Regulation of Reproduction in the Primitively Eusocial Wasp Ropalidia marginata: on the Trail of the Queen Pheromone

Queens and workers are not morphologically differentiated in the primitively eusocial wasp, Ropalidia marginata. Upon removal of the queen, one of the workers becomes extremely aggressive, but immediately drops her aggression if the queen is returned. If the queen is not returned, this hyper-aggressive individual, the potential queen (PQ), will develop her ovaries, lose her hyper-aggression, and become the next colony queen. Because of the non-aggressive nature of the queen, and because the PQ loses her aggression by the time she starts laying eggs, we hypothesized that regulation of worker reproduction in R marginata is mediated by pheromones rather than by physical aggression. Based on the immediate loss of aggression by the PQ upon return of the queen, we developed a bioassay to test whether the queen's Dufour's gland is, at least, one of the sources of the queen pheromone. Macerates of the queen's Dufour's gland, but not that of the worker's Dufour's gland, mimic the queen in making the PQ decrease her aggression. We also correctly distinguished queens and workers of R. marginata nests by a discriminant function analysis based on the chemical composition of their respective Dufour's glands.

Road to Royalty - Transition of Potential Queen to Queen in the Primitively Eusocial Wasp Ropalidia marginata

Ropalidia marginata, a primitively eusocial wasp, is different from typical primitively eusocial species in having docile queens who cannot be using dominance to maintain reproductive monopoly and instead appear to use a pheromone from the Dufour's gland to do so. When a docile queen is removed from her colony, one of the workers (potential queen, PQ) becomes highly aggressive, and if the queen is not returned, gradually loses her aggression and becomes the new docile queen within a few days. We hypothesized that the decrease in aggression of the PQ with time since queen removal should be correlated with her change in ovaries and pheromone profile. Because the Dufour's gland hydrocarbon composition in R.marginata can be correlated with fertility, this also gave us an opportunity to test whether PQ is different from workers in her Dufour's gland hydrocarbons. In this study, we therefore trace the road to royalty in R.marginata, that is, the transition of the PQ during queen establishment, in terms of her ovaries, aggression, and Dufour's gland hydrocarbons. Our study focuses on queen establishment, which is important for understanding how reproductive conflict can be manifested and resolved.

The evolution of complexity in social organization-A model using dominance-subordinate behavior in two social wasp species

Dominance and subordinate behaviors are important ingredients in the social organizations of group living animals. Behavioral observations on the two eusocial species Ropalidia marginata and Ropalidia cyathiformis suggest varying complexities in their social systems. The queen of R. cyathiformis is an aggressive individual who usually holds the top position in the dominance hierarchy although she does not necessarily show the maximum number of acts of dominance, while the R. marginata queen rarely shows aggression and usually does not hold the top position in the dominance hierarchy of her colony. In R. marginata, more workers are involved in dominance-subordinate interactions as compared to R. cyathiformis. These differences are reflected in the distribution of dominance-subordinate interactions among the hierarchically ranked individuals in both the species. The percentage of dominance interactions decreases gradually with hierarchical ranks in R. marginata while in R. cyathiformis it first increases and then decreases. We use an agent-based model to investigate the underlying mechanism that could give rise to the observed patterns for both the species. The model assumes, besides some non-interacting individuals, the interaction probabilities of the agents depend on their pre-differentiated winning abilities. Our simulations show that if the queen takes up a strategy of being involved in a moderate number of dominance interactions, one could get the pattern similar to R. cyathiformis, while taking up the strategy of very low interactions by the queen could lead to the pattern of R. marginata. We infer that both the species follow a common interaction pattern, while the differences in their social organization are due to the slight changes in queen as well as worker strategies. These changes in strategies are expected to accompany the evolution of more complex societies from simpler ones.

Optimal Data Distributions in Machine Learning

In the first part of the thesis we explore three fundamental questions that arise naturally when we conceive a machine learning scenario where the training and test distributions can differ. Contrary to conventional wisdom, we show that in fact mismatched training and test distribution can yield better out-of-sample performance. This optimal performance can be obtained by training with the dual distribution. This optimal training distribution depends on the test distribution set by the problem, but not on the target function that we want to learn. We show how to obtain this distribution in both discrete and continuous input spaces, as well as how to approximate it in a practical scenario. Benefits of using this distribution are exemplified in both synthetic and real data sets.

