Muscle Oxygenation, Heart Rate, and Blood Lactate Concentration During Submaximal and Maximal Interval Swimming

This study aimed to determine the relationship between three testing procedures during different intensity interval efforts in swimming. Twelve national-level swimmers of both genders executed, on different occasions and after a standardized warm-up, a swimming protocol consisting of either a submaximal (Submax: 8 efforts of 50 m) or a maximal interval (Max: 4 efforts of 15 m), followed by two series of four maximal 25 m efforts. Near-infrared spectroscopy in terms of muscle oxygen saturation (SmO2), heart rate (HR), and blood lactate concentration (BLa) were analyzed at three testing points: after the Submax or the Max protocol (TP1), after the 1st 4 × 25-m (TP2), and after the 2nd maximal 4 × 25-m set (TP3). BLa and HR showed significant changes during all testing points in both protocols (P ≤ 0.01; ES range: 0.45–1.40). SmO2 was different only between TP1 and TP3 in both protocols (P ≤ 0.05–0.01; ES range: 0.36–1.20). A large correlation during the Max protocol between SmO2 and HR (r: 0.931; P ≤ 0.01), and also between SmO2 and BLa was obtained at TP1 (r: 0.722; P ≤ 0.05). A range of moderate-to-large correlations was revealed for SmO2/HR, and BLa/HR for TP2 and TP3 after both protocols (r range: 0.595–0.728; P ≤ 0.05) were executed. SmO2 is a novel parameter that can be used when aiming for a comprehensive evaluation of competitive swimmers' acute responses to sprint interval swimming, in conjunction with HR and BLa.

The statistics of k-mers from a sequence undergoing a simple mutation process without spurious matches

K-mer-based methods are widely used in bioinformatics, but there are many gaps in our understanding of their statistical properties. Here, we consider the simple model where a sequence S (e.g. a genome or a read) undergoes a simple mutation process whereby each nucleotide is mutated independently with some probability r, under the assumption that there are no spurious k-mer matches. How does this process affect the k-mers of S? We derive the expectation and variance of the number of mutated k-mers and of the number of islands (a maximal interval of mutated k-mers) and oceans (a maximal interval of non-mutated k-mers). We then derive hypothesis tests and confidence intervals for r given an observed number of mutated k-mers, or, alternatively, given the Jaccard similarity (with or without minhash). We demonstrate the usefulness of our results using a few select applications: obtaining a confidence interval to supplement the Mash distance point estimate, filtering out reads during alignment by Minimap2, and rating long read alignments to a de Bruijn graph by Jabba.

P787 Interstudy reproducibility in the real world of speckle tracking echocardiography in direct comparison with cardiac magnetic resonance

Funding Acknowledgements Fond national de la recherche scientifique (FNRS) Background New research methods to assess cardiac function such as 2D speckle tracking echocardiography (STE) are emerging in clinical practice after showing incremental prognostic information beyond ejection fraction in a variety of settings. However, comprehensive data regarding the day to day reproducibility is still lacking. Aim To assess the inter and especially the day to day intravariability of RV and LV GLS STE in direct comparison with cMR in asymptomatic volunteers and in patients with heart failure. Methods for the volunteers:30 asymptomatic volunteers ( 34 ± 9years, 33% were women) underwent 2 cMR and 2 echocardiography studies with a maximal interval between each study of 6 days and 20 minutes between each technique. RV strain was performed on a RV focus view and LV strain on 4, 3 and 2 chamber views using the segment software. cMR- RVEF and cMR-LVEF was performed in short axis view. Preliminary Results: Volunteers Average values for the the STE measurements was -24.2%±2.3 and -27.4%±2.1 for LV and RV GLS respectively. Average values for the 2 cMR measurements was 61.9% ±4.5 and 56.3%± 6.2% for cMR-LVEF and RVEF respectively. The interstudy varability coefficient of variability was lower in GLS-STE parameters (RV-GLS = 7.7% and LV-GLS = 6.3%) than for the cMR parameters (cMR-LVEF= 8.2% and cMR-RVEF= 12.9%). The superior interstudy reproducibility resulted in lower calculated sample sizes require by GLS compared with cMR to show clinically relevant changes in LV and RV function. (Figure 1) Conclusion LV and RV -GLS- STE has excellent interstudy reproducibility in normal hearts and is as good as cMR- LVEF and RVEF. Echocardiography cMR LV-GLS-STE RV-GLS-STE LVEF RVEF Mean difference ±SD 0.6 ± 1.88 0.5± 1.73 1.14 ± 5.22 0.98 ± 7.23 Coefficient of variation 7.7% 6.3% 8.2% 12.9% Sample Size for 2% absolute change in GLS or 5% absolute change in cMR- EF 18 16 22 44 Sample size required to detect a clinically significant change in global longidutdinal strain speckle tracking (GLS-STE) echocardiographie and cMR - ejection fraction (EF). RV and LV indicate Right ventricular and left ventricular respectively.

