Showing papers by "University of Manitoba published in 1983"
TL;DR: Gupta and Sidki as mentioned in this paper gave a direct construction of an infinite p-group on two generators, each of order p, which is a subgroup of the automorphism group of a regular tree of degree p.
Abstract: Narain Gupta 1,. and Said Sidki 2 1 University of Manitoba, Department of Mathematics, Winnipeg, Manitoba R3T 2N2, Canada 2 University of Brasilia, Department of Mathematics, Brasilia, D.F., Brazil Introduction The generalized Burnside problem refers to the question: Are finitely generated periodic groups finite? This was answered in the negative by Golod [1] who proved that, for each prime p, there exists a finitely generated infinite p-group. Golod's construction in not, however, direct and is based on his celebrated work with Safarevi~. Recently, Grigor~uk [2] has given a direct and elegant construction of an infinite 2-group which is generated by three elements of order 2. In this paper we give, for each odd prime p, a direct construction of an infinite p-group on two generators, each of order p. Our group is a subgroup of the automorphism group of a regular tree of degree p; and as might be expected, it is residually finite and has infinite exponent. Preliminaries. Let p be an odd prime and let T(0) be the infinite regular tree of degree p with vertex 0, so that through each vertex u of T(0) there are p regular subtrees
308 citations
TL;DR: In this paper, the Friedel model is used to evaluate the strength of a single pin in the presence of a wall breakaway from a single wall. But the model is not applicable to the case where the wall is not independent of the applied field.
Abstract: The pinning site inhomogeneities interacting with a domain wall are characterized by the maximum restoring force, f, acting on an area A of domain wall. The critical field, H 0, required to release this area from the pin is given by f/2IA where I is the magnetic moment per unit volume. The area A is not independent of the applied field H and a statistical treatment is required to evaluate it. The Friedel ‘steady state’ model assumes that the volume swept out when a wall breaks away from a pin contains, on average, one replacement pin. This leads to the relation A ∝ 1/H 1/2 and hence to the critical field H 0 = 3ρf 2/(4πγI) where ρ is the pin density and γ is the wall energy per unit area. If the parameter β0 = 3f/(8πγb) > 1, where 4b is the interaction range of the pin, then the Friedel model holds and the pinning is ‘strong'. If β < 1 the Friedel model breaks down and the pinning is ‘weak'. The unpinning process is then no longer connected with unit steps related to breakaway from single pins bu...
239 citations
TL;DR: It is proposed that free radical mediated increase in lipid peroxide activity may have a role in catecholamine-induced heart disease.
Abstract: Results of clinical and experimental animal studies have shown that unusually high levels of catecholamines in the blood cause a variety of morphological and functional changes in the heart (1, 18, 22, 25, 28). The endogenous stores of adenine triphosphate and creatine phosphate are depleted (8, 25, 26) and mitochondrial structure-function is impaired (7, 15). Intracellular increase in calcium has been considered to be a determinant factor in this as well as in variety of other models of heart cell damage (8, 21). In this regard catecholamine-induced cardiomyopathy, has been shown to be accompanied by a significant increase in the myocardial calcium content (8,15) indicating changes in the membrane permeability. Strong evidence for the alterations in the permeability of sarcolemma due to isoproterenol treatment was provided by the intracellular diffusion of horseradish peroxidase, an extracellular protein tracer, following the drug injection (19).
234 citations
TL;DR: It is suggested that BRC suppressed immunity by its inhibition of PRL, and possibly also by inhibition of GH secretion.
227 citations
TL;DR: In this article, secondary ion (CsI)/sub n/Cs)/sup +/ bombardment of CsI was produced by 8-keV Cs/sup+/ bombardment.
Abstract: Secondary ions ((CsI)/sub n/Cs)/sup +/, with n up to approx.40, were produced by 8-keV Cs/sup +/ bombardment of CsI. The yield of clusters decreased smoothly with n when observed in a time-of-flight mass spectrometer at effective times approx.0.2 ..mu..s after emission. Clusters with n>7 were found to be metastable, with lifetimes <<100 ..mu..s. A large anomaly in the population of the disintegration products was measured at approx.70 ..mu..s after emission, n = 13 clusters being favored and n = 14 and 15 suppressed. .ID LV2149
183 citations
TL;DR: The authors compared the relative effectiveness of sexuality variables versus attitudes hypothesized to be rape-supportive in the prediction of "likelihood to rape" (LR) and "like likelihood to use sexual force" (LF) measures.
179 citations
TL;DR: This article found that backward consequence inference is more reliably drawn during the course of reading than are forward consequence inferences, and that backward inference contributes to the coherence of a message more than forward inference.
