153 research outputs found

    JACIE accreditation from the perspective of an accredited centre

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    Physical and Chemical Characteristics of Five Hot Springs in Eritrea

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    Eritrea has a number of hot springs whose physicochemical characteristics are not documented. This study examined the thermal and chemical features of five hot springs located in the eastern escarpment of Eritrea. Field data and water samples were collected from five hot springs namely; Akwar and Maiwooi near Gahtelai, Garbanabra and Gelti near Irafayle at the Gulf of Zula and Elegedi in Alid volcanic center. The water temperatures at source varied from 49.5°C to 100°C while pH levels ranged from 6.97 to 7.54. Elegedi had significantly higher temperature (p < 0.05) than the other four hot springs. Strong correlation was observed between electrical conductivity (EC), total dissolved solid (TDS), salinity, sodium, potassium, calcium and chloride (R2 > 0.9) as well as between temperature and sulphate levels (R2 = 0.96). Evident clustering was noted at p < 0.05, using Non-metric multidimensional scaling (NMDS), between the three locations of the hot springs. Akwar and Maiwooi, situated close to each other, clustered together, Garbanabra and Gelti, which were characterized by higher salinity levels, formed a separate cluster. Elegedi, characterized by high temperature (100°C), sulphate (979.7 mg/l) and NH4+ (196.33 mg/l) levels, clustered separately. Akwar and Maiwooi had high bicarbonate (345 mg/l and 393 mg/l) and fluoride (8.20 mg/l and 6.48 mg/l) levels which are above WHO limits. Electrical conductivity (23,133 mS/cm), total dissolved solid (15,552 mg/l), sodium (3,800 mg/l), potassium (198 mg/l), calcium (1,653 mg/l) and chloride (5,946 mg/l) levels in Garbanabra and Gelti hot springs exceeded WHO limits. Bromine (74.8 mg/l in Garbanabra and 45.2 mg/l in Gelti) and boron (2.21 mg/l in Garbanabra and 1.55 mg/l in Gelti) levels were also above standard limits set for potable water. Maiwooi (1.20) and Elegedi (1.10) were depositional while Akwar water (-0.71) was slightly corrosive. The corrosive nature of the water sample from Akwar, is a public health concern. The waters from the five Eritrean hot springs are thus not fit for human consumption. In addition, the use of thermal spring water for recreational purposes should be closely monitored. Keywords: key words, hot springs, physicochemical, Eritre

    A multidisciplinary study of chemico-physical properties of different classes of 2-aryl-5(or 6)-nitrobenzimidazoles: NMR, electrochemical behavior, ESR, and DFT calculations

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    Continuing in our researches on the syntheses, reactivity, pharmacological/biological activities of heterocyclic compounds containing one or more nitrogen atoms we have examined some chemico-physical properties (1H and 13C NMR, electrochemical behavior, and ESR) of three series of 2-aryl-5(or 6)-nitrobenzimidazoles (1–3) variously substituted in the 2-aryl ring. The electrochemical behavior of the nitro group on the benzimidazole ring has been studied by cyclic voltammetry. This has allowed to point out both the reversibility, the formal potential, and the number of electrons involved in the electrochemical processes, and to evaluate the effect of the substituents present on the aryl ring. The data collected have been able to furnish a complete picture of electronic distribution and have been supported by DFT calculations

    Use of serology in a systematic screening programme for strongyloidiasis in an immigrant population

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    Objectives: The aim of this cross-sectional study was to describe the results of a systematic serological screening programme for strongyloidiasis. Methods: Aprospective serological screeningprogramme for strongyloidiasis wasperformedbetween2009 and2014 for allimmigrantpatients attending theTropicalMedicineUnit. Three formalin-etherconcentrated stool samples and an ELISA for anti-Strongyloides stercoralis antibodies were used as screening tools. Results: Of 659 patients screened, 79 (12%) were positive for S. stercoralis regardless of the diagnostic method used. The prevalence of infection was 42.9% in East African patients, 16.3% in Central African patients,10.9% in those fromSouthAmerica, and 10% in the case ofWestAfrica. Univariate analysis showed thatinfection by S. stercoralis was significantly more frequentinpatients from CentralAfrica (p = 0.026; OR 1.72, 95% CI 1.03–2.85) and East Africa (p<0.001; OR 5.88, 95% CI 1.75–19.32). Taking West Africa as the reference (as the area of lowest prevalence among the positive prevalence areas), the statistical analysis showed that the risk of infection was higher in East Africa (p = 0.001; OR 6.750, 95% CI 2.127–21.423) and Central Africa (p = 0.065; OR 1.747, 95% CI 0.965–3.163). Conclusions: Due to the potential complications of strongyloidiasis infection, we recommend that immigrantpatients fromdevelopingcountriesbe routinelyscreenedfor S. stercoralis, especiallythose from East Africa. A serological test is a highly appropriate screening tool

