48 research outputs found
Spectral analysis and abundances of the post-HB star HD 76431
HD76431 is a slow rotating post-HB star that shows an underabundance of
helium by 0.5 dex relative to the solar value. These observational facts
suggest that atomic diffusion could be active in its atmosphere. We have used
the MMT and Bok spectra to estimate the atmospheric parameters of the target
star using the model atmospheres and synthetic spectra calculated with TLUSTY
and SYNSPEC. The derived values of the effective temperature, surface gravity,
helium abundance are consistent with those obtained by Ramspeck et al. (2001b).
It appears that NLTE effect are not important for HD76431. We have used Stokes
I spectra from ESPaDOnS at CFHT to perform an abundance analysis and a search
for observational evidence of vertical stratification of the abundance of
certain elements. The results of our abundance analysis are in good agreement
with previously published data with respect to average abundances. Our
numerical simulations show that carbon and nitrogen reveal signatures of
vertical abundance stratification in the atmosphere of HD76431. It appears that
the carbon abundance increases toward the deeper atmospheric layers. Nitrogen
also shows a similar behaviour, but in deeper atmospheric layers we obtain a
significant dispersion for the estimates of its abundance. To our knowledge,
this is the first demonstration of vertical abundance stratification of metals
in a post-HB star and up to now it is the hottest star to show such
stratification features. We also report the detection of two SiIII and one
TiIII emission lines in the spectra of HD76431 that were not detected in
previous studies.Comment: 7 pages, 5 figures, accepted for publication in MNRA
The walking estimated limitation stated by history (WELSH): a visual tool to self-reported walking impairment in a predominantly illiterate population
BACKGROUND: The prevalence of cardiovascular diseases is increasing in low-income countries. Various questionnaires to estimate walking capacity in patients are available in multiple languages but they are not suitable for illiterate patients.
OBJECTIVE: The walking estimated limitation stated by history (WELSH) tool aims at rating individual walking disability using only drawings and four items.
METHODS: A six-month prospective study was performed on new patients referred to the Department of Cardiology at the Centre Hospitalier Universitaire SourĂŽ Sanou in Bobo-Dioulasso, Burkina Faso. We administered the WELSH tool after a short oral presentation in the patient\u27s language or dialect. Thereafter, patients performed a six-minute walking test in the hospital corridor under the supervision of a nurse who was blinded to the results of the WELSH score. We performed a step-by-step multilinear regression analysis to determine the factors predicting maximal walking distance (MWD).
RESULTS: There were 40 female and 10 male patients in this study. Their ages ranged from 54.8 ± 10.7 years. Only 32% of the patients had attended primary school. Most patients were classified as stage I to III of the New York Heart Association (NYHA) classification. The objective measurement of MWD during a six-minute walking test showed no association with the subjects\u27 educational level, body mass index, NYHA stage or gender, but a significant correlation with the WELSH scores. The Spearman r-value for the WELSH score-to-MWD relationship was 0.605 (p < 0.001).
