1,424 research outputs found
Chiral extrapolation of baryon mass ratios
We analyze lattice data for octet baryon masses from the QCDSF collaboration
employing manifestly covariant Baryon Chiral Perturbation Theory. It is shown
that certain combinations of low-energy constants can be fixed more accurately
than before from this data. We also examine the impact of this analysis on the
pion-nucleon sigma term, and on the convergence properties of baryon mass
expansions in the SU(3) symmetry limit.Comment: Updated version, to be published in Phys. Rev.
ESMO Minimum Clinical Recommendations for diagnosis, treatment and follow-up of chronic lymphocytic leukemia
The Biological Standard of Living in the two Germanies.
Physical stature is used as a proxy for the biological standard of living in the two Germanies before and after unification in an analysis of a cross-sectional sample (1998) of adult heights, as well as among military recruits of the 1990s. West Germans tended to be taller than East Germans throughout the period under consideration. Contrary to official proclamations of a classless society, there were substantial social differences in physical stature in East-Germany. Social differences in height were greater in the East among females, and less among males than in the West. The difficulties experienced by the East-German population after 1961 is evident in the increase in social inequality of physical stature thereafter, as well as in the increasing gap relative to the height of the West-German population. After unification, however, there is a tendency for East-German males, but not of females, to catch up with their West-German counterparts
Prediction of lethal and synthetically lethal knock-outs in regulatory networks
The complex interactions involved in regulation of a cell's function are
captured by its interaction graph. More often than not, detailed knowledge
about enhancing or suppressive regulatory influences and cooperative effects is
lacking and merely the presence or absence of directed interactions is known.
Here we investigate to which extent such reduced information allows to forecast
the effect of a knock-out or a combination of knock-outs. Specifically we ask
in how far the lethality of eliminating nodes may be predicted by their network
centrality, such as degree and betweenness, without knowing the function of the
system. The function is taken as the ability to reproduce a fixed point under a
discrete Boolean dynamics. We investigate two types of stochastically generated
networks: fully random networks and structures grown with a mechanism of node
duplication and subsequent divergence of interactions. On all networks we find
that the out-degree is a good predictor of the lethality of a single node
knock-out. For knock-outs of node pairs, the fraction of successors shared
between the two knocked-out nodes (out-overlap) is a good predictor of
synthetic lethality. Out-degree and out-overlap are locally defined and
computationally simple centrality measures that provide a predictive power
close to the optimal predictor.Comment: published version, 10 pages, 6 figures, 2 tables; supplement at
http://www.bioinf.uni-leipzig.de/publications/supplements/11-01
Coronary artery size and origin imaging in children: a comparative study of MRI and trans-thoracic echocardiography
BACKGROUND: The purpose of this study was to see how coronary magnetic resonance angiography (CMRA) compared to echocardiography for the detection of coronary artery origins and to compare CMRA measurements for coronary dimensions in children with published echocardiographic reference values.METHODS: Enrolled patients underwent dual cardiac phase CMRA and echocardiography under the same anesthetic. Echocardiographic measurements of the right coronary artery (RCA), left anterior descending (LAD) and left main (LM) were made. CMRA dimensions were assessed manually at the same points as the echocardiographic measurements. The number of proximal LAD branches imaged was also recorded in order to give an estimate of distal coronary tree visualization.RESULTS: Fifty patients (24 boys, mean age 4.0 years (range 18 days to 18 years)) underwent dual-phase CMRA. Coronary origins were identified in 47/50 cases for CMRA (remaining 3 were infants aged 3, 9 and 11 months). In comparison, origins were identified in 41/50 cases for echo (remaining were all older children). CMRA performed better than echocardiography in terms of distal visualization of the coronary tree (median 1 LAD branch vs. median 0; p = 0.001). Bland-Altman plots show poor agreement between echocardiography and CMRA for coronary measurements. CMRA measurements did vary according to cardiac phase (systolic mean 1.90, s.d. 0.05 mm vs. diastolic mean 1.84, s.d. 0.05 mm; p = 0.002).CONCLUSIONS: Dual-phase CMRA has an excellent (94 %) success rate for the detection of coronary origins in children. Newborn infants remain challenging and echocardiography remains the accepted imaging modality for this age group. Echocardiographic reference ranges are not applicable to CMRA measurements as agreement was poor between modalities. Future coronary reference values, using any imaging modality, should quote the phase in which it was measured.</p
