100 research outputs found

    An Empirical Analysis of 'Acting White'

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    There is a debate among social scientists regarding the existence of a peer externality commonly referred to as 'acting white.' Using a newly available data set (the National Longitudinal Study of Adolescent Health), which allows one to construct an objective measure of a student's popularity, we demonstrate that there are large racial differences in the relationship between popularity and academic achievement; our (albeit narrow) definition of 'acting white.' The effect is intensified among high achievers and in schools with more interracial contact, but non-existent among students in predominantly black schools or private schools. The patterns in the data appear most consistent with a two-audience signaling model in which investments in education are thought to be indicative of an individual's opportunity costs of peer group loyalty. Other models we consider, such as self-sabotage among black youth or the presence of an oppositional culture, all contradict the data in important ways.

    AsrR Is an Oxidative Stress Sensing Regulator Modulating Enterococcus faecium Opportunistic Traits, Antimicrobial Resistance, and Pathogenicity

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    Oxidative stress serves as an important host/environmental signal that triggers a wide range of responses in microorganisms. Here, we identified an oxidative stress sensor and response regulator in the important multidrug-resistant nosocomial pathogen Enterococcus faecium belonging to the MarR family and called AsrR (antibiotic and stress response regulator). The AsrR regulator used cysteine oxidation to sense the hydrogen peroxide which results in its dissociation to promoter DNA. Transcriptome analysis showed that the AsrR regulon was composed of 181 genes, including representing functionally diverse groups involved in pathogenesis, antibiotic and antimicrobial peptide resistance, oxidative stress, and adaptive responses. Consistent with the upregulated expression of the pbp5 gene, encoding a low-affinity penicillin-binding protein, the asrR null mutant was found to be more resistant to \u3b2-lactam antibiotics. Deletion of asrR markedly decreased the bactericidal activity of ampicillin and vancomycin, which are both commonly used to treat infections due to enterococci, and also led to over-expression of two major adhesins, acm and ecbA, which resulted in enhanced in vitro adhesion to human intestinal cells. Additional pathogenic traits were also reinforced in the asrR null mutant including greater capacity than the parental strain to form biofilm in vitro and greater persistance in Galleria mellonella colonization and mouse systemic infection models. Despite overexpression of oxidative stress-response genes, deletion of asrR was associated with a decreased oxidative stress resistance in vitro, which correlated with a reduced resistance to phagocytic killing by murine macrophages. Interestingly, both strains showed similar amounts of intracellular reactive oxygen species. Finally, we observed a mutator phenotype and enhanced DNA transfer frequencies in the asrR deleted strain. These data indicate that AsrR plays a major role in antimicrobial resistance and adaptation for survival within the host, thereby contributes importantly to the opportunistic traits of E. faecium

    Susceptibility Testing of Common and Uncommon Aspergillus Species Against Posaconazole and Other Mold-Active Antifungal Azoles Using the Sensititre Method

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    We tested 59 common and 27 uncommon Aspergillus species isolates for the susceptibility to the mold-active azole antifungal agents, itraconazole, voriconazole, and posaconazole, using the Sensititre method. The overall essential agreement with the CLSI reference method was 96.5% for itraconazole and posaconazole, and 100% for voriconazole. By Sensititre, as well as CLSI, all of 10 A. fumigatus isolates with a cyp51 mutant genotype were classified as being non-wild-type (MIC > ECV) to triazoles

    Transgenic Overexpression of LARGE Induces α-Dystroglycan Hyperglycosylation in Skeletal and Cardiac Muscle

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    BACKGROUND: LARGE is one of seven putative or demonstrated glycosyltransferase enzymes defective in a common group of muscular dystrophies with reduced glycosylation of α-dystroglycan. Overexpression of LARGE induces hyperglycosylation of α-dystroglycan in both wild type and in cells from dystroglycanopathy patients, irrespective of their primary gene defect, restoring functional glycosylation. Viral delivery of LARGE to skeletal muscle in animal models of dystroglycanopathy has identical effects in vivo, suggesting that the restoration of functional glycosylation could have therapeutic applications in these disorders. Pharmacological strategies to upregulate Large expression are also being explored. METHODOLOGY/PRINCIPAL FINDINGS: In order to asses the safety and efficacy of long term LARGE over-expression in vivo, we have generated four mouse lines expressing a human LARGE transgene. On observation, LARGE transgenic mice were indistinguishable from the wild type littermates. Tissue analysis from young mice of all four lines showed a variable pattern of transgene expression: highest in skeletal and cardiac muscles, and lower in brain, kidney and liver. Transgene expression in striated muscles correlated with α-dystroglycan hyperglycosylation, as determined by immunoreactivity to antibody IIH6 and increased laminin binding on an overlay assay. Other components of the dystroglycan complex and extracellular matrix ligands were normally expressed, and general muscle histology was indistinguishable from wild type controls. Further detailed muscle physiological analysis demonstrated a loss of force in response to eccentric exercise in the older, but not in the younger mice, suggesting this deficit developed over time. However this remained a subclinical feature as no pathology was observed in older mice in any muscles including the diaphragm, which is sensitive to mechanical load-induced damage. CONCLUSIONS/SIGNIFICANCE: This work shows that potential therapies in the dystroglycanopathies based on LARGE upregulation and α-dystroglycan hyperglycosylation in muscle should be safe

    UK General Population Utility Values for the SIDECAR-D Instrument Measuring the Impact of Caring for People With Dementia

