Changes in classical kinematics and non‐linear parameters after a maximal 100‐m front‐crawl bout

In a linear system there is proportionality between input and output. Under this framework it is expected that the amount of change in sports performance must be proportional to variations in the inputs.info:eu-repo/semantics/publishedVersio

Topological Crystalline Insulators with C2C_2 Rotation Anomaly

Based on first-principles calculations and symmetry-based indicator analysis, we find a class of topological crystalline insulators (TCIs) with $C_2$ rotation anomaly in a family of Zintl compounds, including $\mathrm{Ba}_{3}\mathrm{Cd}_{2}\mathrm{As}_{4}$, $\mathrm{Ba}_{3}\mathrm{Zn}_{2}\mathrm{As}_{4}$ and $\mathrm{Ba}_{3}\mathrm{Cd}_{2}\mathrm{Sb}_{4}$. The nontrivial band topology protected by coexistence of $C_2$ rotation symmetry and time-reversal symmetry $T$ leads to two surface Dirac cones at generic momenta on both top and bottom surfaces perpendicular to the rotation axis. In addition, ($d-2$)-dimensional helical hinge states are also protected along the hinge formed by two side surfaces parallel with the rotation axis. We develop a method based on Wilson loop technique to prove the existence of these surface Dirac cones due to $C_2$ anomaly and precisely locate them as demonstrated in studying these TCIs. The helical hinge states are also calculated. Finally, we show that external strain can be used to tune topological phase transitions among TCIs, strong Z$_2$ topological insulators and trivial insulators.Comment: 10 pages, 10 figure

Polymorphisms of the _ENPP1_ gene are not associated with type 2 diabetes or obesity in the Chinese Han population

*Objective:* Type 2 Diabetes mellitus is a metabolic disorder characterized by chronic hyperglycemia and with a major feature of insulin resistance. Genetic association studies have suggested that _ENPP1_ might play a potential role in susceptibility to type 2 diabetes and obesity. Our study aimed to examine the association between _ENPP1_ and type 2 diabetes and obesity.

*Design:* Association study between two SNPs, rs1044498 (K121Q) and rs7754561 of ENPP1 and diabetes and obesity in the Chinese Han population.

*Subjects:* 1912 unrelated patients (785 male and 1127 female with a mean age 63.8 ± 9 years), 236 IFG/IGT subjects (83 male and 153 female with a mean age 64 ± 9 years) and 2041 controls (635 male and 1406 female with a mean age 58 ± 9 years).
 
*Measurements:* Subjects were genotyped for two SNPs using TaqMan technology on an ABI7900 system and tested by regression analysis.

*Results:* By logistic regression analysis, rs1044498 (K121Q) and rs7754561 showed no statistical association with type 2 diabetes, obesity under additive, dominant and recessive models either before or after adjusting for sex and age. Haplotype analysis found a marginal association of haplotype C-G (p=0.05) which was reported in the previous study.

*Conclusion:* Our investigation did not replicated the positive association found previously and suggested that the polymorphisms of _ENPP1_ might not play a major role in the susceptibility to type 2 diabetes or obesity in the Chinese Han population

The changes in fractal dimension after a maximal exertion in swimming

Quite often linear variables are not sensitive enough to explain the changes in the motor behavior of elite athletes. So, non-linear variables should be selected. The aim was to compare the fractal dimension before and after a maximal bout swimming front-crawl. Twenty-four subjects performed an all-out 100m trial swimming front-crawl. Immediately before (Pre-test) and after the trial (Post-test) a speed-meter cable was attached to the swimmer’s waist to measure the hip speed from which fractal dimension was derived. The fractal dimension showed a significant decrease with a moderate effect size between pre- and post-tests. Twenty-one out of 24 swimmers decreased the fractal dimension. As a conclusion, there is a decrease in the fractal dimension and hence in the swimming behavior complexity being under fatigue after a maximal trial.This research was funded by the grant NIE AcRF 11/13 TB.info:eu-repo/semantics/publishedVersio

High channel count and high precision channel spacing multi-wavelength laser array for future PICs

Multi-wavelength semiconductor laser arrays (MLAs) have wide applications in wavelength multiplexing division (WDM) networks. In spite of their tremendous potential, adoption of the MLA has been hampered by a number of issues, particularly wavelength precision and fabrication cost. In this paper, we report high channel count MLAs in which the wavelengths of each channel can be determined precisely through low-cost standard μm-level photolithography/holographic lithography and the reconstruction-equivalent-chirp (REC) technique. 60-wavelength MLAs with good wavelength spacing uniformity have been demonstrated experimentally, in which nearly 83% lasers are within a wavelength deviation of ±0.20 nm, corresponding to a tolerance of ±0.032 nm in the period pitch. As a result of employing the equivalent phase shift technique, the single longitudinal mode (SLM) yield is nearly 100%, while the theoretical yield of standard DFB lasers is only around 33.3%

