No description available.

No description available.

A botanical inventory of Doe Mountain Recreation Area (DMRA) in northeastern Tennessee was conducted to help guide conservation-based management. A total of 484 species were found in DMRA, comprising 94 families, and 285 genera, 10 species listed in the state rare plant list, and 76 exotic species. Two species, Liatris virgata and Lycopodiella inundata, were new state records. Water in the Lycopodiella seep was an order of magnitude more acid than at other sites. An analysis of the wildland-urban interface showed that only 13% of the area was classified as uninhabited. The inventory-invasion index, introduced to quantify the relative degree of botanical uniqueness, was indicative of an under-explored or unique area but less so compared to some other botanically-rich regional sites. Management should aim to protect acid seeps, arid roadside slopes, curtail mowing a roadside that supports a state endangered species, and avoid herbicides in the biodiverse power line corridor.

Avian pathogenic Escherichia coli (APEC) is a bacterium that is responsible for colibacillosis in birds. However, information about broiler breeder APEC isolates is limited, but the data is critical due to the transfer of this bacteria down the production pyramid to progenies resulting in high mortality. Therefore, we evaluated the phenotypic virulence characteristics of 28 isolates using embryo lethality and day-old chick challenge assays. Also, the in vitro adhesion and invasion potential of selected nine isolates were identified. Results showed more than 1/3rd of the isolates were highly virulent and the virulence increased as the number of virulence-associated genes increased. High adhesion and invasion rates were observed among the isolates. Overall, the study helped us to evaluate the virulence characteristics of APEC from broiler breeders. However, future studies based on whole genome approach would help to identify the specific targets which can be used to develop effective interventions.

L’inclusion récente de la profondeur d’invasion (PI) dans la classification des carcinomes épidermoïdes de la cavité orale de l’American Joint Committee on Cancer (AJCC) a des répercussions cliniques majeures. Plusieurs études ont récemment évalué la fiabilité de diverses modalités d’imagerie et techniques de biopsie pour mesurer la PI en préopératoire. L’objectif premier de ce mémoire est de réviser systématiquement la littérature et comparer les différentes méthodes décrites de mesure de PI en préopératoire pour les carcinomes épidermoïdes de la langue mobile. Le second objectif est d’étudier la précision et la fiabilité de la mesure de PI sur une biopsie au poinçon dans les carcinomes épidermoïdes de stade in situ (Tis)-T1-T2, N0 de la langue mobile. Une revue systématique a été effectuée en suivant le guide PRISMA[1]. Les études évaluant la fiabilité de la PI mesurée sur la biopsie ou l’imagerie médicale, en les comparant à la PI histopathologique finale, ont été inclues dans une méta-analyse afin d’obtenir des coefficients de corrélation combinés pour chaque modalité d’imagerie. L’imagerie par résonnance magnétique (IRM) s’est avérée être la modalité d’imagerie la mieux étudiée et présente une bonne fiabilité. Le computed tomography (CT) scan est peu étudié, mais semble moins fiable. L’échographie linguale ne peut être comparée à ces deux modalités d’imagerie car elle est plus fréquemment utilisée pour mesurer l’épaisseur tumorale que la PI. La seconde étude est une preuve de concept prospective. Un poinçon profond a été utilisé pour échantillonner la portion la plus profonde de carcinomes épidermoïdes de la langue mobile de stade Tis-T1-2, N0 chez 27 patients. Des coefficients de corrélation de Spearman ont été calculés entre la PI estimée à la palpation manuelle, mesurée à la biopsie, et à l’histopathologie. La sensibilité et la spécificité de la biopsie au poinçon pour distinguer le Tis du carcinome épidermoïde invasif ont été calculées. Bien que la PI mesurée à la biopsie ne corrèle pas fortement avec la PI histopathologique, cette preuve de concept est limitée par la taille d’échantillon. La biopsie au poinçon semble toutefois être un outil fiable pour distinguer le Tis de l’invasif. D’autres études sont nécessaires avant de pouvoir recommander l’utilisation systématique de la biopsie pour décider en préopératoire si un évidement cervical électif est nécessaire. / The inclusion of depth of invasion (DOI) in the American Joint Committee on Cancer’s staging system for oral cavity squamous cell carcinoma (SCC) has major clinical impacts. Recent studies have evaluated the reliability of imaging modalities and biopsy techniques to measure DOI preoperatively. The first objective of this master’s thesis is to systematically review and compare the preoperative DOI measurement methods that have been studied so far in oral tongue SCC (OTSCC). The second objective is to prospectively study the precision and reliability of punch biopsy to measure DOI preoperatively in early (in situ (Tis)-T1-T2, N0) OTSCC, and its ability to distinguish Tis from invasive carcinoma. A systematic review was conducted according to the PRISMA guidelines. Studies that evaluated the reliability of DOI measured on biopsy or imaging (rDOI) by comparing it to DOI on histopathology (pDOI) were included in a meta-analysis to obtain pooled correlation coefficients for each imaging modality. Overall, magnetic resonance imaging (MRI) is the better studied modality. It has a good reliability to measure preoperative rDOI in OTSCC. CT is less studied but appears to be less reliable. Ultrasound (US) cannot be compared to these imaging modality as it has been used more often to measure tumor thickness (TT) than DOI. The second study is a prospective proof-of-concept. A deep punch biopsy was used to sample tumors preoperatively in the deepest part of the tumor in 27 patients with early (Tis-T12, N0) oral tongue squamous cell carcinoma. Spearman’s correlations were calculated between DOI measured on digital palpation (cDOI), biopsy (bDOI) and final pDOI. The sensitivity and specificity of punch biopsy to distinguish Tis from invasive carcinoma was also calculated. Although bDOI does not seem to correlate strongly with pDOI, this proof-of-concept was limited by a small sample size. Punch biopsy appears to be a reliable tool to distinguish Tis from invasive carcinoma. Further studies on punch biopsy are needed to recommend its use to evaluate pDOI preoperatively and determine whether elective neck dissection is necessary in early OTSCC.

