The understanding of congruent and incongruent referential gaze in 17-month-old infants: an eye-tracking study comparing human and robot.

Several studies have shown that the human gaze, but not the robot gaze, has significant effects on infant social cognition and facilitate social engagement. The present study investigates early understanding of the referential nature of gaze by comparing-through the eye-tracking technique-infants' response to human and robot's gaze. Data were acquired on thirty-two 17-month-old infants, watching four video clips, where either a human or a humanoid robot performed an action on a target. The agent's gaze was either turned to the target (congruent) or opposite to it (incongruent). The results generally showed that, independent of the agent, the infants attended longer at the face area compared to the hand and target. Additionally, the effect of referential gaze on infants' attention to the target was greater when infants watched the human compared to the robot's action. These results suggest the presence, in infants, of two distinct levels of gaze-following mechanisms: one recognizing the other as a potential interactive partner, the second recognizing partner's agency. In this study, infants recognized the robot as a potential interactive partner, whereas ascribed agency more readily to the human, thus suggesting that the process of generalizability of gazing behaviour to non-humans is not immediate.

Prevention of tumor growth by needle-free jet injection of anti-C7orf24 siRNA.

Chromosome 7 open reading frame 24 (C7orf24), which was identified by proteome analysis, is upregulated in various types of cancer and is associated with cellular proliferation. However, in vivo antitumor effect by knockdown of C7orf24 has not been clarified. In this study, we investigated that the antitumor effect of anti-C7orf24 small interfering RNA (siRNA) administered by needle-free jet injection (JI) on lung cancer-bearing mice. Transfection of anti-C7orf24 siRNA induced cytotoxicity in cultured human lung cancer cells through specific knockdown of C7orf24. Furthermore, JI could effectively deliver anti-C7orf24 siRNA to tumor tissues, and as a result tumor growth was significantly inhibited. Immunohistochemical analysis revealed that C7orf24 levels were significantly reduced within tumor tissues collected from anti-C7orf24 siRNA-administered mice, indicating that the knockdown of C7orf24 induced cytotoxicity in tumor tissue. In conclusion, these data show for the first time that knockdown of C7orf24 prevents tumor growth in vivo following JI-mediated the siRNA delivery.

Genetic structuring and transfer of marine dinoflagellate Cochlodinium polykrikoides in Japanese and Korean coastal waters revealed by microsatellites.

To determine the process of population expansion and ascertain the origin of the Sea of Japan population, in a noxious red tide forming dinoflagellate Cochlodinium polykrikoides, 13 samples, isolated from 11 different localities in Japanese and Korean coasts, were analysed using 10 polymorphic microsatellites. Analyses by nonmetric multidimensional scaling plots of pairwise F(ST), global amova, and genetic admixture analysis identified three clusters--the Sea of Japan populations, Yatsushiro Sea (Kumamoto Pref.) populations, and other populations--indicating genetic structuring of the 13 samples into three distinct populations. In the proportion of shared alleles by pairwise individuals (P(SAxy)) analyses between the Sea of Japan and the other samples, P(SAxy) was extremely low compared with that among the Sea of Japan or among other samples, indicating that a large genetic barrier has occurred between the populations. No significant relationship of isolation-by-distance patterns and almost no genetic distance were detected between pairwise samples of the Sea of Japan, although there is a maximal distance of > 600 km between samples. In addition, P(SAxy) data among the samples were extremely high compared with those among other samples, clearly showing that a large-scale transfer from west to east has occurred via the Tushima Warm Current. In the P(SAxy) data of the Seto Inland Sea and Pacific samples, individuals showing relatively high P(SAxy) were concentrated in the three areas of Nagasaki, Harima, and Mie, suggesting that frequent transfer may have occurred by human-assisted dispersal, although Nagasaki and Mie are separated by a distance of approximately 700 km.

Alteration of adults' subjective feeling of familiarity toward infants' sounds.

