bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isometric torque and shortening velocity following fatigue and recovery of different voluntary tasks in the dorsiflexors
Authors: Cheng Arthur J. , Rice Charles L. 
Published: November 2009

The present study was designed to compare the relative influence of various fatigue-related factors involved in isometric and dynamic task failure following an equivalent decrease in isometric maximum voluntary contraction (MVC) torque. Using a similar duty cycle (∼1-s contraction per 2 s) and contraction load (50% of MVC), 9 young males performed in the dorsiflexors a dynamic task, and on a separate occasion an intermittent isometric task, to an equal decrease in isometric MVC torque. Dynamic contractions had greater motor unit activation and maximum rate of torque development, and required fewer contractions to task failure than the isometric task, indicating a faster development of fatigue during the velocity-dependent dynamic contractions. Peripheral factors, rather than impairments in voluntary drive, were responsible for the equivalent decrease in MVC torque at task failure and its subsequent incomplete recovery. These included, for both tasks, similar changes during fatigue and recovery in voluntary isometric MVC torque, shortening velocity, stimulated twitch and 50 Hz torque, and 50 Hz maximum rate of relaxation. Irrespective of the task, however, the greater reduction in shortening velocity at task failure and its subsequent faster recovery than MVC torque suggest that changes in metabolites affect velocity to a greater extent than isometric torque.
Heart rate variability and nonlinear analysis of heart rate dynamics following single and multiple Wingate bouts
Authors: Millar Philip J. , Rakobowchuk Mark , McCartney Neil , MacDonald Maureen J. 
Published: November 2009

Sprint interval training involves short bouts of high-intensity exercise and has produced training responses similar to those of endurance training. The effects of multiple supramaximal exercise bouts on neurocardiac modulation have not been examined. Therefore, we investigated the recovery of heart rate (HR) variability and nonlinear HR dynamics in 10 young (20.1 ± 1.2 years) healthy males following single (1) and multiple (4) Wingate tests. HR variability was assessed with time and frequency domain measures, whereas nonlinear HR dynamics were determined by assessing the complexity (sample entropy) and fractal nature (detrended fluctuation analysis) of the HR time series. Responses were determined at pre-exercise baseline and at 3 time points during recovery from exercise: Post1 (5–20 min), Post2 (45–60 min), and Post3 (105–120 min). Following a single Wingate test, all temporal and spectral HR measures had returned to baseline by 1 h of recovery. In contrast, these measures were different from baseline at 2 h following multiple Wingate tests. Fractal HR properties were altered (p < 0.05) at Post1 following a single Wingate test and at Post1 and Post2 following multiple Wingate tests. HR complexity was reduced (p < 0.001) throughout the 2-h recovery following both exercise conditions. In conclusion, Wingate tests result in alterations in cardiac autonomic control, with multiple Wingate tests resulting in larger, more prolonged alterations. Based on the results of the single Wingate test, nonlinear measures, such as HR complexity, may be more sensitive in detecting subtle alterations in neurocardiac behaviour, compared with traditional measures of HR variability.
Haematological, inflammatory, and immunological responses in elite judo athletes maintaining high training loads during Ramadan
Authors: Chaouachi Anis , Coutts Aaron J. , Wong Del P. , Roky Rachida , Mbazaa Abderraouf , Amri Mohamed , Chamari Karim 
Published: November 2009

