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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.

The development and evaluation of a selective medium for clostridium bifermentans

de Pascale, Biagio A. 16 November 1999 (has links)
A selective agar medium was developed for the isolation of Clostridium bifermentans. The formulation of the C. bifermentans selective agar (CBSA) was a modification of C. botulinum isolation agar (CBI) medium. The modifications included: a) change of the base medium to promote growth of C. bifermentans, b) increase of antimicrobial concentrations to improve selectivity and, c) lowering of the egg yolk concentration to lower the cost. The CBSA medium contains cycloserine (375 µg/ml), sulfamethoxazole (114 µg/ml) and, trimethoprim (6 µg /ml) as selective inhibitory agents. Quantitation of C. bifermentans strains on CBSA yielded counts comparable to those obtained on egg yolk agar control plates. The increased concentration of the selective agents in CBSA suppressed the growth of the lecithinase producing C perfringens, C. sordellii and other fecal organisms tested. Isolation of C. bifermentans from 20 seeded fecal specimens was readily achieved. The CBSA medium permits quantitative recovery of lecithinase positive colonies of C. bifermentans from human feces and can be used for large scale screening of various clinical specimens.

Frecuency and value of role performance in the Icelandic population

Fenger, Kristjana 20 May 1998 (has links)
Roles organize occupational behavior. They influence time use, performance, manner, style, and content of interaction with others. It is assumed that knowledge of occupational role performance in the general population of Iceland will enable occupational therapists to be more effective in enabling a client's role performance. The purpose of this study was to add to the Icelandic occupational therapists' knowledge base about role performance among the Icelandic population. A random sample of 149 Icelandic subjects, with an age range of 18 to 75 years, was surveyed about the frequency, value, and change in value of role performance in ten occupational roles over time. Results indicated that the most frequently performed roles were: worker, family member, home maintainer, caregiver, and friend. The most valued roles were family member, worker, caregiver, friend, and student. Significant differences were found between various demographic variables and the frequency and value of occupational role performance.

Designing a Service Framework for Electronic Personal Health Records: A Patient-Centred Approach

Leyland, Margaret January 2010 (has links)
<p>With the increase in diabetes prevalence and the resultant greater demand for diabetes services, together with fewer resources to pay for them, diabetes has become a multi-billion dollar economic burden the world over. Electronic personal health records (ePHRs) have been positioned as transformational agents that facilitate productive interactions between patients and their healthcare providers, and support self-management of chronic diseases such as diabetes. In keeping with a patient -centred model of care, healthcare services such as ePHRs that incorporate patients' preferences and level of activation are being sought to increase and sustain patients' utility of these services. This study examines patients' preferences for the attributes of an ePHR service that supports diabetes self-management. It also explores factors that might influence their preferences. Conjoint analysis, one of the most widely used approaches to predict consumer preferences was chosen for this study. Specifically, adaptive choice-based conjoint analysis was used to identify the attributes of a winning ePHR service framework. Using Sawtooth Software's suite of interviewing products, a webbased survey was developed comprising six ePHR service attributes. Hierarchical Bayes estimations were used to quantify patient preferences while latent class analysis was used to segment the sample. Additional statistical analyses were conducted to identify any significant relationships between patient characteristics and their preferences. A stratified sample of 150 patients with Type 1, Type 2, and Prediabetes were unwavering in their preference for an internet-based ePHR service supplied by a physician or specialist. They also preferred to exchange their health information with their physician or nurse, once a month, at no cost. Monthly service fees were considered the most important ePHR service attribute. These results were applied in market simulations and sensitivity analyses to uncover the more complex effects of the ePHR attributes on the overall utility of the service. Exchanging health information every two to three months as opposed to once a month, and offering an ePHR service in the form of a monitoring device as opposed to an internet-based application, may be viable options. Selling an ePHR service directly to patients via a commercial supplier had negative impact on the utility of the service. This research also indicated that it would be prudent to take patients' ages and perceived health status into consideration when developing and marketing an ePHR service. Surprisingly, patients' level of activation for self-management did not appear to playa major role in influencing their preferences for the attributes of the ePHR service framework identified in the study.</p> / Master of Science (MS)

