bluuebunny/crossref_metadata_2025 huggingface dataset:
The Influence of Recovery Duration on High-Intensity Exercise Performance After Oral Creatine Supplementation
Authors: Cooke William H. , Barnes William S.
Published: June 2009

The purpose of this study was to determine the effects of creatine supplementation on the ability to reproduce and maintain a high percentage of peak power output during the second of two bouts of high-intensity cycle sprinting following four different recovery intervals. Eighty healthy, active male subjects were randomly assigned to one of two groups (creatine or placebo) and one of four recovery intervals (30, 60, 90, or 120 s). Two maximal cycle ergometer sprints, separated by the assigned recovery interval were performed before and after a 5-day supplementation protocol in which 20 g/day of creatine (plus 4 g/day glucose) or 24 g/day glucose placebo were ingested by subjects from creatine and placebo groups, respectively. Maximal peak power output (PP) and the absolute time to fatigue (TTF) were compared pre- versus postsupplementation. No significant group interactions were noted in this study. Specifically, creatine supplementation had no effect on subjects' ability to reproduce or maintain a high percentage of PP during the second bout of exercise. Key words: ergogenic aids, cycle ergometry, short-term fatigue
Anaerobic Threshold Determination With Analysis of Salivary Amylase
Authors: Calvo Felipe , Chicharro José L. , Bandrés Fernando , Lucía Alejandro , Pérez Margarita , Álvarez Julián , Mojares Luís L. , Vaquero Almudena F. , Legido Julio C.
Published: June 2009

The purpose of this study was to determine the anaerobic threshold from analysis of amylase concentration in total saliva during a laboratory exercise test. Each of 20 healthy young men performed both a submaximal and a maximal test on a treadmill. During the submaximal test, capillary blood and total saliva samples were collected for determination of anaerobic threshold (AT) and saliva threshold (Tsa), respectively. Tsa was defined as the point at which the first continuous increase in amylase concentration occurred during exercise. The results showed no significant difference between values of AT and Tsa when both were expressed either as running velocity or as heart rate. In addition, there existed a high correlation between AT and Tsa (r = .93, p < .001). It was therefore concluded that the analysis of amylase concentration in total saliva during exercise might be used as a valid new method for determining AT. Key words: exercise, anaerobic threshold, saliva
Comparison of a Mathematical Model to Predict 10-km Performance From the Conconi Test and Ventilatory Threshold Measurements
Authors: Petit Moira A. , Nelson Carey M. , Rhodes Edward C.
Published: June 2009

The purpose of this study was to validate a mathematical model (MM) that evaluates the Conconi test and predicts 10-km race time. In addition, the relationship between ventilatory threshold (Tvent) determined from a laboratory test and heart rate deflection (HRd) from the Conconi test were examined. Seventeen trained runners performed the Conconi test, and performance times were predicted using a MM based on a logistics function. A correlational analysis indicated a highly significant relationship (r = .98, p < .01) between MM predicted time and actual time. Significant relationships were found between velocity at Tvent and HRd (r = .95, p < .01), and predicted times from each method (r = .96, p < .01). Heart rates from Tvent and HRd were also related (r = .79, p < .01). These results suggest that a MM of the Conconi test is a valid method of predicting 10-km performance and is closely related to traditional laboratory measures. Key words: anaerobic threshold, field test, heart rate deflection
The Influence of Intermittent Fatigue Exercise on Early and Late Phases of Relaxation From Maximal Voluntary Contraction
Authors: Jaskólska Anna , Jaskólski Artur
Published: June 2009

Twenty-two young male subjects were tested to estimate the behavior of the early and late phases of relaxation from a 3-s maximal voluntary contraction (MVC) under the influence of fatigue. Less demanding and more demanding protocols of intermittent hand grip exercise were used to fatigue muscle. Before and after fatigue, the early and late relaxation time, maximal relaxation rate, and half-relaxation time were measured. The results showed that during voluntary movement (a) the early phase of relaxation was independent of the mode of intermittent exercise and did not change significantly after fatigue; (b) the late relaxation time and absolute maximal relaxation rate were slower after both protocols, with the changes more pronounced following the more demanding protocol; and (c) the half-relaxation time and relative maximal relaxation rate were changed only in the more demanding protocol. It is concluded that unlike the relaxation following electrical stimulation of isolated muscle, the early phase of relaxation from voluntary contraction appears to be the most resistant to the type of intermittent fatiguing exercise used in the present study, whereas the late relaxation time was the most sensitive to this type of fatigue. Key words: hand grip exercise, late relaxation time, early relaxation time, half-relaxation time
Mechanical Properties and Behaviour of Motor Units in the Tibialis Anterior During Voluntary Contractions
Authors: Cutsem Michaël Van , Feiereisen Patrick , Duchateau Jacques , Hainaut Karl
Published: June 2009

The present work was carried out to analyse the properties and behaviour of Tibialis anterior motor units (MUs) during voluntary contractions in humans. A total of 528 single MU mechanical properties was recorded in 10 subjects by means of the spike-triggered averaging (STA) technique. MU recruitment thresholds and discharge frequencies were recorded during linearly increasing maximal voluntary contraction (MVC). The results indicate a mean (±SD) MU torque of 25.5 ± 21.5 mN•m. and a mean time-to-peak of 45.6 ± 13.6 ms. A comparison of the average MU twitch torque with that of the muscle allowed an estimate of about 300 MUs in the Tibialis anterior. A positive linear relationship was recorded between the MU twitch torque and the recruitment threshold. The mean minimal and maximal discharge frequencies of MUs were 8.4 ± 3.0 Hz and 33.2 ± 14.7 Hz, respectively. The results of the present work indicate that MU behaviour during voluntary contractions is different in the tibialis anterior and in the adductor pollicis. Key words: discharge frequency, recruitment threshold, motor unit count
Ratings of Perceived Exertion to Determine Intensity During Outdoor Running
Authors: Thompson Dixie L. , West Keith A.
Published: June 2009

