1,361 research outputs found

    Trends in Elasticity and Electronic Structure of Transition-Metal Nitrides and Carbides from First Principles

    Full text link
    The elastic properties of the B1B_1-structured transition-metal nitrides and their carbide counterparts are studied using the {\it ab initio\} density functional perturbation theory. The linear response results of elastic constants are in excellent agreement with those obtained from numerical derivative methods, and are also consistent with measured data. We find the following trends: (1) Bulk moduli BB and tetragonal shear moduli G=(C11C12)/2G^{\prime}=(C_{11}-C_{12})/2, increase and lattice constants a0a_{0} decrease rightward or downward on the Periodic Table for the metal component or if C is replaced by N; (2) The inequality B>G>G>0B > G^{\prime} > G > 0 holds for G=C44G=C_{44}; (3) GG depends strongly on the number of valence electrons per unit cell (ZVZ_{V}). From the fitted curve of GG as a function of ZVZ_{V}, we can predict that MoN is unstable in B1B_{1} structure, and transition-metal carbonitrides (e.g.e.g. ZrCx_{x}N1x_{1-x}) and di-transition-metal carbides (e.g.e.g. Hfx_{x}Ta1x_{1-x}C) have maximum GG at ZV8.3Z_{V} \approx 8.3.Comment: 4 pages, 2 figures, submitted to PRL. 2 typos in ref. 15 were correcte

    A facility for high resolution spectroscopy: Laboratory and ground based observations in support of upper atmospheric research

    Get PDF
    This research task consists of operating a facility for making spectroscopic observations in support of upper atmospheric research. The facility responds to the needs and interests of the visiting investigators. Therefore, the research objectives are not predetermined except in broad outline. The emphasis is on studies that take advantage of the particular strengths of the Fourier Transform Spectrometer on Kitt Peak: high spectral resolution combined with wide spectral range and low noise

    Faculty Development As a Tool to Impact Culturally Competent Care of Sexual and Gender Minorities

    Get PDF
    Presentation: 5:39 Background: This poster focuses on the integration of faculty development of sexual and gender identity health knowledge and skill into health education. There is a gap in inclusion of this content in health professional curriculum. While awareness of LGBTQ+ population health has been indirectly addressed within curriculum, a consistent approach targeting all coursework and faculty can increase culturally competent care of patients that identify as LGBTQ+. Faculty confidence, awareness, and experience regarding knowledge, respectful terminology, and skill directly impacts the likelihood of students becoming culturally competent practitioners. Objectives: The objectives of this poster are to share outcomes of faculty development. This poster will: ● Discuss integration of faculty roles in academia and health profession accreditation standards with theories of cultural competence and humility inclusive of sexual and gender minorities; ● Describe a faculty development program to build foundational understanding of respectful terminology to optimize trust and respect when conversing with/about individuals within sexual and gender minority populations; ● Demonstrate changes in knowledge, awareness, skill, and perceived comfort with sexual and gender minority communities following participation in the program. Methods/ Research: Monthly structured learning sessions were paired with 20-30 minute mentoring check-ins with Sexual and Gender Minorities Education and Training (SG-MET) faculty to address components of LGBTQ+ inclusive curriculum. Pre, mid, and post surveys, composed of open and close-ended questions, assessed satisfaction and changes in knowledge, awareness, and perception of skills. Standardized assessments of sexual and gender minority knowledge, experience and clinical skills were completed and collected anonymously through an electronic survey system to protect the faculty’s identification. Conclusions/ Impact: This faculty development program provides pilot data to suggest that this is an effective way to increase knowledge, awareness, and skills in the area of sexual and gender minority health content delivery and practice to impact healthcare disparities in these populations.https://jdc.jefferson.edu/sexandgenderhealth/1001/thumbnail.jp

    Radio Frequency Spectra of 388 Bright 74 MHz Sources

    Full text link
    As a service to the community, we have compiled radio frequency spectra from the literature for all sources within the VLA Low Frequency Sky Survey (VLSS) that are brighter than 15 Jy at 74 MHz. Over 160 references were used to maximize the amount of spectral data used in the compilation of the spectra, while also taking care to determine the corrections needed to put the flux densities from all reference on the same absolute flux density scale. With the new VLSS data, we are able to vastly improve upon previous efforts to compile spectra of bright radio sources to frequencies below 100 MHz because (1) the VLSS flux densities are more reliable than those from some previous low frequency surveys and (2) the VLSS covers a much larger area of the sky (declination >-30 deg.) than many other low frequency surveys (e.g., the 8C survey). In this paper, we discuss how the spectra were constructed and how parameters quantifying the shapes of the spectra were derived. Both the spectra and the shape parameters are made available here to assist in the calibration of observations made with current and future low frequency radio facilities.Comment: Accepted to ApJ

