885 resultados para Graham Centre
Resumo:
We are searching for early-type stars towards the Galactic centre which are potentially young objects situated within the inner few kiloparsecs of the disk. Photographic photometry from the UK Schmidt Telescope has been used to identify the bluest candidates in nineteen Schmidt fields (centred close to the Galactic centre). We have previously obtained FLAIR low dispersion spectroscopy for three of these fields to estimate spectral types and here we present spectroscopy for an additional seven fields. Combining the results for all ten fields, 56 stars were initially classified as early-B type. Estimates of the equivalent widths of their Balmer and He I lines have been used to estimate atmospheric parameters and 32 targets have effective temperatures greater than or equal to 17 000 K (corresponding to a spectral type of B3 or earlier). The spectra of seven of these targets also have absorption lines due to O II and Si III and can be reliably classified as early- B type. Additionally 78 stars have estimated effective temperatures between 11 000 and 16 000 K with a further a further 50 objects identified as late-B (or early-A) type. All but two of the early B-type candidates have magnitudes in the range 12.0 less than or equal to V less than or equal to 16.0, and our best estimates of their distance suggest that they could be close to (i.e. R-g <3 kpc), or even beyond the Galactic centre.
Resumo:
High resolution echelle spectroscopy is presented for thirteen stars lying in the direction of the Galactic centre which, on the basis of photographic photometry and low dispersion spectroscopy, have been classified as early-B-type. Eight of these stars have large rotational velocities which preclude a detailed analysis. The five stars with moderate to low projected rotational velocities have been analysed using model atmosphere techniques to determine atmospheric parameters and chemical compositions. Two of these stars appear to be evolved blue horizontal branch objects on the basis of their chemical compositions and small projected rotational velocity. The evolutionary status of a third is ambiguous but it is probably a post-asymptotic-giant branch star. The remaining two objects are probably young massive stars and show enhanced abundances of N, C, Mg and Si, consistent with their formation in the inner part of the Galactic disk. However their O abundances are normal, confirming results found previously for other early- type stars, which would imply a flat abundance gradient for this element in the inner region of our Galaxy.
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Background: SPARCLE is a cross-sectional survey in nine European regions, examining the relationship of the environment of children with cerebral palsy to their participation and quality of life. The objective of this report is to assess data quality, in particular heterogeneity between regions, family and item non-response and potential for bias. Methods: 1,174 children aged 8–12 years were selected from eight population-based registers of children with cerebral palsy; one further centre recruited 75 children from multiple sources. Families were visited by trained researchers who administered psychometric questionnaires. Logistic regression was used to assess factors related to family non-response and self-completion of questionnaires by children. Results: 431/1,174 (37%) families identified from registers did not respond: 146 (12%) were not traced; of the 1,028 traced families, 250 (24%) declined to participate and 35 (3%) were not approached. Families whose disabled children could walk unaided were more likely to decline to participate. 818 children entered the study of which 500 (61%) self-reported their quality of life; children with low IQ, seizures or inability to walk were less likely to self-report. There was substantial heterogeneity between regions in response rates and socio-demographic characteristics of families but not in age or gender of children. Item non-response was 2% for children and ranged from 0.4% to 5% for questionnaires completed by parents. Conclusion: While the proportion of untraced families was higher than in similar surveys, the refusal rate was comparable. To reduce bias, all analyses should allow for region, walking ability, age and socio-demographic characteristics. The 75 children in the region without a population based register are unlikely to introduce bias
Resumo:
Formation of the coronavirus replication-transcription complex involves the synthesis of large polyprotein precursors that are extensively processed by virus-encoded cysteine proteases. In this study, the coding sequence of the feline infectious peritonitis virus (FIPV) main protease, 3CL(pro), was determined. Comparative sequence analyses revealed that FIPV 3CL(pro) and other coronavirus main proteases are related most closely to the 3C-like proteases of potyviruses. The predicted active centre of the coronavirus enzymes has accepted unique replacements that were probed by extensive mutational analysis. The wild-type FIPV 3CL(pro) domain and 25 mutants were expressed in Escherichia coli and tested for proteolytic activity in a peptide-based assay. The data strongly suggest that, first, the FIPV 3CL(pro) catalytic system employs His(41) and Cys(144) as the principal catalytic residues. Second, the amino acids Tyr(160) and His(162), which are part of the conserved sequence signature Tyr(160)-Met(161)-His(162) and are believed to be involved in substrate recognition, were found to be indispensable for proteolytic activity. Third, replacements of Gly(83) and Asn(64), which were candidates to occupy the position spatially equivalent to that of the catalytic Asp residue of chymotrypsin-like proteases, resulted in proteolytically active proteins. Surprisingly, some of the Asn(64) mutants even exhibited strongly increased activities. Similar results were obtained for human coronavirus (HCoV) 3CL(pro) mutants in which the equivalent Asn residue (HCoV 3CL(pro) Asn(64)) was substituted. These data lead us to conclude that both the catalytic systems and substrate-binding pockets of coronavirus main proteases differ from those of other RNA virus 3C and 3C-like proteases.
