The Local Group Census: planetary nebulae in IC 10, Leo A and Sextans A

In the framework of our narrow-band survey of the Local Group galaxies, we present the results of the search for planetary nebulae (PNe) in the dwarf irregular galaxies IC10, LeoA and SextansA. Using the standard on-band/off-band technique, sixteen new candidate PNe have been discovered in the closest starburst galaxy, IC10. The optical size of this galaxy is estimated to be much larger than previously thought, considering the location of the new PNe in an area of 3.6 kpc X 2.7 kpc. We also confirm the results of previous studies for the other two dwarf irregular galaxies, with the detection of one candidate PN in LeoA and another one in SextansA. We review the number of planetary nebulae discovered in the Local Group to date and their behaviour with metallicity. We suggest a possible fall in the observed number of PNe when [Fe/H]$<<$-1.0, which might indicate that below this point the formation rate of PNe is much lower than for stellar populations of near Solar abundances. We also find non-negligible metallicity effects on the [OIII] luminosity of the brightest PN of a galaxy.Comment: 10 pages, 4 figures, A&A accepte

Understanding the individual to implement the ecosystem approach to fisheries management

Ecosystem-based approaches to fisheries management (EAFMs) have emerged as requisite for sustainable use of fisheries resources. At the same time, however, there is a growing recognition of the degree of variation among individuals within a population, as well as the ecological consequences of this variation. Managing resources at an ecosystem level calls on practitioners to consider evolutionary processes, and ample evidence from the realm of fisheries science indicates that anthropogenic disturbance can drive changes in predominant character traits (e.g. size at maturity). Eco-evolutionary theory suggests that human-induced trait change and the modification of selective regimens might contribute to ecosystem dynamics at a similar magnitude to species extirpation, extinction and ecological dysfunction. Given the dynamic interaction between fisheries and target species via harvest and subsequent ecosystem consequences, we argue that individual diversity in genetic, physiological and behavioural traits are important considerations under EAFMs. Here, we examine the role of individual variation in a number of contexts relevant to fisheries management, including the potential ecological effects of rapid trait change. Using select examples, we highlight the extent of phenotypic diversity of individuals, as well as the ecological constraints on such diversity. We conclude that individual phenotypic diversity is a complex phenomenon that needs to be considered in EAFMs, with the ultimate realization that maintaining or increasing individual trait diversity may afford not only species, but also entire ecosystems, with enhanced resilience to environmental perturbations. Put simply, individuals are the foundation from which population- and ecosystem-level traits emerge and are therefore of central importance for the ecosystem-based approaches to fisheries management

Effects of territorial damselfish on corallivorous fish assemblage composition and coral predation in the Mauritian lagoon

Predation is a significant stressor for many coral species. Understanding how predation interacts with factors such as climate change is key to coral conservation. Territorial damselfish of the genus Stegastes form territories on branching corals (genus Acropora) on which they cultivate algae, and while defending these territories, provide corals with indirect protection from predation. However, it is not known how the protection afforded by Stegastes spp. varies with corallivorous fish assemblage composition, nor whether corallivore assemblages themselves may be affected by the presence of Stegastes spp. and their associated Acropora spp. habitats. This study examined relationships among predation protection by Stegastes spp., branching Acropora coral cover, and the number and species richness of corallivorous fish present within a given area, namely the Mauritian lagoon in the western Indian Ocean. Predation on bleaching-resilient massive Porites lutea corals within and outside Stegastes territories was surveyed at sites around Mauritius island. Corallivorous fish assemblages, branching coral cover, and Stegastes spp. density were also surveyed at each site visit. Results show that high predation was correlated with the presence of high numbers of corallivores, but predation was lower within Stegastes spp. territories irrespective of all observed corallivore densities. Greater numbers of Stegastes spp. were correlated with increasing density of obligate corallivores. Non-Acroporid coral cover was positively correlated with species richness of obligate corallivores, while branching Acropora coral cover was negatively correlated with overall corallivore density. This study shows for the first time that predation on bleaching-resilient massive corals is lower within Stegastes spp. territories regardless of the number of corallivores present, adding to the growing body of knowledge on the complex relationships between Stegastes spp. and their environment. The findings also indicate possible effects of the presence of Stegastes spp. and their branching Acropora habitats on corallivorous fish density in areas with low coral diversity, which may warrant further study

Regulation of the Human Taurine Transporter by Oxidative Stress in Retinal Pigment Epithelial Cells Stably Transformed to Overexpress Aldose Reductase

