Showing papers by "University of Saskatchewan published in 1984"

Bibliography on the Application of Probability Methods in Power System Reliability Evaluation 1996-1999

Abstract: This paper presents a bibliography of papers on the subject of power system reliability evaluation. Papers in such areas as: probabilistic load flow, probabilistic production costing, probabilistic transient stability evaluation, etc. have not been included except where they specifically address power system reliability evaluation. It includes material which has become available since the publication of the four previous papers. 'Bibliography on the Application of Probability Methods in Power System Reliability Evaluation', IEEE Trans. On Power Apparatus and Systems PAS-91, 1972, p.649-660; PAS-97, 1978, p.2235-2242; PAS-103, 1984, p.275-282 and IEEE Trans. On Power Systems, vol.3, no.4,p.1555-1564, 1984. The authors have endeavored to include papers which are readily archival on an international basis. Consequently, the proceedings of such conferences as: CIGRE, Inter-RAM, PMAPS, etc. are regretfully not included. Due to space constraints, only papers written in English were considered for inclusion in this bibliography. >

Determination of kC and kNin situ for calibration of the chloroform fumigation-incubation method

Abstract: 14 C-labelled glucose and 15 N-labelled KNO 3 were added to soil and the microbial biomass during 42 days' incubation was estimated using the chloroform fumigation-incubation method (CFIM). By day 1, most of the glucose (1577 μgCg −1 soil) was metabolized and 110 μg NO − 3 -Ng −1 soil were immobilized. In situ values for the proportions of biomass C ( k C ) and biomass N ( k N ) mineralized during the 10 days after CHCl 3 fumigation were determined on the basis that the immobilized labelled C and N remaining in the soil at this time were present as living microbial cells and their associated metabolites. The tracer data indicated that biomass C could be calculated by applying a k c value of 0.41 to the CO 2 -C evolved from the fumigated sample without subtraction of an unfumigated “control”. Biomass N was estimated from the net NH 4 − -N accumulation during the fumigation-incubation. The problem of reimmobilization of NH + 4 -N where organisms of wide C:N ratio occur was overcome by adjusting the value of k N according to the ratio of CO 2 -C evolved: net NH 4 + -N accumulated during the fumigation-incubation (C F :N F ).A C F :N F ratio of 6:1 resulted in a k N of 0.30 whereas a ratio of 13:1 indicated a k N of 0.20.

A review of electron spin spectroscopy and its application to the study of paramagnetic defects in crystalline quartz

Abstract: A comprehensive review (ca. 230 references) is presented of the present (1983) state of knowledge of paramagnetic defects in crystalline quartz, as derived from electron paramagnetic resonance spectroscopy and related techniques. An auxiliary description of relevant concepts in solid state electron paramagnetic resonance (EPR), suitable for the non-specialist, is included. The centres described include those arising from impurity ions (Al, H, Cu, Ag, Ge, P, Ti, Fe) as well as those (E′) associated with oxygen ions missing in the quartz structure. Emphasis is placed on the structural information derivable from EPR. A brief survey of the present state of understanding of the optical bands caused by the defects is also given.

Epidemiology of parkinsonism: Incidence, classification, and mortality

Abstract: An epidemiological study of parkinsonism over a 13-year period (1967 through 1979) is presented, updating previous reports on incidence and trend in the population of Rochester, Minnesota. The overall average annual incidence of parkinsonism per 100,000 population was 20.5, adjusted to the 1970 total United States population, which is virtually unchanged from previous observations. Incidences calculated for each calendar year (1967 through 1979) revealed no remarkable change following the 1976 swine flu vaccination program. There was no sex difference and the peak incidence occurred between ages 75 and 84 years. Idiopathic Parkinson's disease was the most common variant (86%), followed by drug-induced parkinsonism (7%). There were no new cases of postencephalitic parkinsonism diagnosed during the study period. Relative frequency of other types of Parkinson's disease as identified by practicing neurologists is presented. For each case two age- and sex-matched controls were selected from the Rochester population. The survival rates in the controls were comparable to the general population of the west north central region of the United States. The mortalities in the patients were significantly higher (p = 0.001) than the controls and were unchanged from previous rates reported from the same community. In the 69 (50%) patients treated with levodopa, the mortality was comparable to that in controls. The favorable outcome in these cases is attributed to bias resulting from selection of healthier patients for treatment.

Nutrients and toxicants in rapeseed meal: a review.

