bluuebunny/crossref_metadata_2025 huggingface dataset:
Predictors of changes in body image concerns of Chinese adolescents
Authors: Chen Hong , Jackson Todd
Published: October 2008

This nine‐month prospective study tested the extent to which risk factors implicated in recent accounts of body dissatisfaction predicted changes in body image concerns of adolescent boys and girls in China. A sample of 593 Chinese adolescents (217 boys, 376 girls) completed measures of weight esteem, appearance esteem and physical stature concern in addition to demographics, internalization of attractiveness ideals, negative affect, and appearance pressure, teasing, and comparison at baseline and nine‐month follow‐up. For girls, initial levels of social comparison, and internalized attractiveness ideals predicted decreases in body esteem over time. Time 1 negative affect contributed to changes in both appearance esteem and weight esteem for boys. Baseline level of stature concerns and reported height were the only predictors of later stature concerns within each sex. In sum, this study suggests specific factors previously implicated in Western accounts also have utility for understanding body image concerns of adolescents in China.
Intravenous salbutamol for external cephalic version
Authors: Vani Subramaniam , Lau Soon Yen , Lim Boon Kiong , Omar Siti Zawiah , Tan Peng Chiong
Published: October 2008

Objective

To evaluate the success of external cephalic version (ECV) using an adjusted bolus dose of intravenous salbutamol compared with no tocolysis.

Methods

An open‐label randomized study of 114 women with a term breech fetus randomized to receive either an intravenous bolus dose of 0.1 mg salbutamol with further boluses every 5 minutes, as required, before commencing ECV, or no tocolysis. Primary outcomes were successful ECV and rate of cesarean delivery.

Results

Salbutamol tocolysis resulted in a higher rate of successful ECV compared with no tocolysis (70.2% [40/57] vs 36.8% [21/57]; RR 1.9, 95% CI 1.3–2.8; P < 0.001). Cesarean delivery rate was lower in the salbutamol group compared with the control group (31.6% [18/57] vs 63.2% [36/57]; RR 0.5, 95% CI 0.3–0.8; P = 0.001). Salbutamol dose ranged from 0.1–0.4 mg and outcome was not related to dose.

Conclusion

Adjusted dose intravenous salbutamol tocolysis prior to ECV increases its success rate and reduces the cesarean delivery rate.
EVALUATING COMPLETENESS OF MATERNAL MORTALITY REPORTING IN A RURAL HEALTH AND SOCIAL AFFAIRS UNIT IN VELLORE, INDIA, 2004
Authors: KIM SHIN Y. , ROCHAT ROGER , RAJARATNAM ABEL , DIGIROLAMO ANN
Published: October 2008

Health systems in developing countries infrequently implement and evaluate maternal death surveillance. This study identified under-reported and misclassified maternal deaths among women of reproductive age between 1999 and 2004 in a rural service unit in Vellore, India. In-depth interviews, semi-structured interviews and structured questionnaires were used to identify maternal deaths known to health care providers and community leaders who regularly come in contact with pregnant women. Eighteen under-reported and misclassified cases – or 50% of maternal deaths – were reported. These included 29% of abortion-related and 7% of domestic violence-related deaths. Based on this study’s fieldwork, the existing death surveillance system detected 100% of the maternal deaths reported by hospital staff; however, it missed most maternal deaths reported by community workers. The latter are more likely than deaths reported by hospital workers to result from abortion and family violence. The existing surveillance system should be augmented with a community-based death surveillance system. This comprehensive approach identified twice as many maternal deaths than previously recorded and could be applied in other settings. Appropriate public health interventions should be initiated to prevent maternal deaths in this community.
Association between isolation ofStaphylococcus aureusone week after calving and milk yield, somatic cell count, clinical mastitis, and culling through the remaining lactation
Authors: Whist Anne Cathrine , Østerås Olav , Sølverød Liv
Published: October 2008

Cows with isolation ofStaphylococcus aureusapproximately 1 week after calving and milk yield, somatic cell count (SCC), clinical mastitis (CM), and culling risk through the remaining lactation were assessed in 178 Norwegian dairy herds. Mixed models with repeated measures were used to compare milk yield and SCC, and survival analyses were used to estimate the hazard ratio for CM and culling. On average, cows with an isolate ofStaph. aureushad a significantly higher SCC than culture-negative cows. If no post-milking teat disinfection (PMTD) was used, the mean values of SCC were 42 000, 61 000, 68 000 and 77 000 cells/ml for cows with noStaph. aureusisolate, withStaph. aureusisolated in 1 quarter, in 2 quarters and more than 2 quarters respectively. If iodine PMTD was used, SCC means were 36 000; 63 000; 70 000 and 122 000, respectively. Primiparous cows testing positive forStaph. aureushad the same milk yield curve as culture-negative cows, except for those withStaph. aureusisolated in more than 2 quarters. They produced 229 kg less during a 305-d lactation. Multiparous cows with isolation ofStaph. aureusin at least 1 quarter produced 94–161 kg less milk in 2ndand >3rdparity, respectively, and those with isolation in more than 2 quarters produced 303–390 kg less than multiparous culture-negative animals during a 305-d lactation. Compared with culture-negative cows, the hazard ratio for CM and culling in cows with isolation ofStaph. aureusin at least 1 quarter was 2·0 (1·6–2·4) and 1·7 (1·5–1·9), respectively. There was a decrease in the SCC and in the CM risk in culture-negative cows where iodine PMTD had been used, indicating that iodine PMTD has a preventive effect on already healthy cows. For cows testing positive forStaph. aureusin more than 2 quarters at calving, iodine PMTD had a negative effect on the CM risk and on the SCC through the remaining lactation.
Physical interpretation of spiralling-columnar convection in a rapidly rotating annulus with radial propagation properties of Rossby waves
Authors: TAKEHIRO SHIN-ICHI
Published: October 2008

