4,054 research outputs found

    The effects of alcohol on different classes of motion perception

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    We used a psychophysical approach to investigate how alcohol affected visual sensitivity to perceive different classes of motion. Visual sensitivities were measured in both a non-alcohol and an alcohol condition for three classes of motion: Minimum Motion, Simple Motion, and Complex Motion. Perceptual thresholds, taken as the degree of motion at which an observer responded correctly with an accuracy of 75%, or Weber fractions were compared between the non-alcohol and the alcohol conditions. For Simple and Complex motion, similar comparisons were made as a function of speed (e.g., 2°s-1, 6°s-1, and 12°s-1). Perceptual thresholds were significantly greater in the alcohol condition for the Minimum Motion, and were significantly greater in the alcohol condition for Complex Motion at the fast speed only. We concluded that deficits in motion perception were more from interruptions in cognitive elements brought about by the nature of the visual task, rather than impairments in sensory processing

    Junction Electron-Beam-Induced Current Techniques for the Analysis of Photovoltaic Devices

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    A number of useful electron-beam-induced current (EBIC) techniques have evolved through the study of junction behavior in photovoltaic (PV) devices in cross section as a function of light and voltage bias, temperature, and electron beam scanning parameters. The necessary hardware modifications, the techniques themselves, and their applications are presented. In the case of PV devices, light and/or voltage biasing the entire device while electron probing it in cross section permits the observation of the distribution of the narrowing or extension of the space-charge region. Monitoring the junction behavior as a function of temperature has at least two applications. In situ heating of the device in the junction EBIC (JEBIC) mode permits the observation of the rate of movement of the junction further into the material as a function of time and temperature. Through low-temperature studies of cross sections, the change in the material\u27s electrical properties have been recorded and correlated with device I-V and quantum efficiency measurements at these temperatures. Further, the JEBIC profile has been used to predict the quantum efficiency of the device. In the case of thin-film CdS/CuinSe2 devices, newly developed JEBIC techniques have been instrumental in determining the role of oxygen in improving device performance and stability

    Applications of Charge Collection Microscopy: Electron-Beam-Induced Current to Semiconductor Materials and Device Research

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    Among all of the possible techniques for the micro-characterization of semiconductor materials and devices in a scanning electron microscope (SEM), charge collection microscopy (CCM), more commonly known as electron-beam-induced current (EBIC), is probably both the most easily deployed and the most versatile characterization technique. Following a brief review of the basic theory of the generation and detection of the EBIC signals, various techniques and applications to the micro-characterization of experimental semiconductor materials and devices will be presented. The applications are primarily to emerging photovoltaic materials and devices. This report is not in any way intended as a complete overview of all EBIC related techniques or most material or device applications. Beyond offering a short review of CCM theory, this paper complements the literature (1) as a basic introduction to CCM, and (2) by focusing on the use and extension of CCM techniques for basic studies in experimental electronic materials

    Infrared observations of asteroids from earth and space

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    Infrared reflectances at wavelength between 1 and 4 micrometers are used for determining asteroid surface mineralogy, surface composition, diameters, and albedos. Thermal models were developed for analyzing infrared observations at longer wavelengths. The discovery of a spectral feature due to water of hydration on Ceres seems to contradict the mineralogy inferred from spectrophotometry

    IRAS asteroid families

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    The Infrared Astronomical Satellite (IRAS) sampled the entire asteroid population at wavelengths from 12 to 100 microns during its 1983 all sky survey. The IRAS Minor Planet Survey (IMPS) includes updated results for more recently numbered as well as other additional asteroids with reliable orbital elements. Albedos and diameters were derived from the observed thermal emission and assumed absolute visual magnitudes and then entered into the IMPS database at the Infrared Processing and Analysis Center (IPAC) for members of the Themis, Eos, Koronis and Maria asteroid families and compared with their visual colors. The IMPS results for the small (down to about 20 km) asteroids within these major families confirm trends previously noted for their larger members. Each of these dynamical families which are defined by their similar proper elements appears to have homogeneous physical properties

