681 research outputs found

    Studies of hot B subdwarfs. Part 2: Energy distributions of three bright sdB/sdOB stars in the 950-5500 angstrom range

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    Voyager ultraviolet spectrometer observations of the subdwarf B or OB stars HD 205805, UV 1758+36 and Feige 66 are presented. All three objects display the H I Layman series in absorption. These observations are combined with low dispersion IUE spectrophotometry and with Stroemgren photometry to construct virtually complete energy distributions, which extend over the range 950-5500 angstroms. Effective temperatures based on model atmosphere calculations for high gravity, hydrogen rich stars are determined. Our analyses yield T Sub e 28,200 + or - 1300 K for HD 205805, T sub e 31, 800 + or - 1100 K for UV 1758+36, and T sub e 35,700 + or - 1500 K for Feige 66. The importance of far ultraviolet observations below L sub alpha in reducing the uncertainties associated with the interstellar extinction and the degradation of the IUE sensitivity is emphasized

    Canada’s Earthquakes: ‘The Good, the Bad, and the Ugly’

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    Much of Canada is ‘earthquake country’. Tiny earthquakes (that can only be recorded by seismographs) happen every day. On average, earthquakes large enough to be felt occur every week in Canada, damaging earthquakes are years to decades apart, and some of the world’s largest earthquakes are typically separated by intervals of centuries. In this article, we provide details on the most significant earthquakes that have been recorded in, or near, Canada, including where and when they occurred, how they were felt, and the effects of those earthquakes. We also provide a brief review of how earthquakes are monitored across Canada and some recent earthquake hazard research. It is the results of this monitoring and research, which provide knowledge on earthquake hazard, that are incorporated into the National Building Code of Canada. This, in turn, will contribute to reduced property losses from future earthquakes across Canada. SOMMAIRE Un bonne partie du Canada est un ‘pays de sĂ©ismes’. De petits sĂ©ismes (que seuls les sĂ©ismographes peuvent enregistrer) s’y produisent quotidiennement. En moyenne, un sĂ©isme assez fort pour qu’on le ressente s’y produit Ă  intervalle d’une semaine; assez fort pour causer des dommages s’y produit Ă  intervalle de quelques annĂ©es Ă  quelques dĂ©cennies; alors que l’intervalle de rĂ©currence des plus grands sĂ©ismes est de l’ordre des siĂšcles. Dans le prĂ©sent article on trouvera des dĂ©tails sur les plus importants sĂ©ismes s’étant produits sur ou Ă  proximitĂ© du territoire canadien, incluant le lieu et le moment, leurs manifestations et leurs rĂ©percussions. On y dĂ©crit sommairement les moyens de dĂ©tection dĂ©ployĂ©s sur le territoire canadien ainsi que quelques-unes des recherches rĂ©centes sur les risques sismiques. Ce sont les rĂ©sultats des efforts de surveillance et des recherches sur les tremblements de terre qui ont Ă©tĂ© intĂ©grĂ©s dans le Code national du bĂątiment du Canada. Et cela aidera Ă  amoindrir les rĂ©percussions des sĂ©ismes Ă  venir sur la propriĂ©tĂ©

    Management of type 2 diabetes mellitus in people with severe mental illness: an online cross-sectional survey of healthcare professionals

