242 research outputs found

    Business unusual: collective action against bribery in international business

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    Collective action initiatives in which governments and companies make anti-corruption commitments have proliferated in recent years. This apparently prosocial behavior defies the logic of collective action and, given that bribery often goes undetected and unpunished, is not easily explained by principal-agent theory. Club theory suggests that the answer lies in the institutional design of anti-corruption clubs: collective action can work as long as membership has high entry costs, members receive selective benefits, and compliance is adequately policed. This article contributes to the debate by examining how these conditions manifest in the case of anti-corruption clubs in the realm of international business, with particular focus on the international dimension of many initiatives. This vertical aspect of institutional design creates a richer, more complex set of reputational and material benefits for members, as well as allowing for more credible and consistent monitoring and enforcement

    Trends in utilization and costs of BRCA testing among women aged 18–64 years in the United States, 2003–2014

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    Purpose We examined 12-year trends in BRCA testing rates and costs in the context of clinical guidelines, national policies, and other factors. Methods We estimated trends in BRCA testing rates and costs from 2003 to 2014 for women aged 18–64 years using private claims data and publicly reported revenues from the primary BRCA testing provider. Results The percentage of women with zero out-of-pocket payments for BRCA testing increased during 2013–2014, after 7 years of general decline, coinciding with a clarification of Affordable Care Act coverage of BRCA genetic testing. Beginning in 2007, family history accounted for an increasing proportion of women with BRCA tests compared with personal history, coinciding with BRCA testing guidelines for primary care settings and direct-to-consumer advertising campaigns. During 2013–2014, BRCA testing rates based on claims grew at a faster rate than revenues, following 3 years of similar growth, consistent with increased marketplace competition. In 2013, BRCA testing rates based on claims increased 57%, compared with 11% average annual increases over the preceding 3 years, coinciding with celebrity publicity. Conclusion The observed trends in BRCA testing rates and costs are consistent with possible effects of several factors, including the Affordable Care Act, clinical guidelines and celebrity publicity

    Model-guided therapy for hepatocellular carcinoma: A role for information technology in predictive, preventive and personalized medicine

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    Predictive, preventive and personalized medicine (PPPM) may have the potential to eventually improve the nature of health care delivery. However, the tools required for a practical and comprehensive form of PPPM that is capable of handling the vast amounts of medical information that is currently available are currently lacking. This article reviews a rationale and method for combining and integrating diagnostic and therapeutic management with information technology (IT), in a manner that supports patients through their continuum of care. It is imperative that any program devised to explore and develop personalized health care delivery must be firmly rooted in clinically confirmed and accepted principles and technologies. Therefore, a use case, relating to hepatocellular carcinoma (HCC), was developed. The approach to the management of medical information we have taken is based on model theory and seeks to implement a form of model-guided therapy (MGT) that can be used as a decision support system in the treatment of patients with HCC. The IT structures to be utilized in MGT include a therapy imaging and model management system (TIMMS) and a digital patient model (DPM). The system that we propose will utilize patient modeling techniques to generate valid DPMs (which factor in age, physiologic condition, disease and co-morbidities, genetics, biomarkers and responses to previous treatments). We may, then, be able to develop a statistically valid methodology, on an individual basis, to predict certain diseases or conditions, to predict certain treatment outcomes, to prevent certain diseases or complications and to develop treatment regimens that are personalized for that particular patient. An IT system for predictive, preventive and personalized medicine (ITS-PM) for HCC is presented to provide a comprehensive system to provide unified access to general medical and patient-specific information for medical researchers and health care providers from different disciplines including hepatologists, gastroenterologists, medical and surgical oncologists, liver transplant teams, interventional radiologists and radiation oncologists. The article concludes with a review providing an outlook and recommendations for the application of MGT to enhance the medical management of HCC through PPPM

    Scanpath analysis of expertise and culture in teacher gaze in real-world classrooms

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    Humans are born to learn by understanding where adults look. This is likely to extend into the classroom, making teacher gaze an important topic for study. Expert teacher gaze has mainly been investigated in the laboratory, and has focused mostly on one cognitive process: teacher attentional (i.e., information-seeking) gaze. No known research has made direct cultural comparisons of teacher gaze or successfully found expert–novice differences outside Western settings. Accordingly, we conducted a real-world study of expert teacher gaze across two cultural settings, exploring communicative (i.e., information-giving) as well as attentional gaze. Forty secondary school teachers wore eye-tracking glasses, with 20 teachers (10 expert; 10 novice) from the UK and 20 teachers (10 expert; 10 novice) from Hong Kong. We used a novel eye-tracking scanpath analysis to ascertain the importance of expertise and culture, individually and as a combination. Attentional teacher scanpaths were significantly more similar within than across expertise and expertise + culture sub-groups; communicative scanpaths were significantly more similar within than across expertise and culture. Detailed analysis suggests that (1) expert teachers refer back to students constantly through focused gaze during both attentional and communicative gaze and that (2) expert teachers in Hong Kong scan students more than experts do in the UK

