2,023 research outputs found

    Improving soil health with a multispecies cover cropping system: preliminary and intermediate data and analysis

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    https://scholarworks.moreheadstate.edu/student_scholarship_posters/1172/thumbnail.jp

    Evaluation of the utility of sediment data in NASQAN (National Stream Quality Accounting Network)

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    Monthly suspended sediment discharge measurements, made by the USGS as part of the National Stream Quality Accounting Network (NASQAN), are analysed to assess the adequacy in terms of spatial coverage, temporal sampling frequency, accuracy of measurements, as well as in determining the sediment yield in the nation's rivers. It is concluded that the spatial distribution of NASQAN stations is reasonable but necessarily judgemental. The temporal variations of sediment data contain much higher frequencies than monthly. Sampling error is found to be minor when compared with other causes of data scatter which can be substantial. The usefulness of the monthly measurements of sediment transport is enhanced when combined with the daily measurements of water discharge. Increasing the sampling frequency moderately would not materially improve the accuracy of sediment yield determinations

    Sediment Management for Southern California Mountians, Coastal Plains and Shoreline. Part D: Special Inland Studies

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    In southern California the natural environmental system involves the continual relocation of sedimentary materials. Particles are eroded from inland areas where there is sufficient relief and, precipitation. Then, with reductions in hydraulic gradient along the stream course and at the shoreline, the velocity of surface runoff is reduced and there is deposition. Generally, coarse sand, gravel and larger particles are deposited near the base of the eroding surfaces (mountains and hills) and the finer sediments are deposited on floodplains, in bays or lagoons, and at the shoreline as delta deposits. Very fine silt and clay particles, which make up a significant part of the eroded material, are carried offshore where they eventually deposit in deeper areas. Sand deposited at the shoreline is gradually moved along the coast by waves and currents, and provides nourishment for local beaches. However, eventually much of this littoral material is also lost to offshore areas. Human developments in the coastal region have substantially altered the natural sedimentary processes, through changes in land use, the harvesting of natural resources (logging, grazing, and sand and gravel mining); the construction and operation of water conservation facilities and flood control structures; and coastal developments. In almost all cases these developments have grown out of recognized needs and have well served their primary purpose. At the time possible deleterious effects on the local or regional sediment balance were generally unforeseen or were felt to be of secondary importance. In 1975 a large-scale study of inland and coastal sedimentation processes in southern California was initiated by the Environmental Quality Laboratory at the California Institute of Technology and the Center for Coastal Studies at Scripps Institution of Oceanography. This volume is one of a series of reports from this study. Using existing data bases, this series attempts to define quantitatively inland and coastal sedimentation processes and identify the effects man has had on these processes. To resolve some issues related to long-term sediment management, additional research and data will be needed. In the series there are four Caltech reports that provide supporting studies for the summary report (EQL Report No. 17). These reports include: EQL Report 17-A Regional Geological History EQL Report 17-B Inland Sediment Movements by Natural Processes EQL Report 17-C Coastal Sediment Delivery by Major Rivers in Southern California EQL Report 17-D -- Special Inland Studies Additional supporting reports on coastal studies (shoreline sedimentation processes, control structures, dredging, etc.) are being published by the Center for Coastal Studies at Scripps Institution of Oceanography, La Jolla, California

    Effects of Stride Length and Running Mileage on a Probabilistic Stress Fracture Model

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    The fatigue life of bone is inversely related to strain magnitude. Decreasing stride length is a potential mechanism of strain reduction during running. If stride length is decreased, the number of loading cycles will increase for a given mileage. It is unclear if increased loading cycles are detrimental to skeletal health despite reductions in strain. Purpose: To determine the effects of stride length and running mileage on the probability of tibial stress fracture. Methods: Ten male subjects ran overground at their preferred running velocity during two conditions: preferred stride length and 10% reduction in preferred stride length. Force platform and kinematic data were collected concurrently. A combination of experimental and musculoskeletal modeling techniques was used to determine joint contact forces acting on the distal tibia. Peak instantaneous joint contact forces served as inputs to a finite element model to estimate tibial strains during stance. Stress fracture probability for stride length conditions and three running mileages (3, 5, and 7 miles·d−1) were determined using a probabilistic model of bone damage, repair, and adaptation. Differences in stress fracture probability were compared between conditions using a 2 × 3 repeated-measures ANOVA. Results: The main effects of stride length (P = 0.017) and running mileage (P = 0.001) were significant. Reducing stride length decreased the probability of stress fracture by 3% to 6%. Increasing running mileage increased the probability of stress fracture by 4% to 10%. Conclusions: Results suggest that strain magnitude plays a more important role in stress fracture development than the total number of loading cycles. Runners wishing to decrease their probability for tibial stress fracture may benefit from a 10% reduction in stride length

