scholarly journals CORRELATIONS OF THE POSITION OF CENTER OF BODY MASS WITH BUTTERFLY ESCAPE TACTICS

1993 ◽  
Vol 174 (1) ◽  
pp. 155-166 ◽  
Author(s):  
R. B. Srygley ◽  
R. Dudley
Keyword(s):  
Body Mass ◽  
Body Shape ◽  
Natural Experiment ◽  
Flight Speed ◽  
Flight Performance ◽  
Important Indicator ◽  
Future Studies ◽  
Wing Base ◽  
Palatable Species ◽  
Mass Allocation

Using the evolution of neotropical butterflies as a natural experiment, we examine Ellington's biomechanical hypothesis that the position of center of body mass affects insect maneuverability. We find that the position of center of body mass is correlated with the butterflies' palatability, natural flight speeds and their ability to evade predators in a small cage. Relative to distasteful species, palatable butterflies fly faster and maneuver more successfully to evade attacks from aerial predators. The large thorax and short abdomen of palatable species position the center of body mass near to the wing base, whereas the mass allocation and body shape of distasteful butterflies position center of body mass further posteriorly. The position of center of body mass is an important indicator of flight performance, including both aerial maneuverability and flight speed, that warrants incorporation into future studies of invertebrate and vertebrate flight.

Locomotor mimicry in butterflies? The associations of positions of centres of mass among groups of mimetic, unprofitable prey

1994 ◽  
Vol 343 (1304) ◽  
pp. 145-155 ◽  
Keyword(s):  
The Body ◽  
Flight Speed ◽  
Morphological Parameters ◽  
Flight Performance ◽  
Wing Base ◽  
Distinct Character ◽  
Components Analysis ◽  
Morphological Differences ◽  
Palatable Species ◽  
Radial Moments

With detailed measurements of flight-related morphological parameters of 18 species within the tribe Heliconiini and 10 of their non-heliconiine comimics, I found that morphological parameters relevant to flight biomechanics are associated with three escape tactics of these Neotropical butterflies: evasive flight, distastefulness, and mimicry. Two distinct character suites, one pertaining to the position of centre of body mass and another pertaining to wing shape, were identified using principal-components analysis. A third component correlated most highly with the position of centre of wing mass. Mimicry groups were best discriminated by the positions of centres of body and wing mass, suggesting that these features converged within mimicry groups. Centres of mass were positioned nearer to the wing base in mimicry groups composed of more palatable species, presumably decreasing the radial moments of inertia of the body and wings and increasing flight speed and turning performance. Predation has selected for body morphology that increases flight speed and manoeuvrability in palatable butterflies, whereas the morphology of distasteful species compromises flight performance. Convergent selection may reduce morphological differences of species within mimicry groups arising from distantly related lineages, and hence it may have enhanced the morphological diversification of palatable and unpalatable butterflies within lineages that have more recently evolved distastefulness.

scholarly journals Ontogeny of body size and shape of Antarctic and subantarctic fur seals

2007 ◽  
Vol 85 (12) ◽  
pp. 1275-1285 ◽  
Author(s):  
Sebastián P. Luque ◽  
Edward H. Miller ◽  
John P.Y. Arnould ◽  
Magaly Chambellant ◽  
Christophe Guinet
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Morphological Traits ◽  
Body Shape ◽  
Size And Shape ◽  
Fur Seals ◽  
Fur Seal ◽  
Adult Body ◽  
Weaning Age ◽  
Lactation Duration

Pre- and post-weaning functional demands on body size and shape of mammals are often in conflict, especially in species where weaning involves a change of habitat. Compared with long lactations, brief lactations are expected to be associated with fast rates of development and attainment of adult traits. We describe allometry and growth for several morphological traits in two closely related fur seal species with large differences in lactation duration at a sympatric site. Longitudinal data were collected from Antarctic ( Arctocephalus gazella (Peters, 1875); 120 d lactation) and subantarctic ( Arctocephalus tropicalis (Gray, 1872); 300 d lactation) fur seals. Body mass was similar in neonates of both species, but A. gazella neonates were longer, less voluminous, and had larger foreflippers. The species were similar in rate of preweaning growth in body mass, but growth rates of linear variables were faster for A. gazella pups. Consequently, neonatal differences in body shape increased over lactation, and A. gazella pups approached adult body shape faster than did A. tropicalis pups. Our results indicate that preweaning growth is associated with significant changes in body shape, involving the acquisition of a longer, more slender body with larger foreflippers in A. gazella. These differences suggest that A. gazella pups are physically more mature at approximately 100 d of age (close to weaning age) than A. tropicalis pups of the same age.

