bluuebunny/crossref_metadata_2025 huggingface dataset:
Cell (patho)physiology of magnesium
Authors: Wolf Federica I. , Trapani Valentina
Published: November 2007

There is an unsettled debate about the role of magnesium as a ‘chronic regulator’ of biological functions, as opposed to the well-known role for calcium as an ‘acute regulator’. New and old findings appear to delineate an increasingly complex and important role for magnesium in many cellular functions. This review summarizes the available evidence for a link between the regulation of intracellular magnesium availability and the control of cell growth, energy metabolism and death, both in healthy and diseased conditions. A comprehensive view is precluded by technical difficulties in tracing magnesium within a multicompartment and dynamic environment like the cell; nevertheless, the last few years has witnessed encouraging progress towards a better characterization of magnesium transport and its storage or mobilization inside the cell. The latest findings pave the road towards a new and deeper appreciation of magnesium homoeostasis and its role in the regulation of essential cell functions.
A Multinomial Model for Identifying Significant Pure-Tone Threshold Shifts
Authors: Schlauch Robert S. , Carney Edward
Published: November 2007

Purpose

Significant threshold differences on retest for pure-tone audiometry are often evaluated by application of ad hoc rules, such as a shift in a pure-tone average or in 2 adjacent frequencies that exceeds a predefined amount. Rules that are so derived do not consider the probability of observing a particular audiogram.

Methods

A general solution for evaluating threshold differences on retest was developed on the basis of multinomial probabilities. The model uses the standard deviation of inter-test differences for 1 frequency as a parameter of the underlying Gaussian distribution of test results. The number of test frequencies, the categories of threshold change, and the probability of each category’s occurrence are used to calculate the probability that a given pattern of threshold differences on retest (or 1 rarer) could occur by chance.

Results

The multinomial model was compared with 2 other methods for identifying threshold shifts in persons exposed to high sound pressure levels during concerts. The multinomial model identified the same audiograms as the ad hoc methods.

Conclusion

Tables developed using a multinomial model can provide a clinical tool for evaluating audiograms by identifying statistically significant patterns of test–retest differences in hearing thresholds.
Late Language Emergence at 24 Months: An Epidemiological Study of Prevalence, Predictors, and Covariates
Authors: Zubrick Stephen R. , Taylor Catherine L. , Rice Mabel L. , Slegers David W.
Published: November 2007

Purpose

The primary objectives of this study were to determine the prevalence of late language emergence (LLE) and to investigate the predictive status of maternal, family, and child variables.

Method

This is a prospective cohort study of 1,766 epidemiologically ascertained 24-month-old singleton children. The framework was an ecological model of child development encompassing a wide range of maternal, family, and child variables. Data were obtained using a postal questionnaire. Item analyses of the 6-item Communication scale of the Ages and Stages Questionnaire (ASQ; D. Bricker & J. Squires, 1999; J. Squires & D. Bricker, 1993; J. Squires, D. Bricker, & L. Potter, 1997; J. Squires, L. Potter, & D. Bricker, 1999) yielded a composite score encompassing comprehension as well as production items. OneSDbelow the mean yielded good separation of affected from unaffected children. Analyses of bivariate relationships with maternal, family, and child variables were carried out, followed by multivariate logistic regression to predict LLE group membership.

Results

13.4% of the sample showed LLE via the ASQ criterion, with 19.1% using the single item of “combining words.” Risk for LLE at 24 months was not associated with particular strata of parental educational levels, socioeconomic resources, parental mental health, parenting practices, or family functioning. Significant predictors included familial history of LLE, male gender, and early neurobiological growth. Covariates included psychosocial indicators.

Conclusion

Results are congruent with models of language emergence and impairment that posit a strong role for neurobiological and genetic mechanisms of onset that operate across a wide variation in maternal and family characteristics.
Snow and ice crystals
Authors: Furukawa Yoshinori , Wettlaufer John S.
Published: November 2007

Highly dendritic snowflakes are an aesthetic source of wonder, but the greater challenge for physicists lies in understanding the “simpler” prismatic and planar forms.
Ancient jades map 3,000 years of prehistoric exchange in Southeast Asia
Authors: Hung Hsiao-Chun , Iizuka Yoshiyuki , Bellwood Peter , Nguyen Kim Dung , Bellina Bérénice , Silapanth Praon , Dizon Eusebio , Santiago Rey , Datan Ipoi , Manton Jonathan H.
Published: November 2007

We have used electron probe microanalysis to examine Southeast Asian nephrite (jade) artifacts, many archeologically excavated, dating from 3000 B.C. through the first millennium A.D. The research has revealed the existence of one of the most extensive sea-based trade networks of a single geological material in the prehistoric world. Green nephrite from a source in eastern Taiwan was used to make two very specific forms of ear pendant that were distributed, between 500 B.C. and 500 A.D., through the Philippines, East Malaysia, southern Vietnam, and peninsular Thailand, forming a 3,000-km-diameter halo around the southern and eastern coastlines of the South China Sea. Other Taiwan nephrite artifacts, especially beads and bracelets, were distributed earlier during Neolithic times throughout Taiwan and from Taiwan into the Philippines.
Monte Carlo feature selection for supervised classification
Authors: Dramiński Michał , Rada-Iglesias Alvaro , Enroth Stefan , Wadelius Claes , Koronacki Jacek , Komorowski Jan
Published: November 2007

