bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bayesian Probabilistic Projections of Life Expectancy for All Countries
Authors: Raftery Adrian E. , Chunn Jennifer L. , Gerland Patrick , Ševčíková Hana 
Published: March 2013

AbstractWe propose a Bayesian hierarchical model for producing probabilistic forecasts of male period life expectancy at birth for all the countries of the world to 2100. Such forecasts would be an input to the production of probabilistic population projections for all countries, which is currently being considered by the United Nations. To evaluate the method, we conducted an out-of-sample cross-validation experiment, fitting the model to the data from 1950–1995 and using the estimated model to forecast for the subsequent 10 years. The 10-year predictions had a mean absolute error of about 1 year, about 40 % less than the current UN methodology. The probabilistic forecasts were calibrated in the sense that, for example, the 80 % prediction intervals contained the truth about 80 % of the time. We illustrate our method with results from Madagascar (a typical country with steadily improving life expectancy), Latvia (a country that has had a mortality crisis), and Japan (a leading country). We also show aggregated results for South Asia, a region with eight countries. Free, publicly available R software packages called bayesLife and bayesDem are available to implement the method.
Developmental regulation of neuronal genes by DNA methylation: Environmental influences
Authors: Wilson Melinda E. , Sengoku Tomoko 
Published: March 2013

AbstractSteroid hormones have wide‐ranging organizational, activational and protective actions in the brain. In particular, the organizational effects of early exposure to 17β‐estradiol (E2) and glucocorticoids are essential for long‐lasting behavioral and cognitive functions. Both steroid hormones mediate many of their actions through intracellular receptors that act as transcription factors. In the rodent cerebral cortex, estrogen receptor mRNA and protein expression are high early in postnatal life and declines dramatically as the animal approaches puberty. An understanding of the molecular mechanisms driving this developmental regulation of gene expression is critical for understanding the complex events that determine lasting brain physiology and prime the plasticity of neurons. Gene expression can be suppressed by the epigenetic modification of the promoter regions by DNA methylation that results in gene silencing. Indeed, the decrease in ERα mRNA expression in the cortex during development is accompanied by an increase in promoter methylation. Numerous environmental stimuli can alter the DNA methylation that occurs for ERα, glucocorticoid receptors, as well as many other critical genes involved in neuronal development. For example, maternal behavior toward pups can alter epigenetic regulation of ERα mRNA expression. Additionally perinatal stress and exposure to environmental estrogens can also have lasting effects on gene expression by modifying DNA methylation of these important genes. Taken together, there appears to be a critical window during development where, outside factors that alter epigenetic programming can have lasting effects on neuronal gene expression.
4D ultrasound evaluation of fetal facial expressions during the latter stages of the second trimester
Authors: Kanenishi Kenji , Hanaoka Uiko , Noguchi Junko , Marumo Genzo , Hata Toshiyuki 
Published: March 2013

AbstractObjectiveTo assess the frequency of fetal facial expressions at 25–27 weeks of gestation using 4D ultrasound.MethodsTwenty‐four normal fetuses were examined using 4D ultrasound. The face of each fetus was recorded continuously for 15 minutes. The frequencies of tongue expulsion, yawning, sucking, mouthing, blinking, scowling, and smiling were assessed and compared with those observed at 28–34 weeks of gestation in a previous study.ResultsMouthing was the most common facial expression at 25–27 weeks of gestation; the frequency of mouthing was significantly higher than that of the other 6 facial expressions (P < 0.05). Yawning was significantly more frequent than the other facial expressions, apart from mouthing (P < 0.05). The frequencies of yawning, smiling, tongue expulsion, sucking, and blinking differed significantly between 25–27 and 28–34 weeks (P < 0.05).ConclusionThe results indicate that facial expressions can be used as an indicator of normal fetal neurologic development from the second to the third trimester. 4D ultrasound may be a valuable tool for assessing fetal neurobehavioral development during gestation.
Is gold the best hedge and a safe haven under changing stock market volatility?
Authors: Hood Matthew , Malik Farooq 
Published: March 2013