The Meaning of Spirituality to Person with Schizophrenia: A Hermeneutic Inquiry

Cavey, Ann Nina 05 1900 (has links)
<p>This study sought to explore the meaning of spirituality to individuals living with schizophrenia. Gadamer's philosophy of understanding underpinned this hermeneutic inquiry. The study took place in a community-based psychosocial rehabilitation program in an urban Canadian setting. The sample included 7 English-speaking men and women, ages 25 to 49, who had not been hospitalized for six months or more. Methods involved hermeneutic analysis of verbatim transcripts of open-ended individual interviews. Four major themes were identified: the fractured self: the meaning of a "spiritual holocaust"; the vortex: the meaning of a subverted spirituality; the emergent self: the meaning of spiritual cohesion; and the nurtured self: the meaning of spiritual practices. Findings demonstrated the high value ascribed to spirituality in the lives of participants, regardless of whether they had a religious affiliation. Spirituality was seen as the fundamental connecting force that maintains the integrity of the self against the fragmenting effects of the illness. Participants felt this connectedness could be profoundly challenged as spirituality interacts with delusions. Nevertheless, spiritual connections within the individuals' life stories, with their community and with God provided the stability that helped them develop a robust sense of self while living with the illness. Implications for practice include the need to courageously support consumers in their spiritual meaning- making. Research recommendations encourage replication of this study in a more diverse population in terms of religious affiliation and an exploration of the spiritual meaning of music and art to persons with major mental illness.</p> / Master of Science (MSc)

Extinction to Double Stimutaneous Stimulation and Hemispace Lateralization

Herman, Wilhemine Maria Edith January 1987 (has links)
<p>Extinction to Double Simultaneous Stimulation (EDSS) is a perceptual disorder which occurs with varying frequency following lateralized brain lesions, predominantly in the rifht parietal lobe. Correlated with impaired functional recovery of hemiplegic patients, the phenomenon is characterized by faulty or non-recognition of stimuli on the side of opposite to that of the damaged cerebral hemisphere where these stimuli are presented simultaneously with stimuli on the ipsilesional side. Yet the phenomenon cannot be explained by a simple sensory deficiency since a patient who manifests the syndrome correctly identifies the same stimuli on unilateral presentation. EDSS is considered a (milder) sanifestation of the 'neglect' syndrome, that is, the tendency to neglect the contralesional half of the body and space following brain damage. Although known for a full century, the psychoshysiologic mechanisms underlying the syndromes of EDSS and 'neglect' are still poorly understood and many hypotheses remain speculative. Investigation of an underlying mechanism seems essential for the development of treatment strategies aimed at ameliorating the syndrome and thereby conceivably enhancing the rehabilitation potential of this patient group. Although the unilateral neglect of stimuli may involve different sensory modalities, the present study focuses on somatosensory stimuli. The purpose of the present study was two-fold: first, to test two prevailing theories which account for the syndrome of EDSS in hemiplegic patients, and to distinguish between the respective hypotheses; second, to investigate hemispheric asymmetries in the perception of somatosensory stimuli prior to brain injury as a possible basis for the development of unilateral hemineglect after brain lesions. The postulated mechanisms underlying EDSS, stimulus properties and the hemispace in which the stimuli occur, were therefore tested in both a clinical as well as a neurologically intact population. The research questions were addressed in two parts of the study: in study A, electrical stimuli at perception threshold, systematically varied with respect to duration and the hemispace in which they were delivered, were presented to 68 subjects free of neurological disease (34 males, 34 females). The subjects; report of perceived stimuli was recorded and errors of detection were analyzed. In study B, a similar procedure was performed on 19 hemiplegic patients manifesting EDSS. The results indication that both sensory characteristics and attentional factors influence perception. The findings of study A suggest that: 1. The hemispace in which stimuli are presented play a significant role in their perception. 2. A left hemispace advantage appears to be pre-eminent in females. 3. The right hemisphere may be a better 'watchkeeper' for stimuli directed to the left hemisphere that the left hemisphere is for stimuli directed to the right hemisphere. In hemiplegic patients (study B), neither of the two tested theories could account by itself, under the experimental conditions of the present study, for the syndrome of 'extinction'. Based on the present findings, EDSS is viewed as a deficiency in neurointegrative functioning altering the physiological processing of stimuli.</p> / Doctor of Philosophy (PhD)

