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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.
61

Dissociating Response Prepotency and Response Conflict within Tasks of Action Inhibition among Individuals Scoring High on the Schizotypal Personality Questionnaire

Wilson, Carolyn M. January 2010 (has links)
Theories embedded within evolutionary neurobiology offer useful frameworks within which to understand cognitive impairment in schizophrenia (SCZ). The current research invokes the Dual Trends Theory (DTT), an evolutionary model that posits that neural architecture develops along two separate pathways: the dorsal ‘archicortical’ trend and the ventral ‘paleocortical’ trend. Although various lines of research converge to suggest that SCZ is associated with dorsal trend impairment in the context of relative ventral trend sparing, one persistent inconsistency exists. Specifically, individuals with SCZ routinely show impairment on tasks of action inhibition (AI; the ability to inhibit a pre-planned movement), a function routinely shown to be mediated by the inferior frontal gyrus, a key structure of the ventral trend. Here we argue that conventional tasks of AI conflate AI per se with response conflict (CON) demands, a function shown to be mediated by the anterior cingulate cortex, a key structure of the dorsal trend. We define CON as any aspect of a task that increases the difficulty of deciphering or interpreting the meaning of task stimuli (e.g., greater perceptual similarity between imperative task stimuli). The current research administered novel AI tasks in order to independently examine increases in CON and increases in the prepotency to respond to a pre-planned movement (PREP; considered a more fundamental measure of AI). Consistent with study hypotheses, individuals with Schizoprenia-spectrum disorders (specifically schizotypy) failed to show compensatory response time (RT) slowing when confronted with increasing CON demands yet showed proportional RTs, relative to healthy control participants, as PREP demands increased. These findings were interpreted as reflecting impairment in their ability to detect and/or decipher CON. More broadly, these findings suggest that cognitive abnormalities in SCZ may represent disproportionately impaired dorsal trend circuitry.
62

"Yes, jag klarade det" : En intervjustudie med elever som använder interaktiva svarsdosor på matematiklektioner.

Laupa, Mikael January 2012 (has links)
No description available.
63

En elevtext från skolår 2 : Lärare och blivande lärare analyserar, bedömer och ger respons

Martinsson, Camilla, Rundgren, Åsa January 2006 (has links)
<p>Vårt syfte var att undersöka hur lärare och blivande lärare analyserar och bedömer en elevtext från skolår 2. Vidare ville vi undersöka vilken handledning och respons dessa ville ge eleven. Undersökningen grundade sig på 24 enkäter och 4 intervjuer som tog upp stavningsförmåga, användning av skiljetecken, meningsbyggnad, textens längd och sammanhang i texten. Dessa aspekter har berörts genom att lärarna och de blivande lärarna har fått göra iakttagelser och bedömningar av elevtexten. De har också fått redovisa vilken handledning och respons de vill ge till eleven. Resultaten visade på likheter och skillnader i sättet verksamma lärare och blivande lärare analyserar och bedömer en text. Vi drog slutsatsen att den största skillnaden var att de verksamma lärarna analyserar, bedömer, handleder och ger respons mer detaljerat än de blivande lärarna.</p><p>Nyckelord</p><p>Analys, bedömning, handledning, respons, elevtext, skolår 2, lärare, blivande lärare</p>
64

Scarlett Johansson : en studie i förhållandet mellan filmskådespelare och åskådare

