Apposition and affective communication

This paper focuses on the rhetorical effects of structures which involve the apposition of two (or more) segments with similar, but not identical, interpretations – for example, He felt depressed, flattened. Building on the existing relevance theoretic account of poetic effects (Sperber & Wilson 1995, Pilkington 2000), it aims to show how these structures can be used to communicate an impression of emphasis or intensification which can be compared with the effects achieved by repetitions. It argues that these effects are not achieved in the same way, and that three different cases can be distinguished. First, the use of this structure may lie in the way it encourages the reader to explore the differences between the interpretation of the second segment and the interpretation of the first. Second, it may encourage the reader to explore the total set of contextual assumptions made accessible by both (or all) segments for the derivation of an interpretation which could not be derived from any one segment alone. Finally, the paper considers the use of these structures by authors who use free indirect style to represent a character’s struggle to identify an emotion s/he is experiencing

Efficiency of thin film photocells

We propose a new concept for the design of high-efficiency photocells based on ultra-thin (submicron) semiconductor films of controlled thickness. Using a microscopic model of a thin dielectric layer interacting with incident electromagnetic radiation we evaluate the efficiency of conversion of solar radiation into the electric power. We determine the optimal range of parameters which maximize the efficiency of such photovoltaic element.Comment: 5 pages, 3 figure

Adolescence as a Sensitive Period of Brain Development

Most research on sensitive periods has focussed on early sensory, motor, and language development, but it has recently been suggested that adolescence might represent a second ‘window of opportunity’ in brain development. Here, we explore three candidate areas of development that are proposed to undergo sensitive periods in adolescence: memory, the effects of social stress, and drug use. We describe rodent studies, neuroimaging, and large-scale behavioural studies in humans that have yielded data that are consistent with heightened neuroplasticity in adolescence. Critically however, concrete evidence for sensitive periods in adolescence is mostly lacking. To provide conclusive evidence, experimental studies are needed that directly manipulate environmental input and compare effects in child, adolescent, and adult groups

Electron spin relaxation in bulk GaAs for doping densities close to the metal-to-insulator transition

We have measured the electron spin relaxation rate and the integrated spin noise power in n-doped GaAs for temperatures between 4 K and 80 K and for doping concentrations ranging from 2.7 x 10^{-15} cm^{-3} to 8.8 x 10^{-16} cm^{-3} using spin noise spectroscopy. The temperature dependent measurements show a clear transition from localized to free electrons for the lower doped samples and confirm mainly free electrons at all temperatures for the highest doped sample. While the sample at the metal-insulator-transition shows the longest spin relaxation time at low temperatures, a clear crossing of the spin relaxation rates is observed at 70 K and the highest doped sample reveals the longest spin relaxation time above 70 K.Comment: 6 pages, 4 figure

Developmental differences in the control of action selection by social information

Our everyday actions are often performed in the context of a social interaction. We previously showed that, in adults, selecting an action on the basis of either social or symbolic cues was associated with activations in the fronto-parietal cognitive control network, whereas the presence and use of social versus symbolic cues was in addition associated with activations in the temporal and medial prefrontal cortex (MPFC) social brain network. Here we investigated developmental changes in these two networks. Fourteen adults (21–30 years of age) and 14 adolescents (11–16 years) followed instructions to move objects in a set of shelves. Interpretation of the instructions was conditional on the point of view of a visible “director” or the meaning of a symbolic cue (Director Present vs. Director Absent) and the number of potential referent objects in the shelves (3-object vs. 1-object). 3-object trials elicited increased fronto-parietal and temporal activations, with greater left lateral prefrontal cortex and parietal activations in adults than adolescents. Social versus symbolic information led to activations in superior dorsal MPFC, precuneus, and along the superior/middle temporal sulci. Both dorsal MPFC and left temporal clusters exhibited a Director × Object interaction, with greater activation when participants needed to consider the directors' viewpoints. This effect differed with age in dorsal MPFC. Adolescents showed greater activation whenever social information was present, whereas adults showed greater activation only when the directors' viewpoints were relevant to task performance. This study thus shows developmental differences in domain-general and domain-specific PFC activations associated with action selection in a social interaction context