L’athérosclérose est une pathologie cardiovasculaire chronique impliquant de nombreux acteurs. Les cellules du muscle lisse vasculaire (CMLV) jouent un important rôle dans la pathogénicité. Lors de la formation des plaques athérosclérotiques, ces cellules entraînent l’augmentation de la taille de l’athérome, accentuent la formation du chapeau fibreux et à long terme, contribuent à l’instabilité de la plaque. Dans cette étude, nous nous sommes intéressés à l’impact d’ARF6 sur les cellules du muscle lisse vasculaire et ses implications pathologiques dans l’athérosclérose. Les ARF sont des GTPases agissant comme interrupteurs moléculaires dans divers processus physiologiques tels que le trafic vésiculaire intracellulaire et le remodelage des lipides membranaires. ARF6 est importante pour la prolifération et la migration cellulaire des CMLV, deux phénomènes importants dans le développement de l’athérosclérose. Nous émettons donc l’hypothèse que la GTPase ARF6 est impliquée dans la progression de l’athérosclérose. En premier lieu, nous avons étudié l’effet de la GTPase dans le phénomène de l’invasion cellulaire. Dans l’athérosclérose, plusieurs facteurs environnementaux influencent l’invasion des CMLV. Nous avons voulu vérifier l’effet d’ARF6 sur l’invasion des CMLV médiée par le facteur de croissance dérivé des plaquettes (PDGF-BB) et l’angiotensine II (Ang II). Dans un modèle humain, l’invasion était diminuée en l’absence d’ARF6. Nous avons démontré que ce mécanisme résultait d’un effet d’ARF6 sur l’activité de la métalloprotéinase matricielle MMP14. En second lieu, nous avons voulu évaluer l’effet d’ARF6 dans un modèle in vivo d’athérosclérose. En utilisant un modèle accéléré d’athérosclérose inductible, nous avons inhibé ARF6 dans les cellules du muscle lisse. Après dix semaines de diète riche en gras, nous avons observé une diminution de la taille des lésions athérosclérotiques dans les souris ARF6 KO, accompagnée d’une réduction de l’expression des facteurs pro-inflammatoires tels qu’IL-6. Dans un modèle in vitro, l’absence d’ARF6 réduisait l’absorption lipidique en agissant sur l’expression des transporteurs. De plus, ARF6 régulait des voies de signalisation impliquées dans l’inflammation. En somme, nous avons démontré l’importance d’ARF6 dans la modulation pathologique des CMLV dans l’athérosclérose. Ainsi, ARF6 contribue à la pathogénicité des CMLV en modulant leur invasion cellulaire tout en jouant un rôle pro-inflammatoire. / Atherosclerosis is a chronic cardiovascular disease characterized by an accumulation of lipids, followed by the infiltration of macrophages and vascular smooth muscle cells (VSMC). VSMC are responsible for the increase of lesion size, the formation of a fibrous cap, and eventually contributing to the plaque instability. In this study, we were interested in the role of ARF6 in the vascular smooth muscle cells and its pathological implications in atherosclerosis. ARF are a family of GTPases that act as molecular switches and are involved in diverse physiological mechanisms, such as vesicular traffic and membrane lipid transformation. In VSMC, ARF6 is important for cell proliferation and migration, two processes involved in atherosclerosis. We therefore hypothesize that the GTPase ARF6 is involved in the development of atherosclerosis through its impact on VSMC. First, we studied the role of ARF6 in the mechanism of cell invasion. In atherosclerosis, multiple environmental factors affect VSMC invasion. We verified the impact of ARF6 on platelet-derived growth factor (PDGF-BB) and angiotensin II (Ang II)-mediated invasion. Using a human model, we observed a reduction of invasion in the absence of ARF6. We have demonstrated that this mechanism is due to the effect of ARF6 on the activity of the matrix metalloproteinase MMP14. Second, we wanted to verify the role of ARF6 in atherosclerosis in an in vivo model. Using an accelerated inducible atherosclerosis model, we inhibited ARF6 in smooth muscle cells. After ten weeks of high-fat diet, we observed a reduction in the size of atherosclerotic lesions in ARF6 KO mice. This reduction was accompanied by a decrease in the expression of proinflammatory factors. In our in vitro model, ARF6 depletion reduced lipid uptake by downregulating the lipidic transporter expression. Also, ARF6 was responsible to activate inflammation signaling pathways. In summary, we have demonstrated the impact of ARF6 in the pathological modulation of VSMC in atherosclerosis. Indeed, ARF6 contributes to the pathogenicity of VSMC through its ability to modulate cell invasion and induce proinflammatory actions.

