scholarly journals Swimming kinematics and performance of spinal transected lampreys with different levels of axon regeneration

2021 ◽  
Author(s):  
Jacob. Fies ◽  
Brad J. Gemmell ◽  
Stephanie M. Fogerson ◽  
John H. Costello ◽  
Jennifer R. Morgan ◽  
...  
Keyword(s):  
Swimming Speed ◽  
Axon Regeneration ◽  
Swimming Performance ◽  
Body Wave ◽  
Body Waves ◽  
Wave Frequency ◽  
Behavioral Recovery ◽  
And Performance ◽  
The Relationship ◽  
Swimming Kinematics

AbstractNeural and functional recovery in lampreys from spinal cord transection has been well documented. However, the extent of axon regeneration is highly variable and it is not known whether it is related to the level of behavioral recovery. To address this, we examined how swimming kinematics were related to axon regeneration by quantifying the relationship between swimming performance and percent axon regeneration of transected lampreys after 11 weeks of recovery. We found that swimming speed was not related to percent axon regeneration but it was closely related to body wave frequency and speed. However, wave frequency and speed varied greatly within individuals which resulted in swimming speed also varying within individuals. In fact, most recovered individuals, regardless of percent axon regeneration, could swim at fast and slow speeds. However, none of the transected individuals were able to generate body waves as large as the control lampreys. In order to swim faster, transected lampreys increased their wave frequencies and, as a result, transected lampreys had much higher frequencies than control lamprey at comparable swimming velocities. These data suggest that the control lampreys swam more efficiently than transected lampreys. In conclusion, there appears to be a minimal recovery threshold in terms of percent axon regeneration required for lampreys to be capable of swimming, however, there also seems to be a limit to how much they can behaviorally recover.

scholarly journals Secondary Microseisms generated by typhoons in the Northwestern Pacific Ocean

2021 ◽  
Author(s):  
Nassima Benbelkacem ◽  
Eléonore Stutzmann ◽  
Martin Schimmel ◽  
Véronique Farra ◽  
Fabrice Ardhuin ◽  
...  
Keyword(s):  
Gravity Waves ◽  
Body Wave ◽  
Ocean Waves ◽  
Body Waves ◽  
Northwestern Pacific ◽  
Northwestern Pacific Ocean ◽  
Wave Reflections ◽  
Source Characteristics ◽  
Beamforming Technique ◽  
The Relationship

<p>Secondary Microseisms (SM) are recorded by seismometers in the period band 3-10 s. They are generated by the interaction of ocean gravity waves of similar frequencies and coming from nearly opposite directions. Typhoons create such ocean waves, and the purpose of this study is to investigate the relationship between typhoons and microseism source characteristics. We focused our study on the Northwestern Pacific and we analyzed seismic signals recorded by the Alaska array and the corresponding storm catalog. While P body waves enable to characterize the amplitude and the localization of the sources, secondary microseisms are dominated by surface waves. Therefore, we apply beamforming technique to the vertical components in order to highlight the weaker body wave signals. This analysis permits us to track the localization of SM sources every 6 hours. Our results show three cases: In the case of one active typhoon, the positions of SM sources are localized close to the typhoon position. In the case of two nearby typhoons acting simultaneously, the SM sources are localized in between the typhoons. Finally, when the typhoon arrives close to the coast, we observe sources generated by ocean wave reflections. In conclusion, the three mechanisms proposed by Ardhuin et al., (2011) are necessary to explain secondary microseisms generated by typhoons.</p>

The relationship between specific growth rate and swimming performance in male fathead minnows (Pimephales promelas)

1995 ◽  
Vol 73 (11) ◽  
pp. 2165-2167 ◽  
Author(s):  
Alan S. Kolok ◽  
James T. Oris
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Swimming Speed ◽  
Specific Growth ◽  
Swimming Performance ◽  
Pimephales Promelas ◽  
Significant Negative Correlation ◽  
Fathead Minnows ◽  
Critical Swimming Speed ◽  
The Relationship

The objective of this study was to test the hypothesis that the specific growth rate of male fathead minnows (Pimephales promelas) was positively correlated with swimming performance. Subadult fish were allowed to grow into adults over a period of 31 – 55 days, after which the critical swimming speed of each fish was determined. Variation in critical swimming speed was substantial (greater than 50%), and a significant positive correlation was found between number of growing days and critical swimming speed, whereas a significant negative correlation was found between specific growth rate and critical swimming speed. A multiple regression using specific growth rate and number of growing days explained over 47% of the variation in swimming performance. Fathead minnows that grow fast are poor swimmers, suggesting a trade-off between swimming performance and specific growth rate in this species.

