841 resultados para Research and Innovation


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Solar research is primarily conducted in regions with consistent sunlight, severely limiting research opportunities in many areas. Unfortunately, the unreliable weather in Lewisburg, PA, can prove difficult for such testing to be conducted. As such, a solar simulator was developed for educational purposes for the Mechanical Engineering department at Bucknell University. The objective of this work was to first develop a geometric model to evaluate a one sun solar simulator. This was intended to provide a simplified model that could be used without the necessity of expensive software. This model was originally intended to be validated experimentally, but instead was done using a proven ray tracing program, TracePro. Analyses with the geometrical model and TracePro demonstrated the influence the geometrical properties had results, specifically the reflector (aperture) diameter and the rim angle. Subsequently, the two were approaches were consistent with one another for aperture diameters 0.5 m and larger, and for rim angles larger than 45°. The constructed prototype, that is currently untested, was designed from information provided by the geometric model, includes a metal halide lamp with a 9.5 mm arc diameter and parabolic reflector with an aperture diameter of 0.631 meters. The maximum angular divergence from the geometrical model was predicted to be 30 mRadians. The average angular divergence in TraceProof the system was 19.5 mRadians, compared to the sun’s divergence of 9.2 mRadians. Flux mapping in TracePro showed an intensity of 1000 W/m2 over the target plane located 40 meters from the lamp. The error between spectrum of the metal halide lamp and the solar spectrum was 10.9%, which was found by comparing their respective Plank radiation distributions. The project did not satisfy the original goal of matching the angular divergence of sunlight, although the system could still to be used for optical testing. The geometric model indicated performance in this area could be improved by increasing the diameter of the reflector, as well as decreasing the source diameter. Although ray tracing software provides more information to analyze the simulator system, the geometrical model is adequate to provide enough information to design a system.

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The central thesis of this article is that a single life event has the capacity to affect and change not one but several lives. This thesis is related to theory on attachment, roles, and convoys. The concept of life-event webs is introduced to capture the complex relations between individuals within networks such as families. Research challenges presented by the life-event web perspective include defining networks, assessing the impact of events on each member, and treating the web, not the individual, as the unit of analysis. The web perspective implies that intervention programs should be focused not on the individual but on the web.

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The Gerontological Society of America encourages policymakers and program directors in the field of aging to make policy and program decisions based on applied research. To aid in achieving this goal, the Society conducts the Fellowship Program in Applied Gerontology (FPAG), which places postdoctoral academic gerontologists for 3 months in agencies and organizations that plan or deliver services to older people. The program's history and accomplishments are described and up-dated.

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BACKGROUND: Scientific progress in the biology of hematopoietic stem cells (HSCs) provides opportunities for advances in therapy for different diseases. While stem cell sources such as umbilical cord blood (UCB) are unproblematic, other sources such as human embryonic stem cells (hESCs) raise ethical concerns. STUDY DESIGN AND METHODS: In a prospective survey we established the ethical acceptability of collection, research, and therapy with UCB HSCs versus hESCs among health care professionals, pregnant women, patients undergoing in vitro fertilization therapy, parents, and HSC donors and recipients in Switzerland. RESULTS: There was overall agreement about an ethical justification for the collection of UCB for research and therapy in the majority of participants (82%). In contrast, research and therapy with hESCs was acceptable only by a minority (38% of all responders). The collection of hESCs solely created for HSC collection purposes met overall with the lowest approval rates. Hematologists displayed among the participants the highest acceptance rates for the use of hESCs with 55% for collection, 63% for research, and 73% for therapy. CONCLUSIONS: This is the first study assessing the perception of hESCs for research and therapy in comparison with UCB HSCs in different target groups that are exposed directly, indirectly, or not at all to stem cell-based medicine. Our study shows that the debate over the legitimacy of embryo-destructive transplantation medicine is far from over as particularly hESC research continues to present an ethical problem to an overwhelming majority among laypersons and even among health care professionals.

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PURPOSE: This study (EORTC 30891) attempted to demonstrate equivalent overall survival in patients with localized prostate cancer not suitable for local curative treatment treated with immediate or deferred androgen ablation. PATIENTS AND METHODS: We randomly assigned 985 patients with newly diagnosed prostate cancer T0-4 N0-2 M0 to receive androgen deprivation either immediately (n = 493) or on symptomatic disease progression or occurrence of serious complications (n = 492). RESULTS: Baseline characteristics were well balanced in the two groups. Median age was 73 years (range, 52 to 81). At a median follow-up of 7.8 years, 541 of 985 patients had died, mostly of prostate cancer (n = 193) or cardiovascular disease (n = 185). The overall survival hazard ratio was 1.25 (95% CI, 1.05 to 1.48; noninferiority P > .1) favoring immediate treatment, seemingly due to fewer deaths of nonprostatic cancer causes (P = .06). The time from randomization to progression of hormone refractory disease did not differ significantly, nor did prostate-cancer specific survival. The median time to the start of deferred treatment after study entry was 7 years. In this group 126 patients (25.6%) died without ever needing treatment (44% of the deaths in this arm). CONCLUSION: Immediate androgen deprivation resulted in a modest but statistically significant increase in overall survival but no significant difference in prostate cancer mortality or symptom-free survival. This must be weighed on an individual basis against the adverse effects of life-long androgen deprivation, which may be avoided in a substantial number of patients with a deferred treatment policy.

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This phase III trial compared the efficacy and safety of gemcitabine (Gem) plus capecitabine (GemCap) versus single-agent Gem in advanced/metastatic pancreatic cancer.