Electrostatic space focusing of molecular beams: some methods and applications

Electrostatic space focusing of molecular beams has been introduced by means of a brief review of some methods which have been employed in the development of microwave spectroscopy of molecules. Some electrostatic focuser configurations suitable for space focusing molecules that decrease in energy in an applied eleotric field have been experimentally investigated. These designs include the coaxial, single-wire and a new configuration, the crossed-wire focuser. Characteristic results which have been obtained indicate the crossed-wire focuser to be the most efficient for focusing molecules in the lower inversion states of the rotational energy levels of ammonia. For the first time, the operation of electrostatic focusers has been achieved in a beam maser without recourse to the continual use of external BET supplies. This development involved the employment of electret focusers. In particular, solid ammonia electrets have been formed and the time dependence of their external electric field has been monitored in a beam maser. The method employed here of monitoring the external electret electric field by probing with a neutral molecular beam, has not previously been utilised. A space focused ammonia molecular beam has been used to observe electric resonance "beating of beats". This effect, which is analogous to a similar effect observed in nuclear magnetic resonance, followed the rapid passage of an exciting signal through the resolved components of the naturally split main line of the J - 1, K - 1 inversion transition

A longitudinal study of alcohol use and antisocial behaviour in young people

Aims: To examine the direction of causation between young people's antisocial behaviour and alcohol (mis)use in the longer and shorter term, together with their joint effects on alcohol-related trouble. Methods: A longitudinal study (2586 pupils) supplied data, allowing exploration of the causal effects of alcohol (mis)use and antisocial behaviour between ages 11 and 15, using structural equation models of longer and shorter-term relationships and joint-effects models in respect of alcohol-related trouble at age 15. This method allowed us to evaluate which of three hypotheses, described as ‘disinhibition’ [alcohol (mis)use causes or facilitates antisocial behaviour], ‘susceptibility’ [antisocial behaviour causes alcohol (mis)use] or ‘reciprocal’ [alcohol (mis)use causes antisocial behaviour and the reverse] receives most support, both overall and by gender, social class, and drinking context. Results: Overall, the results support the susceptibility hypothesis, particularly in the longer-term models. There is no support for ‘pure’ disinhibition. However, in the shorter-term and joint-effects models (i.e. as the time lag becomes shorter), there is evidence that in some gender, social class, or drinking contexts, in addition to antisocial behaviour causing alcohol (mis)use, the reverse also applies. Conclusions: Antisocial behaviour is the main predictor of alcohol (mis)use and alcohol-related trouble, with alcohol (mis)use impacting only modestly on antisocial behaviour and alcohol-related trouble in the shorter term

When Is a Sprint a Sprint? A Review of the Analysis of Team-Sport Athlete Activity Profile

The external load of a team-sport athlete can be measured by tracking technologies, including global positioning systems (GPS), local positioning systems (LPS) and vision-based systems. These technologies allow for the calculation of displacement, velocity and acceleration during a match or training session. The accurate quantification of these variables is critical so that meaningful changes in team-sport athlete external load can be detected. High-velocity running, including sprinting, may be important for specific team-sport match activities, including evading an opponent or creating a shot on goal. Maximal accelerations are energetically demanding and frequently occur from a low velocity during team-sport matches. Despite extensive research, conjecture exists regarding the thresholds by which to classify the high velocity and acceleration activity of a team-sport athlete. There is currently no consensus on the definition of a sprint or acceleration effort, even within a single sport. The aim of this narrative review was to examine the varying velocity and acceleration thresholds reported in athlete activity profiling. The purposes of this review were therefore to (1) identify the various thresholds used to classify high-velocity or –intensity running plus accelerations; (2) examine the impact of individualized thresholds on reported team-sport activity profile; (3) evaluate the use of thresholds for court-based team-sports and; (4) discuss potential areas for future research. The presentation of velocity thresholds as a single value, with equivocal qualitative descriptors, is confusing when data lies between two thresholds. In Australian football, sprint efforts have been defined as activity > 4.00 m·s-1 or > 4.17 m·s-1. Acceleration thresholds differ across the literature, with > 1.11 m·s-2, 2.78 m·s-2, 3.00 m·s-2 and 4.00 m·s-2 utilized across a number of sports. It is difficult to compare literature on field-based sports due to inconsistencies in velocity and acceleration thresholds, even within a single sport. Velocity and acceleration thresholds have been determined from physical capacity tests. Limited research exists on the classification of velocity and acceleration data by female team-sport athletes. Alternatively, data mining techniques may be used to report team-sport athlete external load, without the requirement of arbitrary or physiologically defined thresholds

