The centriole is a complex cylindrical assembly found in the cells of ciliated eukaryotes. It serves two important roles in the cell: templating the growth of cilia, and forming the basis of the centrosome, which is the major microtubule organising centre in the cell. Cilia and centrosomes are involved in many cellular processes, from signalling to cell division and differentiation. As such, defects in centriole assembly can have downstream consequences on these processes and are linked to a variety of human diseases including cancer and microcephaly. The complex superstructure of the centriole has fascinated biologists for decades. It comprises a nine-fold, radially symmetric array of microtubule triplet blades attached to a central cartwheel structure. During the last two decades, proteomic analyses have identified many proteins that are associated with the centriole. However, genetic studies have shown that only a surprisingly small number of these proteins are essential for the biogenesis of the centriole. In Drosophila melanogaster, three such essential proteins, SAS-6, Ana2 and SAS-4 are required in the early stages of centriole biogenesis. In this thesis I have investigated the assembly steps involving these key players from a structural perspective. I have identified and recombinantly expressed functional domains of these proteins in order to characterise them in vitro. Using X-ray crystallography and other biophysical techniques, I have been able to define mechanisms for several steps involved in the assembly of these proteins. In collaboration with colleagues in the laboratory I have been able to investigate the biological significance of these essential assembly steps in vivo. This information has provided novel insights into the molecular, and even atomic, detail of the initial steps of centriole assembly, including an explanation of a natural point mutation involved in human microcephaly.

This milestone presents a pool of available indicators and indicator systems which go beyond the narrow concepts of national economic accounts as well as a structuring of the indicators and indices according to central areas of well-being. The milestone builds the basis for Task 202.2, where a subset of indicators will be selected based on different theoretical frameworks, e.g. services / functionings, needs. Some of the indicators will be included in the macro-economic models in order to account for key dimensions of sustainability. / Series: WWWforEurope

Questioning GDP as dominant indicator for economic performance has become commonplace. For economists economic policy always aims for a broader array of goals (like income, employment, price stability, trade balance) alongside income, with income being the priority objective. The Stiglitz-Sen-Fitoussi Commission argued for extending and adapting key variables of macroeconomic analysis. International organisations such as the EC, OECD, Eurostat and UN have proposed extended arrays of macroeconomic indicators (see 'Beyond GDP', 'Compendium of wellbeing indicators', 'GDP and Beyond', 'Green Economy', 'Green Growth', 'Measuring Progress of Societies'). Despite these high profile efforts, few wellbeing and environmental variables are in use in macroeconomic models. The reasons for the low uptake of socio-ecological indicators in macroeconomic models range from path dependencies in modelling, technical limitations, indicator lists being long and unworkable, choices of indicators appearing ad hoc and poor data availability. In this paper we review key approaches and identify a limited list of candidate variables and - as much as possible - offer data sources. / Series: WWWforEurope

Gene therapy holds promise for the treatment a wide range of diseases ranging from cystic fibrosis to cardiovascular disease to cancer. The need for safe and efficient gene delivery methods remains the primary barrier to human gene therapy. Non-viral vector materials, including polymers, can be designed to be biocompatible and non-immunogenic, but lack the efficiency to be clinically relevant. Gene therapy awaits the development of new materials that are both safe and efficient. Here, we have synthesized a series of modified zwitterionic polymers based on the common transfecting agent polyethylenimine (PEI). Using a variety of biochemical and biophysical methods we have studied structure-function relation in zPEI-DNA as a function of percent modification. Our results show significant structural rearrangements in the DNA condensates with increasing zwitterionic character. The percent zwitterionic modification determines not only DNA packaging but the serum stability of the resulting polyplexes with more highly modified zPEI releasing DNA more readily.