A paucity of data exists related to the usefulness of Ratings of Perceived Exertion (RPE) to set exercise intensity in non-laboratory settings. The purpose of this study was to determine if RPE could be used on an outdoor track to generate blood lactate and heart rate (HR) responses similar to those obtained on a treadmill (tm) run. Nine experienced runners (6 males, 3 females; [Formula: see text]) completed a horizontal, incremental tm test. HR, RPE, and lactate were measured for each stage. Subsequently, subjects ran for 30 min on an outdoor track at the RPE corresponding with 2.5 mM lactate during the tm run. Repeated measures ANOVA compared lactate and HR values at 2.5 mM lactate on the tm run and values obtained during the track run. Lactate during the track run was significantly higher (p < .05) than 2.5 mM throughout the 30 min (6.9 ± 2.9, 63 ± 2.9, and 5.8 ± 3.0 mM at 10, 20, and 30 min, respectively). HR at 2.5 mM lactate during the tm run (173 ± 6.1 bpm) was significantly lower (p < .05) than at min 10 and 20 of the track run (182.6 ± 9.3 and 182.9 ± 8.0 bpm, respectively) but not different from min 30 (181.3 ± 10.6 bpm). In summary, it is difficult to generate specific physiological responses using RPE. Key words: RPE, Borg Scale, exercise, lactate, training
The Physiological Effects of Beverage Ingestion During Cross Country Ski Training in Elite Collegiate Skiers
Authors: Seifert John G. , Luetkemeier Maurie J. , White Andrea T. , Mino Liz M.
Published: June 2009

The purpose of this study was to investigate the effects of beverage ingestion on fluid balance during 1.5 hr of low intensity cross country skiing. In Part I, 6 skiers drank water ad libitum during ski training. In Part II, 10 skiers were matched by body weight (BW) and assigned to ingest 2.5 ml kg−1 BW of water or a carbohydrate/electrolyte (CE) beverage every 2.5 km. Skiing speed averaged 11.5 km hr−1 for 90 min around a 5 km groomed track. Following 20 min of seated rest, blood samples were collected immediately before and approximately 30 min after skiing. Part I data indicated that subjects ingested 576 ± 189 ml of fluid and produced 266 ± 205 ml of urine: BW, plasma and urine osmolality, and plasma protein decreased significantly. In Part II, the CE group produced less urine (135 u75 vs 450 ± 262 ml) and had smaller decreases in plasma osmolality (−1.0 ± 1.0 vs. −7.0 ± 2.4 mOsm kg H2O) and protein (−0.11 ± 08 vs. −0.42 ± 0.24 g L−1) than the water group. No differences were observed for BW loss, % change in PV, FWC, or change in urine osmolality. It was concluded that ad lib water ingestion was inadequate to minimize fluid balance disruption, Plain water ingestion also led to significant dilution of the plasma and increased urine output. However, the ingestion of CE led to attenuation of fluid balance disruption, presumably due to the maintenance of osmotic balance in the plasma. Key words: fluid balance, cross country skiing
Probabilities Associated With Counting Average Motor Unit Firing Rates in Active Human Muscle
Authors: Rich Christopher , O′Brien George L. , Cafarelli Enzo
Published: June 2009

Motor unit firing rates in human muscle can be determined from recordings made with small-diameter microelectrodes inserted directly into the muscle during voluntary contraction. Frequently, these counts are pooled to give an average motor unit firing rate under a given set of conditions. Since the fibers of one motor unit are dispersed among the cells of several others, it is conceivable that discharge rates can be measured in more than one cell from the same unit. If this occurred frequently, the distribution of firing rates could be influenced by those from units counted more than once. Based on literature values, we made the following assumptions: vastus lateralis contains approximately 300 motor units, with an average innervation ratio of 1500. Muscle cell diameter is about 50 to 100 μm and cells are randomly distributed over a motor unit territory of 10 μm diameter. The recording range of a microelectrode is about 600 μm. Given the distribution of cells normally found in whole human muscle, the probability of recording from two or more cells of the same motor unit at 50% MVC follows a Poisson distribution with a mean of 0.44. This model suggests that although there is a low probability of some duplication in this technique, the extent to which it influences the distribution of average motor unit firing rates is minimal over the entire range of forces produced by vastus lateralis. Key words: probability, motor unit, single unit recording, human muscle, rate coding
Considerations for Fitness Appraisal, Programming, and Counselling of Individuals With Sensory Impairments
Authors: Longmuir Fatti
Published: June 2009

not available
Considerations for Fitness Appraisal, Programming, and Counselling of People With Intellectual Disabilities
Authors: Seidl Christine
Published: June 2009

not available
The Case for Adaptability of the Neuromuscular Junction to Endurance Exercise Training
Authors: Panenic Robert , Gardiner Phillip F.
Published: June 2009

