density-dependence by using partial correlation coefficients as a test statistic. The extended tests detected delayed density-dependence in 8 15 time series (8.9% 16.7%) at the 5% level (two-tailed test). 5. The high incidence of direct density-dependence and the low, but significant, incidence of delayed density-dependence in these vole populations are discussed. Delayed maturation at high den...

Developmental processes in nature may involve complex changes in the topology, shape, and patterns of growing structures. Processes taking place in one or two dimensions can be visualized as objects in three-dimensional space, obtained by extruding the growing structures along a line or curve representing the progress of time. In this paper, we extend the notion of L-systems with turtle interpr...

Insect host-parasitoid systems are often modeled using delay-differential equations, with a fixed development time for the juvenile host and parasitoid stages. We explore here the effects of distributed development on the stability of these systems, for a random parasitism model incorporating an invulnerable host stage, and a negative binomial model that displays generation cycles. A shifted ga...

Despite the fact that developmental impairments of number skills are common, they remain sparsely investigated. We explored low-level numerical representations and their developmental trajectory in a developmental disorder, Williams syndrome (WS). Groups of WS and typically developing (TD) individuals estimated rapidly-presented arrays of 5, 7, 9, and 11 dots. In comparison to the normal develo...

The conditional independence assumption is commonly used in multivariate mixture models in behavioral research. This assumption postulates the independence of the repeated measurements within an observation, given the status of the observation’s component membership. In this paper, the component distributions in a multivariate mixture model are fitted using an exponential tilt model, in which t...

During embryogenesis tissue layers undergo morphogenetic flow rearranging and folding into specific shapes. While developmental biology has identified key genes and local cellular processes, global coordination of tissue remodeling at the organ scale remains unclear. Here, we combine in toto light-sheet microscopy of the Drosophila embryo with quantitative analysis and physical modeling to rela...