bluuebunny/crossref_metadata_2025 huggingface dataset:
Respiration biofeedback assisted controlled breathing training to enhance shooting performance
Authors: Solanky Anuradha S
Published: July 2011

Good breathing patterns are those that meet our needs and provide optimal conditions for health and performance. Only when corrective breathing is restored, performance can be enhanced to optimal levels.

Purpose

The present research was carried out to assist a national shooter who reported with hyperventilatory breathing patterns (averaging 22–23 breaths/min).

Methods and materials

The shooter (age 26 years) was preparing for an international competition. Breathing patterns were monitored using respiration biofeedback apparatus. Controlled breathing exercises were taught to him.

Results

Three weeks of respiration biofeedback training resulted in considerable decrease in respiration rate as well as jerky breathing patterns exhibited earlier. Following the training, he participated in an international competition where he reported that his performance showed considerable improvement.

Conclusions

The shooter reported to have been able to recover faster, prevent pre-competition anxiety and regulate concentration levels during competition. Corrective breathing patterns lead to enhanced performance levels.
The effects of pilates exercise on blood pressure and selective physical fitness components in sedentary overweight females
Authors: Ali Zeinab Omid , Esfarjani Fahimeh , Bambaeichi Effat , Marandi Mohammad
Published: July 2011

The purpose of this study was to examine the effects of 8 weeks Pilates exercise programme on blood pressure and selective physical fitness components in sedentary overweight females. Thirty sedentary overweight student females (mean ± SD; age: 26 ± 3 years, body mass: 65.9 ± 5.8 kg, height: 1.58 ± 0.08 m, BMI: 26.2 ± 1.8 kg/m2) from Isfahan University participated in this study. Subjects were randomly assigned to either the experimental (n = 15) or control group (n = 15). The experimental group participated in 8 weeks Pilates class, which met for 1 h three times per week, while the control group was prevented from any sport activity and just participated in pre- and post-testing. Systolic and diastolic blood pressure, percentage of total body fat, handgrip, flexibility, aerobic power, abdominal endurance and waist circumference were assessed. There was a significant decrease in fat percentage, fat body mass and waist circumference in the experimental group after 8 weeks Pilates exercise by 7.3%, 8.5% and 4.6%, respectively (p<0.05). Aerobic power, abdominal muscular endurance and hand grip in experimental group compared to control group significantly increased by 12.3%, 9.8% and 23%. In addition, flexibility consists of sit and reach and shoulder reach test in experimental group compared to control group significantly increased by 28% and 22%, respectively (p<0.05). There was no significant difference between experimental and control groups in total body weight, body mass index, lean body mass and systolic and diastolic blood pressure (p>0.05). It is concluded that sedentary females may experience improvement in some physical fitness components and significantly decrease in body fat and waist size following 8 weeks Pilates exercise programme.
Effects of intermittent and continuous training on the blood pressure of Nigerian adolescents and children
Authors: Lawal Wahab B , Kankanala Venkatseswarul
Published: July 2011

Several methods of exercise training are used to promote cardiovascular health. It is not clear as to which of the methods of training are more beneficial in promoting cardiovascular health, especially among children and adolescents. The investigation was therefore, conducted to find out and compare the effects of a 6-week intermittent and continuous training on blood pressure of Nigerian male and female children and adolescents. To achieve this purpose, 15 (10 males and 5 females) children were selected at random from staff school of Ahmadu Bello University, Zaria and another 15 (10 males and 5 females) adolescents were selected from Demonstration Secondary School of the same University. These two groups of children and adolescents were assigned at random to intermittent and continuous training groups. All the subjects were of the same age group, had similar height, weight, blood pressure and activity background. The continuous training group underwent jogging and running at 60% of maximum heart rate for 30 min, three times a week for 6 weeks. Blood pressure and heart rate of all the subjects were recorded before training and after every 2 weeks of training. The result revealed that both intermittent and continuous groups had a significant decline in blood pressure and heart rate of both male and female children and adolescents. However, intermittent group had a greater decline in blood pressure and heart rate of both male and female children and adolescents than their continuous training group counterparts. This reduction was greater in male and female children than in their adolescent counterparts of both training groups.
A comparison of variant of echocardiography of heart in athlete and non-athletic teenagers
Authors: Hajighasemi Alireza
Published: July 2011

Diameters of heart are influenced by age, gender, body surface area and exercise. Extreme volume load and extreme pressure load may cause hypertrophic changes on heart. The aim of this study was a comparison of the rate of changes in end systolic and diastolic diameter and end systolic and diastolic volume and interventricular septum and posterior wall thickness and stroke volume of left ventricle in athlete and non-athlete teenagers. Three groups (each 10 person, 15–17 years old) were included, and matched for weight and body surface area. The first group comprised middle-distance runner athletes, the second group, taekwondo player athletes and the third group, non-athlete controls. Diameters of heart were measured by M-mode and 2-D echocardiography with a single observer in a blinded fashion.

Results

There were no significant differences in mean of end systolic diameter and posterior wall thickness of left ventricle in three groups, but other variables were significantly larger in middle-distance runner and taekwondo groups than the control group. The results of LSD test showed that mean of left ventricle end diastolic volume and interventricular septum thickness were significantly larger in middle-distance runners than taekwondo players.

