499 research outputs found

    Isotropization of a rotating and longitudinally expanding ϕ4\phi^4 scalar system

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    We present numerical simulations for the evolution of an expanding system of massless scalar fields with quartic coupling. By setting a rotating, non-isotropic initial configuration, we compute the energy density, the transverse and longitudinal pressures and the angular momentum of the system. We compare the time scales associated with the isotropization and the decay of the initial angular momentum due to the expansion, and show that even for fairly large initial angular momentum, it decays significantly faster than the pressure anisotropy.Comment: 15 pages, 6 figure

    Mapping industry standards and integration opportunities in business management curricula

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    Industry standards have a significant impact on business as a means to eliminate waste, reduce costs, market products (e.g., for quality, safety, interoperability) and lessen liability (Thompson, 2011). Consequently, an understanding and the ability to use standards, agreed upon practices among interested or vested parties, is a critical workplace competency for those engaged in business and industry. To have a workforce competent in the use of standards, higher education curricula must be developed to integrate standards education at appropriate points within the curriculum. Despite the importance of standards, they are not universally integrated into the college and university curricula. Given the widespread use of standards in business and industry, a study was undertaken by four academic librarians (two business librarians and two engineering librarians) to explore the use and potential integration of standards in undergraduate business management curricula. This was accomplished through curriculum mapping of two top-ranked undergraduate business management programs. Syllabi of the two undergraduate business management programs were examined for pre-established terms (e.g., ISO, standards), as well as potential opportunities for integration of standards in the future. Of the 62 courses examined only five (or 8%) specifically mentioned standards; however, half of the courses examined were found to have potential for the integration of standards across nine business curriculum areas: business and management strategy, business law, ethics and social responsibility, human resources, information systems, international/global, marketing, process/product development, and project management. This study found that few undergraduate business management courses specifically taught or used standards based on the syllabi, but considerable potential exists for the integration of standards into undergraduate business management courses

    Estimating the Impact of Trade and Offshoring on American Workers Using the Current Population Surveys

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    We link industry-level data on trade and offshoring with individual-level worker data from the Current Population Surveys from 1984 to 2002. We find that occupational exposure to globalization is associated with significant wage effects, while industry exposure has no significant impact. We present evidence that globalization has put downward pressure on worker wages through the reallocation of workers away from higher-wage manufacturing jobs into other sectors and other occupations. Using a panel of workers, we find that occupation switching due to trade led to real wage losses of 12 to 17 percentage points

    Plucking enhanced beneath ice sheet margins: evidence from the Grampian Mountains, Scotland

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    Concentrations of boulders are a common feature of landscapes modified by former mid-latitude ice sheets. In many cases, the origin of the boulders can be traced in the up-ice direction to a cliff only tens to hundreds of metres distant. The implication is that a pulse of plucking and short boulder transport occurred beneath thin ice at the end of the last glacial cycle. Here we use a case study in granite bedrock in the Dee Valley, Scotland, to constrain theory and explore the factors involved in such a late phase of plucking. Plucking is influenced by ice velocity, hydrology, effective ice pressure, the extent of subglacial cavities and bedrock characteristics. The balance between these factors favours block removal beneath thin ice near a glacier margin. At Ripe Hill in the Dee Valley, a mean exposure age of 14.2 ka on blocks supports the view that the boulder train formed at the end of ice sheet glaciation. The late pulse of plucking was further enhanced by ice flowing obliquely across vertical joints and by fluctuations in sub-marginal meltwater conditions. An implication of the study is that there is the potential for a wave of ice-marginal plucking to sweep across a landscape as an ice sheet retreats

    TgPRELID, a Mitochondrial Protein Linked to Multidrug Resistance in the Parasite Toxoplasma gondii

