Showing papers by "University of Saskatchewan published in 1975"
TL;DR: The results are compatible with the hypothesis that adenosine depresses neurons by activating an extracellular receptor and that this effect can be blocked by theophylline and caffeine.
159 citations
TL;DR: Cyclic 3',5'-adenosine monophosphate was a less effective depressant than various other adenine nucleotides, including cyclic 2',3'-adenoine monphosphate.
155 citations
TL;DR: In this article, it was shown that the power required from precession to stir the core of a geomagnetic dynamo cannot exceed 108 W if the core flow remains stable.
Abstract: Summary
The power requirement of a stationary geomagnetic dynamo driven by some agency external to the core (e. g. precession) is equal to the ohmic dissipation in the core, Q1. For a dynamo in which differential rotation is important we show that Q1ασ1−2, where σ1∼ 5 × 105 ohm−1 m−1 is the electrical conductivity of the core. Estimates of Q1 for kinematic dynamo models range from 109 to over 1012 Watts, depending on the particular regenerative scheme characterizing the dynamo. Precessional power input to the magnetic field can be estimated in terms of the electromagnetic part of the core-mantle coupling and the tiltover angle (inclination of the core angular momentum vector to that of the mantle). We correct Stacey's estimate of core-mantle coupling to take into account the diurnal frequency of precession-induced flow relative to the mantle, and show that the power available from precession to stir the core cannot exceed 108 W if the core flow remains stable. As a caution against the widespread uncritical acceptance of Malkus’ claims to have demonstrated the energetic adequacy of precession-driven hydromagnetic turbulence, we enumerate the mathematical and physical errors which cast doubt on his theoretical arguments.
141 citations
TL;DR: An equation on an empirical basis is developed which provides an excellent relationship between the excitable state of the brain and a function of GABA metabolism which incorporates both changes in GABA level and changes in GAD activity.
138 citations
TL;DR: In this article, the authors considered a two-location stochastic inventory problem with periodic review, where replenishment may be ordered only at times of periodic review but a provision is made for transfer of stock between the locations at predetermined times within the replenishment cycle.
Abstract: This paper considers a two-location stochastic inventory problem with periodic review. It is assumed that replenishment may be ordered only at times of periodic review but a provision is made for transfer of stock between the locations at predetermined times within the replenishment cycle. Problems of determining jointly optimal stockage and transfer rules according to the expected total cost criterion are investigated. Under certain regularity conditions, the optimality of a simple class of Base Stock Conserving BSC transfer rules is first established. The related optimal stockage rule is then characterized for the single period model of captive sales.
117 citations
TL;DR: This chapter discusses ion and energy metabolism of the brain at the cellular level and focuses the effects of ions (especially K + ) on energy metabolism and of adverse metabolic conditions on ion distribution.
Abstract: Publisher Summary This chapter discusses ion and energy metabolism of the brain at the cellular level. The comparison between metabolism in the brain in vivo and in brain slices and isolated cells has highlighted that ion and energy metabolism of the dissociated cell types corresponds to that in more complex in vitro preparation and under in vivo conditions. Therefore, observations in such preparations of individual cells are relevant for interpretation of physiological and pathological events at the cellular level of the brain cortex. The chapter also focuses the effects of ions (especially K+) on energy metabolism and of adverse metabolic conditions on ion distribution. From a physiological point of view, it is probably of major importance that the potassium concentration in the interstitial fluid becomes considerably increased during neuronal activity. Owing to the pronounced influence of K+ on membrane polarization, efficient and fast removal of excess extracellular potassium is essential.
113 citations
TL;DR: Findings are consistent with the hypothesis that smoking during pregnancy is an important cause of the hyperkinetic syndrome and the reported cigarette consumptions of the fathers showed no significant differences.
Abstract: An apparent increase in hyperkinetic disease (HD) during the past 30 years has coincided with a wide expansion of cigarette smoking especially among women. A patient group of 20 consecutive cases (18 boys and 2 girls; age range 5-15 years) was chosen in which diagnosis of HD was followed by unequivocal improvement on Ritalin. Each child was matched for sex age and social class with a nonhyperkinetic dyslexic (non-HDD) child and also with a normal control. Though HD is associated with low birth weight means of reported weights showed no significant differences between the 3 groups (means: HD 6.83; non-HDD 6.98; controls 6.88). The HD groups also contained a significantly higher proportion of 1st born children (P < .01). Tabulation of the mean numbers of cigarettes smoked per day showed that consumption of the mothers of HD children was significantly higher than that of controls in all 3 categories and the difference rose (P < .001) to maximum in the category of present consumption. Mothers of HD children reported a mean present consumption of 23.3 cigarettes more than 3 times the average for the 2 control groups and more than the present consumption of their husbands. During the corresponding pregnancy the HD group smoked a mean of 14.3 cigarettes daily more than 2 times the amount reported by controls. Cause and effect are suggested.
