bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interaktion Gleis/Brücke bei Stahlbrücken mit Beispielen
Authors: Freystein Hartmut , Geißler Karsten 
Published: February 2013

AbstractDie Interaktion Gleis/Brücke bestimmt maßgeblich Konstruktion und Bemessung von Eisenbahnbrücken. Das geltende Bahnregelwerk enthält Regelungen zur Begrenzung der Schienenspannungen und für die Anwendung eines vereinfachten Nachweisverfahrens. Dieses darf nur für spezifische konstruktive Randbedingungen und Anforderungen an den Oberbau angewendet werden. So ist zur Zeit offen, inwieweit das vereinfachte Verfahren für die häufig im Bahnnetz vorkommenden Schienen 54 E4 und leichteren Schwellenarten übertragbar ist. In einem ersten Schritt werden Erkenntnisse aus den Untersuchungen zu den zulässigen zusätzlichen Schienenspannungen beleuchtet. In einem weiteren Schritt werden die Ergebnisse von Berechnungen an ausgeführten Stahlbrücken im Stützweitenbereich zwischen 70 und 104 m vorgestellt und ein Ausblick für die Fortschreibung des bahntechnischen Regelwerks für die Schienenspannungen und den Anwendungsbereich des vereinfachten Nachweisverfahrens gegeben.Construction and calculation of railway bridges are significantly determined by the interaction track/bridge. The actual regulations contain specifications to limit the rail stresses and the scope of the simplified calculation method. This method can only be used for specific conditions of bridge and track. Thus it is not determined to which extend the simplified calculation method is transferable to rail 54 E4 and lighter sleepers which are frequently used on main lines. At a first step the studies concerning the permissible additional rail stresses are examined. Furthermore the article gives an overview to the results of calculations of executed steel bridges with lengths from 70 to 104m and a prospect to the future update of the regulations concerning the rail stresses and the scope of the simplified calculation method due to interaction rail/bridge.
Comparison between ultrasound parameters and clinical examination to assess fetal head station in labor
Authors: Tutschek B. , Torkildsen E. A. , Eggebø T. M. 
Published: February 2013

ABSTRACTObjectiveSeveral ultrasound parameters, including intrapartum transperineal ultrasound (ITU) head station, angle of progression (AOP), head–perineum distance (HPD) and head‐symphysis distance (HSD), have been suggested to assess fetal head station during labor. The aim of this study was to analyze the relationship between these ultrasound parameters and to compare them with digital palpation.MethodsWe analyzed 106 stored volume dataset pairs that had been acquired at Stavanger University Hospital, Norway, from nulliparous women at term with prolonged first stage of labor. The volumes were acquired using a three‐dimensional transducer applied between the labia majora in a mid‐sagittal plane and perineally in a transverse plane. Digitally palpated head station and cervical dilatation were also noted. The results were compared using regression and correlation coefficients.ResultsThere were good correlations between ITU head station and HPD (r = 0.71), between ITU head station and HSD (r = 0.74) and between HSD and HPD (r = 0.75). Palpated head station showed only moderate correlation with ITU head station (r = 0.52). Cervical dilatation showed a weak correlation with ITU head station (r = 0.30).ConclusionThe ultrasound parameters showed a high degree of correlation with each other, but only moderate correlation to vaginally palpated fetal head station. Copyright © 2013 ISUOG. Published by John Wiley & Sons, Ltd.
Inter‐rater reliability of assessment of levator ani muscle strength and attachment to the pubic bone in nulliparous women
Authors: van Delft K. , Schwertner‐Tiepelmann N. , Thakar R. , Sultan A. H. 
Published: February 2013

