scholarly journals The sources of sex differences in aging in annual fishes

2020 ◽  
Author(s):  
Martin Reichard ◽  
Radim Blažek ◽  
Jakub Žák ◽  
Petr Kačer ◽  
Oldřich Tomášek ◽  
...  
Keyword(s):  
Sex Differences ◽  
Social Environment ◽  
Social Factors ◽  
Environmental Conditions ◽  
Natural Populations ◽  
Experimental Results ◽  
Survival Difference ◽  
Captive Populations ◽  
Baseline Mortality ◽  
In The Wild

AbstractSex differences in lifespan and aging are widespread among animals, with males usually the shorter-lived sex. Despite extensive research interest, it is unclear how lifespan differences between the sexes are modulated by genetic, environmental and social factors. We combined comparative data from natural populations of annual killifishes with experimental results on replicated captive populations, showing that females consistently outlived males in the wild. This sex-specific survival difference persisted in social environment only in two most aggressive species, and ceased completely when social and physical contacts were prevented. Demographically, neither an earlier start nor faster rate of aging accounted for shorter male lifespans, but increased baseline mortality and the lack of mortality deceleration in the oldest age shortened male lifespan. The sexes did not differ in any measure of functional aging we recorded. Overall, we demonstrate that sex differences in lifespan and aging may be ameliorated by modulating social and environmental conditions.

scholarly journals No sex differences in learning in wild bumblebees

2021 ◽  
Author(s):  
Felicity Muth ◽  
Amber D Tripodi ◽  
Rene Bonilla ◽  
James P Strange ◽  
Anne S Leonard
Keyword(s):  
Sex Differences ◽  
Associative Learning ◽  
Sierra Nevada ◽  
Comparative Cognition ◽  
Natural Populations ◽  
Interspecific Variation ◽  
Learning Task ◽  
Learning Ability ◽  
Learning Performance ◽  
Males And Females

Abstract Females and males often face different sources of selection, resulting in dimorphism in morphological, physiological, and even cognitive traits. Sex differences are often studied in respect to spatial cognition, yet the different ecological roles of males and females might shape cognition in multiple ways. For example, in dietary generalist bumblebees (Bombus), the ability to learn associations is critical to female workers, who face informationally rich foraging scenarios as they collect nectar and pollen from thousands of flowers over a period of weeks to months to feed the colony. While male bumblebees likely need to learn associations as well, they only forage for themselves while searching for potential mates. It is thus less clear whether foraging males would benefit from the same associative learning performance as foraging females. In this system, as in others, cognitive performance is typically studied in lab-reared animals under captive conditions, which may not be representative of patterns in the wild. In the first test of sex and species differences in cognition using wild bumblebees, we compared the performance of Bombus vancouverensis nearcticus (formerly bifarius) and Bombus vosnesenskii of both sexes on an associative learning task at Sierra Nevada (CA) field sites. Across both species, we found that males and females did not differ in their ability to learn, although males were slower to respond to the sucrose reward. These results offer the first evidence from natural populations that male bumblebees may be equally as able to learn associations as females, supporting findings from captive colonies of commercial bees. The observed interspecific variation in learning ability opens the door to using the Bombus system to test hypotheses about comparative cognition.

Real-Time Identification and Tracking of Infrared Markers Based on Kalman Filter

2012 ◽  
Vol 249-250 ◽  
pp. 1147-1153
Author(s):  
Qiao Na Xing ◽  
Da Yuan Yan ◽  
Xiao Ming Hu ◽  
Jun Qin Lin ◽  
Bo Yang
Keyword(s):  
Kalman Filter ◽  
Visible Light ◽  
Real Time ◽  
Complex Terrain ◽  
Experimental Results ◽  
Identification Method ◽  
In The Wild ◽  
Real Time Identification

Automatic equipmenttransportation in the wild complex terrain circumstances is very important in rescue or military. In this paper, an accompanying system based on the identification and tracking of infrared LEDmarkers is proposed. This system avoidsthe defect that visible-light identification method has. In addition, this paper presents a Kalman filter to predict where infraredmarkers may appear in the nextframe imageto reduce the searchingarea of infrared markers, which remarkablyimproves the identificationspeed of infrared markers. The experimental results show that the algorithm proposed in this paper is effective and feasible.

