bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fecal incontinence after obstetric anal sphincter injuries
Authors: Huebner Markus , Gramlich Nathanja K. , Rothmund Ralf , Nappi Luigi , Abele Harald , Becker Sven 
Published: January 2013

AbstractObjectiveTo determine obstetric variables associated with the long‐term prevalence of flatal and/or fecal incontinence among women who sustained obstetric anal sphincter injuries (OASIS).MethodsIn a retrospective study of women who gave birth between January 1974 and December 1983 at the University Women's Hospital, Tuebingen, Germany, women with OASIS (n = 460) were identified on the basis of chart review. Eligible women were recruited to participate in a telephone interview regarding symptoms and their retrospective preference about elective cesarean delivery.ResultsThe records of 20 999 deliveries, including all modes of delivery, within the 10‐year study period were reviewed, and 99 women who sustained OASIS agreed to participate. The mean follow‐up was 27.5 ± 2.4 years. Among the participants, 39.4% reported fecal or flatal incontinence. Operative vaginal delivery (forceps and/or vacuum) was significantly associated with fecal but not flatal incontinence (odds ratio, 3.27; 95% confidence interval, 1.12–9.56, P = 0.026). Only 9% of women with flatal incontinence and 13% of women with fecal incontinence would have opted retrospectively for cesarean delivery.ConclusionOperative vaginal delivery was significantly associated with fecal but not flatal incontinence. No other obstetric variables tested were associated with the long‐term prevalence of fecal or flatal incontinence.
The early stages of island-arc plagiogranitoid magmatism in Gornaya Shoriya and West Sayan
Authors: Rudnev S.N. , Babin G.A. , Kovach V.P. , Kiseleva V.Yu. , Serov P.A. 
Published: January 2013

Abstract
The structure, composition, and age of Vendian–Early Cambrian plagiogranitoid associations composing the Kshta and Taraskyr massifs of the Yenisei pluton in the Altai–North Sayan island-arc belt are considered. We have established that these associations formed within 550–520 Ma and differ in petrographic composition and sources. Two stages of island-arc plagiogranitoid magmatism are recognized: early (550–540 Ma, formation of plagiogranitoids of the Kshta (545 ± 8 Ma) and Taraskyr (545 ± 7 Ma) massifs) and late (525–520 Ma, formation of plagiogranitoids of the Maina complex of the Yenisei (524 ± 2 Ma) and Tabat plutons). By petrochemical composition and geochemical characteristics, the rocks of the Kshta massif are high-alumina plagiogranitoids similar to adakites. They might have been produced through the melting of metabasites compositionally similar to N-MORB in equilibrium with garnet-containing restite during the subduction of oceanic slab at ≥ 15 kbar. The rocks of the Taraskyr massif are low-alumina plagiogranites. They formed through the melting of metabasites located in the lower layers and(or) the basement of the island-arc system in equilibrium with plagioclase-containing restite at 3–8 kbar. The low-alumina plagiogranitoids of the Yenisei pluton melted out under the same conditions. Isotope-geochemical studies showed that the Vendian–Early Cambrian plagiogranitoids formed at the early stage are characterized by high positive ∑ Nd(T) values (7.5–4.9), Late Riphean model Nd-age (TNd(DM) = 0.64–0.98 Ga), and Sr isotope ratio varying from 0.7040 to 0.7053. These data point to the juvenile parental melts of the rocks and the varying content of ancient crustal material in the magma generation zone.
Neoproterozoic island arcs in East Sayan: duration of magmatism (from U–Pb zircon dating of volcanic clastics)
Authors: Kuzmichev A.B. , Larionov A.N. 
Published: January 2013

