EVIDENCE OF A RESPONSE-BIAS EXPLANATION OF NONEUCLIDEAN COGNITIVE MAPS*

Two groups of subjects with varying amounts of experience with the city in which they lived judged from memory distances between familiar locations. The distance judgments were processed by a multidimensional scaling algorithm (MULTISCALE) that estimates the parameters of a power function transformation of the response scale and the coordinates of the locations in k-dimensional euclidean space. The results for both subject groups suggested that inaccuracies of distance cognition do not reflect the noneuclidean nature of urban cognitive maps but are caused by response bias.     

The spectrum of the manganese-scandium star ϕ Herculis

Among manganese stars, Herculis is of great interest because of the unusual strength of the scandium lines. We present intensity measurements for numerous lines ofCii, Mgi, Mgii, Siii, Caii, Scii, Tiii, Crii, Mni, Mnii, Fei, Feii, Coii, Srii,Yii, and Zrii.     

Utilisation of the lunar field for interplanetary travel by the Oslo system

This paper presents preliminary results of orbital investigations by a data processing machine aimed at the utilisation of the lunar gravitational field in interplanetary travel. The lunar field is utilised in two successive steps. In the first step a spacecraft in an Earth-bound orbit is deviated into an orbit similar to but separated from the Earth's orbit around the Sun. In a successive approach between the spacecraft and the Earth-Moon system the combined fields of the Earth and the Moon are utilised as a means to convey to the spacecraft a main portion of the momentum required in order to carry it to the proximity of Venus.A substantial portion of the fuel required for space travel can be saved by this kind of procedure.The CD 3300 machine time needed for this investigation was supplied by the computing facility of the University of Oslo at Blindern.     

Cytochromes P-450 in cod (Gadus morhua): Effects of induces on regiospecificity of phenanthrene metabolism and immunochemical properties

The metabolism of some xenobiotics can lead to the formation of reactive intermediates with mutagenic/carcinogenic properties. With the carcinogenic PAH these have been identified as bay-region diol-epoxides.¹ Phenanthrene, a non-carcinogenic, bay-region containing model PAH, is metabolised in vivo by bony fish at the proximate bay-region position, whereas mammals and other marine organisms mainly form the K-region metabolite 9,10-dihydro-9,10-dihydroxy-phenanthrene.² We wanted to investigate this difference more closely by studying the regiospecificity of phenanthrene metabolism in vitro both with microsomes from differently pretreated cod and with isolated cytochrome P-450 isozymes from BNF-induced cod.³ Secondly, by preparing antibodies to the major isozyme isolated (called cod P-450c), we investigated the immunochemical properties of the variously treated cod liver microsomes.     

Correlation of the absorption coefficient with a reduction in mean mass for dissolved organic matter in southwest Florida river plumes

Results are presented from an investigation of the relationship between molecular mass distribution and optical properties for colored dissolved organic matter (CDOM); a complex assembly of organic macromolecules of marine and freshwater origin found throughout the surface ocean. Unique data are derived from the application of a new technique, a combination of a hydrophilic–lipophilic copolymer-based solid phase extraction (SPE) with electrospray ionization (ESI) continuous flowing ion trap mass spectrometry (cf-MS), for the direct determination of CDOM mass distribution. An evaluation of this copolymer-based extraction technique for the analysis of Suwannee River Natural Organic Matter (SRNOM) reference material revealed that the current method compares favorably with C₁₈ modified silica or XAD resin-based extraction methods reported in the literature when considering extraction efficiency or low extraction bias for CDOM. The mass distribution of CDOM in several freshwater to marine transition zones along coastal southwestern Florida has been determined with this technique. All rivers in the study region had a bimodal distribution of masses. A case study of the Caloosahatchee River outflow CDOM mass distribution data are presented as an example of the modification in mass distributions. The lower mass mode of the bimodal distribution was observed to have a relatively stable mean throughout the study region at 406±9 Da, while decreasing in concentration in a non-conservative manner with salinity. In contrast, the upper mass mode of the bimodal distribution was observed to have a variable mean, reaching 1408 Da in the least saline waters and decreasing by 174 Da through the transect toward higher salinity coastal waters. Coinciding with this reduction in mean mass for the upper distribution is a non-conservative reduction in concentration when compared with salinity. We define apparent organic carbon (AOC) as a function of the cf-MS determined total integrated area and use this value to determine concentration of the total extracted CDOM. Unique correlations between the CDOM fluorescence (350-nm excitation/450-nm emission) and the AOC for these coastal samples have been observed for each of three rivers in the study region. The steepest slope and highest correlation between optical and mass spectral properties are observed in rivers with strongly absorbing waters originating in the Florida Everglades and lowest in rivers draining clearer waters from widely variable and anthropogenic influenced regions. The trends in molecular mass distribution and corresponding optical properties support the theory that CDOM in coastal zones is environmentally processed material from terrestrial sources. Probable cause of the reduction in mean mass and suggestions for further investigation of sources and transformations of CDOM are discussed.     

