Hox gene activation is crucial for normal development of most organisms. Because of its importance, in both development and disease, it is intensively studied. Up to now, molecular methods have been almost exclusively used in order to explore the underlying mechanisms in normal embryonic growth (Tarchini and Duboule, 2006; Tschopp et al., 2009). The clustering of Hox genes is of particular inte...

The Hox gene collinearity enigma has often been approached using models based on biomolecular mechanisms. The 'biophysical model', is an alternative approach, speculating that collinearity is caused by physical forces pulling the Hox clusters from a territory where they are inactive to a distinct spatial domain where they are activated in a step by step manner. Hox gene translocations have rece...

Nonlinear spectral mixture analysis (NSMA) is a widely used unmixing algorithm. It can fit the mixed spectra adequately, but collinearity effect among true and virtual endmembers will decrease the retrieval accuracies of endmember fractions. Use of linear spectral mixture analysis (LSMA) can effectively reduce the degree of collinearity in the NSMA. However, the inadequate modeling of mixed spe...

Temporal collinearity is often considered the main force preserving Hox gene clusters in animal genomes. Studies that combine genomic and gene expression data are scarce, however, particularly in invertebrates like the Lophotrochozoa. As a result, the temporal collinearity hypothesis is currently built on poorly supported foundations. Here we characterize the complement, cluster, and expression...

Perception entails interactions between activated brain visual areas and the records of previous sensations, allowing for processes like figure-ground segregation and object recognition. The aim of this study was to characterize top-down effects that originate in the visual cortex and that are involved in the generation and perception of form. We performed a functional magnetic resonance imagin...

The Hox gene collinearity enigma has often been approached using models based on biomolecular mechanisms. The biophysical model is an alternative approach based on the hypothesis that collinearity is caused by physical forces pulling the Hox genes from a territory where they are inactive to a distinct spatial domain where they are activated in a step by step manner. Such Hox gene translocations...

We have previously demonstrated that the mere organization of some elements in the visual field into an object attracts attention automatically. Here, we explored three different aspects of this automatic attentional capture: (a) Does the attentional capture by an object involve a spatial component? (b) Which Gestalt organization factors suffice for an object to capture attention? (c) Does the ...

Spatial integration has been shown to substantially decline with age. We examined the mechanism underlying this age-related impairment. Young and older adults were tested on the ability to integrate contour elements across variations in the collinearity of the target elements, their spatial proximity, and the relative spacing of the target elements to the background noise elements (Δ). The resu...