Motivation: Pre-selection of informative features for supervised classification is a crucial, albeit delicate, task. It is desirable that feature selection provides the features that contribute most to the classification task per se and which should therefore be used by any classifier later used to produce classification rules. In this article, a conceptually simple but computer-intensive approach to this task is proposed. The reliability of the approach rests on multiple construction of a tree classifier for many training sets randomly chosen from the original sample set, where samples in each training set consist of only a fraction of all of the observed features.

Results: The resulting ranking of features may then be used to advantage for classification via a classifier of any type. The approach was validated using Golub et al. leukemia data and the Alizadeh et al. lymphoma data. Not surprisingly, we obtained a significantly different list of genes. Biological interpretation of the genes selected by our method showed that several of them are involved in precursors to different types of leukemia and lymphoma rather than being genes that are common to several forms of cancers, which is the case for the other methods.

Availability: Prototype available upon request.

Contact:  jan.komorowski@lcb.uu.se
Hormone-mediated maternal effects in birds:mechanismsmatter but what do we know of them?
Authors: Groothuis Ton. G.G , Schwabl Hubert
Published: November 2007

Over the past decade, birds have proven to be excellent models to study hormone-mediated maternal effects in an evolutionary framework. Almost all these studies focus on the function of maternal steroid hormones for offspring development, but lack of knowledge about the underlying mechanisms hampers further progress. We discuss several hypotheses concerning these mechanisms, point out their relevance for ecological and evolutionary interpretations, and review the relevant data. We first examine whether maternal hormones can accumulate in the egg independently of changes in hormone concentrations in the maternal circulation. This is important for Darwinian selection and female physiological trade-offs, and possible mechanisms for hormone accumulation in the egg, which may differ among hormones, are reviewed. Although independent regulation of plasma and yolk concentrations of hormones is conceivable, the data are as yet inconclusive for ovarian hormones. Next, we discuss embryonic utilization of maternal steroids, since enzyme and receptor systems in the embryo may have coevolved with maternal effect mechanisms in the mother. We consider dose–response relationships and action pathways of androgens and argue that these considerations may help to explain the apparent lack of interference of maternal steroids with sexual differentiation. Finally, we discuss mechanisms underlying the pleiotropic actions of maternal steroids, since linked effects may influence the coevolution of parent and offspring traits, owing to their role in the mediation of physiological trade-offs. Possible mechanisms here are interactions with other hormonal systems in the embryo. We urge endocrinologists to embark on suggested mechanistic studies and behavioural ecologists to adjust their interpretations to accommodate the current knowledge of mechanisms.
Early growth conditions, phenotypic development and environmental change
Authors: Monaghan Pat
Published: November 2007

Phenotypic development is the result of a complex interplay involving the organism's own genetic make-up and the environment it experiences during development. The latter encompasses not just the current environment, but also indirect, and sometimes lagged, components that result from environmental effects on its parents that are transmitted to their developing offspring in various ways and at various stages. These environmental effects can simply constrain development, for example, where poor maternal condition gives rise to poorly provisioned, low-quality offspring. However, it is also possible that environmental circumstances during development shape the offspring phenotype in such a way as to better prepare it for the environmental conditions it is most likely to encounter during its life. Studying the extent to which direct and indirect developmental responses to environmental effects are adaptive requires clear elucidation of hypotheses and careful experimental manipulations. In this paper, I outline how the different paradigms applied in this field relate to each other, the main predictions that they produce and the kinds of experimental data needed to distinguish among competing hypotheses. I focus on birds in particular, but the theories discussed are not taxon specific. Environmental influences on phenotypic development are likely to be mediated, in part at least, by endocrine systems. I examine evidence from mechanistic and functional avian studies and highlight the general areas where we lack key information.
Androgen Excess Is Associated With Insulin Resistance and the Development of Diabetes in African American Women
Authors: Boyd‐Woschinko Gillian , Kushner Harvey , Falkner Bonita
Published: November 2007

