23 resultados para 31-290
em QUB Research Portal - Research Directory and Institutional Repository for Queen's University Belfast
Resumo:
Absolute and differential chemical abundances are presented for the largest group of massive stars in M31 studied to date. These results were derived from intermediate resolution spectra of seven B-type supergiants, lying within four OB associations covering a galactocentric distance of 5-12 kpc. The results are mainly based on an LTE analysis, and we additionally present a full non-LTE, unified model atmosphere analysis of one star (OB 78-277) to demonstrate the reliability of the differential LTE technique. A comparison of the stellar oxygen abundance with that of previous nebular results shows that there is an off set of between similar to0.15-0.4 dex between the two methods which is critically dependent on the empirical calibration adopted for the R 23 parameter with [O/H]. However within the typical errors of the stellar and nebular analyses (and given the strength of dependence of the nebular results on the calibration used) the oxygen abundances determined in each method are fairly consistent. We determine the radial oxygen abundance gradient from these stars, and do not detect any systematic gradient across this galactocentric range. We find that the inner regions of M31 are not, as previously thought, very "metal rich". Our abundances of C, N, O, Mg, Si, Al, S and Fe in the M31 supergiants are very similar to those of massive stars in the solar neighbourhood.
Resumo:
Objective To determine medical students’ self awareness and ability to discriminate right from left; to identify characteristics associated with this ability; and to identify any techniques used to aid discrimination. Design Questionnaire and psychometric study. Setting Undergraduate medical school, Northern Ireland. Participants 290 first year undergraduate students. Main outcome measure Medical students’ ability to discriminate right from left using the Bergen right-left discrimination test. Results Test scores ranged from 31 to 143 on a scale of 0- 144 (mean 112 (standard deviation 22.2)). Male students significantly outperformed female students (117.18 (26.96) v 110.80 (28.94)). Students who wanted to be surgeons performed significantly better than those who wanted to be general practitioners or medical doctors (119.87 (25.15) v 110.55 (27.36) v 112.50 (26.88)). The interaction effect for sex and career wishes was not significant (P=0.370). Students who used learnt techniques to help them discriminate scored significantly less than those who did not (P
Resumo:
Background: The incidence rates of childhood onset type 1 diabetes are almost universally increasing across the globe but the aetiology of the disease remains largely unknown. We investigated whether birth order is associated with the risk of childhood diabetes by performing a pooled analysis of previous studies. Methods: Relevant studies published before January 2010 were identified from MEDLINE, Web of Science and EMBASE. Authors of studies provided individual patient data or conducted pre-specified analyses. Meta-analysis techniques were used to derive combined odds ratios (ORs), before and after adjustment for confounders, and investigate heterogeneity. Results: Data were available for 6 cohort and 25 case-control studies, including 11 955 cases of type 1 diabetes. Overall, there was no evidence of an association prior to adjustment for confounders. After adjustment for maternal age at birth and other confounders, a reduction in the risk of diabetes in second-or later born children became apparent [fully adjusted OR=0.90 95% confidence interval (CI) 0.83-0.98; P=0.02] but this association varied markedly between studies (I 2=67%). An a priori subgroup analysis showed that the association was stronger and more consistent in children <5years of age (n=25 studies, maternal age adjusted OR=0.84 95% CI 0.75, 0.93; I 2=23%). Conclusion: Although the association varied between studies, there was some evidence of a lower risk of childhood onset type 1 diabetes with increasing birth order, particularly in children aged <5 years. This finding could reflect increased exposure to infections in early life in later born children. Published by Oxford University Press on behalf of the International Epidemiological Association © The Author 2010; all rights reserved.
Resumo:
We examined the relationship between Individualism/Collectivism and generalized social trust across 31 European nations participating in the European Social Survey. Using multi-level regression analyses, the current study provides the first empirical investigation of the effects of cultural norms of Individualism/Collectivism on generalized social trust while accounting for individuals' own cultural orientations within the same analysis. The results provide clear support for Yamagishi and Yamagishi (1994) emancipation theory of trust, showing a significant and positive relationship between Individualism/Collectivism and generalized social trust, over and above the effect of a country political history of communism and ethnic heterogeneity. Having controlled for individual effects of Individualism/Collectivism it is clear that the results of the current analysis cannot be reduced to an individual-level explanation, but must be interpreted within the context Of macrosocial processes. We conclude by discussing potential mechanisms that could explain why national individualism is more likely to foster trust among people than collectivism.
