22 resultados para 860[729.5].09
em Deakin Research Online - Australia
Resumo:
The importance of pacing for middle-distance performance is well recognized, yet previous research has produced equivocal results. Twenty-six trained male cyclists ( V O2peak 62.8+5.9 ml ·kg-1 · min-1· maximal aerobic power output 340+43 W; mean+s) performed three cycling time-trials where the total external work (102.7+13.7 kJ) for each trial was identical to the best of two 5-min habituation trials. Markers of aerobic and anaerobic metabolism were assessed in 12 participants. Power output during the first quarter of the time-trials was fixed to control external mechanical work done (25.7+3.4 kJ) and induce fast-, even-, and slow-starting strategies (60, 75, and 90 s, respectively). Finishing times for the fast-start time-trial (4:53+0:11 min:s) were shorter than for the even-start (5:04+0:11 min:s; 95% CI=5 to 18 s, effect size=0.65, P 50.001) and slow-start time-trial (5:09+0:11 min:s; 95% CI=7 to 24 s, effect size=1.00, P 50.001). Mean VO2 during the fast-start trials (4.31+0.51 litres · min-1) was 0.18+0.19 litres · min-1 (95% CI=0.07 to 0.30 litres · min-1, effect size=0.94, P =0.003) higher than the even- and 0.18+0.20 litres · min-1 (95% CI=0.5 to 0.30 litres · min-1, effect size=0.86, P =0.007) higher than the slow-start time-trial. Oxygen deficit was greatest during the first quarter of the fast-start trial but was lower than the even- and slow-start trials during the second quarter of the trial. Blood lactate and pH were similar between the three trials. In conclusion, performance during a 5-min cycling time-trial was improved with the adoption of a fast- rather than an even- or slow-starting strategy.
Pre-exercise carbohydrate ingestion : effect of the glycemic index on endurance exercise performance
Resumo:
Purpose: This study aimed to examine the effect of glycemic index of pre-exercise carbohydrate (CHO) ingestion on exercise metabolism and performance.
Methods: Eight endurance trained men ingested a high glycemic index (HGI), low glycemic index (LGI), or a placebo (CON) meal 45 min before exercise and then cycled for 50 min at 67% V·O2max. Subjects subsequently performed a 15-min self-paced performance ride in which total work (kJ) was recorded.
Results: Plasma glucose concentrations were higher (P < 0.01) after ingestion in HGI compared with LGI and CON (7.53 ± 0.64 vs 5.55 ± 0.21 and 4.65 ± 0.14 mmol·L-1 for HGI, LGI, and CON, respectively, 30 min postprandial; mean ± SE) but declined at the onset of exercise and were lower (P < 0.01) compared with LGI and CON (4.03 ± 0.31 vs 4.64 ± 0.24 and 5.09 ± 0.16 mmol·L-1 for HGI, LGI, and CON respectively; mean ± SE) at 10 min of exercise. Plasma glucose remained depressed (P < 0.01) until 30 min into exercise in HGI compared with other trials. Plasma insulin concentrations were higher (P < 0.01) following ingestion during rest and exercise in HGI compared with LGI and CON. Plasma FFA concentrations were lower (P < 0.05) following ingestion in HGI and LGI compared with CON and higher (P < 0.05) in LGI compared with HGI at the start and end of exercise. RER and CHO oxidation was higher (P < 0.01) in HGI compared with LGI and CON during submaximal exercise. There were no differences in work output during the performance cycle.
Conclusions: These data indicate that pre-exercise CHO feedings with varying glycemic indexes do not affect exercise performance following short term submaximal exercise despite alterations in metabolism.
Resumo:
Objectives: To describe the incident fracture rate in survivors of critical illness and to compare fracture risk with populationmatched control subjects.
Design: Retrospective longitudinal case– cohort study.
Setting: A tertiary adult intensive care unit in Australia. Patients: All patients ventilated admitted to intensive care and requiring mechanical ventilation for >48 hrs between January 1998 and December 2005.
Interventions: None.
