Dry-Land Force-Velocity, Power-Velocity, and Swimming-Specific Force Relation to Single and Repeated Sprint Swimming Performance.

The aim of this study was to identify the relationship between dry-land and in-water strength with performance and kinematic variables in short-distance, middle-distance, and repeated sprint swimming. Fifteen competitive swimmers applied a bench press exercise to measure maximum strength (MS), maximum power (P), strength corresponding to P (F@P), maximum velocity (MV), and velocity corresponding to P (V@P) using F-V and P-V relationships. On a following day, swimmers performed a 10 s tethered swimming sprint (TF), and impulse was measured (IMP). On three separate days, swimmers performed (i) 50 and 100 m, (ii) 200 and 400 m, and (iii) 4 × 50 m front crawl sprint tests. Performance time (T), arm stroke rate (SR), arm stroke length (SL), and arm stroke index (SI) were calculated in all tests. Performance in short- and middle-distance tests and in 4 × 50 m training sets were related to dry-land MS, P, TF, and IMP (r = 0.51-0.83; p < 0.05). MS, P, and TF were related to SR in 50 m and SI in 50 and 100 m (r = 0.55-0.71; p < 0.05). A combination of dry-land P and in-water TF variables explains 80% of the 50 m performance time variation. Bench press power and tethered swimming force correlate with performance in short- and middle-distance tests and repeated sprint swimming.

Infection rate models for COVID-19: Model risk and public health news sentiment exposure adjustments.

During the COVID-19 pandemic, governments globally had to impose severe contact restriction measures and social mobility limitations in order to limit the exposure of the population to COVID-19. These public health policy decisions were informed by statistical models for infection rates in national populations. In this work, we are interested in modelling the temporal evolution of national-level infection counts for the United Kingdom (UK-Wales, England, Scotland), Germany (GM), Italy (IT), Spain (SP), Japan (JP), Australia (AU) and the United States (US). We model the national-level infection counts for the period January 2020 to January 2021, thus covering both the pre- and post-vaccine roll-out periods, in order to better understand the most reliable model structure for the COVID-19 epidemic growth curve. We achieve this by exploring a variety of stochastic population growth models and comparing their calibration, with respect to in-sample fitting and out-of-sample forecasting, both with and without exposure adjustment, to the most widely used and reported growth model, the Gompertz population model, often referred to in the public health policy discourse during the COVID-19 pandemic. Model risk as we explore it in this work manifests in the inability to adequately capture the behaviour of the disease progression growth rate curve. Therefore, our concept of model risk is formed relative to the standard reference Gompertz model used by decision-makers, and then we can characterise model risk mathematically as having two components: the dispersion of the observation distribution, and the structure of the intensity function over time for cumulative counts of new infections daily (i.e. the force of infection) attributed directly to the COVID-19 pandemic. We also explore how to incorporate in these population models the effect that governmental interventions have had on the number of infected cases. This is achieved through the development of an exposure adjustment to the force of infection comprised of a purpose-built sentiment index, which we construct from various authoritative public health news reporting. The news reporting media we employed were the New York Times, the Guardian, the Telegraph, Reuters global blog, as well as national and international health authorities: the European Centre for Disease Prevention and Control, the United Nations Economic Commission for Europe, the United States Centres for Disease Control and Prevention, and the World Health Organisation. We find that exposure adjustments that incorporate sentiment are better able to calibrate to early stages of infection spread in all countries under study.

Point-of-care testing for celiac disease has a low sensitivity in endoscopy.

BACKGROUND: Celiac disease (CD) is a common but underdiagnosed condition. A rapid point-of-care test (POCT) could reduce lead times and missed diagnoses. OBJECTIVE: To assess the utility of an immunoglobulin (Ig) A tissue transglutaminase (TTG) antibody POCT in an endoscopic setting. DESIGN: Prospective observational study. SETTING: A single UK university hospital. PATIENTS: Patients presenting with suspected CD, known CD, and routine endoscopy for upper GI symptoms. INTERVENTIONS: All patients were tested with POCT, serum TTG, endomysial antibody (EMA), and upper GI endoscopy with duodenal biopsies at the same visit. MAIN OUTCOME MEASUREMENTS: Comparison was made with histology in all cases, with villous atrophy regarded as diagnostic of CD. RESULTS: A total of 576 patients (63.5% female, mean [± standard deviation] age 49.7 years [± 17.6 years]) were recruited. A total of 523 patients had no prior diagnosis of CD, and 53 patients had known CD coming for reassessment. A total of 117 patients were newly diagnosed with CD, and 82 were positively identified by the POCT. Sensitivity, specificity, positive predictive value, and negative predictive value were 70.1%, 96.6%, 85.4%, and 91.8%, respectively. In comparison, TTG and EMA both performed significantly better than the POCT. Sensitivity and specificity of TTG were 91.0% and 83.5%, respectively, and EMA were 83.8% and 97.5%, respectively. Of patients with known CD coming for reassessment, 26 had villous atrophy, and POCT results were positive in 16 (61.5%). There was poor agreement between POCT and standard serology. LIMITATIONS: High pre-test probability of CD. CONCLUSION: The performance of this POCT was disappointing compared with standard serology and cannot at present be recommended within the context of an endoscopy unit.

Effects of tumor necrosis factor alpha inhibition with infliximab on lipid levels and insulin resistance in patients with inflammatory bowel disease.

INTRODUCTION: TNF-alpha is a critical mediator of inflammation with an important role in metabolic profile and insulin resistance. The regulation of these parameters by TNF-alpha in inflammatory bowel disease (IBD) is, however, poorly understood. The aim of this study was to assess the in-vivo TNF-alpha-mediated regulation of insulin resistance and of lipid levels in patients with IBD. METHODS: Twenty-two patients with IBD (eight females; 19 Crohn's disease) received infliximab according to treating physician's assessment at weeks 0, 2 and 6 from baseline and subsequently every 8 weeks and were prospectively followed for 14 weeks. Fasting insulin, total cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, apolipoprotein A1 (apo-A1), apolipoprotein B100 and lipoprotein a were measured in serum at baseline and at week 14. Insulin resistance was calculated with the use of the Homeostasis Model Assessment index. RESULTS: Infliximab therapy induced clinical response or remission in 19 of the 22 patients. C-reactive protein levels were significantly decreased by week 14. Body mass index was increased in all patients. No difference was observed in insulin levels, Homeostasis Model Assessment index, triglycerides, LDL cholesterol, apolipoprotein B100 and lipoprotein a. In contrast, total cholesterol, HDL cholesterol and apo-A1 levels were significantly increased from baseline. CONCLUSION: TNF-alpha inhibition does not alter insulin resistance in IBD patients. In contrast, total cholesterol, HDL cholesterol and apo-A1 levels are significantly increased after infliximab treatment compared with baseline. The importance of these alterations needs to be clarified in future studies.