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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.
281

Awareness, Knowledge and Attitudes about Human Papilloma Virus among Female tertiary students in South Africa

Admire Takuranenhamo Chikandiwa January 2010 (has links)
<p>The study aimed to describe the knowledge and awareness of HPV infection and vaccine of female university students and to determine the predictors of vaccine acceptability.&nbsp / The study found that 70% of the participants were sexually active. Awareness and knowledge on HPV/vaccine were poor / with only 22% being aware of HPV and that a HPV vaccine was available in South Africa. A greater proportion (80%) reported willingness to be vaccinated. Being aware of the existence of a pap smear, higher knowledge about HPV, higher perceived vaccine effectiveness and higher perceived severity of HPV infection were significantly associated with increased willingness to be vaccinated.</p>
282

Faking the Implicit Association Test (IAT): Predictors, Processes, and Detection

Röhner, Jessica 05 February 2014 (has links) (PDF)
Unverfälschbarkeit stellt ein wichtiges Gütekriterium psychologischer Testverfahren dar. Dieses Kriterium gilt dann als erfüllt, wenn das Testverfahren auf Grund seiner Konstruktion keine Steuerung oder Verzerrung der Ausprägung von Testwerten seitens der Versuchspersonen ermöglicht (vgl. Moosbrugger & Kelava, 2012). Im Gegensatz zu direkten Verfahren (z.B. Fragebogen und Interviews), bei welchen die Ausprägung hinsichtlich eines Merkmales durch Selbstbeschreibung der Versuchspersonen erfragt wird und eine Verfälschung (z.B. durch sozial erwünschtes Antwortverhalten) nicht ausgeschlossen werden kann, wurde indirekten Verfahren (z.B. dem Impliziten Assoziationstest; IAT; Greenwald, McGhee, & Schwartz, 1998) lange Zeit Immunität gegen Fälschungsversuche unterstellt. Diese begründet sich unter anderem durch die Annahme, dass mittels indirekter Verfahren implizite Merkmale gemessen werden. Implizite Merkmale unterscheiden sich von den „eher klassischen“ expliziten Merkmalen, welche vorwiegend mittels direkter Verfahren gemessen werden. Ein wesentlicher Unterschied besteht darin, dass Versuchspersonen nicht notwendigerweise um die Ausprägung hinsichtlich ihrer impliziten Merkmale wissen und dass sie diese Ausprägung auch nicht kontrollieren können (vgl. De Houwer, 2006; De Houwer & Moors, 2007, in press). Die theoretischen Annahmen bezüglich der Eigenschaften impliziter Merkmale bzw. Messergebnisse legen zwei Implikationen nahe. Erstens: Wir können implizite Merkmale ausschließlich über indirekte Zugänge erfassen, da diese nicht notwendigerweise bewusst sind und so eine Selbstauskunft nicht möglich erscheint. Zweitens: Personen können ihre impliziten Messergebnisse nicht kontrollieren und folglich auch nicht verfälschen. Vermutlich gab es auch aus diesem Grund vor wenigen Jahren einen regelrechten Boom, der zu der Entwicklung einer Vielzahl indirekter Verfahren zur Erfassung impliziter Merkmale geführt hat. Ob jedoch die Messergebnisse dieser Verfahren tatsächlich implizit und damit nicht verfälschbar sind, darf nicht nur theoretisch unterstellt, sondern muss empirisch überprüft werden (vgl. De Houwer, 2006). Der IAT gilt als das bekannteste, reliabelste und valideste indirekte Verfahren (Bosson, Swan, & Pennebaker, 2000; Rudolph, Schröder-Abé, Schütz, Gregg, & Sedikides, 2008). In meiner Dissertation habe ich mich aus diesem Grund der empirischen Überprüfung auf Verfälschbarkeit des IATs gewidmet. Die vorliegende Dissertation besteht aus insgesamt fünf