Crossmodal content binding in information-processing architectures

Operating in a physical context, an intelligent robot faces two fundamental problems. First, it needs to combine information from its different sensors to form a representation of the environment that is more complete than any of its sensors on its own could provide. Second, it needs to combine high-level representations (such as those for planning and dialogue) with its sensory information, to ensure that the interpretations of these symbolic representations are grounded in the situated context. Previous approaches to this problem have used techniques such as (low-level) information fusion, ontological reasoning, and (high-level) concept learning. This paper presents a framework in which these, and other approaches, can be combined to form a shared representation of the current state of the robot in relation to its environment and other agents. Preliminary results from an implemented system are presented to illustrate how the framework supports behaviours commonly required of an intelligent robot

Marine-Nonmarine Relationships in the Cenozoic Section of California

Highly fossiliferous marine sediments of Cenozoic age are widely distributed in the coastal parts of central and southern California, as well as in the Sacramento-San Joaquin Valley region farther inland. Even more widespread are nonmarine, chiefly terrestrial, sequences of Cenozoic strata, many of which contain vertebrate faunas characterized by a dominance of mammalian forms. These strata are most abundant in the Mojave Desert region and in the interior parts of areas that lie nearer the coast. Marine and nonmarine strata are in juxtaposition or interfinger with one another at many places, especially in the southern Coast Ranges and the San Joaquin basin to the east, in the Transverse Ranges and adjacent basins, and in several parts of the Peninsular Range region and the Coachella-Imperial Valley to the east. These occurrences of closely related marine and nonmarine deposits permit critical comparisons between the Pacific Coast mammalian (terrestrial) and invertebrate (marine) chronologies, and it is with these comparisons-examined in the light of known stratigraphic relations-that this paper is primarily concerned. The writers have drawn freely upon the published record for geologic and paleontologic data. In addition, Durham has reviewed many of the invertebrate faunas and has checked the field relations of marine strata in parts of the Ventura and Soledad basins, the Tejon Hills, and the Cammatta Ranch; Jahns has studied new vertebrate material from the Soledad basin and has mapped this area and critical areas in the vicinity of San Diego, in the Ventura basin, and in the Caliente Range; and Savage has made a detailed appraisal of the vertebrate assemblages, and has mapped critical areas in the Tejon Hills. The areas and localities that have been most carefully scrutinized are shown in figure 1. The manuscript was reviewed in detail by G. Edward Lewis of the U. S. Geological Survey, who made numerous comments and suggestions that resulted in considerable improvement. It should be noted that his views are not wholly compatible with some of those expressed in this paper, and that his critical appraisal thus was particularly helpful

On the observability of resonant structures in planetesimal disks due to planetary migration

We present a thorough study of the impact of a migrating planet on a planetesimal disk, by exploring a broad range of masses and eccentricities for the planet. We discuss the sensitivity of the structures generated in debris disks to the basic planet parameters. We perform many N-body numerical simulations, using the symplectic integrator SWIFT, taking into account the gravitational influence of the star and the planet on massless test particles. A constant migration rate is assumed for the planet. The effect of planetary migration on the trapping of particles in mean motion resonances is found to be very sensitive to the initial eccentricity of the planet and of the planetesimals. A planetary eccentricity as low as 0.05 is enough to smear out all the resonant structures, except for the most massive planets. The planetesimals also initially have to be on orbits with a mean eccentricity of less than than 0.1 in order to keep the resonant clumps visible. This numerical work extends previous analytical studies and provides a collection of disk images that may help in interpreting the observations of structures in debris disks. Overall, it shows that stringent conditions must be fulfilled to obtain observable resonant structures in debris disks. Theoretical models of the origin of planetary migration will therefore have to explain how planetary systems remain in a suitable configuration to reproduce the observed structures.Comment: 16 pages, 13 figures. Accepted for publication in A&

Amino Acid Evidence Indicating Two or More Ages of Pre-Holocene Nonglacial Deposits In Hudson Bay Lowland, Northern Ontario

Amino acid studies have identified pre-Holocene non-glacial sediments in the Hudson Lowland which are significantly younger than Bell Sea sediments of the Missinaibi Formation. This younger unit is represented by marine sediments on the Severn and Abitibi rivers. Buried organic material on Beaver River is correlated with the younger Severn and Abitibi river marine sediments based on amino acid evidence. Assuming that Bell Sea sediments are of last interglacial (130-120 ka) age, the younger nonglacial sediments may have been deposited late in 18O stage 5 (80-75 ka). Paleoecologic studies of the Beaver River organics indicate climate at least as warm as present.Les études par les acides aminés ont permis d'identifier des sédiments non glaciaires d'avant !"Holocène passablement plus jeunes que les sédiments de la Mer Bell de la Formation de Missinaibi. L'unité plus jeune est représentée par des sédiments marins des rivières Severn et Abitibi. Les matériaux organiques enfouis de la Beaver River sont corrélés avec les sédiments marins plus jeunes des rivières Abitibi et Severn grâce aux analyses des acides aminés. En tenant pour acquis que les sédiments de la Mer Bell datent du dernier interglaciaire (130-120 ka). les sédiments non glaciaires plus récents ont pu être mis en place tard au cours du stade isotopique 5 (80-75 ka). Les études paléoécologiques menées sur les sédiments organiques de Beaver River montrent que le climat était au moins aussi chaud que maintenant

Brucellosis and Maltese goats in the Mediterranean

British army doctors studied a fever which affected many servicemen in Malta: now known as the ‘Corps Disease’. Although the organism was found, it was some time before the transmission by goats’ milk was discovered. However, other means of transmission may have been important. About 10% of the milk was infective and measures by the armed forces effectively controlled the disease. For the Maltese, controls were ineffective and cases rose. In 1936 pasteurised milk went on sale. In World War II most goats were eaten, but with peace the disease returned. Eventually strict control measures eliminated the disease – after one small epidemic. Malta Fever, now known as brucellosis was endemic around the Mediterranean. Maltese goats, prized for their prolific milk yield were recognised as carriers of the disease and were sent packing. They had, however, passed on the bacteria to other breeds. Brucellosis is still a serious disease in the region.peer-reviewe