Characterization of the ontogenic program is essential to infer about palnts adaptation strategies. Frequently, morphogenesis of tropical forage grasses is reported to be analogous to that of temperate forage grasses. However, tropical grasses show stem development still during the vegetative phase of growth and under high light availability conditions. Stem elongation potentially impacts plants growth, with implications for grazing management. In tropical conditions, elephantgrass cv. Napier is considered one of the most productive grass species under grazing. The objective of this study was to characterize the ontogenic development of elephantgrass, coordination between phytomers, stem elongation and leaf and internode coordination in main and primary axes, using an isolated plant protocol. The experiment was conducted in Piracicaba, SP, during the Spring (2015), Summer (2016) and Autumn (2016), using a complete randomized block design, with 4 replicates. Eighty fiber cement tanks (0.343 m3) were used. Each block was composed of 20 tanks, 10 used to evaluate the morphogenic and developmental characteristics and 10 for the destructive evaluations. Measurements of leaf and stem elongation were performed every two days to determine the following variables: leaf appearance rate (LAR), leaf elongation rate (LER), leaf elongation duration (LED) and final leaf length (FLL). From day 10 of the evaluation period in Summer and Autumn and day 25 in Spring, 10 cuts were performed for destructive assessments every 5 days. At the time of the destructive evaluations, the following variables were measured: apical meristem heigth (AMH); sheath tube length (STL); number of expanding leaves (NEL); number of expanded leaves (NEXL). Measurements of sheath length (SL) and internode length (IL) were performed only on the main axis. On the main axis LAR (0.02 leaves degree-days-1) and LER (0.26 cm degree-days-1) were constant, whereas LED and FLL increased with leaf rank on the axis. LED ranged from 150 to 280 degree-days from phytomer 10 to 20. In Autumn, due to flowering, LED decreased with leaf rank. SL increased until reaching a maximum value of approximately 10-12 cm from the phytomer 12-13 onwards. When evaluated in phyllochronic units, similar pattern was observed across seasons of the year for a common leaf rank group. However, in all seasons, higher leaf ranks presented greater LED. Higher LAR were reported for topmost primary axes and LER increased with leaf rank until reaching a maximum, remaining constant afterwards. The LED increased with leaf rank in main and primary axes. The stem elongation began from phytomer 8 on the main axis in all seasons of the year, and in earlier phytomers for the other primary axes. In the main axis, internode length ranged from 0.5-2.0 cm for phytomer 8 until reaching a maximum value of 8-10 cm for phytomers 12-13 onwards, in Spring and Summer. During Autumn, maximum values of internode length were approximately 20 cm. Internode elongation begins concomitantly with the cessation of leaf elongation, and after 5 phyllochronic units from leaf appearance. In all axes, STL increased until reaching a maximum value of approximately 12-13 cm in Summer and 11-12 cm in Spring, coinciding with the beginning of stem elongation. The ontogenic development described for elephantgrass differs from that reported for temperate forage grasses. There was a seasonality effect. Axes development presents a hierarchical and synchronized organization. However, for the upper axes and topmost phytomers behavior is different and needs to be investigated. The stem elongation process can be described by the number of produced leaves. This study provides a key element for understanding phenotypic plasticity and corresponds to an useful information to identify the onset of stem elongation in field conditons. This result can potentially be used for functional-structural plant modelling. / A caracterização do desenvolvimento ontogênico é de fundamental importância para inferir sobre estratégias de adaptação das plantas. Frequentemente, a morfogênese de gramíneas tropicais é reportada como análoga à de gramíneas de clima