Toward Large-Area Sub-Arcsecond X-Ray Telescopes II

In order to advance significantly scientific objectives, future x-ray astronomy missions will likely call for x-ray telescopes with large aperture areas (approx. = 3 sq m) and fine angular resolution (approx. = 1"). Achieving such performance is programmatically and technologically challenging due to the mass and envelope constraints of space-borne telescopes and to the need for densely nested grazing-incidence optics. Such an x-ray telescope will require precision fabrication, alignment, mounting, and assembly of large areas (approx. = 600 sq m) of lightweight (approx. = 2 kg/sq m areal density) high-quality mirrors, at an acceptable cost (approx. = 1 M$/sq m of mirror surface area). This paper reviews relevant programmatic and technological issues, as well as possible approaches for addressing these issues-including direct fabrication of monocrystalline silicon mirrors, active (in-space adjustable) figure correction of replicated mirrors, static post-fabrication correction using ion implantation, differential erosion or deposition, and coating-stress manipulation of thin substrates

The devil is in the details: trends in avoidable hospitalization rates by geography in British Columbia, 1990–2000

BACKGROUND: Researchers and policy makers have focussed on the development of indicators to help monitor the success of regionalization, primary care reform and other health sector restructuring initiatives. Certain indicators are useful in examining issues of equity in service provision, especially among older populations, regardless of where they live. AHRs are used as an indicator of primary care system efficiency and thus reveal information about access to general practitioners. The purpose of this paper is to examine trends in avoidable hospitalization rates (AHRs) during a period of time characterized by several waves of health sector restructuring and regionalization in British Columbia. AHRs are examined in relation to non-avoidable and total hospitalization rates as well as by urban and rural geography across the province. METHODS: Analyses draw on linked administrative health data from the province of British Columbia for 1990 through 2000 for the population aged 50 and over. Joinpoint regression analyses and t-tests are used to detect and describe trends in the data. RESULTS: Generally speaking, non-avoidable hospitalizations constitute the vast majority of hospitalizations in a given year (i.e. around 95%) with AHRs constituting the remaining 5% of hospitalizations. Comparing rural areas and urban areas reveals that standardized rates of avoidable, non-avoidable and total hospitalizations are consistently higher in rural areas. Joinpoint regression results show significantly decreasing trends overall; lines are parallel in the case of avoidable hospitalizations, and lines are diverging for non-avoidable and total hospitalizations, with the gap between rural and urban areas being wider at the end of the time interval than at the beginning. CONCLUSION: These data suggest that access to effective primary care in rural communities remains problematic in BC given that rural areas did not make any gains in AHRs relative to urban areas under recent health sector restructuring initiatives. It remains important to continue to monitor the discrepancy between them as a reflection of inequity in service provision. In addition, it is important to consider alternative explanations for the observed trends paying particular attention to the needs of rural and urban populations and the factors influencing local service provision

Contribution of Age and Gender to Outcome of Blunt Splenic Injury in Adults: Multicenter Study of the Eastern Association for the Surgery of Trauma

Background : The purpose of this study was to examine the contribution of age and gender to outcome after treatment of blunt splenic injury in adults. Methods : Through the Multi-Institutional Trials Committee of the Eastern Association for the Surgery of Trauma (EAST), 1488 adult patients from 27 trauma centers who suffered blunt splenic injury in 1997 were examined retrospectively. Results : Fifteen percent of patients were 55 years of age or older. A similar proportion of patients \u3e= 55 went directly to the operating room compared with patients \u3c 55 (41% vs. 38%) but the mortality for patients \u3e= 55 was significantly greater than patients \u3c 55 (43% vs. 23%). Patients \u3e= 55 failed nonoperative management (NOM) more frequently than patients \u3c 55 (19% vs. 10%) and had increased mortality for both successful NOM (8% vs. 4%, p \u3c 0.05) and failed NOM (29% vs. 12%, p = 0.054). There were no differences in immediate operative treatment, successful NOM, and failed NOM between men and women. However, women \u3e= 55 failed NOM more frequently than women \u3c 55 (20% vs. 7%) and this was associated with increased mortality (36% vs. 5%) (both p \u3c 0.05). Conclusion : Patients \u3e= 55 had a greater mortality for all forms of treatment of their blunt splenic injury and failed NOM more frequently than patients \u3c 55. Women \u3e= 55 had significantly greater mortality and failure of NOM than women \u3c 55

Contribution of Age and Gender to Outcome of Blunt Splenic Injury in Adults: Multicenter Study of the Eastern Association for the Surgery of Trauma

Background : The purpose of this study was to examine the contribution of age and gender to outcome after treatment of blunt splenic injury in adults. Methods : Through the Multi-Institutional Trials Committee of the Eastern Association for the Surgery of Trauma (EAST), 1488 adult patients from 27 trauma centers who suffered blunt splenic injury in 1997 were examined retrospectively. Results : Fifteen percent of patients were 55 years of age or older. A similar proportion of patients \u3e= 55 went directly to the operating room compared with patients \u3c 55 (41% vs. 38%) but the mortality for patients \u3e= 55 was significantly greater than patients \u3c 55 (43% vs. 23%). Patients \u3e= 55 failed nonoperative management (NOM) more frequently than patients \u3c 55 (19% vs. 10%) and had increased mortality for both successful NOM (8% vs. 4%, p \u3c 0.05) and failed NOM (29% vs. 12%, p = 0.054). There were no differences in immediate operative treatment, successful NOM, and failed NOM between men and women. However, women \u3e= 55 failed NOM more frequently than women \u3c 55 (20% vs. 7%) and this was associated with increased mortality (36% vs. 5%) (both p \u3c 0.05). Conclusion : Patients \u3e= 55 had a greater mortality for all forms of treatment of their blunt splenic injury and failed NOM more frequently than patients \u3c 55. Women \u3e= 55 had significantly greater mortality and failure of NOM than women \u3c 55

Contribution of age and gender to outcome of blunt splenic injury in adults: multicenter study of the eastern association for the surgery of trauma.

BACKGROUND: The purpose of this study was to examine the contribution of age and gender to outcome after treatment of blunt splenic injury in adults. METHODS: Through the Multi-Institutional Trials Committee of the Eastern Association for the Surgery of Trauma (EAST), 1488 adult patients from 27 trauma centers who suffered blunt splenic injury in 1997 were examined retrospectively. RESULTS: Fifteen percent of patients were 55 years of age or older. A similar proportion of patients \u3e or = 55 went directly to the operating room compared with patients \u3c 55 (41% vs. 38%) but the mortality for patients \u3e or = 55 was significantly greater than patients \u3c 55 (43% vs. 23%). Patients \u3e or = 55 failed nonoperative management (NOM) more frequently than patients \u3c 55 (19% vs. 10%) and had increased mortality for both successful NOM (8% vs. 4%, p \u3c 0.05) and failed NOM (29% vs. 12%, p = 0.054). There were no differences in immediate operative treatment, successful NOM, and failed NOM between men and women. However, women \u3e or = 55 failed NOM more frequently than women \u3c 55 (20% vs. 7%) and this was associated with increased mortality (36% vs. 5%) (both p \u3c 0.05). CONCLUSION: Patients \u3e or = 55 had a greater mortality for all forms of treatment of their blunt splenic injury and failed NOM more frequently than patients \u3c 55. Women \u3e or = 55 had significantly greater mortality and failure of NOM than women \u3c 55