1,408 research outputs found

    Borosilicate wetting on ceramic matrix composites and Si-based substrates

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    The oxidation of Ceramic Matrix Composites (CMCs) is a complex process due to the combined oxidation of ceramic fibers, matrix, and an interphase. In previous work, the oxidation of CVD SiC coated SiC/BN/SiC CMCs with a single uncoated face exposing the fibers, matrix, and interphase was studied at temperatures of 800, 1200, and 1300°C. The thermal oxidation of the exposed face was characterized to understand crack-sealing in CMCs during use. During thermal oxidation, the exposed face of the CMC was sealed by borosilicate glass formation. Oxide droplets were observed to form at BN/SiC interfaces. In this work, stand-alone borosilicate glass cylinders situated on SiC, Si, or SiO2 substrates were heated in air and visualized in situ using a heating microscope. Changes in oxide morphology, volatility, and wetting were characterized as a function of borosilicate and substrate composition. Results from stand-alone glasses were compared with the observations from exposed CMC faces to elucidate mechanisms of composite sealing during thermal oxidation

    Editorial: Relevance Theory and Intercultural Communication Problems

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    This editorial to the special issue of RiL dedicated to relevance theory and problems of intercultural communication addresses the general requirements that a theory of communication must meet to be applicable to the analysis of intercultural communication. Then it discusses criticism levelled against Grice’s theory of conversational implicature and Brown and Levinson’s theory of politeness on the grounds that these theories were not universal enough to be applied to all data. Finally, it offers some remarks on the applicability of relevance theory to intercultural pragmatics

    Prevalence and Predictors of Depressive Symptoms in NCAA Division III Collegiate Athletes

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    Mental health disorders are important health concerns among collegiate athletes. Estimations of elevated depressive symptoms in this population range from 1.1-26%. However, these data are derived mostly from NCAA Division I institutions or professional athletes. Evidence from lower divisions (e.g., NCAA Division III) is currently sparse in the literature. Hence, the primary purpose of the present study was to examine the prevalence of depressive symptoms in NCAA Division III collegiate athletes. The secondary purpose was to examine which mental health indicators predict depressive symptoms. In total, 186 participants completed several mental health scales (e.g., PHQ-9, DASS-21). The results revealed a prevalence of 16.2% of elevated depressive symptoms. A multiple regression predicted 46.1% of the variance of depressive symptoms. Significant predictors were stress, anxiety, devaluation, and emotional exhaustion. While NCAA Division III collegiate athletes may face lower athletic expectations, the prevalence of mental health concerns is similar to those observed in Division I collegiate athletes

    A thematic analysis of smokers’ and non-smokers’ accounts of E-cigarettes

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    This study explored smokers’ and non-smokers’ accounts of E-cigarettes. A total of 51 UK-based participants, 20 men and 31 women, responded to open-ended questions online. Inductive thematic analysis identified that the factors that influence E-cigarette behaviour and opinion in adult smokers and non-smokers are related to social context, informative sources, practical aspects and health implications. Participants presented varying accounts of E-cigarettes, suggesting that individual narratives regarding E-cigarettes are multi-faceted. This is important information for health professionals and policy makers tasked with advising on E-cigarette use

    Phosphofructokinase 1 Glycosylation Regulates Cell Growth and Metabolism

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    Cancer cells must satisfy the metabolic demands of rapid cell growth within a continually changing microenvironment. We demonstrated that the dynamic posttranslational modification of proteins by O-linked β-N-acetylglucosamine (O-GlcNAcylation) is a key metabolic regulator of glucose metabolism. O-GlcNAcylation was induced at serine 529 of phosphofructokinase 1 (PFK1) in response to hypoxia. Glycosylation inhibited PFK1 activity and redirected glucose flux through the pentose phosphate pathway, thereby conferring a selective growth advantage on cancer cells. Blocking glycosylation of PFK1 at serine 529 reduced cancer cell proliferation in vitro and impaired tumor formation in vivo. These studies reveal a previously uncharacterized mechanism for the regulation of metabolic pathways in cancer and a possible target for therapeutic intervention

    A simulation study of BrachyShade, a shadow-based internal source tracking system for HDR prostate brachytherapy

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    This paper presents a simulation study of BrachyShade, a proposed internal source-tracking system for real time quality assurance in high dose rate prostate brachytherapy. BrachyShade consists of a set of spherical tungsten occluders located above a pixellated silicon photodetector. The source location is estimated by minimising the mean squared error between a parametric model of the shadow image and acquired images of the shadows projected on the detector plane. A novel algorithm is finally employed to correct the systemic error resulting from Compton scattering in the medium. The worst-case error obtained with BrachyShade for a 13.5 ms image acquisition is less than 1.3 mm in the most distant part of the treatment volume, while for 75% of source locations an error of less than 0.42 mm was achieved

    The Grizzly, May 1, 1981

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    Kane Appointed to Newly Created Position • St. Andrews Scholarship • APO Chapter Applauded for Achievement • Lewis Thomas to Address Graduates • Education Outside Classroom Stressed • Beta Sig Violates Pledging Guidelines • Transplanted Texan • Music News • Girls\u27 Track First • Lacrosse Tops Penn State • Tennis Completes Seasonhttps://digitalcommons.ursinus.edu/grizzlynews/1059/thumbnail.jp

    Learning to work together - lessons from a reflective analysis of a research project on public involvement

