Thesis ( (M.Sc. Agriculture (Animal Production)) -- University of Limpopo, 2019 / A lack of energy and water in livestock production limit the performance of the animal. Therefore, the objective of this study was to determine the effect of spineless cactus as a source of energy and water on feed intake, feed digestibility and milk production of Holstein cows. Cactus serves as fresh forage or stored as silage for later feeding in livestock. However, there is limited information about cactus nutrients, their proportions in different species and the variability of these proportions with season. A total of four multiparous lactating Holstein cows with an average of 650 ± 80kg live weight were used and assigned to four dietary treatments with four replicates. Each animal was used four times. A cross-over design was used. The four dietary treatments were 0%, 4%, 8% and 12% of spineless cactus meal inclusion levels. The study period was 21 days of adaptation period and 6 days of collection period. Higher digestibility and energy supply (P<0.05) were observed with spineless forage diets compared to the control diet. Inclusion of spineless in the diets improved (P<0.05) diet intake and milk production in Holstein cows. However, an improved performance in milk production was observed with spineless cactus meal inclusion levels of 4%, 8% and 12%. Amongst the diets, 0% inclusion level had lower dry matter intake of 22.7kg (P<0.05) compared to those which had spineless cactus meal. High dry matter intake resulted in higher (P<0.05) milk production of 22.7, 24.7, 23.4 and 23.8 litres for 0, 4, 8 and 12% spineless cactus meal inclusion levels, respectively. However, cows on 4% inclusion level had higher milk yield than the other diets. Milk quality (butter fat, protein, lactose, somatic cell count and milk nitrogen urea) of Holstein cows was not (P>0.05) affected by the level of spineless cactus meal inclusion in the diet. Dry matter intake, neutral detergent fibre intake, acid detergent fibre intake and metabolisble energy intake of the cows were optimized at different spineless cactus meal inclusion levels of 19.427% (r2 = 0.992), 16.375% (r2 = 0.974), 14.0% (r2 = 0.984) and 22.909% (r2 = 0.994), respectively. Spineless cactus meal inclusion had no effect (P>0.05) on ADF intake and crude protein intake. Apparent digestibility values (0.73, 0.76 and 0.76) were not significantly different at 4%, 8% and 12% of spineless cactus meal inclusion levels, respectively. v It is concluded that spineless cactus meal inclusion level in the diet affected (P<0.05) diet intake and milk production of the Holstein cows. However, these variables were optimized at different spineless cactus meal inclusion levels. It could be recommended that spineless cactus can fit perfectly in livestock rations with attention given to their low crude protein content. These opuntia species can be fed to livestock mainly cattle and sheep during any season but are needed the most during drought as supplements when forages are scarce or expensive to feed. It is, therefore, concluded that 8% of spineless cactus inclusion level can be used to maintain productivity of the animals. / National Research Foundation (NRF)

Bovine milk-derived extracellular vesicles (EVs) hold promises as oral drug delivery systems. Since EV bioavailability studies are difficult to compare, key factors regarding EV uptake and intestinal permeability remain little understood. This work aims to critically study uptake and transport properties of milk-derived EVs across the intestinal barrier in vitro by standardization approaches. Therefore, uptake properties were directly compared to liposomes in intestinal Caco-2 cells. Reliable staining results were obtained by the choice of three distinct EV labeling sites, while non-specific dye transfer and excess dye removal were carefully controlled. A novel fluorescence correction factor was implemented to account for different labelling efficiencies. Both EV and liposome uptake occurred mainly energy dependent with the neonatal Fc receptor (FcRn) providing an exclusive active pathway for EVs. Confocal microscopy revealed higher internalization of EVs whereas liposomes rather remained attached to the cell surface. Internalization could be improved when changing the liposomal formulation to resemble the EV lipid composition. In a Caco-2/HT29-MTX co-culture liposomes and EVs showed partial mucus penetration. For transport studies across Caco-2 monolayers we further established a standardized protocol considering the distinct requirements for EVs. Especially insert pore sizes were systematically compared with 3 µm inserts found obligatory. Obtained apparent permeability coefficients (Papp) reflecting the transport rate will allow for better comparison of future bioavailability testing.

