524 research outputs found

    Analytical solution for the cumulative wake of wind turbines in wind farms

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    This paper solves an approximate form of conservation of mass and momentum for a turbine in a wind farm array. The solution is a fairly simple explicit relationship that predicts the streamwise velocity distribution within a wind farm with an arbitrary layout. As this model is obtained by solving flow-governing equations directly for a turbine that is subject to upwind turbine wakes, no ad hoc superposition technique is needed to predict wind farm flows. A suite of large-eddy simulations (LES) of wind farm arrays is used to examine self-similarity as well as validity of the so-called conservation of momentum deficit for turbine wakes in wind farms. The simulations are performed with and without the presence of some specific turbines in the wind farm. This allows us to systematically study some of the assumptions made to develop the analytical model. A modified version of the conservation of momentum deficit is also proposed to provide slightly better results at short downwind distances, as well as in the far wake of turbines deep inside a wind farm. Model predictions are validated against the LES data for turbines in both full-wake and partial-wake conditions. While our results highlight the limitation in capturing the flow speed-up between adjacent turbine columns, the model is overall able to acceptably predict flow distributions for a moderately sized wind farm. Finally, the paper employs the new model to provide insights on the accuracy of common wake superposition methods

    Guidance of sentinel lymph node biopsy decisions in patients with T1-T2 melanoma using gene expression profiling.

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    AIM: Can gene expression profiling be used to identify patients with T1-T2 melanoma at low risk for sentinel lymph node (SLN) positivity? PATIENTS & METHODS: Bioinformatics modeling determined a population in which a 31-gene expression profile test predicted \u3c5% SLN positivity. Multicenter, prospectively-tested (n = 1421) and retrospective (n = 690) cohorts were used for validation and outcomes, respectively. RESULTS: Patients 55-64 years and ≥65 years with a class 1A (low-risk) profile had SLN positivity rates of 4.9% and 1.6%. Class 2B (high-risk) patients had SLN positivity rates of 30.8% and 11.9%. Melanoma-specific survival was 99.3% for patients ≥55 years with class 1A, T1-T2 tumors and 55.0% for class 2B, SLN-positive, T1-T2 tumors. CONCLUSION: The 31-gene expression profile test identifies patients who could potentially avoid SLN biopsy

    Portraying the hosts: Stellar science from planet searches

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    Information on the full session can be found on this website: https://sites.google.com/site/portrayingthehostscs18/We present a compendium of the splinter session on stellar science from planet searches that was organized as part of the Cool Stars 18 conference. Seven speakers discussed techniques to infer stellar information from radial velocity, transit and microlensing data, as well as new instrumentation and missions designed for planet searches that will provide useful for the study of the cool stars

    Observations from a systematic review of pharmacist- led research in solid organ transplantation: An opinion paper of the American College of Clinical Pharmacy Immunology/Transplantation Practice and Research Network

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    IntroductionThe contributions of transplant pharmacists to clinical and translational research in the United States are ill- defined and have not been systematically reviewed.ObjectivesThe American College of Clinical Pharmacy Immunology/Transplantation Practice and Research Network conducted a systematic review of available pharmacist- led research publications involving solid organ transplantation with the intent to quantify and describe pharmacist- led research endeavors and their changes over time.MethodsAn electronic search of Scopus was conducted to identify publications in the field of solid organ transplantation by pharmacist authors between January 1, 1975 and May 25, 2017. Articles were excluded if they were written in non- English languages or originated from non- US countries. Review articles, case reports, surveys, basic science research, pre- clinical studies, and non- transplant research were further excluded. Studies were categorized as one of four phases on the clinical and translational research spectrum, adapted from the Harvard Clinical and Translational Science Center description of a T1 to T4 classification system.ResultsA total of 10- 354 publications were identified by the systematic search with 547 full- text English- language publications included in the analysis. Pharmacists served as the first author in 87% of the articles and as the senior author in 67% of the articles. A total of 71% of the articles included more than one pharmacist author. Transplant pharmacists published more studies that employed a retrospective or observational study design (55% and 78%, respectively). A total of 37% of studies were funded. On the spectrum of clinical and translation research, pharmacists were most involved in T3 (translation to practice) research (72%), followed by T2 (translation to patients) research (23%).ConclusionsTransplant pharmacists are increasingly represented in the US literature and frequently published across domains. Further demonstrating the relevance of pharmacist- delivered interventions and outcomes is a critical area of practice focus.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163590/2/jac51294.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163590/1/jac51294_am.pd

