Decision-Making in Complex Dynamic and Evolutive Systems: The Need for a New Paradigm

For contemporary psychology, decision-making represents behaviours, which are very different from automatic responses. They are developed by implementing integrative cognitive functions adapted to the finalities sought and the situation to treat. Through the diversity of epistemological choices for instance, research in previous decades focused on the individual choices expressed by situations or contexts with a stable structure. The new problems of life in today’s society lead to making decisions on societal problems (climate, energy, etc.), which bring into play systems and no longer variables. This chapter has four aspects. After having characterised the decision-making process as a cognitive behaviour (1), having recalled the best known traditional models (those of Economics and Psychology) (2), this chapter deals with the properties of complex systems (globality, interactivity, dynamism, and scalability), which render decision-making difficult (3), and concludes with the necessity of a change of paradigm by pointing to paths to follow (4)

Making students sensitive to entrepreneurship

The aim of this paper is to present a {proposal to make students sensitive to entrepreneurship} aiming at familiarizing students to the setting up of new firms and stimulating such a course of action. This {{awareness campaign}} would take place during the student's curriculum and rest on a simulation exercise. This campaign is based on the results of a survey conducted at the Technical University of Cartagena (Spain). This study has identified some students’ aspirations to salaried employment and entrepreneurship. This survey also recognized some specific features that the campaign must integrate, in particular the need to make entrepreneurship compatible with the preparation for salaried employment. The results of this study are completed comparing them with the opinion from entrepreneurs of the same region. This comparison highlights some barriers to entrepreneurship among the students population, making it possible to complete the content of the proposed simulation exercise. This paper also highlights the absence of barriers of a psychological nature usually put forward by the literature, such as a low level of the {need for achievement or the propensity for risk-taking}.career, company, entrepreneurship, making sensitive, student

Cognitive Decision-Making in Dynamic Systems: When the Objectivity (of the Processing) Does Not Guarantee the Validity (of the Choice of Action)

Since around 1970, academic studies on decision-making have changed in nature. Whereas they used to be laboratory studies of selected situations giving rise to the expression of individual choices, nowadays studies focus on real situations. These situations are processed in their natural contexts at the time they occur. The decisions to be made concern generally social problems (for instance forest fires, maritime pollution or global warming). This mutation in the nature of situations studied requires a paradigm shift, which leads to elaborate decisions in complex, dynamic and evolving systems, even sometimes resilient to human actions implemented to control them. This chapter analyses, at individual and group level (crisis units), cognitive difficulties encountered by decision-makers in handling such situations. These situations consist in treating information by assigning them, from the outset, meanings (sometimes personal). This is done by looking for temporary interactions, while respecting the global nature of the situation, by focusing on knowing the properties of context as well as those of the temporal evolution of the system concerned. This chapter analyses a case study for which urgent and fundamental decisions could not be taken and proposes an interpretation in terms of paradigms. Previous studies noted that the decision in complex systems, could entail paradoxes. This study on the decision-making dynamic shows that seeking objectivity, as defined under its current intangible form, does not produce a significant increase in the validity of choices made

A Perspective on Cognitive Decision-Making in Dynamic Systems: Are Decision Failures Indicators for a Mutation toward Processing New Concepts?

In numerous scientific disciplines, the decision-making process aims at choosing the most appropriate action to reach a defined objective is a central issue. Scientific literature demonstrates that a wide range of often prescriptive models is available to deal with this sequence. However, one category of situations, involving the intervention of complex, dynamic, and changeable systems (a forest fire for example) generate imprecisions, difficulties, or even incorrect decisions. This largely prospective chapter aims to study these situations from a cognitive point of view to reveal certain recurrent properties of their operation. These indicators may represent milestones for the construction of a new epistemology that would refer to the globality and the dynamism rather than to isolated and analytical entities

Analysis on conservation of disulphide bonds and their structural features in homologous protein domain families

