6,699 research outputs found
Assets at risk:menstrual cycle variation in the envisioned formidability of a potential sexual assailant reveals a component of threat assessment
Abstract Situations of potential agonistic conflict demand rapid and effective deci-sion-making. The process of threat assessment includes assessments of relative fighting capacity, assessments of the likelihood of attack, and assessments of the extent to which one′s assets are at risk. The dimensions of physical size and strength appear to serve as key parameters in a cognitive representation summarizing multiple constituents of threat assessment. Here, we examine the thesis that this same representation summa-rizes asset risk. The fitness costs of sexual assault are in part a function of conception risk, as pregnancy due to assault compromises female choice and imperils existing and subsequent male investment. Prior research indicates that women′s attitudes and behaviors vary systematically across the menstrual cycle in a manner that would have reduced the likelihood of sexual assault during periods of greatest fertility in ancestral women. If the envisioned size and strength of a potential antagonist is used to represent asset risk, and if the threat that sexual assault poses to a woman′s reproductive assets is in part a product of her fertility, then the conceptualized size and strength of a potential sexual assailant should be a function of conception risk. We find support for thi
On the Aging Dynamics in an Immune Network Model
Recently we have used a cellular automata model which describes the dynamics
of a multi-connected network to reproduce the refractory behavior and aging
effects obtained in immunization experiments performed with mice when subjected
to multiple perturbations. In this paper we investigate the similarities
between the aging dynamics observed in this multi-connected network and the one
observed in glassy systems, by using the usual tools applied to analyze the
latter. An interesting feature we show here is that the model reproduces the
biological aspects observed in the experiments during the long transient time
it takes to reach the stationary state. Depending on the initial conditions,
and without any perturbation, the system may reach one of a family of
long-period attractors. The pertrubations may drive the system from its natural
attractor to other attractors of the same family. We discuss the different
roles played by the small random perturbations (noise) and by the large
periodic perturbations (immunizations)
Measuring the importance of the uniform nonsynchronization hypothesis
In this paper we critically reappraise some measures of the importance of time-dependent price setting rules and propose an alternative way to gauge the significance of this type of price setting behaviour. The merits of the proposed measure are highlighted in an application using micro-data. Our results suggest that a large proportion of price trajectories may be compatible with simple time-dependent price setting mechanisms but the strength of this evidence very much depends on the way that is used to evaluate the importance of this type of behaviour. JEL Classification: D40, E31, L11perfect synchronization, Time-dependent price setting models, uniform staggering
Time or state dependent price setting rules? Evidence from Portuguese micro data
In this paper we analyse the ability of time and state dependent price setting rules to explain durations of price spells or the probability of changing prices. Our results suggest that simple time dependent models cannot be seen as providing a reasonable approximation to the data and that state dependent models are required to fully characterise the price setting behaviour of Portuguese firms. Inflation, the level of economic activity and the magnitude of the last price change emerge as relevant variables affecting the probability of changing prices. Moreover, it is seen that the impact differs for negative and positive values of these covariates. JEL Classification: C41, D40, E31CPI data, Hazard functions, inflation
Why are some prices stickier than others? Firm-data evidence on price adjustment lags
Infrequent price changes at the firm level are now well documented in the literature. However, a number of issues remain partly unaddressed. This paper contributes to the literature on price stickiness by investigating the lags of price adjustments to different types of shocks. We find that adjustment lags to cost and demand shocks vary with firm characteristics, namely the firm’s cost structure, the type of pricing policy, and the type of good. We also document that firms react asymmetrically to demand and cost shocks, as well as to positive and negative shocks, and that the degree and direction of the asymmetry varies across firms. JEL Classification: C41, D40, E31Firm heterogeneity, Panel-ordered probit, real rigidities, survey data
Betão com adição de fibras de aço e têxteis reciclados de pneu sujeito a altas temperaturas
O betão é um dos materiais responsáveis pelo aumento do consumo de cimento e
agregados naturais na construção civil, levantando questões de sustentabilidade
dos recursos naturais. Este facto conduz à necessidade de desenvolver
tecnologias inovadoras e materiais alternativos para melhorar não só o nível de
desempenho do betão mas, acima de tudo, apoiar a política de proteção ambiental.
O objetivo deste trabalho é demonstrar, através de investigação experimental, que
a adição de fibras têxteis e de fibras de aço provenientes da reciclagem de pneus é
viável para produzir um betão com um comportamento satisfatório quando
submetido a elevadas temperaturas.info:eu-repo/semantics/publishedVersio
Garantir a validade de conteúdo na construção de instrumentos: O caso do Cenas para Processamento de Informação Social na Adolescência
The Scenes for Social Information Processing in Adolescence (SSIPA) proposes to evaluate several cognitive steps suggested by the social information processing model, in addition to considering emotional states that may interfere with such rational processing of information. Psychometric evaluation of this instrument points to its construct validity but very little information was given on its construction process so as to guarantee that, as claimed, it accurately reflects the adolescents’ unique social experiences. The current work presents detailed information on the three steps undertaken to develop the SSIPA: 1) three focus groups with a total of 23 adolescents and use of their verbalizations for item generation; 2) examination of the face validity of the items by 7 experts, who rated each item according to the content it was intended to evaluate, and 3) evaluation of test usability, understandability, and overall pertinence by a new sample of 23 adolescents. Focus groups and item evaluation procedures were considered optimal tools in helping to formulate items that surpass the initial acceptability threshold and accurately grasp the social information processing of adolescents, resulting in an innovative and psychometrically robust assessment instrument, potentially useful in clinical assessment and research.O Cenas para Processamento de Informação Social na Adolescência (SSIPA) propõe avaliar diversos passos cognitivos sugeridos pelo modelo de processamento de informação social, além de considerar estados emocionais que podem interferir com este processamento racional. A avaliação psicométrica deste instrumento aponta para a sua validade de constructo, mas muito pouca informação foi avançada acerca do seu processo de construção, de forma a garantir que reflete adequadamente, como se propõe, as experiências sociais únicas de adolescentes. Este trabalho apresenta informação detalhada acerca dos três processos que foram considerados para desenvolver o SSIPA: 1) três grupos focais com um total de 23 adolescentes e utilização das suas verbalizações para construção de itens; 2) análise da validade facial dos itens por 7 peritos, que avaliaram cada item de acordo com o conteúdo pretendido para cada item, e 3) avaliação da usabilidade, compreensibilidade e pertinência geral do instrumento numa nova amostra de 23 adolescentes. Os grupos focais e a avaliação dos itens constituíram ferramentas apropriadas para construir itens que cumprissem o princípio de aceitabilidade inicial e captassem com precisão o processamento de informação social de adolescentes, resultando num instrumento inovador e psicometricamente robusto, passível de utilização em contextos clínicos e de investigação
Classificação mensal do regime pluviométrico em normal, seco e chuvoso para o Pantanal Sul-Mato-Grossense.
Distribuació de la Cotorra de pit gris (Myiopsitta monachus) a Catalunya
Es descriu la distribució actual de la cotorra de pit gris a Catalunya. El mapa de distribució s'ha dibuixat en base a les dades aconseguides mitjançant una enquesta. La cotorra de pit gris és una espècie escassa i localitzada que es pot observar principalment a les localitats costaneres, especialment a Barcelona. La distribució actual segueix el clima temperat amb poca pluja, en àrees molt humanitzades i amb jardins amb palmeres. No obstant això, la colonitació encara es troba en un estadi inicial i probablement l'àrea de distribució anirà canviant en els pròxims anys
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