2,070 research outputs found
Anti-predator behavior in two brown frogs: differences in the mean behaviors and in the structure of animal personality variation
Bottom-up creativity and insurgent citizenship in “Afro Lisboa”: Racial difference and cultural commodification in Portugal
This article analyzes recent audio-visual creativity by young Afrodescendants emerging out of
the outskirts of Lisbon. We argue that those cultural productions are challenging unproblematic identifications of the Portuguese capital as a multicultural city shaped by African communities. Responding to issues of racism, police violence, and urban marginalization, but also to celebratory views of Portuguese society as exempt of racial discrimination, the communities inhabiting the neighborhoods of Cova da Moura and Quinta do Mocho are employing creative means to develop a positive identification of afro-diasporic communities. Engaging those means, this article places bottom-up creativity side by side to the activity of Lisbon cultural institutions such as museums and contemporary art centers. It also addresses the relevance of visual and musical creativity to counter the stereotypes and images frequently used to categorize racialized subjects and communities in Portugal. Finally, it explores the strategies employed by the residents of the above mentioned neighborhoods to struggle against the process of cultural gentrification Lisbon is going through.info:eu-repo/semantics/acceptedVersio
Physical profile comparison between 3x3 and 5x5 basketball training
El objetivo del estudio fue comparar las demandas físicas a partir de variables
de distancia, velocidad y aceleración en baloncesto entre dos juegos reducidos, 3x3
y 5x5, mediante tecnología GPS. Diez mujeres (15 ±1,0 años) participaron en el
estudio, durante dos sesiones de entrenamiento. Se aplicaron las reglas de las
competiciones 3 contra 3 en una sola canasta y a media cancha. Las jugadoras
participaron en dos juegos (5x5 y 3x3) durante 5 minutos cada uno. Las jugadoras
fueron organizadas en función de su puesto específico. Las variables utilizadas para
analizar los datos registrados se agruparon en: indicadores físicos globales
(distancia total o DT, velocidad media o DT/min, Player Load o PL y Velocidad
máxima o Vmax), distancia recorrida en diferentes rangos de velocidad y distancia
recorrida en diferentes rangos de aceleración. El análisis de datos mostró valores
más altos en el 3x3, existiendo diferencias significativas en las variables DT, DT/min
y PL, distancia recorrida en el rango de >1,0 m/s-1 y en la mayoría de los rangos de
aceleración. La interpretación de los resultados sugiere que el espacio afectó en la
demanda física de las jugadorasThe aim of the study was to compare the physical requirements taking into account
the variables of distance, velocity and acceleration in basketball between two
small-sided games, 3x3 and 5x5, using GPS technology. Ten women (15 ±1.0
years) participated in the study, during two training sessions. The rules of 3v3
competitions were applied in a single basket half-court. The players participated in
two games (5x5 and 3x3) during 5 minutes each. The players were organized
according to their specific position. The variables used to analyze the recorded
data were grouped into: global physical indicators (total distance or DT, average
speed or DTmin, Player Load or PL and maximum speed or Vmax), traversed
distance in different ranges of speed and traversed distance in different ranges of
acceleration. The data-analysis showed higher values in the 3x3, being significant
differences in the variables DT, DT/min and PL, traversed distance in the range of
1.0 m/s-1 and in most of the ranges of acceleration. The interpretation of the results
suggests that space affected the physical demand of the player
Mean-field analysis of the q-voter model on networks
We present a detailed investigation of the behavior of the nonlinear q-voter
model for opinion dynamics. At the mean-field level we derive analytically, for
any value of the number q of agents involved in the elementary update, the
phase diagram, the exit probability and the consensus time at the transition
point. The mean-field formalism is extended to the case that the interaction
pattern is given by generic heterogeneous networks. We finally discuss the case
of random regular networks and compare analytical results with simulations.Comment: 20 pages, 10 figure
Stress response to cadmium and manganese in Paracentrotus lividus developing embryos is mediated by nitric oxide
Increasing concentrations of contaminants, often resulting from anthropogenic activities, have been reported to occur in the marine environment and affect marine organisms. Among these, the metal ions cadmium and manganese have been shown to induce developmental delay and abnormalities, mainly reflecting skeleton elongation perturbation, in the sea urchin Paracentrotus lividus, an established model for toxicological studies. Here, we provide evidence that the physiological messenger nitric oxide (NO), formed by l-arginine oxidation by NO synthase (NOS), mediates the stress response induced by cadmium and manganese in sea urchins. When NO levels were lowered by inhibiting NOS, the proportion of abnormal plutei increased. Quantitative expression of a panel of 19 genes involved in stress response, skeletogenesis, detoxification and multidrug efflux processes was followed at different developmental stages and under different conditions: metals alone, metals in the presence of NOS inhibitor, NO donor and NOS inhibitor alone. These data allowed the identification of different classes of genes whose metal-induced transcriptional expression was directly or indirectly mediated by NO. These results open new perspectives on the role of NO as a sensor of different stress agents in sea urchin developing embryos. © 2014 Elsevier B.V