In order to apply the dual distribution in the supervised learning scenario where the training data set is fixed, it is necessary to use weights to make the sample appear as if it came from the dual distribution. We explore the negative effect that weighting a sample can have. The theoretical decomposition of the use of weights regarding its effect on the out-of-sample error is easy to understand but not actionable in practice, as the quantities involved cannot be computed. Hence, we propose the Targeted Weighting algorithm that determines if, for a given set of weights, the out-of-sample performance will improve or not in a practical setting. This is necessary as the setting assumes there are no labeled points distributed according to the test distribution, only unlabeled samples.

Finally, we propose a new class of matching algorithms that can be used to match the training set to a desired distribution, such as the dual distribution (or the test distribution). These algorithms can be applied to very large datasets, and we show how they lead to improved performance in a large real dataset such as the Netflix dataset. Their computational complexity is the main reason for their advantage over previous algorithms proposed in the covariate shift literature.

In the second part of the thesis we apply Machine Learning to the problem of behavior recognition. We develop a specific behavior classifier to study fly aggression, and we develop a system that allows analyzing behavior in videos of animals, with minimal supervision. The system, which we call CUBA (Caltech Unsupervised Behavior Analysis), allows detecting movemes, actions, and stories from time series describing the position of animals in videos. The method summarizes the data, as well as it provides biologists with a mathematical tool to test new hypotheses. Other benefits of CUBA include finding classifiers for specific behaviors without the need for annotation, as well as providing means to discriminate groups of animals, for example, according to their genetic line.

Violência familiar e estado nutricional de adolescentes numa unidade de saúde

O presente trabalho teve como objetivos verificar a possível associação entre violência intrafamiliar sofrida por adolescentes e estado nutricional. Foram investigadas as prevalências de agressão verbal, violências física, abuso psicológico e de estado nutricional inadequado dos adolescentes. Para tanto, foi realizado um estudo observacional de corte transversal numa amostra de 201 adolescentes de 10 a 19 anos cadastrados no Programa Bolsa Família e monitorados pelo Serviço de Nutrição de uma unidade de saúde do município do Rio de Janeiro. Junto aos adolescentes foi realizada avaliação antropométrica, e para a determinação do estado nutricional foi analisado o Índice de Massa Corporal (IMC) pelo parâmetro adotado pela OMS a partir de 2007. A violência familiar foi investigada por meio de dois instrumentos. O Conflict Tactics Scales Form R (CTS1) foi utilizado para avaliar os conflitos intrafamiliares no relacionamento entre pais e filhos e a escala de violência psicológica contra adolescentes para identificar a presença de violência psicológica contra os adolescentes. Além disso, foram avaliadas outras co-variáveis que pudessem influenciar a associação entre violência e situação nutricional da população estudada como informações sobre maturação sexual, sócio-demográficas e percepção corporal. No que diz respeito ao IMC, foram identificados 4,5% de baixo peso, 13,4% de sobrepeso e 5% de obesidade. No que se refere à violência familiar, foram observados 83,1% de agressão verbal, 50,2% de violência psicológica, 32,8% de agressão física grave e 48,3% de abuso físico menor. Através da regressão linear múltipla foi observada um associação entre violência familiar e o IMC em adolescentes do sexo feminino. A presença de agressão verbal perpetrada tanto pelo pai como pela mãe está relacionado ao IMC de forma estatisticamente significativa para as meninas. Já para os adolescentes masculinos não foi encontrada nenhuma associação significativa entre os diferentes tipos de violência familiar e o IMC, mas aponta para a redução do IMC. Outras estratégias de pesquisa de natureza qualitativa devem ser realizadas para esclarecer sobre os efeitos desfavoráveis do abuso verbal sobre o IMC junto aos pais e a sociedade já que a agressão verbal é um tipo de abuso normalmente utilizado no ambiente familiar e considerado como algo natural e aceitável

A descontinuidade entre agressividade e violência: uma contribuição psicanalítica às práticas educacionais

