Parasympathetic activity delayed after self-paced exercise

The main purpose of this study was to compare the effect of the constant load and self-paced exercise with similar total work on autonomic control after endurance exercise. Ten physically active men were submitted to (i) a maximal incremental exercise test, (ii) a 4-km cycling time trial (4-km TT), and (iii) a constant workload test with identical total external work performed at 4-km TT. Gas exchange was measured throughout the tests, while blood lactate, heart rate, and heart rate variability (HRV) were measured during the passive recovery. Power output measured at the last lap (i.e. 3600–4000?m) of 4-km TT (316?±?89?W) was statistically higher than power output measured at the end of the constant workload exercise (211?±?42?W). The 4-km TT produced higher values of blood lactate concentration (8.8?±?2.1?mmol?L^?1) than the constant workload test (7.8?±?2.1?mmol?L^?1). The heart rate recovery measured at 60?s (constant workload: 37?±?7?bpm; 4-km TT: 30?±?6) and 120?s (constant workload: 57?±?9?bpm; 4-km TT: 51?±?9?bpm) were higher in the constant workload than in the self-paced exercise. The HRV (i.e. RMSSD30s) was statistically higher in the constant load exercise measured at 120, 420, 450, 480, 540, and 570?s than the self-paced exercise. These findings suggest that the autonomic control responses were dependent of the endurance exercise modalities, with parasympathetic activity being delayed after self-paced exercise, as evidenced by post-exercise heart rate indices.     

Fast distributed algebraic connectivity estimation in large scale networks

This paper presents a distributed method to estimate the algebraic connectivity of fixed undirected communication graphs. The proposed algorithm uses bisection to estimate the second smallest eigenvalue of the Laplacian matrix associated to the graph. In order to decide the sub-interval in which the eigenvalue is contained, a distributed averaging algorithm based on Chebyshev polynomials is considered together with a max consensus algorithm. The information exchanged by neighbors in the graph each communication round is constant and independent of the size of the network, making it scalable to large networks. Besides, exploiting the convergence properties of Chebyshev polynomials we provide a direct estimation of the algebraic connectivity so that, instead of the midpoint of the bisection interval, the new approximation can be used. Finally, our algorithm also provides upper and lower bounds on the algebraic connectivity and an estimation of the Fiedler eigenvector associated to it. Simulations in large networks demonstrate the scalability and accuracy of the algorithm.     

A school-based motivational intervention to promote physical activity from a self-determination theory perspective

The authors analyzed the effects of a multidimensional intervention to promote physical activity (PA) in school, based on self-determination theory. The study involved 88 students, between 14 and 17 years old, who were divided into a control group (n = 59) and an experimental group (n = 29). In the experimental group, a 6-month intervention was conducted, applying a teaching unit of fitness and health in physical education (PE) classes, an extracurricular program of healthy PA, and meetings with families. Questionnaires were administered to measure different motivational variables and PA levels at four time points. Significant differences were found in favor of the experimental group in parental and peer autonomy support; integrated regulation in PE; autonomy, intrinsic, and identified regulation in leisure-time PA; moderate, hard, and very hard PA; and physical self-worth. Motivational effects were maintained over time but the effects on PA levels disappeared at 6 months.     

Memory for recent actions in the bottlenosed dolphin (Tursiops truncatus): Repetition of arbitrary behaviors using an abstract rule

Little is known about how animals represent their own actions in working memory. We investigated whether bottlenosed dolphins could recall actions they had recently performed and reveal those recollections using an abstract rule. Two dolphins were trained to respond to a specific gestural command by repeating the last behavior performed. Both dolphins proved to be able to repeat a wide variety of behaviors on command and were able to generalize the repeating rule to novel behaviors and situations. One dolphin was able to repeat all 36 behaviors she was tested on, including behaviors involving multiple simultaneous actions and self-selected behaviors. These results suggest that dolphins can flexibly access memories of their recent actions and that these memories are of sufficient detail to allow for reenactments. The repeating task can potentially be used to investigate short-term action and event representations in a variety of species.     

Can young infants add and subtract?

