3,241 research outputs found

    The Earned Income Tax Credit: Antipoverty Effectiveness and Labor Market Effects

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    The authors begin with a detailed assessment then perform empirical analyses to predict the outcomes of changes to the structure of the program.https://research.upjohn.org/up_press/1099/thumbnail.jp

    Then and Now: The Earned Income Tax Credit

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    Age-related Hearing Loss and its Association with Reactive Oxygen Species and Mitochondrial DNA damage

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    Age-related hearing loss, known as presbyacusis, is characterized by the progressive deterioration of auditory sensitivity associated with the aging process and is the leading cause of adult auditory deficiency in the USA. Presbyacusis is described as a progressive, bilateral, high-frequency hearing loss that is manifested on audiometric assessment by a moderately sloping pure tone audiogram. Approximately 23% of the population between 65 and 75 years of age, and 40% of the population older than 75 years of age are affected by this condition. It was estimated in 1980 that 11% of the population was 76 years or older and this number is expected to almost double by the year 2030. When one considers that the population over 65 years of age is experiencing the most accelerated development of hearing loss, the potential socioeconomic ramifications are staggering. Curiously, the frequency of presbyacusis varies across different societies. This discrepancy has been attributed to many factors including genetics, diet, socioeconomic factors, and environmental variables. The purpose of this article is to review the various molecular mechanisms underlying presbyacusis and to offer insights into potential methods of mitigating the effects of aging on hearing impairment

    The evolution of interdisciplinarity in physics research

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    Science, being a social enterprise, is subject to fragmentation into groups that focus on specialized areas or topics. Often new advances occur through cross-fertilization of ideas between sub-fields that otherwise have little overlap as they study dissimilar phenomena using different techniques. Thus to explore the nature and dynamics of scientific progress one needs to consider the large-scale organization and interactions between different subject areas. Here, we study the relationships between the sub-fields of Physics using the Physics and Astronomy Classification Scheme (PACS) codes employed for self-categorization of articles published over the past 25 years (1985-2009). We observe a clear trend towards increasing interactions between the different sub-fields. The network of sub-fields also exhibits core-periphery organization, the nucleus being dominated by Condensed Matter and General Physics. However, over time Interdisciplinary Physics is steadily increasing its share in the network core, reflecting a shift in the overall trend of Physics research.Comment: Published version, 10 pages, 8 figures + Supplementary Informatio

    How should we measure psychological resilience in sport performers?

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    Psychological resilience is important in sport because athletes must constantly withstand a wide range of pressures to attain and sustain high performance. To advance psychologists’ understanding of this area, there exists an urgent need to develop a sport-specific measure of resilience. The purpose of this paper is to review psychometric issues in resilience research and to discuss the implications for sport psychology. Drawing on the wider general psychology literature to inform the discussion, the narrative is divided into three main sections relating to resilience and its assessment: adversity, positive adaptation, and protective factors. The first section reviews the different ways that adversity has been measured and considers the potential problems of using items with varying degrees of controllability and risk. The second section discusses the different approaches to assessing positive adaptation and examines the issue of circularity pervasive in resilience research. The final section explores the various issues related to the assessment of protective factors drawing directly from current measures of resilience in other psychology sub-disciplines. The commentary concludes with key recommendations for sport psychology researchers seeking to develop a measure of psychological resilience in athletes

    Cell-specific discrimination of desmosterol and desmosterol mimetics confers selective regulation of LXR and SREBP in macrophages.

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    Activation of liver X receptors (LXRs) with synthetic agonists promotes reverse cholesterol transport and protects against atherosclerosis in mouse models. Most synthetic LXR agonists also cause marked hypertriglyceridemia by inducing the expression of sterol regulatory element-binding protein (SREBP)1c and downstream genes that drive fatty acid biosynthesis. Recent studies demonstrated that desmosterol, an intermediate in the cholesterol biosynthetic pathway that suppresses SREBP processing by binding to SCAP, also binds and activates LXRs and is the most abundant LXR ligand in macrophage foam cells. Here we explore the potential of increasing endogenous desmosterol production or mimicking its activity as a means of inducing LXR activity while simultaneously suppressing SREBP1c-induced hypertriglyceridemia. Unexpectedly, while desmosterol strongly activated LXR target genes and suppressed SREBP pathways in mouse and human macrophages, it had almost no activity in mouse or human hepatocytes in vitro. We further demonstrate that sterol-based selective modulators of LXRs have biochemical and transcriptional properties predicted of desmosterol mimetics and selectively regulate LXR function in macrophages in vitro and in vivo. These studies thereby reveal cell-specific discrimination of endogenous and synthetic regulators of LXRs and SREBPs, providing a molecular basis for dissociation of LXR functions in macrophages from those in the liver that lead to hypertriglyceridemia

