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Troubles de l'attachement et traumatismes chez l'enfant : recension intégratives des écritis
No full textLes troubles de l’attachement dans l’enfance, et plus particulièrement les troubles réactionnels de l’attachement sont complexes. Afin de bien saisir leur complexité et intervenir adéquatement, il faut non seulement bien les comprendre et les cerner, mais aussi bien évaluer les traumatismes associés à ces troubles et les effets des traumatismes vécus par l’enfant. Ce mémoire, construit à l’aide d’une recension intégrative des écrits, vise à offrir quelques pistes de réflexion et de compréhension sur les troubles de l’attachement, dont le trouble réactionnel de l’attachement, les traumatismes, dont les traumatismes sévères vécus dans l’enfance, et les principaux modèles d’intervention pour traiter ces deux problématiques. La discussion porte principalement sur les barrières qui rendent très difficile l’intervention auprès de ces enfants et, plus particulièrement auprès des enfants qui vivent dans le nord de l’Ontario.Maîtrise en service socia
Does exercise-induced inflammation serve a useful purpose across the adult age span?
No full textInflammation is a protective biological response involving immune cells, blood vessels and molecular mediators, initiated upon the induction of cell injury (Abbas, Lichtman, & Pillai, 2007). The purpose of nflammation is to both eliminate the cause of the injurious agent (Abbas et al., 2007) as well as remove dead cells and tissues, damaged from the initial assault (Lapointe, Frenette, & Côté, 2002), and to initiate tissue repair (Ricciotti & FitzGerald, 2011). Inflammation as an event is a generic response to any injurious insult, which includes exercise-induced injury (Nehlsen-Cannarella et al., 1997). Exercise-induced muscle damage is defined as an injury from a mechanical force applied externally, causing structural stress or strain, resulting in cellular or tissue responses (Mueller & Maluf, 2002).
An acute inflammatory response is sometimes instigated during exercise (Nehlsen-Cannarella et al., 1997); its initiation and magnitude depend upon the degree of physiological stress applied during the exercise bout (McFarlin, Flynn, Stewart, & Timmerman, 2004).
Exercise-induced inflammation is typically seen in endurance sports where there is overuse of specific tissues (McFarlin et al., 2004). Physiological stress increases as intensity, duration and internal stimuli (e.g., blood glucose levels) increase (McFarlin et al., 2004). Thus, prolonged and intensive exercises significantly increase the induction of and the magnitude of an inflammatory response (McFarlin et al., 2004).
Exercise-induced inflammation also stimulates the activation of the hypothalamic-pituitary adrenocortical (HPA) axis, characterised by elevated levels of cortisol and other mediators, inducing immune suppressive effects and thereby reinstating immune homeostasis (Tsigos & Chrousos, 2002). However, the immunosuppressive effects of the HPA axis may be detrimental to individuals if over-stimulated (Tsigos & Chrousos, 2002).Various methods have been employed in training regimes to counteract this inflammatory response Exercise-Induced Inflammation 7 (Bleakley, McDonough, & MacAuley, 2004; Gleeson, Nieman, & Pedersen, 2004; Quintero, Wright, Fu, & Huard, 2009). Carbohydrate supplementation is one method (Gleeson et al., 2004; McFarlin et al., 2004; Mitchell et al., 1998; Nehlsen-Cannarella et al., 1997; Nieman et al., 2004; Nieman et al., 1998; Scharhag, Myer, Auracher, Gabriel, & Kindermann, 2006). Others, such as cryotherapy (Bleakley et al., 2004) and RICE (rest, ice, compression, and elevation; Quintero et al., 2009), are also commonly used to reduce the exercise-induced inflammatory response under conditions where muscle soreness and/or injuries occur following physical activity (Bleakley et al., 2004; Quintero et al., 2009). The underlying theory is that reducing the inflammation will improve muscle tissue recovery (Bleakley et al., 2004; Quintero et al., 2009).
The exercise-induced inflammatory response is necessary for performance adaptation (Kurtz, Loebig, Anderson, DeMeo, & Campbell, 1999), although, it may also lead to injury and is often associated with pain or discomfort by the individual (Abbas et al., 2007). Considering these two, opposing concepts, it would be valuable to understand the appropriate management of exercise-induced inflammation for both injury prevention and performance gains.
Further complicating this question are external factors, which can enhance or reduce systemic inflammation (Gomez, Nomellini, Faunce, & Kovacs, 2008; Weiskopf, Weinberger & Grubeck-Loebenstein, 2009). In particular, age has significant impacts on both immune function and underlying inflammatory status (Franceschi et al., 2007; Gomez et al., 2008; Weiskopf et al., 2009). For example, aging impacts immune function by weakening immune responses to infections (Gomez, Boehmer, & Kovacs, 2005).