Measurements and Main Results: New fractures were identified in the study population for the postintensive care unit period (intensive care unit discharge to January 2008). The incident fracture rate and age-adjusted fracture risk of the female intensive care unit population were compared with the general population adult females derived from the Geelong Osteoporosis Study. Over the 8-yr period, a total of 739 patients (258 women, 481 men) were identified. After a median follow-up of 3.7 yrs (interquartile range, 2.0–5.9 yrs) for women and 4.0 yrs (interquartile range, 2.1–6.1 yrs) for men, incident fracture rates (95% confidence interval) per 100 patient years were 3.84 (2.58 –5.09) for females 2.41 (1.73–3.09) for males. Compared with an age-matched random population-based sample of women, elderly women were at increased risk for sustaining an osteoporosisrelated fracture after critical illness (hazard ratio, 1.65; 95% confidence interval, 1.08 –2.52; p .02).
Conclusions: The increase in fracture risk observed in postintensive care unit older females suggests an association between critical illness and subsequent skeletal morbidity. The explanation for this association is not explored in this study and includes the effects of pre-existing patient factors and/or direct effects of critical illness. Prospective research evaluating risk factors, the relationship between critical illness and bone turnover, the extent and duration of bone loss, and the associated morbidity in this population is warranted.
Resumo:
Background People suffering different types of stroke have differing demographic characteristics and survival. However, current estimates of disease burden are based on the same underlying assumptions irrespective of stroke type. We hypothesized that average Quality Adjusted Life Years (QALYs) lost from stroke would be different for ischemic stroke and intracerebral hemorrhage (ICH).
Methods We used 1 and 5-year data collected from patients with first-ever stroke participating in the North East Melbourne Stroke Incidence Study (NEMESIS). We calculated case fatality rates, health-adjusted life expectancy, and quality-of-life (QoL) weights specific to each age and gender category. Lifetime 'health loss' for first-ever ischemic stroke and ICH surviving 28-days for the 2004 Australian population cohort was then estimated. Multivariable uncertainty analyses and sensitivity analyses (SA) were used to assess the impact of varying input parameters e.g. case fatality and QoL weights.
Results Paired QoL data at 1 and 5 years were available for 237 NEMESIS participants. Extrapolating NEMESIS rates, 31,539 first-ever strokes were expected for Australia in 2004. Average discounted (3%) QALYs lost per first-ever stroke were estimated to be 5.09 (SD 0.20; SA 5.49) for ischemic stroke (n = 27,660) and 6.17 (SD 0.26; SA 6.45) for ICH (n = 4,291; p < 0.001). QALYs lost also differed according to gender for both subtypes (ischemic stroke: males 4.69 SD 0.38, females 5.51 SD 0.46; ICH: males 5.82 SD 0.67, females 6.50 SD 0.40).
Discussion People with ICH incurred greater loss of health over a lifetime than people with ischemic stroke. This is explained by greater stroke related case fatality at a younger age, but longer life expectancy with disability after the first 12 months for people with ICH. Thus, studies of disease burden in stroke should account for these differences between subtype and gender. Otherwise, in countries where ICH is more common, health loss for stroke may be underestimated. Similar to other studies of this type, the generalisability of the results may be limited. Sensitivity and uncertainty analyses were used to provide a plausible range of variation for Australia. In countries with demographic and life expectancy characteristics comparable to Australia, our QoL weights may be reasonably applicable.
Resumo:
Nail biting is a common behavioral problem. While there are established behavioral interventions for management, they are of modest efficacy, and there is minimal evidence for effective pharmacotherapy. This study investigated the role of N-acetylcysteine (NAC) a potent glutathione and glutamate modulator for the treatment of pathological nail biting in children and adolescents. This pilot randomized, double-blind, placebo-controlled clinical trial of NAC (800mg/day) or placebo enrolled 42 children and adolescents with chronic nail biting. Nail length was the objective outcome. Evaluations were carried out three times; before treatment, one month after enrollment in the study, and two months after enrollment. The duration (chronicity) of nail biting in the NAC and placebo groups was 3.63(2.45) and 5.09(3.74) years (P=0.14). The mean nail length gradually increased in both the NAC and placebo groups during this trial. There was a statistically significant difference between the two groups regarding increased nail length after the first month of trial [(5.21(5.75) and 1.18(3.02) millimeters], however no difference after two months was observed. Two patients in the NAC group discontinued medication due to adverse events. One patient experienced headache, agitation, and social withdrawal, and another patient expressed severe aggression after taking medication and was withdrawn from the study. This study supports the hypothesis that NAC decreases nail biting behavior in children and adolescents over the short term. NAC is relatively well tolerated and severe adverse effects are rare. However, there was a high rate of dropout. Further studies with longer durations that build on these preliminary data are recommended.