La spectroscopie par résonance magnétique nucléaire (RMN) est un outil puissant permettant d’acquérir des profils biochimiques du cerveau et de quantifier de nombreux paramètres cellulaires in vivo. Au cours de ce travail de thèse, nous nous sommes intéressés à trois techniques : (i) la spectroscopie RMN du 1H pondérée en diffusion, (ii) la spectroscopie RMN du carbone-13 (13C) et (iii) de l’oxygène-17 (17O) pour étudier la microstructure et la fonction cellulaire in vivo.Les métabolites cérébraux sont des traceurs endogènes spécifiques d’un type cellulaire (neurones et astrocytes) dont la diffusion dépend des nombreuses propriétés cellulaires (par exemple la viscosité du cytosol et la restriction intracellulaire). L’étude de la dépendance du coefficient de diffusion (ADC) aux temps de diffusion (td) permet de quantifier chacun de ces paramètres. En particulier, la mesure de l’ADC aux td longs permet d’évaluer la compartimentation des métabolites. Dans une première étude, nous avons mesuré l’ADC de plusieurs métabolites neuronaux et astrocytaires sur une large gamme de td (de ~80 ms à ~1 s) dans un large voxel dans le cerveau du macaque. Aucune dépendance de l’ADC de l’ensemble des métabolites au td n’a été observée suggérant que les métabolites diffusent majoritairement dans les prolongements neuronaux (axones, dendrites) et astrocytaires et ne sont pas confinés dans le corps cellulaire ou les organelles (mitochondries, noyau). La grande taille du voxel, liée à la sensibilité de détection limitée, ne nous a pas permis d’étudier la compartimentation des métabolites dans la substance blanche (SB) et la substance grise (SG). C’est pourquoi, une nouvelle étude a été réalisée dans le cerveau de l’Homme. Les résultats montrent que les métabolites diffusent dans des structures fibrillaires dans la SG et la SB. Enfin, une dernière étude, avec une gamme de td jusqu’à 2 s chez le macaque, nous a permis d’estimer, à l’aide de modèles analytiques simples mimant la structure cellulaire, la longueur des fibres neuronales (~110 μm) et astrocytaires (~70 μm). L’oxydation du glucose au sein des mitochondries permet de produire l’ATP (adénosine triphosphate), la principale source d’énergie de l’organisme. La spectroscopie du 13C permet de mesurer la vitesse de dégradation du glucose dans le cycle de Krebs (VTCA). Cette méthode est largement reconnue pour l’étude du métabolisme. Néanmoins, de nombreuses limitations, en termes de modélisation des données en détection indirecte ou de puissance émise dans le contexte du découplage hétéronucléaire en détection directe, ont été rencontrées sur notre scanner IRM. C’est pourquoi, la spectroscopie du 17O a ensuite été développée afin de quantifier la vitesse de consommation de l’oxygène pendant la phosphorylation oxydative (CMRO2). Des développements méthodologiques et technologiques ont été nécessaires et sont encore en cours pour mettre en place et valider cette technique qui n’a encore jamais été utilisée chez le macaque. / Magnetic Resonance Spectroscopy is a unique tool that allows acquiring brain biochemical profiles and quantifying many cellular parameters in vivo. During this thesis, three different techniques have been developed: (i) 1H diffusion-weighted, (ii) carbone-13 (13C) and (iii) oxygen-17 (17O) NMR spectroscopy to study brain structure and function in vivo. Brain metabolites are cell-specific endogeneous tracers of the intracellular space whose translational diffusion depends on many cellular properties (e.g.: cytosol vicosity and intracellular restriction). Studying the variation of the diffusion coefficient (ADC) as a function of diffusion time (td) allows untangling and quantifying those parameters. In particular, measuring metabolites ADC at long diffusion times gives information about the metabolites compartmentation in cells. In a first study, we measured neuronal and astrocytic metabolites ADC over a large time window (from ~80 ms to ~1 s) in a large voxel in the macaque brain. No dependence of all metabolites ADC on td was observed suggesting that metabolites primarily diffuse in neuronal (dendrites and axons) and astrocytic processes and are not confined inside the cell body and organelles (nucleus, mitochondria). The large size of the voxel, due to low detection sensitivity, did not allow us to study metabolites compartmentation in pure white (WM) and grey matters (GM). Therefore, we performed a new study in the human brain. Results showed that in both WM and GM metabolites diffuse in fiber-like cell structure. Finally, using an even larger time window (up to 2 s) in the macaque brain and analytical models mimicking the cell structure, we estimated the length of neuronal (~110 μm) and astrocytic (~70 μm) processes. ATP (adenosine triphosphate), the main source of energy in the organism, is produced thanks to glucose oxidation inside the mitochondria. 13C NMR spectroscopy is a well-known technique to study brain energy metabolism and can be used to estimate the rate of glucose degradation within the Krebs cycle (VTCA). However, many limitations, concerning data modeling when performing indirect detection or power deposition due to heteronuclear decoupling during direct detection, were encountered on our MRI scanner. Therefore, 17O NMR spectroscopy was developed to quantify the rate of oxygen consumption during oxidative phosphorylation (CMRO2). Methodological and technological developments were necessary and are still ongoing to validate this technique, which has never been used with macaque.

