Linking behavioural type with cannibalism in Eurasian perch

The propensity to kill and consume conspecifics (cannibalism) varies greatly between and within species, but the underlying mechanisms behind this variation remain poorly understood. A rich literature has documented that consistent behavioural variation is ubiquitous across the animal kingdom. Such inter-individual behavioural differences, sometimes referred to as personality traits, may have far-reaching ecological consequences. However, the link between predator personality traits and the propensity to engage in cannibalistic interactions remains understudied. Here, we first quantified personality in Eurasian perch (Perca fluviatilis), measured as activity (time spent moving) and sociability (time spent near conspecifics). We then gave perch of contrasting behavioural types the option to consume either conspecific or heterospecific (roach, Rutilus rutilus) prey. Individual perch characterized by a social-active behavioural phenotype (n = 5) selected roach before being cannibalistic, while asocial-inactive perch (n = 17) consumed conspecific and heterospecific prey evenly. Thus, asocial-inactive perch expressed significantly higher rates of cannibalism as compared to social-active individuals. Individual variation in cannibalism, linked to behavioural type, adds important mechanistic understanding to complex population and community dynamics, and also provides insight into the diversity and maintenance of animal personality.

Suppression of personality variation in boldness during foraging in three-spined sticklebacks

Consistent inter-individual variation in behaviour within a population, widely referred to as personality variation, can be affected by environmental context. Feedbacks between an individual’s behaviour and state can strengthen (positive feedback) or weaken (negative feedback) individual differences when experiences such as predator encounters or winning contests are dependent on behavioural type. We examined the influence of foraging on individual-level consistency in refuge use (a measure of risk-taking, i.e. boldness) in three-spined sticklebacks, Gasterosteus aculeatus, and particularly whether changes in refuge use depended on boldness measured under control conditions. In the control treatment trials with no food, individuals were repeatable in refuge use across repeated trials, and this behavioural consistency did not differ between the start and end of these trials. In contrast, when food was available, individuals showed a higher degree of consistency in refuge use at the start of the trials versus controls but this consistency significantly reduced by the end of the trials. The effect of the opportunity to forage was dependent on behavioural type, with bolder fish varying more in their refuge use between the start and the end of the feeding trials than shyer fish, and boldness positively predicted the likelihood of feeding at the start but not at the end of the trials. This suggests a state-behaviour feedback, but there was no overall trend in how bolder individuals changed their behaviour. Our study shows that personality variation can be suppressed in foraging contexts and a potential but unpredictable role of feedbacks between state and behaviour. Significance statement In this experimental study, we examined how foraging influences consistency in risk-taking in individual three-spined sticklebacks. We show that bolder individuals become less consistent in their risk-taking behaviour than shyer individuals during foraging. Some bolder individuals reinforce their risk-taking behaviour, suggesting a positive feedback between state and behaviour, while others converge on the behaviour of shyer individuals, suggesting a negative feedback. In support of a role of satiation in driving negative feedback effects, we found that bolder individuals were more likely to feed at the start but not at the end of the trials. Overall, our findings suggest that foraging can influence personality variation in risk-taking behaviour; however, the role of feedbacks may be unpredictable.

Theories of Choice

Choice is a key concept of our time. It is a foundational mechanism for every legal order in societies that are, politically, constituted as democracies and, economically, built on the market mechanism. Thus, choice can be understood as an atomic structure that grounds core societal processes. In recent years, however, the debate over the right way to theorise choice—for example, as a rational or a behavioural type of decision making—has intensified. This collection therefore provides an in-depth discussion of the promises and perils of specific types of theories of choice. It shows how the selection of a specific theory of choice can make a difference for concrete legal questions, in particularly in the regulation of the digital economy or in choosing between market, firm, or network. In its first part, the volume provides an accessible overview of the current debates about rational versus behavioural approaches to theories of choice. The remainder of the book structures the vast landscape of theories of choice along three main types: individual, collective, and organisational decision making. As theories of choice proliferate and become ever more sophisticated, however, the process of choosing an adequate theory of choice becomes increasingly intricate, too. This volume addresses this selection problem for the various legal arenas in which individual, organisational, and collective decisions matter. By drawing on economic, technological, political, and legal points of view, the volume shows which theories of choice are at the disposal of the legally relevant decision maker, and how they can be implemented for the solution of concrete legal problems.

