A diversidade beta pode ser definida como a mudança na composição de espécies entre locais em uma determinada área geográfica. Quantificar a contribuição relativa dos diferentes fatores que a afetam é essencial para entender como é mantida a diversidade das comunidades. Nosso estudo tem foco na vegetação lenhosa da região do Alto Camaquã, sul do Brasil (ca.30-31° S, 52-54° W), que está inserida no bioma Pampa e é caracterizada por ampla heterogeneidade ambiental com mosaicos de floresta e campo naturais. Com o objetivo de responder quais fatores tem mais influência na estruturação da comunidade de plantas lenhosas dessa região, distribuímos sistematicamente 60 unidades amostrais onde foram levantadas todas as espécies de plantas lenhosas. Primeiramente particionamos a diversidade beta através de RDA parcial e verificamos que as variáveis ambientais – que incluem variáveis climáticas, topográficas e edáficas – explicaram 28,4% da variação na composição de espécies, a distância geográfica explicou 16,6%, 14,7% foi compartilhado entre os dois componentes e 40,3% permaneceu não explicado. Com isso ficou claro que fatores determinísticos são mais importantes na estruturação das comunidades lenhosas. Em uma posterior análise de árvore de regressão multivariada, as variáveis climáticas foram selecionadas como as mais influentes. Além disso, a região de estudo é uma das mais bem conservadas do Estado. Portanto, em um segundo momento, investigamos a influência de fatores adicionais na diversidade beta das comunidades lenhosas, considerando o histórico de 300 anos de presença de manejo com pecuária familiar do Alto Camaquã. A partir de dados de um zoneamento agroecológico, exploramos a influência das diferentes tipologias de pecuária sobre dois estratos das comunidades de plantas lenhosas, plântulas e adultos, controlando o efeito da variação climática através de correlações matriciais. Encontramos que o manejo não está relacionado com o turnover de espécies de plântulas, contudo explica 12% da variação da diversidade beta de arbóreas. Concluímos, portanto, que a heterogeneidade climática da região gera heterogeneidade ambiental, sendo esta a principal determinante da diversidade das comunidades, apesar de processos neutros também influenciarem, em menor proporção. A presença do manejo não afeta de forma equitativa a comunidade de plantas lenhosas, contribuindo para a heterogeneidade florística da região. / Beta diversity can be defined as the shift in species composition among sites in a geographical area of interest. Quantifying the relative contributions of different processes that affect beta diversity is essential for understanding how diversity is maintained in communities. Our study focuses on the woody vegetation of the Alto Camaquã region, southernmost Brazil (c. 30-31° S, 52-54° W), which is within the domain of the Pampa biome and presents wide environmental heterogeneity showing natural forest-grassland patches. Aiming to answer which factors are most influential in the structuring of the woody plant communities, we systematically placed 60 sampling plots throughout the study area for vegetation survey. We partitioned beta diversity through partial RDA and verified that the environmental variables - which include climatic, topographic and edaphic variables - explained 28.4% of the variation in species composition, geographic distance accounted for 16.6%, 14.7% was shared between the two components and 40.3% of the variation remained unexplained. The deterministic processes are clearly the most important in structuring the woody communities. Further analysis using multivariate regression tree selected the climatic variables as the most influential. The study region shows a well conserved physiognomy, regardless of its 300-years history of land use for family cattleraising; hence in a second moment we investigated additional factors affecting diversity patterns of the plant communities surveyed, starting from available agroecological zoning data for land management. We explored the effect of the different typologies of family cattle-raising over two strata of the woody vegetation community, seedling and adult plants, controlling the effect of climate heterogeneity using matrix correlations (partial Mantel tests). We found that land management is not correlated with the species turnover of seedlings, yet explains 12% of the variation in the adult plants beta diversity. We concluded, hence, that climatic heterogeneity creates habitat heterogeneity, being the main determinant of community diversity, although neutral processes are also influent. Land management does not affect the woody plant community evenly, thus contributing to the floristic heterogeneity of the region.