In diabetes, overexpression of aldose reductase (AR) and consequent glucose-induced impairment of antioxidant defense systems may predispose to oxidative stress and the development of diabetic complications, but the mechanisms are poorly understood. Taurine (2-aminoethanesulfonic acid) functions as an antioxidant, osmolyte, and calcium modulator such that its intracellular depletion could promote cytotoxicity in diabetes. The relationships of oxidative stress and basal AR gene expression to Na+-taurine cotransporter (TT) gene expression, protein abundance, and TT activity were therefore explored in low AR-expressing human retinal pigment epithelial (RPE) 47 cells and RPE 47 cells stably transformed to overexpress AR (RPE 75). Changes in TT gene expression were determined using a 4.6-kb TT promoter-luciferase fusion gene. Compared with RPE 47 cells, in high AR-expressing RPE 75 cells, TT promoter activity was decreased by 46%, which was prevented by an AR inhibitor. TT promoter activity increased up to 900% by prooxidant exposure, which was associated with increased TT peptide abundance and taurine transport. However, induction of TT promoter activity by oxidative stress was attenuated in high AR-expressing cells and partially corrected by AR inhibitor. Finally, exposure of RPE 75 cells to high glucose increased oxidative stress, but down-regulated TT expression. These studies demonstrate for the first time that the TT is regulated by oxidative stress and that overexpression of AR and high glucose impair this response. Abnormal expression of AR may therefore impair antioxidant defense, which may determine tissue susceptibility to chronic diabetic complications. Antioxid. Redox Signal. 7, 1530–1542.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63284/1/ars.2005.7.1530.pd

APEX CO(3-2) observations of NGC6822

We observed the CO(3-2) emission of the emission-line regions HubbleI, HubbleV, HubbleX, Holmberg 18, and the stellar emission-line object S28 in NGC6822 with the ESO Atacama Pathfinder Experiment (APEX) 12m telescope as part of its science verification. The very low system temperature of 130-180K enabled us to achieve detections in 4 single pointings and in a high spatial resolution 70''x70'' map of HubbleV. We compare the spectra with HI observations, obtained with the Australia Telescope Compact Array, of the same regions. In combination with previous multi-line CO observations, we perform a preliminary investigation of the physical conditions in HubbleV using a simple LTE model. We estimate the mass of the HubbleV region and the H_2/I_CO(3-2) conversion factor. Also, we show that HubbleV is located very near the line-width versus size relation traced by the Milky Way and LMC molecular clouds.Comment: 4 pages, 3 figures, accepted for publication in the Astronomy & Astrophysics Letters special issue on the APEX science verificatio

Impact of introducing an electronic physiological surveillance system on hospital mortality

YesBackground Avoidable hospital mortality is often attributable to inadequate patient vital signs monitoring, and failure to recognise or respond to clinical deterioration. The processes involved with vital sign collection and charting; their integration, interpretation and analysis; and the delivery of decision support regarding subsequent clinical care are subject to potential error and/or failure. Objective To determine whether introducing an electronic physiological surveillance system (EPSS), specifically designed to improve the collection and clinical use of vital signs data, reduced hospital mortality. Methods A pragmatic, retrospective, observational study of seasonally adjusted in-hospital mortality rates in three main hospital specialties was undertaken before, during and after the sequential deployment and ongoing use of a hospital-wide EPSS in two large unconnected acute general hospitals in England. The EPSS, which uses wireless handheld computing devices, replaced a paper-based vital sign charting and clinical escalation system. Results During EPSS implementation, crude mortality fell from a baseline of 7.75% (2168/27 959) to 6.42% (1904/29 676) in one hospital (estimated 397 fewer deaths), and from 7.57% (1648/21 771) to 6.15% (1614/26 241) at the second (estimated 372 fewer deaths). At both hospitals, multiyear statistical process control analyses revealed abrupt and sustained mortality reductions, coincident with the deployment and increasing use of the system. The cumulative total of excess deaths reduced in all specialties with increasing use of the system across the hospital. Conclusions The use of technology specifically designed to improve the accuracy, reliability and availability of patients’ vital signs and early warning scores, and thereby the recognition of and response to patient deterioration, is associated with reduced mortality in this study

Prediction of the Onset of Disturbed Eating Behavior in Adolescent Girls With Type 1 Diabetes

OBJECTIVE—The purpose of this study was to identify predictors of the onset of disturbed eating behavior (DEB) in adolescent girls with type 1 diabetes

Conservation physiology across scales: Insights from the marine realm

As the field of conservation physiology develops and becomes increasingly integrated with ecolog