We are currently faced with the global challenge of conserving biological diversity while also increasing food production to meet the demands of a growing human population. Land-use change, primarily resulting from conversion to production land, is currently the leading cause of biodiversity loss. This occurs through habitat loss, fragmentation of remaining natural habitats, and resulting edge effects. Land-sparing and land-sharing approaches have been discussed as alternative ways to engineer landscapes to mitigate biodiversity loss while meeting production objectives. However, these represent extremes on a continuum of real-world landscapes, and it will be important to understand the mechanisms by which adjacent land use affects natural remnant ecosystems in order to make local land-management decisions that achieve conservation, as well as production, objectives. This thesis investigates the impact of juxtaposing production and natural forest on the community-wide interactions between lepidopteran herbivores and their parasitoids, as mediated by parasitoid spillover between habitats. The first and overarching objective was to determine whether herbivore productivity drives asymmetrical spillover of predators and parasitoids, primarily from managed to natural habitats, and whether this spillover alters trophic interactions in the recipient habitat. The study of trophic interactions at a community level requires understanding of both direct and indirect interactions. However, community-level indirect interactions are generally difficult to predict and measure, and these have therefore remained understudied. Apparent competition is an indirect interaction mechanism thought to be very important in structuring host-parasitoid assemblages. However, this is known primarily from studies of single species pairs, and its community-wide impacts are less clear. Therefore, my second objective was to determine whether apparent competition could be predicted for all species pairs within an herbivore assemblage, based on a measure of parasitoid overlap. My third objective was to determine whether certain host or parasitoid species traits can predict the involvement of those species in apparent competition. My key findings were that there is a net spillover of generalist predators and parasitoids from plantation to native forest, and that for generalists, this depends on herbivore abundance in the plantation forest. Herbivore populations across the edge were linked by shared parasitoids in apparent competition. Consequently, an experimental reduction of herbivore density in the plantation forest changed parasitism rates in the natural forest, as predicted based on parasitoid overlap. Finally, several host and parasitoid traits were identified that can predict the degree to which host or parasitoid species will be involved in apparent competition, a finding which may have extensive application in biological control, as well as in predicting spillover edge effects. Overall, this work suggests that asymmetrical spillover between production and natural habitats occurs in relation to productivity differences, with greater movement of predators and parasitoids in the managed-to-natural forest direction. The degree to which this affected species interactions has implications for landscape design to achieve conservation objectives in production landscapes.

La congélation partielle du mix dans un échangeur de chaleur à surface raclée (ECSR)est l'étape la plus critique dans la fabrication d'un sorbet, car c'est la seule étape où de nouveaux cristaux de glace se forment; par la suite ces cristaux ne font que grossir. L'objectif principal est de produire un grand nombre de cristaux les plus petits possibles afin d'obtenir une texture onctueuse. Pendant le procédé de congélation, le produit est soumis à des interactions couplées d'écoulement du fluide, de transfert de chaleur, de changement de phase et de cisaillement. Ces interactions sont déterminées par les conditions opératoires du procédé de congélation et affectent l'évolution de la distribution de taille des cristaux de glace, ainsi que la texture finale du produit. Ce travail présente la caractérisation expérimentale et la modélisation du procédé de congélation d'un sorbet. La congélation du sorbet à été effectuée dans un ECSR à l'échelle pilote. L'objectif principal de ce travail est l'étude de l'influence des conditions opératoires du procédé de congélation sur les caractéristiques finales du produit: distribution de taille de cristaux de glace, température du produit, fraction volumique de glace et viscosité apparente. Le comportement de l'écoulement du produit dans l'ECSR a été caractérisé par une étude expérimentale et une modélisation de la distribution du temps de séjour (DTS). Une approche de modélisation de la cristallisation de la glace couplant le modèle de DTS avec des équations de transfert de chaleur et de bilan de population des différentes classes de taille de cristaux a été développée. À partir d'une première estimation des paramètres, le modèle de cristallisation prédit de façon satisfaisante les tendances expérimentales et donne un bon aperçu de l'évolution de la distribution de taille des cristaux de glace au cours du procédé de congélation dans l'ECSR. / The partial freezing of the mix inside the scraped surface heat exchanger (SSHE) is the most critical step in sorbet manufacturing, since it is the only stage where new ice crystals are produced; further in the process these ice crystals will only grow. The main objective of the freezing process is to form the smallest possible ice crystals, so as to assure a smooth texture in the final product. During the freezing process the product is subjected to coupled interactions of fluid flow, heat transfer, ice phase change and shear. These interactions are determined by the freezing operating conditions and affect the evolution of the ice crystals size distribution (CSD) and the final texture of the product. This work presents the experimental characterization and the modelling of the initial freezing process of a sorbet. The freezing of sorbet was carried out in a SSHE at the pilot scale. The main objective of this work was the study of the influence of the freezing operating conditions on the final product characteristics: ice CSD, product temperature, ice volume fraction, apparent viscosity. The product flow behaviour in the SSHE was characterized by an experimental and modelling study of the residence time distribution (RTD) of the product. An ice crystallization modelling approach, taking into account the coupling of an empirical RTD model with heat transfer equations and a population balance of the different ice crystal size classes was developed. With a first set of estimated parameters, the ice crystallization model predicts satisfactorily the experimental trends, and made it possible to have an insight on the evolution of ice CSD during the freezing process in the SSHE.

