Search results for " modeling"
showing 10 items of 2411 documents
Sex influences rat personality more than geographical origin
2011
Abstract The Norway rat is an indispensable model organism. Behavioral studies on rats usually concentrate on a single trait without considering how different behaviors are linked to each other and whether there are differences in this respect between rat strains or sexes. This study aims to describe the personality structure of the Norway rat, and investigate if the structure of personality varies between sexes or populations, using owner assessments of pet rats. Rat owners from three countries filled out a questionnaire which was analyzed using structural equation modeling. The data were divided between the sexes and populations, resulting in six groups. Preliminary exploratory factor ana…
Open challenges in environmental data analysis and ecological complex systems (a)
2020
Abstract This letter focuses on open challenges in the fields of environmental data analysis and ecological complex systems. It highlights relations between research problems in stochastic population dynamics, machine learning and big data research, and statistical physics. Recent and current developments in statistical modeling of spatiotemporal data and in population dynamics are briefly reviewed. The presentation emphasizes stochastic fluctuations, including their statistical representation, data-based estimation, prediction, and impact on the physics of the underlying systems. Guided by the common thread of stochasticity, a deeper and improved understanding of environmental processes an…
Measuring the potential for growth in populations investing in diapause
2014
AbstractThe intrinsic rate of population increase (r) is a common performance measure in many ecological and evolutionary studies. However, in life cycles with diapause investment resources are split into a short-term (current population growth) and a long-term (population survival through periods of unsuitable habitat conditions) component, which complicates the use of r as a single performance measure. Here we propose a new measure that integrates both performance components into a single parameter, the potential intrinsic growth rate, rpot. This is the rate of increase that a population/genotype would have if no investment in diapausing stages would occur. We show that rpot can be comput…
Opinion dynamics and stubbornness through mean-field games
2013
This paper provides a mean field game theoretic interpretation of opinion dynamics and stubbornness. The model describes a crowd-seeking homogeneous population of agents, under the influence of one stubborn agent. The game takes on the form of two partial differential equations, the Hamilton-Jacobi-Bellman equation and the Kolmogorov-Fokker-Planck equation for the individual optimal response and the population evolution, respectively. For the game of interest, we establish a mean field equilibrium where all agents reach epsilon-consensus in a neighborhood of the stubborn agent's opinion.
Validation of the F-DBQ: A short (and accurate) risky driving behavior questionnaire for long-haul professional drivers
2021
Abstract Although the Driving Behavior Questionnaire (DBQ) remains the most known tool for assessing risky road behaviors among motor vehicle drivers, recent studies have raised several concerns on the specificity of both driving task conditions and behavioral repertory of certain segments of the driving population. Among them, long-haul (cargo) professional drivers constitute one of the “intensive driving” groups for which the existing adapted behavioral research tools are still very scarce. Purpose The aim of the present study was to test and validate the F-DBQ (or “Freight Driving Behavior Questionnaire”), a short version of the DBQ adapted to the occupational driving conditions and typi…
Autism spectrum disorders and anxiety: measurement and treatment
2021
Abstract Autism spectrum disorders (ASDs) are a group of neurodevelopmental disorders that have, in common, deficits in communication and social interaction and present repetitive behaviors and restricted interests. There is a great variability of symptoms associated with ASD. Among them, anxiety disorders are perhaps one of the most frequent and most developmentally disruptive in children, youths, and adults, which generate alterations in family life also. The treatments based on cognitive–behavioral therapy (CBT) have the highest scientific evidence. In a population with ASD, both program adaptations and specific programs have been developed. Due to its characteristics, the most studied p…
Generating a Located Synthetic Population of Individuals, Households, and Dwellings
2017
Some of the new approaches in urban modeling, such as multi-agent systems (MAS) or activity-based models (ABM), require inputs in the form of disaggregated individual data. But for privacy protection reasons, such data is seldom available at this level. One way to get around this obstacle is to generate a synthetic population. This paper presents a method for generating a population from fully aggregated socio-demographic and geographic data. Based on French examples, this method can be reproduced anywhere in the country providing a relevant linkage between the characteristics of agents and those of urban spaces. The proposed method is subdivided into two steps. First, a population of agent…
An individual based model for the conservation of the endangered Large Blue Butterfly, Maculinea arion (Lepidoptera: Lycaenidae)
2002
Abstract European populations of the Large Blue Butterfly Maculinea arion have experienced severe declines during the 20th century, especially in the northern part of the species’ range. This endangered lycaenid butterfly needs two resources for development: flower buds of specific plants ( Thymus spp., Origanum vulgare ), on which young caterpillars briefly feed, and red ants of the genus Myrmica , whose nests support caterpillars during a prolonged final instar. In order to improve understanding of those mechanisms that are most influential to population dynamics of the butterfly, we developed a stochastic population model. This individual based model implements three main biological comp…
Modelling drift of pelagic offspring: the importance of egg surveys in providing a realistic model initialization
2015
Abstract Having valid information about the location and dynamics of biological processes is important for coastal management. In this context modelling, the pelagic drift of early life stages has been shown to be an important tool for understanding the spatial scale of population dynamics in marine systems. Often simulated particles are released in hypothetical quantities at assumed spawning grounds with no or few field data to guide the model parametrization. In this study, we combine high-resolution field data and state-of-the-art oceanographic modelling and use a probabilistic approach to construct kernel density distributions of the dispersal of pelagic fish eggs. Specifically, the pot…