Performance Decrements Research Articles

Sleep Fragmentation Results in Novel Set-shifting Decrements in GCR-exposed Male and Female Rats.

The prolonged exposure to multiple spaceflight stressors during long-duration missions to the Moon and Mars will be challenging to the physical and mental health of the astronauts. Ground-based studies have reported that attentional set-shifting task (ATSET) performance is impaired after space radiation (SR) exposure. At certain times during deep-space missions, astronauts will likely have to contend with the combined impacts of SR and sleep perturbation. In rats, poor quality, fragmented sleep adversely impacts performance in multiple cognitive tasks, including the ATSET task. While both SR and sleep perturbations independently cause cognitive performance deficits, the incidence, severity and exact nature of those decrements following combined exposure to these flight stressors is largely unknown. This study established the impact that a single night of fragmented sleep has on ATSET performance in both male and female rats exposed to 10 cGy of galactic cosmic ray simulation (GCRsim). The GCRsim beam is a complex beam that mimics the mass and energy spectra of the SR particles that an astronaut will be exposed to within the spacecraft. Rats that had no obvious ATSET performance decrements when normally rested were subjected to fragmented sleep and their ATSET performance reassessed. Sleep fragmentation resulted in significant ATSET performance decrements in GCRsim-exposed rats, with specific performance decrements being observed in stages where attention or cue shifting is extensively used. Performance decrements in these stages are rarely observed after SR exposure. While both male and female rats exhibited latent sleep-related performance decrements, these were sex dependent, with male and female rats exhibiting different types of performance decrements (either reduced processing speed or task completion efficiency) in different stages of the ATSET task. This study suggests that SR-induced cognitive impairment may not be fully evident in normally rested rats, with an underestimation of both the incidence and nature of performance decrements that could occur when multiple space flight stressors are present. These data suggest that that there may be synergistic interactions between multiple space flight stressors that may not be easily predicted from their independent actions.

Cognitive performance in ISS astronauts on 6-month low earth orbit missions.

Current and future astronauts will endure prolonged exposure to spaceflight hazards and environmental stressors that could compromise cognitive functioning, yet cognitive performance in current missions to the International Space Station remains critically under-characterized. We systematically assessed cognitive performance across 10 cognitive domains in astronauts on 6-month missions to the ISS. Twenty-five professional astronauts were administered the Cognition Battery as part of National Aeronautics and Space Administration (NASA) Human Research Program Standard Measures Cross-Cutting Project. Cognitive performance data were collected at five mission phases: pre-flight, early flight, late flight, early post-flight, and late post-flight. We calculated speed and accuracy scores, corrected for practice effects, and derived z-scores to represent deviations in cognitive performance across mission phases from the sample's mean baseline (i.e., pre-flight) performance. Linear mixed models with random subject intercepts and pairwise comparisons examined the relationships between mission phase and cognitive performance. Cognitive performance was generally stable over time with some differences observed across mission phases for specific subtests. There was slowed performance observed in early flight on tasks of processing speed, visual working memory, and sustained attention. We observed a decrease in risk-taking propensity during late flight and post-flight mission phases. Beyond examining group differences, we inspected scores that represented a significant shift from the sample's mean baseline score, revealing that 11.8% of all flight and post-flight scores were at or below 1.5 standard deviations below the sample's baseline mean. Finally, exploratory analyses yielded no clear pattern of associations between cognitive performance and either sleep or ratings of alertness. There was no evidence for a systematic decline in cognitive performance for astronauts on a 6-month missions to the ISS. Some differences were observed for specific subtests at specific mission phases, suggesting that processing speed, visual working memory, sustained attention, and risk-taking propensity may be the cognitive domains most susceptible to change in Low Earth Orbit for high performing, professional astronauts. We provide descriptive statistics of pre-flight cognitive performance from 25 astronauts, the largest published preliminary normative database of its kind to date, to help identify significant performance decrements in future samples.