    http://www.medscape.com/viewarticle/714780_print

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    Abstract and Introduction Abstract The fatigue life of bone is inversely related to strain magnitude. Decreasing stride length is a potential mechanism of strain reduction during running. If stride length is decreased, the number of loading cycles will increase for a given mileage. It is unclear if increased loading cycles are detrimental to skeletal health despite reductions in strain. Purpose: To determine the effects of stride length and running mileage on the probability of tibial stress fracture. Methods: Ten male subjects ran overground at their preferred running velocity during two conditions: preferred stride length and 10% reduction in preferred stride length. Force platform and kinematic data were collected concurrently. A combination of experimental and musculoskeletal modeling techniques was used to determine joint contact forces acting on the distal tibia. Peak instantaneous joint contact forces served as inputs to a finite element model to estimate tibial strains during stance. Stress fracture probability for stride length conditions and three running mileages (3, 5, and 7 miles·d −1 ) were determined using a probabilistic model of bone damage, repair, and adaptation. Differences in stress fracture probability were compared between conditions using a 2 × 3 repeated-measures ANOVA. Results: The main effects of stride length (P = 0.017) and running mileage (P = 0.001) were significant. Reducing stride length decreased the probability of stress fracture by 3% to 6%. Increasing running mileage increased the probability of stress fracture by 4% to 10%. Conclusions: Results suggest that strain magnitude plays a more important role in stress fracture development than the total number of loading cycles. Runners wishing to decrease their probability for tibial stress fracture may benefit from a 10% reduction in stride length

    Frailty and Risk of Falls, Fracture, and Mortality in Older Women: The Study of Osteoporotic Fractures

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    Background. A standard phenotype of frailty was associated with an increased risk of adverse outcomes including mortality in a recent study of older adults. However, the predictive validity of this phenotype for fracture outcomes and across risk subgroups is uncertain. Methods. To determine whether a standard frailty phenotype was independently associated with risk of adverse health outcomes in older women and to evaluate the consistency of associations across risk subgroups defined by age and body mass index (BMI), we ascertained frailty status in a cohort of 6724 women ≥ 69 years and followed them prospectively for incident falls, fractures, and mortality. Frailty was defined by the presence of three or more of the following criteria: unintentional weight loss, weakness, self-reported poor energy, slow walking speed, and low physical activity. Incident recurrent falls were defined as at least two falls during the subsequent year. Incident fractures (confirmed with x-ray reports), including hip fractures, and deaths were ascertained during an average of 9 years of follow-up. Results. After controlling for multiple confounders such as age, health status, medical conditions, functional status, depressive symptoms, cognitive function, and bone mineral density, frail women were subsequently at increased risk of recurrent falls (multivariate odds ratio = 1.38, 95% confidence interval [CI], 1.02-1.88), hip fracture (multivariate hazards ratio [MHR] = 1.40, 95% CI, 1.03-1.90), any nonspine fracture (MHR = 1.25, 95% CI, 1.05-1.49), and death (MHR = 1.82, 95% CI, 1.56-2.13). The associations between frailty and these outcomes persisted among women ≥ 80 years. In addition, associations between frailty and an increased risk of falls, fracture, and mortality were consistently observed across categories of BMI, including BMI ≥ 30 kg/m2. Conclusion. Frailty is an independent predictor of adverse health outcomes in older women, including very elderly women and older obese wome

    The role of static disorder in negative thermal expansion in ReO3

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    Time-of-flight neutron powder diffraction and specific heat measurements were used to study the nature of thermal expansion in rhenium trioxide, an electrically conducting oxide with cubic symmetry. The temperature evolution of the lattice parameters show that ReO3 can exhibit negative thermal expansion at low temperatures and that the transition from negative to positive thermal expansion depends on sample preparation; the single crystal sample demonstrated the highest transition temperature, 300 K, and largest negative value for the coefficient of thermal expansion, alpha = -1.1(1)x 10^-6 K^-1. For the oxygen atoms, the atomic displacement parameters are strongly anisotropic even at 15 K, indicative of a large contribution of static disorder to the displacement parameters. Further inspection of the temperature evolution of the oxygen displacement parameters for different samples reveals that the static disorder contribution is greater for the samples with diminished NTE behavior. In addition, specific heat measurements show that ReO3 lacks the low energy Einstein-type modes seen in other negative thermal expansion oxides such as ZrW2O8.Comment: 6 pages, 5 figure

