Thesis (M.P.H.)--University of Michigan, 1944.

Thesis equivalent (M.P.H.)--University of Michigan, 1947.

Thesis (M.P.H.)--University of Michigan, 1944.

Plusieurs travaux ont permis de caractériser le rôle des biais cognitifs dans les situations de créativité. Parmi ces biais, on distingue particulièrement les effets de fixation, c’est à dire les connaissances et solutions habituelles qui viennent spontanément à l’esprit des individus lors d’une situation de créativité (tâche de créativité, de génération d’idées, ou de résolutions de problèmes créatifs), et qui contraignent la génération d’idées et de solutions nouvelles et plus créatives. Ces différentes études ouvrent plusieurs pistes pour enrichir la gestion de ces biais cognitifs dans les processus d’innovation.Le leadership est reconnu pour avoir un rôle fondamental à jouer pour aider une équipe à surmonter ces effets de fixation dans un écosystème en situation de créativité. Le leadership est définit comme étant un processus d’influence social dans lequel un ou plusieurs acteurs (jouant le rôle de leaders) emmènent d’autres acteurs (leurs équipes) à atteindre un objectif commun. Leadership et créativité passent souvent pour antagonistes - soit que les leaders soient « créatifs » à la place de leurs équipes, soit que l'autorité doive disparaître pour libérer leurs créativités.Dans un cadre de recherche multidisciplinaire mixant science de gestion (management de l’innovation), sciences cognitives (biais cognitifs à la créativité) et science de la conception innovante (théorie C-K), les leaders créatifs peuvent jouer des rôles très importants pour aider leurs équipes à surmonter les effets de fixations, et ceci selon des règles expérimentales très précises et contrôlées, consistant d’une part à détecter les phénomènes de blocage (la fixation), et d ‘autres part à entreprendre les modes d’actions appropriés pour les surmonter.De plus, ces règles expérimentales peuvent être contextualisées dans des conditions plus générales en organisation, et ceci via les outils de gestion du leadership organisationnel classique (recrutement, allocations de temps et de ressources, motivation, prise de la décision, évaluation, création de climat, spécification des objectifs, etc..). En effet, les méthodes de recherches utilisés pour cette contextualisation organisationnelle consistent à i) mettre en place des protocoles expérimentaux permettant d’isoler les phénomènes de blocages cognitifs dans des situations de créativité ; ii) à générer des règles expérimentales de défixation cognitive dans des contextes bien contrôlés (laboratoire); et iii) à contextualiser ces règles expérimentales de défixation cognitive en utilisant des études de biographies de grands leaders créatifs de l’histoire tél que : Steve Jobs, Thomas Edison ou Mark Zuckerberg. / Several studies have helped to characterize the role of cognitive biases, which appear in situations of creativity. Among these cognitive biases, we can particularly distinguish the fixation effects, that is to say, the obvious knowledge and solutions that comes spontaneously in individuals’ mind during a situation of creativity (creativity task, idea generation, or creative problem-solving), and which consequently constrain the generation of novel and creative ideas and solutions. These different studies open new sights to enrich the management of these cognitive biases in innovation processes.Leadership is recognized as having a fundamental role to play in helping a team overcome these fixation effects in an ecosystem in situation of creativity. Leadership is commonly defined as a process of social influence, in which one or more actors (acting as leaders), lead other actors (their teams) to achieve a common goal. Leadership and creativity are often seen as antagonistic – whether leaders are « creative » in the place of their teams, or that the authority and control must disappear in order for creativity of their teams to flourish.In a multidisciplinary research framework combining management science (innovation management), cognitive science (cognitive biases to creativity) and innovative design science (C-K theory), creative leaders can play very important roles to help their teams overcome fixation effects, and this according to very precise and controlled experimental rules, consisting on the one hand to detect the cognitive biases against creativity (the fixation), and on the other hand to undertake the appropriate modes of actions to overcome them.In addition, these experimental rules can be contextualized in more general conditions, such as organizational contexts, using traditional leadership organizational tools (recruitment, resources and time allocations, motivation, decision-making, evaluation, climate creation, goal-settings, etc..). Indeed, the research methods used for this organizational contextualization of the defixation rules consist of i) building experimental protocols in order to isolate the cognitive effects related to the fixation effects in situations of creativity; ii) generating experimental rules of cognitive defixation in highly and well-controlled contexts (laboratory settings); and iii) contextualizing these experimental rules for cognitive defixation using biographical studies of great creative and innovative leaders in the history, such as for example: Steve Jobs, Thomas Edison or Mark Zuckerberg.

