bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adiposity and aerobic fitness are associated with metabolic disease risk in children
Authors: Parrett Anne L. , Valentine Rudy J. , Arngrímsson Sigurbjörn Á. , Castelli Darla M. , Evans Ellen M. 
Published: February 2011

To examine the relative association of physical activity, cardiorespiratroy fitness (CRF), and adiposity with risk for metabolic disease in prepubescent children. Forty-six prepubescent children (age, 9.4 ± 1.7 years; 24 males) were assessed for adiposity (%fat) via dual-energy X-ray absorptiometry, CRF with a peak graded exercise test, and physical activity using pedometers. Metabolic disease risk was assessed by a composite score of the following factors: waist circumference (WC), mean arterial pressure (MAP), triacylglycerol (TAG), total cholesterol to high-density lipoprotein cholesterol ratio (TC/HDL-C ratio), glucose, and insulin. Adiposity was correlated with metabolic disease risk score, as well as homeostasis model assessment of insulin resistance (HOMA-IR), TAG, TC/HDL-C ratio, WC, insulin, and MAP (r range = 0.33 to 0.95, all p < 0.05). Physical activity was negatively associated with metabolic disease risk score, as well as HOMA-IR, TAG, WC, insulin, and MAP (r range = –0.32 to –0.49, all p < 0.05). CRF was inversely associated with metabolic disease risk score and HOMA-IR, TAG, TC/HDL-C ratio, WC, insulin, and MAP (r range = –0.32 to –0.63, all p < 0.05). Compared across fitness–physical activity and fatness groups, the low-fit–high-fat and the low-activity–high-fat groups had higher metabolic risk scores than both low-fat groups. Regression analyses revealed sexual maturity (β = 0.27, p = 0.044) and %fat (β = 0.49, p = 0.005) were the only independent predictors of metabolic disease risk score, explaining 4.7% and 9.5% of the variance, respectively. Adiposity appears to be an influential factor for metabolic disease risk in prepubescent children, and fitness is protective against metabolic disease risk in the presence of high levels of adiposity.
Gender differences in whole-body fat oxidation kinetics during exercise
Authors: Chenevière Xavier , Borrani Fabio , Sangsue David , Gojanovic Boris , Malatesta Davide 
Published: February 2011

Discrepancies appear in studies comparing fat oxidation between men and women. Therefore, this study aimed to quantitatively describe and compare whole-body fat oxidation kinetics between genders during exercise, using a sinusoidal (SIN) model. Twelve men and 11 women matched for age, body mass index, and aerobic fitness (maximal oxygen uptake and maximal power output per kilogram of fat-free mass (FFM)) performed submaximal incremental tests (Incr) with 5-min stages and a 7.5% maximal power output increment on a cycle ergometer. Fat oxidation rates were determined using indirect calorimetry, and plotted as a function of exercise intensity. The SIN model, which includes 3 independent variables (dilatation, symmetry, translation) that account for the main quantitative characteristics of kinetics, was used to mathematically describe fat oxidation kinetics and to determine the intensity (Fatmax) eliciting the maximal fat oxidation (MFO). During Incr, women exhibited greater fat oxidation rates from 35% to 85% maximal oxygen uptake, MFO (6.6 ± 0.9 vs. 4.5 ± 0.3 mg·kg FFM−1·min−1), and Fatmax(58.1% ± 1.9% vs. 50.0% ± 2.7% maximal oxygen uptake) than men (p < 0.05). While men and women showed similar global shapes of fat oxidation kinetics in terms of dilatation and symmetry (p > 0.05), the fat oxidation curve tended to be shifted toward higher exercise intensities in women (rightward translation, p = 0.08). These results support the idea that women have a greater reliance on fat oxidation than men during submaximal exercise, but also indicate that this greater fat oxidation is shifted toward higher exercise intensities in women than in men.
Fat adaptation in well-trained athletes: effects on cell metabolism
Authors: Yeo Wee Kian , Carey Andrew L. , Burke Louise , Spriet Lawrence L. , Hawley John A. 
Published: February 2011