This study investigated the role of relative androgen excess, designated by low sex hormone‐binding globulin (SHBG), on development of type 2 diabetes in premenopausal African American women. A prospective, longitudinal study was conducted on premenopausal African American women, initially aged 36 to 43 years (n=119). Patients were reexamined 8 years later to determine whether initial androgen status was associated with insulin resistance and development of diabetes. Among patients in the low SHBG tertile, 18% converted to type 2 diabetes by the second examination, as compared with 5% in the mid SHBG tertile and 2.5% in the high SHBG tertile (P=.04). Insulin sensitivity was significantly different among the 3 tertiles (P<.01). There was no significant difference in total cholesterol, high‐density lipoprotein, low‐density lipoprotein, or triglycerides among the SHBG tertiles. This prospective study demonstrates that relative androgen excess is associated with insulin resistance and increases the risk for development of diabetes in premenopausal African American women.
Zinc inhibition of rat NR1/NR2AN‐methyl‐d‐aspartate receptors
Authors: Erreger Kevin , Traynelis Stephen F.
Published: November 2007

Zinc ions (Zn2+) are localized in presynaptic vesicles at glutamatergic synapses and released in an activity‐dependent manner. Modulation of NMDA‐type glutamate receptors by extracellular Zn2+may play an important role under physiological conditions and during pathologies such as ischaemia or seizure. Zn2+inhibits NMDA receptors containing the NR2A subunit with an IC50value in the low nanomolar concentration range. Here we investigate at the single‐channel level the mechanism of high affinity Zn2+inhibition of recombinant NR1/NR2A receptors expressed in HEK293 cells. Zn2+reversibly decreases the mean single‐channel open duration and channel open probability determined in excised outside‐out patches, but has no effect on single‐channel current amplitude. A parallel series of experiments demonstrates that lowering extracellular pH (increasing proton concentration) has a similar effect on NR1/NR2A single‐channel properties as Zn2+. Fitting the sequence of single‐channel events with kinetic models suggests that the association of Zn2+with its binding site enhances proton binding. Modelling further suggests that protonated channels are capable of opening but with a lower open probability than unprotonated channels. These data and analyses are consistent with Zn2+‐mediated inhibition of NMDA receptors primarily reflecting enhancement of proton inhibition.
Prediction of Leading-Edge Sheet Cavitation Inception on Hydrofoils at Low to Moderate Reynolds Number Flows
Authors: Rusak Zvi , Morris Wallace J. , Peles Yoav
Published: November 2007

The inception of leading-edge sheet cavitation on two-dimensional smooth thin hydrofoils at low to moderately high Reynolds number flows is investigated by an asymptotic approach and numerical simulations. The asymptotic theory is based on the work of Rusak (1994, “Subsonic Flow Around Leading Edge of a Thin Aerofoil With a Parabolic Nose,” Eur. J. Appl. Mech., 5, pp. 283–311) and demonstrates that the flow about a thin hydrofoil can be described in terms of an outer region, around most of the hydrofoil chord, and an inner region, around the nose, which asymptotically match each other. The flow in the outer region is dominated by the classical thin hydrofoil theory. Scaled (magnified) coordinates and a modified (smaller) Reynolds number (ReM) are used to correctly account for the nonlinear behavior and extreme velocity changes in the inner region, where both the near-stagnation and high suction areas occur. It results in a model (simplified) problem of a uniform flow past a semi-infinite smooth parabola with a far-field circulation governed by a parameter Ã that is related to the hydrofoil’s angle of attack, nose radius of curvature, and camber. The model parabola problem consists of a viscous flow that is solved numerically for various values of Ã and ReM to determine the minimum pressure coefficient and the cavitation number for the inception of leading-edge cavitation as function of the hydrofoil’s geometry, flow Reynolds number, and fluid thermodynamic properties. The predictions according to this approach show good agreement with results from available experimental data. This simplified approach provides a universal criterion to determine the onset of leading-edge (sheet) cavitation on hydrofoils with a parabolic nose in terms of the similarity parameters Ã and ReM and the effect of hydrofoil’s thickness ratio, nose radius of curvature, camber, and flow Reynolds number on the onset.
Flow Field Characterization at the Onset of Gas Entrainment in a Single Downward Discharge Using Particle Image Velocimetry
Authors: Bowden R. C. , Hassan I. G.
Published: November 2007

The incipience of two-phase flow in discharging branches from a stratified gas-liquid region has major implications in industrial applications where safety is of concern. An experimental investigation of the liquid side flow field at the onset of gas entrainment, in a single downward oriented discharging branch, was presented. Particle image velocimetry was used to measure the liquid side flow field in horizontal and vertical planes. Averaged velocity profiles were presented and demonstrated a highly radial flow. The particle image velocimetry data were validated using continuity and showed that the mass flow rate to be in the range of 10–25% of the expected value. Further, the vortex-free flow field assumption, used previously in the development of analytical and empirical models, was found to be reasonable.
Flow Regimes and Drag Characteristics of Yawed Elliptical Cavities With Varying Depth
Authors: Hering Thomas , Savory Eric
Published: November 2007

