The total size of the world population is likely to increase from its current 7 billion to 8-10 billion by 2050. This uncertainty is because of unknown future fertility and mortality trends in different parts of the world. But the young age structure of the population and the fact that in much of Africa and Western Asia, fertility is still very high makes an increase by at least one more billion almost certain. Virtually, all the increase will happen in the developing world. For the second half of the century, population stabilization and the onset of a decline are likely. In addition to the future size of the population, its distribution by age, sex, level of educational attainment and place of residence are of specific importance for studying future food security. The paper provides a detailed discussion of different relevant dimensions in population projections and an evaluation of the methods and assumptions used in current global population projections and in particular those produced by the United Nations and by IIASA.

The current and projected low fertility levels for Europe and the continuous increases in life expectancy imply that the region will go through an unprecedented process of population aging, leading to sizeable changes in the age structure of European societies. After reviewing the existing literature on the role played by demographic change as a determinant of economic growth and income convergence, with a focus on the European experience, we analyze the quantitative impact of the projected changes in the age and education composition of the labor force. Using newly available demographic projections, we show that the current demographic trends are expected to cause a slowdown in the speed of income convergence across European countries. Our projection exercise suggests that policies aimed exclusively at improving labor force participation do not appear to be sufficient to counteract the negative effects of aging on income convergence. Instead, we show that reducing the educational attainment gap between Central and Eastern European member states and the rest of the European Union in addition to increasing labor force participation leads to an accelerated pace of income convergence.

Projections of sea level rise for the east coast of North America at 2100CE were generated considering contributions from: ocean warming, land ice melting and isostatic land motion. The primary contribution of this study is the development of an improved Glacial Isostatic Adjustment (GIA) model that includes an assessment of model uncertainty using 36 ice loading histories, 363 Earth models and a new sea level proxy database comprising over 500 sea level index points. We find that, while there are differences between our projections and the Global Mean Sea Level (GMSL) projections from the recent International Panel on Climate Change (IPCC) Assessment Report, the two sets of results agree to within uncertainty largely because some of the regional processes cancel. Our results indicate that the isostatic signal is large, contributing up to 1/4 of sea level change at 2100CE, and so must be included to generate accurate projections for this region.

Given the expansion of multimedia technology and proliferation of moving projections on the theatre stage in the 21st century, this thesis examines how a virtual or projected character can appear to be present without a physical body on the stage. This study is grounded in the theories of effet de présence (effect of presence) as elaborated by Josette Féral, but also uses other theories to look at how productions can create such an effect for virtual characters. Specifically, this thesis examines the character’s relationship with the real, framing devices and actions of the characters. The specific examples of Rwanda 94 (Groupov), La Belle et la Bête (4D Art) and Les Aveugles (UBU CC) are used as case studies in order to focus on these techniques. Partant de l’intégration des nouvelles technologies et la prolifération des projections vidéo au sein des scènes théâtrales du 21e siècle, cette thèse examine les techniques par lesquel les personnages projeté peut sembler présent en l’absence d’un corps physique visible. Cette réflexion est basée sur l’effet de présence, concept élaboré par Josette Féral, ainsi que d’autres théories et examine comment un effet de présence est constitué pour ces personnages virtuels en considérant leur relation au réel (mimesis), les dispositifs de cadrage dans lesquels ils s’inscrivent de même que leurs actions. Cette analyse sera menée à porter de avec trois étudies de cas : Rwanda 94 (Groupov), La Belle et la Bête (4D Art) et Les Aveugles (UBU CC).

