538 research outputs found
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ARMC 5 Variants and Risk of Hypertension in Blacks: MH- GRID Study.
Background We recently found that ARMC 5 variants may be associated with primary aldosteronism in blacks. We investigated a cohort from the MH - GRID (Minority Health Genomics and Translational Research Bio-Repository Database) and tested the association between ARMC 5 variants and blood pressure in black s. Methods and Results Whole exome sequencing data of 1377 black s were analyzed. Target single-variant and gene-based association analyses of hypertension were performed for ARMC 5, and replicated in a subset of 3015 individuals of African descent from the UK Biobank cohort. Sixteen rare variants were significantly associated with hypertension ( P=0.0402) in the gene-based (optimized sequenced kernel association test) analysis; the 16 and one other, rs116201073, together, showed a strong association ( P=0.0003) with blood pressure in this data set. The presence of the rs116201073 variant was associated with lower blood pressure. We then used human embryonic kidney 293 and adrenocortical H295R cells transfected with an ARMC 5 construct containing rs116201073 (c.*920T>C). The latter was common in both the discovery ( MH - GRID ) and replication ( UK Biobank) data and reached statistical significance ( P=0.044 [odds ratio, 0.7] and P=0.007 [odds ratio, 0.76], respectively). The allele carrying rs116201073 increased levels of ARMC5 mRNA , consistent with its protective effect in the epidemiological data. Conclusions ARMC 5 shows an association with hypertension in black s when rare variants within the gene are considered. We also identified a protective variant of the ARMC 5 gene with an effect on ARMC 5 expression confirmed in vitro. These results extend our previous report of ARMC 5's possible involvement in the determination of blood pressure in blacks
Synthesis and X-ray structure of the dysprosium(III) complex derived from the ligand 5-chloro-1,3-diformyl-2-hydroxybenzene-bis-(2-hydroxybenzoylhydrazone) [Dy2(C22H16ClN4O5)3]
The title compound [Dy2(C22H16ClN4O5)3](SCN)3(H2O)(CH3OH) has been synthesized and its crystal structure determined by single X-ray diffraction at room temperature. The two nine coordinated Dy(III) are bound to three macromolecules ligand through the phenolic oxygens of the p-chlorophenol moieties, the nitrogen atoms and the carbonyl functions of the hydrazonic moieties. The phenolic oxygen atoms of the 2-hydroxybenzoyl groups are not bonded to the metal ions. In the bases of the coordination polyhedra the six Dy-N bonds are in the range 2.563(13)-2.656(13) Å and the twelve Dy-O bonds are in the range 2.281(10)-2.406(10) Å. KEY WORDS: Dysprosium(III) complex, 5-Chloro-1,3-diformyl-2-hydroxybenzene-bis-(2-hydroxybenzoylhydrazone), Crystal structure  Bull. Chem. Soc. Ethiop. 2003, 17(2), 167-172
Seasonal cycle of desert aerosols in western Africa: analysis of the coastal transition with passive and active sensors
The impact of desert aerosols on climate, atmospheric processes, and
the environment is still debated in the scientific community. The extent of
their influence remains to be determined and particularly requires a better
understanding of the variability of their distribution. In this work, we
studied the variability of these aerosols in western Africa using different
types of satellite observations. SeaWiFS (Sea-Viewing Wide Field-of-View
Sensor) and OMI (Ozone Monitoring Instrument) data have been used to
characterize the spatial distribution of mineral aerosols from their optical
and physical properties over the period 2005–2010. In particular, we focused
on the variability of the transition between continental western African and
the eastern Atlantic Ocean. Data provided by the lidar scrolling CALIOP
(Cloud-Aerosol Lidar with Orthogonal Polarization) onboard the satellite
CALIPSO (Cloud Aerosol Lidar and Infrared Pathfinder Satellite Observations)
for the period 2007–2013 were then used to assess the seasonal variability
of the vertical distribution of desert aerosols. We first obtained a good
representation of aerosol optical depth (AOD) and single-scattering albedo
(SSA) from the satellites SeaWiFS and OMI, respectively, in comparison with AERONET
estimates, both above the continent and the ocean. Dust occurrence frequency
is higher in spring and boreal summer. In spring, the highest occurrences are
located between the surface and 3 km above sea level, while in summer the
highest occurrences are between 2 and 5 km altitude. The vertical
distribution given by CALIOP also highlights an abrupt change at the coast
from spring to fall with a layer of desert aerosols confined in an
atmospheric layer uplifted from the surface of the ocean. This uplift of the
aerosol layer above the ocean contrasts with the winter season during which
mineral aerosols are confined in the atmospheric boundary layer. Radiosondes
at Dakar Weather Station (17.5° W, 14.74° N) provide basic
thermodynamic variables which partially give a causal relationship between the
layering of the atmospheric circulation over western Africa and their aerosol
contents throughout the year. A SSA increase is observed in winter and spring
at the transition between the continent and the ocean. The analysis of mean
NCEP (National Centers for Environmental Prediction) winds at 925 hPa between
2000 and 2012 suggest a significant contribution of coastal sand sources from
Mauritania in winter which would increase SSA over the ocean
