The rising number of the population that present with major depressive disorder has intensified the need to identify and elucidate new biological markers for the diagnosis and treatment of depression. Depression presents with evidence of changes in the nitric oxide (NO) pathway. In this study, levels of various endogenous markers of the NO cascade, viz. nitrite (NO2–), asymmetrical dimethylarginine (ADMA) and arginase II activity, were investigated in the Flinders Sensitive Line (FSL) rat, a genetic animal model of depression. The aim of the current study was to determine if there are differences between these markers in the plasma of the FSL rat compared to its healthy control, the (Flinders Resistant Line) FRL rat, with the possibility of considering their use as biomarkers of depression. Nitrite was chosen as metabolite over nitrate (NO3–) because the dietary intake of nitrite and/or nitrate does not significantly affect nitrite (NO2–) levels in plasma. Although this is of no significance if applied to rats, it is an important factor to be considered when doing clinical studies. For neurochemical determination of nitrite a sensitive fluorometric reversed phase high–performance liquid chromatographic (HPLC) assay was developed to analyze nitrite in human and rat plasma. Derivatization of sample nitrite was performed with 2,3–diaminonaphthalene (DAN) followed by the quantification of the stable and highly fluorescent product, 2,3–naphthotriazole (NAT). Determination of arginase II activity was performed by measuring L–arginine and L–ornithine concentrations in the plasma, while ADMA was measured simultaneously with L–arginine and L–ornithine using liquid chromatography/tandem mass spectrometry, or LC/MS/MS. Plasma nitrite levels of FSL rats were significantly decreased compared to plasma nitrite levels in the FRL rat, but neither the levels of ADMA nor arginase II activity showed a significant difference between the FSL and FRL rat groups. From these results it is concluded that in accordance with previous studies, the NO pathway plays an important role in the pathophysiology of depression, as depicted in the differences found between plasma nitrite levels in the FSL rat compared to its healthy control. / Thesis (M.Sc. (Pharmacology))--North-West University, Potchefstroom Campus, 2011.

Major depression is a highly prevalent mood disorder with chronic debilitating effects. Additional to a rising rate in incidence, depression is highly co–morbid with other psychiatric disorders, but also chronic cardiometabolic illnesses that present with an inflammatory component. The exact aetiology of depression is still unknown, being multifactorial in its possible aetiology. Various hypotheses have attempted to shed light on both endogenous and exogenous risk factors as well as the underlying pathology that may lead to the development of the disease. This has led to a wide range of mediators being implicated, including biogenic amines, the HPA–axis, neurotrophic factors, inflammatory agents, the cholinergic system and circadian rhythm, to name a few. The mechanisms of action of current treatment strategies, except for a few atypical and novel treatment approaches, are limited to interactions with monoamines and are at best only 65% effective. Many of these are also plagued by troubling side–effects, relapse and recurrence. It has therefore become imperative to explore novel targets for the treatment of depression that may produce more rapid, robust and lasting antidepressant effects with a less daunting side–effect profile. The strong co–morbidity between depression and various cardiometabolic disorders, including cardiovascular disease, atherosclerosis, type 2 diabetes mellitus (T2DM) and metabolic syndrome (MetS) has led to the proposal that a metabolic disturbance may be a vital component that drives inflammatory and immunological dysfunction in depression. Supporting of this is evidence for a role of inflammatory cytokines and neurotrophic factors in the pathogenesis of depression. It has also been demonstrated that a link exists between insulin– and nitric oxide (NO)– mediated pathways in the brain, which further highlights the role of oxidative stress and cell damage. Furthermore, evidence supports a role for oxidative stress and NO in T2DM and/or insulin resistance. Insulin has also been implicated in various physiological processes in the central nervous system (CNS) and may also influence the release and reuptake of neurotransmitters. Preclinical and clinical evidence has provided support for the antidepressant–like effects of insulin–sensitizing peroxisome proliferator activated receptor (PPAR)– agonists, such as rosiglitazone and pioglitazone. In preclinical studies, however, these effects are limited to acute treatment with pioglitazone or sub–chronic (5 days) treatment with rosiglitazone. It is well–recognized that such findings need to be confirmed by chronic treatment paradigms. The aim of the current study was therefore to further investigate the proposed antidepressant–like effects of pioglitazone in a genetic animal model of depression, the Flinders sensitive line (FSL) rat, using a chronic treatment protocol. The FSL rat model was reaffirmed as presenting with inherent depressive–like behaviour compared to its more resilient counterpart, the Flinders resistant line (FRL) rat. Moreover, imipramine demonstrated a robust and reliable antidepressant–like effect in these animals using the forced swim test (FST), thus confirming the face and predictive validity of the FSL rat model for depression. In contrast to previous preclinical studies, acute dose–ranging studies with pioglitazone in Sprague Dawley rats delivered no significant anti–immobility effects in the FST, whereas results similar to that seen in the dose–ranging studies were observed following chronic treatment using FSL rats. Since altered pharmacokinetics could possibly influence the drug’s performance, another route of administration, viz. the subcutaneous route, was utilized as an additional measure to exclude this possibility. The results of the subcutaneous study, however, were congruent with that observed after oral treatment. In order to confirm an association between altered insulin sensitivity and antidepressant action and demonstration by recent studies that thiazolidinediones may augment the efficacy of existing antidepressants, we therefore investigated whether concomitant treatment with gliclazide (an insulin releaser and insulin desensitizer) or pioglitazone (an insulin sensitizer) may alter the antidepressant–like effects evoked by chronic treatment with imipramine. Pioglitazone did not positively or negatively affect the antidepressant effect of imipramine, although gliclazide tended to decrease the anti–immobility effects induced by this antidepressant. Taken together and considering the current available literature, this finding supports evidence linking the insulin–PPAR pathway to depression. However, further explorative studies are required to delineate the role of insulin sensitivity and glucose homeostasis in depression and antidepressant response. / Thesis (M.Sc. (Pharmacology))--North-West University, Potchefstroom Campus, 2012.