During Ramadan, Muslims abstain from food and fluid intake from dawn to sunset for 1 month. These behavioural changes that accompany Ramadan may impact upon Muslim athletes who continue to train intensely. The aim of the present study was to evaluate the effect of Ramadan intermittent fasting (RIF) on the haematological, inflammatory, and immunological measures in elite judo athletes maintaining their usual high training loads. Haematological markers of inflammation, hormones, and immune status were studied in 15 elite male judo athletes before, during, and after Ramadan. The RIF produced small but significant changes in inflammatory, hormonal, and immunological profiles in judo athletes. Serum C-reactive protein increased from 2.93 ± 0.26 mg·L–1 pre-Ramadan to 4.60 ± 0.51 mg·L–1 at the end of Ramadan. Haptoglobin and antitrypsin also significantly increased at different phases during Ramadan, whereas homocysteine and prealbumin remained relatively unchanged. Albumin decreased slightly by mid-Ramadan, then recovered. Immunoglobulin Aincreased from 1.87 ± 0.56 g·L–1 before Ramadan to 2.49 ± 0.75 g·L–1 at the end, and remained high 3 weeks after. There were no changes in the leucocyte cell counts throughout the study. The mean blood level of thyroid-stimulating hormone and free thyroxine increased significantly during RIF. Most of these changes were within the normal ranges. These results suggest that athletes who continue to train intensely during Ramadan are liable to experience a myriad of small fluctuations in hormones, immunoglobulins, antioxidants, and inflammatory responses.
Serum markers of bone turnover are increased by modest weight loss with or without weight-bearing exercise in overweight premenopausal women
Authors: Rector R. Scott , Loethen Joanne , Ruebel Meghan , Thomas Tom R. , Hinton Pamela S. 
Published: November 2009

Weight loss improves metabolic fitness and reduces morbidity and mortality; however, weight reduction also reduces bone mineral density (BMD) and increases bone turnover. Weight-bearing aerobic exercise may preserve bone mass and maintain normal bone turnover during weight reduction. We investigated the impact of weight-bearing and nonweight-bearing exercise on serum markers of bone formation and breakdown during short-term, modest weight loss in overweight premenopausal women. Subjects (n = 36) were assigned to 1 of 3 weight-loss interventions designed to produce a 5% reduction in body weight over 6 weeks: (i) energy restriction only (n = 11; DIET); (ii) energy restriction plus nonweight-bearing exercise (n = 12, CYCLE); or (iii) energy restriction plus weight-bearing exercise (n = 13, RUN). Bone turnover markers were measured in serum collected at baseline and after weight loss. All groups achieved a ∼5% reduction in body weight (DIET = 5.2%; CYCLE = 5.0%; RUN = 4.7%). Osteocalcin (OC) and C-terminal telopeptide of type I collagen (CTX) increased with weight loss in all 3 groups (p < 0.05), whereas bone alkaline phosphatase was unaltered by the weight-loss interventions. At baseline, OC and CTX were positively correlated (r = 0.36, p = 0.03), but the strength of this association was diminished (r = 0.30, p = 0.06) after weight loss. Modest weight loss, regardless of method, resulted in a significant increase in both OC and CTX. Low-impact, weight-bearing exercise had no effect on serum markers of bone formation or resorption in premenopausal women during weight loss. Future studies that examine the effects of high-impact, weight-bearing activity on bone turnover and BMD during weight loss are warranted.
Effect of analgesics on the antibiotic resistance of ammonia-oxidizing organismsA paper submitted to the Journal of Environmental Engineering and Science.
Authors: Koney Prapurna , Morse Audra 
Published: November 2009

The present study was conducted to determine the effect of analgesics (aspirin and salicylic acid) on heterotrophic organisms and ammonia-oxidizing bacteria (AOB) resistance to antibiotics (amoxicillin, ciprofloxacin, and nalidixic acid) using the spread plate method. The bacteria were cultured from a biological graywater reclamation system. The results indicate an increase in ciprofloxacin resistance of AOB at concentrations of 0.5 and 1 mmol/L salicylic acid and aspirin. An increase in resistance of heterotrophic organisms and AOB in the presence of salicylic acid and aspirin was observed at 0.064 and 0.107 mmol/L of nalidixic acid. However, the effect of salicylic acid and aspirin on amoxicillin resistance of heterotrophic organisms and AOB was minimal. This study is important because it focuses on the antibiotic resistance of the less studied environmental microbes by considering the impact of compounds other than antibiotics to induce antibiotic resistance.
Application of a novel decontamination process using gaseous ozone
Authors: Moat John , Cargill James , Shone John , Upton Mathew 
Published: November 2009