AbstractWe evaluate the role of gold and other precious metals relative to volatility (Volatility Index (VIX)) as a hedge (negatively correlated with stocks) and safe haven (negatively correlated with stocks in extreme stock market declines) using data from the US stock market. Using daily data from November 1995 to November 2010, we find that gold, unlike other precious metals, serves as a hedge and a weak safe haven for US stock market. However, we find that VIX serves as a very strong hedge and a strong safe haven during our sample period. We also find that in periods of extremely low or high volatility, gold does not have a negative correlation with the US stock market. Our results show that VIX is a superior hedging tool and serves as a better safe haven than gold during our sample period. We highlight the practical significance of our results for financial market participants by conducting a portfolio analysis.
Thickness of the Earth’s crust in the deep Arctic Ocean: results of a 3D gravity modeling
Authors: Glebovsky V.Yu. , Astafurova E.G. , Chernykh A.A. , Korneva M.A. , Kaminsky V.D. , Poselov V.A. 
Published: March 2013

Abstract
The employed method of 3D gravity modeling is based on calculation of the gravity effects of the main density boundaries of the lithosphere, subtraction of these effects from the observed gravity field, and the subsequent conversion of the residual gravity anomalies first to the Moho depth and then to the total thickness of the Earth’s crust and the thickness of its consolidated part. On the modeling, we also took into account the gravity effects due to an increase in the sediment density with increasing sediment depth and a rise of the top of the asthenosphere beneath the mid-ocean Gakkel Ridge. The resulting 3D models of the Moho topography and crustal thickness are well consistent with the data of deep seismic investigations. They confirm the significant differences in crustal structure between the Eurasian and Amerasian Basins and give an idea of the regional variations in crustal thickness beneath the major ridges and basins of the Arctic Ocean.
Paleoproterozoic granitoids of the Chuya and Kutima complexes (southern Siberian craton): age, petrogenesis, and geodynamic setting
Authors: Donskaya T.V. , Gladkochub D.P. , Mazukabzov A.M. , Presnyakov S.L. , Bayanova T.B. 
Published: March 2013

Abstract
Detailed geochemical, isotope, and geochronological studies were carried out for the granitoids of the Chuya and Kutima complexes in the Baikal marginal salient of the Siberian craton basement. The obtained results indicate that the granitoids of both complexes are confined to the same tectonic structure (Akitkan fold belt) and are of similar absolute age. U–Pb zircon dating of the Kutima granites yielded an age of 2019 ± 16 Ma, which nearly coincides with the age of 2020 ± 12 Ma obtained earlier for the granitoids of the Chuya complex. Despite the close ages, the granitoids of these complexes differ considerably in geochemical characteristics. The granitoids of the Chuya complex correspond in composition to calcic and calc-alkalic peraluminous trondhjemites, and the granites of the Kutima complex, to calc-alkalic and alkali-calcic peraluminous granites. The granites of the Chuya complex are similar to rocks of the tonalite–trondhjemite–granodiorite (TTG) series and are close in CaO, Sr, and Ba contents to I-type granites. The granites of the Kutima complex are similar in contents of major oxides to oxidized A-type granites. Study of the Nd isotope composition of the Chuya and Kutima granitoids showed their close positive values of εNd(T) (+ 1.9 to + 3.5), which indicates that both rocks formed from sources with a short crustal history. Based on petrogeochemical data, it has been established that the Chuya granitoids might have been formed through the melting of a metabasitic source, whereas the Kutima granites, through the melting of a crustal source of quartz–feldspathic composition. Estimation of the PT-conditions of granitoid melt crystallization shows that the Chuya granitoids formed at 735–776 °C (zircon saturation temperature) and &gt; 10 kbar and the Kutima granites, at 819–920 °C and &gt; 10 kbar. It is assumed that the granitoids of both complexes formed in thickened continental crust within an accretionary orogen.
Solving unsolvable problems in stratigraphy (Comments to the paper “New data on the magnetostratigraphy of the Jurassic–Cretaceous boundary interval, Nordvik Peninsula (northern East Siberia)” by V.Yu. Bragin, O.S. Dzyuba, A.Yu. Kazansky, and B.N. Shurygin)
Authors: Guzhikov A.Yu. 
Published: March 2013