Kapiteln. Das 1. Kapitel bildet eine theoretische Einführung zu den Themen Fälschung im diagnostischen Kontext und zum IAT. Grundlegende Befunde und Fragen zur Verfälschbarkeit des IATs werden dargestellt. Kapitel 2 bis 4 bilden empirische Beiträge meiner Forschung, die sich jeweils schwerpunktmäßig mit unterschiedlichen Aspekten der Verfälschbarkeit des IATs beschäftigen. In Kapitel 2 wird der Frage nachgegangen, unter welchen Bedingungen der IAT verfälschbar ist. Bis dato haben die wenigen existierenden Studien ein sehr widersprüchliches Bild bezüglich der Verfälschbarkeit des IATs aufgezeigt. Ein Grund hierfür könnte sein, dass potentiell relevante Faktoren, welche die Verfälschbarkeit des Verfahrens beeinflussen können, noch nie gemeinsam in einer Studie untersucht wurden. Die vorliegende Studie wurde genau mit diesem Ziel konstruiert und durchgeführt. Die Ergebnisse verweisen auf ein komplexes Zusammenspiel verschiedener Faktoren und zeigen auf, unter welchen Bedingungen der IAT verfälschbar ist. Implikationen dieser Ergebnisse werden kritisch diskutiert. In Kapitel 3 werden die Fragen beantwortet, wie Personen den IAT verfälschen und ob Fälschung im IAT detektierbar ist. Die Forschung hat sich bislang nur bedingt damit beschäftigt, was fälschende Personen tun, um ihre Messergebnisse wie gewünscht zu beeinflussen. Es wurde auch noch nicht untersucht, ob Versuchspersonen unter verschiedenen Bedingungen (z.B. Fälschungsziel: hohe vs. niedrige Testwerte) unterschiedliche Strategien anwenden. Dennoch wurden Indices vorgeschlagen, welche in der Lage sein sollen, Fälschung im IAT zu detektieren (Agosta, Ghirardi, Zogmaister, Castiello, & Sartori, 2011; Cvencek, Greenwald, Brown, Gray, & Snowden, 2010). In der vorgestellten Studie habe ich einerseits untersucht, welche Strategien fälschende Personen anwenden und ob sie, je nach Bedingung, zu unterschiedlichen Strategien greifen. Andererseits habe ich untersucht, welche dieser Strategien tatsächlich mit erfolgreicher Fälschung des IATs einhergehen. Schließlich habe ich untersucht, ob die in der Vergangenheit vorgeschlagenen Indices tatsächlich in der Lage sind, erfolgreiche FälscherInnen zu detektieren. Meine Ergebnisse zeigen, dass fälschende Personen unterschiedliche Strategien anwenden, um ihr Ziel zu erreichen. Damit verbunden zeigte sich auch, dass es schwerer ist als bislang angenommen, erfolgreiche FälscherInnen im IAT zu detektieren. Implikationen dieser Ergebnisse werden kritisch diskutiert. Kapitel 4 beschäftigt sich mit der Frage, ob kognitive Fähigkeiten ein erfolgreiches Fälschen im IAT erleichtern. Bisher wurden diese Fähigkeiten nur mit Fälschungserfolg in direkten Verfahren in Verbindung gebracht (vgl. Hartshorne & May, 1928; Nguyen, Biderman, & McDaniel, 2005; Ones, Viswesvaran, & Reiss, 1996; Pauls & Crost, 2005; Snell, Sydell, & Lueke, 1999; Tett, Freund, Christiansen, Fox, & Coaster, 2012; Weiner & Gibson, 2000). In der vorgestellten Studie habe ich untersucht, ob sie auch beim Fälschen des IATs eine Rolle spielen. Besonders habe ich mich dabei für die Rolle des g Faktors der Intelligenz, der Verarbeitungsgeschwindigkeit und der Konzentrationsfähigkeit interessiert. Die Ergebnisse meiner Studie zeigen auf, dass einige dieser Prädiktoren tatsächlich einen Einfluss auf den Fälschungserfolg im IAT haben. Implikationen dieser Ergebnisse werden kritisch diskutiert. Das 5. Kapitel bildet eine Zusammenführung und Integration der Befunde meiner Forschung in die bestehende Theorie. Zudem werden ein Ausblick für die weitere Forschung sowie Empfehlungen für die Praxis gegeben.
283