Therefore, the purpose of this paper is to answer two questions: 1) ‘Does Exercise- Induced Inflammation Serve a Useful Purpose?’; and 2) ‘How Does Aging Affect this Process?’ To address these questions, this paper will first: i) review the role of inflammation as part of the Exercise-Induced Inflammation 8 innate immune response; ii) examine the positive and negative consequences of the exercise induced inflammatory response; and iii) outline the age-related effects on both the immune system and underlying inflammatory status
The role of FGF growth factors in the development of chemotherapy drug resistance in ovarian cancer cells.
No full textOvarian cancer is the most gynecological cancer, it has a 5-year mortality rate greater
than 70%. When ovarian cancer patients undergo chemotherapy their gene expression
changes. This project is studying a particular group of genes called Fibroblast Growth
Factors (FGFs), which have been found to be very important in cancer. The hypothesis
predicted that significant changes in the expression of FGF proteins are associated with
the development of drug resistance in ovarian cancer. Previous work developed three
resistant cell lines from the A2780 ovarian cancer cell line (A2780CBN, A2780DXL,
A2780CBNDXL), In the previous studies, microarray analysis was performed to find
changes in gene expression in the three cell lines. We have been able to confirm some of
the changes that indicated a possible role for FGF gene expression changes in drug
resistance. However, we could only confirm a change in protein expression for one of the
FGF factors, FGF23, which was altered in A2780CBN and A2780CBNDXL resistant cell
lines
The effect of pleasant and unpleasant music on judgments of learning and memory recall
No full textPrevious research has suggested that if music is perceived as pleasant, it will evoke a positive mood and if music is perceived as unpleasant or aversive, it will evoke a negative mood. Mood has an effect on memory, as a positive mood enhances cognitive processes, and a negative mood impairs cognitive processes. Research has suggested that Judgments-of-Learning (JOLs) or the predictions of the likelihood of future recall, are generally accurate. According to the Cue-Utilization-Framework (Koriat, 1997), JOLs depend on intrinsic, mnemonic and extrinsic cues. Extrinsic cues include environmental factors such as background music. The purpose of the current study was to investigate the effect of music as a potential extrinsic cue, as perceived as pleasant or unpleasant, on the accuracy of JOLs and memory recall. It is examined whether or not a congruency in music between the learning and testing periods had an effect on the accuracy of JOLs and memory recall. 62 Undergraduate students attending Laurentian University were randomly assigned to one of four conditions including: Pleasant music during learning, negative music during recall, unpleasant music during learning and negative during recall, pleasant music during both and negative music during both. Participants were asked to complete a six-scale mood rating five times throughout the experiment that included items such as cheerful, content, relaxed, irritated, frustrated, and upset. There were two word lists containing 20 words each, and participants were required to progress through a timed PowerPoint where a word would display for 5 seconds and a JOL was made immediately after (in 4 seconds). They were given 5 minutes to recall at the end of each word list. Results did not support the notion that music is an extrinsic cue affecting JOLs as there were no significant differences between conditions. Also, mood dependent memory did not exert an effect on JOLs and Recall, as incongruent conditions had significantly higher mean JOL-Recall than congruent condition (an opposite effect). Overall, JOLs appear to be an accurate predictor of performance.Honours essa
Synthesis and characterization of novel ethylene copolymers by palladium-diimine catalysts
Get PDFLate transition metal catalysts, especially Pd-diimine catalysts, have been
extensive studied for olefin polymerization. The unique characteristics of Pd–diimine
catalysts, including chain walking mechanism, highly electrophilic cationic metal center
with reduced oxophilicity, the capability of initiating and catalyzing olefin "living"
polymerization, and the sterically tunable–diimine ligands, allow the synthesis of a
range of polyolefins and olefin copolymers with special pedant functionalities and
unique microstructures. The main objective of this thesis research is to synthesize
different new types of polymers and polymer-grafted nanoparticles with Pd–diimine
catalysts by utilizing above unique characteristics.
A broad class of low-polydispersity ethylene–norbornene (E–NB) copolymers
having various controllable comonomer composition distributions, including gradient,
alternating, diblock, triblock, and block-gradient, was synthesized through
“living”/quasi-living E–NB copolymerization facilitated with a single Pd–diimine
catalyst. This synthesis benefits from two remarkable features of the Pd–diimine catalyst,
its high capability in NB incorporation and high versatility in rendering E–NB “living”
copolymerization at various NB feed concentrations ([NB]0) while under an ethylene
pressure of 1 atm and at 15 C.
A class of hyperbranched polyethylene ionomers containing positively charged
tetralkylammonium ions and different counter anions were first synthesized by direct
iv
one-pot copolymerization of ethylene with tetralkylammonium-containing acrylate-type
ionic liquid comonomers. The use of a Pd–diimine catalyst, which shows excellent
stability towards the highly polar ionic group, is key to the direct synthesis. The
resulting ionomers properties including structural, thermal, and melt rheological
properties have also been demonstrated.
