Analysis of error-prone survival data under additive hazards models: measurement error effects and adjustments

Covariate measurement error occurs commonly in survival analysis. Under the proportional hazards model, measurement error effects have been well studied, and various inference methods have been developed to correct for error effects under such a model. In contrast, error-contaminated survival data under the additive hazards model have received relatively less attention. In this paper, we investigate this problem by exploring measurement error effects on parameter estimation and the change of the hazard function. New insights of measurement error effects are revealed, as opposed to well-documented results for the Cox proportional hazards model. We propose a class of bias correction estimators that embraces certain existing estimators as special cases. In addition, we exploit the regression calibration method to reduce measurement error effects. Theoretical results for the developed methods are established, and numerical assessments are conducted to illustrate the finite sample performance of our methods.     

Conceptualizing Emergent States: A Strategy to Advance the Study of Group Dynamics

In this review, we aim to advance work on group and team dynamics by examining how important elements of dynamism are embedded in the current literature on emergent states in groups. We use the concept of emergence as an organizing frame, building block, and critical lens, first summarizing key aspects of the extant literature on emergence, and then drawing four core characteristics of emergent phenomena from this literature. We use these characteristics to organize our review and examine how emergent states are portrayed in the past decade of groups literature. We end by exploring challenges to the development of a more dynamic perspective and by offering specific suggestions to guide and advance future work on groups and teams.     

The Cataloging of E-Book Readers: A Service Model-Oriented Approach

Abstract

The popularity of e-book readers has exploded over the past several years, and many libraries have begun purchasing and providing access to these devices for their patrons. A large body of academic literature addresses the popularity of e-book readers and the issues involved with purchasing them and licensing material for them, but there is a relatively slim body of literature regarding the cataloging of e-book readers. At present, there is no uniform approach to cataloging e-book readers and libraries are currently employing a number of different methods. This article will describe the approach to cataloging e-book readers adopted at the Z. Smith Reynolds Library of Wake Forest University, which is based on the local service model for e-readers that takes into account how patrons are expected to use the devices as well as licensing concerns about the use of titles on e-readers. In order to make the devices discoverable for patrons with a minimum of confusion, certain unusual cataloging practices are employed (such as coding e-readers as “realia” but giving them a general material designation (GMD) of “electronic resource”). This article argues that the RDA code should accommodate e-book readers by creating carrier types that accurately describe these devices in a way that patrons can understand.     

Perceived violence climate: A new construct and its relationship to workplace physical violence and verbal aggression,and their potential consequences

Abstract

Workplace accidents and violence are both potential sources of employee injuries that have been dealt with in entirely separate literatures. In this study we adapted the concept of safety climate from the accident/injury literature to violence in developing the concept of perceived violence climate. A scale was developed to assess perceived violence climate, including items about management attention, concern, and policies designed to keep employees safe from violence. Data were collected from a sample of 198 nurses from a US Hospital. Perceived violence climate was found to correlate significantly with both physical violence and verbal aggression experienced by the nurses, injury from violence, and perceptions of workplace danger. Furthermore, regression analyses showed that climate explained additional variance in psychological strain and perceptions of danger over experienced violence. These results have implications for interventions aimed at producing a good perceived violence climate in order to reduce the incidence of violence and aggression within an organization.     

Vacant lot soil degradation and mowing frequency shape communities of belowground invertebrates and urban spontaneous vegetation

Urban Ecosystems - Vacant land in legacy cities is increasingly recognized as a resource to support biodiversity and improve the quality of life for residents. However, the capacity for vacant lot...