A holistic view of urinary stress incontinence in women

Berglund, Anna-Lena January 1995 (has links)
The present study group consists of 45 women with genuine stress incontinence who were selected for surgical treatment and randomized either to retropubic urethrocystopexy (n=30) or pubococcygeal repair (n=15). The preoperative assessment included medical history, gynecological examination, urine analysis and culture, residual urine, pad test, frequency-continence charts, water urethrocystoscopy, continence test and cystometry with analysis of micturition. Moreover, five semistructured interviews were performed with the women and two with their partner. The following questionnaires were used measuring a) personality characteristics: Karolinska Scales of Personality (KSP), Eysenck Personality Inventory (EPI), b) depression: Beck Depression Inventory (BDI) and c) social support: Interview Schedule for Social Interaction (ISSI). The results have shown that there was no difference in the subjective cure rate between the two surgical methods (73% vs. 80 % respectively). The bladder volume had increased in both groups and the intravesical pressure of the bladder filled to maximum had increased in the pubococcygeal repair group. Other urodynamic variables were unchanged by the operation. Pad tests have demonstrated that 67 % of the women in the urethrocystopexy group and 47 % in the pubococcygeal repair group ceased to leak urine. Postoperatively, 63 % of the women in the urethrocystopexy group needed high doses of analgesics compared with only 33 % in the pubococcygeal repair group. Among the women experiencing severe to very severe pain dysphoric subjects were overrepresented. Postoperative residual urine was a minor nursing problem in both groups. Women with SUI of long duration scored significantly higher than controls on the KSP scales of somatic anxiety, psychic anxiety, psychasthenia, suspicion and on the EPI lie-scale. There was no significant difference in sexual activity before and after surgery. One or two sexual dysfunctions within the desire, excitement, orgasmic and resolution phase were reported by the majority of women both before and after surgical intervention. The cured women reported a higher level of overall activities before surgery than the improved (i.e. not cured) women, whereas post surgery both the cured and the improved women obtained about the same level of activities. Regarding social support, no differences between the cured or improved women occured as concerns attachment. The cured women showed a higher degree of adequacy of social integration compared with the improved women. In order to delineate predictive factors for the surgical outcome the following variables were investigated: age of patient, duration of urine leakage, parity, personality, psychological and social factors. The following predictors of the outcome of surgical treatment emerged: duration of stress incontinence, neuroticism and age of patient. The results of the present study indicate the ecessity of a multidisciplinary approach to the treatment and nursing of women with SUI. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1995</p> / digitalisering@umu
284

Prediction of academic success of first year National Certificate Vocational (Level 2) students at FET colleges / by Colleen Smit.

Smit, Colleen January 2013 (has links)
Since 2006 Further Education and Training (FET) Colleges have been recapitalised through massive government investment in order to improve infrastructure, implement a more relevant curriculum and assist college learners financially to gain access to the different learning programmes. A new curriculum with 11 programmes was introduced and implemented under the National Certificate Vocational (NCV). The results of the 2007 examinations, were disappointing and in general, the national performance of the learners was dismal. Policy requirements for certification and promotion to the next level stipulated that learners need to pass all 7 subjects in a programme. The main aim of the study was to identify variables that are the best predictors of academic success of first year FET students. Thus, if these predictors are considered during the admission process of first year FET students, it could lead to overall improved first year pass rate at FET Colleges and contribute towards the enhancement of human resources and economical development of our country. In order to achieve the research aim and objectives, a literature study and an empirical investigation were conducted. The literature study focussed on cognitive and non-cognitive factors that contribute to academic success of students at colleges. The empirical investigation departed from a positivist paradigm to determine which variables contributed the best towards the prediction of academic success of first year NCV Level 2 students at FET Colleges and a quantitative non-experimental, ex post facto approach was followed .The results of the General Scholastic Aptitude Test (GSAT), the Learning and Study Strategies Inventory – High School version (LASSI-HS), grade mark average and biographical details of the registered first year NCV Level 2 students of the Vuselela FET College (Potchefstroom and Klerksdorp campuses) in 2008 (n=309), were used to determine whether any of these variables significantly predicted the academic success of these students. The investigation revealed that: • None of the LASSI-HS scales were predictors of academic success of the first year NCV Level 2 students; • The GSAT (Total) was a predictor of academic success of these students; • None of the biographical variables, i.e. age or gender, were predictors of academic success; and • Grade mark average on students’ last school reports, was a predictor of academic success. These findings revealed that Grade mark average, and GSAT-(Total) (which is also an indication of intelligence quotient (IQ)) were the best predictors of academic success of first year NCV Level 2 students at the Potchefstroom and Klerksdorp campuses of the Vuselela FET College. / Thesis (MEd (Educational Psychology))--North-West University, Potchefstroom Campus, 2013.
285

Prediction of academic success of first year National Certificate Vocational (Level 2) students at FET colleges / by Colleen Smit.