113 citations
TL;DR: The freezing of water in acclimated and nonacclimated cereals was studied using pulsed nuclear magnetic resonance spectroscopy and the quantity of unfreezable water per unit dry matter was not strongly dependent on the degree of cold acclimation.
Abstract: The freezing of water in acclimated and nonacclimated cereals was studied using pulsed nuclear magnetic resonance spectroscopy. The quantity of unfreezable water per unit dry matter was not strongly dependent on the degree of cold acclimation. In contrast, the fraction of water frozen which was tolerated by nonacclimated winter cereals and by an acclimated spring wheat (Triticum aestivum L.) was less than in acclimated hardy cereals. The freezing curves had the following form:LT = L0ΔTm/T + KLT and L0 are liquid water per unit dry matter at T and 0 C, respectively. ΔTm is the melting point depression and K is the liquid water which does not freeze.
109 citations
01 Jan 1975
TL;DR: The study of vertebrate trace fossils constitutes the oldest branch of ichnology and has much to offer paleontology, stratigraphy, and fades analysis, and these fields would benefit greatly by its increased use and refinement as mentioned in this paper.
Abstract: The study of vertebrate trace fossils constitutes the oldest branch of ichnology, although several problems have hampered its development and ultimate usefulness: obscure publications, inadequate illustrations and text descriptions, poorly preserved specimens that are easily overlooked or misinterpreted, and simply the lack of interest in the field shown by most vertebrate paleontologists Nevertheless, vertebrate ichnology has much to offer paleontology, stratigraphy, and fades analysis, and these fields would benefit greatly by its increased use and refinement
93 citations
TL;DR: The results support the view that adenosine and its nucleotides may be inhibitory transmitters in the cerebral cortex, and it is suggested that adosene and its derivatives may be released from presynaptic nerve terminals.
91 citations
TL;DR: In this paper, a mixture of doubly-labelled microorganisms and their metabolites were extracted by Na 4 P 2 O 7, and the extracted material further separated with phenol.
Abstract: Labelled 14 C-acetate and 15 N-(NH 4 ) 2 SO 4 were added to a clay soil in the laboratory to follow transformations of microbial C and N, A fungal population developed initially, reaching a maximum by day 5, then rapidly declined and was replaced by a population dominated by bacteria and actinomycetes. Soil samples containing doubly-labelled microorganisms and their metabolites were extracted by Na 4 P 2 O 7 , and the extracted material further separated with phenol. The highly labelled acid-soluble (fulvic acid) fraction of the Na 4 P 2 O 7 extract contained extracellular metabolites of low molecular weight which were rapidly attacked and converted to new microbial biomass, metabolites, mineral N or CO 2 . Na 4 P 2 O 7 also removed an acid-insoluble (humic acid) fraction of which up to 70 per cent of the labelled C and N could be removed by phenol. Attack of these recently synthesized extracellular materials was indicated by a rapid decline of Na 4 P 2 O 7 extractable C and N during the growth of bacteria and actinomycetes. Following Na 4 P 2 O 7 extraction, the residue was sonicated and peptized in water and the components of the microbial biomass were partitioned into sedimentation fractions by centrifugation. The components concentrated in the > 0.2 μ m fraction, which were hypothesized as being cell wall components, were more resistant to attack than materials in the μ m fraction. The materials in the latter fraction were thought to originate from cytoplasmic constituents. The labelled materials in the μ m sized fraction, which accumulated as the fungal population developed, were utilized less rapidly by the developing bacterial population. Decomposition of the microbial population resulted in transfer of C and N through various sediment fractions. The organic fraction (considered to be cytoplasmic material and adsorbed extracellular metabolites) which became labelled as the bacterial population developed, was utilized less rapidly by the developing bacterial population than components removable by Na 4 P 2 O 7 . Evolution of 14 CO 2 , production of microbial material and immobilization of N closely paralleled the incorporation and release of these elements from the fractions. The similarity of the behavior patterns of these elements suggested they were intimately associated within the soil microbial system studied. This demonstrated that N transformations were highly dependent on C transformations.
TL;DR: Aminooxyacetic acid was the most efficacious in delaying drug‐induced seizures in mice whereas hydroxylamine brought about only a slight delay in the onset of seizures.