Une assurance indicielle est proposée en réponse à l'augmentation des sécheresses impactant les prairies. Elle se base sur un indice de production fourragère (IPF) obtenu à partir d'images satellitaires de moyenne résolution spatiale pour estimer l'impact de l'aléa dans une zone géographique définie. Le principal enjeu lié à la mise en place d'une telle assurance réside dans la bonne estimation des pertes subies. Les travaux de thèse s’articulent autour de deux objectifs : la validation de l'IPF et la proposition d'amélioration de cet indice. Un protocole de validation est construit pour limiter les problèmes liés à l'utilisation de produit de moyenne résolution et au changement d’échelle. L'IPF, confronté à des données de référence de différentes natures, montre de bonnes performances : des mesures de production in situ (R² = 0,81; R² = 0,71), des images satellitaires haute résolution spatiale (R² = 0,78 - 0,84) et des données issues de modélisation (R² = 0,68). Les travaux permettent également d'identifier des pistes d'amélioration pour la chaîne de traitement de l'IPF. Un nouvel indice, basé sur une modélisation semiempirique combinant les données satellitaires avec des données exogènes relatives aux conditions climatiques et à la phénologie des prairies, permet d'améliorer la précision des estimations de production de 18,6 %. L’ensemble des résultats obtenus ouvrent de nombreuses perspectives de recherche sur le développement de l'IPF et ses potentiels d'application dans le domaine assurantiel. / An index-based insurance is provided in response to the increasing number of droughts impacting grasslands. It is based on a forage production index (FPI) retrieved from medium resolution remote sensing images to estimate the impact of hazard in a specific geographical area. The main issue related to the development of such an insurance is to obtain an accurate estimation of losses. This study focuses on two objectives: the FPI validation and the improvement of this index. A validation protocol is defined to limit problems attached to the use of medium resolution products and scaling issues in the comparisons process. FPI is validated with different data: ground measurements production (R² = 0.81; R² = 0.71), high resolution remote sensing images (R² = 0.78 - 0.84) and modelled data (R² = 0.68). This study also points out areas of improvement for the IPF chain. A new index, based on semi-empirical modeling combining remote sensing data with exogenous data referring to climatic conditions and grassland phenology, allows improving production estimation accuracy by 18.6%. Results of this study open several new research perspectives on FPI development and its potential practical application.

Cette étude présente un modèle biophysique de fonctionnement de culture capable de traduire la dynamique de l'évolution de tout couvert végétal, sous différentes conditions abiotiques du milieu (température, eau et rayonnement) mais aussi de sols et de climats. L'approche développée pour le suivi de la cinétique de croissance et de développement des couverts reste très proche de la réalité physiologique de leurs fonctionnements mais aussi de celle liée aux interventions humaines qui se trouve alors compatible avec l'échelle de notre modélisation. Alors que l'utilisation d'une simple loi linéaire d'action de la température par les modèles de fonctionnements des cultures permet de prendre en partie l'effet de l'action de la température sur une gamme assez limitée de température active des espèces végétales, l'approche, assez originale, adoptée dans ce modèle permet l'utilisation d'une vraie loi d'action de la température sur les différents processus biologiques liés au développement et à la croissance, valable sur toute la gamme des températures biologiquement actives. Aussi, cette approche très générique permet de suivre la cinétique des vitesses d'évolution de toutes entités d'une plante, quelque que soit l'espèce ou la variété, et de travailler à n'importe quelle échelle de temps (jour, heure). L'adaptation du modèle logistique (largement utilisé pour décrire les processus biologiques) au contexte physiologique des plantes a permis une description assez originale de la dynamique de la croissance en fonction du développement, prenant en compte à tout moment l'effet d'une contrainte du milieu et sa rétroaction sur la dynamique d'évolution du couvert. La régulation de la croissance a été possible dans ce modèle de développement-croissance à travers la modulation de sa vitesse de croissance (processus le plus sensible au stress) en fonction de deux stress les plus importants chez les végétaux, soit l'eau et le rayonnement. A partir d'un petit nombre de paramètres facilement abordable en bibliographie, il est possible de caractériser la dynamique d'évolution de tout type de couvert végétal évaluant en conditions de sol et de climat variés. Couplé au modèle de bilan hydrique Bilhyna, ce dernier est capable de fonctionner sous différentes situations du milieu, conditions pluviales limitantes notamment, et de gérer ainsi le manque d'eau avec des apports possibles par irrigation de complément où limitées aux besoins tout au long de la croissance intègre alors la rétroaction d'une contrainte du milieu sur la dynamique de l'évolution du couvert. Pour étudier notre modèle, nous avons confronté dans un premier temps les sorties du modèle de loi d'action de la température sur les vitesses de développement aux résultats expérimentaux concernant les cultures du Lin, du maïs et du blé, issus de plusieurs travaux d'auteurs assez connus et tirés de la bibliographie. La confrontation des résultats modèle-mesures a donné des résultats très satisfaisants. Nous avons dans une seconde partie confronté les sorties de l'ensemble du modèle biophysique couplé à bilhyna aux mesures expérimentales que nous avons réalisé au champ sur une période de cinq années, et portant sur deux cultures : le sorgho et du blé. Nous avons ainsi suivi l'évolution de la dynamique de ces couverts à travers leurs trois composantes (LAI, la hauteur du couvert et la profondeur de ses racines) de même que celle des stocks d'eau du sol durant toute la période de la croissance des cultures. Les résultats de la confrontation des sorties du modèle avec les mesures expérimentales ont été assez satisfaisants. [Suite et fin du résumé dans la thèse]. / This study presents a biophysical model of crop functioning can translate the dynamics of the evolution of any cover crops under different abiotic conditions of the environment (temperature, water and radiation), soil and climate. The approach developed for monitoring the kinetics of growth and development of crops is very close to the physiological reality of their functioning but also those linked to human intervention which is then compatible with the scale of our modeling. While the use of a simple linear law of action of the temperature bay patterns crop functioning model can take part in the effect of the action of temperature on a fairly limited temperature range of plant species active, the original approach which was adopted in this model allows the use of a true law of action of temperature on various biological processes associated with the development and growth, valid over the entire temperature range biologically active. Also, this approach very generic allows to follow the kinetics of the speed of evolution of all entities of a plant, no matter the species or variety, and work at any scale of time (days, hours). The adaptation of the logistic model (widely used to describe biological processes) to the physiological context of the plants has a quite original description of the dynamics of growth in terms of development, taking into account at any time the effect of stress the environment and feedback on the dynamics of cover change. The regulation of growth was possible in this model of development-growth through the modulation of its rate of growth (a process most sensitive to stress) according to two of the most important stress in plants, water and radiation. From a small number of parameters easily affordable in the bibliography, it is possible to characterize the dynamic evolution of all types of vegetation in soil conditions and climate varied. Coupled with the water balance model Bilhyna, it is capable of operating in different situations of the environment, including limiting rained conditions, and managing the water shortage with possible contributions from supplemental irrigation or limited needs throughout growth, then incorporates the feedback of environmental constraints on the dynamics of the cover crop evolution. To study our model, we compared initially exits the model law action of temperature on development rates to the experimental results on flax, corn and wheat from several studies of authors known and fairly drawn from the bibliography. Comparing the results-model measures gave very satisfactory results. We have, in a second part, faced the outputs of the coupled biophysical model bilhyna to experimental measurements we have done in the field over a period of five years, and on two crops: sorghum and wheat. We have followed the evolution of the dynamics of these cover crop through their three components (LAI, canopy height and depth of its roots) as well as stocks of soil water during the entire period of growth cultures. The results of the comparison of model outputs with experimental measurements was quite satisfactory. Last and final summary in the thesis.