Smit, Colleen January 2013 (has links)
Since 2006 Further Education and Training (FET) Colleges have been recapitalised through massive government investment in order to improve infrastructure, implement a more relevant curriculum and assist college learners financially to gain access to the different learning programmes. A new curriculum with 11 programmes was introduced and implemented under the National Certificate Vocational (NCV). The results of the 2007 examinations, were disappointing and in general, the national performance of the learners was dismal. Policy requirements for certification and promotion to the next level stipulated that learners need to pass all 7 subjects in a programme. The main aim of the study was to identify variables that are the best predictors of academic success of first year FET students. Thus, if these predictors are considered during the admission process of first year FET students, it could lead to overall improved first year pass rate at FET Colleges and contribute towards the enhancement of human resources and economical development of our country. In order to achieve the research aim and objectives, a literature study and an empirical investigation were conducted. The literature study focussed on cognitive and non-cognitive factors that contribute to academic success of students at colleges. The empirical investigation departed from a positivist paradigm to determine which variables contributed the best towards the prediction of academic success of first year NCV Level 2 students at FET Colleges and a quantitative non-experimental, ex post facto approach was followed .The results of the General Scholastic Aptitude Test (GSAT), the Learning and Study Strategies Inventory – High School version (LASSI-HS), grade mark average and biographical details of the registered first year NCV Level 2 students of the Vuselela FET College (Potchefstroom and Klerksdorp campuses) in 2008 (n=309), were used to determine whether any of these variables significantly predicted the academic success of these students. The investigation revealed that: • None of the LASSI-HS scales were predictors of academic success of the first year NCV Level 2 students; • The GSAT (Total) was a predictor of academic success of these students; • None of the biographical variables, i.e. age or gender, were predictors of academic success; and • Grade mark average on students’ last school reports, was a predictor of academic success. These findings revealed that Grade mark average, and GSAT-(Total) (which is also an indication of intelligence quotient (IQ)) were the best predictors of academic success of first year NCV Level 2 students at the Potchefstroom and Klerksdorp campuses of the Vuselela FET College. / Thesis (MEd (Educational Psychology))--North-West University, Potchefstroom Campus, 2013.
286