    Taking ACTION to reduce pain: ACTION study rationale, design and protocol of a randomized trial of a proactive telephone-based coaching intervention for chronic musculoskeletal pain among African Americans

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    Abstract Background Rates of chronic pain are rising sharply in the United States and worldwide. Presently, there is evidence of racial disparities in pain treatment and treatment outcomes in the United States but few interventions designed to address these disparities. There is growing consensus that chronic musculoskeletal pain is best addressed by a biopsychosocial approach that acknowledges the role of psychological and environmental factors, some of which differ by race. Methods/Design The primary aim of this randomized controlled trial is to test the effectiveness of a non-pharmacological, self-regulatory intervention, administered proactively by telephone, at improving pain outcomes and increasing walking among African American patients with hip, back and knee pain. Participants assigned to the intervention will receive a telephone counselor delivered pedometer-mediated walking intervention that incorporates action planning and motivational interviewing. The intervention will consist of 6 telephone counseling sessions over an 8–10 week period. Participants randomly assigned to Usual Care will receive an informational brochure and a pedometer. The primary outcome is chronic pain-related physical functioning, assessed at 6 months, by the revised Roland and Morris Disability Questionnaire, a measure recommended by the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT). We will also examine whether the intervention improves other IMMPACT-recommended domains (pain intensity, emotional functioning, and ratings of overall improvement). Secondary objectives include examining whether the intervention reduces health care service utilization and use of opioid analgesics and whether key contributors to racial/ethnic disparities targeted by the intervention mediate improvement in chronic pain outcomes Measures will be assessed by mail and phone surveys at baseline, three months, and six months. Data analysis of primary aims will follow intent-to-treat methodology. Discussion We will tailor our intervention to address key contributors to racial pain disparities and examine the effects of the intervention on important pain treatment outcomes for African Americans with chronic musculoskeletal pain. Trial registration ClinicalTrials.gov: NCT01983228. Registered 6 November 2013

    Taking ACTION to reduce pain: ACTION study rationale, design and protocol of a randomized trial of a proactive telephone-based coaching intervention for chronic musculoskeletal pain among African Americans

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    Abstract Background Rates of chronic pain are rising sharply in the United States and worldwide. Presently, there is evidence of racial disparities in pain treatment and treatment outcomes in the United States but few interventions designed to address these disparities. There is growing consensus that chronic musculoskeletal pain is best addressed by a biopsychosocial approach that acknowledges the role of psychological and environmental factors, some of which differ by race. Methods/Design The primary aim of this randomized controlled trial is to test the effectiveness of a non-pharmacological, self-regulatory intervention, administered proactively by telephone, at improving pain outcomes and increasing walking among African American patients with hip, back and knee pain. Participants assigned to the intervention will receive a telephone counselor delivered pedometer-mediated walking intervention that incorporates action planning and motivational interviewing. The intervention will consist of 6 telephone counseling sessions over an 8–10 week period. Participants randomly assigned to Usual Care will receive an informational brochure and a pedometer. The primary outcome is chronic pain-related physical functioning, assessed at 6 months, by the revised Roland and Morris Disability Questionnaire, a measure recommended by the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT). We will also examine whether the intervention improves other IMMPACT-recommended domains (pain intensity, emotional functioning, and ratings of overall improvement). Secondary objectives include examining whether the intervention reduces health care service utilization and use of opioid analgesics and whether key contributors to racial/ethnic disparities targeted by the intervention mediate improvement in chronic pain outcomes Measures will be assessed by mail and phone surveys at baseline, three months, and six months. Data analysis of primary aims will follow intent-to-treat methodology. Discussion We will tailor our intervention to address key contributors to racial pain disparities and examine the effects of the intervention on important pain treatment outcomes for African Americans with chronic musculoskeletal pain. Trial registration ClinicalTrials.gov: NCT01983228. Registered 6 November 2013
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