    Nasal IL-13 production identifies patients with late phase allergic responses

    Get PDF
    BACKGROUND: There is limited knowledge on how local cytokine secretion patterns after nasal allergen challenge correlate with clinical symptoms especially with regards to the "late allergic response" (LAR) which occurs in approximately 40-50% of allergic patients. OBJECTIVE: In this study we aimed to characterise the immunological and clinical nasal responses to birch pollen allergen challenge with a special focus on the LAR. METHODS: In this randomised double-blinded placebo-control trial, birch pollen allergic participants were challenged with pollen extract (n=20) or placebo (n=10) on three consecutive days. On days one and three nasal secretions were collected at selected time points over a 24h time course for the measurement of 33 inflammatory mediators. Clinical responses were determined through subjective symptom scores and objective nasal airflow measurements. RESULTS: Provoked participants had significantly greater clinical responses and showed significant increases in tryptase and sST2 within minutes compared to placebo. Eight out of 20 provoked participants displayed high IL-13 levels 2-8 hours after allergen provocation. This group also showed significant changes in clinical parameters, with a secondary drop in nasal airflow measured by peak nasal inspiratory flow and increased symptoms of nasal obstruction which significantly differed from IL-13 non responders at 6 hours. CONCLUSION: IL-13 response status correlates with cytokine and clinical responses in the late phase after allergen provocation

    A forming, dust enshrouded disk at z=0.43: the first example of a late type disk rebuilt after a major merger?

    Full text link
    Abreg: By combining HST/UDF imagery with kinematics from VLT/GIRAFFE we derive a physical model of distant galaxy J033245.11-274724.0 in a way similar to what can be done in the nearby Universe. Here we study the properties of a distant compact LIRGs galaxy. Given the photometric and spectro photometric accuracies, we can decompose the galaxy in sub components and correct them for reddening. The galaxy is dominated by a dust enshrouded disk revealed by UDF imagery. The disk radius is half that of the Milky Way and the galaxy have a SFR=20Mo/yr. Morphology and kinematics show that gas and stars together spiral inwards rapidly to feed the disk and the central regions. A combined system of a bar and two non rotating spiral arms regulates the material accretion, induces large sigma, with sigma larger than 100 km/s and redistributes the angular momentum (AM). The detailed physical properties resemble to the expectations from modeling a merger of two equal mass, gaseous rich galaxies, 0.5 Gyr after the merger. In its later evolution, this galaxy could become a late type galaxy which falls on the T-F relation, with an AM mostly induced by the orbital AM of the merger.Comment: (1) GEPI observatoire de Paris Meudon (2) LAM (3) ESO Garching (4) IAP Accepted for publication in A&

    GOLIAH (Gaming Open Library for Intervention in Autism at Home): a 6-month single blind matched controlled exploratory study

    Get PDF
    BackgroundTo meet the required hours of intensive intervention for treating children with autism spectrum disorder (ASD), we developed an automated serious gaming platform (11 games) to deliver intervention at home (GOLIAH) by mapping the imitation and joint attention (JA) subset of age-adapted stimuli from the Early Start Denver Model (ESDM) intervention. Here, we report the results of a 6-month matched controlled exploratory study.MethodsFrom two specialized clinics, we included 14 children (age range 5–8 years) with ASD and 10 controls matched for gender, age, sites, and treatment as usual (TAU). Participants from the experimental group received in addition to TAU four 30-min sessions with GOLIAH per week at home and one at hospital for 6 months. Statistics were performed using Linear Mixed Models.ResultsChildren and parents participated in 40% of the planned sessions. They were able to use the 11 games, and participants trained with GOLIAH improved time to perform the task in most JA games and imitation scores in most imitation games. GOLIAH intervention did not affect Parental Stress Index scores. At end-point, we found in both groups a significant improvement for Autism Diagnostic Observation Schedule scores, Vineland socialization score, Parental Stress Index total score, and Child Behavior Checklist internalizing, externalizing and total problems. However, we found no significant change for by time × group interaction.ConclusionsDespite the lack of superiority of TAU + GOLIAH versus TAU, the results are interesting both in terms of changes by using the gaming platform and lack of parental stress increase. A large randomized controlled trial with younger participants (who are the core target of ESDM model) is now discussed. This should be facilitated by computing GOLIAH for a web platform.Trial registration Clinicaltrials.gov NCT0256041

    Instructional multimedia: An investigation of student and instructor attitudes and student study behavior

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Educators in allied health and medical education programs utilize instructional multimedia to facilitate psychomotor skill acquisition in students. This study examines the effects of instructional multimedia on student and instructor attitudes and student study behavior.</p> <p>Methods</p> <p>Subjects consisted of 45 student physical therapists from two universities. Two skill sets were taught during the course of the study. Skill set one consisted of knee examination techniques and skill set two consisted of ankle/foot examination techniques. For each skill set, subjects were randomly assigned to either a control group or an experimental group. The control group was taught with live demonstration of the examination skills, while the experimental group was taught using multimedia. A cross-over design was utilized so that subjects in the control group for skill set one served as the experimental group for skill set two, and vice versa. During the last week of the study, students and instructors completed written questionnaires to assess attitude toward teaching methods, and students answered questions regarding study behavior.</p> <p>Results</p> <p>There were no differences between the two instructional groups in attitudes, but students in the experimental group for skill set two reported greater study time alone compared to other groups.</p> <p>Conclusions</p> <p>Multimedia provides an efficient method to teach psychomotor skills to students entering the health professions. Both students and instructors identified advantages and disadvantages for both instructional techniques. Reponses relative to instructional multimedia emphasized efficiency, processing level, autonomy, and detail of instruction compared to live presentation. Students and instructors identified conflicting views of instructional detail and control of the content.</p
    corecore