On the nature of the hard X-ray source IGR J2018+4043

We found a very likely counterpart to the recently discovered hard X-ray source IGR J2018+4043 in the multi-wavelength observations of the source field. The source, originally discovered in the 20-40 keV band, is now confidently detected also in the 40-80 keV band, with a flux of (1.4 +/- 0.4) x 10(-11) erg cm(-2) s(-1). A 5 ks Swift observation of the IGR J2018+4043 field revealed a hard point-like source with the observed 0.5-10 keV flux of 3.4(+0.7)(-0.8) x 10(-12) erg cm(-2) s(-1) (90% confidence level) at alpha = 20h18m38.55s, delta = +40d41m00.4s (with a 4.2" uncertainty). The combined Swift-INTEGRAL spectrum can be described by an absorbed power-law model with photon index gamma = 1.3 +/- 0.2 and N_H = 6.1(+3.2)(-2.2) x 10(22) cm(-2). In archival optical and infrared data we found a slightly extended and highly absorbed object at the Swift source position. There is also an extended VLA 1.4 GHz source peaked at a beam-width distance from the optical and X-ray positions. The observed morphology and multiwavelength spectra of IGR J2018+4043 are consistent with those expected for an obscured accreting object, i.e. an AGN or a Galactic X-ray binary. The identification suggests possible connection of IGR J2018+4043 to the bright gamma-ray source GEV J2020+4023 (3EG J2020+4017) detected by COS B and CGRO EGRET in the gamma-Cygni SNR field.Comment: 5 pages, 3 figures, uses emulateapj styl

The binary nature of the Galactic Centre X-ray source CXOGC J174536.1-285638

X-ray and near-IR surveys of the central 2x0.8 degrees of the Galactic Centre have revealed a population of X-ray bright massive stars. However, the nature of the emission, originating in a wind collision zone or via accretion onto a compact object, is uncertain. In order to address this we investigated the nature of the luminous X-ray source CXOGC J174536.1-285638. An analysis of the near-IR spectrum with a non-LTE model atmosphere code demonstrated that it was an highly luminous WN9h star, for which comparison to evolutionary tracks suggests an age of 2-2.5Myr and an initial mass of ~110Msun. The X-ray properties of CXOGC J174536.1-285638 resemble those of 3 of the WN9h stars within the Arches cluster and in turn other very massive WNLh colliding wind binaries. Simple analytical arguments demonstrate consistency between the X-ray emission and a putative WN9h+mid O V-III binary. However, we may not exclude a high mass X-ray binary interpretation, which, if correct, would provide a unique insight into the (post-SN) evolution of extremely massive stars. Irrespective of the nature of the secondary, CXOGC J174536.1-285638 adds to the growing list of known and candidate WNLh binaries. Of the subset of WNLh stars subject to a radial velocity survey, we find a lower limit to the binary fraction of ~45%; of interest for studies of massive stellar formation, given that they currently possess the highest dynamically determined masses of any type of star. [ABRIDGED]Comment: 9 pages, 5 figures, accepted for publication in Astronomy and Astrophysic

Effects of adaptation to sea water, 170% sea water and to fresh water on activities and subcellular distribution of branchial Na + −K + -ATPase, low- and high affinity Ca ++ -ATPase, and ouabain-insensitive ATPase in Gillichthys mirabilis

1. Branchial activities of Na + −K + -ATPase, ouabain-insensitive ATPase, (Mg ++ -ATPase) and Ca ++ -ATPase were measured in Gillichthys mirabilis after adaptation to salinities ranging from 170% SW to FW. Stabilities of these activities against freezing and deoxycholate solubilization and the temperature-dependence of activity rates were also investigated. Subcellular distribution and some kinetic properties of these activities, and of SDH were compared in branchial tissues of fish adapted to 170% SW and to FW.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47126/1/360_2004_Article_BF00782593.pd

Surface-functionalized mesoporous gallosilicate catalysts for the efficient and sustainable upgrading of glycerol to solketal

Two series of functionalized mesoporous Ga silicates were prepared in a straightforward and sustainable one-pot procedure using different alkyl silanes. The efficacy of the adopted co-synthetic approach based on aerosol processing has been proved by 29Si solid-state NMR experiments revealing a degree of functionalization close to the theoretical value. The successful incorporation of gallium as single sites within the silica framework was confirmed via71Ga solid-state magic-angle-spinning NMR measurements. These materials were tested as catalysts for the synthesis of solketal from glycerol at low temperature and under solventless conditions. A systematic study evidenced the importance of a careful tuning of surface polarity, achievable with surface functionalization as well as with different thermal treatments. The solids functionalized with a low degree of methyl groups (5%) displayed enhanced performances compared to the non-functionalized analogues, highlighting the highly beneficial role of surface hydrophobicity as well as the importance of the careful tuning of the hydrophilic/hydrophobic balance. The best functionalized catalysts proved to be easily reusable for multiple catalytic runs. With such a high-performance catalyst in hand, we propose a process which shows a favorable E-factor, indicating that the production of solketal can be envisaged in a sustainable way

Hafnium-doped silica nanotubes for the upgrading of glycerol into solketal: Enhanced performances and in-depth structure-activity correlation

