The Schwinger Variational Method

Variational methods have proven invaluable in theoretical physics and chemistry, both for bound state problems and for the study of collision phenomena. For collisional problems they can be grouped into two types: those based on the Schroedinger equation and those based on the Lippmann-Schwinger equation. The application of the Schwinger variational (SV) method to e-molecule collisions and photoionization has been reviewed previously. The present chapter discusses the implementation of the SV method as applied to e-molecule collisions

Identifying and Prioritizing Greater Sage-Grouse Nesting and Brood-Rearing Habitat for Conservation in Human-Modified Landscapes

BACKGROUND: Balancing animal conservation and human use of the landscape is an ongoing scientific and practical challenge throughout the world. We investigated reproductive success in female greater sage-grouse (Centrocercus urophasianus) relative to seasonal patterns of resource selection, with the larger goal of developing a spatially-explicit framework for managing human activity and sage-grouse conservation at the landscape level. METHODOLOGY/PRINCIPAL FINDINGS: We integrated field-observation, Global Positioning Systems telemetry, and statistical modeling to quantify the spatial pattern of occurrence and risk during nesting and brood-rearing. We linked occurrence and risk models to provide spatially-explicit indices of habitat-performance relationships. As part of the analysis, we offer novel biological information on resource selection during egg-laying, incubation, and night. The spatial pattern of occurrence during all reproductive phases was driven largely by selection or avoidance of terrain features and vegetation, with little variation explained by anthropogenic features. Specifically, sage-grouse consistently avoided rough terrain, selected for moderate shrub cover at the patch level (within 90 m(2)), and selected for mesic habitat in mid and late brood-rearing phases. In contrast, risk of nest and brood failure was structured by proximity to anthropogenic features including natural gas wells and human-created mesic areas, as well as vegetation features such as shrub cover. CONCLUSIONS/SIGNIFICANCE: Risk in this and perhaps other human-modified landscapes is a top-down (i.e., human-mediated) process that would most effectively be minimized by developing a better understanding of specific mechanisms (e.g., predator subsidization) driving observed patterns, and using habitat-performance indices such as those developed herein for spatially-explicit guidance of conservation intervention. Working under the hypothesis that industrial activity structures risk by enhancing predator abundance or effectiveness, we offer specific recommendations for maintaining high-performance habitat and reducing low-performance habitat, particularly relative to the nesting phase, by managing key high-risk anthropogenic features such as industrial infrastructure and water developments

Pancreatic islet autotransplantation with total pancreatectomy for chronic pancreatitis

Achieving pain relief and improving the quality of life are the main targets of treatment for patients with chronic pancreatitis. The use of total pancreatectomy to treat chronic pancreatitis is a radical and in some ways ideal strategy. However, total pancreatectomy is associated with severe diabetic control problems. Total pancreatectomy with islet autotransplantation can relieve severe pain and prevent the development of postsurgical diabetes. With islet autotransplantation, patients with chronic pancreatitis receive their own islet cells and therefore do not require immunosuppressive therapy. In the future, total pancreatectomy with islet autotransplantation may be considered a treatment option for chronic pancreatitis patients

Measures of Health-related Quality of Life for Adults with Acute Sinusitis: A Systematic Review

CONTEXT: Symptoms suggestive of acute sinusitis are a common reason for patients to visit primary care providers. Since objective measures of outcome have not been shown to be related to patient reported outcomes, measures of treatment success have focused on symptom relief and improved health-related quality of life (HRQL). Assessing the appropriate role of treatment — for example, antibiotics for patients with acute sinusitis — requires valid, reliable, and responsive measures of outcome. We identified symptom scores and HRQL instruments for adults with sinusitis and assessed their performance characteristics. DATA SOURCES: Articles identified through computer searches of the medline, premedline, and embase databases, the Cochrane Library, and internet documents; inquiries to experts in sinusitis and outcomes assessment; and review of reference lists. STUDY SELECTION: Studies that used HRQL instruments or evaluated the performance characteristics of symptom scores in adults with sinusitis, published in English after 1966. DATA EXTRACTION: Two reviewers independently extracted data on study design, setting, and patient characteristics; instrument length and format; and instrument validity, reliability, responsiveness to change, and interpretability. Study quality was assessed using a 10-point score. DATA SYNTHESIS: Of 1,340 articles in the original search, 29 articles using 16 HRQL instruments and 5 symptoms scores met inclusion and exclusion criteria. The overall quality of these studies was low; only 4 studies scored higher than 4 of 10 points. Four studies included patients with acute sinusitis, but only 2 included exclusively acute sinusitis patients. Three instruments have been shown to meet basic requirements for validity, reliability, and responsiveness: the Chronic Sinusitis Survey, the Rhinosinusitis Outcome Measure-31, and the Sinonasal Outcome Test-16. No instrument has been validated in a primary care setting or for patients with acute sinusitis. CONCLUSIONS: Few validated measures of sinusitis-specific HRQL are available. The 3 instruments shown to be valid, reliable, and responsive have been assessed in patients with chronic sinusitis. No measure has been validated in primary care settings or for patients with acute sinusitis. A lack of valid, responsive outcome measures may limit current treatment recommendations for patients with acute sinusitis