Of concern in this research were the ecological parameters associated with the establishment of a model invasive plant species, Imperata cylindrica, across a scale of ecological organization. Specifically, the study addressed the species’ ability to: differentially respond to abiotic and biotic constraints during seedling establishment, exhibit a novel underground competitive interference mechanism, and alter the decomposition dynamics in newly invaded ecosystems. Finally, the last portion of the research was centered around creating a predictive habitat model that will provide information on the most important variables responsible for creating habitat for this species. The population level seedling study indicated that soil characteristics and light availability play a significant role in seedling establishment. There were large trends in biomass allocation attributable to soil type with seedlings performing best in high nutrient soils representative of the Mississippi Alluvial Valley physiographic region. I. cylindrica seedlings also showed a positive response to increased seedling density during the initial stages of seedling establishment. The community level research examining a hypothesized novel interference mechanism deployed by I. cylindrica showed a significant and robust pattern of I. cylindrica damaging its own belowground tissue more often than that of its surrounding neighbors. Therefore, it is highly unlikely that I. cylindrica gains a competitive advantage by exposing the native plant assemblage to pathogen invasion (via ruptured tissue) as the plant would expose itself to these pathogens (to which it is evolutionarily naive) at much higher volumes. The ecosystem level examination of this globally important invasive species indicated that I. cylindrica invasion into native systems will significantly accelerate ambient rates of decomposition. Furthermore, fungal community composition in invaded areas was drastically altered as well as bacterial community functional activity in relation to several key enzymes responsible for the decomposition of plant tissue which were produced more abundantly in invaded areas.The landscape-scale analyses and modeling work validated decades of anecdotal evidence and indicated that anthropogenic disturbance factors associated with road maintenance and construction (soil disturbance and vegetation removal) are the principal factors responsible for creating habitat suitable for invasion by this species.

No description available.

The exogenous shock that Russia's invasion of Ukraine entailed brought great challenges and demands for change in companies worldwide. Governing under these conditions is not easy, nor is knowing what is actually right to do. There is research on turbulent environments and exogenous shocks, divestments, and legitimacy, but research on the interaction between these is limited. In this study, we examine how companies have responded to exogenous shocks, more specifically how Swedish MNCs have acted and communicated as a result of Russia's invasion of Ukraine on February 24, 2022. The study consists of 69 Swedish MNCs that were active in Russia pre-invasion and their communications and actions as a result of this event, with data drawn from press releases, company reports, state registers and the media. The results show that many of the examined companies have acted in a similar way and divested the Russian market, albeit with varying quickness and forcefulness, thus adopting an approach consistent with what may be considered to be a legitimate strategy, with a few exceptions where the companies' actions has not been as consistent. What this means is that despite the fact that these decisions are made by the respective company management, the measures are generally in line with each other, which may be a result of pressure from both internal and external stakeholders and society at large.

Ce mémoire a pour but de mettre en lumière les stratégies des deux camps durant F affrontement anglo-américain de 1775-1776 en territoire canadien, lors de la guerre de l'Indépendance des Etats-Unis. À cette fin, il cherche particulièrement à identifier les liens entre la pensée politique, la grande stratégie de la guerre, et la stratégie locale des opérations militaires. Le premier chapitre consiste en une présentation sommaire des principaux événements et faits d'armes de la confrontation. Les quatre autres chapitres portent sur la conduite de la guerre elle-même. Une différence marquée existe entre 1775 et 1776. Du côté américain, le virage vers l'indépendance modifie la perspective de l'utilisation des armes. Chez les Britanniques, le transfert du centre d'opérations de Boston à New York change l'application de la stratégie. Les deux années sont donc analysées séparément, d'abord du côté américain, puis du côté britannique. Le mémoire porte avant tout sur les idées alors en interaction et en évolution. Les principales sources utilisées sont les délibérations du Congrès américain et la correspondance de celui-ci, et des généraux Washington, Schuyler, Montgomery et Arnold. Pour les Britanniques, ont surtout été consultées les lettres du secrétaire aux colonies, Lord Dartmouth puis Lord Germain, et des commandants en chef en Amérique et au Canada, soit les généraux Gage, Howe et Carleton.