Heavy resistance training in hypoxia enhances 1RM squat performance

Purpose: To determine if heavy resistance training in hypoxia (IHRT) is more effective at improving strength, power, and increasing lean mass than the same training in normoxia. Methods: A pair-matched, placebo-controlled study design included 20 resistance-trained participants assigned to IHRT (FIO2 0.143) or placebo (FIO2 0.20), (n = 10 per group). Participants were matched for strength and training. Both groups performed 20 sessions over 7 weeks either with IHRT or placebo. All participants were tested for 1RM, 20-m sprint, body composition, and countermovement jump pre-, mid-, and post-training and compared via magnitude-based inferences. Presentation of Results: Groups were not clearly different for any test at baseline. Training improved both absolute (IHRT: 13.1 ± 3.9%, effect size (ES) 0.60, placebo 9.8 ± 4.7%, ES 0.31) and relative 1RM (IHRT: 13.4 ± 5.1%, ES 0.76, placebo 9.7 ± 5.3%, ES 0.48) at mid. Similarly, at post both groups increased absolute (IHRT: 20.7 ± 7.6%, ES 0.74, placebo 14.1 ± 6.0%, ES 0.58) and relative 1RM (IHRT: 21.6 ± 8.5%, ES 1.08, placebo 13.2 ± 6.4%, ES 0.78). Importantly, the change in IHRT was greater than placebo at mid for both absolute [4.4% greater change, 90% Confidence Interval (CI) 1.0:8.0%, ES 0.21, and relative strength (5.6% greater change, 90% CI 1.0:9.4%, ES 0.31 (relative)]. There was also a greater change for IHRT at post for both absolute (7.0% greater change, 90% CI 1.3:13%, ES 0.33), and relative 1RM (9.2% greater change, 90% CI 1.6:14.9%, ES 0.49). Only IHRT increased countermovement jump peak power at Post (4.9%, ES 0.35), however the difference between IHRT and placebo was unclear (2.7, 90% CI –2.0:7.6%, ES 0.20) with no clear differences in speed or body composition throughout. Conclusion: Heavy resistance training in hypoxia is more effective than placebo for improving absolute and relative strength

Variations in hypoxia impairs muscle oxygenation and performance during simulated team-sport running

