One major assumption for endocrine studies is that hormone titers are consistent within an individual so that if hormone titers are low relative to the cohort on one day, they are relatively low compared to the cohort on other days. This is an especially important assumption for most field studies where researchers may have access to an individual animal only once. We used a laboratory study wi...

OBJECTIVE To compare night visit rates in different electoral wards of one general practice with the Jarman and Townsend deprivation scores and unemployment rates. DESIGN Analysis of computerised workload data. SETTING General practice in centre of Mansfield, Nottinghamshire. OUTCOME MEASURE Visits made in 588 nights to the 11,998 patients on the practice list. RESULTS Night visit rates...

OBJECTIVE Ischaemic stroke occurs only in 20%-40% of patients at night. The aim of the study was to compare sleep and stroke characteristics of patients with and without night time onset of acute ischaemic cerebrovascular events. METHODS A consecutive series of 110 patients with transient ischaemic attack (n=45) or acute ischaemic stroke (n=65) was studied prospectively by means of a standard...

In order to maximize their fitness, organisms in seasonal environments rely on external cues to optimally time their life-history stages. One of the most important zeitgeber to time reproduction is the photoperiod, but further environmental cues are assessed to fine-tune reproduction due to year-to-year variation in environmental conditions. However, in urbanized environments, the pervasive art...

1. In freely moving, unanesthetized rats bile flow was measured continuously over the whole day--night cycle. Bile composition was analysed and the influence of food intake on bile flow was investigated. 2. In both sexes a distinct circadian variation of bile production was observed. The mean night-time production was 50% higher than the day-time value for female rats and 38% for male rats. In ...

BACKGROUND The Emergency Department (ED) is consistently described as a high-risk environment for patients and clinicians that demands colleagues quickly work together as a cohesive group. Communication between nurses, physicians, and other ED clinicians is complex and difficult to track. A clear understanding of communications in the ED is lacking, which has a potentially negative impact on th...

There is increasing evidence that diurnal blood pressure (BP) variation, in addition to high BP per se, is related to target organ damage and the incidence of cardiovascular events. However, the determinants of diurnal BP variation are not adequately understood. This paper tests the hypothesis that cardiovascular reactivity to acute stress and/or delayed recovery predicts greater diurnal BP var...

this was a cross-sectional case-control study in which the effect of night-time ambient light on prevalence of myopia in patients with a history of exposure to night-time light during sleep throughout the first three years of their lives was investigated in 2008. two hundred children aged 3-15 years who were brought to our eye clinic at boo-ali hospital for ophthalmic examination investigated a...

BACKGROUND Light-at-night has been shown in experimental studies to disrupt melatonin production but this has only partly been confirmed in studies of night shift workers. In this cross-sectional study, we examined the circadian variation of melatonin in relation to shift status, individual levels of light-at-night exposure, and diurnal preference, an attribute reflecting personal preference fo...