Sputtered zinc sulphide films on silicon

The design of a triode rf sputtering system for the deposit of high purity films of zinc sulphide is outlined. It is shown that a variety of dopants may be incorporated in the film over wide concentration ranges by means of this technique, and it is also shown that rare earth cathodoluminescent films may be formed. When deposited under suitable conditions a moderate degree of crystallographic orientation of the films has been achieved.     

A note on the factorization of matrices occurring in Wiener-Hopf problems

Simple expressions for the Wiener-Hopf factors of a certain matrix considered by Daniele are given.     

Cytotoxic lesions of the retrohippocampal region attenuate latent inhibition but spare the partial reinforcement extinction effect

The study focuses on the use of brainstorming tool for consensual decision making in nursing services. A qualitative research has been developed with focus group technique use involving 6 workers from a basic health unit in Joao Pessoa city which belongs to the state network of Paraíba State Health Secretary. The results showed the method application plausibility as a strategy to nursing services quality improvement.     

The hippocampus, collateral behavior, and timing.

Male Sprague-Dawley rats with hippocampal (HC) lesions, cortical control lesions, or sham operations were trained to leverpress on a DRL schedule requiring 12 sec between responses. In 4 experiments, factors affecting performance efficiency in this paradigm were manipulated. Providing extra opportunities for collateral mediating behavior (Exp I) aided all groups nondifferentially. Adding a limited hold (Exp II) or administering chlordiazepoxide HCl (Exp III) reduced DRL efficiency in all groups nondifferentially. However, adding an auditory stimulus marking the halfway point in the DRL requirement (Exp IV) differentially aided the HC group. Implications for theories of HC function are discussed. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Estimation of ozone with total ozone portable spectroradiometer instruments. I. Theoretical model and error analysis

Inexpensive devices to measure solar UV irradiance are available to monitor atmospheric ozone, for example, total ozone portable spectroradiometers (TOPS instruments). A procedure to convert these measurements into ozone estimates is examined. For well-characterized filters with 7-nm FWHM bandpasses, the method provides ozone values (from 304- and 310-nm channels) with less than 0.4% error attributable to inversion of the theoretical model. Analysis of sensitivity to model assumptions and parameters yields estimates of ±3% bias in total ozone results with dependence on total ozone and path length. Unmodeled effects of atmospheric constituents and instrument components can result in additional ±2% errors.     

Amygdala and Ventral Hippocampus Contribute Differentially to Mechanisms of Fear and Anxiety.

Cytotoxic ventral hippocampal lesions produced anxiolytic effects on 4 ethologically based, unconditioned tests of anxiety in the rat (hyponeophagia, black/white 2-compartment box test, a successive alleys test that represents a modified version of the elevated plus-maze, and a social interaction test). Dorsal hippocampal lesions did not produce anxiolytic effects on these tests, suggesting a distinct specialization of function within the hippocampus. Furthermore, the effects of ventral hippocampal lesions were also distinct from those of amygdala lesions. This suggests that the effects of ventral hippocampal lesions are not simply due to direct or indirect effects on the amygdala, and that these 2 brain areas contribute differentially to a brain system (or systems) associated with the processing of fearful and/or anxiogenic stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quantum cascade laser sensor for SO2 and SO3 for application to combustor exhaust streams

We have demonstrated a high-sensitivity, room-temperature quantum-cascade (QC) laser sensor for detection of SO2 and SO3 under conditions relevant to aircraft test combustor exhaust. Two QC lasers probe infrared absorption features at 7.50 and 7.16 microm for SO2 and SO3, respectively, with a common dual-beam detection system. We inferred a noise-equivalent absorbance of approximately 1 x 10(-4) Hz(-1/2). We have demonstrated detection limits for both SO2 and SO3 of 1-2 ppmv m/Hz(1/2) (where ppmv is parts in 10(6) by volume) for 300 torr, elevated temperature, and path lengths near 1 m. This level of sensitivity permits measurement of < 1 ppmv of SO2 and SO3 at these conditions with modest signal averaging.     

Anxiolytic effects of cytotoxic hippocampal lesions in rats.

Rats with cytotoxic lesions of the hippocampus were given 3 anxiety tests: social interaction with a novel rat, the elevated zero-maze (a modification of the plus-maze), and hyponeophagia (eating familiar and novel foods in a novel place). Marked anxiolytic effects were seen in the social interaction and hyponeophagia tests, but not on the zero-maze. These results confirm and extend previous experiments that used traditional lesion techniques. The zero-maze result was consistent with other experiments using the plus-maze, in which intrahippocampal administrations of pharmacological agents were not anxiolytic, although variability in ethological tests may also be a factor. As the hyponeophagia test used an elevated apparatus, as in the zero- and plus-mazes, the lack of a lesion effect in the zero-maze was unlikely to have been due to an inability to relieve height-induced anxiety. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The epitaxy of zinc sulphide on silicon

The epitaxy of zinc sulphide films on silicon has been studied by means of X-ray and electron diffraction and by scanning electron microscopy. Results have shown that due to the nature of the stacking of atoms, planar defects will predominate in such a sphalerite structure material; this is similar to the results of Pashley and Stowell on face centred cubic metals. Such defects have been shown to be more prevalent on (111) and (110) orientations, compared with the (100) orientation which gave the best epitaxial single crystal films. These results agree with other work from this laboratory on the epitaxy of zinc selenide on germanium and silicon.     

Critical determinants of nonspatial working memory deficits in rats with conventional lesions of the hippocampus or fornix.

Rats with conventional lesions of the hippocampus or fornix were compared postoperatively with controls on nonspatial memory tasks. Neither lesion impaired delayed matching-to-sample (DMS) performance in a discrete-trial task involving "pseudo-trial-unique" complex stimuli. An impairment emerged if a single pair of complex stimuli was used throughout each day's session, and the greatest impairment was obtained with the use of a single pair of less complex stimuli throughout each day's test. Transfer to continuous DMS task with no explicit intertrial interval produced a different pattern because both lesion and control levels of performance were depressed when 2 complex stimuli were used repeatedly. A final, separate discrimination learning experiment showed that hippocampectomized rats readily discriminated between the stimuli associated with the greatest lesion-induced DMS deficit. Hippocampal dysfunction thus produces clear deficits on nonspatial memory tasks under appropriate test conditions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)