Explaining binge drinking among adolescent males using the Theory of Planned Behaviour

Binge drinking among adolescents in Northern Ireland is prevalent and has detrimental eff ects on public health. Health education interventions, based on valid explanatory models of health behaviour, are required to reduce binge drinking behaviour among adolescents. " is paper examines the utility of the " eory of Planned Behaviour in explaining binge drinking behaviour among adolescent males. Using questionnaire responses from 94 adolescent boys attending secondary schools in the Belfast area, logistic regression modelling suggested that the " eory of Planned Behaviour explained 36% of the variance in self-reported binge drinking behaviour. Attitudes towards binge drinking were the strongest predictor of binge drinking behaviour. Tackling attitudes about binge drinking is a challenge to be considered when designing interventions to reduce binge drinking among this population

Early-type stars in the Galactic halo from the Palomar-Green survey - III. Completion of a magnitude range limited sample

High-resolution (R approximate to 40 000) echelle spectroscopic observations of 13 high-latitude early-type stars are presented. These stars comprise the final part of a complete magnitude range limited sample based on low-resolution spectroscopy of targets drawn from the Palomar-Green survey. The magnitude range under consideration is 13 less than or equal to B-PG less than or equal to 14.6, corresponding to an approximate distance limit for main-sequence B-type objects of 5 less than or equal to d less than or equal to 40 kpc. Three stars are found to be apparently normal, young stars, based on their positions on the (T-eff, log g) diagram, normal abundance patterns and relatively large projected rotational velocities. A further star, PG 1209+263, was found to belong to the chemically peculiar (CP) silicon star class of objects. The remainder are evolved subluminous stars lying on post- horizontal branch (post-HB) tracks, with the exception of PG 2120+062, which appears to be in a post-asymptotic giant branch evolutionary stage. For the young stars in the sample, we have derived distance and age estimates through comparison of the atmospheric parameters with recent theoretical evolutionary models. We discuss formation scenarios by comparing times-of- flight and evolutionary time-scales. It is found that all stars could have formed in the Galactic disc and been ejected from there soon after their birth, with the exception of PG 1209+263. The adopted proper motion is found to be a crucial factor in the kinematical analysis. We also present some number densities for young B-type halo stars, which indicate that they are extremely scarce objects.

A detailed abundance analysis of the hot post-AGB star ZNG-1 in M10

We present a model-atmosphere analysis for the bright (V similar to 13) star ZNG-1, in the globular cluster M10. From high-resolution (R similar to 40 000) optical spectra we confirm ZNG-1 to be a post-asymptotic giant branch (post-AGB) star. The derived atmospheric parameters are T-eff = 26 500 +/- 1000 K and log g = 3.6 +/- 0.2 dex. A differential abundance analysis reveals a chemical composition typical of hot post-AGB objects, with ZNG-1 being generally metal poor, although helium is approximately solar. The most interesting feature is the large carbon underabundance of more than 1.3 dex. This carbon deficiency, along with an observed nitrogen enhancement relative to other elements, may suggest that ZNG-1 evolved off the AGB before the third dredge-up occurred. Also, iron depletions observed in other similar stars suggest that gas- dust fractionation in the AGB progenitor could be responsible for the observed composition of these objects. However, we need not invoke either scenario since the chemical composition of ZNG-1 is in good agreement with abundances found for a Population II star of the same metallicity.

The Low Density Transiting Exoplanet WASP-15b

We report the discovery of a low-density exoplanet transiting an 11th magnitude star in the Southern hemisphere. WASP-15b, which orbits its host star with a period P = 3.7520656 ± 0.0000028 d, has a mass M p = 0.542 ± 0.050 M J and radius R p = 1.428 ± 0.077 R J, and is therefore one of the least dense transiting exoplanets so far discovered (?p = 0.247 ± 0.035 g cm-3). An analysis of the spectrum of the host star shows it to be of spectral type around F5, with an effective temperature T eff = 6300 ± 100 K and [Fe/H] = -0.17 ± 0.11.

Vitamins C and E for prevention of pre-eclampsia in women with type 1 diabetes (DAPIT): a randomised placebo-controlled trial.

Background
Results of several trials of antioxidant use during pregnancy have not shown a reduction in pre-eclampsia, but the eff ect in women with diabetes is unknown. We aimed to assess whether supplementation with vitamins C and E reduced incidence of pre-eclampsia in women with type 1 diabetes.

Methods
We enrolled women from 25 UK antenatal metabolic clinics in a multicentre randomised placebo-controlled trial. Eligibility criteria were type 1 diabetes preceding pregnancy, presentation between 8 weeks’ and 22 weeks’ gestation, singleton pregnancy, and age 16 years or older. Women were randomly allocated in a 1:1 ratio to receive1000 mg vitamin C and 400 IU vitamin E (a-tocopherol) or matched placebo daily until delivery. The randomisation sequence was stratifi ed by centre with balanced blocks of eight patients. All trial personnel and participants were masked to treatment allocation. The primary endpoint was pre-eclampsia, which we defi ned as gestational hypertension with proteinuria. Analysis was by modifi ed intention to treat. This study is registered, ISRCTN27214045.

