Signals from predators, injured conspecifics, and pesticide modify the swimming behavior of the gregarious tadpole Rhinella dorbignyi (Anura: Bufonidae)

Abstract Background Our previous study on the 2016/2017 Serie A season showed that a greater likelihood of reaching the top positions in the Italian league “Serie A” seemed to be mainly related to sprint activity, goal attempts, total throws, target shots and assists. Therefore, we aim to evaluate the following season data in the same league to compare, confirm, and improve these results. Methods The data of all the matches played during the “Serie A” 2017–2018 season were obtained from the Italian soccer league. The teams’ analysis was performed in terms of total distance covered in km, jogging, running and sprint activities, average speed, and match statistics (total shots, shots on target, goal attempts, assists, turnovers, and steals). Results Teams that reached the first four positions revealed a lower percentage of running (65.98 ± 1.51 vs. 66.84 ± 2.18; p < 0.001), a higher percentage of jogging (25.61 ± 1.71 vs. 25.30 ± 1.97; p = 0.037) and sprint activities (8.41 ± 1.04 vs. 7.86 ± 0.82; p < 0.001). Match statistics seem to be statistically different between the first four teams the other teams. The total goals are strongly associated both with the total score at the end of the championship (R = 0.906; p < 0.001) and with the position in the final ranking (R = 0.850; p < 0.001). Conclusions Our results suggest that high-level teams have a lower running rate and a higher percentage of jogging and sprinting than other teams.

Most animals move intermittently, yet many proposed performance limitations of terrestrial locomotion are based on steady-state measurements and assumptions. We examined the effect of work-rest transitions by exercising the ghost crab, Ocypode quadrata (28.1 +/- 8.1 g), intermittently on a treadmill at 0.30 m/s, a supramaximal speed [i.e., greater than the speed that elicits the maximal rate of oxygen consumption (VO2)]. Duration of the exercise and pause periods, ratio of exercise to pause, and speed during the exercise period were varied to determine the effect on performance. Crabs fatigued after 7.5 min of continuous running, a distance capacity (i.e., total distance traveled before fatigue) of 135 m. When the task was done intermittently with 2-min exercise and 2-min pause periods, the crabs fatigued after 87 min (a total distance of 787 m), representing an 5.8-fold increase in distance capacity compared with continuous exercise at the same absolute speed (0.30 m/s) and a 2.2-fold increase in distance capacity compared with continuous exercise at the same average speed (0.15 m/s). Pause periods less than 30 s did not result in greater distance capacity compared with continuous exercise at the same average speed. Longer (3-5 min) and shorter exercise periods (less than or equal to 30 s) decreased distance capacity. Leg muscle lactate increased 10-fold to 15 mumol/g leg during intermittent exercise. However, significant amounts of lactate were cleared from the leg during the brief pause periods.(ABSTRACT TRUNCATED AT 250 WORDS)

ABSTRACT Most motile bacteria are able to bias their movement toward more favorable environments or to escape from obnoxious substances by a process called chemotaxis. Chemotaxis depends on a chemosensory system that is able to sense specific environmental signals and generate a behavioral response. Typically, the signal is transmitted to the bacterial flagellum, ultimately regulating the swimming behavior of individual cells. Chemotaxis is mediated by proteins that assemble into large, highly ordered arrays. It is imperative for successful chemotactic behavior and cellular competitiveness that chemosensory arrays form and localize properly within the cell. Here, we review how chemotaxis arrays form and localize in Vibrio cholerae and Vibrio parahaemolyticus. We focus on how the ParC/ParP system mediates cell cycle-dependent polar localization of chemotaxis arrays and thus ensures proper cell pole development and array inheritance upon cell division.

Background: The purpose of this study is to compare training load (TL) preceding a home versus away match in a top-class elite European team during the 2015–2016 season. Methods: Twenty elite outfield soccer players with a mean ± SD age, height and body mass of 25.9 ± 4.6 years, 183.1 ± 6.6 cm and 78.6 ± 6.6 kg, respectively, participated in this study. Total distance covered, high-speed running distance (HSRD), average speed (AvS), rating of perceived exertion (RPE) multiplied by training duration (s-RPE) and Hooper index (HI) were collected. Data from 24 weeks were analyzed through match-day minus/plus approach (MD-5, -4, -3, -2, -1, MD + 1). Results: All external TL variables indicated a decrease from MD-5 until MD-1 and then an increase to MD + 1 (p < 0.01). HI decreased from MD-5 to MD-1, but s-RPE increased until MD-3 and then decreased until MD + 1. When comparing TL data that preceded home matches versus away matches, for MD-5, HSRD and muscle soreness exhibited higher values when away match neared (p < 0.05). For MD-4 and MD-3, total distance, HSRD and AvS exhibited higher values closer to an away match than a home match (p < 0.05). For MD-1, total distances covered were higher closer to a home match than an away match (p < 0.01). For MD + 1, all HI items and AvS were higher when an away match was played (p < 0.05). Conclusions: This study confirms and provides evidence regarding the influence on internal and external TL data preceding home and away matches from a team that played in European competitions.

This article is a contribution to a special issue aiming at collecting data and documenting the different specificities of the teams which participated into Cybathlon 2016 FES-bike discipline. Our team prepared one paraplegic pilot over one year and developed a FES-cycling device based on existing commercial products. Our pilot (47 y.o, spinal cord lesion T3 AIS A since year 1995) was qualified for the final race and finished in 6th position over 12 participants in the discipline, covering a total distance of 750m at an average speed of 5.71km/h, propelled by his own quadriceps and hamstrings muscles.

