The central nervous system is a complex, yet well-organised, often laminated, tissue. This robust organisation is evident in the architecture of the retina: consisting of 5 different neuronal types organised into distinct layers: Retinal Ganglion Cell (RGC), Amacrine Cell (AC), Bipolar Cell (BP), Horizontal Cell (HC) and Photoreceptor cell (PR) layers. This remarkable organisation is evolutionarily conserved in vertebrates, yet little is known about the mechanisms by which these cells form the correct layers. Live imaging has revealed overlapping periods of birth and extensive inter-digitation followed by cells sorting out into their appropriate positions, suggesting cell-cell interactions are important. To investigate possible cellular and molecular mechanisms responsible for the establishment of the tissue architecture I developed an organoid culture system for zebrafish retinal cells. To identify the cells in culture I used a Spectrum of Fates fish line which is a multiply transgenic line in which each retinal cell type can be identified based on expression of a combination of fluorescently tagged cell fate markers. The development of the protocol by which I cultured the cells and observed their cell-cell interactions involved establishing the best methods to dissociate and culture zebrafish retinal cells in a non-adhesive environment, then imaging the resulting reaggregates to examine the position of the different retinal cell types. By doing this I observed their inherent self-organising properties, in the absence of extrinsic cues or scaffolds. These cells appeared to be arranged in an inside-out layering, although all cell types are layered in the same relative order as they are in vivo. To analyse the organization in these aggregates I developed a Matlab script in collaboration with Leila Muresan which analyses the relative positioning of cells in concentric rings from the periphery to the centre of the aggregates according to the cell fate-tagged fluorescent markers. The script then fits this data as an empirical cumulative distribution function for different groups of cells to determine how spatially distinct populations of cells are. This gave me my measure of organisation. I then investigated the cell-cell interactions involved in this self-organisation by genetically or pharmacologically removing individual cell types and assaying the resulting organisation of the reaggregated, cell-type deficient, retinal organoids. I revealed that Müller Glia are important for retinal cell self-organisation. I also investigated the role of Retinal Pigment Epithelial (RPE) cells and Retinal Ganglion Cells and found they had no impact on the ability of the remaining cell types to organize. I began to investigate the role of Amacrine Cells but found that retinas void of ACs were susceptible to disaggregating in our dissection setup, preventing me from collecting the material needed for culture. I also investigated the role of candidate molecules in this system and revealed that R-Cognin is critical for retinal cells to reaggregate. Not only can I remove cells or molecules from the system, but I show how it can also be manipulated to replace molecules of interest such as laminin, by coating beads with the substance of choice and placing it amongst the cells to see if their organisational behaviour is affected. In summary, I have developed a system which provides a simple and easy platform to manipulate in various ways to help us potentially reveal some of the important players in neuronal patterning.

