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.     

10‐month‐old infants’ inference of invisible agent: Distinction in causality between object motion and human action1

Abstract: Two habituation experiments investigated 10‐month‐old infants’ interpretation of events where a stationary object began to move without any visible causes. During habituation, infants saw that an object partly hidden by an occluder began to move away from the occluder. Then, they were tested with three test events without the occluder: the ?rst event showed a hand pushing the object, the second event showed a hand failing to touch the object, and the last event had no agent. The objects were a ball in Experiment 1, and a person in Experiment 2. The test event that the infants looked at for the shortest duration in Experiment 1 was where the hand pushed the ball, whereas they looked at the three test events almost equal amounts of time in Experiment 2. These results indicate that 10‐month‐old infants responded to the events in terms of causality and could infer the presence of the agent behind the occluder only when they saw the habituation event featuring the ball.     

The use of paraprofessionals in crisis intervention

Single-session crisis services by paraprofessionals (graduate students and community volunteers) in the emergency room of a community hospital were offered to 293 clients. These clients were followed-up 6 to 12 months after their last contact and asked about: (1) the effectiveness of the service, (2) their use of referrals, (3) the major source of change in their crisis situation, and (4) their rating of improvement for their presenting problem. There were 104 clients who completed the follow-up. The results support the interpretation that timely intervention by paraprofessionals may have long-lasting results in specific problem areas. A model emphasizing the use of service deliverers as researchers is proposed.     

Compositional Z: Confluence Proofs for Permutative Conversion

This paper gives new confluence proofs for several lambda calculi with permutation-like reduction, including lambda calculi corresponding to intuitionistic and classical natural deduction with disjunction and permutative conversions, and a lambda calculus with explicit substitutions. For lambda calculi with permutative conversion, naïve parallel reduction technique does not work, and (if we consider untyped terms, and hence we do not use strong normalization) traditional notion of residuals is required as Ando pointed out. This paper shows that the difficulties can be avoided by extending the technique proposed by Dehornoy and van Oostrom, called the Z theorem: existence of a mapping on terms with the Z property concludes the confluence. Since it is still hard to directly define a mapping with the Z property for the lambda calculi with permutative conversions, this paper extends the Z theorem to compositional functions, called compositional Z, and shows that we can adopt it to the calculi.     

Evaluation of third-party reciprocity by squirrel monkeys (<Emphasis Type="Italic">Saimiri sciureus</Emphasis>) and the question of mechanisms

Social evaluation during third-party interactions emerges early in human ontogeny, and it has been shown in adult capuchin monkeys who witness violations of reciprocity in object exchanges: Monkeys were less inclined to accept food from humans who refused to reciprocate with another human. A recent study reporting similar evidence in marmoset monkeys raised the possibility that such evaluations might be based on species’ inherent cooperativeness. We tested a species not renowned for cooperativeness—squirrel monkeys—using the procedure used with marmosets and found a similar result. This finding rules out any crucial role for cooperative tendencies in monkeys’ responses to unfair exchanges. We then tested squirrel monkeys using procedures more similar to those used in the original study with capuchins. Squirrel monkeys again accepted food less frequently from non-reciprocators, but unlike capuchins, they also strongly preferred reciprocators. We conclude that neither squirrel monkeys nor marmoset monkeys engaged in emotional bookkeeping of the type that probably underlies social evaluation in capuchin monkeys; instead, they employed one or more simple behavioral rules. Further comparative studies are required to clarify the mechanisms underlying social evaluation processes across species.     

A simple computational algorithm of model-based choice preference

A broadly used computational framework posits that two learning systems operate in parallel during the learning of choice preferences—namely, the model-free and model-based reinforcement-learning systems. In this study, we examined another possibility, through which model-free learning is the basic system and model-based information is its modulator. Accordingly, we proposed several modified versions of a temporal-difference learning model to explain the choice-learning process. Using the two-stage decision task developed by Daw, Gershman, Seymour, Dayan, and Dolan (2011), we compared their original computational model, which assumes a parallel learning process, and our proposed models, which assume a sequential learning process. Choice data from 23 participants showed a better fit with the proposed models. More specifically, the proposed eligibility adjustment model, which assumes that the environmental model can weight the degree of the eligibility trace, can explain choices better under both model-free and model-based controls and has a simpler computational algorithm than the original model. In addition, the forgetting learning model and its variation, which assume changes in the values of unchosen actions, substantially improved the fits to the data. Overall, we show that a hybrid computational model best fits the data. The parameters used in this model succeed in capturing individual tendencies with respect to both model use in learning and exploration behavior. This computational model provides novel insights into learning with interacting model-free and model-based components.     