Abstract
In this study we analyze the importance of new magnetostratigraphic data on the Nordvik section for solving the problem of detailed Tethyan–Boreal correlation around the Jurassic–Cretaceous boundary with a special emphasis on the aspects of interpretation of the paleomagnetic data in magnetostratigraphic studies and the need for the integrated (paleontological and paleomagnetic) approach to recognition of the base of the Berriasian.
Edges in models of shear flow
Authors: Lebovitz Norman , Mariotti Giulio 
Published: March 2013

AbstractA characteristic feature of the onset of turbulence in shear flows is the appearance of an ‘edge’, a codimension-one invariant manifold that separates ‘lower’ orbits, which decay directly to the laminar state, from ‘upper’ orbits, which decay more slowly and less directly. The object of this paper is to elucidate the structure of the edge that makes this behaviour possible. To this end we consider a succession of low-dimensional models. In doing this we isolate geometric features that are robust under increase of dimension and are therefore candidates for explaining analogous features in higher dimension. We find that the edge, which is the stable manifold of a ‘lower-branch’ state, winds endlessly around an ‘upper-branch’ state in such a way that upper orbits are able to circumnavigate the edge and return to the laminar state.
Transient force generation during impulsive rotation of wall-mounted panels
Authors: Pierides Alexis , Elzawawy Amir , Andreopoulos Yiannis 
Published: March 2013

AbstractSquare and triangular shape actuator panels mounted on the wall of a wind tunnel beneath an air flow have been impulsively rotated with an angular velocity between 3 and $26~\mathrm{rad} ~{\mathrm{s} }^{- 1} $. A custom-designed balance was used to measure the time-dependent lift and drag forces during the deployment of the actuator, the position of which was monitored by a digital encoder. The measured forces have been compensated for inertia effects which are significant. The results indicated that all lift and drag force coefficients during the transient deployment are different than the corresponding coefficients under stationary conditions at the same deployment angle. It was found that these dynamic effects are augmented with increasing velocity ratio $\mathit{Str}$. The square actuator was found to have better aerodynamic performance than the triangular ones. Additional experiments within different boundary layers reveal that the generated unsteady forces on the moving panels are affected by the characteristics of the incoming boundary layers. The results showed that the thinner the boundary layer is the higher the forces are. Time-resolved flow visualization studies indicated that during the deployment of the panel the upstream turbulent boundary layer structures and the free stream fluid are decelerated and squeezed in the longitudinal direction as they approach the moving plate. A very thin and highly sheared wall layer develops over the moving panel, it generates a substantial amount of vorticity and it subsequently separates from the three edges of the panel to form a large-scale ring-like vortical structure which is responsible for the transient augmentation of the aerodynamic forces. This structure consists of wrapped around separated shear layers which contain pockets of compressed eddies and free stream fluid originated in the upstream incoming boundary layer and free stream. A horseshoe vortex starts to form over the moving plate and during the final stages of deployment it has been moved upstream while the incoming boundary layer turbulent structures are pushed and diverted upwards.
Variable density and viscosity, miscible displacements in horizontal Hele-Shaw cells. Part 1. Linear stability analysis
Authors: Talon L. , Goyal N. , Meiburg E. 
Published: March 2013