On the localization of reward effects in overlapping dual tasks

In dual-task (DT) situations, performance deteriorates compared with single-task situations. Such performance decrements are frequently explained with the serial scheduling of the response selection stages constituting a bottleneck. Proof of this assumption stems from the observation that response times for the second task (task 2; RT 2) increase with decreasing stimulus-onset asynchrony (SOA).In this study, we investigated how the reward prospect for task 1 performance affects task 1 and task 2 processing. For that purpose, we relied on the psychological refractory period paradigm (PRP) as a chronometric tool, to determine the locus of the reward effect in the processing chain of both tasks.We obtained improved task 1 and task 2 performance; as indicated by reduced RTs in the reward compared to the no reward condition of task 1 and task 2. Furthermore, the reward effect propagated at short SOA from task 1 onto task 2, suggesting that the locus of the reward effect can be pinpointed before or at the bottleneck of task 1. Importantly, the mean reward effect on task 1 was increased compared to task 2, thus indicating that parts of the reward effect were not propagated onto task 2, therefore affecting task 1 motor processes.In Experiment 2, we tested for the locus of the effect propagation to task 2. Therefore, we implemented a difficulty manipulation of the response selection of task 2. The results indicate that the reward effect is propagated from task 1 onto the response selection stage of task 2.

Evaluating bioenergetic pathway contributions from single to multiple sprints

This study aims to investigate the changes in bioenergetic pathway contributions during repeated sprint exercises with an increasing number of repetitions. Twelve male amateur soccer players executed a single 20 m sprint and three repeated-sprint protocols (5 × 20 m, 10 × 20 m, 15 × 20 m with 15-second rest intervals), analyzing oxidative, glycolytic, and ATP-PCr energy pathways using the PCr-LA-O2 method. Findings revealed a significant decline in energy expenditure and performance outputs as the number of sprint repetitions increased. While the oxidative and ATP-PCr pathways’ energy contributions significantly rose with more sprints, the glycolytic pathway’s contribution notably increased only up to the 10 × 20 m protocol, then stabilized. Although the ATP-PCr pathway’s energy contribution decreased slightly from sprints 1–5 to 11–15, it remained significantly higher than the oxidative and glycolytic pathways throughout. Initially, glycolytic contribution surpassed oxidative in sprints 1–5, equaled it in sprints 6–10, and fell below in sprints 11–15. Glycolytic activity, a major energy source initially (about 36%), diminished substantially with more sprints (below 7% in the 15th sprint). This indicates that the decrease in non-mitochondrial pathway energy, particularly glycolytic, outstrips the aerobic system’s increased tolerance. These findings offer physiological insights into the relationship between performance decrement and bioenergetic metabolism in repeated sprints.

Cognitive and Metacognitive Reading Strategies for Ethiopian Students in English as a Foreign Language

Purpose. This study's purpose is to investigate the effects of explicit cognitive reading strategy training on reading performance and metacognitive reading strategy awareness of Grade 9 students of Heto Secondary School at Hosanna Town, 232, south-west of Addis Ababa. Methodology. For this quasi-experimental study, two parallel home-made tests, a pre-test and a post-test administered before and after the intervention, respectively, and a metacognitive reading strategy awareness questionnaire were used. Data were gathered from 100 participants of experimental and control groups, 50 students from each group, before and after 14 hours strategy training within 12 weeks. SPSS, version 25, was used to analyse data. Independent Samples Test to compare groups, and Paired Samples Test to compare variables/scores of the groups were employed during analysis. Results. The results showed a statistically significant difference between the pre-test and the post-test scores of reading performance (p=.000) of each group. However, the Experimental Group made an increment in reading performance, whereas the Control Group made the opposite, a decrement in reading performance. The relationship of both groups was strong and positive. However, neither group showed significant changes in metacognitive reading strategy awareness. Conclusion. The study concluded that explicit cognitive reading strategy instruction empowered students to outperform reading comprehension and vice versa, though it did not change students’ strategy awareness. This implies that concerned bodies should give due attention to enhancing the explicit approach to cognitive reading strategy teaching.

Examining the Independent and Interactive Carryover Effects of Cognitive and Physical Exertions on Physical Performance.