temperado. No entanto, gramíneas tropicais apresentam colmo ainda na fase vegetativa e com elevada disponibilidade de luz. O alongamento de colmo potencialmente altera a dinâmica do desenvolvimento, com implicações sobre o manejo do pastejo. Em condições tropicais, o capim-elefante cv. Napier é considerado uma das gramíneas mais produtivas sob condições de pastejo. Objetivou-se com esse estudo caracterizar o desenvolvimento ontogênico do capim-elefante, a coordenação entre fitômeros, o alongamento de colmo e a coordenação entre folha e entrenó em perfilhos principais e axilares, em condições de plantas isoladas. O experimento foi conduzido em Piracicaba-SP, durante a Primavera (2015), Verão (2016) e Outono (2016), utilizando um delineamento em blocos completos casualizados, com 4 repetições. Foram instalados 80 tanques de fibrocimento (0,343 m3). Cada bloco era composto por 20 tanques, sendo que 10 foram utilizados para avaliar as características morfogênicas e de desenvolvimento e os outros 10 para as avaliações destrutivas. Medições do alongamento da lâmina foliar e do colmo foram realizadas a cada dois dias, para determinação das variáveis: taxa de aparecimento de folhas (TAF), taxa de alongamento de folhas (TAlF), duração do alongamento de folhas (DAF) e comprimento final da folha (CFF). A partir do dia 10 do período de avaliação no Verão e no Outono e do dia 25 na Primavera, foram feitos 10 cortes para avaliações destrutivas, a cada 5 dias. Por ocasião das avaliações destrutivas, as seguintes variáveis foram medidas: altura do meristema apical (AMA); comprimento do tubo de bainha (CTB); número de folhas em expansão (NFE); número de folhas expandidas (NFEX). Medições da bainha foliar (BF) e do comprimento do entreno (CE) foram realizadas apenas para o eixo principal (perfilho basal). No eixo principal, a TAF (0,02 folhas graus-dias-1) e a TAlF (0,26 cm graus-dias-1) foram constantes, enquanto que a DAF e o CFF aumentou com nível de inserção da folha no perfilho. A DAF variou de 150 a 280 graus-dias do fitômero 10 ao 20. No Outono, em função do florescimento, a DAF diminuiu com o nível de inserção da folha. O comprimento da BF foi crescente até atingir um valor máximo de aproximadamente 10-12 cm do fitômero 12-13 em diante. Quando avaliado em unidades filocrônicas, padrão semelhante foi observado entre épocas do ano para um grupo comum de níveis de inserção de folhas. No entanto, em todas as estações, níveis de inserção de folhas superiores apresentaram maiores DAF. Maiores TAF foram reportadas para eixos primários (perfilhos axilares) localizados acima do nível do solo e a TAlF foi crescente com o nível de inserção da folha até atingir um nível máximo, apartir do qual foi constante. A DAF foi crescente com o nível de inserção da folha em todos os eixos. O alongamento do colmo ocorreu a partir do fitômero 8 no eixo principal em todas as estações do ano, e em fitômeros anteriores para os demais eixos primários. No eixo principal, o CE variou de 0,5-2,0 cm no fitômero 8 até atingir valores máximos de 8-10 cm do fitômero 12-13 em diante, na Primavera e Verão. No Outono, valores máximos de entrenó foram de aproximadamente 20 cm. O alongamento do entrenó inicia-se concomitantemente ao término do alogamento da folha, e a um tempo de 5 filocronos do aparecimento da folha. Em todos os eixos, o CTB aumentou até atingir um valor máximo de aproximadamente 12-13 cm no verão e 11-12 cm na primavera, momento que coincidiu com o início do alongamento do colmo. O desenvolvimento ontogênico descrito para capim-elefante diverge daquele descrito para gramíneas de clima temperado. Houve efeito de sazonalidade. O desenvolvimento dos eixos apresenta organização hierárquica e sincronizada. No entanto, para os eixos superiores e fitômeros acima do nível do solo, o comportamento é diferente. O alongamento do colmo pode ser descrito pelo número de folhas produzidas. Este estudo fornece um elemento-chave para a compreensão da plasticidade fenotítipa e informações úteis para identificar o início do alongamento do colmo no campo. Este resultado pode ser utilizado potencialmente para modelagem de processos estrutura-função da planta.

