Effects of wing-to-body mass ratio on insect flapping flights

2021 ◽  
Vol 33 (2) ◽  
pp. 021902
Author(s):  
Ru Xu ◽  
Xiangdong Zhang ◽  
Hao Liu
Keyword(s):  
Body Mass ◽  
Mass Ratio ◽  
Body Mass Ratio

scholarly journals Using relative brain size to better understand trophic interactions and phenotypic plasticity of invasive lionfish (Pterois volitans)

2020 ◽  
Author(s):  
McKenna Becker
Keyword(s):  
Body Mass ◽  
Brain Size ◽  
Predation Pressure ◽  
Mass Ratio ◽  
Pterois Volitans ◽  
Predator Prey ◽  
Brain Mass ◽  
Body Mass Ratio ◽  
Relative Brain Size ◽  
The Brain

AbstractPredator-prey dynamics provide critical insight into overall coral reef health. It has been shown that predator-prey relationships link the relative brain size of predators to their prey. Predation pressure forces prey to use decision-making skills that require higher cognition by inspecting and identifying predators and then adjusting their behavior to achieve the highest chance for survival. However, the predation pressure that prey face outweighs the pressure predators face to find prey, resulting in prey having larger relative brain sizes than their predators. There is little data on the relative brain size of fishes with few natural predators such as Pterois volitans. This study compared the brain mass to body mass ratio of Pterois volitans, which have very few natural predators and thus very little predation pressure, to the brain mass to body mass ratio of their prey, possible predators, competitors, and taxonomically similar fish. Lionfish had a significantly smaller relative brain size than their predators, prey, and competitors, but was not significantly smaller than taxonomically similar fish. These results demonstrate that the morphological anti-predator adaptation of venomous spines causes little predation pressure. Thus, lionfish do not use the same cognitive skills as other prey or predators and, in turn, have smaller relative brain sizes.

scholarly journals PO-201 Aging attenuates the effect of aerobic capacity in muscle and serum metabolic profile but not in white adipose tissue

2018 ◽  
Vol 1 (5) ◽  
Author(s):  
Haihui Zhuang ◽  
Sari M Karvinen ◽  
Xiaobo Zhang ◽  
Xiaoyan Wang ◽  
Xiaowei Ojanen ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Body Mass ◽  
White Adipose Tissue ◽  
Aerobic Capacity ◽  
Metabolic Profile ◽  
Acid Metabolism ◽  
Mass Ratio ◽  
Metabolic Interactions ◽  
Old Rats ◽  
Body Mass Ratio