Although the adaptability of the neuromuscular junction (NMJ) has been demonstrated using the models of denervation/reinnervation, electrical stimulation, development, aging, and pathological states, relatively little is known about the effects of increased chronic voluntary use on the morphology and physiological function of the NMJ. A review of findings relating to adaptations in the various pre- and postsynaptic components of the NMJ with exercise training is presented. These findings are discussed as they pertain to NMJ function during exercise. Other physiological modulators of the NMJ, such as trophic factors released by nerve terminals and muscles, and circulating substances are discussed in terms of possible roles they may play in training-induced adaptations. Key words: neuromuscular junction, endurance exercise, adaptations, morphology, acetylcholinesterase, physiology, trophic factors
Signal Transduction and Gene Expression in Striated Muscles: A Symposium
Authors: Hood David A. , Mcdermott John C.
Published: June 2009

not available
Effects of Split Exercise Sessions on Excess Postexercise Oxygen Consumption and Resting Metabolic Rate
Authors: Almuzaini Khalid S. , Potteiger Jeffrey A. , Green Samuel B.
Published: June 2009

This study involved examining how splitting a 30-min exercise bout on a cycle ergometer into two equal sessions affects excess postexercise oxygen consumption (EPOC) and resting metabolic rate (RMR). In this study, 10 male volunteers (age = 23 ± 3.8) participated in two exercise trials, which were randomly assigned in a counterbalanced design and separated by 40 hr. One trial was 30 min of exercise at 70% [Formula: see text](CONT), followed by a 40-min measurement of EPOC. The second trial was divided into two 15-min sessions (SPLIT), separated by 6 hr. A 20 min measurement of EPOC followed each SPLIT session. Results indicated that the combined magnitude of EPOCs from SPLIT (7,410 ± 1,851 ml) was significantly greater than that from CONT (5,278 ± 1,305 ml). Data indicate that dividing a 30-min exercise session into two parts for these individuals significantly increases magnitude of EPOC but does not affect RMR. Key words: EPOC, RMR,[Formula: see text], exercise duration
Fuel Metabolism During Exercise: The Role of the Glucose-Fatty Acid Cycle in Mediating Carbohydrate and Fat Metabolism
Authors: Rodgers Carol D.
Published: June 2009

not available
The Role of Glucose in the Regulation of Substrate Interaction During Exercise
Authors: Sidossis Labros S.
Published: June 2009

Glucose and fatty acids are the main energy sources for oxidative metabolism in endurance exercise. Although a reciprocal relationship exists between glucose and fatty acid contribution to energy production for a given metabolic rate, the controlling mechanism remains debatable. Randle et al.'s (1963) glucose-fatty acid cycle hypothesis provides a potential mechanism for regulating substrate interaction during exercise. The cornerstone of this hypothesis is that the rate of lipolysis, and therefore fatty acid availability, controls how glucose and fatty acids contribute to energy production. Increasing fatty acid availability attenuates carbohydrate oxidation during exercise, mainly via sparing intramuscular glycogen. However, there is little evidence for a direct inhibitory effect of fatty acids on glucose oxidation. We found that glucose directly determines the rate of fat oxidation by controlling fatty acid transport into the mitochondria. We propose that the intracellular availability of glucose, rather than fatty acids, regulates substrate interaction during exercise. Key words: mitochondria, malonyl-coenzyme A, carnitine palmitoyltransferase, medium-chain fatty acids, free fatty acids
Sample Size Required for the Accurate Determination of Fiber Area and Capillarity of Human Skeletal Muscle
Authors: Mccall Gary E. , Byrnes William C. , Dickinson Arthur L. , Fleck Steven J.
Published: June 2009

This study aimed to determine the skeletal muscle fiber sample size required for a reliable, valid representation of an individual's average fiber area and capillary contacts (CC) per fiber. Biopsies were obtained from the biceps brachii of 11 college-age, recreational resistance-trained men in conjunction with a study investigating how muscle morphology changed after 12 weeks of resistance training. The effect of additional measurements on the rolling cumulative means for fiber area and CC per fiber was evaluated using sequential estimation analysis. Results showed that group cumulative mean and standard deviation had stabilized by 50 fiber measurements per individual for type I and II fibers and CC per fiber. Significant correlations (.96-.99; p < .05) existed between the 50th and 95th/100th cumulative individual means. These results indicate that a typical skeletal muscle needle biopsy would be sufficient to characterize type I and II fiber areas and CC per fiber of an individual in most subject populations, although the required sample size for characterizing fiber subtypes might be different. Key words: muscle biopsy; sequential estimation analysis
Markers of Excessive Exercise
Authors: Mckenzie Donald C.
Published: June 2009

Overtraining is of serious concern to long-distance runners and will affect 65% of them at some time in their competitive career. The clinical presentation is nonspecific but the classical symptoms include fatigue, mood disturbances, frequent upper respiratory infections and injury, and a decrease in performance. Dysfunction of the hypothalamic pituitary axis from repeated stress, of a physical or nonphysical nature, represents the most likely pathogenesis of this condition. There is no single biological marker that is diagnostic of an overtrained state; however, several parameters deserve further study. The time to volitional fatigue on a cycle ergometer at an intensity of 110% of the individual anaerobic threshold represents a possible laboratory test. Salivary IgA holds promise as a useful immunological marker of the overtrained state and further research is needed to determine the validity of plasma glutamine as a blood marker. The most promising tool at present is a measure of the athlete's mood state, and several psychological tools can be used for this purpose. Key words: overtraining, biological markers, elite athletes
Acute and Chronic Hormonal Responses to Resistance Training Designed to Promote Muscle Hypertrophy
Authors: Mccall Gary E. , Byrnes William C. , Fleck Steven J. , Dickinson Arthur , Kraemer William J.
Published: June 2009