Abstract: — The GABA-elevating agents, aminooxyacetic acid, hydrazine, and hydroxylamine, all possessed anticonvulsant properties, although to a widely varying degree. Aminooxyacetic acid was the most efficacious in delaying drug-induced seizures in mice whereas hydroxylamine brought about only a slight delay in the onset of seizures. The anticonvulsant action was observed against various convulsant agents regardless of whether the convulsant mechanism might involve a deranged GABA metabolism (allylglycine, isonicotinic acid hydrazide, hydrazine), an interference with GABA function (picrotoxin) or some other mechanism (pentylenetetrazol). The anticonvulsant action was not related in a simple manner to either GABA levels or glutamic acid decarboxylase (GAD) activities but the anomalous situation whereby seizures occurred when the GABA content of brain was above normal could be resolved on the basis of an expression which included changes in both GABA levels and GAD activity. The possibility was proposed that the anticonvulsant action of aminooxyacetic acid involved two separate mechanisms.
TL;DR: The microiontophoretic potencies of dopamine, apomorphine and alpha-aminobutyric acid were examined on caudate neurones in control animals and animals that had received 2mg/kg/day of haloperidol for 9 days, indicating the development of a post-synaptic supersensitivity.
TL;DR: The purpose of the present paper has been to study the glutamate content in astrocyte cultures from neonatal rat brain and it has been shown that the concentration of glutamine in the cultivation medium affects the growth of the C6 glioma cell.
Abstract: AN INCREASE or the glutamate concentration (from 5 to about 12 pmol/g wet wt) is one of the characteristics of brain maturation and in the rat this increase occurs during the first postnatal weeks (AGRAWAL et al., 1966; PATEL & BALAZS, 1970). Conceivably this increase might occur in either neurons or glia cells (or both) and the demonstration (HAMBERGER, 1Y71) that bulk prepared glia cells concentrate glutamate suggests that part of the glutamate may be found in glia cells (cf. BENJAMIN & QUASTEL, 1972). Dissociated glia cells cultured from brain hemispheres of new-born rats (BOOHER & SENS~NBRENNEK, 1972) have previously been shown to react metabolically to excess potassium (HERTZ et al., 1973) i.e. display a metabolic pattern characteristic for adult but not for neonatal tissue (HIMWICH et al., 1942). This culture may constitutc a good model for normal, adult aslrocytes, and the purpose of the present paper has been to study the glutamate content in astrocyte cultures from neonatal rat brain. Since it is known that such procedures as withdrawal of serum or addition of dibutyryl cyclic-3', 5'-AMP (BcAMP) cause a morphological and metabolic differentiation of some cultured cell types from the nervous system (e.g. SEEDS et al., 1970; MANDEL et ul., 1973; MOOKEN er ul., 1975) the effect of these procedures was tested. It bas also been shown that the concentration of glutamine in the cultivation medium affects the growth of the C6 glioma cell. line (DONTA, 1973). Accordingly cultures were grown in media containing different concentrations (0.8-8.0 mM) of this amino acid.
TL;DR: The hypothesis that the mechanism of C-banding involves the selective loss of non C- band chromatin is supported, as the evidence indicates that these interchromosomal fibres are artefacts produced by the overlapping of dispersed chromatin fibres.
TL;DR: In this article, a different approach to the design of power stabilizers for damping out tie-line power oscillations in power systems is described, which can be applied directly to systems characterized by lightly damped oscillations and gives an explicit indication of the amount of improvement in system damping for different combinations of stabilizer parameters.
Abstract: This paper describes a different approach to the design of power stabilizers for damping out tie-line power oscillations in power systems. The technique described in this paper was successfully applied at a generating station of the Saskatchewan Power Corporation System with the results from these tests included in the latter part of this paper. The technique can be applied directly to systems characterized by lightly damped oscillations and gives an explicit indication of the amount of improvement in system damping for different combinations of power stabilizer parameters. This procedure allows for a graphical approach to the design of power stabilizers and serves as a synthesis procedure when the design constraints are relaxed so that the speed stabilizer is required to provide an improvement in system damping.
TL;DR: The second-order perturbation energy of a spin Hamiltonian, valid for low symmetry and an arbitrary number of nuclei, is reported and discussed in this article, where the nuclear Zeeman terms, as well as certain cross terms missing in previous publications, have been included.
TL;DR: In this article, Anthracene reacts with ferrocene in the presence of AlCl 3 /Al to form the same mono-and dications derived from 9,10-dihydroanthracene.
TL;DR: In this article, the relative sensitivity of almost all decision variables and performance measures to mean lead time is solely determined by the coefficient of variation of demand, and the implication of the results is discussed and numerical illustrations are provided.
