Despite our visual system receiving irrelevant input that competes with task-relevant signals, we are able to pursue our perceptual goals. Attention enhances our visual processing by biasing the processing of the input that is relevant to the task at hand. The top-down signals enabling these biases are therefore important for regulating lower level sensory mechanisms. In three experiments, we e...

Competitors are known to be important in governing the outcome of evolutionary diversification during an adaptive radiation, but the precise mechanisms by which they exert their effects remain elusive. Using the model adaptive radiation of Pseudomonas fluorescens, we show experimentally that the effect of competition on diversification of a focal lineage depends on both the strength of competit...

OBJECTIVE The aim of this article is to explain the current status of deinstitutionalisation and of community care development in the UK. DESIGN Literature review of articles and reports on deinstitutionalisation. SETTING Articles included in the review related either to the whole of the UK, to England and Wales, or to a specific area such as London. MAIN OUTCOME MEASURES The review was c...

The Howrah Bridge and Second Hooghly Bridge has been serving the city of Kolkata in conjunction with each other by allowing the city to be well connected with the rest of the state and indeed the rest of the country. The bridges by themselves, the former being of balancedcantilever form and the latter being cable-stayed, are marvels of bridge engineering with each being built in very different ...

It has been recognized for a long time that non-market interactions, i.e. interactions between agents that are not mediated by the market, are crucial to explain different economic phenomena such as stock market crashes, growth, education, religion, crime, etc. (for recent surveys, see Glaeser and Scheinkman, 2002, and Durlauf, 2004). In these models, the marginal utility to one person of under...

Eukaryotic cells possess motility mechanisms allowing them not only to self-propel but also to exert forces on obstacles (to push) and to carry cargoes (to pull). To study the inherent asymmetry between active pushing and pulling we model a crawling acto-myosin cell extract as a one-dimensional layer of active gel subjected to external forces. We show that pushing is controlled by protrusion an...

In the study reported here, we investigated intergenerational transmission of life stories in two groups of young adults: a conflict group and a nonconflict group. Only participants in the conflict group had parents who lived through violent political upheaval. All participants recalled and dated 10 important events from one of their parents' lives. There were three main findings. First, both g...

Although the toxic effects of lead on the central nervous system have been well described, the blood concentration at which lead begins to exert adverse effects remains the focus of debate. A meta-analysis of occupational studies was conducted evaluating the association between neurobehavioural testing results and moderate blood lead concentrations.

Endogenously initiated transitions between tasks are associated with inhibition of the attentional set for the task preceding the transition, as demonstrated by slowed reactions to a task most recently switched away from (U. Mayr & S. W. Keele, 2000). Using an altered methodological approach, the authors found that this backward inhibition counteracts perseverative tendencies when switching to ...