ABSTRACTObjectivesThe modified Oxford scale (MOS) has been found previously to have poor inter‐rater reliability, whereas digital assessment of levator ani muscle (LAM) attachment to the pubic bone has been shown to have acceptable reliability. Our aim was to evaluate inter‐rater reliability of the validated MOS and to develop a reliable classification system for digital assessment of LAM attachment, correlating this to findings on transperineal ultrasound (TPUS) examination.MethodsEvaluation of the MOS by palpation was performed in nulliparous women by two investigators. LAM attachment was evaluated using digital palpation, for which a novel classification system was developed with four grades based on the position of the attachment and presence of discernible muscle. Findings were compared with those on TPUS examination. Inter‐rater reliability was assessed using Cohen's kappa statistic.ResultsTwenty‐five nulliparous women were examined. There was agreement in MOS scores between the investigators in 64% of women (n = 16), with a kappa of 0.66 (indicating substantial agreement). There was agreement in palpation of LAM attachment using the new grading system in 96% of women (n = 24), with a kappa of 0.90 (indicating almost perfect agreement). TPUS examination did not show LAM avulsion in any woman, with the exception of one with a partial avulsion.ConclusionIn this group of nulliparous patients, there was substantial agreement between the two investigators in evaluation of the MOS and there was good agreement between grades of LAM attachment using the new classification system, which correlated with findings on TPUS examination. It therefore appears that these results are reproducible in nulliparous women and the techniques can be readily learned and reliably incorporated into clinical practice and research after appropriate training. Further research is required to establish clinical utility of the grading system for LAM attachment in postpartum women and in women with symptomatic pelvic organ prolapse. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd.
Set2 mediated H3 lysine 36 methylation: regulation of transcription elongation and implications in organismal development
Authors: Venkatesh Swaminathan , Workman Jerry L. 
Published: February 2013

AbstractSet2 is a RNA polymerase II (RNAPII) associated histone methyltransferase involved in the cotranscriptional methylation of the H3 K36 residue (H3K36me). It is responsible for multiple degrees of methylation (mono‐, di‐, and trimethylation), each of which has a distinct functional consequence. The extent of methylation and its genomic distribution is determined by different factors that coordinate to achieve a functional outcome. In yeast, the Set2‐mediated H3K36me is involved in suppressing histone exchange, preventing hyperacetylation and promoting maintenance of well‐spaced chromatin structure over the coding regions. In metazoans, separation of this enzymatic activity affords greater functional diversity extending beyond the control of transcription elongation to developmental gene regulation. This review focuses on the molecular aspects of the Set2 distribution and function, and discusses the role played by H3 K36 methyl mark in organismal development. WIREs Dev Biol 2013, 2:685–700. doi: 10.1002/wdev.109This article is categorized under:

Gene Expression and Transcriptional Hierarchies > Regulatory Mechanisms
Gene Expression and Transcriptional Hierarchies > Gene Networks and Genomics
Gene Expression and Transcriptional Hierarchies > Cellular Differentiation
The GA‐minor submotif as a case study of RNA modularity, prediction, and design
Authors: Grabow Wade W. , Zhuang Zhuoyun , Shea Joan‐Emma , Jaeger Luc 
Published: February 2013

AbstractComplex natural RNAs such as the ribosome, group I and group II introns, and RNase P exemplify the fact that three‐dimensional (3D) RNA structures are highly modular and hierarchical in nature. Tertiary RNA folding typically takes advantage of a rather limited set of recurrent structural motifs that are responsible for controlling bends or stacks between adjacent helices. Herein, the GA minor and related structural motifs are presented as a case study to highlight several structural and folding principles, to gain further insight into the structural evolution of naturally occurring RNAs, as well as to assist the rational design of artificial RNAs. WIREs RNA 2013, 4:181–203. doi: 10.1002/wrna.1153This article is categorized under:

RNA Structure and Dynamics > RNA Structure, Dynamics, and Chemistry
RNA Evolution and Genomics > RNA and Ribonucleoprotein Evolution
Children, Kitchen, Church: does ethnicity matter?
Authors: Zaiceva Anzelika , Zimmermann Klaus F. 
Published: February 2013

Abstract
Ethnic differences in the allocation of non-market time are important, as they may shed more light on the integration level of ethnic minorities and on the factors that affect both household productivity and ethnic identity. In this paper we examine the role of ethnicity and gender by analyzing differences in the time spent on a range of activities employing the 2000 UK Time Use Survey. Based on the economics of religion and identity economic models, we hypothesize that if ethnic minority women have lower opportunity costs of time and a strong ‘ethnic’ or ‘traditionally female’ identity, they will engage more in ‘traditional’ home activities. Double-hurdle regression results indicate that while the effect for childcare is not significant when estimated for parents only, non-white women spend significantly more time on food management and particularly religious activities than white women, with the greatest effect of the latter being for Pakistani and Bangladeshi women.
Identifying gender‐specific developmental trajectories of nonviolent and violent delinquency from adolescence to young adulthood
Authors: Zheng Yao , Cleveland H. Harrington 
Published: February 2013