Abstract: The composition of rapeseed meal and hulls is reviewed with emphasis on components of nutritional interest Carbohydrates in rapeseed meal are mainly pectins, pentosans and cellulose and comprise nearly one-half the gross energy The digestibility of energy is lower for rapeseed than for soybean meal Protein is well digested, but the protein digestion coefficient and the availability of amino acids are lower than for soybean meal Data on digestible and metabolizable energy are summarized The kinds of glucosinolates present in high (HG) and low (LG) glucosinolate rapeseed meal and the nature of their hydrolytic products are discussed The toxic effects of oxazolidinethione , isothiocyanates, thiocyanates and nitriles, and their relationship to their parent glucosinolates , to myrosinase action and to conditions during rapeseed processing are reviewed briefly The effects of glucosinolates in animal tissues and products and the effects of converting to LG rapeseed meal are presented Finally, a brief review is given of the responses of swine and cattle to the feeding of HG and LG rapeseed meal The nutritional advantages of LG rapeseed meal, over the older type HG meal, are clearly evident from the feeding trials

High-gravity brewing: effects of nutrition on yeast composition, fermentative ability, and alcohol production.

Abstract: A number of economic and product quality advantages exist in brewing when high-gravity worts of 16 to 18% dissolved solids are fermented Above this level, production problems such as slow or stuck fermentations and poor yeast viability occur Ethanol toxicity has been cited as the main cause, as brewers' yeasts are reported to tolerate only 7 to 9% (vol/vol) ethanol The inhibitory effect of high osmotic pressure has also been implicated In this report, it is demonstrated that the factor limiting the production of high levels of ethanol by brewing yeasts is actually a nutritional deficiency When a nitrogen source, ergosterol, and oleic acid are added to worts up to 31% dissolved solids, it is possible to produce beers up to 162% (vol/vol) ethanol Yeast viability remains high, and the yeasts can be repitched at least five times Supplementation does not increase the fermentative tolerance of the yeasts to ethanol but increases the length and level of new yeast cell mass synthesis over that seen in unsupplemented wort (and therefore the period of more rapid wort attenuation) Glycogen, protein, and sterol levels in yeasts were examined, as was the importance of pitching rate, temperature, and degree of anaerobiosis The ethanol tolerance of brewers' yeast is suggested to be no different than that of sake or distillers' yeast

A single cell high order scheme for the convection-diffusion equation with variable coefficients

Abstract: On propose un schema de differences finies pour l'equation de convection-diffusion a coefficients variables. Le systeme resultant peut etre resolu par des methodes iteratives

Effect of Zinc Deficiency on Serum Somatomedin Levels and Skeletal Growth in Young Rats

Abstract: We have studied potential mechanisms by which zinc deficiency (ZD) may result in growth impairment in young animals. Dietary-induced ZD in young rats resulted in diminished skeletal growth as measured by tibial epiphyseal width. Treatment with bovine GH (bGH) did not increase skeletal growth suggesting GH resistance rather than GH deficiency in zinc-deficient rats. Serum levels of basic somatomedin (SM) were lower in zinc-deficient rats than in control rats receiving a zinc adequate diet, either ad libitum or in pair matched amounts, and were restored to normal by zinc repletion but not by bGH treatment, suggesting that SM production is impaired by ZD. There was a high correlation between tibial epiphyseal widths and serum or femur zinc concentrations. These findings, along with observations that despite similar levels of serum basic SM the bGH-treated zinc-deficient rats had smaller tibial epiphyseal widths than pair fed control rats, additionally suggest that the action of SM on skeletal growth is impaired by ZD.

Power-system reliability in perspective

Abstract: This article discusses several philosophical aspects concerning power-system reliability. It puts the reliability aspects in perspective, describes a hierarchical framework of analysis and discusses how the economics of reliability should be compared.

The Interpretation and Estimation of Effective Sample Size

Abstract: Statistical and dynamical relationships between observed values of a geophysical system or model effectively reduce the number of independent data. This reduction is expressible in terms of the covariance structure of the process and, in some instances, it is reasonable to devise a measure of the “effective sample size” in terms of sample statistics. Here we discuss the concept of “effective sample size,” and, having settled upon one of several possible definitions, examine various methods of estimating this quantity. It is found that “effective sample size” is quite difficult to estimate reliably. However, a procedure is described which we feel could be used successfully; it is noted that the concept could be extended to spatial arrays of data, in some circumstances.

