Experimental study of effectiveness of nonpoint source water pollution control group contract.

The goal of this experimental study was to test an effectiveness of a group contract designed to control nonpoint source water pollution from farms' runoff (Pushkarskaya 2003). In particular, the regulator pays for pollution reduction credits earned by the group of the farmers, who voluntary enter the contract, and is concerned only with the total level of the abatement achieved, while the group of farmers undertakes responsibility to distribute the payment so as to induce the farmers to deliver the desired level of abatement. First round of experiments was conducted using as subjects undergraduate students from the Ohio State University, second round of experiments was conducted using as a subjects Kentucky farmers, who would be an actual subjects to this policy if it is ever implemented. Experiments with farmers can be considered as an intermediate step between traditional experiments with undergraduate students and field experiments. Results of these experiments suggest, in contrast to common believes among environmental economists, that uncertainty, associated with diffusive nature of nonpoint source water pollution, not only does not affect negatively farmers' participation in the program, but also might play a positive role in promoting a cooperation within a group.Environmental Economics and Policy,

The possibility of a rice green revolution in large-scale irrigation schemes in Sub-Saharan Africa

This paper investigates the potential of and constraints to a rice Green Revolution in Sub-Saharan Africa's large-scale irrigation schemes, using data from Uganda, Mozambique, Burkina Faso, Mali, Niger, and Senegal. The authors find that adequate irrigation, chemical fertilizer, and labor inputs are the key to high productivity. Chemical fertilizer is expensive in Uganda and Mozambique and is barely used. This is aggravated when water access is limited because of the complementarities between fertilizer and irrigation. Meanwhile, in the schemes located in four countries in West Africa's Sahel region, where water access is generally good and institutional support for chemical fertilizer exists, rice farmers achieve attractive yields. Some countries'wage rate is high and thus mechanization could be one solution for this constraint. Improvement of credit access also facilitates the purchase of expensive fertilizer or the employment of hired labor.Crops&Crop Management Systems,Irrigation and Drainage,Water Supply and Systems,Regional Economic Development,Water and Industry

Policy and Institutional effects on market participation by smallholder rice farmers: case studies in Burkina Faso, Mali and Niger

Rice sector contributes significantly to secure households with regard to their food needs but also to the creation of employments and income generation. The sector development and its evolution over the years have been marked by various policies and approaches. These development stages of the sector constitute nothing but the impact of the number of factors such as the rice policies put in place. A collaborative multi-country pilot study on policy and institutional arrangements effects on irrigated rice production and commercialization was conducted by WARDA and its country partners of Burkina Faso, Mali, and Niger. In-depth surveys were carried out at both village and household levels to collect qualitative and quantitative data on irrigated rice production, commercialization, and irrigated schemes governance. A common critical constrain cited by the producers in these countries is the commercialization of their product and their inability to take advantage of the market opportunities. Using village and household levels survey data on irrigated rice production and commercialization, this paper attempts to examine the impact of policy and institutional factors in market participation by smallholder rice producers. A farm level supply is estimated using the quantity of rice marketed as the dependant variable and factors such as output and inputs price, and policy and institutional variables as independent ones. The preliminary results indicate that most significant explanatory variable is the average irrigated rice plot (Mali and Niger) and total area of other crops grown by the producer.Agribusiness, Agricultural and Food Policy, Community/Rural/Urban Development, Environmental Economics and Policy, Farm Management, Food Consumption/Nutrition/Food Safety, Food Security and Poverty, Institutional and Behavioral Economics, International Relations/Trade, Labor and Human Capital, Marketing, Production Economics, Research and Development/Tech Change/Emerging Technologies, Research Methods/ Statistical Methods,

Etude Métallogénique du Prospect Aurifère de Woulo-Woulo (Zone d'Afema, sud-est de la Côte d'Ivoire)