This study compared the effects of prior cognitive, physical, and concurrent exertion on physical performance. Fatiguing cognitive and physical exertions have been shown to negatively affect subsequent task performance. However, it is not clearly understood if concurrent physical and cognitive effort may exaggerate the negative carryover effects on physical task performance when compared to cognitive or physical exertion alone. Twenty-five participants completed four isometric handgrip endurance trials on different days. The endurance trials were preceded by four, 15-minute experimental manipulations (cognitive, physical, concurrent, control). Electromyography (EMG) and force tracing performance were monitored, with handgrip strength measured pre and post. Subjective ratings of mental and physical fatigue, as well as affect, motivation, and task self-efficacy, were also assessed. Handgrip strength decreased following both physical (-14.4% MVC) and concurrent (-12.3% MVC) exertion manipulations, with no changes being observed for the cognitive and control conditions. No differences were observed across conditions for endurance time, EMG, nor tracing performance. When compared to the control conditions, perceptions of mental and physical fatigue were higher following the experimental manipulation. Endurance trial self-efficacy was lower for the mental, physical and concurrent conditions compared to control. The concurrent condition resulted in similar decreases in strength as the physical fatigue condition, but otherwise resulted in similar carryover effects on endurance performance across all conditions. Further study is required at higher exposure levels, or for longer exposure durations, to further probe the influence of concurrent physical and cognitive effort on task performance. Concurrent cognitive and physical effort resulted in similar physical performance decrements to physical effort alone.

Lesion and lesion network localization of dysnomia after epilepsy surgery.

Temporal lobe (TL) epilepsy surgery is an effective treatment option for patients with drug-resistant epilepsy. However, neurosurgery poses a risk for cognitive deficits - up to one third of patients have a decline in naming ability following TL surgery. In this study, we aimed to better understand the neural correlates associated with reduced naming performance after TL surgery, with the goal of informing surgical planning strategies to mitigate the risk of dysnomia. We retrospectively identified 85 patients who underwent temporal lobe (TL) resective surgery (49 left TL, 36 right TL) for whom naming ability was assessed before and >3 months post-surgery using the Boston Naming Test (BNT). We used multivariate lesion-symptom mapping to identify resection sites associated with naming decline, and we used lesion-network mapping to evaluate the broader functional and structural connectivity profiles of resection sites associated with naming decline. We validated our findings in an independent cohort of 59 individuals with left temporal lobectomy, along with repeating all analyses after combining the cohorts. Lesion laterality and location were important predictors of post-surgical naming performance. Naming performance significantly improved after right temporal lobectomy (P = 0.015) while a decrement in performance was observed following left temporal lobectomy (P = 0.002). Declines in naming performance were associated with surgical resection of the left anterior middle temporal gyrus (Brodmann area 21, r =0.41, P = <.001), along with a previously implicated basal temporal language area. Resection sites linked to naming decline showed a functional connectivity profile featuring a left-lateralized network closely resembling the extended semantic \ default mode network, and a structural connectivity profile featuring major temporo-frontal association white matter tracts coursing through the temporal stem. This extends prior work by implicating the left anterior middle temporal gyrus in naming decline and provides additional support for the role of the previously identified basal temporal language area in naming decline. Importantly, the structural and functional connectivity profiles of these regions suggest they are key nodes of a broader extended semantic network. Together these regional and network findings may help in surgical planning and discussions of prognosis.

Gesture Imitation Performance and Visual Exploration in Young Children with Autism Spectrum Disorder.

Most studies in children with autism spectrum disorder (ASD) support a decrement in imitation performance. Factors related to visual attention and motor execution have been proposed to explain this phenomenon in ASD. However, studies investigated imitation with various methods, leading to inconsistent findings. Here, we examine imitation performance related to visual attention and motor execution. We focused on the imitation of meaningful and meaningless gestures, consistently reported as more affected than imitation of actions with objects in ASD. The imitation eye-tracking task consisted of a video of an actor demonstrating gestures and prompting children to imitate them. The demonstrations comprised meaningful and meaningless hand gestures, and meaningless facial gestures. We measured the fixation duration to the actor' face during child-directed speech and gesture demonstrations. We video-recorded children to assess their performance. Our sample comprised 100 participants (3.55 ± 1.11years old), including 84 children with ASD. The ASD and typically developing groups displayed the same visual attention toward gesture demonstrations, although children with ASD spent less time looking at the face during facial stimuli. Visual exploration of actors' gestures did not influence imitation performance. Imitation of meaningful gestures was associated with less severe autistic symptoms, whereas imitation of meaningless gestures was correlated with higher non-verbal cognitive and fine-motor skills. These findings contribute to a better understanding of the complexity of imitation. We delineated the distinct nature of imitation of meaningful and meaningless gestures in children with ASD. We discuss clinical implications in relation to assessment and intervention programs.