Insoddisfazione corporea in adolescenza: influenze di fattori bio-psico-sociali

2009 ◽  
pp. 51-65
Author(s):  
Cristina Stefanile ◽  
Camilla Matera ◽  
Elena Pisani ◽  
Ilaria Zambrini
Keyword(s):  
Risk Factors ◽  
Body Mass Index ◽  
Body Dissatisfaction ◽  
Body Mass ◽  
Body Shape ◽  
Eating Habits ◽  
Self Esteem ◽  
Normal Weight ◽  
Sociocultural Influences ◽  
Shape Concern

- Body dissatisfaction is a central aspect for self-evaluation; pressures to maintain an ideal physique can result in disordered eating habits. In young women, body concern and anxiety related to some parts of it can be expressed through their desire to lose weight. The aim of the study is to analyze the role of some risk factors, such as Body Mass Index (BMI), low self-esteem and sociocultural influences in affecting body dissatisfaction, expressed in terms of distance from an ideal and body concern. Participants are 187 adolescent females aged between 14 and 16. Risk factors taken into consideration seem to have a different effect on the two aspects characterizing dissatisfaction. BMI, self-esteem and internalization of a thin ideal seem to influence the distance perceived from an ideal body; pressure, besides BMI and self-esteem, affect weight and body shape concern. Body shape concern seems to be influenced even by internalization and awareness. It can be observed that such risk factors, in particular BMI, play a different role in adolescents classified as normal weight and underweight.Parole chiave: immagine corporea, insoddisfazione corporea, adolescenti femmine, influenze socioculturali, autostima, indice di massa corporeaKey words: body image, body dissatisfaction, adolescent girls, sociocultural influences, selfesteem, body mass index

scholarly journals Kinematics Measurement and Power Requirements of Fruitflies at Various Flight Speeds

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4271
Author(s):  
Hao Jie Zhu ◽  
Mao Sun
Keyword(s):  
The Body ◽  
Flight Speed ◽  
Specific Power ◽  
Flight Performance ◽  
Wingbeat Frequency ◽  
Body Angle ◽  
Flying Insects ◽  
Speed Range ◽  
Full Speed ◽  
Stroke Amplitude

Energy expenditure is a critical characteristic in evaluating the flight performance of flying insects. To investigate how the energy cost of small-sized insects varies with flight speed, we measured the detailed wing and body kinematics in the full speed range of fruitflies and computed the aerodynamic forces and power requirements of the flies. As flight speed increases, the body angle decreases and the stroke plane angle increases; the wingbeat frequency only changes slightly; the geometrical angle of attack in the middle upstroke increases; the stroke amplitude first decreases and then increases. The mechanical power of the fruitflies at all flight speeds is dominated by aerodynamic power (inertial power is very small), and the magnitude of aerodynamic power in upstroke increases significantly at high flight speeds due to the increase of the drag and the flapping velocity of the wing. The specific power (power required for flight divided by insect weigh) changes little when the advance ratio is below about 0.45 and afterwards increases sharply. That is, the specific power varies with flight speed according to a J-shaped curve, unlike those of aircrafts, birds and large-sized insects which vary with flight speed according to a U-shaped curve.

scholarly journals Comparisons of Visceral Adiposity Index, Body Shape Index, Body Mass Index and Waist Circumference and Their Associations with Diabetes Mellitus in Adults

Nutrients ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1580 ◽  
Author(s):  
Wei ◽  
Liu ◽  
Xue ◽  
Wang ◽  
Shi
Keyword(s):  
Body Mass Index ◽  
Waist Circumference ◽  
Body Mass ◽  
Body Shape ◽  
Multivariate Logistic Regression Analysis ◽  
Shape Index ◽  
Visceral Adiposity ◽  
Youden Index ◽  
Visceral Adiposity Index ◽  
Adiposity Index

The associations between visceral adiposity index (VAI), body shape index and diabetes in adults were inconsistent. We assessed the predictive capacity of VAI and body shape index for diabetes by comparing them with body mass index (BMI) and waist circumference (WC). We used the data of 5838 Chinese men and women aged ≥18 years from the 2009 China Health and Nutrition Survey. Multivariate logistic regression analysis was performed to examine the independent associations between Chinese VAI (CVAI) or body shape index and diabetes. The predictive power of the two indices was assessed using the receiver-operating characteristic (ROC) curve analysis, and compared with those of BMI and WC. Both CVAI and body shape index were positively associated with diabetes. The odds ratios for diabetes were 4.9 (2.9–8.1) and 1.8 (1.2–2.8) in men, and 14.2 (5.3–38.2) and 2.0 (1.3–3.1) in women for the highest quartile of CVAI and body shape index, respectively. The area under the ROC (AUC) and Youden index for CVAI was the highest among all four obesity indicators, whereas BMI and WC are better indicators for diabetes screening. Higher CVAI and body shape index scores are independently associated with diabetes risk. CVAI has a higher overall diabetes diagnostic ability than BMI, WC and body shape index in Chinese adults. BMI and WC, however, are more appealing as screening indicators considering their easy use.