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Background: Effective bed use is crucial to an efficient NHS. Current targets suggest a decrease in mean occupancy as the most appropriate method of improving overall efficiency. The elderly and those suffering from complex medical problems are thought to account for a high proportion of overall bed occupancy.
Aim: To assess the effect of prolonged hospital stay (>100 days) on overall bed occupancy in a modern teaching hospital.
Design: Retrospective analysis.
Methods: Analysis of all admission episodes (n = 117 178) over a five-year period in a large teaching hospital in a single UK region, serving a population of approximately 200 000. A logistic regression multi-factorial model was used to assess the effect of demographic and diagnostic variables on duration of stay.
Results: A prolonged stay (>100 days) was seen in 648 admission episodes (0.6%). These accounted for 11% of the overall bed occupancy over the 5-year period. Excluding all prolonged admission episodes from our analysis made no difference to the overall median length of stay.
Discussion: Prolonged hospitalizations have a significant impact on bed occupancy. Targeting these very long (>100 days) hospital stays may better improve overall efficiency, compared to targeting mean or median length of stay.
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The UK PRIME cruise, June-July 1996 in the NE Atlantic, consisted of two legs. During the first, detailed chemical and biological observations were made in time-series mode adjacent to the centre of a cold-core eddy in the vicinity of 59 degreesN 20 degreesW using SF6 tracer techniques as the basis for the Lagrangian study. The eddy, which appeared to have been formed the previous winter, remained coherent over the 9 days of the survey and advected only slowly. The phytoplankton community in the eddy was dominated by the coccolithophorid Coccolithus huxleyi. High microzooplankton grazing rates indicated minimal export losses from the surface layer. Significant shifts in many, but not all, of the chemical and biological properties measured were observed over the course of the experiment, especially after the passage of a storm event, which resulted in considerable deepening of the mixed layer followed by a return to fully stratified conditions. The second leg consisted of a transect from 59 degreesN 20 degreesW to 37 degreesN 19 degreesW, with a further Lagrangian time-series study based on a drogue marker initiated at the southern end of the transect. Maximal biological activity was generally encountered in the region between two fronts located at 52.5 degreesN and 48 degreesN, while to the south of 48 degreesN oligotrophic conditions prevailed. At the southern Lagrangian site, a deep chlorophyll maximum was present and high column new production was recorded as a result of the euphotic zone extending below the depth of the nutricline. Microzooplankton grazing rates were lower at this location than at the northern eddy site. The influx of a warm, saline water body into the upper layers during the southern survey led to a major shift in many of the biological and chemical properties being measured. At both the northern and southern Lagrangian sites, the biomass of the mesozooplankton exceeded that of the microzooplankton. (C) 2001 Elsevier Science Ltd. All rights reserved.
Resumo:
Participation in home, school and community is important for all children; and little is known about the frequency of participation of disabled children. Frequency of participation is a valuable outcome measure for evaluating habilitation programmes for disabled children and for planning social and health services.
