Waiting periods, instructive signals and positional information

Medical waiting periods: imminence, emotions and coping.

The diagnosis and treatment of various medical conditions requires patients to wait for results that are potentially threatening to their wellbeing (e.g., breast biopsy results, pregnancy test results after fertility treatment and genetic screening outcomes). Little research has been carried out to document the psychological processes that unfold during such waiting periods. The aim of the pres...

Handgun waiting periods reduce gun deaths

Handgun waiting periods are laws that impose a delay between the initiation of a purchase and final acquisition of a firearm. We show that waiting periods, which create a "cooling off" period among buyers, significantly reduce the incidence of gun violence. We estimate the impact of waiting periods on gun deaths, exploiting all changes to state-level policies in the Unites States since 1970. We...

Mandatory waiting periods for abortions and female mental health.

Ancient signals: peptides and the interpretation of positional information in ancestral metazoans.

Understanding the 'tool kit' that builds the most fundamental aspects of animal complexity requires data from the basal animals. Among the earliest diverging animal phyla are the Cnidaria which are the first in having a defined body plan including an axis, a nervous system and a tissue layer construction. Here I revise our understanding of patterning mechanism in cnidarians with special emphasi...

Positional information, in bits.

Cells in a developing embryo have no direct way of "measuring" their physical position. Through a variety of processes, however, the expression levels of multiple genes come to be correlated with position, and these expression levels thus form a code for "positional information." We show how to measure this information, in bits, using the gap genes in the Drosophila embryo as an example. Indivi...