1,002 research outputs found
New Pulsating White Dwarfs in Cataclysmic Variables
The number of discovered non-radially pulsating white dwarfs (WDs) in
cataclysmic variables (CVs) is increasing rapidly by the aid of the Sloan
Digital Sky Survey (SDSS). We performed photometric observations of two
additional objects, SDSS J133941.11+484727.5 (SDSS 1339), independently
discovered as a pulsator by Gansicke et al., and SDSS J151413.72+454911.9,
which we identified as a CV/ZZ Ceti hybrid. In this Letter we present the
results of the remote observations of these targets performed with the Nordic
Optical Telescope (NOT) during the Nordic-Baltic Research School at Moletai
Observatory, and follow-up observations executed by NOT in service mode. We
also present 3 candidates we found to be non-pulsating. The results of our
observations show that the main pulsation frequencies agree with those found in
previous CV/ZZ Ceti hybrids, but specifically for SDSS 1339 the principal
period differs slightly between individual observations and also from the
recent independent observation by Gansicke et al. Analysis of SDSS colour data
for the small sample of pulsating and non-pulsating CV/ZZ Ceti hybrids found so
far, seems to indicate that the r-i colour could be a good marker for the
instability strip of this class of pulsating WDs.Comment: 5 pages, 6 figures, 2 tables, accepted for publication in MNRAS
Letter
Overall survival after resection for colon cancer in a national cohort study was adversely affected by TNM stage, lymph node ratio, gender, and old age
Background A national surveillance program of colon cancer treatment was introduced in 2007. We examined prognostic factors for colon cancer operated in 2000 with an aim of improving survival in the new program and a special focus on the merit of lymph node yield. Methods A cohort of 269 patients, 152 women (56.5%), with a mean age of 71 years, was operated for colon cancer in 2000 at three teaching hospitals and followed up for 7 years. Results Overall 5-year survival was 58.0%, and overall hospital mortality was 5.2%, with 4.5% in elective cases and 12.5% after urgent surgery. In only 41.1% of the specimens were 12 or more lymph nodes retrieved, but this did not affect survival in the combined cohort, although one of the hospitals achieved a significantly better result with a harvest of 12 or more lymph nodes. In a multivariate analysis, old age, gender, a high lymph node ratio (LNR) at stage III, and tumor–node–metastasis stage were adverse factors for survival. Conclusions The operative mortality was high and should be reassessed. The lymph node count did not have a significant impact on outcome overall, whereas the LNR proved significant for stage III. A prospective protocol using overall lymph node yield as a surrogate measure for more radical surgery, nevertheless, seems warranted to improve the lymph node harvest according to international recommendations
Expression of EZH2 and Ki-67 in colorectal cancer and associations with treatment response and prognosis
Toward a simulation approach for alkene ring-closing metathesis : scope and limitations of a model for RCM
A published model for revealing solvent effects on the ring-closing metathesis (RCM) reaction of di-Et diallylmalonate 7 has been evaluated over a wider range of conditions, to assess its suitability for new applications. Unfortunately, the model is too flexible and the published rate consts. do not agree with exptl. studies in the literature. However, by fixing the values of important rate consts. and restricting the concn. ranges studied, useful conclusions can be drawn about the relative rates of RCM of different substrates, precatalyst concn. can be simulated accurately and the effect of precatalyst loading can be anticipated. Progress has also been made toward applying the model to precatalyst evaluation, but further modifications to the model are necessary to achieve much broader aims
The use of supportive communication when responding to older people’s emotional distress in home care – An observational study
The state, civil society and social rights in contemporary Russia
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A Large Hadron Electron Collider at CERN
This document provides a brief overview of the recently published report on
the design of the Large Hadron Electron Collider (LHeC), which comprises its
physics programme, accelerator physics, technology and main detector concepts.
The LHeC exploits and develops challenging, though principally existing,
accelerator and detector technologies. This summary is complemented by brief
illustrations of some of the highlights of the physics programme, which relies
on a vastly extended kinematic range, luminosity and unprecedented precision in
deep inelastic scattering. Illustrations are provided regarding high precision
QCD, new physics (Higgs, SUSY) and electron-ion physics. The LHeC is designed
to run synchronously with the LHC in the twenties and to achieve an integrated
luminosity of O(100) fb. It will become the cleanest high resolution
microscope of mankind and will substantially extend as well as complement the
investigation of the physics of the TeV energy scale, which has been enabled by
the LHC
Media events, spectacles and risky globalization: a critical review and possible avenues for future research
We review the research conducted to date on media events and media spectacles. We posit that the main phenomena challenging the current conceptualizations of media event and media spectacle are (1) the understanding of risk, (2) the context of disasters and (3) globalization and the mediation of news in the context of transnational and transitional societies. We suggest that more research on disruptive events is needed. In the context of the new media landscape in particular, the ritual researcher may need to take into account the concepts of temporality and unpredictability as inherent features of media events and rituals – the traumatic events researcher may benefit from the concept of global risk society. Finally, we argue that more research needs to be carried out on transitional societies, as we need to learn more about the role of mediation, events and spectacles in democratization processes and in contemporary revolutions. Overall, our findings indicate that in the context of global risk society, constant disruptions and unplanned events, together with the changes in news transmission, need to be taken as a starting point also in the research frames used to understand the mediation of events in contemporary society
Cytosolic Superoxide Dismutase (SOD1) Is Critical for Tolerating the Oxidative Stress of Zinc Deficiency in Yeast
Zinc deficiency causes oxidative stress in many organisms including the yeast Saccharomyces cerevisiae. Previous studies of this yeast indicated that the Tsa1 peroxiredoxin is required for optimal growth in low zinc because of its role in degrading H2O2. In this report, we assessed the importance of other antioxidant genes to zinc-limited growth. Our results indicated that the cytosolic superoxide dismutase Sod1 is also critical for growth under zinc-limiting conditions. We also found that Ccs1, the copper-delivering chaperone required for Sod1 activity is essential for optimal zinc-limited growth. To our knowledge, this is the first demonstration of the important roles these proteins play under this condition. It has been proposed previously that a loss of Sod1 activity due to inefficient metallation is one source of reactive oxygen species (ROS) under zinc-limiting conditions. Consistent with this hypothesis, we found that both the level and activity of Sod1 is diminished in zinc-deficient cells. However, under conditions in which Sod1 was overexpressed in zinc-limited cells and activity was restored, we observed no decrease in ROS levels. Thus, these data indicate that while Sod1 activity is critical for low zinc growth, diminished Sod1 activity is not a major source of the elevated ROS observed under these conditions
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