Changes in Burst and Spike Propgagtion Associated with Gap Junction Formation in Myometrium at Parturition

Miller, Michael Steven 11 1900 (has links)
<p>The factors regulating the uterus in the maintenance of pregnancy and the onset of labor are two important and unresolved problems in uterine physiology. At term, specialized cell-to-cell contacts, gap junctions, appear between the uterine smooth muscle cells. These structures are thought to allow direct passage of ions and small molecules between cells thus their formation between uterine smooth muscle cells at term may promote propagation of electrical activity and development of contractile synchrony in the uterine wall, necessary for expulsions of the fetus(es). The objective of this thesis was to examine the possible functional role of gap junction formation in the myometrium at parturition. The hypothesis that gap junction formation results improved electrical excitation (which give an indirect measure of cell-to-cell electrical coupling_ in the myometrium before (i.e. at preterm) and after (i.e. at delivery) in situ gap junction formation. Some of the tissues used for these experiments were examined by thin section electron microscopy for the presence of gap junctions. Spontaneous burst discharges propagated other the entire recording distance of 15mm in the longitudinal axis of the myometrium at both preterm and at parturition. Burst activity at both times showed some of the characteristics of a system of coupled relaxation oscillators. However, individual spikes within the bursts propagated further with higher velocity in this axis at parturition as compared to at preterm. In the transverse axis of the myometrium, both bursts and individual spikes within bursts propagated over longer distances at parturition than before. Propagation in this axis at parturition appeared to require an intact or undamaged circular muscle layer. Analysis of the propagation of spikes evoked by electrical stimulation confirmed that spike propagation was improved (e.g. higher velocity and long distance spread) in both the longitudinal and transverse axes of the myometrium at parturition. Electron microscopy studies confirmed that gap junctions were present in large numbers between uterine smooth muscle cells during parturition and were absent or present in very small numbers at preterm. Thus, improved propagation of electrical discharges was associated with an increase in gap junction contact between myometrial cells. These results are consistent with the hypothesis that gap junction formation at the term results in improved electrical coupling of the uterine smooth muscle cells.</p> / Doctor of Philosophy (PhD)

Characterization of the Responses of Human Synovial Fibroblasts In Vitro

Agro, Albert 06 1900 (has links)
<p>The synovial membrane (SM) is a specialized tissue which lines the joint capsule surrounding the interface between bone and cartilage. The intimal layer of the SM, a 1 to 2 cell thick layer of myeloid and mesenchymally-derived cells, has generally been characterized as the population of cells responsible for the secretion of synovial fluid (SF) and with maintaining structural stability within the capsule of diarthrodial joints.</p> <p>In pathological states, the SM is transformed into an aggressive tissue inundated by inflammatory cells and their soluble mediators. The intimal layer of the SM and its resident cells, Type A and Type B synoviocytes, undergo an alteration in phenotype during disease, particularly chronic joint inflammation. These synoviocytes expand in number and activity and have been demonstrated to be involved in part with the arthritic lesions associated with inflammatory joint disease. The purpose of this thesis is to illustrate that the human synovial fibroblast (HSF or Type B synoviocyte) is a dynamic cell both responding to and influencing its local environment. More specifically, it is documented that HSF activity is significantly affected by a host of locally produced soluble mediators released during arthritic diseases. In addition, HSF are shown to respond to their environment by possessing the capability to alter the activity of other inflammatory cells which are present in the joint milieu. We also show that the pathological state of the originating SM is significant in determining the response and activity of HSF. That is, HSF-derived from normal SM respond to some stimuli differently than do HSF derived from SM originating from diseased joints.</p> / Doctor of Philosophy (PhD)

