Showing papers by "University of Calgary published in 1984"
TL;DR: This paper describes how the conflict can be resolved with partial string matching, and reports experimental results which show that mixed-case English text can be coded in as little as 2.2 bits/ character with no prior knowledge of the source.
Abstract: The recently developed technique of arithmetic coding, in conjunction with a Markov model of the source, is a powerful method of data compression in situations where a linear treatment is inappropriate. Adaptive coding allows the model to be constructed dynamically by both encoder and decoder during the course of the transmission, and has been shown to incur a smaller coding overhead than explicit transmission of the model's statistics. But there is a basic conflict between the desire to use high-order Markov models and the need to have them formed quickly as the initial part of the message is sent. This paper describes how the conflict can be resolved with partial string matching, and reports experimental results which show that mixed-case English text can be coded in as little as 2.2 bits/ character with no prior knowledge of the source.
1,318 citations
TL;DR: Patients' perceptions of increased intrusiveness, and their perceptions of limited control over eleven life dimensions, each correlated significantly and uniquely with increased negative and decreased positive mood, suggesting that each of these two factors contributes importantly and independently to patients' distress.
Abstract: The emotional impact of the intrusiveness of illness and patients' reduced control over several aspects of life were examined in the context of end-stage renal disease. A sample of thirty-five hemo...
364 citations
TL;DR: The electrophysiological properties of glial cells were examined in primary culture in the presence of tetraethylammonium and Ba2+, a treatment that reduces K+ permeability of the membrane and enhances currents through voltage-dependent Ca2+ channels.
Abstract: The electrophysiological properties of glial cells were examined in primary culture in the presence of tetraethylammonium and Ba2+, a treatment that reduces K+ permeability of the membrane and enhances currents through voltage-dependent Ca2+ channels. Under these conditions, glial cells showed both spontaneous action potentials and action potentials evoked by the injections of current. These responses appear to represent entry of Ba2+ through Ca2+ channels because they were resistant to tetrodotoxin but were blocked by Mn2+ or Cd2+.
360 citations
TL;DR: The similarities among reactions of early and advanced stage patients and mates were more striking than differences, indicating the profound impact of cancer over the course of the disease on patient and family alike.
242 citations
TL;DR: The adherent glycocalyx is one of the fundamental reasons for increased susceptibility to infection in the presence of biomaterials and compromised tissues and a significant factor in the persistence of such infection until the removal of the prosthetic device.
231 citations
TL;DR: In this paper, a modified form of one of the more promising adaptive control algorithms for power systems is developed and described, and compared results of studies with adaptive stabilizer based on two alternate adaptive control algorithm and a conventional fixed parameter stabilizer show the improvement in response obtained with the adaptive algorithm.
Abstract: Characteristics of certain adaptive control techniques are discussed in this paper with particular emphasis on their application to power systems. A modified form of one of the more promising algorithms that makes it more suitable. for power systems is developed and described. Comparative results of studies with adaptive stabilizer based on two alternate adaptive control algorithms and a conventional fixed parameter stabilizer show the improvement in response obtained with the adaptive algorithm.
210 citations
TL;DR: It is raised the exciting possibility that simple tests of colonization and digestion by specific cellulolytic bacteria (e.g. Bacteroides succinogenes) may provide the basis for the selection and optimization of treatments to increase the digestibility of barley straw, and later, even to provide theBased on the basis of the selection of barley cultivars whose straw is more easily digestible.
206 citations
TL;DR: In this paper, the steady state analysis of self-excited induction generators using balanced terminal capacitors is presented, where both operational and steady state equivalent circuits of the induction machine are employed to predict the steady-state performance under different load conditions.
Abstract: The paper presents a method for the steady state analysis of self-excited induction generators using balanced terminal capacitors. Operational and steady state equivalent circuits of the induction machine are employed to predict the steady state performance under different load conditions. The analytical procedure and the related computer program is described in the paper. Simulated results are presented and compared with corresponding results obtained experimentally.