As imagens de ressonância magnética (RM) ponderadas em Difusão são conhecidas como uma técnica funcional capaz de refletir alterações estruturais e celulares de neoplasias. No câncer de mama, a difusão e sua quantificação através dos valores do coeficiente de difusão aparente (CDA) têm sido utilizados para avaliar resposta tumoral após quimioterapia neoadjuvante (QTN). Os variados desfechos clínicos do câncer de mama, incluindo as diferentes respostas ao tratamento quimioterápico podem estar relacionados à heterogeneidade da doença. A presença das células tronco tumorais (CTT) é uma das hipóteses aceitas para explicar os diferentes comportamentos biológicos dos tumores. Este estudo buscou avaliar uma possível associação entre os valores de CDA nas neoplasias invasivas da mama e a presença de marcadores de CTT e os principais marcadores prognósticos da doença em pacientes tratadas com QTN. Foram avaliadas prospectiva e consecutivamente as imagens de RM pré-tratamento de 27 pacientes com câncer da mama que realizaram QTN seguida de cirurgia. Os valores de CDA média, p10, p25 e p50 foram obtidos através de duas mensurações, uma com único ROI e outra com múltiplos ROIs envolvendo toda extensão tumoral. Esses valores de CDA foram correlacionados: à quantificação por citometria de fluxo de CTT com fenótipos ESA+/CD44+/CD24-, células ESA+ com alta atividade ALDH1 e células ESA+/ABCG2+, à capacidade de formação de mamoesferas, e aos principais fatores prognósticos do câncer de mama, incluindo estágio clínico, doença axilar linfonodal, grau tumoral, receptores de estrógeno (RE), receptores de progesterona (RP) e superexpressão do HER2. Também foi realizada correlação dos valores de CDA com a resposta patológica completa após QTN. A presença de CTT, a capacidade de formação de mamoesferas e a resposta patológica completa não se correlacionaram aos valores de CDA. Para ambas as medidas e todos os parâmetros avaliados de CDA (x10-3mm2/s), os valores foram significantemente menores nos tumores com estágio clínico III e IV vs II (0,90±0,16; 1,02±0,18); com doença linfonodal após QTN vs axila livre (0,89±0,16; 1,01±0,17); RE+ vs RE- (0,90±0,16; 1,00±0,18); RP+ vs RP- (0,91±0,16; 0,98±0,18) e HER2+ vs HER2- (0,92±0,17;0,97±0,18). Tumores grau 1 apresentaram CDA com valores significativamente maiores em relação aos tumores grau 2 (diferença 0,18; CI: 0,03-0,33, p=0,02). Os valores de CDA dos tumores de mama pré-QTN não predizem a presença de CTT, a capacidade de formação de mamoesferas ou a resposta patológica completa, porém se correlacionam com o estágio clínico da doença, doença linfonodal axilar após QTN, grau tumoral e expressão das proteínas RE, RP e HER2, sendo um promissor marcador de agressividade tumoral / The diffusion-weighted magnetic resonance imaging (DWMRI) is a functional technique able to reflect structural and cellular changes in the tumors. In the breast cancer, the diffusion-weighted images and its numeric value known as the apparent diffusion coefficient (ADC) has been applied to evaluate pathologic response in patients treated with neoadjuvant chemotherapy (NC). The difference in the clinical results after breast cancer treatment, including different rates of responses to the NC has been associated to the heterogeneity of the disease. The presence of the breast cancer stem cells (BCSC) is an accepted hypothesis to explain the different biologic breast cancers behaviors. The aim of this study was to correlate the ADC value of invasive breast cancer with the presence of cancer stem cells markers and the major prognostic factors in patients treated with neoadjuvant chemotherapy. Prospectively, the MRI pre-treatment of twenty-seven consecutive patients with invasive breast cancer posteriorly treated with NC followed by surgery were evaluated. The ADC values mean, 10th percentile, 25th percentile, 50th percentile were obtained from two measurements, one of them with a unique ROI and the other with multiple ROIs encompassing the entire lesion. The ADC values were correlated to: presence of BCSCs (cell surface markers CD44+/CD24-, ABCG2 and ALDH1) identified by flow cytometric analysis, tumor grade, breast cancer staging, lymph nodal involvement, expression of estrogen receptors (ER), expression of progesterone receptors (PR) and expression of HER2. The assay mammospheres (Mammocult ®) were analyzed in 18 samples. Additionally, the ADC values were correlated to the pathologic complete response after QN treatment. There were no correlations between ADC values and breast cancer stem cells markers or mammospheres formation efficiency. For all parameters calculated, the ADC values (x10- 3 mm 2 /s) were lower in: breast cancer stage III and IV than stage II (0,90±0,16; 1,02±0,18), tumors with lymph node metastasis than without lymph node metastasis (0,89±0,16; 1,01±0,17), ER expression than ER negative (0,90±0,16; 1,00±0,18), PR expression than PR 10 negative (0,91±0,16; 0,98±0,18) and HER2 expression than HER2 negative (0,92±0,17; 0,97±0,18). The ADC values were significantly higher in grade-1 tumors (difference 0,18; CI: 0,03-0,33) compared to grade-2 tumors (p=0,02). The tumors values of ADC pretreatment were not correlated to the pathologic complete response after NC. The ADC values in pre-treatment invasive breast cancers are not a predictor of BCSC presence, mammospheres formation efficiency or pathologic complete response to QN. However it is correlated to the tumor grade, breast cancer staging, lymph nodal involvement, expression of ER, PR and HER2 and may represent a promising marker of tumor aggressiveness

