THE ROLE OF ENVIRONMENTAL EDUCATION IN PREDICTING ADOPTION OF WIND EROSION CONTROL PRACTICES

Logit and ordered probit analyses were used to identify factors associated with reduced tillage adoption, continuous spring cropping, and the number of changes made in response to wind erosion. Contrary to previous results for water erosion control, simple perception of a wind erosion problem or membership in a particular socioeconomic category did not significantly explain adoption of wind erosion control practices, but participating in a targeted educational program did. This educational program: (a) highlighted the threats of wind erosion to human health and to soil productivity, and (b) described specific potentially profitable farming practices for solving the wind erosion problem.Environmental Economics and Policy,

THE ROLE OF ENVIRONMENTAL EDUCATION IN PREDICTING ADOPTION OF WIND EROSION CONTROL PRACTICES

Logit and ordered probit analyses were used to identify factors affecting reduced tillage adoption, continuous spring cropping use, and the number of changes made in response to wind erosion. We found problem perceptions or common socioeconomic variables couldnt explain adoption of these practices, but participating in an educational program did.Environmental Economics and Policy,

Differences in pathogenicity and virulence of Trypanosoma brucei gambiense field isolates in experimentally infected Balb/C mice

Trypanosoma brucei gambiense (T. b. gambiense) is the major causative agent of human African trypanosomiasis (HAT). A great variety of clinical outcomes have been observed in West African foci, probably due to complex host-parasite interactions. In order to separate the roles of parasite genetic diversity and host variability, we have chosen to precisely characterize the pathogenicity and virulence of T. b. gambiense field isolates in a mouse model. Thirteen T. b. gambiense strains were studied in experimental infections, with 20 Balb/C infected mice per isolate. Mice were monitored for 30 days, in which mortality, parasitemia, anemia, and weight were recorded. Mortality rate, prepatent period, and maximum parasitemia were estimated, and a survival analysis was performed to compare strain pathogenicity. Mixed models were used to assess parasitemia dynamics, weight, and changes in Packed Cell Volume (PCV). Finally, a multivariate analysis was performed to infer relationships between all variables. A large phenotypic diversity was observed. Pathogenicity was highly variable, ranging from strains that kill their host within 9 days to a non-pathogenic strain (no deaths during the experiment). Virulence was also variable, with maximum parasitemia values ranging from 42 million to 1 billion trypanosomes/ml. Reduced PCV and weight occurred in the first two weeks of the infection, with the exception of two strains. Finally, the global analysis highlighted three groups of strains: a first group with highly pathogenic strains showing an early mortality associated with a short prepatent period; a second group of highly virulent strains with intermediate pathogenicity; and a third group of isolates characterized by low pathogenicity and virulence patterns. Such biological differences could be related to the observed clinical diversity in HAT. A better understanding of the biological pathways underlying the observed phenotypic diversity could thus help to clarify the complex nature of the host-parasite interactions that determine the resistance/susceptibility status to T. brucei gambiense

Candidate gene polymorphisms study between human African trypanosomiasis clinical phenotypes in Guinea