Acute and chronic hormonal responses to resistance training were evaluated in 11 college men who completed 12 weeks (33 sessions) of high volume resistance training. No differences in resting concentrations of growth hormone (GH), insulin-like growth factor-I, testosterone, or sex hormone-binding globulin occurred from pre- and posttraining in the trained vs. nontrained control group. However, cortisol (C) decreased 17% for both groups (p < 0.05). There were no differences in exercise-induced responses between Sessions 10 and 20, with all hormone concentrations increasing (p < 0.05) from pre- at mid- and postexercise session. However, after correction for plasma volume decreases, only C and GH showed differences, with C increased from mid- to postsession (48% 10th: 49% 20th), and GH increased from pre- at mid- and postsession for both sessions 10 (0.16 ± 0.42 pre; 4.77 ± 6.24 mid; 6.26 ± 5.19 post; µg L−1) and 20 (0.33 ± 085 pre; 5.42 ± 9.08 mid; 8.24 ± 7.61 post; µg L−1). Significant correlations (p < 0.05) existed only between absolute mean GH increases from presession and the degree of muscle fiber hypertrophy for type I (r = 0.70 mid, 0.74 post) and type II (r = 0.71 post) fibers. In conclusion, resistance training had no effect on resting serum hormone concentrations, whereas similar acute exercise responses occurred between the 10th and 20th training sessions. Keywords: humans, weight training, growth hormone, IGF-I, testosterone, cortisol
Gender Differences in Cardiovascular and Catecholamine Responses to Cold-Air Exposure at Rest
Authors: Pettit Suzanne E. , Marchand Ingrid , Graham Terry
Published: June 2009

Metabolic and cardiovascular responses were examined in 8 men. and 9 women during 2 hrs of sitting at rest in 5 °C. The men and women had similar body fatness and both groups responded with similar changes relative to control in cardiac output, blood pressure, total peripheral resistance, [Formula: see text], respiratory exchange ratio, and rectal temperature. However, greater increases in stroke volume and decreases in heart rate and skin temperature were observed in men compared to women (p < 0.05). The contribution of CHO and fat to the total energy expended differed (p < 0.05) between genders; the CHO: fat ratio was 47:53 in men and 36:64 in women. No gender differences could be observed in plasma catecholamines. It is concluded that there are striking cardiovascular and metabolic gender differences in response to cold stress which cannot be accounted for by body fatness or catecholamine responses. Key words: fat metabolism, epinephrine, heart rate, norepinephrine, stroke volume
Effects of Dehydration on Exercise Performance
Authors: Barr Susan I.
Published: June 2009

Dehydration refers both to hypohydration (dehydration induced prior to exercise) and to exercise-induced dehydration (dehydration that develops during exercise). The latter reduces aerobic endurance performance and results in increased body temperature, heart rate, perceived exertion, and possibly increased reliance on carbohydrate as a fuel source. Although the negative effects of exercise-induced dehydration on exercise performance were clearly demonstrated in the 1940s, athletes continued to believe for years thereafter that fluid intake was not beneficial. More recently, negative effects on performance have been demonstrated with modest (< 2%) dehydration, and these effects are exacerbated when the exercise is performed in a hot environment. The effects of hypohydration may vary, depending on whether it is induced through diuretics or sauna exposure, which substantially reduce plasma volume, or prior exercise, which has much less impact on plasma volume. Hypohydration reduces aerobic endurance, but its effects on muscle strength and endurance are not consistent and require further study. Key words: hypohydration, muscle strength, fluid intake, heat exposure
Alternative Medicine Interventions in Sport: Introduction to the Symposium
Authors: Tiidus Peter M.
Published: June 2009

not available
Effects of Dehydration, Hypohydration, and Hyperhydration on Tolerance During Uncompensable Heat Stress
Authors: Mclellan Tom M. , Cheung Stephen S. , Latzka William A. , Sawka Mike N. , Pandolf Kent B. , Millard Claire E. , Withey W. Reg
Published: June 2009

The present study examined the effects of dehydration from prior exercise on subsequent exercise tolerance time (TT) that involved wearing nuclear, biological, and chemical (NBC) protective clothing. It was hypothesised that TT would be reduced in the dehydrated state. Ten men undertook continuous treadmill walking at 4.8 km • h−1 at 35 °C and 50% relative humidity, wearing NBC clothing while euhydrated (EU) or dehydrated (D) by 2.3% of body weight. Hydration status had no impact on thermoregulatory or cardiovascular responses during exercise. Also rectal temperature at exhaustion did not differ between EU (38.52 ± 0.39 °C) and D (38.43 ± 0.45 °C). Exercise TT during this uncompensable heat stress was reduced significantly for D (47.7 ± 15.3 min) compared with EU (59.0 ± 13.6 min). It was concluded that prior exercise leading to levels of dehydration to 2.3% of body weight, together with subsequent fluid restriction during exposure to uncompensable heat stress, impaired TT while wearing the NBC protective clothing. The integration of these findings together with other comparable studies that have examined the influence of hypo- and hyperhydration on TT while wearing NBC protective clothing revealed that hydration status has less effect on TT as the severity of uncompensable heat stress increases. Key words: thermoregulation, protective clothing, heat tolerance, rectal temperature
Increasing Exercise Duration Does Not Affect the Postexercise Elevation in Esophageal Temperature
Authors: Kenny Glen P. , Denis Paul M. , Boulé Normand G. , Proulx Carolyn E. , Thoden James S. , Reardon Francis D.
Published: June 2009

