249 research outputs found
Inverse Compton Scattering as the Source of Diffuse EUV Emission in the Coma Cluster of Galaxies
We have examined the hypothesis that the majority of the diffuse EUV flux in
the Coma cluster is due to inverse Compton scattering of low energy cosmic ray
electrons (0.16 < epsilon < 0.31 GeV) against the 3K black-body background. We
present data on the two-dimensional spatial distribution of the EUV flux and
show that these data provide strong support for a non-thermal origin for the
EUV flux. However, we show that this emission cannot be produced by an
extrapolation to lower energies of the observed synchrotron radio emitting
electrons and an additional component of low energy cosmic ray electrons is
required.Comment: 11 pages, 5 figure
The VAST Survey - I. Companions and the unexpected X-ray detection of B6-A7 stars
With an adaptive optics imaging survey of 148 B6-A7 stars, we have tested the
hypothesis that unresolved lower-mass companions are the source of the
unexpected X-ray detections of stars in this spectral type range. The sample is
composed of 63 stars detected in X-rays within the ROSAT All-Sky Survey and 85
stars that form a control sample; both subsets have the same restricted
distribution of spectral type, age, X-ray sensitivity and separation coverage.
A total of 68 companion candidates are resolved with separations ranging from
0.3" to 26.2", with 23 new detections. The multiple star frequency of the X-ray
sample based on companions resolved within the ROSAT error ellipse is found to
be 43 (+6,-6)%. The corresponding control sample multiple star frequency is
three times lower at 12 (+4,-3)% -- a difference of 31\pm7%. These results are
presented in the first of a series of papers based on our Volume-limited A-Star
(VAST) survey -- a comprehensive study of the multiplicity of A-type stars.Comment: Accepted for publication in Monthly Notices of the Royal Astronomical
Societ
Neutrino Mass and from a Mini-Seesaw
The recently proposed "mini-seesaw mechanism" combines naturally suppressed
Dirac and Majorana masses to achieve light Standard Model neutrinos via a
low-scale seesaw. A key feature of this approach is the presence of multiple
light (order GeV) sterile-neutrinos that mix with the Standard Model. In this
work we study the bounds on these light sterile-neutrinos from processes like
\mu ---> e + \gamma, invisible Z-decays, and neutrinoless double beta-decay. We
show that viable parameter space exists and that, interestingly, key
observables can lie just below current experimental sensitivities. In
particular, a motivated region of parameter space predicts a value of BR(\mu
---> e + \gamma) within the range to be probed by MEG.Comment: 1+26 pages, 7 figures. v2 JHEP version (typo's fixed, minor change to
presentation, results unchanged
Witnessing (co)datatypes
Datatypes and codatatypes are useful for specifying and reasoning about (possibly infinite) computational processes. The Isabelle/HOL proof assistant has recently been extended with a definitional package that supports both. We describe a complete procedure for deriving nonemptiness witnesses in the general mutually recursive, nested case—nonemptiness being a proviso for introducing types in higher-order logic
Comprehending Isabelle/HOL's consistency
The proof assistant Isabelle/HOL is based on an extension of Higher-Order Logic (HOL) with ad hoc overloading of constants. It turns out that the interaction between the standard HOL type definitions and the Isabelle-specific ad hoc overloading is problematic for the logical consistency. In previous work, we have argued that standard HOL semantics is no longer appropriate for capturing this interaction, and have proved consistency using a nonstandard semantics. The use of an exotic semantics makes that proof hard to digest by the community. In this paper, we prove consistency by proof-theoretic means—following the healthy intuition of definitions as abbreviations, realized in HOLC, a logic that augments HOL with comprehension types. We hope that our new proof settles the Isabelle/HOL consistency problem once and for all. In addition, HOLC offers a framework for justifying the consistency of new deduction schemas that address practical user needs
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Profile of European adults interested in internet-based personalized nutrition: The Food4Me Study
Purpose
Personalised intervention may have greater potential for reducing the global burden of non-communicable diseases and for promoting better health and wellbeing across the life-span than the conventional “one size fits all” approach. However, the characteristics of individuals interested in personalised nutrition (PN) are unclear. Therefore, the aim of this study was to describe the characteristics of European adults interested in taking part in an internet-based PN study.
Methods
Individuals from seven European countries (UK, Ireland, Germany, the Netherlands, Spain, Greece and Poland) were invited to participate in the study via the Food4Me website (http://www.food4me.org). Two screening questionnaires were used to collect data on socio-demographic, anthropometric and health characteristics as well as dietary intakes.
