3,964 research outputs found

    Apollo experience report: Development of guidance targeting techniques for the command module and launch vehicle

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    The development of the guidance targeting techniques for the Apollo command module and launch vehicle is discussed for four types of maneuvers: (1) translunar injection, (2) translunar midcourse, (3) lunar orbit insertion, and (4) return to earth. The development of real-time targeting programs for these maneuvers and the targeting procedures represented are discussed. The material is intended to convey historically the development of the targeting techniques required to meet the defined target objectives and to illustrate the solutions to problems encountered during that development

    Mirrorless all‐optical bistability in bacteriorhodopsin

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    We report direct observations of all‐optical mirrorless bistability associated with saturable absorption in three kinds of bacteriorhodopsin (BR) samples: wild‐type BR in water solution and dispersed in thin films of a polymer matrix as well as water solution of the genetically engineered mutant BRD96N. The experiments are carried out with picosecond pulses at 532 nm. The values measured for the saturation intensity are explained in terms of the relaxation of the excited M state population to the B state of the BR photocycle for the three kinds of samples studied

    Complementary and Alternative Medicine Use in Musculoskeletal Disorders: Does Medical Skepticism Matter?

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    Medical skepticism is the reservation about the ability of conventional medical care to significantly improve health. Individuals with musculoskeletal disorders seeing specialists usually experience higher levels of disability; therefore it is expected they might be more skeptical of current treatment and thus more likely to try Complementary and Alternative Medicine (CAM). The goal of this study was to define these relationships. These data were drawn from a cross-sectional survey from two cohorts: those seeing specialists (n=1,344) and non-specialists (n=724). Site-level fixed effects logistic regression models were used to test associations between medical skepticism and 10 CAM use categories. Some form of CAM was used by 88% of the sample. Increased skepticism was associated with one CAM category for the non-specialist group and six categories for the specialist group. Increased medical skepticism is associated with CAM use, but medical skepticism is more often associated with CAM use for those seeing specialists

    A Multimetric Assessment of Stream Condition in the Northern Lakes and Forests Ecoregion Using Spatially Explicit Statistical Modeling and Regional Normalization

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    We sampled fish communities, water temperature, water chemistry, physical habitat, and catchment characteristics for 94 stream sites selected randomly throughout the Northern Lakes and Forests ecoregion and used those data to explicitly model reference conditions and assess ecological stream condition at each site via a regional normalization framework. The streams we sampled were first order through fourth order, and the catchments ranged from 0.9 to 458 km2. We developed multiple linear regression (MLR) models that predicted fish community metrics, water chemistry characteristics, and local physical habitat from catchment characteristics; we used these models to compare existing conditions with the conditions that would be expected based on the regression models. Our results indicated that the fish communities were relatively unimpaired because the catchment variables associated with human‐induced land use change were important in only 1 of the 10 fish metric models. Agricultural land use was a significant variable in the MLR equation for species of Lepomis (sunfish). Agricultural land use and urban land use were both significant variables in all of the MLR models predicting water chemistry variables; urban land use was a significant variable in the MLR model predicting the percent coverage of all instream cover types. Regional normalization indicated that none of the sites were impaired based on fish community attributes. However, our analysis based on water chemistry metrics indicated that 22– 35% of the sites were impaired and that, based on physical habitat, 6–14% of the sites were impaired. A comparison with other published studies of the ecoregion suggested that the regional normalization process correctly characterized stream condition.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141590/1/tafs0697.pd

