The orbit space of groupoids whose C∗C^*-algebras are GCR

Let $G$ be second countable locally compact Hausdorff groupoid with a continuous Haar system. We remove the assumption of amenability in a theorem by Clark about GCR groupoid $C^*$-algebras. We show that if the groupoid $C^*$-algebra of $G$ is GCR then the orbits of $G$ are locally closed.Comment: 1

Identifying distinct trajectories of acute otitis media in children: A prospective cohort study

Objectives: To identify possibly distinct acute otitis media (AOM) trajectories in childhood and identify determinants associated with specific AOM trajectories. To explore which child will become prone to recurrent AOM episodes and which will not. Des

Acquired hearing loss in children:Prevalence and determinants in the headphone generation

Exposure to loud sounds is a known cause of hearing loss. Currently, exposure to loud music is almost constantly available due to personal music players and smartphones with a music playing function and the use of headphones. This thesis aims to gain a better understanding of (early) acquired hearing loss and its determinants, specifically exposure to loud music and other noise. We studied hearing thresholds at a mid-childhood age, and whether associated in- and extrinsic factors could be identified. Finally, we examined if children with higher hearing thresholds perform differently in daily life. With these findings we hope to learn which children are most susceptible to acquire hearing loss, to what account music exposure and headphone use seems to be related, and which consequences can appear; in order to develop optimal prevention strategies in this and in future headphone generations. Follow-up measurements are important to examine the course of hearing thresholds in children, and whether early exposure suggests (earlier) acquired hearing loss.<br/

Association of Slight to Mild Hearing Loss With Behavioral Problems and School Performance in Children

Importance: Children with severe hearing loss are known to have more behavioral problems and may perform worse at school than children without. Few large-scale studies of slight to mild hearing loss are available. Objective: To examine the relevance of slight to mild hearing loss by studying its association with behavioral problems and school performance. Design, Setting, and Participants: This cross-sectional study was performed within an ongoing prospective birth cohort study in Rotterdam, the Netherlands. Participants were part of a population-based sample of children. Between ages 9 and 11 years, 5355 children underwent audiometric and behavioral evaluations. Children were excluded if they had missing data for either audiometry or both outcomes. Data were collected from April 2012 through October 2015. Data were analyzed from March to June 2018. Exposures: Audiometric evaluation included pure-tone audiometry tests and speech-in-noise testing. Main Outcomes and Measures: Child behavior was rated by the primary caregiver using the Child Behavior Checklist at ages 9 to 11 years (n = 4471). School performance was measured with a standardized test at age 12 years (n = 2399). Results: The final sample included 4779 participants who were a mean (SD) age of 9.8 (0.3) years. The sample had nearly equal distribution between boys (n = 2200; 49.2%) and girls (n = 2271; 50.8%). Associations of hearing thresholds with behavioral problems differed between boys and girls. Among boys, higher pure-tone hearing thresholds at low frequencies were associated with higher total problem, social problem, and attention problem scores (total problems for the better-hearing ear: β = 0.01; 95% CI, 0-0.02). Higher speech reception thresholds were associated with higher attention problem scores among girls (β = 0.04; 95% CI, 0-0.08). Higher speech reception thresholds were associated with poorer school performance scores for both boys and girls (β = -0.06; 95% CI, -0.10 to -0.02). Conclusions and Relevance: Higher hearing thresholds during pure-tone audiometric and speech-in-noise testing were associated with higher behavioral problem scores and poorer school performance. This supports the relevance of slight to mild hearing loss with these outcomes in school-aged children

A smartphone application to objectively monitor music listening habits in adolescents: Personal listening device usage and the accuracy of selfreported listening habits

Background: Listening to music through personal listening devices (PLDs) has become more prevalent during last decades. The aim of this study was to evaluate music listening habits through PLDs in adolescents with a smartphone application, and to assess the accuracy of self-reported listening habits. Methods: This study was embedded in the Generation R Study, a population-based prospective birth cohort in Rotterdam, the Netherlands. A smartphone application for Android operating systems was developed to objectively monitor music listening habits for a period of 35 days. A postal questionnaire was used to subjectively assess listening habits. The level of agreement between the objectively measured and self-reported listening habits were evaluated using weighted kappa coefficients. Data were collected from May 2017 to March 2019. Results: A total of 311 adolescents aged 12 to 15 years were included, of whom 237 (76.2%) completed the postal questionnaire. The results of the smartphone application showed that the median listening frequency was 2.1 days a week (IQR 1.0–3.4), the median listening time 21.1 min a day (IQR 9.1–53.7), and the mean listening level 54.5% (SD 18.1%). There was a slight to fair agreement between the objectively measured, and self-reported listening habits according to the weighted kappa coefficients (k = 0.179 to 0.364). Conclusions: The results of the current study suggest that self-reported measures of listening habits are not always accurate. We consider a smartphone application to monitor listening habits of added value in future research investigating the possible damaging effects of PLDs on hearing acuity. Graphical abstract: [Figure not available: see fulltext.