Effect of Professional Fighters' Weight Class on Regional Brain Volume, Cognition, and Other Neuropsychiatric Outcomes

ObjectiveTo evaluate the relationship between professional fighter weight class and neuropsychiatric outcomes.BackgroundTraumatic brain injury (TBI) is a common source of functional impairment among athletes, military personnel, and the general population. Professional fighters in both boxing and mixed martial arts (MMA) are at particular risk for repetitive TBI and may provide valuable insight into both the pathophysiology of TBI and its consequences. Currently, effects of fighter weight class on brain volumetrics (regional and total) and functional outcomes are unknown.Design/Methodsn = 53 boxers and n = 103 MMA fighters participating in the Professional Fighters Brain Health Study (PRBHS) underwent volumetric magnetic resonance imaging (MRI) and neuropsychological testing. Fighters were divided into lightweight (=139.9 lb), middleweight (140.0–178.5 lb), and heavyweight (>178.5 lb).ResultsCompared with lightweight fighters, heavyweights displayed greater yearly reductions in regional brain volume (boxers: bilateral thalami; MMA: left thalamus, right putamen) and functional performance (boxers: processing speed, simple and choice reaction; MMA: Trails A and B tests). Lightweights suffered greater reductions in regional brain volume on a per-fight basis (boxers: left thalamus; MMA: right putamen). Heavyweight fighters bore greater yearly burden of regional brain volume and functional decrements, possibly related to differing fight dynamics and force of strikes in this division. Lightweights demonstrated greater volumetric decrements on a per-fight basis.ConclusionsAlthough more research is needed, greater per-fight decrements in lightweights may be related to practices of weight-cutting, which may increase vulnerability to neurodegeneration post-TBI. Observed decrements associated with weight class may result in progressive impairments in fighter performance, suggesting interventions mitigating the burden of TBI in professional fighters may both improve brain health and increase professional longevity.

Probabilistic Evaluation of the Exploration–Exploitation Balance during the Search, Using the Swap Operator, for Nonlinear Bijective S-Boxes, Resistant to Power Attacks

During the search for S-boxes resistant to Power Attacks, the S-box space has recently been divided into Hamming Weight classes, according to its theoretical resistance to these attacks using the metric variance of the confusion coefficient. This partition allows for reducing the size of the search space. The swap operator is frequently used when searching with a random selection of items to be exchanged. In this work, the theoretical probability of changing Hamming Weight class of the S-box is calculated when the swap operator is applied randomly in a permutation. The precision of these probabilities is confirmed experimentally. Its limit and a recursive formula are theoretically proved. It is shown that this operator changes classes with high probability, which favors the exploration of the Hamming Weight class of S-boxes space but dramatically reduces the exploitation within classes. These results are generalized, showing that the probability of moving within the same class is substantially reduced by applying two swaps. Based on these results, it is proposed to modify/improve the use of the swap operator, replacing its random application with the appropriate selection of the elements to be exchanged, which allows taking control of the balance between exploration and exploitation. The calculated probabilities show that the random application of the swap operator is inappropriate during the search for nonlinear S-boxes resistant to Power Attacks since the exploration may be inappropriate when the class is resistant to Differential Power Attack. It would be more convenient to search for nonlinear S-boxes within the class. This result provides new knowledge about the influence of this operator in the balance exploration–exploitation. It constitutes a valuable tool to improve the design of future algorithms for searching S-boxes with good cryptography properties. In a probabilistic way, our main theoretical result characterizes the influence of the swap operator in the exploration–exploitation balance during the search for S-boxes resistant to Power Attacks in the Hamming Weight class space. The main practical contribution consists of proposing modifications to the swap operator to control this balance better.

