1,771 research outputs found

    Groundwater flow modelling in the upper Anga’a river watershed, Yaounde, Cameroon

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    The Anga’a River watershed is located within the Yaounde IV district, South-east of Yaounde City, Cameroon. The groundwater flow and particle tracking modelling was carried out to determine in detail the groundwater flow and particle migration in the shallow unconfined aquifer of the Upper Anga’a river watershed. The watershed was modelled with a grid of 106 columns x 68 rows with two layers viz., unconfined and semi-confined aquifers extending up to 50 m depth. The Anga’a river traverses in the central part of the watershed and generally flows North-South. Lateral inflows and outflows were simulated with constant head. The Anga’a river heads and the Lake levels were simulated using a river package. Natural recharge due to rainfall formed the main input to the aquifer system and the output was made of abstraction from pumping wells, base flow to Anga’a River, lake, springs and Evapotranspiration. A steady state groundwater flow simulation was carried out using Visual MODFLOW software and calibrated for the February, 2008 groundwater levels at 18 observation wells. The model computation has converged after 170 iterations with a convergence criterion of 0.01 m. The computed groundwater level contours have been following the trend of observed ones. The computed groundwater balance indicated that the Anga’a river base flows come from the groundwater regime. Groundwater Flow model results indicated that the topography controls groundwater flow in the watershed and that base flow to river is an important factor moderating groundwater movement in the Anga’a river watershed

    An unusual termination of facial vein and anterior division of retromandibular vein into external jugular vein: a case report.

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    Facial vein, being the largest vein of the face forms the common facial vein after joining with the anterior division of retromandibular vein below the angle of the mandible. Usually, it drains into the internal jugular vein. During routine dissection of head and neck region of a male cadaver, aged approximately 50 years, an unusual pattern in the termination of veins on the left side of the neck was observed. The formation, course and termination of external jugular vein were normal. The anterior division of retromandibular vein joined with external jugular vein about 5 cm above the clavicle and the facial vein opened into the external jugular vein about 2.5 cm above the clavicle. In addition, there was a thin venous communication between anterior division of retromandibular vein and external jugular vein. The superficial veins of the neck are often used for cannulation; either for intravenous infusion or for central venous pressure monitoring. Furthermore, these venous segments are used as a patch for carotid endarterectomies. Hence, a thorough knowledge of the normal anatomy and their variations may be useful for performing these procedures

    Evaluation of the CERES-Rice version 3.0 model for the climate conditions of the state of Kerala, India

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    The CERES-Rice version 3.0 crop growth simulation model was calibrated and evaluated for the agroclimatic conditions of the state of Kerala in India. Genetic coefficients were developed for the rice crop variety Jaya and used for the model evaluation studies. In four experiments using different transplanting dates during the virippu season (June to September) under rainfed conditions (i.e. no irrigation), the flowering date was predicted within an error of four days and date of crop maturity within an error of two days. The model was found to predict the phenological events of the crop fairly well. The grain yield predicted by the model was within an error of 3 for all the transplanting dates, but the straw yield prediction was within an error of 27. The high accuracy of the grain yield prediction showed the ability of the model to simulate the growth of the crop in the agroclimatic conditions of Kerala. It can be concluded from this study that the model can be used for making various strategic and tactical decisions related to agricultural planning in the state

    ABCD Neurocognitive Prediction Challenge 2019: Predicting individual residual fluid intelligence scores from cortical grey matter morphology

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    We predicted residual fluid intelligence scores from T1-weighted MRI data available as part of the ABCD NP Challenge 2019, using morphological similarity of grey-matter regions across the cortex. Individual structural covariance networks (SCN) were abstracted into graph-theory metrics averaged over nodes across the brain and in data-driven communities/modules. Metrics included degree, path length, clustering coefficient, centrality, rich club coefficient, and small-worldness. These features derived from the training set were used to build various regression models for predicting residual fluid intelligence scores, with performance evaluated both using cross-validation within the training set and using the held-out validation set. Our predictions on the test set were generated with a support vector regression model trained on the training set. We found minimal improvement over predicting a zero residual fluid intelligence score across the sample population, implying that structural covariance networks calculated from T1-weighted MR imaging data provide little information about residual fluid intelligence.Comment: 8 pages plus references, 3 figures, 2 tables. Submission to the ABCD Neurocognitive Prediction Challenge at MICCAI 201

