991 research outputs found

    Modeling space-time correlations of velocity fluctuations in wind farms

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    An analytical model for the streamwise velocity space-time correlations in turbulent flows is derived and applied to the special case of velocity fluctuations in large wind farms. The model is based on the Kraichnan-Tennekes random sweeping hypothesis, capturing the decorrelation in time while including a mean wind velocity in the streamwise direction. In the resulting model, the streamwise velocity space-time correlation is expressed as a convolution of the pure space correlation with an analytical temporal decorrelation kernel. Hence, the spatio-temporal structure of velocity fluctuations in wind farms can be derived from the spatial correlations only. We then explore the applicability of the model to predict spatio-temporal correlations in turbulent flows in wind farms. Comparisons of the model with data from a large eddy simulation of flow in a large, spatially periodic wind farm are performed, where needed model parameters such as spatial and temporal integral scales and spatial correlations are determined from the large eddy simulation. Good agreement is obtained between the model and large eddy simulation data showing that spatial data may be used to model the full temporal structure of fluctuations in wind farms.Comment: Submitted to Wind Energ

    A Cluster Analysis of Challenging Behaviors in Autism Spectrum Disorder

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    We apply cluster analysis to a sample of 2,116 children with Autism Spectrum Disorder in order to identify patterns of challenging behaviors observed in home and centerbased clinical settings. The largest study of this type to date, and the first to employ machine learning, our results indicate that while the presence of multiple challenging behaviors is common, in most cases a dominant behavior emerges. Furthermore, the trend is also observed when we train our cluster models on the male and female samples separately. This work provides a basis for future studies to understand the relationship of challenging behavior profiles to learning outcomes, with the ultimate goal of providing personalized therapeutic interventions with maximum efficacy and minimum time and cost

    Relationship between Greenland Ice Sheet surface speed and modeled effective pressure

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    Author Posting. © American Geophysical Union, 2018. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Earth Surface 123 (2018): 2258-2278, doi:10.1029/2017JF004581.We use a numerical subglacial hydrology model and remotely sensed observations of Greenland Ice Sheet surface motion to test whether the inverse relationship between effective pressure and regional melt season surface speeds observed at individual sites holds on a regional scale. The model is forced with daily surface runoff estimates for 2009 and 2010 across an ~8,000‐km2 region on the western margin. The overall subglacial drainage system morphology develops similarly in both years, with subglacial channel networks growing inland from the ice sheet margin and robust subglacial pathways forming over bedrock ridges. Modeled effective pressures are compared to contemporaneous regional surface speeds derived from TerraSAR‐X imagery to investigate spatial relationships. Our results show an inverse spatial relationship between effective pressure and ice speed in the mid‐melt season, when surface speeds are elevated, indicating that effective pressure is the dominant control on surface velocities in the mid‐melt season. By contrast, in the early and late melt seasons, when surface speeds are slower, effective pressure and surface speed have a positive relationship. Our results suggest that outside of the mid‐melt season, the influence of effective pressures on sliding speeds may be secondary to the influence of driving stress and spatially variable bed roughness.National Aeronautics and Space Administration (NASA). Grant Number: NXX10AI30G National Science Foundation (NSF) American Geophysical Union Horton Research Grant; National Science Foundation Graduate Research Fellowship; National Science Foundation's Office of Polar Programs (NSF‐OPP) Grant Numbers: PLR‐1418256, ARC‐1023364, ARC‐0520077; Woods Hole Oceanographic Institution's Ocean and Climate Change Institute (OCCI)2019-03-2

    Pediatric Use of Complementary Therapies: Ethical and Policy Choices

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    Objective: Many pediatricians and parents are beginning to integrate use of complementary and alternative medical (CAM) therapies with conventional care. This article addresses ethical and policy issues involving parental choices of CAM therapies for their children. Methods: We conducted a literature search to assess existing law involving parental choice of CAM therapies for their children. We also selected a convenience sample of 18 states of varying sizes and geographic locations. In each state, we inquired within the Department of Health and Human Services whether staff were aware of (1) any internal policies concerning these issues or (2) any cases in the previous 5 years in which either (a) the state initiated proceedings against parents for using CAM therapies for their children or (b) the department received telephone calls or other information reporting abuse and neglect in this domain. We asked the American Academy of Pediatrics and the leading CAM professional organizations concerning any relevant, reported cases. Results: Of the 18 state Departments of Health and Human Services departments surveyed, 6 reported being aware of cases in the previous 5 years. Of 9 reported cases in these 6 states, 3 involved restrictive dietary practices (eg, limiting children variously to a watermelon or raw foods diet), 1 involved dietary supplements, 3 involved children with terminal cancer, and 2 involved religious practices rather than CAM per se. None of the professional organizations surveyed had initiated proceedings or received telephone calls regarding abuse or neglect concerning parental use of CAM therapies. Conclusions: Pediatric use of CAM therapies raises complex issues. Clinicians, hospitals, state agencies, courts, and professional organizations may benefit from a policy framework to help guide decision making

    Music playlists for people with dementia : qualitative evaluation of a guide for caregivers

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    This study aimed to evaluate a set of guidelines for music use with people with dementia. A secondary aim was to identify challenges and barriers to implementation of music interventions by caregivers. Caregivers (n = 16) were interviewed after implementing a music listening programme based on the guidelines with 29 people with dementia in home-care and aged care facilities. Caregivers found the guidelines informative, easy to understand and use. Positive effects on mood, reduced agitation and reduced challenges to care were reported. Difficulties with technology and finding time to implement the music programme were identified. Results highlight the need for more research around appropriate technology and the streamlining of processes and procedures for aged care staff. Further iterations of the guidelines will need to address these issues and consider the differing needs of home-based carers and aged care providers separately

