Game theory elucidates how competitive dynamics mediate animal social networks.

Background: While most game theoretical models assume that individuals randomly interact with all other group members, strong evidence indicates that individuals tend to preferentially interact with some of them. The position of an individual in a network affects, among other factors related to survival, its predation risk and competitive success. Here I then modified the Hawk-Dove game to explore the effect of social network structure on competitive strategy of individuals that differ in their fighting ability and may adjust their use of the Hawk, Dove and Assessor tactics to maximize their foraging success when they meet opponents they are connected with.

Skill trade-offs promote persistent individual differences and specialized tactics.

Individuals generally differ in their ability to perform challenging behaviours, but the causes of such variability remain incompletely understood. Because animals can usually use different behavioural tactics to achieve their goals, we might expect individual differences in skill to be maintained when the available tactics require different abilities to perform well. To explore this idea, I used the producer-scrounger (PS) paradigm, which considers interactions between foragers that may either invest effort in searching for resources (i.

[Challenge and difficulty of diagnosing hemoglobinopathies in newborns: about a case].

The diagnosis of hemoglobinopathy is based on a range of arguments: clinic, results of a blood count, the haemoglobin study and possibly a genetic study of the globin chains. The interpretation of these profiles can be complicated, especially in newborns due to the ontogenesis of globin genes. The clinical impact can range from simple microcytosis without anemia to severe anemia requiring iterative transfusions and various clinical symptoms depending on the number and type of chains produced.

Predation and parasitism as determinants of animal personalities.

Within the same population, proactive (i.e. bolder, more exploratory, active and aggressive) and reactive (i.

Exploring the interplay between natural and intersexual selection on the evolution of a cognitive trait.

There has been an increased focus on the role of natural and sexual selection in shaping cognitive abilities, but the importance of the interaction between both forces remains largely unknown. Intersexual selection through female mate choice might be an important driver of the evolution of cognitive traits, especially in monogamous species, where females may obtain direct fitness benefits by choosing mates with better cognitive abilities. However, the importance given by female to male cognitive traits might vary among species and/or populations according to their life-history traits and ecology.

Games researchers play: conceptual advancement versus validation strategies.

Conceptual advances and validation are critical to research, yet at odds. Using a game theoretical perspective, we show that a mixed strategy combining advances and validation, leads to increases in both individual researchers' and societal gains. This win-win outcome can be used to design new research strategies, funding, and recognition standards.

Managing the risk of shortages and medication errors with curares during the COVID-19 pandemic: a hospital pharmacy experience.

Background: Coronavirus disease 2019 (COVID-19) has spread rapidly around the world. Like many clinical teams, hospital pharmacies have widely contributed in preventing and containing the COVID-19 pandemic. Pharmacies were thus involved in the management of overuse of specific drugs, medication shortages and risk of medication errors.

Consequences of multiple simultaneous opportunities to exploit others' efforts on free riding.

Individuals within a group do not all act in the same way: Typically, the investors (or producers) put efforts into producing resources while the free riders (or scroungers) benefit from these resources without contributing. In behavioral ecology, the prevalence of free riders can be predicted by a well-known game-theoretical model-the producer-scrounger (PS) model-where group members have the options to either search for resources (producers) or exploit the efforts of others (scroungers). The PS model has received some empirical support, but its predictions, surprisingly, are based on the strict assumption that only one resource can be exploited at a time.

Why are some personalities less plastic?

Individuals from the same population typically show consistent differences in behavioural traits that are frequently associated with differences in contextual plasticity. Yet such a correlation might arise either because some individuals are better able than others to detect environmental changes or because the benefits of being plastic are condition-dependent. To discriminate between these two competing hypotheses, I developed an individual-based model that simulates a population in which individuals of varying fighting ability compete by pairwise interactions using either the fixed hawk (aggressive) or dove (peaceful) strategies or a conditional assessment strategy.

Adaptation of a microbead assay for the easy evaluation of traditional anti-sickling medicines: application to DREPANOSTAT and FACA.

Context: Sickle cell disease is a common inherited blood disorder affecting millions of people worldwide. Due to lack of progress in drug discovery for a suitable treatment, sufferers often turn to traditional medicines that take advantage of the plant extracts activity used by traditional healers.

Objective: This study optimizes an anti-sickling screening test to identify preparations capable of reverting sickle cells back to the morphology of normal red blood cells.

Are some individuals generally more behaviorally plastic than others? An experiment with sailfin mollies.

Individuals within the same population generally differ among each other not only in their behavioral traits but also in their level of behavioral plasticity (i.e., in their propensity to modify their behavior in response to changing conditions).

A new approach for diagnosing chronic myelomonocytic leukemia using structural parameters of Sysmex XN analyzers in routine laboratory practice.

According to WHO recommendations, diagnosis of chronic myelomonocytic leukemia (CMML) beforehand requires microscopic examination of peripheral blood to identify dysplasia and/or blasts when monocytes are greater or equal to 1.0 × 10/L and 10% of leucocytes. We analyzed parameters derived from Sysmex XN analyzers to improve the management of microscopic examination for monocytosis.