To aid the physical understanding of spiralling-columnar convection emerging in rapidly rotating spheres and spherical shells, two-dimensional thermal convection in a rapidly rotating annulus is investigated through the radial propagation properties of topographic Rossby waves. Two kinds of the boundaries containing the fluid in the axial direction are considered: a convex type modelling a spherical geometry and a concave type for comparison. The linear stability of a basic state with no motion and uniformly unstable stratification is examined and spirally elongated structures of critical convection are obtained for small Prandtl numbers. An analysis of the energy budget shows that a part of the kinetic energy generated in the region with slightly inclined boundaries is dynamically transferred and dissipates through viscosity in the region with strongly inclined boundaries. This indicates that the Rossby waves propagate from the region with slightly inclined boundaries to the region with strongly inclined boundaries. It is presented that the appearance of a spiral structure corresponds to an increase of the local radial wavenumber of the Rossby waves propagating in the radial direction. The flow patterns obtained using the dispersion relation of the Rossby waves coincide with those of the tailing part of the spiral structure obtained numerically. As the Prandtl number increases, the Rossby waves barely propagate because of strong viscous dissipation, and the flow pattern is localized in the region with slightly inclined boundaries. For convex boundaries with unstable stratification concentrating near the outer boundary and concave boundaries with unstable stratification confined near the inner boundary, the flow patterns tilt in the direction inverse to the case of uniform unstable stratification. The tilting direction of the flow pattern is not determined by the curvature of the boundaries considered but instead by the radial propagation direction of the Rossby waves excited by thermal convection.
Numerical simulation of a two-dimensional internal wave attractor
Authors: GRISOUARD NICOLAS , STAQUET CHANTAL , PAIRAUD IVANE
Published: October 2008

Internal (gravity) wave attractors may form in closed containers with boundaries non-parallel and non-normal to the gravity vector. Such attractors have been studied from a theoretical point of view, in laboratory experiments and using linear numerical computations. In the present paper two-dimensional numerical simulations of an internal wave attractor are reported, based upon the nonlinear and non-hydrostatic MIT-gcm numerical code. We first reproduce the laboratory experiment of a wave attractor performed by Hazewinkel et al. (J. Fluid Mech. Vol. 598, 2008 p. 373) and obtain very good agreement with the experimental data. We next propose simple ideas to model the thickness of the attractor. The model predicts that the thickness should scale as the 1/3 power of the non-dimensional parameter measuring the ratio of viscous to buoyancy effects. When the attractor is strongly focusing, the thickness should also scale as the 1/3 power of the spatial coordinate along the attractor. Analysis of the numerical data for two different attractors yields values of the exponent close to 1/3, within 30%. Finally, we study nonlinear effects induced by the attractor.
On the limitations of Taylor's hypothesis in constructing long structures in a turbulent boundary layer
Authors: DENNIS DAVID J. C. , NICKELS TIMOTHY B.
Published: October 2008

Taylor's hypothesis of frozen flow has frequently been used to convert temporal experimental measurements into a spatial domain. This technique has led to the discovery of long meandering structures in the log-region of a turbulent boundary layer. There is some contention over whether Taylor's approximation is valid over large distances. This paper presents an experiment that compares velocity fields constructed using Taylor's approximation with those obtained from particle image velocimetry (PIV), i.e. spatial data, obtained in the logarithmic region of a turbulent boundary layer.
Transient ventilation dynamics following a change in strength of a point source of heat
Authors: BOWER D. J. , CAULFIELD C. P. , FITZGERALD S. D. , WOODS A. W.
Published: October 2008

We investigate the transient ventilation flow within a confined ventilated space, with high- and low-level openings, when the strength of a low-level point source of heat is changed instantaneously. The steady-flow regime in the space involves a turbulent buoyant plume, which rises from the point source to a well-mixed warm upper layer. The steady-state height of the interface between this layer and the lower layer of exterior fluid is independent of the heat flux, but the upper layer becomes progressively warmer with heat flux. New analogue laboratory experiments of the transient adjustment between steady states identify that if the heat flux is increased, the continuing plume propagates to the top of the room forming a new, warmer layer. This layer gradually deepens, and as the turbulent plume entrains fluid from the original warm layer, the original layer is gradually depleted and disappears, and a new steady state is established. In contrast, if the source buoyancy flux is decreased, the continuing plume is cooler than the original plume, so that on reaching the interface it is of intermediate density between the original warm layer and the external fluid. The plume supplies a new intermediate layer, which gradually deepens with the continuing flow. In turn, the original upper layer becomes depleted, both as a result of being vented through the upper opening of the space, but also due to some penetrative entrainment of this layer by the plume, as the plume overshoots the interface before falling back to supply the new intermediate layer. We develop quantitative models which are in good accord with our experimental data, by combining classical plume theory with models of the penetrative entrainment for the case of a decrease in heating. Typically, we find that the effect of penetrative entrainment on the density of the intruding layer is relatively weak, provided the change in source strength is sufficiently large. However, penetrative entrainment measurably increases the rate at which the depth of the draining layer decreases. We conclude with a discussion of the importance of these results for the control of naturally ventilated spaces.
Macroalgae and seagrass contribution to gastropods in sub-tropical and temperate tidal flats
Authors: Doi Hideyuki , Matsumasa Masatoshi , Fujikawa Mamoru , Kanou Keiichi , Suzuki Takao , Kikuchi Eisuke
Published: October 2008

