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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.
11

The weather and climate of Australia at the Last Glacial Maximum

Hope, Pandora January 2005 (has links) (PDF)
The global climate has experienced four glacial cycles in the last 420,000 years, with each cycle characterised by a prolonged period of cooling culminating in maximal glaciation followed by a brief warm period. The most recent period of maximal glaciation is termed the Last Glacial Maximum (LGM) and occurred about 21,000 years ago. We currently live in one of the warm periods. The global climate is changing, and it is becoming more important to understand the extremes of the climate system and how well our modelling capability can capture those extremes. / There has been a modelling intercomparison project established to examine how global general circulation models compare in simulating past climates, including the LGM. Analysis and comparison of these model results has been presented for many parts of the globe, but there has not been a comparison of the different model results over the Australian region. This thesis aims to fill that gap and explore the simulated LGM weather and climate of Australia and its drivers in more detail. Comparison with proxy evidence is also undertaken, and inconsistencies seen in the literature addressed. / The Australian climate at the LGM was believed to be generally cooler, drier and possibly windier from proxy evidence in the literature. In the comparison done here the mean temperature and precipitation fields from most models show cooler and drier conditions, with some seasonal variability, but there are some strong outliers. It was found that the differences were not dependent on model resolution, but that the surface parameterisations were highly important for these fields. / The shifts in the circulation were examined both in the model results and with a study of the non-linear link between the wind, surface moisture and dunes, which are a proxy for past winds. All the models simulate a southward shift in the westerlies in the Australian region. This is strongly driven byte prescribed sea-surface temperatures. Australia's current wind regime is conducive to dune building. However, the binding effect of soil moisture (or vegetation) is strong enough to limit present day movement, whereas in the drier climate at the LGM there was a capacity for sand movement. The analysis of dune orientations did not produce conclusive evidence for how the westerlies might have shifted at the LGM. / An apparent enigma in the proxy evidence at the LGM is the high lake levels in Australia’s south east, while most inland lakes were dry. Previous authors believed that the precipitation was still low, but the high lake levels were driven by lowered potential evaporation. The hydrological cycle was generally depressed in the LGM simulations, but the potential for evaporation remained high. Thus an alternative hypothesis is posed based on increased run off due to a known shift in the vegetation types and a lag in the timing of the run off due to snowmelt. / The analysis here shows that our capacity to simulate climates quite different from the present is still developing, but that model results can help explain apparent inconsistencies in the reconstruction of past climates from proxies.
12

Knowledge Domains of Geriatric Case Managers in the State of Illinois

Saxon, Verletta Antoinette 01 May 2010 (has links)
This study investigates extant data concerning the current knowledge of geriatric case managers in Illinois who contracted with the Illinois Department on Aging in 2010 in order to provide case management services to adults age 65 and older. In examining the self-reported importance and frequency of geriatric case manager's knowledge domain areas in Illinois, the knowledge domain portion of the Case Manager's Role and Function Survey Instrument (CMRFSI) was utilized. The sample in this study consisted of 192 geriatric case managers. Participants were asked to complete the knowledge domain portion of the CMRFSI which contained a 5-point Likert scale of the importance of knowledge domains and a second 5-point Likert scale of the frequency of knowledge domains performed. Factor analysis was utilized to provide information regarding the underlying relationship between the variables. Factor analysis produced the following four factors: rehabilitation planning, care management, psychosocial aspects of case management, and service coordination/delivery survey. To provide a deeper understanding of the knowledge domain areas of geriatric case managers and the demographic variables of work setting, highest degree completed, major, and race/ethnicity a MANOVA was used. A significant difference was produced for race/ethnicity. Wilks' Lambda was used for multivariate statistical testing resulting in F (10, 4064.13) =1.20, p < .05. Each of the measure indicated that there was a significant (p < .05) difference on the four factors across the two races (White non-Hispanic and Minority). In addition, a univariate statistical test (see table 9) produced a significant (p < .05) alpha on factor I: rehabilitation concepts and factor II: care management indicating that when considered individually and collectively, rehabilitation concepts and care management are significantly different when considering race/ethnicity. Consequently, understanding the knowledge domains of geriatric case managers will assist in designing curriculum, certifications, and preparing students to providing services. In addition, implications, limitations, and suggestions for future research are discussed.
13

