1,217 research outputs found

    The Feasibility of a Computer-Based Library Reference Interview

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    The feasibility of a computer-based library reference interview is forecasted through an analysis of the literature concerned with primary aspects of the library reference interview, concept formation, computer concept formation, computerization of reference service and the future of reference service. The state of the art is discussed in light of specific computer programs currently available for the automation of library reference service. Factors supporting and limiting the automation of library reference service are presented. Conclusions and recommendations are made for the realization of a computer-based library reference interview

    Complex collective states in a one-dimensional two-atom system

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    We consider a pair of identical two-level atoms interacting with a scalar field in one dimension, separated by a distance x21x_{21}. We restrict our attention to states where one atom is excited and the other is in the ground state, in symmetric or anti-symmetric combinations. We obtain exact collective decaying states, belonging to a complex spectral representation of the Hamiltonian. The imaginary parts of the eigenvalues give the decay rates, and the real parts give the average energy of the collective states. In one dimension there is strong interference between the fields emitted by the atoms, leading to long-range cooperative effects. The decay rates and the energy oscillate with the distance x21x_{21}. Depending on x21x_{21}, the decay rates will either decrease, vanish or increase as compared with the one-atom decay rate. We have sub- and super-radiance at periodic intervals. Our model may be used to study two-cavity electron wave-guides. The vanishing of the collective decay rates then suggests the possibility of obtaining stable configurations, where an electron is trapped inside the two cavities.Comment: 14 pages, 14 figures, submitted to Phys. Rev.

    Galactic emission at 19 GHz

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    We cross-correlate a 19 GHz full sky Cosmic Microwave Background (CMB) survey with other maps to quantify the foreground contribution. Correlations are detected with the Diffuse Infrared Background Experiment (DIRBE) 240, 140 and 100 micron maps at high latitudes (|b|>30degrees), and marginal correlations are detected with the Haslam 408 MHz and the Reich & Reich 1420 MHz synchrotron maps. The former agree well with extrapolations from higher frequencies probed by the COBE DMR and Saskatoon experiments and are consistent with both free-free and rotating dust grain emission.Comment: 4 pages, with 4 figures included. Accepted for publication in ApJL. Color figure and links at http://www.sns.ias.edu/~angelica/foreground.html#19 or from [email protected]

    Improving Assessment of Drug Safety Through Proteomics: Early Detection and Mechanistic Characterization of the Unforeseen Harmful Effects of Torcetrapib.

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    BackgroundEarly detection of adverse effects of novel therapies and understanding of their mechanisms could improve the safety and efficiency of drug development. We have retrospectively applied large-scale proteomics to blood samples from ILLUMINATE (Investigation of Lipid Level Management to Understand its Impact in Atherosclerotic Events), a trial of torcetrapib (a cholesterol ester transfer protein inhibitor), that involved 15 067 participants at high cardiovascular risk. ILLUMINATE was terminated at a median of 550 days because of significant absolute increases of 1.2% in cardiovascular events and 0.4% in mortality with torcetrapib. The aims of our analysis were to determine whether a proteomic analysis might reveal biological mechanisms responsible for these harmful effects and whether harmful effects of torcetrapib could have been detected early in the ILLUMINATE trial with proteomics.MethodsA nested case-control analysis of paired plasma samples at baseline and at 3 months was performed in 249 participants assigned to torcetrapib plus atorvastatin and 223 participants assigned to atorvastatin only. Within each treatment arm, cases with events were matched to controls 1:1. Main outcomes were a survey of 1129 proteins for discovery of biological pathways altered by torcetrapib and a 9-protein risk score validated to predict myocardial infarction, stroke, heart failure, or death.ResultsPlasma concentrations of 200 proteins changed significantly with torcetrapib. Their pathway analysis revealed unexpected and widespread changes in immune and inflammatory functions, as well as changes in endocrine systems, including in aldosterone function and glycemic control. At baseline, 9-protein risk scores were similar in the 2 treatment arms and higher in participants with subsequent events. At 3 months, the absolute 9-protein derived risk increased in the torcetrapib plus atorvastatin arm compared with the atorvastatin-only arm by 1.08% (P=0.0004). Thirty-seven proteins changed in the direction of increased risk of 49 proteins previously associated with cardiovascular and mortality risk.ConclusionsHeretofore unknown effects of torcetrapib were revealed in immune and inflammatory functions. A protein-based risk score predicted harm from torcetrapib within just 3 months. A protein-based risk assessment embedded within a large proteomic survey may prove to be useful in the evaluation of therapies to prevent harm to patients.Clinical trial registrationURL: https://www.clinicaltrials.gov. Unique identifier: NCT00134264

    Assessing Retirement Needs and Interest in myRa: Findings From the Refund to Savings Initiative