AbstractA computational investigation of variable density and viscosity, miscible displacements in horizontal Hele-Shaw cells is presented. As a first step, two-dimensional base states are obtained by means of simulations of the Stokes equations, which are nonlinear due to the dependence of the viscosity on the local concentration. Here, the vertical position of the displacement front is seen to reach a quasisteady equilibrium value, reflecting a balance between viscous and gravitational forces. These base states allow for two instability modes: first, there is the familiar tip instability driven by the unfavourable viscosity contrast of the displacement, which is modulated by the presence of density variations in the gravitational field; second, a gravitational instability occurs at the unstably stratified horizontal interface along the side of the finger. Both of these instability modes are investigated by means of a linear stability analysis. The gravitational mode along the side of the finger is characterized by a wavelength of about one half to one full gap width. It becomes more unstable as the gravity parameter increases, even though the interface is shifted closer to the wall. The growth rate is largest far behind the finger tip, where the interface is both thicker, and located closer to the wall, than near the finger tip. The competing influences of interface thickness and wall proximity are clarified by means of a parametric stability analysis. The tip instability mode represents a gravity-modulated version of the neutrally buoyant mode. The analysis shows that in the presence of density stratification its growth rate increases, while the dominant wavelength decreases. This overall destabilizing effect of gravity is due to the additional terms appearing in the stability equations, which outweigh the stabilizing effects of gravity onto the base state.
Nonlinear analysis of shock–vortex interaction: Mach stem formation
Authors: Clavin Paul 
Published: March 2013

AbstractShock–vortex interaction is analysed for strong gaseous shock waves and a ratio of specific heats close to unity. A nonlinear wave equation for the wrinkles of the shock front is obtained for weak vortices. The solution breaks down after a finite time and the slope of the front develops jump discontinuities, indicating the formation of Mach stems. Shock–turbulence interactions are also briefly discussed.
Thermal boundary layer structure in turbulent Rayleigh–Bénard convection in a rectangular cell
Authors: Zhou Quan , Xia Ke-Qing 
Published: March 2013

AbstractWe report high-spatial-resolution measurements of the thermal boundary layer (BL) properties in turbulent thermal convection. The experiment was made near the lower conducting plate of a water-filled rectangular convection cell of height 0.76 m, with a Prandtl number$\mathit{Pr}= 4. 3$and over the Rayleigh-number range$2\times 1{0}^{10} \lt \mathit{Ra}\lt 7\times 1{0}^{11} $. Time series of the local temperature at various vertical distance$z$from the plate were measured. Statistical properties of the profiles of the temperature, i.e. the mean temperature$\langle T\rangle $, fluctuating temperature root mean square (r.m.s.)${\sigma }_{T} $, temperature skewness${S}_{T} $, and flatness${F}_{T} $, and those of the temperature time derivative, i.e. the r.m.s.${ \sigma }_{T}^{\prime } $, skewness${ S}_{T}^{\prime } $and flatness${ F}_{T}^{\prime } $of the derivative, are studied. It is found that most of these quantities exhibit some degree of invariability with$\mathit{Ra}$, especially for the regime inside the thermal BL. When comparing with the mean temperature profiles, the profiles of the second moment of temperature seem to possess a higher level of universality. It is shown that the distance${\delta }_{\sigma } $from the plate to the maximal temperature r.m.s. position provides a natural length scale for the characterization of the thermal BL, as the statistical properties of the temperature field, such as its r.m.s., skewness and flatness, are all sharply different below and above this length scale, i.e. below${\delta }_{\sigma } $,${\sigma }_{T} $increases linearly with the vertical distance$z$from the plate and${S}_{T} $is close to zero and${F}_{T} $is close to three and both quantities remains nearly constant, whereas above${\delta }_{\sigma } $the decay of${\sigma }_{T} $obeys a logarithmic behaviour and${S}_{T} $and${F}_{T} $both exhibit a hill-like structure. It is also found that near the plate$\langle T\rangle $,${\sigma }_{T} $and${ \sigma }_{T}^{\prime } $all increase linearly with$z$. Our observations further reveal that such linear dependence occurs within a self-similar region of the thermal BL, where the temperature probability density functions can be scaled onto a single distribution that differs slightly from the Gaussian distribution. The$\mathit{Ra}$-dependencies of various thermal BL properties are also studied and our results yield${\delta }_{th} / H= (6. 85\pm 0. 70){\mathit{Ra}}^{- 0. 33\pm 0. 03} $,${\delta }_{\sigma } / H= (2. 86\pm 0. 30){\mathit{Ra}}^{- 0. 31\pm 0. 03} $and${ \delta }_{\sigma }^{\prime } / H= (25\pm 3){\mathit{Ra}}^{- 0. 38\pm 0. 05} $, where$H$is the height of the cell,${\delta }_{th} $and${ \delta }_{\sigma }^{\prime } $are the BL thicknesses determined respectively from the profiles of$\langle T\rangle $and${ \sigma }_{T}^{\prime } $.
Zero-R2Hedge Funds and Market Neutrality
Authors: Bollen Nicolas P. B. 
Published: March 2013