Human African trypanosomiasis (HAT), a lethal disease induced by Trypanosoma brucei gambiense, has a range of clinical outcomes in its human host in West Africa: an acute form progressing rapidly to second stage, spontaneous self-cure and individuals able to regulate parasitaemia at very low levels, have all been reported from endemic foci. In order to test if this clinical diversity is influenced by host genetic determinants, the association between candidate gene polymorphisms and HAT outcome was investigated in populations from HAT active foci in Guinea.Samples were collected from 425 individuals; comprising of 232 HAT cases, 79 subjects with long lasting positive and specific serology but negative parasitology and 114 endemic controls. Genotypes of 28 SNPs in eight genes passed quality control and were used for an association analysis. IL6 rs1818879 allele A (p = 0.0001, OR = 0.39, CI95 = [0.24-0.63], BONF = 0.0034) was associated with a lower risk of progressing from latent infection to active disease. MIF rs36086171 allele G seemed to be associated with an increased risk (p = 0.0239, OR = 1.65, CI95 = [1.07-2.53], BONF = 0.6697) but did not remain significant after Bonferroni correction. Similarly MIF rs12483859 C allele seems be associated with latent infections (p = 0.0077, OR = 1.86, CI95 = [1.18-2.95], BONF = 0.2157). We confirmed earlier observations that APOL1 G2 allele (DEL) (p = 0.0011, OR = 2.70, CI95 = [1.49-4.91], BONF = 0.0301) is associated with a higher risk and APOL1 G1 polymorphism (p = 0.0005, OR = 0.45, CI95 = [0.29-0.70], BONF = 0.0129) with a lower risk of developing HAT. No associations were found with other candidate genes.Our data show that host genes are involved in modulating Trypanosoma brucei gambiense infection outcome in infected individuals from Guinea with IL6 rs1818879 being associated with a lower risk of progressing to active HAT. These results enhance our understanding of host-parasite interactions and, ultimately, may lead to the development of new control tools

Macrophage migrating inhibitory factor expression is associated with Trypanosoma brucei gambiense infection and is controlled by trans-acting expression quantitative trait loci in the Guinean population

Infection by Trypanosoma brucei gambiense is characterized by a wide array of clinical outcomes, ranging from asymptomatic to acute disease and even spontaneous cure. In this study, we investigated the association between macrophage migrating inhibitory factor (MIF), an important pro-inflammatory cytokine that plays a central role in both innate and acquired immunity, and disease outcome during T. b. gambiense infection. A comparative expression analysis of patients, individuals with latent infection and controls found that MIF had significantly higher expression in patients (n=141; 1.25 +/- 0.07; p<.0001) and latent infections (n=25; 1.23 +/- 0.13; p=.0005) relative to controls (n=46; 0.94 +/- 0.11). Furthermore, expression decreased significantly after treatment (patients before treatment n=33; 1.40 +/- 0.18 versus patients after treatment n=33; 0.99 +/- 0.10, p=.0001). We conducted a genome wide eQTL analysis on 29 controls, 128 cases and 15 latently infected individuals for whom expression and genotype data were both available. Four loci, including one containing the chemokine CXCL13, were found to associate with MIF expression. Genes at these loci are candidate regulators of increased expression of MIF after infection. Our study is the first data demonstrating that MIF expression is elevated in T. b. gambiense-infected human hosts but does not appear to contribute to pathology

Fertilizer use efficiency and economic viability in maize production in the Savannah and transitional zones of Ghana

Increasing fertilizer use is highly justified for sustainable agricultural intensification if yield response, fertilizer use efficiency (FUE), and economic viability of fertilizer application are high. Despite the increasing fertilizer application rates in Ghana, yields only marginally increased. Also, the recent fertilizer price hikes post COVID-19 revived concern for economic analysis of fertilizers. This study analyzed the FUE and economic viability of fertilizer use in maize production in Guinea/Sudan Savannah and Transitional/Deciduous zones of Ghana. Survey data from 2,673 farmers in the 2019, 2020, and 2021 production seasons were used. The average agronomic efficiency (AE), partial factor productivity (PFP), and value-cost ratio (VCR) of fertilizer use were 2.2 kg of grains per kilogram of fertilizer, 18.3 kg grains per kilogram of fertilizer, and 1.8 Ghana cedis of marginal yield per Ghana cedi spent on fertilizer, respectively. Fertilizer use was economically viable for only 28.1% of farmers with a VCR of 2 or higher, while 52.5% reached the break-even point with a VCR of at least 1. Various fertilizer formulations, including NPK plus sulfur, and adoption of integrated soil fertility management (ISFM) practices, particularly improved seeds, organic fertilizers, and minimum tillage, improved maize yield response to fertilizer and thus the FUE. These low efficiency and economic viability of fertilizer use are prevailing conditions in other sub-Saharan Africa (SSA) countries and these do not guarantee sustainable food security and improved livelihood of the farmers in the region. Ghana’s Ministry of Food and Agriculture (MoFA), together with relevant stakeholders, should provide guidance on ISFM and intensify farmer education through farmer associations to increase the adoption of ISFM. The local government should work with other relevant stakeholders to improve the market conditions within the agriculture sector, for instance, by linking farmers to city markets for favorable output prices