The performance of prolonged (>90 min), continuous, endurance exercise is limited by endogenous carbohydrate (CHO) stores. Accordingly, for many decades, sports nutritionists and exercise physiologists have proposed a number of diet-training strategies that have the potential to increase fatty acid availability and rates of lipid oxidation and thereby attenuate the rate of glycogen utilization during exercise. Because the acute ingestion of exogenous substrates (primarily CHO) during exercise has little effect on the rates of muscle glycogenolysis, recent studies have focused on short-term (<1–2 weeks) diet-training interventions that increase endogenous substrate stores (i.e., muscle glycogen and lipids) and alter patterns of substrate utilization during exercise. One such strategy is “fat adaptation”, an intervention in which well-trained endurance athletes consume a high-fat, low-CHO diet for up to 2 weeks while undertaking their normal training and then immediately follow this by CHO restoration (consuming a high-CHO diet and tapering for 1–3 days before a major endurance event). Compared with an isoenergetic CHO diet for the same intervention period, this “dietary periodization” protocol increases the rate of whole-body and muscle fat oxidation while attenuating the rate of muscle glycogenolysis during submaximal exercise. Of note is that these metabolic perturbations favouring the oxidation of fat persist even in the face of restored endogenous CHO stores and increased exogenous CHO availability. Here we review the current knowledge of some of the potential mechanisms by which skeletal muscle sustains high rates of fat oxidation in the face of high exogenous and endogenous CHO availability.
Energy expenditure characteristics of weight lifting: 2 sets to fatigue
Authors: Scott Christopher B. , Leary Michael P. , TenBraak Andrew J. 
Published: February 2011

We investigated the work performed and energy expenditure characteristics within and among 2 sets of the bench press at 70%, 80%, and 90% of 1 repetition maximum (1RM). For both sets fatigue was the end point. We asked: do multiple sets affect subsequent work output along with aerobic, anaerobic, and excess postexercise oxygen consumption (EPOC) contributions? Ten males participated. Work was significantly less for the 2nd set within the 70% and 80% protocols, but not the 90% protocol. Anaerobic (glycolytic) energy expenditure was less for the 2nd set within all protocols. However, within all protocols, the work / energy expenditure ratio was not different between sets. Overall work was significantly different among protocols, becoming less as the weight lifted was increased: 70%, 637.1 ± 122.4 J; 80%, 512.4 ± 93.4 J; 90%, 324.7 ± 92.6 J (p < 0.001). EPOC was not different among protocols after the 1st set, 2nd set, or combined overall. Moreover, the overall EPOC did not correlate with overall work performed (r = 0.31, p = 0.11). EPOC overall did correlate with aerobic (r = 0.68, p < 0.001) and anaerobic (r = 0.65, p < 0.001) energy expenditures. In terms of a work / energy expenditure ratio, the least amount of completed work at 90% 1RM required greater energy expenditure as compared with 70% and 80% because of an EPOC that is similar for all. As more work is completed (i.e., lower weight, more repetitions), aerobic and anaerobic exercise energy expenditures appear to increase accordingly, yet absolute EPOC remains essentially unchanged, contributing less to the overall energy expenditure.
The extent of aerobic system activation during continuous and interval exercise protocols in young adolescents and men
Authors: Zafeiridis Andreas , Rizos Stylianos , Sarivasiliou Haralampos , Kazias Anastassios , Dipla Konstantina , Vrabas Ioannis S. 
Published: February 2011

This study assessed the extent of aerobic system activation in young adolescents and men during heavy continuous (HC), short-interval (SI), and long-interval (LI) aerobic exercise protocols, and compared this response between the 2 age groups in the 3 protocols. Ten young adolescents (aged 13.2 ± 0.3 years) and 10 men (aged 21.0 ± 1.6 years) completed a maximal incremental test, an HC exercise protocol (83% of maximal aerobic velocity; MAV), an SI exercise protocol (30 s at 110% MAV with 30 s at 50%), and an LI exercise protocol (3 min at 95% MAV with 3 min at 35%). Oxygen consumption and heart rate were measured continuously, and blood samples were obtained for lactate determination. Men completed more runs and distance in the SI protocol (p < 0.05) than adolescents; however, there were no age differences in the number of LI runs and in the duration of HC protocol. In both age groups, more time was spent above 90% and 95% of maximal oxygen consumption (p < 0.05), and a higher percentage of maximal oxygen consumption was reached in the LI compared with the HC and SI protocols, with no differences between the HC and SI protocols. Although within each protocol the percentage of maximal oxygen consumption achieved and time spent above 90% and 95% of maximal oxygen consumption was not different between age groups, the time spent at 80% maximal oxygen consumption was longer for adolescents than men in the HC protocol, and longer for men than boys in the SI protocol (p < 0.05). In conclusion, all protocols elicited high levels of aerobic activation in both age groups. The LI protocol taxed the aerobic system at 90%–100% of maximal oxygen consumption for a longer time when compared with the HC and SI protocols in young adolescents and in men. However, differences were observed between groups in taxing the aerobic system at 80% maximal oxygen consumption: in young adolescents, the HC protocol allowed longer running time than the LI and SI protocols, while in men there were no differences among protocols.
Estimated fluid and sodium balance and drink preferences in elite male junior players during an ice hockey game
Authors: Logan-Sprenger Heather M. , Palmer Matthew S. , Spriet Lawrence L. 
Published: February 2011

