mean value for water pH ranged from 6.9 to 7.2 . However these values fall within the pH range associated with most natural waters of 6.5 to 8.5 . Most ecosystems are sensitive to changes in pH while certain organisms prefer different ranges of pH . The reported land use activities in SWMF do not seem to modify the pH of the water. Indeed soils and land use activities affect the proportion of major ions in water bodies and hence the water pH . On the other hand, along Chemosit river significant differences were observed in total nitrogen between upstream and midstream sampling sites and between upstream and downstream along Kipsonoi river, respectively.

The high Total Nitrogen concentrations of 6.7 mg/l and 5.7 mg/l observed midstream of the two rivers could be associated with adjacent urban and agricultural land use activities. According to agricultural activities can lead to an increased flux of nitrogen into water bodies while use of fertilizers on agricultural land has been associated to high nutrient levels at such sites . Further, total suspended solids, potassium, total phosphorous, cadmium, lead and copper did not however show any significant differences. Total Suspended Solids were highest midstream on both rivers. This variation could be associated to the different land use activities reported for these sites, run-off from agriculture, soil erosion as well as in- stream activities such as car washing. Presence of indigenous forests, absence of agricultural activities, intact riparian zones characterized by dense vegetation explain the low levels of Total Suspended Solids in the upstream of the two rivers . However total suspended solids in SWMF ranged from 24 – 84 mg/l which is below WHO limits of 1000 mg/l of suspended solids of drinking water. Total phosphorous concentrations increased downstream with the highest concentration recorded at midstream and lowest at upstream on both rivers. Natural concen-trations of phosphorous in surface waters usually range from 0.005 to 0.02 mg/l, while the Environmental Protection Agency recommends a 0.1 mg/l for aquatic systems to prevent accelerated eutrophication . Low concentrations of total phosphorus recorded upstream of Chemosit and Kipsonoi rivers is linked to the undisturbed dense network of trees.

In undisturbed forested areas, streams are believed to have good water quality with low concentration of nutrients . The dense riparian vegetation within the forest land use are effective buffers in filtering out most of the nutrients from the surface run-off . These findings mirror previous studies that concluded that water quality is greatly linked to land use in a catchment and confirms several studies that have shown agriculture and urban land use as a primary predictor for nitrogen and phosphorous in stream water . The amount of heavy metals represented by Cd, Cu and Pb did not differ significantly across sites and their concentration did not follow any trend from upstream to downstream. These results agree with previous study that metal concentrations at sites located relatively high up in the catchment were comparable to, or higher than concentrations of these metals downstream. These values are linked to effluent discharge, agricultural and urban run-off, washing and bathing activities by local inhabitants and livestock access to the rivers. In addition degradation of the forest cover and other anthropogenic activities going on inside the forest, atmospheric deposition and geology weathering are potential sources of these metal ions . The low soil pH upstream might be due to the presence of slightly higher organic carbon content in the soil. Variability in total organic carbon along the two river systems is linked to the reduction in organic material being returned to the soil system due to decreasing vegetation cover downstream and oxidation of soil organic matter as a result of continuous cultivation along the riverbanks, uncontrolled grazing and browsing, loss of organic matter by water erosion and removal of green materials.

These results are in agreement with other studies that reported that the soil organic content differed with different land use types . The higher organic matter content upstream may be attributed to a higher accumulation of organic matter due to high inputs from root biomass . Variability in total nitrogen is linked to difference in soil organic matter content, intensities in cultivation and erosion, application of manures, pesticides and fertilizers rich in nitrogen content in the soils.In this study , soil pH ranged between 4.42 and 5.56, implying the soils are strongly acidic and suitable for tea production which was consistent with previous studies carried out in tea plantations . Soil pH was lowest in soils obtained Upstream on both rivers, with significant differences across the sampling sites. Tukey’s test showed that soil pH at upstream differed significantly from soil pH recorded midstream and downstream of Chemosit and Kipsonoi rivers.