Le prospect de Woulo-Woulo est situé au sud-est de la Côte d’Ivoire précisément  dans la zone de Maféré, à environ 8 km à l’ouest du couloir de cisaillement d’Aféma. Le prospect Woulo-Woulo est constitué de métasédiments (métagrauwackes et métaargilites), de métavolcanites (laves andésitiques et brèches) et d’intrusions de métarhyolites porphyriques et de métagabbros. Ces différentes lithologies ont été affectées par une importante activité  hydrothermale matérialisée par des veines et veinules de quartz, carbonates (calcite ± dolomie), ± tourmaline, ± sulfures. La minéralisation aurifère du prospect de Woulo-Woulo est encaissée préférentiellement dans la métarhyolite porphyrique déformée et hydrothermalisée. Cependant, cette minéralisation apparait principalement liée aux veines et veinules de quartz et carbonates et présente donc un contrôle structural. C’est une minéralisation de type filonien et hydrothermale donc épigénétique. Cette activité hydrothermale a induit une altération pervasive des encaissants entrainant une carbonatation, une silicification, une chloritisation, une séricitisation et une épidotisation. La paragenèse métallifère est constituée de pyrite (sulfure principal), blende ou sphalérite et or natif.    The Woulo-Woulo prospect is located in the south-east of Côte d'Ivoire, precisely in the Maféré area, approximately 8 km west of the Aféma shear corridor. The Woulo-Woulo prospect consists of metasediments (metagrauwackes and metaargilites), metavolcanites (andesitic lavas and breccias) and intrusions of porphyry metarhyolites and metagabbros. These different lithologies have been affected by significant hydrothermal activity materialized by quartz, carbonates (calcite ± dolomite), ± tourmaline, ± sulphide veins and veinlets. Gold mineralization at the Woulo-Woulo prospect is hosted preferentially in the deformed and hydrothermalized porphyry metarhyolite. However, this mineralization appears to be mainly related to quartz and carbonate veins and veinlets and is therefore structurally controlled. It is a vein-type and hydrothermal mineralization and therefore epigenetic. This hydrothermal activity has induced a pervasive alteration of the host rock leading to carbonation, silicification, chloritization, sericitization and epidotization. The metalliferous paragenesis consists of pyrite (principal sulfide), blende or sphalerite and native gold

Etude Metallogenique du Prospect Aurifere de Woulo-Woulo (Zone d’Afema, Sud-est de la Cote d’Ivore)

Le prospect de Woulo-Woulo est situé au sud-est de la Côte d’Ivoire, précisément  dans la zone de Maféré, à environ 8 km à l’ouest du couloir de cisaillement d’Aféma. Les activités de terrain et de forage ont montré que certaines formations observées sur le prospect de Woulo-Woulo contiennent de la minéralisation aurifère. L’objectif général de cette étude est de déterminer les caractéristiques pétrographiques et structurales de ces roches et la minéralisation aurifère associée. Ainsi, l’acquisition des données a consisté au prélèvement d’échantillons de roches de terrain et de forage carotté, suivi de leur caractérisation macroscopique et microscopique. Le prospect de Woulo-Woulo est constitué de métasédiments (métagrauwackes et métaargilites), de métavolcanites (laves andésitiques et brèches), de filons acides (métarhyolite à porphyre de quartz) et d’intrusions de métagabbros, tousp affectées par une importante activité hydrothermale, filonienne, qui a induit une altération pervasive des encaissants. La minéralisation aurifère du prospect de Woulo-Woulo est de type filonien et hydrothermal épigénétique liée aux veines et veinules de quartz et carbonates, encaissée préférentiellement dans la métarhyolite porphyrique déformée et hydrothermalisée. Elle présente donc un contrôle structural. La paragenèse de cette minéralisation est constituée de pyrite (sulfure principal), sphalérite et or natif.   The Woulo-Woulo prospect is located in south-eastern Côte d'Ivoire, precisely in the Maféré zone, approximately 8 km west from the Aféma shear zone. Field and drilling activities have shown that certain formations observed at the Woulo-Woulo prospect contain gold mineralization. The overall objective of this study is to determine the petrographic and structural characteristics of these rocks and the associated gold mineralization. Thus, data acquisition consisted of field and core sampling followed by macroscopic and microscopic characterization. The Woulo-Woulo prospect consists of metasediments (metagrauwackes and metaargilites), metavolcanites (andesitic lavas and breccias), felsic veins (quartz porphyry metarhyolite) and metagabbro intrusions, all affected by significant hydrothermal and vein activity, which induced pervasive alteration of host rocks. The gold mineralization at the Woulo-Woulo prospect is vein-type and epigenetic hydrothermal type related to quartz and carbonate veins and veinlets, hosted preferentially in the deformed and hydrothermalized porphyry metarhyolite. It is therefore structurally controlled. The paragenesis of this mineralization consists of pyrite (main sulfide), sphalerite and native gold

Etude Métallogénique du Prospect Aurifère de Woulo-Woulo (Zone d'Afema, sud-est de la Côte d'Ivoire)