Hiperplasia congênita de suprarrenal (CAH) compreende um grupo de transtornos hereditários decorrentes de erros inatos do metabolismo dos esteróides adrenais. O aumento das dimensões das glândulas suprarrenais é um marco morfológico na CAH que pode ser avaliado por métodos de imagem com signifitiva correlação com o controle hormonal dos pacientes. Porém, técnicas de imagem que forneçam informações qualitativas e quantitativas relativas à citoarquitetura das glândulas ainda não foram estabelecidas neste contexto. A difusão por ressonância magnética (DWI) é uma técnica que pode fornecer informações quantitativas dos tecidos através do valor do coeficiente de difusão aparente (ADC). O papel do ADC na avaliação de lesões tumorais adrenais já foi estudado, no entanto, o valor do ADC das glândulas suprarrenais normais ainda não foi descrito. O objetivo geral desta tese foi investigar a utilidade dos métodos de imagem na avaliação da CAH. Os objetivos específicos foram apresentar uma revisão dos métodos por imagem já estabelecidos para avaliação da CAH, validar o cálculo do ADC da glândula suprarrenal e avaliar se o ADC e as dimensões das glândulas suprarrenais poderiam auxiliar no manejo de pacientes com CAH, correlacionando-os com controle hormonal. Esta tese é baseada em artigos, nos quais estão mostrados a metodologia, resultados e discussões relativos a cada uma das etapas. O primeiro artigo, The role of imaging in congenital adrenal hyperplasia, trata de uma revisão sistemática de imagem em CAH, com ênfase em genitografia, ultrassonografia, tomografia computadorizada e ressonância magnética (MRI). O segundo artigo, Apparent Diffusion Coefficient (ADC) of the normal adrenal glands: premilinary results, teve como principal objetivo validar o método de medida do ADC das glândulas suprarrenais. No terceiro artigo, Quantitative magnetic resonance imaging in the evaluation of adrenal glands in children and young adults with congenital adrenal hyperplasia due to 21-hydroxylase deficiency, foram estudados os parâmetros quantitativos por MRI (ADC, volume e medidas lineares) das glândulas suprarrenais que poderiam estar relacionados ao controle hormonal dos pacientes com CAH. Medir o ADC das suprarrenais normais é factível e reprodutível. Em indivíduos saudáveis após a adrenarca o ADC é significativamente menor. Todavia, o ADC não foi capaz de diferenciar indivíduos controles de pacientes com CAH, assim como não apresentou correlação com o status hormonal dos pacientes. O volume e as medidas lineares das glândulas adrenais foram os melhores parâmetros quantitativos por MRI para diferenciar pacientes de indivíduos controles, com correlação positiva com o status hormonal recente dos pacientes com CAH. As dimensões das glândulas suprarrenais avaliadas por MRI podem ser utilizadas como ferramenta auxiliar no acompanhamento dos pacientes e mostrar rapidamente os efeitos da exposição a altos níveis de hormônio adrenocorticotrópico. Apesar de ocorrerem modificações celulares na CAH e de ter sido mostrado neste estudo que em pacientes sem doença hormonal conhecida o ADC é mais baixo após a adrenarca, estas alterações celulares que ocorrem na CAH não foram detectadas pelas medidas de ADC. / Congenital adrenal hyperplasia (CAH) is an autossomic recessive disorder caused by impaired steroidogenesis. A morphological hallmark in CAH is enlarged adrenal glands. Imaging studies have addressed mainly morphological aspects and dimensions of the adrenal glands, which correlate to the patients hormonal statuses. However, no imaging technique was used to evaluate changes in the adrenal glands at a cellular level in these patients. Diffusion-weighted magnetic resonance imaging (DWI) is a magnetic resonance imaging (MRI) technique with the ability to provide quantitative information about intracellular and extracellular space, given by the apparent diffusion coefficient (ADC) values. The role of ADC in evaluation of adrenal lesions has already been studied. However, ADC of the normal adrenals has not yet been described. The main purposes of this study were: to investigate the role of imaging in CAH, to validate the method of calculating ADC values of the normal adrenal glands and to assess hormonal status in patients with CAH and its correlation to quantitative MRI. This is an article-based thesis divided in three articles. The first article, The role of imaging in congenital adrenal hyperplasia, is a systematic review of imaging in congenital adrenal hyperplasia, with emphasis on genitography, ultrasonography, computed tomography and MRI. The article Apparent diffusion coefficient (ADC) of the normal adrenal glands: premilinary results aimed to validate the method of measuring ADC of the adrenal glands. The study of quantitative parameters (ADC, volume and linear measurements) of the adrenals evaluated by MRI that correlate with hormonal status in patients with CAH is described in the third article, Quantitative magnetic resonance imaging in evaluation of the adrenal glands in children and young adults with congenital adrenal hyperplasia due to 21-hydroxylase deficiency. Measuring ADC of the normal adrenal glands is feasible and reproducible. In healthy subjects, ADC values were significantly lower after adrenarche. However, neither a difference between ADC values of controls and patients, nor correlations with patients hormonal statuses were found. Volume and linear measurements of the adrenal glands were the best parameter to differentiate patients from controls. Moreover, a positive correlation was found between short-term hormonal control status and adrenal size. Adrenal size assessed by MRI might be a useful tool in the follow-up of patients with CAH. Although adrenal cell structure modifications in patients with CAH have been described, they were not detectable by DWI.

