188 research outputs found

    The Evolutionary Status of Clusters of Galaxies at z ~ 1

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    Combined HST, X-ray, and ground-based optical studies show that clusters of galaxies are largely "in place" by z∼1z \sim 1, an epoch when the Universe was less than half its present age. High resolution images show that elliptical, S0, and spiral galaxies are present in clusters at redshifts up to z∼1.3z \sim 1.3. Analysis of the CMDs suggest that the cluster ellipticals formed their stars several Gyr earlier, near redshift 3. The morphology--density relation is well established at z∼1z\sim1, with star-forming spirals and irregulars residing mostly in the outer parts of the clusters and E/S0s concentrated in dense clumps. The intracluster medium has already reached the metallicity of present-day clusters. The distributions of the hot gas and early-type galaxies are similar in z∼1z\sim1 clusters, indicating both have largely virialized in the deepest potentials wells. In spite of the many similarities between z∼1z\sim1 and present-day clusters, there are significant differences. The morphologies revealed by the hot gas, and particularly the early-type galaxies, are elongated rather than spherical. We appear to be observing the clusters at an epoch when the sub-clusters and groups are still assembling into a single regular cluster. Support for this picture comes from CL0152 where the gas appears to be lagging behind the luminous and dark mass in two merging sub-components. Moreover, the luminosity difference between the first and second brightest cluster galaxies at z∼1z\sim1 is smaller than in 93% of present-day Abell clusters, which suggests that considerable luminosity evolution through merging has occurred since that epoch. Evolution is also seen in the bolometric X-ray luminosity function.Comment: 18 pages, 12 figures, to appear in Penetrating Bars through Masks of Cosmic Dust: the Hubble Tuing Fork Strikes a New Note, eds. D.L. Block, K.C. Freeman, I. Puerari & R. Groess. Figures degraded to meet astroph size limit; a version with higher resolution figures may be downloaded from: http://acs.pha.jhu.edu/~jpb/z1clusters/ford_clusters.pd

    Pharmacoeconomic analysis of adjuvant oral capecitabine vs intravenous 5-FU/LV in Dukes' C colon cancer: the X-ACT trial

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    Oral capecitabine (Xeloda<sup>®</sup>) is an effective drug with favourable safety in adjuvant and metastatic colorectal cancer. Oxaliplatin-based therapy is becoming standard for Dukes' C colon cancer in patients suitable for combination therapy, but is not yet approved by the UK National Institute for Health and Clinical Excellence (NICE) in the adjuvant setting. Adjuvant capecitabine is at least as effective as 5-fluorouracil/leucovorin (5-FU/LV), with significant superiority in relapse-free survival and a trend towards improved disease-free and overall survival. We assessed the cost-effectiveness of adjuvant capecitabine from payer (UK National Health Service (NHS)) and societal perspectives. We used clinical trial data and published sources to estimate incremental direct and societal costs and gains in quality-adjusted life months (QALMs). Acquisition costs were higher for capecitabine than 5-FU/LV, but higher 5-FU/LV administration costs resulted in 57% lower chemotherapy costs for capecitabine. Capecitabine vs 5-FU/LV-associated adverse events required fewer medications and hospitalisations (cost savings £3653). Societal costs, including patient travel/time costs, were reduced by >75% with capecitabine vs 5-FU/LV (cost savings £1318), with lifetime gain in QALMs of 9 months. Medical resource utilisation is significantly decreased with capecitabine vs 5-FU/LV, with cost savings to the NHS and society. Capecitabine is also projected to increase life expectancy vs 5-FU/LV. Cost savings and better outcomes make capecitabine a preferred adjuvant therapy for Dukes' C colon cancer. This pharmacoeconomic analysis strongly supports replacing 5-FU/LV with capecitabine in the adjuvant treatment of colon cancer in the UK

    Body composition in male elite athletes, comparison of bioelectrical impedance spectroscopy with dual energy X-ray absorptiometry