FcR expression and function in CD4⁺ T cell biology

Simpson, Scott D. 11 1900 (has links)
<p>Receptors that bind immunoglobulin (Ig) via the Fc domain are known as Fc receptors (FcR). These receptors are integral transmembrane glycoproteins that are expressed on virtually every haematopoietic cell. FcR mediate a wide range of immunological functions from phagocytosis to cellular activation, however, the function and expression of FcR on CD4⁺ T cells is unknown. Thus, in vivo and in vitro studies were undertaken to investigate FcR expression and function on CD4+ T cells.</p> <p>Previously it has been demonstrated that CD4⁺ T cells activated with antigen-pulsed macrophages or interleukin 1 (IL-1) generated IgG and IgA binding factors (IgGBF and IgABF). These immunoglobulin binding factors (IgBF) are one component of a soluble macromolecule, known as a contrasuppressor factor (CSF). These CSF act to augment IgG or IgA responses in vivo and in vitro in an isotype-specific manner. Serological and functional data presented here demonstrate that the IgGBF and IgABF are soluble FcϒRII/III and FcαR, respectively. sFcR could functionally substitute for the IgBF and enhanced antibody responses in an isotype-specific manner. Recombinant sFcϒRIII/III, at concentrations of 0.01 to 0.5 ng/mI could augment IgG PFC responses. However, at higher concentrations (10 to 100 ng/ml) it failed to augment IgG PFC responses. Furthermore, the enhancing activity of the IgBF/sFcR was mediated through a subset of T cells that adhered to the lectin Vicia villosa (Vv T cells). In xid mice, which are unable to generate CSF, T cells could generate the IgBF. However, the xid mice lacked circulating regulatory Ig (reg Ig) that is also necessary for the generation of the CSF, resulting in defective CSF.</p> <p>Since activation of CD4⁺T cells induced the generation of sFcϒRII/III, I investigated FcϒR expression on CD4⁺ T cells utilizing an allogeneic activation system. FACS and PCR data from these studies demonstrated that alloactivation of purified CD4⁺ T cells with CH12.LXB cells induced de novo FcΥRIIBI expression within 24 hours and prior to DNA synthesis. The induction of FcΥRIIBI expression could be blocked by anti-MHC class II mAb, however, direct TCR ligation, even in the presence of IL-2, was not sufficient to induce expression. Moreover, the induction of FcΥRIIBi expression on CD4⁺ T cells was not dependent upon the Ig isotype of the CH12.LX B cells. Alloactivation of CD4⁺ T cells with different isotype-switch variants of the CH12.LX B cell line resulted in significant increases in the number of FcΥRIIB1⁺ CD4⁺ T cells. However, alloactivation with the IgG2b⁺ CH12.LX B cell line induced the largest number of FcΥRIIB1⁺ CD4⁺ T cells. Results from this study indicated that the IgG2b⁺ CH12.LX B cell line secreted a soluble factor(s) that augmented FcΥRIIB1 expression on aIloactivated CD4⁺ T cells. Although, the data suggests that this factor is not soluble IgG2b or IL-1, since both failed to induce FcyRIIBI expression on purified CD4⁺ T cells.</p> <p>In conclusion, these data indicate that alloactivation of CD4⁺T cells induces de novo mRNA and surface expression of FcΥRIIBI within 24 hours and prior to DNA synthesis. In addition, CD4⁺ T cell FcΥRIIBI expression can be augmented by a soluble factor(s) secreted by the IgG2b⁺ CH12.LX B cells. Furthermore, activation of CD4⁺ T cells also induces the generation of sFcΥRII/III and sFcαR. These sFcR participate in the formation of CSF that enhance antibody responses in vivo and in vitro, in an isotype-specific manner, through the activation of Vv T cells.</p> / Doctor of Philosophy (PhD)