A diversidade beta pode ser definida como a mudança na composição de espécies entre locais em uma determinada área geográfica. Quantificar a contribuição relativa dos diferentes fatores que a afetam é essencial para entender como é mantida a diversidade das comunidades. Nosso estudo tem foco na vegetação lenhosa da região do Alto Camaquã, sul do Brasil (ca.30-31° S, 52-54° W), que está inserida no bioma Pampa e é caracterizada por ampla heterogeneidade ambiental com mosaicos de floresta e campo naturais. Com o objetivo de responder quais fatores tem mais influência na estruturação da comunidade de plantas lenhosas dessa região, distribuímos sistematicamente 60 unidades amostrais onde foram levantadas todas as espécies de plantas lenhosas. Primeiramente particionamos a diversidade beta através de RDA parcial e verificamos que as variáveis ambientais – que incluem variáveis climáticas, topográficas e edáficas – explicaram 28,4% da variação na composição de espécies, a distância geográfica explicou 16,6%, 14,7% foi compartilhado entre os dois componentes e 40,3% permaneceu não explicado. Com isso ficou claro que fatores determinísticos são mais importantes na estruturação das comunidades lenhosas. Em uma posterior análise de árvore de regressão multivariada, as variáveis climáticas foram selecionadas como as mais influentes. Além disso, a região de estudo é uma das mais bem conservadas do Estado. Portanto, em um segundo momento, investigamos a influência de fatores adicionais na diversidade beta das comunidades lenhosas, considerando o histórico de 300 anos de presença de manejo com pecuária familiar do Alto Camaquã. A partir de dados de um zoneamento agroecológico, exploramos a influência das diferentes tipologias de pecuária sobre dois estratos das comunidades de plantas lenhosas, plântulas e adultos, controlando o efeito da variação climática através de correlações matriciais. Encontramos que o manejo não está relacionado com o turnover de espécies de plântulas, contudo explica 12% da variação da diversidade beta de arbóreas. Concluímos, portanto, que a heterogeneidade climática da região gera heterogeneidade ambiental, sendo esta a principal determinante da diversidade das comunidades, apesar de processos neutros também influenciarem, em menor proporção. A presença do manejo não afeta de forma equitativa a comunidade de plantas lenhosas, contribuindo para a heterogeneidade florística da região. / Beta diversity can be defined as the shift in species composition among sites in a geographical area of interest. Quantifying the relative contributions of different processes that affect beta diversity is essential for understanding how diversity is maintained in communities. Our study focuses on the woody vegetation of the Alto Camaquã region, southernmost Brazil (c. 30-31° S, 52-54° W), which is within the domain of the Pampa biome and presents wide environmental heterogeneity showing natural forest-grassland patches. Aiming to answer which factors are most influential in the structuring of the woody plant communities, we systematically placed 60 sampling plots throughout the study area for vegetation survey. We partitioned beta diversity through partial RDA and verified that the environmental variables - which include climatic, topographic and edaphic variables - explained 28.4% of the variation in species composition, geographic distance accounted for 16.6%, 14.7% was shared between the two components and 40.3% of the variation remained unexplained. The deterministic processes are clearly the most important in structuring the woody communities. Further analysis using multivariate regression tree selected the climatic variables as the most influential. The study region shows a well conserved physiognomy, regardless of its 300-years history of land use for family cattleraising; hence in a second moment we investigated additional factors affecting diversity patterns of the plant communities surveyed, starting from available agroecological zoning data for land management. We explored the effect of the different typologies of family cattle-raising over two strata of the woody vegetation community, seedling and adult plants, controlling the effect of climate heterogeneity using matrix correlations (partial Mantel tests). We found that land management is not correlated with the species turnover of seedlings, yet explains 12% of the variation in the adult plants beta diversity. We concluded, hence, that climatic heterogeneity creates habitat heterogeneity, being the main determinant of community diversity, although neutral processes are also influent. Land management does not affect the woody plant community evenly, thus contributing to the floristic heterogeneity of the region.

