Formulae for Insect Wingbeat Frequency

A formula is developed connecting the wingbeat frequency of insects with their masses and wing areas. It is derived first theoretically, using dimensional analysis, and then it is compared with published measurements. The formula discovered involves two parameters which dimensional analysis alone cannot determine. One of these is evaluated using one among many proposed semi-empirical relationships (the only one that stands scrutiny); the other by fitting a published dataset. It is found that the resulting equation, applying to insects in general, accords well with observation, and indeed is very close to being optimal (in a sense to be defined)

Total hip arthroplasty improves pain and function but not physical activity

Background: People with hip osteoarthritis are likely to limit physical activity (PA) engagement due to pain and lack of function. Total hip arthroplasty (THA) reduces pain and improves function, potentially allowing increased PA. PA of THA patients was quantified to 12m post-operation. The hypothesis was that post-operatively levels of PA would increase. Methods: PA of 30 THA patients (67±7 years) was objectively measured pre-operatively and three and 12 months post-operation. Harris Hip Score (HHS), Oxford Hip Score (OHS) and six minute walk test (6MWT) were recorded. Mixed linear modelling was used to examine relationships of outcomes with time, baseline BMI, age, gender and baseline HHS. Results: Time was not a significant factor in predicting volume measures of PA, including sit-to-stand transitions, upright time and steps. Notably baseline BMI was a significant predictor of upright time, steps, largest number of steps in an upright bout, HHS and 6MWT. Baseline HHS helped predict longest upright bout, cadence of walking bouts >60s and OHS. The significant effect of participant as a random intercept in the model for PA outcomes suggested habituation from pre- to post-surgery. Conclusions: Volume measures of PA did not change from pre- to 12m post-surgery despite improvement in HHS, OHS and 6MWT. Baseline BMI was a more important predictor of upright activity and stepping than time. Pre- and post-operative PA promotion could be used to modify apparently habitual low levels of PA to enable full health benefits of THA to be gained

Short-term reliability of inflammatory mediators and response to exercise in the heat

Prospective application of serum cytokines, lipopolysaccharide, and heat shock proteins requires reliable measurement of these biomarkers that can signify exercise-induced heat stress in hot conditions. To accomplish this, both short-term (seven day) reliability (at rest, n=12) and the acute responsiveness of each biomarker to exercise in the heat (pre and post 60 min cycling, 34.5oC and 70% RH, n=20) were evaluated. Serum was analysed for the concentration of C-reactive protein (CRP), interleukin (IL-6), heat shock protein 72 (eHSP72), immunoglobulin M (IgM) and lipopolysaccharide (LPS). Test-retest reliability was determined as the coefficient of variation (CV). Biomarkers with the least short-term within-subject variation were IL-6 (19%, ± 20%; CV, ± 95% confidence limits) and LPS (23%, ± 13%). Greater variability was observed for IgM, eHSP72 and CRP (CV range 28-38%). IL-6 exhibited the largest increase in response to acute exercise (95%, ± 11%, p = <0.001) and although CRP had a modest CV (12%, ± 7%) it increased substantially post-exercise (p = 0.02, ES; 0.78). In contrast, eHSP72 and LPS exhibited trivial changes post-exercise. It appears variation of common inflammatory markers after exercise in the heat is not always discernible from short-term (weekly) variation

The Effects of Pre-conditioning on Exercise-Induced Muscle Damage: A Systematic Review and Meta-analysis

Background: Several studies have utilised isometric, eccentric and downhill walking pre-conditioning as a strategy for alleviating the signs and symptoms of exercise-induced muscle damage (EIMD) following a bout of damaging physical activity. Objectives: This systematic review and meta-analysis examined the effects of pre-conditioning strategies on indices of muscle damage and physical performance measures following a second bout of strenuous physical activity. Data Sources: PubMed, CINAHL and Scopus. Eligibility Criteria: Studies meeting the PICO (population, intervention/exposure, comparison, and outcome) criteria were included in this review: (1) general population or “untrained” participants with no contraindications affecting physical performance; (2) studies with a parallel design to examine the prevention and severity of muscle-damaging contractions; (3) outcome measures were compared using baseline and post-intervention measures; and (4) outcome measures included any markers of indirect muscle damage and muscular contractility measures. Participants: Individuals with no resistance training experiences in the previous 6 or more months. Interventions: A single bout of pre-conditioning exercises consisting of eccentric or isometric contractions performed a minimum of 24 h prior to a bout of damaging physical activity were compared to control interventions that did not perform pre-conditioning prior to damaging physical activity. Study Appraisal: Kmet appraisal system. Synthesis Methods: Quantitative analysis was conducted using forest plots to examine standardised mean differences (SMD, i.e. effect size), test statistics for statistical significance (i.e. Z-values) and between-study heterogeneity by inspecting I2. Results: Following abstract and full-text screening, 23 articles were included in this paper. Based on the meta-analysis, the pre-conditioning group exhibited lower levels of creatine kinase at 24 h (SMD = − 1.64; Z = 8.39; p = 0.00001), 48 h (SMD = − 2.65; Z = 7.78; p = 0.00001), 72 h (SMD = − 2.39; Z = 5.71; p = 0.00001) and 96 h post-exercise (SMD = − 3.52; Z = 7.39; p = 0.00001) than the control group. Delayed-onset muscle soreness was also lower for the pre-conditioning group at 24 h (SMD = − 1.89; Z = 6.17; p = 0.00001), 48 h (SMD = − 2.50; Z = 7.99; p = 0.00001), 72 h (SMD = − 2.73; Z = 7.86; p = 0.00001) and 96 h post-exercise (SMD = − 3.30; Z = 8.47; p = 0.00001). Maximal voluntary contraction force was maintained and returned to normal sooner in the pre-conditioning group than in the control group, 24 h (SMD = 1.46; Z = 5.49; p = 0.00001), 48 h (SMD = 1.59; Z = 6.04; p = 0.00001), 72 h (SMD = 2.02; Z = 6.09; p = 0.00001) and 96 h post-exercise (SMD = 2.16; Z = 5.69; p = 0.00001). Range of motion was better maintained by the pre-conditioning group compared with the control group at 24 h (SMD = 1.48; Z = 4.30; p = 0.00001), 48 h (SMD = 2.20; Z = 5.64; p = 0.00001), 72 h (SMD = 2.66; Z = 5.42; p = 0.00001) and 96 h post-exercise (SMD = 2.5; Z = 5.46; p = 0.00001). Based on qualitative analyses, pre-conditioning activities were more effective when performed at 2–4 days before the muscle-damaging protocol compared with immediately prior to the muscle-damaging protocol, or 1–3 weeks prior to the muscle-damaging protocol. Furthermore, pre-conditioning activities performed using eccentric contractions over isometric contractions, with higher volumes, greater intensity and more lengthened muscle contractions provided greater protection from EIMD. Limitations: Several outcome measures showed high inter-study heterogeneity. The inability to account for differences in durations between pre-conditioning and the second bout of damaging physical activity was also limiting. Conclusions: Pre-conditioning significantly reduced the severity of creatine kinase release, delayed-onset muscle soreness, loss of maximal voluntary contraction force and the range of motion decrease. Pre-conditioning may prevent severe EIMD and accelerate recovery of muscle force generation capacity

