68 research outputs found

    Nitrate concentration in drinking water supplies in selected communities of Ibadan Southeast local government, Ibadan, Nigeria

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    Elevated levels of nitrate in drinking water have been associated with adverse health effects. Most susceptible to nitrate toxicity are infants under six months of age and pregnant women. This study assesses the nitrate concentration of 48 randomly selected wells in an urban-slum setting in Ibadan South East Local Government Area (IBSELGA), Nigeria. The coordinates of the wells were mapped with a hand-held Global Positioning System (GPS). The nitrate concentration ranged between 0.00 and 42.80 mgL-1 with a mean of log10 of 0.735 and a geometric mean of 5.43 mgL-1; and 0.00 and 93.30 mgL-1 with a mean of log10 of 0.696 and a geometric mean of 4.97 mg L-1 for the wet and dry seasons, respectively. During the wet season, the levels of nitrate in all the wells were within the WHO permissible limit of 45 mg L-1 NO3. However, during the dry season, few of the wells; six (12.5%) dried up completely. Out of the remaining 42 wells, six (14.3%) had nitrate concentration which exceeded the permissible limit. This same set of wells lacked sanitary features such as lining and cover. Out of the 48 wells, 30 (62.5%) and 24 (50%) were located at ≤10 m from the septic tank/pit latrine and refuse  dumps, respectively. Nitrate maps were developed using Georeferenced data for the water points. The nitrate exceedence map produced showed water sources within the study area with nitrate concentration exceeding the recommended limit and therefore requiring urgent intervention. The results of this study will serve as indicator for determining risk areas with respect to nitrate concentration in drinking water and therefore help in decision making activities.Key words: Global positioning system, Ibadan, nitrate, nitrate exceedence, wells, urban slum

    Problematic social media use: results from a large-scale nationally representative adolescent sample

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    Despite social media use being one of the most popular activities among adolescents, prevalence estimates among teenage samples of social media (problematic) use are lacking in the field. The present study surveyed a nationally representative Hungarian sample comprising 5,961 adolescents as part of the European School Survey Project on Alcohol and Other Drugs (ESPAD). Using the Bergen Social Media Addiction Scale (BSMAS) and based on latent profile analysis, 4.5% of the adolescents belonged to the at-risk group, and reported low self-esteem, high level of depression symptoms, and elevated social media use. Results also demonstrated that BSMAS has appropriate psychometric properties. It is concluded that adolescents at-risk of problematic social media use should be targeted by school-based prevention and intervention programs

    Algal Photosynthesis as the Primary Driver for a Sustainable Development in Energy, Feed, and Food Production

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    High oil prices and global warming that accompany the use of fossil fuels are an incentive to find alternative forms of energy supply. Photosynthetic biofuel production represents one of these since for this, one uses renewable resources. Sunlight is used for the conversion of water and CO2 into biomass. Two strategies are used in parallel: plant-based production via sugar fermentation into ethanol and biodiesel production through transesterification. Both, however, exacerbate other problems, including regional nutrient balancing and the world's food supply, and suffer from the modest efficiency of photosynthesis. Maximizing the efficiency of natural and engineered photosynthesis is therefore of utmost importance. Algal photosynthesis is the system of choice for this particularly for energy applications. Complete conversion of CO2 into biomass is not necessary for this. Innovative methods of synthetic biology allow one to combine photosynthetic and fermentative metabolism via the so-called Photanol approach to form biofuel directly from Calvin cycle intermediates through use of the naturally transformable cyanobacterium Synechocystis sp. PCC 6803. Beyond providing transport energy and chemical feedstocks, photosynthesis will continue to be used for food and feed applications. Also for this application, arguments of efficiency will become more and more important as the size of the world population continues to increase. Photosynthetic cells can be used for food applications in various innovative forms, e.g., as a substitute for the fish proteins in the diet supplied to carnivorous fish or perhaps—after acid hydrolysis—as a complex, animal-free serum for growth of mammalian cells in vitro

    Evidence of RNAi in humans from systemically administered siRNA via targeted nanoparticles

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    Therapeutics that are designed to engage RNA interference (RNAi) pathways have the potential to provide new, major ways of imparting therapy to patients. Long, double-stranded RNAs were first shown to mediate RNAi in Caenorhabditis elegans, and the potential use of RNAi for human therapy has been demonstrated by the finding that small interfering RNAs (siRNAs; approximately 21-base-pair double-stranded RNA) can elicit RNAi in mammalian cells without producing an interferon response. We are at present conducting the first in-human phase I clinical trial involving the systemic administration of siRNA to patients with solid cancers using a targeted, nanoparticle delivery system. Here we provide evidence of inducing an RNAi mechanism of action in a human from the delivered siRNA. Tumour biopsies from melanoma patients obtained after treatment show the presence of intracellularly localized nanoparticles in amounts that correlate with dose levels of the nanoparticles administered (this is, to our knowledge, a first for systemically delivered nanoparticles of any kind). Furthermore, a reduction was found in both the specific messenger RNA (M2 subunit of ribonucleotide reductase (RRM2)) and the protein (RRM2) levels when compared to pre-dosing tissue. Most notably, we detect the presence of an mRNA fragment that demonstrates that siRNA-mediated mRNA cleavage occurs specifically at the site predicted for an RNAi mechanism from a patient who received the highest dose of the nanoparticles. Together, these data demonstrate that siRNA administered systemically to a human can produce a specific gene inhibition (reduction in mRNA and protein) by an RNAi mechanism of action

    Structure, Function, and Modification of the Voltage Sensor in Voltage-Gated Ion Channels

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    Fiqh al-lughah wa sirr al-arabiyyah, 3rd.1st. ed./ Abi Manshur as-Sa alabi

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    416 hal.; 422 hal.; 25 cm
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