1,191 research outputs found
Estimation of genomic breeding values for traits with high and low heritability in Brown Swiss bulls
This paper was written in the framework of the LowInputBreeds project: âDevelopment of integrated livestock breeding and management strategies to improve animal health, product quality and performance in European organic and âlow inputâ milk, meat and egg productionâ. The LowInputBreeds project unites 21 partners from Europe and further afield and will develop integrated breeding and management strategies to tackle the issue of improved animal health and food quality. It will run until 2014 and is co-funded by the European Unionâs Seventh Framework Programme for Research and Technological Development
Pion-nucleus optical potential valid up to the DELTA-resonance region
We present in this article an optical potential for the -nucleus
interaction that can be used in various studies involving -nucleus
channels. Based on earlier treatments of the low energy -nucleus optical
potential, we have derived a potential expression applicable from threshold up
to the -resonance region. We extracted the impulse approximation form
for this potential from the scattering amplitude and then added to it
kinematical and physical corrections. The kinematic corrections arise from
transforming the impulse approximation expression from the center of
mass frame to the -nucleus center of mass frame, while the physical
corrections arise mostly from the many-body nature of the -nucleus
interaction. By taking advantage of the experimental progress in our knowledge
of the process, we have updated earlier treatments with parameters
calculated from state-of-the-art experimental measurements.Comment: 23 pages, 12 figures. Accepted for publication in Physical Review
A statistical method for revealing form-function relations in biological networks
Over the past decade, a number of researchers in systems biology have sought
to relate the function of biological systems to their network-level
descriptions -- lists of the most important players and the pairwise
interactions between them. Both for large networks (in which statistical
analysis is often framed in terms of the abundance of repeated small subgraphs)
and for small networks which can be analyzed in greater detail (or even
synthesized in vivo and subjected to experiment), revealing the relationship
between the topology of small subgraphs and their biological function has been
a central goal. We here seek to pose this revelation as a statistical task,
illustrated using a particular setup which has been constructed experimentally
and for which parameterized models of transcriptional regulation have been
studied extensively. The question "how does function follow form" is here
mathematized by identifying which topological attributes correlate with the
diverse possible information-processing tasks which a transcriptional
regulatory network can realize. The resulting method reveals one form-function
relationship which had earlier been predicted based on analytic results, and
reveals a second for which we can provide an analytic interpretation. Resulting
source code is distributed via http://formfunction.sourceforge.net.Comment: To appear in Proc. Natl. Acad. Sci. USA. 17 pages, 9 figures, 2
table
The obesity paradox in lung cancer : associations with body size versus body shape
Background: The association between obesity and lung cancer (LC) remains poorly understood. However, other indices of obesity on the basis of body shape instead of body size have not been examined yet. The aim of this study was to evaluate the association between different indices of body size and body shape and the risk of LC. In particular, this study examined the association between A Body Shape Index, a more precise indicator of abdominal fat than traditional anthropometric measures, and the risk of LC.
Methods: In the prospective cohort the Rotterdam Study, we analysed data of 9,689 participants. LC diagnoses were based on medical records and anthropometric measurements were assessed at baseline. Cox-regression analyses with corresponding Hazard Ratios were used to examine the association between the anthropometric measurements and the risk of LC with adjustment for potential confounders. Potential non-linear associations were explored with cubic splines using the Likelihood ratio (LR) test.
Results: During follow-up, 319 participants developed LC. Body mass Index (BMI) was inversely associated with the risk of lung cancer (HR 0.94, 95% CI: 0.91-0.97) and persisted after excluding lung cancer cases during the first 10 years of follow-up. There was evidence for a non-linear association between BMI and the risk of lung cancer (0,04, df = 1), which indicated that the inverse association between BMI and lung cancer was mainly present in non-obese participants. Waist circumference (WC) (HR 1.03 95% CI: 1.01-1.05), Waist-to-Hip Ratio (WHR) (HR 1.23 95% CI: 1.09-1.38) and ABSI (A Body Shape Index) (HR 1.17 95% CI: 1.05-1.30) were positively and linearly associated with the risk of lung cancer.
