Reliability and validity of the Chester treadmill walk test for the prediction of aerobic capacity

The aim of this dissertaion is to assess the validity and reliability of the Chester Treadmill Walk test (CTWT) for the prediction of aerobic capacity. Four males and three females aged 25.1 (±3.3) years old that were active and healthy volunteered to take part in this study. The CTWT was carried out on two separate days and on the third occasion participants completed a maximal test called the Bruce Protocol treadmill test. Each day of testing was separated by no longer than seven days. Heart rate and RPE were measured during the sub-maximal testing and heart rate, RPE and VO2 were measured during the maximal testing. The bias ±95% limits of agreement technique was used to assess the validity of the CTWT against the maximal testing. No significant differences were found between trial one and maximal testing (0.226) and between trial two and maximal testing (0.252). The CTWT showed over-estimations in VO2max in trial one and trial two by 4.0±15.4 ml•kg-1•min-1 and 4.8±19.7 ml•kg-1•min-1 respectively. Trial one, two and maximal testing obtained VO2max mean values of 49.5±7.8, 50.3±8.4 and 45.5±10.7 ml•kg-1•min-1 respectiviely. 95% LoA technique found an over-estimation of HRmax by 6.4±14.6 beats/min, woth no significant difference found (0.062). ICC and 95% LoA techniques were used to assess VO2 (-0.8±5.2 ml•kg-1•min-1), HR (3.0 ±2.8bpm) and RPE (-0.2±0.6) reliability between trial one and trial two. ICC of 0.95, 0.99 and 0.99 were found between trial one and two in VO2, HR and RPE respectively. It is questionable whether or not the CTWT is a valid sub-maximal test to conduct, however it was found to be a reliable test. VO2max was over-estimated in both trials when compared to actual VO2max but positive relationships were found between the HR and RPE values in trial one and trial two

A Fast and Accessible Methodology for Micro-Patterning Cells on Standard Culture Substrates Using Parafilm™ Inserts

Micropatterning techniques provide direct control over the spatial organization of cells at the sub-mm scale. Regulation of these spatial parameters is important for controlling cell fate and cell function. While micropatterning has proved a powerful technique for understanding the impact of cell organization on cell behaviour, current methods for micropatterning cells require complex, specialized equipment that is not readily accessible in most biological and bioengineering laboratories. In addition, currently available methods require significant protocol optimization to ensure reliable and reproducible patterning. The inaccessibility of current methods has severely limited the widespread use of micropatterning as a tool in both biology and tissue engineering laboratories. Here we present a simple, cheap, and fast method to micropattern mammalian cells into stripes and circular patterns using Parafilm™, a common material found in most biology and bioengineering laboratories. Our method does not require any specialized equipment and does not require significant method optimization to ensure reproducible patterning. Although our method is limited to simple patterns, these geometries are sufficient for addressing a wide range of biological problems. Specifically, we demonstrate i) that using our Parafilm™ insert method we can pattern and co-pattern ARPE-19 and MDCK epithelial cells into circular and stripe micropatterns in tissue culture polystyrene (TCPS) wells and on glass slides, ii) that we can contain cells in the desired patterns for more than one month and iii) that upon removal of the Parafilm™ insert we can release the cells from the containment pattern and allow cell migration outward from the original pattern. We also demonstrate that we can exploit this confinement release feature to conduct an epithelial cell wound healing assay. This novel micropatterning method provides a reliable and accessible tool with the flexibility to address a wide range of biological and engineering problems that require control over the spatial and temporal organization of cells

Repeatability of locomotor performance and morphology-locomotor performance relationships

There is good evidence that natural selection drives the evolution of locomotor performance, but the processes that generate the among-individual variation for selection to act on are relatively poorly understood. We measured prolonged swimming performance, U-crit, and morphology in a large cohort (n=461) of wild-type zebrafish (Danio rerio) at similar to 6 months and again at similar to 9 months. Using mixed-model analyses to estimate repeatability as the intraclass correlation coefficient, we determined that U-crit was significantly repeatable (r=0.55; 95% CI: 0.45-0.64). Performance differences between the sexes (males 12% faster than females) and changes with age (decreasing 0.07% per day) both contributed to variation in U-crit and, therefore, the repeatability estimate. Accounting for mean differences between sexes within the model decreased the estimate of U-crit repeatability to 21% below the naive estimate, while fitting age in the models increased the estimate to 14% above the naive estimate. Greater consideration of factors such as age and sex is therefore necessary for the interpretation of performance repeatability in wild populations. Body shape significantly predicted U-crit in both sexes in both assays, with the morphology-performance relationship significantly repeatable at the population level. However, morphology was more strongly predicative of performance in older fish, suggesting a change in the contribution of morphology relative to other factors such as physiology and behaviour. The morphology-performance relationship changed with age to a greater extent in males than females

A Critique of the Student as Customer Metaphor in Higher Education and Academic Libraries

This paper describes a critique of the trend in higher education and academic libraries to refer to students and library patrons as customers. A survey of education and library literature was conducted to trace the development of this metaphor, particularly in relation to the use of Total Quality Management in higher education. Issues examined in this paper include the role of metaphors, the applicability of business terminology and concepts to education and libraries, the effects of commodification of information and education, and the influence the student/patron as customer metaphor has on information literacy instruction. This paper concludes that usage of the student/patron as customer metaphor indicates an inability to comprehend the role of the student or library patron, and that, by continuing to refer to college students and library patrons as customers, we contribute to the sense that education, research, and access to library services are irrelevant in today's world