    ABCD Neurocognitive Prediction Challenge 2019: Predicting individual fluid intelligence scores from structural MRI using probabilistic segmentation and kernel ridge regression

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    We applied several regression and deep learning methods to predict fluid intelligence scores from T1-weighted MRI scans as part of the ABCD Neurocognitive Prediction Challenge (ABCD-NP-Challenge) 2019. We used voxel intensities and probabilistic tissue-type labels derived from these as features to train the models. The best predictive performance (lowest mean-squared error) came from Kernel Ridge Regression (KRR; λ=10\lambda=10), which produced a mean-squared error of 69.7204 on the validation set and 92.1298 on the test set. This placed our group in the fifth position on the validation leader board and first place on the final (test) leader board.Comment: Winning entry in the ABCD Neurocognitive Prediction Challenge at MICCAI 2019. 7 pages plus references, 3 figures, 1 tabl

    Effects of AR7 Joint Complex on arthralgia for patients with osteoarthritis: Results of a three-month study in Shanghai, China

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    <p>Abstract</p> <p>Background</p> <p>Osteoarthritis-induced arthralgia is a common cause of morbidity in both men and women worldwide. AR7 Joint Complex is a nutritional supplement containing various ingredients including sternum collagen II and methylsulfonylmethane. The product has been marketed in United States for over a decade, but clinical data measuring the effectiveness of this supplement in relieving arthralgia is lacking. The goal of this study was to determine the effect of AR7 Joint Complex on osteoarthritis.</p> <p>Methods</p> <p>A total of 100 patients over the age of 50 who had osteoarthritis were recruited to the double-blind study and randomly assigned into either treatment or placebo control groups. The patients in the treatment group were given AR7 Joint Complex orally, 1 capsule daily for 12 weeks, while the patients in the control group were given a placebo for the same period of time. Prior to and at the end of the study, data including Quality of Life questionnaires (SF-36), visual analog scales (1 to 100 mm), and X-rays of affected joints were collected.</p> <p>Results</p> <p>A total of 89 patients completed the study: 44 from the treatment group and 45 from the control group. No significant change in X-ray results was found in either group after the study. However, there was a significant decrease in patients complaining of arthralgia and tenderness (P < 0.01) in the treatment group and there was also a significant difference between the treatment and control groups at the end of the study. In addition, for Quality of Life data, the body pain index (BP) in the treatment group was significantly improved (P < 0.05) compared to the control group. No significant toxicity was noted in either group.</p> <p>Conclusion</p> <p>AR7 Joint Complex appears to have short-term effects in relieving pain in patients with osteoarthritis. Whether such an effect is long-lasting remains to be seen.</p

    Synthesis, antitubercular activity and mechanism of resistance of highly effective thiacetazone analogues

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    Defining the pharmacological target(s) of currently used drugs and developing new analogues with greater potency are both important aspects of the search for agents that are effective against drug-sensitive and drug-resistant Mycobacterium tuberculosis. Thiacetazone (TAC) is an anti-tubercular drug that was formerly used in conjunction with isoniazid, but removed from the antitubercular chemotherapeutic arsenal due to toxic side effects. However, several recent studies have linked the mechanisms of action of TAC to mycolic acid metabolism and TAC-derived analogues have shown increased potency against M. tuberculosis. To obtain new insights into the molecular mechanisms of TAC resistance, we isolated and analyzed 10 mutants of M. tuberculosis that were highly resistant to TAC. One strain was found to be mutated in the methyltransferase MmaA4 at Gly101, consistent with its lack of oxygenated mycolic acids. All remaining strains harbored missense mutations in either HadA (at Cys61) or HadC (at Val85, Lys157 or Thr123), which are components of the bhydroxyacyl-ACP dehydratase complex that participates in the mycolic acid elongation step. Separately, a library of 31 new TAC analogues was synthesized and evaluated against M. tuberculosis. Two of these compounds, 15 and 16, exhibited minimal inhibitory concentrations 10-fold lower than the parental molecule, and inhibited mycolic acid biosynthesis in a dose-dependent manner. Moreover, overexpression of HadAB HadBC or HadABC in M. tuberculosis led to high level resistance to these compounds, demonstrating that their mode of action is similar to that of TAC. In summary, this study uncovered new mutations associated with TAC resistance and also demonstrated that simple structural optimization of the TAC scaffold was possible and may lead to a new generation of TAC-derived drug candidates for the potential treatment of tuberculosis as mycolic acid inhibitors

