44 research outputs found

    Determining Schistosoma haematobium Population Structures in Ethiopia

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    Schistosomiasis, also known as bilharzia, is a Neglected Tropical Disease caused by parasitic helminths that affects over 240 million people around the world. Praziquantel has been used to treat individuals infected with schistosomiasis through Mass Drug Administration (MDA) programs but a recent reduction in its efficacy has been observed, creating concern that the parasite will evolve to become resistant to the chemotherapy drug. Monitoring changes in the population structure of Schistosoma haematobium using microsatellite markers can be a useful metric to determine praziquantel efficacy since variations in the repeat sequences of microsatellites indicate genetic diversity. Since little is known about the population structure of S. haematobium–despite urogenital schistosomiasis being a pressing issue in Ethiopia–18 microsatellite multiplex assays developed in a prior study were tested on stock DNA to validate them for use to study the effects of praziquantel on parasitic S. haematobium in Ethiopia. Through a combination of bioinformatic analysis, PCR, and Next Generation Sequencing on the MinION, 13 of the 18 microsatellite markers were validated, highlighting the importance of developing microsatellite multiplex assays not only based on length distribution, but also based on Next Generation Sequencing data.https://digitalcommons.unmc.edu/surp2023/1015/thumbnail.jp

    Changes in carbon structure distribution and nanostructure of functionalized biochars

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    Energetic vectors produced from the thermochemical conversion of biomass and waste is considered as environmental-friendly energy. The syngas composed of CO and H2 at convenient ratio, could be used for various subsequent uses. However the industrial development is hold back by the production of unwanted by-products: tars and biochar/ash (aromatic hydrocarbons and solid residues respectively) which decrease the global efficiency yield and require very costly treatments. Some recent studies investigated potential applications to use these biochars for catalytic or sorbent applications, such as catalytic tar cracking or pollutants removal [1]. Biochars are cheap candidates and their functionalization is an opportunity for further development as an inexpensive catalyst from renewable resources. Please click on the file below for full content of the abstract

    Thermal annealing of carbon nanotubes reveals a strong toxicological impact of the structural defects

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    Le document inséré dans cette page comprend des données supplémentaire à l'article " Thermal annealing of carbon nanotubes reveals a toxicological impact of the structural defects" (DOI: 10.1007/s11051-015-2999-0) paru dans Journal of Nanoparticles ResearchInternational audienceThe biological response to pristine and annealed multi-walled carbon nanotubes (MWCNT) was assessed on murine macrophages (RAW 264.7). First, the physicochemical features of the as-produced MWCNT and annealed at 2125 °C for 1 h were fully characterized. A decrease in structural defects, hydrophobicity and catalytic impurities was detected after annealing. Thereafter, their impact on cytotoxicity, oxidative stress, and pro-inflammatory response was investigated at concentrations ranging from 15 to 120 µg mL−1. No effect of the 2125 °C treatment was detected on the cytotoxicity. In contrast, the annealed carbon nanotubes showed a significant increase of the pro-inflammatory response. We assumed that this behavior was due to the reduction in structural defects that may modify the layer of adsorbed biomolecules. Surprisingly, the purification of metallic catalysts did not have any significant impact on the oxidative stress. We suggested that the structural improvements from the 2125 °C treatment can decrease the carbon nanotube scavenging capacity and thus allow a higher free radical release which may counterbalance the decrease of oxidative stress due to a lower content of metallic impurities

    Protuberant Electrode Structures for New Retinal Implants

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    Focal stimulation of neural tissue is a challenge in retinal prosthetic devices in which the aim is to improve the spatial resolution of the stimulation and therefore increase the electrode density of the prosthetic devices. Our work intends to create a new implant able to enhance the focalisation of the stimulation signal through protuberant electrodes. These electrodes are micro fabricated on a soft polyimide substrate using classical metal electrodeposition techniques. Before proceeding with fabrication a FEM model of the electrode’s current density was done to select the best-performing structures and geometries in terms of local stimulation. Based on these models, several prototypes were fabricated and implanted in vivo into a rat’s eye to verify the adaptation to the retina tissue

