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

Numerical Simulation of the Surface Flow on the Companion Star in a Close Binary System II. Construction of Doppler maps and application to Galactic supersoft X-ray sources

We perform three-dimensional numerical simulations of surface flows on the companion star in a semi-detached binary system and construct the corresponding Doppler maps. The mass ratio of the binary system, $q=M_2/M_1$, considered here is $q=0.05, 0.33, 0.5, 1, 2$, and 3. For all cases, we obtain the H-, L1-, and L2-eddies, as found in our previous work, and confirm that the flow pattern does not heavily depend on the mass ratio. We propose that this kind of problem be dubbed ``{\it stellar meteorology}.'' The Doppler maps at the position of the companion show a structure tilted towards clockwise direction and presenting deviations from the critical Roche surface due to the L1-eddy and the L2-eddy on the companion star. We apply our results to the Galactic supersoft X-ray source RX J0019.8+2156 and try to attribute the low radial velocity component of the emission lines of He II ${\lambda}4686$ observed recently to the irradiated spot on the surface of the companion rather than that of the white dwarf or the accretion disc. Based on the comparison between the observations and our constructed Doppler map, we estimate the mass of the companion star in RX J0019.8+2156 to be $\sim 2 M_{\odot}$ assuming the mass of the white dwarf star to be around $0.6 M_{\odot}$.Comment: 8 pages, 9 figures, Accepted for publication in A&

On Haagerup's list of potential principal graphs of subfactors

We show that any graph, in the sequence given by Haagerup in 1991 as that of candidates of principal graphs of subfactors, is not realized as a principal graph except for the smallest two. This settles the remaining case of a previous work of the first author.Comment: 19 page

A Characterization of right coideals of quotient type and its application to classification of Poisson boundaries

Let $G$ be a co-amenable compact quantum group. We show that a right coideal of $G$ is of quotient type if and only if it is the range of a conditional expectation preserving the Haar state and is globally invariant under the left action of the dual discrete quantum group. We apply this result to theory of Poisson boundaries introduced by Izumi for discrete quantum groups and generalize a work of Izumi-Neshveyev-Tuset on $SU_q(N)$ for co-amenable compact quantum groups with the commutative fusion rules. More precisely, we prove that the Poisson integral is an isomorphism between the Poisson boundary and the right coideal of quotient type by maximal quantum subgroup of Kac type. In particular, the Poisson boundary and the quantum flag manifold are isomorphic for any q-deformed classical compact Lie group.Comment: 28 pages, Remark 4.9 adde

Rendezvous of Two Robots with Constant Memory

We study the impact that persistent memory has on the classical rendezvous problem of two mobile computational entities, called robots, in the plane. It is well known that, without additional assumptions, rendezvous is impossible if the entities are oblivious (i.e., have no persistent memory) even if the system is semi-synchronous (SSynch). It has been recently shown that rendezvous is possible even if the system is asynchronous (ASynch) if each robot is endowed with O(1) bits of persistent memory, can transmit O(1) bits in each cycle, and can remember (i.e., can persistently store) the last received transmission. This setting is overly powerful. In this paper we weaken that setting in two different ways: (1) by maintaining the O(1) bits of persistent memory but removing the communication capabilities; and (2) by maintaining the O(1) transmission capability and the ability to remember the last received transmission, but removing the ability of an agent to remember its previous activities. We call the former setting finite-state (FState) and the latter finite-communication (FComm). Note that, even though its use is very different, in both settings, the amount of persistent memory of a robot is constant. We investigate the rendezvous problem in these two weaker settings. We model both settings as a system of robots endowed with visible lights: in FState, a robot can only see its own light, while in FComm a robot can only see the other robot's light. We prove, among other things, that finite-state robots can rendezvous in SSynch, and that finite-communication robots are able to rendezvous even in ASynch. All proofs are constructive: in each setting, we present a protocol that allows the two robots to rendezvous in finite time.Comment: 18 pages, 3 figure

A planar calculus for infinite index subfactors

We develop an analog of Jones' planar calculus for II_1-factor bimodules with arbitrary left and right von Neumann dimension. We generalize to bimodules Burns' results on rotations and extremality for infinite index subfactors. These results are obtained without Jones' basic construction and the resulting Jones projections.Comment: 56 pages, many figure

Toward a unified light curve model for multi-wavelength observations of V1974 Cygni (Nova Cygni 1992)

We present a unified model for optical, ultraviolet (UV), and X-ray light curves of V1974 Cygni (Nova Cygni 1992). Based on an optically thick wind model of nova outbursts, we have calculated light curves and searched for the best fit model that is consistent with optical, UV, and X-ray observations. Our best fit model is a white dwarf (WD) of mass 1.05 M_\sun with a chemical composition of X=0.46, C+N+O=0.15, and Ne = 0.05 by mass weight. Both supersoft X-ray and continuum UV 1455 \AA light curves are well reproduced. Supersoft X-rays emerged on day ~ 250 after outburst, which is naturally explained by our model: our optically thick winds cease on day 245 and supersoft X-rays emerge from self-absorption by the winds. The X-ray flux keeps a constant peak value for ~ 300 days followed by a quick decay on day ~ 600. The duration of X-ray flat peak is well reproduced by a steady hydrogen shell burning on the WD. Optical light curve is also explained by the same model if we introduce free-free emission from optically thin ejecta. A t^{-1.5} slope of the observed optical and infrared fluxes is very close to the slope of our modeled free-free light curve during the optically thick wind phase. Once the wind stops, optical and infrared fluxes should follow a t^{-3} slope, derived from a constant mass of expanding ejecta. An abrupt transition from a t^{-1.5} slope to a t^{-3} slope at day ~ 200 is naturally explained by the change from the wind phase to the post-wind phase on day ~ 200. The development of hard X-ray flux is also reasonably understood as shock-origin between the wind and the companion star. The distance to V1974 Cyg is estimated to be ~ 1.7 kpc with E(B-V)= 0.32 from the light curve fitting for the continuum UV 1455 \AA.Comment: 8 pages, 4 figures, to appear in the Astrophysical Journa