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    Objectives To establish healthcare professionals’ (HCPs) views about clinical roles, and the barriers and enablers to delivery of diabetes care for people with severe mental illness (SMI). Design Cross-sectional, postal and online survey. Setting Trusts within the National Health Service (NHS), mental health and diabetes charities and professional bodies. Participants HCPs who care for people with type 2 diabetes mellitus (T2DM) and/or SMI in the UK. Primary and secondary outcome measures The barriers, enablers and experiences of delivering T2DM care for people with SMI, informed by the Theoretical Domains Framework (TDF). Results Responders were 273 HCPs, primarily mental health nurses (33.7%) and psychiatrists (32.2%). Only 25% of respondents had received training in managing T2DM in people with SMI. Mental health professionals felt responsible for significantly fewer recommended diabetes care standards than physical health professionals (p<0.001). For those seeing diabetes care as part of their role, the significant barriers to its delivery in the regression analyses were a lack of knowledge (p=0.003); a need for training in communication and negotiation skills (p=0.04); a lack of optimism about the health of their clients (p=0.04) and their ability to manage T2DM in people with SMI (p=0.003); the threat of being disciplined (p=0.02); fear of working with people with a mental health condition (p=0.01); a lack of service user engagement(p=0.006) and a need for incentives (p=0.04). The significant enablers were an understanding of the need to tailor treatments (p=0.04) and goals (p=0.02) for people with SMI. Conclusions This survey indicates that despite current guidelines, diabetes care in mental health settings remains peripheral. Even when diabetes care is perceived as part of a HCP’s role, various individual and organisational barriers to delivering recommended T2DM care standards to people with SMI are experienced

    Target blood pressure for septic and vasodilatory shock: what is optimal?

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    International audienc

    A 10-hour period revealed in optical spectra of the highly variable WN8 Wolf-Rayet star WR 123

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    Aims. What is the origin of the large-amplitude variability in Wolf-Rayet WN8 stars in general and WR123 in particular? A dedicated spectroscopic campaign targets the ten-hour period previously found in the high-precision photometric data obtained by the MOST satellite. Methods. In June-August 2003 we obtained a series of high signal-to-noise, mid-resolution spectra from several sites in the {\lambda}{\lambda} 4000 - 6940 A^{\circ} domain. We also followed the star with occasional broadband (Johnson V) photometry. The acquired spectroscopy allowed a detailed study of spectral variability on timescales from \sim 5 minutes to months. Results. We find that all observed spectral lines of a given chemical element tend to show similar variations and that there is a good correlation between the lines of different elements, without any significant time delays, save the strong absorption components of the Hei lines, which tend to vary differently from the emission parts. We find a single sustained periodicity, P \sim 9.8 h, which is likely related to the relatively stable pulsations found in MOST photometry obtained one year later. In addition, seemingly stochastic, large-amplitude variations are also seen in all spectral lines on timescales of several hours to several days.Comment: 6 pages, 4 figures, 2 tables, data available on-line, accepted in A&A Research Note

    Short RNA Guides Cleavage by Eukaryotic RNase III

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    In eukaryotes, short RNAs guide a variety of enzymatic activities that range from RNA editing to translation repression. It is hypothesized that pre-existing proteins evolved to bind and use guide RNA during evolution. However, the capacity of modern proteins to adopt new RNA guides has never been demonstrated. Here we show that Rnt1p, the yeast orthologue of the bacterial dsRNA-specific RNase III, can bind short RNA transcripts and use them as guides for sequence-specific cleavage. Target cleavage occurred at a constant distance from the Rnt1p binding site, leaving the guide RNA intact for subsequent cleavage. Our results indicate that RNase III may trigger sequence-specific RNA degradation independent of the RNAi machinery, and they open the road for a new generation of precise RNA silencing tools that do not trigger a dsRNA-mediated immune response

    Nutrient scarcity as a selective pressure for mast seeding

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    Mast seeding is one of the most intriguing reproductive traits in nature. Despite its potential drawbacks in terms of fitness, the widespread existence of this phenomenon suggests that it should have evolutionary advantages under certain circumstances. Using a global dataset of seed production time series for 219 plant species from all the continents, we tested whether masting behaviour appears predominantly in species with low foliar N and P concentrations, when controlling for local climate and productivity. Here we show that masting intensity is higher in species with low foliar N and P concentrations and especially imbalanced N:P ratios, and that the evolutionary history of masting behaviour has been linked to that of nutrient economy. Our results support the hypothesis that masting is stronger in species growing under limiting conditions and suggest that this reproductive behaviour might have evolved as an adaptation to nutrient limitations and imbalances
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