MeansVariantsMiddle-distance runnerTaekwondo playersNo athletesFpLVESD, mm29.56±3.8829.66±3.2027.51±2.750.8970.42LVEDD, mm50.46±3.2050.17±3.5245.51±3.445.350.012LVEDV, ml89.89±2.6679.11±4.8760.04±2.0516.970LVESV, ml38.70±1.9733.98±2.7027.27±1.366.0820.007SV, ml51.18±5.2645.12±9.2732.76±3.4916.250IVST, mm9.57±0.0248.86±0.0247.97±0.02410.380.001PWT, mm8.67±0.0458.74±0.0407.7±0.0261.440.25

The stroke volume and volume of left ventricle of heart in anaerobic athlete teenagers with 3 years of background dynamic exercise, like taekwondo may increase as well as middle-distance runners. The results of present study are in agreement with the studies of Babet, Bary, Makan and Sanjay. Furthermore, dynamic exercise increases the thickness of walls of ventricle. This result is in accordance to Babet study.
Risk of coronary heart disease (CHD) between sports persons and sedentary persons
Authors: Kumar Rabindra , Purohit Sunil , Kumar Sandeep
Published: July 2011

The purpose of the current study was to know the effect of exercise on coronary heart disease (CHD) between sports persons and sedentary persons. We performed a randomised trial to compare the CHD between sports and sedentary persons. Ten sports persons were compared with 10 sedentary persons. Subjects were assessed for serum total cholesterol, triglycerides (TG), high-density lipoprotein (HDL-C), low-density lipoprotein (LDL-C), very low density lipoprotein (VLDL-C) and C/H-ratio, which are indicators of CHD. Results showed lower levels of TG and VLDL-C but high level of HDL-C (good cholesterol) values (p<0.05) in sports persons as compared to sedentary persons. Results also indicated that total cholesterol mean value of sports persons was lower compared to sedentary persons. Sports persons are at lower risk of development and progression of CHD as compared to sedentary persons, indicating that exercise will help to maintain their lipid profile, which plays a key role in CHD and atherosclerosis. Studies clearly show that sports persons are less likely to develop CHD than sedentary persons. Thus routine exercise is recommended for all sedentary persons in their busy schedules for a good healthy life.
The effect of fast and slow rhythm music on anaerobic performance and salivary cortisol in athlete males
Authors: Ghaderi Mohammad , Azarbayjani Mohammad Ali
Published: July 2011

Introduction

Music has been widely recommended as a technique to enhance the psychophysical state of participants in sport and exercise. However, there is scant scientific evidence in anaerobic performance to clarify its proposed benefits. Therefore, the aim of this study was to determine the effect of fast and slow rhythm music on anaerobic performance and salivary cortisol concentration in trained men.

Methods

Thirty male physical education college students (ages: 25.66±3.89 years, height: 176.65±7.66 cm, weight: 78.45±16.20 kg, body fat percent: 12.86±5.74 and VO2max: 38.36±9.19 ml/kg/min) voluntarily participated in this study and were divided into three groups: fast music, slow music and no music (control). All subjects performed the Cunningham test following a 20% grate and 14.3 km/h speed on the treadmill. For measuring cortisol, not stimulated samples of saliva collected, 15 min before intervention, immediately 5 and the other 30 min after the exercise. The significance level was set at p < 0.05.

Results

There was a no significant difference between the listening of music and anaerobic performance. In addition, salivary cortisol concentration decreased 5 and 30 min after exercise during slow music listening compared with fast and without music (control) treatment, but were not significant. Furthermore, the type of music has no impact on running time for the measure of anaerobic performance and salivary cortisol after exercise.

Discussion

This study provided some support for the hypothesis that fast and slow music listening had no significant impact compared without music during anaerobic exercise.
Evidence-based risk assessment and recommendations for physical activity: arthritis, osteoporosis, and low back pain1This paper is one of a selection of papers published in the Special Issue entitled Evidence-based risk assessment and recommendations for physical activity clearance, and has undergone the Journal’s usual peer-review process.
Authors: Chilibeck Philip D. , Vatanparast Hassanali , Cornish Stephen M. , Abeysekara Saman , Charlesworth Sarah
Published: July 2011

We systematically reviewed the safety of physical activity (PA) for people with arthritis, osteoporosis, and low back pain. We searched PubMed, MEDLINE, Sport Discus, and the Cochrane Central Register of Controlled Trials (1966 through March 2008) for relevant articles on PA and adverse events. A total of 111 articles met our inclusion criteria. The incidence for adverse events during PA was 3.4%–11% (0.06%–2.4% serious adverse events) and included increased joint pain, fracture, and back pain for those with arthritis, osteoporosis, and low back pain, respectively. Recommendations were based on the Appraisal of Guidelines for Research and Evaluation, which applies Levels of Evidence based on type of study ranging from high-quality randomized controlled trials (Level 1) to anecdotal evidence (Level 4) and Grades from A (strong) to C (weak). Our main recommendations are that (i) arthritic patients with highly progressed forms of disease should avoid heavy load-bearing activities, but should participate in non-weight-bearing activities (Level 2, Grade A); and (ii) patients with osteoporosis should avoid trunk flexion (Level 2, Grade A) and powerful twisting of the trunk (Level 3, Grade C); (iii) patients with acute low back pain can safely do preference-based PA (i.e., PA that does not induce pain), including low back extension and flexion (Level 2, Grade B); (iv) arthritic patients with stable disease without progressive joint damage and patients with stable osteoporosis or low back pain can safely perform a variety of progressive aerobic or resistance-training PAs (Level 2, Grades A and B). Overall, the adverse event incidence from reviewed studies was low. PA can safely be done by most individuals with musculoskeletal conditions.
Enhancing the effectiveness of clearance for physical activity participation: background and overall process1This paper is one of a selection of papers published in the Special Issue entitled Evidence-based risk assessment and recommendations for physical activity clearance, and has undergone the Journal's usual peer-review process.
Authors: Jamnik Veronica K. , Warburton Darren E.R. , Makarski Julie , McKenzie Donald C. , Shephard Roy J. , Stone James A. , Charlesworth S. , Gledhill Norman
Published: July 2011

