4,703 research outputs found

    Effects of scopolamine on matching to sample paradigm and related tests in human subjects

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    This was a double-blind placebo-controlled study with a cross-over design to examine the effects of scopolamine on cognitive functions in young healthy subjects. Scopolamine hydrobromide was administered subcutaneously to 12 subjects (mean +/- SD age 23.8 +/- 2.2 years) at doses of 0.3 and 0.6 mg in comparison with two placebo conditions. Scopolamine at both doses produced marked sedation as rated by subjects and an observer. In the continuous performance test, vigilance was impaired by both doses of scopolamine. The span of apprehension test showed differing results (only the high dose of scopolamine showed a performance decrement only in the three-character version of the span of apprehension test). Significant impairment by both doses of scopolamine was seen in immediate and delayed free recall, continuous visual recognition, running word recognition and running picture recognition. While scopolamine caused a significant slowing in average reaction times for simultaneous matching as well as for delayed matching, subjects made more errors under scopolamine compared to placebo only in delayed matching, not in simultaneous matching. Also, the main outcome of matching to sample showed significant effects only in delayed matching, not in simultaneous matching. Notable in this study is the incongruity between the simultaneous matching test and the span of apprehension test on the one hand and the other cognitive tests used on the other. These results demonstrated that scopolamine has a greater effect on memory than on attention. Thus, the scopolamine-induced effects in the present study seem to be more relevant to Alzheimer's disease in an advanced phase than to normal aging. Copyright (C) 2003 S. Karger AG, Basel

    Homography-based ground plane detection using a single on-board camera

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    This study presents a robust method for ground plane detection in vision-based systems with a non-stationary camera. The proposed method is based on the reliable estimation of the homography between ground planes in successive images. This homography is computed using a feature matching approach, which in contrast to classical approaches to on-board motion estimation does not require explicit ego-motion calculation. As opposed to it, a novel homography calculation method based on a linear estimation framework is presented. This framework provides predictions of the ground plane transformation matrix that are dynamically updated with new measurements. The method is specially suited for challenging environments, in particular traffic scenarios, in which the information is scarce and the homography computed from the images is usually inaccurate or erroneous. The proposed estimation framework is able to remove erroneous measurements and to correct those that are inaccurate, hence producing a reliable homography estimate at each instant. It is based on the evaluation of the difference between the predicted and the observed transformations, measured according to the spectral norm of the associated matrix of differences. Moreover, an example is provided on how to use the information extracted from ground plane estimation to achieve object detection and tracking. The method has been successfully demonstrated for the detection of moving vehicles in traffic environments

    Effects of space shuttle launches STS-1 through STS-9 on terrestrial vegetation of John F. Kennedy Space Center, Florida

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    Space Shuttle launches produce a cloud containing hydrochloric acid (HCl), aluminum oxide (Al203), and other substances. Acidities of less than 0.5 pH have been measured routinely in association with the launch cloud. In an area of about 22 ha regularly exposed to the exhaust cloud during most Shuttle launches, acute vegetation damage has resulted from the first nine Shuttle launches. Changes include loss of sensitive species, loss of plant community structure, reduction in total cover, and replacement of some species by weedy invaders. Community level changes define a retrogressive sequence. One-time impacts to strand and dune vegetation occurred after launches of STS-8 and STS-9. Acute vegetation damage occurred especially to sensitive species. Within six months, however, recovery was nearly complete. Sensitivity of species to the launch cloud was partially predicted by previous laboratory studies. Far-field acidic and dry fallout from the cloud as it rises to stabilization and moves with the prevailing winds causes vegetation spotting. Damage from this deposition is minor; typically at most 1% to 5% of leaf surface area is affected. No plant mortality or community changes have occurred from far-field deposition

    Stigma and Discrimination in People Suffering with a Mood Disorder: A Cross-Sectional Study

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    Background. Much research is done on the stigma of mental illness, but little research has been done to characterize these phenomena from the perspective of people with mood disorders. Objective. To characterize the extent to which individuals with bipolar disorder and depression are stigmatized, determine factors related to higher levels of stigmatization, and assess the reliability of the Inventory of Stigmatizing Experiences in a population of people with a mood disorder. Methods. Two hundred and fourteen individuals with depression and bipolar disorder were recruited from a tertiary care psychiatric hospital and surveyed using the Inventory of Stigmatizing Experiences. Results. Participants reported high levels of stigma experiences and this did not differ by diagnosis (P = 0.578). However, people with bipolar disorder reported greater psychosocial impact of stigma on themselves and their family members compared to people with depression (P = 0.019). The two subscales produced internally consistent results with both populations. Conclusion. Stigma negatively affects those with both depression and bipolar disorder but appears to have a greater psychosocial impact on those with bipolar disorder

    Still\u27s Disease in Adults

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    In 1897, Dr. George F. Still described 22 children with a form of chronic joint disease which differed from rheumatic fever. Twelve of these children had a syndrome characterized by glandular and splenic enlargement which, with a characteristic fever pattern, rash, and arthritis, has become known as Still\u27s disease. Subsequent investigators have described patients over age 16 presenting with similar signs and symptoms suggesting that this syndrome is not specific for children. We recently studied a patient in whom the diagnosis of adult onset Still\u27s disease was made

    Magic wavelengths for the 5s18s5s-18s transition in rubidium

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    Magic wavelengths, for which there is no differential ac Stark shift for the ground and excited state of the atom, allow trapping of excited Rydberg atoms without broadening the optical transition. This is an important tool for implementing quantum gates and other quantum information protocols with Rydberg atoms, and reliable theoretical methods to find such magic wavelengths are thus extremely useful. We use a high-precision all-order method to calculate magic wavelengths for the 5s18s5s-18s transition of rubidium, and compare the calculation to experiment by measuring the light shift for atoms held in an optical dipole trap at a range of wavelengths near a calculated magic value

    Strong magnetic coupling of an ultracold gas to a superconducting waveguide cavity

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    Placing an ensemble of 10610^6 ultracold atoms in the near field of a superconducting coplanar waveguide resonator (CPWR) with Q106Q \sim 10^6 one can achieve strong coupling between a single microwave photon in the CPWR and a collective hyperfine qubit state in the ensemble with geff/2π40g_\textit{eff} / {2 \pi} \sim 40 kHz larger than the cavity line width of κ/2π7{\kappa}/{2 \pi} \sim 7 kHz. Integrated on an atomchip such a system constitutes a hybrid quantum device, which also can be used to interconnect solid-state and atomic qubits, to study and control atomic motion via the microwave field, observe microwave super-radiance, build an integrated micro maser or even cool the resonator field via the atoms

    Winterzwiebeln: Anbau IP oder Bio

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    Bei der Sorte Radar führt das Stecken von «grossen» Steckzwiebeln zu einem höheren Ertrag in beiden Anbausystemen, IP und Bio. Auch wird der Anteil an grossen und Metzgerzwiebeln gesteigert, besonders ausgeprägt unter IP-Bedingungen. Dies ging einher mit einer leichten Zunahme (<6%) der Schossneigung bei «grossen» Steckzwiebeln und frühem Stecktermin
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