O objetivos deste trabalho é oferecer aos profissionais de saúde e educação uma ferramenta que ilumine sua compreensão acerca dos comportamentos agressivos e das situações violentas comumente encontradas na instituição escolar. Para isso, a pesquisa se desenvolve em três capítulos e uma seção de considerações e contribuição finais. No primeiro, são apresentadas diferentes ideias sobre as noções de agressividade e violência. Os psicanalistas enfocados são Sigmund Freud, Jacques Lacan e Donald Winnicott. No segundo, é feito um estudo da teoria do desenvolvimento emocional de Winnicott. No segundo, é feito um estudo da teoria do desenvolvimento emocional de Winnicott para, no capítulo que se segue, serem analisados os significados dados pelo autor a tais fenômenos, que nos encaminham à despatologização da agressividade e à desnaturalização da violência. Por último, como uma contribuição mais direta ao campo da educação, são sugeridas reflexões e propostas para que o espaço escolar possa ser um ambiente facilitador da criatividade do sujeito e do exercício de poder do cidadão, colaborando assim, para diminuir as chances de irrupção e reprodução da violência que vem assolando o mundo contemporâneo.

The neural signature of escalating frustration in humans.

Mammalian studies show that frustration is experienced when goal-directed activity is blocked. Despite frustration's strongly negative role in health, aggression and social relationships, the neural mechanisms are not well understood. To address this we developed a task in which participants were blocked from obtaining a reward, an established method of producing frustration. Levels of experienced frustration were parametrically varied by manipulating the participants' motivation to obtain the reward prior to blocking. This was achieved by varying the participants' proximity to a reward and the amount of effort expended in attempting to acquire it. In experiment 1, we confirmed that proximity and expended effort independently enhanced participants' self-reported desire to obtain the reward, and their self-reported frustration and response vigor (key-press force) following blocking. In experiment 2, we used functional magnetic resonance imaging (fMRI) to show that both proximity and expended effort modulated brain responses to blocked reward in regions implicated in animal models of reactive aggression, including the amygdala, midbrain periaqueductal grey (PAG), insula and prefrontal cortex. Our findings suggest that frustration may serve an energizing function, translating unfulfilled motivation into aggressive-like surges via a cortical, amygdala and PAG network.

攻击性、情绪调节评价对青少年攻击行为的作用

The aggressive behavior and the violent crime of the Adolenscents have aroused social widespread attention. The Social Implicit Cognition Method could overcome the insufficiency of explicit research methods such as Self-Report Scale, and carry on the thorough discussion to the intrinsic mechanism of the Adolenscent’s aggressive behavior. In this research, Implicit Association Test and Explicit Questionnaire are synthetically applied to inspect the relations among the aggression, Evaluation of Emotion Regulation and the aggressive behavior of the normal middle-school students and the Adolenscent violent criminals under the explicit and implicit conditions, and have carried the supplement to the internal condition of the General aggression model (GAM). The result indicates, 1. The concept of implicit aggression exists independently and separates from explicit aggression. However the relations between implicit aggression and the groups are remarkable, i.e. both the implicit and explicit aggressions of the Adolenscent violent criminals are remarkably higher than those of the normal middle-school students, but not influenced by sex factors. 2. Implicit Evaluation of Emotion Regulation is suitable to Chinese Adolenscents. The correlation of groups and sex factors exist to Implicit Evaluation of Emotion Regulation, i.e. in the group of criminals, the female inclines to the mood control compared with the male in the aspect of Implicit Evaluation of Emotion Regulation; however, in the group of normal persons, the difference between male and female is not remarkable in the aspect of Implicit Evaluation of Emotion Regulation. 3. Under the explicit conditions, it is discovered that the remarkable explicit aggression can predict violent criminals. But it is adjusted by Explicit Evaluation of Emotion Regulation, i.e. the predicting function is not remarkable when the Explicit Evaluation inclines to expression. Meanwhile, when checking the functions and the effects of the implicit variables after the explicit conditions are under control, it is discovered that the predicting function of implicit aggression is still remarkable, and the predicting function of Implicit Evaluation of Emotion Regulation is remarkable at the edge and also adjusted by sex factors. These findings help us not only understanding thoroughly the intrinsic mechanism of the Adolenscent’s aggressive behavior, discovering the moderating role of Evaluation of Emotion Regulation on aggression, but also providing an academic foundation on the prevention and intervention of the Adolenscent’s aggressive behavior.

Sexually coercive male chimpanzees sire more offspring.