Macroalgal and seagrass communities are widely distributed in marine and brackish shallow water and have high productivity. The primary production in marine costal areas is often transported to intertidal flats by waves and currents and beached on the flats. Thus, we hypothesized that the macroalgae and seagrasses are food sources for benthic communities on intertidal flats where some gastropod species often dominate. We performed comparisons of food sources among different gastropod species on sub-tropical and temperate tidal flats (26° and 38°N, respectively), and used isotope mixing models using carbon and nitrogen stable isotopes. A mixing model for stable isotopes, IsoSource, revealed that main food sources for three snails were macroalgae (50–56%) and seagrass (39–45%) at the temperate site. The contributions of terrestrial plants, sediment organic matter and benthic microalgae were weaker than those of macroalgae and seagrasses. At the sub-tropical site, snails fed mainly on macroalgae. The differences in food sources between snail species were not remarkable, although the nitrogen values were slightly different. It would thus appear that macroalgae and seagrass play an important role in the food webs not only in their own habitats but also on the adjacent tidal flats.
Invariance Principles as Regulative Ideals: From Wigner to Hilbert
Authors: Ryckman Thomas
Published: October 2008

Eugene Wigner's several general discussions of symmetry and invariance principles are among the canonical texts of contemporary philosophy of physics. Wigner spoke from a position of authority, having pioneered (and won the Nobel prize in 1963) for recognition of the importance of symmetry principles from nuclear to molecular physics. But perhaps recent commentators have not sufficiently stressed that Wigner always took care to situate the notion of invariance principles with respect to two others, initial conditions (or events) and laws of nature. Wigner's first such general consideration of invariance principles, an address presented at Einstein's 70th birthday celebration, held in Princeton on 19 March 1949, began by laying out just this distinction, and in a way that seems to suggest that the three notions arise through abstraction in an analysis of the general problem of cognition in the natural sciences:

The world is very complicated and it is clearly impossible for the human mind to understand it completely. Man has therefore devised an artifice which permits the complicated nature of the world to be blamed on something which is called accidental and thus permits him to abstract a domain in which simple laws can be found. The complications are called initial conditions; the domain of regularities, laws of nature. (…) the underlying abstraction is probably one of the most fruitful the human mind has made. It has made the natural sciences possible.
Einstein, Kant, and the A Priori
Authors: Friedman Michael
Published: October 2008

Kant's original version of transcendental philosophy took both Euclidean geometry and the Newtonian laws of motion to be synthetic a priori constitutive principles—which, from Kant's point of view, function as necessary presuppositions for applying our fundamental concepts of space, time, matter, and motion to our sensible experience of the natural world. Although Kant had very good reasons to view the principles in question as having such a constitutively a priori role, we now know, in the wake of Einstein's work, that they are not in fact a priori in the stronger sense of being fixed necessary conditions for all human experience in general, eternally valid once and for all. And it is for precisely this reason that Kant's original version of transcendental philosophy must now be either rejected entirely or (at least) radically reconceived. Most philosophy of science since Einstein has taken the former route: the dominant view in logical empiricism, for example, was that the Kantian synthetic a priori had to be rejected once and for all in the light of the general theory of relativity.
Does the Sun have a subsolar metallicity?
Authors: Asplund Martin
Published: October 2008

The solar chemical composition has recently undergone a drastic revision, in particular in terms of the C, N, O and Ne abundances that have been lowered by almost a factor of two. In this invited review I will describe the different compounding reasons for this change (3D model atmospheres, non-LTE line formation, improved atomic/molecular data) and discuss some astrophysical implications thereof, which fall under both good (solar neighborhood) and bad (helioseismology) news. The most recent literature regarding the solar O abundance is surveyed and a critical evaluation whether or not these support the low solar abundance scale is presented. Finally I venture to make some predictions to what the real solar O abundance may be.
SMART – a computer program for modelling stellar atmospheres
Authors: Aret A. , Sapar A. , Poolamäe R. , Sapar L.
Published: October 2008

Program SMART (Spectra and Model Atmospheres by Radiative Transfer) has been composed for modelling atmospheres and spectra of hot stars (O, B and A spectral classes) and studying different physical processes in them (Sapar & Poolaäe 2003, Sapar et al. 2007). Line-blanketed models are computed assuming plane-parallel, static and horizontally homogeneous atmosphere in radiative, hydrostatic and local thermodynamic equilibrium. Main advantages of SMART are its shortness, simplicity, user friendliness and flexibility for study of different physical processes. SMART successfully runs on PC both under Windows and Linux.
Mixing-length parameter from binaries and clusters
Authors: Yıldız Mutlu
Published: October 2008