A porção sul do Leque Aluvial do Taquari, chamada Nhecolândia, é uma sub-região do Pantanal Mato-Grossense, que apresenta um complexo sistema de lagoas arredondadas, vazantes, cordilheiras, corixos e pequenas depressões. Estudos anteriores mostraram que os fluxos de águas subsuperficiais dependem da intensidade das cheias, e da presença e forma dos horizontes verdes argilosos, localmente cimentados, que limitam fortemente a permeabilidade, e comandam os fluxos laterais. Inicialmente associados a ambientes alcalinos das salinas, esses horizontes também ocorrem em ambientes diluídos, como as pequenas depressões. O objetivo geral deste trabalho é compreender o funcionamento hídrico de três pequenas depressões, em relação com as características morfológicas dos solos. Métodos de indução eletromagnética foram utilizados para mapear a condutividade elétrica aparente (CEa); complementados por métodos de descrições das características morfológicas dos solos, e de análises granulométricas e mineralógicas em laboratório. Estes trabalhos foram complementados por análises físico-químicas das águas nas depressões; e pelo monitoramento do nível do lençol freático entre uma depressão e uma baía. O horizonte verde argiloso, mais ou menos endurecido, aparece na base das sequências de solos nas três pequenas depressões, ao qual se superpõem horizontes arenosos superficiais e subsuperficiais. As principais diferenciações morfológicas observadas referem-se aos processos de redistribuição de ferro e da matéria orgânica, ligados ao regime hídrico. No período seco, quando ocorre um rebaixamento do nível freático, o horizonte verde argiloso funciona como uma soleira e fragmenta o lençol, que passa a funcionar como dois segmentos, um ligado à Depressão Fechada, e outro à Baía. Ao longo do ano, a Depressão Fechada acumula água apenas temporária e fugazmente. Na maior parte do tempo, ela funciona como área dispersora de água às unidades morfológicas adjacentes, salientando sua importância funcional na Nhecolândia. / The southern part of the Taquari alluvial fan, called Nhecolândia, is a sub-region of the Pantanal of Mato-Grosso exhibiting a complex of round shape lakes, draining fields, forested sandy areas, small watercourses and small depressions. Former studies have shown that the sub-superficial water fluxes depend on the intensity of the flood and on the presence and shape of a sandy clay loam greenish horizon, locally cemented, which acts as an impervious layer and drives lateral fluxes. Although its presence has always been associated to the alkaline-saline parts of this singular landscape, it also occurs below small freshwater depressions. The objective of this study is to understand the hydrological functioning of these small depressions in relation to the soil cover layout. Electromagnetic induction methods were used to draw apparent electrical conductivity (CEa) maps, crossed with direct auger holes and pits observations, and laboratory analysis (grain size distribution and mineralogy). Physico-chemical analysis of the ground water in the depressions and a monitoring of the groundwater fluctuation along one year were also performed. The greenish horizon, more or less cemented, occurred at the base of the soil system in all the studied depressions. It was overlaid by more sandy horizons. The main pedological differentiation was organic matter and iron redistribution along the soil sequences, in relation with the hydrological regime. During the dry season, the watertable goes down and the greenish horizon acts as a threshold, disconnecting various watertables in the different parts of the landscape. Along the year, the closed depressions accumulate the water only temporarily and fleetingly. Most of the time, they work as areas of water redistribution towards the surrounding landscape units, and therefore have a essential function in the Nhecolândia.