Abstract
Two island arcs of different ages have been reconstructed in the Neoproterozoic history of southeastern East Sayan: Dunzhugur and Shishkhid. According to earlier concepts, the Dunzhugur arc formed at ∼1020 Ma and underwent collision with the Siberian(?) continent at ∼810 Ma. The Shishkhid arc formed somewhat earlier than 800 Ma and existed till the end of the Late Baikalian (∼600 Ma, from indirect data). This primitive geologic history, when each arc existed for 200 Myr, was suggested because of the deficit of direct data, and its reconstruction cast doubt. In this work we present results of preliminary dating of detrital zircons separated from the volcaniclastic rocks composing the above arcs. We analyzed 12 zircon crystals from the Dunzhugur volcanic clastics, whose 206Pb/238U age varies from 844 ± 8 to 1048 ± 12 Ma (1σ). Five most ancient zircons form a concordant cluster with an age of 1034 ± 9 Ma (2σ). Hence, the arc formed earlier than it was assumed and existed for a long time, most likely, till its collision with the continent. We also studied two zircon samples from the volcaniclastic rocks of the Oka accretionary prism, which probably formed in the Shishkhid arc. All ten crystals of the first sample form a concordant cluster with an age of 813 ± 7 Ma (2σ). The analyzed zircons of the second sample arrange in two clusters, with an age of 775 ± 8 Ma (2σ, nine crystals) and 819 ± 17 Ma (three crystals). Thus, the Shishkhid arc formed earlier than it was assumed, at the end of the Early Baikalian, and underwent active volcanism at least till 775 Ma. Dating of detrital zircons from the volcaniclastics generated at the mature stage of the Shishkhid-arc evolution will help to reconstruct partly or completely its history in the period 775–600 Ma.
The Late Neoproterozoic rift-related metarhyolite–basalt association of the Glushikha trough (Yenisei Ridge): petrogeochemical composition, age, and formation conditions
Authors: Nozhkin A.D. , Kachevskii L.K. , Dmitrieva N.V. 
Published: January 2013

Abstract
New data are presented on the petrogeochemical composition, age, and formation conditions of the Late Neoproterozoic metarhyolite–basalt association of the Glushikha trough (Yenisei Ridge). The association is localized within the subaerial and shallow-water terrigenous-carbonate sediments of the Orlovka Group, which overlies Proterozoic rocks with unconformity. The felsic volcanics are essentially potassic and enriched in Rb, U, Th, and Fe. They show a weakly fractionated REE pattern with a prominent negative Eu anomaly. The basalts and picrite basalts have higher contents of Ti, Fe, P, HFSE, REE, U, Th, Ba, and Sr, and their spidergrams show no Nb or Ta depletion with respect to Th and LREE. These rocks have the petrochemical parameters of intraplate magmatic associations in continental rift zones. New geochronological data (SHRIMP II) on single zircon grains from the felsite porphyry of the metarhyolite–basalt association (717 ± 15 Ma) indicate Late Neoproterozoic volcanism in the Yenisei part of the Central block of the Trans-Angara region. According to Sm–Nd isotopic data, the rhyolites originate from Paleoproterozoic crust (TNd(DM) = 1757 Ma; TNd(DM-2st) = 1651 Ma; ∑Nd(T) = − 2.7). The Orlovka volcanosedimentary rocks are rift-related, as evidenced by the following facts: (1) localization of the volcanosedimentary rocks in a narrow fault-line trough; (2) bimodal rhyolite-basaltic composition of the volcanics; and (3) petrology and geochemistry of the picrite basalts and basalts, typical of intraplate environments. The studies show that Late Neoproterozoic rifting and intraplate plume magmatism took place not only in the Tatarka–Ishimba fault zone but also in the Yenisei fault zone of the Yenisei Ridge.
Hierarchical properties of the tectonic stress field in the source region of the 2003 Chuya earthquake
Authors: Leskova E.V. , Emanov A.A. 
Published: January 2013

Abstract
Local tectonic stress field have been calculated based on aftershock focal mechanisms using materials of epicentral studies with temporary networks of stations in the epicentral area of the 2003 Chuya earthquake. The originality of this work is that the stress state is studied invoking earthquakes with large differences in energy and using highly accurate data on the location and depth in the analysis of events. The main result is the selection of two hierarchical levels of the stress field. It is shown that the stress state determined from data on large earthquakes is homogeneous (horizontal shear) throughout the aftershock zone, and the stress state determined from data on small events varies according to the block structure of the aftershock region.
Unsteady feeding and optimal strokes of model ciliates
Authors: Michelin Sébastien , Lauga Eric 
Published: January 2013

