Nutritional status and the gonadotrophic response to a polar expedition.

Polar expeditions have been associated with changes in the hypothalamic-pituitary-testicular axis consistent with central hypogonadism (i.e., decreased testosterone, luteinising hormone (LH), and follicle stimulating hormone (FSH)). These changes are typically associated with body mass loss. Our aim was to evaluate whether maintenance of body mass during a polar expedition could mitigate against the development of central hypogonadism. Male participants (n = 22) from a 42-day expedition (British Services Antarctic Expedition 2012) volunteered to take part in the study. Body mass, body composition, and strength data were recorded pre- and postexpedition in addition to assessment of serum testosterone, LH, FSH, thyroid hormones, insulin-like growth factor 1 (IGF-1), and trace elements. Energy provision and energy expenditure were assessed at mid- and end-expedition. Daily energy provision was 6335 ± 149 kcal·day(-1). Estimated energy expenditure midexpedition was 5783 ± 1690 kcal·day(-1). Body mass and percentage body fat did not change between pre- and postexpedition. Total testosterone (nmol·L(-1)) (14.0 ± 4.9 vs. 17.3 ± 4.0, p = 0.006), calculated free testosterone (pmol·L(-1)) (288 ± 82 vs. 350 ± 70, p = 0.003), and sex hormone binding globulin (nmol·L(-1)) (33 ± 12 vs. 36 ± 11, p = 0.023) concentrations increased. LH and FSH remained unchanged. Thyroid stimulating hormone (TSH; IU·L(-1)) (2.1 ± 0.8 vs. 4.1 ± 2.1, p < 0.001) and free triiodothyronine (FT3; IU·L(-1)) (5.4 ± 0.4 vs. 6.1 ± 0.8, p < 0.001) increased while free thyroxine, IGF-1, and trace elements remained unchanged. Hand-grip strength was reduced postexpedition but static lift strength was maintained. Maintenance of body mass and nutritional status appeared to negate the central hypogonadism previously reported from polar expeditions. The elevated TSH and free FT3 were consistent with a previously reported "polar T3 syndrome"

Plasticity of human adipose-derived stem cells - relevance to tissue repair.

In contrast to cold blooded vertebrates, the ability to regenerate morphologically and functionally complex structures is limited in adult mammals. Recruitment of progenitor cells is a key step in the regenerative process. The possibility of repairing missing or diseased tissues in humans has been potentiated by the increasing understanding of somatic stem cells, their plasticity and the possibility of modulating it, that could be harnessed either to stimulate endogenous repair or to engineer the required tissue. Here, we focus on human mesenchymal stem cells (MSCs), important players in tissue homeostasis in healthy organisms, with a particular emphasis on those derived from the adipose tissue (ADSCs). While a mark of MSC identity is the ability to differentiate into osteoblasts, chondrocytes and adipocytes, there is evidence that their potential goes beyond these three mesenchymal lineages. We discuss some differentiation and modulatory properties of MSCs and provide an overview of our recent work on ADSCs from paediatric patients (pADSCs) that has shown their ability to give raise to non-mesenchymal cells, consistent with a significant plasticity. Finally, we present novel data indicating that both mesenchymal lineages (adipogenic, chondrogenic and osteogenic) and neural and epithelial lineages can originate from clonal lines that like the parental line express markers of pluripotency as well as the stromal cell marker, GREM1. Together these data support the existence of pADSC multipotent stem cells.Newlife Foundation, NIHR GOSH BRC, MRC and BBSRC

The association between green space and cause-specific mortality in urban New Zealand: an ecological analysis of green space utility

&lt;b&gt;Background:&lt;/b&gt; There is mounting international evidence that exposure to green environments is associated with health benefits, including lower mortality rates. Consequently, it has been suggested that the uneven distribution of such environments may contribute to health inequalities. Possible causative mechanisms behind the green space and health relationship include the provision of physical activity opportunities, facilitation of social contact and the restorative effects of nature. In the New Zealand context we investigated whether there was a socioeconomic gradient in green space exposure and whether green space exposure was associated with cause-specific mortality (cardiovascular disease and lung cancer). We subsequently asked what is the mechanism(s) by which green space availability may influence mortality outcomes, by contrasting health associations for different types of green space. &lt;b&gt;Methods:&lt;/b&gt; This was an observational study on a population of 1,546,405 living in 1009 small urban areas in New Zealand. A neighbourhood-level classification was developed to distinguish between usable (i.e., visitable) and non-usable green space (i.e., visible but not visitable) in the urban areas. Negative binomial regression models were fitted to examine the association between quartiles of area-level green space availability and risk of mortality from cardiovascular disease (n = 9,484; 1996 - 2005) and from lung cancer (n = 2,603; 1996 - 2005), after control for age, sex, socio-economic deprivation, smoking, air pollution and population density. &lt;b&gt;Results:&lt;/b&gt; Deprived neighbourhoods were relatively disadvantaged in total green space availability (11% less total green space for a one standard deviation increase in NZDep2001 deprivation score, p &#60; 0.001), but had marginally more usable green space (2% more for a one standard deviation increase in deprivation score, p = 0.002). No significant associations between usable or total green space and mortality were observed after adjustment for confounders. &lt;b&gt;Conclusion&lt;/b&gt; Contrary to expectations we found no evidence that green space influenced cardiovascular disease mortality in New Zealand, suggesting that green space and health relationships may vary according to national, societal or environmental context. Hence we were unable to infer the mechanism in the relationship. Our inability to adjust for individual-level factors with a significant influence on cardiovascular disease and lung cancer mortality risk (e.g., diet and alcohol consumption) will have limited the ability of the analyses to detect green space effects, if present. Additionally, green space variation may have lesser relevance for health in New Zealand because green space is generally more abundant and there is less social and spatial variation in its availability than found in other contexts

