How optimists face skin cancer information: Risk assessment,attention, memory,and behavior

The purpose of the present study was to investigate how optimists process health-related information. Sixty-five young adults (ages 18–35) reported skin cancer-related knowledge and behaviors, and read slides of information on skin and skin cancer. Visual attention to the slides was recorded using eye tracking, and their memory for the information was measured. Additionally, participants’ self-reported skin cancer-relevant behavior was assessed prospectively in the months following the lab component of the study. Results show that individuals low in dispositional optimism or high in health-related optimism paid more attention when they were at high objective risk of developing skin cancer; and individuals high in dispositional optimism or high in health-related optimism were more likely to perform adaptive, health-promoting behaviors. In addition, optimistic beliefs were found not to be related with unrealistic optimism. Dispositional and health-related optimism therefore appear to predict health-related cognition and behavior in distinct ways.     

Spontaneous growth of tin whiskers on tin−rare-earth alloys

Tin whisker growth has been observed on the surface of bulk Sn–Nd alloys with Nd contents of 30, 5 and 0.5 wt%, under ambient conditions of temperature and atmosphere. It is shown that the whiskers originate from the area of Sn–Nd intermetallic compounds after a very short incubation period and that they exhibit a relatively high growth rate on the surface of the bulk alloys. The results show that these Sn-based, rare-earth alloys have a very strong propensity to grow tin whiskers, i.e. this rare-earth element in tin is a catalytic agent for whisker growth. Direct evidence is also shown that whiskers can grow from the surface of a bulk Sn-based alloy.     

Comments on ‘A model of diffusion-induced grain boundary migration’ by T. K. Chaki

Abstract

Chaki (1988) has recently proposed a model for diffusion-induced grain boundary migration (DIGM). In his Letter he concluded that the interface energy of a grain boundary and the free energy of mixing are responsible for DIGM and, from the equations he derived, it was claimed that they can explain many DIGM experimental results. However, on examining his model closely there appear to be some fundamental difficulties. The following are comments on his Letter:

(1) In Chaki's calculation of ΔG_s he assumed that, after interface 1 had moved a distance δx, the radius of curvature of this interface increased from R to R + δx, which gives a surface energy drop of 2γV_m δx/R². However from many DIGM observations (for example Balluffi and Cahn (1981)) the curvature of a migrating boundary is increased rather then decreased, that is, the surface free- energy term actually prevents a grain boundary from migrating rather than helping it!

(2) Chaki considered ΔG_cryst during the migration of interface 2. It is also necessary to consider AGcrys, during the migration of interface 1, since within the migration distance δx the structure is changed from a crystalline structure to a grain boundary core structure. ΔG_m should also be considered during the migration of interface 2 since the concentration of the area swept by interface 2 will not be the same as that of a grain boundary core.     

The orientation and temperature dependences of dislocation velocity in Ni 3 Al single crystals

The average velocities of screw dislocations in Ni 3 Al single crystals have been directly measured as a function of resolved shear stress (RSS) and orientation in the temperature domain of the flow stress anomaly using the etch-pit technique. The velocity was found to be extremely sensitive to the RSS in all cases. In contrast with ordinary metals, the screw dislocation velocities in Ni 3 Al show anomalous behaviour; under a constant RSS, the velocities decrease dramatically with increasing temperature. Furthermore, the velocities and the tension-compression asymmetry of the velocities depend on the orientation of applied stress.     

Electromechanical behavior of single-walled carbon nanotube thin films

Carbon nanotubes have been intensively studied owing to their great potential in nanoelectronics and nanomechanical devices. Recently, experimental results have shown that single-walled carbon nanotubes (SWCNTs) change their electronic properties when subjected to strain. In this study, the electromechanical characteristics of SWCNT networks were investigated for the application of printable strain sensors on flexible substrates. SWCNT films were formed on plastic substrates of poly(ethylene terephthalate) using a spray process. In this manner, we were able to control the transparency and obtain uniform electrical properties of the films. The films are isotropic on account of the random orientation of bundles of SWCNTs. Experimental results showed a nearly linear change in the resistance across a film when it was subjected to tensile strain, even in the inelastic range of the flexible substrate. The results demonstrate the potential use of SWCNT films for highly sensitive printable strain sensors on a macroscale.     