ABSTRACTMost research examining gender differences in developmental trajectories of antisocial behavior does not consider subtypes of antisocial behavior and is difficult to generalize due to small non‐representative samples. The current study investigated gender difference in developmental trajectories from adolescence to young adulthood while addressing those limitations. Analyses were limited to respondents ages 15 and 16 in wave 1 (16–17 in wave 2, and 21–22 in wave 3) of the National Longitudinal Study of Adolescent Health (n = 6244, 49.5% males). Self‐report nonviolent and violent delinquencies were simultaneously entered into latent class analysis. Four latent classes were identified: low, desister, decliner, and chronic (male‐only). In addition to finding a male‐specific chronic class, gender differences included differences in levels of nonviolent and violent delinquency between synonymous classes of males and females, and differences in prevalence of classes across genders. Neighborhood disadvantage and family support predicted trajectories.
Does social support protect against depression & psychological distress? Findings from the RELACHS study of East London adolescents
Authors: Khatib Yasmin , Bhui Kamaldeep , Stansfeld Stephen A. 
Published: February 2013

ABSTRACTFew prospective studies have examined the relationship between social support and psychological distress and depressive symptoms in adolescents. The aims of this study were to test whether social support is protective against psychological distress and depressive symptoms in an ethnically diverse population of adolescents and whether differences in support are reflected by ethnic differences in psychological distress and depressive symptoms. Based on a longitudinal survey of 821 adolescents, this study found low levels of social support from family members was prospectively associated with depressive symptoms (OR = 2.25, 95% CI 1.43–3.54). Compared with White UK pupils, Black pupils were less likely to display psychological distress (OR = 0.21, 95% CI 0.09–0.51). However, social support did not explain the ethnic variations in psychological distress. Family environment may be a more consistent source of support compared with support from peers. The lower risk of psychological distress among Black pupils compared to White pupils requires further investigation.
Protein phosphatases regulate the growth of developing neurites
Authors: Monroe Jerry D. , Heathcote R. David 
Published: February 2013

AbstractThe mechanisms underlying morphogenesis of axons and dendrites are critical for understanding both the structure and function of the nervous system. Since a number of kinases have a well‐known effect on neurite outgrowth, we tested the hypothesis that specific phosphatases can also play a role in neurite extension and branching. Both protein phosphatase 1 (PP1) and 2A (PP2A) are present in growing processes and can regulate neuronal outgrowth. Loss‐, gain‐ and recovery‐of‐function analyses in cultured hippocampal neurons tested the role of PP1 and PP2A in neurite growth. siRNA partially knocked down specific phosphatase isoforms and showed that reducing PP2A increased neurite length. Broad spectrum pharmacologic inhibition of PP1 caused the opposite effect from RNAi of specific phosphatases, indicating that two phosphatase pathways likely affect neurite morphogenesis. Over‐expression of PP2A resulted in shorter neurites and decreased dendritic branching. Rescue analysis showed that PP2A homologs could restore the longer neurites caused by RNAi, to their normal size, indicating that both reagents target the same pathway. Thus, the well‐known effects of specific kinases can be countered by the activity of phosphatases at different times and locations in the growing neurite. By working together, kinases and phosphatases can play a dynamic role in regulating neurite extension during development.
Managing Psychosocial Contributors in Low Back Pain Patients—A Randomised Controlled Trial
Authors: Angela Lee Wing-Yan , Edwin Lee Wai-Chi , Sheung-Wai Law , Anthony Lau Wing-Keung , Siu-Man Leung , Koon-Man Sieh , Stephanie Luk Fung-Yin , Rainbow Law Ka-Yee 
Published: February 2013