I can’t stop looking at them: Interactive effects of body mass index and weight dissatisfaction on attention towards body shape photographs

Body Image ◽  
2013 ◽  
Vol 10 (2) ◽  
pp. 191-199 ◽  
Author(s):  
Xiao Gao ◽  
Xiaojing Li ◽  
Xiaoying Yang ◽  
Yang Wang ◽  
Todd Jackson ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Body Shape ◽  
Interactive Effects

Assessment of the ideal body image of women in Accra, Ghana

2007 ◽  
Vol 37 (4) ◽  
pp. 241-244 ◽  
Author(s):  
Rosemary B Duda ◽  
Naana Afua Jumah ◽  
Allan G Hill ◽  
Joseph Seffah ◽  
Richard Biritwum
Keyword(s):  
Body Mass Index ◽  
Body Image ◽  
Body Mass ◽  
Body Shape ◽  
Normal Body Mass Index ◽  
Morbidly Obesity ◽  
Ideal Body Image ◽  
Ideal Body ◽  
Ghanaian Women ◽  
The Ideal

The hypothesis tested in this study was that the 'traditional build' is the culturally valued body shape by Ghanaian women. Culturally sensitive figural stimuli were designed to assess the current body image (CBI) and the ideal body image (IBI) of Ghanaian women. The most frequently selected model for the CBI was one that represented a slightly overweight woman; the IBI selected was consistent with a representation of normal body mass index; and the least healthy image was that figure that represented morbidly obesity.

scholarly journals Vitamin C decreases the obesogenic and hyperglycemic effect of invert sugar in prediabetic rats

2017 ◽  
Vol 30 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Patrícia MOLZ ◽  
Alana Nunes RAEL ◽  
Maiara de Queiroz FISCHER ◽  
Luana Beatriz LIMBERGER ◽  
Daniel PRÁ ◽  
...  
Keyword(s):  
Vitamin C ◽  
Glucose Tolerance ◽  
Body Mass ◽  
Wistar Rats ◽  
Area Under The Curve ◽  
Tolerance Test ◽  
Invert Sugar ◽  
Future Studies ◽  
Fasting Glycemia ◽  
Male Wistar Rats

ABSTRACT Objective: To evaluate whether vitamin C can help to prevent obesity and hyperglycemia in Wistar rats treated with excess invert sugar to induce prediabetes. Methods: One hundred-day-old Male Wistar rats with a mean weight of 336.58±23.43g were randomly assigned to the following groups: (1) control, receiving water (C); (2) invert sugar control, receiving a 32% watery solution of invert sugar; (3) vitamin C control, receiving a watery solution of vitamin C (60mg/L), and (4) vitamin C plus invert sugar, receiving a watery solution of vitamin C and invert sugar. All animals had access to chow and water ad libitum and were treated for 17 weeks. Prediabetes was assessed according to two criteria: obesity (based on body mass indexand peritoneal fat content) and impaired glucose tolerance (assessed by the intraperitoneal glucose tolerance test and expressed as area under the curve) . Results: Group invert sugar control gained significantly more weight (p=0.035) and visceral fat (p<0.001) than groups vitamin C control and vitamin C plus invert sugar. Consequently, groups vitamin C control and vitamin C plus invert sugar had gained as little body mass index as group C by the end of the experiment. Vitamin C decreased the fasting glycemia of both groups supplemented with vitamin C and normalized the glucose tolerance of group vitamin C plus invert sugar, whose area under the curve matched that of group C. Conclusion: Vitamin C has anti-obesogenic and glycemia-lowering effects in Wistar rats, which might be promising to prediabetics. Future studies are needed to understand the anti-obesogenic and anti-hyperglycemic mechanisms of vitamin C in prediabetes.

scholarly journals Ultraviolet reflectance by the cere of raptors

2006 ◽  
Vol 2 (2) ◽  
pp. 173-176 ◽  
Author(s):  
François Mougeot ◽  
Beatriz E Arroyo
Keyword(s):  
Mate Choice ◽  
Body Mass ◽  
Male Body ◽  
Sexual Signal ◽  
Future Studies ◽  
Circus Pygargus ◽  
Ultraviolet Reflectance ◽  
Uv Reflectance ◽  
Sexual Signalling ◽  
Carotenoid Pigmentation

Ultraviolet (UV) signals have been shown to play key roles in social and sexual signalling in birds. Using a spectrophotometer, we analysed the colour of the cere (skin above the beak) of a diurnal raptor, the Montagu's harrier ( Circus pygargus ), and show that it reflects in the UV part of the spectrum. The cere is a well-known sexual signal in raptors, with carotenoid based pigmentation being indicative of quality. We thus hypothesized that UV reflectance also signals quality. Accordingly, we found that in our sample of wild males, the location of the UV peak was related to the orangeness of cere and correlated with male body mass and condition (mass corrected for size). Also, males with brighter UV were mated to females that laid earlier, as expected if UV reflectance relates to a male's quality and attractiveness. Future studies should investigate the relationships between UV reflectance and carotenoid pigmentation of cere, and test how UV reflectance influences mate choice.

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