Social gaze cueing elicits facilitatory and inhibitory effects on movement execution when the model might act on an object

Social cues, such as eye gaze and pointing fingers, can increase the prioritization of specific locations for cognitive processing. A previous study using a manual reaching task showed that, although both gaze and pointing cues altered target prioritization (indexed via reaction times [RTs]), only pointing cues affected action execution (indexed via trajectory deviations). This discrepancy in the effects of gaze and pointing cues on action execution could be because the gaze cue was conveyed through a disembodied head; hence, the model lacked the potential for a body part (i.e., hands) to interact with the target. In the present study, the image of a male gaze model, whose gaze direction coincided with two potential target locations, was centrally presented. The model either had his arms and hands extended underneath the potential target locations, indicating the potential to act on the targets (Experiment 1) or had his arms crossed in front of his chest, indicating a lack of potential to act (Experiment 2). Participants reached to a target that followed a nonpredictive gaze cue at one of three stimulus onset asynchronies (SOA; 100, 350, or 850ms). RTs and reach trajectories of the movements to cued and uncued targets were analyzed. RTs showed a facilitation effect for both Experiments 1 and 2, whereas trajectory analysis revealed facilitatory and inhibitory effects, depending on the SOA, but only in Experiment 1. Results of this study confirmed that when the gaze model has the potential to interact with the cued target location, the model’s gaze would not only affect target prioritization, but also movement execution

Extra-cellular matrix proteins induce matrix metalloproteinase-1 (MMP-1) activity and increase airway smooth muscle contraction in asthma

Airway remodelling describes the histopathological changes leading to fixed airway obstruction in patients with asthma and includes extra-cellular matrix (ECM) deposition. Matrix metalloproteinase-1 (MMP-1) is present in remodelled airways but its relationship with ECM proteins and the resulting functional consequences are unknown. We used airway smooth muscle cells (ASM) and bronchial biopsies from control donors and patients with asthma to examine the regulation of MMP-1 by ECM in ASM cells and the effect of MMP-1 on ASM contraction. Collagen-I and tenascin-C induced MMP-1 protein expression, which for tenascin-C, was greater in asthma derived ASM cells. Tenascin-C induced MMP-1 expression was dependent on ERK1/2, JNK and p38 MAPK activation and attenuated by function blocking antibodies against the β1 and β3 integrin subunits. Tenascin-C and MMP-1 were not expressed in normal airways but co-localised in the ASM bundles and reticular basement membrane of patients with asthma. Further, ECM from asthma derived ASM cells stimulated MMP-1 expression to a greater degree than ECM from normal ASM. Bradykinin induced contraction of ASM cells seeded in 3D collagen gels was reduced by the MMP inhibitor ilomastat and by siRNA knockdown of MMP-1. In summary, the induction of MMP-1 in ASM cells by tenascin-C occurs in part via integrin mediated MAPK signalling. MMP-1 and tenascin-C are co-localised in the smooth muscle bundles of patients with asthma where this interaction may contribute to enhanced airway contraction. Our findings suggest that ECM changes in airway remodelling via MMP-1 could contribute to an environment promoting greater airway narrowing in response to broncho-constrictor stimuli and worsening asthma symptoms

Relationship Between Body Mass Index and Hydration Status in Air Force ROTC Cadets