The clinical value of total isovolumic time

Bajraktari, Gani January 2014 (has links)
The objective of this thesis is to evaluate the use of Doppler echocardiography markers ofglobal dyssynchrony [total isovolumic time (t-IVT)] in the following 6 studies: 1) Its prognostic role in predicting cardiac events in patients undergoing CABG surgery,compared with conventional global systolic and diastolic measurements. 2) Its additional value in predicting six minute walk test (6-MWT) in patients with leftventricular (LV) ejection fraction (EF) &lt;45%. 3) Its prognostic value in comparison with other clinical, biochemical and echocardiographicvariables in patients with chronic systolic heart failure (HF). 4) The relationship between 6-MWT and cardiac function measurements in a consecutivegroup of patients, irrespective of EF and to identify predictors of exercise capacity. 5) To investigate the effect of age on LV t-IVT and Tei index compared with conventionalsystolic and diastolic parameters. 6) To assess potential additional value of markers of global LV dyssynchrony in predictingcardiac resynchronization therapy (CRT) response in HF patients. Study I Methods: This study included 74 patients before routine CABG who were followed up for18±12 months. Results: At follow-up, 29 patients were hospitalized for a cardiac event or died. LV-ESD wasgreater (P=0.003), fractional shortening (FS) lower (p&lt;0.001), E:A ratio and Tei index higher(all P&lt;0.001), and t-IVT longer (P&lt;0.001) in patients with events. Low FS [0.66 (0.50–0.87),P&lt;0.001], high E:A ratio [l4.13 (1.17–14.60), P=0.028], large LV-ESD [0.19 (0.05–0.84),P=0.029], and long t-IVT [1.37 (1.02–1.84), P=0.035] predicted events and deaths. Conclusion: Despite satisfactory surgical revascularization, long t-IVT and systolicdysfunction suggest persistent ventricular dyssynchrony that contributes to post-CABGcardiac events. Study II Methods: We studied 77 patients (60±12 year, and 33.3% females) with stable HF using 6-MWT.iii Results: E’ wave (r=0.61, p&lt;0.001), E/e’ ratio (r=-0.49, p&lt;0.001), t-IVT (r=-0.44, p&lt;0.001),Tei index (r=-0.43, p&lt;0.001) and NYHA class (r=-0.53, p&lt;0.001) had the highest correlationwith the 6-MWT distance. In multivariate analysis, only E/e’ ratio [0.800 (0.665-0.961),p=0.017], and t-IVT [0.769 (0.619-0.955), p=0.018] independently predicted poor 6-MWTperformance (&lt;300m). Conclusions: In HF, the higher the filling pressures and the more dyssynchronous the LV, thepoorer is the patient’s exercise capacity. Study III Methods: We studied 107 systolic HF patients; age 68±12 year, 25% females and measuredplasma NT-pro-BNP. Results: Over a follow-up period of 3718 months, t-IVT ≥12.3 sec/min, mean E/Em ratio≥10, log NT-pro-BNP levels ≥2.47 pg/ml and LV EF ≤32.5% predicted clinical events. Theaddition of t-IVT and NT-pro-BNP to conventional clinical and echocardiographic variablessignificantly improved the χ2 for the prediction of outcome from 33.1 to 38.0, (p&lt;0.001). Conclusions: Prolonged t-IVT adds to the prognostic stratification of patients with systolicHF. Study IV Methods: We studied 147 HF patients (61±11 year, 50.3% male) with 6-MWT.Results: The 6-MWT correlated with t-IVT (r=-0.49, p&lt;0.001) and Tei index (r=-0.43,p&lt;0.001) but not with any of the other clinical or echocardiographic parameters. Group Ipatients (&lt;300m) had lower Hb (p=0.02), lower EF (p=0.003), larger left atrium (p=0.02),thicker septum (p=0.02), lower A wave (p=0.01) and lateral wall a’ (p=0.047), longerisovolumic relaxation time (r=0.003) and longer t-IVT (p= 0.03), compared with Group II(&gt;300m). Only t-IVT ratio [1.257 (1.071-1.476), p=0.005], LV EF [0.947 (0.903-0.993),p=0.02], and E/A ratio [0.553 (0.315-0.972), p=0.04] independently predicted poor 6-MWTperformance. Conclusion: In HF, the limited 6-MWT is related mostly to severity of global LVdyssynchrony, more than EF or raised filling pressures. Study V Methods: We studied 47 healthy individuals (age 62±12 year, 24 female), arbitrarilyclassified into: M (middle age), S (seniors), and E (elderly). Results: Age strongly correlated with t-IVT (r=0.8, p&lt;0.001) and with Tei index (r=0.7,p&lt;0.001), E/A ratio (r=-0.6, p&lt;0.001), but not with global or segmental systolic function measurements or QRS duration. The normal upper limit of the t-IVT (95% CI) for the three groups was 8.3 s/min, 10.5 s/min and 14.5 s/min, respectively, being shorter in the S compared with the E group (p=0.001). T-IVT correlated with A wave (r=0.66, p&lt;0.001), E/Aratio (r=-0.56, p&lt;0.001), septal e’ (r=-0.49, p=0.001) and septal a’ (r=0.4, p=0.006), but notwith QRS. Conclusions: In normals, age is associated with exaggerated LV global dyssynchrony anddiastolic function disturbances, but systolic function remains unaffected. Study VI Methods: We studied 103 HF patients (67±12 year, 82.5% male) recruited for CRTtreatment. Results: Prolonged t-IVT [0.878 (0.802-0.962), p=0.005], long QRS duration [0.978 (0.960-0.996), p=0.02] and high tricuspid regurgitation pressure drop (TRPD) [1.047 (1.001-1.096),p=0.046] independently predicted response to CRT. A t-IVT ≥11.6 s/min was 67% sensitiveand 62% specific (AUC 0.69, p=0.001) in predicting CRT response. Respective values for aQRS ≥ 151ms were 66% and 62% (AUC 0.65, p=0.01). Combining the two variables had asensitivity of 67% but higher specificity of 88% in predicting CRT response. In atrialfibrillation (AF) patients, only prolonged t-IVT ≥11 s/min [0.690 (0.509-0.937), p=0.03]independently predicted CRT response with a sensitivity of 69% and specificity of 79% (AUC0.78, p=0.015). Conclusion: Combining prolonged t-IVT and broad QRS had higher specificity in predictingresponse to CRT, with the former the sole predictor of response in AF patients.
287

Aerobic fitness, physical function and falls among older people : a prospective study