Findings
Between April, 2003, and June, 2008, 762 women were randomly allocated to treatment groups (379 vitamin supplementation, 383 placebo). The primary endpoint was assessed for 375 women allocated to receive vitamins, and 374 allocated to placebo. Rates of pre-eclampsia did not differ between vitamin (15%, n=57) and placebo (19%, 70)groups (risk ratio 0·81, 95% CI 0·59–1·12). No adverse maternal or neonatal outcomes were reported.

Interpretation
Supplementation with vitamins C and E did not reduce risk of pre-eclampsia in women with type 1 diabetes. However, the possibility that vitamin supplementation might be benefi cial in women with a low antioxidant status at baseline needs further testing.

WASP-19b: The Shortest Period Transiting Exoplanet Yet Discovered

We report on the discovery of a new extremely short period transiting extrasolar planet, WASP-19b. The planet has mass M pl = 1.15 ± 0.08 MJ , radius R pl = 1.31 ± 0.06 RJ , and orbital period P = 0.7888399 ± 0.0000008 days. Through spectroscopic analysis, we determine the host star to be a slightly super-solar metallicity ([M/H] = 0.1 ± 0.1 dex) G-dwarf with T eff = 5500 ± 100 K. In addition, we detect periodic, sinusoidal flux variations in the light curve which are used to derive a rotation period for the star of P rot = 10.5 ± 0.2 days. The relatively short stellar rotation period suggests that either WASP-19 is somewhat young (~ 600 Myr old) or tidal interactions between the two bodies have caused the planet to spiral inward over its lifetime resulting in the spin-up of the star. Due to the detection of the rotation period, this system has the potential to place strong constraints on the stellar tidal quality factor, Q' s , if a more precise age is determined.

WASP-24 b: A New Transiting Close-in Hot Jupiter Orbiting a Late F-star

We report the discovery of a new transiting close-in giant planet, WASP-24 b, in a 2.341 day orbit, 0.037 AU from its F8-9 type host star. By matching the star's spectrum with theoretical models, we infer an effective temperature T eff = 6075 ± 100 K and a surface gravity of log g = 4.15 ± 0.10. A comparison of these parameters with theoretical isochrones and evolutionary mass tracks places only weak constraints on the age of the host star, which we estimate to be 3.8+1.3 –1.2 Gyr. The planetary nature of the companion was confirmed by radial velocity measurements and additional photometric observations. These data were fit simultaneously in order to determine the most probable parameter set for the system, from which we infer a planetary mass of 1.071+0.036 –0.038 M Jup and radius 1.3+0.039 –0.037 R Jup.

WASP-37b: A 1.8 M J Exoplanet Transiting a Metal-poor Star

We report on the discovery of WASP-37b, a transiting hot Jupiter orbiting an m v = 12.7 G2-type dwarf, with a period of 3.577469 ± 0.000011 d, transit epoch T 0 = 2455338.6188 ± 0.0006 (HJD; dates throughout the paper are given in Coordinated Universal Time (UTC)), and a transit duration 0.1304+0.0018 –0.0017 d. The planetary companion has a mass M p = 1.80 ± 0.17 M J and radius R p = 1.16+0.07 –0.06 R J, yielding a mean density of 1.15+0.12 –0.15 ?J. From a spectral analysis, we find that the host star has M sstarf = 0.925 ± 0.120 M sun, R sstarf = 1.003 ± 0.053 R sun, T eff = 5800 ± 150 K, and [Fe/H] = –0.40 ± 0.12. WASP-37 is therefore one of the lowest metallicity stars to host a transiting planet.

The Yellow Supergiant Progenitor of the Type II Supernova 2011dh in M51

We present the detection of the putative progenitor of the Type IIb SN 2011dh in archival pre-explosion Hubble Space Telescope images. Using post-explosion Adaptive Optics imaging with Gemini NIRI+ALTAIR, the position of the supernova (SN) in the pre-explosion images was determined to within 23 mas. The progenitor candidate is consistent with an F8 supergiant star (logL/L sun = 4.92 ± 0.20 and T eff = 6000 ± 280 K). Through comparison with stellar evolution tracks, this corresponds to a single star at the end of core C-burning with an initial mass of M ZAMS = 13 ± 3 M sun. The possibility of the progenitor source being a cluster is rejected, on the basis of: (1) the source not being spatially extended, (2) the absence of excess Ha emission, and (3) the poor fit to synthetic cluster spectral energy distributions (SEDs). It is unclear if a binary companion is contributing to the observed SED, although given the excellent correspondence of the observed photometry to a single star SED we suggest that the companion does not contribute significantly. Early photometric and spectroscopic observations show fast evolution similar to the transitional Type IIb SN 2008ax and suggest that a large amount of the progenitor's hydrogen envelope was removed before explosion. Late-time observations will reveal if the yellow supergiant or the putative companion star were responsible for this SN explosion.

