Yielding and strain hardening in aluminium single-crystal foils subjected to tension and bending

A series of tensile and microbend tests were conducted on aluminium single-crystal foil specimens with different thicknesses ranging from 20 to 90?µm. Two different crystal orientations relative to the tensile direction were considered in the tests: one is an orientation that was excepted to activate at least four slip systems on four different slip planes, and the other is an orientation that was expected to activate only a single-slip system. In the tensile tests, typical size dependence of initial yield strength was observed. The microbend test method was extended to include a reversal of bending direction. Using the curves of bending moment normalized by the square of foil thickness versus surface strain, which were obtained from the reversed bending tests, the total amounts of strain hardening were divided into isotropic and kinematic hardening components. In the microbend tests, a pronounced size-dependent kinematic hardening behaviour was clearly observed; meanwhile, the amounts of isotropic hardening were very small, particularly for the single-slip orientation.     

Critical roles of mecamylamine-sensitive mushroom body neurons in insect olfactory learning

In insects, cholinergic neurons are thought to transmit olfactory conditioned stimulus (CS) to the sites for associating the CS with unconditioned stimulus (US), but the types of acetylcholine (ACh) receptor used by neurons participating in the association have not been determined. In cockroaches, a type of nicotinic ACh receptor specifically antagonized by mecamylamine (MEC) has been characterized. Here we investigated the roles of neurons possessing MEC-sensitive ACh receptors (MEC-sensitive neurons) in olfactory conditioning of salivation, monitored by changes in activities of salivary neurons, in cockroaches. Local and bilateral microinjection of MEC into each of the three olfactory centers, antennal lobes, calyces of the mushroom bodies and lateral protocerebra, impaired olfactory responses of salivary neurons, indicating that MEC-sensitive neurons in all olfactory centers participate in pathways mediating olfactory responses of salivary neurons. Conditioning of olfactory CS with sucrose US was impaired by injection of MEC into the antennal lobes or calyces, i.e., conditioned responses were absent even after recovery from MEC injection, suggesting that the CS-US association occurs in MEC-sensitive neurons in calyces (most probably Kenyon cells) or in neurons in downstream pathways. In contrast, conditioned responses appeared after recovery from MEC injection into the lateral protocerebra, suggesting that MEC-sensitive neurons in the lateral protocerebra are downstream of the association sites. Since lateral protocerebra are major termination areas of mushroom body efferent neurons, we suggest that input synapses of MEC-sensitive Kenyon cells, or their output synapses upon mushroom body efferent neurons, are the sites for CS-US association for conditioning of salivation.     

Selective bias in retrospective self-reports of negative mood states

Retrospective self-report questionnaires of negative mood states experienced in the past (e.g., the most recent two weeks) tend to be exaggerated in a negative direction relative to the average ratings given to the moods contemporaneously. The present study used three measures that decomposed mood states into their constituent elements to examine whether certain components selectively contributed to this negative bias or all components contributed to this bias equally. Fifty-three participants responded to the questionnaires via the Internet every evening for two weeks. On the final day, participants recalled and retrospectively evaluated their mood state over the previous two weeks as a whole. The results revealed that memory bias occurred selectively for negative mood states. Anxiety, depression, and helplessness were exaggerated in the global compared with the daily ratings. None of the positive mood components showed any bias in the retrospective global ratings. A regression analysis indicated that the difference in daily and global ratings for negative mood was partly explained by peak and final scores. Higher peak scores led to greater overestimation whereas final scores had smaller effects; the higher the final score was, the less participants overestimated their negative mood in the global ratings.     

<Emphasis Type="Italic">Kowakare:</Emphasis> A New Perspective on the Development of Early Mother–Offspring Relationship

The mother–offspring relationship has components of both positivity and negativity. Kowakare is a new concept introduced to explain an adaptive function of the negativity in the early mother-offspring relationship. Kowakare is the psycho-somatic development of the relationship as the process of accumulation in the otherness of offspring. Early human Kowakare has two frameworks, biological inter-body antagonism and socio-cultural allomothering compensating the antagonism. Some features of feeding/weaning, parental aversion to offspring’s bodily products, and transition from dyad to triad relationship (proto–triad relationship) in tactile play are discussed. Early human Kowakare is promoted by allomothering with the nested systems of objects/persons/institutions as interfaces between mother and offspring. Kowakare makes mother–offspring relationship a mutually autonomous and cooperative companionship.     

Apparent depth of pictures reflected by a mirror: The plastic effect

We investigated the plastic effect in picture perception, in which the apparent depth of a picture is increased when it is reflected by a mirror. The plastic effect was well known in the mid-18th century, but very few studies have elucidated its nature. In Experiment 1, we examined how often the plastic effect occurs in different ocular conditions. A group of 22 observers compared directly observed pictures and their mirror-reflected images in each of free-binocular, free-monocular, and restrictive-monocular conditions. When the observers were forced to choose the picture that appeared greater in depth, 73?% of them chose the reflected pictures, regardless of oculomotor condition. In Experiment 2, we examined how often the plastic effect is detected as a function of observation time. When 22 observers compared a directly watched movie and its mirror-reflected movie for 5?min, the number of observers who judged the reflected movie to be greater in depth was about 55?% at the onset of the trial but was 86?% at the end. In Experiment 3, we examined transfer of the plastic effect. Ten observers judged the change in apparent depth of directly observed pictures after prolonged exposure to the same reflected or actual pictures. Transfer was confirmed and was greater for pictures that represented greater depth (r = .88). We suggested that the plastic effect is mainly induced by the double apparent locations of a reflected picture. From the long incubation time and the transfer to real pictures, we also suggested that it involves perceptual learning regarding visual skill.