Recent feedback from physical activity (PA) participants, fitness professionals, and physicians has indicated that there are limitations to the utility and effectiveness of the existing PAR-Q and PARmed-X screening tools for PA participation. The aim of this study was to have authorities in exercise and chronic disease management to work with an expert panel to increase the effectiveness of clearance for PA participation using an evidence-based consensus approach and the well-established Appraisal of Guidelines for Research and Evaluation (AGREE) Instrument. Systematic reviews were conducted to develop a new PA clearance protocol involving risk stratification and a decision-tree process. Evidence-based support was sought for enabling qualified exercise professionals to have a direct role in the PA participation clearance process. The PAR-Q+ was developed to use formalized probes to clarify problematic responses and to explore issues arising from currently diagnosed chronic disease or condition. The original PARmed-X tool is replaced with an interactive computer program (ePARmed-X+) to clear prospective PA participants for either unrestricted or supervised PA or to direct them to obtain medical clearance. Evidence-based validation was also provided for the direct role of highly qualified university-educated exercise professionals in the PA clearance process. The risks associated with exercise during pregnancy were also evaluated. The systematic review and consensus process, conforming to the AGREE Instrument, has provided a sound evidence base for enhanced effectiveness of the clearance process for PA participation of both asymptomatic populations and persons with chronic diseases or conditions.
Evidence-based risk assessment and recommendations for exercise testing and physical activity clearance in apparently healthy individuals1This paper is one of a selection of papers published in this Special Issue, entitled Evidence-based risk assessment and recommendations for physical activity clearance, and has undergone the Journal’s usual peer review process.
Authors: Goodman Jack M. , Thomas Scott G. , Burr Jamie
Published: July 2011

Increased physical activity (PA) is associated with improved health and quality of life in the general population. A dose–response effect is evident between increasing levels of PA participation and a lower relative risk for cardiovascular disease and all-cause mortality. However, there is also clear evidence that PA acutely increases the risk of an adverse cardiovascular (CV) event and sudden cardiac death (SCD) significantly above levels expected at rest. Adverse CV events during PA may be triggered acutely by the physiological stress of exercise. This investigation will review the available literature describing the CV risks of exercise testing and PA participation in apparently healthy individuals. A systematic review of the literature was performed using electronic databases, including Medline, CINAHL, SPORT discus, EMBASE, Cochrane DSR, ACP Journal Club, and DARE; additional relevant articles were hand-picked and the final grouping was used for the review using the AGREE process to assess the impact and quality of the selected articles. Six hundred and sixteen relevant articles were reviewed with 51 being identified as describing adverse CV events during exercise and PA. Data suggests the risks of fatal and nonfatal events during maximal exercise testing in apparently healthy individuals rarely occur (approximately <0.8 per 10 000 tests or 1 per 10 000 h of testing). The incidence of adverse CV events is extremely low during PA of varying types and intensities, with data limited almost exclusively to fatal CV events, as nonfatal events are rarely reported. However, this risk is reduced by 25%–50% in those individuals who have prior experience with increased levels of PA, particularly vigorous PA. Throughout a wide age range, the risk of SCD and nonfatal events during PA remain extremely low (well below 0.01 per 10 000 participant hours), but both increasing age and PA intensity are associated with greater risk. In most cases of exercise-related SCD, undetected pre-existing disease is present and SCD is typically the first clinical event. The risks of an adverse CV event during exercise testing and PA are rare and are outweighed by the health benefits. Given this risk-benefit relationship, the PAR-Q is an appropriate method to identify those at higher risk across a wide age span and should be used in conjunction with appropriate clinical guidelines for guiding individuals towards graduated PA. There are not adequate data to describe the risks of PA in those individuals considered to be at higher risk but without cardiovascular disease.
Evidence-based risk recommendations for best practices in the training of qualified exercise professionals working with clinical populations1This paper is one of a selection of papers published in this Special Issue, entitled Evidence-based risk assessment and recommendations for physical activity clearance, and has undergone the Journal’s usual peer review process.
Authors: Warburton Darren E.R. , Bredin Shannon S.D. , Charlesworth Sarah A. , Foulds Heather J.A. , McKenzie Don C. , Shephard Roy J.
Published: July 2011

