Nepotistic patterns of violent psychopathy: evidence for adaptation?

Psychopaths routinely disregard social norms by engaging in selfish, antisocial, often violent behavior. Commonly characterized as mentally disordered, recent evidence suggests that psychopaths are executing a well-functioning, if unscrupulous strategy that historically increased reproductive success at the expense of others. Natural selection ought to have favored strategies that spared close kin from harm, however, because actions affecting the fitness of genetic relatives contribute to an individual’s inclusive fitness. Conversely, there is evidence that mental disorders can disrupt psychological mechanisms designed to protect relatives. Thus, mental disorder and adaptation accounts of psychopathy generate opposing hypotheses: psychopathy should be associated with an increase in the victimization of kin in the former account but not in the latter. Contrary to the mental disorder hypothesis, we show here in a sample of 289 violent offenders that variation in psychopathy predicts a decrease in the genetic relatedness of victims to offenders; that is, psychopathy predicts an increased likelihood of harming non-relatives. Because nepotistic inhibition in violence may be caused by dispersal or kin discrimination, we examined the effects of psychopathy on (1) the dispersal of offenders and their kin and (2) sexual assault frequency (as a window on kin discrimination). Although psychopathy was negatively associated with coresidence with kin and positively associated with the commission of sexual assault, it remained negatively associated with the genetic relatedness of victims to offenders after removing cases of offenders who had coresided with kin and cases of sexual assault from the analyses. These results stand in contrast to models positing psychopathy as a pathology, and provide support for the hypothesis that psychopathy reflects an evolutionary strategy largely favoring the exploitation of non-relatives

Psychopathy, adaptation, and disorder

In a recent study, we found a negative association between psychopathy and violence against genetic relatives. We interpreted this result as a form of nepotism and argued that it failed to support the hypothesis that psychopathy is a mental disorder, suggesting instead that it supports the hypothesis that psychopathy is an evolved life history strategy. This interpretation and subsequent arguments have been challenged in a number of ways. Here, we identify several misunderstandings regarding the harmful dysfunction definition of mental disorder as it applies to psychopathy and regarding the meaning of nepotism. Furthermore, we examine the evidence provided by our critics that psychopathy is associated with other disorders, and we offer a comment on their alternative model of psychopathy. We conclude that there remains little evidence that psychopathy is the product of dysfunctional mechanisms

On the Mutual Interaction between Mechanical Stresses and Internal Corrosion during Isothermal and Cyclic Oxidation of Nickel-Base Superalloys

Thermal cycling has been observed to cause a transition from superficial alumina formation to internal oxidation and nitridation, an effect that was shown to depend on the specimen thickness and geometry, which can be described by a spalling-probability model. Once protection by a dense and adherent alumina scale got lost, the internal-corrosion rate is determined by the diffusivity and solubility of nitrogen and oxygen in the alloy. These parameters seem to depend not only on the temperature and the alloy composition but also on the applied mechanical stress. Internal nitridation under a superimposed creep loading was found to follow a higher rate constant than under just isothermal exposure. This effect can probably be attributed to dislocation-pipe diffusion, a mechanism which has been claimed also to be relevant for outward solvent diffusion during internal corrosion, a phenomenon, which was observed as a stress-relief mechanism during various internal-reaction processes

On the Mutual Interaction between Mechanical Stresses and Internal Corrosion during Isothermal and Cyclic Oxidation of Nickel-Base Superalloys

Thermal cycling has been observed to cause a transition from superficial alumina formation to internal oxidation and nitridation, an effect that was shown to depend on the specimen thickness and geometry, which can be described by a spalling-probability model. Once protection by a dense and adherent alumina scale got lost, the internal-corrosion rate is determined by the diffusivity and solubility of nitrogen and oxygen in the alloy. These parameters seem to depend not only on the temperature and the alloy composition but also on the applied mechanical stress. Internal nitridation under a superimposed creep loading was found to follow a higher rate constant than under just isothermal exposure. This effect can probably be attributed to dislocation-pipe diffusion, a mechanism which has been claimed also to be relevant for outward solvent diffusion during internal corrosion, a phenomenon, which was observed as a stress-relief mechanism during various internal-reaction processes