Assessment of Body Composition and Sport Performance of Brazilian Paralympic Swim Team Athletes

2016 ◽  
Vol 25 (4) ◽  
pp. 364-370 ◽  
Author(s):  
Radamés M.V. Medeiros ◽  
Eduardo S. Alves ◽  
Valdir A. Lemos ◽  
Paulo A. Schwingel ◽  
Andressa da Silva ◽  
...  
Keyword(s):  
Body Composition ◽  
Outcome Measures ◽  
Fat Mass ◽  
High Performance ◽  
Swimming Performance ◽  
Sport Performance ◽  
Fat Percentage ◽  
Reduced Fat ◽  
And Performance ◽  
The Relationship

Context:Body-composition assessments of high-performance athletes are very important for identifying physical performance potential. Although the relationship between the kinanthropometric characteristics and performance abilities of Olympic swimmers is extremely important, this subject is not completely understood for Paralympic swimmers.Objective:To investigate the relationship between body composition and sport performance in Brazilian Paralympic swimmers 6 mo after training.Design:Experimental pre/posttest design.Setting:Research laboratory and field evaluations of swimming were conducted to verify the 50-m freestyle time of each athlete.Participants:17 Brazilian Paralympic swim team athletes (12 men, 5 women).Main Outcome Measures:Body-composition assessments were performed using a BOD POD, and swimming performance was assessed using the 50-m freestyle, which was performed twice: before and after 6 mo of training.Results:Increased lean mass and significantly reduced relative fat mass and swimming time (P < .05) were observed 6 mo after training. Furthermore, a positive correlation between body-fat percentage and performance (r = .66, P < .05) was observed, but there was no significant correlation between body density and performance (r = –.14, P > .05).Conclusions:After a 6-mo training period, Paralympic swimmers presented reduced fat mass and increased lean body mass associated with performance, as measured by 50-m freestyle time. These data suggest that reduced fat-mass percentage was significantly correlated with improved swimming performance in Paralympic athletes.

scholarly journals Swimming kinematics and performance of spinal transected lampreys with different levels of axon regeneration

2021 ◽  
Author(s):  
Jacob Fies ◽  
Brad J. Gemmell ◽  
Stephanie M. Fogerson ◽  
Jennifer R. Morgan ◽  
Eric D. Tytell ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Functional Recovery ◽  
Axon Regeneration ◽  
Swimming Performance ◽  
High Amplitude ◽  
Body Waves ◽  
Spinal Cord Transection ◽  
Neural Function ◽  
Lower Amplitude ◽  
Cord Injury

Axon regeneration is critical for restoring neural function after spinal cord injury. This has prompted a series of studies on the neural and functional recovery of lampreys after spinal cord transection. Despite this, there are still many basic questions remaining about how much functional recovery depends on axon regeneration. Our goal was to examine how swimming performance was related to degree of axon regeneration in lampreys recovering from spinal cord transection by quantifying the relationship between swimming performance and percent axon regeneration of transected lampreys after 11 weeks of recovery. We found that while swimming speeds varied, they did not relate to percent axon regeneration. In fact, swimming speeds were highly variable within individuals meaning that most individuals could swim at both moderate and slow speeds, regardless of percent axon regeneration. However, none of the transected individuals were able to swim as fast as the control lampreys. To swim fast, control lamprey generated high amplitude body waves with long wavelengths. Transected lampreys generated body waves with lower amplitude and shorter wavelengths than controls and to compensate, transected lamprey increased their wave frequencies to swim faster. As a result, transected lampreys had significantly higher frequencies than control lamprey at comparable swimming velocities. These data suggest that the control lampreys swam more efficiently than transected lampreys. In conclusion, there appears to be a minimal recovery threshold in terms of percent axon regeneration required for lampreys to be capable of swimming, however, there also seems to be a limit to how much they can behaviorally recover.