This systematic review examines critically “best practices” in the training of qualified exercise professionals. Particular attention is given to the core competencies and educational requirements needed for working with clinical populations. Relevant information was obtained by a systematic search of 6 electronic databases, cross-referencing, and through the authors’ knowledge of the area. The level and grade of the available evidence was established. A total of 52 articles relating to best practices and (or) core competencies in clinical exercise physiology met our eligibility criteria. Overall, current literature supports the need for qualified exercise professionals to possess advanced certification and education in the exercise sciences, particularly when dealing with “at-risk” populations. Current literature also substantiates the safety and effectiveness of exercise physiologist supervised stress testing and training in clinical populations.
Evidence-based risk assessment and recommendations for physical activity clearance: respiratory disease1This paper is one of a selection of papers published in the Special Issue entitled Evidence-based risk assessment and recommendations for physical activity clearance, and has undergone the Journal’s usual peer-review process.
Authors: Eves Neil D. , Davidson Warren J.
Published: July 2011

The 2 most common respiratory diseases are chronic obstructive pulmonary disease (COPD) and asthma. Growing evidence supports the benefits of exercise for all patients with these diseases. Due to the etiology of COPD and the pathophysiology of asthma, there may be some additional risks of exercise for these patients, and hence accurate risk assessment and clearance is needed before patients start exercising. The purpose of this review was to evaluate the available literature regarding the risks of exercise for patients with respiratory disease and provide evidence-based recommendations to guide the screening process. A systematic review of 4 databases was performed. The literature was searched to identify adverse events specific to exercise. For COPD, 102 randomized controlled trials that involved an exercise intervention were included (n = 6938). No study directly assessed the risk of exercise, and only 15 commented on exercise-related adverse events. For asthma, 30 studies of mixed methodologies were included (n = 1278). One study directly assessed the risk of exercise, and 15 commented on exercise-related adverse events. No exercise-related fatalities were reported. The majority of adverse events in COPD patients were musculoskeletal or cardiovascular in nature. In asthma patients, exercise-induced bronchoconstriction and (or) asthma symptoms were the primary adverse events. There is no direct evidence regarding the risk of exercise for patients with COPD or asthma. However, based on the available literature, it would appear that with adequate screening and optimal medical therapy, the risk of exercise for these respiratory patients is low.
Evidence-based risk assessment and recommendations for physical activity clearance: an introduction1This paper is one of a selection of papers published in this Special Issue, entitled Evidence-based risk assessment and recommendations for physical activity clearance, and has undergone the Journal’s usual peer review process.
Authors: Warburton Darren E.R. , Jamnik Veronica K. , Bredin Shannon S.D. , McKenzie Don C. , Stone James , Shephard Roy J. , Gledhill Norman
Published: July 2011

The Physical Activity Readiness Questionnaire (PAR-Q) and the Physical Activity Readiness Medical Evaluation (PARmed-X) are internationally renowned and extensively used preparticipation screening tools. However, recent feedback from end-users has identified limitations to the existing PAR-Q and PARmed-X screening process. As such, a systematic evaluation of the PAR-Q and PARmed-X forms was conducted, adhering to the Appraisal of Guidelines for Research and Evaluation (AGREE) criteria. Recognized experts in physical activity (PA) and prominent health conditions worked with an expert consensus panel to increase the effectiveness of the PAR-Q and PARmed-X PA participation clearance process. The systematic review process established that the health benefits of PA participation far outweigh the risks in the vast majority of asymptomatic and symptomatic individuals. A new risk continuum and decision tree process was created to allow for the effective risk stratification of prominent health conditions, reducing greatly the barriers to PA participation for the majority of individuals. The new PA participation clearance process is available in new paper and online versions (PAR-Q+) and the PARmed-X was replaced with an online interactive computer programme (ePARmed-X+). It is anticipated that this new risk stratification and PA clearance process will reduce markedly the barriers for PA participation for both asymptomatic and symptomatic individuals.
Evidence-based risk assessment and recommendations for physical activity clearance: pregnancy1This paper is one of a selection of papers published in this Special Issue, entitled Evidence-based risk assessment and recommendations for physical activity clearance, and has undergone the Journal’s usual peer review process.
Authors: Charlesworth Sarah , Foulds Heather J.A. , Burr Jamie F. , Bredin Shannon S.D.
Published: July 2011

Recommendations for physical activity during pregnancy have progressed significantly in the last 30 years and continue to evolve as an increasing body of scientific evidence becomes available. In addition, there is an increasing number of women who wish to either maintain physical fitness levels during the prenatal period or initiate exercise for a healthier lifestyle during pregnancy. As such, consistent evaluation of the risks associated with exercise during pregnancy is warranted for maternal and fetal well-being. The primary purpose of this systematic review was to evaluate the scientific information available regarding maternal and fetal responses as it relates to the occurrence of adverse exercise-related events in pregnant women without contraindications to exercise. A systematic and evidence-based approach was used to analyze critically the level of evidence for risks associated with acute and chronic exercise during pregnancy in healthy pregnant women. All articles were screened according to standardized evaluation criteria developed by a panel of experts. A total of 74 investigations that involved 3766 pregnant women were included in the analysis. Of the 74 studies, only 35 studies documented the presence or absence of adverse events. The serious adverse event rate for these studies was 1.4 per 10 000 h of exercise. The adverse event rate increased to 6.8 per 10 000 h of exercise when including the occurrence of more mild events and exercise-related fetal bradycardia and tachycardia. Previously inactive or active women (without contraindications) are at a low risk for adverse fetal or maternal events if they participate in routine physical activity during pregnancy.
RULE EXTRACTION FROM MINIMAL NEURAL NETWORKS FOR CREDIT CARD SCREENING
Authors: SETIONO RUDY , BAESENS BART , MUES CHRISTOPHE
Published: July 2011

