1,042 research outputs found
Precision Mass Measurements of 129-131Cd and Their Impact on Stellar Nucleosynthesis via the Rapid Neutron Capture Process
Masses adjacent to the classical waiting-point nuclide 130Cd have been
measured by using the Penning- trap spectrometer ISOLTRAP at ISOLDE/CERN. We
find a significant deviation of over 400 keV from earlier values evaluated by
using nuclear beta-decay data. The new measurements show the reduction of the N
= 82 shell gap below the doubly magic 132Sn. The nucleosynthesis associated
with the ejected wind from type-II supernovae as well as from compact object
binary mergers is studied, by using state-of-the-art hydrodynamic simulations.
We find a consistent and direct impact of the newly measured masses on the
calculated abundances in the A = 128 - 132 region and a reduction of the
uncertainties from the precision mass input data
Impact of FTO genotypes on BMI and weight in polycystic ovary syndrome : a systematic review and meta-analysis
Aims/hypothesis
FTO gene single nucleotide polymorphisms (SNPs) have been shown to be associated with obesity-related traits and type 2 diabetes. Several small studies have suggested a greater than expected effect of the FTO rs9939609 SNP on weight in polycystic ovary syndrome (PCOS). We therefore aimed to examine the impact of FTO genotype on BMI and weight in PCOS.
Methods
A systematic search of medical databases (PubMed, EMBASE and Cochrane CENTRAL) was conducted up to the end of April 2011. Seven studies describing eight distinct PCOS cohorts were retrieved; seven were genotyped for SNP rs9939609 and one for SNP rs1421085. The per allele effect on BMI and body weight increase was calculated and subjected to meta-analysis.
Results
A total of 2,548 women with PCOS were included in the study; 762 were TT homozygotes, 1,253 had an AT/CT genotype, and 533 were AA/CC homozygotes. Each additional copy of the effect allele (A/C) increased the BMI by a mean of 0.19 z score units (95% CI 0.13, 0.24; p = 2.26 × 10−11) and body weight by a mean of 0.20 z score units (95% CI 0.14, 0.26; p = 1.02 × 10−10). This translated into an approximately 3.3 kg/m2 increase in BMI and an approximately 9.6 kg gain in body weight between TT and AA/CC homozygotes. The association between FTO genotypes and BMI was stronger in the cohorts with PCOS than in the general female populations from large genome-wide association studies. Deviation from an additive genetic model was observed in heavier populations.
Conclusions/interpretation
The effect of FTO SNPs on obesity-related traits in PCOS seems to be more than two times greater than the effect found in large population-based studies. This suggests an interaction between FTO and the metabolic context or polygenic background of PCOS
A European Perspective on Auditory Processing Disorder-Current Knowledge and Future Research Focus
Current notions of “hearing impairment,” as reflected in clinical audiological practice, do not acknowledge the needs of individuals who have normal hearing pure tone sensitivity but who experience auditory processing difficulties in everyday life that are indexed by reduced performance in other more sophisticated audiometric tests such as speech audiometry in noise or complex non-speech sound perception. This disorder, defined as “Auditory Processing Disorder” (APD) or “Central Auditory Processing Disorder” is classified in the current tenth version of the International Classification of diseases as H93.25 and in the forthcoming beta eleventh version. APDs may have detrimental effects on the affected individual, with low esteem, anxiety, and depression, and symptoms may remain into adulthood. These disorders may interfere with learning per se and with communication, social, emotional, and academic-work aspects of life. The objective of the present paper is to define a baseline European APD consensus formulated by experienced clinicians and researchers in this specific field of human auditory science. A secondary aim is to identify issues that future research needs to address in order to further clarify the nature of APD and thus assist in optimum diagnosis and evidence-based management. This European consensus presents the main symptoms, conditions, and specific medical history elements that should lead to auditory processing evaluation. Consensus on definition of the disorder, optimum diagnostic pathway, and appropriate management are highlighted alongside a perspective on future research focus
Degradation, Bioactivity, and Osteogenic Potential of Composites Made of PLGA and Two Different Sol–Gel Bioactive Glasses
We have developed poly(l-lactide-co-glycolide) (PLGA) based composites using sol–gel derived bioactive glasses (S-BG), previously described by our group, as composite components. Two different composite types were manufactured that contained either S2—high content silica S-BG, or A2—high content lime S-BG. The composites were evaluated in the form of sheets and 3D scaffolds. Sheets containing 12, 21, and 33 vol.% of each bioactive glass were characterized for mechanical properties, wettability, hydrolytic degradation, and surface bioactivity. Sheets containing A2 S-BG rapidly formed a hydroxyapatite surface layer after incubation in simulated body fluid. The incorporation of either S-BG increased the tensile strength and Young’s modulus of the composites and tailored their degradation rates compared to starting compounds. Sheets and 3D scaffolds were evaluated for their ability to support growth of human bone marrow cells (BMC) and MG-63 cells, respectively. Cells were grown in non-differentiating, osteogenic or osteoclast-inducing conditions. Osteogenesis was induced with either recombinant human BMP-2 or dexamethasone, and osteoclast formation with M-CSF. BMC viability was lower at higher S-BG content, though specific ALP/cell was significantly higher on PLGA/A2-33 composites. Composites containing S2 S-BG enhanced calcification of extracellular matrix by BMC, whereas incorporation of A2 S-BG in the composites promoted osteoclast formation from BMC. MG-63 osteoblast-like cells seeded in porous scaffolds containing S2 maintained viability and secreted collagen and calcium throughout the scaffolds. Overall, the presented data show functional versatility of the composites studied and indicate their potential to design a wide variety of implant materials differing in physico-chemical properties and biological applications. We propose these sol–gel derived bioactive glass–PLGA composites may prove excellent potential orthopedic and dental biomaterials supporting bone formation and remodeling
