5,494 research outputs found

    Adaptive evolution of pelvic reduction in sticklebacks by recurrent deletion of a Pitx1 enhancer

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    ManuscriptThe molecular mechanisms underlying major phenotypic changes that have evolved repeatedly in nature are generally unknown. Pelvic loss in different natural populations of threespine stickleback fish has occurred by regulatory mutations deleting a tissue-specific enhancer of the Pituitary homeobox transcription factor 1 (Pitx1) gene. The high prevalence of deletion mutations at Pitx1 may be influenced by inherent structural features of the locus. Although Pitx1 null mutations are lethal in laboratory animals, Pitx1 regulatory mutations show molecular signatures of positive selection in pelvic-reduced populations. These studies illustrate how major expression and morphological changes can arise by single mutational leaps in natural populations, producing new adaptive alleles via recurrent regulatory alterations in a key developmental control gene

    Fitting Restaurant Service Style to Brand Image for Greater Customer Satisfaction

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    Supported by academic researchers, the restaurant industry has devoted enormous effort to the task of conceptualizing and developing measures of “service quality,” 1 based on the reasonable proposition that restaurant guests’ satisfaction relies on quality of service. However, it has become clear to us that quality alone is not the full measure of how restaurant guests gauge or react to their servers’ actions. Consequently, in this CHR report, we measure the effects of “service style,” which we conceptualize as a manner of delivering guest service that is specifically identifiable on some dimension other than quality. We feel that this issue of service style has largely been overlooked, and we believe it’s important to assess the effectiveness of different service styles in a particular restaurant context

    The Role of Surgery, Radiosurgery and Whole Brain Radiation Therapy in the Management of Patients with Metastatic Brain Tumors

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    Brain tumors constitute the most common intracranial tumor. Management of brain metastases has become increasingly complex as patients with brain metastases are living longer and more treatment options develop. The goal of this paper is to review the role of stereotactic radiosurgery (SRS), whole brain radiation therapy (WBRT), and surgery, in isolation and in combination, in the contemporary treatment of brain metastases. Surgery and SRS both offer management options that may help to optimize therapy in selected patients. WBRT is another option but can lead to late toxicity and suboptimal local control in longer term survivors. Improved prognostic indices will be critical for selecting the best therapies. Further prospective trials are necessary to continue to elucidate factors that will help triage patients to the proper brain-directed therapy for their cancer

    Capturing Information Flow with Concatenated Dynamic Taint Analysis

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    Dynamic taint analysis (DTA) is a technique used for tracking information flow by propagating taint propagation across memory locations during program execution. Most implementations of DTA are based on dynamic binary instrumentation (DBI) frameworks or whole-system emulators/virtual machine monitors. The boundary of information tracking with DBI frameworks is a single process, while system emulators can cover a host, including the OS. Using system emulators, it may be possible to consider taint propagation across multiple processes executing locally, within the emulator. However, there is an increasing need for tracking information flow across single-system boundaries and across the whole enterprise. We describe a proof-of-concept architecture for tracking multiple mixed-information flows among several processes across a distributed enterprise. Our DTA tool is based on PIN, a DBI framework by Intel, and the concatenated DTA processing is realized with per-host flow managers. We have tested our prototype with typical enterprise applications. As a motivating example, we track information leakage due to a SQL injection attack from a web-based database server query. Our work is of an exploratory nature, aiming to expose our early findings and identify areas where additional research is needed in improving usability and performance

    Tunable microwave signal generator with an optically-injected 1310nm QD-DFB laser

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    Tunable microwave signal generation with frequencies ranging from below 1 GHz to values over 40 GHz is demonstrated experimentally with a 1310nm Quantum Dot (QD) Distributed-Feedback (DFB) laser. Microwave signal generation is achieved using the period 1 dynamics induced in the QD DFB under optical injection. Continuous tuning in the positive detuning frequency range of the quantum dot's unique stability map is demonstrated. The simplicity of the experimental configuration offers promise for novel uses of these nanostructure lasers in Radio-over-Fiber (RoF) applications and future mobile networks. © 2013 Optical Society of America

    Randomized clinical trial of the effects of screening and brief intervention for illicit drug use: the Life Shift/Shift Gears study.

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    BackgroundAlthough screening, brief intervention, and referral to treatment (SBIRT) has shown promise for alcohol use, relatively little is known about its effectiveness for adult illicit drug use. This randomized controlled trial assessed the effectiveness of the SBIRT approach for outcomes related to drug use among patients visiting trauma and emergency departments (EDs) at two large, urban hospitals.MethodsA total of 700 ED patients who admitted using illegal drugs in the past 30 days were recruited, consented, provided baseline measures of substance use and related problems measured with the Addiction Severity Index-Lite (ASI-Lite), and then randomized to the Life Shift SBIRT intervention or to an attention-placebo control group focusing on driving and traffic safety (Shift Gears). Both groups received a level of motivational intervention matched to their condition and risk level by trained paraprofessional health educators. Separate measurement technicians conducted face-to-face follow-ups at 6 months post-intervention and collected hair samples to confirm reports of abstinence from drug use. The primary outcome measure of the study was past 30-day drug abstinence at 6 months post-intervention, as self-reported on the ASI-Lite.ResultsOf 700 participants, 292 (42%) completed follow-up. There were no significant differences in self-reported abstinence (12.5% vs. 12.0% , p = 0.88) for Life Shift and Shift Gears groups, respectively. When results of hair analyses were applied, the abstinence rate was 7 percent for Life Shift and 2 percent for Shift Gears (p = .074). In an analysis in which results were imputed (n = 694), there was no significant difference in the ASI-Lite drug use composite scores (Life Shift +0.005 vs. Shift Gears +0.017, p = 0.12).ConclusionsIn this randomized controlled trial, there was no evidence of effectiveness of SBIRT on the primary drug use outcome.Trial registrationClinicalTrials.gov NCT01683227

    Surviving and Thriving in the New World of Web Aggregators

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    This paper examines the development of aggregators, entities that collect information from a wide range of sources, with or without prior arrangements, and add value through post-aggregation services. New Web-page extraction tools, context sensitive mediators, and agent technologies have greatly reduced the barriers to constructing aggregators. We predict that aggregators will soon emerge in industries where they were not formerly present. Through studying over a hundred existing and emerging aggregators, we present a model for understanding the aggregator's strategic interaction with the incumbent. We also suggest different business models as possible aggregator entry points into an industry and describe their impact
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