    Impact of Irrigation Development on Income and Trade: Eastern and Central South Dakota

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    This investigation has been concerned with impacts from the adoption of irrigation on farm expenditures, area personal incomes, and the volume of retail and service trade. Other effects were not estimated in this analysis. They include, however, benefits for the processing and handling industries stemming from increased farm production. Also any effects from development of irrigation potential other than that investigated by the feasibility studies cited in this report were not considered in the measure of impacts on an area economy. The study has sought to estimate a significant share, but not all, of the impacts on communities in regions having potential for irrigation which, it is assumed, could be developed according to proposed plans

    Pharmacologically relevant intake during chronic, free-choice drinking rhythms in selectively bred high alcohol-preferring mice

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    Multiple lines of high alcohol-preferring (HAP) mice were selectively bred for their intake of 10% ethanol (v/v) during 24-hour daily access over a 4-week period, with the highest drinking lines exhibiting intakes in excess of 20 g/kg/day. We observed circadian drinking patterns and resulting blood ethanol concentrations (BECs) in the HAP lines. We also compared the drinking rhythms and corresponding BECs of the highest drinking HAP lines to those of the C57BL/6J (B6) inbred strain. Adult male and female crossed HAP (cHAP), HAP replicate lines 1, 2, 3 and B6 mice had free-choice access to 10% ethanol and water for 3 weeks prior to bi-hourly assessments of intake throughout the dark portion of the light-dark cycle. All HAP lines reached and maintained a rate of alcohol intake above the rate at which HAP1 mice metabolize alcohol, and BECs were consistent with this finding. Further, cHAP and HAP1 mice maintained an excessive level of intake throughout the dark portion of the cycle, accumulating mean BEC levels of 261.5 ± 18.09 and 217.9 ± 25.02 mg/dl, respectively. B6 mice drank comparatively modestly, and did not accumulate high BEC levels (53.63 + 8.15 mg/dl). Free-choice drinking demonstrated by the HAP1 and cHAP lines may provide a unique opportunity for modeling the excessive intake that often occurs in alcohol-dependent individuals, and allow for exploration of predisposing factors for excessive consumption, as well as the development of physiological, behavioral and toxicological outcomes following alcohol exposure

    Emotional reactivity to incentive downshift as a correlated response to selection of high and low alcohol preferring mice and an influencing factor on ethanol intake

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    Losing a job or significant other are examples of incentive loss that result in negative emotional reactions. The occurrence of negative life events is associated with increased drinking (Keyes, Hatzenbuehler, & Hasin, 2011). Further, certain genotypes are more likely to drink alcohol in response to stressful negative life events (Blomeyer et al., 2008; Covault et al., 2007). Shared genetic factors may contribute to alcohol drinking and emotional reactivity, but this relationship is not currently well understood. We used an incentive downshift paradigm to address whether emotional reactivity is elevated in mice predisposed to drink alcohol. We also investigated if ethanol drinking is influenced in High Alcohol Preferring mice that had been exposed to an incentive downshift. Incentive downshift procedures have been widely utilized to model emotional reactivity, and involve shifting a high reward group to a low reward and comparing the shifted group to a consistently rewarded control group. Here, we show that replicate lines of selectively bred High Alcohol Preferring mice exhibited larger successive negative contrast effects than their corresponding replicate Low Alcohol Preferring lines, providing strong evidence for a genetic association between alcohol drinking and susceptibility to the emotional effects of negative contrast. These mice can be used to study the shared neurological and genetic underpinnings of emotional reactivity and alcohol preference. Unexpectedly, an incentive downshift suppressed ethanol drinking immediately following an incentive downshift. This could be due to a specific effect of negative contrast on ethanol consumption or a suppressive effect on consummatory behavior in general. These data suggest that either alcohol intake does not provide the anticipated negative reinforcement, or that a single test was insufficient for animals to learn to drink following incentive downshift. However, the emotional intensity following incentive downshift provides initial evidence that this type of emotional reactivity may be a predisposing factor in alcoholism
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