    Music playlists for people with dementia : trialing a guide for caregivers

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    Background: Music programs have the potential to provide an effective non-pharmacological tool for caregivers to reduce depression and agitation and increase quality of life in people with dementia. However, where such programs are not facilitated by a trained music therapist, caregivers need greater access to information about how to use music most effectively in response to key challenges to care, and how to pre-empt and manage adverse responses. Objective: This study reports on the trial of a Guide for use of music with 45 people with dementia and their caregivers in residential care facilities and home-based care. Methods: The study used a pre-post experimental design in which participants were randomly allocated to a treatment group or a waitlist control group. Results: Improvements to quality of life were found in the experimental group over the 6-week period. Significant increases in Interest, Responsiveness, Initiation, Involvement, and Enjoyment were reported for individual listening sessions. Conclusion: The Guide can provide an effective protocol for caregivers to follow in selecting music to manage particular challenges to care, confirming the need for caregivers to be prepared to monitor and manage potential negative responses

    Regional Climate Trends and Scenarios for the U.S. National Climate Assessment Part 4. Climate of the U.S. Great Plains

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    This document is one of series of regional climate descriptions designed to provide input that can be used in the development of the National Climate Assessment (NCA). As part of a sustained assessment approach, it is intended that these documents will be updated as new and well-vetted model results are available and as new climate scenario needs become clear. It is also hoped that these documents (and associated data and resources) are of direct benefit to decision makers and communities seeking to use this information in developing adaptation plans. There are nine reports in this series, one each for eight regions defined by the NCA, and one for the contiguous U.S. The eight NCA regions are the Northeast, Southeast, Midwest, Great Plains, Northwest, Southwest, Alaska, and Hawai‘i/Pacific Islands. These documents include a description of the observed historical climate conditions for each region and a set of climate scenarios as plausible futures – these components are described in more detail below. While the datasets and simulations in these regional climate documents are not, by themselves, new, (they have been previously published in various sources), these documents represent a more complete and targeted synthesis of historical and plausible future climate conditions around the specific regions of the NCA. There are two components of these descriptions. One component is a description of the historical climate conditions in the region. The other component is a description of the climate conditions associated with two future pathways of greenhouse gas emissions

    Linking glacially modified waters to catchment-scale subglacial discharge using autonomous underwater vehicle observations

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    © The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Cryosphere 10 (2016): 417-432, doi:10.5194/tc-10-417-2016.Measurements of near-ice (<  200 m) hydrography and near-terminus subglacial hydrology are lacking, due in large part to the difficulty in working at the margin of calving glaciers. Here we pair detailed hydrographic and bathymetric measurements collected with an autonomous underwater vehicle as close as 150 m from the ice–ocean interface of the Saqqarliup sermia–Sarqardleq Fjord system, West Greenland, with modeled and observed subglacial discharge locations and magnitudes. We find evidence of two main types of subsurface glacially modified water (GMW) with distinct properties and locations. The two GMW locations also align with modeled runoff discharged at separate locations along the grounded margin corresponding with two prominent subcatchments beneath Saqqarliup sermia. Thus, near-ice observations and subglacial discharge routing indicate that runoff from this glacier occurs primarily at two discrete locations and gives rise to two distinct glacially modified waters. Furthermore, we show that the location with the largest subglacial discharge is associated with the lighter, fresher glacially modified water mass. This is qualitatively consistent with results from an idealized plume model.Support was provided by the National Science Foundation’s Office of Polar Programs (NSF-OPP) through PLR-1418256 to F. Straneo, S. B. Das and A. J. Plueddemann, PLR-1023364 to S. B. Das, and through the Woods Hole Oceanographic Institution Ocean and Climate Change Institute Arctic Research Initiative to F. Straneo, S. B. Das, and A. J. Plueddemann. L. A. Stevens was also supported by a National Science Foundation Graduate Research Fellowship. S. B. Das was also supported by the Woods Hole Oceanographic Institution James E. and Barbara V. Moltz Research Fellowship. M. Morlighem was supported by the National Aeronautics and Space Administration’s (NASA) Cryospheric Sciences Program through NNX15AD55G

    Impact of HuR inhibition by the small molecule MS-444 on colorectal cancer cell tumorigenesis.

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    Colorectal cancer (CRC) is the third most common cancer and a leading cause of cancer-related mortality. Observed during CRC tumorigenesis is loss of post-transcriptional regulation of tumor-promoting genes such as COX-2, TNFα and VEGF. Overexpression of the RNA-binding protein HuR (ELAVL1) occurs during colon tumorigenesis and is abnormally present within the cytoplasm, where it post-transcriptionally regulates genes through its interaction with 3\u27UTR AU-rich elements (AREs). Here, we examine the therapeutic potential of targeting HuR using MS-444, a small molecule HuR inhibitor. Treatment of CRC cells with MS-444 resulted in growth inhibition and increased apoptotic gene expression, while similar treatment doses in non-transformed intestinal cells had no appreciable effects. Mechanistically, MS-444 disrupted HuR cytoplasmic trafficking and released ARE-mRNAs for localization to P-bodies, but did not affect total HuR expression levels. This resulted in MS-444-mediated inhibition of COX-2 and other ARE-mRNA expression levels. Importantly, MS-444 was well tolerated and inhibited xenograft CRC tumor growth through enhanced apoptosis and decreased angiogenesis upon intraperitoneal administration. In vivo treatment of MS-444 inhibited HuR cytoplasmic localization and decreased COX-2 expression in tumors. These findings provide evidence that therapeutic strategies to target HuR in CRC warrant further investigation in an effort to move this approach to the clinic
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