Mottagargrupper : En webbapplikation med AG-Grid

Holmström, Emilia January 2022 (has links)
The project is about a GS1-verified input system Prevas GCM, which is a web service for suppliers to send article information to receivers. With the current system the suppliers need to select each receiver individually when sending information. The purpose with the project is to develop a system that let suppliers create receivers groups from receivers. The preparatory work consist of create prototypes in Adobe XD. Thereafter the web application produced in two steps. The project has mostly used the programming language JavaScript together with AG-Grid. In addition html and css have been used. The result was a almost launch-ready product with minor fixes left. / Projektet har handlat om GS1-verifierat inmatningssystemet Prevas GCM, som är en webbtjänst som låter leverantörer skicka ut artikelinformation till mottagare. Den nuvarande lösningen innebär att leverantörerna måste välja alla mottagare enskilt. Syftet med projektet blev att utveckla en webbapplikation som låter leverantörer skapa mottagargrupper av mottagare. Förarbetet bestod av att skapa prototyper i Adobe XD. Därefter har webbapplikation tagits fram i två steg. Projektet har huvudsakligen använt programmeringsspråket JavaScript ihop med AG-Grid. Utöver det har HTML och CSS används. Resultatet blev nästan en lanserings-klar produkt med mindre fix kvar.
14

Partitioning oracle attacks against variants of AES-GCM and ChaCha20-Poly1305

Tordsson, Pontus January 2021 (has links)
We investigate so-called partitioning oracle attacks against AES-GCM and ChaCha20-Poly1305 along with some improvements. Such attacks against these two cryptosystems are efficient because they can be reduced to solving linear systems of equations over finite fields. We show, with some randomness assumptions, that such linear systems must have at least as many columns as rows. We have also chosen two finite (non-field) rings, as replacement for the respective fields used by AES-GCM and ChaCha20-Poly1305 for message authentication. These rings make the problem of linear system arrangement in a partitioning oracle attack extremely hard for large linear system dimensions.
15

An Investigation of the Role of Contrast Cues in Parainformative Categorization

Wimsatt, Jay A., Jr. 28 September 2020 (has links)
No description available.
16

A Dinâmica de Resposta dos Furacões do Oceano Atlântico Tropical Norte sobre a Atmosfera da América do Sul / North Atlantic Hurricanes Activity and its Dynamical Response over South America

