Model for the Dynamics of the Cytoskeleton.

Particle tracking of microbeads attached to the cytoskeleton (CSK) reveals an intermittent dynamic. The mean squared displacement (MSD) is subdiffusive for small Δt and superdiffusive for large Δt, which are associated with periods of traps and periods of jumps respectively. The analysis of the displacements has shown a non-Gaussian behavior, what is indicative of an active motion, classifying the cells as a far from equilibrium material. Using Langevin dynamics, we reconstruct the dynamic of the CSK. The model is based on the bundles of actin filaments that link themself with the bead RGD coating, trapping it in an harmonic potential. We consider a one- dimensional motion of a particle, neglecting inertial effects (over-damped Langevin dynamics). The resultant force is decomposed in friction force, elastic force and random force, which is used as white noise representing the effect due to molecular agitation. These description until now shows a static situation where the bead performed a random walk in an elastic potential. In order to modeling the active remodeling of the CSK, we vary the equilibrium position of the potential. Inserting a motion in the well center, we change the equilibrium position linearly with time with constant velocity. The result found exhibits a MSD versus time ’tau’ with three regimes. The first regime is when ‘tau’ < ‘tau IND 0’, where ‘tau IND 0’ is the relaxation time, representing the thermal motion. At this regime the particle can diffuse freely. The second regime is a plateau, ‘tau IND 0’ < ‘tau’ < ‘tau IND 1’, representing the particle caged in the potential. Here, ‘tau IND 1’ is a characteristic time that limit the confinement period. And the third regime, ‘tau’ > ‘tau IND 1’, is when the particles are in the superdiffusive behavior. This is where most of the experiments are performed, under 20 frames per second (FPS), thus there is no experimental evidence that support the first regime. We are currently performing experiments with high frequency, up to 100 FPS, attempting to visualize this diffusive behavior. Beside the first regime, our simple model can reproduce MSD curves similar to what has been found experimentally, which can be helpful to understanding CSK structure and properties.CNPqFAPES

Post break-up stalking: police-officers' perceptions

Stalking is characterized by persistent unwanted behaviors and can disrupt the lives of victims. Its prevalence has been increasing with time. Due to the recent criminalization of stalking in Portugal and its being an understudied phenomenon, the objective of this study is to assess the perceptions of police officers (n = 1212) about stalking post intimate relationship breakup. We developed an adaptation of the questionnaire "Reasonable Perceptions of Stalking", using vignettes that describe stalking scenarios with the manipulation of severity, and victim and perpetrator sex. The main effects of severity, as well as the victim and the perpetrator's sex, were significant intrasubject variables in the perceptions of stalking and its severity, criminality, victim alert, fear of violence, victim-blaming, and the need for intervention. Participants' sex, previous training, and personal and/or professional experience with stalking were also significant variables concerning participants' perceptions. Our findings show that gender stereotypes are still perpetuated and have important implications for police officer training and intervention.- (undefined

Intent Detection at Scale: Tuning a Generic Model using Relevant Intents

Accurately predicting the intent of customer support requests is vital for efficient support systems, enabling agents to quickly understand messages and prioritize responses accordingly. While different approaches exist for intent detection, maintaining separate client-specific or industry-specific models can be costly and impractical as the client base expands. This work proposes a system to scale intent predictions to various clients effectively, by combining a single generic model with a per-client list of relevant intents. Our approach minimizes training and maintenance costs while providing a personalized experience for clients, allowing for seamless adaptation to changes in their relevant intents. Furthermore, we propose a strategy for using the clients relevant intents as model features that proves to be resilient to changes in the relevant intents of clients -- a common occurrence in production environments. The final system exhibits significantly superior performance compared to industry-specific models, showcasing its flexibility and ability to cater to diverse client needs.Comment: 6 pages, 6 tables, 2 figures, ICMLA 202

O CONHECIMENTO TÁTICO DOS ALUNOS DURANTE UMA UNIDADE HÍBRIDA DO MODELO DE EDUCAÇÃO DESPORTIVA E DO MODELO DE ABORDAGEM PROGRESSIVA AO JOGO NO VOLEIBOL