Research in many sports suggests that losing ∼2% of body mass (BM) through sweating impairs athletic performance, although this has not been tested in ice hockey players. This study investigated pregame hydration, and on-ice sweat loss, fluid intake, and sodium (Na+) balance of elite male junior players during an ice hockey game. Twenty-four players (2 goalies, 7 defensemen, 15 forwards) volunteered to participate in the study (age, 18.3 ± 0.3 years; weight, 86.5 ±1.6 kg; height, 184.1 ± 1.3 cm). Players were weighed pre- and postgame, fluid and sodium intake were monitored throughout the game, and fluid and Na+ balance were determined within the time between BM measurements. Sweat Na+ loss was calculated based on sweat loss and sweat [Na+] determined from sweat-patch analysis on the same players during an intense practice. Players arrived at the rink in a euhydrated state and drank 0.6 ± 0.1 L of fluid before the game. Mean playing time for the forwards was 18:85 ± 1:15 min:s and playing time for the defense was 24:00 ± 2:46 min:s. Sweat loss was 3.2 ± 0.2 L and exceeded net fluid intake (2.1 ± 0.1 L). Mean BM loss was 1.3% ± 0.3%, with 8/24 players losing between 1.8% to 4.3% BM. Players preferred to drink water and a carbohydrate electrolyte solution before the game and during intermissions, while only water was consumed during each period. Practice mean forehead sweat [Na+] was 74 mmol·L–1. Estimated sweat Na+ losses of 3.1 ± 0.4 g (∼8 g NaCl) coupled with low Na+ intake of 0.8 ± 0.2 g (∼2 g NaCl) resulted in a significant Na+ deficit by the end of the game. This study demonstrated that despite abundant opportunities to hydrate during a hockey game, one-third of the players did not drink enough fluid to prevent sweat losses of 2% BM or higher. Losing 2% BM has been associated with decreases in athletic performance.
How to test maximal oxygen uptake: a study on timing and testing procedure of a supramaximal verification test
Authors: Scharhag-Rosenberger Friederike , Carlsohn Anja , Cassel Michael , Mayer Frank , Scharhag Jürgen 
Published: February 2011

Verification tests are becoming increasingly common for confirming maximal oxygen uptake (VO2 max) attainment. Yet, timing and testing procedures vary between working groups. The aims of this study were to investigate whether verification tests can be performed after an incremental test or should be performed on a separate day, and whether VO2 max can still be determined within the first testing session in subjects not satisfying the verification criterion. Forty subjects (age, 24 ± 4 years; VO2 max, 50 ± 7 mL·min–1·kg–1) performed a maximal incremental treadmill test and, 10 min afterwards, a verification test (VerifDay1) at 110% of maximal velocity (vmax). The verification criterion was a VerifDay1 peak oxygen uptake (VO2 peak) ≤5.5% higher than the incremental test value. Subjects not achieving the verification criterion performed another verification test at 115% vmax (VerifDay1′) 10 min later, trying to confirm VerifDay1 VO2 peak as VO2 max. All other subjects exclusively repeated VerifDay1 on a separate day (VerifDay2). Of the 40 subjects, 6 did not satisfy the verification criterion. In 4 of them, attainment of VO2 max was confirmed by VerifDay1′. VO2 peak was equivalent between VerifDay1 and VerifDay2 (3722 ± 991 mL·min–1 vs. 3752 ± 995 mL·min–1, p = 0.56), whereas time to exhaustion was significantly longer in VerifDay2 (2:06 ± 0:22 min:s vs. 2:42 ± 0:38 min:s, p < 0.001, n = 34). The verification test VO2 peak does not seem to be affected by a preceding maximal incremental test. Incremental and verification tests can therefore be performed within the same testing session. In individuals not achieving the verification criterion, VO2 max can be determined by means of a subsequent, more intense verification test in most but not all cases.
New Canadian Physical Activity Guidelines
Authors: Tremblay Mark S. , Warburton Darren E.R. , Janssen Ian , Paterson Donald H. , Latimer Amy E. , Rhodes Ryan E. , Kho Michelle E. , Hicks Audrey , LeBlanc Allana G. , Zehr Lori , Murumets Kelly , Duggan Mary 
Published: February 2011