In sexually reproducing animals, male and female reproductive strategies often conflict. In some species, males use aggression to overcome female choice, but debate persists over the extent to which this strategy is successful. Previous studies of male aggression toward females among wild chimpanzees have yielded contradictory results about the relationship between aggression and mating behavior. Critically, however, copulation frequency in primates is not always predictive of reproductive success. We analyzed a 17-year sample of behavioral and genetic data from the Kasekela chimpanzee (Pan troglodytes schweinfurthii) community in Gombe National Park, Tanzania, to test the hypothesis that male aggression toward females increases male reproductive success. We examined the effect of male aggression toward females during ovarian cycling, including periods when the females were sexually receptive (swollen) and periods when they were not. We found that, after controlling for confounding factors, male aggression during a female's swollen periods was positively correlated with copulation frequency. However, aggression toward swollen females was not predictive of paternity. Instead, aggression by high-ranking males toward females during their nonswollen periods was positively associated with likelihood of paternity. This indicates that long-term patterns of intimidation allow high-ranking males to increase their reproductive success, supporting the sexual coercion hypothesis. To our knowledge, this is the first study to present genetic evidence of sexual coercion as an adaptive strategy in a social mammal.

Do protected areas mitigate the effects of fisheries-induced evolution on parental care behaviour of a recreationally-important teleost fish?

Human-induced selection on animals and plants has been highly influential throughout our history and resulted in both intentional benefits and unintended detriments. Fisheries-induced evolution (FIE) describes the unintended selection on wild fish populations by fishing that has resulted in the evolution of exploited populations. While the use of aquatic protected areas that exclude angling might be considered an evolutionarily-enlightened management approach to dealing with issues arising from FIE little is known about the effectiveness of this approach for maintaining the phenotypic diversity of traits in protected areas versus those outside of their boundaries. In species that exhibit parental care, including the largemouth bass (Micropterus salmoides), active nest guarding and aggression towards potential brood predators by males increases the survival of offspring. This aggression may render these individuals particularly vulnerable to capture via angling as a result of increased propensity to attack fishing lures near their nests. Relative levels of aggression by these males during the parental care period correlate with their vulnerability to angling year round. Inasmuch as this parental behavior is heritable, this selective removal of more aggressive individuals by anglers should drive population-average phenotypes towards lower levels of aggression. To assess the effectiveness of protected areas at mitigating FIE, I compared the nest guarding behaviours of wild, free-swimming male bass during the early nesting period for bass within and outside protected areas. I found that nesting males within long-standing fishing sanctuaries (>70 yrs) were more aggressive towards captive bluegill sunfish (Lepomis macrochirus) placed directly on their nests, and patrolled larger areas around their nests compared to bass outside of sanctuaries. Males within protected areas were more likely to strike at artificial fishing lures and more prone to capture during experimental angling events. Collectively, my findings suggest that recreational angling selects for individual bass with lower levels of parental care and aggression, and that the establishment of protected areas may mitigate potential FIE. The extent to which this phenomenon occurs in other species and systems likely depends on the reproductive strategies of the fishes being considered, their spatial ecology relative to sanctuary boundaries, and habitat quality within protected areas.

Aggressive responses to broadband trills are related to subsequent pairing success in nightingales

In sexually selected signals, distinct components often have specific signal value in mate choice or male-male competition. In songbirds, structural song traits such as trills, that is, a series of repetitive notes, can be important in female choice. However, little is known about their signal value in male-male interactions. Here, we investigated the hypothesis that males assess the competitive abilities of rivals based on the use and performance of rapid broadband trills produced within songs. Using a 2-speaker playback experiment, we exposed territorial male nightingales, Luscinia megarhynchos, that differed in their subsequent pairing success, to a simulated vocal interaction between 2 unfamiliar rivals. The singing of the 2 simulated rivals differed in the number of songs containing rapid broadband trills. Subjects responded significantly more strongly to the loudspeaker that broadcast songs containing such trills than to the loudspeaker that broadcast exclusively songs without such trills. Moreover, responses also depended on the fine structure of trills. Males that became paired later in the season significantly increased their response intensity with increasing trill performance, whereas males that remained unpaired responded in the opposite way and decreased their response intensity with increasing trill performance. These results indicate that rapid broadband trills are a signal of aggression and that the nature of the response in vocal interactions reflects aspects of the challenged male's fitness. © The Author 2008. Published by Oxford University Press on behalf of the International Society for Behavioral Ecology. All rights reserved.


