42,643 research outputs found

    The Possible Role of Extra-ocular Photoreceptors in the Entrainment of Lobster Circadian Rhythms to Light:Dark Cycles

    Get PDF
    The American lobster, Homarus americanus, is a decapod crustacean whose daily nocturnal rhythms of activity are driven, in part, by an internal biological clock. While this circadian clock is capable of producing a rhythm of approximately 24 hours on its own, it can also be entrained to light:dark cycles. Recent findings in our laboratory suggest that lobsters have photosensitive neurons throughout their nervous system (extra-ocular photoreceptors). The objective of this research was to test the hypothesis that these extra-ocular photoreceptors aid in entraining their daily rhythm of activity. First, the locomotion of juvenile American lobsters was measured in trials under a normal 24 hour light:dark cycle. Then, after this “control” period, the lobsters’ eyes were painted with black nail polish and their activity was monitored under the same conditions. The lobsters were also exposed to DD conditions with their eyes covered in one of the trials. During the control LD cycle, lobsters expressed increased locomotion at night, demonstrating their daily rhythm. The DD cycle had a consistent rhythm with an elongated period of activity. Interestingly, half of the lobsters continued to follow the same pattern of activity despite the visual impairment and half expressed a diurnal rhythm. Although there was variation in the locomotor activity, a periodicity of ~24 hours was maintained throughout the LD cycles. This indicates that H. americanus receives photoperiod input from both their eyes and extra-ocular photoreceptors that help synchronize their locomotor activity to LD cycles

    On non-asymptotic bounds for estimation in generalized linear models with highly correlated design

    Full text link
    We study a high-dimensional generalized linear model and penalized empirical risk minimization with 1\ell_1 penalty. Our aim is to provide a non-trivial illustration that non-asymptotic bounds for the estimator can be obtained without relying on the chaining technique and/or the peeling device.Comment: Published at http://dx.doi.org/10.1214/074921707000000319 in the IMS Lecture Notes Monograph Series (http://www.imstat.org/publications/lecnotes.htm) by the Institute of Mathematical Statistics (http://www.imstat.org

    Interviewer Assessments of Applicant Fit : An Exploratory Investigation

    Get PDF
    Although both strategic management theorists and practicing recruiters endorse selecting applicants on the basis of fit, precise delineation of fit in a selection context remains elusive. Moreover, the majority of previous work in this area has been based on anecdotes, case studies, or prescriptions rather than empirical evidence. The present investigation examines interviewers\u27 assessments of job applicants in terms of both general and firm-specific employability (i.e., fit). Results suggest that (1) assessments of general employability differ from firm-specific assessments, (2) there is a firm-specific component to interviewers\u27 evaluations of job applicants, and (3) interpersonal skills, goal orientation, and physical attractiveness contribute to assessments of fit (holding general employability constant), while objective qualifications (e.g., grade point average, extracurricular offices, years experience) do not. Suggestions for future research are offered

    Bridge 2018 Information Literacy Curriculum Report

    Get PDF
    A uniform curriculum has been in place in Bridge Information Literacy (IL) sessions since Fall 2015. To assess the curriculum and student learning, multiple evaluations are implemented: a student end-of-class evaluation; a faculty end-of-Bridge evaluation; and an in-class worksheet. This report summarizes student performance in Bridge as well as student and faculty evaluation responses

    Comparative thermal performance test for GGBS and OPC concrete mixes

    Get PDF
    The research investigates the effect of heating two concrete types and profiles to evaluate the most effective material during diurnal heating and cooling cycles. Plain and finned concrete slabs were manufactured from concrete with a 100% - PC binder (CEM 1) and a binder using 50% - PC and 50% GGBS (CEM 111). The slabs were subject to mainly radiative heat for a 7.5 hour daytime period and left to cool for 16.5 hours. Comparative readings were taken to measure the temperature difference between the two types of concrete during heating and cooling. The findings showed concrete manufactured with GGBS had a lower heat build up and release when compared to concrete manufactured with 100% CEM 1 binder. The research was limited to one comparative test at a single concrete strength with a single water cement ratio, and 50% GGBS cement replacement. Various GGBS cement replacement percentages could be tried to evaluate heat build up and release. Further research on U and Y values are also worthy of further investigation. Thermal mass could be improved thus reducing the need to use energy intensive air conditioning systems