Environmental disinfection in a health care setting is an important aspect of infection control. Recently, there has been interest in the use of vapor- and gas-based treatments for decontamination of surfaces and rooms. We describe preliminary results for an ozone-based decontamination of surfaces seeded with a range of vegetative cells and spores of bacteria of clinical relevance. The efficacy of the approach for room sanitization was also assessed. The protocol included use of a quenching agent to rapidly reduce ozone concentrations to safe levels allowing treatment times of less than 1 h for the majority of organisms tested. Using bacteria seeded onto agar plates and solid surfaces, reductions in bacterial load of greater than 3 log values were recorded for a number of organisms including Escherichia coli and methicillin-resistant Staphylococcus aureus . Application of the process in a 30 m3room showed similar reductions in viable counts for these organisms and for Clostridium difficile spores. We suggest that the potential of this ozone–quench approach should be further evaluated for disinfection or decontamination of healthcare environments.
Identification of secreted and surface proteins from Enterococcus faecalis
Authors: Benachour Abdellah , Morin Thierry , Hébert Laurent , Budin-Verneuil Aurélie , Le Jeune André , Auffray Yanick , Pichereau Vianney 
Published: November 2009

Secreted and surface proteins of bacteria are key molecules that interface the cell with the environment. Some of them, corresponding to virulence factors, have already been described for Enterococcus faecalis , the predominant species involved in enterococcal nosocomial infections. In a global proteomic approach, the identification of the most abundant secreted and surface-associated proteins of E. faecalis JH2-2 strain was carried out. These proteins were separated by gel electrophoresis or directly subjected to in vivo trypsinolysis and then analyzed by liquid chromatography – electrospray ion trap tandem mass spectrometry. Putative functions were assigned by homology to the translated genomic database of E. faecalis. A total of 44 proteins were identified, eight secreted proteins from the supernatant culture and 38 cell surface proteins from two-dimensional gel electrophoresis and in vivo trypsinolysis among which two are common to the two groups. Their sequences analysis revealed that 35 of the 44 proteins harbour characteristic features (signal peptide or transmembrane domains) consistent with an extracellular localization. This study may be considered as an important step to encourage proteomic-based investigations of E. faecalis cell surface associated proteins that could lead to the discovery of virulence factors and to the development of new therapeutic tools.
Contribution of cysteine residue to the properties of Listeria monocytogenes listeriolysin O
Authors: Stachowiak Radosław , Wiśniewski Jarosław , Osińska Olga , Bielecki Jacek 
Published: November 2009

Listeriolysin (LLO) is the key virulence factor critical for Listeria monocytogenes pathogenesis. Listerial cytolysin belongs to the family of cholesterol-dependent cytolysins (CDCs), a group of pore-forming toxins produced by related gram-positive bacteria. Most CDCs contain a cysteine residue in the conserved undecapeptide — a sequence that is highly preserved among this group of proteins. Substitutions of cysteine do not always lead to loss of hemolytic activity, questioning the purpose of such strong conservation of this amino acid in the sequence of CDC. The properties of 3 L. monocytogenes strains, a wild type and 2 mutants expressing modified LLO within the cysteine residue, were analyzed in this work. The first of these mutants producing a toxin with cysteine to alanine substitution showed similar features to the wild type except that a thiol-reducing agent was not necessary for hemolytic activity. Another strain secreting LLO containing serine instead of cysteine exhibited strikingly different properties than the wild type. Modified toxin is independent of the reducing reagents, less stable, and shows accelerated kinetics of cytolysis in comparison with the unchanged protein. However, both mutant strains are less invasive in the cell culture model showing the important role of cysteine in L. monocytogenes virulence.
Contribution of ClpE to virulence ofStreptococcus pneumoniae
Authors: Zhang Qun , Xu Song-Xiao , Wang Hong , Xu Wen-Chun , Zhang Xue-Mei , Wu Kai-Feng , Liu Lan , Yin Yi-Bing 
Published: November 2009