Mixing length parameter of the mixing length theory is a free parameter and used to calibrate radii of late-type stars. From the Hyades cluster and the α Centauri system, we find that the parameter depends on the stellar mass and some other properties of stars. Considering some other systems, we describe how the parameter depends on stellar parameters.
Non-LTE Spectral Analysis of Extremely Hot Post-AGB Stars: Constraints for Evolutionary Theory
Authors: Rauch Thomas , Werner Klaus , Ziegler Marc , Koesterke Lars , Kruk Jeffrey W.
Published: October 2008

Spectral analysis by means of Non-LTE model-atmosphere techniques has arrived at a high level of sophistication: fully line-blanketed model atmospheres which consider opacities of all elements from H to Ni allow the reliable determination of photospheric parameters of hot, compact stars. Such models provide a crucial test of stellar evolutionary theory: recent abundance determinations of trace elements like, e.g., F, Ne, Mg, P, S, Ar, Fe, and Ni are suited to investigate on AGB nucleosynthesis. E.g., the strong Fe depletion found in hydrogen-deficient post-AGB stars is a clear indication of an efficient s-process on the AGB where Fe is transformed into Ni or even heavier trans iron-group elements. We present results of recent spectral analyses based on high-resolution UV observations of hot stars.
The Dynamics Of Galactic Globular Cluster
Authors: Ding Chen
Published: October 2008

We have used the Hubble Space Telescope (HST) to measure proper motion of the globular cluster NGC 6656 (M22) with respect to the background bulge stars and its internal velocity dispersion profile. With the space velocity of (Π, Θ, W) = (184±3, 209±14, 132±15) km s−1, we also calculate the orbit of the cluster. The central velocity dispersion in both components of the proper motion of cluster stars is 16.99 km s−1. We derive the mass-to-ration (M/L)∼1.7 which is relatively higher than the past works.
Tidal disruption of stripped red giants by massive black holes
Authors: Lu Y. , Huang Y. F. , Zhang S. N. , Lu P.
Published: October 2008

We investigate the tidal disruption of a red giant whose envelope is thought to be stripped off when it passed by a massive black hole. Since the low-density stellar envelope would be lost, the tidal disruption of a red giant by massive black hole is regarded as primarily happening in its core region. The object is called a stripped red giant (SRG). Comparing our results with the three candidate tidal disruption events detected by Chandra in 2001 and 2002, i.e., the X-ray flares of NGC 5905, RX J1242.6-1119A, and RX J1624.9+7554, we argue that the tidal disruption of a stripped red giant is strongly ruled out.
Advanced test of the model stellar atmospheres: the nature of the light variability of magnetic chemically peculiar stars
Authors: Krtička J. , Mikulášek Z. , Zverko J. , Žižňovský J. , Zvěřina P.
Published: October 2008

The magnetic chemically peculiar stars exhibit both inhomogeneous horizontal distribution of chemical elements on their surfaces and the light variability. We show that the observed light variability of these stars can be successfully simulated using models of their stellar atmospheres and adopting the observed surface distribution of elements. The most important elements that influence the light variability are silicon, iron, and helium.
A Spectroscopic Study of Blue Stragglers in M67
Authors: Liu G. Q. , Deng L. , Chávez M. , Bertone E.
Published: October 2008

Spectrophotometric observations of the complete sample of twenty four blue stragglers (BSs) in the old galactic open cluster M67 (NGC2682) have been collected, using the Guillermo Haro Observatory in Cananea, Mexico. All the calibrated spectra were re-calibrated by the Beijing Arizona Taipei Connecticut (BATC) photometric system which includes fluxes in 11 photometric bands covering ~3600–10000 Å. The goal of the current work is to provide observational constraints on spectral properties of BSs by determining the effective temperature (Teff) and surface gravity (log g). The overall results, obtained by applying the flux fitting method, indicate that Teff and surface gravities of BSs in M67 are fully compatible with those expected for main sequence stars.
The Missing Population of Be+Black Hole X-Ray Binaries
Authors: Sadowski Aleksander , Ziółkowski J. , Belczyński K. , Bulik T.
Published: October 2008

At present, 117 Be/neutron star (Be/NS) X-ray binaries (XRBs) are known in the Galaxy and the Magellanic Clouds, but not a single Be/black hole (Be/BH) binary was found so far. We carried out the calculations of stellar population synthesis to investigate the case of the apparently missing population of Be/BH XRBs. According to our calculations, the main reason of this disparity is the fact that within the orbital period range where Be XRBs are found (~10 to ~300 days), these systems are formed predominantly with a NS component. The systems with a BH component are formed predominantly with much longer orbital periods and they are not easy to detect.
The Y2 Isochrones Getting an Extra Dimension
Authors: Yi Sukyoung K. , Kim Yong-Cheol , Demarque Pierre , Lee Young-Wook , Han Sang-Il , Kim Do Gyun
Published: October 2008

The Yonsei-Yale Isochrones have been widely used since its birth in 2001. We announce a major upgrade mainly making varieties of helium values available. The recent works on the globular clusters with extreme helium abundances have called for such a need. The new version of the Y2 Isochrones are available for [α/Fe] = 0 through 0.6, ΔY/ΔZ = 1.5 through 3.0, and extreme helium abundances (Y = normal 0.05, 0.1, 0.15, 0.2), and for 11 metallicity grids, with full capability of interpolation. The database will be powerful for making population models. Besides, the accuracy of the models on the lower main sequence has been substantially improved. We illustrate the major upgrades and demonstrate the power of the new grids.
Blue Stragglers from Primordial Binary Evolution
Authors: Chen Xuefei , Han Zhanwen
Published: October 2008