Knochen und Muskel sind die wichtigsten Gewebe im muskuloskelettalen System welche dem Körper die Bewegungen möglich machen. Beide Gewebetypen sind hochgradig strukturierter Extrazellulärmatrix zugrundegelegt, welche die mechanischen und biologischen Funktionen bestimmen. In dieser Studie wurden die räumliche Verteilung der anisotropen elastischen Eigenschaften und der Gewebemineralisation im humanen kortikalen Femur untersucht mit akustischer Mikroskopie und Synchrotron-µCT. Die homogenisierten elastischen Eigenschaften wurden aus einer Kombination der Porosität und der Gewebeelastizitätsmatrix mit Hilfe eines asymptotischen Homogenisierungsmodells ermittelt. Der Einfluss der Gewebemineralisierung und der Strukturparameter auf die mikroskopischen und mesoskopischen elastischen Koeffizienten wurde unter Berücksichtigung der anatomischen Position des Femurschaftes untersucht. Es wurde ein Modell entwickelt, mit welchem der intramuskuläre Fettgehalt des porcinen musculus longissimus nichtinvasiv mittels quantitativem Ultraschall und dessen spektraler Analyze des Echosignals bestimmt werden kann. Muskelspezifische Parameter wie Dämpfung, spectral slope, midband fit, apparent integrated backscatter und cepstrale Paramter wurden aus den RF-Signalen extrahiert. Die Einflüsse der Muskelkomposition und Strukturparameter auf die spektralen Ultraschallparameter wurden untersucht. Die akustischer Parameter werden durch die Muskelfaserorientierung beeinflusst und weisen höhere Werte parallel zur Faserlängsrichtung als senkrecht zur Faserorientierung auf. Die in dieser Studie gewonnenen detaillierten und lokal bestimmten Knochendaten können möglicherweise als Eingabeparameter für numerische 3D FE-Simulationen. Darüber hinaus kann die Untersuchung von Veränderungen der lokalen Gewebeanisotropie neue Einsichten in Studien über Knochenumbildung geben. Diese auf Gewebeebene bestimmten Daten von Muskelgewebe können in numerischen Simulationen von akustischer Rückstreuung genutzt werden um diagnostische Methoden und Geräte zu verbessern. / Bone and muscle are the most important tissues in the musculoskeletal system that gives the ability to move the body. Both tissues have the highly oriented underlying extracellular matrix structure for performing mechanical and biological functions. In this study, the spatial distribution of anisotropic elastic properties and tissue mineralization within a human femoral cortical bone shaft were investigated using scanning acoustic microscopy and synchrotron radiation µCT. The homogenized meoscopic elastic properties were determined by a combination of porosity and tissue elastic matrix using a asymptotic homogenization model. The impact on tissue mineralization and structural parameters of the microscopic and mesocopic elastic coefficients was analyzed with respect to the anatomical location of the femoral shaft. A model was developed to estimate intramuscular fat of porcine musculus longissimus non-invasively using a quantitative ultrasonic device by spectral analysis of ultrasonic echo signals. Muscle specific acoustic parameters, i.e. attenuation, spectral slope, midband fit, apparent integrated backscatter, and cepstral parameters were extracted from the measured RF echoes. The impact of muscle composition and structural properties on ultrasonic spectral parameters was analyzed. The ultrasound propagating parameters were affected by the muscle fiber orientation. The most dominant direction dependency was found for the attenuation. The detailed locally assessed bone data in this study may serve as a real-life input for numerical 3D FE simulation models. Moreover, the assessment of changes of local tissue anisotropy may provide new insights into the bone remodelling studies. The data provided at tissue level and investigated ultrasound backscattering from muscle tissue, can be used in numerical simulation FE models for acoustical backscattering from muscle for the further improvement of diagnostic methods and equipment.

Submitted by PPG Medicina e Ci?ncias da Sa?de (medicina-pg@pucrs.br) on 2018-07-20T19:52:55Z No. of bitstreams: 1 M?RCIA_CRISTINA_GON?ALVES_DE_OLIVEIRA_MARAES.pdf: 3458644 bytes, checksum: 005c22fed45246220ed1f2e0de9490a9 (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-07-30T12:47:18Z (GMT) No. of bitstreams: 1 M?RCIA_CRISTINA_GON?ALVES_DE_OLIVEIRA_MARAES.pdf: 3458644 bytes, checksum: 005c22fed45246220ed1f2e0de9490a9 (MD5) / Made available in DSpace on 2018-07-30T12:58:07Z (GMT). No. of bitstreams: 1 M?RCIA_CRISTINA_GON?ALVES_DE_OLIVEIRA_MARAES.pdf: 3458644 bytes, checksum: 005c22fed45246220ed1f2e0de9490a9 (MD5) Previous issue date: 2017-08-30 / Abstract: Today, the incidence of prostate cancer is considered high, however, unlike other malignant tumours, there is an expressive number of cases in which prostate cancer does not progress to clinical disease. The management of patients with prostate cancer should be individually fitted due to the broad behaviour spectrum of this cancer, ranging from low grade tumours with low aggressive biological characteristics to high grade tumours with metastatic capacity. The possibility of predicting the future behavior of the disease