Machado, Laís Tabosa 29 April 2019 (has links)
A pesquisa teve como objetivo central investigar se os furacões do Oceano Atlântico Tropical Norte são capazes de influenciar a América do Sul (AS), principalmente no que se refere aos padrões de precipitação e circulação atmosférica. No entanto, como os furacões possuem uma gama de variedades de trajetórias, gêneses e decaimento, a pesquisa se restringiu apenas a avaliação dos furacões que poderiam causar maiores impactos na atmosfera da AS, sobretudo no norte do continente. Nesse sentido duas hipóteses foram estabelecidas concernente a trajetória e intensidades dos furacões. Para a trajetória a hipótese era de que quanto mais próximo da AS os furacões transitassem maior seria seu grau de interação com o continente ao passo que os furacões que atingissem a categoria 5 na escala de intensidade Saffir-Simpson também poderiam exercer maiores influências. Assim, através desses critérios, 6 furacões foram selecionados entre os anos de 1988-2017 e estes foram avaliados com base nos dados do CHIRPS e da reanálise ERA Interim, além de simulações numéricas com o modelo dinâmico GCM DREAM. Os resultados mostraram que, de fato, os furacões conseguiam impactar a atmosfera da AS uma vez que nos baixos níveis da troposfera foram observados modificações nos alísios, interferência na posição da Zona de Convergência Intertropical (ZCIT) e influência na nebulosidade, pressão, temperatura e umidade do norte da AS. Além disso, foram constatadas interações entre os furacões e a Alta Subtropical do Atlântico Sul (ASAS), onde essa última canalizava parte dos seus escoamentos para os furacões que, por sua vez, se intensificavam. Já para os altos níveis da troposfera, foram observados o surgimento de um anticiclone no Noroeste (NO) da AS como resposta a existência dos furacões, sendo que após formado esse anticiclone sugere uma possível interação com os furacões uma vez que ele se deslocava segundo o movimento dos mesmos. Além dessas duas abordagens a pesquisa também se utilizou das Funções dos Modos Normais no sentido de reconstituir o campo de vento horizontal através da contribuição individual de cada onda atmosférica excitada a partir de um furacão. Nessa etapa escolheu-se um dos furacões selecionados e os resultados indicaram que as principais ondas envolvidas nas características observadas nos baixos níveis da troposfera como, por exemplo, ciclones ou sistemas frontais, vinham das ondas de Rossby e Gravidade-Inercial (GI). Já para os altos níveis as ondas atmosféricas envolvidas no processo de formação do anticiclone no NO da AS foram as ondas de Rossby, GI e as ondas Mistas de Rossby-Gravidade (MRG), sendo que essa última indicava justamente uma comunicação entre os dois hemisférios. No que se refere as ondas de Rossby elas se sobressaíram em todos nos níveis atmosféricos devido a relação delas com a geostrofia ao passo que as ondas GI ficaram restritas em mostrar apenas processos de divergência, logo elas foram úteis para identificar regiões ligadas a precipitação. Com relação aos resultados para os padrões de precipitação foram observadas durante a passagem dos furacões anomalias positivas no norte da AS e anomalias negativas no Brasil Central, sendo que esse resultado foi interpretado como sendo um reflexo do aumento das concentrações de momento e umidade na região norte da AS por onde os furacões transitavam. Por fim, foi avaliado o caso do furacão Irma que teve uma trajetória distante da AS. Esse furacão foi avaliado no sentindo de testar as hipóteses feitas anteriormente e os resultados mostraram que esse furacão não conseguiu exercer impacto na atmosfera da AS. Desse modo, concluiu-se que os furacões do Oceano Atlântico conseguem impactar a atmosfera da AS como indicou os resultados, porém que isso só ocorrerá se eles descreverem uma trajetória muito próxima ao continente sul-americano. / The main objective of this research is to investigate whether hurricanes from the North Tropical Atlantic Ocean can influence the South Americans atmosphere, especially in terms of circulation and precipitation patterns. However, since hurricanes have a great range of trajectories, genesis and decay this research only focused the study of hurricanes that may impact the South American, particularly in the northern continental region. In this sense, two hypotheses were established about the trajectory and intensities of hurricanes. For the trajectory, the hypothesis is that the closer the hurricanes pass by South America the greater would be their degree of interaction with the South American atmosphere variability. Also, the higher the Hurricanes classification, for instance, category 5 on the Saffir-Simpson Scale, the influence could be increased. Following this criteria 6 hurricanes were selected between the years 1988-2017 and they were evaluated based on ERA Interim reanalysis and CHIRPS data, as well as numerical simulations using the dynamic GCM DREAM model. The results showed that these hurricanes really impacted the atmosphere of the South America. At lower levels of the troposphere, the passage of hurricanes caused trade winds deformation, interference in the Intertropical Convergence Zones (ITCZ) position, besides of the influence on the cloudiness, pressure, temperature and moist in the north of the continent. In addition, it was detected interactions between hurricanes and the South Atlantic Subtropical High (SASH), where the SASH sustained the wind flows towards the hurricanes, supporting their intensification. Regarding the results for the upper levels of the troposphere it was observed the development of an anticyclone in the Northwest of South America as a response to the hurricane presence. It was noticed that this anticyclone interacts with the hurricanes once it moves according to their movement. In addition to these two approaches, it was also used the Normal Mode Functions in order to reconstruct the horizontal wind field through the individual contribution of each atmospheric waves excited from a hurricane. One of the selected hurricanes was chosen and the results indicated the main waves related to the characteristics observed at lower levels of the troposphere are the Rossby and Gravity-Inertial (GI) waves. For the upper levels, the atmospheric waves related with the formation of the anticyclone in northwestern South Americas were the Rossby, GI and the Mixed Rossby-Gravity (MRG) modes, where the MRG waves clearly show the interaction between the two hemispheres. The Rossby waves excelled at all atmospheric levels due to their relationship to the geostrophic approach, while the GI waves only showed divergence processes, being useful to identify regions linked to precipitation. The precipitation patterns during the hurricanes passage generates positive anomalies in the north of the South America and negative anomalies in central Brazil. This result was interpreted as an increase of momentum and moist concentrations in the South Americas northern region due to the interaction with the hurricanes. As a case study the hurricane Irma was investigated. This hurricane was intense but its track was distant of the South America being evaluated in the order to test the hypotheses previously assumed. The results indicated that the hurricane Irma did not have any impact in the South Americans atmosphere, where not interations with SASH, temperature or moist were observed. In summary, it was observed that North Atlantic Ocean hurricanes can influence the South Americas atmosphere when their trajectories are close to the South American continent.
17