Revisiting the Immune Trypanolysis Test to Optimise Epidemiological Surveillance and Control of Sleeping Sickness in West Africa

Human African trypanosomiasis (HAT) due to Trypanosoma brucei (T.b.) gambiense is usually diagnosed using two sequential steps: first the card agglutination test for trypanosomiasis (CATT) used for serological screening, followed by parasitological methods to confirm the disease. Currently, CATT will continue to be used as a test for mass screening because of its simplicity and high sensitivity; however, its performance as a tool of surveillance in areas where prevalence is low is poor because of its limited specificity. Hence in the context of HAT elimination, there is a crucial need for a better marker of contact with T.b. gambiense in humans. We evaluated here an existing highly specific serological tool, the trypanolysis test (TL). We evaluated TL in active, latent and historical HAT foci in Guinea, Côte d'Ivoire and Burkina Faso. We found that TL was a marker for exposure to T.b. gambiense. We propose that TL should be used as a surveillance tool to monitor HAT elimination

Seasonal Price Variability And The Effective Demand For Nutrients: Evidence From Cereals Markets In Mali

A key outcome of the food policy reforms initiated in the 1980s in Mali was the liberalization of the cereals markets in order to stimulate agricultural production and reduce reliance on imported rice. These market reforms resulted in more variable food prices because grain prices were no longer fixed by the government but rather influenced by the seasonal pattern of production and availability, regional and international supply and demand conditions. Malian policy makers have often expressed their concerns about seasonal grain price variation in Mali. However, measurements of its immediate effects on households&apos; effective demand for nutrients have been relatively scarce. This study uses panel data from a 2000-2001 household consumption survey undertaken in Bamako to estimate nutrient-income and price elasticities by season and for the entire year and examine the effects of intra-year price variation on nutrient demand. The study finds that real income has a statistically significant positive impact on the demand for calories, protein, calcium, vitamin A, and iron and that the income elasticities for calories (from 0.102 to 0.193) varies less across seasons than those for micronutrients (for example vitamin A from 0.492 to 0.725). During the lean season, a 10 percent increase in real incomes will improve calorie availability from staples and other foods by 1.36 and 3.36 percent, respectively. The pooled data results show that a 10 percent growth in real incomes will increase the demand for calories (+1.62 %), protein (+1.91%), calcium (+1.98%), vitamin A (+7.21%) and iron (+1.29%). The findings of this study have several implications for food policy design in Mali, and possibly for other Sahelian countries. The most striking result is that in the face of seasonal variations in the price of staples, Bamako households attempt to “defend” their calorie consumption by reducing the consumption of higher-cost but more nutrient-rich foods. Thus, the price fluctuations of staples can significantly affect the consumption of protein and micronutrients that the staples themselves do not contain. Measures to bring about more stability of the staple-food markets (regional trade policies, better infrastructure) would thus have impacts on nutrition and on the demands for other more nutrient-rich products well beyond the staple-foods. In other words, if you are interested in Vitamin A or iron consumption, the path to affect those most may be through the staple foods market, even though most Malian staples are not rich in those micronutrients

Economic case studies of eastern Washington and northern Idaho no-till farmers growing wheat, barley, lentils, and peas in the 19-22 inch precipitation zone

This publication presents production costs, cultural practices, and profitability of dryland farming systems used by six leading no-till farmers in the 19-22 inch precipitation zone of the Pacific Northwest. It is hoped this record will be useful to farmers contemplating adopting no-till, ag lenders and business reps, researchers, extension workers, and government service agency personnel. 52 pages