AbstractThe flow field created by swimming micro-organisms not only enables their locomotion but also leads to advective transport of nutrients. In this paper we address analytically and computationally the link between unsteady feeding and unsteady swimming on a model micro-organism, the spherical squirmer, actuating the fluid in a time-periodic manner. We start by performing asymptotic calculations at low Péclet number ($\mathit{Pe}$) on the advection–diffusion problem for the nutrients. We show that the mean rate of feeding as well as its fluctuations in time depend only on the swimming modes of the squirmer up to order ${\mathit{Pe}}^{3/ 2} $, even when no swimming occurs on average, while the influence of non-swimming modes comes in only at order ${\mathit{Pe}}^{2} $. We also show that generically we expect a phase delay between feeding and swimming of $1/ 8\mathrm{th} $ of a period. Numerical computations for illustrative strokes at finite $\mathit{Pe}$ confirm quantitatively our analytical results linking swimming and feeding. We finally derive, and use, an adjoint-based optimization algorithm to determine the optimal unsteady strokes maximizing feeding rate for a fixed energy budget. The overall optimal feeder is always the optimal steady swimmer. Within the set of time-periodic strokes, the optimal feeding strokes are found to be equivalent to those optimizing periodic swimming for all values of the Péclet number, and correspond to a regularization of the overall steady optimal.
Subcritical bifurcation and bistability in thermoacoustic systems
Authors: Subramanian Priya , Sujith R. I. , Wahi P. 
Published: January 2013

AbstractThis paper analyses subcritical transition to instability, also known as triggering in thermoacoustic systems, with an example of a Rijke tube model with an explicit time delay. Linear stability analysis of the thermoacoustic system is performed to identify parameter values at the onset of linear instability via a Hopf bifurcation. We then use the method of multiple scales to recast the model of a general thermoacoustic system near the Hopf point into the Stuart–Landau equation. From the Stuart–Landau equation, the relation between the nonlinearity in the model and the criticality of the ensuing bifurcation is derived. The specific example of a model for a horizontal Rijke tube is shown to lose stability through a subcritical Hopf bifurcation as a consequence of the nonlinearity in the model for the unsteady heat release rate. Analytical estimates are obtained for the triggering amplitudes close to the critical values of the bifurcation parameter corresponding to loss of linear stability. The unstable limit cycles born from the subcritical Hopf bifurcation undergo a fold bifurcation to become stable and create a region of bistability or hysteresis. Estimates are obtained for the region of bistability by locating the fold points from a fully nonlinear analysis using the method of harmonic balance. These analytical estimates help to identify parameter regions where triggering is possible. Results obtained from analytical methods compare reasonably well with results obtained from both experiments and numerical continuation.
Effect of tilting on turbulent convection: cylindrical samples with aspect ratio
Authors: Weiss Stephan , Ahlers Guenter 
Published: January 2013

AbstractWe report measurements of the properties of turbulent thermal convection of a fluid with a Prandtl number $\mathit{Pr}= 4. 38$ in a cylindrical cell with an aspect ratio $\Gamma = 0. 50$. The rotational symmetry was broken by a small tilt of the sample axis relative to gravity. Measurements of the heat transport (as expressed by the Nusselt number Nu), as well as properties of the large-scale circulation (LSC) obtained from temperature measurements along the sidewall, are presented. In contradistinction to similar experiments using containers of aspect ratio $\Gamma = 1. 00$ (Ahlers et al., J. Fluid Mech., vol. 557, 2006b, pp. 347–367) and $\Gamma = 0. 50$ (Chillà et al., Eur. Phys. J. B, vol. 40, 2004, pp. 223–227; Sun, Xi & Xia, Phys. Rev. Lett., vol. 95, 2005, p. 074502; Roche et al., New J. Phys., vol. 12, 2010, p. 085014), we see a very small increase of the heat transport for tilt angles up to about 0.1 rad. Based on measurements of properties of the LSC we explain this increase by a stabilization of the single-roll state (SRS) of the LSC and a destabilization of the double-roll state (DRS) (it is known from previous work that the SRS has a slightly larger heat transport than the DRS). Quantitative measurements of the strength and the orientation of the LSC show that its azimuthal diffusion is suppressed with increasing tilt whereas the torsional oscillation becomes more pronounced and its frequency increases.
Spatially and temporally resolved measurements of bead resuspension and saltation in a turbulent water channel flow
Authors: van Hout René 
Published: January 2013

