95 research outputs found

    Multi-national perceptions on challenges, opportunities, and support structures for Dual Career migrations in European studentathletes

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    Despite Dual Careers (sports and education) and mobility of students being priorities in the funding policies of the European Commission, migrating student-athletes report severe challenges and decreased performance or dropouts at sport and academic levels. The objective of this study was to depict and assess the perceptions on challenges, support services, and their effectiveness in consideration of specific characteristics of participants and migrations. Based on a meta-synthesis and previous findings, a 50-items questionnaire was developed and completed by 245 student-athletes in 5 European countries. Participants with Dual Careers migration experience (n = 140) were considered for analyses of qualitative and quantitative (ordinal 5pt-Likert-scaled and metric) data on the Dual Career status, migration characteristics, received services, and outcomes. Chi-square-tests were conducted for differences between countries and genders at a significance level of p < .05. Country-related differences were found for experiences and intentions to migrate (X2(12) = 50.52, p<0.001), duration of the migration (X2(16) = 38.20, p = 0.001), financial support (X2(8) = 29.87, p<0.001), and decreased performances in academics (X2(16) = 56.12, p<0.001) and sports (X2(16) = 31.79, p = 0.01). Gender-related difference emerged in financial support (X2(4) = 10.68, p = 0.03), duration of the migration (X2(4) = 14.56, p = 0.01), and decreased academic performance (X2(4) = 10.57, p = 0.03). Tutoring and counselling support was ranked as the most effective support, especially when received from the academic field (4.0±1.0 pt) and others (4.1±0.8 pt), followed by online services from sport and academic sectors (both: 3.9±0.9 pt). Considering the pervasive globalization of sport and education, Dual Career migration can contribute to the development of a European sport culture. The high ratio of migrating student-athletes underlines the relevance of migrations in the field of Dual Careers. This study contributes to the literature by adding insights on practices, challenges, supports, and outcomes perceived by student-athletes migrating in Europe. Moreover, country- and gender-related differences support the consideration of specific characteristics and reveal critical factors in specific target groups. The findings contribute to identifying requirements and effective support measures in Dual Career migrations and can be used to improve support services

    Probing Real Sensory Worlds of Receivers with Unsupervised Clustering

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    The task of an organism to extract information about the external environment from sensory signals is based entirely on the analysis of ongoing afferent spike activity provided by the sense organs. We investigate the processing of auditory stimuli by an acoustic interneuron of insects. In contrast to most previous work we do this by using stimuli and neurophysiological recordings directly in the nocturnal tropical rainforest, where the insect communicates. Different from typical recordings in sound proof laboratories, strong environmental noise from multiple sound sources interferes with the perception of acoustic signals in these realistic scenarios. We apply a recently developed unsupervised machine learning algorithm based on probabilistic inference to find frequently occurring firing patterns in the response of the acoustic interneuron. We can thus ask how much information the central nervous system of the receiver can extract from bursts without ever being told which type and which variants of bursts are characteristic for particular stimuli. Our results show that the reliability of burst coding in the time domain is so high that identical stimuli lead to extremely similar spike pattern responses, even for different preparations on different dates, and even if one of the preparations is recorded outdoors and the other one in the sound proof lab. Simultaneous recordings in two preparations exposed to the same acoustic environment reveal that characteristics of burst patterns are largely preserved among individuals of the same species. Our study shows that burst coding can provide a reliable mechanism for acoustic insects to classify and discriminate signals under very noisy real-world conditions. This gives new insights into the neural mechanisms potentially used by bushcrickets to discriminate conspecific songs from sounds of predators in similar carrier frequency bands

    Matched Filters, Mate Choice and the Evolution of Sexually Selected Traits

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    Background Fundamental for understanding the evolution of communication systems is both the variation in a signal and how this affects the behavior of receivers, as well as variation in preference functions of receivers, and how this affects the variability of the signal. However, individual differences in female preference functions and their proximate causation have rarely been studied. Methodology/Principal Findings Calling songs of male field crickets represent secondary sexual characters and are subject to sexual selection by female choice. Following predictions from the “matched filter hypothesis” we studied the tuning of an identified interneuron in a field cricket, known for its function in phonotaxis, and correlated this with the preference of the same females in two-choice trials. Females vary in their neuronal frequency tuning, which strongly predicts the preference in a choice situation between two songs differing in carrier frequency. A second “matched filter” exists in directional hearing, where reliable cues for sound localization occur only in a narrow frequency range. There is a strong correlation between the directional tuning and the behavioural preference in no-choice tests. This second “matched filter” also varies widely in females, and surprisingly, differs on average by 400 Hz from the neuronal frequency tuning. Conclusions/Significance Our findings on the mismatch of the two “matched filters” would suggest that the difference in these two filters appears to be caused by their evolutionary history, and the different trade-offs which exist between sound emission, transmission and detection, as well as directional hearing under specific ecological settings. The mismatched filter situation may ultimately explain the maintenance of considerable variation in the carrier frequency of the male signal despite stabilizing selection

    Match running performance and physical capacity profiles of U8 and U10 soccer players