Conclusions: Body shape rather than body size may be an important risk indicator of LC. Future research should focus on the role of visceral fat and the risk of LC as well as the underlying mechanisms
Ăkologische Milchviehzucht: Entwicklung und Bewertung zĂŒchterischer AnsĂ€tze unter BerĂŒcksichtigung der Genotyp x Umwelt-Interaktion und Schaffung eines Informationssystems fĂŒr nachhaltige Zuchtstrategien
In dem Projekt wurden fĂŒr verschiedene Merkmalskomplexe an zwei verschiedenen DatensĂ€tzen Genotyp x Umwelt-Interaktionen zwischen ökologischen und konventionellen Produktionssystemen geschĂ€tzt. Anhand Schweizer Daten wurden fĂŒr Braunvieh und Fleckvieh fĂŒr Milchleistungsmerkmale Korrelationen > 0.9 zwischen beiden Betriebsformen geschĂ€tzt, wohingegen die genetische Korrelationen fĂŒr funktionale Merkmale (Rastzeit, Zellzahl) geringer (0.8 bis 0.9) waren. Diese Korrelationen konnten fĂŒr die Rasse Holstein Friesian auf Grund einer Auswertung Deutscher Daten bestĂ€tigt werden. Generell liegt fĂŒr Leistungsmerkmale keine und fĂŒr funktionale Merkmale eine geringe Genotyp x Umwelt-Interaktion zwischen ökologischen und konventionellen Betrieben vor, wobei insbesondere fĂŒr letztere die Informationsbasis begrenzt ist. Auswertungen der Betriebsdaten von > 450 ökologisch wirtschaftenden Milchviehbetrieben und Befragungen der Betriebsleiter haben ergeben, dass sich diese Betriebe in ihren zĂŒchterischen Zielen kaum und in ihrem zĂŒchterischen Handeln gar nicht von konventionellen Betrieben unterscheiden. Zuchtplanerische Rechnungen haben ergeben, dass unter den gefundenen genetischen Parametern weder ein geschlossenes noch ein offenes eigenes Zuchtprogramm im ökologischen Sektor wirtschaftlich gerechtfertigt ist. Vielmehr ist anzustreben, dass sich ökologisch wirtschaftende Milchviehbetriebe stĂ€rker aktiv an etablierten Zuchtprogrammen beteiligen, z.B. durch den stĂ€rkeren Einsatz von Testbullen. Es wird vorgeschlagen, aufgrund der bestehenden Teilzuchtwerte einen Ăkologischen Gesamtzuchtwert zu entwickeln, in dem funktionale Merkmale stĂ€rker gewichtet werden. Ein im Projekt entwickeltes Internetportal und eine entsprechend angepasste Anpaarungssoftware kann die Umsetzung dieses Vorschlags unterstĂŒtzen. Erforderlich ist allerdings eine vollstĂ€ndigere Erfassung der ökologischen Milchviehbetriebe als Voraussetzung fĂŒr eine bessere UnterstĂŒtzung der ökologischen Milchviehzucht
Distribution of echocardiographic parameters and their associations with cardiovascular risk factors in the Rotterdam Study
Insight into echocardiographic parameters in the general population may facilitate early recognition of ventricular dysfunction, reducing the population morbidity and mortality of heart failure. We examined the distribution of structural, systolic and diastolic echocardiographic parameters and their associations with cardiovascular risk factors in the Rotterdam Study, a population-based cohort study in men and women aged â„55Â years. Participants with prevalent heart failure, myocardial infarction and atrial fibrillation and flutter were excluded. Echocardiographic parameters were assessed using two-dimensional, M-mode and Doppler echocardiography. Echocardiograms were available in 4,425 participants. Structural parameters were generally larger in men, and most consistently associated with age, body mass index and blood pressure in both sexes. Prevalence of moderate or poor left ventricular systolic function was 3.9% in men and 2.1% in women. Age, body mass index and blood pressure were most consistently associated with systolic function. E/A ratio was lower in women than in men. Age and diastolic blood pressure were most consistently associated with E/A ratio in both sexes. In conclusion, ventricular systolic and diastolic dysfunction is present in asymptomatic individuals. Selected established cardiovascular risk factors are associated with structural, systolic and diastolic parameters
Na2IrO3 as a spin-orbit-assisted antiferromagnetic insulator with a 340 meV gap
We study Na2IrO3 by ARPES, optics, and band structure calculations in the
local-density approximation (LDA). The weak dispersion of the Ir 5d-t2g
manifold highlights the importance of structural distortions and spin-orbit
coupling (SO) in driving the system closer to a Mott transition. We detect an
insulating gap {\Delta}_gap = 340 meV which, at variance with a Slater-type
description, is already open at 300 K and does not show significant temperature
dependence even across T_N ~ 15 K. An LDA analysis with the inclusion of SO and
Coulomb repulsion U reveals that, while the prodromes of an underlying
insulating state are already found in LDA+SO, the correct gap magnitude can
only be reproduced by LDA+SO+U, with U = 3 eV. This establishes Na2IrO3 as a
novel type of Mott-like correlated insulator in which Coulomb and relativistic
effects have to be treated on an equal footing.Comment: Accepted in Physical Review Letters. Auxiliary and related material
can be found at:
http://www.phas.ubc.ca/~quantmat/ARPES/PUBLICATIONS/articles.htm
Einfluss der genetischen Architektur auf die empirische Genauigkeit der genomischen ZuchtwertschÀtzung
Einfluss der genetischen Architektur auf die empirische
Genauigkeit der genomischen ZuchtwertschÀtzung.
Das Projekt wird als Verbundprojekt von der EuropĂ€ischen Kommission im siebten Rahmenprogramm fĂŒr Forschung und Entwicklung ko-finanziert (Vertrag Nr. 222623)
Utilisation of cardiac pacemakers over a 20-year period: Results from a nationwide pacemaker registry
The implantation of cardiac pacemakers has become a well-established therapy for conduction disorders and sinus node dysfunction. In many countries pacemaker registries have been initiated in order to collect information on patient characteristics, trends in numbers and the types of pacemakers used, to identify problematic devices, and for safety monitoring. For this utilisation study the Central Pacemaker Patients Registration (CPPR) from the Netherlands Pacemaker Registry Foundation (CPPR-SPRN) containing data collected for more than 20 years was used. During this period nearly 97,000 first pacemakers were implanted. Analyses show an increase in the rate of implanted devices. The change in pacemaker type from VVI to DDD, followed by biventricular stimulation, is reflected by the number of simultaneously implanted leads, which is partly a consequence of cardiac resynchronisation therapy. Our data demonstrate that indications for implantation and type of pacemaker are comparable with other European countries
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