Showing papers by "University of Victoria published in 1981"
TL;DR: Differences in neuroanatomical organization of the cerebral hemispheres may account for two fundamental distinctions in processing: the right hemisphere has a greater ability to perform intermodal integration and to process novel stimuli and the left hemisphere is more capable of unimodal and motor processing as well as the storage of compact codes.
516 citations
01 Feb 1981
Abstract: related by interaction, identity, and interdependence.&dquo; The members of a group interact more often with one another than they do with outsiders; each member can identify himself or herself and all the other individuals as belonging to the group; and all group members depend on one another for the attainment of individual and collective goals (Cartwright and Zander, 1968; Crosbie, 1975; Mills, 1967; Shepherd, 1964). It can be argued that the fundamental bond among the members of any group is their dependence on one another and, by implication, on the group itself. This interdependence is sometimes called &dquo;division of labor&dquo; by sociologists, although the use of the term often is applied principally to large social units such as societies and organizations. The purpose of this article is to show how the term &dquo;division of labor&dquo; can be applied to small groups, and to clarify some of the dimensions of the concept. Task specialization is seen as the most direct indicator of the interdependence dimension and as a direct cause of cohesion. However, actor specialization is associated with task specialization and produces isolation, which tends to reduce cohesion in the group. These
452 citations
166 citations
TL;DR: An actual problem involving data from the Florida Longitudinal Project is presented to provide a practical example of many of the processes and problems involved in cluster analytic techniques.
Abstract: This report presents a selective overview of the cluster analysis literature and its potential uses in neuropsychology. In addition, an actual problem involving data from the Florida Longitudinal Project is presented to provide a practical example of many of the processes and problems involved in cluster analytic techniques. It is hoped that the reader will gain a theoretical and practical understanding of such methods and their potential usefulness in neuropsychology and other related areas.
157 citations
TL;DR: The change in the classification of this fish pathogen is based on differences between the classical V. anguillarum andV.
Abstract: Vibrio ordalii sp. nov. is the name proposed for the bacterium previously designated asV. anguillarum biotype 2. The change in the classification of this fish pathogen is based on differences between the classicalV. anguillarum andV. ordalii in cultural and biochemical characteristics, and in deoxyribonucleic acid (DNA) sequence relatedness. Phenotypically,V. ordalii was distinguishable fromV. anguillarum based on: negative Voges-Proskauer reaction; negative reaction with arginine in Moeller's medium; negative Simmons' and Christensen's citrate test; negative ONPG test; failure to hydrolyze starch; failure to show lipase activity; inability to grow at 37°C; and failure to ferment cellobiose, glycerol, sorbitol, and trehalose. Genotypically, strain ofV. ordalii formed a highly conserved DNA homology group which showed 83 to 100% within-group homology and only 58 to 69% relatedness toV. anguillarum. In contrast, theV. anguillarum strains tested showed greater than 70% withingroup homology and 53 to 67% relatedness toV. ordalii. NeitherV. ordalii norV. anguillarum were related toV. parahaemolyticus orV. alginolyticus. The proposed type strain (holotype) ofV. ordalii is ATCC 33509 (=DF3K=Dom F3 kid).
152 citations
TL;DR: In this paper, a comparative study of three different types of destination area, seeking community reactions to the industry and ways in which such information may guide future strategies is presented; the aesthetics and community impact of local tourism are identified as major concerns in the three towns, and their relative position on these two functions is used to provide some elementary guidance to improve the industry's local image.
115 citations
TL;DR: A conjecture of Hoyler and Cockayne [9], namely i+@b=<2p + 2@d - 22p@d, is proved and sufficient conditions for the equality of the three upper parameters are given.
112 citations
TL;DR: This paper contains linear algorithms for finding the Jordan center, the weighted Jordan center and the path center of a tree that take advantage of an efficient data structure for representing a tree called a canonical recursive representation.
Abstract: This paper contains linear algorithms for finding the Jordan center, the weighted Jordan center and the path center of a tree. All of these algorithms take advantage of an efficient data structure for representing a tree called a canonical recursive representation. As a result, the first two algorithms are different from and faster than similar algorithms in the literature. This paper also defines a new parameter of a graph called the path center, and shows that the path center of a tree T consists of a unique subpath of T.
88 citations
TL;DR: It is hypothesized that in addition to tentacle number and length, the following factors strongly influence feeding efficiency: tentacle posture, velocity of tentacles moving through water, swimming pattern of medusa, streamlining effects of Medusa bell on water flow, diameter of prey, and swimming pattern and velocity of prey.