Purpose: To quantify the effect of acute hypoxia on muscle oxygenation and power during simulated team-sport running. Methods: Seven individuals performed repeated and single sprint efforts, embedded in a simulated team-sport running protocol, on a non-motorized treadmill in normoxia (sea-level), and acute normobaric hypoxia (simulated altitudes of 2,000 and 3,000 m). Mean and peak power was quantified during all sprints and repeated sprints. Mean total work, heart rate, blood oxygen saturation, and quadriceps muscle deoxyhaemoglobin concentration (assessed via near-infrared spectroscopy) were measured over the entire protocol. A linear mixed model was used to estimate performance and physiological effects across each half of the protocol. Changes were expressed in standardized units for assessment of magnitude. Uncertainty in the changes was expressed as a 90% confidence interval and interpreted via non-clinical magnitude-based inference. Results: Mean total work was reduced at 2,000 m (−10%, 90% confidence limits ±6%) and 3,000 m (−15%, ±5%) compared with sea-level. Mean heart rate was reduced at 3,000 m compared with 2,000 m (−3, ±3 min(−1)) and sea-level (−3, ±3 min(−1)). Blood oxygen saturation was lower at 2,000 m (−8, ±3%) and 3,000 m (−15, ±2%) compared with sea-level. Sprint mean power across the entire protocol was reduced at 3,000 m compared with 2,000 m (−12%, ±3%) and sea-level (−14%, ±4%). In the second half of the protocol, sprint mean power was reduced at 3,000 m compared to 2,000 m (−6%, ±4%). Sprint mean peak power across the entire protocol was lowered at 2,000 m (−10%, ±6%) and 3,000 m (−16%, ±6%) compared with sea-level. During repeated sprints, mean peak power was lower at 2,000 m (−8%, ±7%) and 3,000 m (−8%, ±7%) compared with sea-level. In the second half of the protocol, repeated sprint mean power was reduced at 3,000 m compared to 2,000 m (−7%, ±5%) and sea-level (−9%, ±5%). Quadriceps muscle deoxyhaemoglobin concentration was lowered at 3,000 m compared to 2,000 m (−10, ±12%) and sea-level (−11, ±12%). Conclusions: Simulated team-sport running is impaired at 3,000 m compared to 2,000 m and sea-level, likely due to a higher muscle deoxygenation

Negative pressure wound therapy for treating foot wounds in people with diabetes mellitus (Review)

Diabetes mellitus is a common condition that leads to high blood glucose concentrations, with around 2.8 million people affected in the UK (approximately 4.3% of the population). Some people with diabetes can develop ulcers on their feet. These wounds can take a long time to heal, be painful and become infected. Ulceration of the foot in people with diabetes can also lead to a higher risk of amputation of parts of the foot or leg. Generally, people with diabetes are at a higher risk of lower-limb amputation than people without diabetes. Negative pressure wound therapy is a wound treatment which involves applying suction to a wound; it is used increasingly around the world but it is not clear how effective it is. It also expensive compared with treatments such as dressings. We found five randomised controlled trials that compared negative pressure wound therapy with other treatments. We found some preliminary evidence that negative pressure wound therapy increases the healing of foot wounds on people with diabetes compared with other treatments. However, the findings are not conclusive and more, better quality randomised controlled trials are required

Editor's Choice - Re-interventions After Repair of Ruptured Abdominal Aortic Aneurysm: A Report From the IMPROVE Randomised Trial.

OBJECTIVE/BACKGROUND: The aim was to describe the re-interventions after endovascular and open repair of rupture, and investigate whether these were associated with aortic morphology. METHODS: In total, 502 patients from the IMPROVE randomised trial (ISRCTN48334791) with repair of rupture were followed-up for re-interventions for at least 3 years. Pre-operative aortic morphology was assessed in a core laboratory. Re-interventions were described by time (0-90 days, 3 months-3 years) as arterial or laparotomy related, respectively, and ranked for severity by surgeons and patients separately. Rare re-interventions to 1 year, were summarised across three ruptured abdominal aortic aneurysm trials (IMPROVE, AJAX, and ECAR) and odds ratios (OR) describing differences were pooled via meta-analysis. RESULTS: Re-interventions were most common in the first 90 days. Overall rates were 186 and 226 per 100 person years for the endovascular strategy and open repair groups, respectively (p = .20) but between 3 months and 3 years (mid-term) the rates had slowed to 9.5 and 6.0 re-interventions per 100 person years, respectively (p = .090) and about one third of these were for a life threatening condition. In this latter, mid-term period, 42 of 313 remaining patients (13%) required at least one re-intervention, most commonly for endoleak or other endograft complication after treatment by endovascular aneurysm repair (EVAR) (21 of 38 re-interventions), whereas distal aneurysms were the commonest reason (four of 23) for re-interventions after treatment by open repair. Arterial re-interventions within 3 years were associated with increasing common iliac artery diameter (OR 1.48, 95% confidence interval [CI] 0.13-0.93; p = .004). Amputation, rare but ranked as the worst re-intervention by patients, was less common in the first year after treatment with EVAR (OR 0.2, 95% CI 0.05-0.88) from meta-analysis of three trials. CONCLUSION: The rate of mid-term re-interventions after rupture is high, more than double that after elective EVAR and open repair, suggesting the need for bespoke surveillance protocols. Amputations are much less common in patients treated by EVAR than in those treated by open repair