Une nouvelle cascade régulant l'hématopoïèse et la réponse inflammatoire chez la drosophile / A novel cascade controlling hematopoiesis and the inflammatory response in flies

Bazzi, Wael 18 September 2017 (has links)
Les cellules immunitaires provenant des deux vagues hématopoïétiques jouent des rôles distincts dans la réponse immunitaire, ce qui pose la question d’une potentielle communication entre les deux vagues d’hématopoïèse. De plus, la réponse immunitaire joue un rôle primordial dans la progression des tumeurs. Les cascades inflammatoires telles que la voie JAK/STAT et la voie Toll régulent l’hématopoïèse et les mutations affectant ces voies sont associées à des défauts hématopoïétiques et au développement de cancer du sang chez l’humain. Les deux voies de signalisation sont conservées au cours de l’évolution. La voie Toll a notamment été découverte chez la drosophile. Comme chez les mammifères, les mutations dans ces cascades produisent chez la larve des tumeurs des cellules du « sang » appelées tumeurs mélanotiques qui sont dues à la prolifération et à la présence d’hémocytes à l’état inflammatoire qui s’agrègent et forment des masses noires mélanisées. Au cours de mon doctorat, j’ai caractérisé l’impact de Gcm, le seul facteur de transcription spécifique de l’hématopoïèse primitive, sur la réponse immunitaire innée et l’activation de l’inflammation. Je me suis concentré sur les voies Toll et JAK/STAT en utilisant le modèle de la drosophile. J’ai pu montrer que Gcm inhibe la formation des tumeurs mélanotiques provoquées par l’activation constitutive de l’une ou l’autre voie. Gcm agit en activant l’expression d’inhibiteurs de chacune des deux voies. De plus, mes données montrent pour la première fois l’interaction entre les vagues d’hématopoïèses primitive et définitive, une interaction qui est nécessaire pour monter une réponse inflammatoire efficace. Dans ce système, Gcm inhibe la sécrétion de cytokines pro-inflammatoire Upd2 et Upd3 des hémocytes embryonnaires. Mes résultats indiquent également que Gcm a un impact sur l’expression de gènes mitochondriaux dans un fond génétique qui conduit au développement de tumeurs mélanotiques et à un état inflammatoire. Enfin, j’ai transposé mes résultats à un système mammifère en montrant que chez la souris, Gcm induit l’expression d’inhibiteur de la voie JAK/STAT dans une lignée cellulaire leucémique humaine. Pour conclure, mes données mettent en évidence l’importance de la communication entre les deux vagues d’hématopoïèse dans le système immunitaire et montrent qu’une voie de régulation développementale régule la capacité du système à répondre à l’inflammation. / Immune cells originating from different hematopoietic waves play role in mounting an efficient immune response, which raises the aspect of communication between distinct waves. In addition, immune responses have pivotal roles in modulating tumor progression. Inflammatory cascades, such as the JAK/STAT and Toll pathways are also known to regulate hematopoiesis and mutations in either of them are associated with hematopoietic defects and blood cancers in humans. Both pathways are highly conserved in evolution and interestingly, the Toll cascade was initially discovered in Drosophila. Like in mammals, mutations within these cascades produce the so called “melanotic tumors” in Drosophila larvae, which are due to blood cell proliferation and to the presence of hemocytes in an inflammatory state that aggregate and form black melanized masses. During my PhD, I proposed to decipher the impact of Gcm, the only known transcription factor specific to embryonic hematopoiesis on innate immune response and inflammation, by focusing on the JAK/STAT and Toll signaling cascades in vivo using the simple Drosophila model. I was able to show that Gcm inhibits melanotic tumors formation induced by the over-activation of both the JAK/STAT and Toll cascades. This is mediated by inducing the expression of JAK/STAT and Toll cascades inhibitors. In addition, my data describes for the first time the interaction occurring between the primitive and definitive hematopoietic waves and necessary to trigger an appropriate inflammatory response, where Gcm inhibits the secretion of the proinflammatory cytokines Upd2 and Upd3 from embryonic hemocytes. Moreover, I show that Gcm impacts the molecular landscape of mitochondrial genes in genetic backgrounds that lead to melanotic tumors and to an inflammatory state. Interestingly, I transpose my findings to vertebrates by showing that a GCM murine gene induces the expression of JAK/STAT inhibitors in a human leukemia cell line. In conclusion, my data highlights the importance of hematopoietic wave communication in the immune response and show that a developmental pathway regulates the competence to respond to inflammation.
18

