Search results for "SELECTION"
showing 10 items of 1940 documents
Role of Symbiosis in Evolution
2013
The biological relevance of the widespread prokaryote–eukaryote symbioses as a source of evolutionary innovation has been unveiled by the advent of the Genomic era, allowing deep knowledge on single or consortia uncultivable species. The establishment and maintenance of symbiosis are complex issues where partners’ fitness determines the evolutionary outcome. Comparative genomics allows to dissect the evolutionary process that begins with host invasion, takes the path from facultative to obligate symbiosis, and ends up in replacement or coexistence with new bacterial symbionts. Whole genomes of several intracellular bacterial symbionts have been sequenced, allowing the comparison among the d…
Mate choice for indirect genetic benefits: scrutiny of the current paradigm
2007
Summary 1Sexual selection through mate choice, and in particular female choice for indirect fitness benefits for their offspring, is a major paradigm that currently seems to enjoy almost unequivocal acceptance. A large body of theoretical work has been built to explain the evolution of mate choice in the absence of direct benefits, and the empiricists have enthusiastically verified the various assumptions and predictions of the theory. 2However, the relative importance of mate choice for indirect benefits in comparison to choice for direct benefits or to other mechanisms of sexual selection such as male–male competition or sensory exploitation remains a controversial issue, and this seems t…
Childhood football play and practice in relation to self-regulation and national team selection; a study of Norwegian elite youth players.
2018
Childhood sport participation is argued to be important to understand differences in self-regulation and performance level in adolescence. This study sought to investigate if football-specific activities in childhood (6–12 years of age) is related to self-regulatory skills and national under 14- and 15-team selection in Norwegian elite youth football. Data of practice histories and self-regulatory skills of 515 youth football players selected at Norwegian regional level were collected and further analysed using multilevel analyses. The results revealed that high self-regulated players were more likely to be selected for national initiatives, and increased their involvement in peer-led footb…
Pulsed-Resource Dynamics Constrain the Evolution of Predator-Prey Interactions
2011
Although temporal variability in the physical environment plays a major role in population fluctuations, little is known about how it drives the ecological and evolutionary dynamics of species interactions. We studied experimentally how extrinsic resource pulses affect evolutionary and ecological dynamics between the prey bacterium Serratia marcescens and the predatory protozoan Tetrahymena thermophila. Predation increased the frequency of defensive, nonpigmented prey types, which bore competitive costs in terms of reduced maximum growth rate, most in a constant-resource environment. Furthermore, the predator densities of the pulsed-resource environment regularly fluctuated above and below …
Optimal design of flax fiber reinforced polymer composite as a lightweight component for automobiles from a life cycle assessment perspective
2019
The present study combines the generalized rule-of-mixture (ROM) model and the Ashby material selection method for the life cycle assessment (LCA) of flax fiber reinforced polymers (FRPs) and glass FRPs (GFRPs). The ROM model allows life cycle environmental impact predictions according to specific parameters of flax FRPs such as fiber format, volume fraction, manufacturing technique, and load-bearing capacity. The comparisons applied in this study are constructed on two common composite structures: mat panels and injection molded struts with equal stiffness and strength as the design criteria. On the one hand, the parametric LCA predicts that the equal strength design criterion for flax FRP…
Local operators to detect regions of interest
1997
The performance of a visual system is strongly influenced by the information processing that is done in the early vision phase. The need exists to limit the computation on areas of interest to reduce the total amount of data and their redundancy. This paper describes a new method to drive the attention during the analysis of complex scenes. Two new local operators, based on the computation of local moments and symmetries, are combined to drive the selection. Experimental results on real data are also reported. © 1997 Elsevier Science B.V.
Multimodal data as a means to understand the learning experience
2019
Most work in the design of learning technology uses click-streams as their primary data source for modelling & predicting learning behaviour. In this paper we set out to quantify what, if any, advantages do physiological sensing techniques provide for the design of learning technologies. We conducted a lab study with 251 game sessions and 17 users focusing on skill development (i.e., user's ability to master complex tasks). We collected click-stream data, as well as eye-tracking, electroencephalography (EEG), video, and wristband data during the experiment. Our analysis shows that traditional click-stream models achieve 39% error rate in predicting learning performance (and 18% when we perf…
Seeking Information on Social Commerce: An Examination of the Impact of User- and Marketer-generated Content Through an Eye-tracking Study
2021
Following the growing popularity of social commerce sites, there is an increased interest in understanding how consumers decide what products to purchase based on the available information. Consumers nowadays are confronted with the task of assessing marketer-generated (MGC) as well as user-generated information (UGC) in a range of different forms to make informed purchase-related decisions. This study examines the information types and forms that influence consumers in their decision-making process on social commerce. Building on uses and gratifications and dual-process theories, we distinguish between marketer and user generated content, and differentiate formats into informational and no…
Default effects in app selection: German adolescents’ tendency to adhere to privacy or social relatedness features in smartphone apps
2019
Cognitive biases such as default effects impact on user preferences for a broad range of different choices. This paper investigates these default effects among adolescents configuring apps that either satisfy relatedness or enhance autonomy by protecting privacy. Relatedness and privacy are two innate needs that adolescents can satisfy with the use of smartphone apps. This study argues that adolescents’ choice of features supporting either privacy protection or social relatedness is a consequence of default effects, so that adolescents adhere to preselected defaults. We test this assumption in an experimental survey design including four app configuration tasks with N = 280 German adolesce…
On the Coincidence of the Feedback Nash and Stackelberg Equilibria in Economic Applications of Differential Games
2002
In this paper the scope of the applicability of the Stackelberg equilibrium concept in differential games is investigated. Firstly, conditions for obtaining the coincidence between the Stackelberg and Nash equilibria are defined in terms of the instantaneous pay-off function and the state equation of the game. Secondly, it is showed that for a class of differential games with state-interdependence both equilibria are identical independently of the player being the leader of the game. A survey of different economic models shows that this coincidence is going to occur for a good number of economic applications of differential games. This result appears because of the continuous-time setting i…