allows the selection of the most appropriate conduct for each case. Studies have shown that mpMRI (multiparametric Magnetic Resonance Imaging) has a high negative predictive value for clinically significant prostate cancer, indicating that its application as a screening method and as assessment method of disease progression is promising. To standardize the protocols and reports of prostate mpMRI, the PI-RADS v2 (Prostate Imaging Reporting and Data System version 2) was launched in 2015. Multiparametric Magnetic Resonance Imaging standardized by PI-RADSv2 has been taking a prominent place in the management of prostate cancer, but the specificity and positive predictive value still need to be improved. Purpose: To assess whether the ADC (Apparent diffusion coefficient) value and tumour ADC ratio associated with PI-RADS v2 may increase accuracy in predicting clinically significant prostate cancer. Materials and methods: 91 individuals with suspected prostate cancer were retrospectively studied through mpMRI imaging standardized by PI-RADS v2, obtaining the ADC value from the tumour and the contralateral tissue. The findings were correlated to anatomopathological study (biopsy, prostatectomy or transurethral resection). Results: Accuracy, sensitivity, specificity, positive predictive value and negative predictive value for the consensus between the two reviewers using PI-RADS v2, category 3 associated with categories 4 and 5 for the detection of clinically significant cancer were 70.3%, 97.4%, 50.9%, 58.7% and 96.4% (p <0.001), respectively. The association of the ADC value (<0.795x10-3) to categories 3, 4 and 5 of the PI-RADSv2, in turn, demonstrated accuracy, specificity and positive predictive value of 78.9%, 84.9% and 76.5%; and the association with the tumour ADC ratio (<0.62) presented 77.5%, 86.5% and 77.4% of accuracy, specificity and positive predictive value, respectively. Conclusion: The association of the ADC value and the tumour ADC ratio to the PI-RADS v2 in mpMRI increases the accuracy, specificity and positive predictive value in the detection of aggressive prostate cancer, and may help in the screening of individuals who would undergo invasive procedures and radical therapy, or conservative management, as active surveillance or watchful waiting. / Introdu??o: ? considerada alta a incid?ncia de c?ncer de pr?stata na atualidade, contudo, diferentemente de outras neoplasias, existe um n?mero expressivo de casos em que o c?ncer de pr?stata n?o evolui para a doen?a cl?nica. Por este motivo, o manejo dos pacientes com neoplasia prost?tica deve ser moldado individualmente face ao amplo espectro que varia desde tumores de baixo grau, com caracter?sticas biol?gicas de baixa agressividade, a tumores de alto grau, com capacidade metast?tica. A possibilidade de prever o comportamento futuro da doen?a permite a sele??o da conduta mais adequada para cada caso. Estudos vem comprovando que a Resson?ncia Magn?tica multiparam?trica (RMmp) apresenta um alto valor preditivo negativo para o c?ncer de pr?stata com signific?ncia cl?nica, indicando que sua aplica??o como m?todo de triagem e na avalia??o da progress?o da doen?a ? promissora. Para padronizar os protocolos e os relat?rios da RMmp da pr?stata foi lan?ado em 2015 o PI-RADS v2 (?Prostate Imaging Reporting and Data System? vers?o 2). A RMmp padronizada pelo PI-RADS v2 vem assumindo um lugar de destaque no manejo do c?ncer de pr?stata, contudo, ainda s?o considerados baixos a Especificidade e o Valor Preditivo Positivo. Objetivos: Avaliar se o valor de ADC (?Apparent diffusion coefficient? = Coeficiente de Difus?o Aparente) e a raz?o tumoral do ADC associados ao PI-RADS v2 podem aumentar a acur?cia da RMmp na predi??o do c?ncer de pr?stata com signific?ncia clinica. Materiais e m?todos: Foram estudados retrospectivamente 91 indiv?duos com suspeita de c?ncer de pr?stata, submetidos a RMmp padronizada pelo PI-RADS v2, obtendo-se o ADC quantitativo da les?o e do tecido contralateral. Os achados foram correlacionados ao estudo anatomopatol?gico (bi?psia, prostatectomia ou ressec??o transuretral). Resultados: A acur?cia, sensibilidade, especificidade, valor preditivo positivo e valor preditivo negativo para o consenso entre os dois avaliadores utilizando a RMmp padronizada pelo PI-RADS v2, com a categoria 3 associada as categorias 4 e 5 para a detec??o do c?ncer com signific?ncia cl?nica foram 70,3%; 97,4%; 50,9%; 58,7% e 96,4% (p<0,001), respectivamente. A associa??o do valor do ADC (<0,795x10-3) ?s categorias 3, 4 e 5 do PI-RADS v2, por sua vez, demonstrou acur?cia, especificidade e valor preditivo positivo de 78,9%; 84,9% e 76,5%; e a associa??o com a raz?o tumoral do ADC (< 0,62), apresentou 77,5%; 86,5% e 77,4% de acur?cia, especificidade e valor preditivo positivo, respectivamente. Conclus?o: A associa??o do valor do ADC e da raz?o tumoral do ADC ao PI-RADS v2 na RMmp aumenta a acur?cia, especificidade e valor preditivo positivo na detec??o do c?ncer agressivo da pr?stata, podendo auxiliar na triagem dos indiv?duos e na decis?o entre a conduta agressiva, com procedimentos invasivos e terapia radical, ou a conduta conservadora, com vigil?ncia ativa ou observa??o.