While feedforward neural networks have been widely accepted as effective tools for solving classification problems, the issue of finding the best network architecture remains unresolved, particularly so in real-world problem settings. We address this issue in the context of credit card screening, where it is important to not only find a neural network with good predictive performance but also one that facilitates a clear explanation of how it produces its predictions. We show that minimal neural networks with as few as one hidden unit provide good predictive accuracy, while having the added advantage of making it easier to generate concise and comprehensible classification rules for the user. To further reduce model size, a novel approach is suggested in which network connections from the input units to this hidden unit are removed by a very straightaway pruning procedure. In terms of predictive accuracy, both the minimized neural networks and the rule sets generated from them are shown to compare favorably with other neural network based classifiers. The rules generated from the minimized neural networks are concise and thus easier to validate in a real-life setting.
HYBRID NEURAL INTELLIGENT SYSTEM TO PREDICT BUSINESS FAILURE IN SMALL-TO-MEDIUM-SIZE ENTERPRISES
Authors: BORRAJO M. LOURDES , BARUQUE BRUNO , CORCHADO EMILIO , BAJO JAVIER , CORCHADO JUAN M.
Published: July 2011

During the last years there has been a growing need of developing innovative tools that can help small to medium sized enterprises to predict business failure as well as financial crisis. In this study we present a novel hybrid intelligent system aimed at monitoring the modus operandi of the companies and predicting possible failures. This system is implemented by means of a neural-based multi-agent system that models the different actors of the companies as agents. The core of the multi-agent system is a type of agent that incorporates a case-based reasoning system and automates the business control process and failure prediction. The stages of the case-based reasoning system are implemented by means of web services: the retrieval stage uses an innovative weighted voting summarization of self-organizing maps ensembles-based method and the reuse stage is implemented by means of a radial basis function neural network. An initial prototype was developed and the results obtained related to small and medium enterprises in a real scenario are presented.
IMPROVING CLASSIFICATION ACCURACY AND CAUSAL KNOWLEDGE FOR BETTER CREDIT DECISIONS
Authors: WU WEI-WEN
Published: July 2011

Numerous studies have contributed to efforts to boost the accuracy of the credit scoring model. Especially interesting are recent studies which have successfully developed the hybrid approach, which advances classification accuracy by combining different machine learning techniques. However, to achieve better credit decisions, it is not enough merely to increase the accuracy of the credit scoring model. It is necessary to conduct meaningful supplementary analyses in order to obtain knowledge of causal relations, particularly in terms of significant conceptual patterns or structures involving attributes used in the credit scoring model. This paper proposes a solution of integrating data preprocessing strategies and the Bayesian network classifier with the tree augmented Na"ıve Bayes search algorithm, in order to improve classification accuracy and to obtain improved knowledge of causal patterns, thus enhancing the validity of credit decisions.
ARTIFICIAL METAPLASTICITY NEURAL NETWORK APPLIED TO CREDIT SCORING
Authors: MARCANO-CEDEÑO ALEXIS , MARIN-DE-LA-BARCENA A. , JIMENEZ-TRILLO J. , PIÑUELA J. A. , ANDINA D.
Published: July 2011

The assessment of the risk of default on credit is important for financial institutions. Different Artificial Neural Networks (ANN) have been suggested to tackle the credit scoring problem, however, the obtained error rates are often high. In the search for the best ANN algorithm for credit scoring, this paper contributes with the application of an ANN Training Algorithm inspired by the neurons' biological property of metaplasticity. This algorithm is especially efficient when few patterns of a class are available, or when information inherent to low probability events is crucial for a successful application, as weight updating is overemphasized in the less frequent activations than in the more frequent ones. Two well-known and readily available such as: Australia and German data sets has been used to test the algorithm. The results obtained by AMMLP shown have been superior to state-of-the-art classification algorithms in credit scoring.
NONLINEAR SYSTEM IDENTIFICATION AND CONTROL BASED ON MODULAR NEURAL NETWORKS
Authors: PUSCASU GHEORGHE , CODRES BOGDAN
Published: July 2011

A new approach for nonlinear system identification and control based on modular neural networks (MNN) is proposed in this paper. The computational complexity of neural identification can be greatly reduced if the whole system is decomposed into several subsystems. This is obtained using a partitioning algorithm. Each local nonlinear model is associated with a nonlinear controller. These are also implemented by neural networks. The switching between the neural controllers is done by a dynamical switcher, also implemented by neural networks, that tracks the different operating points. The proposed multiple modelling and control strategy has been successfully tested on simulated laboratory scale liquid-level system.
Alteration in body composition in the portacaval anastamosis rat is mediated by increased expression of myostatin
Authors: Dasarathy Srinivasan , Muc Sean , Runkana Ashok , Mullen Kevin Daniel , Kaminsky-Russ Kristine , McCullough Arthur Joseph
Published: July 2011