171 citations
TL;DR: The kinetic disposition of morphine was compared in 13 young and 7 older healthy subjects after a single intravenous dose of 10 mg/70 kg morphine, and it was indicated that drug concentration in this kinetic space was higher in older subjects for 1.5 hr after dosing.
Abstract: The kinetic disposition of morphine was compared in 13 young and 7 older healthy subjects after a single intravenous dose of 10 mg/70 kg morphine. The apparent volume of distribution at steady state in elderly subjects was only half of that in young subjects. This difference was derived from reductions in both central and peripheral kinetic compartment volumes in the older subjects. The beta elimination phase for morphine was more rapid, but its plasma clearance was reduced in older subjects. Calculation of the peripheral compartment morphine concentration for these subjects indicated that drug concentration in this kinetic space was higher in older subjects for 1.5 hr after dosing.
170 citations
TL;DR: In this article, the use of small particles instead of thin films has some advantages for the study of the magnetic properties of surfaces, such as surface anisotropy and interfacial interactions.
158 citations
TL;DR: In this paper, the authors discuss the extent of the erosion of the traditional notion of consciousness by recent empirical findings and suggest that a similar fate may befall concepts respected and revered in our own prevailing conception of how humans works, and the concept on which they focus is consciousness.
Abstract: It sometimes happens in the history of science that well-used, highly entrenched, revered and respected concepts come unstuck. That is, under the suasion of a variety of empirical-cum-theoretical forces, certain concepts lose their integrity and fall apart. Their niche in the theoretical and explanatory scheme of things is reconstructed and reconstrued, and new concepts with quite different dimensions and dynamics come to occupy the newly carved niche. The ‘spirits’ and ‘prin ciples’ of alchemy, the ‘crystal spheres’ of pre-Galilean astronomy, ‘daemonic possession’ of Medieval medicine, ‘phlogiston’, ‘ether’, and ‘signatures’, are now nought but dry bones of an earlier intellectual ecology. The theme of this paper is that a similar fate may befall concepts respected and revered in our own prevailing conception of how humans works, and the concept on which I mean to focus is consciousness. To the degree that there are already afoot misgivings about the integrity of the traditional conception of consciousness, some of the problems discussed will be familiar, especially to psychologists. But the extent of the erosion of the concept by recent empirical findings is, I suspect, greater than hitherto reckoned. The aspects of the orthodox concept which I shall discuss include the alleged transparency of the mental, the supposed unity of conscious ness and the idea of the self, and the allegedly special relation thought to obtain between language and consciousness.
TL;DR: In kindled rats, immunoreactive somatostatin was increased significantly in amygdala, sensorimotor, piriform, and entorhinal cortex, and the results suggest that changes in som atostatin may be associated with epileptic susceptibility induced by the electrical kindling procedure.
TL;DR: TheAnkylosed osteoporotic spines of patients with long-standing ankylosing spondylitis are prone to fracture and management may be conservative or surgical and is complicated by increased instability of the fracture site, spinal osteoporeosis, and deformity.
Abstract: Twenty-two spinal fractures in 20 patients with chronic ankylosing spondylitis are reported. Nineteen fractures occurred in the cervical region. Fourteen of the fractures were caused by minor falls, 3 by falls down steps, 4 by motor vehicle accidents, and 1 by cardiopulmonary resuscitation. Long-term followup (mean 3.2 years) of 9 fractures diagnosed early and managed conservatively showed bony union of all fractures. No patient deteriorated neurologically and 3 patients made major recovery. Long-term followup is also reported on 6 patients in whom the diagnosis was delayed. The difficulties in diagnosis and management are discussed.
TL;DR: Ease in interfacing user written control system models with the network solution is presented along with discussion of means to simplify dc valve group representation in simulation.
Abstract: This paper discusses the digital simulation of HVDC transmission and ac machines by an electromagnetic transients computer program. Ease in interfacing user written control system models with the network solution is presented along with discussion of means to simplify dc valve group representation in simulation. A working digital simulator has been developed enabling flexible in-house studies to be undertaken. Test results of its performance are presented.
TL;DR: This procedure provides a simple and reliable method for the quantitation of uric acid in avian excreta and is compatible with a recently developed high-performance liquid chromatographic procedure.
TL;DR: It is demonstrated that the mechanism of autoregulation is functionally developed in the mature fetal lamb, but operationally dependent upon arterial oxygen concentration.