Financial management practice amongst SMEs

While deficiencies in financial management have been repeatedly cited as a root cause of business failure (Najak and Greenfield 1994) two arguments are advanced for such deficiencies in SMEs; that new accounting is not relevant and that SME managers are unable to make use of accounting. Here it is argued that accounting ideas are relevant to SMEs but that a process of innovation combining both knowledge to overcome a barrier of belief and an external shock are necessary in order for innovation to take place. These ideas were explored through a survey of SMEs from both service and manufacturing business in the Greater Manchester region. It was observed that the use of accounting techniques is negatively related to growth in turnover. However the use of accounting techniques that were related to product market was found to be positively related to growth in turnover and that owner/managers belief in the importance of accounting in business decisions was strongly related to growth in turnover. These results were the more interesting when it was observed that growth was negatively related to size. A second theme of the research was the significance of the role of external advisors. Prima facie it was suggested that external advisors may be key agents of change, but the study found that their (accountants, academics and consultants) perceived value was relatively low. The findings of this survey suggest that when accounting is perceived to be relevant then its use does support business growth but innovation in accounting in SME requires further research

Endovascular or open repair strategy for ruptured abdominal aortic aneurysm: 30 day outcomes from IMPROVE randomised trial.

OBJECTIVE: To assess whether a strategy of endovascular repair (if aortic morphology is suitable, open repair if not) versus open repair reduces early mortality for patients with suspected ruptured abdominal aortic aneurysm. DESIGN: Randomised controlled trial. SETTING: 30 vascular centres (29 UK, 1 Canadian), 2009-13. PARTICIPANTS: 613 eligible patients (480 men) with a clinical diagnosis of ruptured aneurysm. INTERVENTIONS: 316 patients were randomised to the endovascular strategy (275 confirmed ruptures, 174 anatomically suitable for endovascular repair) and 297 to open repair (261 confirmed ruptures). MAIN OUTCOME MEASURES: 30 day mortality, with 24 hour and in-hospital mortality, costs, and time and place of discharge as secondary outcomes. RESULTS: 30 day mortality was 35.4% (112/316) in the endovascular strategy group and 37.4% (111/297) in the open repair group: odds ratio 0.92 (95% confidence interval 0.66 to 1.28; P=0.62); odds ratio after adjustment for age, sex, and Hardman index 0.94 (0.67 to 1.33). Women may benefit more than men (interaction test P=0.02) from the endovascular strategy: odds ratio 0.44 (0.22 to 0.91) versus 1.18 (0.80 to 1.75). 30 day mortality for patients with confirmed rupture was 36.4% (100/275) in the endovascular strategy group and 40.6% (106/261) in the open repair group (P=0.31). More patients in the endovascular strategy than in the open repair group were discharged directly to home (189/201 (94%) v 141/183 (77%); P<0.001). Average 30 day costs were similar between the randomised groups, with an incremental cost saving for the endovascular strategy versus open repair of £1186 (€1420; $1939) (95% confidence interval -£625 to £2997). CONCLUSIONS: A strategy of endovascular repair was not associated with significant reduction in either 30 day mortality or cost. Longer term cost effectiveness evaluations are needed to assess the full effects of the endovascular strategy in both men and women. TRIAL REGISTRATION: Current Controlled Trials ISRCTN48334791

Wound Complications in Preoperatively Irradiated Soft-Tissue Sarcomas of the Extremities

To determine whether the involvement of plastic surgery and the use of vascularized tissue flaps reduces the frequency of major wound complications after radiation therapy for soft-tissue sarcomas (STS) of the extremities