The portacaval anastamosis (PCA) rat is a model to examine nutritional consequences of portosystemic shunting in cirrhosis. Alterations in body composition and mechanisms of diminished fat mass following PCA were examined. Body composition of male Sprague-Dawley rats with end-to-side PCA and pair-fed sham-operated (SO) controls were studied 3 wk after surgery by chemical carcass analysis ( n=8 each) and total body electrical conductivity ( n=6 each). Follistatin, a myostatin antagonist, or vehicle was administered to PCA and SO rats ( n=8 in each group) to examine whether myostatin regulated fat mass following PCA. The expression of lipogenic and lipolytic genes in white adipose tissue (WAT) was quantified by real-time PCR. Body weight, fat-free mass, fat mass, organ weights, and food efficiency were significantly lower ( P < 0.001) in the PCA than SO rats. Adipocyte size and triglyceride content of epididymal fat in PCA rats were significantly lower ( P < 0.01) than in SO rats. Myostatin expression was higher in the WAT of PCA compared with SO rats and was accompanied by an increase in phospho-AMP kinase Thr172. Follistatin increased whole body fat and WAT mass, adipocyte size, and expression of lipogenic genes in WAT in PCA, but not in SO rats. Myostatin and phospho-AMP kinase protein and lipolytic gene expression were lower with follistatin. We conclude that PCA results in loss of fat mass due to an increased expression of myostatin in adipose tissue with lower lipogenic and higher fatty acid oxidation gene expression.
Tolerance to central hypovolemia: the influence of oscillations in arterial pressure and cerebral blood velocity
Authors: Rickards Caroline A. , Ryan Kathy L. , Cooke William H. , Convertino Victor A.
Published: July 2011

Higher oscillations of cerebral blood velocity and arterial pressure (AP) induced by breathing with inspiratory resistance are associated with delayed onset of symptoms and increased tolerance to central hypovolemia. We tested the hypothesis that subjects with high tolerance (HT) to central hypovolemia would display higher endogenous oscillations of cerebral blood velocity and AP at presyncope compared with subjects with low tolerance (LT). One-hundred thirty-five subjects were exposed to progressive lower body negative pressure (LBNP) until the presence of presyncopal symptoms. Subjects were classified as HT if they completed at least the −60-mmHg level of LBNP (93 subjects; LBNP time, 1,880 ± 259 s) and LT if they did not complete this level (42 subjects; LBNP time, 1,277 ± 199 s). Middle cerebral artery velocity (MCAv) was measured by transcranial Doppler, and AP was measured at the finger by photoplethysmography. Mean MCAv and mean arterial pressure (MAP) decreased progressively from baseline to presyncope for both LT and HT subjects ( P < 0.001). However, low frequency (0.04–0.15 Hz) oscillations of mean MCAv and MAP were higher at presyncope in HT subjects compared with LT subjects (MCAv: HT, 7.2 ± 0.7 vs. LT, 5.3 ± 0.6 (cm/s)2, P = 0.075; MAP: HT, 15.3 ± 1.4 vs. 7.9 ± 1.2 mmHg2, P < 0.001). Consistent with our previous findings using inspiratory resistance, high oscillations of mean MCAv and MAP are associated with HT to central hypovolemia.
Pulmonary hemodynamics and vascular reactivity in asphyxiated term lambs resuscitated with 21 and 100% oxygen
Authors: Lakshminrusimha Satyan , Steinhorn Robin H. , Wedgwood Stephen , Savorgnan Fabio , Nair Jayasree , Mathew Bobby , Gugino Sylvia F. , Russell James A. , Swartz Daniel D.
Published: July 2011

An increase in oxygen tension is an important factor in decreasing pulmonary vascular resistance (PVR) at birth. Birth asphyxia results in acidosis and increased PVR. We determined the effect of resuscitation with 21 vs. 100% O2 on pulmonary hemodynamics, pulmonary arterial (PA) reactivity, and oxidant stress in a lamb model of in utero asphyxia. Term fetal lambs were acutely asphyxiated by intrauterine umbilical cord occlusion for 10 min resulting in acidosis (pH 6.96 ± 0.05 and Pco2 103 ± 5 Torr), bradycardia, systemic hypotension, and increased PVR. Lambs were treated with 30 min of resuscitation with 21% or 100% O2 ( n = 6 each). PaO2 was significantly elevated with 100% O2 resuscitation compared with 21% O2 (430 ± 38 vs. 64 ± 8 Torr), but changes in pH and PaCO2 were similar. The 100% O2 induced greater increase in pulmonary blood flow and decrease in PVR at 1 min of life, but subsequent values were similar to 21% O2 group between 2 and 30 min of life. Oxygen uptake from the lung and systemic oxygen extraction was similar between the two groups. Pulmonary arteries showed increased staining for superoxide anions and increased contractility to norepinephrine following resuscitation with 100% O2. The increased PA contractility induced by 100% O2 was reversed by scavenging superoxide anions with superoxide dismutase and catalase. We conclude that resuscitation of asphyxiated lambs with 100% O2 increases PaO2 but does not improve lung oxygen uptake, decrease PVR at 30 min, or increase systemic oxygen extraction ratios. Furthermore, 100% O2 also induces oxidative stress and increases PA contractility. These findings support the new neonatal resuscitation guidelines recommending 21% O2 for initial resuscitation of asphyxiated neonates.
Effects of high- and low-velocity resistance training on the contractile properties of skeletal muscle fibers from young and older humans
Authors: Claflin Dennis R. , Larkin Lisa M. , Cederna Paul S. , Horowitz Jeffrey F. , Alexander Neil B. , Cole Neil M. , Galecki Andrzej T. , Chen Shu , Nyquist Linda V. , Carlson Bruce M. , Faulkner John A. , Ashton-Miller James A.
Published: July 2011

