bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative analysis of skeletal muscle oxidative capacity in children and adults: a 31P-MRS study
Authors: Ratel Sébastien , Tonson Anne , Le Fur Yann , Cozzone Patrick , Bendahan David 
Published: July 2008

The aim of the present study was to compare the oxidative capacity of the forearm flexor muscles in vivo between children and adults using 31-phosphorus magnetic resonance spectroscopy. Seven boys (11.7 ± 0.6 y) and 10 men (35.6 ± 7.8 year) volunteered to perform a 3 min dynamic finger flexions exercise against a standardized weight (15% of the maximal voluntary contraction). Muscle oxidative capacity was quantified on the basis of phosphocreatine (PCr) post-exercise recovery kinetics analysis. End-of-exercise pH was not significantly different between children and adults (6.6 ± 0.2 vs. 6.5 ± 0.2), indicating that indices of PCr recovery kinetics can be reliably compared. The rate constant of PCr recovery (kPCr) and the maximum rate of aerobic ATP production were about 2-fold higher in young boys than in men (kPCr: 1.7 ± 1.2 vs. 0.7 ± 0.2 min–1; Vmax: 49.7 ± 24.6 vs. 29.4 ± 7.9 mmol·L–1·min–1, p < 0.05). Our results clearly illustrate a greater mitochondrial oxidative capacity in the forearm flexor muscles of young children. This larger ATP regeneration capacity through aerobic mechanisms in children could be one of the factors accounting for their greater resistance to fatigue during high-intensity intermittent exercise.
The influence of sex, menstrual cycle phase, estrogen, obesity, and endurance training on carbohydrate and lipid metabolism at rest and during moderate-intensity endurance exercise
Authors: Devries Michaela C. 
Published: July 2008

Carbohydrate (CHO) and fat constitute the main fuels used during endurance exercise. The purpose of this thesis was to determine how sex, menstrual cycle phase, estrogen, obesity, and endurance training (ET) influence substrate metabolism. In study 1, men (n = 11) and women (n = 13) underwent primed constant infusion of [6,6-2H] glucose with muscle biopsies taken before and after a 90 min bike ride at 65% VO2 peak. Luteal-phase women had lower muscle glycogen utilization compared with follicular-phase women. Women had lower respiratory exchange ratio (RER) and plasma glucose utilization than men. In study 2, men (n = 17) and women (n = 19) had muscle biopsies taken before and after a 90 min bike ride at 65% VO2 peak. Women had greater intramyocellular lipid (IMCL) content and lower RER during exercise, with no effect of sex on net IMCL utilization. In study 3, Men (n = 11) were treated with 17-β-estradiol (E2, 2 mg·d–1, 8 d) and placebo and underwent primed constant infusion of [6,6–2H] glucose with muscle biopsies taken before and after a 90 min bike ride at 65% VO2 peak. E2 lowered RER and plasma glucose oxidation during exercise, with no effect on muscle glycogen utilization. In study 4, lean (n = 12) and obese (n = 11) women underwent 12 weeks of ET with muscle biopsies taken before and after training. Obese women were insulin resistant compared with lean women. ET increased oxidative capacity and β-oxidation capacity, as well as mitochondrial content. ET redistributed IMCL from the subsarcolemmal region to the intermyofibrillar region of the muscle fibre. These studies demonstrate that substrate metabolism is affected by many factors in health and disease and the ability to manipulate these factors is of importance to athletes wishing to improve performance, as well as to obese individuals attempting to normalize an altered metabolic state.
Use of nondestructive testing to establish mechanistic-based seasonal load-carrying capacity of thin-paved highways in Saskatchewan
Authors: Berthelot Curtis , Stuber Erin , Podborochynski Diana , Fair Jena , Marjerison Brent 
Published: July 2008

It has long been known that increased load-carrying capacity during the winter months is very beneficial to rural road transportation in Saskatchewan. However, it has been observed that rapid weakening of thin-paved roads during spring thaw is highly detrimental to the load-carrying capacity of these roads. Direct measures of the structural integrity of Saskatchewan roads as a function of seasonal changes have not been quantified in the past. The objective of this study was to directly quantify the impact frost action has on the load-carrying capacity of thin-surfaced roads. This study examined the magnitude and rate of change of in situ structural deflection responses of a typical Saskatchewan thin-surfaced road during fall freeze-up and spring thaw in 2006–2007. This study showed that structural deflection responses significantly improved with frost depth greater than 50 cm and that deflection response significantly worsened with minimal thaw depth, as expected. The data obtained also indicated a significant increase in nonlinear strain weakening behavior during fall freeze-up at frost depths less than 50 cm. Therefore, based on the findings of this study, the frost thickness and the rate of change in frost thickness need to be directly considered in the fall and in the spring when calculating seasonal load limits of thin-paved roads.
Experimental study of interaction and coupling effects in pile groups subjected to torsion
Authors: Kong L. G. , Zhang L. M. 
Published: July 2008

