Illumination from space with orbiting solar-reflector spacecraft

The feasibility of using orbiting mirrors to reflect sunlight to Earth for several illumination applications is studied. A constellation of sixteen 1 km solar reflector spacecraft in geosynchronous orbit can illuminate a region 333 km in diameter to 8 lux, which is brighter than most existing expressway lighting systems. This constellation can serve one region all night long or can provide illumination during mornings and evenings to five regions across the United States. Preliminary cost estimates indicate such an endeavor is economically feasible. The studies also explain how two solar reflectors can illuminate the in-orbit nighttime operations of Space Shuttle. An unfurlable, 1 km diameter solar reflector spacecraft design concept was derived. This spacecraft can be packaged in the Space, Shuttle, transported to low Earth orbit, unfurled, and solar sailed to operational orbits up to geosynchronous. The necessary technical studies and improvements in technology are described, and potential environmental concerns are discussed

Prospective evaluation of chronic pain associated with posterior autologous iliac crest bone graft harvest and its effect on postoperative outcome

<p>Abstract</p> <p>Background</p> <p>Autogenous Iliac Crest Bone Graft (ICBG) has been the "gold standard" for spinal fusion. However, bone graft harvest may lead to complications, such as chronic pain, numbness, and poor cosmesis. The long-term impact of these complications on patient function and well-being has not been established but is critical in determining the value of expensive bone graft substitutes such as recombinant bone morphogenic protein. We thus aimed to investigate the long-term complications of ICBG. Our second aim was to evaluate the psychometric properties of a new measure of ICBG morbidity that would be useful for appropriately gauging spinal surgery outcomes.</p> <p>Methods</p> <p>Prospective study of patients undergoing spinal fusion surgery with autologous ICBG. The SF-36v2, Oswestry Disability Index, and a new 14-item follow-up questionnaire addressing persistent pain, functional limitation, and cosmesis were administered with an 83% response rate. Multiple regression analyses examined the independent effect of ICBG complications on physical and mental health and disability.</p> <p>Results</p> <p>The study population included 170 patients with a mean age of 51.1 years (SD = 12.2) and balanced gender (48% male). Lumbar fusion patients predominated (lumbar = 148; cervical n = 22). At 3.5 years mean follow-up, 5% of patients reported being bothered by harvest site scar appearance, 24% reported harvest site numbness, and 13% reported the numbness as bothersome. Harvest site pain resulted in difficulty with household chores (19%), recreational activity (18%), walking (16%), sexual activity (16%), work activity (10%), and irritation from clothing (9%). Multivariate regression analyses revealed that persistent ICBG complications 3.5 years post-surgery were associated with significantly worse disability and showed a trend association with worse physical health, after adjusting for age, workers' compensation status, surgical site pain, and arm or leg pain. There was no association between ICBG complications and mental health in the multivariate model.</p> <p>Conclusion</p> <p>Chronic ICBG harvest site pain and discomfort is reported by a significant percentage of patients undergoing this procedure more than three years following surgery, and these complications are associated with worse patient-reported disability. Future studies should consider employing a control group that does not include autologous bone graft harvest, e.g., a group utilizing rhBMP, to determine whether eliminating harvest-site morbidity does indeed lead to observable improvement in clinical outcome sufficient to justify the increased cost of bone graft substitutes.</p

Policing Schools: Examining the Impact of Place Management Activities on School Violence

The present study examines whether the presence of school resource officers (SROs) and their level of involvement in place management activities are associated with higher or lower rates of school-based serious violence. This study uses data from the 2010 School Survey on Crime and Safety (SSOCS) conducted by National Center for Educational Statistics. Propensity score matching is used to create a quasi-experimental design and isolate the influence of SROs and their level of involvement in place management activities on school-based serious violence. The analysis reveals that schools with a school resource officer are associated with higher rates of reported serious violence and those schools with SROs that participate in more place manager duties are also associated with higher rates of reported serious violence. These findings do not support the notion that SROs are acting as effective place managers and through this place management, reducing reported serious violence. Rather, it appears that the presences of a SRO and their execution of place manager duties is associated with an increase in the reporting of serious violence. Policy implications and limitations of the current research are also discussed

Hyperkalemia in the Elderly: Drugs Exacerbate Impaired Potassium Homeostasis

OBJECTIVE: To review the pathophysiology underlying the predisposition to hyperkalemia in the elderly; the medications that disrupt potassium balance and promote the development of hyperkalemia in the elderly; the prevention of hyperkalemia in elderly patients treated with potassium-altering medications; and the appropriate management of hyperkalemia when it develops. METHODS AND MAIN RESULTS: A MEDLINE search of the literature (1966 –1996) using the terms hyperkalemia, drugs, elderly, and treatment was conducted and pertinent review articles, textbooks, and personal files were consulted. Elderly subjects appear to be predisposed to the development of hyperkalemia on the basis of both innate disturbances in potassium homeostasis and comorbid disease processes that impair potassium handling. Hyperkalemia in the elderly is most often precipitated by medications that impair cellular uptake or renal disposal of potassium. This electrolyte disorder is best prevented by recognition of at-risk physiology in the aged, avoidance of therapy with certain high-risk medications, and monitoring of plasma potassium concentration and renal function at intervals appropriate for the medication prescribed. Management of hyperkalemia entails identification of the clinical manifestations of severe hyperkalemia, stabilization of cardiac tissue, promotion of cellular potassium uptake, and ultimately removal of potassium from the body. CONCLUSIONS: Geriatric patients should be considered at risk of developing hyperkalemia, especially when they are prescribed certain medications. Potassium levels should be monitored at appropriate intervals when these patients are treated with potassium-altering medications. Appropriate management of hyperkalemia in the elderly can avoid life-threatening neuromuscular and cardiac complications

The prevalence and determinants of antepartum mental health problems among women in the USA: a nationally representative population-based study

Mental health problems disproportionately affect women, particularly during childbearing years. We sought to estimate the prevalence of antepartum mental health problems and determine potential risk factors in a representative USA population. We examined data on 3,051 pregnant women from 11 panels of the 1996–2006 Medical Expenditure Panel Survey. Poor antepartum mental health was defined by self report of mental health conditions or symptoms or a mental health rating of “fair” or “poor.” Multivariate regression analyses modeled the odds of poor antepartum mental health; 7.8% of women reported poor antepartum mental health. A history of mental health problems increased the odds of poor antepartum mental health by a factor of 8.45 (95% CI, 6.01–11.88). Multivariate analyses were stratified by history of mental health problems. Significant factors among both groups included never being married and self-reported fair/poor health status. This study identifies key risk factors associated with antepartum mental health problems in a nationally representative sample of pregnant women. Women with low social support, in poor health, or with a history of poor mental health are at an increased risk of having antepartum mental health problems. Understanding these risk factors is critical to improve the long-term health of women and their children