A two-arm, prospective, randomized, controlled trial study was conducted to investigate the effects of movement velocity during progressive resistance training (PRT) on the size and contractile properties of individual fibers from human vastus lateralis muscles. The effects of age and sex were examined by a design that included 63 subjects organized into four groups: young (20–30 yr) men and women, and older (65–80 yr) men and women. In each group, one-half of the subjects underwent a traditional PRT protocol that involved shortening contractions at low velocities against high loads, while the other half performed a modified PRT protocol that involved contractions at 3.5 times higher velocity against reduced loads. Muscles were sampled by needle biopsy before and after the 14-wk PRT program, and functional tests were performed on permeabilized individual fiber segments isolated from the biopsies. We tested the hypothesis that, compared with low-velocity PRT, high-velocity PRT results in a greater increase in the cross-sectional area, force, and power of type 2 fibers. Both types of PRT increased the cross-sectional area, force, and power of type 2 fibers by 8–12%, independent of the sex or age of the subject. Contrary to our hypothesis, the velocity at which the PRT was performed did not affect the fiber-level outcomes substantially. We conclude that, compared with low-velocity PRT, resistance training performed at velocities up to 3.5 times higher against reduced loads is equally effective for eliciting an adaptive response in type 2 fibers from human skeletal muscle.
Metoprolol impairs resistance artery function in mice
Authors: El Beheiry Mostafa H. , Heximer Scott P. , Voigtlaender-Bolz Julia , Mazer C. David , Connelly Kim A. , Wilson David F. , Beattie W. Scott , Tsui Albert K. Y. , Zhang Hangjun , Golam Kabir , Hu Tina , Liu Elaine , Lidington Darcy , Bolz Steffen-Sebastian , Hare Gregory M. T.
Published: July 2011

Acute β-blockade with metoprolol has been associated with increased mortality by undefined mechanisms. Since metoprolol is a relatively high affinity blocker of β2-adrenoreceptors, we hypothesized that some of the increased mortality associated with its use may be due to its abrogation of β2-adrenoreceptor-mediated vasodilation of microvessels in different vascular beds. Cardiac output (CO; pressure volume loops), mean arterial pressure (MAP), relative cerebral blood flow (rCBF; laser Doppler), and microvascular brain tissue Po2(G2 oxyphor) were measured in anesthetized mice before and after acute treatment with metoprolol (3 mg/kg iv). The vasodilatory dose responses to β-adrenergic agonists (isoproterenol and clenbuterol), and the myogenic response, were assessed in isolated mesenteric resistance arteries (MRAs; ∼200-μm diameter) and posterior cerebral arteries (PCAs ∼150-μm diameter). Data are presented as means ± SE with statistical significance applied at P < 0.05. Metoprolol treatment did not effect MAP but reduced heart rate and stroke volume, CO, rCBF, and brain microvascular Po2, while concurrently increasing systemic vascular resistance ( P < 0.05 for all). In isolated MRAs, metoprolol did not affect basal artery tone or the myogenic response, but it did cause a dose-dependent impairment of isoproterenol- and clenbuterol-induced vasodilation. In isolated PCAs, metoprolol (50 μM) impaired maximal vasodilation in response to isoproterenol. These data support the hypothesis that acute administration of metoprolol can reduce tissue oxygen delivery by impairing the vasodilatory response to β2-adrenergic agonists. This mechanism may contribute to the observed increase in mortality associated with acute administration of metoprolol in perioperative patients.
Chromogranin A Restricts Drug Penetration and Limits the Ability of NGR-TNF to Enhance Chemotherapeutic Efficacy
Authors: Dondossola Eleonora , Gasparri Anna Maria , Colombo Barbara , Sacchi Angelina , Curnis Flavio , Corti Angelo
Published: July 2011

NGR-TNF is a derivative of TNF-α that targets tumor blood vessels and enhances penetration of chemotherapeutic drugs. Because of this property, NGR-TNF is being tested in combination with chemotherapy in various phase II and III clinical trials. Here we report that chromogranin A (CgA), a protein present in variable amounts in the blood of normal subjects and cancer patients, inhibits the synergism of NGR-TNF with doxorubicin and melphalan in mouse models of lymphoma and melanoma. Pathophysiologically relevant levels of circulating CgA blocked NGR-TNF–induced drug penetration by enhancing endothelial barrier function and reducing drug extravasation in tumors. Mechanistic investigations done in endothelial cell monolayers in vitro showed that CgA inhibited phosphorylation of p38 MAP kinase, disassembly of VE-cadherin–dependent adherence junctions, paracellular macromolecule transport, and NGR-TNF–induced drug permeability. In this system, the N-terminal fragment of CgA known as vasostatin-1 also inhibited drug penetration and NGR-TNF synergism. Together, our results suggest that increased levels of circulating CgA and its fragments, as it may occur in certain cancer patients with nonneuroendocrine tumors, may reduce drug delivery to tumor cells particularly as induced by NGR-TNF. Measuring CgA and its fragments may assist the selection of patients that can respond better to NGR-TNF/chemotherapy combinations in clinical trials. Cancer Res; 71(17); 5881–90. ©2011 AACR.
MK-1775, a Novel Wee1 Kinase Inhibitor, Radiosensitizes p53-Defective Human Tumor Cells
Authors: Bridges Kathleen A. , Hirai Hiroshi , Buser Carolyn A. , Brooks Colin , Liu Huifeng , Buchholz Thomas A. , Molkentine Jessica M. , Mason Kathryn A. , Meyn Raymond E.
Published: July 2011

Purpose: Radiotherapy is commonly used to treat a variety of solid tumors. However, improvements in the therapeutic ratio for several disease sites are sorely needed, leading us to assess molecularly targeted therapeutics as radiosensitizers. The aim of this study was to assess the wee1 kinase inhibitor, MK-1775, for its ability to radiosensitize human tumor cells.