It has previously been observed that (a) following 15 min of intense exercise, esophageal temperature (Tes), remains elevated at a plateau value equal to that at which active vasodilation had occurred during exercise (i.e., esophageal temperature threshold for cutaneous vasodilation [ThVD]); and (b) exercise/recovery cycles of identical intensity and duration, when sequential, result in progressively higher Tes at the beginning and end of exercise. In the latter case, parallel increases in both the exercise ThVD and postexercise plateau of Tes were noted. This study was conducted to determine if the elevated postexercise Tes is related to increases in whole-body heat content. On separate occasions, 9 subjects completed 3 bouts of treadmill exercise at 70% [Formula: see text] max, 29 °C ambient temperature. Each exercise bout lasted either 15, 30, or 45 min and was followed by 60 min of inactive recovery. Esophageal temperatures were similar at the start of each exercise bout, but the rise in Tes during exercise nearly doubled from 1.0 °C after 15 min of exercise to 1.9 °C after 45 min of exercise. There were no intercondition differences among the exercise ThVD (∼0.36 °C above baseline) or postexercise plateau values for Tes (∼0.40 °C above baseline). Thus the relationship between the ThVD during exercise and the postexercise Tes did not appear to be dependent on changes in whole-body heat content as produced by endogenous heating during exercise of different duration. Key words: cutaneous vasodilation threshold, exercise hyperthermia. temperature elevation
Development of a Hockey-Specific, Skate-Treadmill Protocol
Authors: Dreger Randy William , Quinney H. Arthur
Published: June 2009

The purpose of this study was to investigate a protocol for the determination of [Formula: see text] utilizing a motor-driven skate treadmill (ST). On separate days, 6 male hockey players completed a ST and a cycle ergometer (BK) [Formula: see text] protocol. The results showed no significant difference between the ST and BK protocols for relative (60.4 + 5.09 vs. 59.0 ± 8.31 ml kg−1 min−1) and absolute [Formula: see text] values (4.51 ± 0.50 vs. 4.39 ± 0.59 L min−1), respectively. Significantly higher HR max was recorded during the ST protocol (202.3 + 4.27 vs. 200.7 ± 4.55 b min−1) (p < 0.05). Peak VE and VT were nonsignificant between the two conditions. However, peak f was higher for the ST protocol (63.0 + 7.56 vs. 60.2 ± 7.76 breath min−1) (p < 0.05). Although the physiological response to both protocols was similar, the ST protocol replicates a hockey stride, which may provide more applicable information for the development of training programs. Key words: ice hockey, aerobic power test, sport-specific
REWRITING LOGIC-BASED SEMANTICS OF P SYSTEMS AND THE MAXIMAL CONCURRENCY
Authors: LUCANU DOREL
Published: June 2009

We use distributed labeled transition systems and their modal logics in order to compare the concurrency degrees of the P systems and their encoding as rewrite theories in rewriting logic. We show that the maximal concurrency given by the maximal parallel rewriting semantics of the P systems can be expressed in rewriting logic only by interleaving semantics. The maximal concurrency of the membrane interactions is only partially captured.
SPECTRUM BASED TECHNIQUES FOR GRAPH ISOMORPHISM
Authors: RAJASEKARAN SANGUTHEVAR , KUNDETI VAMSI
Published: June 2009

The graph isomorphism problem is to check if two given graphs are isomorphic. Graph isomorphism is a well studied problem and numerous algorithms are available for its solution. In this paper we present algorithms for graph isomorphism that employ the spectra of graphs. An open problem that has fascinated many a scientist is if there exists a polynomial time algorithm for graph isomorphism. Though we do not solve this problem in this paper, the algorithms we present take polynomial time. These algorithms have been tested on a good collection of instances. However, we have not been able to prove that our algorithms will work on all possible instances. In this paper, we also give a new construction for cospectral graphs.
THE INFORMATIONAL CONTENT OF CANONICAL DISJOINT NP-PAIRS
Authors: GLAßER CHRISTIAN , SELMAN ALAN L. , ZHANG LIYU
Published: June 2009

We investigate the connection between propositional proof systems and their canonical pairs. It is known that simulations between propositional proof systems translate to reductions between their canonical pairs. We focus on the opposite direction and study the following questions.

Q1: For which propositional proof systems f and g does the implication [Formula: see text] hold, and for which does it fail?

Q2: For which propositional proof systems of different strengths are the canonical pairs equivalent?

Q3: What do (non-)equivalent canonical pairs tell about the corresponding propositional proof systems?

Q4: Is every NP-pair (A, B), where A is NP-complete, strongly many-one equivalent to the canonical pair of some propositional proof system?

In short, we show that Q1 and Q2 can be answered with 'for almost all', which generalizes previous results by Pudlák and Beyersdorff. Regarding Q3, inequivalent canonical pairs tell that the propositional proof systems are not "very similar," while equivalent, P -inseparable canonical pairs tell that they are not "very different." We can relate Q4 to the open problem in structural complexity that asks whether unions of disjoint NP-complete sets are NP-complete. This demonstrates a new connection between propositional proof systems, disjoint NP-pairs, and unions of disjoint NP-complete sets.
THE NON-VISCOUS BURGERS EQUATION ASSOCIATED WITH RANDOM POSITION IN COORDINATE SPACE: A THRESHOLD FOR BLOW UP BEHAVIOUR
Authors: ALBEVERIO SERGIO , ROZANOVA OLGA
Published: June 2009