An unprecedented type of Hf-doped silica nanotubes was synthesized using a straightforward one-pot sol–gel procedure. The well-defined nanotubes with a diameter of 14–20 nm exhibited high specific surface area and a widely open texture. The method – involving a key pH adjustment step – allowed a quantitative insertion of hafnium in the materials (Si/Hf = 74) and favored the insertion of Hf as dispersed species. Depending on the synthesis parameters, the chemical environment around Hf was modified, as evidenced by XPS, NH3-TPD and NH3-IR. Hf-doped silica nanotubes showed excellent activity in the conversion of glycerol to solketal, a reaction of high relevance in the context of biorefineries. Importantly, the turnover frequency and the acidity were unambiguously correlated with the insertion of Hf in the silica matrix. The best catalyst was proven to be stable and recyclable, and this sustainable reaction was also amenable to further catalytic enhancement upon optimized reaction conditions

Data from: Integrating the pace-of-life syndrome across species, sexes and individuals: covariation of life history and personality under pesticide exposure

The pace-of-life syndrome (POLS) hypothesis integrates covariation of life-history traits along a fast–slow continuum and covariation of behavioural traits along a proactive–reactive personality continuum. Few studies have investigated these predicted life-history/personality associations among species and between sexes. Furthermore, whether and how contaminants interfere with POLS patterns remains unexplored. We tested for covariation patterns in life history and in behaviour, and for life-history/personality covariation among species, among individuals within species and between sexes. Moreover, we investigated whether pesticide exposure affects covariation between life history and behaviour and whether species and sexes with a faster POLS strategy have a higher sensitivity to pesticides. We reared larvae of four species of Ischnura damselflies in a common garden experiment with an insecticide treatment (chlorpyrifos absent/present) in the final instar. We measured four life-history traits (larval growth rate during the pesticide treatment, larval development time, adult mass and life span) and two behavioural traits (larval feeding activity and boldness, each before and after the pesticide treatment). At the individual level, life-history traits and behavioural traits aligned along a fast–slow and a proactive–reactive continuum, respectively. Species-specific differences in life history, with fast-lived species having a faster larval growth and development, a lower mass at emergence and a shorter life span, suggested that time constraints in the larval stage were predictably driving life-history evolution both in the larval stage and across metamorphosis in the adult stage. Across species, females were consistently more slow-lived than males, reflecting that a large body size and a long life span are generally more important for females. In contrast to the POLS hypothesis, there was only little evidence for the expected positive coupling between life-history pace and proactivity. Pesticide exposure decreased larval growth rate and affected life-history/personality covariation in the most fast-lived species. Our study supports the existence of life-history and behavioural continua with limited support for life-history/personality covariation. Variation in digestive physiology may explain this decoupling of life history and behaviour and provide valuable mechanistic insights to understand and predict the occurrence of life-history/personality covariation patterns

Self-Efficacy and Pressure Ulcer Prevention After Spinal Cord Injury-Results From a Nationwide Community Survey in Switzerland (SwiSCI)

Background: Pressure ulcers (PUs) are a common and severe health condition in persons with spinal cord injury (SCI). Skin-care strategies for PU prevention are usually provided during initial rehabilitation. However, individuals with SCI often do not perform these strategies continuously, especially after discharge. The influence of psychological factors such as general self-efficacy (GSE) on the performance of PU prevention behavior has not yet been sufficiently explored. Objective: To investigate whether persons with greater levels of GSE are more likely to perform skin-care strategies for PU prevention regularly. Design: Nationwide cross-sectional survey within the Swiss Spinal Cord Injury Cohort Study. Setting: Community setting, data collection between 2011 and 2013. Participants: A total of 456 subjects with a traumatic or nontraumatic SCI living in Switzerland. Methods: Associations between GSE and PU prevention behavior were analyzed by multivariate proportional odds regression models, including potential sociodemographic, lesion-related, and lifestyle-related confounders without and with interaction terms between GSE and potential effect modifiers. Main outcome measurements: Self-efficacy was assessed by the GSE scale comprising 10 items. PU preventive behavior was operationalized using 5 items of an adapted version of the Spinal Cord Injury Lifestyle scale. Both measurements were components of a self-administered questionnaire. Results: Based on the regression model without interaction terms, GSE levels were not associated with skin-care PU prevention. After we included interaction terms, the final model showed statistically significant associations between GSE and 3 skin-care items with odds ratios ranging from 1.09 to 1.17 (all P < .001). The slightly positive effect of GSE on PU prevention behavior was restricted to persons who sustained their SCI at a younger age. Conclusions: GSE was generally not associated with skin-care PU prevention behavior among persons with SCI in this study. In further research, it might be of interest to assess SCI-specific concepts of self-efficacy. Level of evidence: III

The Active State of Supported Ruthenium Oxide Nanoparticles during Carbon Dioxide Methanation

Ruthenium catalysts supported on TiO2 have been shown to have competitive activity and selectivity for the methanation of CO2. In particular, a catalyst using preformed RuO2 nanoparticles deposited on a TiO2 support showed competitive performances in a previous study. In this work, ambient-pressure X-ray photoelectron spectroscopy was employed to determine the chemical state of this catalyst under reaction conditions. The active state of ruthenium was found to be the metallic one. Surface adsorbates were monitored in the steady state, and CHx species were found to be favored over adsorbed carbon monoxide at increasing temperatures