Les mouvements locomoteurs rythmiques nécessitent l’intervention de circuits neuronaux qui coordonnent l’activité motrice des deux parties du corps. Ces circuits sont formés majoritairement par les projections des interneurones commissuraux de la moelle épinière. Des facteurs de guidage comme la Nétrine, les Slits jouent un rôle fondamental dans la mise en place de ces projections. Une étude a également montré qu’une signalisation impliquant le récepteur Neuropiline2 (Nrp2) des signaux Sémaphorines de la classe 3 (Sema3), participe au guidage de ces projections et cela uniquement après la traversée de la ligne médiane (Zou et al. 2000). Ma thèse porte sur l’étude fonctionnelle d’un ligand de la Nrp2, la Sema3B dans le développement de ce système de projections. J’ai analysé une souris invalidée pour Sema3B et observé de nombreuses erreurs de trajectoires après la traversée de la ligne médiane. Je me suis ensuite intéressée aux mécanismes sous-jacents au gain de réponse : par une approche pharmacologique et biochimique j’ai pu montrer que le signal de la plaque du plancher inhibe une activité de dégradation dépendante de la calpaine1. L’inhibition de cette voie conduit à la stabilisation d’un co-récepteur de la Nrp2, la Plexine A1 dont l’expression est très faible dans les axones n’ayant pas encore traversé la ligne médiane. Cette régulation permet alors l’assemblage d’un complexe récepteur fonctionnel de Sema3B, comprenant cette Plexine associée à la Nrp2 au niveau des cônes de croissance. J’ai identifié la molécule d’adhérence NrCAM, et le facteur neurotrophique GDNF comme étant les facteurs de la plaque du plancher déclencheurs de la réponse / Rhythmic locomotor movements require neuronal circuits ensuring left-right coordination. Spinal commissural projections participate to left-right coordination of limb movements by mediating reciprocal inhibition in synchrony. Extensive research of the mechanisms governing the formation of commissural pathways focused on dorsally-located spinal commissural neurons, establishing a fundamental role for multiple guidance cues derived for the midline and surrounding tissues, including Netrins, Slits and various morphogens. Semaphorin (Sema2)/Neuropilin-2 (Nrp2) signaling has been proposed to contribute to the guidance of commissural projections in the spinal cord at the post- but not pre-crossing stage (Zou et al, 2000). My PhD project aimed at analyzing the role of a Nrp2 ligand, Sema3B, in the guidance of spinal commissural projections, whose expression is dynamic and restricted to some territories, including the floor plate in which axons cross the midline. Analysis of Sema3B null mice showed that the loss of Sema3B induces a range of guidance defects of post-crossing commissural pathways. I investigated the underlying mechanisms and found that the floor plate signal induces through blockade of a calpain 1-dependant pathway the stabilization of the Nrp2 co-receptor Plexin-A1, and enable the assembly of Nrp2/Plexin-A1 sub-units into functional complexes for Sema3B in post-crossing commissural growth cones. I identified the cell adhesion molecule NrCAM and the neurotrophic factor GDNF as being the floor-platederived signals triggering the gain of response