Bakkenberg, Mikael January 2010 (has links)
Filmen är ett medium som knyter samman filmskapare, filmskådespelare, medier och åskådare med varandra i intrikata relationer. Filmbolag producerar och auteurer skapar filmer, skådespelare medverkar i filmerna, medierna marknadsför såväl filmerna som filmskådespelarna och åskådare ser filmerna. Filmskaparen behöver åskådare för att kunna tjäna pengar eller bli omtalad, och behöver filmskådespelare för att få åskådare till sin film. Filmskådespelaren i sin tur behöver åskådare för att bli berömd men det kräver att det finns en film som åskådarna kan se. Skådespelaren är således beroende av det finns filmskapare. Åskådaren behöver filmskapare för att kunna se film men frågan är vad åskådaren behöver filmskådespelare till? Det är idag fullt möjligt att göra filmer utan skådespelare som fysiska aktörer på filmduken. Åskådaren behöver alltså inte filmskådespelare för att kunna se filmen, likväl är skådespelare beundrade av åskådare.        Syftet med denna uppsats är att undersöka förhållandet mellan filmskådespelare och åskådare genom att ta reda på hur en filmskådespelare konstrueras i två filmer och se hur man har uppfattat denna konstruktion. Vad är det för bild man målar upp av filmskådespelaren och hur har folk reagerat på den? Den valda filmstjärnan är Scarlett Johansson och de två filmer som kommer att studeras är Den svarta dahlian samt Lost in Translation. Min frågeställning är:       Hur konstrueras Scarlett Johanssons persona i filmerna? Hur har åskådare reagerat på Scarlett Johanssons karaktärer och skådespeleri?        Scarlett Johanssons persona i såväl Lost in Translation som Den svarta dahlian är två unga kvinnor som använder andra för sina egna syften. I det förstnämnda fallet använder Scarletts karaktär Charlotte Bill Murrays Bob som en läromästare och som en vän. I det andra fallet är Scarlett Johanssons Kay Lake mer att likna vid en femme fatale som använder Josh Hartnetts Bleichert för sexuella syften. Scarlett Johanssons filmiska persona framställs på ett tvåsidigt sätt: dels Charlotte och Kay Lake som prydliga unga damer när de uppträder som offentliga personer, dels Charlotte och Kay Lake som utmanande, ohämmade unga kvinnor när de uppträder som privatpersoner.           Responsen på Scarlett Johansson uppvisar en del variationer i hur man har talat om Scarlett och hur man har använt henne. När det gäller åsikter har man varit mestadels positiv till Scarlett Johansson i Lost in Translation medan man har varit mestadels negativ när det gäller hennes insats i Den svarta dahlian. Såväl recensenter som amatörtyckare har uttalat sig om Scarlett Johanssons utseende och hennes skådespeleri. Att jämföra Scarlett Johansson med antingen en motspelare eller hennes insats med tidigare roller har varit vanligt bland responsen.
65

Med en fot inne och den andra ute. : – En kvalitativ studie om vikariers och timanställdas upplevelse av sin anställningsform.

Anderssons, Paolina, Norwaths, Justina January 2009 (has links)
Sex personer har intervjuats för att ta reda på hur de ser på sin arbetssituation, samt vad skillnaden är mellan deras upplevelser. Vi intervjuade växeltelefonister och fritidsledare. Samtliga respondenter saknade fast anställning alltså, tillsvidareanställning. Växeltelefonister och fritidsledare är två exempel på yrken som har många timanställda och vikarier. Som timanställd och vikarie lever man under en viss press. Det finns många teorier om vad som krävs för att man ska må bra på arbetet. Deltagande, kontroll, självbestämmande, erkännande, gemenskap och kommunikation är de viktigaste bitarna enligt Dahlgren &amp; Dahlgren (1981). Socialt stöd är en angelägen del för att tillfredsställelse ska uppnås på arbetet (Karasek och Theorell, 1990; Dahlgren &amp; Dahlgren, 1981; Näswall, 2003). Som timanställd och vikarie uppfylls inte alla dessa kriterier. Trots detta skiljer sig dessa två yrken åt. Växeltelefonisterna som är timanställda, känner sig mer utsatta på arbetsplatsen än vad vikarierna som arbetar som fritidsledare gör. Exempelvis genom att de inte kände sig som en del av gemenskapen.
66

Dissociating Response Prepotency and Response Conflict within Tasks of Action Inhibition among Individuals Scoring High on the Schizotypal Personality Questionnaire