Binaries exist in all clusters and much evidence suggests that close-binary evolution makes an important contribution to the blue straggler population, at least in some clusters as well as in the field. Here we present different channels to blue stragglers from primordial binary evolution and examine their contributions to the integrated spectral energy distribution of the host clusters in theory via binary population synthesis.
A Model for Adiabatic Mass-loss
Authors: Ge Hongwei. , Webbink R. F. , Han Z.
Published: October 2008

We describe our work on the development and application of a stellar structure code to compute model sequences representing donor stars in interacting binaries subject to rapid (adiabatic) mass-loss. The donor star is assumed to remain in hydrostatic equilibrium, but no heat flow is allowed. These sequences can be used to define bifurcation sequences in close binary evolution, and to circumscribe possible survivors of common envelope evolution.
Structure and evolution of W UMa-type systems
Authors: Li Lifang , Zhang Fenghui , Han Zhanwen , Jiang Dengkai , Jiang Tianyu
Published: October 2008

We summarize and discuss our recent works on the structure and evolution of low-mass W UMa-type contact binary stars. Three conclusions are given as followings: (1) The energy transfer is taken place in the radiative region of common envelope of W UMa systems; (2) The magnetic activity level of W UMa systems is weaker than that of non-contact binaries or rapid-rotating single stars; (3) The evolutionary outcome of W UMa systems might be the rapid-rotating single stars, and an average lifetime is derived to be about 7 Gyr for W UMa systems.
Learning the law
Authors: ENGEL CHRISTOPH
Published: October 2008

In the population, the knowledge of the law is at best fragmentary. It takes law students years to handle the law properly. How is the law nonetheless able to govern people's lives? To find an explanation, this paper draws on neurobiology, developmental psychology, and the psychology of learning.

Typically, the law reaches its addressees indirectly. The law is not followed, it is learned. There are two learning objects. In childhood, individuals acquire normative proficiency, i.e. the ability to handle normative expectations. This procedural knowledge is gradually filled with the declarative knowledge of individual normative expectations of legal origin.

If the law changes, through secondary learning, individuals must acquire new normative expectations. To that end, some intermediary must translate the new rule into a more contextualized social mirror rule. If changes are fundamental, as after the fall of the iron curtain, individuals must also learn new ways to handle normative expectations.
Individual Differences in the Attentional Blink
Authors: Martens Sander , Valchev Nikola
Published: October 2008

A well-established phenomenon in the study of attention is the attentional blink (AB): a deficit in reporting the second of two targets when it occurs 200–500 ms after the first. Although the effect has been shown to be robust in a wide variety of task conditions, we recently reported that some individuals show little or no AB, and presented psychophysiological evidence that target processing differs in nonblinkers (who do not show an AB) and blinkers (who do show an AB). Here we present evidence that the level of distractor processing and subsequent interference with target identification processes also differs between the two groups. In one task, two masked targets were centrally presented at varying temporal intervals, with or without additional distractors. In a second task, the masked targets were presented eccentrically, with or without the presence of a central sequential stream of the task-irrelevant distractors. In both cases, the presence of distractors led to an increased AB magnitude in blinkers, whereas performance for nonblinkers remained relatively unaffected. The results thus support the hypothesis that nonblinkers are more efficient in ignoring irrelevant information than blinkers.
Lexical Predictability Exerts Robust Effects on Fixation Duration, but not on Initial Landing Position During Reading
Authors: Vainio Seppo , Hyönä Jukka , Pajunen Anneli
Published: October 2008

An eye movement experiment was conducted to examine effects of local lexical predictability on fixation durations and fixation locations during sentence reading. In the high-predictability condition, a verb strongly constrained the lexical identity of the following word, while in the low-predictability condition the target word could not be predicted on the basis of the verb. The results showed that first fixation and gaze duration on the target noun were reliably shorter in the high-predictability than in the low-predictability condition. However, initial fixation location was not affected by lexical predictability. As regards eye guidance in reading, the present study indicates that local lexical predictability influences when decisions but not where the initial fixation lands in a word.
Seasonal variations of semidiurnal tidal perturbations in mesopause region temperature and zonal and meridional winds above Fort Collins, Colorado (40.6°N, 105.1°W)
Authors: Yuan Tao , Schmidt Hauke , She C. Y. , Krueger David A. , Reising Steven
Published: October 2008