    Use of Complementary and Alternative Medicine Among Patients With Arthritis

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    Introduction: Previous studies suggest that people with arthritis have high rates of using complementary and alternative medicine (CAM) approaches for managing their arthritis, in addition to conventional treatments such as prescription medications. However, little is known about the use of CAM by diagnosis, or which forms of CAM are most frequently used by people with arthritis. This study was designed to provide detailed information about use of CAM for symptoms associated with arthritis in patients followed in primary care and specialty clinics in North Carolina. Methods: Using a cross-sectional design, we drew our sample from primary care (n = 1,077) and specialist (n = 1,063) physician offices. Summary statistics were used to calculate differences within and between diagnostic groups, practice settings, and other characteristics. Logistic regression models clustered at the site level were used to determine the effect of patient characteristics on ever and current use of 9 CAM categories and an overall category of "any use." Results: Most of the participants followed by specialists (90.5%) and a slightly smaller percentage of those in the primary care sample (82.8%) had tried at least 1 complementary therapy for arthritis symptoms. Participants with fibromyalgia used complementary therapies more often than those with rheumatoid arthritis, osteoarthritis, or chronic joint symptoms. More than 50% of patients in both samples used over-the-counter topical pain relievers, more than 25% used meditation or drew on religious or spiritual beliefs, and more than 19% used a chiropractor. Women and participants with higher levels of education were more likely to report current use of alternative therapies. Conclusion: Most arthritis patients in both primary care and specialty settings have used CAM for their arthritis symptoms. Health care providers (especially musculoskeletal specialists) should discuss these therapies with all arthritis patients

    Diet Significantly Influences the Immunopathology and Severity of Kidney Injury in Male C57Bl/6J Mice in a Model Dependent Manner

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    Diet is a leading causative risk factor for morbidity and mortality worldwide, yet it is rarely considered in the design of preclinical animal studies. Several of the nutritional inadequacies reported in Americans have been shown to be detrimental to kidney health; however, the mechanisms responsible are unclear and have been largely attributed to the development of diabetes or hypertension. Here, we set out to determine whether diet influences the susceptibility to kidney injury in male C57Bl/6 mice. Mice were fed a standard chow diet, a commercially available “Western” diet (WD), or a novel Americanized diet (AD) for 12 weeks prior to the induction of kidney injury using the folic acid nephropathy (FAN) or unilateral renal ischemia reperfusion injury (uIRI) models. In FAN, the mice that were fed the WD and AD had worse histological evidence of tissue injury and greater renal expression of genes associated with nephrotoxicity and monocyte infiltration as compared to mice fed chow. Mice fed the AD developed more severe renal hypertrophy following FAN, and gene expression data suggest the mechanism for FAN differed among the diets. Meanwhile, mice fed the WD had the greatest circulating interleukin-6 concentrations. In uIRI, no difference was observed in renal tissue injury between the diets; however, mice fed the WD and AD displayed evidence of suppressed inflammatory response. Taken together, our data support the hypothesis that diet directly impacts the severity and pathophysiology of kidney disease and is a critical experimental variable that needs to be considered in mechanistic preclinical animal studies

    Emergence of winner-takes-all connectivity paths in random nanowire networks

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    Nanowire networks are promising memristive architectures for neuromorphic applications due to their connectivity and neurosynaptic-like behaviours. Here, we demonstrate a self-similar scaling of the conductance of networks and the junctions that comprise them. We show this behavior is an emergent property of any junction-dominated network. A particular class of junctions naturally leads to the emergence of conductance plateaus and a “winner-takes-all” conducting path that spans the entire network, and which we show corresponds to the lowest-energy connectivity path. The memory stored in the conductance state is distributed across the network but encoded in specific connectivity pathways, similar to that found in biological systems. These results are expected to have important implications for development of neuromorphic devices based on reservoir computing

    Report of the Commission Appointed by Governor C. C. Young to Investigate the Causes Leading to the Failure of the St. Francis Dam Near Saugus, California

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    This report embodies the conclusions of the commission appointed to investigate the causes for the failure of the St. Francis Dam on March 12, 1928. California deplores the heavy loss of life and property that this disaster entailed. To prevent a recurrence of a like catastrophe, we believe it imperative that whatever lessons the failure of this dam may teach should be made public for the benefit of the people of our state. It was also our thought that the investigation into the causes of the failure of this dam should be made by an agency that was not in any way connected with the preparation of the plans, the construction, or the operation of the dam. Accordingly a commission of engineers and geologists of expert knowledge and eminent reputation was appointed to make this study. The instructions given its members appear in the body of their report. Despite the arduous service that the investigation required, the members of the commission served without personal compensation to them- selves, thus placing their report upon a high plane of unselfish public service. On behalf of the people of California, I extend to them the thanks of the state. As the future of California depends in a large measure upon the storage of water, and the construction of dams, it is gratifying to note that this report finds that such structures can be built with entire safety when due regard is paid to suitability of foundations and correctness of design. This is the great lesson of the disaster. C. C. Young, Governor of California

