9,105 research outputs found

    Dynamic magnetic response of infinite arrays of ferromagnetic particles

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    Recently developed techniques to find the eigenmodes of a ferromagnetic particle of arbitrary shape, as well as the absorption in the presence of an inhomogeneous radio-frequency field, are extended to treat infinite lattices of such particles. The method is applied to analyze the results of recent FMR experiments, and yields substantially good agreement between theory and experiment

    Research with bereaved families

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    Theoretical debates about the nature of grief and bereavement draw attention to the sensitivity of carrying out research with bereaved people, the possible threats that this may pose and the ethical considerations required to ameliorate potentially damaging outcomes. The authors of this article present a framework for ethical decision-making that has been successfully developed in the context of research with bereaved families. The discussion focuses on application and evaluation of the framework during research with family members who were approached about the donation of a deceased relative’s organs and/or tissues for transplantation. Practical strategies of relevance to the processes of participant recruitment, the interview encounter and follow-up care in the post-interview period are identified and discussed. Concerns about the possible impact of bereavement research are balanced with the views of family members who gave credence to the therapeutic and cathartic benefits of participating in sensitive, death-related research. </jats:p

    Childhood traumatic infarction causing left ventricular aneurysm: Diagnosis by two-dimensional echocardiography

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    After being struck by an automobile, a 9 year old boy developed transient right bundle branch block followed by electrocardiographic changes of inferior wall myocardial infarction and an increase of serum cardiac enzymes. Two-dimensional echocardiography demonstrated a prominent septal aneurysm. Subsequent cardiac catheterization confirmed septal aneurysm and demon- strated an additional inferior aneurysm. Six weeks after the accident, resection of the inferior aneurysm was performed. At 1 year follow-up study, residual septal aneurysm and cardiomegaly are present, but the boy is asymptomatic

    Hartford Hub: Transforming Lower Lincoln

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    Breeah S. Carey received her degree in speech, language, and hearing sciences with minors in Spanish and psychology from Purdue University in May 2018. She is currently pursuing her master’s degree in speech-language pathology at Purdue University and wants to serve pediatric clients in school and clinic settings. She has volunteered in various schools in Newark, New Jersey, as a tutor in her mother’s after-school program and as a speaker for the Diamond’s in the Rough Program at Belmont Runyon Elementary School, where she encouraged minority girls to attend college in the future. Lauren Jankowski is a senior in interdisciplinary engineering who plans to pursue graduate school and focus her research on mental illness. She has volunteered with several organizations, such as St. Vincent de Paul, Hannah’s House, and Upward Basketball, since early high school. Madison Long received her degree in accounting from Purdue University in 2017 and began her career with Microsoft Corporation in Seattle, Washington, in their finance division. At Purdue, she frequently participated in local Lafayette community initiatives centered around child literacy and engagement, including United Way’s Read to Succeed Program and the Beck Lane Boys and Girls Club after-school volunteering program. Joshua Walker is a senior in mechanical engineering with a minor in computer science and plans to earn a master’s degree in mechanical engineering after a few years of work experience. He has provided one-on-one assistance with students at the free Math and Science Tutoring Center in his high school, refurbished bicycles intended for community use at Revolutions Bicycle Cooperative in Memphis, Tennessee, and worked with Engineers for a Sustainable World to keep tailgating parties at Purdue clean of trash

    Boussinesq/Boussinesq systems for internal waves with a free surface, and the KdV approximation

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    We study here some asymptotic models for the propagation of internal and surface waves in a two-fluid system. We focus on the so-called long wave regime for one dimensional waves, and consider the case of a flat bottom. Starting from the classical Boussinesq/Boussinesq system, we introduce a new family of equivalent symmetric hyperbolic systems. We study the well-posedness of such systems, and the asymptotic convergence of their solutions towards solutions of the full Euler system. Then, we provide a rigorous justification of the so-called KdV approximation, stating that any bounded solution of the full Euler system can be decomposed into four propagating waves, each of them being well approximated by the solutions of uncoupled Korteweg-de Vries equations. Our method also applies for models with the rigid lid assumption, and the precise behavior of the KdV approximations depending on the depth and density ratios is discussed for both rigid lid and free surface configurations. The fact that we obtain {\it simultaneously} the four KdV equations allows us to study extensively the influence of the rigid lid assumption on the evolution of the interface, and therefore its domain of validity. Finally, solutions of the Boussinesq/Boussinesq systems and the KdV approximation are rigorously compared and numerically computed.Comment: To appear in M2A