Lonely adatoms in space
There is a close relation between the problems of second layer nucleation in
epitaxial crystal growth and chemical surface reactions, such as hydrogen
recombination, on interstellar dust grains. In both cases standard rate
equation analysis has been found to fail because the process takes place in a
confined geometry. Using scaling arguments developed in the context of second
layer nucleation, I present a simple derivation of the hydrogen recombination
rate for small and large grains. I clarify the reasons for the failure of rate
equations for small grains, and point out a logarithmic correction to the
reaction rate when the reaction is limited by the desorption of hydrogen atoms
(the second order reaction regime)
The lifespan method as a tool to study criticality in absorbing-state phase transitions
In a recent work, a new numerical method (the lifespan method) has been
introduced to study the critical properties of epidemic processes on complex
networks [Phys. Rev. Lett. \textbf{111}, 068701 (2013)]. Here, we present a
detailed analysis of the viability of this method for the study of the critical
properties of generic absorbing-state phase transitions in lattices. Focusing
on the well understood case of the contact process, we develop a finite-size
scaling theory to measure the critical point and its associated critical
exponents. We show the validity of the method by studying numerically the
contact process on a one-dimensional lattice and comparing the findings of the
lifespan method with the standard quasi-stationary method. We find that the
lifespan method gives results that are perfectly compatible with those of
quasi-stationary simulations and with analytical results. Our observations
confirm that the lifespan method is a fully legitimate tool for the study of
the critical properties of absorbing phase transitions in regular lattices
Produção cultural e engajamento político na Afro-Lisboa
O objetivo deste capítulo será debater a arte urbana e as configurações identitárias pós-coloniais em Portugal, centrando-se em algumas produções artísticas e culturais que incorporam nos seus “modos de fazer” (Certeau, 1980) elementos políticos, naquilo que alguns autores consideram ser um processo de politização da arte e cultura (Sant’anna et al., 2017; Raposo, 2015; Wright, 1998). Centraremos nosso olhar em dois bairros “periféricos” da Região Metropolitana de Lisboa –Cova da Moura e Quinta do Mocho –marcados pela presença de populações de origem africana. Examinaremos em ambos os espaços como a criatividade urbana desafia a compreensão simplese pouco problematizada da relação do país com o seu passado colonial, ganhando terreno expressões artístico-culturais que também funcionam como atos de resistência. Associados à violência e à marginalidade no imaginário português, os dois bairros racializados são hoje em dia contextos ativos de produção cultural, particularmente férteis no que concerne à música e à arte urbana. Atualmente, estão integrados nos circuitos artísticos de Lisboa, cidade que se tornou um dos principais referenciais culturais e turísticos internacionais. Analisar as contradições trazidas por esse processo, bem como os engajamentos políticos de certos artistas e agentes culturais constituem a preocupação central deste ensaio.info:eu-repo/semantics/acceptedVersio
Uso del espacio en pelota vasca en edad escolar: aplicación del análisis secuencial
El presente estudio aborda la búsqueda de patrones de conductaasociados al uso del espacio llevadas a cabo por jugadores benjamines (8-10años) y alevines (10-12 años) de pelota a mano que participan en deporteescolar. La muestra estuvo compuesta por doce partidos (60 jugadores), seisde benjamines (30 jugadores) y seis de alevines (30 jugadores). El registro sellevó a cabo mediante un instrumento de observación diseñado ad hoc paraanalizar el uso estratégico del espacio realizado, que incluía los siguientescriterios: zona de golpeo y dirección del saque, resto y golpeos de intercambio.A partir del análisis secuencial de retardos se estimaron patrones deconducta para ambas edades, encontrando una mayor cantidad, variedad ylongitud de comportamientos de los jugadores alevines respecto a los benjamines.Los golpeos de los alevines se iniciaron y finalizaron en todas laszonas de la cancha y combinaron direcciones de la pelota tanto en el ejelateral (izquierda y derecha) como longitudinal (media y corta distancia).Su aplicación en el ámbito de la iniciación permitirá a los técnicos implementarestrategias de intervención adecuadas con el objetivo de optimizarlas respuestas motrices dadas por los jugadores
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