The rising number of the population that present with major depressive disorder has intensified the need to identify and elucidate new biological markers for the diagnosis and treatment of depression. Depression presents with evidence of changes in the nitric oxide (NO) pathway. In this study, levels of various endogenous markers of the NO cascade, viz. nitrite (NO2–), asymmetrical dimethylarginine (ADMA) and arginase II activity, were investigated in the Flinders Sensitive Line (FSL) rat, a genetic animal model of depression. The aim of the current study was to determine if there are differences between these markers in the plasma of the FSL rat compared to its healthy control, the (Flinders Resistant Line) FRL rat, with the possibility of considering their use as biomarkers of depression. Nitrite was chosen as metabolite over nitrate (NO3–) because the dietary intake of nitrite and/or nitrate does not significantly affect nitrite (NO2–) levels in plasma. Although this is of no significance if applied to rats, it is an important factor to be considered when doing clinical studies. For neurochemical determination of nitrite a sensitive fluorometric reversed phase high–performance liquid chromatographic (HPLC) assay was developed to analyze nitrite in human and rat plasma. Derivatization of sample nitrite was performed with 2,3–diaminonaphthalene (DAN) followed by the quantification of the stable and highly fluorescent product, 2,3–naphthotriazole (NAT). Determination of arginase II activity was performed by measuring L–arginine and L–ornithine concentrations in the plasma, while ADMA was measured simultaneously with L–arginine and L–ornithine using liquid chromatography/tandem mass spectrometry, or LC/MS/MS. Plasma nitrite levels of FSL rats were significantly decreased compared to plasma nitrite levels in the FRL rat, but neither the levels of ADMA nor arginase II activity showed a significant difference between the FSL and FRL rat groups. From these results it is concluded that in accordance with previous studies, the NO pathway plays an important role in the pathophysiology of depression, as depicted in the differences found between plasma nitrite levels in the FSL rat compared to its healthy control. / Thesis (M.Sc. (Pharmacology))--North-West University, Potchefstroom Campus, 2011.