Adolescence, stress, and psychological well-being.

Abstract: The present study analyzes the mental-health consequences of stress in a sample of 1,038 adolescents (526 females and 512 males) from a Canadian prairie city. The study examined the relationship between perceived stress in family, school, and peer-group situations and four measures of psychological well-being, i.e., anxiety, depression, social dysfunction, and anergia. The moderator effects of locus of control orientation (mastery) on stress-outcome relationships were also examined, as were the sex differences in health and the perception of stress. All three sources of stress were found to be related to the four measures of mental health, with family stress having the strongest negative health impact. The health-protective role of locus of control was limited for the large part to the stresses emanating from school and peer groups. Substantial sex differences were found in the perception of family- and peer-related stresses as well as in levels of psychological distress. A tentative explanation of these differences was examined with reference to prevailing structural conditions and differences in locus of control orientation, with female adolescents showing greater externality. Implications of the results are drawn for the long-standing debate on the relative impact of stress and its sources on adolescents' psychosocial development and for a current controversy in adolescent theory between proponents of “classical” and proponents of “empirical” conceptions of adolescence.

Astrocyte cell lineage. V. Similarity of astrocytes that form in the presence of dBcAMP in cultures to reactive astrocytes in vivo.

Abstract: The relationship between astrocytes forming in the presence of dibutyryl cyclic AMP (dBcAMP) in culture and reactive astrocytes responding to a cerebral cortex stab wound was investigated using computerized image analysis (Zeiss IBAS 1) and immunocytochemical staining. The diameters of the nuclei of astrocytes in primary cultures of newborn mouse neopallial cells were compared to those of the nuclei of normal and reactive astrocytes in histological sections of mouse cerebral cortex. We found that the nuclei of astrocytes that formed in the presence of dBcAMP in cultures are significantly larger than those of spontaneously occurring small stellate astrocytes in culture and of normal astrocytes of the cerebral cortex in vivo but corresponded more closely to the nuclei of reactive astrocytes in the area surrounding a stab wound in the cerebral cortex. Large stellate cells formed in the presence of dBcAMP had vimentin and an increase in GFP-containing intermediate filaments. Formation of reactive astrocytes in vivo is also associated with an increase in both vimentin and GFP-containing intermediate filaments. These observations indicate a closer relationship of astrocytes formed in the presence of dBcAMP in cultures to the reactive astrocytes in the cerebral cortex than to normal astrocytes. We propose, therefore, that the large stellate astrocytes that form in the presence of dBcAMP be referred to as reactive astrocytes in culture.

Alterations in uptake and release rates for GABA, glutamate, and glutamine during biochemical maturation of highly purified cultures of cerebral cortical neurons, a GABAergic preparation.

Abstract: This study demonstrates that virtually homogenous cultures of mouse cerebral neurons, obtained from 15-day-old embryos, differentiate at least as well as cultures which in addition contain astrocytes This was indicated by glutamate decarboxylase activity which within 2 weeks rose from a negligible value to twice the level in the adult mouse cerebral cortex, and by a gamma-aminobutyric acid (GABA) uptake rate which quadrupled during the second week in culture and reached higher values than in brain slices Within the same period, the GABA content increased four to five times to 75 nmol/mg protein, and a potassium-induced increase in [14C]GABA efflux became apparent Although the development was faster than in vivo, optimum differentiation required maintenance of the cultures beyond the age of 1 week Uptake and release rates for glutamate and glutamine underwent much less developmental alteration At no time was there any potassium-induced release of radioactivity after exposure to [14C]glutamate, and the glutamate uptake was only slightly increased during the period of GABAergic development This indicates that exogenous glutamate is not an important GABA precursor Similarly, glutamine uptake was unaltered between days 7 and 14, although a small potassium-induced release of radioactivity after loading with glutamine suggests a partial conversion to GABA

Changes in the Amino Acid Content of Nerve Endings (Synaptosomes) Induced by Drugs that Alter the Metabolism of Glutamate and γ‐Aminobutyric Acid

Abstract: The study was centered on the changes in the amino acid content of nerve endings (synaptosomes) induced by drugs that alter the metabolism of glutamate or gamma-aminobutyric acid (GABA), and that possess convulsant or anticonvulsant properties. The onset of seizures induced by various convulsant agents was associated with a decreased content of GABA and an increased content of glutamate in synaptosomes. The concurrent administration of pyridoxine prevented both the biochemical changes and the convulsions. The administration of gabaculine to mice resulted in large increases in the GABA content of synaptosomes that were counteracted by decreases in glutamate, glutamine, and aspartate levels such that the total content of the four amino acids remained unchanged. The administration of aminooxyacetic acid (0.91 mmol/kg) resulted initially in seizure activity, but subsequently in an anticonvulsant action. No simple relationship existed between the excitable state of the brain induced by aminooxyacetic acid and the changes in the synaptosomal levels of any of the amino acid transmitters. A hypothesis was, however, formulated that explained the convulsant-cum-anticonvulsant action of aminooxyacetic acid on the basis of compartmentation of GABA within the nerve endings.

