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Population Shows (population + shows)
Selected AbstractsThe stellar population content of the thick disc and halo of the Milky Way analogue NGC 891MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 3 2009M. Rejkuba ABSTRACT We present deep VI images obtained with the Advanced Camera for Surveys on board the Hubble Space Telescope, covering three fields in the north-east side of the edge-on disc galaxy NGC 891. The observed fields span a wide range of galactocentric distances along the eastern minor axis, extending from the plane of the disc to 12 kpc, and out to ,25 kpc along the major axis. The photometry of individual stars reaches ,2.5 mag below the tip of the red giant branch. We use the astrophotometric catalogue to probe the stellar content and metallicity distribution across the thick disc and spheroid of NGC 891. The colour,magnitude diagrams of thick disc and spheroid population are dominated by old red giant branch stars with a wide range of metallicities, from the sparsely populated metal-poor tail at [Fe/H],,2.4 dex, up to about half-solar metallicity. The peak of the metallicity distribution function of the thick disc is at ,0.9 dex. The inner parts of the thick disc, within ,14 kpc along the major axis show no vertical colour/metallicity gradient. In the outer parts, a mild vertical gradient of ,(V,I)0/,|Z| = 0.1 ± 0.05 kpc,1 or less than 0.1 dex kpc,1 is detected, with bluer colours or more metal-poor stars at larger distances from the plane. This gradient is, however, accounted for by the mixing with the metal-poor halo stars. No metallicity gradient along the major axis is present for thick-disc stars, but strong variations of about 0.35 dex around the mean of [Fe/H]=,1.13 dex are found. The properties of the asymmetric metallicity distribution functions of the thick-disc stars show no significant changes in both the radial and the vertical directions. The stellar populations situated within the solar-cylinder-like distances show strikingly different properties from those of the Galaxy populating similar distances. This suggests that the accretion histories of both galaxies have been different. The spheroid population, composed of the inner spheroid and the halo, shows remarkably uniform stellar population properties. The median metallicity of the halo stellar population shows a shallow gradient from about ,1.15 dex in the inner parts to ,1.27 dex at 24 kpc distance from the centre, corresponding to ,13reff. Similar to the thick-disc stars, large variations around the mean relation are present. [source] Are psychotropics drugs used in pregnancy?,PHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 9 2007Carlos De las Cuevas Abstract Purpose To assess the prevalence and characteristics of psychiatric drug use in pregnancy. Methods A prospective observational study was performed on a total of 1332 consecutive women admitted for delivery, during a 3 months period, in the public obstetric services of Tenerife Island (covering a population of 1,000,000 inhabitants). Results Less than 4% (3.6%) of the women recognised having a psychiatric disorder, and only 2.5% were receiving psychiatric drug treatment at the moment they knew they were pregnant; of those, 68.7% introduced substantial modifications in their treatment at that moment, 47.9% did not report any change with respect to the period before pregnancy and 35.4% recognised that their mood was worse than previously. Although patients affected by a psychiatric disorder registered a higher rate of abdominal delivery, no differences in delivery or obstetric complications were found between women with and without psychiatric illness or in relation to psychiatric drug treatment. Conclusions Compared to the literature, the studied population shows a lower rate of psychiatric problems and pharmacological treatment. This might reflect underrecognition or undertreatment. Copyright © 2007 John Wiley & Sons, Ltd. [source] Usefulness of single spot plasma glucose at a routine clinic: a preliminary reportPRACTICAL DIABETES INTERNATIONAL (INCORPORATING CARDIABETES), Issue 2 2008OR Adetunji MBBS Fellow of the West African College of Physicians (FWACP), Research Registrar, Senior Registrar Abstract While glycated haemoglobin remains the gold standard for assessing glycaemic control, the facilities for measuring it are not readily available in resource-poor health systems like that which exists in Nigeria. This study set out to determine the usefulness of fasting single spot plasma glucose at clinic visits in the management of diabetes. Fifty consecutive patients with type 2 diabetes attending the medical outpatient department at the University College