The effect of yaw angle and cavity depth on the resulting flow field of cavities with elliptical planform areas embedded in a low velocity turbulent boundary layer was investigated experimentally. A 2:1 elliptical cavity with depth to minor axis ratios ranging from 0.1 to 1.0 was tested in a wind tunnel facility. Surface pressure measurements and wake velocity measurements, using hot-wire anemometry, were conducted to examine the resulting flow regimes. The results indicated several different flow regimes for the different yaw angle and cavity depth configurations. Cellular structures were observed when the minor axis was aligned with the streamwise direction. Yawing the cavity with respect to the streamwise direction resulted in a highly asymmetric flow regime. This flow regime was also associated with high drag for certain cavity depth configurations. A nominally two-dimensional flow regime was observed for large yaw angles, when the major axis of the cavity was aligned with the streamwise direction. The yaw angle had only a minor effect on the flow regimes associated with the shallowest and deepest cavities examined. A strong resemblance was found between the flow regimes associated with elliptical and rectangular cavities for similar yaw and depth configurations. This similarity was also observed in the lift and drag coefficients for the different yaw angles and cavity depths. This indicated that the wall radius of curvature of elliptical cavities has a negligible effect on the resulting flow regimes when compared to rectangular cavities.
Implicit Large-Eddy Simulation in Meteorology: From Boundary Layers to Climate
Authors: Smolarkiewicz Piotr K. , Margolin Len G. , Wyszogrodzki Andrzej A.
Published: November 2007

The dynamics of the atmosphere and oceans pose a severe challenge to the numerical modeler, due in large part to the broad range of scales of length and time that are encompassed. Modern numerical methods based on nonoscillatory finite volume (NFV) approximations provide a simple and effective means for mitigating this challenge by reproducing the large scale behavior of turbulent flows with no need for explicit subgrid-scale models. In this paper, we describe the remarkable properties of a particular NFV model, multidimensional positive definite advection transport algorithm, and highlight its application to a variety of meteorological and turbulent flows.
Axisymmetric two-sphere sedimentation in a shear thinning viscoelastic fluid: Particle interactions and induced fluid velocity fields
Authors: Verneuil Emilie , Phillips Ronald J. , Talini Laurence
Published: November 2007

We investigate the link between particle interactions and induced flow patterns around two identical spheres sedimenting along their centerline in a polymeric fluid. The fluid is strongly shear thinning and, in agreement with previous results, the spheres are observed to chain even at large initial separation distances. The wake of a single particle displays an upward motion of fluid, i.e., a “negative wake” that is commonly observed in fluids with low extensional viscosities. We show that the features of this negative wake vary only weakly with the Deborah number. In the two-sphere case, the pattern of the induced flow depends on the sphere separation distance. The change in the flow pattern does not, however, induce any significant qualitative change in the sphere interactions. Upstream of the leading sphere and downstream of the trailing one along the sedimentation axis, the variations of the fluid velocity are well described by a single master curve for different values of the sphere separation distance. The existence of such a curve indicates that non-Newtonian effects near each particle are dominated by local conditions near the sphere surfaces, and are only weakly influenced by the presence of a second sphere.
Flow–induced chain scission in dilute polymer solutions: Algorithm development and results for scission dynamics in elongational flow
Authors: Sim H. G. , Khomami B. , Sureshkumar R.
Published: November 2007

Based on covalent bond scission force estimates from single molecule experiments and a statistical analysis of the instantaneous segmental tension (ST) distribution in bead-rod chains, a new algorithm has been developed for the simulation of flow-induced polymer chain scission. This algorithm overcomes the nonphysical time-step dependence inherent in stochastic chain scission simulations that employ instantaneous ST-based criteria to identify scission events. This is accomplished by the use of a normalized ST profile that is independent of the elongation rate E for asymptotically large values of the Weissenberg number, defined as the ratio of the longest relaxation time of the chain to 1∕E. The algorithm is employed to study chain scission in steady and transient elongational flows as well as the effect of hydrodynamic interactions on chain scission in steady elongational flow. Simulation results for steady elongational flow reproduce the experimentally observed scaling law for the critical elongation rate Ec∝Mw−2 where Mw denotes the molecular weight. Moreover, for E≈Ec, the chains unravel via a coil-to-stretch configurational transition. Since ST attains its maximum at the midpoint of the chain, the midpoint scission hypothesis (MSH) is valid. This leads to a relatively narrow distribution of daughter chains. However, for E≫Ec, sufficiently large ST could develop in the elongated portions of partially coiled chains. Consequently, chain scission could occur farther from the midpoint. MSH is not valid under such conditions, and the resulting distribution of daughter chains is relatively broad. Hydrodynamic interactions are shown to slow down chain unraveling leading to an increase in Ec with the scaling Ec∝Mw−1.7. The effect of polymer residence time on Ec is examined by investigating scission of polymer chains that traverse the centerline of a regularized contraction flow. It is found that the scaling relationship between Ec and Mw remains the same as that for steady elongational flow given that the residence time exceeds 5% of the longest relaxation time of the chain. This result suggests that the inverse proportionality of Ec to Mw observed experimentally in contraction flow might be due to preshearing effects. Finally, the effect of loading rate onscission probability is discussed in the context of an extended thermally activated barrier to scission model.
Linear and nonlinear viscoelastic behavior of very concentrated plate-like kaolin suspensions
Authors: Bossard Frédéric , Moan Michel , Aubry Thierry
Published: November 2007

