1,782 research outputs found
An Objective Analysis Technique for Constructing Three-Dimensional Urban-Scale Wind Fields
An objective analysis procedure for generating mass-consistent, urban-scale three-dimensional wind fields is presented together with a comparison against existing techniques. The algorithm employs terrain following coordinates and variable vertical grid spacing. Initial estimates of the velocity field are developed by interpolating surface and upper level wind measurements. A local terrain adjustment technique, involving solution of the Poisson equation, is used to establish the horizontal components of the surface field. Vertical velocities are developed from successive solutions of the continuity equation followed by an iterative procedure which reduces anomalous divergence in the complete field. Major advantages of the procedure are that it is computationally efficient and allows boundary values to adjust in response to changes in the interior flow. The method has been successfully tested using field measurements and problems with known analytic solutions
Computer Modeling of a Liquid Fuel Spray
This project was designed to find an accurate and convenient method of computing fuel spray parameters. The project centers around an experimental setup which basically fires a laser beam through a fuel spray mist. A concentric ring detector then measures energy from the scattered light.
A computer code was written which solves a governing equation to give computed values of the energy from scattered light. Comparison of the experimental energy and the computed energy tells how well the fuel parameters of the computer model matches those of the real spray of the experiment. An iteration technique then manipulates the computer model until the unknown parameters are solved for.
The computer code designed here works very well with calibration or known data. However, actual test data causes the computer code to crash. New techniques and approaches are currently being employed to salvage the code
An Iterative Algorithm for Objective Wind Field Analysis
A wind field interpolated from a limited supply of observed data often implies a specific field of divergence, or a violation of the conservation of mass. To minimize the divergence, various objective analyses have been proposed. Three different methods of analysis are investigated and compared with respect to the degree of minimization of wind divergence and the accuracy of wind data at a measured station. The methods are a variational formulation in which the residual error in the continuity equation is minimized, a fixed-vorticity technique, and the presently proposed algorithm in which the measured winds are held fixed while winds at adjacent points are adjusted in order to reduce the divergence. The reduction of wind divergence and the convergence of the iterative scheme are examined. Results of the objective wind field analysis at times depend on subjective judgment in selecting the appropriate initialization algorithm especially for regions with scattered stations
Greater socioenvironmental risk factors and higher chronic pain stage are associated with thinner bilateral temporal lobes
INTRODUCTION: Previous research indicates ethnic/race group differences in pain and neurodegenerative diseases. Accounting for socioenvironmental factors reduces ethnic/race group differences in clinical and experimental pain. In the current study sample, we previously reported that in individuals with knee pain, ethnic/race group differences were observed in bilateral temporal lobe thickness, areas of the brain associated with risk for Alzheimer\u27s disease, and related dementias. The purpose of the study was to determine if socioenvironmental factors reduce or account for previously observed ethnic/race group differences and explore if a combined effect of socioenvironmental risk and chronic pain severity on temporal lobe cortices is evident.
METHODS: Consistent with the prior study, the sample was comprised of 147 adults (95 women, 52 men), 45-85 years of age, who self-identified as non-Hispanic Black (n = 72) and non-Hispanic White (n = 75), with knee pain with/at risk for osteoarthritis. Measures included demographics, health history, pain questionnaires, cognitive screening, body mass index, individual- and community-level socioenvironmental factors (education, income, household size, marital and insurance status, and area deprivation index), and brain imaging. We computed a summative socioenvironmental risk index.
RESULTS: Regression analyses showed that with the inclusion of socioenvironmental factors, the model was significant (p \u3c .001), and sociodemographic (ethnic/race) group differences were not significant (p = .118). Additionally, findings revealed an additive stress load pattern indicating thinner temporal lobe cortices with greater socioenvironmental risk and chronic pain severity (p = .048).
IMPLICATIONS: Although individual socioenvironmental factors were not independent predictors, when collectively combined in models, ethnic/race group differences in bilateral temporal lobe structures were not replicated. Further, combined socioenvironmental risk factors and higher chronic pain severity were associated with thinner bilateral temporal lobes
Validity and Accuracy of Atmospheric Air Quality Models
Effective evaluation of air pollution
control strategies requires the use of validated
and reliable mathematical models that can relate
pollutant emissions to atmospheric air quality.
The derivation and use of such models, at least
for inert and linearly decaying pollutants such
as CO and SO_2, has received a great deal of
attention. Much less work has been devoted to
assessing how the model predictions are related
to actual atmospheric concentrations. The
objectives of this paper are to formulate the
concepts of validity and accuracy and to suggest
and describe some experiments that can be performed
to assess these features
Mathematical modeling of photochemical air pollution
A particularly serious problem facing densely populated areas is the environmental degradation caused by the presence of photochemical air pollution. The problem is both pervasive and difficult to control. An important element of any rational approach directed at attempting to improve the situation is a reliable means for evaluating the air quality impact of alternative control measures. This report presents such a capability in the form of a mathematical description of the production and transport of photochemical oxidants within an urban airshed
Leadership Theory and Behavior: America Takes a Selfie
This paper explores the changing nature of the United States, and to some extent the world at large, and identifies major issues likely to influence and impact leadership theory and behavior in the next 50 years. The paper investigates issues related to world security, population shifts, values and morality changes, technology impact, and other social and political issues. The article emphasizes the role of the millennial generation in securing and carrying out the current or new principles defining leadership theory and behavior. The paper is an idea-generating process and connects its content to the field of problem-based learning. No solutions are given, but the article is left open for personal interpretation and thinking about leadership theory and behavior for the future
Pharmacists\u27 Role in Harm Reduction: A Survey Assessment of Kentucky Community Pharmacists\u27 Willingness to Participate in Syringe/Needle Exchange
Background: Pharmacists\u27 role in harm reduction is expanding in many states, yet there are limited data on pharmacists\u27 willingness to participate in harm reduction activities. This study assessed community pharmacists\u27 willingness to participate in one harm reduction initiative: syringe/needle exchange.