International audienceBackground: Disulphide bridges are well known to play key roles in stability, folding and functions of proteins. Introduction or deletion of disulphides by site-directed mutagenesis have produced varying effects on stability and folding depending upon the protein and location of disulphide in the 3-D structure. Given the lack of complete understanding it is worthwhile to learn from an analysis of extent of conservation of disulphides in homologous proteins. We have also addressed the question of what structural interactions replaces a disulphide in a homologue in another homologue.Results: Using a dataset involving 34,752 pairwise comparisons of homologous protein domains corresponding to 300 protein domain families of known 3-D structures, we provide a comprehensive analysis of extent of conservation of disulphide bridges and their structural features. We report that only 54% of all the disulphide bonds compared between the homologous pairs are conserved, even if, a small fraction of the non-conserved disulphides do include cytoplasmic proteins. Also, only about one fourth of the distinct disulphides are conserved in all the members in protein families. We note that while conservation of disulphide is common in many families, disulphide bond mutations are quite prevalent. Interestingly, we note that there is no clear relationship between sequence identity between two homologous proteins and disulphide bond conservation. Our analysis on structural features at the sites where cysteines forming disulphide in one homologue are replaced by non-Cys residues show that the elimination of a disulphide in a homologue need not always result in stabilizing interactions between equivalent residues.Conclusion: We observe that in the homologous proteins, disulphide bonds are conserved only to a modest extent. Very interestingly, we note that extent of conservation of disulphide in homologous proteins is unrelated to the overall sequence identity between homologues. The non-conserved disulphides are often associated with variable structural features that were recruited to be associated with differentiation or specialisation of protein function

Reproducibility and sensitivity to change of various methods to measure joint space width in osteoarthritis of the hip: a double reading of three different radiographic views taken with a three-year interval

Joint space width (JSW) and narrowing (JSN) measurements on radiographs are currently the best way to assess disease severity or progression in hip osteoarthritis, yet we lack data regarding the most accurate and sensitive measurement technique. This study was conducted to determine the optimal radiograph and number of readers for measuring JSW and JSN. Fifty pairs of radiographs taken three years apart were obtained from patients included in a structure modification trial in hip osteoarthritis. Three radiographs were taken with the patient standing: pelvis, target hip anteroposterior (AP) and oblique views. Two trained readers, blinded to each other's findings, time sequence and treatment, each read the six radiographs gathered for each patient twice (time interval ≥15 days), using a 0.1 mm graduated magnifying glass. Radiographs were randomly coded for each reading. The interobserver and intraobserver cross-sectional (M0 and M36) and longitudinal (M0–M36) reproducibilities were assessed using the intraclass coefficient (ICC) and Bland–Altman method for readers 1 and 2 and their mean. Sensitivity to change was estimated using the standardized response mean (SRM = change/standard deviation of change) for M0–M36 changes. For interobserver reliability on M0–M36 changes, the ICCs (95% confidence interval [CI]) were 0.79 (0.65–0.88) for pelvic view, 0.87 (0.78–0.93) for hip AP view and 0.86 (0.76–0.92) for oblique view. Intraobserver reliability ICCs were 0.81 (0.69–0.89) for observer 1 and 0.97 (0.95–0.98) for observer 2 for the pelvic view; 0.87 (0.78–0.92) and 0.97 (0.96–0.99) for the hip AP view; and 0.73 (0.57–0.84) and 0.93 (0.88–0.96) for the oblique view. SRMs were 0.61 (observer 1) and 0.82 (observer 2) for pelvic view; 0.64 and 0.75 for hip AP view; and 0.77 and 0.70 for oblique view. All three views yielded accurate JSW and JSN. According to the best reader, the pelvic view performed slightly better. Both readers exhibited high precision, with SRMs of 0.6 or greater for assessing JSN over three years. Selecting a single reader was the most accurate method, with 0.3 mm precision. Using this cutoff, 50% of patients were classified as 'progressors'

A short survey on protein blocks.