CONCLUSIONS: The WELSH tool is feasible and correlated with measured MWD in a population of predominantly illiterate patients
From regional pulse vaccination to global disease eradication: insights from a mathematical model of Poliomyelitis
Mass-vaccination campaigns are an important strategy in the global fight
against poliomyelitis and measles. The large-scale logistics required for these
mass immunisation campaigns magnifies the need for research into the
effectiveness and optimal deployment of pulse vaccination. In order to better
understand this control strategy, we propose a mathematical model accounting
for the disease dynamics in connected regions, incorporating seasonality,
environmental reservoirs and independent periodic pulse vaccination schedules
in each region. The effective reproduction number, , is defined and proved
to be a global threshold for persistence of the disease. Analytical and
numerical calculations show the importance of synchronising the pulse
vaccinations in connected regions and the timing of the pulses with respect to
the pathogen circulation seasonality. Our results indicate that it may be
crucial for mass-vaccination programs, such as national immunisation days, to
be synchronised across different regions. In addition, simulations show that a
migration imbalance can increase and alter how pulse vaccination should
be optimally distributed among the patches, similar to results found with
constant-rate vaccination. Furthermore, contrary to the case of constant-rate
vaccination, the fraction of environmental transmission affects the value of
when pulse vaccination is present.Comment: Added section 6.1, made other revisions, changed titl
Farmers' perceptions on mechanical weeders for rice production in sub-Saharan Africa
Competition from weeds is one of the major biophysical constraints to rice (Oryza spp.) production in sub-Saharan Africa. Smallholder rice farmers require efficient, affordable and labour-saving weed management technologies. Mechanical weeders have shown to fit this profile. Several mechanical weeder types exist but little is known about locally specific differences in performance and farmer preference between these types. Three to six different weeder types were evaluated at 10 different sites across seven countries â i.e., Benin, Burkina Faso, CĂŽte d'Ivoire, Ghana, Nigeria, Rwanda and Togo. A total of 310 farmers (173 male, 137 female) tested the weeders, scored them for their preference, and compared them with their own weed management practices. In a follow-up study, 186 farmers from Benin and Nigeria received the ring hoe, which was the most preferred in these two countries, to use it during the entire crop growing season. Farmers were surveyed on their experiences. The probability of the ring hoe having the highest score among the tested weeders was 71%. The probability of farmersâ preference of the ring hoe over their usual practices â i.e., herbicide, traditional hoe and hand weeding â was 52, 95 and 91%, respectively. The preference of this weeder was not related to gender, years of experience with rice cultivation, rice field size, weed infestation level, water status or soil texture. In the follow-up study, 80% of farmers who used the ring hoe indicated that weeding time was reduced by at least 31%. Of the farmers testing the ring hoe in the follow-up study, 35% used it also for other crops such as vegetables, maize, sorghum, cassava and millet. These results suggest that the ring hoe offers a gender-neutral solution for reducing labour for weeding in rice as well as other crops and that it is compatible with a wide range of environments. The implications of our findings and challenges for out-scaling of mechanical weeders are discussed
Effectiveness of food supplements on fat-free tissue accretion in children with moderate acute malnutrition: a randomized 2x2x3 factorial trial in Burkina Faso
BACKGROUND:
Children with moderate acute malnutrition (MAM) are treated with lipid-based nutrient supplement (LNS) or corn-soy blend (CSB). We assessed the effectiveness of (a) matrix, i.e., LNS or CSB, (b) soy quality, i.e., soy isolate (SI) or dehulled soy (DS), and (c) percentage of total protein from dry skimmed milk, i.e., 0%, 20%, or 50%, in increasing fat-free tissue accretion.
METHODS AND FINDINGS:
Between September 9, 2013, and August 29, 2014, a randomised 2 Ă 2 Ă 3 factorial trial recruited 6- to 23-month-old children with MAM in Burkina Faso. The intervention comprised 12 weeks of food supplementation providing 500 kcal/day as LNS or CSB, each containing SI or DS, and 0%, 20%, or 50% of protein from milk. Fat-free mass (FFM) was assessed by deuterium dilution technique. By dividing FFM by length squared, the primary outcome was expressed independent of length as FFM index (FFMI) accretion over 12 weeks. Other outcomes comprised recovery rate and additional anthropometric measures. Of 1,609 children, 4 died, 61 were lost to follow-up, and 119 were transferred out due to supplementation being switched to non-experimental products. No children developed allergic reaction. At inclusion, 95% were breastfed, mean (SD) weight was 6.91 kg (0.93), with 83.5% (5.5) FFM. In the whole cohort, weight increased 0.90 kg (95% CI 0.88, 0.93; p 0.05). LNS compared to CSB resulted in 128 g (95% CI 67, 190; p < 0.01) greater weight gain if both contained SI, but there was no difference between LNS and CSB if both contained DS (mean difference 22 g; 95% CI â40, 84; p = 0.49) (interaction p = 0.017). Accordingly, SI compared to DS increased weight by 89 g (95% CI 27, 150; p = 0.005) when combined with LNS, but not when combined with CSB. A limitation of this and other food supplementation trials is that it is not possible to collect reliable data on individual adherence.