The viscoelastic behavior of very concentrated and electrostatically stabilized suspensions of kaolinite particles has been investigated in the linear and nonlinear regime as a function of volume fraction, ionic strength and in the presence of polymer at various concentrations. Material properties such as linear viscoelastic moduli and cohesive energy density are extensively enhanced by either increasing volume fraction or decreasing ionic strength. Attention has been paid to the large amplitude oscillatory shear behavior of concentrated suspensions of plate-like particles, characterized by a hump in G″ curves. Rheological investigation shows the extreme sensitivity of the intensity of the strain hardening in G″ to excluded volume, electrostatic and steric interactions. A physical interpretation of this nonlinear behavior has been proposed.
Fourier-transform rheology under medium amplitude oscillatory shear for linear and branched polymer melts
Authors: Hyun Kyu , Baik En Su , Ahn Kyung Hyun , Lee Seung Jong , Sugimoto Masataka , Koyama Kiyohito
Published: November 2007

Nonlinear response of linear and branched polymers has been investigated under medium strain amplitude oscillatory shear (strain amplitude range from 10% to 100%) with Fourier-transform rheology. A power law relationship was found between the relative third intensity (I3∕I1), which is an indicator of nonlinearity, and the strain amplitude at low and medium strain amplitudes. On a log-log plot, the intercept and slope of I3∕I1 were investigated at different excitation frequencies and temperatures. Simulation results with three different constitutive equations [Giesekus, exponential Phan-Thien Tanner (E-PTT), pom-pom model] were also compared. Experimental results show that the intercept was affected by the excitation frequency and temperature, and the slope of I3∕I1 for linear polymer remained constant regardless of molecular weight, molecular weight distribution, and excitation frequency in accordance with the predictions of the constitutive equations (Giesekus and E-PTT). It should be noted that the slope of I3∕I1 for branched polymer was lower than that of linear polymer, unlike the prediction of the pom-pom model. Among the molecular architecture and processing parameters (e.g., molecular weight, molecular weight distribution, frequency, and temperature), the slope of I3∕I1 under medium amplitude oscillatory shear was found to depend only on the long chain branching, which means that it can be used as a measure of the degree of branching. The failure of the pom-pom model in predicting the nonlinear shear behavior was also pointed out.
Effect ofGanoderma lucidumcapsules on T lymphocyte subsets in football players on “living high−training low”
Authors: Zhang Y , Lin Z , Hu Y , Wang F
Published: November 2007

Objective:

G lucidumis a popular Chinese herb with an impressive array of reputed health benefits. The purpose of this study was to provide information related to the modulating effect ofG lucidumcapsules on T lymphocyte subsets in football players during a 28-day “living high−training low ”(LHTL) trial and their possible mechanism of action.

Methods:

Forty male football players were randomly assigned to four groups: control (living at sea level), LHTL1, LHTL2 and LHTL3. The three LHTL groups had stayed in normobaric hypoxic rooms for 28 days. The four groups trained together at sea level. LHTL1, LHTL2 and LHTL3 groups were provided with placebo,G lucidum10 capsules/day andG lucidum20 capsules/day, respectively, for 6 weeks (2 weeks baseline supplementation followed by 28 days of the treatment protocol). Lymphocyte subsets were quantitated using flow cytometry.

Results:

In the LHTL1 group, when the CD4+/CD8+ratio was expressed as relative changes from the baseline, a significant decrease was seen following the 28-day trial compared to the baseline. Furthermore, a significant decrease was observed between LHTL1 and control groups at 21 days. In the LHTL2 group, the relative change of CD4+/CD8+ratio from the baseline was significantly lower at 28 days compared with the pretrial baseline. Generally, in the LHTL3 group there was a trend for the per cent changes of the CD4+/CD8+ratio from the baseline to be higher than the values for the LHTL1 and LHTL2 groups, but this was not significant.

Conclusion:

LHTL could affect T lymphocyte subsets significantly as a result of the two simultaneous stimuli of physical activity and exposure to hypoxia. The ingestion ofG lucidumin the LHTL3 group could help to ameliorate the variation of the CD4+/CD8+ratio in LHTL training, and polysaccharides fromG lucidummight be the main active components for the cell-mediated immune function.
Osteoporotic fracture in an elite male Kenyan athlete: Figure 1
Authors: Pollock N , Hamilton B
Published: November 2007

An elite Kenyan runner presented with a tibial fracture sustained during an international cross-country race. There was no clear history of symptoms suggestive of preceding overload and no radiological features of stress fracture. He was found to have sustained an osteoporotic, insufficiency fracture. There are no previous case reports of an osteoporotic fracture in a male athlete. Possible aetiologies and directions for future investigation are presented.
Off-the-shelf in-shoe heel inserts: does cost matter?
Authors: Ramanathan A K , John M C , Arnold G P , Cochrane L A , Abboud R J
Published: November 2007

Objective:

A growing exercise culture has lead to an increase in the use of off-the-shelf heel inserts. While there are a variety of designs in a spectrum of cost ranges, probably the ease of availability and cost would mainly determine the choice of purchase. This study was designed to determine whether expensive designs provide better pressure attenuation under the heel than their less expensive counterparts.