Many adults may have lower subjective feelings of familiarity toward infants' vocalizations since infants' sounds are different from those of adults. However, mothers frequently exposed to infants' vocalizations may be more familiar and less averse. To test this hypothesis, 21 mothers (M age = 31.1 yr., SD = 4.3) of infants (M age = 8.2 mo., SD = 3.5), 18 mothers (M age = 34.4 yr., SD = 4.8) of children between two and five years of age (M age = 2.8 yr., SD = 1.0), and 17 women (M age = 29.2 yr., SD = ll.1) with no children were exposed to 20 types of sounds. Of these sounds, 14 were produced by infants. Although the mothers of infants did not recognize sounds as those of an infant's vocalization, they showed higher subjective feelings of familiarity toward the timbres of the vowel-like stimuli than did the other groups. By contrast, the subjective feelings of familiarity for nonspeech sounds did not differ among groups. Maternal experiences may change women's recognition of perceived sounds.

Mesenchymal stem cells facilitate the induction of mixed hematopoietic chimerism and islet allograft tolerance without GVHD in the rat.

Induction of hematopoietic chimerism and subsequent donor-specific immune tolerance via bone marrow transplantation is an ideal approach for islet transplantation to treat type-1 diabetes. We examined the potential of mesenchymal stem cells (MSCs) in the induction of chimerism and islet allograft tolerance without the incidence of graft-versus-host disease (GVHD). Streptozotocin-diabetic rats received a conditioning regimen consisting of antilymphocyte serum and 5 Gy total body irradiation, followed by an intraportal co-infusion of allogeneic MSCs, bone marrow cells (BMCs) and islets. Although all the recipients rejected the islets initially, half of them developed stable mixed chimerism and donor-specific immune tolerance, shown by the engraftment of donor skin and second-set islet transplants and acute rejection of a third-party skin. The engraftment of the primary islet allografts with stable chimerism was achieved by the addition of a 2-week peritransplant administration of 15-deoxyspergualin (DSG). Without MSCs, none of the recipients treated with DSG developed chimerism or reversal of diabetes. GVHD was not observed in any of the recipients infused with MSCs (0/15), whereas it occurred in 4/11 recipients without MSCs. These results indicate a potential use of MSCs for induction of hematopoietic chimerism and subsequent immune tolerance in clinical islet transplantation.

Expression of Golf in the rat placenta: Possible implication in olfactory receptor transduction.

Olfactory receptors are G-protein coupled receptors and are encoded by an extremely large and diverse family of genes in mammals. There is increasing evidence that olfactory receptors are widely distributed in many organs, suggesting that olfactory receptors do not only recognize airborne odorants but also play important roles in chemotaxis or organ construction in embryo. In this study, we investigated whether olfactory receptors and their transduction molecule, Golf are expressed in the rat placenta. By RT-PCR, we identified 11 different olfactory receptor genes, which are all members of class II, in the rat placenta cDNAs, and our results suggested that particular members of the olfactory receptor gene family might be preferentially expressed in the placenta. By western blot analysis, we demonstrated that Golf protein is expressed in the placenta and its expression levels are developmentally regulated. We found that Golf immunoreactivity is exclusively localized to giant cell trophoblasts and spongiotrophoblast cells. These findings raised a possibility that a particular subset of olfactory receptors might be coupled with Golf and function in giant cell trophoblasts and spongiotrophoblast cells.

Attention to repeated events in human infants (Homo sapiens): effects of joint visual attention versus stimulus change.

The goal of this study was to examine the effect of joint visual attention on infants' behavior during subsequent events. Thirty-seven mother-infant (aged from 9 to 13 months) pairs were twice shown a pair of line drawing stimuli on a computer screen. For the control group, the mother never paid attention to the stimuli. For experimental group 1, the mother pointed to one stimulus in the first presentation but did not point to it in the second presentation. The infants gazed longer at the stimulus pointed to by their mothers in the first presentation. In the second presentation, during which mothers did not attend to the stimuli, infants gazed longer at the stimulus which had been pointed to by the mothers in the first presentation. In experimental group 2, one of two stimuli blinked during the first presentation but not the second presentation. Infants gazed for longer at the blinking stimulus in the first presentation, but there was no difference in looking time toward the two stimuli in the second presentation. These results suggest that joint visual attention affects infants' looking behavior during subsequent events, and that simple stimulus change does not.

