Correlations between linear sprint with the ball, linear sprint without the ball, and change-of-direction without the ball in professional female soccer players.

The evolution of female soccer is related to the increase in high-intensity actions and choosing the abilities that best characterize the players' performance. Determining the capabilities that best describe the players' performance becomes essential for coaches and technical staff to obtain the results more efficiently within the competitive calendar. Thus, the study aimed to analyze the correlations between performance in the 20-m sprint tests with and without the ball and the Zigzag 20-m change-of-direction (COD) test without the ball in professional female soccer players. Thirty-three high-level professional female soccer players performed the 20-m sprint tests without a ball, 20-m sprint tests with the ball, and the Zigzag 20-m COD test without the ball. The shortest time obtained in the three trials was used for each test. The fastest time in the three trials was used for each test to calculate the average test speed. The Pearson product-moment correlation test was applied to analyze the correlation between the performance in the tests. Pearson's product-moment correlation test was used to analyze the correlation between the performance in the trials, with a significance level of α < 0.05. The average speed in the 20-m sprint tests with ball showed very large and significant correlations with the speed in the Zigzag 20-m COD test (r = 0.822; p < 0.001; 95% CI = 0.666 to 0.909). The 20-m sprint tests with ball and 20-m sprint tests without ball showed moderate, positive and significant correlation (r = 0.363; p = 0.038; 95% CI = 0.023-0.628). The tests of 20-m sprint tests without ball and Zigzag 20-m COD test also showed moderate, positive and significant correlation (r = 0.415; p = 0.016; 95% CI = 0.084-0.664). The female-female soccer players with a better ability to change direction may also have a better technical ability to drive the ball at high speed. However, they will not necessarily be the fastest in the linear sprint without the ball. Coaches and technical staff may choose to perform tests seeking efficiency and practicality, especially in a congested competitive period.

Follow the sound of my violin: Granger causality reflects information flow in sound.

Recent research into how musicians coordinate their expressive timing, phrasing, articulation, dynamics, and other stylistic characteristics during performances has highlighted the role of predictive processes, as musicians must anticipate how their partners will play in order to be together. Several studies have used information flow techniques such as Granger causality to show that upcoming movements of a musician can be predicted from immediate past movements of fellow musicians. Although musicians must move to play their instruments, a major goal of music making is to create a joint interpretation through the sounds they produce. Yet, information flow techniques have not been applied previously to examine the role that fellow musicians' sound output plays in these predictive processes and whether this changes as they learn to play together. In the present experiment, we asked professional violinists to play along with recordings of two folk pieces, each eight times in succession, and compared the amplitude envelopes of their performances with those of the recordings using Granger causality to measure information flow and cross-correlation to measure similarity and synchronization. In line with our hypotheses, our measure of information flow was higher from the recordings to the performances than vice versa, and decreased as the violinists became more familiar with the recordings over trials. This decline in information flow is consistent with a gradual shift from relying on auditory cues to predict the recording to relying on an internally-based (learned) model built through repetition. There was also evidence that violinists became more synchronized with the recordings over trials. These results shed light on the planning and learning processes involved in the aligning of expressive intentions in group music performance and lay the groundwork for the application of Granger causality to investigate information flow through sound in more complex musical interactions.

Creating a shared musical interpretation: Changes in coordination dynamics while learning unfamiliar music together.

The ability to coordinate with others is fundamental for humans to achieve shared goals. Often, harmonious interpersonal coordination requires learning, such as ensemble musicians rehearing together to synchronize their low-level timing and high-level aesthetic musical expressions. We investigated how the coordination dynamics of a professional string quartet changed as they learned unfamiliar pieces together across eight trials. During all trials, we recorded each musician's body sway motion data, and quantified the group's body sway similarity (cross-correlation) and information flow (Granger causality) on each trial. In line with our hypothesis, group similarity increased, while group information flow decreased significantly across trials. In addition, there was a trend such that group similarity, but not information flow, was related to the quality of the performances. As the ensemble converged on a joint interpretation through rehearsing, their body sways reflected the change from interpersonal information flow for coordinative mutual adaptations and corrections, to synchronous musical coordination made possible by the musicians learning a common internally based expressive interpretation.

A comparison of the internal and external load demands imposed on professional soccer referees in FIFA's current model of physical test in relation to games.