Neuropsychological Characteristics of Positive and Negative Symptoms of Schizophrenia: Implications for Cognitive Remediation

Bird, Ralph Daniel January 1990 (has links)
<p>This study examines the relationship between neuropsychological functioning and positive versus negative symptoms of schizophrenia in order to test the hypothesis that negative symptoms are uniquely associated with cognitive deficits and attentional impairment. Forty chronic schizophrenics were subtyped on the basis of symptoms which were predominantly positive (n=10), predominantly negative (n=10), both positive and negative (n=10), or neither positive nor negative (n=10) and administered a battery of neuropsychological tests. The possibility that patterns of deficits among subtypes, if found, reflect lateralized or localized dysfunction was also examined.</p> <p>Test data revealed that positive- and negative-symptom schizophrenics are equally impaired according to several global indices of neuropsychological functioning as well as on various measures of attention. These findings are inconsistant with the hypothesis that cognitive and attentional deficits are unique to negative-symptom schizophrenia as has been reported in the literature. Further analysis of deficit patterns revealed that positive-symptom schizophrenics, relative to the asymptomatic group, showed more marked deficits in verbal learning and memory whereas negative-symptom schizophrenics, based on identical comparisons, showed greater impairment on measures of fluency and productivity. No relation was observed between neuropsychological indicies of right versus left or, anterior versus posterior dysfunction and a patient's symptom status. In fact, the low correlation between psychiatric symptoms and neuropsychological performance was generally observed. Reconceptualization regarding defining characteristics of postive- and negative-symptom syndrome, particularly with respoect to assumptions about attention and cognition, is suggested.</p> <p>The heterogeneity of neuropsychological deficits found among schizophrenics and their dissociation from the patients psychiatric presentation, stress the need for independent, individual assessment of cognitive functioning. Given that neuropsychological deficits, when identified, likely contribute to imparied social and occupational functioning, improvement in neuropsychological status may translate into improvement in these areas of everyday living. Preliminary results of an attempt at computer-based cognitive remediation in a seleted subset of schizophrenics are presented and a neuropsychological approach to psychiatric rehabilitation is proposed.</p> / Doctor of Philosophy (PhD)

A Statistical Rank Test For Analysing Biomedical Data

Magee, Alexander Robert 08 1900 (has links)
<p>In the analysis of biomedical data, a question commonly asked by researchers involves the determination of the "best " or "worst" member of a group of results and an associated measure of the probability that this member is the "best" or "worst". Commonly, analysis of variance is suggested as the test of choice. Unfortunately, this test does not exactly answer the original question and further testing must be done to satisfy the question completely. This thesis presents a non-parametric rank test which directly answers the question of "best" or "worst".</p> <p>Before applying this test to biomedical problems, the probability tables associated with this test are expanded and the methods used are presented and discussed. An analogous parametric test is then described and compared in performance with the non-parametric test throughout the remainder of the thesis. Power curves for both the nonparametric and parametric test are developed for several population distributions and the results compared. The three areas of application are; chromosome frequencies in the culture of human melanoma tissue; scoring patterns among evaluators of letters of applications to medical school; and the determination of outliers when relating vital capacity to ventilatory response.</p> <p>It was found that except for cases where the number of objects was less than 10, the parametric test has equal or greater power than the non-parametric test when analysing continuous data, regardless of the population distribution. For less than 10 objects, the non-parametric test had greater power regardless of population distribution. Subsequent to analysis in the three areas cited, it was concluded that the two tests agreed very highly in selecting extreme deviates although the non-parametric, test was consistently more conservative in its probability measure. The problem of ties was found to weaken the power of the non-parametric test as did the ranking procedure itself but its ease of application and superior power with small sample sizes is a distinct advantage. The robustness of the parametric test is obvious throughout the examples. A method of selecting data values which are second or third most extreme was tested and it became obvious that the data must be displayed to show its distributional characteristics before this type of analysis could be carried out or interpreted.</p> / Master of Science (MS)

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