AbstractResuspension and saltation of nearly neutrally buoyant polystyrene beads $({d}_{p} = 583\pm 14. 4~\lrm{\ensuremath{\mu}} \mathrm{m} , {\rho }_{p} = 1050~\mathrm{kg} ~{\mathrm{m} }^{\ensuremath{-} 3} )$ in a turbulent boundary layer were studied using time-resolved particle image velocimetry and particle tracking velocimetry in a horizontal water channel facility $({\mathit{Re}}_{h} = 7353)$. The time difference between frames was $ \mrm{\Delta} {t}^{+ } = 0. 297$, comparable to the particle Stokes number, ${ \tau }_{p}^{+ } = 0. 267$. Near-wall coherent structures were visualized using spatial distributions of vorticity and swirling strength in combination with those of the instantaneous ${u}_{1} {u}_{2} $ correlations and ${u}_{1} $. Two case studies, the first on resuspension and the second on saltation, showed that in all cases lift-off coincided with the passage of a vortex core, creating an ejection-sweep cycle (‘burst’) responsible for lift-off. In all cases beads left the wall when immersed in near-wall ejections and exposed to positive shear. As a consequence, a high shear-induced lift force coincided with bead lift-off, while the Magnus force due to bead rotation and translation-induced lift were negligible. The wall-normal component of the drag force mostly opposed lift-off, causing the bead’s deceleration. The difference between resuspension and saltation was governed by the type of coherent flow structures encountered by the beads when lifted out of the viscous sublayer. Resuspension was observed when beads were carried upwards by the combined action of a strong, spatially coherent upstream fast moving $({u}_{1} \gt 0)$ flow structure and a downstream ejection. On the other hand, saltation was accompanied by similar but weaker and spatially less coherent near-wall turbulence structures.
Dynamics and rheology of elastic particles in an extensional flow
Authors: Gao Tong , Hu Howard H. , Ponte Castañeda Pedro 
Published: January 2013

AbstractWe investigate the dynamics and rheology of elastic particles in a viscous extensional flow under Stokes flow conditions by means of the large deformation method developed by Gao, Hu & Ponte Castañeda (J. Fluid Mech., vol. 687, 2011, pp. 209–237). The particles are assumed to be homogeneous, incompressible and neo-Hookean solids. When subjected to extensional flow, an initially ellipsoidal (elliptical) elastic particle stretches and rotates simultaneously, tending to deform into a stable ellipsoidal shape with the initial major axis aligned with the extension direction. However, the steady-state solutions may not exist when the particle stiffness is lower than a certain critical value. By using the solution of a single particle, the macroscopic rheological properties are evaluated for a dilute suspension of elastic particles under extension. Similar to some polymer blends, softer particles lead to a larger extensional viscosity for the suspension.
Minimum power consumption for drag reduction on a circular cylinder by tangential surface motion
Authors: Shukla Ratnesh K. , Arakeri Jaywant H. 
Published: January 2013

AbstractWe investigate the effect of a prescribed tangential velocity on the drag force on a circular cylinder in a spanwise uniform cross flow. Using a combination of theoretical and numerical techniques we make an attempt at determining the optimal tangential velocity profiles which will reduce the drag force acting on the cylindrical body while minimizing the net power consumption characterized through a non-dimensional power loss coefficient (${C}_{\mathit{PL}} $). A striking conclusion of our analysis is that the tangential velocity associated with the potential flow, which completely suppresses the drag force, is not optimal for both small and large, but finite Reynolds number. When inertial effects are negligible ($\mathit{Re}\ll 1$), theoretical analysis based on two-dimensional Oseen equations gives us the optimal tangential velocity profile which leads to energetically efficient drag reduction. Furthermore, in the limit of zero Reynolds number ($\mathit{Re}\ensuremath{\rightarrow} 0$), minimum power loss is achieved for a tangential velocity profile corresponding to a shear-free perfect slip boundary. At finite $\mathit{Re}$, results from numerical simulations indicate that perfect slip is not optimum and a further reduction in drag can be achieved for reduced power consumption. A gradual increase in the strength of a tangential velocity which involves only the first reflectionally symmetric mode leads to a monotonic reduction in drag and eventual thrust production. Simulations reveal the existence of an optimal strength for which the power consumption attains a minima. At a Reynolds number of 100, minimum value of the power loss coefficient (${C}_{\mathit{PL}} = 0. 37$) is obtained when the maximum in tangential surface velocity is about one and a half times the free stream uniform velocity corresponding to a percentage drag reduction of approximately 77 %; ${C}_{\mathit{PL}} = 0. 42$ and $0. 50$ for perfect slip and potential flow cases, respectively. Our results suggest that potential flow tangential velocity enables energetically efficient propulsion at all Reynolds numbers but optimal drag reduction only for $\mathit{Re}\ensuremath{\rightarrow} \infty $. The two-dimensional strategy of reducing drag while minimizing net power consumption is shown to be effective in three dimensions via numerical simulation of flow past an infinite circular cylinder at a Reynolds number of 300. Finally a strategy of reducing drag, suitable for practical implementation and amenable to experimental testing, through piecewise constant tangential velocities distributed along the cylinder periphery is proposed and analysed.
Associations between dietary patterns and demographics, lifestyle, anthropometry and blood pressure in Chinese community-dwelling older men and women
Authors: Chan Ruth , Chan Dicken , Woo Jean 
Published: January 2013

