Simulated lights for an airfield model

A light at an aircraft landing site is simulated on a model board by the protruding output end of a precision cut optical fiber. The fiber is secured within a counterbore of a counterbored hole in the model board. The length of the precision cut fiber and the depth of the counterbore are closely controlled to ensure that the output end of the fiber protrudes a desired distance. The input end of the precision cut fiber is optically coupled to a collimated light source by a second optical fiber extending through the smaller diameter bore of the counterbored hole

Fictive Gill and Lung Ventilation in the Pre- and Postmetamorphic Tadpole Brain Stem

Torgerson, C. S., M. J. Gdovin, and J. E. Remmers. Fictive gill and lung ventilation in the pre- and postmetamorphic tadpole brain stem. J. Neurophysiol. 80: 2015–2022, 1998. The pattern of efferent neural activity recorded from the isolated brain stem preparation of the tadpole Rana catesbeiana was examined to characterize fictive gill and lung ventilations during ontogeny. In vitro recordings from cranial nerve (CN) roots V, VII, and X and spinal nerve (SN) root II of premetamorphic tadpoles showed a coordinated sequence of rhythmic bursts occurring in one of two patterns, pattern1, high-frequency, low-amplitude bursts lacking corresponding activity in SN II and pattern 2, low-frequency, high-amplitude bursts with coincident bursts in SN II. These two patterns corresponded to gill and lung ventilatory burst patterns, respectively, recorded from nerve roots of decerebrate, spontaneously breathing tadpoles. Similar patterns were observed in brain stem preparations from postmetamorphic tadpoles except that they showed a greater frequency of lung bursts and they expressed fictive gill ventilation in SN II. The laryngeal branch of the vagus (Xl) displayed efferent bursts in phase with gill and lung activity, suggesting fictive glottal constriction during gill ventilation and glottal dilation during lung ventilation. The fictive gill ventilatory cycle of pre- and postmetamorphic tadpoles was characterized by a rostral to caudal sequence of CN bursts. The fictive lung ventilatory pattern in the premetamorphic animal was initiated by augmenting CN VII discharge followed by synchronous bursts in CN V, X, SN II, and Xl. By contrast, postmetamorphic patterns of fictive lung ventilation were characterized by lung burst activity in SN II that preceded burst onset in CN V and followed the lead burst in CN VII. We conclude that recruitment and timing of pattern 1 and pattern 2 rhythmic bursts recorded in vitro closely resemble that recorded during spontaneous respiratory behavior, indicating that the two patterns are the neural equivalent of gill and lung ventilation, respectively. Further, fictive gill and lung ventilatory patterns in postmetamorphic tadpoles differ in burst onset latency from premetamorphic tadpole patterns and resemble fictive oropharyngeal and pulmonary burst cycles in adult frogs.</jats:p

EVALUATING IN-SCHOOL PHYSICAL ACTIVITY MOVEMENT PATTERNS IN RELATION TO STATE MANDATE

Riley Galloway1, Hunter Haynes1, Jacob Gdovin2, Junyoung Kim3. 1The University of Southern Mississippi, Hattiesburg, MS. 2Winthrop University, Rock Hill, SC. 3Missouri State University, Springfield, MO. Background: As evidence continues to grow strengthening the associations between morbidity and childhood obesity, school-based physical activity (PA) policies remain ill-defined, underfunded, and difficult for most schools to implement along with no accountability metric in place. A dramatic decline in PA participation with progressing school years testifies to the urgency for schools to implement mandatory policies for the accumulation of age appropriate moderate-to-vigorous PA (MVPA) for children. This study sought to quantify in-school PA levels among elementary students during recess, physical education (P.E.), and classroom movement integration. Methods: Third through sixth grade public school students (N=78: male=31, female=47) were asked to participate by donning an accelerometer (ActiGraph GT9X+, ActiGraph LLC, Pensacola, FL) on the right hip during school hours for 5 consecutive days. Tri-axial movement was recorded from 5-second ‘epochs’ and converted to minutes of PA according to previously established cut-points. PA logs were kept by teachers. All data was imported to ActiLife (v6.13.4) software and analyzed by one-way ANOVA using SPSS (version 24, Chicago, IL). Results: Results show students spent a concerning amount of time as sedentary during PA opportunities. During recess, 40.1% of offered time (336.9±23.1 min.) was completely sedentary. Combining sedentary and light categories accounted for 75.5% of recess. MVPA accounted for 24.8% of recess time (18.1±10.4 min./day). During P.E. opportunities (84.6±24.8 min.), 43.1% was considered completely sedentary while 75.6% of the time was accounted for when combining sedentary and light PA. Only 19.8% of P.E. was considered MVPA (3.9±4.1 min./day). Lastly, of classroom movement integration opportunities (10.9±12.6 min.), 38.1% was considered sedentary with 68.7% of the time accounted for by combining sedentary and light PA. A limited 3.1% was considered MVPA (0.6±1.2 min./day). Conclusions: Overall, students fell short of the mandate recommended 30 minutes of MVPA per day during school hours and the recommended amount of P.E. that should be at least moderate intensity. Due to a significant portion of childhood waking hours being spent in school, this information provides valuable insight to the PA levels and potential health status of children in school hours, which supports the need for enhanced attention to accountability of school-based PA