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    New drugs to control infection with the protozoan parasite Toxoplasma gondii are needed as current treatments exert toxic side effects on patients. Approaches to develop novel compounds for drug development include screening of compound libraries and targeted inhibition of essential cellular pathways. We identified two distinct compounds that display inhibitory activity against the parasite's replicative stage: F3215-0002, which we previously identified during a compound library screen, and I-BET151, an inhibitor of bromodomains, the "reader" module of acetylated lysines. In independent studies, we sought to determine the targets of these two compounds using forward genetics, generating resistant mutants and identifying the determinants of resistance with comparative genome sequencing. Despite the dissimilarity of the two compounds, we recovered resistant mutants with nonsynonymous mutations in the same domain of the same gene, TGGT1_254250, which we found encodes a protein that localizes to the parasite mitochondrion (designated TgPRELID after the name of said domain). We found that mutants selected with one compound were cross resistant to the other compound, suggesting a common mechanism of resistance. To further support our hypothesis that TgPRELID mutations facilitate resistance to both I-BET151 and F3215-0002, CRISPR (clustered regularly interspaced short palindromic repeat)/CAS9-mediated mutation of TgPRELID directly led to increased F3215-0002 resistance. Finally, all resistance mutations clustered in the same subdomain of TgPRELID. These findings suggest that TgPRELID may encode a multidrug resistance factor or that I-BET151 and F3215-0002 have the same target(s) despite their distinct chemical structures. IMPORTANCE We report the discovery of TgPRELID, a previously uncharacterized mitochondrial protein linked to multidrug resistance in the parasite Toxoplasma gondii. Drug resistance remains a major problem in the battle against parasitic infection, and understanding how TgPRELID mutations augment resistance to multiple, distinct compounds will reveal needed insights into the development of new therapies for toxoplasmosis and other related parasitic diseases

    Extracorporeal Membrane Oxygenation for COVID-19-Associated Multisystem Inflammatory Syndrome in a 5-year-old

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    Severe acute respiratory distress syndrome coronavirus 2 (SARS-CoV-2) is associated with multisystem inflammatory syndrome in children (MIS-C) that ranges from mild symptoms to cardiopulmonary collapse. A 5-year-old girl presented with shock and a rapid decline in left ventricular function requiring intubation. SARS-CoV-2 was diagnosed by viral Polymerase Chain Reaction (PCR), and she received remdesivir and COVID-19 convalescent plasma. Initial echocardiogram (ECHO) demonstrated low normal left ventricular function and mild left anterior descending coronary artery dilation. She remained hypotensive, despite high-dose epinephrine and norepinephrine infusions as well as stress-dose hydrocortisone. Admission SARS-CoV-2 IgG assay was positive, meeting the criteria for MIS-C. An ECHO 9 hours after admission demonstrated a severe decline in left ventricular function. Due to severe cardiogenic shock, she was cannulated for venoarterial extracorporeal support (ECMO). During her ECMO course, she was treated with remdesivir, intravenous methylprednisolone, intravenous immunoglobulin, and anakinra. She was decannulated on ECMO day 7, extubated the following day, and discharged home 2 weeks later without respiratory or cardiac support. The use of ECMO for cardiopulmonary support for pediatric patients with MIS-C is feasible and should be considered early as part of the treatment algorithm for patients with severe cardiopulmonary dysfunction

    “Whoa! we’re going deep in the trees!”: patterns of collaboration around an interactive information visualization exhibit

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    In this paper we present a qualitative analysis of natural history museum visitor interaction around a multi-touch tabletop exhibit called DeepTree that we designed around concepts of evolution and common descent. DeepTree combines several large scientific datasets and an innovative visualization technique to display a phylogenetic tree of life consisting of over 70,000 species. After describing our design, we present a study involving pairs of children interacting with DeepTree in two natural history museums. Our analysis focuses on two questions. First, how do dyads negotiate their moment-to-moment exploration of the exhibit? Second, how do dyads develop and negotiate their understanding of evolutionary concepts? In order to address these questions we present an analytical framework that describes dyads’ exploration along two dimensions: coordination and target of action. This framework reveals four distinct patterns of interaction, which, we argue, are relevant for similar interactive designs. We conclude with a discussion of the role of design in helping visitors make sense of interactive experiences involving the visualization of large scientific datasets