Wilson, Carolyn M. January 2010 (has links)
Theories embedded within evolutionary neurobiology offer useful frameworks within which to understand cognitive impairment in schizophrenia (SCZ). The current research invokes the Dual Trends Theory (DTT), an evolutionary model that posits that neural architecture develops along two separate pathways: the dorsal ‘archicortical’ trend and the ventral ‘paleocortical’ trend. Although various lines of research converge to suggest that SCZ is associated with dorsal trend impairment in the context of relative ventral trend sparing, one persistent inconsistency exists. Specifically, individuals with SCZ routinely show impairment on tasks of action inhibition (AI; the ability to inhibit a pre-planned movement), a function routinely shown to be mediated by the inferior frontal gyrus, a key structure of the ventral trend. Here we argue that conventional tasks of AI conflate AI per se with response conflict (CON) demands, a function shown to be mediated by the anterior cingulate cortex, a key structure of the dorsal trend. We define CON as any aspect of a task that increases the difficulty of deciphering or interpreting the meaning of task stimuli (e.g., greater perceptual similarity between imperative task stimuli). The current research administered novel AI tasks in order to independently examine increases in CON and increases in the prepotency to respond to a pre-planned movement (PREP; considered a more fundamental measure of AI). Consistent with study hypotheses, individuals with Schizoprenia-spectrum disorders (specifically schizotypy) failed to show compensatory response time (RT) slowing when confronted with increasing CON demands yet showed proportional RTs, relative to healthy control participants, as PREP demands increased. These findings were interpreted as reflecting impairment in their ability to detect and/or decipher CON. More broadly, these findings suggest that cognitive abnormalities in SCZ may represent disproportionately impaired dorsal trend circuitry.
67

Comparing autonomic and cardiovascular responses in African and Caucasian men : the SABPA study / Aletta Sophia Uys.