La lignée transgénique pMBP-eGFP-NTR, que nous avons générée chez Xenopus laevis, permet une ablation conditionnelle des oligodendrocytes myélinisants, dont la conséquence est une démyélinisation. Dans cette lignée transgénique, le transgène est formé par une protéine de fusion entre le rapporteur GFP (Green Fluorescent Protein= protéine fluoresçant en vert) et une enzyme de sélection, la nitroréductase d’E. Coli. Cette enzyme, a la propriété de réduire le radical nitrite (NO2) de certains substrats (comme le métronidazole) en dérivé hydroxylamine extrêmement toxique pour la cellule qui l’exprime. L’expression de ce transgène est contrôlée par la portion proximale du gène MBP (myelin basic protein), séquence régulatrice, dont l’équipe avait démontré, chez la souris, qu’elle ne s’exprime que dans les oligodendrocytes myélinisants, ce qui c’est vérifié chez le xénope. Mon projet se proposait d’étudier les conséquences de la démyélinisation et de la remyélinisation dans cette lignée transgénique de Xenopus laevis. Mon objectif avait pour but de répondre à deux questions; Tout d’abord, qu’elle est la nature des cellules qui remplacent les oligodendrocytes éliminés: Nous montrons que les cellules responsables de la remyélinisation sont les précurseurs des oligodendrocytes (OPCs), cellules GFP négatives caractérisées par l’expression du facteur de transcription Sox10. Ces cellules OPCs sont déjà présentent dans le nerf optique avant l’événement de démyélinisation. La seconde question visait à examiner les conséquences d’une démyélinisation sur l’arborisation des axones des cellules ganglionnaires de la rétine. A cette fin nous avons mis au point un outil expérimental permettant de visualiser l’arborisation des projections tectales des axones des cellules ganglionnaires de la rétine par microscopie in vivo réalisée sur le têtard au stade 55. Nous montrons que bien que cette arborisation soit plus sensible à l’imagerie après démyélinisation, chez le transgénique que chez le contrôle, cela n’entraine pas de changement de la motilité de l’arborisation. / We have generated a Xenopus laevis transgenic line, pMBP-eGFP-NTR, allowing conditional ablation of myelin-forming oligodendrocytes. In this transgenic line the transgene is driven by the proximal portion of myelin basic protein (MBP) regulatory sequence, specific to mature oligodendrocytes. The transgene protein is formed by GFP reporter fused to the E. coli nitroreductase (NTR) selection enzyme. This enzyme converts the innocuous pro-drug metronidazole (MTZ) to a cytotoxin. My PhD project is to study the effect of demyelination and remyelination in Xenopus Laevis in this transgenic line. We wish to answer two questions using this transgenic. First, the origin of remyelinating cells that replace the ablated oligodendrocytes. We have shown that, Sox10+ OPCs, which are already present in the optic nerve prior to the experimentally induced demyelination, are responsible for remyelination. The second question is to examine the effect of demyelination of retinal ganglion cell (RGC) axonal arbor morphology. We developed an experimental set up to image the RGC arbor morphology in an awake stage 55 tadpole in real time. We show that the arbor is more sensitive than the control to imaging but there is no change in motility of the arbor.

Modificações nas posições médias dos centros de tempestades intensas assim como nos seus sentidos de propagação estão sendo sugeridas por diversos estudos sobre mudanças climáticas. Este fato pode ser determinante para a geração de ondas sobre os oceanos, e consequentemente para o conhecimento das climatologias de ondas. Na costa brasileira a falta de observações diretas em escala climática justifica o uso de técnicas de modelagem numérica para representação do fenômeno. Este trabalho apresenta resultados de simulações numéricas para caracterizar a climatologia das ondas de superfície e suas correspondentes perspectivas de mudanças para um futuro próximo sobre a região do Atlântico Sudoeste. Uma estratégia complexa de modelagem de ondas global, para assegurar a propagação de swell, e uma grade regional forçada por um ventos superficiais obtidos com um modelo de meso-escala atmosférico foi desenvolvida neste estudo. Os modelos utilizados foram o WAVEWATCH-III e o BRAMS. O período de 1982-1999 foi escolhido para representação do século XX com campos atmosféricos provenientes da REANÁLISE-I do NCEP, os quais são utilizados como controle do experimento. O período de 2030-2049 é investigado com base em dois cenários de projeções futuras CCSM3. Os valores médios de altura significativa para a porção Sudoeste do Atlântico Sul são superestimados no conjunto de simulação histórica do CCSM3; ao se considerar dois pontos de localização sobre a Bacia de Campos e Bacia de Santos, valores máximos do ciclo anual são encontrados durante os meses de outono enquanto que o conjunto referência apresenta valores máximos durante os meses de inverno. O estabelecimento de probabilidades de ocorrência de swell e wind sea revelam que o conjunto CCSM3 superestima a influência de swell gerados remotamente. Em termos das projeções climáticas para as bacias de Campos e Santos, pequenas diferenças nos valores médios de altura significativas aparecem de Maio a Dezembro, quando os resultados sugerem um leve aumento das alturas de ondas para as duas bacias quando comparadas com as respectivas médias do século XX. Por outro lado, a obtenção de séries de tendências durante os anos de 2030-2049 demonstram um padrão variável mas um fato comum aparece nos dois cenários de projeções climáticas: diminuição das alturas de ondas na área de oceano aberto e numa porção da região costeira próxima aos 20S, enquanto a porção sudoeste da região de estudo apresenta um pequeno aumento. Isto não é um desenvolvimento monotônico pois variabilidades interanuais de decadais estão evidentes para os dois cenários com diferentes amplitudes e fases entre elas. / Modifications in the mean position of the storm tracks as well as in the direction of propagation of severe storms have been suggested by many studies about climate change. This fact can be determined for the wind-wave generation over the oceans, and consequently for the wave climatology knowledge. In the coast of Brazil, the lack of long term direct observations of wave characteristics leads to the use of numerical modeling techniques to represent the phenomena. This study presents analysis of numerical simulations to characterize the climatology of surface gravity waves and the determined perspectives of changing in the near future for the Western South Atlantic region, with focus on its southern portion, off the southern Brazil coast. A complex strategy of global wave modeling to represent swell propagation associated with regional wave modeling forced by mesoscale winds is adopted; the models employed are WAVEWATCH-III and BRAMS. The period 1982-1999 is used to represent the 20th century with atmospheric fields from NCEP/Reanalysis-I, which results are used as reference. The period 2030-2049 is investigated based on two projected scenarios of the coupled climate model CCSM3. The average significant wave height for the Western South Atlantic is overestimated by the historical run of CCSM3; when considering two locations of interest, Campos and Santos Basins, the maximum values of the annual cycle are found during the autumn, while the reference field presents maximum values during the late winter. The evaluation of probabilities of occurrences of swell and wind sea revealed that CCSM3 overestimated the influence of remotely generated swell for the Western South Atlantic region. In terms of projected scenarios for Campos Basin and Santos Basin, some small differences in the average significant wave height appear from May to December, when the results suggest a small increase of wave height in both locations compared to the correspondent 20th century results. On the other hand, the obtained spatial distribution of trends during the period 2030-2049 shows a variable pattern, but a common feature appears in both projected scenarios of CCSM3: decrease of the wave heights in the open ocean area and part of the shelf around 20ºS, while the southwestern portion of the study region presents a small increase. This is not a monotonic behavior, because interannual and decadal variability are evident in both scenarios, with different amplitudes and phases between them.