Piles in a pile group subjected to torsion simultaneously mobilize lateral and torsional resistances. Hence, complicated pile–soil–pile interaction effects and load deformation coupling effects occur in the pile group. In this study, a series of centrifuge model tests were carried out to investigate these effects in three-diameter spaced 1 × 2, 2 × 2, and 3 × 3 pile groups subjected to torsion in both loose and dense sands. The test results showed that the effect of horizontal movement of a pile on lateral behaviors of its adjacent piles is significant in 3 × 3 pile groups and such effect varies with group configuration and pile position. The p-multiplier concept can be used to quantify the effect and values for the p-multiplier are suggested. The effect of lateral movement of a pile on the torsional resistances of its adjacent piles and the effect of torsional movement of a pile on the lateral resistances of its adjacent piles were found to be minor in these tests. For an individual pile in a pile group subjected to torsion, the mobilized lateral resistance was found to substantially increase the torsional resistance of the pile. Such a coupling effect is quantified by a coupling coefficient, β, which describes the contribution of subgrade reaction to the increase of torsional shear resistance.
Variation in yeast mitochondrial activity associated with asci
Authors: Swart Chantel W. , van Wyk Pieter W.J. , Pohl Carolina H. , Kock Johan L.F. 
Published: July 2008

An increase in mitochondrial membrane potential (ΔΨm) and mitochondrially produced 3-hydroxy (3-OH) oxylipins was experienced in asci of the nonfermentative yeasts Galactomyces reessii and Lipomyces starkeyi and the fermentative yeasts Pichia farinosa and Schizosaccharomyces octosporus . Strikingly, asci of Zygosaccharomyces bailii showed no increase in mitochondrial activity (ΔΨm and oxylipin production). As expected, oxygen deprivation only inhibited ascus formation in those yeasts with increased ascus mitochondrial activity. We conclude that ascus formation in yeasts is not always dependent on mitochondrial activity. In this case, fermentation may provide enough energy for ascus formation in Z. bailii.
Helicobacter pylori produces unique filaments upon host contact in vitro
Authors: Couturier Marc Roger , Stein Markus 
Published: July 2008

Helicobacter pylori exists in 2 distinct morphological states, helicoid and coccoid. Both have been observed in in vitro culture and in gastric biopsies. We visualized H. pylori during AGS cell infections using immunofluorescence microscopy. Anti-H. pylori mouse serum as well as human serum from H. pylori-positive patients recognized long, thin bacterial filaments, which formed on helicoids and more frequently on coccoids. These filaments reached lengths of 59 μm and often connected bacteria. Periodate oxidation abolished antibody recognition, suggesting that carbohydrates compose a major antigenic component of the filaments. Similar to results obtained using immunofluorescence microscopy, scanning electron microscopy imaging revealed thin filamentous structures, which were absent on uninfected cells. Both coccoid conversion and filament development increased over the time course of infection with peak filament formation at 4 h. The number of visible filaments then decreased as bacteria clustered on the apical surface of AGS cells. Since the observed filaments were clearly distinct from previously described surface structures, including flagella and the cag type IV secretion system, our results demonstrate that these filaments represent a unique, previously unrecognized, organelle.
Virulence properties and antimicrobial susceptibility of Shiga toxin-producing Escherichia coli strains isolated from healthy cattle from Paraná State, Brazil
Authors: Pigatto Caroline P. , Schocken-Iturrino Ruben P. , Souza Emanuel M. , Pedrosa Fábio O. , Comarella Larissa , Irino Kinue , Kato Maria Aidê M.F. , Farah Sônia M.S.S. , Warth José F. , Fadel-Picheth Cyntia M.T. 
Published: July 2008