Resumo:
This study examined if the relative birth distribution of drafted under 18 (U18) Australian football (AF) players influenced their physical and anthropometric profile. Birthdate, physical (vertical jump, agility, 20m sprint, 20m multistage fitness test) and anthropometric (standing height, body mass) data were obtained from U18 players drafted into the Australian Football League between 2010 to 2013 (n = 212). Birth distribution did not change across quartile (χ23 = 5.09, P > 0.05) or half year (χ21= 2.50, P > 0.05). Physical and anthropometric profiles did not differ according to quartile or half year (P > 0.05). Relative birth distribution did not appear to influence draft success or physical/anthropometric profile. This study provides insight into a phenomenon not always observed in team sport.
Resumo:
The computer based human motion tracking systems are widely used in medicine and sports. The accurate determination of limb lengths is crucial for not only constructing the limb motion trajectories which are used for evaluation process of human kinematics, but also individually recognising human beings. Yet, as the common practice, the limb lengths are measured manually which is inconvenient, time-consuming and requires professional knowledge. In this paper, the estimation process of limb lengths is automated with a novel algorithm calculating curvature using the measurements from inertial sensors. The proposed algorithm was validated with computer simulations and experiments conducted with four healthy subjects. The experiment results show the significantly low root mean squared error percentages such as upper arm - 5.16%, upper limbs - 5.09%, upper leg - 2.56% and lower extremities - 6.64% compared to measured lengths.
Resumo:
Effluents from the juice and fruit processing industries have high organic matter content. Discharge of these effluents without appropriate treatment would therefore have a negative impact on the environment. High organic contents and low contamination levels make such effluents suitable for biological treatment, especially anaerobic digestion. In the latter process, significant amounts of digester gas can be produced, turning a waste stream into a source of renewable energy that can be used for electricity and heat production, leading to financial benefits.This paper investigates the feasibility of anaerobic digestion and the gas generation potential of five different effluents from the carrot-juice, orange-juice and sultana processing industries. Benefits are assessed in terms of digester gas production and organic matter reduction. The results show that the specific gas production ranges between 665 and 860 m3 per tonne of effluent treated (as organic dry matter). Furthermore, nearly 100% of the organic matter is converted into gas in the case of the carrot- and orange-juice processing residues, while a 84.5% reduction of the organic matter was found to be achievable in the case of the sultana wastes. While these results are promising, further testing will be required to validate them in a larger scale.
Resumo:
'Preventive detention' refers to detention by executive order as a precautionary measure based on predicted criminal conduct. Detention is without criminal charge or trial as detention is based on the prediction of a future offence. This paper examines Article 5 of the European Convention for the Protection of Human Rights and Fundamental Freedoms ('ECHR'), in particular Article 5(1)(c) and Article 5(3). To explore this issue, this paper conducts a textual analysis of Article 5 and examines both the travaux preacuteparatoires of the ECHR, as well as jurisprudence of the European Court of Human Rights. This article argues that preventive detention is specifically provided for under the second ground of detention in Article 5(1)(c). A person in preventive detention, however, must be brought promptly before judicial authority under Article 5(3).
Resumo:
Purpose: To describe longitudinal changes in leisure-time sedentary behavior among girls, during early to mid-adolescence. Methods: A 2.5-year prospective cohort study, comprising 5 data collections, 6 months apart, between 2000 and 2002. Girls aged 12–15 years (n = 200) from 8 high schools located in Sydney, Australia, self-reported the usual time spent each week in a comprehensive range of sedentary behaviors. Results: Retention rate for the study was 82%. Girls aged 12.8 years spent approximately 45% of their discretionary time in sedentary behavior, which increased to 63% at age 14.9 years. Watching TV, videos, and playing video games (small screen recreation; SSR) was the most popular sedentary pastime, accounting for 33% of time spent in sedentariness, followed by homework and reading (25%). Sedentary behavior increased 1.4 and 3.3 hours on week and weekend days, respectively. On weekdays, increased time was spent on hobbies (27 min/day) and on weekend days, increased time was spent sitting around talking with friends (60 min/day), computer use (37 min/day), and television viewing (34 min/day). Conclusions: Among girls, the transition between early and mid-adolescence was accompanied by a significant increase in leisure-time sedentary behavior. Interventions to reduce sedentariness among adolescent girls are best to focus on weekend behaviors. Studies seeking to examine the association between inactivity and the development of chronic health problems need to examine a diverse range of activities that comprehensively measure sedentariness. This information will provide a better understanding of inactivity patterns among adolescent girls.