Abstract: In the (Q, R) inventory model with variable lead time the relative sensitivity of almost all decision variables and performance measures to mean lead time unlike that to the variance of lead time is solely determined by the coefficient of variation of demand The implication of the results is discussed and numerical illustrations are provided
TL;DR: The M1 form factor for the 0 + (3.562 MeV, T = 1) level in 6 Li has been measured in the momentum transfer range q = 0.16 ± 0.19eV by extrapolation to the photon point as mentioned in this paper.
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TL;DR: In this paper, it was shown that structures resulting from plant activity afford important information both to ichnologists and to paleo-biologists in general, and merit fuller study than they have hitherto received.
Abstract: Discriminating between plant body-fossils and biogenic structures resulting from plant activity is often difficult This difficulty is a consequence not only of their modes of life but also of semantic problems and differences in viewpoint among various workers However, structures resulting from plant activity afford important information both to ichnologists and to paleo-biologists in general, and merit fuller study than they have hitherto received
TL;DR: In this paper, the authors present a further step in the development of accurate and consistent techniques for the reliability evaluation of transmission and distribution systems, and a three state weather model is developed to illustrate the effect of severe adverse weather periods on the system reliability performance.
Abstract: This paper presents a further step in the development of accurate and consistent techniques for the reliability evaluation of transmission and distribution systems. A theoretically accurate Markov approach6is limited in application because of computer storage requirements and the rounding errors which occur in the solution of relatively large systems. This paper extends the modified approximate technique presented in reference (P) to permit evaluation of the contribution to the system reliability indices of different modes of component outage. The equations developed give results which compare very closely those predicted by the Markov approach. A three state weather model is developed to illustrate the effect of severe adverse weather periods on the system reliability performance. The load point failure modes considered are those which arise due to component permanent, temporary, maintenance and overload outages.
TL;DR: The methodology is proposed as a constructive solution to three criticisms of the “state of the art” in real-time system design, and central to the design methodology is RTS writing.
Abstract: A methodology is described which facilitates the design and implementation of software for real-time system (RTS) applcation. The methodology is proposed as a constructive solution to three criticisms of the “state of the art” in real-time system design. Central to the design methodology is n RTS writing e . The components and uses of the syst m are described and two of the major dynamic models in the system (processor allocation and shared data set control) are discussed in some detail. The user of the system writes real-time algorithms appropriate to a particular application in a high level language called RUDIL. Certain constructs in RUDIL invoke operating system type routines that are collectively called the NUCLEUS system. This NUCLEUS, along with the RUDIL compiler, provides the link between machineindependent RUDIL programs and the computer configuration in the real-time system.
TL;DR: The patterns of distribution of the array points were such that the eight parents could be classified into two well-separated groups, one comprising the isogenic lines which carried most of the dominant alleles and the other comprising the cultivars carrying largely the recessive alleles.
Abstract: A complete diallel cross was made among eight homozygous barley genotypes. Four of the parents were commercially grown cultivars and the remaining four consisted of isogenic derivatives of a California cultivar, Atlas. In a replicated experiment grown in two seasons, measurements were recorded on days to heading, days to maturity, plant height, grain yield and seed size. These data were then used to estimate variances (Vr) and covariances (Wr) of arrays in each season and a genetical interpretation of the relations between these statistics was sought. For days to heading, days to maturity and plant height, the Wr/Vr graphs provided an evaluation of genetic relationship among the parental genotypes. As expected on the basis of their known genetic similarity, the isogenic lines of Atlas were close together on the Wr/Vr graph. Contrary to the expectation, however, remarkable similarity among the commercially grown genotypes was indicated by the proximity of the array points representing them. The patterns of distribution of the array points were such that the eight parents could be classified into two well-separated groups, one comprising the isogenic lines which carried most of the dominant alleles and the other comprising the cultivars carrying largely the recessive alleles. A seasonal difference in the genetic behaviour of the parents was also observed. Although some of the observed genetic differences between the two parental groups in one season disappeared in the following season, the positions of the array points were consistent in depicting substantial differences between the groups in both seasons. In most cases a graphical analysis was possible when a number of parents were removed from the diallel table. Non-random distribution of genes among the parents did not appear to be a common cause of disturbance in the relations between Wr and Vr even when the number of parents were very small. For two economically important characters, kernel size and grain yield, a graphical analysis was not possible, presumably because of the failure of a number of hypotheses underlying the analysis.
TL;DR: A number of nuclear-substituted styryl ketones, the related Mannich bases, and allyl alcohols were synthesized and evaluated for antitumor activity, principally in the L-1210 lymphoid leukemia and P-388 lymphocytic leukemia screening tests.
