ClimApp-Integrating Personal Factors with Weather Forecasts for Individualised Warning and Guidance on Thermal Stress.

This paper describes the functional development of the ClimApp tool (available for free on iOS and Android devices), which combines current and 24 h weather forecasting with individual information to offer personalised guidance related to thermal exposure. Heat and cold stress assessments are based on ISO standards and thermal models where environmental settings and personal factors are integrated into the ClimApp index ranging from -4 (extremely cold) to +4 (extremely hot), while a range of -1 and +1 signifies low thermal stress. Advice for individuals or for groups is available, and the user can customise the model input according to their personal situation, including activity level, clothing, body characteristics, heat acclimatisation, indoor or outdoor situation, and geographical location. ClimApp output consists of a weather summary, a brief assessment of the thermal situation, and a thermal stress warning. Advice is provided via infographics and text depending on the user profile. ClimApp is available in 10 languages: English, Danish, Dutch, Swedish, Norwegian, Hellenic (Greek), Italian, German, Spanish and French. The tool also includes a research functionality providing a platform for worker and citizen science projects to collect individual data on physical thermal strain and the experienced thermal strain. The application may therefore improve the translation of heat and cold risk assessments and guidance for subpopulations. ClimApp provides the framework for personalising and downscaling weather reports, alerts and advice at the personal level, based on GPS location and adjustable input of individual factors.

An analysis of the pacing strategy adopted by elite competitors in 2000 m rowing.

OBJECTIVES: To determine the pacing strategies adopted by elite rowers in championship 2000 m races. METHODS: Split times were obtained for each boat in every heavyweight race of the Olympic Games in 2000 and World Championships in 2001 and 2002, and the top 170 competitors in the British Indoor Rowing Championships in 2001 and 2002. Data were only included in subsequent analysis if there was good evidence that the athlete or crew completed the race in the fastest possible time. The remaining data were grouped to determine if there were different strategies adopted for on-water versus ergometer trials, "winners" versus "losers", and men versus women. RESULTS: Of the 1612 on-water race profiles considered, 948 fitted the inclusion criteria. There were no differences in pacing profile between winners and losers, and men and women, although on-water and ergometry trials showed a competitively meaningful significant difference over the first 500 m sector. The average profile showed that rowers performed the first 500 m of the race faster than subsequent sectors-that is, at a speed of 103.3% of the average speed for the whole race, with subsequent sectors rowed at 99.0%, 98.3%, and 99.7% of average speed for on-water rowing, and 101.5%, 99.8%, 99.0%, and 99.7% for ergometry. CONCLUSIONS: These data indicate that all athletes or crews adopted a similar fast start strategy regardless of finishing position or sex, although the exact pace profile was dependent on rowing mode. This strategy should be considered by participants in 2000 m rowing competitions.

The amplitude of the slow component of oxygen uptake is related to muscle contractile properties.

During constant-load exercise above the lactate threshold, oxygen-uptake kinetics deviate from the pattern seen below the threshold, with an additional, delayed component superimposed on the monoexponential pattern. It was hypothesised that this slow component is due to the progressive recruitment of type II muscle fibres. Oxygen uptake was measured for six male power athletes (group P) and six male endurance athletes (group E) during constant-load knee extension exercise tests in order to determine slow component amplitude. In addition, an electrical stimulation protocol was employed in order to assess the functional contractile profile and fatiguability of the knee extensors. The amplitude of the slow component during exercise was significantly ( P<0.05) greater in group P than in group E when expressed as an absolute value [mean (SEM)=77 (17) ml min(-1) and 24 (16) ml min(-1)] and when normalised to end-exercise oxygen uptake, VO(2) [8.2 (0.5)% and 2.6 (1.8)%]. Group differences were observed for percentage force loss during the electrical stimulation protocol [50.0 (3.4)% and 31.5 (3.7)% for groups P and E, respectively], increase in relaxation time from start to end of the fatigue test [87.9 (15.5)% and 31.1 (11.9)%], and relaxation time for fresh muscle [32.4 (1.0) ms and 40.6 (2.1) ms]. These contractile parameters may indicate a higher proportion of type II fibres in group P compared with group E. These experiments have shown evidence of a relationship between the amplitude of the slow component and muscle contractile properties, indicating that the origin of the slow component may lie in the pattern of different muscle fibre types.

DXA longitudinal quality control: a comparison of inbuilt quality assurance, visual inspection, multi-rule Shewhart charts and Cusum analysis.