    Investigation of irradiated monolithic transistors for space applications

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    In this paper experimental results on radiation effects on a BICMOS high speed commercial technology, manufactured by STMicroelectronics, are reported. Bipolar transistors were irradiated by neutrons, ions, or by both of them. Fast neutrons, as well as other types of particles, produce defects, mainly by displacing silicon atoms from their lattice positions to interstitial locations, i.e. generating vacancy-interstitial pairs, the so-called Frenkel pairs (FP). Defects introduce trapping energy states which degrade the common emitter current gain β. The gain degradation has been investigated for collector current Ic between 1 μA and 1 mA. It was found a linear dependence of Δ(1/β)=1/βi−1/β (where βi and β are the gain after and before the irradiation) as a function of the concentration of FP. The bipolar transistors made on this technology have shown to be particularly radiation resistant. Both base and collector currents have been also systematically investigated

    Current status specifiers for patients at clinical high risk for psychosis

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    Background: Longitudinal studies of the clinical high risk (CHR) syndrome for psychosis have emphasized the conversion vs non-conversion distinction and thus far have not focused intensively on classification among non-converters. The present study proposes a system for classifying CHR outcomes over time when using the Structured Interview for Psychosis-risk Syndromes and evaluates its validity. Method: The system for classifying CHR outcomes is referred to as current status specifiers, with current meaning over the month prior to the present evaluation and specifiers indicating a set of labels and descriptions of the statuses. Specifiers for four current statuses are described: progression, persistence, partial remission, and full remission. Data from the North American Prodromal Longitudinal Study were employed to test convergent, discriminant, and predictive validity of the current status distinctions. Results: Validity analyses partly supported current status distinctions. Social and role functioning were more impaired in progressive and persistent than in remitted patients, suggesting a degree of convergent validity. Agreement between CHR current statuses and current statuses for a different diagnostic construct (DSM-IV Major Depression) was poor, suggesting discriminant validity. The proportion converting to psychosis within a year was significantly higher in cases meeting progression criteria than in those meeting persistence criteria and tended to be higher than in those meeting full remission criteria, consistent with a degree of predictive validity. Discussion: CHR syndrome current status specifiers could offer a potentially valid and useful description of current clinical status among non-converters. Study in additional samples is needed. (C) 2014 Published by Elsevier B.V

    Erratum to: Specificity of incident diagnostic outcomes in patients at clinical high risk for psychosis

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    Š The Author(s) 2018. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. An error in statistical syntax defining baseline disorder led to misidentification of baseline anxiety disorder in five cases in one of the two reported samples (PREDICT). NAPLS-1 data and previous publications of PREDICT data were not affected. The error affected rows in Table 1 labeled \u27DSM-IV anxiety\u27 and \u27Any mood/anx disorder\u27 and rows in Table 3 labeled \u27Baseline Anxiety Excluded\u27 and \u27Any Baseline Mood/ Anxiety Excluded.\u27 Corrected Tables are shown below with corrected numbers in bold. Tables S1-S5 in the data supplement were also affected. Note that the online paper has also been replaced. The abstract is unchanged, and overall findings and conclusions are not affected. One paragraph in the Results describing supplementary tables 1 and 2 is slightly changed (changes in bold): Sensitivity analyses showed that the CHR vs HSC difference for incident psychosis continued to hold whether analyses included or excluded subjects with each or any baseline disorder from the model (all p\u27s = 0.001, Table S1). Similarly, the lack of CHR vs HSC differences for incident nonpsychotic disorders also continued to hold whether models included subjects with baseline disorder (as non-cases of emergent disorder) or excluded them (all p\u27s = 0.390, Table S2). We regret the error
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