The presence of Shiga toxin-producing Escherichia coli (STEC) strains in feces samples of cattle was determined using the cytotoxicity assay on Vero cells and a screening PCR system to detect stx genes. The STEC isolates were serotyped, tested for antimicrobial susceptibility, and analyzed for virulence genes using multiplex PCR. The verocytotoxin-producing E. coli – reverse passive latex agglutination (VTEC–RPLA) assay was also used to detect Shiga toxin production. The frequency of cattle shedding STEC was 36%. The isolates belonged to 33 different serotypes, of which O10:H42, O98:H41, and O159:H21 had not previously been associated with STEC. The most frequent serotypes were ONT:H7 (10%), O22:H8 (7%), O22:H16 (7%), and ONT:H21 (7%). Most of the strains (96%) were susceptible to all antimicrobial agents tested. Shiga toxin was detected by the VTEC–RPLA assay in most (89%) of the STEC strains. The frequency of virulence markers was as follows: stx1, 10%; stx2, 43%; stx1 plus stx2, 47%; ehxA, 44%; eae, 1%; and saa, 38%. Several strains belong to serotypes associated with human disease, and most of them carried a stx2-type gene, suggesting that they represent a risk to human health. The screening PCR assay showed fewer false-negative results for STEC than the Vero-cell assay and is suitable for laboratory routine.
ON THE EXISTENCE OF BRANCHED COVERINGS BETWEEN SURFACES WITH PRESCRIBED BRANCH DATA, II
Authors: PERVOVA EKATERINA , PETRONIO CARLO 
Published: July 2008

If [Formula: see text] is a branched covering between closed surfaces, there are several easy relations one can establish between the Euler characteristics [Formula: see text] and χ(Σ), orientability of Σ and [Formula: see text], the total degree, and the local degrees at the branching points, including the classical Riemann–Hurwitz formula. These necessary relations have been shown to be also sufficient for the existence of the covering except when Σ is the sphere 𝕊 (and when Σ is the projective plane, but this case reduces to the case Σ = 𝕊). For Σ = 𝕊 many exceptions are known to occur and the problem is widely open.Generalizing methods of Baránski, we prove in this paper that the necessary relations are actually sufficient in a specific but rather interesting situation. Namely under the assumption that Σ = 𝕊, that there are three branching points, that one of these branching points has only two pre-images with one being a double point, and either that [Formula: see text] and that the degree is odd, or that [Formula: see text] has genus at least one, with a single specific exception. For the case of [Formula: see text] we also show that for each even degree there are precisely two exceptions.
Common MMP-7 Polymorphisms and Breast Cancer Susceptibility: A Multistage Study of Association and Functionality
Authors: Beeghly-Fadiel Alicia , Long Ji-Rong , Gao Yu-Tang , Li Chun , Qu Shimian , Cai Qiuyin , Zheng Ying , Ruan Zhi-Xian , Levy Shawn E. , Deming Sandra L. , Snoddy Jay R. , Shu Xiao-ou , Lu Wei , Zheng Wei 
Published: July 2008

Abstract
Matrix metalloproteinase-7 (MMP-7) is a small secreted proteolytic enzyme with broad substrate specificity against ECM and non-ECM components. Known to be vital for tumor invasion and metastasis, accumulating evidence also implicates MMP-7 in cancer development. Using data from the Shanghai Breast Cancer Study, we conducted a two-stage study to evaluate the association of MMP-7 single nucleotide polymorphisms (SNPs) with breast cancer risk. Additionally, associated SNPs were characterized by laboratory assays. In stage 1, 11 SNPs were genotyped among 1,079 incident cases and 1,082 community controls using an Affymetrix Genotyping System. Promising SNPs were selected for stage 2 evaluation and genotyped by TaqMan allelic discrimination assays in an independent set of 1,911 cases and 1,811 controls. Three SNPs were selected for stage 2 validation (rs880197, rs10895304, and rs12184413); one had highly consistent results between the two stages of the study. In combined analysis, homozygosity for the variant T allele for rs12184413 was associated with an odds ratio (OR) of 0.7 [95% confidence interval (95% CI), 0.6–0.9] compared with the common C allele. This effect was slightly more pronounced in postmenopausal women (OR, 0.6; 95% CI, 0.4–0.8) than in premenopausal women (OR, 0.8; 95% CI, 0.6–1.1). This SNP is located 3′ of the MMP-7 gene, in an area enriched with CTCF binding sites. In silico analysis suggested a regulatory role for this region, and our in vitro assays showed an allelic difference in nuclear protein binding capacity. Results from our study suggest that common MMP-7 genetic polymorphisms may contribute to breast cancer susceptibility. [Cancer Res 2008;68(15):6453–9]
A Bulk Turbulent Air–Sea Flux Algorithm for High-Wind, Spray Conditions
Authors: Andreas Edgar L. , Persson P. Ola G. , Hare Jeffrey E. 
Published: July 2008