    Improving access to care for people who inject drugs: qualitative evaluation of Project ITTREAT - an integrated community hepatitis C service

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    Achieving hepatitis C virus (HCV) elimination by 2030 requires an increased linkage to care for people who inject drugs (PWID). Project ITTREAT was established to mitigate barriers to HCV care by providing an integrated service within a local drug and alcohol treatment centre. This study aimed to explore the experiences of clients and staff involved in Project ITTREAT and assess the facilitators and barriers to a community‐based HCV service. Between October 2014 and April 2016, drug and alcohol treatment attendees were interviewed using one‐to‐one semi‐structured interviews. Drug and alcohol treatment staff took part in focus groups. All data were recorded, transcribed verbatim and analysed using thematic content analysis. Fifteen drug and alcohol treatment attendees with current/previous HCV infection were interviewed, and 15 staff members contributed across two focus groups. Drug and alcohol treatment staff and attendees reported that Project ITTREAT facilitated access to HCV care by mitigating previous negative hospital‐based experiences. Other key facilitators were positive narratives around HCV care, and drug and alcohol treatment attendees being well engaged in their drug/alcohol recovery. Barriers included a lack of stability in drug and alcohol treatment attendees, negative discourse around testing/treatment and stigma associated with attending the drug and alcohol treatment to access HCV treatment in some who had successfully achieved drug rehabilitation. Our findings indicate the positive impact of an integrated and personalized community‐based service delivered by a dedicated hepatitis nurse. This played a crucial role in reducing barriers to HCV care for PWID. Our work also highlights areas for future investment including non–DAT‐based community services and increasing awareness of new treatments amongst this cohort

    Bushfires and Mothers’ Mental Health in Pregnancy and Recent Post-Partum

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    Background: The compounding effects of climate change catastrophes such as bushfires and pandemics impose significant burden on individuals, societies, and their economies. The enduring effects of such syndemics on mental health remain poorly understood, particularly for at-risk populations (e.g., pregnant women and newborns). The aim of this study was to investigate the impact of direct and indirect exposure to the 2019/20 Australian Capital Territory and South-Eastern New South Wales bushfires followed by COVID-19 on the mental health and wellbeing of pregnant women and mothers with newborn babies. Methods: All women who were pregnant, had given birth, or were within three months of conceiving during the 2019/2020 bushfires, lived within the catchment area, and provided consent were invited to participate. Those who consented were asked to complete three online surveys. Mental health was assessed with the DASS-21 and the WHO-5. Bushfire, smoke, and COVID-19 exposures were assessed by self-report. Cross-sectional associations between exposures and mental health measures were tested with hierarchical regression models. Results: Of the women who participated, and had minimum data (n = 919), most (&gt;75%) reported at least one acute bushfire exposure and 63% reported severe smoke exposure. Compared to Australian norms, participants had higher depression (+12%), anxiety (+35%), and stress (+43%) scores. Women with greater exposure to bushfires/smoke but not COVID-19 had poorer scores on all mental health measures. Conclusions: These findings provide novel evidence that the mental health of pregnant women and mothers of newborn babies is vulnerable to major climate catastrophes such as bushfires.</p

    Near-Infrared Photometric Survey of Proto-Planetary Nebula Candidates

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    We present JHK' photometric measurements of 78 objects mostly consisting of proto-planetary nebula candidates. Photometric magnitudes are determined by means of imaging and aperture photometry. Unlike the observations with a photometer with a fixed-sized beam, the method of imaging photometry permits accurate derivation of photometric values because the target sources can be correctly identified and confusion with neighboring sources can be easily avoided. Of the 78 sources observed, we report 10 cases in which the source seems to have been misidentified or confused by nearby bright sources. We also present nearly two dozen cases in which the source seems to have indicated a variability which prompts a follow-up monitoring. There are also a few sources that show previously unreported extendedness. In addition, we present H band finding charts of the target sources.Comment: 3 tables, 1 figur
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