Molecular dynamics of MHC genesis unraveled by sequence analysis of the 1,796,938-bp HLA class I region.

The intensely studied MHC has become the paradigm for understanding the architectural evolution of vertebrate multigene families. The 4-Mb human MHC (also known as the HLA complex) encodes genes critically involved in the immune response, graft rejection, and disease susceptibility. Here we report the continuous 1,796,938-bp genomic sequence of the HLA class I region, linking genes between MICB and HLA-F. A total of 127 genes or potentially coding sequences were recognized within the analyzed sequence, establishing a high gene density of one per every 14.1 kb. The identification of 758 microsatellite provides tools for high-resolution mapping of HLA class I-associated disease genes. Most importantly, we establish that the repeated duplication and subsequent diversification of a minimal building block, MIC-HCGIX-3.8-1-P5-HCGIV-HLA class I-HCGII, engendered the present-day MHC. That the currently nonessential HLA-F and MICE genes have acted as progenitors to today's immune-competent HLA-ABC and MICA/B genes provides experimental evidence for evolution by "birth and death," which has general relevance to our understanding of the evolutionary forces driving vertebrate multigene families.

Hydroxyl radical generation by an extracellular low-molecular-weight substance and phenol oxidase activity during wood degradation by the white-rot basidiomycete Trametes versicolor.

One-electron oxidation activity, as measured by ethylene generation from 2-keto-4-thiomethylbutyric acid, phenol oxidase activity, and the generation of hydroxyl radical were examined in cultures of the lignin-degrading white-rot basidiomycete fungus, Trametes (Coriolus) versicolor. The activity levels of specific lignin-degrading enzymes and cellulases, as well as the rate of wood degradation, also were examined. The fungus secreted a low-molecular-weight substance (M(r) 1000-5000) that catalyzed a redox reaction between molecular oxygen and an electron donor, to produce the hydroxyl radical via hydrogen peroxide. During wood decay, T. versicolor also produced significant amounts of laccase and lignin peroxidase, carboxymethyl cellulase, and Avicelase. The roles of the hydroxyl radical, phenol oxidases, and cellulases in wood degradation by white-rot fungi are discussed. That the hydroxyl radical produced by the low-molecular-weight substance secreted by T. versicolor results in new phenolic substructures on the lignin polymer, making it susceptible to attack by laccase or manganese peroxidase is suggested.

Mapping of a novel human carbonyl reductase, CBR3, and ribosomal pseudogenes to human chromosome 21q22.2.

To find the genes contributing to Down syndrome, we constructed a 4-Mb sequence-ready map spanning chromosome 21q22.2 with megabase-sized cosmid/P1-derived artificial chromosome (PAC) contigs. The restriction map with rare cutting enzymes, followed by sequencing from the clustering sites, has defined CpG islands and revealed the genes associated with CpG islands (Accession No. D85771). Of these, two human carbonyl reductases (CBR; EC1.1.1.184) were found in a PAC 25P16 clone. CBR catalyzes the reduction of a large number of biologically and pharmacologically active carbonyl compounds to their corresponding alcohols and has been mapped in 21q22.1. To confirm these results, we sequenced the PAC clone in shotgun strategies and identified a novel carbonyl reductase, designated CBR3, 62 kb downstream from the original CBR. In addition, three ribosomal pseudogenes, L23a, S9, and L3, and some cDNAs with ESTs were mapped in the sequence. In conclusion, the sequence analysis for CpG islands predicted from the megabase-sized contigs will reveal and identify the genes involved in Down syndrome.

Use of experimenter-given cues during object-choice tasks by chimpanzees (Pan troglodytes), an orangutan (Pongo pygmaeus), and human infants (Homo sapiens).

In a series of experiments, chimpanzees (Pan troglodytes), an orangutan (Pongo pygmaeus), and human infants (Homo sapiens) were investigated as to whether they used experimenter-given cues when responding to object-choice tasks. Five conditions were used in different phases: the experimenter tapping on the correct object, gazing plus pointing, gazing closely, gazing alone, and glancing without head orientation. The 3 subject species were able to use all of the experimenter-given cues, in contrast to previous reports of limited use of such cues by monkeys.

