Early Gender Differences in Valuing Strength.

Being strong is a prominent male stereotype that children learn early in life; however, it is unknown as to when children start to value being strong and when gender differences in valuing strength might emerge. In the current study, we interviewed an ethnically diverse sample of 168 3-5 year-olds (88 girls, 80 boys) to address this gap in the literature. Results showed that boys as young as age 3 generally valued strength more than girls: (1) boys, on average, said it was more important to be strong than girls did, and (2) boys were more likely to prefer strength-related occupations than girls. Boys were also more likely to select boys than girls as the gender who cares more about physical strength. Additionally, with age, both girls and boys demonstrated knowledge of the stereotype that boys care about physical strength, with girls also being less likely to associate being a girl with being strong. Overall, the results suggest that valuing physical strength starts in early childhood, and gender differences in valuing strength are evident at the eve of gender identity development. Possible implications for boys' later well-being and health are discussed.

Physical Strength Partly Explains Sex Differences in Trait Anxiety in Young Americans.

Among the most consistent sex differences to emerge from personality research is that women score higher than men on the Big Five personality trait Neuroticism. However, there are few functionally coherent explanations for this sex difference. The current studies tested whether this sex difference is due, in part, to variation in physical capital. Two preregistered studies (total N = 878 U.S. students) found that sex differences in the anxiety facet of Neuroticism were mediated by variation in physical strength and self-perceived formidability. Study 1 (N = 374) did not find a predicted mediation effect for overall Neuroticism but found a mediation effect for anxiety (the facet of Neuroticism most strongly associated with grip strength). Study 2 (N = 504) predicted and replicated this mediation effect. Further, sex differences in anxiety were serially mediated by grip strength and self-perceived formidability. These findings add to a nascent literature suggesting that differences in physical attributes may partially explain sex differences in personality.

Improvements in Physical Fitness are Associated with Favorable Changes in Blood Lipid Concentrations in Children.

Although accumulating evidence suggests the benefits of cardiorespiratory fitness and muscular fitness, little knowledge exists on how other physical fitness (PF) components are associated with cardiovascular disease (CVD) risk markers in children. Additionally, much of the relevant evidence is from longitudinal studies with CVD risk markers at a single time point (i.e., baseline) rather than changes in PF. The purpose of the present study was to examine whether initial 1-year changes in different performance measures of PF (i.e., endurance performance, muscular strength/endurance, flexibility, agility, and speed) can predict the subsequent changes (2-year change) in blood lipid concentrations in children. This 2-year longitudinal study included a total of 251 Japanese children (mean age 9.2 ± 0.4). PF tests were performed to comprehensively evaluate the participant's fitness levels (handgrip strength [upper body muscular strength], bent-leg sit-ups [muscular endurance], sit-and-reach [flexibility], side-step [agility], 20-meter shuttle run [endurance performance], 50-meter sprint [speed], standing long jump [lower body muscular strength], and softball throw [explosive arm strength and throwing ability]). Fasting lipid profile was assayed for triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and non-HDL-C concentration. Multilevel linear regressions were used to examine the associations between the preceding changes (over 1-year) in PF and subsequent changes (over 2-years) in blood lipid concentrations. We also examined the simultaneous associations between 2-year changes in PF and 2-year changes in blood lipid concentrations. For boys, preceding improvement in handgrip strength was negatively associated with TG concentration (ß = -0.260, p = 0.030); improvements in bent-leg sit-ups were negatively associated with clustered lipid scores (ß = -0.301, p = 0.038) and non-HDL-C (ß = -0.310, p = 0.044); and improvements in 50m sprinting were associated with subsequent changes in non-HDL-C (ß = 0.348, p = 0.006) and LDL-C (ß = 0.408, p = 0.001). For girls, improvements in handgrip strength was negatively associated with TG concentration (ß = -0.306, p = 0.017); and improvements in standing long jump were negatively associated with non-HDL-C (ß = -0.269, p = 0.021) and LDL-C (ß = -0.275, p = 0.019). For boys and girls, there were no significant simultaneous associations between 2-year changes in PF and 2-year changes in blood lipid concentrations. In conclusion, preceding change in physical fitness in relation to change in blood lipid concentration likely reflect a physiological adaptation to growth and maturation since these associations diminished in the subsequent year.