Three experiments (N = 68), using Wynn's procedure, tested 5-month-old infants' looking time reactions to correct and incorrect results of simple addition and subtraction transformations. The aim was to investigate both the robustness and the parameters of infants' arithmetic competence. Experiments 1 and 2 (N = 44) were replications of Wynn's first two experiments in which infants were shown addition (1 + 1 = 1 or 2) and subtraction (2 - 1 = 1 or 2) requiring imprecise calculation. Experiment 3 (N = 24) was a subtraction counterpart (3 - 1 = 1 or 2) to Wynn's third experiment requiring precise calculation of addition (1 + 1 = 2 or 3). Unlike Wynn, we found no systematic evidence of either imprecise or precise adding and subtracting in young infants. Our results, together with the mix of both positive and negative findings from other studies of infant arithmetic, suggest that infants' reactions to displays of adding and subtracting are variable and, therefore, that infants' numerical competencies are not robust. This conclusion is consistent with previous findings indicating that simple adding and subtracting develops gradually and continuously throughout infancy and early childhood.     

Science-based laboratory comprehension: an examination of effective practices within traditional,online and blended learning environments

An increase in online education is causing science educators to evaluate student cognitive understanding after completing virtual, computer-simulated laboratories. Online education has demonstrated comparable learning gains when analysed to those of the traditional classroom, but research is mixed when reviewing students’ ability to manipulate tangible laboratory equipment after participating in online experimentation. The question remains, are students who are exclusively enrolled in online science courses equipped with the cognitive ability to operate laboratory equipment within a physical laboratory? When considering the optimal learning environment for science majors, educators have discovered the blended classroom may provide the perfect opportunity to combine the benefits of face-to-face instruction and feedback with the reinforcement of scientific theory through technology integration. New advances in virtual education provide promising examples of enhancing the online classroom laboratory in all scientific disciplines. Further insight into the blended classroom has the potential to influence the field of education towards an optimal learning environment for science majors in colleges and universities.     

NASA-TLX for predictability and measurability of instructional design models: case study in design methods

Educational technology research and development - Innovation projects has established as an emerging field of research, a number of issues have emerged; among the others, measurability and...     

A shorter set reduces the loss of cardiac autonomic and baroreflex control after resistance exercise

Set configuration may affect the recovery pattern of cardiac vagal autonomic and reflex modulation after a resistance exercise, since it is closely associated with intensity and volume and determines the metabolic involvement of the session. We tested the hypothesis that longer set configurations have a higher impact on cardiac autonomic control and baroreflex sensitivity compared with shorter set configurations. We studied the effects of three set configurations with the same components of work on the cardiac autonomic control and baroreflex sensitivity. Seventeen subjects performed one control session and three experimental sessions of a leg-press exercise with the same volume (40 repetitions), resting time (720?s) and intensity (10RM load): (a) 5 sets of 8 repetitions with 3?min of rest between sets (8S), (b) 10 sets of 4 repetitions with 80?s of rest between sets (4S) and (c) 40 sets of 1 repetition with 18.5?s of rest between each repetition (1S). Longer set configurations (8S and 4S) induced greater reductions of the vagal cardiac autonomic control and baroreflex sensitivity (p?≤?.001) compared with a shorter set configuration (1S). Also, 1S had non-significant reductions versus the control session (p?>?.05). These findings suggest that a shorter set configuration can reduce the impact of resistance exercise on the post-exercise cardiac vagal autonomic control and baroreflex sensitivity.     

Exploring the Impact of Receiving Sender‐Based Negative and Positive Feedback on Team‐Level Process Outcomes Using a Mobile Application

Team‐based projects continue to be important for structuring work in many organizations, and employees are increasingly using mobile applications (apps) for peer evaluations as part of a performance appraisals process. Since a graduating student can expect to work in a team at some point in their career, exposure to class‐related group projects is important. This study explored using a mobile application (app) called DevelapMe (DMe), which allowed for 273 business undergraduates in 54 teams to give and receive real‐time peer‐based feedback during a 5‐week group project. Prior empirical research has shown that technology can improve the group development process, but such research has not used a mobile app. The general goal of this study was to investigate how receiving real‐time feedback through a mobile app (DMe) can affect the team development process over time. Two online surveys, Time 1 (T1) and Time 2 (T2), were administered over a 5‐week period. Results showed that two of the three team‐level process outcomes, team trust and team commitment (but not team value‐goal fit), significantly increased from T1 to T2. Results also showed that receiving T1 sender‐based positive, but not negative, feedback scales had a significant impact on all three team‐level process outcomes.     

Accounting for Students’ Schemes in the Development of a Graphical Process for Solving Polynomial Inequalities in Instrumented Activity

This paper provides an instrumental account of precalculus students’ graphical process for solving polynomial inequalities. It is carried out in terms of the students’ instrumental schemes as mediated by handheld graphing calculators and in cooperation with their classmates in a classroom setting. The ethnographic narrative relays an instrumental sociogenetic account of mathematical knowledge construction and foregrounds a progressive evolution of mathematical knowledge from the concrete to the abstract phase.