Playful expressions of one-year-old chimpanzee infants in social and solitary play contexts

Knowledge of the context and development of playful expressions in chimpanzees is limited because research has tended to focus on social play, on older subjects, and on the communicative signaling function of expressions. Here we explore the rate of playful facial and body expressions in solitary and social play, changes from 12- to 15-months of age, and the extent to which social partners match expressions, which may illuminate a route through which context influences expression. Naturalistic observations of seven chimpanzee infants (Pan troglodytes) were conducted at Chester Zoo, UK (n = 4), and Primate Research Institute, Japan (n = 3), and at two ages, 12 months and 15 months. No group or age differences were found in the rate of infant playful expressions. However, modalities of playful expression varied with type of play: in social play, the rate of play faces was high, whereas in solitary play, the rate of body expressions was high. Among the most frequent types of play, mild contact social play had the highest rates of play faces and multi-modal expressions (often play faces with hitting). Social partners matched both infant play faces and infant body expressions, but play faces were matched at a significantly higher rate that increased with age. Matched expression rates were highest when playing with peers despite infant expressiveness being highest when playing with older chimpanzees. Given that playful expressions emerge early in life and continue to occur in solitary contexts through the second year of life, we suggest that the play face and certain body behaviors are emotional expressions of joy, and that such expressions develop additional social functions through interactions with peers and older social partners

Sense of Self in Baby Chimpanzees

Philippe Rochat and his colleague tentatively proposed that young infants' propensity to engage in self-perception and systematic exploration of the perceptual consequences of their own action plays and is probably at the origin of an early sense of self: the ecological self. Rochat and Hespos (1997) reported that neonates discriminate between external and self-stimulation. Neonate tended to display significantly more rooting responses (i.e., head turn towards the stimulation with mouth open and tonguing) following external compared to self-stimulation. Rochat et al. (1998) also reported that 2-month-olds showed clear sign of modulation of their oral activity on the pacifier as a function of analog versus non-analog condition. Rochat and his colleague concluded that these observations are interpreted as evidence of self-exploration and the emergence of a sense of self-agency by 2-month-olds. We tried to replicate these findings in infant chimpanzees. We observed rooting responses of three baby chimpanzees in two condition, self-stimulation and external stimulation. In external stimulation condition, the index finger of the experimenter or small stick touched one of the infant's cheeks. In self-stimulation condition, the experimenter took infant's hand and touched his or her cheek with their fingers. In Rochat and Hespos, they recorded and analyzed several measures such as state, head movement, mouth activity and so on. How ever, we analyzed only mouth activities tentatively. We found infant chimpanzees tended to show more rooting responses following external stimulation compared to self-stimulation as well as human infants. We also carried out sucking experiment with two baby chimpanzees. The experimenter held the pacifier and put the artificial nipple into the infant's mouth. A session started when the infant take the nipple inside the his or her mouth. Auditory stimulus, which was a complex tone comprised of six harmonics with equal intensity, was given to the chimpanzee according to the test condition during their sucking. There were four test conditions and each condition consisted with three types of feedback as follows: 1) silent baseline, contingent, and steady, 2) contingent baseline, 1-sec delay, and 3-sec delay, 3) contingent baseline, 6-sec delay, and 12-sec delay, 4) contingent baseline, 1/2 efficiency, and 1/4 efficiency. In test 1, one infant chimpanzee showed decrease of the minimum pressure of sucking in the contingent condition. In test 2, one subject showed shorter intervals of sucking in 3-sec delay condition. This seems to be similar to human infant's. We may be able to postulate ecological self in baby chimpanzees according to the self-exploration. In test 3 and 4, we did not obtain any effects of stimulus conditions. Results of these studies. These studies were conducted as the parts of the chimpanzee development project in Primate Research Institute, Kyoto University, organized by Professor Tetsuro Matsuzawa

Mathematical Modelling in PET Studies

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Dipole-Quadrupole Theory of Surface Enhanced Infrared Absorption and Appearance of Forbidden Lines in the SEIRA Spectra of Symmetrical Molecules

The paper presents main aspects of the Dipole-Quadrupole theory of Surface Enhanced Infrared Absorption (SEIRA). It is pointed out the possibility of appearance of the lines, caused by totally symmetric vibrations transforming after the unit irreducible representation, which are forbidden in usual infrared absorption spectra in molecules with sufficiently high symmetry. Observation of such lines in the SEIRA spectra of diprotonated and ethylene, adsorbed on and on mordenites is pointed out. The results well agree with our ideas about surface enhanced optical processes, based on the conception of a strong quadrupole light-molecule interaction, which allows us to develop the SERS and SEHRS theories.Comment: 15 pages,3 figures, 1 tabl

Biochemical Investigation of 18F-Labeled Pyrimidines and 3H-Deoxythymidine in Tumor-Bearing Rats and Mice

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Creation of an isolated turbulent blob fed by vortex rings

Turbulence is hard to control. A plethora of experimental methods have been developed to generate this ephemeral state of matter, leading to fundamental insights into its statistical and structural features as well as its onset at ever higher Reynolds numbers. In all cases however, the central role played by the material boundaries of the apparatus poses a challenge on understanding what the turbulence has been fed, and how it would freely evolve. Here, we build and control a confined state of turbulence using only elemental building blocks: vortex rings. We create a stationary and isolated blob of turbulence ($Re_\lambda$=50-300) in a quiescent environment, initiated and sustained solely by vortex rings. We assemble a full picture of its three-dimensional structure, onset, energy budget and tunability. Crucially, the incoming vortex rings can be endowed with conserved quantities, such as helicity, which can then be controllably transferred to the turbulent state. Our `one eddy at a time' approach paves the way for sculpting turbulent flows much as a state of matter, `printing' it at a targeted position, localizing it, and ultimately harnessing it. Our work paves the way to gaining a complete picture of this ephemeral state of flow.Comment: 68 pages, 43 figures, manuscript and supplementary informatio

High Resolution T-O-F Positron Emission Tomograph

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