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Event attribution science in adaptation decision-making: the context of extreme rainfall in urban Senegal
Event attribution assesses the effect of climate change on individual extreme events. While scientists have suggested that results could be relevant for climate adaptation policy, this has had little empirical investigation, particularly in developing regions. Taking the case of Senegal, the national adaptation policy context regarding extreme precipitation and flooding in urban areas, and the scientific information needed to support this policy, is investigated using key informant interviews, a workshop and document analysis. Flooding in Senegal was found to be viewed primarily as an urban planning concern rather than a climate change issue, with actions to address the impacts focussing on current vulnerabilities of urban communities without considering changing climate risks. While stakeholders thought event attribution might be useful to inform about climate change impacts and future risks of extreme events, it is unclear whether there would be opportunity for this at present, due to the limited role climate information has in adaptation decision-making. While addressing vulnerability to extremes is necessary whether or not the risk is climate change-related, if long-term planning is to be resilient then knowledge about future changes in risks of extremes will need to be considered, even if individual events are not attributed to climate change
Seismic chimney characterisation in the North Sea – Implications for pockmark formation and shallow gas migration
Fluid-escape structures within sedimentary basins permit pressure-driven focused fluid flow through inter-connected faults, fractures and sediment. Seismically-imaged chimneys are recognised as fluid migration pathways which cross-cut overburden stratigraphy, hydraulically connecting deeper strata with the seafloor. However, the geological processes in the sedimentary overburden which control the mechanisms of genesis and temporal evolution require improved understanding. We integrate high resolution 2D and 3D seismic reflection data with sediment core data to characterise a natural, active site of seafloor methane venting in the UK North Sea and Witch Ground Basin, the Scanner pockmark complex. A regional assessment of shallow gas distribution presents direct evidence of active and palaeo-fluid migration pathways which terminate at the seabed pockmarks. We show that these pockmarks are fed from a methane gas reservoir located at 70 metres below the seafloor. We find that the shallow reservoir is a glacial outwash fan, that is laterally sealed by glacial tunnel valleys. Overpressure generation leading to chimney and pockmark genesis is directly controlled by the shallow geological and glaciogenic setting. Once formed, pockmarks act as drainage cells for the underlying gas accumulations. Fluid flow occurs through gas chimneys, comprised of a sub-vertical gas-filled fracture zone. Our findings provide an improved understanding of focused fluid flow and pockmark formation within the sediment overburden, which can be applied to subsurface geohazard assessment and geological storage of CO2
Assessing and Strengthening African Universities' Capacity for Doctoral Programmes
Imelda Bates and colleagues developed and validated an evidence-based tool for evaluating doctoral programmes in African universities
Pilot feasibility study of an emergency paediatric kit for intra-rectal quinine administration used by the personnel of community-based health care units in Senegal
<p>Abstract</p> <p>Background</p> <p>Quinine injection is the reference treatment for malaria when oral administration is impossible. Quinine can also be administered by the intra-rectal route and, over the last ten years, a series of studies have been conducted in children to determine the ideal dose and dilution in the African situation. The aim of the present study was to evaluate the feasibility and usefulness of a kit for an immediate administration of quinine alkaloids (Quinimax<sup>®</sup>) by community health workers, prior to transfer of the child to a more sophisticated health care establishment.</p> <p>Methods</p> <p>A prospective, open, descriptive community intervention study conducted in northern Senegal at six village Health Units in children fewer than ten years of age with non-per-os malaria. Controls were given the routine care prior to transfer to a Health Center, and cases were in addition administered Quinimax<sup>® </sup>(20 mg/ml) via the intra-rectal route before transfer. Patients were followed through complete cure and parasitological tests were carried out on Days 0, 3 and 7.</p> <p>Results</p> <p>134 patients (79 cases/55 controls) were recruited between November 2003 and May 2004 or October and November 2004. The two groups were comparable at inclusion. In the case group, oral drugs could be administered after a mean of <it>16.8 hours </it>versus <it>33.6 hours </it>in the control group. Time-to cure was shorter in cases than in controls. Complete parasite clearance was obtained in all patients by Day 7. The kit was well accepted by all concerned and more than 80% of community health workers judged the kit easy to use.</p> <p>Conclusion</p> <p>The emergency paediatric kit is a useful tool in the management of malaria in children who cannot be treated orally. It is feasible and easy to use for health workers in community-based Health Units where, according to the WHO, nearly 80% of malarial morbidity and mortality occurs.</p
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