It is well known that the solutions to the non-viscous Burgers equation develop a gradient catastrophe at a critical time provided the initial data have a negative derivative in certain points. We consider this equation assuming that the particle paths in the medium are governed by a random process with a variance which depends in a polynomial way on the velocity. Given an initial distribution of the particles which is uniform in space and with the initial velocity linearly depending on the position, we show both analytically and numerically that there exists a threshold effect: if the power in the above variance is less than 1, then the noise does not influence the solution behavior, in the following sense: the mean of the velocity when we keep the value of position fixed goes to infinity outside the origin. If, however, the power is larger or equal to 1, then this mean decays to zero as the time tends to a critical value.
A GLOBALLY CONVERGENT GUMMEL MAP FOR OPTIMAL DOPANT PROFILING
Authors: BURGER MARTIN , PINNAU RENÉ
Published: June 2009

We study a generalized Gummel iteration for the solution of an abstract optimal semiconductor design problem, which covers a wide range of semiconductor models. The algorithm is to exploit the special structure of the KKT system and it can be interpreted as a descent algorithm for an appropriately defined cost functional. This allows for a convergence proof which does not need the assumption of small biasing voltages. The algorithm is explicitly stated for the (quantum) drift diffusion model, the energy transport model and the microscopic Schrödinger–Poisson model.
ANALYSIS OF A DIFFUSE INTERFACE APPROACH TO AN ADVECTION DIFFUSION EQUATION ON A MOVING SURFACE
Authors: ELLIOTT CHARLES M. , STINNER BJÖRN
Published: June 2009

A diffuse interface model for an advection diffusion equation on a moving surface is formulated involving a small parameter ε related to the thickness of the interfacial layer. The coefficient functions degenerate on the boundary of the diffuse interface. In appropriately weighted Sobolev spaces, existence and uniqueness of weak solutions is shown. Using energy methods the convergence of solutions to the diffuse interface model to the solution to the equation on the moving surface as ε → 0 is proved. The approach is intended to be applied to phase field models describing the surface motion. Among other problems we have surfactants on liquid-liquid interfaces and species diffusion on moving grain boundaries in mind.
GLOBAL C1 MAPS ON GENERAL DOMAINS
Authors: LØVGREN ALF EMIL , MADAY YVON , RØNQUIST EINAR M.
Published: June 2009

In many contexts, there is a need to construct C1 maps from a given reference domain to a family of deformed domains. In our case, the motivation comes from the application of the Arbitrary Lagrangian Eulerian (ALE) method and also the reduced basis element method. In these methods, the maps are used to construct the grid-points needed on the deformed domains, and the corresponding Jacobian of the map is used to map vector fields from one domain to another. In order to keep the continuity of the mapped vector fields, the Jacobian must be continuous, and thus the maps need to be C1. In addition, the constructed grids on the deformed domains should be quality grids in the sense that, for a given partial differential equation defined on any of the deformed domains, the solution should be accurate. Since we are interested in a family of deformed domains, we consider the solutions of the partial differential equation to be a family of solutions governed by the geometry of the domains. Different mapping strategies are discussed and compared: the transfinite interpolation proposed by Gordon and Hall,12 the pseudo-harmonic extension proposed by Gordon and Wixom,13 a new generalization of the Gordon–Hall method (e.g., to general polygons in two dimensions), the harmonic extension, and the mean-valued extension proposed by Floater.8
DECOUPLED SCHWARZ ALGORITHMS FOR IMPLICIT DISCRETIZATIONS OF NONLINEAR MONODOMAIN AND BIDOMAIN SYSTEMS
Authors: MUNTEANU MARILENA , PAVARINO LUCA F.
Published: June 2009

Novel decoupled Schwarz algorithms for the implicit discretizations of the Monodomain and Bidomain systems in three dimensions are constructed and analyzed. Both implicit Euler and linearly implicit Rosenbrock time discretizations are considered. Convergence rate estimates are proven for a domain decomposition preconditioner based on overlapping additive Schwarz techniques and employed in a Newton–Krylov–Schwarz method for the Euler scheme. An analogous result is proven for the same preconditioner applied to the linear systems originated in the Rosenbrock scheme. Several parallel numerical results in three dimensions confirm the convergence rates predicted by the theory and study the performance of our algorithms for a complete heartbeat, for both Bidomain and Monodomain models, Euler and Rosenbrock schemes, fixed time step and adaptive strategies. The results also show the considerable CPU-time reduction of our decoupled Schwarz solvers with respect to fully-implicit Schwarz solvers.
Charmless Hadronic B Meson Decays
Authors: Cheng Hai-Yang , Smith James G.
Published: June 2009

We give an overview of the experimental measurements and the theoretical understanding of the branching fractions and CP-violating asymmetries of charmless B meson decays. Most experimental results are from the BaBar and Belle Collaborations’ data, accumulated during the past decade. The global features of these experimental results are typically well described by quantum chromodynamics (QCD)-motivated theories such as QCD factorization, perturbative QCD, and soft-collinear effective theory. The agreement between theory and experiment is generally satisfactory, although there remain some unsolved puzzles that pose a great challenge to both theorists and experimentalists.
From Gauge-String Duality to Strong Interactions:A Pedestrian's Guide
Authors: Gubser Steven S. , Karch Andreas
Published: June 2009

We survey recent progress in relating string theory to quantum chromodynamics (QCD), focusing on (a) holographic models of gauge theories that are similar to QCD and (b) applications to heavy-ion collisions.
Statistical Methods for Cosmological Parameter Selection and Estimation
Authors: Liddle Andrew R.
Published: June 2009

