514 research outputs found

    Disorder-dependent superconducting phase-diagram at high magnetic fields in Fe1+y_{1 + y}Sex_{x}Te1x_{1-x} (x0.4x \sim 0.4)

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    We compare the superconducting phase-diagram under high magnetic fields (up to H=45H = 45 T) of Fe1+y_{1+y}Se0.4_{0.4}Te0.6_{0.6} single crystals originally grown by the Bridgman-Stockbarger (BRST) technique, which were annealed to display narrow superconducting transitions and the optimal transition temperature Tc14T_c \gtrsim 14 K, with the diagram for samples of similar stoichiometry grown by the traveling-solvent floating-zone technique as well as with the phase-diagram reported for crystals grown by a self-flux method. We find that the so-annealed samples tend to display higher ratios Hc2/TcH_{c2}/T_c, particularly for fields applied along the inter-planar direction, where the upper critical field Hc2(T)H_{c2}(T) exhibits a pronounced downward curvature followed by saturation at lower temperatures TT. This last observation is consistent with previous studies indicating that this system is Pauli limited. An analysis of our Hc2(T)H_{c2}(T) data using a multiband theory suggests the emergence of the Farrel-Fulde-Larkin-Ovchnikov state at low temperatures. A detailed structural x-ray analysis, reveals no impurity phases but an appreciable degree of mosaicity in as-grown BRST single-crystals which remains unaffected by the annealing process. Energy-dispersive x-ray analysis showed that the annealed samples have a more homogeneous stoichiometric distribution of both Fe and Se with virtually the same content of interstitial Fe as the non-annealed ones. Thus, we conclude that stoichiometric disorder, in contrast to structural disorder, is detrimental to the superconducting phase diagram of this series under high magnetic fields. Finally, a scaling analysis of the fluctuation conductivity in the superconducting critical regime, suggests that the superconducting fluctuations have a two-dimensional character in this system.Comment: 13 pages, 10 figures, submitted to Physical Review

    Assessment of agricultural practices by Ethiopian women farmers: existence of gender disparities in access to mycotoxins training

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    Ethiopia is one of the countries with the lowest gender-equality performance in sub-Saharan Africa being ranked 121/134 in terms of the magnitude and scope of gender disparities by the United Nations Women’s Organisation. Within the farming communities, women represent 70% of the labour force, but they are neglected from accessing training events run by Ethiopian Universities (e.g. Haramaya University). A survey to assess the existence of gender disparities among Ethiopian women farmers with respect to agricultural labour and mycotoxins knowledge was conducted on three hundred and forty-nine women from the Oromia and Amhara regions. A higher illiteracy rate was found in women compared to men from both Oromia and Amhara regions. Women played a key role in agricultural activities while having limited access to modern technologies compared to their male counterparts. Women were mainly responsible for sorting spoiled crops. Especially in Amhara, these were intended for home consumption, representing a serious health risk for local people. Overall, women from Amhara were more aware than women from Oromia about what mycotoxins are (e.g. aflatoxins), their impact and risk of occurrence in crops. Women in Amhara were also more intended to act towards mycotoxins in the future compared to women from Oromia. Only 0.24% of women have previously attended a training on mycotoxins. The radio seemed to be the most efficient way to deliver training to Ethiopian women farmers from these regions. Mycotoxins trainings were the second option of choice by all women surveyed. Such findings clearly stated the existence of gender inequality in the two Ethiopian regions considered. Empower women’s knowledge about mycotoxins will not only benefit agricultural income and the national economy, but it will also provide women the recognition they equally deserve alongside their male counterparts in future agricultural training programs and interventions.This research was supported by a Global Challenges Research Fund Quality-Research (QR-GCRF) to Cranfield University

    Provision of non-invasive coronary and carotid vascular imaging results on changes in diet and physical activity in asymptomatic adults: A scoping review

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    Background: Although a healthy diet and physical activity have been shown to prevent or delay cardiovascular disease (CVD) hospitalizations and deaths, most adults do not meet current guidelines. Provision of coronary artery calcification (CAC) and carotid ultrasound (CUS) imaging results may motivate beneficial lifestyle changes. We scoped the existing literature for studies providing non-invasive vascular imaging results and reporting diet, physical activity, and/or anthropometric measures to identify knowledge gaps and opportunities for further research. Methods: A systematic search was performed across three electronic databases, in line with PRISMA ScR guidelines and Arksey and O\u27Malley\u27s scoping review framework. Results: Twenty studies (thirteen observational and seven randomized controlled trials) examining the impact of provision of CAC/CUS imaging results on diet and/or physical activity behaviors were included. Nearly half the studies did not clearly state whether participants received dietary and physical activity advice along with vascular imaging results, and these were secondary outcomes in most studies, with data assessment and reporting being inconsistent. Conclusion: Well-designed clinical trials with consistent and clear messaging based on detailed subjective and objective measures of diet and physical activity are needed to determine whether this approach may stimulate long-term dietary and physical activity change