91 Assessing Variability of Herd Sire Economic Value for Commercial Operations

Number of calves (n = 596) and weaning calf value (n = 574) from natural service, multi-sire breeding groups were evaluated in a crossbred research herd. Sires and dams that were F1 crosses of Angus (A) and Nellore (N) were mated annually during 60 to 90-day breeding seasons to produce spring-born calves in 2009–2015. Numbers of sires used annually varied from 5 to 9; numbers of females exposed per bull ranged from 14 to 22 across years. Bulls were pastured together throughout the year as well as breeding seasons. Sires were identified based on calf DNA genotyping. Calf number, birth date, birth weight, weaning weight, and economic value were determined per bull annually. Calf value was based on weaning weight and reported prices for respective weaning dates. Calf prices were calculated separately for steers and heifers relative to 22.7 kg (50 lb) increments for corresponding weight class and year. Mixed model analyses were conducted that included fixed categorical effects of calf birth year, type of F1 sire (A-sired vs. N-sired), sire nested within type, calf sex, and the interaction of F1 sire type with calf sex. Covariates of Julian birth date and calf weaning age were included for birth weight and weaning weight, respectively. Large differences in calf numbers and performance (P < 0.05) were observed. Weaned calves produced annually per sire ranged from 0 to 48. Average annual calf performance per sire ranged from 28.4 to 50.8 kg for birth weight and 146.5 to 249.0 kg for weaning weight. Annual economic value per sire ranged from $0 to $30,870 when considering half of each calf’s value as attributed to the sire. Commercial producers should consider potential sire variability for calf numbers, birth date distribution, and ratio of female-to-male calves in combination with calf performance for economic assessments.

6 Does Bedding Influence Lying Behaviour of Cattle Unloaded for Rest During Long-distance Transportation?

In Canada, cattle must be unloaded, fed, watered, and rested after 36 h of transport; however, little is known about what constitutes appropriate rest station conditions. The objective of this study was to determine the relationship between providing straw bedding (14-cm deep) and trip, load, and commercial rest station characteristics, on lying behaviour. Truckloads (n = 13) were split; half the animals were assigned to either bedded (n = 452 cattle) or non-bedded (n = 470 cattle) pens. Trip characteristics [time in motion (TIM), duration of stops en route (DUR_STOPS)], load characteristics (sex: heifers, steers, both; and load weight), and rest station characteristics [ambient temperature at unloading; rest pen space allowance (k_PEN); time in resting pen (TIP)] were recorded. Once unloaded we counted the number of cattle lying/pen, every 10 min for 8 h. A mixed logistic regression model with random intercepts for load and truck compartment was fitted to examine associations between the proportion of animals lying and the independent variables (i.e., treatment, trip, load, and rest station characteristics). Odds of lying increased with load weight (i.e., cattle weight class, P = 0.02) and with DUR_STOPS (P < 0.03). There was an interaction (P < 0.01) between treatment and TIM: as TIM increased, the odds of observing cattle lying showed a notable increase for cattle rested in bedded pens, whereas for those rested in non-bedded pens, the odds showed little change as TIM increased. An interaction (P < 0.01) was also found between treatment and TIP: early in the observation period, the odds of cattle lying were greater in bedded pens. Both groups showed an increase in the probability of lying over time, plateauing at similar levels, near the end of the 8-h observation period. In conclusion, providing straw bedding at rest stations influenced cattle’s motivation to lie, particularly following longer transport durations.

Adequacy of setting standards for kick impact in the Taekwondo electronic scoring system: comparison of a reference group model based on empirical data

Background In Taekwondo competitions, the rule is that points are scored when the impact of the kick reaches a predetermined threshold of strength. This study aimed to explore the adequacy of the protector and scoring system (PSS) designed to determine taekwondo body scoring based on a reference group model (RGM). Specifically, the kicking impact of the PSS was calculated using data from 188 matches fought during of 2018 Jakarta Asian Games. The RGM was designed based on empirical data by classifying the victory and defeat groups by gender and weight class, and the scoring method was set according to these criteria. Result The result of this study are as follows. First, there was no difference in the average impact of kicks of taekwondo players by weight class. Second, result of setting up the kick scoring impact standards of taekwondo PSS by classifying the winning and non-winning groups, the kick scoring impact set by the WT was found to be high in all weight classes except 58 kg. Lastly, result of comparing the settings of impact to score according to weight classes, the kick scoring impact standard set by the WT was higher in heavyweight (men's: under 80 kg, + 80 kg, women's: under 67 kg, over 67 kg) than in the lightweight (men's: under 58 kg, under 63 kg, under 68 kg, women's: under 49 kg, under 53 kg, under 57 kg). Conclusion The kick scoring impact set by the WT was found to be high in all weight classes except for the under 58 kg class defining kick scoring impact based on the standards of WT-certified PSS by classifying the matches into winning and non-winning groups. Finally, as a result of comparing the scoring impact settings according to weight class, the kick scoring impact standard set by the WT was higher for the heavier weight classes than for the lighter weight classes.