scholarly journals The relationship between visual function and performance in Para-swimming

2021 ◽  
Author(s):  
Daniel Fortin-Guichard ◽  
Rianne Ravensbergen ◽  
Kai Krabben ◽  
Peter M. Allen ◽  
David L. Mann
Keyword(s):  
Visual Field ◽  
Visual Function ◽  
Swimming Performance ◽  
Light Sensitivity ◽  
Start Time ◽  
Race Time ◽  
Straight Line ◽  
And Performance ◽  
Partially Sighted ◽  
The Relationship

Abstract Paralympic swimmers with vision impairment (VI) currently compete in one of three classes depending on their visual acuity (VA) and/or visual field. However, there is no evidence to suggest that a three-class system is the most legitimate approach for classification in swimming, or that the tests of VA and visual field are the most suitable. An evidence-based approach is required to establish the relationship between visual function and performance in the sport. Therefore, the aim of this study was to establish the relationship between visual function and performance in VI swimming. The swimming performance of 45 elite VI swimmers was evaluated during international competitions by measuring the total race time, start time, clean swim velocity, ability to swim in a straight line, turn time and finish time. Visual function was measured using a test battery that included VA, contrast sensitivity, light sensitivity, depth perception, visual search, and motion perception. Results revealed that VA was the best predictor of total race time, though the relationship was not linear. Decision-tree analysis suggested that only two classes were necessary for legitimate competition in VI swimming, with a single cut-off between 2.6–3.5 logMAR. No further significant association remained between visual function and performance in either of the two resulting classes. Results suggest that legitimate competition in VI swimming requires one class for partially sighted and another for functionally blind athletes.

Effects of temperature on sustained swimming performance and swimming kinematics of the chub mackerelScomber japonicus

2002 ◽  
Vol 205 (7) ◽  
pp. 969-980 ◽  
Author(s):  
Kathryn A. Dickson ◽  
Jeanine M. Donley ◽  
Chugey Sepulveda ◽  
Lisa Bhoopat
Keyword(s):  
Water Temperature ◽  
Swimming Speed ◽  
Swimming Performance ◽  
Energetic Cost ◽  
Published Data ◽  
Chub Mackerel ◽  
Fish Size ◽  
Effects Of Temperature ◽  
Swimming Kinematics ◽  
Tail Beat

SUMMARYThe effects of a 6°C difference in water temperature on maximum sustained swimming speed, swimming energetics and swimming kinematics were measured in the chub mackerel Scomber japonicus (Teleostei:Scombridae), a primarily coastal, pelagic predator that inhabits subtropical and temperate transition waters of the Atlantic, Pacific and Indian Oceans. New data for chub mackerel acclimated to 18°C are compared with published data from our laboratory at 24°C. Twelve individuals acclimated to each of two temperatures (15.6-26.3 cm fork length, FL, and 34-179g at 18°C; 14.0-24.7 cm FL and 26-156g at 24°C) swam at a range of speeds in a temperature-controlled Brett-type respirometer, at the respective acclimation temperature. At a given fish size, the maximum speed that S. japonicus was able to maintain for a 30-min period, while swimming steadily using slow, oxidative locomotor muscle (Umax,c),was significantly greater at 24 than at 18°C (52.5-97.5 cm s-1at 18°C and 70-120 cm s-1 at 24°C). At a given speed and fish size, the rate of oxygen consumption(V̇O2) was significantly higher at 24 than at 18°C because of a higher net cost of transport (1073-4617 J km-1 kg-1 at 18°C and 2708-14895 J km-1 kg-1 at 24°C). Standard metabolic rate, calculated by extrapolating the logV̇O2versus swimming speed relationship to zero speed, did not vary significantly with temperature or fish mass (126.4±67.2 mg O2 h-1 kg-1 at 18°C and 143.2±80.3 mg O2 h-1 kg-1 at 24°C; means ±S.D., N=12). Swimming kinematics was quantified from high-speed (120 Hz) video recordings analyzed with a computerized, two-dimensional motion-analysis system. At a given speed and fish size, there were no significant effects of temperature on tail-beat frequency, tail-beat amplitude or stride length, but propulsive wavelength increased significantly with temperature as a result of an increase in propulsive wave velocity. Thus, the main effects of temperature on chub mackerel swimming were increases in both Umax,c and the net cost of swimming at 24°C. Like other fishes, S. japonicus apparently must recruit more slow,oxidative muscle fibers to swim at a given sustainable speed at the lower temperature because of the reduced power output. Thus, the 24°C mackerel reach a higher speed before they must recruit the fast, glycolytic fibers,thereby increasing Umax,c at 24°C. By quantifying in vivo the effects of temperature on the swimming performance of an ectothermic species that is closely related to the endothermic tunas, this study also provides evidence that maintaining the temperature of the slow,oxidative locomotor muscle at 6°C or more above ambient water temperature in tunas should significantly increase sustainable swimming speeds, but also increase the energetic cost of swimming, unless cardiac output limits muscle performance.