La formation des trois feuillets embryonnaires primordiaux et leur régionalisation selon les axes embryonnaires sont des étapes cruciales au cours du développement précoce. Dans ce contexte, nous avons montré que XDSCR6, un inducteur du mésoderme et des axes embryonnaires qui présente des propriétés dorsalisantes, interagit physiquement et fonctionnellement avec le facteur de transcription XSTAT3. Au cours des étapes précoces du développement, XSTAT3 est active pendant la gastrulation et l'activation anormale de cette protéine dans la région dorsale induit la ventralisation des tissus embryonnaires. Par ailleurs, nous avons montré que XDSCR6 et XSTAT3 présentent des rôles antagonistes in vivo au cours de la mise en place des axes embryonnaires. Cet antagonisme peut être expliqué par le fait que XDSCR6 régule négativement l'activité transcriptionnelle de XSTAT3 en modulant sa méthylation sur les résidus lysine. L'ensemble de nos résultats a permis de déterminer l'importance cruciale de cette modification post-traductionnelle dans les propriétés ventralisantes de XSTAT3. Par ailleurs, nous avons montré que la méthyltransférase XEZH2 méthyle et active XSTAT3 in vivo. Des travaux antérieurs de l'équipe avaient montré que les propriétés dorsalisantes de XDSCR6 reposent sur sa capacité à inhiber l'activité épigénétique répressive de XEZH2 sur les gènes du mésoderme dorsal. Ainsi, nos travaux suggèrent que XDSCR6 est un modulateur transcriptionnel situé à l'interface entre certains régulateurs chromatiniens et des facteurs de transcription pendant la mise en place des axes embryonnaires. / One of the most challenging questions in developmental biology is to understand how a totipotent zygote differentiates into an organism containing all cell lineages. The formation of the three germ layers and the establishment of embryonic axis are fundamental events during early development. In this context, we demonstrated that XDSCR6, a mesoderm and embryonic axis inducer that exhibits dorsalizing properties, physically and functionally interacts with the transcriptional factor XSTAT3. During early development, XSTAT3 is active throughout gastrulation step and its abnormal activation in dorsal region leads to embryonic tissues ventralization. Furthermore, we showed that XDSCR6 and XSTAT3 have antagonistic roles in vivo during axis formation. This antagonism can be explained by the fact that XDSCR6 negatively regulates the transcriptional activity of XSTAT3 by interfering with its methylation on lysine residues. Moreover, this post-translational modification plays a crucial role in the ventralization abilities of XSTAT3. In a previous study, it has been shown that XDSCR6 negatively regulates the XEZH2 repressive epigenetic activity on dorsal mesoderm genes. Thus, we propose that XDSCR6 is a transcriptional modulator acting between epigenetic regulators and transcriptional factors during embryonic axis formation.

Alzheimer’s disease (AD) is the most common form of dementia and a growing disease burden that has seen pharmacological interventions primarily fail. Instead, it has been suggested that preventative measures such as a healthy diet may be the best way in preventing AD. Prebiotics are one such potential measure and are fermented into metabolites by the gut microbiota and acting as gut-brain axis components, beneficially impact the brain. However, the impact of prebiotics in AD prevention is unknown. Here we show that the prebiotic inulin increased multiple gut-brain axis components such as scyllo-inositol and short chain fatty acids in the gut, periphery, and in the case of scyllo-inositol, the brain. We found in E3FAD and E4FAD mice fed either a prebiotic or control diet for 4-months, that the consumption of the prebiotic inulin can beneficially alter the gut microbiota, modulate metabolic function, and dramatically increase scyllo-inositol in the brain. This suggests that the consumption of prebiotics can beneficially impact the brain by enhancing metabolism, helping to decrease AD risk factors.

The Mediterranean diet (Medi) has been highlighted as the golden diet rich in protective properties associated with cognitive- and emotional health. The foundation of the Medi comprises vegetables, fruits, nuts and seeds, legumes, and extra virgin olive oil. Research has been conducted in both holistic dietary approach and single nutrient approach regarding the impact of nutrition and diet, in this case, the Medi‟s effect on brain health. This review aims to give an up to date overview of the Mediterranean diet, outline some of the diet's abundant nutrients, and discuss studies linking the nutrient's potential effect on depression, cognitive decline, dementia, and brain structure and function. In addition, this review will attempt to assess whether the Medi as a whole or if a single nutrient approach is accountable for the health-promoting findings. Furthermore, the gut-brain axis, and other potential underlying mechanisms involved in the modulation of food- and nutrient intake and their effects on the brain, will be outlined. A diet high in fruit-, vegetable-, polyunsaturated fatty acid-, and monounsaturated fatty acid content has great power for health-maintenance and decreases the risk of suffering cognitive decline, dementia, and potentially depression. More randomized controlled trials are however eagerly awaited to give more substance to previous findings.

