A Novel Single-Loop Mechanism and the Associated Cylindrical Deployable Mechanisms

This paper presents a new type of 2-DOF single-loop mechanism inspired by the Sarrus mechanism, and it utilizes this mechanism to construct 2-DOF cylindrical deployable mechanisms. First, the motion pattern of the single-loop mechanism is analyzed utilizing screw theory. According to the structural symmetries, the cylindrical deployable mechanisms are constructed through the linear pattern combination and circular pattern combination of the single-loop mechanisms. After the geometrical analysis and interference condition analysis, the axial, circumferential and area magnification ratios are defined and, furthermore, applied to the parameter optimization of the deployable mechanisms, forming an example surface. Finally, a simplified 1-DOF single-loop mechanism is derived from the proposed 2-DOF mechanism, which is used to construct 1-DOF cylindrical deployable mechanisms with singular free workspaces.

Sleep-dependent offline performance gain in visual perceptual learning is consistent with a learning-dependent model

SummaryAre the sleep-dependent offline performance gains of visual perceptual learning (VPL) consistent with a use-dependent or learning-dependent model? Here, we found that a use-dependent model is inconsistent with the offline performance gains in VPL. In two training conditions with matched visual usages, one generated VPL (learning condition), while the other did not (interference condition). The use-dependent model predicts that slow-wave activity (SWA) during posttraining NREM sleep in the trained region increases in both conditions, in correlation with offline performance gains. However, compared with those in the interference condition, sigma activity, not SWA, during NREM sleep and theta activity during REM sleep, source-localized to the trained early visual areas, increased in the learning condition. Sigma activity correlated with offline performance gain. These significant differences in spontaneous activity between the conditions suggest that there is a learning-dependent process during posttraining sleep for the offline performance gains in VPL.

A Highly Efficient Visible Absorber Coating on a Curved Substrate

In this study, we propose and fabricate a perfect absorber on a planar substrate using alternate silicon dioxide and ultrathin metallic lossy chromium (Cr) films. Furthermore, we transfer the absorber to a curved substrate via an optimization design of symmetric structures. The absorber exhibits a highly efficient absorption and large incident-angular tolerance characteristics in the whole visible region. We investigate each layer contribution to the absorption theoretically, and find that ultrathin (~5 nm) lossy Cr films play a dominant absorptive role. Using the effective interface method, we calculate the phase difference on the lossy Cr front surface. It is close to the destructive interference condition, from which we clarify why the proposed structures can produce a highly efficient absorption.

Beneficial effect of minimal interference on item memory but not on source memory in Alzheimer's disease

Objectives: Research suggests beneficial effects of minimal interference on item memory in mild Alzheimer’s disease (AD). We conducted a study to test whether these beneficial effects extend to source memory, i.e., the ability to remember the episodic context in which an information was previously acquired. Method: Twenty-six mild AD participants and 28 controls manipulated six objects or watched the experimenter manipulating six other objects. After immediate item recall (“what were the items?”) and source recall (“by whom the items were previously manipulated?”), an interference or a minimal interference condition was administrated. In the interference condition, participants were assessed with neuropsychological tests for 10 min. In the minimal interference condition, they rested alone in a dark and quiet room for 10 minutes. Both interference and minimal interference conditions were followed by the delayed recall, on which participants were asked to remember the previously-presented objects and their source. Results: Higher item memory was observed following minimal interference than following interference in AD participants (p < .01) and controls (p < .01). Also, AD participants demonstrated higher item memory on immediate recall than following interference (p < .001) or minimal interference (p < .001); controls also demonstrated higher item memory on immediate recall than following interference (p < .001) or minimal interference (p < .001). Considering source memory, similar source memory was observed following interference and minimal interference in AD participants (p > .1) and controls (p > .1). Also, AD participants demonstrated higher source memory on immediate recall than following interference (p < .001) or minimal interference (p < .001); controls also demonstrated higher source memory on immediate recall than following interference (p < .001) or minimal interference (p < .001). Conclusion: Failures of hippocampus-dependent associative or consolidation processes in AD may preclude benefits of minimal interference for source memory. Nevertheless, AD patients may show some capacity to retain simple material, should the material presentation be followed by short delays that are free of further stimuli.

Interference in Geometrical Stoop like Task among Different Handed Persons

The Geometrical Stroop like task was administered to study the amount of interference in different handed persons in naming geometrical word and their shape when stimuli were presented in two different conditions congruent and incongruent in two visual fields (RVF and LVF). It was hypothesized that, the ability of visual perception can be differing of a person in terms of their handedness. 149 subjects were voluntary participated in this study in which 80 subjects were predominantly Right handed and rest of them were non-right handed, between 17 and 21 years old. Each pair of stimulus was presented for 180msec preceded by a fixation dot for 2000msec. Subjects were asked to respond as fast and as accurately as they could either the geometrical words or the shape or both, depending upon the conditions. Reaction times of correct responses were analyzed. As expected, the results of this study on the basis of Stroop-like experiment give us enough findings in support of hypothesis. The findings of current study indicate that congruency effect in both of the groups. A significantly higher accuracy rates were obtained in non right handed person under the Stroop interference condition. Under this same condition, reaction time analysis yielded also significant differences between two groups.