Endocytosis of cationized ferritin by coated vesicles of soybean protoplasts.

Abstract: Soybean (Glycine max (L.) Merr.) protoplasts have been surface-labelled with cationized ferritin, and the fate of the label has been followed ultrastructurally. Endocytosis of the label occurs via the coated-membrane system. The pathway followed by the label, once it has been taken into the interior of the protoplast, appears to be similar to that found during receptor-mediated endocytosis in animal cells. Cationized ferritin is first seen in coated vesicles but rapidly appears in smooth vesicles. Labelled, partially coated vesicles are occasionally observed, indicating that the smooth vesicles may have arisen by the uncoating of coated vesicles. Structures which eventually become labelled with cationized ferritin include multivesicular bodies, dictyosomes, large smooth vesicles, and a system of partially coated reticula.

Effect of age and sex on the plasma binding of acidic and basic drugs

Abstract: Protein binding of chlorpromazine, propranolol, meperidine, desipramine, salicylic acid and phenytoin was determined in plasma of 64 healthy volunteers (35 males and 29 females). An attempt was made to identify factors affecting the plasma protein binding of these drugs. Whereas plasma albumin levels decreased as a function of age in both sexes, α1-acid glycoprotein levels increased with age, but the increase was more pronounced in males. The free plasma fraction of the acidic drugs (salicylic acid, phenytoin) and despiramine (a base) showed a significant (p<0.005) negative correlation with plasma albumin levels. The free fractions of the other three basic drugs (chlorpromazine, propranolol, meperidine) in plasma showed a significant (p<0.005) negative correlation with α1-acid glycoprotein plasma levels. Plasma protein binding of salicylic acid, phenytoin and desipramine decreased as a function of age. Plasma protein binding of chlorpromazine, propranolol and meperidine was virtually unaffected by age or was slightly increased (chlorpromazine). Only in the case of salicylic acid could a statistically significant difference be demonstrated between males and females in the free fraction-age relationship. Stepwise multiple linear regression analysis, including age and blood chemistry values such as hematocrit, bilirubin, cholesterol, triglycerides, creatinine, BUN, albumin and α1-acid glycoprotein as independent variables, identified age as the variable explaining most of the variability in plasma binding of salicylic acid, phenytoin and desipramine. For chlorpromazine, propranolol and meperidine α1-acid glycoprotein was the most important determinant of plasma protein binding.

The binding of dietary protein by sorghum tannins in the digestive tract of pigs.

Abstract: The effects of reconstitution of sorghums on dry matter, energy, protein and amino acid digestibilities, and the nature of protein binding by sorghum tannins during digestion were investigated. Grains from a high and a low tannin sorghum were reconstituted by adding 30% (wt/wt) distilled water to the grain and stored at 25 degrees C for 20 days with an acetic-propionic acid mixture added to deter fungal growth. Another lot of grain from the same sources was untreated and used as control. The sorghum grains were then incorporated at an 85% level in diets for a digestibility trial with pigs cannulated at the terminal ileum. The digestibilities of dry matter, protein and amino acids at the terminal ileum were lower than the corresponding values measured over the total digestive tract. Reconstitution improved the digestibilities of dry matter, energy, protein and amino acids in the high but not low tannin sorghum diets. The improvement in digestibility of individual amino acids ranged from 7.5 to 23.5%. The tannin-associated proteins were more hydrophobic than the dietary protein. The results suggest that hydrophobic bonding is important in the formation of tannin-protein complexes in the digestive tract of pigs.