Bell, Rebecca A. January 2008 (has links)
Falls in people aged over 65 years account for the largest proportion of all injury-related deaths and hospitalisations within Australia. Falls contributed to 1,000 deaths and 50,000 hospitalisations in older people during 1998 (Commonwealth Department of Health and Aged Care 2001). It has been predicted that by 2016, 16% of the Australian population will be aged over 65 years (Australian Bureau of Statistics 1999) placing considerable pressure on the health care system. Furthermore, prospective studies have shown that 30-50% of people aged 65 years and over, will experience a fall (Tinetti et al. 1988b; Campbell et al. 1989; Lord et al. 1994b; Hill 1999; Brauer et al. 2000; Stalenhoef et al. 2002) and this figure increases exponentially with age (Lord et al. 1994b). Many physiological falls risk factors have been established including reduced leg strength, poor balance, impaired vision, slowed reaction time and proprioception deficits. However, little research has been conducted to determine whether performance on aerobic fitness tasks is also a physiological falls risk factor. Aerobic fitness has previously been related to an individual's ability to perform activities of daily living, which in turn has been linked to falls. It was therefore proposed that aerobic fitness might also be a risk factor for falls among community dwelling older people. This research aimed to provide clinical evidence to inform public health practice. This thesis comprised of four objectives: the first to find suitable measures of aerobic fitness for older people; the second investigated relationships between existing clinical tests and future falls; the third explored relationships between aerobic fitness tests and future falls; the final objective was to examine the independent relationships between falls and clinical and physiological characteristics. The participants were recruited through a random sample from the local electoral roll, with an average age of 73 ±6 years. Of the 87 participants who completed the prospective component of the study, 37% were male and 63% were female. Sixty-three participants (65%) reported no previous falls, 19 (20%) reported a single fall, and 16 (15%) reported two or more falls in the previous 12 months. The first objective required participants recruited from the community to take part in submaximal and maximal fitness tests in order to find suitable measures of aerobic fitness. A further objective was to determine whether older people were able to fulfil the 'standard' criteria for completion of a maximum oxygen consumption test. The measures used in this research included: maximum oxygen consumption, peak oxygen consumption, ventilatory threshold, oxygen uptake kinetics, oxygen deficit, efficiencies, oxygen consumption at zero, 30 and 50 watts, predicted max and Six-Minute Walk Test distance. Only weak relationships were observed between submaximal aerobic measures and peak oxygen consumption. Furthermore, only 54% of participants were able to fulfil the criteria to complete a test of maximum oxygen consumption, indicating it was not a suitable measure for use among a sample of community dwelling older people. Therefore submaximal aerobic variables were used in the following chapters. The second objective investigated the relationship between clinical measures and falls among older people and was carried out to enable comparisons between the population in this study and those described in the literature. This research found that the Timed Up and Go (TUG) test was the most sensitive of all clinical tests (including the Berg Balance Scale, Function Reach, Performance Oriented Mobility Assessment and Physiological Profile Assessment) for the assessment of future falls. The TUG requires participants to stand up, walk 3m, turn, walk back, and sit down. Time taken to complete the test is the recorded value. For this study, a cut-off value of 7-seconds was established, above which individuals were at increased risk of falls. Previous research suggested cut-off times of over 10s were appropriate for older people. However, this is the first study to assess falls prospectively and definitively find that the TUG can discriminate between future fallers and non-fallers. This research also investigated the differences in falls risk factors for functionally different subsamples, as defined by their ability to undertake and complete the cycle test. The participants who could complete the test had significantly better balance ability and strength than those unable to undertake or complete the cycle test. However, this inability to undertake or complete the cycle test was not itself a predictor of future falls. These two groups also differed in the relationships between clinical test results and falls risk. Participants in the no-cycle group had very similar results to that of the entire cohort. Even after adjustment for age, the TUG, foot and hand reaction times and knee flexion strength were all performed better by non-fallers than fallers. However, none of these differed between fallers and non-fallers for participants in the cycle group. This group had better balance ability and strength than the no-cycle group. These results indicated that the cycle group differed from the no-cycle group and the entire sample, further indicating that factors other than the physiological variables measured in this research influence falls risk in strong participants with good balance ability. Similar results were reported when aerobic tests and falls were investigated in the third objective. In the whole sample, the fallers walked significantly less distance than non-fallers for the 6-MWT. Similar results were found for participants in the no-cycle group but not the cycle group. All participants were able to complete the Six-Minute Walk Test (6-MWT) although only 74% were able to undertake and complete the cycle test. The fourth objective was to consider all measures from the previous chapters as potential predictors of falls. The variables most predictive of future falls were the TUG and having experienced one or more falls in the previous 12 months. As a result they could be used as screening tools for the identification of high-risk fallers who require referral for further assessment. This could be completed by a General Practitioner or Practice Nurse, which would ensure that screening is being undertaken in the wider population. If the patient is at high risk they should be referred for falls risk factor assessment to determine an optimal tailored intervention to reduce future falls. Low risk patients should be referred for preventive evidence-based activities. These steps can potentially improve quality of life for individuals, and if effective in preventing future falls, will result in reduced costs to the individual and the Australian public. The results of this work demonstrate that the best screening tests are simple tasks like the TUG and asking an individual if they have experienced a fall in the last 12 months. This research also found that strong, mobile older people who could undertake and complete a submaximal cycle ergometer test, still experienced falls in the following 12 months, although the causes of this are currently unknown. This research showed that physiological falls risk factors are less relevant as these highly functional older people do not have physiological deficits. However, this research found that the 6-MWT showed promise as a predictor of falls in a group who could not complete a submaximal cycle ergometer test, who had lower strength, balance and functional fitness scores than a group who could complete this cycle test. The results showed that physiological falls risk factors are still very important for older people with lower physical abilities, and this is where aerobic fitness may still be related to falls. While the association between aerobic fitness and falls remains unclear, these are novel and provocative findings highlighting the need for future falls risk investigations to consider aerobic fitness as a contributing factor.
288

