York University

About: York University is a education organization based out in Toronto, Ontario, Canada. It is known for research contribution in the topics: Population & Poison control. The organization has 18899 authors who have published 43357 publications receiving 1568560 citations.

Sleep problems during the COVID-19 pandemic by population: a systematic review and meta-analysis.

Abstract: STUDY OBJECTIVES: No systematic review or meta-analysis has yet been conducted to examine the impact of the pandemic on the prevalence of sleep problems among the general population, healthcare workers, or COVID-19 patients. Therefore, this systematic review was conducted to assess the impact and prevalence of sleep problems among those categories. METHODS: APA PsycINFO; Cochrane; Cumulative Index to Nursing and Allied Health Literature (CINAHL); EBSCOhost; EMBASE; Google Scholar; MEDLINE; ProQuest Medical; ScienceDirect; Scopus; and Web of Science from 01 November 2019 to 05 July 2020. Additionally, four preprints servers (medRxiv.org; Preprints.org; psyarxiv.com; arXiv.org; biorxiv.org) were also searched for papers accepted after peer-review but not yet published and indexed. There was no language restriction. The random-effect models meta-analysis model were used with the DerSimonian and Laird methodology. RESULTS: Forty-four papers, involving a total of 54,231 participants from 13 countries, were judged relevant and contributed to the systematic review and meta-analysis of sleep problems during COVID-19. The global pooled prevalence rate of sleep problems among all populations was 35.7% [95%CI 29.4-42.4%]. COVID-19 patients appeared to be the most affected group, with a pooled rate of 74.8% [95%CI 28.7-95.6%]. Healthcare workers and the general population had comparative rates of sleep problems with rates of 36.0% [95%CI 21.1-54.2%] and 32.3% [95%CI 25.3-40.2%], respectively. CONCLUSIONS: The prevalence of sleep problems during the COVID-19 pandemic is high and approximately affect 40% of people from the general and healthcare populations. COVID-19 active patients appeared to have higher prevalence rates of sleep problems.

Design and perceptual validation of performance measures for salient object segmentation

Abstract: Empirical evaluation of salient object segmentation methods requires i) a dataset of ground truth object segmentations and ii) a performance measure to compare the output of the algorithm with the ground truth. In this paper, we provide such a dataset, and evaluate 5 distinct performance measures that have been used in the literature practically and psychophysically. Our results suggest that a measure based upon minimal contour mappings is most sensitive to shape irregularities and most consistent with human judgements. In fact, the contour mapping measure is as predictive of human judgements as human subjects are of each other. Region-based methods, and contour methods such as Hausdorff distances that do not respect the ordering of points on shape boundaries are significantly less consistent with human judgements. We also show that minimal contour mappings can be used as the correspondence paradigm for Precision-Recall analysis. Our findings can provide guidance in evaluating the results of segmentation algorithms in the future.

Reputation, Diversification, and Organizational Explanations of Performance in Professional Service Firms

Abstract: Growing interest in knowledge as a competitive asset suggests the benefit of studying professional service firms (PSFs). These firms are highly successful examples of organizations whose ability to manage knowledge is critical to their success. Furthermore, they are worthy of study because they constitute a significant sector of the economy, whether measured by their size, numbers, or influence. Despite their significance, little is known of the determinants of their performance. This paper proposes that the core tasks of PSFs raise unusual strategic and organizational challenges, the resolution of which affects organizational performance. We elaborate the effects of reputation and diversification and contrast them to theory for goods-producing industries. We also hypothesize that PSF managers face a choice in designing structures between the retention and motivation of the professional workforce and transferring knowledge from partners to other professionals. These predictions are tested and supported by data from the largest 100 U.S. accounting firms for the period 1991-2000. The paper thus contributes to a theory of professional service firm management.

Investment in general training: the role of information and labour mobility*

Abstract: Following the seminal work of Becker (I964), it is widely accepted in the literature that firms will be unwilling to finance training which workers may use in other firms. This paper takes issue with this prediction and suggests that firms will frequently share in the cost of such general training.1 Becker argues that a firm which pays for the training of workers in skills of potential use to other firms will lose these workers: since other firms bear none of the costs of general training, they can attract a worker with such training by outbidding the firm which trained him. Recognising this absence of property rights over an investment in general training, firms will refuse to provide it. Hence, if general training is to take place, the trainee will have to pay for it. If potential trainees are unwilling or unable to pay, general training will not take place. A shortage in general training is likely to emerge; this may be especially pronounced in developing countries.2 In contrast, the outlook for