6,481 research outputs found

    Probing the Rosette Nebula Stellar Bubble with Faraday Rotation

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    We report the results of Faraday rotation measurements of 23 background radio sources whose lines of sight pass through or close to the Rosette Nebula. The Rosette Nebula is an excellent candidate for studies of super bubbles associated with young star clusters. We made linear polarization measurements with the Karl G. Jansky Very Large Array (JVLA) at frequencies of 4.4GHz, 4.9GHz, and 7.7GHz. We are able to establish a background rotation measure in this part of the sky due to the Galaxy of +147 rad m^-2. Sources whose lines of sight pass through the nebula have an excess rotation measure of 50-750 rad m^-2, which we attribute to the plasma shell of the Rosette Nebula. We consider two simple plasma shell models and how they reproduce the magnitude and sign of the rotation measure, and its dependence on distance from the center of the nebula. These two models represent different modes of interaction of the Rosette Nebula star cluster with the surrounding interstellar medium. Both can reproduce the magnitude and spatial extent of the rotation measure enhancement, given plausible free parameters. We contend that the model based on a stellar bubble more closely reproduces the observed dependence of rotation measure on distance from the center of the nebula.Comment: 10 figure

    Effects of Laryngeal Restriction on Pharyngeal Peristalsis and Biomechanics: Clinical Implications

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    To date, rehabilitative exercises aimed at strengthening the pharyngeal muscles have not been developed due to the inability to successfully overload and fatigue these muscles during their contraction, a necessary requirement for strength training. The purpose of this study was to test the hypothesis that applying resistance against anterosuperior movement of the hyolaryngeal complex will overload the pharyngeal muscles and by repetitive swallowing will result in their fatigue manifested by a reduction in pharyngeal peristaltic amplitude. Studies were done in two groups. In group 1 studies 15 healthy subjects (age: 42 ± 14 yr, 11 females) were studied to determine whether imposing resistance to swallowing using a handmade device can affect the swallow-induced hyolaryngeal excursion and related upper esophageal sphincter (UES) opening. In group 2, an additional 15 healthy subjects (age 56 ± 25 yr, 7 females) were studied to determine whether imposing resistance to the anterosuperior excursion of the hyolaryngeal complex induces fatigue manifested as reduction in pharyngeal contractile pressure during repeated swallowing. Analysis of the video recordings showed significant decrease in maximum deglutitive superior laryngeal excursion and UES opening diameter (P \u3c 0.01) due to resistive load. Consecutive swallows against the resistive load showed significant decrease in pharyngeal contractile integral (PhCI) values (P \u3c 0.01). Correlation analysis showed a significant negative correlation between PhCI and successive swallows, suggesting “fatigue” (P \u3c 0.001). In conclusion, repeated swallows against a resistive load induced by restricting the anterosuperior excursion of the larynx safely induces fatigue in pharyngeal peristalsis and thus has the potential to strengthen the pharyngeal contractile function

    Blending Learning: The Evolution of Online and Face-to-Face Education from 20082015

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    In 2008, iNACOL produced a series of papers documenting promising practices identified throughout the field of K–12 online learning. Since then, we have witnessed a tremendous acceleration of transformative policy and practice driving personalized learning in the K–12 education space. State, district, school, and classroom leaders recognize that the ultimate potential for blended and online learning lies in the opportunity to transform the education system and enable higher levels of learning through competency-based approaches.iNACOL's core work adds significant value to the field by providing a powerful practitioner voice in policy advocacy, communications, and in the creation of resources and best practices to enable transformational change in K–12 education.We worked with leaders throughout the field to update these resources for a new generation of pioneers working towards the creation of student-centered learning environments.This refreshed series, Promising Practices in Blended and Online Learning, explores some of the approaches developed by practitioners and policymakers in response to key issues in K–12 education, including:Blended Learning: The Evolution of Online and Face-to-Face Education from 2008-2015;Using Blended and Online Learning for Credit Recovery and At-Risk Students;Oversight and Management of Blended and Online Programs: Ensuring Quality and Accountability; andFunding and Legislation for Blended and Online Education.Personalized learning environments provide the very best educational opportunities and personalized pathways for all students, with highly qualified teachers delivering world-class instruction using innovative digital resources and content. Through this series of white papers, we are pleased to share the promising practices in K–12 blended, online, and competency education transforming teaching and learning today

    Nutrition Education in Vermont Public Schools

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    Introduction. Despite positive changes, childhood obesity and food insecurity remain prevalent across the country. Vermont is not immune to these issues. We set out to: research the level of nutrition education Vermont elementary schools provide their students, understand teacher perceptions of these programs, and recommend ways to fill identified gaps. Methods. Our study is a cross-sectional survey of Vermont educators around nutrition education. The survey consisted of 17 questions, used LimeSurvey, and included demographic and nutrition education questions. The survey was distributed statewide through newsletters and list-servers. Results. 64 responses met inclusion criteria. Vermont elementary school (K-6) teachers report a mean satisfaction score of 2.51 out of 5.0 for their schools\u27 current nutrition education programs. School nurses reported a score of 2.5 out of 5.0. Highest satisfaction scores included school administrators and health and wellness coordinators (3.3 out of 5.0). When comparing teachers to non-classroom educators (administrators and nutrition educators) data showed a significant difference between high satisfaction (3-5) and low satisfaction (1-2); (Fischer p = 0.009). Overall, Vermont elementary school teachers report a high level of knowledge about nutrition, (4.1/5.0), but a lower level of understanding in their students (2.5/5.0). Conclusions. Given teacher perceptions regarding current school nutrition education programs, development and implementation of a state-wide nutrition education curriculum with dedicated teaching time may be warranted. Programs recommended by the CDC include Eat Well & Get Moving and Planet Health, designed by the Harvard School of Public Health. These could be adapted as a framework for Vermont.https://scholarworks.uvm.edu/comphp_gallery/1244/thumbnail.jp