Experimental Design: Human tumor cells derived from lung, breast, and prostate cancers were tested for radiosensitization by MK-1775 using clonogenic survival assays. Both p53 wild-type and p53-defective lines were included. The ability of MK-1775 to abrogate the radiation-induced G2 block, thereby allowing cells harboring DNA lesions to prematurely progress into mitosis, was determined using flow cytometry and detection of γ-H2AX foci. The in vivo efficacy of the combination of MK-1775 and radiation was assessed by tumor growth delay experiments using a human lung cancer cell line growing as a xenograft tumor in nude mice.

Results: Clonogenic survival analyses indicated that nanomolar concentrations of MK-1775 radiosensitized p53-defective human lung, breast, and prostate cancer cells but not similar lines with wild-type p53. Consistent with its ability to radiosensitize, MK-1775 abrogated the radiation-induced G2 block in p53-defective cells but not in p53 wild-type lines. MK-1775 also significantly enhanced the antitumor efficacy of radiation in vivo as shown in tumor growth delay studies, again for p53-defective tumors.

Conclusions: These results indicate that p53-defective human tumor cells are significantly radiosensitized by the potent and selective wee1 kinase inhibitor, MK-1775, in both the in vitro and in vivo settings. Taken together, our findings strongly support the clinical evaluation of MK-1775 in combination with radiation. Clin Cancer Res; 17(17); 5638–48. ©2011 AACR.
Interplay Between pVHL and mTORC1 Pathways in Clear-Cell Renal Cell Carcinoma
Authors: Kucejova Blanka , Peña-Llopis Samuel , Yamasaki Toshinari , Sivanand Sharanya , Tran Tram Anh T. , Alexander Shane , Wolff Nicholas C. , Lotan Yair , Xie Xian-Jin , Kabbani Wareef , Kapur Payal , Brugarolas James
Published: July 2011

mTOR complex 1 (mTORC1) is implicated in cell growth control and is extensively regulated. We previously reported that in response to hypoxia, mTORC1 is inhibited by the protein regulated in development and DNA damage response 1 (REDD1). REDD1 is upregulated by hypoxia-inducible factor (HIF)-1, and forced REDD1 expression is sufficient to inhibit mTORC1. REDD1-induced mTORC1 inhibition is dependent on a protein complex formed by the tuberous sclerosis complex (TSC)1 and 2 (TSC2) proteins. In clear-cell renal cell carcinoma (ccRCC), the von Hippel-Lindau (VHL) gene is frequently inactivated leading to constitutive activation of HIF-2 and/or HIF-1, which may be expected to upregulate REDD1 and inhibit mTORC1. However, mTORC1 is frequently activated in ccRCC, and mTORC1 inhibitors are effective against this tumor type; a paradox herein examined. REDD1 was upregulated in VHL-deficient ccRCC by in silico microarray analyses, as well as by quantitative real-time PCR, Western blot, and immunohistochemistry. Vhl disruption in a mouse model was sufficient to induce Redd1. Using ccRCC-derived cell lines, we show that REDD1 upregulation in tumors is VHL dependent and that both HIF-1 and HIF-2 are, in a cell-type-dependent manner, recruited to, and essential for, REDD1 induction. Interestingly, whereas mTORC1 is responsive to REDD1 in some tumors, strategies have evolved in others, such as mutations disrupting TSC1, to subvert mTORC1 inhibition by REDD1. Sequencing analyses of 77 ccRCCs for mutations in TSC1, TSC2, and REDD1, using PTEN as a reference, implicate the TSC1 gene, and possibly REDD1, as tumor suppressors in sporadic ccRCC. Understanding how ccRCCs become refractory to REDD1-induced mTORC1 inhibition should shed light into the development of ccRCC and may aid in patient selection for molecular-targeted therapies. Mol Cancer Res; 9(9); 1255–65. ©2011 AACR.
Oxidative and Nitrosative Stress Markers in Patients on Hemodialysis and Peritoneal Dialysis
Authors: Köse Fadime Aydın , Seziş Meltem , Akçiçek Fehmi , Pabuççuoğlu Aysun
Published: July 2011

Aim: The aim of this study was to evaluate the effects of hemodialysis (HD) and peritoneal dialysis (PD) treatments on oxidative and nitrosative stress markers comparatively. Methods: Twenty HD and 20 PD patients as well as 20 healthy individuals were included in this study. Plasma advanced oxidation protein products, myeloperoxidase, thiol group and 3-nitrotyrosine (3-NT) levels were measured in all subjects. Results: Plasma advanced oxidation protein products and myeloperoxidase levels were elevated by HD and PD treatments when compared to the control group. Conversely, plasma thiol group levels were decreased in HD and PD patients. 3-NT levels were increased by HD treatment only. Conclusions: The elevated plasma 3-NT levels in pre-HD and post-HD patients suggest that those patients have a considerably increased risk for nitrosative tissue injury. However, similar 3-NT levels of the control and PD groups support the advantage of PD therapy in terms of nitrosative tissue injury.