The Air Force Reserve Officer Training Corps (AFROTC) program prepares young individuals for their future as officers in the United States Air Force. This is a unique population because these cadets are college students who must maintain physical fitness through regular group exercise training. Previous research has identified that proper hydration is important to optimize training sessions. However, it is unknown whether the body size of this population is connected to their hydration status before and after exercise. PURPOSE: To examine the relationship between body mass index (BMI) and hydration status and the differences between BMI classifications of AFROTC cadets. METHODS: Eighteen (13 male and 5 female) AFROTC cadets volunteered for this study (mean ± SD; age: 21.4 ± 3.2 y, height: 168.6 ± 6.3 cm, body mass: 67.3 ± 10.3 kg). Before training, height was measured with a stadiometer, and nude body mass was measured with an electronic scale. BMI was expressed as kg·m-2. Hydration status was determined with analysis of urine specific gravity (USG) through a urine sample collected before and after exercise. RESULTS: There was no correlation between BMI and pre-exercise USG (r= -0.116, p= 0.646) and post-exercise USG (r= -0.224, p= 0.372). There was no difference in USG between normal and overweight cadets before exercise (normal weight USG: 1.024 ± 0.007, overweight USG: 1.022 ± 0.004; t(16) = 0.777, p = 0.448) and after exercise (normal weight USG: 1.021 ± 0.007, overweight USG: 1.018 ± 0.004; t(16) = 0.916, p = 0.373). CONCLUSION: There was no relationship between BMI and hydration status. There was also no difference in hydration status between normal and overweight cadets. The normal weight group remained above the 1.020 threshold, while the overweight group dropped below 1.020 suggesting their hydration status may have improved through voluntary fluid intake during exercise. Future research should examine the relationship between BMI and hydration status amongst other BMI categories (as our study excluded underweight & obese groups) and study the drinking behaviors of the differing groups

Relationship Between Exercise Intensity and Voluntary Fluid Intake in Air Force ROTC Cadets

Air Force ROTC cadets are college students simultaneously receiving training to serve as officers in the United States Air Force. Regular group exercise is part of this training program, and good hydration habits would be conducive to optimizing the exercise sessions. However, it is unclear whether exercise intensity might influence this special population\u27s voluntary drinking behaviors in a manner that is sufficient for optimizing exercise training sessions. PURPOSE: Therefore, the purpose of this study was to examine the relationship between exercise intensity and voluntary fluid intake in Air Force ROTC cadets during a typical training session. METHODS: Nine male and 2 female Air Force ROTC cadets (mean ± SD; age: 22 ± 3 y, height: 170.0 ± 5.1 cm, mass: 71.2 ± 9.5 kg) were fitted with heart rate (HR) monitors prior to exercise. Intensity was expressed as a percentage of HR reserve. A hydration station was set up in the exercise area where water bottles were made readily available. Fluid intake was calculated as the difference in the water bottle mass before and after the exercise session. RESULTS: During the 60-min exercise session, participants exercised at a moderate intensity based on a percentage of HR reserve (50.1 ± 10.2%) with a mean HR of 129 ± 15 beats·min-1. Mean voluntary fluid intake volume was 404.5 ± 168.2 mL. There was no correlation between fluid intake volume and exercise intensity (r = 0.186, p = 0.584). CONCLUSION: It is possible that another mechanism stronger than exercise intensity would stimulate the thirst mechanism to drive voluntary fluid intake. It is also possible the cadets did not have sufficient fluid breaks, although this was not tracked in the current study. This study lends further support of incorporating structured water breaks and individualized hydration strategies during exercise training, especially for cadets training to become tactical operators

Correlation Between Voluntary Fluid Intake and Sweat Rate of Air Force ROTC Cadets During Outdoor Exercise