Assessment of physical strength from gait: data from the Maasai of Tanzania.

In industrialized societies, male gait provides information about physical strength. Male physical strength may be used by men and women to assess the fighting ability of rivals and the quality of potential mates, respectively. Women more than men discriminate between strong and weak walkers when assessing gait attractiveness. We presented videos of British men's gait-pre-categorized into strong and weak walkers-to male and female members ( n = 100) of the traditional Maasai in northern Tanzania in Africa. Maasai men and women judged the gaits of physically strong men less attractive than those of weak men and judged strong walkers to be weaker than weak walkers. These findings counter results from industrialized societies where participants accurately assessed strength from gait, thus arguing against a universal perception of physical strength from gait information.

Force versus fury: Sex differences in the relationships among physical and psychological threat potential, the facial width-to-height ratio, and judgements of aggressiveness.

Individuals with larger facial width-to-height ratios (FWHRs) are judged as more threatening, and engage in more threat-related behavior, than do individuals with smaller FWHRs. Here we identified components of threat potential that are related to the FWHR. In Study 1, the FWHR was correlated positively with physical threat potential (bicep size) in women and with both physical and psychological (anger proneness) threat potential in men. Behavioral aggression was measured in a subset of these participants using the Point Subtraction Aggression Paradigm (costly aggression) and a Money Allocation Task (non-costly aggression). Psychological (but not physical) threat potential predicted non-costly aggression and physical (but not psychological) threat potential predicted costly aggression. In Study 2, a separate set of participants judged the anger proneness, strength, or aggressiveness of male participants photographed in Study 1. Participants' judgements of all three characteristics were associated with the FWHR, and there were sex differences in how aggressiveness was conceptualized (for women, aggressiveness was associated with anger proneness, for men, aggressiveness was associated with strength). These results are consistent with the hypothesis that the FWHR may be an adaptation to cue the threat potential of men.

Cues of upper body strength account for most of the variance in men's bodily attractiveness.

Evolution equips sexually reproducing species with mate choice mechanisms that function to evaluate the reproductive consequences of mating with different individuals. Indeed, evolutionary psychologists have shown that women's mate choice mechanisms track many cues of men's genetic quality and ability to invest resources in the woman and her offspring. One variable that predicted both a man's genetic quality and his ability to invest is the man's formidability (i.e. fighting ability or resource holding power/potential). Modern women, therefore, should have mate choice mechanisms that respond to ancestral cues of a man's fighting ability. One crucial component of a man's ability to fight is his upper body strength. Here, we test how important physical strength is to men's bodily attractiveness. Three sets of photographs of men's bodies were shown to raters who estimated either their physical strength or their attractiveness. Estimates of physical strength determined over 70% of men's bodily attractiveness. Additional analyses showed that tallness and leanness were also favoured, and, along with estimates of physical strength, accounted for 80% of men's bodily attractiveness. Contrary to popular theories of men's physical attractiveness, there was no evidence of a nonlinear effect; the strongest men were the most attractive in all samples.

Sex difference in attractiveness perceptions of strong and weak male walkers.

OBJECTIVES: Men and women accurately assess male physical strength from facial and body morphology cues. Women's assessments of male facial attractiveness, masculinity, and dominance correlate positively with male physical strength. A positive relationship also has been reported between physical strength and attractiveness of men's dance movements. Here, we investigate men's and women's attractiveness, dominance, and strength assessments from brief samples of male gait. METHODS: Handgrip strength (HGS) was measured in 70 heterosexual men and their gait was motion-captured. Men and women judged 20 precategorized strong (high HGS) and weak (low HGS) walkers on attractiveness, dominance, and strength, and provided a measure of their own HGS. RESULTS: Both men and women judged strong walkers higher on dominance and strength than weak walkers. Women but not men judged strong walkers more attractive than weak walkers. These effects were independent of observers' physical strength. CONCLUSIONS: Male physical strength is conveyed not only through facial and body morphology, but also through body movements. We discuss our findings with reference to studies suggesting that physical strength provides information about male quality in contexts of inter- and intrasexual selection. Am. J. Hum. Biol. 28:913-917, 2016. © 2016Wiley Periodicals, Inc.