On the basis of Colorado State University (CSU) Na lidar observations over full diurnal cycles from May 2002 to April 2006, a harmonic analysis was performed to extract semidiurnal perturbations in mesopause region temperature and zonal and meridional winds over Fort Collins, Colorado (40.6°N, 105.1°W). The observed monthly results are in good agreement with MF radar tidal climatology for Urbana, Illinois, and with predictions of the Hamburg Model of the Neutral and Ionized Atmosphere (HAMMONIA), sampled at the CSU Na lidar coordinates. The observed semidiurnal tidal period perturbation within the mesopause region is found to be dominated by propagating modes in winter and equinoctial months with a combined vertical wavelength varying from 50 km to almost 90 km and by a mode with evanescent behavior and longer vertical wavelength (100–150 km) in summer months, most likely due to dominance of (2, 2) and (2, 3) tidal (Hough) modes. The observed semidiurnal tidal amplitude shows strong seasonal variation, with a large amplitude during the winter months, with a higher growth rate above ∼85–90 km, and minimal amplitudes during the summer months. Maximum tidal amplitudes over 50 m/s for wind and 12 K for temperature occur during fall equinox. A detailed comparison with HAMMONIA predictions shows excellent agreement in semidiurnal phases. HAMMONIA‐predicted semidiurnal amplitudes generally agree well with observations; however, HOMMONIA underestimates temperature amplitudes in some of the nonsummer months as well as zonal wind and meridional wind amplitudes in April and September but overestimates them in February. To reveal the effects of the atmospheric background on vertical propagation of tidal modes and their relative importance in the composite semidiurnal tide during different seasons, we use the lidar‐observed monthly mean temperature and zonal wind from the same data set as well as HAMMONIA output to calculate the vertical wave number seasonal variations of the major tidal modes of the migrating semidiurnal tide. This leads to a qualitative understanding of the lidar‐observed and HAMMONIA‐predicted seasonal variation of the semidiurnal tidal perturbation.
Estimation of bathymetric depth and slope from data assimilation of swath altimetry into a hydrodynamic model
Authors: Durand Michael , Andreadis Konstantinos M. , Alsdorf Douglas E. , Lettenmaier Dennis P. , Moller Delwyn , Wilson Matthew
Published: October 2008

The proposed Surface Water and Ocean Topography (SWOT) mission would provide measurements of water surface elevation (WSE) for characterization of storage change and discharge. River channel bathymetry is a significant source of uncertainty in estimating discharge from WSE measurements, however. In this paper, we demonstrate an ensemble‐based data assimilation (DA) methodology for estimating bathymetric depth and slope from WSE measurements and the LISFLOOD‐FP hydrodynamic model. We performed two proof‐of‐concept experiments using synthetically generated SWOT measurements. The experiments demonstrated that bathymetric depth and slope can be estimated to within 3.0 microradians or 50 cm, respectively, using SWOT WSE measurements, within the context of our DA and modeling framework. We found that channel bathymetry estimation accuracy is relatively insensitive to SWOT measurement error, because uncertainty in LISFLOOD‐FP inputs (such as channel roughness and upstream boundary conditions) is likely to be of greater magnitude than measurement error.
Automated detection and location of Cascadia tremor
Authors: Wech Aaron G. , Creager Kenneth C.
Published: October 2008

A new autonomous seismic location and detection methodology enables real‐time opportunities for high‐resolution spatio‐temporal monitoring of non‐volcanic tremor. Combining a unique cross‐correlation technique with epicenter clustering analysis in northern Cascadia automatically yields thousands of tremor epicenters from the May 2008 Episodic Tremor and Slip (ETS) event while routinely detecting and locating inconspicuous inter‐ETS tremor bursts. Although ETS events in this area produce about two weeks of continuous tremor, we find a nearly equal amount of tremor during the last 15‐month inter‐ETS period. The resulting ETS and inter‐ETS epicenters occur in the slow slip region where the plate interface is 30–45 km deep and have a sharp, well‐resolved updip boundary about 75 km east of the downdip edge of the seismogenic megathrust zone. This ability to track tremor with high spatio‐temporal resolution facilitates automatic tremor monitoring and the mapping of the transition zone and regions of locked zone stress accumulation.
Mycophagous growth of Collimonas bacteria in natural soils, impact on fungal biomass turnover and interactions with mycophagous Trichoderma fungi
Authors: Höppener-Ogawa Sachie , Leveau Johan H J , van Veen Johannes A , De Boer Wietse
Published: October 2008

Bacteria of the genus Collimonas are widely distributed in soils, although at low densities. In the laboratory, they were shown to be mycophagous, that is, they are able to grow at the expense of living hyphae. However, so far the importance of mycophagy for growth and survival of collimonads in natural soil habitats is unknown. Using a Collimonas-specific real-time PCR assay, we show here that the invasion of field soils by fungal hyphae (Absidia sp.) resulted in a short-term, significant increase (average fourfold) of indigenous collimonads. No such responses were observed for other soil bacteria studied (Pseudomonas, Burkholderia, PCR-denaturing gradient gel electrophoresis patterns of total bacteria and Burkholderia). Hence, it appears that the stimulation of growth of Collimonas bacteria by fungal hyphae is not common among other soil bacteria. In the same field soils, Trichoderma, a fungal genus known for mycophagous (mycoparasitic) growth, increased upon introduction of Absidia hyphae. Hence, mycophagous growth by Collimonas and Trichoderma can occur in the same soils. However, in controlled experiments (sand microcosms), collimonads appeared to have a negative effect on mycophagous growth of a Trichoderma strain. The effect of mycophagous growth of collimonads on fungal biomass dynamics was studied in sand microcosms using the same Absidia sp. as a test fungus. The growth of collimonads did not cause a significant reduction in the Absidia biomass. Overall, the study indicates that mycophagous nutrition may be important for collimonads in natural soils, but the impact on fungal biomass turnover is likely to be minor.
Gene cassettes encoding resistance to quaternary ammonium compounds: a role in the origin of clinical class 1 integrons?
Authors: Gillings Michael R , Xuejun Duan , Hardwick Simon A , Holley Marita P , Stokes H W
Published: October 2008

