Not Breathing During the Approach Phase Ameliorates Freestyle Turn Performance in Prepubertal Swimmers

This study compared the effects of two breathing conditions during the freestyle turn approach phase in swimmers. Thirty-four prepubertal swimmers (mean ± SD: 10.59 ± 0.97 years) were divided into two groups: No Breath (NB), not breathing at the last stroke, and Breath Stroke (BS). Swimmers performed three turns with 5 min of rest between the repetitions. Kinematic parameters were recorded with two underwater and two surface cameras. Total turn time (NB: 9.31 ± 1.34 s; BS: 10.31 ± 1.80 s; p = 0.049), swim-in time (NB: 3.89 ± 0.63 s; BS 4.50 ± 0.79 s; p = 0.02) and rotation time (NB: 2.42 ± 0.29 s; BS: 3.03 ± 0.41 s; p = 0.0001) were significantly shorter and swim-in distance [NB: 0.70 (0.58,0.77) m; BS: 0.47 (0.34,0.55) m; p = 0.0001], glide distance (NB: 1.06 ± 0.21 m; BS: 0.70 ± 0.20 m; p = 0.0001) and surfacing distance [NB: 1.79 (1.19,2.24) m; BS: 1.18 (0.82,1.79) m; p = 0.043] were significantly longer in NB than in BS. Moreover, speed-in (NB: 1.04 ± 0.14 m/s; BS: 0.93 ± 0.14 m/s; p = 0.031) and push-off speed (NB: 2.52 ± 0.30 m/s; BS: 1.23 ± 0.20 m/s; p = 0.001) were significantly higher in NB than in BS. Swim-in time was positively and negatively correlated with rotation time and glide distance, respectively, whilst negative relationships between total turn time and swim-in distance, total turn time and surfacing distance and total turn time and speed-in were found. Our study showed that in prepubertal swimmers not breathing at the last stroke during the approach phase positively affected kinematic parameters of the turn, allowing to approach the wall faster, rotate the body quicker, increase push-off speed, reduce turn execution time, thus improving overall turn performance.

Dopamine release in nucleus accumbens core during social behaviors in mice

Social behaviors are among the most important and rewarding motivational behaviors. How dopamine, a "reward" signal, releases in the nucleus accumbens (NAc) during social behaviors has become a topic of interest for decades. However, limitations in early recording methods, such as microdialysis, prevented a complete understanding of moment-to-moment dopamine responses during social behaviors. Here, we employ a genetically encoded dopamine sensor, GRABDA2h, to record dopamine activity in the NAc core in mice and find acute changes in extracellular dopamine levels during all three phases of social behaviors: approach, investigation and consummation. Dopamine release during approach phase correlates with animal's motivation towards the conspecific whereas its release during consummatory phase signals the valence of the experience. Furthermore, dopamine release during sexual and aggressive behaviors shows sex differences that correlate with the potential value of those experiences. Overall, our results reveal rich and temporally precise motivation and value information encoded by NAc dopamine during social behaviors and beyond.

A Multidimensional Method for Pilot Workload Assessment and Diagnosis

INTRODUCTION: Pilot workload assessment plays an important role on flight safety evaluation, interface design, and airworthiness certification. The design of an effective and reliable workload assessment method is a difficult problem in the human factors field.METHOD: This study proposed to assess pilot workload from four dimensions: cognitive activity, control activity, stress, and flight performance. A set of physiological, behavioral, and flight parameters were recorded and combined hierarchically to achieve overall workload assessment. A simulated flight experiment consisting of three flight phases (standard instrument departure, autopilot cruise, and nonprecision approach) was conducted to test the effectiveness of the proposed workload assessment method.RESULT: Experimental results determined the changes of each objective measure. The overall workload index could significantly distinguish the difference in workload caused by changing task difficulty and the result was consistent with the NASA-TLX. The four workload dimensions provided detailed differences about workload: during nonprecision approach there were more control activities and stress than in other flight phases; during autopilot cruise there were the least control activities and the highest flight performance. The correlation between workload dimensions provided extra diagnostic information: the cognitive and control activities in the approach phase were more stressful than in the takeoff phase; the correlation between control activity and performance was higher in the approach phase than in the takeoff phase.CONCLUSION: This study proposed an effective pilot workload assessment method which could also provide detailed and diagnostic information. It could be used as an auxiliary tool for the development and evaluation of pilot-cockpit interaction.Wang Z, Lu Y, Fu S. A multidimensional method for pilot workload assessment and diagnosis. Aerosp Med Hum Perform. 2020; 91(12):932939.

Internal state transition to switch behavioral strategies in cricket phonotaxis

ABSTRACTAnimals employ multiple behavioral strategies for exploring food and mating partners based on both their internal state and external environment. Here, we examined how cricket phonotaxis, which was considered an innate reactive behavior of females to approach the calling song of conspecific males, depended on these internal and external conditions. Our observation revealed that the phonotaxis process consisted of two distinctive phases: wandering and approaching. In the latter phase, crickets moved directly towards the sound source. The transition into this phase, referred to as the ‘approach phase’, was based on changes in the animal's internal state. Moreover, retention of the approach phase required recognition of the calling song, while song loss downregulated cricket mobility and induced frequent stopping. This is a typical movement in local search behaviors. Our results indicate that phonotaxis is not only a reactive response but a complicated process including multiple behavioral strategies.

Safety Implications of GNSS Signal Interference at Zilina Airport

The paper deals with the issue of GNSS interference and its subsequent impact on airport approach procedures. It discusses the problem of GNSS signal interference and interference identification on a practical example of a small regional airport in Zilina, located close to the highway, through research aimed at its identification, a proposal for the location of a monitoring station and subsequent practical verification. The paper seeks to analyse and provide recommendations for enhancing safety and reliability in GNSS approaches. Given the need to develop the air transport, it is important to ensure the safety and continuity of service provision at small regional airports. The GNSS approach at airports with insufficiently equipped navigation infrastructure seems to be one of the most suitable. Introduction of the GNSS interference monitoring in the final instrument approach phase would increase the safety and reliability of the flight.