The effects of winter ice cover on the trophic ecology of whitefish (Coregonus lavaretus L.) in subarctic lakes

Lakes in Arctic and subarctic regions display extreme levels of seasonal variation in light, temperature and ice cover. Comparatively little is known regarding the effects of such seasonal variation on the diet and resource use of fish species inhabiting these systems. Variation in the diet of European whitefish Coregonus lavaretus (L.) during periods of ice cover in this region is often regarded as 'common knowledge'; however, this aspect of the species' ecology has not been examined empirically. Here, we outline the differences in invertebrate community structure, fish activity, and resource use of monomorphic whitefish populations between summer (August-September) and winter (February-March) in three subarctic lakes in Finnish Lapland. Benthic macroinvertebrate densities did not exhibit measurable differences between summer and winter. Zooplankton diversity and abundance, and activity levels of all fish species (measured as catch per unit effort) were lower in winter. The summer diet of C. lavaretus was typical of a generalist utilising a variety of prey sources. In winter, its dietary niche was significantly reduced, and the diet was dominated by chironomid larvae in all study sites. Pelagic productivity decreases during winter, and fish species inhabiting these systems are therefore restricted to feeding on benthic prey. Sampling time has strong effect on our understanding of resource utilisation by whitefish in subarctic lakes and should be taken into account in future studies of these systems. © 2012 John Wiley & Sons A/S.

The making of a void sovereignty: political implications of the military checkpoints in the West Bank

Research on the Israeli checkpoints in the West Bank has emphasized not only that these checkpoints have dire implications for the Palestinians living there, at the personal, familial, and communal levels, and devastating eff ects on the Palestinian economy, but also that they have far-reaching consequences for the ability of the Palestinians to establish an independent political entity. At the same time, analysis of the Israeli forms of domination over the Palestinians has also stressed the role of a Palestinian governing authority in sustaining the Israeli rule, since the former relieves the latter of its responsibility to care for the occupied Palestinian population. This paper aims to address this apparent contradiction claiming that a comprehensive analysis of Israeli forms of domination requires a spatial examination of the operation of sovereignty with an assessment of governmentalizing arrays. This combined analysis suggests that a Palestinian sovereignty, but one which is emptied of its actual ruling power, is construed at the checkpoints as an epiphenomenon of Israeli apparatuses of control. © 2013 Pion and its Licensors.

Discovery of WASP-65b and WASP-75b: Two hot Jupiters without highly inflated radii

We report the discovery of two transiting hot Jupiters, WASP-65b (M_pl = 1.55 ± 0.16 M_J; R_pl = 1.11 ± 0.06 R_J), and WASP-75b (M_pl = 1.07 ± 0.05 M_J; R_pl = 1.27 ± 0.05 R_J). They orbit their host star every ∼2.311, and ∼2.484 days, respectively. The planet host WASP-65 is a G6 star (T_eff = 5600 K, [Fe/H] = −0.07 ± 0.07, age 8 Gyr); WASP-75 is an F9 star (T_eff = 6100 K, [Fe/H] = 0.07 ± 0.09, age ∼ 3 Gyr). WASP-65b is one of the densest known exoplanets in the mass range 0.1 and 2.0 MJ (ρpl = 1.13 ± 0.08 ρJ), a mass range where a large fraction of planets are found to be inflated with respect to theoretical planet models. WASP-65b is one of only a handful of planets with masses of ∼1.5 MJ, a mass regime surprisingly underrepresented among the currently known hot Jupiters. The radius of WASP-75b is slightly inflated (10%) as compared to theoretical planet models with no core, and has a density similar to that of Saturn (ρpl = 0.52 ± 0.06 ρJ). Key words. planetary systems – stars: individual:

An Energy Descriptor To Quantify Methane Selectivity in Fischer-Tropsch Synthesis:A Density Functional Theory Study

Selectivity is a fundamental issue in heterogeneous catalysis. In this study, the CH(4) selectivity in Fischer-Tropsch synthesis is chosen to be investigated: CH4 selectivity on Rh, Co, Ru, Fe, and Re surfaces is computed by first-principles methods. In conjunction with kinetic analyses, we are able to derive the effective barrier difference between methane formation and chain growth (Delta E(eff)) to quantify the CH(4) selectivity. By using this energy descriptor, the ranking of methane selectivity predicted from density functional theory (DFT) calculations is consistent with experimental work. Moreover, a linear correlation between Delta E(eff) and the chemisorption energy of C + 4H (Delta H) is found. This fundamental finding possesses the following significance: (i) it shows that the selectivity, which appears to have kinetic characteristics, is largely determined by thermodynamic properties; and (ii) it suggests that an increase of the binding strength of C + 4H will suppress methane selectivity.