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    Aim This study aimed to characterize match running performance of very young soccer players and evaluate the relationship between these data and physical capacities and technical skills. Methods Distances covered at different speed thresholds were measured during 31 official matches using GPS technology in U10 (n = 12; age 10.1 ± 0.1 years) and U8 (n = 15; age 7.9 ± 0.1 years) national soccer players. Counter movement jump performance (CMJ), 20 m shuttle running (20 m-SR), linear sprint performance (10, 20, 30 m), shuttle (SHDT) and slalom dribble tests (SLDT) were performed to determine the players physical capacities and technical skills. Results Physical capacities and technical skills were higher in U10 versus U8 players [P 0.05, ES: 0.74). The U10 players covered more total (TD) and high-intensity running distance (HIRD) than their younger counterparts did (P 0.05, ES: 0.99). TD and HIRD covered across the three 15 min periods of match play did not decline (P > 0.05, ES: 0.02–0.55). Very large magnitude correlations were observed between the U8 and U10 players performances during the 20 m-SR versus TD (r = 0.79; P < 0.01) and HIRD (r = 0.82; P < 0.01) covered during match play. Conclusions Data demonstrate differences in match running performance and physical capacity between U8 and U10 players, and large magnitude relationships between match play measures and physical test performances. These findings could be useful to sports science staff working within the academies

    Finding Your Mate at a Cocktail Party: Frequency Separation Promotes Auditory Stream Segregation of Concurrent Voices in Multi-Species Frog Choruses

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    Vocal communication in crowded social environments is a difficult problem for both humans and nonhuman animals. Yet many important social behaviors require listeners to detect, recognize, and discriminate among signals in a complex acoustic milieu comprising the overlapping signals of multiple individuals, often of multiple species. Humans exploit a relatively small number of acoustic cues to segregate overlapping voices (as well as other mixtures of concurrent sounds, like polyphonic music). By comparison, we know little about how nonhuman animals are adapted to solve similar communication problems. One important cue enabling source segregation in human speech communication is that of frequency separation between concurrent voices: differences in frequency promote perceptual segregation of overlapping voices into separate “auditory streams” that can be followed through time. In this study, we show that frequency separation (ΔF) also enables frogs to segregate concurrent vocalizations, such as those routinely encountered in mixed-species breeding choruses. We presented female gray treefrogs (Hyla chrysoscelis) with a pulsed target signal (simulating an attractive conspecific call) in the presence of a continuous stream of distractor pulses (simulating an overlapping, unattractive heterospecific call). When the ΔF between target and distractor was small (e.g., ≤3 semitones), females exhibited low levels of responsiveness, indicating a failure to recognize the target as an attractive signal when the distractor had a similar frequency. Subjects became increasingly more responsive to the target, as indicated by shorter latencies for phonotaxis, as the ΔF between target and distractor increased (e.g., ΔF = 6–12 semitones). These results support the conclusion that gray treefrogs, like humans, can exploit frequency separation as a perceptual cue to segregate concurrent voices in noisy social environments. The ability of these frogs to segregate concurrent voices based on frequency separation may involve ancient hearing mechanisms for source segregation shared with humans and other vertebrates

    A life course examination of the physical environmental determinants of physical activity behaviour: A “Determinants of Diet and Physical Activity” (DEDIPAC) umbrella systematic literature review.

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    Background: Participation in regular physical activity is associated with a multitude of health benefits across the life course. However, many people fail to meet PA recommendations. Despite a plethora of studies, the evidence regarding the environmental (physical) determinants of physical activity remains inconclusive. Objective: To identify the physical environmental determinants that influence PA across the life course. Methods: An online systematic literature search was conducted using MEDLINE, ISI Web of Science, Scopus and SPORTDiscus. The search was limited to studies published in English (January 2004 to April 2016). Only systematic literature reviews (SLRs) and meta-analyses (MAs) of observational studies, that investigated the association between physical determinants and physical activity outcomes, were eligible for inclusion. The extracted data were assessed on the importance of determinants, strength of evidence and methodological quality. Results: The literature search identified 28 SLRs and 3 MAs on 67 physical environmental characteristics potentially related to physical activity that were eligible for inclusion. Among preschool children, a positive association was reported between availability of backyard space and outdoor toys/equipment in the home and overall physical activity. The availability of physical activity programs and equipment within schools, and neighbourhood features such as pedestrian and cyclist safety structure were positively associated with physical activity in children and adolescents. Negative street characteristics, for example, lack of sidewalks and streetlights, were negatively associated with physical activity in adults. Inconsistent associations were reported for the majority of reviewed determinants in adults. Conclusion: This umbrella SLR provided a comprehensive overview of the physical environment determinants of physical activity across the life course and has highlighted, particularly amongst youth, a number of key determinants that may be associated with overall physical activity. Given the limited evidence drawn mostly from cross-sectional studies, longitudinal studies are needed to further explore these associations

    From uni- to multimodality: towards an integrative view on anuran communication

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    Effects of a judo training on functional fitness, anthropometric, and psychological variables in old novice practitioners

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    This study aimed to investigate the effects of a 4-month judo training (1 hr session, biweekly) on physical and mental health of older adults (69.7 ± 4.2 years). Participants (N = 30) were assigned to a judo novice practitioners group (n = 16) or a control group (n = 14), which did not receive any training. Before and after the program, they underwent anthropometric (body mass index and waist and hip circumferences); functional fitness (upper and lower body flexibility and strength, coordination); and psychological assessments (perceived physical and mental health, body image, and fear of falling). The judo group showed reductions of waist circumference (Δ = -1%, d = 0.2) and improvements for lower and upper body flexibility (Δ = +69%, d = 0.4 and Δ = +126%, d = 0.5, respectively) and strength (Δ = +12%, d = 0.6 and Δ = +31%, d = 1.6, respectively). The control group showed a decline in lower body strength (Δ = -12%, d = 0.8). Psychological variables did not reveal statistically significant effects. Judo seems beneficial for improving anthropometric and functional fitness variables, relevant aspects of successful aging
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