Finite volume corrections to the electromagnetic current of the nucleon
We compute corrections to both the isovector anomalous magnetic moment and
the isovector electromagnetic current of the nucleon to in the
framework of covariant two-flavor Baryon Chiral Perturbation Theory. We then
apply these corrections to lattice data for the anomalous magnetic moment from
the LHPC, RBC & UKQCD and QCDSF collaborations
Experiencing male infertility: A review of the qualitative research literature
This article examines the qualitative research literature that exists in relation to men’s experiences of male infertility. Since men have often been marginalized in the realm of reproduction, including academic research on infertility, it is important to focus on any qualitative research that gives voices to male perspectives and concerns. Given the distress documented by studies of infertile women, we focus in particular on the emotive responses and lived experiences of men in relation to infertility. In this article then, we present an analysis of the core themes across 19 qualitative articles, which include “infertility as crisis”; “emoting infertility- men as “being strong”’ “infertility as a source of stigma”; and the “desire for fatherhood.” In light of these insights, we identify key areas for future research and development including men’s emotional responses to infertility, how men seek support for infertility, the intersection between masculinity and infertility, the relationship between the desire to father and infertility, and the outcomes of infertility for men in terms of other aspects of their lives. We suggest that such research would facilitate making the experiences of men more central within our understandings of infertility within a field that has primarily been female focused
Optical study of the band structure of wurtzite GaP nanowires
We investigated the optical properties of wurtzite (WZ) GaP nanowires by performing photoluminescence (PL) and time-resolved PL measurements in the temperature range from 4 K to 300 K, together with atom probe tomography to identify residual impurities in the nanowires. At low temperature, the WZ GaP luminescence shows donor-acceptor pair emission at 2.115 eV and 2.088 eV, and Burstein-Moss band-filling continuum between 2.180 and 2.253 eV, resulting in a direct band gap above 2.170 eV. Sharp exciton α-β-γ lines are observed at 2.140-2.164-2.252 eV, respectively, showing clear differences in lifetime, presence of phonon replicas, and temperature- dependence. The excitonic nature of those peaks is critically discussed, leading to a direct band gap o
Accelerated aortic plaque imaging using small field of view imaging and quadruple inversion recovery magnetization preparation
Asymmetric Hybridization and Introgression between Pink Salmon and Chinook Salmon in the Laurentian Great Lakes
Among Pacific salmon collected in the St. Marys River, five natural hybrids of pink salmon Oncorhynchus gorbuscha and chinook salmon O. tshawytscha and one suspected backcross have been detected using morphologic, meristic, and color evidence. One allozyme (LDH, l‐lactate dehydrogenase from muscle) and one nuclear DNA locus (growth hormone) for which species‐specific fixed differences exist were analyzed to detect additional hybrids and to determine if introgression had occurred. Restriction fragment length polymorphism of mitochondrial DNA (mtDNA) was used to identify the maternal parent of each hybrid. Evidence of introgression was found among the five previously identified hybrids. All hybrid specimens had chinook salmon mtDNA, indicating that hybridization between chinook salmon and pink salmon in the St. Marys River is asymmetric and perhaps unidirectional. Ecological, physiological, and sexual selection forces may contribute to this asymmetric hybridization. Introgression between these highly differentiated species has implications for management, systematics, and conservation of Pacific salmon.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142073/1/tafs0670.pd
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