Forests perform many important ecological functions and provide numerous environmental services to humanity. Currently forests are under ever increasing pressures from humans through deforestation, changes in land use, and anthropogenic climate change. Managed forests play an important role in supplying forest products to the global population, necessitating the need to predict how forests will respond to climate change and how this will influence future wood product supplies. In this dissertation I used loblolly pine (Pinus taeda), the most extensively cultivated tree species in the United States, as a study system to simulate how climate change and forest management could alter the dynamics of managed forests in the future. Using the land component (the Community Land Model) of the widely used Community Earth System Model (CESM), I developed and validated a set of tools necessary to simulate the loblolly pine plantation system using the vegetation demography model embedded in CESM (FATES). This included developing a representation of loblolly pine using data from the literature, which was better able to capture forest growth and development observed in field studies than FATES's existing conifer tree representation. I added the ability to simulate several aspects of forest management not previously supported in FATES by creating the Vegetation Management Module, which I showed was able to realistically reproduce the common management practice of stand thinning. I used these new tools to perform simulations of how loblolly pine will grow across the Southeastern United States until the end of the 21st century, under the high and low climate change scenarios developed by the scientific community in the Coupled Model Intercomparison Project Phase 6 (CMIP6). Our experiments show that loblolly pine productivity may as much as double by the end of the century, with total wood harvest over that period increasing by almost half. I also showed that different management activities had significant effects on loblolly plantation yields, with mid-rotation stand thinning having an effect under both climate scenarios on par with increases due to the extreme climate change scenario SSP5 RCP8.5. I showed that these changes in wood yields could decrease the forest area in the Southeast required to meet the wood product demands over the rest of the century. These changes in plantation productivity could interact with socioeconomic factors to drive changes in land use and carbon storage in the Southeastern U.S. This work increases our understanding of how managed forests in the U.S.\ will be affected by climate change and how our management choices modulate that response. The techniques and tools developed here open up new areas of research into the role of forest management in the climate system. / Doctor of Philosophy / Forests benefit humans by regulating Earth's climate and by providing natural resources such as wood. In the Southeastern United States forestry is an important industry. Tree farms of southern pine trees produce a large percentage of the region's wood. Predicting how forests will grow in the future is important for planning and making investments. However, the burning of fossil fuels has increased carbon dioxide in the atmosphere and is changing Earth's climate. This is affecting how fast trees grow and how much wood can be harvested from forests. The methods that foresters have traditionally used to predict how trees will grow in the future do not account for climate change, and thus may not be as accurate in the future. An alternative is to use the computer models that scientists have developed to predict both how global climate will change in the future and how forests are influenced by climate. These computer programs can be used to predict how natural forests will grow in the future, but aren't set up to predict managed forests well. I made changes to one of these programs to make it possible to simulate the managed loblolly pine forests of the Southeastern United States. First, I tested these changes to make sure that simulated forests grew like real forests do today. Then I simulated how pine forests in Southeastern United States could grow over the next century with climate change. I found that pine forests will grow faster and allow more wood to be harvested as carbon dioxide in the atmosphere increases. If climate changes are extreme, loblolly forests could produce 70\% more wood than today by the end of the 21st century. I also showed that the manner in which forests were managed in simulations changes the amount of wood they produced, with some management practices increasing wood harvested by 50\% over the rest of the century. Because climate change could increase the amount of wood that can be produced from a fixed area of forest, I investigated how this might change the area of forest plantation in the Southeastern United States. Based on projections of demand for wood for the rest of the century I calculated how much loblolly pine forest would be needed to produce this wood over the next century. I found that increases in forest productivity due to climate change and forest management could decrease the forest area required to grow the wood we need. This could change how we use forests in the Southeastern United States, which in turn could have impacts on the climate.

Doctorat en philosophie et lettres / info:eu-repo/semantics/nonPublished

We have previously shown that the arcuate organization of cell fates within the ventral midbrain critically depends upon the morphogen, Sonic Hedgehog (SHH), which is secreted from a signaling center located along the ventral midline, called the floor plate (FP). Thus, it is ultimately the specification of the FP that is responsible for the patterning and specification of ventral midbrain cell fates. Interestingly, we have found that the chick midbrain FP can be divided into medial (MFP) and lateral (LFP) regions on the basis of gene expression, mode of induction and function. Overexpression of SHH alone is sufficient to recapitulate the entire pattern of ventral cell fates, although remarkably it cannot induce MFP, consistent with the observation that the MFP is refractory to any perturbations of HH signaling. In contrast, overexpression of the winged-helix transcription factor FOXA2/HNF3[beta]robustly induced the MFP fate throughout ventral midbrain while blocking its activity resulted in the absence of the MFP. Thus, by analyzing the differences between SHH and FOXA2 blockade and overexpression, we were able to attribute functions to each the LFP and the MFP. Notably, we observed that FOXA2 overexpression caused a bending of the midbrain neurepithelium that resembled the endogenous median hinge-point observed during neurulation. Additionally, FOXA2 misexpression led to a robust induction of DA progenitors and neurons that was never observed after SHH expression alone. In contrast, we found that all other ventral cell types required HH signaling directly, at a distance and early on in the development of the midbrain when its tissue size is relatively small. Additionally, HH blockade resulted in increased cell-scatter of the arcuate territories and in the disruption of the regional boundaries between the ventral midbrain and adjacent tissue. Thus, we bring new insight into the mechanism by which midbrain FP is specified and ascribe functional roles to its subregions. We propose that while the MFP regulates the production of dopaminergic progenitors and the changes in cellshape required for bending and shaping the neural tube, the LFP appears to be largely responsible for cell survival and the formation of a spatially coherent pattern of midbrain cell fates. / text

