67 research outputs found
Statistics of extinction and survival in Lotka-Volterra systems
We analyze purely competitive many-species Lotka-Volterra systems with random
interaction matrices, focusing the attention on statistical properties of their
asymptotic states. Generic features of the evolution are outlined from a
semiquantitative analysis of the phase-space structure, and extensive numerical
simulations are performed to study the statistics of the extinctions. We find
that the number of surviving species depends strongly on the statistical
properties of the interaction matrix, and that the probability of survival is
weakly correlated to specific initial conditions.Comment: Previous version had error in authors. 11 pages, including 5 figure
Prospectively predicting dietary restraint: The role of interpersonal self-efficacy, weight/shape self-efficacy, and interpersonal stress
This study investigated how the precursors of interpersonal self-efficacy and weight/shape self-efficacy would interact in the face of interpersonal stress to prospectively predict dietary restraint. Three models were explored, each with a different type of interpersonal stress: stress from same sex friendships, opposite sex friendships, or romantic relationships
Collective motions in globally coupled tent maps with stochastic updating
We study a generalization of globally coupled maps, where the elements are
updated with probability . When is below a threshold , the
collective motion vanishes and the system is the stationary state in the large
size limit. We present the linear stability analysis.Comment: 6 pages including 5 figure
Mutual synchronization and clustering in randomly coupled chaotic dynamical networks
We introduce and study systems of randomly coupled maps (RCM) where the
relevant parameter is the degree of connectivity in the system. Global
(almost-) synchronized states are found (equivalent to the synchronization
observed in globally coupled maps) until a certain critical threshold for the
connectivity is reached. We further show that not only the average
connectivity, but also the architecture of the couplings is responsible for the
cluster structure observed. We analyse the different phases of the system and
use various correlation measures in order to detect ordered non-synchronized
states. Finally, it is shown that the system displays a dynamical hierarchical
clustering which allows the definition of emerging graphs.Comment: 13 pages, to appear in Phys. Rev.
An enquiry into the attitudes of Muslim Asian mothers regarding infant feeding practices and dental health
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