The ATP-dependent caseinolytic proteases (Clp) play a fundamental role in stress tolerance and virulence in many pathogenic bacteria. Although ClpE of Streptococcus pneumoniae is required for growth at high temperatures, little is known about the role of ClpE in pathogenesis. In this study, we observed that the virulence of the clpE mutant of S. pneumoniae strain D39 was strongly reduced in a mouse intraperitoneal infection model. The clpE mutant also showed substantially reduced adherence to the human lung epithelial carcinoma A549 cell line and human umbilical-vein-derived endothelial cells. The underlying mechanism of virulence attenuation induced by the mutation of clpE was further investigated with real-time RT–PCR and 2-dimensional protein gel analysis. The results indicate that ClpE affects pneumococcal pathogenesis by modulating the expression of some important virulence determinants and metabolism-related factors in S. pneumoniae.
High molecular weight FGF-2 promotes postconditioning-like cardioprotection linked to activation of the protein kinase C isoforms Akt and p70 S6 kinaseThis article is one of a selection of papers published in a special issue celebrating the 125th anniversary of the Faculty of Medicine at the University of Manitoba.
Authors: Jiang Zhi-Sheng , Wen Ge-Bo , Tang Zhi-Han , Srisakuldee Wattamon , Fandrich Robert R. , Kardami Elissavet 
Published: November 2009

Fibroblast growth factor 2 (FGF-2) is a multifunctional protein translated as high and low molecular weight isoforms (hi- and lo-FGF-2, respectively). Although the postconditioning cardioprotective effect of lo-FGF-2 (18 kDa) has been documented, hi-FGF-2 is less well studied. We used an isolated perfused rat heart model of ischemia–reperfusion to study the effects of postischemic (during reperfusion) administration of hi-FGF-2 on recovery of contractile function and tissue salvage, as indicated by decreased cytosolic cytochrome c levels. Compared with the vehicle-treated group, hi-FGF-2-treated hearts had significantly improved recovery of systolic pressure, developed pressure, rates of contraction and relaxation, and coronary flow, as well as decreased relative levels of cytosolic cytochrome c. The effects of hi-FGF-2 on functional recovery and cytosolic cytochrome c were indistinguishable from those induced by lo-FGF-2. Both hi- and lo-FGF-2 upregulated relative levels of phosphorylated (activated) Akt and p70 S6 kinase, and they both promoted translocation of α, ε, and ζ isoforms of protein kinase C (PKC) to the particulate fraction of reperfused hearts. The magnitude of the effect on PKCζ and p70 S6 kinases, however, was significantly more potent in the hi-FGF-2 than in the lo-FGF-2 group. We conclude that acute postischemic cardioprotection by hi- or lo-FGF-2 is isoform nonspecific and likely to be mediated by PKC and Akt. Nevertheless, isoform-specific functions are suggested by the augmented sensitivity of p70 S6 and PKCζ to hi-FGF-2.
N-methyl-d-aspartate-evoked adenosine and inosine release from neurons requires extracellular calciumThis article is one of a selection of papers published in a special issue celebrating the 125th anniversary of the Faculty of Medicine at the University of Manitoba.
Authors: Zamzow Christina R. , Bose Ratna , Parkinson Fiona E. 
Published: November 2009

The nucleoside adenosine (ADO) is a neuromodulator in brain. ADO and its metabolite inosine (INO) have been shown to increase cell viability in stroke models. During ischemia, extracellular levels of both ADO and INO are increased. In this study, we treated rat cortical neurons with N-methyl-d-aspartate (NMDA) to initiate excitotoxicity and then investigated the mechanisms of ADO and INO release. NMDA induced a significant increase in ADO and INO production. The effect of NMDA receptor antagonists on NMDA-evoked ADO and INO release was examined. MK-801 (1 µmol/L), a potent antagonist that lacks receptor subunit selectivity, completely blocked evoked release of both ADO and INO. Memantine (10 µmol/L), a lower affinity antagonist that also lacks subunit selectivity, blocked INO, but not ADO, release. Ifenprodil (10 µmol/L), an inhibitor selective for NMDA receptors containing the NR2Bsubunit, completely blocked evoked ADO and INO release. NVP-AAM077 (NVP, 0.4 µmol/L), an inhibitor selective for NMDA receptors containing the NR2Asubunit, did not significantly block evoked release of either ADO or INO. Removal of extracellular Ca2+abolished NMDA-evoked release of both ADO and INO. BAPTA (25 µmol/L), which chelates intracellular Ca2+, had no significant effect on either ADO or INO release unless extracellular Ca2+was also removed. Inhibitors of Ca2+/calmodulin-dependent protein kinase II (CaMKII) prevented NMDA-evoked ADO and INO release and decreased nucleoside transporter function. These data indicate that NMDA-evoked ADO and INO release is dependent on subunit composition of NMDA receptors. As well, NMDA-evoked ADO and INO release requires nucleoside transporters and extracellular Ca2+and is enhanced by activation of CaMKII.
AUTOMATED BIFURCATION ANALYSIS FOR NONLINEAR ELLIPTIC PARTIAL DIFFERENCE EQUATIONS ON GRAPHS
Authors: NEUBERGER JOHN M. , SIEBEN NÁNDOR , SWIFT JAMES W. 
Published: November 2009

