The unexpected dominance of secondary over primary nucleation.

It is still a challenge to control the formation of particles in industrial crystallization processes. In such processes, new crystals can be generated either by primary or secondary nucleation. While in continuous stirred tank crystallization processes, secondary nucleation is thought to occur due to the shear or attrition of already present larger crystals; in antisolvent crystallization processes, where mixing at the inlets locally causes high supersaturations, primary nucleation is understood to be the main mechanism.

Adaptation to proprioceptive targets following visuomotor adaptation.

In the following study, we asked if reaches to proprioceptive targets are updated following reach training with a gradually introduced visuomotor perturbation. Subjects trained to reach with distorted hand-cursor feedback, such that they saw a cursor that was rotated or translated relative to their actual hand movement. Following reach training trials with the cursor, subjects reached to Visual (V), Proprioceptive (P) and Visual + Proprioceptive (VP) targets with no visual feedback of their hand.

The rapid-chase theory does not extend to movement execution.

It is assumed that the processing of a prime followed by a mask occurs sequentially in a feedforward manner when the three (initiation, takeover, and independence) criteria outlined by the rapid-chase theory are met. The purpose of the current study was to determine if the processing of the prime and mask fit the predictions of the rapid-chase theory when the prime and mask are presented during an ongoing movement. In two experiments, participants made rapid pointing movements to a target indicated by the mask.

HIV and AIDS: transmission, testing and treatment.

Human immunodeficiency virus (HIV) rates are increasing in the UK. However, the public's knowledge of HIV and routes of transmission is reducing. A third of people who are HIV positive in the UK are unaware of their diagnosis.

Promoting sexual health: practical guidance on male condom use.

Condoms are the only form of contraception that, when used correctly, can reduce the risk of pregnancy and transmission of sexually transmitted infections. This article outlines strategies for promoting correct male condom use. The availability, variety and history of condoms are explored.