Objective Aerobic capacity is a quantitative predictor of the morbidity and mortality in many diverse patient populations. While aging is the main factor affecting aerobic capacity. The present study aimed to assess the effect of aerobic capacity and aging on metabolic profile in rats and to investigate the metabolic interactions between white adipose tissue (WAT), muscle and serum. Methods In this study, we used rat models that were selectively bred to differ in maximal running capacity (High capacity runners (HCR) and Low capacity runners (LCR)). Part of the rats were sacrificed after 9 months and the rest at 21 months. The effect of aerobic capacity on metabolic profile was assessed from 9 months old young rats (HCR-Y and LCR-Y), while the effect of aging on the metabolic profile in different capacity rats was determined comparing 9 months to 21 months old rats (HCR-O and LCR-O). Nuclear magnetic resonance (NMR) spectroscopy was performed to detect the metabolomics of WAT, muscle and serum. Partial least-squares-discriminant analysis (PLS-DA) was used for pattern recognition between HCR-Y and LCR-Y and between HCR-O and LCR-O. Metabolites with variable influence on projection (VIP) >1.0 and p<0.05 were classified as significantly different metabolites between groups. Spearman correlation was used to assess the metabolic interactions between white adipose tissue (WAT), muscle and serum. Results  HCR-Y rats had significantly higher skeletal muscle mass-to-body mass ratio (p<0.001), while lower body mass (p<0.001), fat mass (p<0.001), skeletal muscle mass (p=0.035) and fat mass to body mass ratio (p=0.004) than LCR-Y rats. The running capacity of HCR-Y rats was 132.7% (best running speed) better than LCR-Y rats (p<0.001). However, with age, the difference between body compositions between the two capacity groups became insignificant. HCR-O only had significantly lower body mass than the LCR-O (p=0.02). Running capacity (p=0.06) was 86.4% (best running speed) higher in the HCR-O rats than that of the LCR-O rats. PLS-DA revealed marked effects of aerobic capacity on metabolic profile in all three tissue types between HCR-Y and LCR-Y. The metabolic profile classification and prediction was best (i.e. sharper) in muscle than in WAT and serum. In addition, muscle and serum contained more significantly different metabolites than WAT in HCR-Y than in LCR-Y. Pathway analysis of the significantly different metabolites between HCR-Y and LCR-Y revealed that all the pathways belong to the lipid metabolism and amino acid metabolism in muscle while in serum it is only amino acid metabolism. However, in the case of the old groups, the PLS-DA gave reversed results. It revealed that WAT performed best in terms of classification and prediction of metabolites between HCR-O and LCR-O and had the most significantly different metabolites out of the three tissue types. The significantly different metabolites’ pathways belong to lipid metabolism in WAT. When assessing the metabolic interaction between different tissue types, all significantly different metabolites between HCR and LCR rats in young and old groups were moderately or strongly correlated (Spearman correlation between 0.45-0.9) with one or more metabolites in any of the three tissues. Conclusions In this study, we assessed the metabolic profile and body composition of WAT, muscle and serum in young and old rats with different aerobic capacities. We found that aerobic capacity greatly impacts body composition and the metabolic profile in muscle and serum in young rats, however the impact is attenuated with age. In addition, it is aging and not aerobic capacity that had the most influence on WAT metabolites. This suggest that WAT has more important role in aging process than previously assumed.

A comparison of men's and women's strength to body mass ratio and varus/valgus knee angle during jump landings

2011 ◽  
Vol 29 (13) ◽  
pp. 1435-1442 ◽  
Author(s):  
Tracie L. Haines ◽  
Jeffrey M. McBride ◽  
N. Travis Triplett ◽  
Jared W. Skinner ◽  
Kimberly R. Fairbrother ◽  
...  
Keyword(s):  
Body Mass ◽  
Valgus Knee ◽  
Mass Ratio ◽  
Knee Angle ◽  
Body Mass Ratio ◽  
Jump Landings

Seasonal Changes of Body Mass, Body Composition, and Muscular Performance in Collegiate Wrestlers

2008 ◽  
Vol 3 (2) ◽  
pp. 176-184 ◽  
Author(s):  
Thomas W. Buford ◽  
Douglas B. Smith ◽  
Matthew S. O’Brien ◽  
Aric J. Warren ◽  
Stephen J. Rossi
Keyword(s):  
Body Composition ◽  
Body Mass ◽  
Peak Torque ◽  
Mass Ratio ◽  
Leg Extension ◽  
Performance Variables ◽  
Muscular Performance ◽  
National Competition ◽  
Consecutive Time ◽  
Body Mass Ratio

Purpose:The purpose of the present investigation was to examine the physiological response of collegiate wrestlers to their competitive season.Methods:Eleven Division I collegiate wrestlers (mean ± SD; 19.45 ± 1.13 y) volunteered and completed 4 testing sessions throughout the course of the collegiate wrestling season. Testing sessions were conducted pre-, mid-, and postseason, as well as before the national tournament. Testing consisted of weigh-in, skinfold body composition testing, and a 50-rep concentric, isokinetic leg extension muscle endurance test (180°/s). Muscular performance variables measured included peak torque, peak torque at fatigue, percent decline, and peak torque/body mass ratio.Results:A significant increase (P < .05) of 2.9% was observed for body mass between midseason and postseason (2.38 kg). From pre- to postseason, a mean increase of 3.8% (3.1 kg) was observed for body mass. An increase (P < .05) in BF% of 2.9% was observed between prenationals and postseason. No significant differences (P > .05) were observed between consecutive time points for quadriceps peak torque; however, there was a significant increase (P < .05) between preseason and prenationals (23.39 N·m). Peak torque at fatigue was greater (P < .05) at midseason than preseason, representing an increase of 9.82 N·m. Between midseason and prenationals testing, we observed an 11% increase (P < .05) in %DCLN. Finally, we noted an increase (P < .05) from 0.6 to 0.69 in peak torque/body mass ratio between preseason and prenationals.Conclusions:Our results indicate that while force values seem to suffer at midseason, the wrestlers compensated and were strongest just before their national competition.

