Associative tolerance to nicotine analgesia in the rat: Tail-flick and hot-plate tests.

Previous assessments of associative nicotine tolerance may have confounded associative effects with novelty-induced stress effects, instrumental learning effects, or both. That is, subjects were tested in novel environments, allowed to practice the test response, or both during the tolerance development phase. In the first study, 32 male Sprague-Dawley rats were injected with various doses of nicotine and tested for nociception in the tail-flick and hot-plate tests to assess nicotine's analgesic effects. In the second study, 35 rats received nicotine explicitly paired or unpaired with a distinctive test context. All animals were equally preexposed to the test environment, and none had the opportunity to practice the test response. Paired rats developed greater nicotine tolerance than unpaired rats. This context-dependent (associative) tolerance effect was found with both tail-flick and hot-plate tests. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reestimating Zajonc's confluence effects on the SAT.

In response to the article by R. B. Zajonc (see record 1987-02628-001) on the confluence model and prediction of national Scholastic Aptitude Test (SAT) scores, the present authors reestimate Zajonc's model using their estimates of proportion of high school seniors taking the SAT. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nontidal wetland mapping in South Carolina using airborne multispectral scanner data

High resolution multispectral scanner (MSS) imagery of Savannah River nontidal wetlands were analyzed to identify 1) useful spectral bands for discriminating among National Wetland Inventory classes, 2) where the classes cluster in n-dimensional feature space, and 3) what wetland classification accuracies can be expected. Spectral measurements in the green (0.55–0.60 μm), red (0.65–0.70 μm), and near-infrared wavelengths (0.70–0.79 μm and 0.92–1.10 μm) provided the most useful information. Emergent marsh (both persistent and nonpersistent), scrub-shrub, mixed deciduous swamp forest, and mixed deciduous upland forest were found to cluster in somewhat predictable regions of 2- and 3-dimensional feature space. The overall classification accuracy of the Steel Creek delta study area was 83% and was assessed by comparing the remote sensing derived thematic map with 1325 linear meters of transects sampled in situ. These results suggest that high resolution aircraft MSS data can provide detailed vegetation type information for mapping both thermally affected and rejuvenating nontidal wetland in the South Carolina Savannah River Swamp System.     

Convection in stars

This paper reviews work on stellar convection theory with a particular emphasis on numerical simulations of convection. The Boussinesq and the anelastic approximations of the fluid equations are introduced and solutions of the linearized equations for the onset of convection are described. Non-linear numerical solutions to the Boussinesq equations are discussed. Next, the character of stellar convection is considered. Convection is found to be intimately linked with a number of proceses in the stellar interior. Studies of stellar convection have either attempted to model a star with a very simplified treatment of convection or to solve the fluid equations for a range of parameters less extreme than those found in stars. Finally, a brief review is given of some of the numerical methods that have been employed.     

Precision in the measurement of meat texture

The relationships between the level of precision, the variability within muscles and the number of measurements required to assess toughness were quantified in an attempt to rationalise the measurement of meat texture. Variability within M. longissimus dorsi was higher than in other hindquarter muscles of lamb and beef and was less in pork than in beef or lamb. Ten replicate determinations on lamb and beef and seven on pork M. longissimus dorsi would be suited to research work. Under these conditions, 95% of values for each muscle would lie within one-sixth of the texture scale from the mean for 85% of muscles and would lie within one-tenth of the texture scale from the mean for 50% of muscles.     

Redispersion of indoor surface contamination: A review

The importance of surface contamination as a potential source of exposure to hazardous materials is discussed. Data from the literature concerning the resuspension of indoor surface contamination are presented. Reported procedures for quantitating surface contamination are compared. It is suggested that, despite its limitations, surface contamination monitoring may be useful in estimating potential risks from hazardous materials.     

Star couplers using fused biconically tapered multimode fibres

We report the fabrication and testing of 4-, 7-and 19-fibre fused biconical taper transmissive star couplers for use with single multimode fibres. Overall insertion losses on six couplers range from ?1.3 dB to ?2.6 dB. Losses are nearly independent of N, the number of fibres, but dispersion of the powers in the output fibres increases significantly with N.     

On the application of fourier transform infrared spectroscopy to the elucidation of specific interactions in miscible polyester-poly(vinyl chloride) blends

FT-IR spectroscopic studies have been performed in an attempt to elucidate the nature of the specific interactions occurring in miscible poly(?-caprolactone) (PCL)-poly (vinyl chloride) (PVC) blends. Studies of low molecular weight analogues, polymer/solvent mixtures and blends of PCL and α-deuterated PVC are presented. The results strongly suggest that a hydrogen bonding type of interaction between the carbonyl bond of PCL and the α-hydrogen of PVC exists in compatible PCL-PVC blends.     

Affect, generalization, and the perception of risk.

Investigated the role of affect in judgments of risk in 4 experiments. 557 Ss were recruited on college campuses and read paragraphs modeled after newspaper reports that described fatal or nonfatal accidents or (Exp III) positive events. Ss were later asked to estimate the chances of specific fatal or nonfatal accidents happening to them and/or to the population in general. Experimental manipulations of affect induced by report of a tragic event produced a pervasive increase in Ss' estimates of the frequency of many risks and other undesirable events. Contrary to expectation, the effect was independent of the similarity between the report and the estimated risk: An account of a fatal stabbing did not increase the frequency estimate of homicide more than the estimates of unrelated risks such as natural hazards. An account of a happy event that created positive affect produced a comparable global decrease in judged frequency of risks. (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Commodity trade,corporate ownership and urban growth

Two sources of urban growth differentials that intimately stem from the interdependencies between cities are unequal gains from interurban commodity trade, and spatial differentials in corporate ownership. Each of these phenomena has the potential of redistributing the physical and monetary surplus accruing from production unevenly between cities. This study develops a theoretical model to examine these problems, taking as its starting point a Marxian model of reproduction, prices, profits and wages. An interurban model of production and trade for a capitalist society with production restricted to small enterprises is constructed. Some system-wide and local accounting relationships are formulated that reveal the flows of profits, investment income, and surplus value between cities as a result of the postulated trading patterns. These are used to demonstrate the difference between profit and surplus value movements among locations, and to mathematically formulate the classical problem of unequal exchange of labour values relative to monetary values.