    Mortality and Disability-adjusted Life-years (DALYs) for common neglected tropical Diseases in Ethiopia, 1990 to 2015: evidence from the Global Burden of Disease Study 2015

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    Introduction: Neglected tropical diseases (NTDs) are important public health problems in Ethiopia. In 2013, the Federal Ministry of Health (FMOH) has launched a national NTD master plan to eliminate major NTDs of public health importance by 2020. Benchmarking the current status of NTDs in the country is important to monitor and evaluate the progress in the implementation of interventions and their impacts. Therefore, this study aims to assess the trends of mortality and Disability-adjusted Life-Years (DALY) for the priority NTDs over the last 25 years. Methods: We used the Global Burden of Disease (GBD) 2015 estimates for this study. The GBD 2015 data source for cause of death and DALY estimation included verbal autopsy (VA), Demographic and Health Surveys (DHS), malaria indicator surveys (MICS) and other disease specific surveys, Ministry of Health reports submitted to United Nations (UN) agencies and published scientific articles. Cause of Death Ensemble modeling (CODEm) and/or natural history models were used to estimate malaria and NTDs mortality rates. DALY were estimated as the sum of Years of Life Lost (YLL) due to premature mortality and Years Lived with Disability (YLD). Results: All NTDs caused an estimated of 6,293 deaths (95% uncertainty interval (UI): 3699 – 10,080) in 1990 and 3,593 deaths (95% UI: 2051 – 6178) in 2015, a 70% reduction over the 25 years. Age-standardised mortality rates due to schistosomiasis, STH and leshmaniasis have declined by 91.3%, 73.5% and 21.6% respectively between 1990 to 2015. The number of DALYs due to all NTDs has declined from 814.4 thousand (95% UI: 548 thousand–1.2 million) in 1990 to 579.5 thousand (95%UI: 309.4 thousand – 1.3 million) in 2015. Age-standardised DALY rates due to all NTDs declined by 30.4%, from 17.6 per 1000(95%UI: 12.5-26.5) in 1990 to 12.2 per 1000(95%UI: 6.5 – 27.4) in 2015. Age-standardised DALY rate for trachoma declined from 92.7 per 100,000(95% UI: 63.2 – 128.4) in 1990 to 41.2 per 100,000(95%UI: 27.4 – 59.2) in 2015, a 55.6% reduction between 1990 and 2015. Age-standardised DALY rates for onchocerciasis, schistosomiasis and lymphiatic filariasis decreased by 66.2%, 29.4% and 12.5% respectively between 1990 and 2015. DALY rate for ascariasis fell by 56.8% over the past 25 years. Conclusions: Ethiopia has made a remarkable progress in reducing the DALY rates for most of the NTDs over the last 25 years. The rapid scale of interventions and broader system strengthening may have a lasting impact on achieving the 2020 goal of elimination of most of NTDs. Ethiopia should strengthen the coverage of integrated interventions of NTD through proper coordination with other health programs and sectors and community participation to eliminate NTDs by 2020

    Risk factors of visceral leishmaniasis: a case control study in north-western Ethiopia

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    Background Visceral leishmaniasis (VL, also called “kala-azar”), is a life threatening neglected tropical infectious disease which mainly affects the poorest of the poor. VL is prevalent in Ethiopia particularly in the northwest of the country. Understanding the risk factors of VL infection helps in its prevention and control. The aim of the present study was to identify the factors associated with VL. Methods A case–control study was carried out during the period of January-July 2013 in northwest Ethiopia. Cases and controls were diagnosed using clinical presentation, the rk39 rapid diagnostic test and Direct Agglutination Test (DAT). A total of 283 (84.8% males versus 15.2% females) participants were interviewed. 90 cases and 193 controls were involved, matched by age, sex and geographical location with a ratio of 1:2 (case: controls). Univariate and backward multivariate conditional logistic regression were used to identify risk factors of VL. Results Elevated odds of VL was associated with goat ownership (OR = 6.4; 95%: confidence interval [Cl]: 1.5-28.4), living in houses with cracked wall (OR = 6.4; 95% Cl: 1.6-25.6), increased family size (OR = 1.3; 95% Cl: 1.0-1.8) and the number of days spent in the farm field (OR = 1.1; 95% Cl: 1.0-1.2). However, daily individual activities around the home and farm fields, mainly sleeping on a bed (OR = 0.2; 95%: Cl 0.03-0.9), sleeping outside the house under a bed net (OR = 0.1; 95% Cl: 0.02-0.36)] and smoking plant parts in the house during the night time (OR = 0.1; 95% Cl: 0.01-0.6) were associated with decreased odds of being VL case. Conclusion Our findings showed that use of bed net and smoke could be helpful for the prevention of VL in the area particularly among individuals who spend most of their time in the farm. VL control effort could be focused on improving housing conditions, such as sealing cracks and crevices inside and outside houses. Further research is warranted to elucidate the role of goats in the transmission of L. donovani, assess the impact of bed nets and the role of the traditional practice of smoking plants