Correlation between shell-body mass ratio and hydrostatic settling characteristics of mollusc species

2018 ◽  
Vol 38 (18) ◽  
Author(s):  
罗渡 LUO Du ◽  
汪学杰 WANG Xuejie ◽  
徐猛 XU Meng ◽  
顾党恩 GU Dang'en ◽  
牟希东 MU Xidong ◽  
...  
Keyword(s):  
Body Mass ◽  
Mass Ratio ◽  
Mollusc Species ◽  
Body Mass Ratio ◽  
Settling Characteristics

Sex differences in the resistive and elastic work of breathing during exercise in endurance-trained athletes

2009 ◽  
Vol 297 (1) ◽  
pp. R166-R175 ◽  
Author(s):  
Jordan A. Guenette ◽  
Jordan S. Querido ◽  
Neil D. Eves ◽  
Romeo Chua ◽  
A. William Sheel
Keyword(s):  
Sex Differences ◽  
Body Mass ◽  
Minute Ventilation ◽  
Work Of Breathing ◽  
Esophageal Pressure ◽  
Work Rate ◽  
Mass Ratio ◽  
Volume Data ◽  
Exercising Women ◽  
Body Mass Ratio

It is not known whether the high total work of breathing (WOB) in exercising women is higher due to differences in the resistive or elastic WOB. Accordingly, the purpose of this study was to determine which factors contribute to the higher total WOB during exercise in women. We performed a comprehensive analysis of previous data from 16 endurance-trained subjects (8 men and 8 women) that underwent a progressive cycle exercise test to exhaustion. Esophageal pressure, lung volumes, and ventilatory parameters were continuously monitored throughout exercise. Modified Campbell diagrams were used to partition the esophageal-pressure volume data into inspiratory and expiratory resistive and elastic components at 50, 75, 100 l/min and maximal ventilations and also at three standardized submaximal work rates (3.0, 3.5, and 4.0 W/kg). The total WOB was also compared between sexes at relative submaximal ventilations (25, 50, and 75% of maximal ventilation). The inspiratory resistive WOB at 50, 75, and 100 l/min was 67, 89, and 109% higher in women, respectively ( P < 0.05). The expiratory resistive WOB was 131% higher in women at 75 l/min ( P < 0.05) with no differences at 50 or 100 l/min. There were no significant sex differences in the inspiratory or expiratory elastic WOB across any absolute minute ventilation. However, the total WOB was 120, 60, 50, and 45% higher in men at 25, 50, 75, and 100% of maximal exercise ventilation, respectively ( P < 0.05). This was due in large part to their much higher tidal volumes and thus higher inspiratory elastic WOB. When standardized for a given work rate to body mass ratio, the total WOB was significantly higher in women at 3.5 W/kg (239 ± 31 vs. 173 ± 12 J/min, P < 0.05) and 4 W/kg (387 ± 53 vs. 243 ± 36 J/min, P < 0.05), and this was due exclusively to a significantly higher inspiratory and expiratory resistive WOB rather than differences in the elastic WOB. The higher total WOB in women at absolute ventilations and for a given work rate to body mass ratio is due to a substantially higher resistive WOB, and this is likely due to smaller female airways relative to males and a breathing pattern that favors a higher breathing frequency.

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