EXAMINING THE RELATIONSHIP BETWEEN LATERAL ROTATIONAL BROAD JUMPS AND BAT SPEED FOR COLLEGE BASEBALL PLAYERS

Brennen Hogan1, Colin Corcoran1, Jacob Gdovin2, Charles Williams1. 1University of North Flordia, Jacksonville, FL. 2Winthrop University, Rock Hill, SC. Strength professionals commonly incorporate field-based exercises designed to translate to a particular sport movement. Swinging a bat involves a complex, sequential movement pattern through multiple planes of movement. PURPOSE: The purpose of this study was to examine the relationship between lateral rotational jumps on bat velocity and peak hand speed in collegiate baseball players. METHODS: Thirteen college baseball players (age: 20.15 ± 1.77, height: 180.25 ± 6.74 cm, weight: 86.66 ± 10.77 kg) completed a baseline testing session of lateral rotational broad jumps. Athletes completed a dynamic warm-up followed by 2 attempts of lateral rotational broad jumps for lead and trail leg based on their respective batting stance. On a separate day, athletes took 5 swings with their game bat (33in/30 oz, 34in/31oz) off a tee with 20 seconds in between each swing to mimic the time between pitches. Each participant was instructed to step up into the batter’s box as they would in a practice/game situation while the investigator placed the tee in the middle of each of their respective strike zone based on batting stance. Each participant was instructed to hit a line drive over the shortstop or second baseman’s head depending on which side the athlete hit from. A blast motion sensor was used to collect swing metrics of each swing trial. The average of the 3 best swing attempts were taken based on bat velocity. Researchers collected and analyzed possible relationships between lateral rotational jumps of the lead and trail leg on swing outcomes of interest. A series of Pearson’s correlation coefficients were used at an alpha level of p&It.05 to determine if a significant relationship was found. RESULTS: A negative association was found in lateral rotational jumps of the trail leg on bat velocity of -.538 with a p&It.05. No other significant relationships were observed in lateral rotational jumps on the remaining swing outcomes. CONCLUSION: Strength professionals can use this data to incorporate multi-planar exercises in their programs to help aid in bat velocity

Ontogeny of Central Chemoreception During Fictive Gill and Lung Ventilation in an <i>In Vitro</i> Brainstem Preparation of <i>Rana Catesbeiana</i>

ABSTRACT An isolated brainstem preparation of the bullfrog tadpole, Rana catesbeiana, displays coordinated rhythmic bursting activities in cranial nerves V, VII and X in vitro. In decerebrate, spontaneously breathing tadpoles, we have previously shown that these bursts correspond to fluctuations in buccal and lung pressures and to bursts of activity in the buccal levator muscle H3a. This demonstrates that the rhythmic bursting activities recorded in vitro represent fictive gill and lung ventilation. To investigate the ontogeny of central respiratory chemoreception during the transition from gill to lung ventilation, we superfused the isolated brainstems of four larval stage groups with oxygenated artificial cerebrospinal fluid at various levels of . We measured shifts in the pattern of fictive respiratory output and the response to central hypercapnic stimulation throughout development. At normal (2.3 kPa), stage 3–9 tadpoles displayed rhythmic neural bursts associated with gill ventilation, while stages 10–14 and 15–19 tadpoles produced oscillating bursting activity associated with both gill and lung respiration, and tadpoles at stages 20–25 displayed neural activity predominantly associated with lung ventilation. In stage 3–9 tadpoles, variations in of the superfusate (0.5–6.0 kPa) caused almost no change in fictive gill or lung ventilation. By contrast, stage 10–14 tadpoles showed a significant hypercapnic response (P&amp;lt;0.05) in the amplitude and frequency of fictive gill ventilation, which was accompanied by a significant increase (P&amp;lt;0.05) in the burst amplitude and respiratory output of cranial nerve X over that occurring at all other stages. The amplitude and frequency of fictive gill ventilation in stages 15–19 increased significantly (P&amp;lt;0.05) in response to pH reduction, but became insensitive to hypercapnia at stages 20–25. The frequency of fictive lung ventilation was unresponsive to hypercapnia in stage 10–14, increased significantly by stage 15–19 (P&amp;lt;0.05) and became maximal (P&amp;lt;0.05) in stages 20–25. Overall, we describe the ontological development of central respiratory chemoreceptors driving respiratory output in the larval amphibian, demonstrating transfer in central chemoreceptive influence from gill to lung regulation during metamorphic stages. In addition, we provide novel evidence for the stimulatory influence of central chemoreceptors on fictive gill ventilation in response to CO2.</jats:p