The Air Force Reserve Officer Training Corps (ROTC) is a training program that gives individuals the opportunity to become leaders in and outside of the classroom while they prepare for their careers as officers in the United States Air Force or Space Force. This is a unique group of college students training to become tactical operators, which involves participating in regular group physical training. To optimize training, cadets should incorporate proper hydration strategies. Ideally, fluid intake volume should match sweat losses, however ROTC cadets’ hydration practices remain unclear. PURPOSE: The purpose of this study was to examine the relationship between voluntary fluid intake and whole-body sweat rate (WBSR) of Air Force ROTC cadets during a typical outdoor exercise session to determine whether their hydration behaviors are appropriate. METHODS: Five men and three women (mean ± SD; 22 ± 3 y, 168.3 ± 4.7 cm, 68.2 ± 9.5 kg) completed their regular 60-min training session in outdoor conditions. Nude body mass was measured before and after exercise to determine whole-body sweat rate. Water bottles were made readily available in the exercise area, and cadets drank voluntarily. Fluid intake was quantified as the difference in the water bottle weight before and after exercise. RESULTS: Mean voluntary fluid replenishment (309.5 ± 208.9 mL) during the 60-min exercise bout did not match mean sweat rate (407.5 ± 89.2 mL/h). There was no correlation between fluid intake volume and whole-body sweat rate (r = 0.234, p = 0.576). CONCLUSION: When cadets were drinking voluntarily, this was not sufficient to replace sweat loss during the exercise bout, and there was no relationship between how much they drank and how much they sweated. This study lends support to previous reports that voluntary fluid intake is insufficient to replace sweat losses. Moreover, there might be other mechanisms that influence voluntary fluid ingestion other than whole-body sweat rate. While this population is undergoing physical training for a unique purpose, this study shows that their drinking behaviors are not different from other types of exercisers

Social gaze cueing elicits facilitatory and inhibitory effects on movement execution when the model might act on an object

Social cues, such as eye gaze and pointing fingers, can increase the prioritization of specific locations for cognitive processing. A previous study using a manual reaching task showed that, although both gaze and pointing cues altered target prioritization (indexed via reaction times [RTs]), only pointing cues affected action execution (indexed via trajectory deviations). This discrepancy in the effects of gaze and pointing cues on action execution could be because the gaze cue was conveyed through a disembodied head; hence, the model lacked the potential for a body part (i.e., hands) to interact with the target. In the present study, the image of a male gaze model, whose gaze direction coincided with two potential target locations, was centrally presented. The model either had his arms and hands extended underneath the potential target locations, indicating the potential to act on the targets (Experiment 1) or had his arms crossed in front of his chest, indicating a lack of potential to act (Experiment 2). Participants reached to a target that followed a nonpredictive gaze cue at one of three stimulus onset asynchronies (SOA; 100, 350, or 850ms). RTs and reach trajectories of the movements to cued and uncued targets were analyzed. RTs showed a facilitation effect for both Experiments 1 and 2, whereas trajectory analysis revealed facilitatory and inhibitory effects, depending on the SOA, but only in Experiment 1. Results of this study confirmed that when the gaze model has the potential to interact with the cued target location, the model’s gaze would not only affect target prioritization, but also movement execution

Effect of Daily Training on Hydration Status of Elite Marching Arts Performers: A Pilot Study

Every year, elite groups of of marching arts performers travel across the United States during the summer months of June through August, where they encounter different climates. Daily training for marching arts performers often takes place outdoors in the heat, but it is unclear what these individuals experience with regard to their hydration levels. PURPOSE: The purpose of this study was to investigate daily changes in hydration status among marching arts performers. METHODS: For this pilot investigation, we studied 3 men and 1 woman (mean ± SD; age: 20 ± 1 y, height: 174.1 ± 4.6 cm, body mass: 70.0 ± 8.6 kg) and completed measurements on three training sessions, across three consecutive days. To assess their hydration status, urine samples were collected before and after a 4-hour training block for urine specific gravity (USG) analysis. RESULTS: There was no interaction between Day (1-3) and Time (p = 0.519; Day 1-Pre: 1.022 ± 0.002, Post: 1.012 ± 0.010; Day 2-Pre: 1.024 ± 0.002, Post: 1.018 ± 0.006; Day 3-Pre: 1.025 ± 0.004, Post: 1.020 ± 0.004), and there was no main effect of Time (p = 0.069). There was a main effect of Day (p = 0.021), with post-hoc analyses revealing that USG was significantly higher on Day 3 (1.022 ± 0.003) compared to Day 1 (1.017 ± 0.008). CONCLUSION: This pilot study suggests that these elite level performers progressively became more hypohydrated with each day of training. Further exploration of this topic should elucidate the magnitude of dehydration experienced by these individuals with daily training, which should help exercise professionals create more individualized hydration plans