Resumo:
Objective: The foods sold in school canteens have a significant role to play in ensuring children consume a healthy balance of nutritious foods. However, no research to date has described the foods that Australian children are purchasing at school canteens, or the perceptions held about school canteens by students, teachers and parents.
Design: An exploratory cross-sectional survey was used to obtain information from students, parents and teachers through self completion questionnaires.
Subjects: There were 384 children aged nine to 12 years, 404 parents and 41 teachers involved.
Settings: The study was conducted in 12 primary schools in Victoria, Australia.
Main outcome measures: Types of foods purchased at school canteens, school canteen usage, parents' and teachers' perceptions of the role of the school and canteen in influencing children's eating habits.
Results: More than 50% of the children surveyed used the school canteen at least once per week. Children identified preference for unhealthy alternatives and availability as key barriers to choosing healthy foods at the canteen and suggested increased availability, advertisements and cost reductions as aids to purchasing healthy foods. Teachers placed more importance on the role of the canteen than parents did.
Statistical analyses: Frequencies, cross-tabulation analyses and chi square tests were undertaken using the SPSS 11 computer program.
Conclusions: These Victorian primary school children and their teachers, and to a lesser extent parents, had a clear understanding of healthy foods. Children and teachers identified barriers that prevent school canteens
from providing healthy foods. There is likely to be strong support from these stakeholders for novel health promoting policies.
Resumo:
Rank-order and paired comparison tests are widely used methods to assess previous termsensorynext term perception of young children. Small age differences could, however, influence the ability of children to carry out such tasks. This study compared rank-order and paired comparison tests for previous termconsistencynext term in previous term4next term- and 5-year-old children. During previous termfournext term sessions, 22 young adults, 21 previous term4next term-year-old and 47 5-year-old children carried out rank-order and paired comparison tests to measure discriminatory ability (0.22 M, 0.25 M, 0.29 M, 0.34 M, 0.39 M sucrose in orangeade) and preference (0.14 M, 0.20 M, 0.29 M, 0.42 M, 0.61 M sucrose in orangeade). Young adults and 5-year-old children were able to discriminate between all solutions and showed a high previous termconsistencynext term between the rank-order and pair-wise tests for discriminatory ability (>76% previous termconsistency)next term and preference (>71% previous termconsistency)next term. In contrast, previous term4next term-year-olds detected differences in sweetness during the preference tests, but failed to distinguish sweetness intensities during the discriminatory ability tests. It is concluded that the dissimilarity between previous term4next term-and 5-year-olds in performing previous termsensorynext term tests was due to a difference in their cognitive skills rather than their previous termsensorynext term perceptual differences.
Resumo:
Herein we report a short and efficient synthesis of N6-substituted 5′-modified adenosines, which was achieved in four steps from 2′,3′,5′-tris-O-(tert-butyldimethylsilyl)inosine.
Resumo:
The serotonin transporter gene (5-HTT) encodes a transmembrane protein that plays an important role in regulating serotonergic neurotransmission and related aspects of mood and behaviour. The short allele of a 44 bp insertion/deletion polymorphism (S-allele) within the promoter region of the 5-HTT gene (5-HTTLPR) confers lower transcriptional activity relative to the long allele (L-allele) and may act to modify the risk of serotonin-mediated outcomes such as anxiety and substance use behaviours. The purpose of this study was to determine whether (or not) 5-HTTLPR genotypes moderate known associations between attachment style and adolescent anxiety and alcohol use outcomes. Participants were drawn from an eight-wave study of the mental and behavioural health of a cohort of young Australians followed from 14 to 24 years of age (Victorian Adolescent Health Cohort Study, 1992 - present). No association was observed within low-risk attachment settings. However, within risk settings for heightened anxiety (ie, insecurely attached young people), the odds of persisting ruminative anxiety (worry) decreased with each additional copy of the S-allele (B30% per allele: OR 0.77, 95% CI 0.62–0.97, P¼0.029). Within risk settings for binge drinking (ie, securely attached young people), the odds of reporting persisting high-dose alcohol consumption (bingeing) decreased with each additional copy of the S-allele (B35% per allele: OR 0.74, 95% CI 0.64–0.86, Po0.001). Our data suggest that the S-allele is likely to be important in psychosocial development, particularly in those settings that increase risk of anxiety and alcohol use problems.