The Canadian Society for Exercise Physiology (CSEP), in cooperation with ParticipACTION and other stakeholders, and with support from the Public Health Agency of Canada (PHAC), has developed the new Canadian Physical Activity Guidelines for Children (aged 5–11 years), Youth (aged 12–17 years), Adults (aged 18–64 years), and Older Adults (aged ≥65 years). The new guidelines include a preamble to provide context and specific guidelines for each age group. The entire guideline development process was guided by the Appraisal of Guidelines for Research Evaluation (AGREE) II instrument, which is the international standard for clinical practice guideline development. Thus, the guidelines have gone through a rigorous and transparent developmental process; we based the recommendations herein on evidence from 3 systematic reviews, and the final guidelines benefitted from an extensive online and in-person consultation process with hundreds of stakeholders and key informants, both domestic and international. Since 2006, the products of our efforts resulted in the completion of 21 peer-reviewed journal articles (including 5 systematic reviews) that collectively guided this work. The process that Canadian researchers undertook to update the national physical activity guidelines represents the most current synthesis, interpretation, and application of the scientific evidence to date.
Behavior of mine tailings under cyclic hydraulic loading
Authors: Geremew Africa M. , Yanful Ernest K. 
Published: February 2011

Shallow water cover is one of the most effective methods of managing sulfide-bearing reactive mine tailings. Unless sufficient water cover depth is provided, surface erosion by wind-induced waves and pressure-driven currents can re-suspend the tailings and expose them to dissolved oxygen and affect the quality of the water cover. The present study gives a simple approach for the estimation of the critical shear stress for surface erosion of mine tailings and cohesive sediments under shallow water cover. Erosion tests were carried out in a Plexiglas laboratory annular column on mine tailings and sediments under a 50 cm water cover. The annular column was 30 cm in diameter, 120 cm in height and had a 9 cm annular flow width. Shear stress was introduced through a motor driven Teflon stirrer to investigate the initiation of motion and subsequent re-suspension of newly deposited mine tailings and sediments. The velocity field and the pressure change in the boundary layer were measured by laser Doppler velocimeter (LDV) and Preston tube, respectively. The ranges of critical shear stress for the tailings and sediments were estimated by the LDV and Preston tube measurements and visual observation. The results showed that the erosion behavior of most of the mine tailings can be explained by a power law erosion equation.
Characterization of intronic structures and alternative splicing in Phytophthora sojae by comparative analysis of expressed sequence tags and genomic sequences
Authors: Shen Danyu , Ye Wenwu , Dong Suomeng , Wang Yuanchao , Dou Daolong 
Published: February 2011

The oomycetes, a distinct phylogenetic lineage of fungus-like microorganisms, are heterokonts (stramenopiles) belonging to the supergroup Chromalveolata. Although the complete genomic sequences of a number of oomycetes have been reported, little information regarding the introns therein is available. Here, we investigated the introns of Phytophthora sojae , a pathogen that causes soybean root and stem rot, by a comparative analysis of genomic sequences and expressed sequence tags. A total of 4013 introns were identified, of which 96.6% contained canonical splice sites. The P. sojae genome possessed features distinct from other organisms at 5′ splice sites, polypyrimidine tracts, branch sites, and 3′ splice sites. Diverse repeating sequences, ranging from 2 to 10 nucleotides in length, were found at more than half of the intron–exon boundaries. Furthermore, 122 genes underwent alternative splicing. These data indicate that P. sojae has unique splicing mechanisms, and recognition of those mechanisms may lead to more accurate predictions of the location of introns in P. sojae and even other oomycete species.
The polymicrobial nature of airway infections in cystic fibrosis: Cangene Gold Medal LectureThis article is based on a presentation by Dr. Christopher Sibley at the 60th Annual Meeting of the Canadian Society of Microbiologists in Hamilton, Ontario, on 15 June 2010. Dr. Sibley was the recipient of the 2010 Cangene Gold Medal as the Canadian Graduate Student Microbiologist of the Year, an annual award sponsored by Cangene Corporation intended to recognize excellence in graduate research.
Authors: Sibley Christopher D. , Surette Michael G. 
Published: February 2011