    Perceived Discrimination and Self-Reported Quality of Care Among Latinos in the United States

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    Given the persistence of health and health-care disparities among Latinos in the United States and evidence that discrimination affects health and health care, an investigation of the relationship between perceived discrimination and quality of health care among Latinos is warranted. To examine the relationship of perceived discrimination (in general and in regard to doctors and medical personnel) with self-reported quality of health care and doctor-patient communication in a nationally representative Latino population sample. Participants were 1,067 Latino adults aged ≥18 years living in the US selected via random-digit dialing. Telephone interviews were conducted in 2008 during Wave 2 of the Pew Hispanic Center/Robert Wood Johnson Foundation Hispanic Healthcare Survey. US-born Latinos were twice as likely to report general discrimination as foreign born: 0.32 SD versus −0.23 SD (P &lt; 0.001) on the Detroit Area Survey (DAS) discrimination scale. Higher DAS discrimination was associated with lower self-reported quality of care in US-born Latinos [OR = 0.5; 95% CI (0.3, 0.9); P = 0.009]. For foreign-born Latinos, report of any doctor or medical staff discrimination was associated with lower quality of care [OR = 0.5; 95% CI (0.3, 0.9); P = 0.03], but the DAS was not. For US-born Latinos, doctor discrimination and higher DAS were jointly associated with worse doctor-patient communication. For foreign-born Latinos, the effect of discrimination on doctor-patient communication was significantly smaller than that observed in US-born Latinos. Given the association between perceived discrimination and quality of care, strategies to address discrimination in health-care settings may lead to improved patient satisfaction with care and possibly to improved treatment outcomes

    Detection of regulator genes and eQTLs in gene networks

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    Genetic differences between individuals associated to quantitative phenotypic traits, including disease states, are usually found in non-coding genomic regions. These genetic variants are often also associated to differences in expression levels of nearby genes (they are "expression quantitative trait loci" or eQTLs for short) and presumably play a gene regulatory role, affecting the status of molecular networks of interacting genes, proteins and metabolites. Computational systems biology approaches to reconstruct causal gene networks from large-scale omics data have therefore become essential to understand the structure of networks controlled by eQTLs together with other regulatory genes, and to generate detailed hypotheses about the molecular mechanisms that lead from genotype to phenotype. Here we review the main analytical methods and softwares to identify eQTLs and their associated genes, to reconstruct co-expression networks and modules, to reconstruct causal Bayesian gene and module networks, and to validate predicted networks in silico.Comment: minor revision with typos corrected; review article; 24 pages, 2 figure

    Interaction of C-Terminal Truncated Human αA-Crystallins with Target Proteins

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    Significant portion of alphaA-crystallin in human lenses exists as C-terminal residues cleaved at residues 172, 168, and 162. Chaperone activity, determined with alcohol dehydrogenase (ADH) and betaL-crystallin as target proteins, was increased in alphaA(1-172) and decreased in alphaA(1-168) and alphaA(1-162). The purpose of this study was to show whether the absence of the C-terminal residues influences protein-protein interactions with target proteins.Our hypothesis is that the chaperone-target protein binding kinetics, otherwise termed subunit exchange rates, are expected to reflect the changes in chaperone activity. To study this, we have relied on fluorescence resonance energy transfer (FRET) utilizing amine specific and cysteine specific fluorescent probes. The subunit exchange rate (k) for ADH and alphaA(1-172) was nearly the same as that of ADH and alphaA-wt, alphaA(1-168) had lower and alphaA(1-162) had the lowest k values. When betaL-crystallin was used as the target protein, alphaA(1-172) had slightly higher k value than alphaA-wt and alphaA(1-168) and alphaA(1-162) had lower k values. As expected from earlier studies, the chaperone activity of alphaA(1-172) was slightly better than that of alphaA-wt, the chaperone activity of alphaA(1-168) was similar to that of alphaA-wt and alphaA(1-162) had substantially decreased chaperone activity.Cleavage of eleven C-terminal residues including Arg-163 and the C-terminal flexible arm significantly affects the interaction with target proteins. The predominantly hydrophilic flexible arm appears to be needed to keep the chaperone-target protein complex soluble
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