Orientador: Carlos Alexandre Costa Crusciol / Banca: Denizart Bolonhez / Banca: Edson Lazarini / Resumo: Áreas que vem sendo cultivadas com pastagens por vários anos podem apresentar deficiências nutricionais e a população de bactérias fixadoras do nitrogênio atmosférico pode estar reduzida. O molibdênio é um micronutriente que faz parte da enzima nitrogenase, a qual é responsável pela fixação simbiótica do nitrogênio nas leguminosas, e está presente nos bacteróides nodulares. Com base nisso, o presente trabalho teve por objetivo avaliar o efeito da aplicação de molibdênio e inoculante, na cultura do amendoim em semeadura direta sobre palhada de forrageiras. Foram conduzidos quatro experimentos, dois no ano agrícola 2008/09 e dois no ano agícola 2009/10, onde a cultura do amendoim foi semeada, respectivamente, sobre as palhadas da Brachiaria brizantha, Brachiaria ruziziensis, Brachiaria brizantha e Brachiaria decumbens no delineamento de blocos casualizados, em esquema de parcelas subdivididas, com quatro repetições. As parcelas dos experimentos foram constituídas por dois tratamentos, com e sem aplicação de inoculante (1- inoculação artificial com estirpe específica de bactéria Bradyrhizobium spp. para a cultura do amendoim e 2- sem inoculação artificial) e as subparcelas dos experimentos do ano agrícola 2008/09 por três doses de molibdênio (27,5, 55, 110g ha-1) aplicadas via tratamento de sementes, na forma de molibdato de amônio e a testemunha. As subparcelas dos experimentos do ano agrícola 2009/10 constituíram-se de três doses de molibdênio (50, 100, 200g ha-1) aplicadas via foliar, na forma de molibdato de amônio e a testemunha. Foram avaliados o estado nutricional das plantas, a nodulação (número e matéria seca de nódulos por planta), a atividade da enzima nitrogenase pelo método da redução do acetileno, a atividade específica da nitrogenase, os componentes da produção... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The areas that have been cultivated with pasture for several years may have nutritional deficiencies and the population of atmospheric nitrogen fixing bacteria may be reduced. Molybdenum, a nutrient that is part of the nitrogenase enzyme, is responsible for symbiotic nitrogen fixation in legumes and is present in bacteria from the nodules. This study aimed at evaluating the effect of molybdenum and inoculant application, in peanut crop sown on a straw of forages. Four experiments were carried out, two in 2008/09 crop year and two in 2009/10 crop year, where peanut crop was directly sown, respectively, on the straws of Brachiaria brizantha, Brachiaria ruziziensis, Brachiaria brizantha and Brachiaria decumbens in the design of randomized blocks in a split-plot with four replications. The plots comprised two treatments, with and without inoculant application (1 - artificial inoculation with specific strain of Bradyrhizobium spp. for peanut crop and 2 - without artificial inoculation) and the subplots of the experiments carried out in the 2008/09 crop year in three molybdenum rates (27,5, 55 e 110 g ha-1) applied in the form of ammonium molybdate by seeds treatment and a control. The subplots of the experiments carried out in the 2009/10 crop year comprised three molybdenum rates (50, 100 e 200 g ha-1) applied as ammonium molybdate by foliar spraying and a control. The nutritional status of plants, nodulation (number and mass of dry matter of the nodules per plant), the activity of nitrogenase enzyme by acetylene reduction method, the specific activity of nitrogenase, yield components and the yield of pods and grains were evaluated. The data of each experiment were subjected to analysis of variance following the split plot model. To compare the average of inoculation, the method of comparison of unprotected average... (Complete abstract click electronic access below) / Mestre