    Compatibility between Calpurnia aurea leaf extract, attraction aggregation, and attachment pheromone and entomopathogenic fungus Metarhizium anisopliae on viability, growth, and virulence of the pathogen

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    Metarhizium anisopliae sensu stricto (ss) (Metsch.) Sorok. isolate ICIPE 07 is being developed as biopesticide for the control of ticks. In addition, leaf extracts of Calpurnia aurea Benth, and the attraction aggregation and attachment pheromone (AAAP) are being used as ticks’ attractant. The three agents are being considered for use in combination in an autodissemination approach, whereby ticks that are attracted to semiochemicals are infected with the inoculum. Experiments were therefore conducted to evaluate in vitro the compatibility between C. aurea, AAAP, and the M. anisopliae on vegetative growth, conidial production, and spore viability. Calpurnia aurea leaf extract was compatible with the fungus at all the concentrations tested, whereas AAAP inhibited all the fungal growth parameters. The virulence of M. anisopliae formulated in emulsifiable extracts of C. aurea was also tested against different developmental stages of Rhipicephalus appendiculatus in laboratory bioassays. No significant differences in virulence were observed between M. anisopliae applied alone and M. anisopliae formulated in different concentrations of C. aurea leaf extracts. These results suggest that C. aurea leaf extracts is compatible with M. anisopliae and could be mixed together for “spot-spray” treatments as low-cost and environmental-friendly technology to control ticks in grazing field, while AAAP should be used separately.Bioscience Eastern and Central Africa Network (BecANet) and the Canadian International Development Agency (CIDA).http://link.springer.com/journal/10340hb2013mn201

    Biogeographical survey of soil microbiomes across sub-Saharan Africa:structure, drivers, and predicted climate-driven changes

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    BACKGROUND: Top-soil microbiomes make a vital contribution to the Earth’s ecology and harbor an extraordinarily high biodiversity. They are also key players in many ecosystem services, particularly in arid regions of the globe such as the African continent. While several recent studies have documented patterns in global soil microbial ecology, these are largely biased towards widely studied regions and rely on models to interpolate the microbial diversity of other regions where there is low data coverage. This is the case for sub-Saharan Africa, where the number of regional microbial studies is very low in comparison to other continents. RESULTS: The aim of this study was to conduct an extensive biogeographical survey of sub-Saharan Africa’s top-soil microbiomes, with a specific focus on investigating the environmental drivers of microbial ecology across the region. In this study, we sampled 810 sample sites across 9 sub-Saharan African countries and used taxonomic barcoding to profile the microbial ecology of these regions. Our results showed that the sub-Saharan nations included in the study harbor qualitatively distinguishable soil microbiomes. In addition, using soil chemistry and climatic data extracted from the same sites, we demonstrated that the top-soil microbiome is shaped by a broad range of environmental factors, most notably pH, precipitation, and temperature. Through the use of structural equation modeling, we also developed a model to predict how soil microbial biodiversity in sub-Saharan Africa might be affected by future climate change scenarios. This model predicted that the soil microbial biodiversity of countries such as Kenya will be negatively affected by increased temperatures and decreased precipitation, while the fungal biodiversity of Benin will benefit from the increase in annual precipitation. CONCLUSION: This study represents the most extensive biogeographical survey of sub-Saharan top-soil microbiomes to date. Importantly, this study has allowed us to identify countries in sub-Saharan Africa that might be particularly vulnerable to losses in soil microbial ecology and productivity due to climate change. Considering the reliance of many economies in the region on rain-fed agriculture, this study provides crucial information to support conservation efforts in the countries that will be most heavily impacted by climate change. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40168-022-01297-w
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