    β-diketonate versus β-ketoiminate:the importance of a ferrocenyl moiety on improving the anticancer potency

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    Herein we present a library of fully characterized beta-diketonate and beta-ketoiminate compounds that are functionalized with a ferrocenyl moiety. Their cytotoxic potential has been determined by screening against human breast adenocarcinomas (MCF-7 and MDA-MB-231), human colorectal carcinoma p53 wild type (HCT116 p53(+/+)) and normal human prostate (PNT2) cell lines. The ferrocenyl beta-diketonate compounds are more than 18 times more cytotoxic than the ferrocenyl beta-ketoiminate analogues. Against MCF-7, compounds functionalized at the meta position are up to nine times more cytotoxic than when functionalized at the para position. The ferrocenyl beta-diketonate compounds have increased selectivity towards MCF-7 and MDA-MB-231, with several complexes having selectivity index (SI) values that are more than nine times (MCF-7) and more than six times (MDA-MB-231) that of carboplatin. The stability of these compounds in dimethyl sulfoxide (DMSO) and dimethylformamide (DMF) has been assessed by NMR spectroscopy and mass spectrometry studies, and the compounds show no oxidation of the iron center from Fe-II to Fe-III. Cytotoxicity screening was performed in both DMSO and DMF, with no significant differences observedin their potency

    The Extremely Luminous Quasar Survey in the Pan-STARRS 1 Footprint (PS-ELQS)

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    We present the results of the Extremely Luminous Quasar Survey in the 3π3\pi survey of the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS; PS1). This effort applies the successful quasar selection strategy of the Extremely Luminous Survey in the Sloan Digital Sky Survey footprint (12,000deg2\sim12,000\,\rm{deg}^2) to a much larger area (21486deg2\sim\rm{21486}\,\rm{deg}^2). This spectroscopic survey targets the most luminous quasars (M145026.5M_{1450}\le-26.5; mi18.5m_{i}\le18.5) at intermediate redshifts (z2.8z\ge2.8). Candidates are selected based on a near-infrared JKW2 color cut using WISE AllWISE and 2MASS photometry to mainly reject stellar contaminants. Photometric redshifts (zregz_{\rm{reg}}) and star-quasar classifications for each candidate are calculated from near-infrared and optical photometry using the supervised machine learning technique random forests. We select 806 quasar candidates at zreg2.8z_{\rm{reg}}\ge2.8 from a parent sample of 74318 sources. After exclusion of known sources and rejection of candidates with unreliable photometry, we have taken optical identification spectra for 290 of our 334 good PS-ELQS candidates. We report the discovery of 190 new z2.8z\ge2.8 quasars and an additional 28 quasars at lower redshifts. A total of 44 good PS-ELQS candidates remain unobserved. Including all known quasars at z2.8z\ge2.8, our quasar selection method has a selection efficiency of at least 77%77\%. At lower declinations 30Decl.0-30\le\rm{Decl.}\le0 we approximately triple the known population of extremely luminous quasars. We provide the PS-ELQS quasar catalog with a total of 592 luminous quasars (mi18.5m_{i}\le18.5, z2.8z\ge2.8). This unique sample will not only be able to provide constraints on the volume density and quasar clustering of extremely luminous quasars, but also offers valuable targets for studies of the intergalactic medium.Comment: 34 pages, 10 figures, accepted to ApJ

    Effects of aging on identifying emotions conveyed by point-light walkers

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    M.G. was supported by EC FP7 HBP (grant 604102), PITN-GA-011-290011 (ABC) FP7-ICT-2013-10/ 611909 (KOROIBOT), and by GI 305/4-1 and KA 1258/15-1, and BMBF, FKZ: 01GQ1002A. K.S.P. was supported by a BBSRC New Investigator Grant. A.B.S. and P.J.B. were supported by an operating grant (528206) from the Canadian Institutes for Health Research. The authors also thank Donna Waxman for her valuable help in data collection for all experiments described here.Peer reviewedPostprin

    The rapid emergence of stimulus specific perceptual learning

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    Is stimulus specific perceptual learning the result of extended practice or does it emerge early in the time course of learning? We examined this issue by manipulating the amount of practice given on a face identification task on Day 1, and altering the familiarity of stimuli on Day 2. We found that a small number of trials was sufficient to produce stimulus specific perceptual learning of faces: on Day 2, response accuracy decreased by the same amount for novel stimuli regardless of whether observers practiced 105 or 840 trials on Day 1. Current models of learning assume early procedural improvements followed by late stimulus specific gains. Our results show that stimulus specific and procedural improvements are distributed throughout the time course of learning
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