Resumo:
This article documents the addition of 512 microsatellite marker loci and nine pairs of Single Nucleotide Polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Alcippe morrisonia morrisonia, Bashania fangiana, Bashania fargesii, Chaetodon vagabundus, Colletes floralis, Coluber constrictor flaviventris, Coptotermes gestroi, Crotophaga major, Cyprinella lutrensis, Danaus plexippus, Fagus grandifolia, Falco tinnunculus, Fletcherimyia fletcheri, Hydrilla verticillata, Laterallus jamaicensis coturniculus, Leavenworthia alabamica, Marmosops incanus, Miichthys miiuy, Nasua nasua, Noturus exilis, Odontesthes bonariensis, Quadrula fragosa, Pinctada maxima, Pseudaletia separata, Pseudoperonospora cubensis, Podocarpus elatus, Portunus trituberculatus, Rhagoletis cerasi, Rhinella schneideri, Sarracenia alata, Skeletonema marinoi, Sminthurus viridis, Syngnathus abaster, Uroteuthis (Photololigo) chinensis, Verticillium dahliae, Wasmannia auropunctata, and Zygochlamys patagonica. These loci were cross-tested on the following species: Chaetodon baronessa, Falco columbarius, Falco eleonorae, Falco naumanni, Falco peregrinus, Falco subbuteo, Didelphis aurita, Gracilinanus microtarsus, Marmosops paulensis, Monodelphis Americana, Odontesthes hatcheri, Podocarpus grayi, Podocarpus lawrencei, Podocarpus smithii, Portunus pelagicus, Syngnathus acus, Syngnathus typhle,Uroteuthis (Photololigo) edulis, Uroteuthis (Photololigo) duvauceli and Verticillium albo-atrum. This article also documents the addition of nine sequencing primer pairs and sixteen allele specific primers or probes for Oncorhynchus mykiss and Oncorhynchus tshawytscha; these primers and assays were cross-tested in both species.
Resumo:
We have carried out a survey of the Andromeda galaxy for unresolved microlensing (pixel lensing). We present a subset of four short timescale, high signal-to-noise microlensing candidates found by imposing severe selection criteria: the source flux variation exceeds the flux of an R = 21 magnitude star and the full width at half maximum timescale is less than 25 days. Remarkably, in three out of four cases, we have been able to measure or strongly constrain the Einstein crossing time of the event. One event, which lies projected on the M 31 bulge, is almost certainly due to a stellar lens in the bulge of M 31. The other three candidates can be explained either by stars in M 31 and M 32 or by MACHOs.
Resumo:
Abstract Background IL-31 is a novel cytokine that has been implicated in allergic diseases such as atopic dermatitis and more recently asthma. While IL-31 has been well studied in skin conditions such as atopic dermatitis, little is known about the role IL-31 plays in asthma and specifically the differentiation process of the bronchial epithelium, which is central to the pathogenesis of allergic asthma. Methods We examined the effects of IL-13 (20 ng/ml), IL-31 (20 ng/ml) and an IL-13/IL-31 combination stimulation (20 ng/ml each) on the in vitro mucociliary differentiation of paediatric bronchial epithelial cells (PBECs) from healthy patients (n=6). IL-31 receptor (IL-31-RA) expression, markers of differentiation (goblet and ciliated cells), transepithelial electrical resistance (TEER), quantification of goblet and ciliated cells, real time PCR for MUC5AC, ELISA for VEGF, EGF and MCP-1 (CCL-2) and ELISA for MUC5AC were assessed. Results We found that well-differentiated PBECs expressed IL-31-RA however it's expression did not increase upon stimulation with IL-31 or either of the other treatments. TEER indicated good formation of tight junctions which was found to be similar across all treatment groups (p=0.9). We found that IL-13 alone significantly reduced the number of ciliated cells compared with unstimulated (IL-13 stimuation: mean=4.8% (SD=2.5); unstimulated: mean=15.9%, (SD=7.4), p
Resumo:
Objective
This study aimed to evaluate the extent to which patient-related factors and physicians' country of practice (Northern Ireland [NI] and the Republic of Ireland [RoI]) influenced decision making regarding medication use in patients with end-stage dementia.
Methods
The study utilised a factorial survey design comprising four vignettes to evaluate initiating/withholding or continuing/discontinuing specific medications in patients with dementia nearing death. Questionnaires and vignettes were mailed to all hospital physicians in geriatric medicine and to all general practitioners (GPs) in NI (November 2010) and RoI (December 2010), with a second copy provided 3 weeks after the first mailing. Logistic regression models were constructed to examine the impact of patient-related factors and physicians' country of practice on decision making. Significance was set a priori at p ≤ 0.05. Free text responses to open questions were analysed qualitatively using content analysis.
Results
The response rate was 20.6% (N = 662) [21.1% (N = 245) for GPs and 52.1% (N = 38) for hospital physicians in NI, 18.3% (N = 348) for GPs and 36.0% (N = 31) for hospital physicians in RoI]. There was considerable variability in decision making about initiating/withholding antibiotics and continuing/discontinuing the acetylcholinesterase inhibitor and memantine hydrochloride, and less variability in decision making regarding statins and antipsychotics. Patient place of residence and physician's country of practice had the strongest and most consistent effects on decision making although effect sizes were small.
Conclusions
Further research is required into other factors that may impact upon physicians' prescribing decisions for these vulnerable patients and to clarify how the factors examined in this study influence prescribing decisions.