Abstract
Sensible and latent heat can cross the air–sea interface by two routes: as interfacial fluxes controlled by molecular processes right at the interface, and as spray fluxes from the surface of sea spray droplets. Once the 10-m wind speed over the ocean reaches approximately 11–13 m s−1, the spray sensible and latent heat fluxes become significant fractions (i.e., 10% or greater) of the corresponding interfacial fluxes. The analysis here establishes that result by combining the Tropical Ocean-Global Atmosphere Coupled Ocean–Atmosphere Response Experiment (COARE) version 2.6 bulk interfacial flux algorithm with a microphysical spray model to partition measured heat fluxes from two good high-wind datasets into spray and interfacial flux contributions. The measurements come from the Humidity Exchange over the Sea (HEXOS) experiment and the Fronts and Atlantic Storm-Tracks Experiment (FASTEX); wind speeds in these two datasets span 5 to 20 m s−1.
After the measured heat fluxes are separated into spray and interfacial contributions, the spray fluxes are used to develop a fast spray flux algorithm to combine with the COARE version 2.6 interfacial flux algorithm in a unified turbulent surface flux algorithm for use in large-scale and ocean storm models. A sensitivity analysis of the spray and interfacial components of this unified flux algorithm demonstrates how the two component fluxes scale differently with the mean meteorological variables and why they must therefore be parameterized separately in models intended to treat air–sea fluxes in high winds.
Large-Eddy Simulation of Langmuir Turbulence in Pure Wind Seas
Authors: Harcourt Ramsey R. , D’Asaro Eric A. 
Published: July 2008

Abstract
The scaling of turbulent kinetic energy (TKE) and its vertical component (VKE) in the upper ocean boundary layer, forced by realistic wind stress and surface waves including the effects of Langmuir circulations, is investigated using large-eddy simulations (LESs). The interaction of waves and turbulence is modeled by the Craik–Leibovich vortex force. Horizontally uniform surface stress τ0 and Stokes drift profiles uS(z) are specified from the 10-m wind speed U10 and the surface wave age CP/U10, where CP is the spectral peak phase speed, using an empirical surface wave spectra and an associated wave age–dependent neutral drag coefficient CD. Wave-breaking effects are not otherwise included. Mixed layer depths HML vary from 30 to 120 m, with 0.6 ≤ CP/U10 ≤ 1.2 and 8 m s−1 &lt; U10 &lt; 70 m s−1, thereby addressing most possible oceanic conditions where TKE production is dominated by wind and wave forcing.
The mixed layer–averaged “bulk” VKE 〈w2〉/u*2 is equally sensitive to the nondimensional Stokes e-folding depth D*S/HML and to the turbulent Langmuir number Lat = u*/US, where u* = |τ0|/ρw in water density ρw and US = |uS|z=0. Use of a D*S scale-equivalent monochromatic wave does not accurately reproduce the results using a full-surface wave spectrum with the same e-folding depth. The bulk VKE for both monochromatic and broadband spectra is accurately predicted using a surface layer (SL) Langmuir number LaSL = u*/〈uS〉SL, where 〈uS〉SL is the average Stokes drift in a surface layer 0 &gt; z &gt; − 0.2HML relative to that near the bottom of the mixed layer. In the wave-dominated limit LaSL → 0, turbulent vertical velocity scales as wrms ∼ u*La−2/3SL. The mean profile (z) of VKE is characterized by a subsurface peak, the depth of which increases with D*S/HML to a maximum near 0.22HML as its relative magnitude /〈w2〉 decreases. Modestly accurate scalings for these variations are presented. The magnitude of the crosswind velocity convergence scales differently from VKE. These results predict that for pure wind seas and HML ≅ 50 m, 〈w2〉/u*2 varies from less than 1 for young waves at U10 = 10 m s−1 to about 2 for mature seas at winds greater than U10 = 30 m s−1. Preliminary comparisons with Lagrangian float data account for invariance in 〈w2〉/u*2 measurements as resulting from an inverse relationship between U10 and CP/U10 in observed regimes.
Vorticity and Divergence of Surface Velocities Near Shore
Authors: Smith Jerome A. 
Published: July 2008