Différenciation et plasticité des cellules souches neurales / Neural stem cells plasticity and differentiation

Flici, Hakima 21 September 2012 (has links)
L’étude de la plasticité cellulaire est un puissant outil pour comprendre le choix du destin cellulaire pendant la différenciation et dans les processus cancéreux lors de la transformation d’une cellule normale en une cellule maligne. Chez la drosophile, le facteur de transcription Gcm contrôle la détermination du destin glial. Dans des mutants gcm, les cellules qui se développent normalement en glie entrent dans la voie de différenciation neuronale alors que l’expression ectopique de gcm dans des progéniteurs neuronaux induit de la glie. Ces données font de Gcm un outil important pour comprendre les bases de la plasticité cellulaire. Mon projet de thèse vise à comprendre les mécanismes contrôlant la plasticité des cellules souches neurales. Nous avons ainsi montré que la capacité des CSNs à se convertir en glie après expression forcée de Glide/Gcm décline avec l'âge et que lors de l'entrée en phase quiescente ou apoptotique, ils ne peuvent plus être convertis. Nous avons aussi découvert que le processus de conversion du destin ne se manifeste pas uniquement par l’expression de marqueurs gliaux mais aussi par des changements spécifiques au niveau de la chromatine. D’une manière intéressante, nous avons aussi montré que la stabilité de la protéine Glide/Gcm est contrôlée par deux voies opposées, où Repo et l’histone acetyltransférase CBP jouent un rôle majeur. / The study of cellular plasticity is a powerful tool to understand the mechanisms directing cell fate choice during differentiation and transformation of a normal cell into a cancerous one. In Drosophila, the transcription factor Gcm control glial fate determination. In gcm mutants, cells that normally develop into glia enter the path of neuronal differentiation, whereas ectopic expression of gcm in neural progenitors induces glia. These properties make gcm an important tool for understanding the basics of cellular plasticity. My thesis project aims to understand the mechanisms controlling the plasticity of neural stem cells (NSCs). Based on this aim, we showed that the ability of NSCs to be transformed into glia, after forced expression of Gcm, declines with age and that upon entry into quiescence or apoptosis, they cannot be converted. We also found that the process of fate conversion does not manifest itself only through the expression of glial markers but also by specific changes in the level of chromatin. Remarkably, we also showed that the stability of the protein Gcm is controlled by two opposite and interconnected loops, where Repo and the histone acetyltransferase CBP play a major role.
19

Etude des mécanismes de la différenciation cellulaire impliquant le facteur de transcription Glide/Gcm chez la drosophile / The molecular mechanisms underlying glial cellular differentiation and involving the Glide/Gcm transcription factor in Drosophila