Gravitational Waves From Known Pulsars: Results From The Initial Detector Era
We present the results of searches for gravitational waves from a large selection of pulsars using data from the most recent science runs (S6, VSR2 and VSR4) of the initial generation of interferometric gravitational wave detectors LIGO (Laser Interferometric Gravitational-wave Observatory) and Virgo. We do not see evidence for gravitational wave emission from any of the targeted sources but produce upper limits on the emission amplitude. We highlight the results from seven young pulsars with large spin-down luminosities. We reach within a factor of five of the canonical spin-down limit for all seven of these, whilst for the Crab and Vela pulsars we further surpass their spin-down limits. We present new or updated limits for 172 other pulsars (including both young and millisecond pulsars). Now that the detectors are undergoing major upgrades, and, for completeness, we bring together all of the most up-to-date results from all pulsars searched for during the operations of the first-generation LIGO, Virgo and GEO600 detectors. This gives a total of 195 pulsars including the most recent results described in this paper.United States National Science FoundationScience and Technology Facilities Council of the United KingdomMax-Planck-SocietyState of Niedersachsen/GermanyAustralian Research CouncilInternational Science Linkages program of the Commonwealth of AustraliaCouncil of Scientific and Industrial Research of IndiaIstituto Nazionale di Fisica Nucleare of ItalySpanish Ministerio de Economia y CompetitividadConselleria d'Economia Hisenda i Innovacio of the Govern de les Illes BalearsNetherlands Organisation for Scientific ResearchPolish Ministry of Science and Higher EducationFOCUS Programme of Foundation for Polish ScienceRoyal SocietyScottish Funding CouncilScottish Universities Physics AllianceNational Aeronautics and Space AdministrationOTKA of HungaryLyon Institute of Origins (LIO)National Research Foundation of KoreaIndustry CanadaProvince of Ontario through the Ministry of Economic Development and InnovationNational Science and Engineering Research Council CanadaCarnegie TrustLeverhulme TrustDavid and Lucile Packard FoundationResearch CorporationAlfred P. Sloan FoundationAstronom
Less-simplified models of dark matter for direct detection and the LHC
We construct models of dark matter with suppressed spin-independent scattering cross section utilizing the existing simplified model framework. Even simple combinations of simplified models can exhibit interference effects that cause the tree level contribution to the scattering cross section to vanish, thus demonstrating that direct detection limits on simplified models are not robust when embedded in a more complicated and realistic framework. In general for fermionic WIMP masses ≳ 10 GeV direct detection limits on the spin-independent scattering cross section are much stronger than those coming from the LHC. However these model combinations, which we call less-simplified models, represent situations where LHC searches become more competitive than direct detection experiments even for moderate dark matter mass. We show that a complementary use of several searches at the LHC can strongly constrain the direct detection blind spots by setting limits on the coupling constants and mediators’ mass. We derive the strongest limits for combinations of vector + scalar, vector + “squark”, and “squark” + scalar mediator, and present the corresponding projections for the LHC 14 TeV for a number of searches: mono-jet, jets + missing energy, and searches for heavy vector resonances
Virgo calibration and reconstruction of the gravitational wave strain during VSR1
Virgo is a kilometer-length interferometer for gravitational waves detection
located near Pisa. Its first science run, VSR1, occured from May to October
2007. The aims of the calibration are to measure the detector sensitivity and
to reconstruct the time series of the gravitational wave strain h(t). The
absolute length calibration is based on an original non-linear reconstruction
of the differential arm length variations in free swinging Michelson
configurations. It uses the laser wavelength as length standard. This method is
used to calibrate the frequency dependent response of the Virgo mirror
actuators and derive the detector in-loop response and sensitivity within ~5%.
The principle of the strain reconstruction is highlighted and the h(t)
systematic errors are estimated. A photon calibrator is used to check the sign
of h(t). The reconstructed h(t) during VSR1 is valid from 10 Hz up to 10 kHz
with systematic errors estimated to 6% in amplitude. The phase error is
estimated to be 70 mrad below 1.9 kHz and 6 micro-seconds above.Comment: 8 pages, 8 figures, proceedings of Amaldi 8 conference, to be
published in Journal of Physics Conference Series (JPCS). Second release:
correct typo
A First Search for coincident Gravitational Waves and High Energy Neutrinos using LIGO, Virgo and ANTARES data from 2007
We present the results of the first search for gravitational wave bursts
associated with high energy neutrinos. Together, these messengers could reveal
new, hidden sources that are not observed by conventional photon astronomy,
particularly at high energy. Our search uses neutrinos detected by the
underwater neutrino telescope ANTARES in its 5 line configuration during the
period January - September 2007, which coincided with the fifth and first
science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed
for candidate gravitational-wave signals coincident in time and direction with
the neutrino events. No significant coincident events were observed. We place
limits on the density of joint high energy neutrino - gravitational wave
emission events in the local universe, and compare them with densities of
merger and core-collapse events.Comment: 19 pages, 8 figures, science summary page at
http://www.ligo.org/science/Publication-S5LV_ANTARES/index.php. Public access
area to figures, tables at
https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=p120000
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