Legumes play an important role in agriculture as major food sources for humans and as feed for animals. Bioavailable nitrogen is a limiting nutrient for crop growth. Legumes are important because they can form a symbiotic relationship with soil bacteria called rhizobia that results in nitrogen-fixing root nodules. In this symbiosis, rhizobia provide nitrogen to the legumes and the legumes provide carbon sources to the rhizobia. The Medicago truncatula NPF1.7/NIP/LATD gene is essential for root nodule development and also for proper development of root architecture. Work in our lab on the MtNPF1.7/MtNIP/LATD gene has established that it encodes a nitrate transporter and strongly suggests it has another function. Mtnip-1/latd mutants have pleiotropic defects, which are only partially explained by defects in nitrate transport. MtNPF1.7/NIP/LATD is a member of the large and diverse NPF/NRT1(PTR) transporter family. NPF/NRT1(PTR) members have been shown to transport other compounds in addition to nitrate: nitrite, amino acids, di- and tri-peptides, dicarboxylates, auxin, abscisic acid and glucosinolates. In Arabidopsis thaliana, the AtNPF6.3/NRT1.1( CHL1) transporter was shown to transport auxin as well as nitrate. Atchl1 mutants have defects in root architecture, which may be explained by defects in auxin transport and/or nitrate sensing. Considering the pleiotropic phenotypes observed in Mtnip-1/latd mutant plants, it is possible that MtNPF1.7/NIP/LATD could have similar activity as AtNPF6.3/NRT1.1(CHL1). Experimental evidence shows that the MtNPF1.7/NIP/LATD gene is able to restore nitrate-absent responsiveness defects of the Atchl1-5 mutant. The constitutive expression of MtNPF1.7/NIP/LATD gene was able to partially, but not fully restore the wild-type phenotype in the Atchl1-5 mutant line in response to auxin and cytokinin. The constitutive expression of MtNPF1.7/NIP/LATD gene affects the lateral root density of wild-type Col-0 plants differently in response to IAA in the presence of high (1mM) or low (0.1 mM) nitrate. MtNPF1.7/NIP/LATD gene expression is not regulated by nitrate at the concentrations tested and MtNPF1.7/NIP/LATD does not regulate the nitrate-responsive MtNRT2.1 gene. Mtnip-1 plants have an abnormal gravitropic root response implicating an auxin defect. Together with these results, MtNPF1.7/NIP/LATD is associated with nitrate and auxin; however, it does not act in a homologous fashion as AtNPF6.3/NRT1.1(CHL1) does in A. thaliana.

When removal of primary tumors is performed by surgery, the surgeon andthe patient would benefit from using intraoperative feedback to evaluate thetumor resection margin. If intraoperative feedback is not provided there isadditional risk of treatment of the tumor. With improvements to the fixationtime of soft tissue, phase-contrast computed tomography (PC-CT) could allow3D intraoperative feedback to the surgeons.The focus of this project has been to develop a method for measuring fixationtime on soft tissue samples and examine ways to decrease the required fixationtime. Furthermore, evaluation of fixatives to achieve image contrast that wouldbe sufficient to accomplish the possibility of intraoperative tumor feedback, inPC-CT images has been performed in this project. / När avlägsnande av primära tumörer utförs av kirurger, skulle både kirurgenoch patienten gynnas av intraoperativ återkoppling för att bedöma resektions-marginalen. Utan intraoperativ återkoppling finns det risk för att yttrligarebehandling av tumören är nödvändig. Med förbättringar inom fixeringstid avmjukvävnad skulle faskontrast-CT möjliggöra 3D intraoperativ återkopplingtill kirurgen.Fokuset inom detta projekt har varit att ta fram en metod för mätning av fixe-ringstid av mjukvävnadsprover och undersöka tillvägagångssätt för att minskaden behövda fixeringstiden. Vidare så har utvärdering av fixeringsvätskor föratt uppnå bildkontrast som skulle vara bra nog att fungera som intraoperativåterkoppling av tumör-information, inom faskontrast-CT utförts i detta projekt.

Pulse crops included in a crop rotation can reduce nitrogen (N) requirements via biological N2 fixation (BNF) and provide greater carbon (C) inputs to soil than non-pulse crops in rotation. The goal of this research was to estimate the BNF and C input to soil by various pulse crops (chickpea, lentil and field pea) grown in rotation with pulse crops and non-pulse crops. Soil cores from three crop rotations (chickpea-wheat, lentil-wheat and pea-wheat) were collected from Swift Current, SK. Additional soil cores from two rotations (canola-wheat and wheat-canola) were extracted from a field used for commercial cropping in Central Butte, SK. The 15N dilution method and continuous labelling with depleted 13CO2 were used to estimate BNF and 13C input to soil by pulse crops grown in a greenhouse. The continuous labelling with depleted 13CO2 was effective in depleting 13C in plants. The movement of 13C from plant to soil C pools via rhizodeposition was also observed. However, an accurate amount of 13C transferred was not measurable. Different pulse crop performed differently in rotation. Pea had the greatest amount of BNF and produced the most residue-C (pods, stems, leaves and roots) compared to chickpea and lentil. The crop grown in the first year of the three-year rotation also influenced the pulse crops grown in the third year of the rotation. Cropping the same first year and third year pulse crop in rotation (chickpea-wheat-chickpea and lentil-wheat-lentil) performed better than growing different first year and third year pulse crops in rotation (pea-wheat-chickpea and pea-wheat-lentil). Pulse crops grown immediately after wheat yielded better and fixed more N than those after canola. Growing a pulse crop after canola is not recommended in this soil zone.