An ecosystem modeling approach to predicting cod recruitment

The Norwegian Ecological Model (NORWECOM) biophysical model system implemented with the ROMS ocean circulation model has been run to simulate conditions over the last 25 years for the North Atlantic. Modeled time series of water volume fluxes, primary production, and drift of cod larvae through their modeled ambient temperature fields have been analyzed in conjunction with VPA estimated time series of 3-year-old cod recruits in the Barents Sea. Individual time series account for less than 50% of the recruitment variability; however, a combination of simulated flow of Atlantic water into the Barents Sea and local primary production accounts for 70% of the variability with a 3-year lead. The associated regression predicts increased recruitment between 2007 and 2008 from about 450–700 million individuals with a standard error of nearly 150 million.     

The Effects of Reduced Oxygen Content on Predation and Siphon Cropping by the Brown Shrimp, Crangon crangon

Abstract. Aquarium experiments were performed to test for critical oxygen levels in relation to the predation efficiency of C. crangon . Short-term (60 h) experiments where done in normoxia (> 95%). 50, 40.30, and 20% oxygen saturation with the amphipod Bathyporeiapilosa as prey. A significantly reduced predation rate was detected at 30% oxygen. Sublethal effects of C. crangon on adult Macoma balthica (mainly by siphon cropping) were studied by measuring the condition of the clams (morphometric, somatic, and biochemical). To test for these effects experiments were conducted under normoxia and moderate hypoxia (40% oxygen); Condition and siphon indices revealed no change in condition after a 3-week exposure to moderate hypoxia, while a significant reduction in the condition of adult clams was found in both normoxia and hypoxia when subjected to siphon cropping by C. crangon . No enhanced siphon cropping could be detected due to hypoxia.
The results indicate that C. crangon is able to maintain its predatory role until a level of 30% oxygen in short-term exposure. After a 20% oxygen level, however, the abiotic stress alters the functional role of C. crangon as a predator, indicating a threshold of 20–302 oxygen for the normal functioning of the predator-prey food webs.     

Bottom friction caused by boundary layer streaming beneath random waves for laminar and smooth turbulent flow

The effect of boundary layer streaming on the sea bed shear stresses, beneath random waves, is investigated for laminar flow as well as smooth turbulent flow. It is demonstrated how bottom friction formulas for regular waves can be used to obtain the bed shear stresses resulting from steady streaming under random waves. As a result, friction factors for steady streaming under random waves are provided, and the effect of streaming versus the effect of linear waves is discussed. For laminar flow the effect of second order Stokes waves is also included. Examples are included to illustrate the applicability of the present practical method, and results are obtained using data typical for field conditions.     

A comparison of Stokes' numerical integration and collocation,and a new combination technique

Summary Basically two different evaluation methods are available to compute geoid heights from residual gravity anomalies in the inner zone: numerical integration and least squares collocation.If collocation is not applied to a global gravity data set, as is usually the case in practice, its result will not be equal to the numerical integration result. However, the cross covariance function between geoid heights and gravity anomalies can be adapted such that the geoid contribution is computed only from a small gravity area up to a certain distance _o from the computation point. Using this modification, identical results are obtained as from numerical integration.Applying this modification makes the results less dependent on the covariance function used. The difference between numerical integration and collocation is mainly caused by the implicitly extrapolated residual gravity anomaly values, outside the original data area. This extrapolated signal depends very much on the covariance function used, while the interpolated values within the original data area depend much less on it.As a sort of by-product, this modified collocation formula also leads to a new combination technique of numerical integration and collocation, in which the optimizing practical properties of both methods are fully exploited.Numerical examples are added as illustration.