This Thesis is a characterization study on substances having potency as drugs as well as on a lipid based drug-delivery matrix. The optical properties of newly synthesized molecules with proven pilicide properties have been characterized with several spectroscopic methods. These methods include optical absorption and fluorescence as well as time-resolved fluorescence. Upon covalently linking compounds with high quantum yields of fluorescence to specific parts of the pilicide, the biological impact was found to increase for some of the derivatives. Furthermore, by expanding the aromatic part of the pilicide molecule, a significant increase in the inherent fluorescence was obtained. The S0-S1 absorption band for these molecules was found to originate from an impure electronic transition, vibronically promoted by intensity borrowing from higher electronic states. Included in this Thesis is the measurement of how deeply some in this class of newly synthesized molecules become situated when placed inside ganglioside GM1 micelles, and how the molecules’ reorientation is affected. By means of radiation-less energy transfer, it was shown that the molecules place themselves close to the hydrophobic-hydrophilic interface inside the GM1 micelles. As a consequence they are exposed to a densely packed environment, which inhibits the free tumbling of the molecule. This restricted tumbling could be measured by means of time-resolved depolarization experiments. The release of drug-like fluorescent molecules is investigated from a lipid mixture, which upon equilibrium with water forms a mixture of inverted hexagonal and cubic phases. The lipid matrix displayed an extended release over the course of weeks, in vitro, for molecules having a large variation in hydrophobicity.