Theresienstadt gehört zu den bekanntesten Haftstätten des „Dritten Reiches“. Der Name steht als Chiffre für die nationalsozialistische Segregation, Verfolgung und Ermordung der Juden. Doch hinter dem plakativ gebrauchten Terminus verschwinden vielfach die Geschichte und der historische Ort. Bis heute existiert keine den neuesten Forschungsstand rezipierende Gesamtdarstellung. Nicht zuletzt aus diesem Grund wurde 2012 die umfangreiche Arbeit von H.G. Adler aus dem Jahr 1955 noch einmal aufgelegt. Adler gehörte als ehemaliger Insasse zu den direkt Betroffenen. Von dessen Studie setzt sich Wolfgang Benz verständnisvoll, doch pointiert ab. Unter Berücksichtigung der aktuellen Literatur gelingt ihm ein ausgewogener Blick auf die Gemeinschaft der Inhaftierten, die als „Zwangsgemeinschaft“ auch im Mittelpunkt der Untersuchung Adlers gestanden hatte. Benz’ Darstellung erweist sich so auch als Zwiegespräch mit dem wirkmächtigen Vorläufer.

No description available.

The thesis deals with the Želiv Premonstrate Monastery and the fates of its members in the 1940s and 1950s. The introduction briefly outlines the history of the monastery and the Premonstrate Order. The central part of the thesis deals with the Želiv Monastery as a whole. It describes economic measures that were introduced against it by the Communist regime. It also generally describes the preparations for cancelling monasteries and the progress of this action directly in Želiv. The third part deals with the fate of the Želiv abbot Bohumil Vít Tajovský as well as with the fates of other members of the Želiv Monastery who were oppressed by the Communist regime.

La roue des existences, image célèbre du bouddhisme himalayen, représente les différents mondes de renaissances, les causes et mécanismes de leurs enchaînements, elle illustre enfin la possibilité d’échapper au cycle samsarique. Les dates, la situation géographique, les emplacements des représentations, comme leur complexité et leur variété, suscitent de nombreuses questions qui nous ont conduit à étudier les textes canoniques anciens qui en posent les bases, à analyser les nombreux concepts représentés, mais aussi et surtout à examiner l’iconographie d’un corpus de soixante-dix-neuf roues réparties sur le territoire de quatre pays : l’Inde, le Népal, le Bhoutan et la Chine. Nos observations, résultat d’un long travail sur l’ensemble des informations et des thèmes contenus dans chaque roue, permettent de constater que la roue de la vie était connue dans un vaste territoire qui dépassait largement le monde himalayen, que sa fonction a évolué pendant une période de plus de quinze siècles, qu’il s’agit d’un thème très ancien toujours d’actualité, dont les variations révèlent le degré d’initiative des peintres et témoignent parfois d’ interprétations doctrinales différentes, reflétant des talents divers et le souci systématique de différencier chaque oeuvre des autres peintures. / One of the most famous images of Himalayan Buddhism is the wheel of existence (bhavacakra); it represents the various worlds of rebirths, the causes and mechanisms of their sequences and finally it illustrates the possibility of escaping the samsaric cycle. The age, the geographic situation, the complexity, the location and the variety of the representations raise many questions which lead to study the old canonical texts on which they are based, to analyze the many concepts represented, but also and especially examin the iconography of a corpus of seventy nine wheels to be found over the territory of the four countries which are today, India, Nepal, Bhutan and China. A long and extensive study of the vast amount of information contained in each wheel, makes it possible to say that the wheel of existence was known in a very large territory which greatly exceeded the Himalayan area, that its function evolved over a period of more than fifteen centuries, that it is a very old topic still relevant today and, that the works and the initiatives of the painters reveal variations which show their degrees of initiatives, sometimes different doctrinal interpretations, but also different talents and the systematic concern to be different from each other.

No description available.

Master of Visual Arts / This Dissertation explores the metaphor of Ariadne’s thread in terms of interconnection, when an element from the everyday is used as a locus linking broader concepts of time and space. Such experiences and associations are reflected in the work of Louise Bourgeois, Eva Hesse, Doris Salcedo, Lucio Fontana, Richard Tuttle, Mona Hatoum, Simone Mangos, Anya Gallaccio and Yoshihiro Suda. In relation to my own work, the metaphor of interconnecting thread allows a sense of freedom and journey of discovery. My studio and related research are closely aligned in developing my understanding of interconnection, through my studio process of making and continuing experiences of looking at and interpreting others artists’ work.