Learning and Exposure Affect Environmental Perception Less than Evolutionary Navigation Costs

Russell E. Jackson is with University of Idaho, Chéla R. Willey is with University of California Los Angeles, Lawrence K. Cormack is with UT Austin.Most behaviors are conditional upon successful navigation of the environment, which depends upon distance perception learned over repeated trials. Unfortunately, we understand little about how learning affects distance perception–especially in the most common human navigational scenario, that of adult navigation in familiar environments. Further, dominant theories predict mutually exclusive effects of learning on distance perception, especially when the risks or costs of navigation differ. We tested these competing predictions in four experiments in which we also presented evolutionarily relevant navigation costs. Methods included within- and between-subjects comparisons and longitudinal designs in laboratory and real-world settings. Data suggested that adult distance estimation rapidly reflects evolutionarily relevant navigation costs and repeated exposure does little to change this. Human distance perception may have evolved to reflect navigation costs quickly and reliably in order to provide a stable signal to other behaviors and with little regard for objective accuracy.Psycholog

Absolute total apparent ionization, electron stripping, electron capture, and partial ionization cross sections in the energy range 015-100 MeV

Ph.D.David W. Marti

The influence of a high power diode laser (HPDL) generated glaze on the wetting characteristics and the subsequent HPDL enamelling of ordinary Portland cement

High power diode laser (HPDL) surface glazing of the ordinary Portland cement (OPC) surface of concrete was found to effect significant changes in the wettability characteristics of the OPC. This behaviour was identified as being primarily due to: (i) the polar component of the OPC surface energy increasing after HPDL glazing from 3.46 to 15.56 mJm-2, (ii) the surface roughness of the OPC decreasing from an Ra value of 21.91 to 2.88 m after HPDL glazing and (iii) the relative surface O2 content of the OPC increasing by 4.5at% after HPDL glazing. HPDL glazing was consequently identified as occasioning a decrease in the enamel contact angle from an initial value of 1090 to 310, thus allowing the vitreous enamel to wet the OPC surface

Geology of the Ponteland-Morpeth district: 1:10,000 sheets NZ 17 NE, SE and NZ 18 NE, SE: parts of 1:50,000 Sheets 9 (Rothbury) and 14 (Morpeth)

The geology, mineral resources and geotechnical characteristics of the Ponteland-Morpeth district (NZ17NE, SE and NZ18NE, SE)are described. Information on former workings in coal, sandstone and clays together with details of made ground are tabulated

Rent Subsidies

Several studies have evaluated the experimental housing allowance program authorized by Congress in 1970 and implemented by the Department of Housing and Urban Development. The studies that are relied upon most have nevertheless been considered inadequate because they were essentially case studies. An evaluation design has recently been suggested, the random-comparison-group design, that makes the data from the Administrative Agency Experiment useful for evaluation. The outcomes in the AAE program sites are compared here to projected outcomes based on an analysis of Annual Housing Survey data. The evaluation finds that rent burdens were reduced and housing quality was improved jor many who lived in substandard units. These impacts were achieved without producing inflation. Substantial confidence in the findings is permitted not only by the logic of the method itself, but by corroboration from other research. The design employed is found to be practical and powerful for certain evaluations, and its use in connection with other public programs can be recommended. The random- comparison-group design could substitute for randomized experiments in situations in which such controlled experimentation is not possible or was not carried out.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66611/2/10.1177_0193841X8601000404.pd

A survey of the medical examination methods and procedures in the Massachusetts and Rhode Island Young Men's Christian Associations

Thesis (Ed.M.)--Boston Universit