    Youth sport during the COVID-19 pandemic: The influence of race and affluence on parents’ perspectives of youth participation

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    COVID-19 restrictions led to a nearly 50% decline in youth sport participation across the United States (Dorsch et al., 2021). Today, communities and sport organizations have resumed sport. However, research has yet to fully elucidate how COVID-19 restrictions impacted youth participation across different sociodemographic groups during the pandemic. The present study explored the association between race and affluence and their relationship with parents' attitudes toward children's youth sport participation before, during, and after the COVID-19 pandemic. Online questionnaires were completed by a nationally representative sample of 3706 parents (Mage = 39.57 ± 9.03 years) who had a child regularly participating in youth sport before COVID-19. Multivariate Analyses of Variance using Tukey post-hoc tests were conducted to examine the main effect differences by race and affluence and the interactive effects of race and affluence. Results suggest that race and affluence -- independently and in combination -- were salient categorical variables of children's weekly hours of sport participation during the COVID-19 pandemic. Findings highlight that White*high affluent groups had the highest rates of sport participation during the COVID-19 pandemic and that these families desire to invest more time and money at greater rates upon returning. Theoretically, designed intersectionality research is recommended to explore further effects of race and affluence in youth sport

    Walnut oil increases cholesterol efflux through inhibition of stearoyl CoA desaturase 1 in THP-1 macrophage-derived foam cells

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    Extent: 13p.Background: Walnuts significantly decrease total and low-density lipoprotein cholesterol in normo- and hypercholesterolemic individuals. No study to date has evaluated the effects of walnuts on cholesterol efflux, the initial step in reverse cholesterol transport, in macrophage-derived foam cells (MDFC). The present study was conducted to investigate the mechanisms by which walnut oil affects cholesterol efflux. Methods: The extract of English walnuts (walnut oil) was dissolved in DMSO and applied to cultured THP-1 MDFC cells (0.5 mg/mL). THP-1 MDFC also were treated with human sera (10%, v:v) taken from subjects in a walnut feeding study. Cholesterol efflux was examined by liquid scintillation counting. Changes in gene expression were quantified by real time PCR. Results: Walnut oil treatment significantly increased cholesterol efflux through decreasing the expression of the lipogenic enzyme stearoyl CoA desaturase 1 (SCD1) in MDFC. Alpha-linolenic acid (ALA), the major n-3 polyunsaturated fatty acids found in walnuts, recaptured SCD1 reduction in MDFC, a mechanism mediated through activation of nuclear receptor farnesoid-X-receptor (FXR). Postprandial serum treatment also increased cholesterol efflux in MDFC. When categorized by baseline C-reactive protein (CRP; cut point of 2 mg/L), subjects in the lower CRP sub-group benefited more from dietary intervention, including a more increase in cholesterol efflux, a greater reduction in SCD1, and a blunted postprandial lipemia. Conclusion: In conclusion, walnut oil contains bioactive molecules that significantly improve cholesterol efflux in MDFC. However, the beneficial effects of walnut intake may be reduced by the presence of a pro-inflammatory state.Jun Zhang, Jessica A Grieger, Penny M Kris-Etherton, Jerry T Thompson, Peter J Gillies, Jennifer A Fleming and John P Vanden Heuve

    Convenient Shorthand: The Supreme Court and the Language of State Sovereignty

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    A symposium on the health significance of dietary fat in the prevention and treatment of the metabolic syndrome (MetS) was held at the 20th International Congress of Nutrition in Granada, Spain, on September 19, 2013. Four nutrition experts addressed the topics of dietary fat and obesity, effects of dietary fat quality in obesity and insulin resistance, influence of early nutrition on the later risk of MetS and the relative merits of high- or low-fat diets in counteracting MetS. Participants agreed that preventing weight gain and achieving weight loss in overweight and obese patients were key strategies for reducing MetS. Both low-fat and low-carbohydrate diets are associated with weight loss, but adherence to the diet is the most important factor in achieving success. Avoidance of high saturated fats contributes to lower health risks among obese, MetS and diabetic patients. Further, healthy maternal weight at conception and in pregnancy is more important that weight gain during pregnancy for reducing the risk of obesity in the offspring. The effects of different polyunsaturated fatty acids on MetS and weight loss require clarification. (C) 2014 S. Karger AG, Base

    Preventing Fetal Alcohol Spectrum Disorder in Aboriginal Communities: A Methods Development Project

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    The authors describe their three-year project working collaboratively with Aboriginal communities to prevent fetal alcohol spectrum disorder
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