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    Abstract Background Patient and public involvement (PPI) is now an expectation of research funders, in the UK, but there is relatively little published literature on what this means in practice – nor is there much evaluative research about implementation and outputs. Policy literature endorses the need to include PPI representation at all stages of planning, performing and research dissemination, and recommends resource allocation to these roles; but details of how to make such inputs effective in practice are less common. While literature on power and participation informs the debate, there are relatively few published case studies of how this can play out through the lived experience of PPI in research; early findings highlight key issues around access to knowledge, resources, and interpersonal respect. This article describes the findings of a case study of PPI within a study about PPI in research. Methods The aim of the study was to look at how the PPI representatives’ inputs had developed over time, key challenges and changes, and lessons learned. We used realist evaluation and normalisation process theory to frame and analyse the data, which was drawn from project documentation, minutes of meetings and workshops, field notes and observations made by PPI representatives and researchers; documented feedback after meetings and activities; and the structured feedback from two formal reflective meetings. Findings Key findings included the need for named contacts who support, integrate and work with PPI contributors and researchers, to ensure partnership working is encouraged and supported to be as effective as possible. A structure for partnership working enabled this to be enacted systematically across all settings. Some individual tensions were nonetheless identified around different roles, with possible implications for clarifying expectations and deepening understandings of the different types of PPI contribution and of their importance. Even in a team with research expertise in PPI, the data showed that there were different phases and challenges to ‘normalising’ the PPI input to the project. Mutual commitment and flexibility, embedded through relationships across the team, led to inclusion and collaboration. Conclusion Work on developing relationships and teambuilding are as important for enabling partnership between PPI representatives and researchers as more practical components such as funding and information sharing. Early explicit exploration of the different roles and their contributions may assist effective participation and satisfaction

    High-dispersion absorption-line spectroscopy of AE Aqr

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    High-dispersion time-resolved spectroscopy of the unique magnetic cataclysmic variable AE Aqr is presented. A radial velocity analysis of the absorption lines yields K2= 168.7 ± 1 km s−1. Substantial deviations of the radial velocity curve from a sinusoid are interpreted in terms of intensity variations over the secondary star's surface. A complex rotational velocity curve as a function of orbital phase is detected which has a modulation frequency of twice the orbital frequency, leading to an estimate of the binary inclination angle that is close to 70°. The minimum and maximum rotational velocities are used to indirectly derive a mass ratio of q= 0.6 and a radial velocity semi-amplitude of the white dwarf of K1= 101 ± 3 km s−1. We present an atmospheric temperature indicator, based on the absorption-line ratio of Fe I and Cr I lines, whose variation indicates that the secondary star varies from K0 to K4 as a function of orbital phase. The ephemeris of the system has been revised, using more than 1000 radial velocity measurements, published over nearly five decades. From the derived radial velocity semi-amplitudes and the estimated inclination angle, we calculate that the masses of the stars are M1= 0.63 ± 0.05 M⊙; M2= 0.37 ± 0.04 M⊙, and their separation is a= 2.33 ± 0.02 R⊙. Our analysis indicates the presence of a late-type star whose radius is larger, by a factor of nearly 2, than the radius of a normal main-sequence star of the same mass. Finally, we discuss the possibility that the measured variations in the rotational velocity, temperature and spectral type of the secondary star as functions of orbital phase may, like the radial velocity variations, be attributable to regions of enhanced absorption on the star's surface

    Evaluation of an ambulatory system for the quantification of cough frequency in patients with chronic obstructive pulmonary disease

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    BACKGROUND: To date, methods used to assess cough have been primarily subjective, and only broadly reflect the impact of chronic cough and/or chronic cough therapies on quality of life. Objective assessment of cough has been attempted, but early techniques were neither ambulatory nor feasible for long-term data collection. We evaluated a novel ambulatory cardio-respiratory monitoring system with an integrated unidirectional, contact microphone, and report here the results from a study of patients with COPD who were videotaped in a quasi-controlled environment for 24 continuous hours while wearing the ambulatory system. METHODS: Eight patients with a documented history of COPD with ten or more years of smoking (6 women; age 57.4 ± 11.8 yrs.; percent predicted FEV(1 )49.6 ± 13.7%) who complained of cough were evaluated in a clinical research unit equipped with video and sound recording capabilities. All patients wore the LifeShirt(® )system (LS) while undergoing simultaneous video (with sound) surveillance. Video data were visually inspected and annotated to indicate all cough events. Raw physiologic data records were visually inspected by technicians who remained blinded to the video data. Cough events from LS were analyzed quantitatively with a specialized software algorithm to identify cough. The output of the software algorithm was compared to video records on a per event basis in order to determine the validity of the LS system to detect cough in COPD patients. RESULTS: Video surveillance identified a total of 3,645 coughs, while LS identified 3,363 coughs during the same period. The median cough rate per patient was 21.3 coughs·hr(-1 )(Range: 10.1 cghs·hr(-1 )– 59.9 cghs·hr(-1)). The overall accuracy of the LS system was 99.0%. Overall sensitivity and specificity of LS, when compared to video surveillance, were 0.781 and 0.996, respectively, while positive- and negative-predictive values were 0.846 and 0.994. There was very good agreement between the LS system and video (kappa = 0.807). CONCLUSION: The LS system demonstrated a high level of accuracy and agreement when compared to video surveillance for the measurement of cough in patients with COPD
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