Do bantams (Gallus gallus domesticus) amodally complete partly occluded lines? An analysis of line classification performance

Humans perceive a line touching an edge of a large rectangle longer than the reality. Kanizsa (1979) has suggested that this illusion occurs because we perceive that the line is partly "hidden" behind the rectangle and automatically completes it. We tested whether bantams (Gallus gallus domesticus) would experience this perceptual phenomenon using a line classification task on the touch monitor, which was used in our previous study with rhesus monkeys and pigeons (Fujita, 2001). We trained three bantams to classify six lengths of black target lines into two categories, "short" or "long," ignoring a gray rectangle (Experiment 1) or a gray area (i.e., a left or a right half of the monitor was filled with gray; Experiment 2) located at the same distance (8 pixels) from the target line. In the test, the gap between the line and the gray rectangle (or area) sometimes changed (0, 4, or 8 pixels; we labeled these stimuli as G0, G4, and G8 respectively). Both of the two successfully trained bantams showed an illusion for G0, but the direction of illusion was reversed; that is, they judged the line in G0 to be "shorter" than that in G4 and G8. Further analyses proved that neither the gaps between the target line and the gray rectangle nor the total widths of the stimuli could account for the bantams' responses. These results suggest that bantams do not complete the "occluded" portion even when identification of its shape is not required.     

Facial perception of conspecifics: chimpanzees (Pan troglodytes) preferentially attend to proper orientation and open eyes

This paper reports on the use of an eye-tracking technique to examine how chimpanzees look at facial photographs of conspecifics. Six chimpanzees viewed a sequence of pictures presented on a monitor while their eye movements were measured by an eye tracker. The pictures presented conspecific faces with open or closed eyes in an upright or inverted orientation in a frame. The results demonstrated that chimpanzees looked at the eyes, nose, and mouth more frequently than would be expected on the basis of random scanning of faces. More specifically, they looked at the eyes longer than they looked at the nose and mouth when photographs of upright faces with open eyes were presented, suggesting that particular attention to the eyes represents a spontaneous face-scanning strategy shared among monkeys, apes, and humans. In contrast to the results obtained for upright faces with open eyes, the viewing times for the eyes, nose, and mouth of inverted faces with open eyes did not differ from one another. The viewing times for the eyes, nose, and mouth of faces with closed eyes did not differ when faces with closed eyes were presented in either an upright or inverted orientation. These results suggest the possibility that open eyes play an important role in the configural processing of faces and that chimpanzees perceive and process open and closed eyes differently.     

Tufted capuchin monkeys (<Emphasis Type="Italic">Cebus apella</Emphasis>) show understanding of human attentional states when requesting food held by a human

Researchers have investigated to what extent non-human primates understand others’ attentional states, as this ability is considered an important prerequisite for theory of mind. However, previous studies using food requesting tasks have failed to show that non-human primates attribute perception to others as a function of their attentional states. One possible reason is that food requesting tasks may require subjects not only to take into account an experimenter’s attentional state but also to direct it toward the food. The present study tested tufted capuchin monkeys’ (Cebus apella) understanding of others’ attentional states in a food requesting task. In the first situation, monkeys were required only to attract an experimenter’s attention. In the second situation, the monkeys were required to both attract the experimenter’s attention and direct it toward food on a table. The results revealed that capuchin monkeys showed evidence of understanding the experimenter’s attentional variations only in the former condition. This suggests that previous tasks, requiring referential gestures, lacking in most non-human primates, failed to reveal sensitivity to human attentional states because the subjects might not have understood the requesting situation. In conclusion, capuchin monkeys can understand variations in others’ attentional states, although this ability appears limited compared to what is seen in humans.     

Proper Semantics for Substructural Logics,from a Stalker Theoretic Point of View

We study filters in residuated structures that are associated with congruence relations (which we call -filters), and develop a semantical theory for general substructural logics based on the notion of primeness for those filters. We first generalize Stone’s sheaf representation theorem to general substructural logics and then define the primeness of -filters as being “points” (or stalkers) of the space, the spectrum, on which the representing sheaf is defined. Prime FL-filters will turn out to coincide with truth sets under various well known semantics for certain substructural logics. We also investigate which structural rules are needed to interpret each connective in terms of prime -filters in the same way as in Kripke or Routley-Meyer semantics. We may consider that the set of the structural rules that each connective needs in this sense reflects the difficulty of giving the meaning of the connective. A surprising discovery is that connectives , ⅋ of linear logic are linearly ordered in terms of the difficulty in this sense. Presented by Wojciech Buszkowski