Introduction The efficacy of integrated physiotherapy work rehabilitation program to occupational nonspecific low back pain (NSLBP) patients triaged by Orebro Musculoskeletal Pain Questionnaire (OMPQ) for psychosocial risks was investigated. Methods 47 subjects were recruited and randomly allocated to either the integrated physiotherapy group or the conventional group. Red flags signs were screened out. The range of the age of the patients was between 18 and 55. They either had history injuries at work or were on sick leave upon recruitment with moderate psychosocial risk. Results Statistics was performed on an intention-to-treat analysis. At discharge, the patients of integrated physiotherapy group displayed significant improvement of work recovery expectation, pain self-efficacy, overall subjective progress and satisfaction in comparison with the conventional group ( p < 0.05). Both groups demonstrated significant improvement of all outcome measures except the recovery expectation showed no difference in the conventional group. Conclusion The work related treatment components of integrated physiotherapy group adopted a cognitive behavioral approach may contribute to better improvement.
Höhere Qualität und Effizienz: Kooperation von Ärzten und Pflegeheimen im Kinzigtal
Authors: Konnegen Dirk , Roth Monika , Deschler Thomas , Boschert Silke 
Published: February 2013

Einleitung
Pflegeheime, Ärzte und Physiotherapeuten schaffen es, im Versorgungsumfeld Gesundes Kinzigtal die Qualität der Versorgung zu steigern und gleichzeitig in der Relation zu den deutschlandtypischen Ausgaben die Mehrkosten für pflegebedürftige Heimbewohner deutlich zu senken und die erzielte Gesundheitseffizienz zu erhöhen. Die Klinikeinweisungen wurden deutlich gesenkt, verminderte Psycholeptika Verordnungen für Demenzerkrankte sind nachgewiesen. Die Autoren beschreiben die Erfolge und gehen auch auf die Aufwände ein, die notwendig sind, um diesen Erfolg zu erzielen.
Mean ergodic theorems on norming dual pairs
Authors: GERLACH MORITZ , KUNZE MARKUS 
Published: February 2013

AbstractWe extend the classical mean ergodic theorem to the setting of norming dual pairs. It turns out that, in general, not all equivalences from the Banach space setting remain valid in our situation. However, for Markovian semigroups on the norming dual pair $({C}_{b} (E), \mathscr{M} (E))$ all classical equivalences hold true under an additional assumption which is slightly weaker than the e-property.
Singular behaviour of a rarefied gas on a planar boundary
Authors: Takata Shigeru , Funagane Hitoshi 
Published: February 2013

AbstractSingular behaviour of a rarefied gas on a planar boundary is clarified on the basis of the Boltzmann equation. The thermal transpiration between two parallel plates is taken as a specific example. First, the flow velocity is shown to behave like$x\ln x$in the vicinity of the boundary, where$x$is a distance from the boundary. This implies a logarithmic divergence of the flow velocity gradient as$x\rightarrow 0$. Then, such a spatial singularity is shown to induce a similar singularity of the velocity distribution function (VDF) with respect to${\zeta }_{n} $on the boundary, where${\zeta }_{n} $is a normal component of the molecular velocity to the boundary. Moreover, the spatial singularity is shown to be quantitatively related to the discontinuity of the VDF on the boundary at${\zeta }_{n} = 0$. These macroscopic and microscopic singularities should be observed generally in a rarefied gas on a planar boundary.
Transient perturbation growth in time-dependent mixing layers
Authors: Arratia C. , Caulfield C. P. , Chomaz J.-M. 
Published: February 2013

AbstractWe investigate numerically the transient linear growth of three-dimensional (3D) perturbations in a homogeneous time-evolving mixing layer in order to identify which perturbations are optimal in terms of their kinetic energy gain over a finite, predetermined time interval. We model the mixing layer with an initial parallel velocity distribution $\mathbi{U}(y)= {U}_{0} \tanh (y/ d)\mathbi{e}_{x}$ with Reynolds number $Re= {U}_{0} d/ \nu = 1000$, where $\nu $ is the kinematic viscosity of the fluid. We consider a range of time intervals on both a constant ‘frozen’ base flow and a time-dependent two-dimensional (2D) flow associated with the growth and nonlinear saturation of two wavelengths of the most-unstable eigenmode of linear theory of the initial parallel velocity distribution, which rolls up into two classical Rayleigh instabilities commonly referred to as Kelvin–Helmholtz (KH) billows, which eventually pair to form a larger vortex. For short times, the most-amplified perturbations on the frozen $\tanh $ profile are inherently 3D, and are most appropriately described as oblique wave ‘OL’ perturbations which grow through a combination of the Orr and lift-up mechanisms, while for longer times, the optimal perturbations are 2D and similar to the KH normal mode, with a slight enhancement of gain. For the time-evolving KH base flow, OL perturbations continue to dominate over sufficiently short time intervals. However, for longer time intervals which involve substantial evolution of the primary KH billows, two broad classes of inherently 3D linear optimal perturbation arise, associated at low wavenumbers with the well-known core-centred elliptical translative instability, and at higher wavenumbers with the braid-centred hyperbolic instability. The hyperbolic perturbation is relatively inefficient in exploiting the gain of the OL perturbations, and so only dominates the smaller wavenumber (ultimately) core-centred perturbations when the time evolution of the base flow or the start time of the optimization interval does not allow the OL perturbations much opportunity to grow. When the OL perturbations can grow, they initially grow in the braid, and then trigger an elliptical core-centred perturbation by a strong coupling with the primary KH billow. If the optimization time interval includes pairing of the primary billows, the secondary elliptical perturbations are strongly suppressed during the pairing event, due to the significant disruption of the primary billow cores during pairing.
Disintegrating supercritical jets in a subcritical environment
Authors: Roy Arnab , Joly Clement , Segal Corin 
Published: February 2013