Sex Differences in Interpreting Male-Female Dyad Interactions: Males' Predominance in Perceiving Sexual Intent

2002 ◽  
Vol 9 (3) ◽  
pp. 289-297 ◽  
Author(s):  
Aldert Vrij ◽  
Emma Kirby
Keyword(s):  
Gender Differences ◽  
Sex Differences ◽  
Social Environment ◽  
Rape Myths ◽  
Rape Myth ◽  
Sexual Intent ◽  
Female Dyad ◽  
Acceptance Scale ◽  
Males And Females ◽  
The Impact

Astudy is reported investigating gender differences in judging the behaviour of males and females during mixed-dyad conversations and the impact of the endorsement of rape myths in explaining these gender differences. A total of 51 males and 40 females watched a videotape of a male actor and female actor verbally interacting in a social environment and were asked to give their impression about this interaction. They were also requested to fill in the Rape Myths Acceptance Scale (1980). Results revealed that compared to females, males had a stronger tendency to see the interaction in sexual terms. Also, male participants endorsed rape myths more strongly. Finally, gender differences in rape myth endorsements accounted for gender differences in perceiving male-female mixed-dyad interactions to alimited extent. Implications of the findings are discussed.

A Comparison of Sport and Nonsport Occupational Aspirations among Disadvantaged Youth

1981 ◽  
Vol 3 (1) ◽  
pp. 58-68 ◽  
Author(s):  
Mary A. McElroy
Keyword(s):  
Sex Differences ◽  
Discriminant Analysis ◽  
Social Environment ◽  
Career Aspirations ◽  
Lower Class ◽  
Occupational Aspirations ◽  
Disadvantaged Youth ◽  
Related Factors ◽  
Sport Careers

Sport and nonsport career choices among economically disadvantaged adolescents enrolled in a summer sports program were explored. It was hypothesized that youngsters with sport career aspirations would demonstrate differences in sport-related attitudes and experiences when compared to youngsters with nonsport career aspirations. Nonsport career aspirations were categorized into two groups: one representing “high prestige” occupations and one representing “low prestige” occupations. Discriminant analysis revealed that disadvantaged youths' career aspirations were differentially related to the sport-related factors. Contrary to warnings of the potential dysfunctional consequences for those who aspire to sport careers, adolescents with sport career aspirations consistently scored higher on achievement-related socialization factors than those aspiring for traditional low-prestige occupations. Sex differences were noted and discussed in light of the role of sport in the lower class social environment.

An ecological explanation for hyperallometric scaling of reproduction

2021 ◽  
Author(s):  
Tomos Potter ◽  
Anja Felmy
Keyword(s):  
Body Size ◽  
Reproductive Output ◽  
Resource Competition ◽  
Natural Populations ◽  
Scaling Exponent ◽  
Wild Populations ◽  
Wet Season ◽  
Size Dependent ◽  
In The Wild ◽  
The Relationship

AbstractIn wild populations, large individuals have disproportionately higher reproductive output than smaller individuals. We suggest an ecological explanation for this observation: asymmetry within populations in rates of resource assimilation, where greater assimilation causes both increased reproduction and body size. We assessed how the relationship between size and reproduction differs between wild and lab-reared Trinidadian guppies. We show that (i) reproduction increased disproportionately with body size in the wild but not in the lab, where effects of resource competition were eliminated; (ii) in the wild, the scaling exponent was greatest during the wet season, when resource competition is strongest; and (iii) detection of hyperallometric scaling of reproduction is inevitable if individual differences in assimilation are ignored. We propose that variation among individuals in assimilation – caused by size-dependent resource competition, niche expansion, and chance – can explain patterns of hyperallometric scaling of reproduction in natural populations.