The study was conducted at the vicinity of the rural town of Doka in an area of about 55 x 40 km2. The aim of the study was to map and model the influences of the introduction of mechanized rain-fed agriculture and its rapid expansion on the natural vegetation in the southern Gadarif Region. To achieve these objectives the study utilized a series of techniques. Beside the intensive use of remote sensing imagery, interviews with key informants and farmers as well as detailed field surveys were carried out. Multi-temporal analyses of remote sensing imagery showed that during the seventies the average natural vegetation clearing rate increased most rapidly and then began to slow down. Farmers are aware that land degradation, in various forms, is taking place on their cultivated agricultural land. This is based on their perception and the interpretation of indicators such as weed infestation, reduced soil fertility and soil compaction. Continuous cropping, mono-cropping, rainfall shortage and the use of inferior seeds were the main reasons of land degradation indicated by the farmers. Abandonment of agricultural land to restore soil fertility is a common practice among farmers in the Gadarif Region. The study proved that the subsequent natural regeneration of plant species and the vegetation development on abandoned agricultural land are subject to the previous cultivation period and the duration of the fallow. The current regeneration capacity of the abandoned land may not be sufficient to reach full restoration of the previous vegetation climax except for some pockets which received more regenerative resources. Field surveys in conjunction with remotely sensed and topographic data have the potential to explain the restoration and rehabilitation patterns of degraded/abandoned agricultural land to a good extent. The findings of the study seem to be representative not only for the whole Gadarif Region or other areas in Sudan, but also for other regions in the Sahel Zone with similar problems and environmental and social conditions. One of the most practical conservation approaches is to let farmers play an active role in managing their abandoned land. Such management aims to allow for a certain level of use and benefits while maintaining the natural vegetation development on theses area in order to achieve maximal restoration. Although the study investigated the vegetation development in abandoned mechanized rainfed agricultural land, a full understanding of the path-way needs surveys that include more types of abandoned land and investigation of the effects of other local environmental factors (e.g. fire, grazing, distance from forests etc.) for more than one season.

This research adopts a multi-scale approach to examine the patterns, processes, and perceptions of landscape change within the core and buffer zone of Huascaran National Park, Peru. Within the park’s boundaries are the extensively glaciated Cordillera Blanca Mountains, where runoff from glaciers feeds into lakes, streams, and wetlands to provide hydrologic resources to populations on the periphery for agriculture, as well as hydropower to populations in distant urban areas. Inhabitants living on the periphery have livelihoods that are dependant upon land and natural resources found within the park’s core and buffer zone, while governance institutions mediate access and resource use. Landscape transformations occurring within and around the park are a result of human agency, biophysical change, and global climate change. A suite of qualitative and quantitative methodologies were used to investigate the coupled social and ecological dynamics of conservation, land use, and implications of climate change in Huascaran National Park. The principal objectives of this research were to assess the spatial and temporal patterns of landscape change using land-use and land-cover data from remotely sensed imagery and to examine the role of institutions on resource governance at multiple scales. A hybrid classification method was used to classify Landsat (TM and ETM+) satellite data for the years of 1987 and 2001. Hypotheses regarding the spatial and temporal dynamics of land-cover change were tested. Results indicate that the percent of land cover from the woodland, cropland, and snow and ice classes were reduced internal to the core of the national park, while the land-cover class of shrubland increased. Interviews with 143 informants revealed perceptions of landscape change and narratives of socio-political land use change. Interview data corroborated the findings of reduced land cover in the snow and ice class. Data also demonstrated that legacies of land tenure and governance are essential for evaluating the adaptive capacity of different institutions and communities confronting conditions of climate change. This research contributes to literature on dynamics and processes of landscape change by bridging analytical frameworks from landscape ecology, cultural and political ecology, and land change science and contributing to human dimensions of global change research. / text

This Thesis presents a framework for modelling species-specific site quality index (SQI) at a spatial resolution of 250 m by integrating biophysical variables of growing degree days (GDD), soil water content (SWC), and incident photosynthetically active radiation (PAR) in descriptions of potential tree growth. Development of GDD maps is based on processing and blending remotely-sensed data acquired with the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor on the Terra satellite and ETM+ sensor on Landsat-7 satellite at spatial resolutions of 250 m and 28.5 m. Descriptions of SWC are based on a temperature-vegetation wetness index (TVWI) that relies on MODIS-based optical and thermal image products. PAR is estimated with an existing solar-radiation distribution model. SQI is defined as a function of species vital attributes and species environmental response to GDD, TVWI, and PAR. The methods are applied to a balsam fir [bF; Abies balsamea (L.) Mill.] dominated region in northwest New Brunswick. Comparisons between SQI and field-based estimates of site index and enhanced vegetation index showed that about 66 and 88% of the values corresponding to a series of Forest Development Survey lines (691 in total) were within 16% of SQI values. On average 92.1% of high bF-content stands (> 50% composition) in the area fell on medium-to-very high SQI values (> 0.50). Based on these agreements, SQI can be perceived as a good predictor of potential tree-species growth in the selection of optimal sites for biomass and wood fibre production.