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    <p>Abstract</p> <p>Background</p> <p>The aim of this study was to compare body composition results from bioelectrical spectroscopy (BIS) with results from dual energy X-ray absorptiometry (DXA) in a population of male elite athletes. Body composition was assessed using DXA (Lunar Prodigy, GE Lunar Corp., Madison, USA) and BIS (Hydra 4200, Xitron Technologies Inc, San Diego, California, USA) at the same occasion. Agreement between methods was assessed using paired t-tests and agreement-plots.</p> <p>Results</p> <p>Thirty-three male elite athletes (soccer and ice hockey) were included in the study. The results showed that BIS underestimates the proportion of fat mass by 4.6% points in the ice hockey players. In soccer players the BIS resulted in a lower mean fat mass by 1.1% points. Agreement between the methods at the individual level was highly variable.</p> <p>Conclusion</p> <p>Body composition results assessed by BIS in elite athletes should be interpreted with caution, especially in individual subjects. BIS may present values of fat mass that is either higher or lower than fat mass assessed by DXA, independent of true fat content of the individual.</p

    Psychometric Evaluation of the HIV Stigma Scale in a Swedish Context

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    Background HIV-related stigma has negative consequences for infected people's lives and is a barrier to HIV prevention. Therefore valid and reliable instruments to measure stigma are needed to enable mapping of HIV stigma. This study aimed to evaluate the psychometric properties of the HIV stigma scale in a Swedish context with regard to construct validity, data quality, and reliability. Methods The HIV stigma scale, developed by Berger, Ferrans, and Lashley (2001), was distributed to a cross-sectional sample of people living with HIV in Sweden (n = 194). The psychometric evaluation included exploratory factor analysis together with an analysis of the distribution of scores, convergent validity by correlations between the HIV stigma scale and measures of emotional well-being, and an analysis of missing items and floor and ceiling effects. Reliability was assessed using Cronbach's α. Results The exploratory factor analysis suggested a four-factor solution, similar to the original scale, with the dimensions personalised stigma, disclosure concerns, negative self-image, and concerns with public attitudes. One item had unacceptably low loadings and was excluded. Correlations between stigma dimensions and emotional well-being were all in the expected direction and ranged between −0.494 and −0.210. The instrument generated data of acceptable quality except for participants who had not disclosed their HIV status to anybody. In line with the original scale, all subscales demonstrated acceptable internal consistency with Cronbach's α 0.87–0.96. Conclusion A 39-item version of the HIV stigma scale used in a Swedish context showed satisfactory construct validity and reliability. Response alternatives are suggested to be slightly revised for items assuming the disclosure of diagnosis to another person. We recommend that people that have not disclosed should skip all questions belonging to the dimension personalised stigma. Our analysis confirmed construct validity of the instrument even without this dimension

    A phase I study of pemetrexed (LY231514) supplemented with folate and vitamin B12 in Japanese patients with solid tumours

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    The purpose of this study was to determine the maximum tolerated dose (MTD) and recommended dose (RD) of pemetrexed with folate and vitamin B12 supplementation (FA/VB12) in Japanese patients with solid tumours and to investigate the safety, efficacy, and pharmacokinetics of pemetrexed. Eligible patients had incurable solid tumours by standard treatments, a performance status 0–2, and adequate organ function. Pemetrexed from 300 to 1200 mg m−2 was administered as a 10-min infusion on day 1 of a 21-day cycle with FA/VB12. Totally, 31 patients were treated. Dose-limiting toxicities were alanine aminotransferase (ALT) elevation at 700 mg m−2, and infection and skin rash at 1200 mg m−2. The MTD/RD were determined to be 1200/1000 mg m−2, respectively. The most common grade 3/4 toxicities were neutropenia (grade (G) 3:29, G4:3%), leucopenia (G3:13, G4:3%), lympopenia (G3:13%) and ALT elevation (G3:13%). Pemetrexed pharmacokinetics in Japanese were not overtly different from those in western patients. Partial response was achieved for 5/23 evaluable patients (four with non-small cell lung cancer (NSCLC) and one with thymoma). The MTD/RD of pemetrexed were determined to be 1200/1000 mg m−2, respectively, that is, a higher RD than without FA/VB12 (500 mg m−2). Pemetrexed with FA/VB12 showed a tolerable toxicity profile and potent antitumour activity against NSCLC in this study

