159 research outputs found
COMPARING THE PROFITABILITY OF CASSAVA-BASED PRODUCTION SYSTEMS IN THREE WEST AFRICAN COUNTRIES: COTE D'IVOIRE, GHANA AND NIGERIA
Sub-Saharan Africa (SSA) cassava-producing countries such as Nigeria, Ghana, and CĂ´te d'Ivoire have developed, in recent years, a renewed interest in cassava as an alternative food crop. This has led to a major expansion in cassava-based production systems in Nigeria and Ghana, whereas there has been a slower growth in CĂ´te d'Ivoire (Nweke et al., 1998). This paper is based on the argument that the difference in various factors such as agricultural policies (i.e., trade and price policies, domestic production taxes or subsidies), location and technologies (production and processing) between Nigeria, Ghana and CĂ´te d'Ivoire the difference in the level of growth in cassava-based production systems. The paper examines, using the Policy Analysis Matrix (PAM), the magnitude of the impact of these factors on the private and social profitability of cassava production and post-production processing in CĂ´te d'Ivoire, Ghana and Nigeria. The topic has not been examined in previous studies. The paper relies primarily on data for CĂ´te d'Ivoire, Ghana and Nigeria from the Collaborative Study of Cassava in Africa (COSCA) survey. The baseline results demonstrate the similarity in efficiencies of production in these West African countries. The simulation findings indicated that, in CĂ´te d'Ivoire, farmers benefited from the depreciation of the equilibrium exchange rate while farmers in Ghana and Nigeria suffered losses. Simulation results also indicated that Ivorian and Ghanaian cassava/maize farmers could benefit from growing IITA's improved variety and adopting mechanized processing methods.Crop Production/Industries,
Limestone cliff - face and cave use by wild ring-tailed lemurs (Lemur catta) in southwestern Madagascar
Ring - tailed lemurs live in a range of habitats in southwestern Madagascar. To date, much of the knowledge of ring - tailed lemur ecology, biology and behavior come from riverine gallery forests sites. Recent years have seen an expansion of comprehensive research on this resilient species, including areas of limestone spiny forest along Madagascar’s southwestern coast. This work is documenting newly discovered behaviors by this species. The regular use of cliff - faces and embedded crevices and caves by ring - tailed lemurs in southwestern Madagascar are reported here. Cave use by several anthropoid primates has been explained as a thermoregulatory behavior. It is suggested that cliff - face and cave use by these ring-tailed lemurs serves several purposes, including resource acquisition, thermoregulation, and as an anti - predator avoidance strategy in the absence of suitable large sleeping trees. Observations indicate that the limestone boundaries of the Mahafaly Plateau and their associated xerophytic scrub forests warrant further conservation attention, given the presence of behavioral variation and increasing threats to this endangered primate species
Epilepsie et permis de conduire au Mali : connaissances, attitudes et pratiques des moniteurs d’auto-école et des candidats au permis de conduire
Introduction: L’un des sujets les plus controversés dans le domaine de l’épilepsie est la problématique de la conduite chez l’épileptique.Objectif: Nous avons initié une étude, en collaboration avec l’Agence Nationale de la Sécurité Routière au Mali (ANASER), ayant pour but de faire l’état des lieux sur les connaissances, attitudes et pratiques des conducteurs, moniteurs et inspecteurs d’auto-écoles en matière d’épilepsie.Methode: Il s’agissait d’une étude longitudinale, prospective, descriptive et analytique qui s’est déroulée de juin 2009 à  juin 2010. Elle a porté sur 31 auto-écoles du district de Bamako. 568 personnes ont été interrogées (488 candidats au permis de conduire, 70 moniteurs d’auto-école et 10 inspecteurs).Resultats: Près de 60 % des personnes interrogées accordaient une origine surnaturelle à l’épilepsie ; plus de 85 % indiquaient que l’épilepsie était incompatible avec la conduite automobile. Plus de la moitié ignorait l’existence d’une réglementation. Près de 70 % pensaient que l’épilepsie était pourvoyeuse d’accident de la voie publique.Conclusion: A l’instar de nos précédentes études communautaires au Mali, ce travail a permis de mettre l’accent, d’une part, sur l’importance des connaissances erronées sur l’épilepsie et, d’autre part, sur la nécessité d’actualiser la réglementation en matière de conduite