Major depression is a highly prevalent mood disorder with chronic debilitating effects. Additional to a rising rate in incidence, depression is highly co–morbid with other psychiatric disorders, but also chronic cardiometabolic illnesses that present with an inflammatory component. The exact aetiology of depression is still unknown, being multifactorial in its possible aetiology. Various hypotheses have attempted to shed light on both endogenous and exogenous risk factors as well as the underlying pathology that may lead to the development of the disease. This has led to a wide range of mediators being implicated, including biogenic amines, the HPA–axis, neurotrophic factors, inflammatory agents, the cholinergic system and circadian rhythm, to name a few. The mechanisms of action of current treatment strategies, except for a few atypical and novel treatment approaches, are limited to interactions with monoamines and are at best only 65% effective. Many of these are also plagued by troubling side–effects, relapse and recurrence. It has therefore become imperative to explore novel targets for the treatment of depression that may produce more rapid, robust and lasting antidepressant effects with a less daunting side–effect profile. The strong co–morbidity between depression and various cardiometabolic disorders, including cardiovascular disease, atherosclerosis, type 2 diabetes mellitus (T2DM) and metabolic syndrome (MetS) has led to the proposal that a metabolic disturbance may be a vital component that drives inflammatory and immunological dysfunction in depression. Supporting of this is evidence for a role of inflammatory cytokines and neurotrophic factors in the pathogenesis of depression. It has also been demonstrated that a link exists between insulin– and nitric oxide (NO)– mediated pathways in the brain, which further highlights the role of oxidative stress and cell damage. Furthermore, evidence supports a role for oxidative stress and NO in T2DM and/or insulin resistance. Insulin has also been implicated in various physiological processes in the central nervous system (CNS) and may also influence the release and reuptake of neurotransmitters. Preclinical and clinical evidence has provided support for the antidepressant–like effects of insulin–sensitizing peroxisome proliferator activated receptor (PPAR)– agonists, such as rosiglitazone and pioglitazone. In preclinical studies, however, these effects are limited to acute treatment with pioglitazone or sub–chronic (5 days) treatment with rosiglitazone. It is well–recognized that such findings need to be confirmed by chronic treatment paradigms. The aim of the current study was therefore to further investigate the proposed antidepressant–like effects of pioglitazone in a genetic animal model of depression, the Flinders sensitive line (FSL) rat, using a chronic treatment protocol. The FSL rat model was reaffirmed as presenting with inherent depressive–like behaviour compared to its more resilient counterpart, the Flinders resistant line (FRL) rat. Moreover, imipramine demonstrated a robust and reliable antidepressant–like effect in these animals using the forced swim test (FST), thus confirming the face and predictive validity of the FSL rat model for depression. In contrast to previous preclinical studies, acute dose–ranging studies with pioglitazone in Sprague Dawley rats delivered no significant anti–immobility effects in the FST, whereas results similar to that seen in the dose–ranging studies were observed following chronic treatment using FSL rats. Since altered pharmacokinetics could possibly influence the drug’s performance, another route of administration, viz. the subcutaneous route, was utilized as an additional measure to exclude this possibility. The results of the subcutaneous study, however, were congruent with that observed after oral treatment. In order to confirm an association between altered insulin sensitivity and antidepressant action and demonstration by recent studies that thiazolidinediones may augment the efficacy of existing antidepressants, we therefore investigated whether concomitant treatment with gliclazide (an insulin releaser and insulin desensitizer) or pioglitazone (an insulin sensitizer) may alter the antidepressant–like effects evoked by chronic treatment with imipramine. Pioglitazone did not positively or negatively affect the antidepressant effect of imipramine, although gliclazide tended to decrease the anti–immobility effects induced by this antidepressant. Taken together and considering the current available literature, this finding supports evidence linking the insulin–PPAR pathway to depression. However, further explorative studies are required to delineate the role of insulin sensitivity and glucose homeostasis in depression and antidepressant response. / Thesis (M.Sc. (Pharmacology))--North-West University, Potchefstroom Campus, 2012.

Stereology supplies image sampling rules to estimate geometric quantities such as volume, surface area, feature length and number. The method is well suited to non-invasive image acquisition methods such as Magnetic Resonance Imaging (MRI). Meanwhile, in Magnetic Resonance (MR) images analysis area, automated software packages have been continuously developed and become well-established tools especially in human brainMR images processing. The aims of the thesis are (1) to combine proper rules to sample MR images with automated or semi-automated data acquisition methods, in order to implement four different design unbiased stereological volume estimators in the study of the human brain, and (2) to compare volume estimates with those obtained from automated software packages.