Acetylene and N-serve effects upon N2O emissions from NH4+ and NO3− treated soils under aerobic and anaerobic conditions

Abstract: N 2 O emissions from soils treated with NH 4 + -N under aerobic conditions in the laboratory were 3- to 4-fold higher than those from controls (no extra N added) or when NO 3 − -N was added. Although the emission of N 2 O-N in these field and laboratory experiments represented only 0.1–0.8% of the applied fertilizer NH 4 + -N and are therefore not significant from an agronomic standpoint, these studies have conclusively demonstrated that the oxidation of applied ammoniacal fertilizers (nitrification) could contribute significantly to the stratospheric N 2 O pool. Like N-serve, acetylene was shown to be a potent inhibitor of nitrification as it stopped the oxidation of NH 4 + -N to (NO 3 + -N + NO 2 − )-N and hence reduced the evolution of N 2 O from nitrification within 60 min after its addition. Although high amounts of NO 3 − -N were present, the rate of denitrification was very low from soils with moisture up to 60% saturation. The further increase in the degree of saturation resulted in several-fold increase of denitrification which eventually became the predominant mechanism of gaseous N losses under anaerobic conditions.

Alcoholism, anxiety disorders, and agoraphobia.

Abstract: A group of 48 inpatient alcoholics were studied using the Schedule for Affectve Disorders and Schizophrenia–Life-time Version (SADS-L) and the Brief Standard Self-rating for Phobic Patients. Approximately one-quarter of the patients were diagnosed as suffering from agoraphobia and social and mixed phobias. Approximately 44% were diagnosed as suffering from anxiety disorders and 46% had suffered from an episode of major depression. Data from the self-rating questionnaire were consistent with the diagnostic data. The alcoholics with phobias had experienced more severe dysphoric feelings than nonphobic alcoholics with other psychiatric disorders.

Influence of pathological concentrations of ammonia on metabolic fate of 14C-labeled glutamate in astrocytes in primary cultures

Abstract: Rates of glutamine formation and of carbon dioxide production (as an indication of oxidative deamination of glutamate) were determined in primary cultures of astrocytes exposed to 50 microM labeled glutamate in the absence or presence of added ammonia (0.1-3 mM). Glutamine formation (1.7 nmol/min/mg protein) was unaffected by all concentrations of added ammonia. This probably reflects the presence of a low content of ammonia (0.1-0.2 mM), originating from degradation of glutamine, in the cells even in the absence of added ammonia, and it shows that pathophysiological concentrations of ammonia do not increase the formation of glutamine from exogenous glutamate. The carbon dioxide production rate was 5.9 nmol/min/mg protein, i.e., three to four times higher than the rate of glutamine formation. It was significantly reduced (to 3.5 nmol/min/mg protein) in the presence of 1 mM or more of ammonia. This is in keeping with suggestions by others that toxic levels of ammonia affect oxidative metabolism.

Kinetic studies of corn stover saccharification using sulphuric acid.

Abstract: The kinetics of crystalline cellulose and hemicellulose hydrolysis in corn stover were studied with a nonisothermal technique. Reactions were arrested at temperatures between 160 and 240 degrees C and product sugars were analyzed using a Bio-Rad HPX-85 liquid chromatographic column. A simple first-order series reaction model was used for both cellulose and hemicellulose hydrolysis reactions. Kinetic parameters were obtained for three different sulphuric acid concentrations (0.49, 0.92, and 1.47 wt %). Activation energies remained constant over this acid concentration range but the preexponential factors showed an increase with acid concentration. Relationships were obtained between the preexponential factors and acid concentrations. Cellulose hydrolysis and glucose degradation reactions were observed to be of higher order with respect to acid concentration in comparison with the previous studies with other raw materials.

Intense furosemide-sensitive potassium accumulation in astrocytes in the presence of pathologically high extracellular potassium levels

Abstract: An intense K+ accumulation in primary cultures of astrocytes, occurring when external K+ was increased from 5.4 to 54 mM, was investigated. This increase resulted in a doubling of the K+ content within 10 s. Thirty percent of the accumulation was inhibited by furosemide (2 mM). This drug had no effect on the unidirectional influx of K+ at 5.4 mM K+, but when the extracellular K+ concentration was increased, there appeared to be a furosemide-sensitive component of the influx. This component increased with increasing external K+ levels, reaching 44% of the total influx at 72 mM. These results show that astrocytes exhibit an intense furosemide-sensitive K+ accumulation which is activated by K+ levels resembling those occurring in the extracellular compartment during pathological events. Previous studies on a furosemide-sensitive Cl- pump in cultured astrocytes suggest that this accumulation might be via KCl cotransport, which in other systems is involved in volume control.