Regularity results for shortest billiard trajectories in convex bodies in Rn\mathbb{R}^n

We derive properties of closed billiard trajectories in convex bodies in $\mathbb{R}^n$. Building on techniques introduced by K. and D. Bezdek we establish two regularity results for length minimizing closed billiard trajectories: one for billiard trajectories in general convex bodies, the other for billiard trajectories in the special case of acute convex polytopes. Moreover, we attach particular importance to various examples, also including examples which show the sharpness of the first regularity result. Finally, we show how our results can be used in order to calculate (analytically and by computer) length minimizing closed regular billiard trajectories in convex polytopes.Comment: 34 pages, 9 figures, 1 table, chapter 6 adde

Static Code Analysis with CodeChecker

CodeChecker is an open source project that integrates different static analysis tools such as the Clang Static Analyzer and Clang-Tidy into the build systems, continuous integration loops, and development workflows of C++ programmers. It has a powerful issue management system to make it easier to evaluate the reports of the static analysis tools. This document was handed out as supportive material for a code analysis lecture at the 2018 3COWS conference in Kosice, Slovakia

Neural Architecture of Hunger-Dependent Multisensory Decision Making in C. elegans

Little is known about how animals integrate multiple sensory inputs in natural environments to balance avoidance of danger with approach to things of value. Furthermore, the mechanistic link between internal physiological state and threat-reward decision making remains poorly understood. Here we confronted C. elegans worms with the decision whether to cross a hyperosmotic barrier presenting the threat of desiccation to reach a source of food odor. We identified a specific interneuron that controls this decision via top-down extrasynaptic aminergic potentiation of the primary osmosensory neurons to increase their sensitivity to the barrier. We also establish that food deprivation increases the worm's willingness to cross the dangerous barrier by suppressing this pathway. These studies reveal a potentially general neural circuit architecture for internal state control of threat-reward decision making

Duetting as a collective behavior

Sherpa Romeo green journal. Open access article. Creative Commons Attribution License (CC BY) applies.Mated birds of many species vocalize together, producing duets. Duetting behavior occurs at two levels of organization: the individual level and the pair level. Individuals initiate vocalizations, answer their mates’ vocalizations, and control the structure and timing of their own vocalizations. Pairs produce duets that vary with respect to duration, temporal coordination, and phrase-type combinations, among other properties. To make sense of this hierarchical structure, organize duetting research, and identify new avenues of investigation, we advocate a “collective behavior” approach to the study of duets. We critically review key terminology in the duetting literature in light of this approach, and elucidate six insights that emerge from the collective behavior approach: (1) Individual-level behaviors describe pair-level behaviors, but the opposite is not true; (2) The level of organization informs how we test for the rules that govern behavior; (3) Functional hypotheses about duetting must distinguish individual from group characters; (4) Stimulus-response, cybernetics, and entrainment offer alternative hypotheses for the cognitive control of duetting behavior; (5) Avian duetting has the potential to be a model system for the ontogeny of vocal interaction; and (6) The collective behavior approach suggests new avenues of research. Ultimately, we argue that nearly every aspect of duetting research stands to benefit from adopting a collective behavior approach. This approach also has applications to other forms of interactive vocal communication in birds and primates, including humans.Ye

AF4-UV-MALS-ICP-MS/MS, spICP-MS, and STEM-EDX for the Characterization of Metal-Containing Nanoparticles in Gas Condensates from Petroleum Hydrocarbon Samples

Dr. Andrea Raab (University of Aberdeen, U.K.) is thanked for her advice on ICP-MS, which has helped to achieve this work. D.R. thanks Johnson Matthey, U.K. for the provided studentship; special thanks go to Colin Baptist, Lucy Barrass, Matt Lunn, Stefano Martinuzzi, Katie Smart and Bradley Waldron for the fruitful discussions and support; as well as Emily Brooke for her help with the STEM-EDX analyses. K.N. acknowledges the support provided by the University of Aberdeen through the Elphinstone scholarship. Authors also gratefully acknowledge Postnova Analytics UK for the loan of the AF4 system together with training, support and advice on the technique. Special thanks go to Dr. Bassem Sabagh for his help.Peer reviewedPostprin