The scope of this thesis is to process and analyze statistically Magnetic Resonance Images (MR-T1) from Parkinson’s disease patients in order to detect brain areas that exhibit brain change which is caused by the disease. Parkinson’s disease is an idiopathic disease which means that its cause is yet unknown. It is a chronic neurodegenerative disorder of the central nervous system which causes the progressive death of specific brain neurons that leads to motor impairments (tremor, bradykinesia, muscle rigidity) and non motor ones (cognitive, sleep, sensation disturbances). Magnetic Resonance Images (T1-weighted) were acquired from both Parkinson’s patients and healthy subjects (Controls) at intervals of 0 and 5 years. The data have undergone longitudinal (two-time-point), cross sectional (single-time-point) and statistical analysis with the use of FSL software library. Evidence of atrophy among Parkinson’s patients aroused, in brain areas near the ventricles and the middle temporal gyrus, after statistical analysis / Ο σκοπός αυτής της εργασίας είναι η επεξεργασία και στατιστική ανάλυση μαγνητηκών τομογραφιών (MR-T1) από ασθενείς με Πάρκινσον για την ανίχνευση περιοχών του εγκεφάλου που παρουσιάζουν μεταβολές που οφείλονται στην ασθένεια. Η ασθένεια Πάρκινσον είναι ιδιοπαθής, δηλαδή ασθένεια της οποίας η αιτία παραμένει ακόμη άγνωστη. Είναι μια χρόνια δυσλειτουργία λόγω εκφυλισμού των νευρώνων του κεντρικού νευρικού συστήματος η οποία προκαλεί τη σταδιακή νεκρωση συγκεκριμένης ομάδας εγκεφαλικών νευρώνων. Αυτή η νέκρωση οδηγεί σε κινητικές δυσλειτουργίες (τρέμουλο, βραδυκινησία, και μυϊκή δυσκαμψία και σε μή κινητικές όπως γνωστικές, διαταραχής ύπνου,διαταραχές αφής κ.α. Μαγνητικές τομογραφίες (τύπου Τ1) ασθενών και υγιών ελήφθησαν σε διαστήματα 0 και 5 ετών. Τα δεδομένα αναλύθηκαν με δυο μεθόδους (longitudinal και cross-sectional) και εν συνεχεία έγινε στατιστική επεξεργασία των αποτελεσμάτων. Έγινε χρήση της βιβλιοθήκης FSL Μετά από στατιστική ανάλυση προέκυψαν ενδείξεις ατροφίας στους ασθενείς με Πάρκινσον σε περιοχές του εγεκφάλου κοντά στις εγκεφαλικές κοιλίες (ventricles) και στη μέσο-κροταφική έλικα (middle temporal gyrus).

Since 2003, the Canadian government has repeatedly called for research into innovative ways to teach Core French (CF) – a non-immersion program, where French as a Second Language (FSL) is taught on a daily basis, or a few times per week. This exploratory study investigates the driving forces behind the widespread popularity of a CF method called the Accelerative Integrated Method (AIM), which combines target language use with gestures, high-frequency vocabulary, and drama to accelerate the development of fluency from the onset of classroom instruction. In order to learn more about the “meaningfulness” of this growing trend (Fullan, 2007), this mixed-method inquiry attempts to shift the focus from product to process, comparing educator perspectives and AIM implementation within two Ontario contexts: (a) where AIM was mandated for elementary (Grades 4-6) FSL instruction, and (b) where AIM was an optional method for FSL teachers to use (or not). Survey and interview data were collected from and triangulated across a variety of educators from both contexts, including FSL consultants (n = 18), principals (n = 8), CF teachers (n = 9), and one Ontario Ministry of Education representative. Four semi-structured interviews and multiple observations were also conducted with those CF teachers who were using AIM (n = 8). An additional CF teacher who had attempted to use AIM, and had subsequently rejected it, was also interviewed. Findings showed that AIM implementation and educator perspectives did not vary significantly based on whether AIM was mandated or optional for CF instruction. A clear preference emerged towards using AIM and the accompanying resources during the beginning stages of CF instruction. Discussion about the growing popularity of AIM was positive; however, it also exposed a range of emotions about when and how AIM should be used. In terms of implementation, while some AIM routines, activities, and strategies were used by all, each AIM teacher exercised their agency while using the method, supplementing and adapting for different reasons. Implications include the need to reexamine the objectives of micro-level AIM policies, recognize the adaptability of AIM, and consider including detailed observations in future research linking AIM to student achievement.