Results
A total of 5662 individuals expressed an interest in the study (mean age 40 ± 12.7; range 15-87 years). Of these 64.6% were female and 96.9% were Caucasian. Overall, 12.9% were smokers and 46.8% reported the presence of a clinically diagnosed disease. Furthermore, 46.9% were overweight or obese and 34.9% were sedentary during leisure time. Assessment of dietary intakes showed that 54.3% of individuals reported consuming at least 5 portions of fruit and vegetables per day, 45.9% consumed more than 3 servings of wholegrains and 37.2% limited their salt intake to less than 5.75g per day.
Conclusions
Our data indicate that individuals volunteering to participate in an internet-based PN study are broadly representative of the European adult population, most of whom had adequate nutrient intakes but who could benefit from improved dietary choices and greater physical activity. Future use of internet-based PN approaches is thus relevant to a wide target audience
Towards the clinical implementation of pharmacogenetics in bipolar disorder.
BackgroundBipolar disorder (BD) is a psychiatric illness defined by pathological alterations between the mood states of mania and depression, causing disability, imposing healthcare costs and elevating the risk of suicide. Although effective treatments for BD exist, variability in outcomes leads to a large number of treatment failures, typically followed by a trial and error process of medication switches that can take years. Pharmacogenetic testing (PGT), by tailoring drug choice to an individual, may personalize and expedite treatment so as to identify more rapidly medications well suited to individual BD patients.DiscussionA number of associations have been made in BD between medication response phenotypes and specific genetic markers. However, to date clinical adoption of PGT has been limited, often citing questions that must be answered before it can be widely utilized. These include: What are the requirements of supporting evidence? How large is a clinically relevant effect? What degree of specificity and sensitivity are required? Does a given marker influence decision making and have clinical utility? In many cases, the answers to these questions remain unknown, and ultimately, the question of whether PGT is valid and useful must be determined empirically. Towards this aim, we have reviewed the literature and selected drug-genotype associations with the strongest evidence for utility in BD.SummaryBased upon these findings, we propose a preliminary panel for use in PGT, and a method by which the results of a PGT panel can be integrated for clinical interpretation. Finally, we argue that based on the sufficiency of accumulated evidence, PGT implementation studies are now warranted. We propose and discuss the design for a randomized clinical trial to test the use of PGT in the treatment of BD
Hulless Barley – A Rediscovered Source for Functional Foods Phytochemical Profile and Soluble Dietary Fibre Content in Naked Barley Varieties and Their Antioxidant Properties
X-ray Observations of the New Pulsar--Supernova Remnant System PSR J1119-6127 and SNR G292.2-0.5
PSR J1119-6127 is a recently discovered 1700-year-old radio pulsar that has a
very high inferred surface dipolar magnetic field. We present a detailed
analysis of a pointed ASCA observation and archival ROSAT data of J1119-6127
and its surroundings. Both data sets reveal extended emission coincident with
the newly-discovered radio supernova remnant G292.2-0.5, reported in a
companion paper by Crawford et al. (astro-ph/0012287).. A hard point source,
offset ~1.5' from the position of the radio pulsar, is seen with the ASCA GIS.
No pulsations are detected at the radio period with a pulsed fraction upper
limit of 61% (95% confidence). The limited statistics prevent a detailed
spectral analysis, although a power-law model with photon index (Gamma=~1-2)
describes the data well. Both the spectral model and derived X-ray luminosity
are consistent with those measured for other young radio pulsars, although the
spatial offset renders an identification of the source as the X-ray counterpart
of the pulsar uncertain.Comment: Accepted by ApJ; 12 Pages in emulated ApJ format with embedded tables
and color figure
Seal of transparency heritage in the CISMeF quality-controlled health gateway
BACKGROUND: It is an absolute necessity to continually assess the quality of health information on the Internet. Quality-controlled subject gateways are Internet services which apply a selected set of targeted measures to support systematic resource discovery. METHODS: The CISMeF health gateway became a contributor to the MedCIRCLE project to evaluate 270 health information providers. The transparency heritage consists of using the evaluation performed on providers that are referenced in the CISMeF catalogue for evaluating the documents they publish, thus passing on the transparency label from the publishers to their documents. RESULTS: Each site rated in CISMeF has a record in the CISMeF database that generates an RDF into HTML file. The search tool Doc'CISMeF displays information originating from every publisher evaluated with a specific MedCIRCLE button, which is linked to the MedCIRCLE central repository. Starting with 270 websites, this trust heritage has led to 6,480 evaluated resources in CISMeF (49.8% of the 13,012 resources included in CISMeF). CONCLUSION: With the MedCIRCLE project and transparency heritage, CISMeF became an explicit third party
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