    Interventions to prevent youth violence in Latin America: a systematic review

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    Objectives: This review aims to summarise evidence on the effectiveness of interventions to prevent youth violence in Latin America. Methods: A systematic search on 13 academic databases was conducted to locate studies evaluating a primary or secondary prevention intervention in Latin America. Studies could use any type of quantitative design to assess outcomes related to youth violence. A search of websites, references and citation searching was also carried out. The quality of each study was assessed. Results: Nine studies were identified. Most documented positive effects of the interventions on the perception of youth violence present in the community/school. Evidence was found of a reduction in homicides and juvenile crimes in three studies, two of which evaluated a community-based intervention. There were mixed results for the self-report of participation on violent acts. The majority of the studies lacked of a rigorous design. Conclusions: Most of the interventions had some promising results, including the reduction of homicides within communities. Community-based programmes were the most consistent regarding an effectiveness to prevent violence. However, the evidence for Latin America is still scarce and relies on non-rigorously designed studies

    Cross-Sectional Study into the Costs and Impact on Family Functioning of 4-Year-Old Children with Aggressive Behavior

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    Early-onset aggressive behavior is known for its negative developmental consequences, and the associated high costs for families, the health care system and wider society. Although the origins of aggressive behavior are to be found in early childhood, the costs incurred by aggressive behavior of young children have not been studied extensively. The present study aimed to investigate whether preschool children with a high level of aggressive behavior already differ in the generated amount of costs and impact on family functioning from children with lower levels of aggressive behavior. A population-based sample of 317 preschool children was divided into four groups with different levels of aggression (moderate, borderline, clinical). Parents filled out questionnaires to assess service use (lifetime and past 3 months) and impact on family functioning. Over the past 3 months as well as over the first 4 years of life, children with a clinical level of aggression were more costly than children with a low level of aggression (mean total costs over the past 3 months: low = €167,05 versus clinical € = 1034,83 and mean lifetime costs: low € = 817,37 versus clinical € = 1433,04), due to higher costs of services used by the child. In addition, families of children with a borderline or clinical level of aggressive behavior reported more impairment in their daily functioning than families of children with lower levels of aggression. The findings demonstrate that a high level of aggressive behavior results in high costs and impaired family functioning in the preschool years already

    Ultrasound evaluation in combination with finger extension force measurements of the forearm musculus extensor digitorum communis in healthy subjects

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    <p>Abstract</p> <p>Background</p> <p>The aim of this study was to evaluate the usefulness of an ultrasound-based method of examining extensor muscle architecture, especially the parameters important for force development. This paper presents the combination of two non-invasive methods for studying the extensor muscle architecture using ultrasound simultaneously with finger extension force measurements.</p> <p>Methods</p> <p>M. extensor digitorum communis (EDC) was examined in 40 healthy subjects, 20 women and 20 men, aged 35–73 years. Ultrasound measurements were made in a relaxed position of the hand as well as in full contraction. Muscle cross-sectional area (CSA), pennation angle and contraction patterns were measured with ultrasound, and muscle volume and fascicle length were also estimated. Finger extension force was measured using a newly developed finger force measurement device.</p> <p>Results</p> <p>The following muscle parameters were determined: CSA, circumference, thickness, pennation angles and changes in shape of the muscle CSA. The mean EDC volume in men was 28.3 cm<sup>3 </sup>and in women 16.6 cm<sup>3</sup>. The mean CSA was 2.54 cm<sup>2 </sup>for men and 1.84 cm<sup>2 </sup>for women. The mean pennation angle for men was 6.5° and for women 5.5°. The mean muscle thickness for men was 1.2 cm and for women 0.76 cm. The mean fascicle length for men was 7.3 cm and for women 5.0 cm. Significant differences were found between men and women regarding EDC volume (p < 0.001), CSA (p < 0.001), pennation angle (p < 0.05), muscle thickness (p < 0.001), fascicle length (p < 0.001) and finger force (p < 0.001). Changes in the shape of muscle architecture during contraction were more pronounced in men than women (p < 0.01). The mean finger extension force for men was 96.7 N and for women 39.6 N. Muscle parameters related to the extension force differed between men and women. For men the muscle volume and muscle CSA were related to extension force, while for women muscle thickness was related to the extension force.</p> <p>Conclusion</p> <p>Ultrasound is a useful tool for studying muscle architectures in EDC. Muscle parameters of importance for force development were identified. Knowledge concerning the correlation between muscle dynamics and force is of importance for the development of new hand training programmes and rehabilitation after surgery.</p
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