AbstractThis cross-sectional study examined dietary patterns, and the associations of these patterns with demographics, lifestyle, anthropometry and blood pressure in 3707 Chinese people aged 65 years and above taking part in a population-based cohort study investigating the risk factors for osteoporosis. Baseline dietary data were collected using a validated FFQ. Dietary patterns were identified using factor analysis. Scores were calculated for each pattern. Demographics, lifestyle factors and self-reported hypertension history were collected through a questionnaire. BMI, waist circumference (WC), hip circumference (HC), waist-to-hip ratio, systolic blood pressure and diastolic blood pressure (DBP) were measured. Three dietary patterns were identified, namely ‘vegetables–fruit’, ‘snacks–drinks–milk products’ and ‘meat–fish’. Participants who were more physically active, more educated, non-smokers and non-drinkers were more likely to have higher ‘vegetables–fruit’ dietary pattern scores. Current smoking habit and alcohol use were associated with higher ‘snacks–drinks–milk products’ dietary pattern scores and ‘meat–fish’ dietary pattern scores. ‘Vegetables–fruit’ dietary pattern scores were inversely (unstandardised regression coefficient B = −0·60 mmHg, 95 % CI −1·04, −0·16) and ‘snacks–drinks–milk products’ dietary pattern scores were positively (B = 0·50 mmHg, 95 % CI 0·08, 0·92) associated with DBP in men in multiple regressions. Higher ‘meat–fish’ dietary pattern scores were associated with higher BMI (B = 0·19 kg/m2, 95 % CI 0·06, 0·33), waist-to-hip ratio (B = 0·004, 95 % CI 0·002, 0·007) and WC (B = 0·57 cm, 95 % CI 0·18, 0·97) in men, and higher BMI (B = 0·40 kg/m2, 95 % CI 0·22, 0·57), WC (B = 0·87 cm, 95 % CI 0·39, 1·36) and HC (B = 0·61 cm, 95 % CI 0·26, 0·96) in women in multiple regressions. The influence of demographic and lifestyle characteristics on dietary patterns and the health risks associated with dietary patterns provides insights for the provision of tangible dietary advice to this population.
Spirulina can increase total-body vitamin A stores of Chinese school-age children as determined by a paired isotope dilution technique
Authors: Li Lei , Zhao Xianfeng , Wang Jie , Muzhingi Tawanda , Suter Paolo M. , Tang Guangwen , Yin Shi-an 
Published: January 2013

AbstractSpirulina is an alga rich in high-quality protein and carotenoids. It is unclear whether spirulina can improve the total-body vitamin A stores of school-age children in China with a high prevalence of vitamin A malnutrition. We aimed to evaluate the efficacy of spirulina in improving the total-body vitamin A stores of school-age children in rural areas of China when they consumed spirulina in their daily meals. A total of 228 children (6–11 years) were recruited and randomly divided into three groups supplemented with 4 g (containing 4·18 µg β-carotene), 2 g (containing 2·54 µg β-carotene) or 0 g spirulina 5 d/week for 10 weeks, respectively. Before and after the intervention period, each child was given 0·5 mg [2H4]retinyl acetate and [2H8]retinyl acetate, respectively. To assess vitamin A stores, blood samples (3 ml) were collected on the third and the twenty-first day after each labelled retinyl acetate dose for a retinol enrichment analysis using a GC mass spectrometer. The concentrations of retinol and β-carotene in serum samples were also determined by using HPLC. After the 10-week intervention, serum β-carotene concentrations of children with 2 or 4 g spirulina supplement increased by 0·160 and 0·389 µmmol/l, respectively. Total-body vitamin A stores increased significantly, with a median increase of 0·160 mmol in children taking 2 g spirulina and of 0·279 mmol in children taking 4 g spirulina. Spirulina is a good dietary source of β-carotene, which may effectively increase the total-body vitamin A stores of Chinese school-age children.