Les activités motrices de la vie quotidienne ou sportive se caractérisent par des mouvements de rotations complexes 3D des membres supérieurs pouvant s’effectuer autour d’axes de rotation distincts (i) articulaires (ii) d’inertie ou (iii) passant par le centre de masse du bras, chacun relevant de référentiels distincts. Une étude récente a montré que selon les contraintes de vitesse, un changement d’axe de rotation s’opère dans le cadre de l’exécution d’un mouvement simple de rotation du bras par rapport au tronc (Isableu et al., 2009). Dans ce cadre, l’objectif de la thèse a été de compléter cette première analyse et d’évaluer la robustesse de l’hypothèse selon laquelle les axes autour desquels s’organise le mouvement dépendent de la vitesse du mouvement et des contraintes liées à la tâche en général. L’hypothèse formulée est que l’axe correspondant à l’inertie minimum verra sa variabilité diminuée avec des vitesses qui augmentent par rapport à un axe lié au centre de masse (épaule-centre de masse du membre supérieur) ou géométrique (axe-épaule–coude). Cette étude s’effectue en considérant des mouvements « simples » et plus complexes incluant des gestes sportifs. Ainsi, les études effectuées ont porté sur l’influence des contraintes liées à la tâche et leur incidence sur le choix des axes de rotation. Tout d'abord le rôle de l'instruction initiale est testé. Deuxièmement, la variabilité de l'axe d’inertie minimum est évaluée au cours d'une tâche de précision. Troisièmement, l’hypothèse est testée dans le cadre d’une tâche d’interception qui implique des contraintes de temps. Enfin, nous avons testé le rôle des axes lors de gestes complexes, à grande vitesse, notamment lors de lancer à bras cassé et lors du service au tennis. Les résultats obtenus permettent de discuter l’hypothèse de l’importance de l’axe d’inertie minimum lors de l’exécution de mouvements volontaires du membre supérieur. / Motor activities of daily life or sports are characterized by complex 3D rotational movements of the upper limbs can be done around distinct axes of rotation (i) joint (ii) inertia or (iii) through the center mass of arms, each under separate repositories. A recent study showed that within the constraints of speed, a change of axis of rotation occurs in the context of the implementation of a simple rotation of the arm relative to the trunk (Isableu et al., 2009) . In this context, the aim of the thesis was to complete this first analysis to evaluate the robustness of the assumption that the axes around which organizes the movement depends on the speed of motion and the constraints task in general. The assumption is that the axis corresponding to the minimum inertia reduced variability seen with speeds which increase with respect to a center axis associated with the mass (shoulder mass center of the upper limb) and geometric (pin-shoulder elbow). This study is done by considering "simple" and complex athletic movements including movements. Thus, studies have focused on the influence of the task constraints and their impact on the choice of axes of rotation. Firstly the role of initial instruction is tested. Secondly, the variability of the axis of minimum inertia is estimated in a precise task. Thirdly, the hypothesis is tested in an interception task that involves time constraints. Finally, we tested the role of axes in complex gestures, high speed, especially during launch and broken arm during the tennis serve. The results are used to discuss the hypothesis of the importance of the axis of minimum inertia during the execution of voluntary movements of the upper limb.