Participants and Design:

Six brands of off-the-shelf heel inserts were tested. Selection of these was based purely on their availability in all sizes. Cost per pair ranged from £6 to £30. Thirty-five asymptomatic subjects walked on a 10 m walkway, once with no inserts and once with each pair of inserts. The Pedar in-shoe system recorded a range of parameters under the heel.

Setting:

Institute of Motion Analysis and Research, Ninewells Hospital and Medical School, University of Dundee.

Main outcome measures:

Evaluation of plantar pressure parameters under the heel.

Results:

All inserts reduced peak pressure under the heel. Maximum force and pressure-time integral also decreased. Contact time generally increased with the use of inserts. Values of contact area with and without inserts were comparable.

Conclusions:

No significant differences were observed under the heel between the pressure attenuation properties of the lowest-priced and the most expensive designs, and hence the less expensive inserts can be considered as good as the expensive brands. However, the endurance power of these inserts may differ and this should be evaluated.
Energy expenditure during a single-handed transatlantic yacht race
Authors: Myers S D , Leamon S M , Nevola V R , Llewellyn M G L
Published: November 2007

Background:

The popularity of sports that expose people to consecutive days of high-intensity physical activity continues to increase. The ability to adequately nourish the human body to sustain the required level of competitive performance may be a key contributor to success in such events.

Methods:

The energy expenditure of a male competitor in a single-handed, transatlantic race (Transat 2004) was assessed using the doubly-labelled water technique.

Results:

Mean total daily energy expenditure (TDEE) during the race (13 days) was 14.5 MJ/day with a peak expenditure of 18.6 MJ during the most physically demanding 24-hour period.

Discussion:

This mean TDEE was approximately 25% lower than that reported in a previous study (14.5 vs. 19.3 MJ/day) for a 13-day leg of a fully crewed offshore race. The difference in results was probably due to the fact that in the previous study, the crew operated in “watches” (work shifts), affording each crew member greater opportunity to eat, rest and sleep. Effective planning and efficient management of resources is essential to the success of the solo sailor. However, the extent to which maintenance of energy balance underpins competitive success remains to be established. To maintain energy balance during the race, a mean daily energy intake of 14.5 MJ/day was necessary for the subject in this study. However, this mean value for energy intake would have been inadequate to match the peak energy expended during the most physically demanding 24 hours of the race.
Injuries to junior club cricketers: the effect of helmet regulations
Authors: Shaw L , Finch C F
Published: November 2007

Objective:

Despite the popularity of cricket at the junior community level, few studies have described injuries for this level of play. This study describes the epidemiology of cricket injuries in junior club cricket across three playing seasons to identify priorities for prevention.

Design:

Prospective on-field injury data collection during match observation of acute injuries. Pre and post observational evaluation of mandatory helmet wearing.

Setting:

The Sutherland Shire Junior Cricket Association, New South Wales, Australia during the 2002–03, 2003–04 and 2004–05 playing seasons.

Participants:

All junior teams (Under 8 (U8)–U16).

Intervention:

Compulsory headgear introduced for all batters before the 2004–05 season.

Main outcome measures:

Frequency of injury according to age level, grade of play and playing position, and injury rates per 100 registered players.

Results:

155 injuries were reported. No U8 player sustained an injury, and injury frequency increased with age. Traditional cricket was associated with more injuries than modified cricket. At each age level, the most skilled players had the lowest frequency of injury. Overall, batting accounted for 49% of all injuries and 29% occurred when fielding; contact with a moving ball was responsible for 55% of injuries. The most commonly injured body region was the face (20%), followed by the hand (14%). In batters, the frequency of head/neck/facial injuries fell from 62% in 2002/03 to 35% in 2003–04 to just 4% in 2004–05 after headgear use was compulsory.

Conclusions:

Injury rates in junior players are low, but increase with age and level of play. Use of protective headgear, particularly by batters, leads to a significant reduction in injuries.
Specific diving training-induced arterial circulation changes
Authors: Gole Y , Louge P , Boussuges A
Published: November 2007

Objective:

Several stressors such as cold water immersion, hyperoxic exposure and decompression-induced circulating bubbles can alter arterial circulation after a dive. The aim of this study was to investigate the arterial modifications induced by a specific diving training including repeated hyperbaric exposures and physical training.

Method:

Arterial pressure measurement and pulse wave velocity (PWV) recordings were performed in 12 student military divers before and after 15 weeks’ training. The results were compared with the same investigations performed in 12 non-diver healthy subjects.

Results:

A decrease in systolic blood pressure and pulse pressure was observed at both upper and lower limbs in student military divers after the training. Non-significant decreases in both carotido-femoral PWV and carotido-pedal PWV were found after the training. When the pulse time transit was divided by the cardiac cycle length between two R peaks ((RR) interval), a significant increase was observed between the carotid and femoral sensors. On the other hand, some differences were noticed between military divers and controls. Controls and divers were matched appropriately according to age and height, although the divers had a higher aerobic capacity as well as lower resting heart rate and lower pulse wave velocity.

Conclusion:

In trained military subjects, a training which includes repeated diving exposures and endurance exercises leads to vascular modifications suggesting an increase in central arterial compliance. There was no sign of arterial alteration induced by repeated diving exposures.
Isolated proximal tibiofibular joint dislocation in an elite rugby union player: Figure 1
Authors: MacGiobain S , Quinlan J F , O’Malley N , Brophy D , Quinlan W R
Published: November 2007

The case is presented of a professional international rugby union player who sustained an isolated proximal tibiofibular dislocation in a training ground injury. Diagnosis was made based on clinical details, plain radiography and magnetic resonance imaging. An initial attempt at closed reduction failed. Open reduction and internal fixation were subsequently carried out. Following early rehabilitation, the patient made a successful try-scoring return to international rugby union.
From cure to palliation: concept, decision and acceptance: Table 1
Authors: Löfmark R , Nilstun T , Bolmsjö I Ågren
Published: November 2007

The aim of this paper is to present and discuss nurses’ and physicians’ comments in a questionnaire relating to patients’ transition from curative treatment to palliative care. The four-page questionnaire relating to experiences of and attitudes towards communication, decision-making, documentation and responsibility of nurses and physicians and towards the competence of patients was developed and sent to a random sample of 1672 nurses and physicians of 10 specialties. The response rate was 52% (n = 844), and over one-third made comments. The respondents differed in their comments about three areas: the concept of palliative care, experiences of unclear decision-making and difficulties in acceptance of the patient’s situation. The responses are analysed in terms of four ethical theories: virtue ethics, deontology, consequentialism and casuistry. Many virtues considered to be appropriate for healthcare personnel to possess were invoked. Compassion, honesty, justice and prudence are especially important. However, principles of medical ethics, such as the deontological principle of respect for self-determination and the consequence of avoidance of harm, are also implied. Casuistry may be particularly helpful in analysing certain areas of difficulty—namely, what is meant by “palliative care”, decision-making and accepting the patient’s situation. Keeping a patient in a state of uncertainty often causes more suffering than necessary. Communication among the staff and with patients must be explicit. Many of the staff have not had adequate training in communicating with patients who are at the end of their life. Time for joint reflection has to be regained, and training in decision-making is essential. In our opinion, palliative care in Sweden is in need of improvement.
The intersubjective and the intrasubjective in the patient–physician dyad: implications for medical humanities education
Authors: Kuper Ayelet
Published: November 2007

At the heart of medicine is the patient, and the fundamental relationship in medicine is the patient–physician dyad. Smith’s argument for the intersubjective creation of knowledge, which is itself indebted to Bakhtin’s notion of the utterance and of the necessity of “the other” in the development of meaning, enables an exploration of the creation of meaning during the patient–physician encounter. The analysis is enriched by Haraway’s concepts of partial perspectives and of dispersion, which expose the many roles and voices in which the physician and patient may interact. This approach emphasises the use of the medical humanities as a tool to teach medical students about the ambiguities of clinical practice, in which there is often no “right answer” except what is appropriate for the individual patient.
A dynamic model of nutrient pathways, growth, and body composition in fish
Authors: Bar Nadav S , Sigholt Trygve , Shearer Karl D , Krogdahl Åshild
Published: November 2007

The growth and body composition of an organism are dynamic and depend on available diet, as well as other environmental variables. A structured model is described predicting growth, body composition, and the first limiting amino acid for a variety of feeding regimes over a relatively long time scale. This model continuously provides, as a function of time, the flow of nutrients and metabolites through the principal metabolic pathways leading to tissue growth. Measurements of growth and whole body composition (including amino acid composition) from a large-scale experiment with Atlantic salmon (Salmo salar) have been employed to calibrate this model. Comparisons of simulations with the results of feeding experiments validate the predictive ability of the model. These types of simulations will be valuable in studying the quantitative relationships between intracellular energy levels and nutrient distribution in tissues. They will also provide data for balancing diet composition and amino acid profile in order to optimize growth with respect to factors such as body weight, body composition, and ambient temperature. As a result of its modularity, the model can be easily extended to include additional physiological and metabolic processes.
Effects of predation from pelagic 0-group cod (Gadus morhua) on mortality rates of capelin (Mallotus villosus) larvae in the Barents Sea
Authors: Hallfredsson Elvar H , Pedersen Torstein
Published: November 2007

Surveys were carried out in 2002 and 2003 to test whether predation from pelagic 0-group cod (Gadus morhua) juveniles affects mortality rates of Barents Sea capelin (Mallotus villosus) larvae. In 2002, capelin larvae were observed in 17% of the cod stomachs and predation was observed at 19 of 50 stations. In 2003, capelin larvae were observed in 8% of the cod stomachs and predation was observed at 19 of 37 stations. The stomach contents and zooplankton samples were dominated by copepods and krill. The number of capelin larvae in cod stomachs increased with increasing capelin larvae abundance and cod length and decreased with increasing stomach content of copepods and prey abundance of krill. The time when capelin larvae could be recognised after ingestion in the cod stomachs was estimated experimentally and depended on predator and prey lengths. The estimated overall predation mortality rate from juvenile cod on capelin larvae was about 1.5% per day for both years and can potentially have a significant effect on the survival of capelin larvae, depending on the overlap in the different years.
Effect of detritus quality on growth and survival of gizzard shad (Dorosoma cepedianum): potential importance to benthic–pelagic coupling
Authors: Kim Gene W , Wintzer Alpa P , Menker Trisha K , Stein Roy A , Dettmers John M , Wright Russell A , DeVries Dennis R
Published: November 2007

Gizzard shad (Dorosoma cepedianum) population characteristics vary with lake productivity, competing with and providing prey for sport fishes. Because age-0 gizzard shad (>30 mm total length) are facultative detritivores, they can link benthic energy, carbon, and nutrients to pelagic food webs. To determine how age-0 gizzard shad success varies along a detritus-quality gradient, we completed a 15-day laboratory experiment in which age-0 gizzard shad fed lake sediment and starved gizzard shad both suffered high mortality, whereas fish fed zooplankton grew and survived well. This suggested that detritus alone is insufficient to ensure gizzard shad growth and survival. When sediment quality was high in outdoor mesocosms, density-dependent factors led to rapid growth only at low fish density and high-quality sediments; however, survival generally increased with sediment quality, regardless of gizzard shad density. In four small reservoirs, annual growth of gizzard shad increased with sediment quality. Collectively, our findings suggest that detritus quality ultimately can contribute to regulation of community and ecosystem productivity, mediated by its influence on gizzard shad biomass available for trophic transfer to gape-limited predators (i.e., piscivorous fish). This role of gizzard shad can link higher trophic levels in aquatic food webs to allochthonous detritus subsidies from the surrounding watershed.
Association mapping of leaf traits, flowering time, and phytate content inBrassica rapa
Authors: Zhao Jianjun , Paulo Maria-João , Jamar Diaan , Lou Ping , van Eeuwijk Fred , Bonnema Guusje , Vreugdenhil Dick , Koornneef Maarten
Published: November 2007

Association mapping was used to investigate the genetic basis of variation within Brassica rapa , which is an important vegetable and oil crop. We analyzed the variation of phytate and phosphate levels in seeds and leaves and additional developmental and morphological traits in a set of diverse B. rapa accessions and tested association of these traits with AFLP markers. The analysis of population structure revealed four subgroups in the population. Trait values differed between these subgroups, thus defining associations between population structure and trait values, even for traits such as phytate and phosphate levels. Marker–trait associations were investigated both with and without taking population structure into account. One hundred and seventy markers were found to be associated with the observed traits without correction for population structure. Association analysis with correction for population structure led to the identification of 27 markers, 6 of which had known map positions; 3 of these were confirmed in additional QTL mapping studies.
Bacterial artificial chromosome–based physical map ofGibberella zeae(Fusarium graminearum)
Authors: Chang Yueh-Long , Cho Seungho , Kistler H. Corby , Hsieh Chun-Sheng , Muehlbauer Gary J.
Published: November 2007

Fusarium graminearum is the primary causal pathogen of Fusarium head blight of wheat and barley. To accelerate genomic analysis of F. graminearum, we developed a bacterial artificial chromosome (BAC)–based physical map and integrated it with the genome sequence and genetic map. One BAC library, developed in the HindIII restriction enzyme site, consists of 4608 clones with an insert size of approximately 107 kb and covers about 13.5 genome equivalents. The other library, developed in the BamHI restriction enzyme site, consists of 3072 clones with an insert size of approximately 95 kb and covers about 8.0 genome equivalents. We fingerprinted 2688 clones from the HindIII library and 1536 clones from the BamHI library and developed a physical map of F. graminearum consisting of 26 contigs covering 39.2 Mb. Comparison of our map with the F. graminearum genome sequence showed that the size of our physical map is equivalent to the 36.1 Mb of the genome sequence. We used 31 sequence-based genetic markers, randomly spaced throughout the genome, to integrate the physical map with the genetic map. We also end-sequenced 17 BamHI BAC clones and identified 4 clones that spanned gaps in the genome sequence. Our new integrated map is highly reliable and useful for a variety of genomics studies.