    Screening for Significant Behavior Problems in Diverse Young Children Living in Poverty

    Get PDF
    The development and use of first line screening instruments is an essential first step in assessing behavior disorders in very young children. The Early Childhood Behavior Screen (ECBS) is a parent-report measure for behavior disorders and is normed on young children (1–5 years old) living in poverty. The current study presents psychometric support for the discriminative validity of the ECBS’s 10-item Challenging Behavior Scale (CBS) as a first-line screener for externalizing behavior problems for preschool aged-children in poverty. The study’s sample included 673 participants (M age years = 2.81; 63.2 % male; 65.8 % African American) that all met the federal definitional standard for living in poverty. A confirmatory factor analysis was run to provide support for the ECBS factor structure. Receiver operating characteristics (ROC) curve analyses were used to test the CBS’s ability to distinguish between 428 clinic-referred children and 245 non-clinic-referred children. Results showed an acceptable fit model for the ECBS, providing further evidence of its construct validity. Optimal cut-scores by child age derived from the ROC curve analyses were provided with corresponding levels of sensitivity, specificity, and positive and negative predictive values. Sensitivity rates for cut scores ranged from 0.76 to 0.83 and specificity rates ranged from 0.88 to 0.95. Acceptable test–retest reliability and good internal consistency also was observed. The CBS quickly identifies young children from low-income, urban, diverse populations that may be at-risk for developing significant behavior disorders and should be considered by health care professionals who work with very young children

    Profiling and targeting HER2-positive breast cancer using trastuzumab emtansine.

    Get PDF
    PurposeThis article reviews the mechanism of action of trastuzumab emtansine (T-DM1), existing clinical data relating to its use for human growth factor receptor 2 (HER2)-positive breast cancer, potential pathways of resistance, and ongoing studies evaluating this novel agent.BackgroundThe development of HER2-targeted therapies has dramatically improved clinical outcomes for patients with any stage of HER2-positive breast cancer. Although the positive effect of these treatments cannot be overstated, treatment resistance develops in the vast majority of those diagnosed with stage IV HER2-positive breast cancer. Moreover, HER2-directed therapies are most effective when combined with cytotoxic chemotherapy. The need for chemotherapy leads to significant adverse effects and a clear decrease in quality of life for those dealing with a chronic incurable disease. T-DM1 is a recently developed, novel antibody-drug conjugate in which highly potent maytanisinoid chemotherapy is stably linked to the HER2-targeted monoclonal antibody, trastuzumab.ResultsPreclinical and phase 1-3 clinical data support the significant antitumor activity of T-DM1. Importantly, several randomized studies also now demonstrate its clear superiority in terms of tolerability compared with standard chemotherapy-containing regimens. Its role in the treatment of trastuzumab-resistant metastatic breast cancer has now been established on the basis of the results of two phase 3 randomized studies, EMILIA (An Open-label Study of Trastuzumab Emtansine (T-DM1) vs Capecitabine + Lapatinib in Patients With HER2-positive Locally Advanced or Metastatic Breast Cancer) and TH3RESA (A Study of Trastuzumab Emtansine in Comparison With Treatment of Physician's Choice in Patients With HER2-positive Breast Cancer Who Have Received at Least Two Prior Regimens of HER2-directed Therapy). The most common toxicities seen with T-DM1 are thrombocytopenia and an elevation in liver transaminases. Significant cardiac toxicity has not been demonstrated. Both in vitro cell line-based studies as well as exploratory analyses of archived tumor samples from the clinical trials are seeking to understand potential mechanisms of resistance to T-DM1. Ongoing studies are also evaluating the use of T-DM1 in the first-line metastatic, neoadjuvant, and adjuvant settings, as well as in combination with other targeted therapies.ConclusionT-DM1 represents the first successfully developed antibody drug conjugate for the treatment of HER2-positive advanced breast cancer
    corecore