BACKGROUND: Based on the need to investigate the demands imposed on referees in the current model of physical evaluation and during professional games, this study's objective was to compare these demands in the physical test versus the games. METHODS: Thus, it evaluated the heart rate, distance covered, time, and speed of all 14 referees in the physical test and during Brazil's first division state championship games using a Global Positioning System enabled heart rate monitor. RESULTS: The maximum heart rate (HRmax) and maximum speed were higher in the physical test (183.86±12.79 bpm) and (26.80±0.96 km/h), respectively, than in the games (170.25±17.71 bpm) (P=0.008) and (24.27±1.68 km/h) (P=0.001), respectively. In the HRmax zone ≥90 and ≤100%, the time and percentage distance were greater in the physical test (47.87±16.60% and 58.57±22.78%), respectively, than in the games (17.82±18.29% and 18.84±18.92%, respectively; P<0.001). However, in the speed zone <13 km/h, the time and the percentage distance were longer in the game (93.73±1.26% and 86.13±2.31%), respectively, than in the physical test (68.73±12.31% and 39.65±9.74%, respectively; P<0.001). CONCLUSIONS: Thus, it is concluded that the professional referees perform at greater intensities during the physical test than in the games. In contrast, the demands for intensities corresponding to aerobic metabolism are greater in games or equal to those in physical testing, depending on the intensity reference.

Heart rate profile and heart rate variability in volleyball athletes: a systematic review with meta-analyses

Abstract Background: Physiological parameters can be objectively measured for controlling and quantifying physical activity levels. Aims: This study aimed to systematically review the literature on volleyball athletes' profile regarding heart rate (HR) and HR variability (HRV). Methods: PubMed, Scopus, Embase and SportDiscus databases were searched to find studies presenting resting HR, maximal HR, mean HR and time domain HRV during training sessions and matches. Results: Volleyball athletes' profile was HRrest 66 ± 2.5 bpm (minimum 41 ± 10 bpm; maximum 82.4 ± 2.1 bpm), HRmax was 184 ± 1.3 bpm (minimum 170 ± 8.0 bpm; maximum 192 ± 3.0 bpm), HRtraining data was in average 150 ± 12 bpm (minimum 124.8 ± 6.2 bpm; maximum 171.5 ± 11.0 bpm) and mean HRmatch was 154 ± 5.5 bpm (minimum 105.3 ± 12.8 bpm; maximum 182.3 ± 5.2 bpm). The RR interval data resulting in a mean value of 1096 ± 4 ms (minimum 1027.6 ± 168.9 ms; maximum 1097.0 ± 59.5 ms) and the rMSSD index presented a mean value of 44 ± 14 ms (minimum 42.2 ± 19.8 ms; maximum 93.2 ± 65.8 ms). SDNN data were extracted, however, no meta-analysis was performed. Conclusion: Resting HR were high for the athletes' fitness level, maximal HR and RR intervals were very similar to athletes from other sports. Mean HR data do not seem to represent the real physical demand in matches and training. HRV time domain index showed low values and could be related to training loads or fatigue situations.

Analyzing the Wave Nature of Hot Electrons with a Molecular Nanoprobe.

We report on a novel method, the molecular nanoprobe (MONA) technique, which allows us to measure the nanoscale quasiparticle transport between two arbitrary surface points. In these experiments, hot electrons are injected into the sample surface from the probe tip of a scanning tunneling microscope (STM) and detected by tautomerization switching events of a single deprotonated phthalocyanine (H2Pc) molecule. By making use of atom-by-atom-engineered interferometers on a Ag(111) surface, we demonstrate that the quantum-mechanical wave nature of hot electrons leads to characteristic oscillations of the molecule tautomerization probability. Two interferometers can be combined to build an energy-dependent selector, which allows it to selectively switch one out of two molecules without changing the position of the STM tip. The MONA technique is compared with conventional d I/d U measurements, where the injection and detection point of hot electrons is intrinsically tied to the same tip location.

Coronary stent occlusion after platelet transfusion: a case series.

Early stent occlusion after myocardial infarction is associated with increased morbidity and mortality, and antiplatelet drugs are applied to prevent these complications. We report on 3 patients with gastrointestinal bleeding or who were scheduled for emergency surgery and who received donor platelet transfusion early in the course after stenting. These patients had symptomatic coronary artery stenoses and were treated with antiplatelet therapy. Stent occlusion was diagnosed 6 to 17 hours after donor platelet transfusion, suggested by electrocardiographic and, in 1 patient, angiographic findings. One patient died of intractable bleeding from the gastrointestinal tract. Our observations emphasize the risks involved in platelet transfusion, and support withholding such therapy, unless vitally indicated, in patients who have undergone recent bare-metal coronary artery stent implantation.

Glucose-insulin-potassium echocardiography detects improved segmental myocardial function and viable tissue shortly after acute myocardial infarction.

Previous studies showed that glucose-insulin-potassium (GIK) increases cardiac output in patients after cardiac surgery and improves segmental myocardial wall motion. We hypothesized that GIK improves regional wall motion, detects contractile reserve, and predicts functional recovery at follow-up to a similar extent as low-dose dobutamine (LDD) in patients with recent myocardial infarction. Forty-one patients underwent LDD and GIK echocardiography. Data were analyzed according to a 13-segment model. Segments were scored from 0 (normokinesia) to 2 (a-/dyskinesia). Wall motion score index was calculated for baseline and intervention. During GIK, wall motion score index improved from 0.60 +/- 0.25 to 0.39 +/- 0.20 (P < .0001) and from 0.58 +/- 0.25 to 0.39 +/- 0.21 (P < .0001) during LDD. Overall agreement between GIK and LDD echocardiography to detect contractile reserve (improvement of segmental function by >or= 1 point) was 93% with a kappa value of 0.88. Sensitivity, specificity, and positive and negative predictive values of GIK echocardiography to predict functional recovery at follow-up (mean time to follow-up, 13 months) were 74%, 84%, 85%, and 72% respectively, and values were similar to LDD echocardiography. Thus, GIK infusion improves regional left ventricular function and allows the detection of myocardial viability to a similar extent as LDD in patients shortly after infarction.