No description available.

Energy-economy models are important tools used by policy-makers and researchers to design effective climate policy. However, there has been limited research that compares models against consistent characteristics to understand their impacts on climate policy projections. This can make it difficult for policy-makers to identify suitable models for their specific policy questions and develop effective climate policies. A web-based survey of energy-economy model users and developers in Canada’s public, private, and non-profit sectors (n=14) was conducted to systematically compare seventeen models against a framework of seven characteristics: technology characteristics, micro-, and macro-economic characteristics, policy representations, treatment of uncertainty, high-resolution spatial and temporal representations, and data transparency. It was found that for the most part, models represent technology, micro-, and macro-economic characteristics according to the classic typology of bottom-up, top-down, and hybrid models. However, our findings show that several modelling evolutions have occurred. Some top-down models can explicitly represent technologies and some bottom-up models incorporate microeconomic characteristics. Models differ in the types of policies they can simulate, sometimes underrepresenting performance regulations, government procurement, and research and development programs. All models incorporate at least one type of uncertainty analysis, models infrequently have high-resolution spatial and/or temporal representations, and most models lack publicly accessible methodological documents. Implications for researchers and policy-makers that use energy-economy models and/or develop policies are discussed. / Graduate

This thesis covers the topic of determination of geographical location of a host in internet network while utilizing measurement of the end to end delay and implementation of Constraint-Based Geolocation. Gradually I go through issue of the delay in computer networks and ways how to measure it. Next chapter describes a few ways to geolocate host in internet network with emphasis on the CBG method. Another chapter is dedicated to describing a way to project spherical coordinates to the two dimensional space, which has been used in implementation of geolocation method. Chapter about implementation builds upon the facts given in previous chapters while functions of the program written in the JAVA programing language are being explained. Two similar geolocation methods were implemented. By comparing the results gained by implementation, new method of geolocation is proposed and devised. It combines properities of both previous methods. There are results of the implemented methods and their comparation to the one of the source documents used in creation of this thesis in summary section.