DNA sequencing, phylogenetic and mapping studies suggest that the class 1 integron found in pathogens arose when one member of the diverse family of environmental class 1 integrons became embedded into a Tn402 transposon. However, the timing of this event and the selective forces that first fixed the newly formed element in a bacterial lineage are still unknown. Biocides have a longer use in clinical practice than antibiotics, and a qac (quaternary ammonium compound) resistance gene, or remnant thereof, is a normal feature of class 1 integrons recovered from clinical isolates. Consequently, it is possible that the initial selective advantage was conferred by resistance to biocides, mediated by qac. Here, we show that diverse qac gene cassettes are a dominant feature of cassette arrays from environmental class 1 integrons, and that they occur in the absence of any antibiotic resistance gene cassettes. They are present in arrays that are dynamic, acquiring and rearranging gene cassettes within the arrays. The abundance of qac gene cassettes makes them a likely candidate for participation in the original insertion into Tn402, and as a source of a readily selectable phenotype. More broadly, the increasing use of qac and other biocides at the present time seems likely to promote the fixation of further novel genetic elements, with unpredictable and potentially adverse consequences for human health and agriculture.
The genetic equidistance result of molecular evolution is independent of mutation rates
Authors: Huang Shi
Published: October 2008

The well-established genetic equidistance result shows that sister species are approximately equidistant to a simpler outgroup as measured by DNA or protein dissimilarity. The equidistance result is the most direct evidence, and remains the only evidence, for the constant mutation rate interpretation of this result, known as the molecular clock. However, data independent of the equidistance result have steadily accumulated in recent years that often violate a constant mutation rate. Many have automatically inferred non-equidistance whenever a non-constant mutation rate was observed, based on the unproven assumption that the equidistance result is an outcome of constant mutation rate. Here it is shown that the equidistance result remains valid even when different species can be independently shown to have different mutation rates. A random sampling of 50 proteins shows that nearly all proteins display the equidistance result despite the fact that many proteins have non-constant mutation rates. Therefore, the genetic equidistance result does not necessarily mean a constant mutation rate. Observations of different mutation rates do not invalidate the genetic equidistance result. New ideas are needed to explain the genetic equidistance result that must grant different mutation rates to different species and must be independently testable.
Waist‐to‐height Ratio and Coronary Artery Disease in Taiwanese Type 2 Diabetic Patients
Authors: Tseng Chin‐Hsiao
Published: October 2008

Waist circumference (WC), waist‐to‐hip ratio (WHR), waist‐to‐height ratio (WHeiR), and BMI are indicators for obesity. This study examined the usefulness of these indicators for coronary artery disease (CAD) in Taiwanese type 2 diabetic patients. A total of 1,345 (646 men and 699 women) patients aged 63.3 ± 11.5 years were studied. CAD was defined by history or Minnesota‐coded electrocardiogram. The relative importance was evaluated by the magnitude of adjusted odds ratio per 1‐s.d. increment, the decrease in −2 log likelihood after adding the index to the logistic model, the c‐index, and the Akaiki's information criterion (AIC). Results showed that the four indices were highly intercorrelated and except BMI for men, all indices differed significantly between patients with and without CAD in either sex. In logistic regressions, the respective adjusted odds ratios for WC, WHR, WHeiR, and BMI for every 1‐s.d. increment were 1.209 (1.010–1.448), 1.109 (0.935–1.316), 1.231 (1.027–1.474), and 1.207 (0.997–1.461) for men; and were 1.176 (0.995–1.390), 1.105 (0.923–1.322), 1.280 (1.079–1.518), and 1.277 (1.083–1.507) for women. Only WHeiR was significant for both sexes and it also showed the greatest decrease in −2 log likelihood, the largest magnitude of odds ratio, and the smallest AIC while compared with the other indices in either sex. It is concluded that WHeiR has the superiority of independent association with CAD and the highest magnitude of association than WC, WHR, and BMI in both sexes. The usefulness of WHeiR should not be neglected in clinical practice.
Ethnicity and Weight Status Affect the Accuracy of Proxy Indices of Insulin Sensitivit
Authors: Alvarez Jessica A. , Bush Nikki C. , Hunter Gary R. , Brock David W. , Gower Barbara A.
Published: October 2008

This study tested the hypotheses that correlations between direct measures of insulin sensitivity and proxy indices of insulin sensitivity derived from fasting values, (i) would not be affected by ethnicity, and (ii) would be stronger in overweight vs. weight‐reduced states. We further hypothesized that associations between proxy indices and fat distribution would be similar to those between directly measured insulin sensitivity and fat distribution. Testing was performed in weight‐stable conditions in 59 African‐American (AA) and 62 white‐American (WA) overweight, premenopausal women before and after a weight loss intervention. Subjects were retested 1 year following weight loss. Proxy indices were correlated against the insulin sensitivity index SI determined via minimal modeling. Fat distribution was assessed using computed tomography. Correlations between Si and proxy indices were consistently stronger among overweight women (r = 0.44–0.52) vs. weight‐reduced women (r = 0.18–0.32), and among AA (r = 0.49–0.56, baseline; 0.24–0.36, weight‐reduced) vs. WA (r = 0.38–0.46, baseline; 0.19–0.31, weight‐reduced). Among subjects who regained >3 kg after 1 year, correlations between SI and proxy indices were similar to those observed at baseline, whereas correlations were weak among women who maintained their reduced body weight. SI and all proxy indices were similarly correlated with intra‐abdominal adipose tissue (IAAT) at baseline, but not after weight loss. In conclusion, correlations between SI and proxy indices were affected by both ethnicity and weight status. If proxy indices are used in multiethnic populations, or in populations including both lean and overweight/obese subjects, data should be interpreted with caution.
Influence of Central and Extremity Circumferences on All‐cause Mortality in Men and Women
Authors: Mason Caitlin , Craig Cora L. , Katzmarzyk Peter T.
Published: October 2008