South Africa has an array of mining commodities which all play an integral role in our everyday surroundings, income, and most importantly, in the economy of the country. These mining activities also produce vast amounts of discard material, better known as tailings material, which is stored in different ways after extraction has taken place. Usually, storage entails the construction of tailings storage facilities, normal discard or tailings dumps. The upper surfaces of these anthropogenic structures are usually unstable and are, in most cases, characterised by different forms of erosion. This can be due to the chemical and physical properties of the materials of which they are constructed, but mainly due to unstable construction geomorphology, steep slopes, which leads to poor water run-off management and subsequent instability. Therefore, these structures need to be actively managed in order to increase and maintain their stability. Grass establishment, as a stabilisation technique, is the most effective out of all of the techniques, but there are certain constraints regarding this method (Titshall et al. 2013). The most costly constraint is nutrient supplementation during aftercare phases. In order to minimize this cost, new and innovative technologies need to be explored, and trialled. The contribution of soil biological processes in this regard was assessed, in order to minimise anthropogenic inputs. These biological processes refer to the fixation of atmospheric nitrogen by nodular root bacteria that grow on a group of plants referred to as legumes. These bacteria, also known as rhizobia, live in a symbiotic relationship with the host plant where they receive energy in the form of nutrients by trading nitrogen, which is an essential plant nutrient. Nine different tailings materials from different commodities available from South African Mines were selected. For a control medium, a well-drained soil type with an apedel structure and a clay content of approximately 6% was selected in order to promote optimal natural growth. These materials were chemically and physically analysed in order to develop a more holistic understanding on a micro scale level, as well as to ascertain possible constraints in this regard. Pot trials were selected as the experimental method in order to apply more specific control over root growth, plant development and growing conditions. The experimental data were collected over one growing season for both live forms. For this study, seven legume species were selected for establishment in the tailings materials in order to investigate their establishment potential in the growth mediums and their ability to fixate nitrogen. Based on the data, specific species were identified as viable options to include in future tailings amelioration projects; it can be assumed that the nitrogen produced by these species will be available in the growth medium for uptake by neighbouring plants that lack this biological function. These plants will also play a vital role in the long-term sustainable development of vegetation in the anthropogenic growth mediums. Sericea lespedeza had the highest enrichment ability during this study. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

South Africa has an array of mining commodities which all play an integral role in our everyday surroundings, income, and most importantly, in the economy of the country. These mining activities also produce vast amounts of discard material, better known as tailings material, which is stored in different ways after extraction has taken place. Usually, storage entails the construction of tailings storage facilities, normal discard or tailings dumps. The upper surfaces of these anthropogenic structures are usually unstable and are, in most cases, characterised by different forms of erosion. This can be due to the chemical and physical properties of the materials of which they are constructed, but mainly due to unstable construction geomorphology, steep slopes, which leads to poor water run-off management and subsequent instability. Therefore, these structures need to be actively managed in order to increase and maintain their stability. Grass establishment, as a stabilisation technique, is the most effective out of all of the techniques, but there are certain constraints regarding this method (Titshall et al. 2013). The most costly constraint is nutrient supplementation during aftercare phases. In order to minimize this cost, new and innovative technologies need to be explored, and trialled. The contribution of soil biological processes in this regard was assessed, in order to minimise anthropogenic inputs. These biological processes refer to the fixation of atmospheric nitrogen by nodular root bacteria that grow on a group of plants referred to as legumes. These bacteria, also known as rhizobia, live in a symbiotic relationship with the host plant where they receive energy in the form of nutrients by trading nitrogen, which is an essential plant nutrient. Nine different tailings materials from different commodities available from South African Mines were selected. For a control medium, a well-drained soil type with an apedel structure and a clay content of approximately 6% was selected in order to promote optimal natural growth. These materials were chemically and physically analysed in order to develop a more holistic understanding on a micro scale level, as well as to ascertain possible constraints in this regard. Pot trials were selected as the experimental method in order to apply more specific control over root growth, plant development and growing conditions. The experimental data were collected over one growing season for both live forms. For this study, seven legume species were selected for establishment in the tailings materials in order to investigate their establishment potential in the growth mediums and their ability to fixate nitrogen. Based on the data, specific species were identified as viable options to include in future tailings amelioration projects; it can be assumed that the nitrogen produced by these species will be available in the growth medium for uptake by neighbouring plants that lack this biological function. These plants will also play a vital role in the long-term sustainable development of vegetation in the anthropogenic growth mediums. Sericea lespedeza had the highest enrichment ability during this study. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015