Optimized extraction of anthocyanins from Reid Fruits' Prunus avium 'Lapins' cherries.

The influence of process parameters on the extraction of anthocyanins from the edible portion of fresh, sweet cherry were investigated. The optimal extraction time and temperature were determined as 90 min and 37 °C, respectively. A solvent/solid ratio of 10 mL/g using 100% acidified solvent resulted in the greatest anthocyanin yield. No significant difference was observed between the use of methanol or ethanol as the extraction solvent. Ultra Performance Liquid Chromatography-MS analysis of the extract identified four anthocyanins, with cyanidin-3-rutinoside and peonidin-3-rutinoside accounting for over 95% of the anthocyanin content, while cyanidin-3-glucoside and pelargonidin-3-rutinoside accounted for the remaining 5%. 244 mg/100 g fresh weight total anthocyanins were determined in the fresh cherries using the optimal extraction conditions.

Integrating muscle cell biochemistry and whole-body physiology in humans:(31)P-MRS data from the InSight trial.

We acquired (31)P-MRS data from skeletal muscle of subjects of mixed gender and ethnicity, combined with a panel of physiological characteristics, and tested several long-standing hypotheses regarding relationships between muscle cell biochemistry and whole-body physiology with unusually high statistical power. We hypothesized that i) whole-body VO(2)max would correlate with muscle respiratory capacity, ii) resting muscle phosphocreatine concentration ([PCr]) would negatively correlate with delta efficiency and iii) muscle mitochondrial function would positively correlate with both resting VO(2) and total daily energy expenditure (TDEE). Muscle respiratory capacity explained a quarter of the variation in VO(2)max (r(2) = 26, p < .001, n = 87). There was an inverse correlation between muscle [PCr] and delta efficiency (r = -23, p = 046, n = 87). There was also a correlation between [PCr] recovery halftime and TDEE (r = -23, p = 035, n = 87). Our data not only provide insights into muscle cell chemistry and whole-body physiology but our mixed cohort means that our findings are broadly generalizable.

Relative vs. absolute physiological measures as predictors of mountain bike cross-country race performance.

The aims of this study were to document the effect terrain has on the physiological responses and work demands (power output) of riding a typical mountain bike cross-country course under race conditions. We were particularly interested in determining whether physiological measures relative to mass were better predictors of race performance than absolute measures. Eleven A-grade male cross-country mountain bike riders (VO2max 67.1 +/- 3.6 ml x kg(-1) x min(-1)) performed 2 tests: a laboratory-based maximum progressive exercise test, and a 15.5-km (six 2.58-km laps) mountain bike cross-country time trial. There were significant differences among the speed, cadence, and power output measured in each of 8 different terrain types found in the cross-country time trial course. The highest average speed was measured during the 10-15% downhill section (22.7 +/- 2.6 km x h(-1)), whereas the cadence was highest in the posttechnical flat sections (74.3 +/- 5.6 rpm) and lowest on the 15-20% downhill sections (6.4 +/- 12.1 rpm). The highest mean heart rate (HR) was obtained during the steepest (15-20% incline) section of the course (179 +/- 8 b x min(-1)), when the power output was greatest (419.8 +/- 39.7 W). However, HR remained elevated relative to power output in the downhill sections of the course. Physiological measures relative to total rider mass correlated more strongly to average course speed than did absolute measures (peak power relative to mass r = 0.93, p < 0.01, vs. peak power r = 0.64, p < 0.05; relative VO2max r = 0.80, p < 0.05, vs. VO2max r = 0.66, p < 0.05; power at anaerobic threshold relative to mass r = 0.78, p < 0.05, vs. power at anaerobic threshold r = 0.5, p < 0.05). This suggests that mountain bike cross-country training programs should focus upon improving relative physiological values rather than focusing upon maximizing absolute values to improve performance.

Airway distensibility in normal and asthmatic subjects and partitioning of the Fowler dead space.

Anatomical dead space measured by the Fowler method (VDF) is the sum of 2 serial volume compartments (VDF = VDp1 + VDp2). VDF has been shown to increase linearly with end-inspiratory lung volume (EILV) and the gradient of the relationship (DeltaVDF) has been used as an index of airway distensibility. The aim of this study was to partition VDF into its serial compartments VDp1 and VDp2 to test the hypothesis that, given the greater distensibility of distal airways, VDp2 would demonstrate greater volume dependence than VDp1. The relationships between each measure of VD (VDF, VDp1, and VDp2) and EILV were studied in 16 healthy subjects and 16 mildly asthmatic subjects. Significant (p < 0.05) linear relationships were obtained between each measure of VD and EILV in both subject groups. Changes in VDp1 with EILV (DeltaVDp1) accounted for 78.6% +/- 5.6% (mean +/- SEM) and 72.6% +/- 6.3% of DeltaVDF in the healthy and asthmatic groups, respectively. DeltaVDp1 was greater in the healthy subjects than in asthmatic subjects (18.4 versus 13.1 mL/L, p = 0.005). We conclude that in both asthmatic and healthy subjects, the major component of DeltaVDF was DeltaVDp1 and not DeltaVDp2, as originally hypothesized. We believe our results are reflecting the degree of asynchronous airway emptying.