CONCLUSIONS:
Based on this study, children with MAM mainly gain fat-free tissue when rehabilitated. Nevertheless, LNS yields more fat-free tissue and higher recovery rates than CSB. Moreover, current LNSs with DS may be improved by shifting to SI. The role of milk relative to soy merits further research
Challenges in measuring measles case fatality ratios in settings without vital registration
Measles, a highly infectious vaccine-preventable viral disease, is potentially fatal. Historically, measles case-fatality ratios (CFRs) have been reported to vary from 0.1% in the developed world to as high as 30% in emergency settings. Estimates of the global burden of mortality from measles, critical to prioritizing measles vaccination among other health interventions, are highly sensitive to the CFR estimates used in modeling; however, due to the lack of reliable, up-to-date data, considerable debate exists as to what CFR estimates are appropriate to use. To determine current measles CFRs in high-burden settings without vital registration we have conducted six retrospective measles mortality studies in such settings. This paper examines the methodological challenges of this work and our solutions to these challenges, including the integration of lessons from retrospective all-cause mortality studies into CFR studies, approaches to laboratory confirmation of outbreaks, and means of obtaining a representative sample of case-patients. Our experiences are relevant to those conducting retrospective CFR studies for measles or other diseases, and to those interested in all-cause mortality studies
Trends in Immunization Completion and Disparities in the Context of Health Reforms: The case study of Tanzania
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Of global concern is the decline in under five children mortality which has reversed in some countries in sub Saharan Africa (SSA) since the early 1990 s which could be due to disparities in access to preventive services including immunization. This paper is aimed at determining the trend in disparities in completion of immunization using Tanzania Demographic and Health Surveys (DHS). DHS studies randomly selected representative households from all regions in Tanzania since 1980 s, is repeated every five years in the same enumeration areas. The last three data sets (1990, 1996 and 2004) were downloaded and analyzed using STATA 9.0. The analysis included all children of between 12-23 months who would have completed all vaccinations required at 12 months. Across the time periods 1990, 1996 to 2004/05 the percentage of children completing vaccination was similar (71.0% in 1990, 72.7% in 1996 and 72.3% in 2005). There was no disparity in completion of immunization with wealth strata in 1990 and 1996 (p > 0.05) but not 2004. In 2004/05 there was marked disparity as most poor experienced significant decline in immunization completion while the least poor had significant increase (p < 0.001). All three periods children from households whose head had low education were less likely to complete immunization (p < 0.01). Equity that existed in 1990 and more pronounced in 1996 regressed to inequity in 2005, thus though at national level immunization coverage did not change, but at sub-group there was significant disparity associated with the changing contexts and reforms. To address sub-group disparities in immunization it is recommended to adopt strategies focused at governance and health system to reach all population groups and most poor.\u
Epidemiological survey of Lutzomyia longipalpis infected by Leishmania infantum in an endemic area of Brazil
How Burkina Faso used evidence in deciding to launch its policy of free healthcare for children under five and women in 2016