We investigated how frequency of participation varied between children with cerebral palsy and the general population; and examined variation across countries to understand better how the environmental factors such as legislation, public attitudes and regulation in different countries might influence participation.
We undertook a multi-centre, population-based study in children with and without cerebral palsy. Working from the Life-H instrument, we developed a questionnaire to capture frequency of participation in 8–12-year-old children. In nine regions of seven European countries, parents of 813 children with cerebral palsy and 2939 children from the general populations completed the questionnaire.
Frequency of participation for each question was dichotomised about the median; multivariable logistic regressions were carried out.
In the general population, frequency of participation varied between countries. Children with cerebral palsy participated less frequently in many but not all areas of everyday life, compared with children from the general population. There was regional variation in the domains with reduced participation and in the magnitude of the differences. We discuss how this regional variation might be explained by the different environments in which children live. Attending a special school or class was not associated with further reduction in participation in most areas of everyday life.
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Aim The aim of this report is to describe the health status of 8–12-year-old children with cerebral palsy (CP) of all severities in Europe using the Child Health Questionnaire (CHQ).
Method A total of 818 children with CP from nine centres in defined geographical areas participated. CP type, gross and fine motor function, additional impairments were classified and family data were obtained. The CHQ was used to measure the parent's perception of their child's physical (PHY) and psychosocial (PSY) health.
Results PHY scores were lower than the reference samples with a median of 46. The severity of gross motor function influenced the CHQ scores significantly in the PHY scale with the lowest scores for children with least gross motor function. There were significant differences between the CP types in PHY with the higher scores for children with unilateral spastic and the lowest scores for children with bilateral spastic and dyskinetic CP type. Fine motor function severity significantly affected both the PHY and PSY scales. The severity of intellectual impairment was significantly associated with CHQ scores in most dimensions with higher scores for higher IQ level in PHY and PSY. Children with seizures during the last year had a significantly lower health compared with children without seizures. The results of the multivariate regression analyses (forward stepwise regression) of CHQ scores on CP subtype, gross and fine motor function, cognitive function, additional impairments, seizures, parental education and employment revealed gross motor function, cognitive level and type of school attended were significant prognostic factors.
Conclusion This report is based on the largest sample to date of children with CP. Health status as measured using the CHQ was affected in all children and was highly variable. Gross motor function level correlates with health from the PHY well-being perspective but the PSY and emotional aspects do not appear to follow the same pattern.
Resumo:
This paper is concerned with the production and reproduction of segregation in Northern Ireland and how territoriality has impacted on the Protestant community in Derry/Londonderry. The city was pivotal in the development of the most recent conflict, has a majority Catholic population, sits on a contested border and has attempted to respond to expressions of alienation that have emerged from the Protestant community. The research used multiple methods to understand the nature of alienation and exclusion using secondary data, a quantitative household survey, in-depth interviews and focus
groups. This empirical commitment was important in identifying and unpacking the claims of various stakeholders with an interest in the use and development of the area. It is argued here that a version of Collaborative Planning provides a loosely articulated conceptual and methodological framework for drawing Protestant communities into the wider planning framework for the city. The data, however, suggest that the nature of stakeholders is complex and contradictory, and discursive practice that seeks consensus has limits, especially in validating or legitimating the assertions of self-acclaimed stakeholders. The research shows that the Protestant community had declined and residualised but had little experience of direct conflict with the majority community. Moreover, the Protestant community is now more likely to use the city centre (a predominantly Catholic space) for consumption and work, and its demographic decline has stopped. These findings are important as policy responses and community relations programmes have failed to distinguish between measurable socioeconomic needs and claims concerning ethnic alienation based on emotion and manipulation. Such alienation has tended to bolster single identity communities who have little or no prospect and/or knowledge of the collaborative efforts required to deliver meaningful regeneration. More realistic strategies based on agonism focus attention on power relations and the authenticity of positions adopted by competing interests in land use management and change. The paper concludes by highlighting the need to acknowledge and value contestation but to challenge sectarian discourses represented as legitimate claims about community needs and priorities.