Manual action in infant chimpanzees: a preliminary study.

In human infants, index finger extension is shown frequently even from 3 months old, and it is considered that such pointing develops into deictic and communicative pointing however, there are many reports that chimpanzees do not point with the index finger. In the present study the manual actions of two infant chimpanzees were observed when the experimenter was trying to make eye contact with them. The result shows that pointing was shown very rarely by these infant chimpanzees even morphologically.

Differentiated responses to different human conditions by chimpanzees.

Chimpanzees' responses to human conditions were investigated. In the experimental condition, the experimenter pretended to injure the index finger, and in the control condition, the experimenter smiled and waved her hand to the chimpanzees. Although looking behavior was observed in both conditions, there was a difference in these types of behavior. Subjects seemed to concentrate their gaze on the experimenter's behavior in the experimental condition. The finding suggests the possibility that such different behaviors may be a basis for empathic behavior similar to that of human infants.

Recognition of line-drawing representations by a chimpanzee (Pan troglodytes).

The ability of a chimpanzee to recognize individuals portrayed in line drawings was evaluated. A 12-year-old female chimpanzee with extensive prior experience in the use of visual symbols matched the line drawings of chimpanzees, humans, and an orangutan with a specific letter of the alphabet. When a line drawing of a familiar individual was presented on the computer screen, the chimpanzee responded by punching a key with the letter of the alphabet that corresponded to the individual's name. Results indicate that the chimpanzee is able to categorize individuals from novel line-drawing representations.

Cutaneous pattern perception on foreheads in 3- and 4-year-old children.

In the present study, we investigated how 3- and 4-year-old children perceived mirror-image stimuli traced on their foreheads. First, the subjects were taught matching-to-sample tasks with symmetrically shaped and asymmetrically shaped figures (called mirror-image stimuli) on cards. Then the subjects were taught cutaneous perception of a figure traced by the experimenter's finger on the forehead. Last, the subjects were tested with mirror-image stimuli in cutaneous perception tasks. The results of these experiments indicated that the subjects who could discriminate the mirror-image stimuli could also perceive asymmetrical stimuli as mirror reversals.

An exploratory study of mirror-image shape discrimination in young children: vision and touch.

30 children (18 boys and 12 girls) with a mean age of 4 yr., 8. mo. were subjects in an experiment testing the relative dominance of visual and tactual modalities in mirror-image shape discrimination. The sets of unfamiliar stimuli (written and wooden letters of the English alphabet, P, B, C, U, R, F) were presented to the children randomly. Children matched the stimulus with either another visual or another tactual shape. Analysis suggests touch is not inferior to vision in mirror-image shape discrimination. These results are different from those of previous reports comparing tactual and visual discrimination with nonmirror-image patterns.

Force-generating domain of myosin motor.

To understand the underlying mechanism of force generation by myosin motor, it is crucial to know which part of the molecule is essential for the process. Recent structure determination of myosin motor domain at atomic resolution has revealed that the domain comprises two smaller domains, the "ATPase domain" consisting of only an N-terminal segment of the heavy chain and the "neck domain" consisting of a long alpha-helix of the heavy chain and two light chains. This atomic structure begs the question of whether both domains are required for force generation. To answer it, we genetically truncated the head to generate a recombinant fragment composed of the "ATPase domain" alone. The truncated head drove sliding movement of actin filaments and generated force in a novel in vitro assay system, which allows us to hold a specific site of the head on a glass surface. These results indicate that the compact ATPase domain functions as a force-generating machinery of the myosin motor.

Emotional behavior during the learning of a contingency task in a chimpanzee.

A female chimpanzee's behavior was videotaped during the learning of contingency tasks and used to code her facial expressions, vocal expressions, and other behavior. The chimpanzee showed negative emotional behaviors to negative feedback and seemed to depend not only on the lack of food as reward. The most negative emotional situation for the chimpanzee seemed to be one in which she made an error.