Model-based research has been enhancing the positive effectiveness of both Sport Education and Step-Game Approach on students’ technical, tactical and game-play improvements. Nevertheless, the analysis of students’ declarative understanding on the game in this area was scarce. This study examined their declarative understanding on the game during their participation in a hybrid Sport Education/Step-Game Approach teaching unit. Ninety-six students with no previous experience in either model participated in a 24-lesson volleyball season. A video-based test was developed to assess students’ declarative game understanding and applied before and after the teaching unit. Results showed that they improved in all tactical content taught during the unit. These results can find explanation on Sport Education features such as cooperative team practices and the possibility for being in roles other than players. Beyond that, instructional procedures considered by the Step-Game-Approach stimulated the development of students’ tactical awareness.La investigación en los modelos de instrucción ha enaltecido el impacto positivo del Modelo de Educación Deportiva y del Modelo de Aproximación Progresiva al Juego en el desarrollo técnico y táctico de los alumnos, así como también en el desempeño general en el juego. Sin embargo, el análisis del conocimiento táctico de los alumnos en este ámbito ha sido escaso. El presente estudio tiene como propósito analizar el conocimiento táctico declarado de los alumnos durante una unidad híbrida de estos dos modelos en la modalidad de Voleibol. 96 alumnos sin experiencia previa en los dos modelos participaron en una temporada deportiva con 24 clases. Se desarrolló un test de vídeo para analizar el desarrollo del conocimiento táctico declarado de los alumnos, que se aplicó antes y después de la unidad. Todos los alumnos mejoraron en los contenidos tácticos enseñados, lo que puede encontrar explicación en el trabajo colaborativo en equipos, en la posibilidad de que los alumnos participen en otros papeles además de como jugadores y en los procesos de instrucción, características de los dos modelos.  A investigação nos modelos instrucionais tem enaltecido o impacto positivo do Modelo de Educação Desportiva e do Modelo de Abordagem Progressiva ao Jogo no desenvolvimento técnico e tático dos alunos, assim como no desempenho geral no jogo. Todavia, a análise do conhecimento tático dos alunos neste âmbito tem sido escassa. O presente estudo tem como propósito analisar o conhecimento tático declarativo dos alunos durante uma unidade híbrida desses dois modelos na modalidade de voleibol. Noventa e seis alunos sem experiência prévia nos dois modelos participaram numa época desportiva com 24 aulas. Foi desenvolvido um teste de vídeo para analisar o desenvolvimento do conhecimento tático declarativo dos alunos, o qual foi aplicado antes e depois da unidade. Todos os alunos melhoraram nos conteúdos táticos ensinados, o que pode encontrar explicação no trabalho colaborativo em equipas, na possibilidade dos alunos participarem noutros papéis para além de jogadores e nos processos instrucionais, características dos dois modelos.

Ecological aspects of the casque-headed frog Aparasphenodon brunoi (Anura, Hylidae) in a Restinga habitat in southeastern Brazil

We describe some aspects of the ecology of Aparasphenodon brunoi, a species associated with bromeliads. We comment on the relationships of this species with bromeliad size, microhabitat use, diet and sexual dimorphism. This study was conducted on a Restinga habitat near Presidente Kennedy, state of Espírito Santo, southeastern coast of Brazil. When the animals were found inside the bromeliads, we measure bromeliad and head size of frogs. We analyzed stomach contents and determined the sex and reproductive condition. We found 17 individuals (58.6%) in bromeliad leafs, six (20.7%) in Cactaceae, three (10.3%) in liana and three (10.3%) on trunks. The correlation between head measurements and bromeliad size were high, indicating that animals apparently use bromeliads based on their size, which could be related to the minimization of water loss. The most common prey items were beetles, ants, and insect larvae, suggesting that the species is relatively generalist in prey consumption. Aparasphenodon brunoi showed significant sexual size and shape dimorphism with females having larger bodies than males (size) and females having tibia, eye diameter and SVL larger than males (shape), but larger sample size and more detailed ecological and life history data are needed to elucidate the factors that have led to sexual size dimorphism