Le prospect de Woulo-Woulo est situé au sud-est de la Côte d’Ivoire précisément  dans la zone de Maféré, à environ 8 km à l’ouest du couloir de cisaillement d’Aféma. Le prospect Woulo-Woulo est constitué de métasédiments (métagrauwackes et métaargilites), de métavolcanites (laves andésitiques et brèches) et d’intrusions de métarhyolites porphyriques et de métagabbros. Ces différentes lithologies ont été affectées par une importante activité  hydrothermale matérialisée par des veines et veinules de quartz, carbonates (calcite ± dolomie), ± tourmaline, ± sulfures. La minéralisation aurifère du prospect de Woulo-Woulo est encaissée préférentiellement dans la métarhyolite porphyrique déformée et hydrothermalisée. Cependant, cette minéralisation apparait principalement liée aux veines et veinules de quartz et carbonates et présente donc un contrôle structural. C’est une minéralisation de type filonien et hydrothermale donc épigénétique. Cette activité hydrothermale a induit une altération pervasive des encaissants entrainant une carbonatation, une silicification, une chloritisation, une séricitisation et une épidotisation. La paragenèse métallifère est constituée de pyrite (sulfure principal), blende ou sphalérite et or natif.    The Woulo-Woulo prospect is located in the south-east of Côte d'Ivoire, precisely in the Maféré area, approximately 8 km west of the Aféma shear corridor. The Woulo-Woulo prospect consists of metasediments (metagrauwackes and metaargilites), metavolcanites (andesitic lavas and breccias) and intrusions of porphyry metarhyolites and metagabbros. These different lithologies have been affected by significant hydrothermal activity materialized by quartz, carbonates (calcite ± dolomite), ± tourmaline, ± sulphide veins and veinlets. Gold mineralization at the Woulo-Woulo prospect is hosted preferentially in the deformed and hydrothermalized porphyry metarhyolite. However, this mineralization appears to be mainly related to quartz and carbonate veins and veinlets and is therefore structurally controlled. It is a vein-type and hydrothermal mineralization and therefore epigenetic. This hydrothermal activity has induced a pervasive alteration of the host rock leading to carbonation, silicification, chloritization, sericitization and epidotization. The metalliferous paragenesis consists of pyrite (principal sulfide), blende or sphalerite and native gold

Integrasi dan disintegrasi dalam perspektif budaya

Dinamika dan perkembangan tata kemasyarakatan cenderung meningkat dengan arah yang tidak dapat terduga. Dalam tataran global, tata dunia baru dibentuk dengan berbasiskan pada penghilangan hambatan-hambatan struktural sehingga dunia dipandang seolah "tanpa batas". Kondisi ini pada gilirannya menampilkan impaknya p-ada dinamika sosial, ekonomi, politik, dan budaya masyarakat yang dalam tataran tertentu "relatif " sulit untuk dikendalikan

Baseline trachoma prevalence in Guinea: Results of national trachoma mapping in 31 health districts.

BACKGROUND: Based on previous studies, historical records and risk factors, trachoma was suspected to be endemic in 31 health districts (HDs) in Guinea. To facilitate planning for the elimination of trachoma as a public health problem, national trachoma surveys were conducted between 2011 and 2016 to determine the prevalence of trachomatous inflammation-follicular (TF) and trachomatous trichiasis (TT) in all 31 endemic HDs. METHODOLOGY/PRINCIPAL FINDINGS: A total of 27 cross-sectional surveys were conducted, each using two-stage cluster sampling (one survey in 2011 covered five HDs). Children aged 1-9 years and adults aged ≥15 years were examined for TF and TT, respectively, using the World Health Organization (WHO) simplified grading system. Indicators of household access to water, sanitation and hygiene (WASH) were also collected. A total of 100,051 people from 13,725 households of 556 clusters were examined, of whom 44,899 were male and 55,152 were female. 44,209 children aged 1-9-years and 48,745 adults aged ≥15 years were examined. The adjusted prevalence of TF varied between 1.0% (95%CI: 0.6-1.5%) to 41.8% (95%CI: 39.4-44.2%), while the adjusted prevalence of TT ranged from 0.0% (95%CI: 0.0-0.2%) to 2.8% (95%CI: 2.3-3.5%) in the 27 surveys. In all, 18 HDs had a TF prevalence ≥5% in children aged 1-9 years and 21 HDs had a TT prevalence ≥0.2% in adults aged ≥15 years. There were an estimated 32,737 (95% CI: 19,986-57,811) individuals with TT living in surveyed HDs at the time of surveys. CONCLUSIONS/SIGNIFICANCE: Trachoma is a public health problem in Guinea. 18 HDs required intervention with at least one round of mass drug administration and an estimated 32,737 persons required TT surgery in the country. The results provided clear evidence for Guinea to plan for national trachoma elimination

Evaluation of sesamum gum as an excipient in matrix tablets

In developing countries modern medicines are often beyond the affordability of the majority of the population. This is due to the reliance on expensive imported raw materials despite the abundance of natural resources which could provide an equivalent or even an improved function. The aim of this study was to investigate the potential of sesamum gum (SG) extracted from the leaves of Sesamum radiatum (readily cultivated in sub-Saharan Africa) as a matrix former. Directly compressed matrix tablets were prepared from the extract and compared with similar matrices of HPMC (K4M) using theophylline as a model water soluble drug. The compaction, swelling, erosion and drug release from the matrices were studied in deionized water, 0.1 N HCl (pH 1.2) and phosphate buffer (pH 6.8) using USP apparatus II. The data from the swelling, erosion and drug release studies were also fitted into the respective mathematical models. Results showed that the matrices underwent a combination of swelling and erosion, with the swelling action being controlled by the rate of hydration in the medium. SG also controlled the release of theophylline similar to the HPMC and therefore may have use as an alternative excipient in regions where Sesamum radiatum can be easily cultivated

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century