Uys, Aletta Sophia January 2012 (has links)
Motivation Hypertension is a pertinent health problem for urban black African men (hereafter referred to as African). Sympathetic hyperactivity and a dominant α-adrenergic response pattern have both been implicated as contributing factors to their poor cardiovascular health. In addition to the deleterious effect of neurogenic hypertension on target organs, sympathetic hyperactivity may promote the accelerated progression of left ventricular hypertrophy and structural vascular disease. Aim The overarching aim of this study is to scrutinize autonomic control of the cardiovascular system in a cohort of urban African and Caucasian men during a mental challenge. Associations were investigated between potential sympatho-vagal imbalance, blood pressure and target organ damage markers to determine cardiovascular risk in ethnic male groups. Methodology The SABPA (Sympathetic activity and Ambulatory Blood Pressure in Africans) study involved the participation of 200 male teachers (99 African and 101 Caucasian) in the Kenneth Kaunda Education District of the North-West Province, South Africa. Of the participant group, HIV-infected (13 African) and clinically confirmed diabetics (1 Caucasian and 6 African men) were excluded from further analyses. Stratification was based on ethnicity and further as indicated through statistical interaction effects. Cardiovascular and autonomic responses were assessed during rest and on stressor exposure (cold pressor test and Stroop colour-word conflict test). Autonomic measures included baroreceptor sensitivity (BRS), 3-methoxy-4-hydroxy-phenylglycol (MHPG) and nitric oxide metabolite (NOx) levels. Cardiovascular variables consisted of blood pressure, cardiac output, stroke volume, total peripheral resistance, heart rate, arterial compliance and ST-segment from the 12-lead electrocardiogram. Markers of target organ damage included the Cornell product (indication of left ventricular hypertrophy) and carotid intima-media thickness as indication of structural vascular disease. Means and proportions were compared by means of standard t-test and Chi-square test, respectively. Significant differences of mean cardiovascular and autonomic measures between ethnic male groups were also determined through analysis of covariance. Uni- and multivariate regression analyses were employed to demonstrate associations between target organ damage, cardiovascular and autonomic markers. Results and conclusion of each manuscript To assess autonomic nervous system and cardiovascular function as well as target organ damage, we clearly focussed on responses where our participants were challenged. Markers of autonomic responses assessed were baroreceptor sensitivity, 3-methoxy-4-hydroxyphenylglycol and nitric oxide metabolites.  The first manuscript (Chapter 2) focused on left ventricular hypertrophy as marker of target organ damage, blood pressure and baroreceptor sensitivity as marker of autonomic function. The objective was to determine whether BRS was significantly lower in African men than in the Caucasian men. Furthermore, the possible association between attenuation of BRS and increased levels of ambulatory blood pressure as well as left ventricular hypertrophy was investigated in these population groups. Results revealed that the African men had significantly lower BRS stress responses. This attenuated BRS profile was coupled with dominant α-adrenergic response patterns, which was associated with an elevation of ambulatory blood pressure. BRS attenuation (rest and stress response) was not associated with left ventricular hypertrophy. It was concluded that lower BRS, especially during stress, may pose a significant health threat for urban African men regarding the development or promotion of α-adrenergic-driven hypertension and higher cardiovascular disease risk.  The aim of the second sub-study (Chapter 3) was to investigate possible associations between structural vascular disease (carotid intima-media thickness as marker), autonomic function (MHPG as marker) and nocturnal blood pressure in the African and Caucasian men. Results showed a higher prevalence of nocturnal hypertension in the African men, with night-time blood pressure significantly higher compared to the Caucasian men. In the African and Caucasian men, carotid intima-media thickness was linearly predicted by nocturnal systolic and diastolic blood pressure respectively. In conclusion, no associations were demonstrated between MHPG and carotid intimamedia thickness or between MHPG and nocturnal blood pressure. Elevated nocturnal blood pressure evidently seems to promote structural vascular disease in this cohort of urban African and Caucasian men.  The aim of the third manuscript presented in Chapter 4, was to investigate bioavailability of NO during mental challenge (autonomic function marker) and the possible association with structural vascular disease (carotid intima-media thickness as marker). In the African men, an attenuated NOx response was demonstrated to the Stroop colour-word conflict test. After stratification into high and low NOx response groups, in the African men with a low NOx response enhanced α-adrenergic with significant STsegment depression responses was demonstrated indicating reduced myocardial oxygen supply during mental stressor exposure. Only in the African men, a ST-segment depression was significantly associated with structural vascular disease. It was concluded that the African men demonstrated a vulnerable cardiovascular profile. In this cohort of African men, the significant association between structural vascular disease and myocardial ischemia may particularly indicate a possible higher risk for future cardiovascular events. General conclusion Through the assessment of autonomic and cardiovascular responses a possible higher cardiovascular risk was demonstrated in the African men. In this cohort sympathetic hyperactivity was evident, coupled with dominant vascular response patterns and reduced myocardial oxygen supply during mental stress exposure. Based on these findings, this population group’s risk for accelerated target organ damage, as well as for future cardiovascular events, appear significantly higher than those of the Caucasian male cohort. / Thesis (PhD (Physiology))--North-West University, Potchefstroom Campus, 2013.
68

Comparing autonomic and cardiovascular responses in African and Caucasian men : the SABPA study / Aletta Sophia Uys.