Abstract: Feeding behaviors of the following 4 species of hydromedusae are described from field and laboratory observations: Probosidactyla flavicirrata, Stomotoca atra, Phialidium gregarium and Polyorchis penicillatus. Feeding efficiency of medusae has previously been considered equivalent to fishing with a given amount (combined tentacle length) of adhesive “fishing line”; however, detailed observation shows that behavior of medusae greatly modifies the fishing capacity of each species. It is hypothesized that in addition to (1) tentacle number and length, the following factors strongly influence feeding efficiency: (2) tentacle posture, (3) velocity of tentacles moving through water (4) swimming pattern of medusa, (5) streamlining effects of medusa bell on water flow, (6) diameter of prey, (7) swimming pattern and velocity of prey. Each species of hydromedusa utilizes the above factors in different combinations.
81 citations
TL;DR: Histological and ultrastructural observations of the digestive tract of eight-armed plutei of Dendraster excentricus are reported, finding that the intestine is comprised of relatively unspecialized cells and probably functions primarily as a conductive tube for the elimination of undigested materials.
Abstract: Histological and ultrastructural observations of the digestive tract of eight-armed plutei of Dendraster excentricus are reported. The esophagus is divided into two regions. The uppermost is a narrow tube comprised of ciliated cells that assist in transporting food to the more bulbous lower esophagus where food particles are formed into a bolus prior to entering the stomach. The esophagus is surrounded by a network of smooth muscle fibers that are predominantly oriented circumferentially in the upper esophagus, and longitudinally in the lower esophagus. The musculature of the upper esophagus produces peristaltic contractions, whereas contractions of the muscle of the lower esophagus open the cardiac sphincter and force food from the lower esophagus into the stomach. Axons are associated with the ciliated cells and the muscles of the upper esophagus. The cardiac sphincter consists of a ring of myoepithelium, with cross-striated myofibrils oriented around the bases of the cells. The gastric epithelium is comprised of two cell types. Type I cells, which predominate, absorb and store nutrients, and may be the source of secreted digestive enzymes. Type II cells apparently phagocytize and intracellularly digest whole algal cells. The intestine is comprised of relatively unspecialized cells and probably functions primarily as a conductive tube for the elimination of undigested materials.
69 citations
TL;DR: Seasonal shifts are shown to occur in the oligochaetes Limnodrilus hoffmeisteri, Tubifex tubifex, Tubificoides gabriellae, Paranais litoralis, Specaria fraseri, Nais communis and Nais elinguis, and of the polychaetes Eteone longa, Amphicteis sp.
Abstract: The subtidal benthic fauna of the lower Fraser River, a salt-wedge estuary, was sampled monthly from June 1977 to August 1978 in mud substrates at six stations ranging from oligohaline to polyhaline. Subtidal interstitial salinities were also measured and were related to the seasonal distribution of the estuarine benthic fauna. Interstitial salinities of silty sediments do not vary diurnally, but the transition zone between salt and fresh interstitial water is cyclically shifted up- and downstream in relation to freshwater discharge, leading to seasonal shifts in the distribution of benthic infaunal species. Seasonal shifts are shown to occur in the oligochaetes Limnodrilus hoffmeisteri, Tubifex tubifex, Tubificoides gabriellae, Paranais litoralis, Specaria fraseri, Nais communis and Nais elinguis, and of the polychaetes Eteone longa, Amphicteis sp. and Polydora kempi japonica. These species comprised over 25% of the total taxa collected and over 60% of the individuals collected. The data on other species distributions do not conflict with the hypothesis of cyclic changes related to seasonal interstitial salinities. The changes vary in extent in relation to runoff, and appear to be a feature of salt-wedge estuaries in general.
TL;DR: The Arctic beetle, Pytho americanus Kirby, is frost tolerant in both larval and adult stages, a situation which would be congruous with its northern distribution and allow it to spread its life cycle over a number of growing seasons, and glycerol may further serve to minimize dehydration in the overwintering insect by increasing the level of bound water.
TL;DR: Nine species of insects from three different geographical regions of Canada were examined for freezing tolerance, supercooling capacity, water content and changes in biochemical characteristics during acclimation to subzero temperatures to indicate that cold tolerance mechanisms have evolved independently on a number of different occassions.
