https://www.selleckchem.com/products/akti-1-2.html The aim of this study was to explore social engagement and social comparisons as mechanisms to increase physical activity among older adults. Participants (N = 60, mean age = 65.7) were randomly assigned to one of two conditions. Participants in the treatment condition used the application to track their daily walking steps and interact via text messages with their group members for 4 weeks. Participants in the control group used the application only to track their own walking steps. Outcome variables included mean weekly steps, exercise self-efficacy, and social engagement. The results revealed that participants in the experimental condition significantly increased their mean weekly steps and social engagement from the pretest to the posttest whereas the control group did not. #link# These effects were maintained at the 1-month follow up. The study expands our understanding of the motivational role of social engagement and social comparison in increasing PA among older adults. The study expands our understanding of the motivational role of social engagement and social comparison in increasing PA among older adults. Readmission following total joint arthroplasty has become a closely watched metric for many hospitals in the United States due to financial penalties imposed by Centers for Medicare and Medicaid Services. The purpose of this study was to identify both preoperative and postoperative reasons for readmission within 30 days following primary total hip and total knee arthroplasty (TKA). Retrospective data were collected for patients who underwent elective primary total hip arthroplasty (THA; CPT code 27130) and TKA (27447) from 2008 to 2013 at our institution. The sample was separated into readmitted and nonreadmitted cohorts. Demography, comorbidities, Charlson comorbidity index (CCI), operative parameters, readmission rates, and causes of readmission were compared between the groups using univariate and mul