The VLT-FLAMES Tarantula Survey: XIX. B-type supergiants: Atmospheric parameters and nitrogen abundances to investigate the role of binarity and the width of the main sequence

Context: Model atmosphere analyses have been previously undertaken for both Galactic and extragalactic B-type supergiants. By contrast, little attention has been given to a comparison of the properties of single supergiants and those that are members of multiple systems. 

Aims: Atmospheric parameters and nitrogen abundances have been estimated for all the B-type supergiants identified in the VLT-FLAMES Tarantula survey. These include both single targets and binary candidates. The results have been analysed to investigate the role of binarity in the evolutionary history of supergiants. 

Methods: tlusty non-local thermodynamic equilibrium (LTE) model atmosphere calculations have been used to determine atmospheric parameters and nitrogen abundances for 34 single and 18 binary supergiants. Effective temperatures were deduced using the silicon balance technique, complemented by the helium ionisation in the hotter spectra. Surface gravities were estimated using Balmer line profiles and microturbulent velocities deduced using the silicon spectrum. Nitrogen abundances or upper limits were estimated from the Nii spectrum. The effects of a flux contribution from an unseen secondary were considered for the binary sample. Results. We present the first systematic study of the incidence of binarity for a sample of B-type supergiants across the theoretical terminal age main sequence (TAMS). To account for the distribution of effective temperatures of the B-type supergiants it may be necessary to extend the TAMS to lower temperatures. This is also consistent with the derived distribution of mass discrepancies, projected rotational velocities and nitrogen abundances, provided that stars cooler than this temperature are post-red supergiant objects. For all the supergiants in the Tarantula and in a previous FLAMES survey, the majority have small projected rotational velocities. The distribution peaks at about 50 km s^-1 with 65% in the range 30 km s^-1 ≤ ν_e sin i ≤ 60 km s^-1. About ten per cent have larger ve sin i (≥100 km s^-1), but surprisingly these show little or no nitrogen enhancement. All the cooler supergiants have low projected rotational velocities of ≤70 km s^-1 and high nitrogen abundance estimates, implying that either bi-stability braking or evolution on a blue loop may be important. Additionally, there is a lack of cooler binaries, possibly reflecting the small sample sizes. Single-star evolutionary models, which include rotation, can account for all of the nitrogen enhancement in both the single and binary samples. The detailed distribution of nitrogen abundances in the single and binary samples may be different, possibly reflecting differences in their evolutionary history. 

Conclusions: The first comparative study of single and binary B-type supergiants has revealed that the main sequence may be significantly wider than previously assumed, extending to T_eff = 20 000 K. Some marginal differences in single and binary atmospheric parameters and abundances have been identified, possibly implying non-standard evolution for some of the sample. This sample as a whole has implications for several aspects of our understanding of the evolutionary status of blue supergiants.

The VLT-FLAMES Tarantula Survey: XXIII. Two massive double-lined binaries in 30 Doradus

Aims: We investigate the characteristics of two newly discovered short-period, double-lined, massive binary systems in the Large Magellanic Cloud, VFTS 450 (O9.7 II-Ib + O7::) and VFTS 652 (B1 Ib + O9: III:). 

Methods: We perform model-atmosphere analyses to characterise the photospheric properties of both members of each binary (denoting the "primary" as the spectroscopically more conspicuous component). Radial velocities and optical photometry are used to estimate the binary-system parameters. 

Results: We estimate T_eff = 27 kK, log g = 2.9 (cgs) for the VFTS 450 primary spectrum (34 kK, 3.6: for the secondary spectrum); and T_eff = 22 kK, log g = 2.8 for the VFTS 652 primary spectrum (35 kK, 3.7: for the secondary spectrum). Both primaries show surface nitrogen enrichments (of more than 1 dex for VFTS 652), and probable moderate oxygen depletions relative to reference LMC abundances. We determine orbital periods of 6.89 d and 8.59 d for VFTS 450 and VFTS 652, respectively, and argue that the primaries must be close to filling their Roche lobes. Supposing this to be the case, we estimate component masses in the range ∼20-50 M_⊙. 

Conclusions: The secondary spectra are associated with the more massive components, suggesting that both systems are high-mass analogues of classical Algol systems, undergoing case-A mass transfer. Difficulties in reconciling the spectroscopic analyses with the light-curves and with evolutionary considerations suggest that the secondary spectra are contaminated by (or arise in) accretion disks.