    Impact of trichiasis surgery on daily living: A longitudinal study in Ethiopia

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    Background: Trachomatous trichiasis (TT) may lead to disability, impeding productive activities, resulting in loss of income. This study was conducted to determine if trichiasis surgery improves participation in productive and leisure activities, and ability to perform activities without difficulty or assistance. Methods: We recruited 1000 adults with trichiasis (cases) and 200 comparison participants, matched to every fifth trichiasis case on age (+/- two years), sex and location. The ‘Stylised Activity List’ tool, developed for the World Bank Living Standard Measurement Survey, was adapted to collect data on activity in the last week (participation in activity, difficulty with activity, requirement of assistance for activity), at baseline and 12 months later. All trichiasis cases received trichiasis surgery at baseline. Random effect logistic regression was used to compare cases and comparison participants. Results: There was strong evidence that trichiasis surgery substantially improves the ability of trichiasis cases to perform all the productive and leisure activities investigated without difficulty, with large increases in processing agricultural products, 21.1% to 87.0% (p&lt;0.0001), farming, 19.1% to 82.4% (p&lt;0.0001), and fetching wood, 25.3% to 86.0% (p&lt;0.0001). Similarly, there was a significant increase in the proportion of cases who could perform activities without assistance, with the largest increases in animal rearing 54.2% to 92.0% (p&lt;0.0001) and farming 73.2% to 96.4% (p&lt;0.0001). There was no change in the proportion of comparison participants performing activities without difficulty or assistance. The change in most of the activities in cases was independent of visual acuity improvement and recurrent TT at 12 months. One year after trichiasis surgery, the proportion of cases reporting ocular pain reduced from 98.9% to 33.7% (p&lt;0.0001). Conclusions: Eyelid surgery for TT improves functional capabilities regardless of vision gains. These data lend strong support to the view that TT surgery improves function and contributes to improved household income and wealth.</ns4:p

    The Global Trachoma Mapping Project: Methodology of a 34-Country Population-Based Study.

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    PURPOSE: To complete the baseline trachoma map worldwide by conducting population-based surveys in an estimated 1238 suspected endemic districts of 34 countries. METHODS: A series of national and sub-national projects owned, managed and staffed by ministries of health, conduct house-to-house cluster random sample surveys in evaluation units, which generally correspond to "health district" size: populations of 100,000-250,000 people. In each evaluation unit, we invite all residents aged 1 year and older from h households in each of c clusters to be examined for clinical signs of trachoma, where h is the number of households that can be seen by 1 team in 1 day, and the product h × c is calculated to facilitate recruitment of 1019 children aged 1-9 years. In addition to individual-level demographic and clinical data, household-level water, sanitation and hygiene data are entered into the purpose-built LINKS application on Android smartphones, transmitted to the Cloud, and cleaned, analyzed and ministry-of-health-approved via a secure web-based portal. The main outcome measures are the evaluation unit-level prevalence of follicular trachoma in children aged 1-9 years, prevalence of trachomatous trichiasis in adults aged 15 + years, percentage of households using safe methods for disposal of human feces, and percentage of households with proximate access to water for personal hygiene purposes. RESULTS: In the first year of fieldwork, 347 field teams commenced work in 21 projects in 7 countries. CONCLUSION: With an approach that is innovative in design and scale, we aim to complete baseline mapping of trachoma throughout the world in 2015

    Mapping local patterns of childhood overweight and wasting in low- and middle-income countries between 2000 and 2017

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    A double burden of malnutrition occurs when individuals, household members or communities experience both undernutrition and overweight. Here, we show geospatial estimates of overweight and wasting prevalence among children under 5 years of age in 105 low- and middle-income countries (LMICs) from 2000 to 2017 and aggregate these to policy-relevant administrative units. Wasting decreased overall across LMICs between 2000 and 2017, from 8.4% (62.3 (55.1–70.8) million) to 6.4% (58.3 (47.6–70.7) million), but is predicted to remain above the World Health Organization’s Global Nutrition Target of <5% in over half of LMICs by 2025. Prevalence of overweight increased from 5.2% (30 (22.8–38.5) million) in 2000 to 6.0% (55.5 (44.8–67.9) million) children aged under 5 years in 2017. Areas most affected by double burden of malnutrition were located in Indonesia, Thailand, southeastern China, Botswana, Cameroon and central Nigeria. Our estimates provide a new perspective to researchers, policy makers and public health agencies in their efforts to address this global childhood syndemic

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

    An open dataset of Plasmodium falciparum genome variation in 7,000 worldwide samples.

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    MalariaGEN is a data-sharing network that enables groups around the world to work together on the genomic epidemiology of malaria. Here we describe a new release of curated genome variation data on 7,000 Plasmodium falciparum samples from MalariaGEN partner studies in 28 malaria-endemic countries. High-quality genotype calls on 3 million single nucleotide polymorphisms (SNPs) and short indels were produced using a standardised analysis pipeline. Copy number variants associated with drug resistance and structural variants that cause failure of rapid diagnostic tests were also analysed.  Almost all samples showed genetic evidence of resistance to at least one antimalarial drug, and some samples from Southeast Asia carried markers of resistance to six commonly-used drugs. Genes expressed during the mosquito stage of the parasite life-cycle are prominent among loci that show strong geographic differentiation. By continuing to enlarge this open data resource we aim to facilitate research into the evolutionary processes affecting malaria control and to accelerate development of the surveillance toolkit required for malaria elimination
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