Uys, Aletta Sophia January 2012 (has links)
Motivation Hypertension is a pertinent health problem for urban black African men (hereafter referred to as African). Sympathetic hyperactivity and a dominant α-adrenergic response pattern have both been implicated as contributing factors to their poor cardiovascular health. In addition to the deleterious effect of neurogenic hypertension on target organs, sympathetic hyperactivity may promote the accelerated progression of left ventricular hypertrophy and structural vascular disease. Aim The overarching aim of this study is to scrutinize autonomic control of the cardiovascular system in a cohort of urban African and Caucasian men during a mental challenge. Associations were investigated between potential sympatho-vagal imbalance, blood pressure and target organ damage markers to determine cardiovascular risk in ethnic male groups. Methodology The SABPA (Sympathetic activity and Ambulatory Blood Pressure in Africans) study involved the participation of 200 male teachers (99 African and 101 Caucasian) in the Kenneth Kaunda Education District of the North-West Province, South Africa. Of the participant group, HIV-infected (13 African) and clinically confirmed diabetics (1 Caucasian and 6 African men) were excluded from further analyses. Stratification was based on ethnicity and further as indicated through statistical interaction effects. Cardiovascular and autonomic responses were assessed during rest and on stressor exposure (cold pressor test and Stroop colour-word conflict test). Autonomic measures included baroreceptor sensitivity (BRS), 3-methoxy-4-hydroxy-phenylglycol (MHPG) and nitric oxide metabolite (NOx) levels. Cardiovascular variables consisted of blood pressure, cardiac output, stroke volume, total peripheral resistance, heart rate, arterial compliance and ST-segment from the 12-lead electrocardiogram. Markers of target organ damage included the Cornell product (indication of left ventricular hypertrophy) and carotid intima-media thickness as indication of structural vascular disease. Means and proportions were compared by means of standard t-test and Chi-square test, respectively. Significant differences of mean cardiovascular and autonomic measures between ethnic male groups were also determined through analysis of covariance. Uni- and multivariate regression analyses were employed to demonstrate associations between target organ damage, cardiovascular and autonomic markers. Results and conclusion of each manuscript To assess autonomic nervous system and cardiovascular function as well as target organ damage, we clearly focussed on responses where our participants were challenged. Markers of autonomic responses assessed were baroreceptor sensitivity, 3-methoxy-4-hydroxyphenylglycol and nitric oxide metabolites.  The first manuscript (Chapter 2) focused on left ventricular hypertrophy as marker of target organ damage, blood pressure and baroreceptor sensitivity as marker of autonomic function. The objective was to determine whether BRS was significantly lower in African men than in the Caucasian men. Furthermore, the possible association between attenuation of BRS and increased levels of ambulatory blood pressure as well as left ventricular hypertrophy was investigated in these population groups. Results revealed that the African men had significantly lower BRS stress responses. This attenuated BRS profile was coupled with dominant α-adrenergic response patterns, which was associated with an elevation of ambulatory blood pressure. BRS attenuation (rest and stress response) was not associated with left ventricular hypertrophy. It was concluded that lower BRS, especially during stress, may pose a significant health threat for urban African men regarding the development or promotion of α-adrenergic-driven hypertension and higher cardiovascular disease risk.  The aim of the second sub-study (Chapter 3) was to investigate possible associations between structural vascular disease (carotid intima-media thickness as marker), autonomic function (MHPG as marker) and nocturnal blood pressure in the African and Caucasian men. Results showed a higher prevalence of nocturnal hypertension in the African men, with night-time blood pressure significantly higher compared to the Caucasian men. In the African and Caucasian men, carotid intima-media thickness was linearly predicted by nocturnal systolic and diastolic blood pressure respectively. In conclusion, no associations were demonstrated between MHPG and carotid intimamedia thickness or between MHPG and nocturnal blood pressure. Elevated nocturnal blood pressure evidently seems to promote structural vascular disease in this cohort of urban African and Caucasian men.  The aim of the third manuscript presented in Chapter 4, was to investigate bioavailability of NO during mental challenge (autonomic function marker) and the possible association with structural vascular disease (carotid intima-media thickness as marker). In the African men, an attenuated NOx response was demonstrated to the Stroop colour-word conflict test. After stratification into high and low NOx response groups, in the African men with a low NOx response enhanced α-adrenergic with significant STsegment depression responses was demonstrated indicating reduced myocardial oxygen supply during mental stressor exposure. Only in the African men, a ST-segment depression was significantly associated with structural vascular disease. It was concluded that the African men demonstrated a vulnerable cardiovascular profile. In this cohort of African men, the significant association between structural vascular disease and myocardial ischemia may particularly indicate a possible higher risk for future cardiovascular events. General conclusion Through the assessment of autonomic and cardiovascular responses a possible higher cardiovascular risk was demonstrated in the African men. In this cohort sympathetic hyperactivity was evident, coupled with dominant vascular response patterns and reduced myocardial oxygen supply during mental stress exposure. Based on these findings, this population group’s risk for accelerated target organ damage, as well as for future cardiovascular events, appear significantly higher than those of the Caucasian male cohort. / Thesis (PhD (Physiology))--North-West University, Potchefstroom Campus, 2013.
69