Since 2003, the Canadian government has repeatedly called for research into innovative ways to teach Core French (CF) – a non-immersion program, where French as a Second Language (FSL) is taught on a daily basis, or a few times per week. This exploratory study investigates the driving forces behind the widespread popularity of a CF method called the Accelerative Integrated Method (AIM), which combines target language use with gestures, high-frequency vocabulary, and drama to accelerate the development of fluency from the onset of classroom instruction. In order to learn more about the “meaningfulness” of this growing trend (Fullan, 2007), this mixed-method inquiry attempts to shift the focus from product to process, comparing educator perspectives and AIM implementation within two Ontario contexts: (a) where AIM was mandated for elementary (Grades 4-6) FSL instruction, and (b) where AIM was an optional method for FSL teachers to use (or not). Survey and interview data were collected from and triangulated across a variety of educators from both contexts, including FSL consultants (n = 18), principals (n = 8), CF teachers (n = 9), and one Ontario Ministry of Education representative. Four semi-structured interviews and multiple observations were also conducted with those CF teachers who were using AIM (n = 8). An additional CF teacher who had attempted to use AIM, and had subsequently rejected it, was also interviewed. Findings showed that AIM implementation and educator perspectives did not vary significantly based on whether AIM was mandated or optional for CF instruction. A clear preference emerged towards using AIM and the accompanying resources during the beginning stages of CF instruction. Discussion about the growing popularity of AIM was positive; however, it also exposed a range of emotions about when and how AIM should be used. In terms of implementation, while some AIM routines, activities, and strategies were used by all, each AIM teacher exercised their agency while using the method, supplementing and adapting for different reasons. Implications include the need to reexamine the objectives of micro-level AIM policies, recognize the adaptability of AIM, and consider including detailed observations in future research linking AIM to student achievement.

A focal concern amid Canadian French immersion students upon completion of their secondary school studies is a shared belief and feeling that they are limited in their ability to communicate with francophone communities (Howard, 2007; Schaffer, 2013; The Globe and Mail, Friesen, 2013). Furthermore, it has been widely discussed that French immersion students are finding themselves in the midst of language identity crisis, unable to find a place among either of the dominant monolingual groups (Roy, 2010). This case study examined the potential persistence of language identity crisis in three French immersion students who extended their French as a second language education by pursuing post-secondary education in a French immersion program at a large bilingual university. The study reveals the linguistic identity construction of these students by clarifying how each participant positioned (Davies & Harré, 1990) herself towards Francophone language and culture. It exposes the factors which influenced the linguistic positioning of the participants and comments on patterns in the factors which affected their linguistic identity in particular.

Cette recherche vise la mise au jour du lien entre la formation à la méthodologie de l’enseignement du français comme langue étrangère et le développement de l’agir professionnel de l’enseignant novice. Elle s’inscrit dans le cadre plus général des travaux ayant pour objet la formation des enseignants et leurs pratiques effectives. La mise en place d’un appareillage, la trame méthodique repère (TMR), destiné à la conception d’unités didactiques et à la formation des pratiques professionnelles enseignantes, est au coeur de la première partie de cette étude qui, dans un second temps, montre de quelle manière la modélisation proposée par la TMR rend possible la circulation des savoirs d’ingénierie, de la formation au développement de l’agir des enseignants novices. / This research brings to light the link between French second language teacher training and the development of beginning teachers’ actions. It is set in the wider field of language teacher education research and teachers’ real practice. The first part of this study presents the implementation of a language teaching methodological framework aimed at lesson design and language teacher training. The second part shows how the sequence of language objects and activities of the framework makes it possible for vocational language teaching knowledge to evolve from training to teaching.