Reaching the cognitive-motor interface: effects of cognitive load on arm choice and motor performance after stroke.

A vexing characteristic of motor disability after stroke is that many individuals fail to use their affected arm effectively despite having the capacity to do so, a phenomenon termed arm nonuse. Based on the hypothesis that nonuse is influenced by the competing cognitive demands of many daily activities, we examined the effects of cognitive load on arm choice and motor performance in individuals with stroke using a novel virtual reality paradigm that mimics the demands of real-life visual search, object selection, and reaching to targets. Twenty individuals with single left or right hemispheric chronic stroke (11 left cerebrovascular accident; 9 right cerebrovascular accident) and 10 age-matched neurotypical participants completed the Virtual Reality Arm Choice task, in which they reached for target objects in an array under varied cognitive demand. To manipulate cognitive demand, we varied the semantic similarity of objects in the reaching space and the presence or absence of a secondary task. The results showed reduced use of the paretic arm under increased demand. Under cognitive load, participants with stroke also showed slower reach initiation, slower movements, increased reach curvature, and increased performance differences between the paretic and non-paretic arms. The arm choice of neurotypical individuals was also modulated under cognitive load. These data indicate that cognitive factors influence arm choice and motor performance in naturalistic reaching tasks in individuals with chronic stroke. Performance decrements under cognitive load may in turn influence reduced paretic arm use during daily activities.

Driving performance and ocular activity following acute administration of 10 mg methylphenidate: A randomised, double-blind, placebo-controlled study.

Methylphenidate is a routinely prescribed treatment for attention-deficit/hyperactivity disorder with misuse potential owing to its perceived performance-enhancing and euphoric properties. Although clinically effective, there is limited understanding of how methylphenidate affects safety-sensitive tasks such as driving when used by healthy individuals. Explore the acute effects of 10 mg methylphenidate on driving performance and gaze behaviour. Twenty-five fully licensed, healthy adults (mean age = 33.5 ± 7.8 years, 64% male) took part in two 40-min simulated highway drives with simultaneous eye movements monitored using a proprietary automotive-grade driver monitoring system (Seeing Machines). Driving performance was assessed using the standard deviation of lateral position, standard deviation of speed and steering variability. Visual scanning efficiency was determined using ocular metrics, such as fixation duration and rate, gaze transition entropy, and stationary gaze entropy, were assessed to determine visual scanning efficiency. Methylphenidate significantly improved driving performance by reducing lane weaving and speed variation, particularly in the latter half of the drive. Although a significant reduction in fixation duration was observed, all other ocular metrics remained unchanged. Methylphenidate mitigates performance decrements typically associated with prolonged and monotonous driving. The absence of pronounced oculomotor effects suggests that a single 10 mg dose of methylphenidate has no deleterious impact on visual scanning behaviour during driving tasks with low-to-moderate cognitive demand. Future research should investigate the effects of methylphenidate under various dosing and driving conditions to better understand its impact. ACTRN12620000499987.

Gender Differences in Performing an Overhead Drilling Task Using an Exoskeleton-A Cross-Sectional Study.

(1) Exoskeletons offer potential benefits for overhead working tasks, but gender effects or differences are unclear. This study aimed to compare the performance as well as subjective body strain and comfort of men and women using an upper-body exoskeleton. (2) n = 20 female and n = 16 male participants performed an overhead drilling task with and without a passive upper-body exoskeleton in a randomized cross-over study. The task performance of different movement phases, perceived exertion, and ease of use were measured to compare gender differences. One- and two-way analyses were used to compare genders in the different conditions. The body mass index (BMI) was included as a covariate. (3) Gender differences in task performance were found for error integrals (p < 0.001) with higher values in male participants. Moreover, there was a significant interaction effect for gender x exoskeleton use. While females showed performance decrements in aiming with exoskeleton use, the males' performance increased (p = 0.025). No other gender differences were observed. (4) Gender differences in task performance using an upper-body industrial exoskeleton were less detectable than expected, indicating that body composition and anthropometrics might be valuable indicators for performance including assisting devices. Moreover, future studies should also integrate the examination of muscle activity to gain more insights into potential gender movement control patterns.