185 citations
TL;DR: It is suggested that the hsp 70 gene is activated in corn by a variety of diverse stresses, being induced within 3 hours of the imposition of the stress, but declining after reaching a maximum at 9 hours.
Abstract: Exposure of the excised growing region of the mesocotyl of young corn seedlings to heat shock stimulated the production of specific heat shock proteins and the intensification of synthesis of two proteins with a molecular weight of approximately 70,000. Water stress and abscisic acid also stimulated synthesis of these 70,000-dalton proteins, and other unique proteins distinct from those induced by heat shock. Growing tissues of intact corn mesocotyls exposed to heat shock, water stress, or abscisic acid accumulated mRNA species homologous to a cloned genomic probe of the 5' end of the 70,000-dalton Drosophila heat shock protein gene. Since cut segments of the mesocotyl under unstressed conditions produced a similar mRNA, we suggest that the hsp 70 gene is activated in corn by a variety of diverse stresses. Production of the mRNA is rapid, but transient, being induced within 3 hours of the imposition of the stress, but declining after reaching a maximum at 9 hours.
180 citations
TL;DR: The Milan method of working with families includes a number of unique innovations, such as a pattern of creative teamwork that clearly separates the cognitive constructions of the therapist in contrast to the belief systems of the family, a style of interviewing that releases information latent in the family and some novel interventions that facilitate the family's capacity to discover its own nonsymptomatic solutions as mentioned in this paper.
Abstract: The Milan method of working with families includes a number of unique innovations. Among these are a pattern of creative teamwork that clearly separates the cognitive constructions of the therapist in contrast to the belief systems of the family, a style of interviewing that releases information latent in the family, and some novel interventions that facilitate the family's capacity to discover its own non-symptomatic solutions.
168 citations
TL;DR: The Milan systemic approach as mentioned in this paper was a significant advance in the field of family therapy and possibly in psychotherapy in general, and it has been widely used in the world of psychotherapy.
Abstract: The Milan systemic approach probably reflects a significant advance in the field of family therapy and possibly in psychotherapy in general. This, the first of two papers, provides a historical overview of the development of the approach, an articulation of some major assumptions and background theory, and a brief description of the overall pattern of practice.
TL;DR: Sediment cores up to 6.5 m in length from the South Arm of Great Salt Lake, Utah, have been correlated with radiocarbon ages and volcanic tephra layers indicate a record of greater than 30,000 years.
Abstract: Sediment cores up to 6.5 m in length from the South Arm of Great Salt Lake, Utah, have been correlated. Radiocarbon ages and volcanic tephra layers indicate a record of greater than 30,000 years. A variety of approaches have been employed to collect data used in stratigraphic correlation and lake elevation interpretation; these include acoustic stratigraphy, sedimentologic analyses, mineralogy, geochemistry (major element, C, O and S isotopes, and organics), paleontology and pollen. The results indicate that prior to 32,000 year B.P. an ephemeral saline lake-playa system was present in the basin. The perennial lake, which has occupied the basin since this time, rose in a series of three major steps; the freshest water conditions and presumably highest altitude was reached at about 17,000 year B.P. The lake remained fresh for a brief period, followed by a rapid increase in salinity and sharp lowering in elevation to levels below that of the present Great Salt Lake. The lake remained at low elevations, and divided at times into a north and south Basin, until about 8,000 year B.P. Since that time, with the exception of two short rises to about 1290 m, the lake level has remained near the present elevation of 1280 m.
TL;DR: The findings suggest that anaphylactic reactions to food proteins in the intestine lead to abnormalities of water and electrolyte absorption and that histamine, or other mast cell mediators, or both, may be responsible.
TL;DR: The lower William River in northwestern Saskatchewan, Canada, presents an excellent and unambiguous example of rapid channel adjustment to abrupt additions of sandy bed load as mentioned in this paper, with a relatively narrow and deep single-channel stream as it flows northward to Lake Athabasca, the river picks up a 40-fold increase of bed load over a 27 km reach as it encounters a large dune field just south of the lake.