Crystallization behaviour of Al-based amorphous alloy and nanocomposites by rapid quenching

The microstructure and crystallization behaviour of melt-spun Al₈₈Ni₉Ce₂Fe₁ amorphous alloy and nanophase composites have been studied by means of X-ray diffraction, transmission electron microscopy and scanning and isothermal calorimetry. The diffraction patterns from Al₈₈Ni₉Ce₂Fe₁ amorphous alloys are diffuse, indicating a basically amorphous structure but contain two rings presumed to be associated with quenched-in nuclei. In the cases of Al₈₈Ni₉Ce₂Fe₁ nanophase composites, nanoscale precipitated particles are homogeneously dispersed in an amorphous matrix, and the crystallite diameter and volume fraction are sensitive to quenching conditions. During thermal crystallization, a two-step phase transformation occurs in the amorphous alloy and nanocomposites, which is characterized by a diffusion-controlled precipitation of nanoscale Al particles and the growth of a Al₃(Ni, Fe) nanophase prior to a Al₁₁Ce₃ nanophase. This study gives insight into structure-control for obtaining nanophases dispersed in an amorphous matrix by rapid quenching.     

Opinions From Others Like You: The Role of Perceived Source Similarity

A theoretical framework is proposed to test the influence of opinions of other consumers, based on perceived similarity, in two contexts. The perceived similarity of the source may be diagnostic for consumers who are concerned about mispurchase. Experiment 1, therefore, compared the effects of ads featuring a consumer versus an expert as an endorser, with participant use status as a moderator that may affect concerns about mispurchase. Potential product users rated the consumer endorser higher on perceived similarity, which increased ad credibility and resulted in better ad and brand attitudes. Experiment 2 compared the effects of information about a product delivered on a consumer blog with that of information from the advertiser's official Web site, with concern about mispurchase as a moderator. More concerned consumers rated the blogger higher than the advertiser on perceived similarity, leading to greater information credibility and more favorable attitudes toward the blog and the product.     

Capturing and evaluating blinks from video-based eyetrackers

Blinks are related to several emotional states, and the present report describes a simple, reliable way to measure blinks from the video stream of an eye obtained during eyetracking, where the source of the eye video is a video camera attached to a head-mounted eyetracker. Computer vision techniques are employed to determine the moments that a blink starts and ends, for the purpose of calculating blink frequency and duration. The video is first processed to show blocks of eyelid and pupil movements, and is then analyzed for blink starts and ends. The moment of a blink start is reported when the eyelid starts to move quickly, exceeding a predetermined threshold. The end of a blink arises when the pupil size increases by less than a separate threshold. We observed several different blink patterns from different subjects, and our algorithm was designed to work for all of these patterns. We evaluated our algorithm by manually measuring the true blinks of five different subjects while they were eyetracked. To test the sensitivity and specificity of the algorithm, we employed a series of threshold values to plot the receiver operating characteristic curves. Using the best thresholds, we achieved excellent sensitivity (>90 %) and specificity (>99 %) over the five subjects. Potential applications of this research include real-time, nonintrusive, continuous and automated measurements of mental workload and other emotional states related to blink rates and durations.     

Verifying properties of concepts spontaneously requires sharing resources with same-modality percept

In the present experiments, participants had to verify properties of concepts but, depending on the trial condition, concept-property pairs were presented via headphones or on the screen. The results showed that participants took longer and were less accurate at verifying conceptual properties when the channel used to present the CONCEPT-property pair and the type of property matched in sensory modality (e.g., LEMON-yellow on screen; BLENDER-loud in headphones) compared to when properties and channel did not match (e.g., LEMON-yellow in headphones; BLENDER-loud on screen). Such interference is consistent with theories of embodied cognition holding that knowledge is grounded in modality-specific systems (Barsalou in Behav Brain Sci 22:577–660, 1999). When the resources of one modality are burdened during the task, processing costs are incurred in a conceptual task (Vermeulen et al. in Cognition 109:287–294, 2008).