HOMOLOGY MODELING AND MOLECULAR DYNAMICS STUDIES OF THE OLIGOPEPTIDASE B FROM SERRATIA PROTEAMACULANS. INSIGHTS INTO THE ENZYMATIC ACTIVATION MECHANISM

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Correlation Between Pre-Exercise Hydration Status and Heart Rate of Female Division II Collegiate Distance Runners During a Training Session

Female athletes participating in Division II collegiate sports are an understudied population. While athletes’ pre-exercise hydration status is known to have an important impact on a variety of performance metrics, it is unknown whether their pre-exercise hydration is associated with heart rate responses during a subsequent exercise bout. PURPOSE: The purpose of this study was to examine the correlation between pre-exercise hydration status and exercise heart rate (HR) of female distance runners on a Division II collegiate track and field team. METHODS: 8 female distance runners (Mean ± SD; age: 21 ± 1.8 y, height: 161.2 ± 10.8 cm, mass: 54.7 ± 7.9 kg) provided a urine sample for urine specific gravity (USG) analysis prior to two team training sessions. Exercise HR was recorded with an HR monitor during two separate training sessions, one indoors and one outdoors. RESULTS: Pre-exercise USG was not different between sessions (indoors: 1.021 ± 0.006; outdoors: 1.019 ± 0.008; t(7) = 0.64, p = 0.542). Mean HR during exercise was also not different between sessions (indoors: 169 ± 17 beats/min; outdoors: 172 ± 12 beats/min; t(7) = -1.00, p = 0.349). There was no significant correlation between pre-exercise USG and session HR for either session (indoors: r = -0.121, p = 0.776; outdoors: r = 0.447, p = 0.267). CONCLUSIONS: In this study, an individual’s hydration status at exercise onset was not related to mean HR during the exercise bout. It is possible that the homogeneity of this sample of trained runners with similar pre-exercise hydration states near borderline hypohydration might have given a limited view of the relationship between the two variables. Exercise professionals should continue to encourage athletes in this level of competition to begin exercise in a well hydrated state as research on this population continues to develop

Relationship Among BMI, Body Surface Area, Fluid Intake, and Sweat Rate on Elite Marching Arts Performers: A Pilot Study

Elite groups of marching arts performers train at various intensities for long durations. They travel the country through a variety of climates, making hydration an important consideration. PURPOSE: The purpose of our pilot study was to evaluate the relationships between body mass index (BMI), body surface area (BSA), fluid intake, and sweat rate in elite marching arts performers. METHODS: We sampled 6 male and 1 female elite marching arts performers (mean ± SD; age: 20 ± 1 y, height: 177.0 ± 6.0 cm, body mass: 72.3 ± 9.1 kg). BMI was calculated by collecting height on a stadiometer and nude body mass on an electronic scale. Nude body mass was taken before and after participants’ rehearsal block to calculate sweat rate. Pre-measured water containers were provided to participants to track fluid intake. BSA was calculated using the DuBois formula. RESULTS: There were statistically significant, strong positive correlations between BMI and sweat rate (r = 0.838, p = .019), fluid intake and sweat rate (r = 0.776, p = .040), and fluid intake and BSA (r = 0.865, p = .012). While there were strong positive correlations between BMI and fluid intake (r = 0.755, p = .050), as well as between sweat rate and BSA (r = 0.721, p = .067), these were not statistically significant. DISCUSSION: This population of elite performers has been under-studied and learning about them would benefit their safety and performance. Part of the intention of the current pilot study was to determine if it was feasible to measure this type of traveling group. This initial study has given us insight into the requisite protocols and logistics, paving the way for continued research with a larger sample size and in varying climates