Fatigue and physical function after hysterectomy measured by SF-36, ergometer, and dynamometer.

PURPOSE: Information is limited on the early postoperative rehabilitation following hysterectomy. Our purpose was to evaluate the different perioperative modalities of fatigue, pain, quality of life, and physical performance and their time-related. METHODS: A prospective, follow-up study of a cohort of women undergoing abdominal and vaginal hysterectomy at the Gynecology Department at Herning Hospital, Denmark. Data from 108 women with elective hysterectomy were compared pre- and postoperatively. The fatigue level was scored on a visual analogue scale and SF-36. Objective measurements were performed by dynamometer of hand grip, knee extension strength, and postural stability; further, by ergometer cycle work capacity and by impedance lean body mass. Quality of life was assessed using the SF-36 questionnaire. Patients were examined preoperatively and twice postoperatively. RESULTS: Women lost lean body mass 13 and 30 days after their hysterectomy (p < 0.01). Strength in hand (p < 0.05) and knees (p < 0.01) increased compared to preoperative values but no change in postural stability and work capacity was noted. Fatigue resumed to preoperative levels after 30 days. SF-36 revealed that the modality of 'physical functioning' and 'role limitations due to physical problems' remained significantly decreased at the end of the study (p < 0.01) CONCLUSION: Hysterectomy was associated with reduction in physical function assessed by SF-36 30 days after surgery. No impairment of performance was found in physical tests at days 13 and 30 postoperatively.

Aggressive-antisocial boys develop into physically strong young men.

Young men with superior upper-body strength typically show a greater proclivity for physical aggression than their weaker male counterparts. The traditional interpretation of this phenomenon is that young men calibrate their attitudes and behaviors to their physical formidability. Physical strength is thus viewed as a causal antecedent of aggressive behavior. The present study is the first to examine this phenomenon within a developmental framework. We capitalized on the fact that physical strength is a male secondary sex characteristic. In two longitudinal cohorts of children, we estimated adolescent change in upper-body strength using the slope parameter from a latent growth model. We found that males' antisocial tendencies temporally precede their physical formidability. Boys, but not girls, with greater antisocial tendencies in childhood attained larger increases in physical strength between the ages of 11 and 17. These results support sexual selection theory, indicating an adaptive congruence between male-typical behavioral dispositions and subsequent physical masculinization during puberty.

Face of a fighter: Bizygomatic width as a cue of formidability.

Humans can accurately extract information about men's formidability from their faces; however, the actual facial cues that inform these judgments have not been established. Here, through three studies, we test the hypothesis that bizygomatic width (i.e. facial width-to-height ratio, fWHR) covaries with actual physical formidability (hypothesis #1) and that humans use this cue when making assessments of formidability (hypothesis #2). Our data confirm that fWHR is predictive of actual fighting ability among professional combatants (study 1). We further show that subjects' assessments of formidability covary with the target's fWHR on natural faces (study 2), computer-generated images of strong and weak faces (study 2), and experimentally manipulated computer-generated faces (study 3). These results support the hypothesis that bizygomatic width is a cue of formidability that is assessed during agonistic encounters.

A Cross-Sectional Study of Gender-Specific Influences of Orthopedic Subspecialty Selection.