Methods: In 2015, all Kentucky pharmacists with active licenses were emailed a survey that examined attitudes towards participation in syringe/needle exchange. Response frequencies were calculated for community pharmacist respondents. Ordinal logistic regression estimated the impact of community pharmacist characteristics and attitudes on willingness to provide clean needles/syringes to people who inject drugs and to dispose of used syringes/needles, where both dependent variables were defined as Likert-type questions on a scale of 1 (not at all willing) to 6 (very willing).
Results: Of 4699 practicing Kentucky pharmacists, 1282 pharmacists responded (response rate = 27.3%); the majority (n = 827) were community pharmacists. Community pharmacists were divided on willingness to provide clean needles/syringes, with 39.1% not willing (score 1 or 2 of 6) and 30% very willing (score 5 or 6 of 6). Few were willing to dispose of used needles/syringes, with only 18.7% willing. Community pharmacists who agreed that pharmacists could have significant public health impact by providing access to clean needles expressed 3.56 times more willingness to provide clean needles (95% CI 3.06-4.15), and 2.04 times more willingness to dispose of used needles (95% CI 1.77-2.35). Chain/supermarket pharmacists (n = 485, 58.6% of community pharmacies) were 39% less likely to express willingness to dispose of used needles (95% CI 0.43-0.87) when compared with independent community pharmacists (n = 342, 41.4% of community pharmacies). Independent pharmacists reported different barriers (workflow) than their chain/supermarket pharmacist colleagues (concerns of clientele).
Conclusions: Kentucky community pharmacists were more willing to provide clean needles than to dispose of used needles. Strategies to mitigate barriers to participation in syringe/needle exchange are warranted
Identifying a Test to Monitor Weightlifting Performance in Competitive Male and Female Weightlifters
Monitoring tests are commonly used to assess weightlifter’s preparedness for competition. Although various monitoring tests have been used, it is not clear which test is the strongest indicator of weightlifting performance. Therefore, the purpose of this study was to (1) determine the relationships between vertical jump, isometric mid-thigh pull (IMTP) and weightlifting performance; and (2) compare vertical jumps to IMTP as monitoring tests of weightlifting performance in a large cohort of male and female weightlifters. Methods: Fifty-two competitive weightlifters (31 males, 21 females) participated in squat and countermovement jump testing (SJ, CMJ), and IMTP testing performed on force plates. All laboratory testing data was correlated to a recent competition where the athletes had attempted to peak. Results: Squat jump height (SJH) was the strongest correlate for men and women with the Sinclair Total (r = 0.686, p ≤ 0.01; r = 0.487, p ≤ 0.05, respectively) compared to countermovement jump height (r = 0.642, p ≤ 0.01; r = 0.413, p = 0.063), IMTP peak force allometrically scaled to body mass (r = 0.542, p ≤ 0.01; r = −0.044, p = 0.851) and rate of force development at 200 ms (r = 0.066, p = 0.723; r = 0.086, p = 0.711), respectively. Further, SJH was a stronger correlate of relative weightlifting performance compared to IMTP peak force in females (p = 0.042), but not male weightlifters (p = 0.191). Conclusions: Although CMJ and IMTP are still considered strong indicators of weightlifting performance, SJH appears to be the most indicative measure of weightlifting performance across a wide-range of performance levels. Thus, SJH can be used as a reliable measure to monitor weightlifting performance in male and female weightlifters
Risk Stratification for Bleeding Complications in Patients With Venous Thromboembolism: Application of the HAS-BLED Bleeding Score During the First 6 Months of Anticoagulant Treatment
Background—The Hypertension, Abnormal renal/liver function, Stroke, Bleeding, Labile International Normalized Ratio (INR), Elderly, Drugs or alcohol use (HAS-BLED) score has strong predictive validity for major bleeding complications, but limited validation has been conducted in venous thromboembolism (VTE). This study evaluates the HAS-BLED score in a large cohort of VTE patients.
Methods and Results—A retrospective cohort of adults ≥ 18 years with primary diagnosis of VTE between January 1, 2010 and November 31, 2013 were identified in an insurance claims database. Patients were tracked until death, any bleed event, or end of study period. HAS-BLED score and components were evaluated via proportional hazard models. Cumulative incidence functions were reported at 30, 60, 90, and 180 days. N=132 280 patients with a VTE were identified, with 73.8% having HAS-BLED scores of 0 to 2, 3.6% score ≥ 4, and 4789 bleeding events (3.6% all patients). A 1-point HAS-BLED score increase was associated with 20% to 30% bleeding rate increase overall, but in a cancer cohort only the increase from 3- to 4-points was significant for all bleeds (csHR=1.41, 95% CI: 1.17-1.69; sdHR=1.40, 95% CI: 1.17-1.69) and major bleeds (csHR=1.66, 95% CI: 1.26-2.20; sdHR=1.66, 95% CI: 1.25-2.19). Adding cancer to the model as an independent covariate provided the strongest association among all covariates, with csHR=2.25 (95% CI: 1.98-2.56) and sdHR=2.11 (95% CI: 1.85-2.41) in the model for major bleeds.
Conclusions—The HAS-BLED score has good predictive validity for bleeding risks in patients with VTE. The addition of cancer as an independent bleeding risk factor merits consideration, possibly as part of the B criterion ( bleeding tendency or predisposition )
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