International audienceProtein structures are classically described in terms of secondary structures. Even if the regular secondary structures have relevant physical meaning, their recognition from atomic coordinates has some important limitations such as uncertainties in the assignment of boundaries of helical and β-strand regions. Further, on an average about 50% of all residues are assigned to an irregular state, i.e., the coil. Thus different research teams have focused on abstracting conformation of protein backbone in the localized short stretches. Using different geometric measures, local stretches in protein structures are clustered in a chosen number of states. A prototype representative of the local structures in each cluster is generally defined. These libraries of local structures prototypes are named as "structural alphabets". We have developed a structural alphabet, named Protein Blocks, not only to approximate the protein structure, but also to predict them from sequence. Since its development, we and other teams have explored numerous new research fields using this structural alphabet. We review here some of the most interesting applications

An archaeal family-B DNA polymerase variant able to replicate past DNA damage: occurrence of replicative and translesion synthesis polymerases within the B family

A mutant of the high fidelity family-B DNA polymerase from the archaeon Thermococcus gorgonarius (Tgo-Pol), able to replicate past DNA lesions, is described. Gain of function requires replacement of the three amino acid loop region in the fingers domain of Tgo-Pol with a longer version, found naturally in eukaryotic Pol zeta (a family-B translesion synthesis polymerase). Inactivation of the 3'–5' proofreading exonuclease activity is also necessary. The resulting Tgo-Pol Z1 variant is proficient at initiating replication from base mismatches and can read through damaged bases, such as abasic sites and thymine photo-dimers. Tgo-Pol Z1 is also proficient at extending from primers that terminate opposite aberrant bases. The fidelity of Tgo-Pol Z1 is reduced, with amarked tendency tomake changes at G:C base pairs. Together, these results suggest that the loop region of the fingers domain may play a critical role in determining whether a family-B enzyme falls into the accurate genome-replicating category or is an errorprone translesion synthesis polymerase. Tgo-Pol Z1 may also be useful for amplification of damaged DNA

Methamphetamine-Induced Dopamine-Independent Alterations in Striatal Gene Expression in the 6-Hydroxydopamine Hemiparkinsonian Rats

Unilateral injections of 6-hydroxydopamine into the medial forebrain bundle are used extensively as a model of Parkinson's disease. The present experiments sought to identify genes that were affected in the dopamine (DA)–denervated striatum after 6-hydroxydopamine-induced destruction of the nigrostriatal dopaminergic pathway in the rat. We also examined whether a single injection of methamphetamine (METH) (2.5 mg/kg) known to cause changes in gene expression in the normally DA-innervated striatum could still influence striatal gene expression in the absence of DA. Unilateral injections of 6-hydroxydopamine into the medial forebrain bundle resulted in METH-induced rotational behaviors ipsilateral to the lesioned side and total striatal DA depletion on the lesioned side. This injection also caused decrease in striatal serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) levels. DA depletion was associated with increases in 5-HIAA/5-HT ratios that were potentiated by the METH injection. Microarray analyses revealed changes (± 1.7-fold, p<0.025) in the expression of 67 genes on the lesioned side in comparison to the intact side of the saline-treated hemiparkinsonian animals. These include follistatin, neuromedin U, and tachykinin 2 which were up-regulated. METH administration caused increases in the expression of c-fos, Egr1, and Nor-1 on the intact side. On the DA-depleted side, METH administration also increased the expression of 61 genes including Pdgf-d and Cox-2. There were METH-induced changes in 16 genes that were common in the DA-innervated and DA-depleted sides. These include c-fos and Nor-1 which show greater changes on the normal DA side. Thus, the present study documents, for the first time, that METH mediated DA-independent changes in the levels of transcripts of several genes in the DA-denervated striatum. Our results also implicate 5-HT as a potential player in these METH-induced alterations in gene expression because the METH injection also caused significant increases in 5-HIAA/5-HT ratios on the DA-depleted side