<p>In  this  Master Thesis  a  review  of  different  type  of  vertical  axis  wind turbines (VAWT)  and  a preliminary investigation of a new kind of VAWT are presented.</p><p>After an introduction about the historical background of wind power, the report deals with a more accurate analysis of the main type of VAWT, showing their characteristics and their operations. The aerodynamics of the wind turbines and a review of different type on generators that can be used to connect the wind mill to the electricity grid are reported as well.</p><p>Several statistics are also presented, in order to explain how the importance of the wind energy has grown  up  during  the  last  decades  and  also  to  show  that  this development  of  the  market  of  wind power  creates  new  opportunity  also  for VAWT,  that  are  less  used  than  the  horizontal  axis  wind turbine (HAWT).</p><p>In the end of 2009 a new kind of vertical axis wind turbine, a giromill 3 blades type, has been built in Falkenberg, by the Swedish company VerticalWind. The tower of this wind turbine is made by wood,  in  order  to  get  a  cheaper  and  more environment  friendly  structure,  and  a  direct  driven synchronous multipole with permanent magnents generator is located at its bottom. This 200 kW VAWT represents the intermediate step between the 12 kW prototype, built in collaboration with the Uppsala University, and the common Swedish commercial size of 2 MW, which is the goal of the company.</p><p>A  preliminary  investigation  of  the  characteristics  of  this  VAWT  has  been done, focusing  in particular on the value of the frequency of resonance of the tower, an important value that must be never reached during the operative phase in order to avoid serious damage to all the structure, and on the power curve, used to evaluate the coefficient of power (Cp) of the turbine. The results of this investigation and  the steps  followed  to  get  them  are  reported.  Moreover  a  energy production analysis of the turbine has been done using WindPro, as well as a comparison with and older type on commercial VAWT.</p>

<p>3D fractals can be visualized as 3D objects with complex structure and has unlimited details. This thesis will be about methods to render 3D fractals effectively and efficiently, both to explore it in real-time and to create beautiful high resolution images with high details. The methods discussed is direct volume rendering with ray-casting and cut plane rendering to explore the fractal and an approach that uses super sampling to create high resolution images. Stereoscopic rendering is discussed and how it enhance the visual perception of the fractal</p>

Telomeres are the outermost parts of linear chromosomes. They consist of tandemly repeated non-coding short nucleotide sequences (TTAGGG in all vertebrates), in humans spanning over the last 2 to 15 kilobase pairs of the chromosome. Due to the end-replication problem, telomeres shorten with each cellular division. A critically short telomere will trigger the cell to enter a state of cellular senescence or to apoptose. The rate of telomere shortening can be accelerated by factors such as oxidative stress and inflammation. Taken together, this contributed to making telomere length a candidate biomarker of health and aging. Studies have shown that leukocyte telomere length progressively shortens with age, and that it independent of age is associated with age-related morbidity, lifestyle factors, and mortality. This thesis was aimed at exploring the relationships of leukocyte telomere length with various functional and structural attributes of the brain. In Paper I, telomere length was shown to be longer among non-demented carriers of the apolipoprotein E (APOE) ε4 allele, a well-established risk factor for Alzheimer’s disease. However, the rate of telomere shortening was greater among the ε4 carriers, possibly due to the higher levels of oxidative stress and inflammation associated with this allele. Furthermore, performance on episodic memory tests was inversely related to telomere length among ε4 carriers. The results may contribute to a better understanding of the pathophysiology related to the APOE ε4 allele. The volume of the hippocampus, a structure in the brain critical for episodic memory function, was in Paper II found to be inversely related to telomere length among non-demented APOE ε3/ε3 carriers. No correlation between hippocampal volume and telomere length was discernible among ε4 carriers, but they fit the pattern exhibited by the ε3/ε3 carriers as they tended to have smaller hippocampi and longer telomere length compared with the ε3/ε3 carriers. The results are possibly explained by a low proliferative activity among subjects with smaller hippocampi, which might also explain the inverse association between telomere length and episodic memory performance in Paper I. In Paper III, we describe results corroborating earlier findings of shorter telomere length among individuals suffering from depression. Moreover, we found that the shorter telomere length among the patients to a large extent could be linked to a hypocortisolemic state; a state which has been associated with chronic stress. The findings corroborate the link between telomere length and stress, and underline the role of stress in depressive illness. Two prominent manifestations of the aging brain are atrophy and white matter hyperintensities. In Paper IV, we report that white matter hyperintensities and cerebral subcortical atrophy were associated with shorter telomere length in aged non-demented individuals. Cortical atrophy was not associated with telomere length. Inflammation may be the underlying cause of the associations, as it is linked to telomere attrition, subcortical atrophy, and white matter hyperintensities. Taken together, these results show that leukocyte telomere length has the potential of being used as a biomarker for structural and functional attributes of the brain. Furthermore, the findings can provide new insights into mechanisms of disease and aging of the brain