Microbial communities characterize the airways of cystic fibrosis (CF) patients. Members of these diverse and dynamic communities can be thought of as pathogens, benign commensals, or synergens — organisms not considered pathogens in the traditional sense but with the capacity to alter the pathogenesis of the community through microbe–microbe or polymicrobe–host interactions. Very few bacterial pathogens have been implicated as clinically relevant in CF; however, the CF airway microbiome can be a reservoir of previously unrecognized but clinically relevant organisms. A combination of culture-dependent and culture-independent approaches provides a more comprehensive perspective of CF microbiology than either approach alone. Here we review these concepts, highlight the future challenges for CF microbiology, and discuss the implications for the management of CF airway infections. We suggest that the success of treatment interventions for chronic CF lung disease will rely on the context of the microbes within microbial communities. The microbiology of CF airways may serve as a model to investigate the emergent properties of other clinically relevant microbial communities in the human body.
Genetic diversity of picoeukaryotes in eight lakes differing in trophic status
Authors: Zhao Biying , Chen Meijun , Sun Ying , Yang Jiaxin , Chen Feizhou 
Published: February 2011

The genetic diversity of picoeukaryotes (0.2–5.0 µm) was investigated in 8 lakes differing in trophic status in Nanjing, China. Denaturing gradient gel electrophoresis (DGGE) and cloning and sequencing of 18S rRNA genes were applied to analyze the picoeukaryotic communities. DGGE analysis showed that among the 8 lakes, the diversity of picoeukaryotes was greatest in the mesotrophic Lake Nan (24 bands) and least in the oligotrophic Lake Qian (12 bands). Cluster analysis of DGGE profiles revealed that the 8 lakes were grouped into 2 distinct clusters. Cluster 1 contained lakes Mochou, Zixia, Huashen, Nan, Pipa, and Qian, while cluster 2 contained lakes Xuanwu and Baijia. Clone libraries were constructed from the mesotrophic Lake Xuanwu and the oligotrophic Lake Zixia, and the 2 libraries were compared using the program LIBSHUFF. This analysis indicated that the picoeukaryotic community composition differed significantly between the 2 lakes (p = 0.001). A total of 25 operational taxonomic units were detected; 18 (62 clones) were related to known eukaryotic groups, while 7 (30 clones) were not affiliated with any known eukaryotic group. Alveolates and stramenopiles were the dominant groups in Lake Xuanwu, while alveolates and chlorophyta predominated in Lake Zixia. Multivariate statistical analysis indicated that the differences in the picoeukaryotic community composition of the 8 lakes might be related to trophic status and top-down regulation by metazooplankton.
Composition of the bacterial biota in slime developed in two machines at a Canadian paper mill
Authors: Disnard Julie , Beaulieu Carole , Villemur Richard 
Published: February 2011

During the process of papermaking by pulp and paper plants, a thick and viscous deposits, termed slime, is quickly formed around the paper machines, which can affect the papermaking process. In this study, we explored the composition of the bacterial biota in slime that developed on shower pipes from 2 machines at a Canadian paper mill. Firstly, the composition was assessed for 12 months by DNA profiling with polymerase chain reaction coupled with denaturing gradient gel electrophoresis. Except for short periods (2–3 months), clustered analyses showed that the bacterial composition of the slime varied substantially over the year, with less than 50% similarity between the denaturing gradient gel electrophoresis profiles. Secondly, the screening of 16S rRNA gene libraries derived from 2 slime samples showed that the most abundant bacteria were related to 6 lineages, including Chloroflexi, candidate division OP10, Clostridiales, Bacillales, Burkholderiales, and the genus Deinococcus . Finally, the proportion of 8 bacterial lineages, such as Deinococcus sp., Meiothermus sp., and Chloroflexi, was determined by the Catalyzed Reporter Deposition – Fluorescence In Situ Hybridization in 2 slime samples. The results showed a high proportion of Chloroflexi, Tepidimonas spp., and Schlegelella spp. in the slime samples.