Hospital, Ibadan, Nigeria, were recruited after informed written consent was obtained. HbA1c was measured using boronate affinity technique with a portable , Primus' autoanalyser, NycoCard® Reader II, which was standardised to the DCCT. Fasting plasma glucose (FPG) was measured in mg/dl but converted to mmol/L. Anthropometric measurements were taken from the patients. The results showed that the mean HbA1c in the population was 7.4% and the mean FPG was 7.0mmol/L. There was a significant correlation between FPG and HbA1c, (p<0.0001, r2 = 0.749). We concluded that the significant correlation between the HbA1c and FPG in this patient population shows that the FPG remains a useful tool for assessing control at routine outpatient clinics and its continued use is recommended. Copyright © 2008 John Wiley & Sons. [source] Geographical segregation in Dunlin Calidris alpina populations wintering along the East Atlantic migratory flyway , evidence from mitochondrial DNA analysisDIVERSITY AND DISTRIBUTIONS, Issue 5 2008Ricardo J. Lopes ABSTRACT Dunlin Calidris alpina is one of the most abundant shorebirds using coastal habitats in the East Atlantic migratory flyway, that links arctic breeding locations (Greenland to Siberia) with wintering grounds (West Europe to West Africa). Differential migration and winter segregation between populations have been indicated by morphometrics and ringing recoveries. Here, we analyse the potential of genetic markers (mitochondrial DNA , mtDNA) to validate and enhance such findings. We compared mtDNA haplotypes frequencies at different wintering sites (from north-west Europe to West Africa). All birds from West Africa had western (European) haplotypes, while the eastern (Siberian) haplotypes were only present in European winter samples, reaching higher frequencies further north in Europe. Compilation of published results from migrating birds also confirmed these differences, with the sole presence of European haplotypes in Iberia and West Africa and increasingly higher frequencies of Siberian haplotypes from south-west to north-west Europe. Comparison with published haplotype frequencies of breeding populations shows that birds from Greenland, Iceland, and North Europe were predominant in wintering grounds in West Africa, while populations wintering in West Europe originated from more eastern breeding grounds (e.g. North Russia). These results show that genetic markers can be used to enhance the integrative monitoring of wintering and breeding populations, by providing biogeographical evidence that validate the winter segregation of breeding populations. [source] Regional assessment of the impact of climatic change on the distribution of a tropical conifer in the lowlands of South AmericaDIVERSITY AND DISTRIBUTIONS, Issue 6 2007Marie-Pierre Ledru Abstract For decades, palynologists working in tropical South America are using the genus Podocarpus as a climate indicator although without referring to any modern data concerning its distribution and limiting factors. With the aim to characterize the modern and past distribution of the southern conifer Podocarpus in Brazil and to obtain new information on the distribution of the Atlantic rainforest during the Quaternary, we examined herbarium data to locate the populations of three Brazilian endemic Podocarpus species: P. sellowii, P. lambertii, and P. brasiliensis, and extracted DNA from fresh leaves from 26 populations. Our conclusions are drawn in the light of the combination of these three disciplines: botany, palynology, and genetics. We find that the modern distribution of endemic Podocarpus populations shows that they are widely dispersed in eastern Brazil, from north to south and reveals that the expansion of Podocarpus recorded in single Amazonian pollen records may have come from either western or eastern populations. Genetic analysis enabled us to delimit regional expansion: between 5° and 15° S grouping northern and central populations of P. sellowii expanded c. 16,000 years ago; between 15° and 23° S populations of either P. lambertii or sellowii expanded at different times since at least the last glaciation; and between 23° and 30° S, P. lambertii appeared during the recent expansion of the Araucaria forest. The combination of botany, pollen, and molecular analysis proved to be a rapid tool for inferring distribution borders for sparse populations and their regional evolution within tropical ecosystems. Today the refugia of rainforest communities we identified are crucial hotspots to allow the Atlantic forest to survive under unfavourable climatic conditions and, as such, offer the only possible opportunity for this type of forest to expand in the event of a future climate change. [source] | ||||||||||