TL;DR: It is proposed that oliPR1 is a mutation resulting in the alteration of plasma membrane permeability to many diverse inhibitors that causes anaerobic and temperature sensitization to ethidium bromide, paromomycin and neomycin.
Abstract: A meiotic segregant (oliPR1) was isolated with a phenotype of multiple cross resistance and collateral sensitivity. Strain oliPR1 has increased sensitivity to ethidium bromide, dequalinium chloride, acriflavin, paromomycin and neomycin, and increased resistance to oligomycin, rutamycin, venturicidin, triethyltin bromide, antimycin, carbonylcynamide-m-chlorophenylhydrazone, tetra-N-butylammonium bromide, dibenzyldimethylammonium chloride, triphenylmethlphosphonium bromide, chloramphenicol, carbomycin, tetracycline, triton X-165 and cycloheximide. Single gene inheritance of the cross resistance and collateral sensitivity was shown by 2:2 parental ditype segregation and reversion of the complete phenotype by a spontaneous revertant. The locus conferring the oliPR1 phenotype was mapped 11.7 units from an unspecified centromere. Antibiotic resistance showed incomplete dominance, with the level of hybrid resistance dependent upon the inhibitor tested. Resistant diploids that produced four resistant ascospores were the result of mitotic recombination prior to meiosis. A partial revertant phenotype (sensitive to all inhibitors except oligomycin, antimycin and carbonylcyanide-m-chlorophenylhydrazone) was shown to be due to a single nuclear gene causing partial suppression of oliPR1. Anaerobic pretreatment, 37degrees and 0.5 MKC1 were observed to reduce the growth of oliPR1 when challenged with seven diverse inhibitors (antimycin, carbonylcyanide-m-chlorophenylhydrazone,-chloramphenicol, cycloheximide, oligomycin, triethyltin bromide, and triphenylmethylphosphonium bromide). Resistance to cycloheximide was not altered by the [rho--] state. A revertant of oliPR1 (sensitive to the above inhibitors but resistant to ethidium bromide, paromycin and neomycin) showed anaerobic and temperature sensitization to ethidium bromide, paromomycin and neomycin. Continuous monitoring of oxygen uptake by the revertant afteranaerobic pretreatment revealed that anaerbiosis sensitized respiratory adaptation of the revertant to neomycin. It is proposed that oliPR1 is a mutation resulting in the alteration of plasma membrane permeability to many diverse inhibitors.
TL;DR: The 39 schizophrenic patients in that project showed greater amounts of delta induction than the 37 depressive patients as well as greater increases in mean integrated amplitude (MIA) and the coefficient of variation (CV), the usual measure of variability with integrated EEG, dropped slightly.
Abstract: * Paper read at the Annual Meeting. Canadian Psychiatric Association, Ottawa, October 1974. 1-3 Department of Psychiatry, University of Saskatchewan and the Psychiatric Research Unit, University Hospital, Saskatoon, Saskatchewan. gion. The 39 schizophrenic patients in that project showed greater amounts of delta induction than the 37 depressive patients as well as greater increases in mean integrated amplitude (MIA). However, the schizophrenic patients received on the average nine ECT and the depressives only seven and therefore it could not be determined whether length of treatment rather than diagnosis was the source of the difference. In 1973 d' Elia had reported (2) that in a study of convulsive therapy of 18 depressives with integrated EEG measures before treatment and four days after, the left central-occipital signal showed a significant increase in the variance of its amplitude, while the variance of MIA on the right side was increased slightly but not significantly. The coefficient of variation (CV), the usual measure of variability with integrated EEG, dropped slightly.
TL;DR: In this paper, the principal phenolic constituents tentatively identified in de-hulled flour were p-hydroxybenzoic, trans-cinnamic and sinapic acids while small quantities of p-coumaric, ferulic, caffeic, chlorogenic and two unknown acids were also detected by gas-liquid chromatography.
Abstract: Total ether-extractable phenolic compounds in Span rapeseed constituted 1.5 and 0.2% of dehulled and diffusion-extracted flours, respectively. The principal phenolic constituents tentatively identified in de-hulled flour were p-hydroxybenzoic, trans-cinnamic and sinapic acids while small quantities of p-coumaric, ferulic, caffeic, chlorogenic and two unknown acids were also detected by gas-liquid chromatography. Five phenolic acids which occurred in the ester form in the dehulled flour also occurred in the diffusion extracted flour. The sinapic acid ester constituted 85% of the phenolic compounds in the diffusion extracted flour and, because of its low taste threshold, may contribute adverse flavors to rapeseed food products.