Trebuchet, Guillaume 25 September 2014 (has links)
La différenciation cellulaire implique des facteurs clés. Chez la drosophile, le facteur de transcription Glide/Gcm est impliqué dans la différenciation de deux types de cellules immunitaires : les macrophages circulants, qui ont une origine hématopoïétique, et les cellules gliales, macrophages résidents du système nerveux central, qui sont issues des précurseurs neuraux. J'ai d'abord entrepris la caractérisation du potentiel hématopoïétique de Gcm et l'identification de ses cibles dans les hémocytes. Ensuite, pour comprendre comment plusieurs types cellulaires peuvent être spécifiés par un même facteur de transcription, j'ai étudié comment s'effectue le choix entre le destin glial et le destin hémocytaire de la cellule. J'ai en particulier misen évidence le rôle clé des gènes agissant en aval de Gcm, ceux impliqués dans la consolidation et le maintien de l'identité cellulaire. Finalement, j'ai participé à la caractérisation du territoire d'expression de Gcm au niveau protéique et découvert un nouveau rôle de Gcm dans la différenciation de cellules neurosécrétrices, cellules indispensable pour initier le signal hormonal déclenchant le phénomène de mue chez les insectes. / Cell fate determination involves key transcription factors. ln Drosophila, the transcription factor Glide/Gcm is required for the differentiation of two immune cell types: circulating macrophages,which arise from hematopoietic precursors, and glial cells, resident macrophages of the central nervous system, which differentiate from neural precursors. ln first, 1 characterized Gcm hematopoietic potential and identified its target genes in hemocytes. Then, to get an insight intomolecular mechanisms underlying the acquisition of several identities with a single fate determinant, 1 investigated how the choice between the hemocyte and the glial fates is regulated.Being necessary to consolidate and to maintain a specific fate, 1 highlight the key role of genes acting downstream of a fate determinant. Finally, 1 contribute to characterize Gcm expression profile at the protein level and highlight a new role of Gcm in the differentiation of neurosecretory cells, cells absolutely required to initiate the hormonal signal triggering the molting process in insects.
20

Deciphering intrinsic and extrinsic machinery underlying collective glia migration using Drosophila as a model organism / Caractérisation de la machinerie controlant la migration collective de la glie en utilisant la Drosophile comme modèle

Gupta-Bosch, Tripti 11 March 2016 (has links)
La capacité remarquable des neurones et des cellules gliales à migrer collectivement sur de longues distances assure l’architecture finale du cerveau. Ce processus est extrêmement dynamique et dépend non seulement de l’interaction entre les cellules mais aussi de la présence de facteurs de transcriptions spécifiques au sein de la cellule migrante. Les protéines d’adhésion comme les cadhérines et les chimioattractants/chimiorépulsifs sont connus pour réguler et guider la migration. Si le mode d’action de ces molécules a été extensivement étudié, les cascades de signalisation qui déclenchent le chimiotropisme sont loin d’être élucidées. Au cours de mon doctorat, j’ai analysé la régulation et le rôle d’un récepteur des chimioattractant au cours de la migration de la glie. Pour ceci j’ai utilisé le modèle du développement de la chaine gliale dans l’aile de la drosophile qui représente un outil de choix pour étudier les mécanismes moléculaires régulant la migration collective. / The remarkable ability of neurons and glia to undergo long distance and collective migration ensures the final architecture and function of the brain. This is an extremely dynamic process that not only depends on cell interactions, but also on the presence of specific transcription factors in the migrating cells. Adhesion molecules such as classic cadherins and chemoattractants/repellants are known to regulate directional migration, however, how are these pathways regulated is largely unknown. While the role of these molecules controlling cell interactions has been extensively investigated, the signaling cascades that trigger chemotropism are not understood. During the course of my PhD I have analyzed the role of an adhesion molecule and the impact of a chemoattractant receptor regulated by an early transcription factor in the process. The glial chain in a developing Drosophila wing provides an excellent tool to study the molecular pathway underlying collective migration.

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