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    Objectives: Dementia affects many people, with numbers expected to grow as populations age. Many people with dementia receive informal/family/unpaid care, for example, from a spouse or child, which may affect carer quality of life. Measuring the effectiveness of health/social care interventions for carers requires a value measure of the quality-of-life impact of caring. This motivated development of the Scales Measuring the Impact of Dementia on Carers-D (SIDECAR-D) instrument. This study aimed to obtain general population values for SIDECAR-D to aid incorporating the impact of caring in economic evaluation. Methods: Members of the UK general public completed a best–worst scaling object case survey, which included the 18 SIDECAR-D items and EQ-5D-3L descriptions. Responses were analyzed using scale-adjusted finite mixture models. Relative importance scores (RISs) for the 18 SIDECAR-D items formed the SIDECAR-D relative scale measuring the relative impact of caring. The SIDECAR-D tariff, on the full health = 1, dead = 0 scale, was derived by rescaling EQ-5D-3L and SIDECAR-D RISs so the EQ-5D-3L RISs equaled anchored valuations of the EQ-5D-3L pits state from a visual analog scale task. Results: Five hundred ten respondents completed the survey. The model had 2 parameter and 3 scale classes. Additive utility decrements of SIDECAR-D items ranged from –0.05 to –0.162. Utility scores range from 0.95 for someone affirming 1 item to –0.297 for someone affirming all 18. Conclusion: SIDECAR-D is a needs-based scale of the impact on quality of life of caring for someone with dementia, with a valuation tariff to support its use in economic evaluation

    Alcohol drinking and head and neck cancer risk: the joint effect of intensity and duration

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    Background: Alcohol is a well-established risk factor for head and neck cancer (HNC). This study aims to explore the effect of alcohol intensity and duration, as joint continuous exposures, on HNC risk. Methods: Data from 26 case-control studies in the INHANCE Consortium were used, including never and current drinkers who drunk ≤10 drinks/day for ≤54 years (24234 controls, 4085 oral cavity, 3359 oropharyngeal, 983 hypopharyngeal and 3340 laryngeal cancers). The dose-response relationship between the risk and the joint exposure to drinking intensity and duration was investigated through bivariate regression spline models, adjusting for potential confounders, including tobacco smoking. Results: For all subsites, cancer risk steeply increased with increasing drinks/day, with no appreciable threshold effect at lower intensities. For each intensity level, the risk of oral cavity, hypopharyngeal and laryngeal cancers did not vary according to years of drinking, suggesting no effect of duration. For oropharyngeal cancer, the risk increased with durations up to 28 years, flattening thereafter. The risk peaked at the higher levels of intensity and duration for all subsites (odds ratio = 7.95 for oral cavity, 12.86 for oropharynx, 24.96 for hypopharynx and 6.60 for larynx). Conclusions: Present results further encourage the reduction of alcohol intensity to mitigate HNC risk

    International Economics Understanding the Forces of Globalization for Managers Second Edition

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    Today’s news media displays an intense fascination with the global economy—and for good reason. The degree of worldwide economic integration is unprecedented, and rising globalization has lifted living standards and reduced poverty. Foreign markets and new technologies continue to present opportunities for entrepreneurs and corporations. Still, economic shocks can spread across the world in minutes, impacting billions of lives. Citizens are understandably anxious in this age of macroeconomic turbulence and overextended governments. Modern economics offers a powerful framework for understanding globalization, international trade, and economic growth. Many managers possess years of hands-on experience dealing with business cycles and foreign competitive pressures, yet these leaders may not have a solid grounding in economic concepts that shed light on the forces of globalization. This book explains economics in everyday language, using little or no math, giving businesspersons better tools to interpret current events as well as long-term economic and political developments. Keywords economics, human capital, ?nancial crisis, macroeconomics, comparative advantage, absolute advantage, emerging economy, international trade, business strategy, economic growth, economic history, international economics, political economy, economic development, industrialization, labor market, convergence, New World, mercantilism, Industrial Revolution, productivity, technology, capital control, intellectual property, research and development, productivity slowdown, Adam Smith, factor proportions model, gravity model, infant industry, import substitution, Asian Tiger, trade policy, tariff, public choice, rent seeking, trade agreement, free trade, liberalization, information and communications technology, vertical integration, supply chain, poverty trap, big push, coordination failure, industrial policy, diversi?cation, value added, managerial capital, skill biased technological change, population growth, wage inequality, middle income trap, tradable sector, offshoring, outsourcing, foreign direct investment, skill upgrading, immigration, wage structure, regulation, competitiveness, corruption, democracy, autocracy, socialism, communism, controlled capitalism, gold standard, natural resource curse, business cycle, collective bargaining, social insurance, safety net, labor union, Washington Consensus, multinational enterprise, exchange rate, sweatshop, spillover, human rights, labor standard, property rights, Dutch disease, extractive industry, negative externality, pollution haven, greenhouse gas, global warming, climate chang

    International Economics Understanding the Forces of Globalization for Managers

    No full text
    Today’s news media displays an intense fascination with the global economy—and for good reason. The degree of worldwide economic integration is unprecedented, and rising globalization has lifted living standards and reduced poverty. Foreign markets and new technologies continue to present opportunities for entrepreneurs and corporations. Still, economic shocks can spread across the world in minutes, impacting billions of lives. This book will help you learn about economics in everyday language, using little or no math, giving you better tools to interpret current events as well as long-term economic and political developments. Modern economics offers a powerful framework for understanding globalization, international trade, and economic growth. You may possess years of hands-on experience dealing with business cycles and foreign competitive pressures, but lack a solid grounding in economic concepts that shed light on the forces of globalization. This book is here to help
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