Effects of different pre-exercise strategies on jumping performance in female volleyball players.

The present study aimed to compare different pre-exercise strategies on jumping performance in female volleyball players. Fifteen healthy female volleyball players (age=18±0.6 years; training experience = 7.3±1.4 years; height = 164.8±5.4 cm; body mass = 57.2±8.1 kg) volunteered to participate in the study. Three different pre-exercise conditions (5 repetition maximum knee extension, electromyostimulation [EMS] and ischemic preconditioning [IPC]) were applied to the subjects and compared to a control condition performing a standardized warmup. Subjects performed the squat jump and 15 sec repeated countermovement jumps following a rest period. Measures associated with jumping performance were collected and compared between conditions. Rating of perceived exertion was also collected after each performance test. No pre-exercise condition outperformed a standardized warm-up on inducing improvements in jumping performance and in fact, EMS and IPC conditions resulted in performance decrements compared to control (P<0.05). We conclude that a standardized warm-up is enough to induce improvements in jumping performance in female volleyball players. Future research should examine alternative strategies alongside standardized warm-up to determine how best to prepare for jumping and related sport-specific tasks in female volleyball players.

On-field concurrent validity of flight time-based countermovement jump height during fatigue: A comparison between inertial measurement units worn at different locations on the body

ABSTRACT We explored the feasibility of utilizing immediate changes in flight time-based vertical countermovement jump height as an on-field measure for fatigue-induced decrements in performance. Comparing Inertial Measurement Units (IMUs) worn at five body locations (feet, shorts for thighs and pelvis, waist strap, and thorax in a standard GPS vest) with a force plate as a reference, we enlisted 19 amateur football players who performed a series of 10 maximal 30 m sprints (initiated every minute). Maximal jumps were executed immediately before and after each sprint, with the latter jumps recorded on a force plate integrated into the field. Bland Altman’s bias (−0.49 cm) and limits of agreement (1.01 cm) were minimal for the feet IMUs. The thorax IMU had the highest bias (−6.35 cm), but the limits of agreement (2.73 cm) were similar to the other locations. Repeated measures correlations (rmcorr) between force plate and IMUs were excellent for the feet (rmcorr = 0.98) and good for the thorax (rmcorr = 0.86) and other locations except for the waist strap. In the fatigued state, within-session coefficients of variation ranged from 4.0% (pelvis in shorts) to 6.5% (waist strap). These findings suggest that body-worn IMUs possess the potential for a prompt and straightforward on-field vertical jump assessment to monitor acute fatigue.

Energy expenditure during physical work in cold environments: physiology and performance considerations for military service members.

Effective execution of military missions in cold environments requires highly trained, well-equipped, and operationally ready service members. Understanding the metabolic energetic demands of performing physical work in extreme cold conditions is critical for individual medical readiness of service members. In this narrative review, we describe 1) the extreme energy costs of performing militarily relevant physical work in cold environments, 2) key factors specific to cold environments that explain these additional energy costs, 3) additional environmental factors that modulate the metabolic burden, 4) medical readiness consequences associated with these circumstances, and 5) potential countermeasures to be developed to aid future military personnel. Key characteristics of the cold operational environment that cause excessive energy expenditure in military personnel include thermoregulatory mechanisms, winter apparel, inspiration of cold air, inclement weather, and activities specific to cold weather. The combination of cold temperatures with other environmental stressors, including altitude, wind, and wet environments, exacerbates the overall metabolic strain on military service members. The high energy cost of working in these environments increases the risk of undesirable consequences, including negative energy balance, dehydration, and subsequent decrements in physical and cognitive performance. Such consequences may be mitigated by the application of enhanced clothing and equipment design, wearable technologies for biomechanical assistance and localized heating, thermogenic pharmaceuticals, and cold habituation and training guidance. Altogether, the reduction in energy expenditure of modern military personnel during physical work in cold environments would promote desirable operational outcomes and optimize the health and performance of service members.