AbstractSupercritical fluid injection using a single round injector into a quiescent atmosphere at subcritical and supercritical conditions was studied experimentally with particular attention paid to supercritical-into-subcritical injection and the reassertion of surface tension. The entire system was binary since the surrounding atmosphere consisted of an inert gas of a different composition than that of the injected fluid. Average densities and density gradients were quantified and a method was applied to quantify the resulting drop formation due to the disintegration of the jet based on the experimental conditions. The evolution of drop size with distance from the injector was identified.
Dynamics of particle settling and resuspension in viscous liquid films
Authors: Murisic N. , Pausader B. , Peschka D. , Bertozzi A. L. 
Published: February 2013

AbstractWe develop a dynamic model for suspensions of negatively buoyant particles on an incline. Our model includes settling due to gravity and resuspension of particles by shear-induced migration. We consider the case where the particles settle onto the solid substrate and two distinct fronts form: a faster liquid and a slower particle front. The resulting transport equations for the liquid and the particles are of hyperbolic type and we study the dilute limit for which we compute exact solutions. We also carry out systematic laboratory experiments, focusing on the motion of the two fronts. We show that the dynamic model predictions for small to moderate values of the particle volume fraction and the inclination angle of the solid substrate agree well with the experimental data.
Capillary breakup of a liquid torus
Authors: Mehrabian Hadi , Feng James J. 
Published: February 2013

AbstractCapillary instability of a Newtonian liquid torus suspended in an immiscible Newtonian medium is computed using a Cahn–Hilliard diffuse-interface model. The main differences between the torus and a straight thread are the presence of an axial curvature and an external flow field caused by the retraction of the torus. We show that the capillary wave initially grows linearly as on a straight thread. The axial curvature decreases the growth rate of the capillary waves while the external flow enhances it. Breakup depends on the competition of two time scales: one for torus retraction and the other for neck pinch-off. The outcome is determined by the initial amplitude of the disturbance, the thickness of the torus relative to its circumference, and the torus-to-medium viscosity ratio. The linearly dominant mode may not persist till nonlinear growth and breakup. The numerical results are generally consistent with experimental observations.
Reynolds- and Mach-number effects in canonical shock–turbulence interaction
Authors: Larsson Johan , Bermejo-Moreno Ivan , Lele Sanjiva K. 
Published: February 2013

AbstractThe interaction between isotropic turbulence and a normal shock wave is investigated through a series of direct numerical simulations at different Reynolds numbers and mean and turbulent Mach numbers. The computed data are compared to experiments and linear theory, showing that the amplification of turbulence kinetic energy across a shock wave is described well using linearized dynamics. The post-shock anisotropy of the turbulence, however, is qualitatively different from that predicted by linear analysis. The jumps in mean density and pressure are lower than the non-turbulent Rankine–Hugoniot results by a factor of the square of the turbulence intensity. It is shown that the dissipative scales of turbulence return to isotropy within about 10 convected Kolmogorov time scales, a distance that becomes very small at high Reynolds numbers. Special attention is paid to the ‘broken shock’ regime of intense turbulence, where the shock can be locally replaced by smooth compressions. Grid convergence of the probability density function of the shock jumps proves that this effect is physical, and not an artefact of the numerical scheme.