    The burden of neglected tropical diseases in Ethiopia, and opportunities for integrated control and elimination

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    Background: Neglected tropical diseases (NTDs) are a group of chronic parasitic diseases and related conditions that are the most common diseases among the 2·7 billion people globally living on less than US$2 per day. In response to the growing challenge of NTDs, Ethiopia is preparing to launch a NTD Master Plan. The purpose of this review is to underscore the burden of NTDs in Ethiopia, highlight the state of current interventions, and suggest ways forward. Results: This review indicates that NTDs are significant public health problems in Ethiopia. From the analysis reported here, Ethiopia stands out for having the largest number of NTD cases following Nigeria and the Democratic Republic of Congo. Ethiopia is estimated to have the highest burden of trachoma, podoconiosis and cutaneous leishmaniasis in sub-Saharan Africa (SSA), the second highest burden in terms of ascariasis, leprosy and visceral leishmaniasis, and the third highest burden of hookworm. Infections such as schistosomiasis, trichuriasis, lymphatic filariasis and rabies are also common. A third of Ethiopians are infected with ascariasis, one quarter is infected with trichuriasis and one in eight Ethiopians lives with hookworm or is infected with trachoma. However, despite these high burdens of infection, the control of most NTDs in Ethiopia is in its infancy. In terms of NTD control achievements, Ethiopia reached the leprosy elimination target of 1 case/10,000 population in 1999. No cases of human African trypanosomiasis have been reported since 1984. Guinea worm eradication is in its final phase. The Onchocerciasis Control Program has been making steady progress since 2001. A national blindness survey was conducted in 2006 and the trachoma program has kicked off in some regions. Lymphatic Filariasis, podoconiosis and rabies mapping are underway. Conclusion: Ethiopia bears a significant burden of NTDs compared to other SSA countries. To achieve success in integrated control of NTDs, integrated mapping, rapid scale up of interventions and operational research into co implementation of intervention packages will be crucial

    A possible role for Phlebotomus (Anaphlebotomus) rodhaini (Parrot, 1930) in transmission of Leishmania donovani

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    <p>Abstract</p> <p>Background</p> <p>Visceral leishmaniasis (VL, kala azar), caused by <it>Leishmania donovani </it>is a major health problem in Sudan and other East African countries. In this region the only proven vectors of <it>L. donovani </it>are <it>Phlebotomus orientalis </it>in eastern Sudan, Ethiopia and Upper Nile areas of Southern Sudan and <it>Phlebotomus martini </it>in Ethiopia, Kenya and Southern Sudan. In this report, we present the first evidence that <it>Phlebotomus rodhaini </it>may also play a role in maintaining transmission of <it>L. donovani </it>between animal reservoir hosts in eastern Sudan. The study was conducted in a zoonotic focus of visceral leishmaniasis in Dinder National Park, eastern Sudan, where previous work showed high infection rates of <it>L. donovani </it>in <it>P. orientalis</it>. Sand flies, captured by CDC traps were dissected and examined for infection with <it>Leishmania </it>parasites. Parasite isolates were subjected to <it>L. donovani </it>specific PCR. Field experiments were also carried out to compare efficiency of rodent baited and un-baited CDC traps in collection of <it>P. rodhaini </it>and determine its man-biting rate.</p> <p>Results</p> <p>Three female <it>P. rodhain</it>i were found infected with <it>Leishmania </it>parasites in an astonishingly small number of flies captured in three separate field trips. Two of these isolates were typed by molecular methods as <it>L. donovani</it>, while the third isolate was inoculated into a hamster that was subsequently lost. Although <it>P. rodhaini is </it>generally considered a rare species, results obtained in this study indicate that it can readily be captured by rodent-baited traps. Results of human landing collection showed that it rarely bites humans in the area.</p> <p>Conclusion</p> <p>It is concluded that <it>P. rodhaini </it>is a possible vector of <it>L. donovani </it>between animal reservoir hosts but is not responsible for infecting humans. It is suggested that the role of <it>P</it>. <it>rodhaini </it>in transmission of <it>L. donovani </it>in other zoonotic foci of visceral leishmaniasis in Africa should be re-examined.</p
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