Background: Per the American Academy of Orthopaedic Surgeons, 6.5% of practicing orthopedic surgeons are female and a majority subspecialize in pediatrics, hand, and foot and ankle surgery. The study purpose is to evaluate influences of orthopedic subspecialty selection, specifically factors such as perceived strength, lifestyle, and mentorship influence on subspecialty decisions and to identify if gender plays a role in these perceptions. Methods: An IRB approved cross-sectional study was conducted via email distribution of a REDCapTM survey to U.S. licensed orthopedic surgeons. Data regarding demographics, professional degree, training and current practice location, and perceptions regarding orthopedic surgery was obtained using Likert rating scales. Data was analyzed using descriptive statistics with two-tailed student's t-tests (α=0.05). Results: The survey yielded 282 responses (182 females and 100 males). Overall, the distribution of residents (28%), fellows (6%), and attendings (66%) correlates well with the prevalence of each respective physician category in the field of orthopedic surgery. The study demonstrated no difference in subspecialty choice based on mentorship, work-life-balance, career advancement, subspecialty culture, salary potential, family planning, or schedule. However, a statistically significant difference exists regarding stereotypes, perceived strength required, and perception of discrimination from pursuing a specific orthopedic subspecialty. 27% of females and 10% of males reported discouragement from any subspecialty (p<0.05). Adult reconstructive and oncology were most frequently discouraged. Women reported not choosing a subspecialty because of perceived physical demands more often than men (p<0.001). Women reported an increased use of adaptive strategies in the operating room (p<0.001). Women were also more likely to report feeling discouraged from pursuing a subspecialty due to their gender (p<0.001). Both men and women reported mentorship as the most influential factor in subspecialty selection. Conclusion: Women and men reported different factors were important in their decision of subspecialty. Women were more likely to be discouraged from a subspecialty and experience discrimination based on their perceived strength compared to male peers. Residents, fellows, and attending surgeons valued mentorship as the most influential in their subspeciality choice. This study suggests intrinsic and extrinsic influences that may differentially affect male and female orthopedic surgeons when they choose a subspecialty. Level of Evidence: III.

Escalation on Kihon Checklist Scores Preceding the Certification of Long-Term Care Need in the Older Population in Japan. A 9-Year Retrospective Study.

Objectives: The Kihon Checklist (KCL) is valuable for predicting long-term care (LTC) certification. However, the precise association between KCL scores and the temporal dynamics of LTC need certification remains unclear. This study clarified the characteristic trajectory of KCL scores in individuals certified for LTC need. Methods: The KCL scores spanning from 2011 to 2019 were obtained from 5630 older individuals, including those certified for LTC need in November 2020, in Iiyama City, Nagano, Japan. We analyzed the KCL score trajectories using a linear mixed model, both before and after propensity score matching. Results: Throughout the 9-year observation period, the KCL scores consistently remained higher in the certified group compared to the non-certified group. Notably, a significant score increase occurred within the 3 years preceding LTC certification. Discussion: Our findings highlight the effectiveness of continuous surveillance using the KCL in identifying individuals likely to require LTC within a few years.

Synergistic effect of cellulo-xylanolytic and laccase enzyme consortia for improved deinking of waste papers.

This study reports the cellulo-xylanolytic cocktail production from Hypocrea lixii GGRK4 using multi-objective genetic algorithm-artificial neural network tool, resulting in 8.32 ± 1.07 IU/mL, 51.53 ± 3.78 IU/mL activity of CMCase and xylanase, respectively with more than 85 % residual activity at 60 °C and pH 6.0. Interestingly, metal ions viz. K+ and Ca2+ stimulated the enzyme activity, whereas Fe2+ and Cu2+ reduced the activity. Significant amounts of hydrophobic compounds, chromophores, and phenolics were released after wastepapers deinking. The deinking efficiency of 73.60 ± 2.45 % and 38.60 ± 1.34 % was obtained for photocopier paper and newspaper, respectively, whereas brightness of 89.90 ± 2.10 % ISO and 44.90 ± 1.63 % ISO was reported for both types of waste papers. The physical strength of deinked photocopier paper and newspapers, i.e., tensile index (3.10 and 0.50 %), tearing index (7.10 and 4.83 %), and burst factor (8.61) were enhanced whereas double fold property was decreased proving wastepaper reusability. This consortium showed effective and significant enzymatic deinking efficiency for recycled wastepapers.

Hands-Only Cardiopulmonary Resuscitation Education for Elementary School Students in Korea: Tracking by School Grade, Physical Characteristics, and Physical Strength.