The changes in classical and nonlinear parameters after a maximal bout to elicit fatigue in competitive swimming

The aim was to assess the effect of fatigue on linear and nonlinear parameters in swimming. Twenty-four fitness-oriented swimmers performed a maximal bout of 100m at front-crawl to elicit fatigue. Before (pre-) and immediately after (post-test) the bout, participants swam an allout 25m to derive the speed fluctuation (dv), approximate entropy (ApEn) and fractal dimension (FD) from the speed-time series collected by a speedo-meter. Swim speed was 10.85% slower in the post-test than in the pre-test (p < .001, η2=0.72). There was an effect of the fatigue on the dv with a moderate effect size. The dv increased shifting the 95CI band from 0.116–0.134 to 0.140–0.161. The ApEn showed non-significant variations between the pre- and post-test having the 95CI of pre- and post-test overlapped (pre: 0.659–0.700; post: 0.641–0.682). The FD showed as well a significant variation (the 95CI moved from 1.954–1.965 to 1.933–1.951). It can be concluded that in swimming there are changes in classical and nonlinear parameters under fatigue.This research was funded by the NIE AcRF grant (RI 11/13 TB)info:eu-repo/semantics/acceptedVersio

Changes in classical kinematics and non-linear parameters after a maximal 100-m front-crawl bout

In a linear system there is proportionality between input and output. Under this framework it is expected that the amount of change in sports performance must be proportional to variations in the inputs. However, as far as elite performance goes, this is not a straightforward assumption. Sometimes the variables selected are not sensitive enough. Hence, there is the need of having non-linear concepts underpinning such analysis. The aim was to compare classical kinematics and non-linear parameters after a maximal 100-m front-crawl bout. Twenty-four subjects (12 males and 12 females; 22.38±1.68-y) were invited to perform a 100-m freestyle race at maximal pace. Before (pre-test, i.e. rested) and immediately after (post-test, i.e. under fatigue) the maximal bout, they performed two maximal 25m swims at freestyle with push-off start. A speedo-meter cord (Swim speedo-meter, Swimsportec, Hildesheim, Germany) was attached to the swimmer’s hip (Barbosa et al., 2015) in the two 25m trials collecting the instantaneous speed. It was computed the speed fluctuation (dv; Barbosa et al., 2015), approximate entropy (ApEn; Barbosa et al., 2015) and fractal dimension (FD; Higuchi, 1988). Repeated measures ANOVAs (pre-test vs. post-test; P≤0.05), effect sizes (eta squared) and 95% of confidence intervals (95CI) were computed. The speed was 1.44±0.24 and 1.28±0.23m/s in the pre- and post/test, respectively (F=55.136, P<0.001)info:eu-repo/semantics/publishedVersio

Relations of Sex Hormone Levels to Leukocyte Telomere Length in Black, Hispanic, and Asian/Pacific Islander Postmenopausal Women

Background Sex hormones may play important roles in sex-specific biological aging. We specifically examined the associations between circulating concentrations of sex hormones and leukocyte telomere length (TL). Methods We conducted a cross-sectional study of 1124 black, 444 Hispanic, and 289 Asian/Pacific Islander women in the Women's Health Initiative Observational Cohort. Concentrations of estradiol and testosterone were measured using electrochemiluminescence immunoassays. TL was measured using quantitative PCR. Results Women included in the study were 50 to 79 years of age. Levels of estradiol were not significantly associated with TL in this sample of women. The associations between total and free testosterone and TL differed by race/ethnicity (P for interaction = 0.03 for total testosterone and 0.05 for free testosterone). Total and free testosterone concentrations were not associated with TL in black and Hispanic women, whereas in Asian/Pacific Islanders, their concentrations were inversely associated with TL (P-trend = 0.003 for both). These associations appeared robust in multiple subgroup analysis and multivariable models adjusted for potential confounding factors. In Asian/Pacific Islanders, doubling of serum free testosterone concentration was associated with 202 bp shorter TL (95% CI, 51 to 353 bp), and doubling of total testosterone concentration was associated with 203 bp shorter TL (95% CI, 50 to 355 bp). Conclusions Serum concentration of estradiol was not associated with leukocyte TL in this large sample of postmenopausal women. Total and free testosterone levels were inversely associated with TL in Asian/Pacific Islander women but not in black and Hispanic women, although future studies to replicate our observations are warranted particularly to address potential ethnicity-specific relations. The significant findings of the study This study elucidates the potential roles of sex hormones in biological aging, and identified that total and free testosterone levels were inversely associated with telomere length in Asian/Pacific Islander women but not in black and Hispanic women. The study adds The findings of this study suggest that Asian/Pacific Islander women may be susceptible to the potential detrimental effects of high testosterone level on biologic aging