Abstract: Summary: We examined autoregulation of cerebral blood flow (CBF) over the range of oxygen tension commonly observed in the chronic fetal lamb preparation. Seventeen animals were surgically prepared under general anesthesia for chronic in utero studies. Based on measured resting arterial Po2 and calculated % saturation 24–48 h after surgery, two groups were defined: a normoxic group of eight with saturation of 57% or higher (our laboratory normal for physiologically stable preparations) and an hypoxic group of nine with saturation less than 57%. Regional CBF was measured with radiolabeled 15-μm microspheres. Autoregulation of CBF was assessed by measuring the change in CBF when fetal mean arterial blood pressure (MABP) was acutely decreased and increased by withdrawal and reinfusion of fetal blood. In normoxic animals CBF was constant over an MABP range of 42–61 torr in all four areas of the brain examined: cerebral hemispheres, basal ganglia, cerebellum, and brain stem. In hypoxic animals CBF was pressure dependent in all areas over an MABP range of 46–73 torr, i.e., autoregulation was abolished. These studies demonstrate that the mechanism of autoregulation is functionally developed in the mature fetal lamb, but operationally dependent upon arterial oxygen concentration. Below a saturation of approximately 50–60% CBF varies directly with perfusion pressure.
TL;DR: Of 300 men in Nairobi, Kenya, with culture-proven chancroid, 57% had acquired infection from prostitutes, and no evidence of transmission of H ducreyi by women without clinical Chancroid was detected.
TL;DR: In a double-blind trial, the efficacy and safety of inhaled salbutamol (albuterol), nebulized with oxygen by face mask, and subcutaneous epinephrine in 40 children with acute asthma were compared.
TL;DR: Two fababean cultivars were germinated over a 10-day period and the levels ofphytate and activity of phytase monitored and in both cultivars there was a marked increase inphytase activity which was accompanied by a concomitant decrease in phytate.
Abstract: Two fababean cultivars were germinated over a 10-day period and the levels of phytate and activity of phytase monitored. In both cultivars there was a marked increase in phytase activity which was accompanied by a concomitant decrease in phytate. The enzyme level reached a maximum 6 days following germination and was much higher in Ackerperle compared to Diana. Nevertheless a marked reduction in phytate levels was evident at the end of 10 days which accounted for a decrease of 71.2% and 77.3% in Ackerperle and Diana, respectively.
TL;DR: The results show that endogenous immunoreactive somatostatin has a role in the development of seizures in amygdaloid kindled rats.
TL;DR: GH (GHR) and lactogenic receptors were analyzed after use of the cross-linking reagent ethylene glycol bis-(succinimidyl succinate) to attach covalently iodinated human GH (hGH) to binding proteins 1) on intact IM-9 lymphocytes, 2) in a partially purified GHR preparation from rabbit liver, and 3) in crude microsomal fractions from rabbit Liver, rabbit mammary gland, and rat liver.
Abstract: GH (GHR) and lactogenic receptors were analyzed after use of the cross-linking reagent ethylene glycol bis- (succinimidyl succinate) to attach covalently iodinated human GH (hGH) to binding proteins 1) on intact IM-9 lymphocytes, 2) in a partially purified GHR preparation from rabbit liver, and 3) in crude microsomal fractions from rabbit liver, rabbit mammary gland, and rat liver. The latter two microsomal preparations contain primarily lactogenic receptors, whereas in IM-9 lymphocytes and the rabbit liver preparations, GHR predominate. Cross-linked [125I]hGH-receptor complexes were solubilized, reduced, and separated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Analysis of proteins cross-linked to [125I]hGH in the microsomal fraction from rabbit liver showed a specifically labeled complex with an estimated molecular weight (mol wt) of 75K. A slightly lower mol wt (71K) was determined for the complex labeled in the purified GHR preparation. In contrast to the relatively low mol wt comple...
TL;DR: The authors found that ratings of career attractiveness and willingness to refer vary in sex-role stereotypic directions as a function of degree of exposure to sexist language, and found that women rated the attractiveness of a career in psychology for males and females, and their own tendency to refer a male or female friend to a psychologist.
Abstract: Despite recent efforts to eliminate sexist language from journal and other publications, controversy persists over whether sexist language contributes to the perpetuation of sex bias. Seventy-two female and 57 male undergraduates were exposed to three levels of sexist noun and pronoun usage in a description of “Ethical Standards of Psychologists.” All subjects then rated the attractiveness of a career in psychology for males and females, and their own willingness to refer a male or female friend to a psychologist. In several instances, ratings of career attractiveness and willingness to refer were found to vary in sex-role stereotypic directions as a function of degree of exposure to sexist language. Recent demands for nonsexist language may be supportable on the basis of a genuine relationship between sexist language and the maintenance of sex-biased perceptions.
