301 research outputs found

    Hearing loss by week of gestation and birth weight in very preterm neonates

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    OBJECTIVE: To gain insight into health and related costs associated with very preterm births, one needs accurate information about the prevalence of the disabling conditions, including neonatal hearing loss (NHL).STUDY DESIGN: We assessed the prevalence of NHL by week of gestation and categories of birth weight in very preterm neonates. Results of the 2-stage Automated Auditory Brainstem Response nationwide Newborn Hearing Screening Program in Dutch Neonatal Intensive Care Units and diagnostic examinations were centrally registered between October 1998 and December 2012 and included in this study. NHL was defined as impaired when the neonate conventional Auditory Brainstem Response level exceeded 35 dB near Hearing Level at diagnostic examination. Birth weight was stratified into &lt;750 g, 750-999 g, 1000-1249 g, 1250-1499 g, and ≥ 1500 g, and by small for gestational age (SGA; &lt;10th percentile) vs appropriate for gestational age. Logistic regression analyses and recursive partitioning were performed.RESULTS: In total, 18,564 very preterm neonates were eligible. The prevalence of NHL consistently increased with decreasing week of gestation (1.2%-7.5% from 31 to 24 weeks) and decreasing birth weight (1.4%-4.8% from ≥ 1500 g to &lt;750 g, all P &lt; .002). Most vulnerable to NHL were girls &lt;28 weeks, boys &lt;30 weeks, and SGA neonates. The SGA effect started at 27 weeks.CONCLUSIONS: Gestational age and birth weight quantify the risk of NHL. This information can be used at the individual level for parent counseling and at the population level for medical decision making.</p

    Evaluation of Treatment Thresholds for Unconjugated Hyperbilirubinemia in Preterm Infants:Effects on Serum Bilirubin and on Hearing Loss?

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    Background: Severe unconjugated hyperbilirubinemia may cause deafness. In the Netherlands, 25% lower total serum bilirubin (TSB) treatment thresholds were recently implemented for preterm infants.Objective: To determine the rate of hearing loss in jaundiced preterms treated at high or at low TSB thresholds.Design/Methods: In this retrospective study conducted at two neonatal intensive care units in the Netherlands, we included preterms (gestational age 35 dB).Results: There were 479 patients in the high and 144 in the low threshold group. Both groups had similar gestational ages (29.5 weeks) and birth weights (1300 g). Mean and mean peak TSB levels were significantly lower after the implementation of the novel thresholds: 152 +/- 43 mu mol/L and 212 +/- 52 mu mol/L versus 131 +/- 37 mu mol/L and 188 +/- 46 mu mol/L for the high versus low thresholds, respectively (PConclusions: Implementation of lower treatment thresholds resulted in reduced mean and peak TSB levels. The incidence of hearing impairment in preterms with a gestational age</p

    Memory Inflation during Chronic Viral Infection Is Maintained by Continuous Production of Short-Lived, Functional T Cells

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    SummaryDuring persistent murine cytomegalovirus (MCMV) infection, the T cell response is maintained at extremely high intensity for the life of the host. These cells closely resemble human CMV-specific cells, which compose a major component of the peripheral T cell compartment in most people. Despite a phenotype that suggests extensive antigen-driven differentiation, MCMV-specific T cells remain functional and respond vigorously to viral challenge. We hypothesized that a low rate of antigen-driven proliferation would account for the maintenance of this population. Instead, we found that most of these cells divided only sporadically in chronically infected hosts and had a short half-life in circulation. The overall population was supported, at least in part, by memory T cells primed early in infection, as well as by recruitment of naive T cells at late times. Thus, these data show that memory inflation is maintained by a continuous replacement of short-lived, functional cells during chronic MCMV infection

    Reproducibility via coordinated standardization:A multi-center study in a Shank2 genetic rat model for Autism Spectrum Disorders

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    Inconsistent findings between laboratories are hampering scientific progress and are of increasing public concern. Differences in laboratory environment is a known factor contributing to poor reproducibility of findings between research sites, and well-controlled multisite efforts are an important next step to identify the relevant factors needed to reduce variation in study outcome between laboratories. Through harmonization of apparatus, test protocol, and aligned and non-aligned environmental variables, the present study shows that behavioral pharmacological responses in Shank2 knockout (KO) rats, a model of synaptic dysfunction relevant to autism spectrum disorders, were highly replicable across three research centers. All three sites reliably observed a hyperactive and repetitive behavioral phenotype in KO rats compared to their wild-type littermates as well as a dose-dependent phenotype attenuation following acute injections of a selective mGluR1 antagonist. These results show that reproducibility in preclinical studies can be obtained and emphasizes the need for high quality and rigorous methodologies in scientific research. Considering the observed external validity, the present study also suggests mGluR1 as potential target for the treatment of autism spectrum disorders

    An Environmental and Climate History of the Roman Expansion in Italy

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    A first synthesis of available data for the period of Rome’s expansion in Italy (about 400–29 b.c.e.) shows the role of climate and environment in early Roman imperialism. Although global indices suggest a warmer phase with relatively few short-term climate events occuring around the same time as the expansion, local data emphasize the highly variable timing and expression of these trends. This variability casts doubt on ideas of a unitary, historically consequential “Roman Warm Period.” The historical importance of climate and environment to socioeconomic development merits emphasis, but should be understood in terms of evolving, contingent forms of resilience and risk-mitigating behavior by Italian communities during Roman expansion

    How do you say ‘hello’? Personality impressions from brief novel voices

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    On hearing a novel voice, listeners readily form personality impressions of that speaker. Accurate or not, these impressions are known to affect subsequent interactions; yet the underlying psychological and acoustical bases remain poorly understood. Furthermore, hitherto studies have focussed on extended speech as opposed to analysing the instantaneous impressions we obtain from first experience. In this paper, through a mass online rating experiment, 320 participants rated 64 sub-second vocal utterances of the word ‘hello’ on one of 10 personality traits. We show that: (1) personality judgements of brief utterances from unfamiliar speakers are consistent across listeners; (2) a two-dimensional ‘social voice space’ with axes mapping Valence (Trust, Likeability) and Dominance, each driven by differing combinations of vocal acoustics, adequately summarises ratings in both male and female voices; and (3) a positive combination of Valence and Dominance results in increased perceived male vocal Attractiveness, whereas perceived female vocal Attractiveness is largely controlled by increasing Valence. Results are discussed in relation to the rapid evaluation of personality and, in turn, the intent of others, as being driven by survival mechanisms via approach or avoidance behaviours. These findings provide empirical bases for predicting personality impressions from acoustical analyses of short utterances and for generating desired personality impressions in artificial voices

    Viscous-Inviscid Interactions in a Boundary-Layer Flow Induced by a Vortex Array

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    In this paper we investigate the asymptotic validity of boundary layer theory. For a flow induced by a periodic row of point-vortices, we compare Prandtl's solution to Navier-Stokes solutions at different ReRe numbers. We show how Prandtl's solution develops a finite time separation singularity. On the other hand Navier-Stokes solution is characterized by the presence of two kinds of viscous-inviscid interactions between the boundary layer and the outer flow. These interactions can be detected by the analysis of the enstrophy and of the pressure gradient on the wall. Moreover we apply the complex singularity tracking method to Prandtl and Navier-Stokes solutions and analyze the previous interactions from a different perspective
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