For a given level of adiposity, greater lower body circumferences appear to exert a protective effect on several disease outcomes including cardiovascular disease and diabetes; however, the independent associations between extremity circumferences and mortality have not been widely investigated. The purpose of this study was to determine the independent and shared influences of upper‐ and lower‐body circumferences on the risk of mortality in a population‐based sample of adults. The sample included 10,638 adults 20–69 years of age (5,012 men; 5,626 women) from the nationally representative 1981 Canada Fitness Survey (CFS), who were monitored for over 12 years for mortality. BMI was calculated from measured height and weight. Waist, hip, thigh, calf, and upper arm circumferences were measured using a flexible, nonelastic anthropometric tape. Sex‐specific proportional hazards regression models were used to evaluate the relationship between standardized values (Z‐scores) of extremity circumference measures, waist circumference (WC) and mortality. Age, smoking status, alcohol consumption, and leisure‐time physical activity were collected by questionnaire and were included as covariates. During 131,563 person‐years of follow‐up, there were 340 deaths in men and 231 in women. After mutual adjustment, WC was positively associated with mortality whereas arm, thigh, and calf circumferences were significantly protective in men, and arm and thigh circumferences were protective in women. In conclusion, waist and extremity circumferences appear to have opposite, independent effects on mortality in this sample of Canadians. Independent of BMI and WC, men and women with larger extremity circumferences had a lower risk of mortality.
Lp(a) and Risk of Recurrent Cardiac Events in Obese Postinfarction Patients
Authors: Corsetti James P. , Ryan Dan , Rainwater David L. , Moss Arthur J. , Zareba Wojciech , Block Robert C. , Sparks Charles E.
Published: October 2008

Studies of recurrent coronary events in obese postinfarction patients show mixed results despite potential importance of obesity‐related pathophysiologic processes and associated markers in establishing and predicting risk. The study aim was to determine specific markers of recurrent risk in obese postinfarction patients. Nondiabetic patients of the Thrombogenic Factors and Recurrent Coronary Events (THROMBO) postinfarction study were classified according to BMI as normal weight (<25 kg/m2), overweight (25.0–29.9 kg/m2), and obese (≥30 kg/m2). Cox multivariable regression with adjustment for significant clinical covariates was performed in each group monitoring outcome (cardiac death, myocardial infarction (MI), or unstable angina with 26 months follow‐up) as a function of 17 thrombogenic, inflammatory, and metabolic blood markers and 17 cardiovascular disease‐associated genetic polymorphisms. Results revealed no statistically significant genetic or blood marker variables in normal or overweight patients. For obese postinfarction patients, elevated lipoprotein(a) (Lp(a))was found to be a highly significant risk marker with hazard ratio and 95% confidence interval of 3.94 (2.11–7.35), P = 0.000017 (upper tertile vs. lower two tertiles). Additionally, elevated Lp(a) was found to interact with the −75G>A polymorphism of the apolipoprotein A‐I gene and the −250G>A polymorphism of the hepatic lipase gene in establishing risk. We conclude that interactions of elevated Lp(a) with polymorphisms of the apolipoprotein A‐I and hepatic lipase genes, primarily reflective of altered lipoprotein metabolism, play an important role in the establishment of recurrent coronary event risk in obese, nondiabetic postinfarction patients. These findings suggest close monitoring and consideration of weight reduction for obese postinfarction patients with elevated Lp(a) levels.
Molecular cloning, characterization and expression of a jasmonate biosynthetic pathway gene encoding allene oxide cyclase from Camptotheca acuminata
Authors: Pi Yan , Liao Zhihua , Jiang Keji , Huang Beibei , Deng Zhongxiang , Zhao Dongli , Zeng Hainian , Sun Xiaofen , Tang Kexuan
Published: October 2008

AOC (allene oxide cyclase; EC 5.3.99.6), an essential enzyme in jasmonic acid and its methyl ester biosynthesis, was cloned from Camptotheca acuminata (named as CaAOC), a native medicinal plant species in China. CaAOC had significant similarity at the amino-acid level with AOCs from other plant species. Comparison between the sequences of the full-length cDNA and genomic DNA of CaAOC revealed that the genomic DNA of CaAOC contained an 89-bp intron and a 240-bp intron. Southern-blot analysis indicated that CaAOC was a multiple-copy gene, and real-time quantitative PCR analysis showed that CaAOC was expressed constitutively in all organs tested, with the highest expression level in leaves. The results from treatment experiments using different signalling components, including methyl jasmonate, abscisic acid, salicylic acid and H2O2, revealed that expression of CaAOC had a prominent diversity. Heavy metal (copper) significantly enhanced CaAOC expression, whereas wounding (induced by UV-B) was not so effective.