The performance of dual-energy X-ray absorptiometry (DXA) instruments can be monitored using various quality control (QC) procedures. It has not been established which of these is most appropriate. The aim of this study was to determine which of four QC procedures is the best to use for longitudinal monitoring. Eighteen centres with DXA instruments scanned an aluminium spine phantom weekly for up to 16 months, and the bone mineral density data were used for the QC procedures. The methods investigated were the instrument's inbuilt quality assurance (QA) procedure, visual inspection, multi-rule Shewhart control charts, and Cusum analysis using a truncated-V mask. True and false positive fractions (TPF and FPF) of each method were calculated, including those for a range of action levels for the Shewhart charts and dimensions of the Cusum mask. For Shewhart, the action levels giving the most desirable TPF and FPF were whole multiples of the standard deviation (SD). For Cusum, the most desirable mask dimensions were 3.6 SD for the total height of the vertical section and 0.9 SD per data point for the gradient of the wings. Predictive power of each method as a means of fault detection was decided by the number of faults detected out of a total of 8 non-mechanical faults subsequently diagnosed. The inbuilt QA detected 2, visual inspection 7, Shewhart chart 7 and Cusum analysis 7. The FPFs were: visual inspection 0.09, Shewhart 0.04, Cusum 0.08. At these levels of FPF, the average time in days (range) from onset of a fault to detection was 39 (6-82) for visual inspection, 39 (4-116) for Shewhart and 21 (1-49) for Cusum. All three "phantom" methods are excellent for DXA QC, with modified Cusum analysis being the most effective. The inbuilt QA appears of little use on its own for longitudinal QC.

Evaluation of the European Spine Phantom in a multi-centre clinical trial.

The European Spine Phantom (ESP) has recently been developed as a universal standard for instruments measuring bone density. The ESP is composed of three semi-anthropomorphic hydroxyapatite vertebrae of varying densities surrounded by soft tissue equivalent plastic designed to resemble human bone and soft tissue when scanned on bone densitometers. In multi-centre studies it is particularly important to verify that each participating bone densitometer is performing in a stable and linear fashion. The aim of this study was to evaluate the ESP within the context of a multi-centre clinical trial. Eighteen centres in the UK and Canada with dual-energy X-ray absorptiometry (DXA) instruments (Lunar DPX, DPX-alpha and DPX-L) participated in the study. The ESP was scanned 10 times on each instrument without repositioning using standardized protocols. The precision of the bone mineral density (BMD) measurements (LI-3) expressed as a coefficient of variation ranged from 0.4% to 1.1% (mean 0.7%). The mean BMD of each instrument was expressed as a percentage difference from the overall mean and ranged from -1.33% to 1.33%. Linear regression analysis showed that all instruments behaved in a linear fashion across the range of densities with correlation coefficients all > or = 0.999 and standard errors of the estimate < 1.5% of the mean BMD ESP value. The data from this study demonstrate that the ESP is a useful phantom for assessing the linearity, stability and differences between DXA instruments from one manufacturer.

Dual-energy X-ray absorptiometry for the measurement of gross body composition in rats.

Dual-energy X-ray absorptiometry (DXA) is a novel, non-invasive technique for the measurement of gross body composition in small animals. In the present study the absolute accuracy of the Hologic QDR-1000W scanner was assessed by comparison with direct analysis in twelve rats with a range of body fat and bone mineral content (BMC) values. Fat masses measured by DXA and petroleum-ether extraction were significantly different (P < 0.0023). The DXA technique consistently overestimated fat mass by approximately one third of the measured fat content. BMC derived from the measurement of Ca in ash gave a mean of 8.26 (range 1.57-15.71)g. BMC measured by DXA was not significantly different for the group as a whole. However, there was a trend for DXA to overestimate BMC in animals with low BMC and underestimate in those with higher BMC, compared with direct analysis, such that the 95% limits of agreement for the two techniques were +2.73 to -2.58 g. These results suggest that the present small-animal software developed for use with currently available Hologic machines does not give an accurate measure of gross body composition compared with the results from classical direct analysis.

Role of oral pamidronate in preventing bone loss in postmenopausal women.

We have performed a 2-year prospective double-masked study to determine whether the bisphosphonate pamidronate can prevent bone loss in postmenopausal women and its optimal dosage regimen. One hundred and twenty-one such women (mean +/- SD age 57.6 +/- 3.4 years; mean +/- SD time since menopause 7.5 +/- 3.5 years) were randomized to receive either oral pamidronate (300 mg/day) for 4 weeks every 4 months (group A), oral pamidronate (150 mg/day) for 4 weeks every 2 months (group B) or identical placebo capsules (group C). Bone mineral density (BMD) measurements at the lumbar spine and proximal femur were performed at baseline and at 6-month intervals for 2 years using dual-energy X-ray absorptiometry. BMD at the lumbar spine (L2-4) increased significantly in groups A and B after 2 years of treatment (mean +/- SD 2.8 +/- 2.1% and 3.0 +/- 2.9% respectively, both p < 0.001) but decreased in the placebo group (-1.6 +/- 3.1%, p < 0.01). Identical results were seen for BMD at the femoral neck, which increased significantly in groups A and B after 2 years of treatment (1.2 +/- 2.3% and 1.3 +/- 2.9% respectively, both p < 0.05) but decreased in the placebo group (-1.9 +/- 3.9%, p < 0.05). There were significant differences over 2 years between the groups at all anatomical sites (lumbar spine, femoral neck and trochanteric region, all p < 0.001; Ward's triangle, p < 0.01). However, there were no significant differences between groups A and B, suggesting that the two treatment regimens were equally effective in conserving BMD. There were, however, marked differences in tolerability between the two treatment regimens: 13 women (34%) in group A withdrew from the study because of side-effects, but only 5 women (12%) in group B, which was comparable with placebo. These data demonstrate that intermittent oral pamidronate will prevent bone loss from the lumbar spine and proximal femur of postmenopausal women, and that the more frequent but lower dose regimen is well tolerated.