TL;DR: A cyclic, constant parameter epidemiological model is described for a closed population divided into susceptible, exposed and infectious classes and the model is formulated as two coupled Volterra integral equations.
Abstract: A cyclic, constant parameter epidemiological model is described for a closed population divided into susceptible, exposed and infectious classes. Distributed delays are introduced and the model is formulated as two coupled Volterra integral equations. The delays do not change the general nature of thresholds or asymptotic stability; in all cases considered the disease either dies out, or approaches an endemic steady state.
TL;DR: In this article, a linear transformation τ on J is an isometry of J onto itself if and only if there are unitary operators U and V on H such that either τ(X) = UXV or τ[X] = UXtV, where Xt denotes the transpose of X with respect to a fixed orthonormal basis of H.
TL;DR: It is suggested that low-frequency stimulation is more effective than high- frequency stimulation in inducing seizure development in a variety of forebrain sites.
TL;DR: The hexactinellid sponge Rhabdocalyptus dawsoni is capable of arresting its exhalant water current in response to mechanical and electrical stimuli by coordinated by a conduction system with a precise threshold of excitability and a chronaxie of 38 milliseconds.
Abstract: The hexactinellid sponge Rhabdocalyptus dawsoni is capable of arresting its exhalant water current in response to mechanical and electrical stimuli. The arrest is coordinated by a conduction system with a precise threshold of excitability and a chronaxie of 38 milliseconds. The response is propagated throughout the sponge at a mean velocity of 0.22 centimeter per second, and conduction is unpolarized.
01 Oct 1981-Cartographica: The International Journal for Geographic Information and Geovisualization
TL;DR: In this paper, the authors argue that there is a need in cartographic research for all three kinds of experiments: the primarily-psychophysical, the primarily cognitive, and the integrated psychophysical/cognitive.
Abstract: The interface of psychophysical and cognitive research is not an edge but an intersection. This has important implications for cartographers who often turn to the discipline of psychology for theory and methods that can be applied to the study of maps and map-use. In the past, cartographers frequently have taken a psychophysical viewpoint in their experiments. This approach has been criticized, however, and recently, a few studies have appeared which employed a cognitive or an integrated cognitive/psychophysical viewpoint. The position is taken here that there is a need in cartographic research for all three kinds of experiments: the primarily-psychophysical, the primarily cognitive, and the integrated psychophysical/cognitive. This belief is based on two factors: 1 there are certain cartographic questions that can best be answered through a specific experimental paradigm; and 2 the interaction between cognitive and psychophysical relationships in perception creates the need for some understanding of both...
TL;DR: In this paper, a number of different designs for high-energy spark igniters of the sort where sufficient energy is dissipated in the discharge so that the plasma is injected into the gas mixture that is to be ignited are discussed.
TL;DR: The rapid changes in ( P max B ) that occurred during spring and late summer coincided with changes in daylength and in concentrations of phytoplankton carbon and taxonomic compositions, but timing of these changes was not predicted by changes in irradiation and turbulence expressed as ratios of critical to mixed depths.
TL;DR: The structural changes undergone by the digestive system of a phytoplanktotrophic nudibranch larva during metamorphosis into a benthic carnivore are described using histological and electron microscopic techniques.
Abstract: The structural changes undergone by the digestive system of a phytoplanktotrophic nudibranch larva during metamorphosis into a benthic carnivore are described using histological and electron microscopic techniques. The relative positions of the stomach, digestive gland, and distal end of the intestine are rearranged at metamorphosis by the actions of the larval retractor muscle and the accessory pedal retractor muscle. Although the anus and distal end of the intestine are secondarily displaced to the posterior end of the gastropod, the stomach undergoes further torsional displacement at metamorphosis. The tissues of the larval stomach and distal end of the larval esophagus undergo drastic alteration at metamorphosis. The larval stomach consists of a ciliated vestibule, which receives the openings of the esophagus and left digestive gland, a gastric shield, a style sac, and an intestinal groove. All of these areas, except the vestibule, are destroyed by cell dissociation at metamorphosis. The vestibule becomes the ventral stomach of the benthic stage and the proximal end of the intestine becomes enlarged and muscularized to form the dorsal ‘stomach’ of the benthic stage. The metamorphic changes involving the distal end of the esophagus include the continued development of the radula and oral lip glands, which both appear in rudimentary form during the larval stage, and differentiation of the buccal pump, salivary glands, and oral lips.