    A Software Platform for Post-Processing Waveform-Based NDE

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    Ultrasonic, microwave, and terahertz nondestructive evaluation imaging systems generally require the acquisition of waveforms at each scan point to form an image. For such systems, signal and image processing methods are commonly needed to extract information from the waves and improve resolution of, and highlight, defects in the image. Since some similarity exists for all waveform-based NDE methods, it would seem a common software platform containing multiple signal and image processing techniques to process the waveforms and images makes sense where multiple techniques, scientists, engineers, and organizations are involved. This presentation describes NASA Glenn Research Center's approach in developing a common software platform for processing waveform-based NDE signals and images. This platform is currently in use at NASA Glenn and at Lockheed Martin Michoud Assembly Facility for processing of pulsed terahertz and ultrasonic data. Highlights of the software operation will be given. A case study will be shown for use with terahertz data. The authors also request scientists and engineers who are interested in sharing customized signal and image processing algorithms to contribute to this effort by letting the authors code up and include these algorithms in future releases

    Control of cell surface expression of GABAA receptors by a conserved region at the end of the N-terminal extracellular domain of receptor subunits

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    Type A γ-aminobutyric acid receptors (GABAARs) represent a family of pentameric GABA-gated Cl-/HCO3- ion channels which mediate inhibitory transmission in the central nervous system (CNS). Cell surface expression of GABAARs, a prerequisite for their function, is dependent on the appropriate assembly of the receptor subunits and their transient interactions with molecular chaperones within the endoplasmic reticulum (ER) and Golgi apparatus. Here we describe a highly conserved amino acid sequence within the extracellular N-terminal domain of the receptor subunits adjoining the first transmembrane domain (TM1) as a region important for GABAAR processing within the ER. Modifications of this region in the α1, β3 and γ2 subunits using insertion or site-directed mutagenesis impaired GABAAR trafficking to the cell surface in heterologous cell systems although they had no effect on the subunit assembly. We found that mutated receptors accumulated in the ER where they were shown to associate with chaperones calnexin, BiP and Grp94. However, their surface expression was increased when ER-associated degradation or proteosome function was inhibited, while modulation of ER calcium stores had little effect. When compared to the wild-type, mutated receptors showed decreased interaction with calnexin, similar binding to BiP and increased association with Grp94. Structural modelling of calnexin interaction with the wt or mutated GABAAR revealed that disruption in structure caused by mutations in the conserved region adjoining the TM1 may impair calnexin binding. Thus, this previously uncharacterised region plays an important role in intracellular processing of GABAARs at least in part by stabilizing their interaction with calnexin

    Stepping Up Telehealth: Using telehealth to support a new model of care for type 2 diabetes management in rural and regional primary care

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    Our proposal is to pilot the feasibility and acceptability of a telehealth intervention to enhance care in rural general practice for people with out-of-target Type 2 Diabetes (T2D). Our research program builds on the UK Medical Research Council framework in developing a model of care intervention that is well matched to the setting of General Practice and to the experiences and priorities of patients. We undertook an exploratory qualitative study, leading to the development of a practice-based intervention that we pilot tested for feasibility and acceptability before undertaking a larger pilot and a cluster RCT. We based our work on Normalisation Process Theory (NPT), a sociological theory of implementation, which describes how new practices become incorporated into routine clinical care as a result of individual and collective work. NPT suggested that our model of care intervention would need to be patient centred and include all members of the multidisciplinary diabetes team, including Endocrinologist, RN-CDE General Practitioners (GP), and generalist Practice Nurses (PNs). All of these groups are involved in the �work� of insulin initiation.The research reported in this paper is a project of the Australian Primary Health Care Research Institute which is supported by a grant from the Australian Government Department of Health and Ageing under the Primary Health Care Research Evaluation and Development Strategy

    Complex coordination of cell plasticity by a PGC-1α-controlled transcriptional network in skeletal muscle

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    Skeletal muscle cells exhibit an enormous plastic capacity in order to adapt to external stimuli. Even though our overall understanding of the molecular mechanisms that underlie phenotypic changes in skeletal muscle cells remains poor, several factors involved in the regulation and coordination of relevant transcriptional programs have been identified in recent years. For example, the peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) is a central regulatory nexus in the adaptation of muscle to endurance training. Intriguingly, PGC-1α integrates numerous signaling pathways and translates their activity into various transcriptional programs. This selectivity is in part controlled by differential expression of PGC-1α variants and post-translational modifications of the PGC-1α protein. PGC-1α-controlled activation of transcriptional networks subsequently enables a spatio-temporal specification and hence allows a complex coordination of changes in metabolic and contractile properties, protein synthesis and degradation rates and other features of trained muscle. In this review, we discuss recent advances in our understanding of PGC-1α-regulated skeletal muscle cell plasticity in health and disease
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