de véhicules motorisés pour ces patients.Mots clés: Attitudes, Épilepsie, Mali, Permis de conduire, Conduite automobileEnglish Title: Epilepsy and driving licence in Mali : knowledge, attitudes and practices of driving schools monitors and the candidates for the licenceEnglish AbstractBackground: One of the most controversial topics in the field of epilepsy remains the issue of driving license for epileptic patients.Purpose: We initiated a study in collaboration with ANASER (National Agency for Road Safety in Mali) with the goal, on one hand, of assessing the knowledge, attitudes and practices of drivers and driving school authorities on epilepsy and, on the other hand, to analyze the current regulations on issuance of license to epileptic patients.Methods: Il s’agissait d’une étude longitudinale, prospective, descriptive et analytique qui s’est déroulée de juin 2009 à  juin 2010. We interviewed 568 sujects, including 488 candidates for driver’s license, 70 driving school monitors and 10 inspectors.Results: About 60% gave a supernatural origin of the disease, and more than 85% believed that epilepsy was incompatible with driving. More than half were unaware of regulations. Approximately, 70% of respondents believed that epilepsy was a contributory factor to road accident.Conclusion: As in our previous community studies in Mali, this study emphasizes the importance of misconceptions about epilepsy, and has shown the need to update the regulations regarding the driving of motorized vehicles for these patients.Keywords: Epilepsy, Attitudes, Driving , Driving License, Mal
Extent and Dynamics of Polymorphism in the Malaria Vaccine Candidate Plasmodium falciparum Reticulocyte-Binding Protein Homologue-5 in Kalifabougou, Mali
Reticulocyte-binding homologues (RH) are a ligand family that mediates merozoite invasion of erythrocytes in Plasmodium falciparum. Among the five members of this family identified so far, only P. falciparum reticulocyte-binding homologue-5 (PfRH5) has been found to be essential for parasite survival across strains that differ in virulence and route of host-cell invasion. Based on its essential role in invasion and early evidence of sequence conservation, PfRH5 has been prioritized for development as a vaccine candidate. However, little is known about the extent of genetic variability of RH5 in the field and the potential impact of such diversity on clinical outcomes or on vaccine evasion. Samples collected during a prospective cohort study of malaria incidence conducted in Kalifabougou, in southwestern Mali, were used to estimate genetic diversity, measure haplotype prevalence, and assess the within-host dynamics of PfRH5 variants over time and in relation to clinical malaria. A total of 10 nonsynonymous polymorphic sites were identified in the Pfrh5 gene, resulting in 13 haplotypes encoding unique protein variants. Four of these variants have not been previously observed. Plasmodium falciparum reticulocyte-binding homologue-5 had low amino acid haplotype (h = 0.58) and nucleotide (Ď€ = 0.00061) diversity. By contrast to other leading blood-stage malaria vaccine candidate antigens, amino acid differences were not associated with changes in the risk of febrile malaria in consecutive infections. Conserved B- and T-cell epitopes were identified. These results support the prioritization of PfRH5 for possible inclusion in a broadly cross-protective vaccine
Fabrication and characterization of micro-inductors deposited on magnetic thin and thick layers
This paper presents two fabrication techniques of spiral integrated inductors based on magnetic materials. For the first one, the magnetic core is a thin film deposited by RF magnetron sputtering, for the second technique the magnetic core is a thick layer of YIG obtained by micromachining. The addition of the magnetic material is expected to improve the performances of the integrated structure with electromagnetic shield. Low and high frequency equipment are used to characterize the manufactured components. A good correlation is obtained between the results by simulation and measurements for the two manufacturing techniques. These results show that the inductance increases when the thickness of the magnetic layer increases, we can double the inductance value for a thickness sufficiently high
Pyronaridine-artesunate or dihydroartemisinin-piperaquine combined with single low-dose primaquine to prevent Plasmodium falciparum malaria transmission in Ouélessébougou, Mali: a four-arm, single-blind, phase 2/3, randomised trial.