Abstract: The lower William River in northwestern Saskatchewan, Canada, presents an excellent and unambiguous example of rapid channel adjustment to abrupt additions of sandy bed load. A relatively narrow and deep single-channel stream as it flows northward to Lake Athabasca, the river picks up a 40-fold increase of bed load over a 27-km reach as it encounters a large dune field just south of the lake. As a result of the large infusion of eolian sand, the channel develops a thoroughly braided pattern while undergoing a 5-fold increase in width and a 10-fold increase in width/depth ratio.
TL;DR: The authors described research related to the XV Olympic Winter Games to be held in Calgary, and provided an overview of a comprehensive ideal research program, initial economic impacts of the games are summarized, and findings from a May 1983 survey of Calgary residents are presented.
Abstract: This article describes research related to the XV Olympic Winter Games to be held in Calgary. An overview of a comprehensive ideal research program is given, initial economic impacts of the games are summarized, and findings from a May 1983 survey of Calgary residents are presented.
TL;DR: Antibiotics used to treat sequestered infections should be tested against populations of pathogens in intact biofilms to determine the ability of the antibiotics to penetrate the glycocalyces and to kill the component bacteria.
Abstract: The growth and survival mechanisms used by Pseudomonas aeruginosa in human infections are similar to those used by the organism in aquatic systems. P. aeruginosa attaches to inert solid or tissue surfaces and grows predominantly in biofilms that release mobile swarmer cells into the surrounding fluid phase. These natural and pathogenic biofilms are covered by an exopolysaccharide matrix (glycocalyx) that serves as a barrier against hostile environmental factors, such as host defense mechanisms and antibiotics. Glycocalyx-enclosed biofilms of P. aeruginosa or other bacteria have been identified in experimental or clinical infections arising from contaminated prostheses and in chronic refractory infections, such as endocarditis, osteomyelitis, and P. aeruginosa pneumonia associated with cystic fibrosis. Conventional in vitro antibiotic susceptibility tests are directed against unprotected, mobile, swarmer cells. Antibiotics used to treat sequestered infections should be tested against populations of pathogens in intact biofilms to determine the ability of the antibiotics to penetrate the glycocalyces and to kill the component bacteria.
TL;DR: Evidence is obtained by these different spectroscopic techniques that poly(G-C)·poly(C) undergoes a transition from the A-form to a left-handed Z-form in conditions of high ionic strength and at temperatures above 35°C, of relevance to the biological situations in which double-stranded RNA occurs.
Abstract: In contrast to double-stranded DNA, there has so far been little evidence that double-stranded RNA can undergo major conformational transitions. We have investigated the conformation in different conditions of the double-stranded RNA molecule poly(G-C).poly(G-C), by NMR, circular dichroism and absorbance spectroscopy. We report here evidence obtained by these different spectroscopic techniques that poly(G-C).poly(G-C) undergoes a transition from the A-form to a left-handed Z-form in conditions of high ionic strength and at temperatures above 35 degrees C. This conformational transition may be of relevance to the biological situations in which double-stranded RNA occurs, such as in ribosomes and in some viruses.
TL;DR: The activity of TiO2 can be precisely defined as a function of pressure, temperature and activities of other components for common mineral assemblages in metapelites and metabasites.