The estimation of cosmological parameters from precision observables is an important industry with crucial ramifications for particle physics. In this article, I discuss the statistical methods presently used in cosmological data analysis, highlighting the main assumptions and uncertainties. The topics covered are parameter estimation, model selection, multimodel inference, and experimental design, all primarily from a Bayesian perspective.
COMP-angiopoietin-1 enhances skeletal muscle blood flow and insulin sensitivity in mice
Authors: Sung Hoon Ki , Kim Yong-Woon , Choi Soo Jeong , Kim Jong-Yeon , Jeune Kyung Hee , Won Kyu-Chang , Kim Jason K. , Koh Gyu Young , Park So-Young
Published: June 2009

To test whether chronic enhanced blood flow alters insulin-stimulated glucose uptake, we measured skeletal muscle glucose uptake in chow-fed and high-fat-fed mice injected with adenovirus containing modified angiopoietin-1, COMP-Ang1, via euglycemic-hyperinsulinemic clamp. Blood flow rates and platelet endothelial cell adhesion molecule-1 positive endothelial cells in the hindlimb skeletal muscle were elevated in COMP-Ang1 compared with control LacZ. Whole body glucose uptake and whole body glycogen/lipid synthesis were elevated in COMP-Ang1 compared with LacZ in chow diet. High-fat diet significantly reduced whole body glucose uptake and whole body glycolysis in LacZ mice, whereas high-fat-fed COMP-Ang1 showed a level of whole body glucose uptake that was comparable with chow-fed LacZ and showed increased glucose uptake compared with high-fat-fed LacZ. Glucose uptake and glycolysis in gastrocnemius muscle of chow-fed COMP-Ang1 were increased compared with chow-fed LacZ. High-fat diet-induced whole body insulin resistance in the LacZ was mostly due to ∼40% decrease in insulin-stimulated glucose uptake in skeletal muscle. In contrast, COMP-Ang1 prevented diet-induced skeletal muscle insulin resistance compared with high-fat-fed LacZ. Akt phosphorylation in skeletal muscle was increased in COMP-Ang1 compared with LacZ in both chow-fed and high-fat-fed groups. These results suggest that increased blood flow by COMP-Ang1 increases insulin-stimulated glucose uptake and prevents high-fat diet-induced insulin resistance in skeletal muscle.
Regulation of basal, pulsatile, and entropic (patterned) modes of GH secretion in a putatively low-somatostatin milieu in women
Authors: Veldhuis Johannes D. , Hudson Susan A. , Bailey Joy N. , Erickson Dana
Published: June 2009

Somatostatin (SS) released by hypothalamic neurons inhibits GH exocytosis noncompetitively. Therefore, we postulated that attenuation of GH feedback-induced SS outflow would help to unmask covariates of endogenous secretagogue drive. To this end, 42 healthy pre- and postmenopausal women were randomly assigned to receive leuprolide plus estradiol (E2) or leuprolide plus placebo. A putatively low-SS milieu was imposed by l-arginine infusion. Deconvolution and regularity analyses were applied to 6-h GH concentration-time profiles. By two-way ANOVA, age negatively ( P < 0.001) and E2 positively ( P = 0.001) determined pulsatile GH secretion in the presumptively SS-deficient milieu ( P < 0.001). Comparable effects were exerted on the mass of GH secreted per burst per unit distribution volume (age P = 0.001, E2 P < 0.001, overall P < 0.001). E2 alone predicted basal (nonpulsatile) GH secretion ( P = 0.004). Stepwise forward-selection multivariate regression demonstrated that age ( P = 0.0017) and E2 ( P = 0.0002) together explained 46% of intersubject variability in pulsatile GH secretion ( P < 0.001) and fully replaced the negative univariate effect of abdominal visceral fat ( r2 = 0.32, P < 0.001). Moreover, age and E2 (but not AVF) interacted to supervise GH regularity ( P = 0.007). We conclude that age and E2 availability individually and together constitute primary predictors of basal, pulsatile, and patterned GH secretion in an inferentially feedback-silenced context in healthy women. Therefore, both factors must be considered in framing hypotheses of endogenous GH drive.
Reversal of high pancreatic islet and white adipose tissue blood flow in type 2 diabetic GK rats by administration of the β3-adrenoceptor inhibitor SR-59230A
Authors: Pettersson U. S. , Henriksnäs J. , Jansson L.
Published: June 2009

Previous studies have shown that the Goto-Kakizaki (GK) rat, a nonobese type 2 diabetes model, has an increased white adipose tissue (WAT) and islet blood flow when compared with control rats. The aim of the study was to examine if these increased blood flow values in GK rats could be affected by the β3-adrenoceptor antagonist SR-59230A. We measured organ blood flow with a microsphere technique 10 min after administration of SR-59230A (1 mg/kg body wt), or the corresponding volume of 0.9% NaCl solution (1 ml/kg body wt) in rats anaesthetized with thiobutabarbital. The GK rat had an increased blood flow in all intra-abdominal adipose tissue depots except for the sternal fat pad compared with Wistar-Furth (WF) rats. However, no differences were seen in the blood perfusion of subcutaneous white or brown adipose tissue. The blood flow was also increased in both the pancreas and in the islets in the GK rat compared with WF rats. SR-59230A treatment affected neither WAT nor pancreatic blood flow in WF rats. In GK rats, on the other hand, SR-59230A decreased both WAT and islet blood flow values to values similar to those seen in control WF rats. The whole pancreatic blood flow was not affected by SR-59230A administration in GK rats. Interestingly, the brown adipose tissue blood flow in GK rats increased after SR-59230A administration. These results suggest that β3-adrenoceptors are involved in regulation of blood flow both in islet and in adipose tissue.
Effects of exercise training on subcutaneous and visceral adipose tissue in normal- and high-fat diet-fed rats
Authors: Gollisch Katja S. C. , Brandauer Josef , Jessen Niels , Toyoda Taro , Nayer Ali , Hirshman Michael F. , Goodyear Laurie J.
Published: June 2009

