Working memory capacity and the top-down control of visual search: Exploring the boundaries of "executive attention".

The executive attention theory of working memory capacity (WMC) proposes that measures of WMC broadly predict higher order cognitive abilities because they tap important and general attention capabilities (R. W. Engle & M. J. Kane, 2004). Previous research demonstrated WMC-related differences in attention tasks that required restraint of habitual responses or constraint of conscious focus. To further specify the executive attention construct, the present experiments sought boundary conditions of the WMC-attention relation. Three experiments correlated individual differences in WMC, as measured by complex span tasks, and executive control of visual search. In feature-absence search, conjunction search, and spatial configuration search, WMC was unrelated to search slopes, although they were large and reliably measured. Even in a search task designed to require the volitional movement of attention (J. M. Wolfe, G. A. Alvarez, & T. S. Horowitz, 2000), WMC was irrelevant to performance. Thus, WMC is not associated with all demanding or controlled attention processes, which poses problems for some general theories of WMC. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Automatic dispensing of dichlorvos to control Ephestia kuehniella Zell. (Lepidoptera: Phycitidae) in flour mills

Dichlorvos applied weekly at the rate of 14.0 μg/l gave good control of Ephestia kuehniella in a flour mill. Other insects were also controlled. The insecticide was dispensed automatically by electrically operated sprayers when the mill was unoccupied. Exposure of test insects and chemical determinations of atmospheric concentrations showed that good distribution of vapour was obtained. Concentrations of dichlorvos were at a safe level for working well before the mill reopened after 8 hr. Contamination of flour was negligible. The method involves no disruption of routine working and there is no vapour hazard to workers.     

Enhanced Photocurrent Production by Photosystem I Multilayer Assemblies

The long‐term success of photosynthetic organisms has resulted in their global superabundance, which is sustained by their widespread, continual mass‐production of the integral proteins that photocatalyze the chemical processes of natural photosynthesis. Here, a fast, general method to assemble multilayer films composed of one such photocatalytic protein complex, Photosystem I (PSI), onto a variety of substrates is reported. The resulting films, akin to the stacked thylakoid structures of leaves, consist of a protein matrix that is permeable to electrochemical mediators and contain a high concentration of photoelectrochemically active redox centers. These multilayer assemblies vastly outperform previously reported monolayer films of PSI in terms of photocurrent production when incorporated into an electrochemical system, and it is shown that these photocatalytic properties increase with the film thickness. These results demonstrate how the assembly of micron‐thick coatings of PSI on non‐biological substrates yields a biohybrid ensemble that manifests the photocatalytic activity of the film’s individual protein constituents, and represent significant progress toward affordable, biologically‐inspired renewable energy conversion platforms.     

The role of thermal diffusivity in the machining performance of oxide ceramic cutting tool materials

The machining performance of oxide ceramic cutting tools was correlated with their values of thermal diffusivity, hardness and density. It was found that high crater wear resistance requires high values of the thermal diffusivity, hardness and density. High flank wear resistance requires a high value of thermal diffusivity, but is independent of hardness. In contrast, a good surface finish of the steel workpiece (AISI 4340) requires a combination of low thermal diffusivity and low hardness.     

Grating compensation of third-order material dispersion in thenormal dispersion regime: Sub-100-fs chirped-pulse amplification using afiber stretcher and grating-pair compressor

We describe a method for compensating large amounts of second- and third-order material dispersion, and we present two simple, compact and robust stretcher-compressor systems for microjoule-and millijoule-level chirped-pulse amplification. These systems, which use dispersive material to stretch and a modified grating pair to compress the pulse, provide expansion and compression with full cubic-phase compensation. Unlike previous fiber-stretcher systems which were limited to picosecond pulse durations, these systems can be used effectively with 50-fs microjoule pulses or 100-fs millijoule pulses. The results of our model are described, including the quartic-phase limitations for both systems. We discuss other applications of this grating pair to other areas of ultrafast optics, including intracavity dispersion compensation for femtosecond oscillators