Estimateurs fonctionnels récursifs et leurs applications à la prévision / Recursive functional estimators with application to nonparametric prediction

Amiri, Aboubacar 06 December 2010 (has links)
Nous nous intéressons dans cette thèse aux méthodes d’estimation non paramétriques par noyaux récursifs ainsi qu’à leurs applications à la prévision. Nous introduisons dans un premier chapitre une famille d’estimateurs récursifs de la densité indexée par un paramètre ℓ ∈ [0, 1]. Leur comportement asymptotique en fonction de ℓ va nous amener à introduire des critères de comparaison basés sur les biais, variance et erreur quadratique asymptotiques. Pour ces critères, nous comparons les estimateurs entre eux et aussi comparons notre famille à l’estimateur non récursif de la densité de Parzen-Rosenblatt. Ensuite, nous définissons à partir de notre famille d’estimateurs de la densité, une famille d’estimateurs récursifs à noyau de la fonction de régression. Nous étudions ses propriétés asymptotiques en fonction du paramètre ℓ. Nous utilisons enfin les résultats obtenus sur l’estimation de la régression pour construire un prédicteur non paramétrique par noyau. Nous obtenons ainsi une famille de prédicteurs non paramétriques qui permettent de réduire considérablement le temps de calcul. Des exemples d’application sont donnés pour valider la performance de nos estimateurs / The aim of this thesis is to study methods of nonparametric estimation based on recursive kernel and their applications to forecasting. We introduce in the first chapter a family of recursive density estimators indexed by a parameter ℓ ∈ [0, 1]. We study their asymptotic behavior according to ℓ, and then we introduce criteria of comparison based on bias, variance and asymptotic quadratic error. For these criteria, we compare our estimators in terms of ℓ, and also compare our family to the non-recursive density estimator of Parzen-Rosenblatt. As for density, we define a family of recursive kernel estimators of regression function. We study its asymptotic properties according to the parameter ℓ. Finally, results of regression estimation are applied to define a family of nonparametric predictors that reduce considerably the computing time and examples of application are given to validate the performance of our methods
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Imagery, Self-Concept, Anxiety, and Stress as Predictors of Seriousness of Disease

Harris, Jerry Lon 05 1900 (has links)
This research study was designed to investigate the relationships of imagery, self-concept, anxiety, stress, subjective stress and seriousness of illness and to determine the potential of certain cognitive mediating variables, especially imagery and an interaction between self-concept and imagery, to significantly increase the efficiency of stress as a predictor of seriousness of illness. The purposes of this study were: (1) to determine the efficiency of stress as a predictor of disease, (2) to determine if cognitive mediating variables will significantly increase the predictive efficiency between stress and disease, (3) to investigate selected correlations among the variables, (4) to provide a research base for current treatment procedures using imagery treating various illnesses.
290

Prótese valvar mitral : 20 anos de seguimento de uma amostra de pacientes operados no Hospital de Clínicas de Porto Alegre, Rio Grande do Sul, Brasil