The Effect of Maximal Interval Training Sets on Metabolic Markers in Adolescent Competitive Swimmers

AIM: Although high-intensity interval sets are routinely used in the training regimen of competitive swimmers, information about the acute metabolic effects of such sets is lacking. Thus, the aim of the present study was to evaluate the effects of swimming training sets of maximal intensity and different volumes on blood metabolic markers in adolescent swimmers. MATERIAL & METHOD: Twenty-four adolescent competitive swimmers (12 female and 12 male) completed two training sets of 8 × 50 m and 8 × 25 m. Both sets were performed in freestyle, at maximal intensity and at a work-to-rest ratio of 1:1. They were spaced one week apart and were performed in a random and counterbalanced order. Blood samples were taken before, immediately after and one hour after both sets for the determination of glucose and uric acid (at all three time-points, spectrophotometrically), as well as irisin, insulin, glucagon, and cortisol (in pre- and immediately post-exercise samples, through enzyme immunoassays), in plasma. Three-way analysis of variance (set × time × gender) was used for the statistical analysis. The level of statistical significance was set at α = 0.05. RESULTS: Glucose was higher immediately post-exercise compared to pre- and 1 h post-exercise (p = 0.001). Uric acid was higher immediately and 1 h post-exercise (p < 0.001). Irisin exhibited a time × gender interaction (p = 0.005) due to the fact that exercise caused an increase in females and a decrease in males. Insulin, glucagon, and cortisol increased with exercise (p < 0.001). No gender effect was found for any of the markers except for uric acid, of which males had higher concentrations than females (p < 0.001). CONCLUSIONS: Maximal interval swimming sets induced remarkable increases in plasma glucose, uric acid, insulin, glucagon, and cortisol, suggesting a satisfactory metabolic effectiveness of such types of exercise training. Despite the difference in volume, the two training sets did not induce different metabolic responses in adolescent competitive swimmers. This is also true of blood lactate response, which has been presented previously.

Horospherical convex hypersurfaces contracting of the hyperbolic space by functions of the mean curvature

This paper concerns the evolution of a closed hypersurface of the hyperbolic space, convex by horospheres, in direction of its inner unit normal vector, where the speed equals a smooth function depending only on the mean curvature, and satisfies some further restrictions, without requiring homogeneity. It is shown that the flow exists on a finite maximal interval, convexity by horospheres is preserved and the hypersurfaces shrink down to a single point as the final time is approached. This generalizes the previous result [S. Guo, Convex hypersurfaces evolving by functions of the mean curvature, preprint (2016), arXiv:1610.08214 ] for convex hypersurfaces in the Euclidean space by the author to the setting in the hyperbolic space for the same class of flows.

Continuity of care in general practice at cancer diagnosis (COOC-GP study): a national cohort study of 2853 patients

BackgroundAt cancer diagnosis, it is unclear whether continuity of care (COC) between the patient and GP is safeguarded.AimTo identify patient–GP loss of COC around the time of, and in the year after, a cancer diagnosis, together with its determinants.Design and settingA post-hoc analysis of data from a prospective cohort of GPs in France, taken from a survey by the Observatoire de la Médecine Générale.MethodA prospective GP cohort (n = 96) filed data on patients who were diagnosed with incident cancer between 1 January 2000 and 31 December 2010. COC was assessed by ascertaining the frequency of consultations and the maximal interval between them. (In France, patients see their referring/named GP in most cases.) A loss of COC was measured during the trimester before and the year after the cancer diagnosis, and the results compared with those from a 1-year baseline period before cancer had been diagnosed. A loss of COC was defined as a longer interval (that is, the maximum number of days) between consultations in the measurement periods than at baseline. Determinants of the loss in COC were assessed with univariate and multivariate logistic regression models.ResultsIn total, 2853 patients were included; the mean age was 66.1 years. Of these, 1440 (50.5%) were women, 389 (13.6%) had metastatic cancer, and 769 (27.0%) had a comorbidity. The mean number of consultations increased up to, and including, the first trimester after diagnosis. Overall, 26.9% (95% confidence interval [CI] = 25.3 to 28.6) of patients had a loss of COC in the trimester before the diagnosis, and 22.3% (95% CI = 20.7 to 23.9) in the year after. Increasing comorbidity score was independently associated with a reduction in the loss of COC during the year after diagnosis (adjusted odds ratio [OR] comorbidity versus no comorbidity 0.61, 95% CI = 0.48 to 0.79); the same was true for metastatic status (adjusted OR metastasis versus no metastasis 0.49, 95% CI = 0.35 to 0.70).ConclusionAs COC is a core value for GPs and for most patients, special care should be taken to prevent a loss of COC around the time of a cancer diagnosis, and in the year after.

Image reconstruction algorithms for the microwave holographic vision system with reliable gap detection at theoretical limits

We present a reliable image reconstruction algorithm suitable for a microwave holographic vision system with several sensors coupled to the spin-diode based microwave detector and a single emission source. An objective is, by reconstructing the spatial microwave scattering density on the scene, to detect the presence and the nature of road obstacles impeding driving in the near vehicle zone. The idea of holographic visualization is to reconstruct the spatial microwave scattering density of an object by detecting an amplitude and phase of a reflected signal by lattice of sensors. We discuss versions of an algorithm, determine and analyse its resolution limits for various distances with different number of sensors for a one-dimensional test problem of detecting two walls (or posts) separated by a gap at a fixed distance. The maximal interval between sensors needed for a reliable reconstruction equals approximately Fresnel zone width. We show that maximal resolution achieved by our algorithm with an appropriate number of sensors was about 40% of Fresnel zone width for wall detection and about 30% of zone width for gap detection.

ESTIMATES OF POSITIVE NONTRIVIAL SOLUTIONS OF A DIFFERENTIAL EQUATION WITH POWER NONLINEARITY

Differential equations in paper with power nonlinearity are considered. Solutions which are defined in some neighborhood of plus infinity are called proper solutions. It is proved that propersolution to the equation is kneser solution, which means that solution and it’s quasiderivatives change their signs and tend to zero. The integral representation for proper solutions is proved. Upper estimates for solution and it’s quasiderivatives for proper solutions with maximal interval of existence is positive semiaxis to the equation with quasiderivative are proved. Upper and lowerestimates of solution and it’s derivatives for proper solutions with maximal interval of existence is positive semiaxis to the equation with derivative are provedDifferential equationsy[n] = rn(x)ddx(rn