The 1983 drought in the West Sahel: a case study

Some drought years over sub-Saharan west Africa (1972, 1977, 1984) have been previously related to a cross-equatorial Atlantic gradient pattern with anomalously warm sea surface temperatures (SSTs) south of 10°N and anomalously cold SSTs north of 10°N. This SST dipole-like pattern was not characteristic of 1983, the third driest summer of the twentieth century in the Sahel. This study presents evidence that the dry conditions that persisted over the west Sahel in 1983 were mainly forced by high Indian Ocean SSTs that were probably remanent from the strong 1982/1983 El Niño event. The synchronous Pacific impact of the 1982/1983 El Niño event on west African rainfall was however, quite weak. Prior studies have mainly suggested that the Indian Ocean SSTs impact the decadal-scale rainfall variability over the west Sahel. This study demonstrates that the Indian Ocean also significantly affects inter-annual rainfall variability over the west Sahel and that it was the main forcing for the drought over the west Sahel in 1983

Captive reptile mortality rates in the home and implications for the wildlife trade

The trade in wildlife and keeping of exotic pets is subject to varying levels of national and international regulation and is a topic often attracting controversy. Reptiles are popular exotic pets and comprise a substantial component of the live animal trade. High mortality of traded animals raises welfare concerns, and also has implications for conservation if collection from the wild is required to meet demand. Mortality of reptiles can occur at any stage of the trade chain from collector to consumer. However, there is limited information on mortality rates of reptiles across trade chains, particularly amongst final consumers in the home. We investigated mortality rates of reptiles amongst consumers using a specialised technique for asking sensitive questions, additive Randomised Response Technique (aRRT), as well as direct questioning (DQ). Overall, 3.6% of snakes, chelonians and lizards died within one year of acquisition. Boas and pythons had the lowest reported mortality rates of 1.9% and chameleons had the highest at 28.2%. More than 97% of snakes, 87% of lizards and 69% of chelonians acquired by respondents over five years were reported to be captive bred and results suggest that mortality rates may be lowest for captive bred individuals. Estimates of mortality from aRRT and DQ did not differ significantly which is in line with our findings that respondents did not find questions about reptile mortality to be sensitive. This research suggests that captive reptile mortality in the home is rather low, and identifies those taxa where further effort could be made to reduce mortality rate

Gla-rich protein function as an anti-inflammatory agent in monocytes/macrophages: implications for calcification-related chronic inflammatory diseases

Calcification-related chronic inflammatory diseases are multifactorial pathological processes, involving a complex interplay between inflammation and calcification events in a positive feed-back loop driving disease progression. Gla-rich protein (GRP) is a vitamin K dependent protein (VKDP) shown to function as a calcification inhibitor in cardiovascular and articular tissues, and proposed as an anti-inflammatory agent in chondrocytes and synoviocytes, acting as a new crosstalk factor between these two interconnected events in osteoarthritis. However, a possible function of GRP in the immune system has never been studied. Here we focused our investigation in the involvement of GRP in the cell inflammatory response mechanisms, using a combination of freshly isolated human leucocytes and undifferentiated/differentiated THP-1 cell line. Our results demonstrate that VKDPs such as GRP and matrix gla protein (MGP) are synthesized and gamma-carboxylated in the majority of human immune system cells either involved in innate or adaptive immune responses. Stimulation of THP-1 monocytes/macrophages with LPS or hydroxyapatite (HA) up-regulated GRP expression, and treatments with GRP or GRP-coated basic calcium phosphate crystals resulted in the down-regulation of mediators of inflammation and inflammatory cytokines, independently of the protein gamma-carboxylation status. Moreover, overexpression of GRP in THP-1 cells rescued the inflammation induced by LPS and HA, by down-regulation of the proinflammatory cytokines TNF alpha, IL-1 beta and NFkB. Interestingly, GRP was detected at protein and mRNA levels in extracellular vesicles released by macrophages, which may act as vehicles for extracellular trafficking and release. Our data indicate GRP as an endogenous mediator of inflammatory responses acting as an anti-inflammatory agent in monocytes/macrophages. We propose that in a context of chronic inflammation and calcification-related pathologies, GRP might act as a novel molecular mediator linking inflammation and calcification events, with potential therapeutic application.Portuguese Science and Technology Foundation (FCT) [PTDC/SAU-ORG/117266/2010, PTDC/BIM-MEC/1168/2012, UID/Multi/ 04326/2013]; FCT fellowships [SFRH/BPD/70277/2010, SFRH/BD/111824/2015

Gravitational Waves from Gravitational Collapse

Gravitational wave emission from the gravitational collapse of massive stars has been studied for more than three decades. Current state of the art numerical investigations of collapse include those that use progenitors with realistic angular momentum profiles, properly treat microphysics issues, account for general relativity, and examine non--axisymmetric effects in three dimensions. Such simulations predict that gravitational waves from various phenomena associated with gravitational collapse could be detectable with advanced ground--based and future space--based interferometric observatories.Comment: 68 pages including 13 figures; revised version accepted for publication in Living Reviews in Relativity (http://www.livingreviews.org