Determination of static space requirements for finishing bulls based on image analysis

In Europe, conventional housing systems for finishing bulls (Bos taurus) tend to consist of group pens with a high stocking density. Up until now there have been no regulations in place defining bulls' space requirements, even although insufficient space allowance is considered to impair animal welfare. Our study aimed to measure the surface area that finishing bulls occupy in standing and lying positions. We observed 46 bulls on a German fattening farm. The animals from one pen were assigned to one of three weight classes (W1: < 450 kg; W2: 450–649 kg; W3: ≥ 650 kg), and two pens of each weight class were examined. For image recordings, a camera trap was installed above the pens. To analyse the covered surface, the recorded images (n = 242) were edited. Furthermore, the observed lying postures were differentiated in terms of lying position and stretched-out legs. On average, the areas covered by the bulls increased with class of bodyweight. A finishing bull covered up to 1.21 m2 in a standing position and up to 1.57 m2 in a lying position, the most space being needed in an outstretched position. The calculated values provide information only about the surface a finishing bull covered in different positions in the pen. In practice, additional dynamic and social space must be taken into account for recommendations on space requirements, in order to ensure adequate inter-individual distances, social interaction and characteristic behaviours to improve animal welfare.

Effect of landscape modification on primate assemblages of the Magdalena River Valley, Colombia

Population and community dynamics are affected by local landscape disturbances, and the answer of each species to these changes could differentially affect species survival. Natural land cover in the Magdalena River valley, Colombia, has been reduced by almost 70 % and fragmented. There inhabit isolated and reduced populations of Alouatta seniculus, Ateles hybridus, Cebus versicolor, and Saguinus leucopus (Primates). To understand the effect of fragmentation over these species, the relationship between altitude, landscape and class metrics, and plant structure and diversity with the population density of these four primates in 20 localities were assessed. Additionally, the relationship between the density of A. hybridus, assumed as a better competitor, and the density of the other primates was assessed. Mean shape index was the most related variable and affected positively the density of A. hybridus, C. versicolor, and S. leucopus and negatively that of A. seniculus. Weight class index was the second more important variable, the four primates increased their density where more mature is the plant cover. Diameter at breast height was positively related with the density of A. hybridus and C. versicolor, negatively related for A. seniculus and not related to S. leucopus density. Tree density was related negatively with the density of A. seniculus and positively with S. leucopus. A. hybridus was related to the density of the other primates, positively to A. seniculus and negatively to the other two species.

A Critical Review of Eating Disorders in Female Athletes and Evidence-based Interventions for Sports Coaches

Eating disorders (ED) are serious mental disorders, which can have serious health consequences and high mortality rates. Due to facing unique risk factors female athletes have increased susceptibility for ED. Female athletes are also at risk for subclinical conditions such as the Female Athlete Triad. There is a dearth of studies on preventing and identifying ED in female athletes and the role and responsibility of the sports coach is unclear. This study aimed to address the questions of whether female athletes are at increased risk for ED, what interventions currently show promise and what is the role of the sports coach in the intervention process. The study was based on a systematic review of relevant literature retrieved through PubMed and Sports Discus databases. Despite heterogeneity in prevalence studies, findings suggest that female athletes are at higher risk than male athletes and non-athletes and those in elite level sports or sports categorised as lean, aesthetic, endurance and weight-class are at increased risk for clinical and subclinical ED. Risk-factors unique to the sports environment such as weight pressures, competitive thinness and revealing uniforms, may lead to increased risk in female athletes. Despite a dearth of studies on interventions for ED in sport, findings suggest that primary prevention programs based on educating athletes such as ATHENA show most promise in prevention. Secondary prevention should focus on early identification using athlete-specific screening tools. Symptom checklists and pre-participation examinations can also assist coaches in early identification. Psychotherapy interventions such as CBT have had the best results for treatment. Sports coaches’ play a critical role in, early identification, referral, management and prevention of ED in female athletes. However, current findings suggest that many coaches lack knowledge about ED and require education to be able to intervene successfully in female athletes with ED. Inappropriate coaching behaviours have also been found to act as an additional risk-factor for ED. Recommendations for sports coaches in N.I. are provided to assist them in successful intervention, management and return to play of female athletes with ED.