In a further study, HBPE ionomers encapsulating self-supported Pd(0)
nanoparticles (NPs) as efficient and recyclable supported Pd catalysts were synthesized
with a Pd–diimine catalyst. The Pd(0) NPs were immobilized on the ionomer matrix
through ionic interaction directly during the copolymerization of ethylene with
polymerizable ionic liquid comonomer. The resulting ionomer supported Pd(0)
nanocatalysts have been utilized to catalyze carbon-carbon cross coupling reactions
(Suzuki and Heck reactions) and semi-hydrogenation of alkynes.
Moreover, the successful tuning of structural parameters of PE brushes in
surface-initiated ethylene “living” polymerization from two types of silica nanoparticles
were studied. The brush parameters that are controlled herein include brush length,
density, and topology. The PE-grafted silicas with varying brush density and length are
also used as nanofillers to construct polymer nanocomposites with an elastomeric
ethylene-olefin copolymer (EOC) as the matrix polymer. The effects of brush length and
density on the nanofiller dispersion, rheological properties, and tensile properties of the
composites are examined (The preparation and characterization of the nanocomposites
were carried out by K. Petrie and M. Kontopoulou at Queen’s University)
Cytokine-mediated regulation of catecholamine biosynthetic enzymes in adrenal chromaffin cells
No full textThe immune system is increasingly recognized for its role in the genesis and progression of hypertension. Catecholamines function in the neuro-hormonal regulation of blood pressure and have a well-established link to hypertension. It was hypothesized that cytokine signalling within the adrenal medulla influences catecholamine biosynthesis, thereby potentially impacting blood pressure. This study reports that IFN-α, IL-1β, IL-2, IL-6, IL-10, TNF-α, and CCL2 affected transcript levels of tyrosine hydroxylase, dopamine β-hydroxylase, and phenylethanolamine N-methyltransferase (PNMT) in PC12 cells. Further, simultaneous treatment with dexamethasone or forskolin produced context-dependent changes in the transcripts, some of which corresponded to alterations in PNMT promoter activation, but not to localization of glucocorticoid receptor. Thus, cytokines exert transcriptional control over catecholamine biosynthetic enzymes and cytokine signalling is integrated with hormonal and neural regulatory mechanisms in PC12 cells. Changes in adrenal cytokines during hypertension may promote blood pressure elevation by influencing catecholamine biosynthesis
Enfants et jeunes adultes avec besoins complexes en communication et habiletés cognitives impliquées dans la navigation d’une aide à la communication avec sortie vocale
No full textProblèmes de consommation d’alcool et les biais attentionnels : étude de population en traitement
Get PDFLa présente thèse comprend trois chapitres. Dans le premier chapitre, une revue de théories populaires portant sur les problèmes de consommation d’alcool est présentée dans le but d’en faire un compte rendu pour ensuite se pencher sur une explication spécifique : les biais attentionnels. Les biais attentionnels se produisent lorsque les processus d’attention sélective favorisent systématiquement un stimulus spécifique tout en excluant d’autres stimuli pertinents. De nombreuses études ont montré un lien entre la consommation problématique d’alcool et les biais attentionnels (voir Wiers & Stacy, 2006). Or, ce lien a été établi sur la base de tâches artificielles qui ne permettent pas de généraliser ces observations aux activités quotidiennes. Le deuxième chapitre comprend un article empirique soumis pour publication dans la Revue canadienne des sciences du comportement. Cet article a comme objectif de vérifier la présence de biais attentionnels chez les participants parmi les plus sollicités ces dernières années, c’est-à-dire les consommateurs étudiants binges1 et légers ainsi que les consommateurs en cours de traitement, en se servant d’une tâche naturelle. Pour ce faire, les mouvements oculaires des participants sont enregistrés lorsqu’ils observent des scènes complexes (ex. des scènes de bar comprenant plusieurs individus et objets). Le nombre de saccades, l’orientation initiale, la proportion de temps passé sur les stimuli liés à l’alcool et le temps total d’observation sont mesurés. De plus, les participants ont complété le Khavari Alcohol Test (KAT) pour mesurer leurs comportements de consommation d’alcool dans le but de les regrouper sur la base de la fréquence et du volume de consommations rapportées. Les résultats les plus pertinents révèlent que les participants classés comme consommateurs binges regardent les zones d’intérêt plus
rapidement que les deux autres groupes peu importe le contenu de l’image (liée à l’alcool ou neutre). Aussi, les consommateurs en traitement passent significativement plus de temps que les consommateurs légers dans les zones d’intérêt, peu importe le contenu (liée à l’alcool ou non). Il est à noter que l’échantillon est petit et que les participants varient en âge; des variables devant être prises en considération dans l’interprétation des résultats. Finalement, le troisième chapitre se veut une discussion et une conclusion faisant le lien entre des théories populaires expliquant la consommation problématique d’alcool, les résultats de l’étude empirique de l’article soumis et des liens pratiques pouvant en découler