Abstract: The activity of TiO2 can be precisely defined as a function of pressure, temperature and activities of other components for common mineral assemblages in metapelites (ilmenite-quartz-garnet-plagioclase-Al2SiO5) and in metabasites (plagioclase-sphene-ilmenite-quartzgarnet). These mineral assemblages can be modelled by the equilibria: 1) 3ilmenite+Al2SiO5+2quartz=almandine+3TiO2 2) anorthite + 2sphene = grossular + 2TiO2 + quartz 3) 3anorthite+3quartz+6ilmenite = grossular+ 6TiO2+2almandine. These mineral assemblages can be used at \(a_{{\text{Tio}}_{\text{2}} } = 1\) (rutile saturation) and a given T to get maximum pressure limits of some metapelites and metabasites. When electron microprobe analyses of mineral grains adjacent to Ti-bearing phases are made, these data give maximum pressure estimates in reasonable agreement with other geobarometers. The activity of TiO2 in many metapelites is very near rutile saturation, but for metabasites the activity of TiO2 in some sillimanite zone rocks is as low as 0.6. The solubility of TiO2 in biotite, hornblende and garnet is a complex function of T, P, the activities of components in coexisting minerals and crystal chemical constraints in these minerals. At a given P and T the solubility of TiO2 in biotite and hornblende does not appear to be strongly dependent upon \(a_{{\text{Tio}}_{\text{2}} } = 1\) for sphene and ilmenite versus rutile-bearing assemblages.
TL;DR: In institutionalized elderly men permanently resident on two wards of a veterans' hospital, infections occur more frequently in residents who have greater functional impairment and mortality is common only with pneumonia.
Abstract: Surveillance of infectious episodes in institutionalized elderly men permanently resident on two wards of a veterans' hospital was undertaken for a 12-month period. One-hundred eleven episodes were identified in 50 residents (74 per cent). The most frequent infections included lower respiratory tract infections (incidence 59/100 patient-years), febrile episodes with no source (43.4), skin and soft tissue infections (36.5), and gastroenteritis (33). Only pneumonia was associated with significant mortality. A specific etiologic agent was seldom identified other than for skin and soft tissue infections. Antimicrobial therapy was prescribed for 87 per cent of all infections. Ward staff absenteeism was associated with peak occurrences of infections in residents. Resident characteristics that correlated with infection were incontinence of bladder and of bowel. Mental status or degree of mobility did not correlate. While infections occur frequently in this population, mortality is common only with pneumonia. Infections occur more frequently in residents who have greater functional impairment.
TL;DR: Results indicate that parietal and visceral endoderm cells actively express the metallothionein gene and further suggest that expression may be initiated at the earlier stage of primitive endODerm.
01 Jan 1984
Journal Article•
TL;DR: It was concluded that vasodilator doses of dopamine and Epi decrease oxygen delivery to the intestine at least in part due to a decrease in mucosal blood flow; this probably involves action on alpha adrenoreceptors.
Abstract: Mesenteric blood flow returned to control values promptly upon termination of i.a. infusions of vasodilator doses of acetylcholine (ACh) and isoproterenol (Iso) into the canine superior mesenteric artery (SMA). However, termination of vasodilator infusions of dopamine (DA) and epinephrine (Epi) into the SMA resulted in an additional increase in flow resembling the reactive hyperemic response observed upon termination of norepinephrine infusion into the SMA. In experiments that measured the effect of these agents on intestinal oxygen kinetics, i.a. ACh and Iso increased oxygen uptake but did not affect percent oxygen extraction. Equivasodilator i.a. infusions of DA and Epi decreased percent oxygen extraction. DA decreased oxygen uptake whereas Epi did not alter oxygen uptake. After administration of phenoxybenzamine, the effects of i.a. DA and Epi on oxygen kinetics became identical to those produced by equivasodilator infusions of ACh or Iso. Moreover, the reactive hyperemia-like response on cessation of DA and Epi infusions was abolished. In experiments that utilized 125I absorption from the jejunum as a measure of intestinal mucosal blood flow, i.a. ACh and Iso were found to increase mucosal blood flow in proportion to the increase in total SMA flow. In contrast, i.a. doses of DA and Epi that increased SMA flow nevertheless decreased mucosal flow. It was concluded that vasodilator doses of dopamine and Epi decrease oxygen delivery to the intestine at least in part due to a decrease in mucosal blood flow; this probably involves action on alpha adrenoreceptors.
TL;DR: In this article, a comparative study of the dry thermolysis of tetrahydrothiophene has been carried out and a mechanism for this reaction is proposed and investigations into the aqueous decomposition of butanal have been conducted to support this mechanism.