    Report of the Commission Appointed by Governor C. C. Young to Investigate the Causes Leading to the Failure of the St. Francis Dam Near Saugus, California

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    This report embodies the conclusions of the commission appointed to investigate the causes for the failure of the St. Francis Dam on March 12, 1928. California deplores the heavy loss of life and property that this disaster entailed. To prevent a recurrence of a like catastrophe, we believe it imperative that whatever lessons the failure of this dam may teach should be made public for the benefit of the people of our state. It was also our thought that the investigation into the causes of the failure of this dam should be made by an agency that was not in any way connected with the preparation of the plans, the construction, or the operation of the dam. Accordingly a commission of engineers and geologists of expert knowledge and eminent reputation was appointed to make this study. The instructions given its members appear in the body of their report. Despite the arduous service that the investigation required, the members of the commission served without personal compensation to them- selves, thus placing their report upon a high plane of unselfish public service. On behalf of the people of California, I extend to them the thanks of the state. As the future of California depends in a large measure upon the storage of water, and the construction of dams, it is gratifying to note that this report finds that such structures can be built with entire safety when due regard is paid to suitability of foundations and correctness of design. This is the great lesson of the disaster. C. C. Young, Governor of California

    Dantrolene for the Prevention and Treatment of Cerebral Vasospasm after Subarachnoid Hemorrhage – a Randomized Placebo-Controlled Trial to assess Safety, Tolerability and Feasibility

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    Introduction: Dantrolene is neuroprotective in animal models and may attenuate cerebral vasospasm (cVSP) after aneurysmal subarachnoid hemorrhage (aSAH) in humans. We evaluated safety/tolerability and feasibility of intravenous dantrolene (IV-D) after aSAH. Methods: In this single-center, randomized, double blind, placebo-controlled trial, 31 patients with acute aSAH were randomized to IV-D 1.25 mg IV every 6 hours x 7 days (n=16) or placebo (n=15). Primary endpoint was incidence of hyponatremia (sNa ≤ 134 mmol/L) and liver toxicity (% patients with ALT, AST and AlkPhos \u3e5x upper limit of normal). Secondary safety endpoints included tolerability, systemic hypotension and intracranial hypertension. Efficacy was explored by clinical, transcranial Doppler (TCD) or angiographic cVSP occurrence, delayed cerebral ischemia (DCI) and 3-month modified-Rankin-Scale, Glasgow Outcome Scale and Barthel Index. Statistical analysis was performed using non-parametric tests, generalized estimating equations and mixed models. Results: Between IV-D vs. placebo, no differences were observed in the primary outcome (hyponatremia: 44% vs. 67% [p=0.29]; liver toxicity 6% vs. 0% [p=1.0]). Numerically more AEs and SAEs were seen in the IV-D group, but did not reach statistical significance (16 vs. 5 AEs, of which 5 vs. 2 were severe; RR 2.2; 95% CI 0.7-6.7; p=0.16). Three IV-D vs. two placebo patients reached stop criteria: one IV-D patient developed liver toxicity; two patients in each group developed brain edema requiring osmotherapy. No differences in angiographic, TCD, clinical cVSP, DCI, or 3-month functional outcomes were seen. Quantitative angiogram analysis revealed a trend towards increased vessel diameters in the IV-D group after the 7-day infusion-period (p=0.05). Conclusions: In this small trial, IV-Dantrolene after aSAH was feasible, tolerable and safe, but was underpowered to show efficacy or outcome differences
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