We seek solutions u ∈ ℝn to the semilinear elliptic partial difference equation -Lu + fs(u) = 0, where L is the matrix corresponding to the Laplacian operator on a graph G and fs is a one-parameter family of nonlinear functions. This article combines the ideas introduced by the authors in two papers: (a) Nonlinear elliptic partial difference equations on graphs (J. Experimental Mathematics, 2006), which introduces analytical and numerical techniques for solving such equations, and (b) Symmetry and automated branch following for a semilinear elliptic PDE on a fractal region (SIAM J. Dynamical Systems, 2006), wherein we present some of our recent advances concerning symmetry, bifurcation and automation for PDE. We apply the symmetry analysis found in the SIAM paper to arbitrary graphs in order to obtain better initial guesses for Newton's method, create informative graphics, and better understand the role of symmetry in the underlying variational structure. We use two modified implementations of the gradient Newton–Galerkin algorithm (GNGA, Neuberger and Swift) to follow bifurcation branches in a robust way. By handling difficulties that arise when encountering accidental degeneracies and higher-dimensional critical eigenspaces, we can find many solutions of many symmetry types to the discrete nonlinear system. We present a selection of experimental results which demonstrate our algorithm's capability to automatically generate bifurcation diagrams and solution graphics starting with only an edgelist of a graph. We highlight interesting symmetry and variational phenomena.
VARIATIONAL PRINCIPLES IN IMAGE PROCESSING AND THE REGULARIZATION OF ORIENTATION FIELDS
Authors: CISTERNAS JAIME , GÁLVEZ MARCELO , STIELTJES BRAM , LAUN FREDERIK B. 
Published: November 2009

Variational principles and partial differential equations have proved to be fundamental elements in the mathematical modeling of extended systems in physics and engineering. Of particular interest are the equations that arise from a free energy functional. Recently variational principles have begun to be used in Image Processing to perform basic tasks such as denoising, debluring, etc. Great improvements can be achieved by selecting the most appropriate form for the functional. In this article we show how these ideas can be applied not just to scalar fields (i.e. grayscale images) but also to curved manifolds such as the space of orientations. This work is motivated by the denoising of images acquired with Magnetic Resonance scanners using diffusion-sensitized magnetic gradients.
Strong Convergence Theorems for Infinitely Nonexpansive Mappings in Hilbert Space
Authors: Chen Yi-An 
Published: November 2009

AbstractWe introduce a modified Ishikawa iterative process for approximating a fixed point of two infinitely nonexpansive self-mappings by using the hybrid method in a Hilbert space and prove that the modified Ishikawa iterative sequence converges strongly to a common fixed point of two infinitely nonexpansive self-mappings.
Common Fixed Points for Multimaps in Metric Spaces
Authors: Espínola Rafa , Hussain Nawab 
Published: November 2009

AbstractWe discuss the existence of common fixed points in uniformly convex metric spaces for single-valued pointwise asymptotically nonexpansive or nonexpansive mappings and multivalued nonexpansive, "Equation missing"-nonexpansive, or "Equation missing"-semicontinuous maps under different conditions of commutativity.
A Hybrid Projection Algorithm for Finding Solutions of Mixed Equilibrium Problem and Variational Inequality Problem
Authors: Cianciaruso Filomena , Marino Giuseppe , Muglia Luigi , Yao Yonghong 
Published: November 2009

AbstractWe propose a modified hybrid projection algorithm to approximate a common fixed point of a "Equation missing"-strict pseudocontraction and of two sequences of nonexpansive mappings. We prove a strong convergence theorem of the proposed method and we obtain, as a particular case, approximation of solutions of systems of two equilibrium problems.