Peak Bone Mass and Quantitative Ultrasound Bone Properties in Young Adulthood : A Study in the PEAK-25 Cohort of Women

Peak bone mass is normally reached in the third decade of life. Previously, in the population-based PEAK-25 cohort (n = 1061, age 25.5 ± 0.2), we demonstrated that bone mineral density in the population-based PEAK-25 cohort is comparatively high; therefore, this study aimed to determine if the calcaneus microarchitecture mirrored this. In the process, we describe normative quantitative ultrasound (QUS) values for 25-yr-old women and the relationship between QUS values and extremes of body weight. QUS variables speed of sound (SOS), broadband ultrasound attenuation (BUA), and stiffness index were measured. Young adult values were based on the manufacturer-supplied QUS reference values. Analyses were performed in the cohort as a whole, and additionally, to understand the relationship between body weight and QUS values in young women, the variables were categorized into octiles for weight or body mass index (BMI) and the lowest and highest octiles were compared. In the cohort, SOS values, reflecting bone density, were higher (108 ± 18%), whereas BUA values, reflecting bone complexity, were lower (90 ± 14%) compared to the young adult reference population. SOS did not correlate with body weight or BMI. In the cohort, overall correlations between BUA weight, and BMI were small and positive (Pearson's r coefficients 0.261 and 0.197, respectively; p <0.001), although in the low-weight group, r coefficients were higher (r = 0.313 and 0.268; p <0.05). In contrast, in the high-weight group, correlation with BUA values tended to be small, negative, and nonsignificant. Correlation between QUS and dual-energy X-ray absorptiometry-measured bone mineral density was low to moderate and significant at all skeletal sites (r = 0.37-0.52). Whereas coefficients tended to be higher in the low-weight group, the reverse was apparent for the low-BMI group. In these 25-yr-old women, a comparatively high dual-energy X-ray absorptiometry-measured bone mass is offset by less complex bone structures assessed by QUS. This may have implications for later osteoporosis assessment and future fracture risk

Agility demands of Gaelic football match-play: a time-motion analysis

Research into the physical demands of Gaelic football is limited with no research into the agility or change of direction (CoD) demands of the sport. This study examined the CoD demands of Gaelic football via a time-motion analysis of senior inter-county match play. The Bloomfield movement classification (BMC) was adapted for application to Gaelic football. A new “descriptor” was used in an effort to account for the decision-making component of agility by isolating actions that occurred during active engagement with play. Of 1,899 changes of direction (CoDs) identified, 1,035 occurred during active engagement in play. The left/right split for CoDs during active engagement in play was 47.1/49.9%, indicating no preference for completing actions to one side over the other. Whilst the most common CoDs were ≤90° (74.9%), 80% of CoDs greater than 270° took place during active engagement in play. CoD actions are very common in Gaelic football and may be more common than in other field and court sports. It is important that athletes are physically prepared to cope with the demands of very acute CoDs during meaningful periods of match play

Effects of a six-week strength training programme on change of direction performance in youth team sport athletes

This study investigated the effects of eccentric phase-emphasis strength training (EPE) on unilateral strength and performance in 180- and 45-degree change of direction (COD) tasks in rugby union players. A 12-week cross-over design was used to compare the efficacy of resistance training executed with 3 s eccentric duration (EPE, n = 12) against conventional strength training, with no constraints on tempo (CON, n = 6). Players in each condition were categorised as ‘fast’ (FAST) or ‘slow’ (SLOW) using median trial times from baseline testing. Players recorded greater isometric strength improvements following EPE (ES = −0.54 to 1.80). Whilst these changes were not immediate, players improved in strength following cessation. Improvements in 180-degree COD performance was recorded at all test-points following EPE (ES = −1.32 to −0.15). Improvements in 45-degree COD performance were apparent for FAST following CON (ES = −0.96 to 0.10), but CON was deleterious for SLOW (ES = −0.60 to 1.53). Eccentric phase-emphasis strength training shows potential for sustained strength enhancement. Positive performance changes in COD tasks were category- and condition-specific. The data indicate the greatest improvement occurred at nine weeks following resistance training in these players. Performance benefits may also be specific to COD task, player category, and relative to emphasis on eccentric phase activity

Evaporation of a two-dimensional charged black hole

We construct a dilatonic two-dimensional model of a charged black hole. The classical solution is a static charged black hole, characterized by two parameters, $m$ and $q$, representing the black hole's mass and charge. Then we study the semiclassical effects, and calculate the evaporation rate of both $m$ and $q$, as a function of these two quantities. Analyzing this dynamical system, we find two qualitatively different regimes, depending on the electromagnetic coupling constant $g_{A}$. If the latter is greater than a certain critical value, the charge-to-mass ratio decays to zero upon evaporation. On the other hand, for $g_{A}$ smaller than the critical value, the charge-to-mass ratio approaches a non-zero constant that depends on $g_{A}$ but not on the initial values of $m$ and $q$.Comment: Latex, 30 pages, accepted for publication in Phys. Rev.