BACKGROUND: Pyronaridine-artesunate is the most recently licensed artemisinin-based combination therapy. WHO has recommended that a single low dose of primaquine could be added to artemisinin-based combination therapies to reduce Plasmodium falciparum transmission in areas aiming for elimination of malaria or areas facing artemisinin resistance. We aimed to determine the efficacy of pyronaridine-artesunate and dihydroartemisinin-piperaquine with and without single low-dose primaquine for reducing gametocyte density and transmission to mosquitoes. METHODS: We conducted a four-arm, single-blind, phase 2/3, randomised trial at the Ouélessébougou Clinical Research Unit of the Malaria Research and Training Centre of the University of Bamako (Bamako, Mali). Participants were aged 5-50 years, with asymptomatic P falciparum malaria mono-infection and gametocyte carriage on microscopy, haemoglobin density of 9·5 g/dL or higher, bodyweight less than 80 kg, and no use of antimalarial drugs over the past week. Participants were randomly assigned (1:1:1:1) to one of four treatment groups: pyronaridine-artesunate, pyronaridine-artesunate plus primaquine, dihydroartemisinin-piperaquine, or dihydroartemisinin-piperaquine plus primaquine. Treatment allocation was concealed to all study staff other than the trial pharmacist and treating physician. Dihydroartemisinin-piperaquine and pyronaridine-artesunate were administered as per manufacturer guidelines over 3 days; primaquine was administered as a single dose in oral solution according to bodyweight (0·25 mg/kg; in 1 kg bands). The primary endpoint was percentage reduction in mosquito infection rate (percentage of mosquitoes surviving to dissection that were infected with P falciparum) at 48 h after treatment compared with baseline (before treatment) in all treatment groups. Data were analysed per protocol. This trial is now complete, and is registered with ClinicalTrials.gov, NCT04049916. FINDINGS: Between Sept 10 and Nov 19, 2019, 1044 patients were assessed for eligibility and 100 were enrolled and randomly assigned to one of the four treatment groups (n=25 per group). Before treatment, 66 (66%) of 100 participants were infectious to mosquitoes, with a median of 15·8% (IQR 5·4-31·9) of mosquitoes becoming infected. In individuals who were infectious before treatment, the median percentage reduction in mosquito infection rate 48 h after treatment was 100·0% (IQR 100·0 to 100·0) for individuals treated with pyronaridine-artesunate plus primaquine (n=18; p<0·0001) and dihydroartemisinin-piperaquine plus primaquine (n=15; p=0·0001), compared with -8·7% (-54·8 to 93·2) with pyronaridine-artesunate (n=17; p=0·88) and 50·4% (13·8 to 70·9) with dihydroartemisinin-piperaquine (n=16; p=0·13). There were no serious adverse events, and there were no significant differences between treatment groups at any point in the frequency of any adverse events (Fisher's exact test p=0·96) or adverse events related to study drugs (p=0·64). The most common adverse events were headaches (40 events in 32 [32%] of 100 participants), rhinitis (31 events in 30 [30%]), and respiratory infection (20 events in 20 [20%]). INTERPRETATION: These data support the use of single low-dose primaquine as an effective supplement to dihydroartemisinin-piperaquine and pyronaridine-artesunate for blocking P falciparum transmission. The new pyronaridine-artesunate plus single low-dose primaquine combination is of immediate relevance to regions in which the containment of partial artemisinin and partner-drug resistance is a growing concern and in regions aiming to eliminate malaria. FUNDING: The Bill & Melinda Gates Foundation. TRANSLATIONS: For the French, Spanish and Swahilil translations of the abstract see Supplementary Materials section
Fabrication and characterization of micro-inductors deposited on magnetic thin and thick layers
This paper presents two fabrication techniques of spiral integrated inductors based on magnetic materials. For the first one, the magnetic core is a thin film deposited by RF magnetron sputtering, for the second technique the magnetic core is a thick layer of YIG obtained by micromachining. The addition of the magnetic material is expected to improve the performances of the integrated structure with electromagnetic shield. Low and high frequency equipment are used to characterize the manufactured components. A good correlation is obtained between the results by simulation and measurements for the two manufacturing techniques. These results show that the inductance increases when the thickness of the magnetic layer increases, we can double the inductance value for a thickness sufficiently high
Developing a Set of Core Outcomes for Trials in Haemodialysis: An International Delphi Survey
AIM: To generate a consensus-based, prioritized list of core outcomes for trials in haemodialysis.
