SHOTGLAS: II. MUSE spectroscopy of blue horizontal branch stars in the core of Omega Centauri and NGC6752

Galaxie

Global Change Could Amplify Fire Effects on Soil Greenhouse Gas Emissions

Background: Little is known about the combined impacts of global environmental changes and ecological disturbances on ecosystem functioning, even though such combined impacts might play critical roles in shaping ecosystem processes that can in turn feed back to climate change, such as soil emissions of greenhouse gases.[br/] Methodology/Principal Findings: We took advantage of an accidental, low-severity wildfire that burned part of a long-term global change experiment to investigate the interactive effects of a fire disturbance and increases in CO(2) concentration, precipitation and nitrogen supply on soil nitrous oxide (N(2)O) emissions in a grassland ecosystem. We examined the responses of soil N(2)O emissions, as well as the responses of the two main microbial processes contributing to soil N(2)O production - nitrification and denitrification - and of their main drivers. We show that the fire disturbance greatly increased soil N(2)O emissions over a three-year period, and that elevated CO(2) and enhanced nitrogen supply amplified fire effects on soil N(2)O emissions: emissions increased by a factor of two with fire alone and by a factor of six under the combined influence of fire, elevated CO(2) and nitrogen. We also provide evidence that this response was caused by increased microbial denitrification, resulting from increased soil moisture and soil carbon and nitrogen availability in the burned and fertilized plots. [br/] Conclusions/Significance: Our results indicate that the combined effects of fire and global environmental changes can exceed their effects in isolation, thereby creating unexpected feedbacks to soil greenhouse gas emissions. These findings highlight the need to further explore the impacts of ecological disturbances on ecosystem functioning in the context of global change if we wish to be able to model future soil greenhouse gas emissions with greater confidence

Background document: cytochrome P450 1A activity (EROD).

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Angiographie und Morphometrie bei glomerulaeren und vaskulaeren Nierenerkrankungen ohne glomerulaere Funktionseinschraenkung

SIGLECopy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

SHOTGLAS

Aims. We want to study the population of blue horizontal branch (HB) stars in the centres of globular clusters (GC) for the first time by exploiting the unique combination of MUSE spectroscopy and HST photometry. In this work, we characterize their properties in the GCs ω Cen and NGC 6752. Methods. We use dedicated model atmospheres and grids of synthetic spectra computed using a hybrid LTE/NLTE modeling approach to fit the MUSE spectra of HB stars hotter than 8000 K in both clusters. The spectral fits provide estimates of the effective temperature (Teff), surface gravity (log ɡ), and helium abundance of the stars. The model grids are further used to fit the HST magnitudes of the stars, that is, their spectral energy distributions (SEDs). From the SED fits, we derive the average reddening, radius, luminosity, and mass of the stars in our sample. Results. The atmospheric and stellar properties that we derive for the stars in our sample are in good agreement with theoretical expectations. In particular, the stars cooler than ~15 000 K closely follow the theoretical predictions on radius, log ɡ, and luminosity for helium-normal (Y = 0.25) models. In ω Cen, we show that the majority of these cooler HB stars cannot originate from a helium-enriched population with Y > 0.35. The properties of the hotter stars (radii and luminosities) are still in reasonable agreement with theoretical expectations, but the individual measurements show a large scatter. For these hot stars, we find a mismatch between the effective temperatures indicated from the MUSE spectral fits and the photometric fits, with the latter returning Teff lower by ~3000 K. We use three different diagnostics, namely the position of the G-jump and changes in metallicity and helium abundances, to place the onset of diffusion in the stellar atmospheres at Teff between 11 000 and 11 500 K. Our sample includes two stars known as photometric variables; we confirm one to be a bona fide extreme HB object but the other is a blue straggler star. Finally, unlike what has been reported in the literature, we do not find significant differences between the properties (e.g., log ɡ, radius, and luminosity) of the stars in the two clusters. Conclusions. We show that our analysis method – combining MUSE spectra and HST photometry of HB stars in GCs – is a powerful tool for characterising their stellar properties. With the availability of MUSE and HST observations of additional GCs, we have a unique opportunity to combine homogeneous spectroscopic and photometric data to study and compare the properties of blue HB stars in different GCs

Warwick-Edinburgh Mental Well-being Scale (WEMWBS) : validated for teenage school students in England and Scotland : a mixed methods assessment

Background: Understanding and measuring mental health and wellbeing amongst teenagers has recently become a priority. The Warwick-Edinburgh Mental Well-being Scale (WEMWBS) is validated for measuring mental wellbeing in populations aged 16 years and over in the UK. We report here a study designed to establish the validity and reliability of WEMWBS in teenagers in the UK. Methods: WEMWBS and comparator scales, together with socio-demographic information and self-reported health, were incorporated into a self-administered questionnaire given to pupils aged 13 to 16 years in six schools in Scotland and England. Psychometric properties including internal consistency, correlations with comparator scales, test-retest stability and unidimensionality were investigated for WEMWBS. Twelve focus groups were undertaken to assess acceptability and comprehensibility of WEMWBS and were taped, transcribed and analysed thematically. Results: A total of 1,650 teenagers completed the questionnaire (response rate 80.8%). Mean WEMWBS score was 48.8 (SD 6.8; median 49). Response scores covered the full range (from 14 to 70). WEMWBS demonstrated strong internal consistency and a high Cronbach’s alpha of 0.87 (95% CI (0.85-0.88), n = 1517). Measures of construct validity gave values as predicted. The correlation coefficient for WEMWBS total score and psychological wellbeing domain of the Kidscreen-27 was 0.59 (95% CI [0.55; 0.62]); for the Mental Health Continuum Short Form (MHC-SF) was 0.65, 95% CI [0.62; 0.69]; and for the WHO (WHO-5) Well-being Index 0.57 (95% CI [0.53; 0.61]). The correlation coefficient for the Strengths and Difficulties Questionnaire (SDQ) was -0.44 (95% CI [-0.49; -0.40]) and for the 12-item General Health Questionnaire (GHQ12) -0.45 (95% CI [-0.49; -0.40]). Test-retest reliability was acceptable (Intraclass correlation coefficient (ICC) 0.66 (95% CI [0.59; 0.72] n = 212)). Confirmatory factor analysis demonstrated one underlying factor. WEMWBS was significantly associated with the Family Affluence Score (WEMWBS increased with increasing household socio-economic status) and had a positive association with the physical health dimension of the Kidscreen-27, but was unrelated to age, gender or location/school. Eighty students took part in focus groups. In general, although some students considered some items open to misunderstanding or misinterpretation, WEMWBS was received positively and was considered comprehensible, and acceptable. Conclusions: WEMWBS is a psychometrically strong population measure of mental wellbeing, and can be used for this purpose in teenagers aged 13 and over

The origin of lactate in peritumoral edema as measured by proton-magnetic resonance spectroscopic imaging

Using in vivo proton-magnetic resonance spectroscopy (H-1-MRS), which allows the measurement of metabolites of adequate tissue concentration, the origin of lactate in peritumoral edema has been assessed by comparison with lactate levels in the central and marginal areas of the tumor in 18 patients with cerebral gliomas. In the majority of cases lactate content in the area of peritumoral edema was lower than that in the tumor margin or tumor center, which is consistent with the assumption that the tumor is the source of lactate, which then reaches the surrounding area of edema by diffusion. In 3 of the 18 cases the amount of lactate in the peritumoral edematous tissue was higher than in the tumor, indicating that the lactate is locally produced on account of ischemia due to regional elevation of tissue pressure in the edematous area