    Developing Single-Molecule TPM Experiments for Direct Observation of Successful RecA-Mediated Strand Exchange Reaction

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    RecA recombinases play a central role in homologous recombination. Once assembled on single-stranded (ss) DNA, RecA nucleoprotein filaments mediate the pairing of homologous DNA sequences and strand exchange processes. We have designed two experiments based on tethered particle motion (TPM) to investigate the fates of the invading and the outgoing strands during E. coli RecA-mediated pairing and strand exchange at the single-molecule level in the absence of force. TPM experiments measure the tethered bead Brownian motion indicative of the DNA tether length change resulting from RecA binding and dissociation. Experiments with beads labeled on either the invading strand or the outgoing strand showed that DNA pairing and strand exchange occurs successfully in the presence of either ATP or its non-hydrolyzable analog, ATPγS. The strand exchange rates and efficiencies are similar under both ATP and ATPγS conditions. In addition, the Brownian motion time-courses suggest that the strand exchange process progresses uni-directionally in the 5′-to-3′ fashion, using a synapse segment with a wide and continuous size distribution

    A hierarchical Bayesian model for understanding the spatiotemporal dynamics of the intestinal epithelium

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    Our work addresses two key challenges, one biological and one methodological. First, we aim to understand how proliferation and cell migration rates in the intestinal epithelium are related under healthy, damaged (Ara-C treated) and recovering conditions, and how these relations can be used to identify mechanisms of repair and regeneration. We analyse new data, presented in more detail in a companion paper, in which BrdU/IdU cell-labelling experiments were performed under these respective conditions. Second, in considering how to more rigorously process these data and interpret them using mathematical models, we use a probabilistic, hierarchical approach. This provides a best-practice approach for systematically modelling and understanding the uncertainties that can otherwise undermine the generation of reliable conclusions-uncertainties in experimental measurement and treatment, difficult-to-compare mathematical models of underlying mechanisms, and unknown or unobserved parameters. Both spatially discrete and continuous mechanistic models are considered and related via hierarchical conditional probability assumptions. We perform model checks on both in-sample and out-of-sample datasets and use them to show how to test possible model improvements and assess the robustness of our conclusions. We conclude, for the present set of experiments, that a primarily proliferation-driven model suffices to predict labelled cell dynamics over most time-scales

    Oxidant-NO dependent gene regulation in dogs with type I diabetes: impact on cardiac function and metabolism

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    <p>Abstract</p> <p>Background</p> <p>The mechanisms responsible for the cardiovascular mortality in type I diabetes (DM) have not been defined completely. We have shown in conscious dogs with DM that: <it>1</it>) baseline coronary blood flow (CBF) was significantly decreased, <it>2</it>) endothelium-dependent (ACh) coronary vasodilation was impaired, and <it>3</it>) reflex cholinergic NO-dependent coronary vasodilation was selectively depressed. The most likely mechanism responsible for the depressed reflex cholinergic NO-dependent coronary vasodilation was the decreased bioactivity of NO from the vascular endothelium. The goal of this study was to investigate changes in cardiac gene expression in a canine model of alloxan-induced type 1 diabetes.</p> <p>Methods</p> <p>Mongrel dogs were chronically instrumented and the dogs were divided into two groups: one normal and the other diabetic. In the diabetic group, the dogs were injected with alloxan monohydrate (40-60 mg/kg iv) over 1 min. The global changes in cardiac gene expression in dogs with alloxan-induced diabetes were studied using Affymetrix Canine Array. Cardiac RNA was extracted from the control and DM (n = 4).</p> <p>Results</p> <p>The array data revealed that 797 genes were differentially expressed (P < 0.01; fold change of at least ±2). 150 genes were expressed at significantly greater levels in diabetic dogs and 647 were significantly reduced. There was no change in eNOS mRNA. There was up regulation of some components of the NADPH oxidase subunits (gp91 by 2.2 fold, P < 0.03), and down-regulation of SOD1 (3 fold, P < 0.001) and decrease (4 - 40 fold) in a large number of genes encoding mitochondrial enzymes. In addition, there was down-regulation of Ca<sup>2+ </sup>cycling genes (ryanodine receptor; SERCA2 Calcium ATPase), structural proteins (actin alpha). Of particular interests are genes involved in glutathione metabolism (glutathione peroxidase 1, glutathione reductase and glutathione S-transferase), which were markedly down regulated.</p> <p>Conclusion</p> <p>our findings suggest that type I diabetes might have a direct effect on the heart by impairing NO bioavailability through oxidative stress and perhaps lipid peroxidases.</p

    At the bottom of the differential diagnosis list: unusual causes of pediatric hypertension

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    Hypertension affects 1–5% of children and adolescents, and the incidence has been increasing in association with obesity. However, secondary causes of hypertension such as renal parenchymal diseases, congenital abnormalities and renovascular disorders still remain the leading cause of pediatric hypertension, particularly in children under 12 years old. Other less common causes of hypertension in children and adolescents, including immobilization, burns, illicit and prescription drugs, dietary supplements, genetic disorders, and tumors will be addressed in this review
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