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Attitudes of qualified versus student mental health nurses towards an individual diagnosed with schizophrenia

Aims: This paper is the report of a study which sought to compare the attitudes held by student and qualified mental health nurses towards individuals with schizophrenia in the Republic of Ireland. Background: Media portrayals of individuals with schizophrenia often include images of aggression and violence. With global initiatives aimed at reducing the stigma and exclusion associated with mental illness, the attitudes of those who care for people with schizophrenia are of particular interest. Methods: A survey was administered to 66 student mental health nurses, and 121 qualified mental health nurses. Participants completed the community attitudes to mental illness scale (CAMI) and the social interaction scale (SIS) in 2009. Multivariate analysis of variance was used to test for the effects of qualification, work setting, years of experience and education on the measures. Results: A statistically significant difference was found between community mental health nurses and those employed in an inpatient setting on the social restrictiveness and community mental health ideology subscales of the CAMI and on the SIS. Findings also showed a statistically significant difference between nurses in the 10-14 years of experience group and the 5-9 years of experience group on the SIS. Conclusions: Mental health nurses employed in an inpatient setting are often confronted with patients who have challenging behavioural presentations which may explain their socially restrictive attitudes. However, nurses must be alerted to the fact that such negative attitudes may adversely affect the therapeutic relationship and ultimately lead to stigmatisation and its negative consequences.

Procesamiento de la Información Social, Relaciones entre Iguales y Ajuste Social: Agresión y Victimización

El presente estudio fue realizado en tres clases del Centro de Educación Primaria "Filósofo Séneca" de Madrid. El objetivo fue determinar la forma en que los niños de 5º y 6º de educación primaria procesan la información social y su relación con el nivel de ajuste social manifestado, expresado en términos de agresividad y victimización. El estudio, se basa en el Modelo de Procesamiento de la Información Social propuesto por Crick y Dodge (1994) y examina el cuarto paso de éste, la generación de respuestas alternativas. Se recogieron datos de forma individualizada de n=55 niños, 24 niños y 31 niñas. La hipótesis principal, formulada como que un déficit en el procesamiento de la información social se relacionará con unos niveles más altos de agresión y victimización, se mantiene.

The following study was implemented in three classes of the Primary EducationCentre «Filósofo Séneca». Its aim was to determine the way that children of this age processsocial information and the relation between this and the level of aggression or victimizationthey show.The study is based on the Model of Social Information Processing proposed byCrick and Dodge in 1994, and examines the fourth step of this model, the generation of alternative responses. The principal hypothesis, that a deficit in social information process-ing will be related to higher levels of aggression and victimization, is supported.

Tragedy, Euripides, Melodrama: Hamartia, Medea, Liminality

This article examines socio-historical dimensions and cultural and dramaturgic implications of the Greek playwright Euripides’ treatment of the myth of Medea. Euripides gives voice to victims of adventurism, aggression and betrayal in the name of ‘reason’ and the ‘state’ or ‘polity.’ Medea constitutes one of the most powerful mythic forces to which he gave such voice by melodramatizing the disturbing liminality of Greek tragedy’s perceived social and cultural order. The social polity is confronted by an apocalyptic shock to its order and its available modes of emotional, rational and social interpretation. Euripidean melodramas of horror dramatize the violation of rational categories and precipitate an abject liminality of the tragic vision of rational order. The dramaturgy of Euripides’ Medea is contrasted with the norms of Greek tragedy and examined in comparison with other adaptations — both ancient and contemporary — of the myth of Medea, in order to unfold the play’s transgression of a tragic vision of the social polity.

Abstinence from alcohol may indeed be the best policy: 32 month longitudinal outcomes among adolescents in the United Kingdom.

The present study investigated the longitudinal relationship between alcohol consumption at age 13, and at age 16. Alcohol-specific measures were frequency of drinking, amount consumed at last use and alcohol related harms. Self-report data were gathered from 1113 high school students at T1, and 981 students at T2. Socio-demographic data were gathered, as was information on context of use, alcohol-related knowledge and attitudes, four domains of aggression and delay reward discounting. Results indicated that any consumption of alcohol, even supervised consumption, at T1 was associated with significantly poorer outcomes at T2. In other words, compared to those still abstinent at age 13, those engaging in alcohol use in any context reported significantly more frequent drinking, more alcohol-related harms and more units consumed at last use at age 16. Results also support the relationship between higher levels of physical aggression at T1 and a greater likelihood of more problematic alcohol use behaviours at T2. The findings support other evidence suggesting that abstinence in early adolescence has better longitudinal outcomes that supervised consumption of alcohol. These results suggest support for current guidance on adolescent drinking in the United Kingdom (UK).