Stability of the EasyOne ultrasonic spirometer for use in general practice.

OBJECTIVE AND BACKGROUND: Spirometry is recommended for the diagnosis and management of chronic respiratory diseases in the community. Spirometer accuracy is critical, but few general practitioners meet the American Thoracic Society and European Respiratory Society (ATS/ERS) recommendation for daily calibration. The aim of this study was to assess the accuracy and stability of a portable ultrasonic spirometer (EasyOne) that the manufacturer claims does not require regular calibration. METHODS: Six EasyOne spirometers were used in a practice-based spirometry study. Inspiratory and expiratory accuracy was checked periodically using a certified 3-L syringe. Paired calibration checks were performed using a dedicated mouthpiece assembly (spirette) and randomly selected spirettes. RESULTS: The six spirometers were used for up to 26 weeks (mean 23.9 weeks) and a total of 1041 spirometry tests and 75 syringe calibrations were performed. All inspiratory and expiratory calibration checks using a dedicated or randomly selected spirette met the ATS/ERS accuracy criterion (3.00+/-0.105 L). The mean (range) expiratory volume deviation from target volume (3.00 L) was 0.011 L (-0.06-0.09 L) using a dedicated spirette and 0.046 L (-0.09-0.10 L) using randomly selected spirettes. The deviation from target was not affected by the mean flow generated during the calibration procedure. There was no change in calibration during the study. CONCLUSIONS: This study supports the manufacturer's claim that the EasyOne spirometer maintains its calibration during routine clinical use in general practice and does not require daily calibration as specified in international spirometry guidelines.

Reflective critique and collaborative practice in evaluation: promoting change in medical education.

The School of Medicine at the University of Tasmania has recently begun to implement a process of curriculum evaluation,which aims to reflect contemporary best practice in evaluation in tertiary pedagogy and medical education. Best practice must accommodate a broadening interest in cooperative and collaborative evaluation strategies among stakeholders, advances in applied qualitative educational research and recognition that critical reflection on practice is the cornerstone of professional education. This paper reports a recent evaluation strategy in a specific year-long unit in the second year of a six-year undergraduate medical degree. The paper begins by presenting the context; it then discusses and rationalises the evaluation strategy and presents findings. The paper concludes by arguing that curriculum evaluation as best practice must be reflective, informed by the scholarship of medical education, and internalized as a dynamic process that can promote sustainable change and improvement in medical curricula. Such an approach will contribute to an undergraduate medical curriculum that prepares students for the demands and complexities of medical practice.

Exercise-induced oxyhaemoglobin desaturation, ventilatory limitation and lung diffusing capacity in women during and after exercise.

Arterial haemoglobin saturation during exercise in healthy young women [eight subjects mean (SEM) age 20.8 (1.8) years] was measured to confirm the theory that young women experience exercise-induced arterial hypoxaemia (EIAH) at a lower relative percentage of maximal oxygen uptake (VO(2max)) than has been documented in their male counterparts. To determine if flow limitation [the percentage of the tidal volume ( V(T)) that met or exceeded the boundary established by multiple maximal expiratory manoeuvres] and/or post-exercise lung diffusing capacity are linked to EIAH in women, and to investigate the influence of exercise intensity and duration on post-exercise carbon monoxide lung diffusing capacity ( D(L, CO)), these parameters were measured during and after three exercise tests (incremental test until exhaustion, 5 km run and 5 km run with sprint). All subjects experienced physiologically significant EIAH (a fall of more than 3% in oxygen saturation of arterial blood from levels at rest) and seven subjects experienced flow limitation during the VO(2max) protocol [mean (SD) 12.2 (8.8)% of V(T)]. Even though there was no significant relationship between aerobic capacity and the degree of flow limitation ( r=0.33, P>0.05), the flow limitation was related to absolute ventilation in the subjects studied ( r=0.82, P<0.05). There was no significant relationship between decrements in post exercise D(L, CO) and EIAH ( r=0.05, P>0.05), however there was a strong correlation between the extent of flow limitation (% of V(T)) and EIAH ( r=0.71). Significant decreases in D(L, CO) lasted for up to 16 h after each of the exercise tests ( P<0.05) and lasted for a further 8 h after the maximal test ( P<0.05). Exercise intensity was the main contributing factor to the observed decreases in post-exercise D(L, CO) with the percentage of VO(2max) attained during the various tests being significantly related to the fall in D(L, CO) for 1, 2, 3, 16 and 24 h after exercise ( P<0.05). As the appearance of flow limitation closely coincided with the appearance of EIAH, the results from the present study suggest that flow limitation is a contributing factor to EIAH in women although the exact mechanism remains unclear.