Session Coalgebras: A Coalgebraic View on Session Types and Communication Protocols

Compositional methods are central to the development and verification of software systems. They allow breaking down large systems into smaller components, while enabling reasoning about the behaviour of the composed system. For concurrent and communicating systems, compositional techniques based on behavioural type systems have received much attention. By abstracting communication protocols as types, these type systems can statically check that programs interact with channels according to a certain protocol, whether the intended messages are exchanged in a certain order. In this paper, we put on our coalgebraic spectacles to investigate session types, a widely studied class of behavioural type systems. We provide a syntax-free description of session-based concurrency as states of coalgebras. As a result, we rediscover type equivalence, duality, and subtyping relations in terms of canonical coinductive presentations. In turn, this coinductive presentation makes it possible to elegantly derive a decidable type system with subtyping for $$\pi $$ π -calculus processes, in which the states of a coalgebra will serve as channel protocols. Going full circle, we exhibit a coalgebra structure on an existing session type system, and show that the relations and type system resulting from our coalgebraic perspective agree with the existing ones.

LEGAL MODELING AS A METHOD OF CIVIL RESEARCH

Introduction: the authors of the scientific works on civil law often refer to the use of legal modelling methods as the methodological basis of their work. However, from the text of the work it is not always clear where and for what reasons the above method was used by the researcher. This situation is largely caused by the lack of sufficient knowledge about the essence and possibilities of this scientific cognition method, as well as about the rules, situations and order of its use. Purpose: to reveal the contents and show the perspectives of using the legal modelling method for performing private law researches. Methods: the general scientific cognition methods were mainly used (analysis, synthesis, induction, deduction, comparison, description and others), along with the specific juridical methods (juridical-dogmatic method, legal modelling method and others). Results: the possibility and (in some cases) the necessity to use both the theoretical legal modelling method and the empiric legal modelling method was proved. The essence of two types of legal modelling was explained: of the normative-legal type and of the behavioural type which should be used in dialectical unity and interrelation. Three stages of legal modelling were identified: building a legal model; comparing the constructed model with the actual legal phenomenon; forecasting the prospects for the development of the legal phenomenon on the basis of the constructed model.

PATTERNING TYPES OF AGGRESSIVE BEHAVIOUR OF PRIMARY SCHOOL CHILDREN WITH SPEECH DISORDERS / PRADINIŲ KLASIŲ MOKINIŲ, TURINČIŲ KALBĖJIMO SUTRIKIMŲ, AGRESYVAUS ELGESIO TIPAI

<p>In order to understand the relationship between speech disorders and aggressive behaviour, the dependence of aggressive behaviour in young school-age children on their speech disorders was studied experimentally. The study had 286 children (6 to 10 years old), 57% of them with typical psychophysical development and 43% with speech disorders in Ukrainian schools. According to the results of the summary of the scientific methods, there have been discoveries of three types of aggression and six subtypes of aggression and also their features: the self-regulating type of aggression incorporates the controlled and the competitive subtypes; covert type – defensive and depressive; behavioural type – demonstrative and physical. The findings indicate that the more complex the speech disorder is, the greater the manifestation of depressive, demonstrative and physical aggression is. The more complex the state of aggression is, the harder it is to realize it. A child cannot always overcome such states on his/her own; therefore, he/she needs co-education, adult assistance.</p><p>Norint suprasti ryšį tarp kalbos sutrikimų ir agresyvaus elgesio, buvo eksperimentiškai tiriama jaunesniojo mokyklinio amžiaus vaikų agresyvaus elgesio priklausomybė nuo jų kalbos sutrikimų. Tyrime dalyvavo 286 Ukrainos mokyklų mokiniai (nuo 6 iki 10 metų), iš jų 57% – tipiškos psichofizinės raidos ir 43% – turintys kalbos sutrikimų. Remiantis mokslinių metodų santraukos rezultatais, buvo nustatyti trys agresijos tipai ir šeši agresijos potipiai, taip pat jų ypatybės: savireguliacinis agresijos tipas apima kontroliuojamą ir konkurencinį agresijos potipius; paslėptas tipas – gynybinį ir depresinį; elgesio tipas – demonstratyvųjį ir fizinį. Išvados rodo, kad kuo sudėtingesnis yra kalbos sutrikimas, tuo labiau pasireiškia depresinė, demonstratyvi ir fizinė agresija. Kuo sudėtingesnė agresijos būsena, tuo sunkiau ją suvokti. Vaikas ne visada pats gali įveikti tokias būsenas; todėl jam reikalingas mokymasis kartu, suaugusiųjų pagalba.</p><p> </p><p> </p>

Individual determinants of social foraging tactic use when resources are defendable: An experiment with zebra finches