TL;DR: It is shown that if G is a simple graph on n 1 + n 2 vertices and the minimum degree of G, δ ( G), is at least 1, then G contains two independent circuits of lengths n 1 and n 2.
TL;DR: Survival was significantly improved for patients treated with MDF compared to patientstreated with CF and the addition of MISO to MDF did not result in further improvement in survival.
Abstract: Multiple daily fractionated radiation therapy (MDF) may be more effective than conventionally fractionated radiation therapy (CF) in the treatment of malignant glioma. The hypoxic cell sensitizer misonidazole (MISO) could be more effective when employed with small fractions of radiation every 4 hours to take advantage of the long half-life of the drug. To evaluate MDF and MDF in combination with MISO, a randomized prospective trial was initiated. Between January 1981, and December 1982, patients with histologically verified astrocytoma with anaplastic foci or glioblastoma multiforme were randomized to CF (5800 cGy, 30 fractions, 6 weeks), MDF (6141 cGy, 69 fractions, 4 1/2 weeks, at 89 cGy every 4 hours 3 times daily) and MDF in combination with MISO (1.25 gm/M2 three times weekly for the first 3 weeks). In January 1983, the CF arm was dropped and a high dose MDF arm added (7120 cGy, 80 fractions, 5 1/2 weeks, at 89 cGy per fraction every 4 hours 3 times daily). CCNU chemotherapy was given at the time of tumor progression. One hundred and twenty-eight patients were evaluated (38 CF, 42 MDF, 37 MDF plus MISO, and 11 high dose MDF). Median survival was 29 weeks for CF, 45 weeks for MDF and 50 weeks for MDF plus MISO. Survival was significantly improved for patients treated with MDF compared to patients treated with CF (p less than .002). The addition of MISO to MDF did not result in further improvement in survival. Acute toxicity was acceptable. No clinically apparent delayed toxicity was observed.
01 Jan 1984
TL;DR: In this paper, le processus electrochimique faisant intervenir des intermediaires de reaction qui sont des dimeres complexes adsorbes sur l'electrode and on essaie d'identifier la nature.
TL;DR: Evidence that proteoglycans are involved in cell adhesion and related behavior is considered, together with their putative role(s) during tumorigenesis, and data suggest any putative roles will be related to the adhesive properties that these molecules confer to cells.
Abstract: In this review, evidence that proteoglycans are involved in cell adhesion and related behavior is considered, together with their putative role(s) during tumorigenesis. Proteoglycans are large, carboxylated and/or sulfated structures that interact with specific binding sites on cell surfaces. Their distribution and synthesis in tissues alter with the onset of tumorigenesis so that hyaluronic acid is generally increased and heparan sulfate decreased in the developing tumor and surrounding tissue. However, the precise role of proteoglycans during the tumorigenic process is far from clarified. Data suggest any putative roles will be related to the adhesive properties that these molecules confer to cells. Hyaluronic acid and chondroitin sulfate appear to be weakly adhesive molecules that may promote ‘transformed’ characteristics when they occur on cells in large amounts. These characteristics include reduced cell spreading, increased cell motility, as well as reduced contact inhibition. Consistent with such properties, neither hyaluronic acid nor chondroitin sulfate are localized in specialized adhesion sites such as focal or close contacts. In contrast, heparan sulfate is associated with increased cell-substratum adhesion and is involved in the spreading of cells onto fibronectin and other substrata. Its presence is generally associated with reduced motility and with a well-spread morphology. Unlike hyaluronate and chondroitin sulfate, heparan sulfate is found in specialized contacts. These adhesive properties of proteoglycans predict an instructive role in tumor development, and recent experiments have defined an involvement of these molecules in metastatic arrest. Additional studies utilizing invasive and metastatic tumor variants including tumor cells that employ different mechanisms to invade are required to clarify the role of proteoglycans in tumor progression.