Impulsiveness does not prevent cooperation from emerging but reduces its occurrence: an experiment with zebra finches.

Reciprocal altruism, the most probable mechanism for cooperation among unrelated individuals, can be modelled as a Prisoner's Dilemma. This game predicts that cooperation should evolve whenever the players, who expect to interact repeatedly, make choices contingent to their partner's behaviour. Experimental evidence, however, indicates that reciprocity is rare among animals.

Male foraging efficiency, but not male problem-solving performance, influences female mating preferences in zebra finches.

Experimental evidence suggests that females would prefer males with better cognitive abilities as mates. However, little is known about the traits reflecting enhanced cognitive skills on which females might base their mate-choice decisions. In particular, it has been suggested that male foraging performance could be used as an indicator of cognitive capacity, but convincing evidence for this hypothesis is still lacking.

How the cascading effects of a single behavioral trait can generate personality.

INDIVIDUALS FROM THE SAME POPULATION GENERALLY VARY IN SUITES OF CORRELATED BEHAVIORAL TRAITS: personality. Yet, the strength of the behavioral correlations sometimes differs among populations and environmental conditions, suggesting that single underlying mechanisms, such as genetic constraints, cannot account for them. We propose, instead, that such suites of correlated traits may arise when a single key behavior has multiple cascading effects on several other behaviors through affecting the range of options available.

Audience effect alters male mating preferences in zebra finches (Taeniopygia guttata).

The social environment of animals strongly influences the mating preferences of both the choosing and the observing individuals. Notably, there is recent evidence that polygamous males decrease their selectivity when being observed by competitors in order to direct their rivals' attention away from their true interest and, consequently, reduce sperm competition risk. Yet, other mechanisms, whose importance remains unexplored, could induce similar effects.

Frequency-dependent payoffs and sequential decision-making favour consistent tactic use.

Although natural selection should have favoured individuals capable of adjusting the weight they give to personal and social information according to circumstances, individuals generally differ consistently in their individual weighting of both types of information. Such individual differences are correlated with personality traits, suggesting that personality could directly affect individuals' ability to collect personal or social information. Alternatively, the link between personality and information use could simply emerge as a by-product of the sequential decision-making process in a frequency-dependent context.

Neighbours' breeding success and the sex ratio of their offspring affect the mate preferences of female zebra finches.

Several hypotheses on divorce predict that monogamous pairs should split up more frequently after a breeding failure. Yet, deviations from the expected pattern "success-stay, failure-leave" have been reported in several species. One possible explanation for these deviations would be that individuals do not use only their own breeding performance (i.

Learning in a game context: strategy choice by some keeps learning from evolving in others.

Behavioural decisions in a social context commonly have frequency-dependent outcomes and so require analysis using evolutionary game theory. Learning provides a mechanism for tracking changing conditions and it has frequently been predicted to supplant fixed behaviour in shifting environments; yet few studies have examined the evolution of learning specifically in a game-theoretic context. We present a model that examines the evolution of learning in a frequency-dependent context created by a producer-scrounger game, where producers search for their own resources and scroungers usurp the discoveries of producers.

Long-term social bonds promote cooperation in the iterated Prisoner's Dilemma.

Reciprocal altruism, one of the most probable explanations for cooperation among non-kin, has been modelled as a Prisoner's Dilemma. According to this game, cooperation could evolve when individuals, who expect to play again, use conditional strategies like tit-for-tat or Pavlov. There is evidence that humans use such strategies to achieve mutual cooperation, but most controlled experiments with non-human animals have failed to find cooperation.

Distraction sneakers decrease the expected level of aggression within groups: a game-theoretic model.

Hawk-dove games have been extensively used to predict the conditions under which group-living animals should defend their resources against potential usurpers. Typically, game-theoretic models on aggression consider that resource defense may entail energetic and injury costs. However, intruders may also take advantage of owners who are busy fighting to sneak access to unguarded resources, imposing thereby an additional cost on the use of the escalated hawk strategy.

The forager's dilemma: food sharing and food defense as risk-sensitive foraging options.

Although many variants of the hawk-dove game predict the frequency at which group foraging animals should compete aggressively, none of them can explain why a large number of group foraging animals share food clumps without any overt aggression. One reason for this shortcoming is that hawk-dove games typically consider only a single contest, while most group foraging situations involve opponents that interact repeatedly over discovered food clumps. The present iterated hawk-dove game predicts that in situations that are analogous to a prisoner's dilemma, animals should share the resources without aggression, provided that the number of simultaneously available food clumps is sufficiently large and the number of competitors is relatively small.

Mate fidelity and coloniality in waterbirds: a comparative analysis.

Increased opportunities for information are one potential benefit of sociality. We apply this idea to the advantages of colonial breeding in bird species that are typically monogamous within a breeding season but often form new pair-bonds in subsequent seasons. Individuals may benefit from nesting in colonies at high density by identifying good-quality potential alternative mates among their neighbours.