Ribeiro, Angela Henrique Silva January 2013 (has links)
Este estudo avalia mortalidade, reoperação e eventos hemorrágicos em pacientes submetidos à cirurgia para troca valvar mitral utilizando substituto biológico ou mecânico. O delineamento do estudo foi do tipo coorte histórica. Entre todos os registros, foram selecionados 352 prontuários de pacientes submetidos à cirurgia para troca valvar mitral entre 1990 e 2008, que tiveram seguimento mínimo de 5 e máximo de 23 anos. Para avaliar o tempo de sobrevida, a probabilidade de reoperação e de eventos hemorrágicos, foi utilizada a curva de Kaplan-Meier. Foi aplicado, para comparar as curvas entre os grupos, o teste qui-quadrado de Log-rank. A análise multivariada de Regressão de Cox foi utilizada para identificar preditores independentes de mortalidade, reoperação e eventos hemorrágicos. A sobrevivência em 5, 10, 15 e 20 anos após cirurgia utilizando substituto mecânico foi de 87,7%, 74,2%, 69,3% e 69,3% e, para substituto biológico, foi de 87,6%, 71,0%, 64,2%, e 56,6%, respectivamente. Não houve diferença significativa entre a mortalidade entre os dois grupos (p=0,38). Na análise multivariada, os fatores associados com o óbito foram: idade, eventos hemorrágicos e insuficiência renal. A probabilidade de permanecer livre de reoperação em 5, 10, 15 e 20 anos após cirurgia utilizando substituto mecânico foi de 94,4%, 92,7%, 92,7% e 92,7% e, para bioprótese, foi de 95,9%, 86,4%, 81,2% e 76,5%, respectivamente (p=0.073), com uma incidência significativamente maior de reoperação para bioprótese (p=0,008). Os fatores associados com reoperação foram: sexo masculino, diâmetro da prótese e endocardite. A probabilidade de permanecer livre de eventos hemorrágicos em 5, 10, 15 e 20 anos após cirurgia utilizando substituto mecânico foi de 95,0%, 91,0%, 89,6% e 89,6% e, para bioprótese, foi de 96,9%, 94,0%, 94,0% e 94,0%, respectivamente (p=0,267). Os fatores associados com eventos hemorrágicos foram: IMC (índice de massa corporal) superior à 30 kg/m2, doença pulmonar obstrutiva crônica, tempo de ventilação mecânica na Unidade de Tratamento Intensivo superior a 30 dias e presença insuficiência mitral. Os autores concluíram que: 1) a mortalidade foi estatisticamente semelhante entre os dois grupos no seguimento; 2) houve tendência maior à reoperação no grupo com bioprótese; 3) após 10 anos de seguimento, a probabilidade de permanecer livre de reoperação não mudou para pacientes com substitutos valvares mecânicos; 4) a probabilidade de permanecer livre de eventos hemorrágicos não mudou após 10 anos de seguimento para portadores de biopróteses; 5) as características basais dos pacientes foram os maiores determinantes de mortalidade tardia após a cirurgia; 6) o tipo de prótese não foi fator preditor independente associado a nenhum dos desfechos avaliados na análise multivariada. / This study assessed mortality, reoperation and bleeding events in patients who underwent mitral valve replacement surgery with a biological or mechanical substitute. This was a historical cohort study. In total, 352 inpatients clinical health records who underwent mitral valve replacement surgery between 1990 and 2008 with 5 to 23 years of follow-up were selected. A Kaplan-Meier curve was used to evaluate the survival time, the probability of reoperation and bleeding events. A log-rank chi-square test was applied to compare the curves between groups. Multivariate Cox regression analysis was used to identify independent predictors of mortality, reoperation and bleeding events. The 5, 10, 15 and 20 year survival rates after surgery using a mechanical substitute were 87.7%, 74.2%, 69.3% and 69.3%, respectively, while the survival rates after surgery with a biological substitute were 87.6%, 71.0%, 64.2% and 56.6%, respectively. There was no significant difference in mortality between the two groups (p = 0.38). In the multivariate analysis, the factors associated with death were age, bleeding events and renal failure. The probabilities of being free of reoperation at 5, 10, 15 and 20 years after surgery using a mechanical substitute were 94.4%, 92.7%, 92.7% and 92.7%, respectively, while after surgery with a bioprosthesis, they were 95.9%, 86.4%, 81.2% and 76.5%, respectively (p = 0.073); therefore, there was a significantly higher incidence of reoperation for patients receiving a bioprosthesis (p = 0.008). The factors associated with reoperation were male gender, diameter of the prosthesis and endocarditis. The probabilities of remaining free of bleeding events at 5, 10, 15 and 20 years after surgery using a mechanical substitute were 95.0%, 91.0%, 89.6% and 89.6, respectively, while after surgery with a bioprosthesis, they were 96.9%, 94.0%, 94.0% and 94.0%, respectively (p = 0.267). The factors associated with bleeding events were BMI (body mass index) greater than 30 kg/m2, chronic obstructive pulmonary disease, mechanical ventilation at an Intensive Care Unit for longer than 30 days and mitral regurgitation. The authors concluded that: 1) mortality during follow-up was statistically similar in both groups; 2) there was a greater tendency to reoperation in the bioprosthesis group; 3) the probability of survival free from reoperation did not change for patients with mechanical valves after 10 years’ follow-up; 4) the probability of survival free from bleeding events did not change after 10 years’ follow-up for bioprostheses patients; 5) patients’ baseline characteristics were the greatest determinants of late mortality after mitral valve replacement surgery; 6) the type of prosthesis fitted was not an independent predictive factor of any of the outcomes analyzed in the multivariate analysis.

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