Dynamic Analysis of a Floating Offshore Wind Turbine Under Extreme Environmental Conditions

2012 ◽  
Author(s):  
Tomoaki Utsunomiya ◽  
Shigeo Yoshida ◽  
Hiroshi Ookubo ◽  
Iku Sato ◽  
Shigesuke Ishida
Keyword(s):  
Dynamic Analysis ◽  
Wind Turbine ◽  
Environmental Conditions ◽  
Aerodynamic Force ◽  
Experimental Results ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Analysis Tool ◽  
Simulation Code ◽  
Floating Offshore Wind Turbine

This paper is concerned with the development of a Floating Offshore Wind Turbine (FOWT) utilizing spar-type floating foundation. In order to design such a structure, it is essential to evaluate the dynamic response under extreme environmental conditions. In this study, therefore, a dynamic analysis tool has been developed. The dynamic analysis tool consists of a multi-body dynamics solver (MSC.Adams), aerodynamic force evaluation library (NREL/AeroDyn), hydrodynamic force evaluation library (In-house program named SparDyn), and mooring force evaluation library (In-house program named Moorsys). In this paper, some details of the developed dynamic analysis tool are given. In order to validate the program, comparison with the experimental results, where the wind, current and wave are applied simultaneously, has been made. The comparison shows that satisfactory agreements between the simulation and the experimental results are obtained. However, when VIM (Vortex Induced Motion) occurs, the current loads and cross flow responses (sway and roll) are underestimated by the simulation since the simulation code does not account for the effect of VIM.

scholarly journals REPRODUCTION IN CAGE POPULATIONS OF A POLYMORPHISM REGULARLY OBSERVED IN THE NATURAL POPULATIONS OF DROSOPHILA MELANOGASTER IN FRANCE

Genetics ◽  
1978 ◽  
Vol 88 (4) ◽  
pp. 755-759
Author(s):  
Annie Fleuriet
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Populations ◽  
Rate Of Return ◽  
Rapid Rate ◽  
Experimental Conditions ◽  
Co2 Sensitivity ◽  
In The Wild ◽  
Strong Forces

ABSTRACT Polymorphism for both alleles of a gene ref(2)P, which is a usual trait of French natural populations of Drosophila melanogaster, can be reproduced in experimental conditions. ref(2)P is a gene for resistance to the hereditary, noncontagious Rhabdovirus α, responsible for CO2 sensitivity in Drosophila melanogaster. The equilibrium frequencies observed in cages are the same as in the wild, whether α virus is present or not. The rapid rate of return to these equilibrium frequencies indicates that strong forces, which remain to be determined, are responsible for the maintenance of this polymorphism.

Hybridization of Biogeography-Based Optimization and Gravitational Search Algorithm for Efficient Face Recognition

2019 ◽  
pp. 258-279
Author(s):  
Lavika Goel ◽  
Lavanya B. ◽  
Pallavi Panchal
Keyword(s):  
Face Recognition ◽  
Evolutionary Algorithm ◽  
Search Algorithm ◽  
Gravitational Search Algorithm ◽  
Recognition Rate ◽  
Experimental Results ◽  
Nature Inspired Algorithm ◽  
In The Wild ◽  
Gravitational Search

This chapter aims to apply a novel hybridized evolutionary algorithm to the application of face recognition. Biogeography-based optimization (BBO) has some element of randomness to it that apart from improving the feasibility of a solution could reduce it as well. In order to overcome this drawback, this chapter proposes a hybridization of BBO with gravitational search algorithm (GSA), another nature-inspired algorithm, by incorporating certain knowledge into BBO instead of the randomness. The migration procedure of BBO that migrates SIVs between solutions is done between solutions only if the migration would lead to the betterment of a solution. BBO-GSA algorithm is applied to face recognition with the LFW (labelled faces in the wild) and ORL datasets in order to test its efficiency. Experimental results show that the proposed BBO-GSA algorithm outperforms or is on par with some of the nature-inspired techniques that have been applied to face recognition so far by achieving a recognition rate of 80% with the LFW dataset and 99.75% with the ORL dataset.

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