TL;DR: Poly(A) + RNA was isolated from maize by affinity chromatography on columns of oligo(dT)-cellulose and the major sequence containing N 6 -methyladenosine was found to be Pu-m 6 A-C.
TL;DR: In the absence of P22 mediated cotransduction with 16 adjacent chromosomal markers the srlA and tct loci were bridged by using a series of tct flanking Tn10 insertions, and by newly isolated and characterized nalB mutants.
Abstract: Spontaneous and Tn10 induced fluorocitrate resistant mutants were isolated and characterized These mutants were unable to grow on either cis-aconitate or DL-isocitrate but were still able to grow slowly on sodium citrate and normally on potassium or potassium-plus-sodium citrate These mutants were defective in both citrate transport and citrate binding to periplasmic proteins Tn10 insertion mutants were unable to produce immunologically detectable amounts of the citrate inducible periplasmic C protein previously shown to bind tricarboxylates Using a series of tct::Tn10 directed Hfrs the tct locus was accurately positioned at 59 units between srlA and pheA, but was not cotransducible with either gene In the absence of P22 mediated cotransduction with 16 adjacent chromosomal markers the srlA and tct loci were bridged by using a series of tct flanking Tn10 insertions, and by newly isolated and characterized nalB mutants In addition the hyd and recA loci were located establishing the gene order in this region of the chromosome as: pheA tct nalB recA srlA hyd cys Nitrosoguanidine derived tricarboxylate mutations (Imai 1975) were also mapped within the tct locus
TL;DR: It is confirmed that 6-hydroxydopamine-induced depletion of noradrenaline facilitates amygdaloid kindling and this effect was found to be independent of the intensity of stimulation used for kindling.
TL;DR: The transplant of sea otters to British Columbia from Alaska has survived a decade but without increase in population numbers, i.e. 70 + animals as mentioned in this paper but without increasing the number of animals.
TL;DR: Evidence is presented which suggests that cell death in Chinese hamster cells following angelicin photosensitization is not clearly related to the production of sister-chromatid exchanges, and 5MOP in some sun-tan preparations is not acceptable in view of the present evidence of its biological activity.
Abstract: The comparative photosensitizing effects to near-UV irradiation (UVA) of several naturally occurring furocoumarins, 5-methoxypsoralen (5MOP), psoralen, 8-methoxypsoralen (8MOP) and angelicin in producing chromosome damage in vitro in cells derived from hamster, normal human, ataxia telangiectasia (AT) and xeroderma pigmentosum (XP) patients were studied. In Chinese hamster cells, lethality was greatest with psoralen and least with angelicin; 8MOP and 5MOP were intermediate. 8MOP and 5MOP produced sister-chromatid exchanges with almost equal efficiency and to a larger extent by far than angelicin. In all human cell lines studied, 8MOP and 5MOP were similarly effective in the production of sister-chromatid exchanges and chromosomal aberrations. AT and XP cells responded with higher frequencies of sister-chromatid exchanges as well as chromosomal aberrations than normal human cells to 5MOP, 8MOP and angelicin. Evidence is presented which suggests that cell death in Chinese hamster cells following angelicin photosensitization is not clearly related to the production of sister-chromatid exchanges. AT cells were unexpectedly more sensitive to angelicin than normal cells. The presence of 5MOP in some sun-tan preparations is not acceptable in view of the present evidence of its biological activity.
TL;DR: In this paper, the authors compared sediment interstitial salinities with those of the immediately overlying water at five stations in the Fraser River estuary, B.C. They found that the interstitial and overlying salinity variations closely followed diurnal salinity changes in the water column.
Abstract: Diurnal comparisons of sediment interstitial salinities with those of the immediately overlying water were conducted subtidally at five stations in the Fraser River estuary, B.C. These in situ studies indicated that the interstitial salinities of sediments containing a high proportion of silt were relatively constant despite large fluctuations in water column salinities; however, in sands, interstitial salinities closely followed diurnal salinity variations in the water column. Laboratory penetration studies were conducted using relatively undisturbed natural sediments. The results of the in situ and laboratory studies indicated that exchange between the interstitial and overlying water was influenced by three major factors: the rate of water flow above the sediment, the relative salinities of the interstitial and overlying water and the sediment composition.
TL;DR: Waber's claim that individual differences in cognition reflect variations in rate of maturation was tested by correlating the performance of 50 right-handed females in verbal and spatial tasks with their age of onset of menstruation.