610 research outputs found
Counterfactual Thinking and Entrepreneurial Self‐Efficacy: The Moderating Role of Self‐Esteem and Dispositional Affect
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97291/1/etap472.pd
Supernova Bounds on Majoron-emitting decays of light neutrinos
Neutrino masses arising from the spontaneous violation of ungauged
lepton-number are accompanied by a physical Goldstone boson, generically called
Majoron. In the high-density supernova medium the effects of Majoron-emitting
neutrino decays are important even if they are suppressed in vacuo by small
neutrino masses and/or small off-diagonal couplings. We reconsider the
influence of these decays on the neutrino signal of supernovae in the light of
recent Super-Kamiokande data on solar and atmospheric neutrinos. We find that
majoron-neutrino coupling constants in the range 3\times 10^{-7}\lsim g\lsim
2\times 10^{-5} or g \gsim 3 \times 10^{-4} are excluded by the observation
of SN1987A. Then we discuss the potential of Superkamiokande and the Sudbury
Neutrino Observatory to detect majoron neutrino interactions in the case of a
future galactic supernova. We find that these experiments could probe majoron
neutrino interactions with improved sensitivity.Comment: 28 pages, 5 figure
Risk stratification of individuals with low-risk colorectal adenomas using clinical characteristics: A pooled analysis
Objective For individuals with 1-2 small (<1 cm) low-risk colorectal adenomas, international guidelines range from no surveillance to offering surveillance colonoscopy in 5-10 years. We hypothesised that the risks for metachronous advanced neoplasia (AN) among patients with low-risk adenomas differ based on clinical factors distinct from those currently used. Design We pooled data from seven prospective studies to assess the risk of metachronous AN. Two groups with 1-2 small adenomas were defined based on guidelines from the UK (n=4516) or the European Union (EU)/US (n=2477). Results Absolute risk of metachronous AN ranged from a low of 2.9% to a high of 12.2%, depending on specific risk factor and guideline used. For the UK group, the highest absolute risks for metachronous AN were found among individuals with a history of prior polyp (12.2%), villous histology (12.2%), age ≥70 years (10.9%), high-grade dysplasia (10.9%), any proximal adenoma (10.2%), distal and proximal adenoma (10.8%) or two adenomas (10.1%). For the EU/US group, the highest absolute risks for metachronous AN were among individuals with a history of prior polyp (11.5%) or the presence of both proximal and distal adenomas (11.0%). In multivariate analyses, strong associations for increasing age and history of prior polyps and odds of metachronous AN were observed, whereas more modest associations were shown for baseline proximal adenomas and those with villous features. Conclusions Risks of metachronous AN among individuals with 1-2 small adenomas vary according to readily available clinical characteristics. These characteristics may be considered for recommending colonoscopy surveillance and require further investigation
SPECTRA OF YOUNG GALAXIES
Invited review, Ringberg conference on "Galaxies in the Young Universe"
(Sept94)Comment: 12 pages, uuencoded compressed Postscript fil
Models for Type Ia supernovae and related astrophysical transients
We give an overview of recent efforts to model Type Ia supernovae and related
astrophysical transients resulting from thermonuclear explosions in white
dwarfs. In particular we point out the challenges resulting from the
multi-physics multi-scale nature of the problem and discuss possible numerical
approaches to meet them in hydrodynamical explosion simulations and radiative
transfer modeling. We give examples of how these methods are applied to several
explosion scenarios that have been proposed to explain distinct subsets or, in
some cases, the majority of the observed events. In case we comment on some of
the successes and shortcoming of these scenarios and highlight important
outstanding issues.Comment: 20 pages, 2 figures, review published in Space Science Reviews as
part of the topical collection on supernovae, replacement corrects typos in
the conclusions sectio
Astronomical Distance Determination in the Space Age: Secondary Distance Indicators
The formal division of the distance indicators into primary and secondary leads to difficulties in description of methods which can actually be used in two ways: with, and without the support of the other methods for scaling. Thus instead of concentrating on the scaling requirement we concentrate on all methods of distance determination to extragalactic sources which are designated, at least formally, to use for individual sources. Among those, the Supernovae Ia is clearly the leader due to its enormous success in determination of the expansion rate of the Universe. However, new methods are rapidly developing, and there is also a progress in more traditional methods. We give a general overview of the methods but we mostly concentrate on the most recent developments in each field, and future expectations. © 2018, The Author(s)
ENIGMA and global neuroscience: A decade of large-scale studies of the brain in health and disease across more than 40 countries
This review summarizes the last decade of work by the ENIGMA (Enhancing NeuroImaging Genetics through Meta Analysis) Consortium, a global alliance of over 1400 scientists across 43 countries, studying the human brain in health and disease. Building on large-scale genetic studies that discovered the first robustly replicated genetic loci associated with brain metrics, ENIGMA has diversified into over 50 working groups (WGs), pooling worldwide data and expertise to answer fundamental questions in neuroscience, psychiatry, neurology, and genetics. Most ENIGMA WGs focus on specific psychiatric and neurological conditions, other WGs study normal variation due to sex and gender differences, or development and aging; still other WGs develop methodological pipelines and tools to facilitate harmonized analyses of "big data" (i.e., genetic and epigenetic data, multimodal MRI, and electroencephalography data). These international efforts have yielded the largest neuroimaging studies to date in schizophrenia, bipolar disorder, major depressive disorder, post-traumatic stress disorder, substance use disorders, obsessive-compulsive disorder, attention-deficit/hyperactivity disorder, autism spectrum disorders, epilepsy, and 22q11.2 deletion syndrome. More recent ENIGMA WGs have formed to study anxiety disorders, suicidal thoughts and behavior, sleep and insomnia, eating disorders, irritability, brain injury, antisocial personality and conduct disorder, and dissociative identity disorder. Here, we summarize the first decade of ENIGMA's activities and ongoing projects, and describe the successes and challenges encountered along the way. We highlight the advantages of collaborative large-scale coordinated data analyses for testing reproducibility and robustness of findings, offering the opportunity to identify brain systems involved in clinical syndromes across diverse samples and associated genetic, environmental, demographic, cognitive, and psychosocial factors
On the mechanisms governing gas penetration into a tokamak plasma during a massive gas injection
A new 1D radial fluid code, IMAGINE, is used to simulate the penetration of gas into a tokamak plasma during a massive gas injection (MGI). The main result is that the gas is in general strongly braked as it reaches the plasma, due to mechanisms related to charge exchange and (to a smaller extent) recombination. As a result, only a fraction of the gas penetrates into the plasma. Also, a shock wave is created in the gas which propagates away from the plasma, braking and compressing the incoming gas. Simulation results are quantitatively consistent, at least in terms of orders of magnitude, with experimental data for a D 2 MGI into a JET Ohmic plasma. Simulations of MGI into the background plasma surrounding a runaway electron beam show that if the background electron density is too high, the gas may not penetrate, suggesting a possible explanation for the recent results of Reux et al in JET (2015 Nucl. Fusion 55 093013)
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