292 research outputs found

    Essential pediatric hypertension: defining the educational needs of primary care pediatricians

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    BACKGROUND: In order to better understand the educational needs regarding appropriate recognition, diagnosis and management of pediatric hypertension (HTN), we asked practicing pediatricians questions regarding their educational needs and comfort level on this topic. METHODS: We conducted 4 focus group sessions that included 27 participants representing pediatric residents, adolescent medicine physicians, clinic based pediatricians and office based pediatricians. Each focus group session lasted for approximately an hour and 90 pages of total transcriptions were produced verbatim from audio recordings. RESULTS: Four reviewers read each transcript and themes were elucidated from these transcripts. Overall, 5 major themes related to educational needs and clinical concerns were found: utilization of resources to define blood pressure (BP), correct BP measurement method(s), co-morbidities, barriers to care, and experience level with HTN. Six minor themes were also identified: differences in BP measurement, accuracy of BP, recognition of HTN, practice pattern of care, education of families and patients, and differences in level of training. The focus group participants were also questioned on their preferences regarding educational methods (i.e. e-learning, small group sessions, self-study, large group presentations) and revealed varied teaching and learning preferences. CONCLUSIONS: There are multiple methods to approach education regarding pediatric HTN for primary care pediatricians based on provider preferences and multiple educational activities should be pursued to achieve best outcomes. Based on this data, the next direction will be to develop and deliver multiple educational methods and to evaluate the impact on practice patterns of care for children and adolescents with HTN

    Dynamics of monatomic liquids

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    We present a theory of the dynamics of monatomic liquids built on two basic ideas: (1) The potential surface of the liquid contains three classes of intersecting nearly-harmonic valleys, one of which (the ``random'' class) vastly outnumbers the others and all whose members have the same depth and normal mode spectrum; and (2) the motion of particles in the liquid can be decomposed into oscillations in a single many-body valley, and nearly instantaneous inter-valley transitions called transits. We review the thermodynamic data which led to the theory, and we discuss the results of molecular dynamics (MD) simulations of sodium and Lennard-Jones argon which support the theory in more detail. Then we apply the theory to problems in equilibrium and nonequilibrium statistical mechanics, and we compare the results to experimental data and MD simulations. We also discuss our work in comparison with the QNM and INM research programs and suggest directions for future research.Comment: 53 pages, 16 figures. Differs from published version in using American English spelling and grammar (published version uses British English

    Observation of Single Transits in Supercooled Monatomic Liquids

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    A transit is the motion of a system from one many-particle potential energy valley to another. We report the observation of transits in molecular dynamics (MD) calculations of supercooled liquid argon and sodium. Each transit is a correlated simultaneous shift in the equilibrium positions of a small local group of particles, as revealed in the fluctuating graphs of the particle coordinates versus time. This is the first reported direct observation of transit motion in a monatomic liquid in thermal equilibrium. We found transits involving 2 to 11 particles, having mean shift in equilibrium position on the order of 0.4 R_1 in argon and 0.25 R_1 in sodium, where R_1 is the nearest neighbor distance. The time it takes for a transit to occur is approximately one mean vibrational period, confirming that transits are fast.Comment: 19 pages, 8 figure

    Test of a theoretical equation of state for elemental solids and liquids

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    We propose a means for constructing highly accurate equations of state (EOS) for elemental solids and liquids essentially from first principles, based upon a particular decomposition of the underlying condensed matter Hamiltonian for the nuclei and electrons. We also point out that at low pressures the neglect of anharmonic and electron-phonon terms, both contained in this formalism, results in errors of less than 5% in the thermal parts of the thermodynamic functions. Then we explicitly display the forms of the remaining terms in the EOS, commenting on the use of experiment and electronic structure theory to evaluate them. We also construct an EOS for Aluminum and compare the resulting Hugoniot with data up to 5 Mbar, both to illustrate our method and to see whether the approximation of neglecting anharmonicity et al. remains viable to such high pressures. We find a level of agreement with experiment that is consistent with the low-pressure results.Comment: Minor revisions for consistency with published versio

    Race Differences in Initial Presentation, Early Treatment, and 1-year Outcomes of Pediatric Crohnʼs Disease: Results from the ImproveCareNow Network

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    BACKGROUND: Racially disparate care has been shown to contribute to suboptimal health care outcomes for minorities. Using the ImproveCareNow network, we investigated differences in management and outcomes of pediatric patients with Crohn's disease at diagnosis and 1-year postdiagnosis. METHODS: ImproveCareNow is a learning health network for pediatric inflammatory bowel disease. It contains prospective, longitudinal data from outpatient encounters. This retrospective study included all patients with Crohn's disease ≤21 years, September 2006 to October 2014, with the first recorded encounter ≤90 days from date of diagnosis and an encounter 1 year ±60 days. We examined the effect of race on remission rate and treatment at diagnosis and 1 year from diagnosis using t-tests, Wilcoxon rank-sum tests, χ statistic, and Fisher's exact tests, where appropriate, followed by univariate regression models. RESULTS: Nine hundred seventy-six patients (Black = 118 (12%), White = 858 (88%), mean age = 13 years, 63% male) from 39 sites were included. Black children had a higher percentage of Medicaid insurance (44% versus 11%, P < 0.001). At diagnosis, Black children had more active disease according to physician global assessment (P = 0.027), but not by short Pediatric Crohn's Disease Activity Index (P = 0.67). Race differences in treatment were not identified. Black children had lower hematocrit (34.8 versus 36.7, P < 0.001) and albumin levels (3.6 versus 3.9, P = 0.001). At 1 year, Black children had more active disease according to physician global assessment (P = 0.016), but not by short Pediatric Crohn's Disease Activity Index (P = 0.06). CONCLUSIONS: Black children with Crohn's disease may have more severe disease than White children based on physician global assessment. Neither disease phenotype differences at diagnosis nor treatment differences at 1-year follow-up were identified