The aim of this doctoral thesis was to study neuropsychological function in relation to structural and functional brain changes in Alzheimer´s disease (AD). In the first study relations between hippocampal volume, neuropsychological function and limbic-hypothalamic-pituitary-adrenal (LHPA) axis disturbances in AD were investigated with magnetic resonance imaging (MRI). Reduced hippocampal CA1 volume and suppressed cortisol levels in combination, best predicted the variation in neuropsychological performance. The conclusion was that reduced hippocampal volume and LHPA axis disturbances are associated to level of cognitive function in AD. The second study focused on whether patients with early AD showed an altered regional cerebral blood flow (rCBF) pattern compared to control persons, correlation between performance on memory tests and rCBF in sub-lobar volumes of the brain were investigated. The rCBF was measured with single photon emission computed tomography (SPECT). AD-patients showed a significantly lower rCBF in temporoparietal regions including left hippocampus compared to controls. The diagnostic sensitivity and specificity for AD was high in temporoparietal regions. AD-patients had significantly lower performance on semantic and, in particular, episodic memory-tests compared to the controls, and their performance on several episodic tests correlated with rCBF in parietal and temporal regions including left hippocampus, which suggest that abnormalities in the rCBF pattern underlie impaired episodic memory functioning in AD. The conclusion was that an observer-independent analyzing method for SPECT with sub-lobar volumes VOI´s is promising in the diagnosis of AD. In a third study possible differences in memory-related functional brain activation between persons with high versus low risk for AD were examined with functional magnetic resonance imaging (fMRI). The high-risk individuals performed worse than low-risk individuals on tests of episodic memory. Patterns of brain activity during episodic encoding and retrieval showed significant group differences. During both encoding and retrieval, the low-risk persons showed increased activity relative to a baseline condition in prefrontal and hippocampal brain regions that previously have been implicated in episodic memory. By contrast, the high-risk persons did not significantly activate any prefrontal regions, but instead showed increased activity in visual occipito-temporal regions. The conclusion was that patterns of prefrontal brain activity related to episodic memory differed between persons with high versus low risk for AD, and lowered prefrontal activity may predict subsequent disease. In a final study SPECT was used to map patterns of rCBF in an activated state (an episodic encoding task) and in a rest condition in persons with mild AD and in healthy elderly control persons. A reduction of rCBF in temporoparietal regions that was more pronounced in mild AD in the activated encoding task was observed. The conclusion was that there are rCBF differences between mild AD patients and healthy controls in temporoparietal regions, and the temporoparietal reduction is more pronounced during activation than during rest which might be important in the early diagnosis of AD. Taken together, these findings show that level of neuropsychological function, notably episodic memory, can be systematically related to functional disturbances in the LHPA axis and to the function of temporoparietal and prefrontal brain regions in AD patients. These changes are detectable in patients with risk for AD and in an early phase of AD which suggests that the obtained results might be important for early diagnosis of AD.

Wind power is a renewable energy source that is increasingly used all over the world. Most wind turbines have a horizontal axis of rotation but a few have a vertical axis of rotation. The concept presented in this thesis is a straight-bladed vertical axis wind turbine with a direct driven cable-wound permanent magnet synchronous generator. A comparison of the two different types of wind turbines, vertical axis wind turbines and horizontal axis wind turbines, have been performed considering several different aspects. However, the main focus in this thesis is on the generator. Several generators have been modelled with a combined field and circuit model, which has been solved by using the finite element method. A 12 kW generator has been designed, which has a high overall efficiency and a high overload capability. The generator has been constructed at the department and was tested in the laboratory before being mounted in a vertical axis wind turbine. Results from experiments correspond well with results from simulations. The generator has been tested for different loading conditions and the harmonic content of the voltage has been analysed. A 12 kW vertical axis wind turbine was completed and tests have been performed. The results are encouraging and further studies on the prototype will be performed in the future. The simulation method has been used to study electromagnetic losses in several generators. The comparison showed that the average losses should be considered when a variable speed generator for wind power is designed and it concluded that the design optimization process becomes a compromise between lowering the electromagnetic losses and having high overload capability. When constructing a wind turbine, it is important to consider vibrations in the structure. Torsional vibrations in the drive shaft connecting the turbine to the rotor of the generator have been studied. It is shown that a direct driven generator is to prefer over an induction generator with a gearbox when torsional vibrations are concerned. This thesis is based on eight papers all concerning vertical axis wind turbines with three of them focusing on the generator.