Preparation for fatherhood: A role for olfactory communication during human pregnancy?

There is evidence across a range of bi-parental species that physiological changes may occur in partnered males prior to the birth of an infant. It has been hypothesised that these hormonal changes might facilitate care-giving behaviours, which could augment infant survival. The mechanism that induces these changes has not been identified, but evidence from several species suggests that odour may play a role. The current study investigated this in humans by recording testosterone and psychological measures related to infant interest and care in men (n = 91) both before and after exposure to odours from either pregnant women or non-pregnant control women. We found no evidence for an effect of odour cues of pregnancy on psychological measures including self-reported sociosexual orientation and social dominance scores, ratings of infant or adult faces, or testosterone levels. However, we found that brief exposure to post-partum odours significantly increased the reward value of infant faces. Our study is the first to show that the odour of peri-partum women may lead to upregulation of men's interest in infants.

Epidemiology of systematic reviews in imaging journals: evaluation of publication trends and sustainability?

PURPOSE: To evaluate the epidemiology of systematic reviews (SRs) published in imaging journals. METHODS: A MEDLINE search identified SRs published in imaging journals from 1 January 2000-31 December 2016. Articles retrieved were screened against inclusion criteria. Demographic and methodological characteristics were extracted from studies. Temporal trends were evaluated using linear regression and Pearson's correlation coefficients. RESULTS: 921 SRs were included that reported on 27,435 primary studies, 85,276,484 patients and were cited 26,961 times. The SR publication rate increased 23-fold (r=0.92, p<0.001) while the proportion of SRs to non-SRs increased 13-fold (r = 0.94, p<0.001) from 2000 (0.10%) to 2016 (1.33%). Diagnostic test accuracy (DTA) SRs were most frequent (46.5%) followed by therapeutic SRs (16.6%). Most SRs did not report funding status (54.2%). The median author team size was five; this increased over time (r=0.20, p<0.001). Of the studies, 67.3% included an imaging specialist co-author; this decreased over time (r=-0.57, p=0.017). Most SRs included a meta-analysis (69.6%). Journal impact factor positively correlated with SR publication rates (r=0.54, p<0.001). Magnetic resonance imaging (MRI) and 'vascular and interventional radiology' were the most frequently studied imaging modality and subspecialty, respectively. The USA, UK, China, Netherlands and Canada were the top five publishing countries. CONCLUSIONS: The SR publication rate is increasing rapidly compared with the rate of growth of non-SRs; however, they still make up just over 1% of all studies. Authors, reviewers and editors should be aware of methodological and reporting standards specific to imaging systematic reviews including those for DTA and individual patient data. KEY POINTS: • Systematic review publication rate has increased 23-fold from 2000-2016. • The proportion of systematic reviews to non-systematic reviews has increased 13-fold. • The USA, UK and China are the most frequent published countries; those from the USA and China are increasing the most rapidly.