In a social foraging context where individuals can search either for food (i.e. produce) or for opportunities to join (i.e. scrounge), bold individuals, generally, tend to produce more than shy individuals. Yet, the underlying cause of this link remains poorly understood. In particular, bold individuals might rely more on the producer tactic because they have less chance to detect joining opportunities compared to shy individuals or because they prefer more risky and uncertain behavioural tactics. To assess the importance of both mechanisms, we conducted a laboratory experiment with zebra finches (Taenyopigia guttata) that were observed while searching for defendable food patches using either the producer or the scrounger tactic, when their arrival order on the grid was either free or imposed by the experimenter. As anticipated, we detected a strong effect of neophobia on producer-scrounger tactic use, but contrary to most previous experiments in which food patches were not defendable, shy individuals, in the present study, relied more on the producer tactic. In addition, we found that arrival order had no significant effect on foraging tactic use in bold and shy individuals. Thus, our results support the hypothesis that producer-scrounger tactic use would not be determined by the ability of individuals to detect scrounging opportunities, but rather by their tolerance to uncertainty and risk. Furthermore, our findings have important evolutionary implications as they suggest that temporal and/or spatial heterogeneity in resource distribution, through influencing the success of each behavioural type, would contribute in maintaining personality differences within populations.

Individual determinants of social foraging tactic use when resources are defendable: An experiment with zebra finches

In a social foraging context where individuals can search either for food (i.e. produce) or for opportunities to join (i.e. scrounge), bold individuals, generally, tend to produce more than shy individuals. Yet, the underlying cause of this link remains poorly understood. In particular, bold individuals might rely more on the producer tactic because they have less chance to detect joining opportunities compared to shy individuals or because they prefer more risky and uncertain behavioural tactics. To assess the importance of both mechanisms, we conducted a laboratory experiment with zebra finches (Taenyopigia guttata) that were observed while searching for defendable food patches using either the producer or the scrounger tactic, when their arrival order on the grid was either free or imposed by the experimenter. As anticipated, we detected a strong effect of neophobia on producer-scrounger tactic use, but contrary to most previous experiments in which food patches were not defendable, shy individuals, in the present study, relied more on the producer tactic. In addition, we found that arrival order had no significant effect on foraging tactic use in bold and shy individuals. Thus, our results support the hypothesis that producer-scrounger tactic use would not be determined by the ability of individuals to detect scrounging opportunities, but rather by their tolerance to uncertainty and risk. Furthermore, our findings have important evolutionary implications as they suggest that temporal and/or spatial heterogeneity in resource distribution, through influencing the success of each behavioural type, would contribute in maintaining personality differences within populations.

Does the behavioural type-specific approach for type 2 diabetes promote changes in lifestyle? Protocol of a cluster randomised trial in Japan

IntroductionType 2 diabetes (T2D) is a significant problem, and lifestyle modifications including self-management are important. We have developed a structured individual-based lifestyle education (SILE) programme for T2D. With attention now being paid to techniques to change behaviour, we recently developed a behavioural type-specific SILE (BETSILE) programme. We aimed to evaluate the effectiveness of the BETSILE programme compared with the SILE programme for reducing glycated haemoglobin (HbA1c) in patients with T2D and special behavioural types by a cluster randomised controlled trial.Methods and analysisThis is a 6-month cluster randomised controlled trial with two intervention arms (BETSILE vs SILE) provided in a medical care setting by randomising registered dietitians for patients with T2D aged 20–79 years. Patients’ behavioural types were classified into four types (BT1 to BT4) using an assessment sheet. We will perform independent trials for BT1 and BT2. The primary endpoint is a change from the baseline HbA1c value at 6 months. Differences between the SILE and BETSILE groups will be primarily analysed following the intention-to-treat principle. Crude and multivariate adjusted effects will be examined after adjusting for covariates, using a general linear mixed-effects model for continuous variables and a logistic regression mixed-effects model for dichotomous variables. Sample sizes needed were calculated assuming effect sizes of 0.42 and 0.33 for BT1 and BT2, respectively, an intraclass correlation of 0.02, a significance level of 5% (two-sided), a power of 80%, and equal allocation of clusters to the two arms, with each cluster having three BT1 patients for the SILE and BETSILE arms and six BT2 patients for the SILE and BETSILE arms. We will need 16 dietitians for each arm, and a total 288 patients will be required.Ethics and disseminationThis study has been approved by the Medical Ethical Committee of Teikyo University (No.15–222). Findings will be disseminated widely through peer-reviewed publications, etc.Trial registration numberUMIN 000023087; Pre-results.