Ancients inspire modern memory

A stencilling technique for depositing arrays of nanoscale ferroelectric capacitors on a surface could be useful in data storage devices.

Accumulation of entanglement in a continuous variable memory

We study entanglement accumulation in a memory built out of two continuous variable systems interacting with a qubit that mediates their indirect coupling. We show that, in contrast with the case of bidimensional Hilbert spaces, entanglement superior to one ebit can be accumulated in the memory, even though no entangled resource is used. The protocol is immediately implementable and we assess the role of the main imperfections.

Errorless learning and memory performance in schizophrenia

There is evidence that patients with schizophrenia have impaired explicit memory and intact implicit memory. The present study sought to replicate and extend that of O'Carroll et al. [O'Carroll, R.E., Russell, H.H., Lawrie, S.M. and Johnstone, E.C., 1999. Errorless learning and the cognitive rehabilitation of memory-impaired schizophrenic patients. Psychological Medicine 29, 105-112.] which reported that for memory-impaired patients with schizophrenia performance on a (cued) word recall task is enhanced using errorless learning techniques (in which errors are prevented during learning) compared to errorful learning (the traditional trial-and-error approach). Thirty patients with a DSM-IV diagnosis of schizophrenia and fifteen healthy controls (HC) participated. The Rivermead Behavioural Memory Test was administered and from their scores, the schizophrenic patients were classified as either memory-impaired (MIS), or memory-unimpaired (MUS). During the training phase two lists of words were learned separately, one using the errorless learning approach and the other using an errorful approach. Subjects were then tested for their recall of the words using cued recall. After errorful learning training, performance on word recall for the MIS group was impaired compared to the MUS and HC groups. However, after errorless learning training, no significant differences in performance were found between the three groups. Errorless learning may play an important role in remediation of cognitive deficits for patients with schizophrenia. (c) 2007 Elsevier Ireland Ltd. All rights reserved.

Shared or unshared parental care in overwintering brent geese (Branta bernicla hrota)

We examine brood size effects on the behaviour of wintering parent and juvenile brent geese (Branta bernicla hrota) to test predictions of shared and unshared parental care models. The behaviour of both parents and offspring appear to be influenced by declining food availability over the winter. Parental vigilance increased with brood size and may be explained by vigilance having functions in addition to antipredator behaviour where the benefits are shared among the brood. There was no increase in parental aggression with brood size and this does not fit the prediction of shared care. Nevertheless, large families are able to monopolize better feeding areas compared with smaller families and large families static feed more but walk feed less than do small families, the former apparently being the preferred mode. The presence of additional young, rather than increasing the amount of parental aggression, seems to enhance the family's competitive ability. Because parents with large broods benefit from enhanced access to resources there is likely to be no additional significant cost in the parental care of larger broods (sensu Trivers 1972).