PRESEASON VERSUS INSEASON WORKLOAD COMPARISON BY VELOCITY BAND IN MENS COLLEGIATE SOCCER

Dylan Wright1, Evan Kilby1, Jacob Gdovin2, Charles Williams1. 1University of North Florida, Jacksonville, FL. 2Winthrop University, Rock Hill, SC. BACKGROUND: The law of specificity underlies the importance of strength and conditioning which ensures athletes train to meet the demands of their respective sport. Monitoring tools such as Global Positioning Systems (GPS) aid professionals in prescribing individualized and categorized needs-based training loads to improve sport performance while also reducing the risk of injury. PURPOSE: The purpose of this study compared differences between preseason and in-season external workload metrics such as total distance traveled (TDT) and distance traveled within velocity distance bands (VDBs); defined by the manufacturer for collegiate male soccer players: Tier I-1-3 m/s, Tier II-3-5 m/s, Tier III-5-7 m/s, Tier IV-7-9 m/s. METHODS: Twenty-one (age: 19.6±1.2 years, height: 180.7±8.3 cm, mass: 75.6±7.4 kg) collegiate men’s soccer players participated in the current study. Workload data of practices and games were collected during a two-week preseason and ten-week in-season period using a 10Hz Titan 1+ (Integrated Bionics, Houston, Texas, USA - 2”x1.5”x.25”). GPS devices were secured by a jersey resting between the scapulae for every practice and competitive match. The sport coach activated and distributed the devices 15 minutes prior to each participant taking the field and was subsequently turned off following each session to standardized workload data across the competitive period. Paired samples t-tests were used to compare differences in TDT between preseason and in season periods. A 2x4 (Time [preseason, in-season]) X (VDBs [Tier I, II, III, IV]) repeated measures ANOVA with an alpha level of p\u3c0.05 was used for all analyses. Participants were removed from the analysis if they participated in \u3c75% of the total number of training sessions or matches (n=2) RESULTS: Significant differences (p\u3c.001) were observed between preseason TDT (19285.4±6419.6m) compared to in-season TDT (25714.3±6716.8m). Significant main effect differences (p\u3c.001) were seen in pre-season VBDs (Tier I: 1189.9±3856.7m, Tier II: 3294.5±1903m, Tier III: 572.2±419m, Tier IV: 63.9±63.1m) when compared to in-season VBDs (Tier I: 14840.7±3977.8m, Tier II: 4545.2±2323.8m, Tier III: 798.1±485.2m, Tier IV:73±69.7m). CONCLUSION: Coaches can utilize this data to monitor and alter individual and team workloads to attenuate soft tissue injuries that occur with overtraining and ensure off-season training are at intensities that match in-season demands

EXAMINING SPRINT DEMANDS DURING THE COMPETITiVE SEASON IN COLLEGIATE MENS SOCCER PLAYERS

Evan D. Kilby1, Dylan Wright1, Jacob Gdovin2, Charles C. Williams1. 1University of North Florida, Jacksonville, FL. 2Winthrop University, Rock Hill, SC. BACKGROUND: Significant advancements have been made in the field of sport science technology, allowing for methods of tracking objective measures longitudinally across an entire team. The sport of soccer is characterized by short bouts of intense sprints and high-speed distance running. Sprint and workload demand of players such as total sprint volume (TSV) provide implications for athletic personnel to prescribe appropriate, individual-based training loads. PURPOSE: The purpose of this study examined TSV differences over a full competitive season (preseason vs in-season) in collegiate male soccer players. TSV was measured by collecting sprint metrics of distance traveled ≥5.14 m/s for all practices and matches. Sprint count (SPC) was defined by the Titan sensor algorithm as the occurrence of an athlete reaching a minimum speed threshold during a session (≥5.14m/s for ≥1.5 seconds). METHODS: Twenty-one (age:19.6 ± 1.2years, height:180.7 ± 8.3cm, mass:75.6 ± 7.4kg) Division I collegiate male soccer players were monitored using wearable Global Positioning Systems (GPS) using a 10Hz Titan +1sensor (Houston, Texas, United States). Devices were secured by jerseys and rested between the scapulae of each participant during every training session and match across the competitive season (preseason: 2 weeks, in-season: 10 weeks). Sensors were activated and distributed by the assistant coach fifteen minutes prior to players taking the field to allow for adequate synchronization. Sensors were collected and turned off immediately following completion of a session. To ensure adequate session monitoring over this period, participants were excluded from analysis if \u3c75% of the total number of practice sessions or matches were not recorded (n=2). A series of Paired samples t-tests with an alpha level set at p\u3c0.05 were used to compare differences in sprint outcomes between preseason and in-season time periods. RESULTS: Significant differences (p\u3c.01) between preseason TSV (878.4±655.9m) and in-season TSV (1179.6 ± 737.3m) were present. Significant differences in total SPC were also observed between pre-season (41.9 ± 30.2) vs in season (54.9 ± 34.7) (p\u3c.01). CONCLUSION: This study provides sport coaches and strength and conditioning staff with workload reports that can aid in the development of training programs based on varying demands including an athlete’s position and timeline of competitive seasons