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    As part of the U.S. Department of the Treasury’s ongoing effort to promote the myRA starter retirement account, we used the Refund to Savings Initiative’s Household Financial Survey to assess low- to moderate-income tax filers’ retirement needs, attitudes towards retirement, and interest in a myRA-type account. We also tested different messaging approaches for promoting myRA. The report found that 32% of survey respondents did not own a retirement account and that lack of money and lack of access to an employer-based account were major impediments to retirement account ownership. The report also found that only 10% to 15% of respondents felt on track to retire comfortably. Several aspects of myRA appealed to respondents including the absence of a minimum balance and the absence of penalties for early withdrawal. Additionally, a simple, direct, informational approach to promotional messaging proved more effective than personal messaging at driving interest in myRA

    Coping With a Crisis: Financial Resources Available to Low- and Moderate-Income Households in Emergencies

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    Using data from tax records and a longitudinal survey, this brief investigates the choices low- and moderate-income households make about their tax withholding and their preferences for withholding. The relationship between withholding preferences and the use of the tax refund, measures of material hardship, and the use of alternative financial services is also explored. We find that almost half of all survey respondents preferred to overwithhold their income each year in order to get a larger tax refund. Yet despite preferring to take home less income during the year, these households experienced higher levels of material hardship than those who preferred to break even in their withholding, and were more likely to use alternative financial services like payday lenders. Further, households that preferred to overwithhold were less likely to save their refund. We also find that respondents who preferred to break even on their withholding or underwithhold on their taxes still overwithheld a substantial amount of income, indicating that LMI households have difficulty withholding their preferred amounts. Implications of these findings for policy are discussed

    The Role of Health Insurance in the Financial Lives of Low- and Moderate-Income Households

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    Health insurance is an important resource for enabling access to and use of medical care, and is associated with reduced risk for mortality and poor health outcomes. Health insurance also protects households from incurring major medical expenses and unmanageable levels of medical debt. About a quarter of a sample of low- and moderate-income (LMI) tax filers have no health insurance, compared to 10% of all individuals in the United States. As of 2014, the proportion of filers without insurance was 11 percentage points higher in states that had not expanded Medicaid through the Affordable Care Act (ACA) than it was in expansion states. Lack of insurance is associated with lower income and assets, and higher unsecured debt, as well as greater likelihood of experiencing financial difficulties and material hardship. Despite progress in expanding health insurance coverage under the ACA, additional efforts are needed, including effort to further expand Medicaid and high-risk insurance pools, strengthen charity care policies and practices, and forgive medical debt

    Gene expression in Leishmania is regulated predominantly by gene dosage

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    ABSTRACT Leishmania tropica, a unicellular eukaryotic parasite present in North and East Africa, the Middle East, and the Indian subcontinent, has been linked to large outbreaks of cutaneous leishmaniasis in displaced populations in Iraq, Jordan, and Syria. Here, we report the genome sequence of this pathogen and 7,863 identified protein-coding genes, and we show that the majority of clinical isolates possess high levels of allelic diversity, genetic admixture, heterozygosity, and extensive aneuploidy. By utilizing paired genome-wide high-throughput DNA sequencing (DNA-seq) with RNA-seq, we found that gene dosage, at the level of individual genes or chromosomal “somy” (a general term covering disomy, trisomy, tetrasomy, etc.), accounted for greater than 85% of total gene expression variation in genes with a 2-fold or greater change in expression. High gene copy number variation (CNV) among membrane-bound transporters, a class of proteins previously implicated in drug resistance, was found for the most highly differentially expressed genes. Our results suggest that gene dosage is an adaptive trait that confers phenotypic plasticity among natural Leishmania populations by rapid down- or upregulation of transporter proteins to limit the effects of environmental stresses, such as drug selection. IMPORTANCE Leishmania is a genus of unicellular eukaryotic parasites that is responsible for a spectrum of human diseases that range from cutaneous leishmaniasis (CL) and mucocutaneous leishmaniasis (MCL) to life-threatening visceral leishmaniasis (VL). Developmental and strain-specific gene expression is largely thought to be due to mRNA message stability or posttranscriptional regulatory networks for this species, whose genome is organized into polycistronic gene clusters in the absence of promoter-mediated regulation of transcription initiation of nuclear genes. Genetic hybridization has been demonstrated to yield dramatic structural genomic variation, but whether such changes in gene dosage impact gene expression has not been formally investigated. Here we show that the predominant mechanism determining transcript abundance differences (>85%) in Leishmania tropica is that of gene dosage at the level of individual genes or chromosomal somy

    On Hirschman and log-Sobolev inequalities in mu-deformed Segal-Bargmann analysis

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    We consider a deformation of Segal-Bargmann space and its transform. We study L^p properties of this transform and obtain entropy-entropy inequalities (Hirschman) and entropy-energy inequalities (log-Sobolev) that generalize the corresponding known results in the undeformed theory.Comment: 42 pages, 3 figure
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