Regular physical activity improves glucose tolerance and decreases adiposity. Our aim was to investigate the effects of exercise training on subcutaneous (inguinal) and visceral (parametrial) adipose tissue in rats that were fed a chow diet (13% fat) or made insulin resistant by a high-fat diet (60% fat). Sprague-Dawley rats performed 4 wk of voluntary wheel running or were kept as sedentary controls. The training groups fed chow and the high-fat diet achieved similar running distances (8.8 ± 1.8 and 9.3 ± 1.9 km/day, respectively). Training improved oral glucose tolerance in chow-fed rats and prevented the glucose intolerance that occurred in sedentary rats fed the high-fat diet. In both subcutaneous and visceral adipose tissue, the high-fat diet-induced increases in fat pad weight (67% and 133%, respectively), adipocyte size (20% and 43%), and cell number (36% and 65%) were completely prevented by exercise training. Cytokine mRNA expression in visceral fat did not change with exercise training. However, in subcutaneous fat, training actually increased mRNA expression of several cytokines [IL-6: 80% ( P < 0.05); TNF-α: 100% ( P < 0.05); IL-1 receptor antagonist (IL-1Ra): 57% ( P = 0.08)] with no detectable increases in serum cytokine concentrations. In summary, exercise training can overcome high-fat diet-induced impairments in glucose tolerance and increases in adipocyte size, cell number, and fat pad mass. Improved glucose tolerance was accompanied by an increase in cytokine gene expression in subcutaneous fat. This finding raises the possibility of a specific role of subcutaneous adipose tissue in adaptive responses to exercise training.
A high-salt diet does not influence renal sympathetic nerve activity: a direct telemetric investigation
Authors: McBryde Fiona D. , Malpas Simon C. , Guild Sarah-Jane , Barrett Carolyn J.
Published: June 2009

The importance of dietary salt in the development of hypertension has long been a source of controversy. Recent studies suggest a combination of high-salt and ANG II infusion may increase sympathetic drive; however, the effect of a change in dietary salt alone is unclear. Using telemetry, we recorded renal sympathetic nerve activity (RSNA), arterial pressure (MAP), and heart rate (HR) in seven New Zealand white rabbits before and during a 6-day period of increased salt intake (normal NaCl 0.5 g·kg−1·day−1, high NaCl 2.5 g·kg−1·day−1) and a second group of seven rabbits with normal salt intake throughout. The responses to stressful stimuli encountered in the laboratory were recorded and compared with rest in control and high-salt groups. Resting MAP, HR, and RSNA were not significantly altered with high salt intake [88 ± 5 vs. 91 ± 6 mmHg; 251 ± 8 vs. 244 ± 9 beats per minute (bpm); 9.7 ± and 1.2 vs. 10.8 ± 1.7 normalized units (nu)] despite significant reductions in plasma renin activity (1.88 ± 0.18 vs. 1.27 ± 0.15 nmol ANG I·l−1·h−1; P < 0.05) and ANG II (7.5 ± 1.2 vs. 4.3 ± 0.8 pmol/l). Increasing levels of stressful stimuli (resting in home cage, containment in box, handling, and nasopharyngeal activation) in animals on a normal salt diet caused graded increases in MAP (89 ± 2 mmHg, 95 ± 2 mmHg, 107 ± 4 mmHg, and 122 ± 5 mmHg, respectively) and RSNA (9.7 ± 0.9 nu; 11.8 ± 2.7 nu; 31.4 ± 3.7 nu; 100 nu) but not HR (245 ± 8 bpm; 234 ± 8 bpm; 262 ± 9 bpm; 36 ± 5 bpm). High dietary salt did not significantly alter the responses to stress. We conclude that a 6-day period of high salt intake does not alter the level of RSNA, with non-neural mechanisms primarily responsible for the observed renin-angiotensin system suppression.
2-Deoxy-d-glucose, but not mercaptoacetate, increases food intake in decerebrate rats
Authors: Darling Rebecca A. , Ritter Sue
Published: June 2009

We examined food intake in chronically maintained decerebrate rats in response to two antimetabolic drugs known to stimulate food intake, 2-mercaptoacetate (MA) and 2-deoxy-d-glucose (2DG). MA reduces fatty acid oxidation, and 2DG reduces glucose utilization. Because previous work has shown that insulin-induced hypoglycemia increases food intake in decerebrate rats, we predicted that 2DG would have this same effect. MA-induced feeding requires vagal sensory neurons that terminate in the hindbrain. Cholecystokinin-induced suppression of feeding, which likewise requires vagal sensory neurons, has been shown to suppress food intake in decerebrate rats. Therefore, we predicted that MA's effects on feeding would also persist in decerebrate rats. In our experiments, the test diet (40% milk, diluted with water) was infused intraorally through a chronic cheek fistula. We found that sham controls consumed 258% and 230% of their baseline milk intake in response to 2DG and MA, respectively. Decerebrates consumed 239% of their baseline milk intake in response to 2DG, but did not increase their intake in response to MA. Because decerebration separates the hindbrain from the forebrain, these results indicate that 2DG-induced glucoprivation is capable of acting within the hindbrain to activate fundamental reflex circuitry for consummatory feeding responses, as shown previously for hypoglycemia. In contrast, MA affects food consumption only after forebrain processing of MA-induced vagal afferent signals and in the presence of intact ascending and descending neural pathways.