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This research tested the hypothesis that enabling leadership behaviors are positively related to the objective and subjective dimensions of teamwork effectiveness. Hypotheses testing was done during a laboratory task in which 40 teams of 5 people each (N = 200) engaged in a simulation task using the pc game SimCity4. The results suggest that enabling leadership and task cohesion are not related to team performance, R2 = .08, MSE = 1.02, F(4, 35) = .79, p = .54; and that enabling leadership is positively related to team viability, mediated by task cohesion, R2 = .71, MSE = 0.31, F(4, 35) = 21.87, p < .001. These findings also suggest that engaging in enabling leadership behaviors promotes team member commitment to a shared goal, which in turn enhances the shared perception that the team has the necessary conditions to keep working together on future assignments.

Esta investigação testou a hipótese de que os comportamentos de facilitação estão positivamente relacionados com as dimensões objetiva e subjetiva da eficácia das equipas de trabalho. Participaram neste estudo 40 equipas de 5 elementos (N = 200), onde se utilizou o jogo de computador SimCity4. A análise dos efeitos diretos e indiretos sugere que os comportamentos de facilitação e a coesão de tarefa não se relacionam com o desempenho, R2 = .08, M.S.E = 1.02, F(4, 35) = .79, p = .54; e que a coesão de tarefa medeia a relação entre comportamentos de facilitação e a viabilidade, R2 = .71, MSE = 0.31, F(4, 35) = 21.87, p < .001. Estes resultados sugerem que a prática de comportamentos de facilitação promove a união dos membros da equipa, o que por sua vez é importante para a crença partilhada de que a equipa tem condições para continuar unida no futuro.

La presente investigación probó la hipótesis de que los comportamientos de facilitación están positivamente relacionados con las dimensiones objetiva y subjetiva de la eficacia de los equipos de trabajo. En este estudio participaron 40 equipos de 5 elementos (N = 200), donde se utilizó el juego de ordenador SimCity4. El análisis de los efectos directos e indirectos sugiere que el comportamiento de facilitación y la cohesión de tareas no están relacionados con el rendimiento, R2 = .08, MSE = 1.02, F(4, 35) = .79, p = .54; y que la cohesión de tarea media la relación entre comportamientos de facilitación y la viabilidad, R2 = .71, MSE = 0.31, F(4, 35) = 21.87, p < .001. Estos resultados sugieren que la práctica de comportamiento de facilitación promueve la unión de los miembros del equipo, así como la creencia compartida de que el equipo tiene condiciones para continuar unido en el futuro.

RESUMO

We introduce a simple procedure of multivariate signal analysis to uncover the functional connectivity among cells composing a living tissue and describe how to apply it for extracting insight on the effect of drugs in the tissue. The procedure is based on the covariance matrix of time resolved activity signals. By determining the time-lag that maximizes covariance, one derives the weight of the corresponding connection between cells. Introducing simple constraints, it is possible to conclude whether pairs of cells are functionally connected and in which direction. After testing the method against synthetic data we apply it to study intercellular propagation of Ca(2+) waves in astrocytes following an external stimulus, with the aim of uncovering the functional cellular connectivity network. Our method proves to be particularly suited for this type of networking signal propagation where signals are pulse-like and have short time-delays, and is shown to be superior to standard methods, namely a multivariate Granger algorithm. Finally, based on the statistical analysis of the connection weight distribution, we propose simple measures for assessing the impact of drugs on the functional connectivity between cells.

Assuntos

RESUMO

We investigate pattern formation and evolution in coupled map lattices when advection is incorporated, in addition to the usual diffusive term. All patterns may be suitably grouped into five classes: three periodic, supporting static patterns and traveling waves, and two nonperiodic. Relative frequencies are determined as a function of all model parameters: diffusion, advection, local nonlinearity, and lattice size. Advection plays an important role in coupled map lattices, being capable of considerably altering pattern evolution. For instance, advection may induce synchronization, making chaotic patterns evolve periodically. As a byproduct we describe a practical algorithm for classifying generic pattern evolutions and for measuring velocities of traveling waves.

RESUMO

Ordinarily, two different topologies have been used to model spatiotemporal chaos and to study complexity in networks of maps: one where sites interact only with nearest neighbors (e.g., the standard diffusive coupling) and one where sites interact with all sites in the network (global coupling). Here we investigate intermediate regimes considering the interaction range as a free tunable parameter. The synchronization behavior normally seen in globally coupled maps is found to set in for interaction ranges considerably smaller than the system size. In addition, we analytically derive stability conditions for the onset of coherent states (full synchronization) from which the minimum interaction range needed to induce coherence in homogeneously coupled maps can be determined. Such conditions are also obtained for inhomogeneous situations when the coupling strength decreases linearly with the distance. The characteristic range for the onset of coherence is studied in detail as a function of model parameters.