Beyond shareholder primacy? Reflections on the trajectory of UK corporate governance.

Core institutions of UK corporate governance, in particular the City Code on Takeovers and Mergers, the Combined Code on Corporate Governance and the law on directors’ duties, are strongly orientated towards the norm of shareholder primacy. Beyond the core, however, stakeholder interests are better represented, in particular at the intersection of insolvency and employment law. This reflects the influence of European Community laws on information and consultation of employees. In addition, there are signs that some institutional shareholders are redirecting their investment strategies, under government encouragement, away from a focus on short-term returns, in such a way as to favour stakeholder-inclusive practices by firms. On this basis we suggest that the UK system is currently in a state of flux and that the debate over shareholder primacy has not been concluded

Inflammation and immunity in schizophrenia: implications for pathophysiology and treatment.

Complex interactions between the immune system and the brain might have important aetiological and therapeutic implications for neuropsychiatric brain disorders. A possible association between schizophrenia and the immune system was postulated over a century ago, and is supported by epidemiological and genetic studies pointing to links with infection and inflammation. Contrary to the traditional view that the brain is an immunologically privileged site shielded behind the blood-brain barrier, studies in the past 20 years have noted complex interactions between the immune system, systemic inflammation, and the brain, which can lead to changes in mood, cognition, and behaviour. In this Review, we describe some of the important areas of research regarding innate and adaptive immune response in schizophrenia and related psychotic disorders that, we think, will be of interest to psychiatric clinicians and researchers. We discuss potential mechanisms and therapeutic implications of these findings, including studies of anti-inflammatory drugs in schizophrenia, describe areas for development, and offer testable hypotheses for future investigations.The work was supported by a doctoral clinical research training fellowship grant from the Wellcome Trust to Golam Khandaker (094790/Z/10/Z; 2010-‘13), grants from the Stanley Medical Research Institute and the National Institutes of Mental Health (grant# MH-94268) to Robert Yolken, and grants from the Wellcome Trust (095844/Z/11/Z & 088869/Z/09/Z), and the NIHR (RP-PG-0606-1335) to Peter Jones.This is the accepted manuscript. The final version is available from Elsevier at http://www.thelancet.com/journals/lanpsy/article/PIIS2215-0366%2814%2900122-9/abstrac

Equal pay as a moving target: International perspectives on forty-years of addressing the gender pay gap

This paper provides an overview of the key factors impacting upon the gender pay gap in the UK, Europe and Australia. Forty years after the implementation of the first equal pay legislation, the pay gap remains a key aspect of the inequalities women face in the labour market. While the overall pay gap has tended to fall in many countries over the past forty years, it has not closed; in some countries it has been stubbornly resistant, or has even widened. In reviewing the collection of papers that make up this special issue we identify four broad themes with which to group the contributions and draw out the explanations for diverse trends: theoretical and conceptual debates; legal developments and their impacts; wage setting institutions and changing employer demands; and newly emerging pay inequalities between and within educational and ethnic groups. Across the four themes we underline how the trends in the gender pay gap capture the dynamism of inequalities, as the market power of different groups and stakeholders changes over times. Three key dimensions emerge from the papers to provide a framework for future research and policy discourse: the relationship between litigation and bargaining strategies; the interaction between wage-setting institutions and new organisational practices; and the increasing and range of diversity or equality strands competing for equal treatment. We conclude that progress towards closing the gender pay gap will not be easy, will require a collective effort of various actors, and will not be quick