TL;DR: The dominant physical and chemical processes which are responsible for and act upon the sediment vary widely, mainly in response to basin morphology and brine chemistry as mentioned in this paper, and experimental data suggests mixed layer smectites may form authigenically in some lakes.
Abstract: Southern Saskatchewan and portions of adjacent Alberta, North Dakota and Montana are occupied by hundreds of saline and hypersaline lakes ranging in size from small prairie potholes (less than 1 km2) to relatively large bodies of water (greater than 300 km2). From a sedimentological perspective, distinction must be made between two basic types of saline lakes: playas and perennial lakes. Calcium, sodium and magnesium sulfates, carbonates and bicarbonates form as chemical precipitates in lakes with more concentrated brines. In addition, experimental data suggests mixed layer smectites may form authigenically in some lakes. Clastic sediments in the salt lakes consist mainly of silt and clay-sized quartz, feldspars, carbonates and clay minerals. The dominant physical and chemical processes which are responsible for and act upon the sediment vary widely, mainly in response to basin morphology and brine chemistry. Evaporative concentration and significant groundwater contributions affect all the saline lakes. However, other processes are different in the two basic types of basins. The playa lakes are influenced by: evaporitic pumping and the formation of efflorescent crusts and intrasedimentary crystals, cyclic wetting and drying, precipitation of highly soluble salt layers, and influx of clastic debris by sheetflood and wind. In contrast, in the permanent lakes, precipitation of sparingly soluble salts occurs due to the interaction of biological activity, seasonal temperature fluctuations and brine mixing. In addition, many of the permanent lakes undergo freeze-out precipitation of very soluble salts under a winter ice cover. Detrital sediments are distributed within the basins by normal lacustrine processes, including shoreline deposition and erosion, turbidity flow and pelagic fallout.
TL;DR: In this article, the authors argue for the utility of a peer, intergenerational distinction, highlighting nonfamily age peers as an important but relatively neglected area of study, and present empirical data exploring these concepts.
Abstract: This article points to the current popularity of a family-nonfamily conceptual distinction in current gerontological research. It argues for the utility of a peer, intergenerational distinction, highlighting nonfamily age peers as an important but relatively neglected area of study. It presents empirical data exploring these concepts. It is only after a diversity of types of supports are examined (including availability of social support, interaction in and satisfaction with these relationships, and participation in various recreational activities) that the particular importance of nonfamily age peers becomes apparent. The data indicate the importance of these concepts, differentially, depending on the activity and type of interaction examined.
TL;DR: In this article, the asymptotically stable motion of two rigid masses separated by a clearance is formulated most generally when the masses collide periodically, and a technique is proposed for determining a clearance's dimensions in situ which could provide a basis for detecting progressive wear in mechanisms like gear trains.
TL;DR: The experiments indicate that the pituitary gland has the potential of regulating contact sensitivity and treatment with prolactin or growth hormone antagonizes restoration of Hypo‐X rats.
Abstract: Hypophysectomized (Hypo-X) rats do not develop contact sensitivity to dinitrochlorobenzene (DNCB). Daily treatment with prolactin or growth hormone completely restores the DNCB-reactivity of Hypo-X animals. Treatment of such animals with ACTH, FSH, LH, TSH or HCG has no restoring potential. Treatment with ACTH in addition to prolactin or growth hormone antagonizes restoration of Hypo-X rats. These experiments indicate that the pituitary gland has the potential of regulating contact sensitivity.
TL;DR: The data suggest that alcohol has a specific toxic effect on the fetal brain that is not linked with smoking habits and the neonatal electroencephalogram is affected even in the absence of dysmorphology and thus may be the most sensitive indicator of fetal alcohol toxicity.
TL;DR: The investigation of patient satisfaction while limited in the critical information it can provide for the evaluation of services, will help pinpoint areas where the most patient dissatisfaction exists and Methodological suggestions to improve the validity of the data gathered are concluded.
Abstract: The survey of patient satisfaction with the mental health services provided is recommended but involves a methodological dilemma. Concerns include a definition problem, the delineation of a representative sample, the selection of a survey technique and the type of questions to be used. A literature review and the authors' own experience with the process are presented. The investigation of patient satisfaction while, as yet, limited in the critical information it can provide for the evaluation of services, will help pinpoint areas where the most patient dissatisfaction exists. The process can also be useful therapeutically, but patient satisfaction, although an important outcome measure, is not systematically related to other measures of treatment success. Methodological suggestions to improve the validity of the data gathered conclude the paper.