The lived experience of Anishinaabe people with cancer: a focus on Indigenous healing, Western medicine and Minobimaadiziwin
Get PDFCancer is a leading cause of death in Anishinaabe people and the incidence is increasing. Despite reported successes of integrating Indigenous healing and Western medicine in the treatment of addictions, domestic violence, mental health, palliative care and chronic illness, there is a paucity of such information for cancer. A number of studies highlighted the need for awareness for policy makers and physicians of the contribution of Indigenous healing to cancer care, as well as the need for cultural safety. This Indigenous inquiry examined potential benefits and challenges of including Indigenous healing in cancer care. Using a participatory approach, I investigated how the cancer experience was affected when Anishinaabe people included both Indigenous and Western medicine in treatment and when they did not. This inquiry also examined how Indigenous healing assisted in achieving Minobimaadiziwin, an Anishinaabe understanding of health. Interviews were conducted with thirteen adults diagnosed with cancer from five Manitoulin First Nation communities. Seventeen key informant interviews were conducted with those working from Indigenous and Western health perspectives. A conversational method was employed in this Indigenous research as it honoured the oral tradition of the Anishinaabe and was concerned with co-creating knowledge in a relational context. Understanding stories involved Indigenous knowledge and Western theory, framed as two-eyed seeing. Participants recognized that Minobimaadiziwin could not be realized with Western medicine alone. With the inclusion of IH/TM and recognition of the spiritual component of life, a person can approach Minobimaadiziwin despite the obstacle of cancer along their path. This is best iv facilitated by braiding the two types of healing. Dissemination of results took two forms: a collective, teaching story for the Anishinaabe people concerning cancer and Minobimaadiziwin and publications concerning potential benefits of and challenges with pluralistic medicine for Anishinaabe cancer care
Enzymatic and immunological comparison of Mycobacterium tuberculosis and a clinical isolate of streptomyces.
Get PDFTuberculosis is a bacterial infection that affects one-third of the global population. The pathogen responsible for the vast majority of these cases is Mycobacterium tuberculosis and the current vaccines are insufficiently effective. The current vaccine against Tuberculosis is the live bacille Calmette-Guérin (BCG) vaccine with efficacy varying between 0% and 60% depending on the population demographics. DNA, cellular fractions of the pathogen, and subunit vaccines failed to provide protection beyond what the BCG vaccine can provide. Streptomyces, phylogenetic relatives of the mycobacteria, have been suggested as heterologous systems to formulate new vaccines against Tuberculosis. The main research objective of this study is to establish a functional relationship between M. tuberculosis and a clinical isolate of streptomyces using enzymatic and immunological profiling. This clinical isolate was confirmed to be related to Streptomyces albus. Enzymatic profiling of the culture filtrate showed that out of a total of 19 enzyme activities investigated, eight were common between S. albus and M. tuberculosis. These were: alkaline phosphatase, esterase lipases (C8), lipase (C14), leucine arylamidase, valine arylamidase, acid phosphatase, naphthol-ASBI-
phosphohydrolase, and B-glucosidase. Highest levels of acid phosphatase activity was
found in the culture filtrate protein (CFP) fraction of S. albus cultured in media containing glycine as a nitrogen source but was highest in the cytoplasmic fractions of cells grown with nitrate as a nitrogen source. The opposite was true for alkaline phosphatase where the highest activity was detected in the media with asparagine as a nitrogen source. Alanine dehydrogenase, alcohol dehydrogenase, and catalase/peroxidase showed highest levels in the CFP fraction of the media supplemented with nitrate as the nitrogen source whereas it was highest in the cytoplasmic fraction of cells harvested from media with glycine as the nitrogen source. Gelatinase zymography showed that the cytoplasmic fraction of cells grown in Sauton’s media with ammonium chloride and nitrate as nitrogen sources contained the highest activities. The zymograms showed two distinct bands corresponding to approximately 120 kDa and 70 kDa and two minor bands at 48 kDa and 20 kDa. In the CFP
fraction, one minor band was visible only in the medium with nitrate as a nitrogen source,
corresponding to approximately 50 kDa in size. Additionally, seven monoclonal antibodies specific for seven distinct antigens of M. tuberculosis were used to screen for cross reactivity with the secretory fractions of S. albus. Of the seven antibodies, only one (F181-ID3-2) gave
a positive reaction. This is a monoclonal antibody directed at a specific internal amino acid sequence in the secreted acid phosphatase of mycobacteria (SapM). This protein has a size of about 28kDa and is implicated in the pathogenesis of M. tuberculosis