Search results for "Models"
showing 10 items of 8211 documents
A computational model for motor learning in insects
2013
The aim of this paper is to propose a computational model, inspired by Drosophila melanogaster, able to handle problems related to motor learning. The role of the Mushroom Bodies and the Central Complex in solving this problem is analyzed and plausible biologically inspired models are proposed. The designed computational models have been evaluated in simulation using a dynamic structure inspired by the fruit fly. The obtained results open the way to new neurobiological experiments focused to better understand the underlined mechanisms involved, to verify the feasibility of the hypotheses formulated and the significance of the obtained results.
The Structure and Behavioural Effects of Revealed Social Identity Preferences
2020
A large body of evidence shows that social identity affects behaviour. However, our understanding of the substantial variation of these behavioural effects is still limited. We use a novel laboratory experiment to measure differences in preferences for social identities as a potential source of behavioural heterogeneity. Facing a trade-off between monetary payments and belonging to different groups, individuals are willing to forego significant earnings to avoid belonging to certain groups. We then show that individual differences in these foregone earnings correspond to the differences in discriminatory behaviour towards these groups. Our results illustrate the importance of considering in…
Solving the Problems of Inspection Planning under Parametric Uncertainty of Underlying Models
2013
Certain fatigued structures must be inspected in order to detect fatigue damages that would otherwise not be apparent. A technique for obtaining optimal inspection strategies is proposed for situations where it is difficult to quantify the costs associated with inspections and undetected failure. For fatigued structures for which failures (fatigue damages) are only detected at the time of inspection, it is important to be able to determine the optimal times of inspection. Fewer inspections will lead to lower fatigue reliability of the structure upon demand, and frequent inspection will lead to higher cost. When there is a fatigue reliability requirement, the problem is usually to develop an…
The Principle of Stasis: Why drift is not a Zero-Cause Law
2016
This paper analyses the structure of evolutionary theory as a quasi-Newtonian theory and the need to establish a Zero-Cause Law. Several authors have postulated that the special character of drift is because it is the default behaviour or Zero-Cause Law of evolutionary systems, where change and not stasis is the normal state of them. For these authors, drift would be a Zero-Cause Law, the default behaviour and therefore a constituent assumption impossible to change without changing the system. I defend that drift's causal and explanatory power prevents it from being considered as a Zero-Cause Law. Instead, I propose that the default behaviour of evolutionary systems is what I call the Princ…
Biproportional Method for Analysing Interindustry Dynamics: the case of France
1990
Two elements are being presented in this paper: (1) A new and original method for analysing matrix dynamics, called the synthetical biproportional projector method (SBP), which can be used to project input–output tables and compare one with another. (2) Some results for France for the important period 1970–85. The paper starts with the observation that no systematic study of the change in the French productive structure as displayed In the input–output tables (tableaux entries-sorties in France) has ever been made. This is unfortunate, since a complete series of data is now available concerning a key period of the French economic evolution including the petroleum crisis, European integratio…
Assessing pupils' skills : Implications for research in education
2010
10002; The object of this article is the structure and evolution of skills developed by pupils at primary level. Starting from an analysis of the panel data provided by the French Ministry of Education, the main object of this paper is an original measurement of skills using structural models. The findings of this research raise two complementary issues. The first issue concerns the cross-curricular nature of skills suggesting a logic of disciplinary interdependence. The acquisition of a skill may be strongly correlated to the acquisition of other skills belonging to the same subject area or to other subject areas. The notion of a set of skills is used to account for the connections between…
To Hit or Not to Hit, That Is the Question - Genome-wide Structure-Based Druggability Predictions for Pseudomonas aeruginosa Proteins.
2015
Pseudomonas aeruginosa is a Gram-negative bacterium known to cause opportunistic infections in immune-compromised or immunosuppressed individuals that often prove fatal. New drugs to combat this organism are therefore sought after. To this end, we subjected the gene products of predicted perturbative genes to structure-based druggability predictions using DrugPred. Making this approach suitable for large-scale predictions required the introduction of new methods for calculation of descriptors, development of a workflow to identify suitable pockets in homologous proteins and establishment of criteria to obtain valid druggability predictions based on homologs. We were able to identify 29 pert…
A comparative study of carboxy myoglobin in saccharide-water systems by molecular dynamics simulation.
2007
Results from room-temperature molecular dynamics simulation on a system containing carboxy-myoglobin, water, and maltose molecules are reported. Protein atomic fluctuations, protein−solvent and solvent−solvent hydrogen bonding have been analyzed and compared to the ones in trehalose−water and sucrose−water systems (Proteins 2005, 59, 291−302). Results help in rationalizing, at a molecular level, the effects of homologues disaccharides on protein structure/dynamics experimentally observed. Furthermore, the effectiveness of disaccharides in bioprotection in terms of peculiar protein−matrix coupling is also discussed.
Impact of Destroying the Structure of Model Gels on Volatile Release
2007
International audience; The release of a strawberry aroma from different composite gels taken as models of fruit preparations and from a sucrose solution was investigated. The composition of the model systems differed with regard to the gelling agent, either pectin or carrageenan, and to the rigidity of the gel. With the use of atmospheric pressure chemical ionization−mass spectrometry, the release profiles of the aroma compounds were determined under stirring. At the same time, purge and trap measurements were performed to determine the release profiles of the aroma compounds without stirring. The comparison of the patterns obtained using these two complementary methods made it possible to…
Noninvasive Flap Preconditioning by Foam-Mediated External Suction Improves the Survival of Fasciocutaneous Axial-Pattern Flaps in a Type 2 Diabetic …
2018
Background Advances in reconstructive surgery are leading to an increased number of flaps at risk for ischemic necrosis, because of either intrinsic (e.g., larger flap size) or extrinsic (e.g., diabetes) factors. Methods to preoperatively improve flap vascularity and limit postoperative ischemia are lacking. Noninvasive suction, using either a macrodeformational silicone cup interface (external volume expansion) or a microdeformational polyurethane foam interface (foam-mediated external volume expansion), has been shown to induce angiogenesis in tissues. The authors investigated whether the preoperative use of external volume expansion/foam-mediated external volume expansion improves flap s…