ABSTRACT
While most mammals show birth hour peaks at times of the 24-h cycle when they are less active, there are exceptions to this general pattern. Such exceptions have been little explored, but may clarify evolutionary reasons for the diel timing of births. We investigated intraspecific variation in birth hour in wild blue monkeys Cercopithecus mitis stuhlmanni, a diurnal primate, to identify factors that differentiated daytime versus nighttime births. Behavioral and life history data from 14 groups over 14 years revealed that 4% of 484 births occurred during the day. Probability of daytime birth varied with mother's age, peaking at 15.7 years. Births whose annual timing deviated most from the population's peak birth months were 5 times more likely to occur during daytime than those that deviated less. There was no evidence that mother's rank or infant sex influenced birth hour, and mixed evidence that daytime births were more probable in larger groups. Survivorship did not differ significantly for infants born during the day versus night. Prime-aged mothers may be able to handle the consequences of an unusual birth hour more successfully than mothers with less experience or those weakened by age. Daytime birth may be more advantageous in the off-season because nights are colder at that time of year. These findings are consistent with hypotheses relating birth hour to the risk of losing social protection in group-living animals, but are not consistent with those emphasizing risk of conspecific harassment. Patterns of within-species variation can help in evaluating evolutionary hypotheses for non-random birth hour.
ABSTRACT
Rehabilitation prior to orthopedic surgery (prehab) has been studied with more frequency and studies have shown reduced costs and improved functional outcomes among patients who have undergone total hip arthroplasty (THA) and total knee arthroplasty (TKA). This literature review is to determine whether prehab improves functional outcomes and reduces costs following spinal surgery. PubMed, CINHAL via EBSCO and EMBASE via Ovid were searched with publication date restrictions from May 2006 to May 2016 for the terms 'physical therapy', 'physiotherapy', 'prehabilitation' or 'prehab', 'spine' or 'spinal', and 'preoperative' or 'pre-op'. The search yielded 737 eligible articles which were screened by two independent reviewers. Randomized controlled trials (RCT) with adults who participated in preoperative exercise interventions as part of a prehab or preoperative exercise program for spinal surgery versus standard care were included. Methodology and results of the studies were critically appraised in conformity with PRISMA guidelines. Three RCTs were included, all of which analyzed outcomes of prehab following lumbar spinal surgery. Two of the articles were of high quality and three were of low quality. None of the studies demonstrated a statistically significant difference in pain scores or disability questionnaires in the intervention groups postoperatively, however, no negative effects were reported either. With neuroscience education, patient's reported feeling prepared for surgery and expressed positive outlook regarding the intervention. Two of the studies found perioperative intervention reduced the total cost of healthcare spending associated with spinal surgery. Due to the heterogeneity of the outcome measures, a meta-analysis was not possible. There is lack of significant evidence looking at functional outcomes using physical therapy prior to spinal surgery. Prehab should continue to be researched prior to spinal surgery to determine effectiveness in patient outcomes.