Objectives: This study aimed to assess variations in chest compression depth among Korean elementary school students based on grade, physical characteristics, and strength. Methods: The study involved 140 children in the third to sixth grades from elementary schools. Before providing cardiopulmonary resuscitation (CPR) education, we assessed height, weight, BMI, grip strength, and back strength. Subsequently, CPR education was administered, followed by individual measurements of compression depth. The factors related to compression depths was analyzed using t-test, ANOVA and multivariable regression. Results: The mean compression depth was consistently lower than the guideline standard across all grades, indicating grade-dependent differences (p = 0.000). Moreover, height, weight, BMI, grip strength and back strength increased, exhibited significant increases with grade (p = 0.000). In multivariable regression analysis, it was observed that as grade increased, chest compression depth increased by 0.701 cm (p = 0.000). Conclusion: School grade significantly influenced achieving the proper chest compressions depth, no notable correlation found for physical factors. Thus, a strategy emphasizing the importance of sufficient chest compressions during CPR education, particularly targeting elementary school students, seems necessary to encourage greater effort.

Longitudinal Development of Physical Characteristics and Function in Japanese Junior Rugby Union Players.

PURPOSE: To longitudinally investigate the development of physical characteristics and function during 3 years of high school among Japanese junior rugby players and examine the differences in these parameters between the positions. METHODS: In 83 junior rugby players (forwards: n = 46, backs: n = 37) from one Japanese high school team who had participated in national high school competitions, anthropometric variables (height, body mass, fat and lean body mass, and body mass index), upper- and lower-body strength (eg, 1-repetition-maximum [1RM] bench press, isokinetic knee muscle strength at 60°/s and 180°/s), and sprint and jump performance were measured. Upper- and lower-body strength relative to body mass and lean body mass were also calculated. RESULTS: All anthropometric indices improved with increasing age, and the values were higher in forwards than in backs (all P < .05). The 1-repetition maximum bench press (forwards: 40.8%, backs: 52.5%) and isokinetic knee strength (eg, extension at 60°/s, forwards: 15.4%, backs: 10.0%) improved with age (from 16 to 18 y), and they were higher in forwards than in backs (all P < .05). Meanwhile, the 1RM bench press relative to lean body mass did not differ between the positions. Isokinetic knee muscle strength at 60°/s and 180°/s relative to lean body mass and sprint and jump performance did not improve with age. CONCLUSION: These results indicate that Japanese junior rugby players need to develop larger physiques and continuously increase their lower-body strength to improve sprint and jump performance.

Subliminal mortality salience does not increase physical strength output in double-blind randomized controlled trial.

Introduction: Using the morality salience paradigm, this research tested whether subliminal death stimuli lead to increased physical strength. Moreover, it was investigated if mindfulness and self-esteem instability influence terror management. Methods: In total, data from 160 undergraduate sports students were analyzed. Participants completed a word decision task in which they were presented with either the word death or pain for 28.5 ms. Before and after the task, their grip strength was measured using a hand dynamometer. Results: Linear mixed models could neither confirm the effect of the mortality salience hypothesis on strength nor an influence of mindfulness and self-esteem. Discussion: The results raise the question of a potential influence of subliminal mortality salience on athletic performance and how mindfulness and self-esteem instability affect terror management.

Application of resistance trainer for dynamic mechanical properties of conjugated polymer materials in daily physical strength tensile training.

Resistance training is an important means to improve human function and health level, and tensile training, as an important form, has significant effects on enhancing muscle strength, improving body flexibility, and promoting body coordination. Tensile training can provide external resistance through the use of resistance trainers, allowing muscle groups to work under load. This load stimulation can gradually promote muscle adaptation and enhancement. This article took conjugated polymer materials as the research object. By analyzing and testing their dynamic mechanical properties, the mechanical response characteristics of polyacetylene materials were analyzed using strain rate functions. The mechanical properties and deformation behavior of polyacetylene materials under different conditions were evaluated. It was found that conjugated polymer materials had good strength, elasticity, and wear resistance, making them suitable for making resistance trainers. The experimental results indicated that this study used a conjugated polymer material resistance trainer to train the testing personnel for a period of 3 months. During this training period, the tester's endurance increased by 21%-29%, flexibility increased by 17%-25%, and explosive power increased by 24%-31%. The research results indicated that conjugated polymer materials had good plasticity and adjustability in the preparation of resistance training devices. Resistance devices of different shapes, sizes, and intensities can be prepared according to the needs and purposes of trainers, providing diverse and personalized choices for daily physical tensile training. The conjugated polymer material resistance trainer has significant effects and can effectively improve the physical fitness of testers. In addition, conjugated polymer materials exhibit excellent tensile performance and durability in resistance training, which can effectively meet the needs and requirements of trainers.

