The pattern of growth hormone secretion during the menstrual cycle in normal and depressed women

Objective Major depression is associated to altered hypothalamic pituitary function. Stress is linked to elevated cortisol as well as menstrual cycle disturbance; however, there is no known relationship between depression and menstrual cycle disruption. The aim of this study was to investigate changes of growth hormone (GH) secretion during the menstrual cycle in normal and depressed women. Design Case-control study. Patients and methods Nineteen women affected with depression and 24 normal controls were included. The two groups had comparable body mass index (BMI), and age (29·4 ±9·8 vs. 28·6 ± 9·7 years). Nine depressed and 10 controls were studied in the follicular phase, while 10 depressed and 14 controls were studied in the luteal phase of the cycle. GH was sampled every 10 min for 24 h, and the data were analysed by the cluster pulse detection method. Results There was no difference in 24-h mean GH concentrations between depressed and control subjects (P =0·93), even after accounting for menstrual cycle phase (P = 0·38). GH pulse frequency was higher during the follicular phase of the cycle (P =0·032), and nocturnal GH was higher in the follicular phase of the cycle (P =0·05, and after adjusting for 24-h GH, P= 0·0138) regardless of whether thesubjects were depressed or healthy. Conclusions In studies of GH secretion in women with or without depression, it is necessary to control for the phase of menstrual cycle.NIMH MH 50030 NICHD K12HD01438Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/49486/2/KasaVubuYoung.pd

Dynamic stability of coral reefs on the West Australian coast

Monitoring changes in coral cover and composition through space and time can provide insights to reef health and assist the focus of management and conservation efforts. We used a meta-analytical approach to assess coral cover data across latitudes 10-35°S along the west Australian coast, including 25 years of data from the Ningaloo region. Current estimates of coral cover ranged between 3 and 44% in coral habitats. Coral communities in the northern regions were dominated by corals from the families Acroporidae and Poritidae, which became less common at higher latitudes. At Ningaloo Reef coral cover has remained relatively stable through time (∼28%), although north-eastern and southern areas have experienced significant declines in overall cover. These declines are likely related to periodic disturbances such as cyclones and thermal anomalies, which were particularly noticeable around 1998/1999 and 2010/2011. Linear mixed effects models (LME) suggest latitude explains 10% of the deviance in coral cover through time at Ningaloo. Acroporidae has decreased in abundance relative to other common families at Ningaloo in the south, which might be related to persistence of more thermally and mechanically tolerant families. We identify regions where quantitative time-series data on coral cover and composition are lacking, particularly in north-western Australia. Standardising routine monitoring methods used by management and research agencies at these, and other locations, would allow a more robust assessment of coral condition and a better basis for conservation of coral reefs

The state of Western Australia’s coral reefs

Western Australia’s coral reefs have largely escaped the chronic pressures affecting other reefs around the world, but are regularly affected by seasonal storms and cyclones, and increasingly by heat stress and coral bleaching. Reef systems north of 18°S have been impacted by heat stress and coral bleaching during strong El Niño phases and those further south during strong La Niña phases. Cumulative heat stress and the extent of bleaching throughout the northern reefs in 2016 were higher than at any other time on record. To assess the changing regime of disturbance to reef systems across Western Australia (WA), we linked their site-specific exposure to damaging waves and heat stress since 1990 with mean changes in coral cover. Since 2010, there has been a noticeable increase in heat stress and coral bleaching across WA. Over half the reef systems have been severely impacted by coral bleaching since 2010, which was further compounded by cyclones at some reefs. For most (75%) reef systems with long-term data (5–26 yrs), mean coral cover is currently at (or near) the lowest on record and a full recovery is unlikely if disturbances continue to intensify with climate change. However, some reefs have not yet experienced severe bleaching and their coral cover has remained relatively stable or increased in recent years. Additionally, within all reef systems the condition of communities and their exposure to disturbances varied spatially. Identifying the communities least susceptible to future disturbances and linking them through networks of protected areas, based on patterns of larval connectivity, are important research and management priorities in coming years while the causes of climate change are addressed