AbstractFactor models yield an R2 insignificantly different from 0 for one-third of hedge funds in a broad sample. These funds illustrate the concept of market neutrality and feature lower volatilities, higher Sharpe ratios, and higher alphas than other funds, indicating that they provide a successful alternative investment. However, large portfolios of zero-R2 funds contain fully half the volatility of portfolios of other funds, suggesting that they feature substantial systematic risk. Furthermore, these funds display an increased probability of failure even after controlling for idiosyncratic volatility. These results indicate the presence of an omitted factor that exposes investors to significant downside risk.
Habitat degradation impacts black howler monkey (Alouatta pigra) gastrointestinal microbiomes
Authors: Amato Katherine R , Yeoman Carl J , Kent Angela , Righini Nicoletta , Carbonero Franck , Estrada Alejandro , Rex Gaskins H , Stumpf Rebecca M , Yildirim Suleyman , Torralba Manolito , Gillis Marcus , Wilson Brenda A , Nelson Karen E , White Bryan A , Leigh Steven R 
Published: March 2013

Abstract
The gastrointestinal (GI) microbiome contributes significantly to host nutrition and health. However, relationships involving GI microbes, their hosts and host macrohabitats remain to be established. Here, we define clear patterns of variation in the GI microbiomes of six groups of Mexican black howler monkeys (Alouatta pigra) occupying a gradation of habitats including a continuous evergreen rainforest, an evergreen rainforest fragment, a continuous semi-deciduous forest and captivity. High throughput microbial 16S ribosomal RNA gene sequencing indicated that diversity, richness and composition of howler GI microbiomes varied with host habitat in relation to diet. Howlers occupying suboptimal habitats consumed less diverse diets and correspondingly had less diverse gut microbiomes. Quantitative real-time PCR also revealed a reduction in the number of genes related to butyrate production and hydrogen metabolism in the microbiomes of howlers occupying suboptimal habitats, which may impact host health.
Chlamydomonas reinhardtii thermal tolerance enhancement mediated by a mutualistic interaction with vitamin B12-producing bacteria
Authors: Xie Bo , Bishop Shawn , Stessman Dan , Wright David , Spalding Martin H , Halverson Larry J 
Published: March 2013

Abstract
Temperature is one of the most important environmental factors affecting the growth and survival of microorganisms and in light of current global patterns is of particular interest. Here, we highlight studies revealing how vitamin B12 (cobalamin)-producing bacteria increase the fitness of the unicellular alga Chlamydomonas reinhardtii following an increase in environmental temperature. Heat stress represses C. reinhardtii cobalamin-independent methionine synthase (METE) gene expression coinciding with a reduction in METE-mediated methionine synthase activity, chlorosis and cell death during heat stress. However, in the presence of cobalamin-producing bacteria or exogenous cobalamin amendments C. reinhardtii cobalamin-dependent methionine synthase METH-mediated methionine biosynthesis is functional at temperatures that result in C. reinhardtii death in the absence of cobalamin. Artificial microRNA silencing of C. reinhardtii METH expression leads to nearly complete loss of cobalamin-mediated enhancement of thermal tolerance. This suggests that methionine biosynthesis is an essential cellular mechanism for adaptation by C. reinhardtii to thermal stress. Increased fitness advantage of METH under environmentally stressful conditions could explain the selective pressure for retaining the METH gene in algae and the apparent independent loss of the METE gene in various algal species. Our results show that how an organism acclimates to a change in its abiotic environment depends critically on co-occurring species, the nature of that interaction, and how those species interactions evolve.