Estradiol increases consumption of a chocolate cake mix in female rats.

Female Sprague-Dawley rats were given an opportunity to eat chocolate cake mix (CCM) using a common brand of cake mix, while standard laboratory food was also available. They took large amounts of the CCM, often taking more than 20 g in 24 h. Some animals were given a single injection of 1 of 6 doses of estradiol valerate (ranging from 0.09 to 10.0 mg/kg) and others were given vehicle. Estradiol valerate provides for sustained release of estradiol. Those receiving estradiol ate more than those receiving vehicle at doses larger than 0.09 mg/kg. Further, with a dose of 10 mg/kg, greater intake among estradiol-treated females was apparent 2 months post-injection. Methodological issues of neophobia and conditioned avoidance were addressed in the study's design and may explain why increased intakes were observed here in contrast to the consensus that estradiol reduces food intake.

Quantitative evaluation of myocardial perfusion in patients with revascularized myocardial infarction: comparison between intravenous myocardial contrast echocardiography and 99mTc-sestamibi single photon emission computed tomography.

AIMS: This two-center study compared quantitative segmental perfusion mapping by intravenous myocardial contrast echocardiography (ivMCE) and scintigraphy (SPECT) in patients in the subacute phase of myocardial infarction (AMI). METHODS AND RESULTS: Sixteen patients underwent ivMCE using 1:1 intermittent harmonic imaging 24 h after first AMI treated with PTCA and stenting. Apical contrast echocardiograms were obtained after the injections of Sonazoid. Baseline-corrected peak myocardial videointensity (bcPMVI) was determined automatically in 16 segments. Resting 99mTc-sestamibi SPECT was performed within one day after ivMCE. SPECT images were reoriented matching the ivMCE views, and divided into the same segments as in ivMCE, from which mean count rate values were obtained. After exclusion due to artifacts or attenuation, 208/256 (82%) segments remained for analysis. Normalized SPECT count rate and bcPMVI correlated linearly: bcPMVI = 1.237 x SPECT - 35; r = 0.74, p < 0.0001. The relation remained identical in subgroup analysis based on participating center, echocardiographic view, perfusion territory, infarct zone, or function. Using SPECT as reference, mean bcPMVI was 77+/-19% in normal segments, 53+/-29% in mild-moderate defects and 25+/-18% in severe defects (p<0.001 for all comparisons). CONCLUSION: The videointensity increase observed in quantitative ivMCE clearly correlated with SPECT tracer uptake. This further substantiates the use of ivMCE as a valid technique for myocardial perfusion imaging.

Use of arterialised venous instead of arterial blood for measurement of myocardial glucose metabolism during euglycaemic-hyperinsulinaemic clamping.

Sampling of arterialised venous blood (AVB) is often used as an alternative to sampling of arterial blood when determining the myocardial metabolic rate of glucose (MRGlu). This method, however, has not yet been validated for measurement of plasma fluorine-18 fluorodeoxyglucose (FDG) activity during a euglycaemic-hyperinsulinaemic clamp (EHC). In this study, dynamic FDG scans were performed with arterial blood sampling during EHC. Samples of arterial and AVB or venous blood were simultaneously withdrawn at five time points for measurement of FDG activity and plasma glucose in 36 patients. Both venous to arterial and AVB to arterial ratios were calculated for FDG activity and plasma glucose. Mean ratios between AVB and arterial FDG activity were then used to create calculated arterialised venous input functions from corresponding arterial input functions. The mean effect of arterialisation on the calculation of K(i) was assessed. In nine additional patients, K(i) obtained with continuous sampling of AVB was compared with K(i) obtained with a corresponding (quality-controlled) image-derived input function from the ascending aorta. Using AVB, measurements of FDG activity were much more reliable than with venous blood sampling. As compared with arterial sampling, however, FDG activity was underestimated early after injection, while it was overestimated after 20 min. In both analyses, AVB resulted in approximately 10%+/-10% overestimation of K(i). Because of a 5%+/-5% underestimation of plasma glucose concentration with AVB, the net effect on the final calculation of MRGlu was small (on average 5% overestimation). It is concluded that the use of AVB has a small average effect on the determination of MRGlu. This method does, however, contribute to variability in the results. This variability cannot be explained by different degrees of arterialisation.