    Racial Disparities in Readmission, Complications, and Procedures in Children with Crohnʼs Disease:

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    Racial disparities in care and outcomes contribute to mortality and morbidity in children however the role in pediatric Crohn’s disease (CD) is unclear. In this study, we compared cohorts of Black and White children with CD to determine the extent race is associated with differences in readmissions, complications, and procedures among hospitalizations in the United States

    V-T Theory of Self Dynamic Response in a Monatomic Liquid

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    A new theoretical model for self dynamic response is developed using Vibration-Transit (V-T) theory, and is applied to liquid sodium at all wavevectors q from the hydrodynamic regime to the free particle limit. In this theory the zeroth-order Hamiltonian describes the vibrational motion in a single random valley harmonically extended to infinity. This Hamiltonian is tractable, is evaluated a priori for monatomic liquids, and the same Hamiltonian (the same set of eigenvalues and eigenvectors) is used for equilibrium and nonequlibrium theory. Here, for the self intermediate scattering function Fself(q,t) we find the vibrational contribution is in near perfect agreement with molecular dynamics (MD) through short and intermediate times, at all q. This is direct confirmation that normal mode vibrational correlations are present in the motion of the liquid state. The primary transit effect is diffusive motion of the vibrational equilibrium positions, as the liquid transits rapidly among random valleys. This motion is modeled as a standard random walk, and the resulting theoretical Fself(q,t) is in excellent agreement with MD results at all q and t. In the limit for q to infinity, the theory automatically exhibits the correct approach to the free-particle limit. Also in the limit for q to zero, the hydrodynamic limit emerges as well. In contrast to the benchmark theories of generalized hydrodynamics and mode coupling, the present theory is near a priori, while achieving modestly better accuracy. Therefore, in our view, it constitutes an improvement over the traditional theories.Comment: 16 pages, 11 figures, Journal Paper. Following referee's comments, Section IID has been completely rewritten and a new Section IIE has been adde

    The just meaningful difference in speech-to-noise ratio

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    The speech-to-noise ratio (SNR) in an environment plays a vital role in speech communication for both normal-hearing (NH) and hearing-impaired (HI) listeners. While hearing-assistance devices attempt to deliver as favorable an SNR as possible, there may be discrepancies between noticeable and meaningful improvements in SNR. Furthermore, it is not clear how much of an SNR improvement is necessary to induce intervention-seeking behavior. Here we report on a series of experiments examining the just-meaningful difference (JMD) in SNR. All experiments used sentences in same-spectrum noise, with two intervals on each trial mimicking examples of pre- and post-benefit situations. Different groups of NH and HI adults were asked (a) to rate how much better or worse the change in SNR was in a number of paired examples, (b) if they would swap the worse for the better SNR (e.g., their current device for another) or (c) if they would be willing to go to the clinic for the given increase in SNR. The mean SNR JMD based on better/worse ratings (one arbitrary unit) was similar to the just-noticeable difference, approximately 3 dB. However, the mean SNR JMD for the more clinically relevant tasks -- willingness (at least 50% of the time) to swap devices or attend the clinic for a change in SNR -- was 6-8 dB regardless of hearing ability. This SNR JMD of the order of 6 dB provides a new benchmark, indicating the SNR improvement necessary to immediately motivate participants to seek intervention

    Lattice Dynamics and the High Pressure Equation of State of Au

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    Elastic constants and zone-boundary phonon frequencies of gold are calculated by total energy electronic structure methods to twofold compression. A generalized force constant model is used to interpolate throughout the Brillouin zone and evaluate moments of the phonon distribution. The moments are used to calculate the volume dependence of the Gruneisen parameter in the fcc solid. Using these results with ultrasonic and shock data, we formulate the complete free energy for solid Au. This free energy is given as a set of closed form expressions, which are valid to compressions of at least V/V_0 = 0.65 and temperatures up to melting. Beyond this density, the Hugoniot enters the solid-liquid mixed phase region. Effects of shock melting on the Hugoniot are discussed within an approximate model. We compare with proposed standards for the equation of state to pressures of ~200 GPa. Our result for the room temperature isotherm is in very good agreement with an earlier standard of Heinz and Jeanloz.Comment: 13 pages, 8 figures. Accepted by Phys. Rev.

    Twelve tips for organising speed mentoring events for healthcare professionals at small or large-scale venues

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    Mentors play a critical role in the development of professionals, influencing their job satisfaction, career aspirations and evolving professional identity. A variety of mentoring models exist, each with distinct benefits and challenges. Speed mentoring, based on the concept of speed dating, provides mentees with opportunities to meet multiple mentors over a short time and pose focussed career development questions. At large-scale events such as the annual AMEE (Association for Medical Education in Europe) meeting, speed mentoring sessions can successfully connect aspiring, novice and mid-career educators with international educational leaders to facilitate transfer of valuable insights for professional growth. For some mentors and mentees, this might spur ongoing communications or even longitudinal relationships. In this paper, we aim to provide strategies for planning and implementing speed mentoring events, combining insights gained from the literature and our experience of organising speed mentoring at the 2019 AMEE meeting in Vienna. These tips will be useful to a variety of professionals planning to organise speed mentoring initiatives
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