A moderated mediation approach to deciphering the effects of leader knowledge hiding behaviour in industry 4.0

ABSTRACT Leader knowledge-hiding behaviour (LKHB) has long-term adverse effects on employees and on overall organization performance. Top-down knowledge sharing is vital in Industry 4.0 for employees to acquire essential skills. Grounded in the Conservation of Resources (COR) model, our study presents a moderated mediation model that sheds light on the effects of LKHB. Based on longitudinal data, we found that LKHB leads to job performance decrement and enhances turnover intentions, with LKHB resulting in lower employee intrinsic motivation, underscoring its importance of as a mediating factor. Our findings support the significant influence of enterprise social media (ESM) on the relationship between LKHB and job performance decrement, turnover intentions, and employee phubbing through intrinsic motivation. The study offers new insights into LKHB outcomes and explores underlying reasons thereby broadening COR Theory applications. This research is innovative in its examination of ESM influences on LKHB and suggests strategies to mitigate its detrimental effects.

Repeated Sprint Variations According to Circadian Rhythm at Different Menstrual Cycle Phases.

This study assessed the repeated sprint performance in relation to circadian rhythm during different menstrual cycle phases (MCP). Twelve volunteer eumenorrheic women team sport athletes performed 5×6-s cycling sprints in morning (9 am to 10 am) and evening (6 pm to 7 pm) sessions during the mid-follicular (FP, 6th-10th d) and luteal phases (LP, 19th-24th d). Body weight, oral body temperature, resting heart rate and lactate levels together with estradiol, progesterone and cortisol levels were determined before tests. Relative peak and mean power and performance decrements were determined as performance variables and maximum heart rate, lactate and ratings of perceived exertion were determined as physiological variables. Evening body temperatures were significantly higher. Cortisol levels were higher in the morning and in the FP. Resting lactate levels did not vary with MCP or time of day, but a significant MCP x time of day interaction was observed. Body weight showed no change according to time of day and MCP. There was no significant effect of MCP and time of day on performance and physiological variables, in contrast, maximum lactate values were notably higher in the evening. In conclusion, MCP and time of day need not be considered during repeated sprint exercises of eumenorrheic women athletes.

Different spectrum of space radiation induced cognitive impairments in radiation-naïve and adapted rats

NASA's decision to resume manned deep space mission, first to the Moon and then Mars, necessitated a detailed assessment of the potential health effects that astronauts may experience on long-duration missions. Multiple studies suggest that there may be significant space radiation (SR)-induced impairment of neurocognitive processes, including advanced executive functions. However, given the multitude of SR-induced changes in the CNS, it is possible that completely different SR-induced sequelae will be induced in previously exposed individuals. Thus, current risk estimates are likely to be pertinent only for the early stages of a deep space mission, and even then only for astronauts that have no previous experience in space.In this study, rats that maintained high attentional set shifting (ATSET) performance after an initial exposure to 10 cGy of SR (either 250 MeV/n He or GCRsim), were exposed to an additional dose of 10 cGy GCRsim and their ATSET performance reassessed. The re-irradiated rats exhibited significant impairment of ATSET performance, however, the performance decrements differed in two important aspects from those typically observed after single exposures. First, the decrements were manifested when the rats were required to perform set shifting, specifically in the IDR and EDS stages of the ATSET test. Secondly, the main performance decrement was in a loss of processing speed, which in the IDR stage resulted in the re-irradiated rats taking 2-fold more time to solve the problem than did Sham rats. The functional consequence of this decrement was that compared to Sham rats, 20 % fewer SR-exposed rats solved the IDS and EDR problems within 20 s.These data suggests that prior SR exposure alters nature of ATSET impairments from that observed in radiation-naïve individuals. Risk estimates derived from studies that use radiation naïve rats may thus not fully reflect the incidence and nature of ATSET performance deficits that could occur over the entire duration of a mission to Mars, or in astronauts who return to deep space on multiple occasions. It would thus be germane to conduct in-flight monitoring for cognitive performance decrements observed in both radiation naïve and exposed rats during the mission, and ensure that the crew has sufficient overlapping skill sets to minimize the operational impact of these additional cognitive impairments.