Development of a Digital Healthcare Management System for Lower-Extremity Amputees: A Pilot Study.

The research, which was designed as a "pre- and post-single group" study, included patients with lower-limb amputation and aimed to evaluate the effectiveness of self-directed physical-strength training and cardiovascular exercise using a novel digital healthcare management service three times a week for 12 weeks. Muscle strength, thigh circumference, lipid profile and glycated hemoglobin levels, pulmonary function, quality of life, and physical activity level were evaluated before and after the intervention, while satisfaction was measured after the study. Among the 14 included patients, the proportion of adherence to the physical-strength training and physical-strengthening activity were 85.2% and 75.8%, respectively. The level of satisfaction with the digital healthcare management system was high. Significant changes were observed in the muscle-strength tests (dominant grip power and muscle strength of knee flexion and extension of the intact side), thigh circumference, and glycated hemoglobin levels. Further, the quality-of-life score showed improvement, although without significant differences. Individualized exercise management using the novel digital healthcare management system for lower-limb amputees could induce interest in self-care and promote physical activity and healthy behavior. Through this effect, we can expect a reduction in the incidence of cardiovascular diseases, diabetes mellitus, dyslipidemia, and severe injuries from falling.

Bio-preservation of raw hides/skins: A review on greener substitute to conventional salt curing.

Raw hides/skins are considered to be the prime component for leather industry, which once flayed from animals, plummets to microbial attack. Their preservation combats putrefaction wherein curing using sodium chloride (NaCl) is by and large the most widely accepted method. However, there are few stumble blocks in using NaCl in terms of pollution load generated such as high total dissolved solids (TDS), total suspended solids (TSS), biological oxygen demand (BOD), chemical oxygen demand (COD) and chlorides (Cl-). Additionally, this effluent when discharged affects the quality of the water, soil and plants causing huge ecological damage. To evade these problems, researches are being carried out to explore alternative preservation techniques which are either salt free or with reduced amount of salt. Different methods were proposed time and again which remained unfeasible due to associated drawbacks like high cost, health hazards and environmental concerns. Therefore, finding cheaper, eco-friendly and sustainable method for preservation has become the need of the hour for this industry. This review meticulously summarizes the changing trends in preservation techniques for past few decades with special emphasis on bio-based preservation. The diversity of the natural preservatives explored for the said purpose has been systematically reviewed. The enormous environmental benefits that can be obtained by adopting bio-based preservation and future avenues of research have been discussed.

Strength Enhancement of Regenerated Cellulose Fibers by Adjustment of Hydrogen Bond Distribution in Ionic Liquid.

To improve the physical strength of regenerated cellulose fibers, cellulose dissolution was analyzed with a conductor-like screening model for real solvents in which 1-allyl-3-methylimidazolium chloride (AMIMCl) worked only as a hydrogen bond acceptor while dissolving the cellulose. This process could be promoted by the addition of urea, glycerol, and choline chloride. The dissolution and regeneration of cellulose was achieved through dry-jet and wet-spinning. The results demonstrated that the addition of hydrogen bond donors and acceptors either on their own or in combination can enhance the tensile strength, but their effects on the crystallinity of the regenerated fibers were quite limited. Compared with the regenerated fibers without any additives, the tensile strength was improved from 54.43 MPa to 139.62 MPa after introducing the choline chloride and glycerol, while related the crystallinity was only changed from 60.06% to 62.97%. By contrast, a more compact structure and fewer pores on the fiber surface were identified in samples with additives along with well-preserved cellulose frameworks. Besides, it should be noted that an optimization in the overall thermal stability was obtained in samples with additives. The significant effect of regenerated cellulose with the addition of glycerol was attributed to the reduction of cellulose damage by slowing down the dissolution and cross-linking in the cellulose viscose. The enhancement of the physical strength of regenerated cellulose fiber can be realized by the appropriate adjustment of the hydrogen bond distribution in the ionic liquid system with additives.