Objective After optogenetics activing SNc DANs, locomotor activity ability of exercise-induced fatigue rats were recorded to research the role of nigra-striatum DA system in central mechanism of motor control. Methods Used male SD rats (220~240g), randomly divided into 6 groups: sham control group (SCG), optogenetics control group (OCG), fatigue group (FG), sham fatigue group (SFG) and optogenetics fatigue group (OFG). Virus ware injected in the right SNc at coordinates (AP:-5.30 mm, R: 2.00 mm, H-8.00 mm). The SCG/SFG injected 1 μ l saline, OCG/OFG injected 1 μl mixed virus(ChR2 with TH Cre,1:1), the fiber implantation site was deeper than the virus injection about 1 mm. Three weeks after surgery, rats attend 7D exhaustive treadmill exercise. After fatigue running, OCG/OFG/SCG/SFG were in the open field. We used two different light delivery schedules: 10 ms pulses at 20 Hz (10s) and 10 ms pulses at 3 Hz (10s). Sampling time were quiet state, 1D exhaustion, 7D exhaustion and recovery 24h. Animals were euthanized after completion of the behavioral tests. Brains were sectioned coronally in 50-μm slices, images were taken using a fluorescence microscope and determined the anatomical location of the optical fiber. Results (1) OCG/OFG obtain expression of ChR2 in DANs, this was not observed in SCG/SFG; Activation of OCG DANs with 20Hz increased the normalized mean global activity (laser on/laser off), and a significant increment in normalized mean global activity (laser on/laser off) when DANs were activated with 3Hz/20Hz in OFG (p<0.05), showing successful transfection of OCG/OFG. (2) Stimulation at 20 Hz was sufficient to improve global activity, the effects of 3 Hz did not significant, showing 20Hz stimulation possibility be related to motor regulation. (3)The global activity and total distance of rats after 7D exhaustion ware significantly lower than of quiet state (p<0.05), the difference from the quiet state and after 24h recovery is not significant, indicating that the decline in locomotor ability caused by exercise induced-fatigue is reversible. (4) The 20 Hz stimulation significantly improved the global activity of 1D and 7D exhausted rats (p<0.05), indicating that 20 Hz stimulation can effectively improve the rats locomotor activity with exercise-induced fatigue compared with 3 Hz stimulation. Conclusions (1) ChR2 virus transfection can effectively active the nigra-striatum DA system, causing changes in motor performance and increasing the locomotor ability of rats; (2) The locomotor ability of rats with exercise-induced fatigue to decrease. The total distance and global activity decreased significantly with exercise-induced fatigue; (3) Photoactivation of SNc DANs can improve the locomotor activity of rats with exercise-induced fatigue. From the perspective of stimulating effect, 20Hz is the most obvious activation reference point (NSFC: 31401018, SKXJX: 2014014, Corresponding [email protected]).

The aims of this study were to compare the external workload in win, draw and defeat matches and to compare first and second halves in the Iranian Premier League. Observations on individual match performance measures were undertaken on thirteen outfield players (age, 28.6 ± 2.7 years; height, 182.1 ± 8.6 cm; body mass, 75.3 ± 8.2 kg; BMI, 22.6 ± 0.7 kg/m2) competing in the Iranian Premier League. High-speed activities selected for analysis included total duration of matches, total distance, average speed, high-speed running distance, sprint distance, maximal speed and GPS-derived body load data. In general, there were higher workloads in win matches when compared with draw or defeat for all variables; higher workloads in the first halves of win and draw matches; higher total distance, high-speed running distance and body load in the second half in defeat matches. Specifically, lower average speed was found in matches with a win than with draw or defeat (p < 0.05). Sprint distance was higher in the first half of win than defeat matches and high-speed running distance was lower in draw than defeat matches (all, p < 0.05). In addition, first half presented higher values for all variables, regardless of the match result. Specifically, high-speed running distance was higher in the first half of matches with a win (p = 0.08) and total distance was higher in the first half of matches with a draw (p = 0.012). In conclusion, match result influences the external workload demands and must be considered in subsequent training sessions and matches.

We evaluated a computer-based learning environment that uses multiple representations to improve students' conception of the average speed of a round trip. The instruction explained that average speed is a weighted average of the component speeds in which the weights reflect the amount of time spent traveling at each speed. Students then improved their estimates of average speed by using visual feedback provided by a simulation. Correct answers and estimates were plotted on a graph to encourage students to discover the principle that average speed cannot be greater than twice the slower speed. A conceptual explanation (average speed as the ratio of total distance to total time) and an algebraic explanation (the limit of a function) helped integrate the multiple representations of the concept. Students' responses during the instruction and to a questionnaire provided useful information for improving the program, which was then reevaluated in a second study. The concluding discussion summarizes how the multiple representations were used in the instruction and examines the different functions of the representations based on Ainsworth's (1999) taxonomy.

Bacterial chemotaxis is a paradigm for how environmental signals modulate cellular behavior. Although the network underlying this process has been studied extensively, we do not yet have an end-to-end understanding of chemotaxis. Specifically, how the rotational states of a cell’s flagella cooperatively determine whether the cell ‘runs’ or ‘tumbles’ remains poorly characterized. Here, we measure the swimming behavior of individual E. coli cells while simultaneously detecting the rotational states of each flagellum. We find that a simple mathematical expression relates the cell’s run/tumble bias to the number and average rotational state of its flagella. However, due to inter-flagellar correlations, an ‘effective number’ of flagella—smaller than the actual number—enters into this relation. Data from a chemotaxis mutant and stochastic modeling suggest that fluctuations of the regulator CheY-P are the source of flagellar correlations. A consequence of inter-flagellar correlations is that run/tumble behavior is only weakly dependent on number of flagella.