Rödpennan är död : En sociokulturell studie av skrivundervisning i gymnasieskolan nu jämfört med då / The red marker is dead : A socio-cultural study about giving feedback on written assignments in the Swedish high school

Welinder, Sanna January 2014 (has links)
Uppsatsens syfte är att undersöka om det går att se förändringar i gymnasieskolans skrivundervisning över en tidsperiod på tretton år. Den teoretiska utgångspunkten är ett sociokulturellt synsätt där dialogismens tankar är dominerande. Materialet består av enkätsvar från gymnasieelever, fokusgruppsamtal med gymnasieelever och intervjuer med gymnasielärare. Det samlades in under 2013 och har analyserats med hjälp av innehållsanalys och tematisering för att se mönster i hur eleverna uttalar sig om responsen. Elevernas perspektiv är i fokus och deras tankar och känslor gällande lärarnas respons jämförs med andra elevers upplevelser från tidigt 2000-tal. Dessa upplevelser, tankar och känslor är hämtade från Suzanne Parmenius Swärds avhandling som berör samma ämne. Jämförelsen visar stora skillnader. I denna undersökning berättar eleverna om en dialogisk respons och aktiva klassrum medan Parmenius Swärds avhandling visade motsatsen, nämligen en monoligisk bristfokuserad responskultur. Detta pekar mot att skrivundervisningen håller på att förändras till att bli mer formativ.
70

Computerized achievement tests : sequential and fixed length tests

Wiberg, Marie H. January 2003 (has links)
The aim of this dissertation is to describe how a computerized achivement test can be constructed and used in practice. Throughout this dissertation the focus is on classifying the examinees into masters and non-masters depending on their ability. However, there has been no attempt to estimate their ability. In paper I, a criterion-referenced computerized test with a fixed number of items is expressed as a statistical inference problem. The theory of optimal design is used to find the test that has the strongest power. A formal proof is provided showing that all items should have the same item characteristics, viz. high discrimination, low guessing and difficulty near the cutoff score, in order to give us the most powerful statistical test. An efficiency study shows how many times more non-optimal items are needed if we do not use optimal items in order to achieve the same power in the test. In paper II, a computerized mastery sequential test is examined using sequential analysis. The focus is on examining the sequential probability ratio test and to minimize the number of items in a test, i.e. to minimize the average sample number function, abbreviated as the ASN function. Conditions under which the ASN function decreases are examined. Further, it is shown that the optimal values are the same for item discrimination and item guessing, but differ for item difficulty compared with tests with fixed number of items. Paper III presents three simulation studies of sequential computerized mastery tests. Three cases are considered, viz. the examinees' responses are either identically distributed, not identically distributed, or not identically distributed together with estimation errors in the item characteristics. The simulations indicate that the observed results from the operating characteristic function differ significantly from the theoretical results. The mean number of items in a test, the distribution of test length and the variance depend on whether the true values of the item characteristics are known and whether they are iid or not. In paper IV computerized tests with both pretested items with known item parameters, and try-out items with unknown item parameters are considered. The aim is to study how the item parameters for try-out items can be estimated in a computerized test. Although the unknown examinees' abilities may act as nuisance parameters, the asymptotic variance of the item parameter estimators can be calculated. Examples show that a more reliable variance estimator yields much larger estimates of the variance than commonly used variance estimators.

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