The Influence of Cognitive and Affective Reactions to Feedback on Subsequent Goals

2010 ◽  
Vol 15 (2) ◽  
pp. 121-131 ◽  
Author(s):  
Remus Ilies ◽  
Timothy A. Judge ◽  
David T. Wagner
Keyword(s):  
Performance Feedback ◽  
Business School ◽  
Structural Equation ◽  
Emotional Reactions ◽  
Equation Model ◽  
Proposed Model ◽  
And Performance ◽  
Dispositional Measure ◽  
The Relationship ◽  
Reactions To Feedback

This paper focuses on explaining how individuals set goals on multiple performance episodes, in the context of performance feedback comparing their performance on each episode with their respective goal. The proposed model was tested through a longitudinal study of 493 university students’ actual goals and performance on business school exams. Results of a structural equation model supported the proposed conceptual model in which self-efficacy and emotional reactions to feedback mediate the relationship between feedback and subsequent goals. In addition, as expected, participants’ standing on a dispositional measure of behavioral inhibition influenced the strength of their emotional reactions to negative feedback.

Cognitive Factors Mediate the Relation Between Age and Flight Path Maintenance in General Aviation

2016 ◽  
Vol 6 (2) ◽  
pp. 81-90 ◽  
Author(s):  
Kathleen Van Benthem ◽  
Chris M. Herdman
Keyword(s):  
Cognitive Functioning ◽  
Flight Path ◽  
General Aviation ◽  
Cognitive Factors ◽  
Pilot Performance ◽  
Pilot Error ◽  
Age Related ◽  
And Performance ◽  
Relationship Of ◽  
The Relationship

Abstract. Identifying pilot attributes associated with risk is important, especially in general aviation where pilot error is implicated in most accidents. This research examined the relationship of pilot age, expertise, and cognitive functioning to deviations from an ideal circuit trajectory. In all, 54 pilots, of varying age, flew a Cessna 172 simulator. Cognitive measures were obtained using the CogScreen-AE ( Kay, 1995 ). Older age and lower levels of expertise and cognitive functioning were associated with significantly greater flight path deviations. The relationship between age and performance was fully mediated by a cluster of cognitive factors: speed and working memory, visual attention, and cognitive flexibility. These findings add to the literature showing that age-related changes in cognition may impact pilot performance.

Work Engagement and Research Output Among Female and Male Scientists

2016 ◽  
Vol 15 (2) ◽  
pp. 55-65 ◽  
Author(s):  
Lonneke Dubbelt ◽  
Sonja Rispens ◽  
Evangelia Demerouti
Keyword(s):  
Work Engagement ◽  
Research Output ◽  
Research Performance ◽  
Daily Work ◽  
Time Control ◽  
Science Technology ◽  
And Performance ◽  
And Mathematics ◽  
Number Of Publications ◽  
The Relationship

Abstract. Women have a minority position within science, technology, engineering, and mathematics and, consequently, are likely to face more adversities at work. This diary study takes a look at a facilitating factor for women’s research performance within academia: daily work engagement. We examined the moderating effect of gender on the relationship between two behaviors (i.e., daily networking and time control) and daily work engagement, as well as its effect on the relationship between daily work engagement and performance measures (i.e., number of publications). Results suggest that daily networking and time control cultivate men’s work engagement, but daily work engagement is beneficial for the number of publications of women. The findings highlight the importance of work engagement in facilitating the performance of women in minority positions.

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