BACKGROUND: Survival and quality of life for patients on haemodialysis remain poor despite substantial research efforts. Existing trials often report surrogate outcomes that may not be relevant to patients and clinicians. A core outcome set that reflects stakeholder priorities would improve the relevance, efficiency, and comparability of haemodialysis trials.
METHODS: In an online Delphi survey, participants rated the importance of outcomes using a 9-point Likert scale. In Round 2 and 3, participants reviewed the scores and comments of other respondents and re-rated the outcomes. For each outcome, we calculated the median, mean, and proportion rating 7-9 (“critically important”).
RESULTS: 1,181 participants (202 [17%] patients/caregivers, 979 health professionals) from 73 countries completed Round 1 and 838 (150 [18%] patients/caregivers) completed Round 3 (71% response rate). Outcomes achieving consensus as high priorities across both groups were: vascular access complications, cardiovascular disease, mortality, dialysis adequacy and fatigue. Patients/caregivers rated four outcomes higher than health professionals: ability to travel (mean difference 0.9), dialysis-free time (0.5), dialysis adequacy (0.3), and washed out after dialysis (0.2). Health professionals rated 11 outcomes higher: mortality (1.0), hospitalization (1.0), drop in blood pressure (1.0), vascular access complications (0.9), depression (0.9), cardiovascular disease (0.8), target weight (0.7), infection (0.4), potassium (0.4), ability to work (0.3), and pain (0.3).
CONCLUSIONS: The top stakeholder prioritized outcomes were vascular access problems, cardiovascular disease, mortality, dialysis adequacy and fatigue. Patients/caregivers gave higher priority to lifestyle-related outcomes than health professionals. This prioritized set of outcomes can inform the establishment of a core outcome set, to improve the value of trial evidence to support decision-making for people on haemodialysis
Standard of care in advanced HIV disease: review of HIV treatment guidelines in six sub-Saharan African countries.
BACKGROUND: The World Health Organization (WHO) recommends an evidence-based package of care to reduce mortality and morbidity among people with advanced HIV disease (AHD). Adoption of these recommendations by national guidelines in sub-Saharan Africa is poorly documented. We aimed to review national guidelines for AHD management across six selected countries in sub-Saharan Africa for benchmarking against the 2021 WHO recommendations. METHODS: We reviewed national guidelines from six countries participating in an ongoing randomized controlled trial recruiting people with AHD. We extracted information addressing 18 items of AHD diagnosis and management across the following domains: [1] Definition of AHD, [2] Screening, [3] Prophylaxis, [4] Supportive care, and [5] HIV treatment. Data from national guideline documents were compared to the 2021 WHO consolidated guidelines on HIV and an agreement score was produced to evaluate extent of guideline adoption. RESULTS: The distribution of categories of agreement varied for the national documents. Four of the six countries addressed all 18 items (Malawi, Nigeria, Sierra Leone, Uganda). Overall agreement with the WHO 2021 guidelines ranged from 9 to 15.5 out of 18 possible points: Malawi 15.5 points, Nigeria, and Sierra Leone 14.5 points, South Africa 13.5 points, Uganda 13.0 points and Botswana with 9.0 points. Most inconsistencies were reported for the delay of antiretroviral therapy (ART) in presence of opportunistic diseases. None of the six national guidelines aligned with WHO recommendations around ART timing in patients with tuberculosis. Agreement correlated with the year of publication of the national guideline. CONCLUSION: National guidelines addressing the care of advanced HIV disease in sub-Saharan Africa are available. Besides optimal timing for start of ART in presence of tuberculosis, most national recommendations are in line with the 2021 WHO standards
- …