Abstract
The nearshore environment is complex, with many competing dynamical elements. Surface waves and edge waves (a form of surface wave trapped to the shore) can generally be separated from other forms of motion because of their fast propagation speeds. However, other motions such as internal waves, shear waves, density flows, and isolated vortex pairs can move at comparable speeds. A tool to help separate these dynamical elements is decomposition of the surface 2D flow into two parts, one nondivergent and the other irrotational (solenoidal and potential flows, respectively). Here, an efficient algorithm for this separation is developed and applied, and two examples are examined from data taken at Duck, North Carolina, in 1997 as part of the SandyDuck experiment. The first example is a fresher-water density flow propagating downcoast (probably from the Chesapeake Bay). It is seen that 1) the wave-driven alongshore flow leads the flow, generating a “surge” of offshore surface flow in its wake; 2) the isolation of the irrotational (2D divergent) part of the flow permits estimates of some dynamical characteristics of the flow; and 3) the nondivergent part of the flow indicates a meander in the alongshore flow that moves downcoast with the surge. The second example is a hypothesized form of isolated vortical structure, such as might be generated by a pulsed rip current that detaches from the shore and bottom and coasts offshore some distance before dissipating. A kinematically self-consistent structure is formulated that would have both divergence and vorticity fields associated with it. However, the observations inspiring the hypothesis are inconclusive, so the existence of such a structure has not been verified.
Value of Real-Time Vegetation Fraction to Forecasts of Severe Convection in High-Resolution Models
Authors: James Kenneth A. , Stensrud David J. , Yussouf Nusrat 
Published: July 2008

Abstract
Near-real-time values of vegetation fraction are incorporated into a 2-km nested version of the Advanced Research Weather Research and Forecasting (ARW) model and compared to forecasts from a control run that uses climatological values of vegetation fraction for eight severe weather events during 2004. It is hypothesized that an improved partitioning of surface sensible and latent heat fluxes occurs when incorporating near-real-time values of the vegetation fraction into models, which may result in improved forecasts of the low-level environmental conditions that support convection and perhaps even lead to improved explicit convective forecasts. Five of the severe weather events occur in association with weak synoptic-scale forcing, while three of the events occur in association with moderate or strong synoptic-scale forcing.
Results show that using the near-real-time values of the vegetation fraction alters the values and structure of low-level temperature and dewpoint temperature fields compared to the forecasts using climatological vegetation fractions. The environmental forecasts that result from using the real-time vegetation fraction are more thermodynamically supportive of convection, including stronger and deeper frontogenetic circulations, and statistically significant improvements of most unstable CAPE forecasts compared to the control run. However, despite the improved environmental forecasts, the explicit convective forecasts using real-time vegetation fractions show little to no improvement over the control forecasts. The convective forecasts are generally poor under weak synoptic-scale forcing and generally good under strong synoptic-scale forcing. These results suggest that operational forecasters can best use high-resolution forecasts to help diagnose environmental conditions within an ingredients-based forecasting approach.
Predicting Atlantic Tropical Cyclone Seasonal Activity in April
Authors: Keith Elinor , Xie Lian 
Published: July 2008

AbstractSeasonal hurricane forecasts are continuing to develop skill, although they are still subject to large uncertainties. This study uses a new methodology of cross-correlating variables against empirical orthogonal functions (EOFs) of the hurricane track density function (HTDF) to select predictors. These predictors are used in a regression model for forecasting seasonal named storm, hurricane, and major hurricane activity in the entire Atlantic, the Caribbean Sea, and the Gulf of Mexico. In addition, a scheme for predicting landfalling tropical systems along the U.S. Gulf of Mexico, southeastern, and northeastern coastlines is developed, but predicting landfalling storms adds an extra layer of uncertainty to an already complex problem, and on the whole these predictions do not perform as well.The model performs well in the basin-wide predictions over the entire Atlantic and Caribbean, with the predictions showing an improvement over climatology and random chance at a 95% confidence level. Over the Gulf of Mexico, only named storms showed that level of predictability. Predicting landfalls proves more difficult, and only the prediction of named storms along the U.S. southeastern and Gulf coasts shows an improvement over random chance at the 95% confidence level. Tropical cyclone activity along the U.S. northeastern coast is found to be unpredictable in this model; with the rarity of events, the model is unstable.