First-order formalism for dark energy and dust

This work deals with first-order formalism for dark energy and dust in standard cosmology, for models described by real scalar field in the presence of dust in spatially flat space. The field dynamics may be standard or tachyonic, and we show how the equations of motion can be solved by first-order differential equations. We investigate a model to illustrate how the dustlike matter may affect the cosmic evolution using this framework.Comment: 5 pages, 1 figure; title changed, new author included, discussions extended, references added, version to appear in EPJ

Integrating sequence and array data to create an improved 1000 Genomes Project haplotype reference panel

A major use of the 1000 Genomes Project (1000GP) data is genotype imputation in genome-wide association studies (GWAS). Here we develop a method to estimate haplotypes from low-coverage sequencing data that can take advantage of single-nucleotide polymorphism (SNP) microarray genotypes on the same samples. First the SNP array data are phased to build a backbone (or 'scaffold') of haplotypes across each chromosome. We then phase the sequence data 'onto' this haplotype scaffold. This approach can take advantage of relatedness between sequenced and non-sequenced samples to improve accuracy. We use this method to create a new 1000GP haplotype reference set for use by the human genetic community. Using a set of validation genotypes at SNP and bi-allelic indels we show that these haplotypes have lower genotype discordance and improved imputation performance into downstream GWAS samples, especially at low-frequency variants. © 2014 Macmillan Publishers Limited. All rights reserved

Variation in monitoring and treatment policies for intracranial hypertension in traumatic brain injury: A survey in 66 neurotrauma centers participating in the CENTER-TBI

Background: No definitive evidence exists on how intracranial hypertension should be treated in patients with traumatic brain injury (TBI). It is therefore likely that centers and practitioners individually balance potential benefits and risks of different intracranial pressure (ICP) management strategies, resulting in practice variation. The aim of this study was to examine variation in monitoring and treatment policies for intracranial hypertension in patients with TBI. Methods: A 29-item survey on ICP monitoring and treatment was developed based on literature and expert opinion, and pilot-tested in 16 centers. The questionnaire was sent to 68 neurotrauma centers participating in the Collaborative European Neurotrauma Effectiveness Research (CENTER-TBI) study. Results: The survey was completed by 66 centers (97% response rate). Centers were mainly academic hospitals (n = 60, 91%) and designated level I trauma centers (n = 44, 67%). The Brain Trauma Foundation guidelines were used in 49 (74%) centers. Approximately ninety percent of the participants (n = 58) indicated placing an ICP monitor in patients with severe TBI and computed tomography abnormalities. There was no consensus on other indications or on peri-insertion precautions. We found wide variation in the use of first- and second-tier treatments for elevated ICP. Approximately half of the centers were classified as having a relatively aggressive approach to ICP monitoring and treatment (n = 32, 48%), whereas the others were considered more conservative (n = 34, 52%). Conclusions: Substantial variation was found regarding monitoring and treatment policies in patients with traumatic brain injury and intracranial hypertension. The results of this survey indicate a lack of consensus between European neurotrauma centers and provide an opportunity and necessity for comparative effectiveness research

Effects of magnetic anisotropy and exchange in TmFe17

Neutron diffraction experiments have been carried out to study the magnetocrystalline anisotropy of two 2b and 2d Tm sublattices and four 4f, 6g, 12j, and 12k Fe sublattices in ferrimagnetic compound Tm2Fe17 space group P63 mmc . We have determined the temperature dependence of the magnitude and orientation of magnetization for each of the thulium and iron sublattices in the range 10 300 K. A spontaneous rotation at about 90 K of the Tm and Fe sublattice magnetizations from the c axis to the basal plane is accompanied by a drastic change in the magnetization magnitude, signifying a large magnetization anisotropy. Both Tm sublattices exhibit an easy axis type of the magnetocrystalline anisotropy. The Fe sublattices manifest both the uniaxial and planar anisotropy types. The sublattice formed by Fe atoms at the 4f position reveals the largest planar anisotropy constant. The Fe atoms at the 12j position show a uniaxial anisotropy. We find that the inelastic neutron scattering spectra measured below and above the spin reorientation transition are remarkably differen

Laserinduzierte Fertigungsverfahren - Abtragen mit Laserphotonen, Praezisionsbearbeitung von Glas und duennen Schichten mit Laserstrahlung. Teilvorhaben: Ersatz teurer kristalliner Substrate durch laserstrukturierte kostenguenstige Glaeser Abschlussbericht

SIGLEAvailable from TIB Hannover: F01B269+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

PROBE. Grundlagen der praezisen, optischen Behandlung von Festkoerpern. Teilvorhaben: Grundlagenuntersuchungen zur Materialstrukturierung und -modifizierung mit ultrakurzen Laserimpulsen Endbericht

Main goal of our study ws a better understanding on laser-induced micro-machining of brittle substances that are difficult to process mechanically, such as the technically very interesting transparent dielectric materials (e.g. SiO_2, CaF_2, Al_2O_3, etc.). Quality, topography and morphology of the processed area and ablation rate were analysed in respect to the different optical parameters (pulse width, energy, number of shots, wavelength, etc.) that were varied in our study. One important part of our investigation was the determination of the (surface) damage threshold at different pulse widths and short numbers. We obtained first time results of the shape of bulk modifications through self-focusing of ultra-short laser pulses at different pulse widths, pulse energies and number of shots. We demonstrated the feasibility to utilise this technique for a controlled three dimensional micro-structuring in the bulk, without altering the surfaces. On the basis of Molecular Dynamis (MD) simulation we were able to present theoretical results on the ablation process on an atomic scale in sub-ps time resolution for the first time. As target material we have chosen crystalline silicon for the theoretical modelling of the ablation with ultra-short pulses. To investigate the dynamics of the ablation we successfully introduced a pump-probe-technique monitoring the changes of the scattered light.The experimental results were compared with the theoretical model using the MD simulation. (orig.)SIGLEAvailable from TIB Hannover: F98B1780+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman