bluuebunny/crossref_metadata_2025 huggingface dataset:
Temporal and spatial variations in maximum river discharge from a new Russian data set
Authors: Shiklomanov A. I. , Lammers R. B. , Rawlins M. A. , Smith L. C. , Pavelsky T. M.
Published: November 2007

Floods cause more damage in Russia than any other natural disaster, and future climate model projections suggest that the frequency and magnitude of extreme hydrological events will increase in Russia with climate change. Here we analyze daily discharge records from a new data set of 139 Russian gauges in the Eurasian Arctic drainage basin with watershed areas from 16.1 to 50,000 km2 for signs of change in maximum river discharge. Several hypotheses about changes in maximum daily discharge and their linking with trends in precipitation over the cold season were tested. For the magnitude of maximum daily discharge we found relatively equal numbers of significant positive and negative trends across the Russian Arctic drainage basin, which draws into question the hypothesis of an increasing risk of extreme floods. We observed a significant shift to earlier spring discharge, which is consistent with documented changes in snowmelt and freeze‐thaw dates. Spatial analysis of changes in maximum discharge and cold season precipitation revealed consistency across most of the domain, the exception being the Lena basin. Trends in maximum discharge of the small‐ to medium‐sized rivers were generally consistent with aggregated signals found for the downstream gauges of the six largest Russian rivers. Although we observe regional changes in maximum discharge across the Russian Arctic drainage basin, no evidence of widespread trends in extreme discharge can be assumed from our analysis.
Simple approximations of quasi‐linear diffusion coefficients
Authors: Albert J. M.
Published: November 2007

Quasi‐linear diffusion by cyclotron‐resonant plasma waves is likely a key ingredient of the behavior of electrons in the Earth's radiation belts. Multidimensional dynamical simulations are under development, which require the diffusion coefficients to be evaluated quickly as well as accurately. The recently developed parallel propagation approximation replaces the integration over wavenormal distribution with a closed form expression, and can be quite accurate. However, it can also perform badly, especially for electron energy ≥1 MeV. Here, the accuracy, justification, and limits of the approximation are explored, and an improved version is presented. It is based on a previously developed procedure for identifying wavenormal angles compatible with imposed cutoffs on the wave frequency distribution. Because it also requires evaluation at only a small number of points, it features computational efficiency comparable to the parallel propagation version, while preserving contributions from oblique waves and all relevant harmonic numbers. Detailed comparisons are presented using an established model of nightside chorus.
Developmental Effects of Multiple Looks in Speech Sound Discrimination
Authors: Holt Rachael Frush , Carney Arlene Earley
Published: November 2007

Purpose

The change/no-change procedure (J. E. Sussman & A. E. Carney, 1989), which assesses speech discrimination, has been used under the assumption that the number of stimulus presentations does not influence performance. Motivated by the tenets of the multiple looks hypothesis (N. F. Viemeister & G. H. Wakefield, 1991), work by R. F. Holt and A. E. Carney (2005) called this assumption into question (at least for adults): Nonsense syllable discrimination improved with more stimulus presentations. This study investigates the nature of developmental differences and the effects of multiple stimulus presentations in the change/no-change procedure.

Method

Thirty normal-hearing children, ages 4.0–5.9 years, were tested on 3 consonant–vowel contrasts at various signal-to-noise ratios using combinations of 2 and 4 standard and comparison stimulus repetitions.

Results

Although performance fell below that which is predicted by the multiple looks hypothesis in most conditions, discrimination was enhanced with more stimulus repetitions for 1 speech contrast. The relative influence of standard and comparison stimulus repetitions varied across the speech contrasts in a manner different from that of adults.

Conclusion

Despite providing no additional sensory information, multiple stimulus repetitions enhanced children’s discrimination of 1 set of nonsense syllables. The results have implications for models of developmental speech perception and assessing speech discrimination in children.
Training Japanese Listeners to Perceive American English Vowels: Influence of Training Sets
Authors: Nishi Kanae , Kewley-Port Diane
Published: November 2007

Purpose

Studies on speech perception training have shown that adult 2nd language learners can learn to perceive non-native consonant contrasts through laboratory training. However, research on perception training for non-native vowels is still scarce, and none of the previous vowel studies trained more than 5 vowels. In the present study, the influence of training set sizes was investigated by training native Japanese listeners to identify American English (AE) vowels.

Method

Twelve Japanese learners of English were trained 9 days either on 9 AE monophthongs (fullset training group) or on the 3 more difficult vowels (subset training group). Five listeners served as controls and received no training. Performance of listeners was assessed before and after training as well as 3 months after training was completed.

Results

Results indicated that (a) fullset training using 9 vowels in the stimulus set improved average identification by 25%; (b) listeners in both training groups generalized improvement to untrained words and tokens spoken by novel speakers; and (c) both groups maintained improvement after 3 months. However, the subset group never improved on untrained vowels.

Conclusions

Training protocols for learning non-native vowels should present a full set of vowels and should not focus only on the more difficult vowels.
Use of Speaker Intent and Grammatical Cues in Fast-Mapping by Adolescents With Down Syndrome
Authors: McDuffie Andrea S. , Sindberg Heidi A. , Hesketh Linda J. , Chapman Robin S.
Published: November 2007

Purpose

The authors asked whether adolescents with Down syndrome (DS) could fast-map novel nouns and verbs when word learning depended on using the speaker’s pragmatic or syntactic cues. Compared with typically developing (TD) comparison children, the authors predicted that syntactic cues would prove harder for the group with DS to use and that action verbs would be harder to fast-map than nouns.

Method

Twenty participants with DS, aged 12–18 years, and 19 TD participants, aged 3–6 years, were matched on syntax comprehension and engaged in 4 fast-mapping tasks. Both comprehension and production of novel words were assessed for each task. Through use of hierarchical regression models, hearing, cognition, and working memory were considered as predictors of total comprehension and production performance for each group.

Results

Both groups used speaker intent in fast-mapping labels to object referents but performed more poorly on fast-mapping verbs. Neither group appeared to use grammatical cues to disambiguate the intended referent. Syntax comprehension was replicated as a predictor of fast-mapping comprehension for the DS group. Syntax comprehension and chronological age were replicated as predictors of TD fast-mapping.

Conclusion

Participants with DS had better recall for the object or action seen most recently during speaker intent tasks. They had better recall for the object presented first and the action presented last during grammatical cue tasks. Response patterns may have depended on the structure of specific task paradigms. Verb acquisition may be facilitated when either the action or label is familiar.
Geodetic laser scanning
Authors: Carter William E. , Shrestha Ramesh L. , Slatton K. Clint
Published: November 2007

Producing surface maps at submeter resolution, even over heavily forested terrain, GLS can reveal the fine structure of such features as faults, landslides, and drainage patterns.
Gravitational dynamos and the low-frequency geomagnetic secular variation
Authors: Olson P.
Published: November 2007

Self-sustaining numerical dynamos are used to infer the sources of low-frequency secular variation of the geomagnetic field. Gravitational dynamo models powered by compositional convection in an electrically conducting, rotating fluid shell exhibit several regimes of magnetic field behavior with an increasing Rayleigh number of the convection, including nearly steady dipoles, chaotic nonreversing dipoles, and chaotic reversing dipoles. The time average dipole strength and dipolarity of the magnetic field decrease, whereas the dipole variability, average dipole tilt angle, and frequency of polarity reversals increase with Rayleigh number. Chaotic gravitational dynamos have large-amplitude dipole secular variation with maximum power at frequencies corresponding to a few cycles per million years on Earth. Their external magnetic field structure, dipole statistics, low-frequency power spectra, and polarity reversal frequency are comparable to the geomagnetic field. The magnetic variability is driven by the Lorentz force and is characterized by an inverse correlation between dynamo magnetic and kinetic energy fluctuations. A constant energy dissipation theory accounts for this inverse energy correlation, which is shown to produce conditions favorable for dipole drift, polarity reversals, and excursions.
RReportGenerator: automatic reports from routine statistical analysis using R
Authors: Raffelsberger Wolfgang , Krause Yannick , Moulinier Luc , Kieffer David , Morand Anne-Laure , Brino Laurent , Poch Olivier
Published: November 2007

Summary: With the establishment of high-throughput (HT) screening methods there is an increasing need for automatic analysis methods. Here we present RReportGenerator, a user-friendly portal for automatic routine analysis using the statistical platform R and Bioconductor. RReportGenerator is designed to analyze data using predefined analysis scenarios via a graphical user interface (GUI). A report in pdf format combining text, figures and tables is automatically generated and results may be exported. To demonstrate suitable analysis tasks we provide direct web access to a collection of analysis scenarios for summarizing data from transfected cell arrays (TCA), segmentation of CGH data, and microarray quality control and normalization.

Availability: RReportGenerator, a user manual and a collection of analysis scenarios are available under a GNU public license on http://www-bio3d-igbmc.u-strasbg.fr/~wraff

Contact:  wolfgang.raffelsberger@igbmc.u-strasbg.fr
Probabilistic path ranking based on adjacent pairwise coexpression for metabolic transcripts analysis
Authors: Takigawa Ichigaku , Mamitsuka Hiroshi
Published: November 2007

Motivation: Pathway knowledge in public databases enables us to examine how individual metabolites are connected via chemical reactions and what genes are implicated in those processes. For two given (sets of) compounds, the number of possible paths between them in a metabolic network can be intractably large. It would be informative to rank these paths in order to differentiate between them.

Results: Focusing on adjacent pairwise coexpression, we developed an algorithm which, for a specified k, efficiently outputs the top k paths based on a probabilistic scoring mechanism, using a given metabolic network and microarray datasets. Our idea of using adjacent pairwise coexpression is supported by recent studies that local coregulation is predominant in metabolism. We first evaluated this idea by examining to what extent highly correlated gene pairs are adjacent and how often they are consecutive in a metabolic network. We then applied our algorithm to two examples of path ranking: the paths from glucose to pyruvate in the entire metabolic network of yeast and the paths from phenylalanine to sinapyl alcohol in monolignols pathways of arabidopsis under several different microarray conditions, to confirm and discuss the performance analysis of our method.

Contact:  takigawa@kuicr.kyoto-u.ac.jp

Supplementary information: Supplementary data are available at Bioinformatics online.
Prediction of both conserved and nonconserved microRNA targets in animals
Authors: Wang Xiaowei , El Naqa Issam M.
Published: November 2007

Motivation: MicroRNAs (miRNAs) are involved in many diverse biological processes and they may potentially regulate the functions of thousands of genes. However, one major issue in miRNA studies is the lack of bioinformatics programs to accurately predict miRNA targets. Animal miRNAs have limited sequence complementarity to their gene targets, which makes it challenging to build target prediction models with high specificity.

Results: Here we present a new miRNA target prediction program based on support vector machines (SVMs) and a large microarray training dataset. By systematically analyzing public microarray data, we have identified statistically significant features that are important to target downregulation. Heterogeneous prediction features have been non-linearly integrated in an SVM machine learning framework for the training of our target prediction model, MirTarget2. About half of the predicted miRNA target sites in human are not conserved in other organisms. Our prediction algorithm has been validated with independent experimental data for its improved performance on predicting a large number of miRNA down-regulated gene targets.

Availability: All the predicted targets were imported into an online database miRDB, which is freely accessible at http://mirdb.org.

Contact:  xwang@radonc.wustl.edu

Supplementary information: Supplementary data are available at Bioinformatics online.
Control of the annual cycle in birds: endocrine constraints and plasticity in response to ecological variability
Authors: Dawson Alistair
Published: November 2007

This paper reviews information from ecological and physiological studies to assess how extrinsic factors can modulate intrinsic physiological processes. The annual cycle of birds is made up of a sequence of life-history stages: breeding, moult and migration. Each stage has evolved to occur at the optimum time and to last for the whole duration of time available. Some species have predictable breeding seasons, others are more flexible and some breed opportunistically in response to unpredictable food availability. Photoperiod is the principal environmental cue used to time each stage, allowing birds to adapt their physiology in advance of predictable environmental changes. Physiological (neuroendocrine and endocrine) plasticity allows non-photoperiodic cues to modulate timing to enable individuals to cope with, and benefit from, short-term environmental variability. Although the timing and duration of the period of full gonadal maturation is principally controlled by photoperiod, non-photoperiodic cues, such as temperature, rainfall or food availability, could potentially modulate the exact time of breeding either by fine-tuning the time of egg-laying within the period of full gonadal maturity or, more fundamentally, by modulating gonadal maturation and/or regression. The timing of gonadal regression affects the time of the start of moult, which in turn may affect the duration of the moult. There are many areas of uncertainty. Future integrated studies are required to assess the scope for flexibility in life-history strategies as this will have a critical bearing on whether birds can adapt sufficiently rapidly to anthropogenic environmental changes, in particular climate change.
Trends in recent temperature and radial tree growth spanning 2000 years across northwest Eurasia
Authors: Briffa Keith R , Shishov Vladimir V , Melvin Thomas M , Vaganov Eugene A , Grudd Håken , Hantemirov Rashit M , Eronen Matti , Naurzbaev Muktar M
Published: November 2007

This paper describes variability in trends of annual tree growth at several locations in the high latitudes of Eurasia, providing a wide regional comparison over a 2000-year period. The study focuses on the nature of local and widespread tree-growth responses to recent warming seen in instrumental observations, available in northern regions for periods ranging from decades to a century. Instrumental temperature data demonstrate differences in seasonal scale of Eurasian warming and the complexity and spatial diversity of tree-growing-season trends in recent decades. A set of long tree-ring chronologies provides empirical evidence of association between inter-annual tree growth and local, primarily summer, temperature variability at each location. These data show no evidence of a recent breakdown in this association as has been found at other high-latitude Northern Hemisphere locations. Using Kendall's concordance, we quantify the time-dependent relationship between growth trends of the long chronologies as a group. This provides strong evidence that the extent of recent widespread warming across northwest Eurasia, with respect to 100- to 200-year trends, is unprecedented in the last 2000 years. An equivalent analysis of simulated temperatures using the HadCM3 model fails to show a similar increase in concordance expected as a consequence of anthropogenic forcing.
The Metabolic Syndrome in East Asians
Authors: Hoang Khiet C. , Le Truc Vy , Wong Nathan D.
Published: November 2007

The metabolic syndrome is an emerging epidemic in developing nations, including East Asian countries such as China, Japan, and Korea. Studies examining the metabolic syndrome have used different definitions, with prevalence often highly dependent on the cut points for abdominal obesity utilized, which have been recommended by the International Diabetes Federation to be lower than standards used in Caucasians and other ethnic groups. Prevalence rates have generally varied from 8% to 13% in men and 2% to 18% in women, depending on ethnic group and definition used, and are consistently lower than most Western Caucasian populations. While recent dramatic changes in lifestyle from Westernization of dietary habits and reduced physical activity present challenges, an emphasis on healthful lifestyle changes remains the cornerstone for metabolic syndrome management. In addition, clinical management focusing on control of obesity, elevated blood pressure, dyslipidemia, and hyperglycemia, with consideration of pharmacologic therapy issues unique to certain Asian populations, remains important for reducing associated cardiometabolic risks.
Apical SK potassium channels and Ca2+‐dependent anion secretion in endometrial epithelial cells
Authors: Palmer Melissa L. , Schiller Katherine R. , O'Grady Scott M.
Published: November 2007

Apical uridine triphosphate (UTP) stimulation was shown to increase short circuit current (Isc) in immortalized porcine endometrial gland epithelial monolayers. Pretreatment with the bee venom toxin apamin enhanced this response. Voltage‐clamp experiments using amphotericin B‐permeablized monolayers revealed that the apamin‐sensitive current increased immediately after UTP stimulation and was K+ dependent. The current–voltage relationship was slightly inwardly rectifying with a reversal potential of −52 ± 2 mV, and the PK/PNa ratio was 14, indicating high selectivity for K+. Concentration–response relationships for apamin and dequalinium had IC50 values of 0.5 nm and 1.8 μm, respectively, consistent with data previously reported for SK3 channels in excitable cells and hepatocytes. Treatment of monolayers with 50 μm BAPTA‐AM completely blocked the effects of UTP on K+ channel activation, indicating that the apamin‐sensitive current was also Ca2+ dependent. Moreover, channel activation was blocked by calmidazolium (IC50= 5 μm), suggesting a role for calmodulin in Ca2+‐dependent regulation of channel activity. RT‐PCR experiments demonstrated expression of mRNA for the SK1 and SK3 channels, but not SK2 channels. Treatment of monolayers with 20 nm oestradiol‐17β produced a 2‐fold increase in SK3 mRNA, a 2‐fold decrease in SK1 mRNA, but no change in GAPDH mRNA expression. This result correlated with a 2.5‐fold increase in apamin‐sensitive K+ channel activity in the apical membrane. We speculate that SK channels provide a mechanism for rapidly sensing changes in intracellular Ca2+ near the apical membrane, evoking immediate hyperpolarization necessary for increasing the driving force for anion efflux following P2Y receptor activation.
The KCNQ/M‐current modulates arterial baroreceptor function at the sensory terminal in rats
Authors: Wladyka Cynthia L. , Feng Bin , Glazebrook Patricia A. , Schild John H. , Kunze Diana L.
Published: November 2007

The ion channels responsible for the pattern and frequency of discharge in arterial baroreceptor terminals are, with few exceptions, unknown. In this study we examined the contribution of KCNQ potassium channels that underlie the M‐current to the function of the arterial baroreceptors. Labelled aortic baroreceptor neurons, immunohistochemistry and an isolated aortic arch preparation were used to demonstrate the presence and function of KCNQ2, KCNQ3 and KCNQ5 channels in aortic baroreceptors. An activator (retigabine) and an inhibitor (XE991) of the M‐current were used to establish a role for these channels in setting the resting membrane potential and in regulating the response to ramp increases in arterial pressure. Retigabine raised the threshold for activation of arterial baroreceptors and shifted the pressure–response curve to higher aortic pressures. XE991, on the other hand, produced an increase in excitability as shown by an increase in discharge at elevated pressures as compared to control. We propose that KCNQ2, KCNQ3 and KCNQ5 channels provide a hyperpolarizing influence to offset the previously described depolarizing influence of the HCN channels in baroreceptor neurons and their terminals.
Functional role of cyclic nucleotide‐gated channels in rat medial vestibular nucleus neurons
Authors: Podda Maria Vittoria , D'Ascenzo Marcello , Leone Lucia , Piacentini Roberto , Azzena Gian Battista , Grassi Claudio
Published: November 2007

Although cyclic nucleotide‐gated (CNG) channels are expressed in numerous brain areas, little information is available on their functions in CNS neurons. The aim of the present study was to define the distribution of CNG channels in the rat medial vestibular nucleus (MVN) and their possible involvement in regulating MVN neuron (MVNn) excitability. The majority of MVNn expressed both CNG1 and CNG2 A subunits. In whole‐cell current‐clamp experiments carried out on brainstem slices containing the MVNn, the membrane‐permeant analogues of cyclic nucleotides, 8‐Br‐cGMP and 8‐Br‐cAMP (1 mm), induced membrane depolarizations (8.9 ± 0.8 and 9.2 ± 1.0 mV, respectively) that were protein kinase independent. The cGMP‐induced depolarization was associated with a significant decrease in the membrane input resistance. The effects of cGMP on membrane potential were almost completely abolished by the CNG channel blockers, Cd2+ and l‐cis‐diltiazem, but they were unaffected by blockade of hyperpolarization‐activated cyclic nucleotide‐gated channels. In voltage‐clamp experiments, 8‐Br‐cGMP induced non‐inactivating inward currents (−22.2 ± 3.9 pA) with an estimated reversal potential near 0 mV, which were markedly inhibited by reduction of extracellular Na+ and Ca2+ concentrations. Membrane depolarization induced by CNG channel activation increased the firing rate of MVNn without changing the action potential shape. Collectively, these findings provide novel evidence that CNG channels affect membrane potential and excitability of MVNn. Such action should have a significant impact on the function of these neurons in sensory–motor integration processes. More generally, it might represent a broad mechanism for regulating the excitability of different CNS neurons.
Flow Past a Sphere With Surface Blowing and Suction
Authors: Bagchi Prosenjit
Published: November 2007

The effect of uniform surface blowing and suction on the wake dynamics and the drag and lift forces on a sphere is studied using a high-resolution direct numerical simulation technique. The sphere Reynolds number Re, based on its diameter and the freestream velocity, is in the range 1–300. The onset of recirculation in the sphere wake occurs at higher Re, and the transition to nonaxisymmetry and unsteadiness occurs at lower Re in the presence of blowing. The size of the recirculation region increases with blowing, but it nearly disappears in the case of suction. Wake oscillation also increases in the presence of blowing. The drag coefficient in the presence of blowing is reduced compared to that in uniform flow, in the range 10<Re<250, whereas it is increased in the presence of suction. The reduction in the wake pressure minimum associated with the enhanced vortical structures is the primary cause for drag reduction in the case of blowing. In the case of suction, it is the increased surface vorticity associated with the reduction of the boundary layer that results into increased drag. The fluctuations in the instantaneous lift and drag coefficients are significant for blowing, and they result from the asymmetric movement of the wake pressure minimum associated with the shedding process.
Large-Eddy Simulation of Shock-Wave-Induced Turbulent Mixing
Authors: Thornber Ben , Drikakis Dimitris
Published: November 2007

The paper presents implicit large-eddy simulation (ILES) simulation of a shock tube experiment involving compressible turbulent mixing. A new characteristic-based approximate Riemann solver is derived, and employed in a second-order and fifth-order finite volume Godunov-type ILES framework. The methods are validated against (qualitative) experimental data and then compared and contrasted in terms of resolved turbulent kinetic energy and mixing parameters as a function of grid resolution. It is concluded that both schemes represent the experiment with good accuracy. However, the fifth-order results are approximately equivalent to results gained on double the grid size at second order, whereas the fifth-order method requires only approximately 20% extra computational time.
ILES and LES of Complex Engineering Turbulent Flows
Authors: Fureby C.
Published: November 2007

The present study concerns the application of large eddy simulation (LES) and implicit LES (ILES) to engineering flow problems. Such applications are often very complicated, involving both complex geometries and complex physics, such as turbulence, chemical reactions, phase changes, and compressibility. The aim of the study is to illustrate what problems occur when attempting to perform such engineering flow calculations using LES and ILES, and put these in relation to the issues originally motivating the calculations. The issues of subgrid modeling are discussed with particular emphasis on the complex physics that needs to be incorporated into the LES models. Results from representative calculations, involving incompressible flows around complex geometries, aerodynamic noise, compressible flows, combustion, and cavitation, are presented, discussed, and compared with experimental data whenever possible.
Million-Degree Plasma Pervading the Extended Orion Nebula
Authors: Güdel Manuel , Briggs Kevin R. , Montmerle Thierry , Audard Marc , Rebull Luisa , Skinner Stephen L.
Published: November 2007

Most stars form as members of large associations within dense, very cold (10 to 100 kelvin) molecular clouds. The nearby giant molecular cloud in Orion hosts several thousand stars of ages less than a few million years, many of which are located in or around the famous Orion Nebula, a prominent gas structure illuminated and ionized by a small group of massive stars (the Trapezium). We present x-ray observations obtained with the X-ray Multi-Mirror satellite XMM-Newton, revealing that a hot plasma with a temperature of 1.7 to 2.1 million kelvin pervades the southwest extension of the nebula. The plasma flows into the adjacent interstellar medium. This x-ray outflow phenomenon must be widespread throughout our Galaxy.
French district nurses’ opinions towards euthanasia, involvement in end-of-life care and nurse–patient relationship: a national phone survey: Table 1
Authors: Bendiane MK , Galinier A , Favre R , Ribiere C , Lapiana J-M , Obadia Y , Peretti-Watel P
Published: November 2007

Objectives:

To assess French district nurses’ opinions towards euthanasia and to study factors associated with these opinions, with emphasis on attitudes towards terminal patients.

Design and setting:

An anonymous telephone survey carried out in 2005 among a national random sample of French district nurses.

Participants:

District nurses currently delivering home care who have at least 1 year of professional experience. Of 803 district nurses contacted, 602 agreed to participate (response rate 75%).

Main outcome measures:

Opinion towards the legalisation of euthanasia (on a five-point Likert scale from “strongly agree” to “strongly disagree”), attitudes towards terminal patients (discussing end-of-life issues with them, considering they should be told their prognosis, valuing the role of advance directives and surrogates).

Results:

Overall, 65% of the 602 nurses favoured legalising euthanasia. Regarding associated factors, this proportion was higher among those who discuss end-of-life issues with terminal patients (70%), who consider competent patients should always be told their prognosis (81%) and who value the role of advance directives and surrogates in end-of-life decision-making for incompetent patients (68% and 77% respectively). Women and older nurses were less likely to favour legalising euthanasia, as were those who believed in a god who masters their destiny.

Conclusions:

French nurses are more in favour of legalising euthanasia than French physicians; these two populations contrast greatly in the factors associated with this support. Further research is needed to investigate how and to what extent such attitudes may affect nursing practice and emotional well-being in the specific context of end-of-life home care.
Written role models in professionalism education
Authors: Coulehan J
Published: November 2007

After more than a generation of neglect in medical education, professionalism has now been restored to the classroom and clinic. However, the current emphasis on teaching and evaluating professionalism in clinical education risks failure because of the large gap between explicit professional ideals and today’s culture of medical education. For professionalism curricula to be successful, they must be narrative-based, rather than rule-based. This requires substantial increases in appropriate role modeling, opportunities to develop self-awareness, development of narrative competence and investment in community service. Fictional and non-fictional written narratives can play an important supplemental role throughout medical training by introducing additional role model physicians and, more importantly, by promoting discussion and analysis of professional virtue in practice. Using “The Steel Windpipe”, “Darkness”, “Malingerers” and “The Good Doctor” as examples, the author illustrates the use of short stories to help medical students explore the meaning of professionalism from a narrative perspective.
Reading between the lines: the experiences of taking part in a community reading project
Authors: Hodge S , Robinson J , Davis P
Published: November 2007

Despite the popularity of reading groups, and the increased number of general-practitioner-referred bibliotherapy schemes in the UK, there has been relatively little research on the effects of reading works of literature on the well-being and health of readers. This paper reports the findings of a study set up to explore people’s experiences of taking part in community reading groups run by the Get into Reading Project in Wirral, Merseyside, UK. A qualitative approach was adopted, using three methods. These were participant observation with five reading groups, a key stakeholder interview and, with a sixth group, a single case study that consisted of observation and interviews with group members. The fieldwork conducted with the six groups took place in a variety of settings, including libraries, a residential drug rehabilitation unit and a hostel for homeless men. The research participants were all over 18 years of age, and all were members or facilitators of Get into Reading reading groups. The data were analysed thematically using NVivo qualitative analysis software. The findings show that the groups do not have a specific, targeted, therapeutic function, their primary purpose being more broadly literary, with literature itself trusted both to serve a coalescing social purpose and to offer non-specified but individual therapeutic benefits. Further work should be undertaken to explore the social and therapeutic benefits of reading literature in community settings.
Estimating meiotic chromosome pairing and recombination parameters in telocentric trisomics
Authors: Sybenga J. , Verhaar H. , Botje D.G.A.
Published: November 2007

Telocentric trisomics (telotrisomics; one arm of a metacentric chromosome present in addition to two complete genomes) are used in theoretical studies of pairing affinities and chiasma formation in competitive situations and applied in genome analysis, gene localization, gene transfer, and breakage of close linkages. These applications require knowledge of the recombination characteristics of telotrisomics. Appropriate cytological and molecular markers and favorable chromosome morphology are not always available or applicable for quantitative analyses. We developed new mathematical models for extracting the maximum information from simple metaphase I observations. Two types of telotrisomics of the short arm of chromosome 1R of rye ( Secale cereale ), including several genotypes, were used as test material. In simple telotrisomics, pairing between morphologically identical complete chromosomes was more frequent than pairing between the telocentric and either of the normal chromosomes. In the telocentric substitution, morphologically identical telocentrics paired less frequently with each other than either one with the normal chromosome. Pairing partner switch was significant. Interaction between the two arms was variable. Variation within plants was considerable. Telotrisomics without markers are suitable for analyzing pairing preferences, for gene localization and gene transfer, and for breaking tight linkages, but less so for genome analysis.
Evidence of the modulation of mRNA splicing fidelity in humans by oxidative stress and p53
Authors: Disher Kim , Skandalis Adonis
Published: November 2007

The majority of human genes generate mRNA splice variants and while there is little doubt that alternative splicing is an important biological phenomenon, it has also become apparent that some splice variants are associated with disease. To elucidate the molecular mechanisms responsible for generating aberrant splice variants, we have investigated alternative splicing of the human genes HPRT and POLB following oxidative stress in different genetic backgrounds. Our study revealed that splicing fidelity is sensitive to oxidative stress. Following treatment of cells with H2O2, the overall frequency of aberrant, unproductive splice variants increased in both loci. At least in POLB, splicing fidelity is p53 dependent. In the absence of p53, the frequency of POLB splice variants is elevated but oxidative stress does not further increase the frequency of splice variants. Our data indicate that mis-splicing following oxidative stress represents a novel and significant genotoxic outcome and that it is not simply DNA lesions induced by oxidative stress that lead to mis-splicing but changes in the alternative splicing machinery itself.
Molecular cloning, heterologous expression, and phylogenetic analysis of a novel y-type HMW glutenin subunit gene from the G genome of Triticum timopheevi
Authors: Li Xiaohui , Zhang Yanzhen , Gao Liyan , Wang Aili , Ji Kangmin , He Zhonghu , Appels Rudi , Ma Wujun , Yan Yueming
Published: November 2007

A novel y-type high molecular weight (HMW) glutenin subunit gene from the G genome of Triticum timopheevi (2n = 4x = 28, AAGG) was isolated and characterized. Genomic DNA from accession CWI17006 was amplified and a 2200 bp fragment was obtained. Sequence analysis revealed a complete open reading frame including N- and C-terminal ends and a central repetitive domain encoding 565 amino acid residues. The molecular weight of the deduced subunit was 77 031, close to that of the x-type glutenin subunits. Its mature protein structure, however, demonstrated that it was a typical y-type HMW subunit. To our knowledge, this is the largest y-type subunit gene among Triticum genomes. The molecular structure and phylogenetic analysis assigned it to the G genome and it is the first characterized y-type HMW glutenin subunit gene from T. timopheevi. Comparative analysis and secondary structure prediction showed that the subunit possessed some unique characters, especially 2 large insertions of 45 (6 hexapeptides and a nonapeptide) and 12 (2 hexapeptides) amino acid residues that mainly contributed to its higher molecular weight and allowed more coils to be formed in its tertiary structure. Additionally, more α-helixes in the repeat domain of the subunit were found when compared with 3 other y-type subunits. We speculate that these structural characteristics improve the formation of gluten polymer. The novel subunit, expressed as a fusion protein in E. coli, moved more slowly in SDS–PAGE than the subunit Bx7, so it was designated Gy7*. As indicated in previous studies, increased size and more numerous coils and α-helixes of the repetitive domain might enhance the functional properties of HMW glutenins. Consequently, the novel Gy7* gene could have greater potential for improving wheat quality.
Identification and analysis of differentially expressed genes in differentiating xylem of Chinese fir (Cunninghamia lanceolata) by suppression subtractive hybridization
Authors: Wang Guifeng , Gao Yan , Yang Liwei , Shi Jisen
Published: November 2007

Wood is an important raw material for global industries with rapidly increasing demand. To isolate the genes differentially expressed during xylogenesis of Chinese fir ( Cunninghamia lanceolata (Lamb.) Hook.), we used a novel system. Forward and reverse subtracted cDNA libraries were constructed using the suppression subtractive hybridization method; for the forward library we used cDNA from the mutant Dugansha as the tester and cDNA from the wild-type clone Jurong 0 as the driver, and for the reverse library we used Jurong 0 cDNA as the tester and Dugansha cDNA as the driver. Transcriptional profiling was performed using a macroarray with 4 digoxigenin-labeled probes. We obtained 618 and 409 clones from the forward and the reverse subtracted library, respectively. A total of 405 unique expressed sequence tags (ESTs) were obtained. Forty percent of the ESTs exhibited homologies with proteins of known function and fell into 4 major classes: metabolism, cell wall biogenesis and remodeling, signal transduction, and stress. Real-time PCR was performed to confirm the results. The expression levels of 11 selected ESTs were consistent with both macroarray and real-time PCR results. The systematic analysis of genes involved in wood formation in Chinese fir provides valuable insights into the molecular mechanisms involved in xylem differentiation and is an important resource for forest research that can be directed toward understanding the genetic control of wood formation and future endeavors to modify wood and fiber properties for industrial use.
The effect of pre-test carbohydrate ingestion on the anaerobic threshold, as determined by the lactate-minimum test
Authors: Rotstein Arie , Dotan Raffy , Zigel Levana , Greenberg Tally , Benyamini Yael , Falk Bareket
Published: November 2007

The purpose of this study was to investigate the effect of pre-test carbohydrate (CHO) ingestion on anaerobic-threshold assessment using the lactate-minimum test (LMT). Fifteen competitive male distance runners capable of running 10 km in 33.5–43 min were used as subjects. LMT was performed following CHO (2 × 300 mL, 7% solution) or comparable placebo (Pl) ingestion, in a double-blind, randomized order. The LMT consisted of two high-intensity 1 min treadmill runs (17–21 km·h–1), followed by an 8 min recovery period. Subsequently, subjects performed 5 min running stages, incremented by 0.6 km·h–1 and separated by 1 min blood-sampling intervals. Tests were terminated after 3 consecutive increases in blood-lactate concentration ([La]) had been observed. Finger-tip capillary blood was sampled for [La] and blood-glucose determination 30 min before the test’s onset, during the recovery phase following the 2 high-intensity runs, and following each of the subsequent 5 min stages. Heart rate (HR) and rating of perceived exertion (RPE) were recorded after each stage. The lactate-minimum speed (LMS) was determined from the individual [La]–velocity plots and was considered reflective of the anaerobic threshold. Pre-test CHO ingestion had no effect on LMS (13.19 ± 1.12 km·h–1 vs. 13.17 ± 1.08 km·h–1 in CHO and Pl, respectively), nor on [La] and glucose concentration at that speed, or on HR and RPE responses. Pre-test CHO ingestion therefore does not affect LMS or the LMT-estimated anaerobic threshold.
Ethnic differences in adiposity and body composition: the First Nations bone health study
Authors: Leslie William D. , Weiler Hope A. , Nyomba B.L. Grégoire
Published: November 2007

The purpose of this study was to compare patterns of adiposity and soft tissue composition in First Nations and white Canadian women. A population-based cross-sectional study was performed. A random age-stratified sample of 206 urban First Nations women and 177 white women was recruited. Soft tissue composition was analyzed with dual-energy X-ray absorptiometry. Analysis of covariance (ANCOVA) models were used to assess ethnicity in models that adjusted for body mass, body mass index (BMI), and socio-demographic factors. Obesity (BMI ≥ 30.0 kg/m2) was more common in First Nations women (48.1%) than in white women (36.2%, Fisher’s exact test p = 0.012). Mean trunk fat tissue mass fraction and total body fat mass fraction (as a percent of soft tissue) were greater in First Nations women than in white women (p < 0.0001). Trunk lean tissue was also greater in First Nations women (p = 0.027), but total body lean tissue was similar. The mean trunk adiposity index was strongly related to ethnicity (First Nations +0.5% ± 2.5% versus white –1.7% ± 2.6%, p < 0.0001). Preferential fat accumulation in the trunk of First Nations women persisted after adjustment for body mass, BMI, and other socio-demographic variables (p < 0.0001). First Nations women differ from white women in terms of fat and lean tissue mass and distribution. First Nations women had a preferential increase in trunk fat and this may contribute to high reported rates of diabetes, metabolic syndrome, and cardiovascular events.
Effects of 22 °C muscle temperature on voluntary and evoked muscle properties during and after high-intensity exercise
Authors: Drinkwater Eric J. , Behm David G.
Published: November 2007

The purpose of this study was to investigate the effect of 22 °C local muscle temperature of intact human plantar flexors performing fatiguing contractions on evoked and voluntary contractile properties before and after fatigue. Twelve subjects were tested on plantar flexor voluntary torque, percent muscle activation derived from twitch interpolation, integrated electromyographic (iEMG) activity, and evoked torque and temporal characteristics of maximal twitch and tetanic stimulations before fatigue and 1, 5, and 10 min after intermittent, high-intensity, isometric fatigue under both normothermic and hypothermic conditions. Hypothermic and normothermic changes between time points were analysed by repeated-measures analysis of variance. Normothermic fatigue induced small to large effects (Cohen’s d: 0.29–3.06) on voluntary and evoked contractile properties, whereas most effects of unfatigued hypothermia were limited to rate-dependent processes (Cohen’s d: 0.78–1.70). Most tetanic properties were potentiated 1 min after normothermic fatigue, but remained unchanged by hypothermic fatigue, resulting in significant differences between the two conditions. Soleus iEMG significantly declined 1 min after normothermic fatigue (–29%), but not after hypothermic fatigue. Twitch torque was potentiated by 29% one minute after fatigue while normothermic, but was potentiated by 46% while hypothermic; rate of twitch torque development and time to peak twitch were potentiated by 39% and 10% while normothermic, but 89% and 28% while hypothermic. Although voluntary contractile properties are generally impaired soon after normothermic fatigue, most were not after hypothermic fatigue. Furthermore, evoked contractile properties were generally higher 1 min after hypothermic fatigue. We conclude that the hypothermic condition slows the recovery of potentiated evoked contractile properties back to baseline values.
Glutamine and carbohydrate supplements reduce ammonemia increase during endurance field exercise
Authors: Carvalho-Peixoto Jacqueline , Alves Robson Cardilo , Cameron Luiz-Claudio
Published: November 2007

Blood ammonia concentration increases during endurance exercise and has been proposed as a cause for both peripheral and central fatigue. We examined the impact of glutamine and (or) carbohydrate supplementation on ammonemia in high-level runners. Fifteen men in pre-competitive training ran 120 min (~34 km) outdoors on 4 occasions. On the first day, the 15 athletes ran without the use of supplements and blood samples were taken every 30 min. After that, each day for 4 d before the next 3 exercise trials, we supplemented the athletes’ normal diets in bolus with carbohydrate (1 g·kg–1·d–1), glutamine (70 mg·kg–1·d–1), or a combination of both in a double-blind study. Blood ammonia level was determined before the run and every 30 min during the run. During the control trial ammonia increased progressively to approximately 70% above rest concentration. Following supplementation, independent of treatment, ammonia was not different (p > 0.05) for the first 60 min, but for the second hour it was lower than in the control (p < 0.05). Supplementation in high-level, endurance athletes reduced the accumulation of blood ammonia during prolonged, strenuous exercise in a field situation.