Production of Thermoplastic Starch-Aloe Vera Gel Film Embedded with Polyethylene for Improved Tensile Strength and Water Absorption

The water absorption characteristics of thermoplastic starch (TPS) reveal its ability to interact with and absorb water, influencing its overall performance in various applications. The introduction of aloe vera (AV) gel into the TPS polymeric matrix film has proven beneficial in enhancing tensile strength but a notable deficiency is observed in lowering water absorption percentage. Therefore, this paper aims to reduce the water absorption of the TPS30AV polymer matrix film by utilizing polyethylene (PE) without reducing the tensile strength performance of the TPS30AV film. The TPS30AV film was produced using melt-blending and hot-press techniques. Six samples were presented consisting of a control film (TPS30AV) and TPS30AV film with different concentrations of PE resins (5%, 10%, 20%, 30%, and 40%). The film's performance was assessed by examining its mechanical properties, water absorption, and water solubility. The finding shows that TPS30AV with 40% PE has the highest improvement in water absorption percentage which reduces from 309.86% to 34.16% but a tremendous decrement in tensile strength performance. However, TPS30AV with 10% PE has the highest tensile strength, 9.65 MPa with a 20.99% improvement in water absorption reduction. The properties obtained for TPS30AV10PE were also good inYoung's modulus and water solubility percentage. It shows that the film formulated is comparable with previous studies, and improvement has been achieved. As a conclusion, adding PE improved the polymeric structure of TPS30AV and can be used as a biodegradable food-packaging film.

The flag effect on the physical performance of soccer assistant referees

The aim of the study is to compere the performance of the assistant referee without and with the flag, based on existing and novel tests. Introduction: Millions of fans around the world are invested in the game of soccer, cheering on their favorite team, practicing their skills in the park, or simply watching from afar via the media. As such, fairness in refereeing is of the utmost importance, regardless of the level of game or the teams who are playing. The refereeing team plays a critical role in enforcing the rules of the game and ensuring fair play on the field. In addition to working together in the utmost coordination, the referee, two assistant referees, and the standby official are required to oversee the entire match, while making crucial decisions in split seconds. In addition to their verbal communications, assistant referees must carry and use their flag throughout the game, as means for signally their decisions. When running along the sideline, assistant referees hold the flag in opposite hand to the direction in which they’re moving at that time – resulting in up to 30% of their movements during the game being sideways movements. Testing and comparing the athletic abilities of assistant referees is therefore an essential component in ensuring the accuracy and fairness of soccer matches. Assistant referees play a critical role in enforcing the rules of the game, and their ability to run quickly and accurately while holding a flag can have a significant impact on the outcome of the performance. Participants: 18 assistant referees (two female) who are on the staff of the National League in the Israel Soccer Association. The participants’ mean (±SD) variables were as follows: age=29yrs (±3.4); height=178cm (±0.06); weight=68.22kg (±10.45); fat percent=14.67% (±4.86); and seniority on the league=3.11yrs (±1.45). Results: Show that in all the tests the performance was significant better without the flag (RST, agility test and linear speed), the performance decrement % (RST), show no significant result, P&lt;0.05, t (0.91) = 17. Conclusions: the referee run faster without the flags but the no deferent in the fatigue, so they have to train and testing with flags like in the game.

Time-on-task-related decrements in performance in the rodent continuous performance test are not caused by physical disengagement from the task.

Attention deficits, a hallmark of many neuropsychiatric disorders, significantly impair quality of life and functional outcome for patients. Continuous Performance Tests (CPTs) are widely used to assess attentional function in clinical settings and have been adapted for mice as the rodent Continuous Performance Test (rCPT). In this study, we combined traditional analyses of rCPT performance with markerless pose estimation using DeepLabCut and visual field analysis (VFA) to objectively measure the orientation of mice toward stimuli during rCPT sessions. Additionally, we extended session lengths to assess performance decrements over time. Our findings show that extending rCPT sessions from 45 to 90 minutes results in a significant decline in performance in male mice, which aligns with performance decrements observed in clinical research. Importantly, physical engagement with the task remained relatively stable throughout the session, even as performance deteriorated. This suggests that the performance decline specifically reflects a time-on-task (TOT)-dependent vigilance decrement rather than physical disengagement. We also investigated the effects of amphetamine, an FDA-approved treatment for attention-deficit/hyperactivity disorder (ADHD), on rCPT performance. Amphetamine significantly improved rCPT performance in male mice by reducing false alarms without modulating orientation or physical engagement with the task stimuli. Collectively, these findings validate a behavioral tracking platform for objectively measuring physical engagement in the rCPT and a task modification that accentuates TOT-dependent performance decrements, enhancing the translational value of the rCPT for studies related to human neuropsychiatric disorders.