High-resolution electron microscope studies of irradiation-induced crystalline-to-amorphous transition in boron carbide

Abstract

The crystalline-to-amorphous (C-A) transition in boron carbide induced by 2 MeV electron irradiation was studied by high-resolution electron microscopy. It is revealed that the C-A transition takes place not homogeneously but heterogeneously over the irradiated volume and the volume fraction of the amorphous phase continuously increases with increasing dose of electrons.     

In situ simultaneous measurements of photodarkening and photoinduced defect creation in amorphous As2Se3 films

To understand the direct correlation between photodarkening (PD) and photoinduced defect creation (PDC) observed in amorphous chalcogenides, in situ simultaneous measurements of PD and photocurrent (PC) have been performed on amorphous As₂Se₃ films. The time evolution of PD and PDC during light excitations are empirically described by a stretched exponential function; 1 ??exp[?(t/τ) ^β ], where τ is the effective response time and β the dispersion parameter. The value of τ for the PDC is very much smaller than that for the PD, suggesting that there is no direct correlation between the two.     

Secondary defects induced by ion and electron irradiation of GaSb

Secondary defects induced by ion and electron irradiation up to 6?dpa (displacements per atom) at liquid-nitrogen temperature in GaSb thin films are compared. For Sn ion (60?keV) irradiation, voids were observed. However, for high-energy electron (2?MeV) irradiation, interstitial-type dislocation loops were produced. The densities of voids and interstitial-type dislocation loops were almost equivalent (8?×?10¹⁴?voids/m² and 3?×?10¹⁴?loops/m²) after irradiations at the same damage level of 6?dpa. It is concluded that the formation of voids by ion irradiation follows the creation of localised vacancy defects in cascade damage.     

Motion illusion reveals fixation stability of karate athletes

To investigate the effect of smooth pursuit effort against optokinetic nystagmus (OKN) on the magnitude of induced motion, we measured the magnitude of induced motion and eye movements of karate athletes and novices. In Experiment 1, participants were required to pursue a horizontally moving fixation stimulus against a vertically moving inducing stimulus and to point at the most distorted position of the perceived pathway of the fixation stimulus. In Experiments 2 and 3, participants were presented with the inducing stimulus with or without a static fixation stimulus. Experiments 1 and 2 showed a larger magnitude of induced motion and more stable fixation for the athletes than for the novices. Experiment 3 showed no difference in eye movements between the two groups. These results suggest that the magnitude of induced motion reflects fixation stability that may have been strengthened in karate athletes through their experience and training.     

Addressing the Mental Health Concerns of International Students

International students on the American college campus are a diverse and increasing population whose unique concerns are traditionally overlooked. However, given the evidence that the demands for cultural adjustments frequently place international students at greater risk for various psychological problems than are students in general, it is important that sufficient and readily accessible mental health services be established for them. This article examines the sources of international students' psychological concerns, the reasons for their notable underutilization of existing counseling services, and the ways to provide more culturally sensitive services.     

Correlation between gray/white matter volume and cognition in healthy elderly people

This study applied volumetric analysis and voxel-based morphometry (VBM) of brain magnetic resonance (MR) images to assess whether correlations exist between global and regional gray/white matter volume and the cognitive functions of semantic memory and short-term memory, which are relatively well preserved with aging, using MR image data from 109 community-dwelling healthy elderly individuals. We used the Information and Digit Span subtests of the Wechsler Adult Intelligent Scale-Revised as measures of semantic memory and short-term memory, respectively. We found significant positive correlations between the gray matter ratio, the percentage of gray matter volume in the intracranial volume, and performance on the Digit Span subtest, and between the regional gray matter volumes of the bilateral anterior temporal lobes and performance on the Information subtest. No significant correlations between performance on the cognitive tests and white matter volume were found. Our results suggest that individual variability in specific cognitive functions that are relatively well preserved with aging is accounted for by the variability of gray matter volume in healthy elderly subjects.     

Eyewitness memory following discussion: using the MORI technique with a Western sample

Researchers studying memory conformity have made significant advances in our understanding of the phenomenon, but have used methods with significant shortcomings. Mori's three‐stage method addresses many of these concerns. To date the technique has not been replicated on a Western sample. We present such a study, and discuss two significant improvements to Mori's method. We found that subjects were more likely to report the correct answer for non‐discussed critical details than discussed critical details. Our data also suggested that when subjects agreed with their partner's information during the discussion, they did so because they thought that information was accurate; only a minority of the time did they go along with their partner during discussion and revert to their own answer at the test. We draw parallels between the unknown mechanisms driving memory conformity effects and the search for mechanisms driving the misinformation effect two decades ago. Copyright © 2007 John Wiley & Sons, Ltd.     

Expert anticipation from deceptive action

Expertise in sports enhances the ability to anticipate forthcoming events from the observation of a player’s actions. In the present study, we investigated whether this ability is applicable to deceptive action. In three experiments, performance at anticipating the direction change of a running opponent was examined with experienced rugby players and novice counterparts. These experiments were conducted with reaction-time and temporal-occlusion tasks, in combination with eye movement recordings and the presentation of filmed actions and their point-light representations. The main finding was that the experienced players were superior to the novices in their anticipation of deceptive actions, although their performance was still impaired by the deception, in comparison with their anticipation of nondeceptive actions. We also found that the experienced players anticipated nondeceptive actions less accurately than the novices, suggesting that the players’ expectations of deceptive actions worked negatively on their judgments of nondeceptive actions. The results obtained with the point-light representations closely resembled those obtained with the filmed sequences, indicating that anticipation was based on the kinematics of the running action. These results are discussed in the context of recent developments in research on expertise and deception in sports.     

Validity of the MMPI-2 and Beck Depression Inventory for making decisions of organ allocation in renal transplantation

Psychosocial factors are presented which affect clinical decision-making regarding the allocation of renal organs. Patients were rated as being either High Risk or Low Risk transplant candidates. High Risk candidates were scored as being significantly different from the Low Risk candidates on many psychosocial variables. Interestingly, significant differences were not found between these two groups on either the MMPI-2 or the Beck Depression Inventory. The validity of using information from these inventories to allocate organs is discussed.