In March 2016, the newly elected government of Burkina Faso decided on a major change in health financing policy: it abolished direct payment for healthcare for women and children under five. Unlike other countries in Africa, this decision took a long time, given that the first pilot projects for this policy instrument date from 2008. This article describes that political process and presents a reflexive analysis by two authors who were at the heart of events between 2008 and 2018. The analysis shows that, while the decision took a long time and certainly amounted to a policy paradigm shift, it was the result of a complex series of events and activities whose specific contributions are difficult to identify. Crucial to the decision was long-term funding of pilot projects to test the new policy instrument, associated with the generation of evidence mobilised through a myriad of knowledge transfer activities. Moreover, it took the continued mobilisation of advocacy coalitions, action to counter preconceived notions about this instrument, and the emergence of an essential window of opportunity-the 2014 popular uprising-for the decision to be possible. In this discussion, we generalise to the conceptual and theoretical levels, but also share practical lessons learned for those interested in engaging in evidence-informed decision-making. The main lessons are: recruit, train, and mobilise people and/or services responsible for knowledge transfer activities; identify and partner with political entrepreneurs early and regularly; be persistent and consistent in producing rigorous and useful knowledge; favour independent evaluation teams using mixed methods; train researchers in policy decision-making processes and decision-makers in knowledge production issues; adapt (content, format, vocabulary, language, etc.) the evidence to the needs of the knowledge users in close collaboration with researchers and disseminate it to target audiences; understand the sometimes different logics of researchers and decision-makers and encourage their interaction; to seize opportunities, regularly analyse the political decision-making processes specific to the national context as well as the social and political contexts favourable (or not) to decision-making
C52 - AutomĂ©dication Ă lâĂšre du numĂ©rique : enquĂȘte auprĂšs de la population de la ville de Ouagadougou (Burkina Faso)
Introduction : LâautomĂ©dication est un phĂ©nomĂšne frĂ©quent avec des consĂ©quences telle que lâĂ©mergence des rĂ©sistances bactĂ©riennes. Cette tendance pourrait ĂȘtre en pleine croissance avec lâĂšre du numĂ©rique avec lâamĂ©lioration de lâaccĂšs Ă internet et aux informations. Lâobjet de notre Ă©tude Ă©tait de dĂ©crire lâimpact dâinternet sur la pratique de lâautomĂ©dication dans la ville de Ouagadougou.
MĂ©thodes : Nous avons rĂ©alisĂ© une Ă©tude transversale Ă visĂ©e descriptive dans la ville de Ouagadougou du juin Ă Octobre 2023. Elle a concernĂ© les personnes ĂągĂ©es de plus de 18 ans venant acheter des mĂ©dicaments en pharmacies. Le choix des pharmacies a Ă©tĂ© faite de maniĂšre proportionnelle en tenant compte des groupes dĂ©finis par lâordre des pharmacies. Cette Ă©tude a concernĂ© lâautomĂ©dication habituelle avec lâaide dâinternet.
RĂ©sultats : Sur 30 pharmacies identifiĂ©e, nous avons notĂ© 17 acceptations, cinq refus et huit attentes des rĂ©ponses. Nous avons enquĂȘtĂ© 509 personnes avec un Ăąge moyen de 28 ans avec des extrĂȘmes de 18 et 70 ans et un sex ratio de 1,3. Nous avons notĂ© un taux de pĂ©nĂ©tration dâinternet de 97% avec un accĂšs par les smartphones dans 93% des cas. La frĂ©quence de lâautomĂ©dication Ă©tait de 55%. Les facteurs associĂ©s Ă la pratique de lâautomĂ©dication Ă©taient lâutilisation dâinternet, la recherche dâinformation sur la santĂ©, la perception de suretĂ© de lâautomĂ©dication par internet (p<0,001). Les mĂ©dicaments associĂ©s Ă la pratique de lâautomĂ©dication Ă©taient les antibiotiques, les anti-inflammatoires et les antalgiques (p<0,001). Les principaux motifs de recours Ă lâautomĂ©dication Ă©taient les expĂ©riences antĂ©rieures positives (57%), dĂ©lai des rendez-vous long (42%) et le coĂ»t des mĂ©dicaments prescrits en consultation (35%).
Conclusion : lâaccessibilitĂ© Ă lâinformation Ă travers internet et aux smartphones a contribuĂ© Ă la pratique dâune automĂ©dication habituelle au chez les personnes enquĂȘtĂ©es. Cette pratique pourrait avoir des consĂ©quences nĂ©fastes de santĂ© publique. Il serait important de mettre en place des stratĂ©gies pour lâaccĂšs Ă lâinformation de qualitĂ© sur les mĂ©dicaments