A diversidade beta pode ser definida como a mudança na composição de espécies entre locais em uma determinada área geográfica. Quantificar a contribuição relativa dos diferentes fatores que a afetam é essencial para entender como é mantida a diversidade das comunidades. Nosso estudo tem foco na vegetação lenhosa da região do Alto Camaquã, sul do Brasil (ca.30-31° S, 52-54° W), que está inserida no bioma Pampa e é caracterizada por ampla heterogeneidade ambiental com mosaicos de floresta e campo naturais. Com o objetivo de responder quais fatores tem mais influência na estruturação da comunidade de plantas lenhosas dessa região, distribuímos sistematicamente 60 unidades amostrais onde foram levantadas todas as espécies de plantas lenhosas. Primeiramente particionamos a diversidade beta através de RDA parcial e verificamos que as variáveis ambientais – que incluem variáveis climáticas, topográficas e edáficas – explicaram 28,4% da variação na composição de espécies, a distância geográfica explicou 16,6%, 14,7% foi compartilhado entre os dois componentes e 40,3% permaneceu não explicado. Com isso ficou claro que fatores determinísticos são mais importantes na estruturação das comunidades lenhosas. Em uma posterior análise de árvore de regressão multivariada, as variáveis climáticas foram selecionadas como as mais influentes. Além disso, a região de estudo é uma das mais bem conservadas do Estado. Portanto, em um segundo momento, investigamos a influência de fatores adicionais na diversidade beta das comunidades lenhosas, considerando o histórico de 300 anos de presença de manejo com pecuária familiar do Alto Camaquã. A partir de dados de um zoneamento agroecológico, exploramos a influência das diferentes tipologias de pecuária sobre dois estratos das comunidades de plantas lenhosas, plântulas e adultos, controlando o efeito da variação climática através de correlações matriciais. Encontramos que o manejo não está relacionado com o turnover de espécies de plântulas, contudo explica 12% da variação da diversidade beta de arbóreas. Concluímos, portanto, que a heterogeneidade climática da região gera heterogeneidade ambiental, sendo esta a principal determinante da diversidade das comunidades, apesar de processos neutros também influenciarem, em menor proporção. A presença do manejo não afeta de forma equitativa a comunidade de plantas lenhosas, contribuindo para a heterogeneidade florística da região. / Beta diversity can be defined as the shift in species composition among sites in a geographical area of interest. Quantifying the relative contributions of different processes that affect beta diversity is essential for understanding how diversity is maintained in communities. Our study focuses on the woody vegetation of the Alto Camaquã region, southernmost Brazil (c. 30-31° S, 52-54° W), which is within the domain of the Pampa biome and presents wide environmental heterogeneity showing natural forest-grassland patches. Aiming to answer which factors are most influential in the structuring of the woody plant communities, we systematically placed 60 sampling plots throughout the study area for vegetation survey. We partitioned beta diversity through partial RDA and verified that the environmental variables - which include climatic, topographic and edaphic variables - explained 28.4% of the variation in species composition, geographic distance accounted for 16.6%, 14.7% was shared between the two components and 40.3% of the variation remained unexplained. The deterministic processes are clearly the most important in structuring the woody communities. Further analysis using multivariate regression tree selected the climatic variables as the most influential. The study region shows a well conserved physiognomy, regardless of its 300-years history of land use for family cattleraising; hence in a second moment we investigated additional factors affecting diversity patterns of the plant communities surveyed, starting from available agroecological zoning data for land management. We explored the effect of the different typologies of family cattle-raising over two strata of the woody vegetation community, seedling and adult plants, controlling the effect of climate heterogeneity using matrix correlations (partial Mantel tests). We found that land management is not correlated with the species turnover of seedlings, yet explains 12% of the variation in the adult plants beta diversity. We concluded, hence, that climatic heterogeneity creates habitat heterogeneity, being the main determinant of community diversity, although neutral processes are also influent. Land management does not affect the woody plant community evenly, thus contributing to the floristic heterogeneity of the region.

Dans cette thèse, nous nous sommes intéressés à la mesure et à la modélisation des propriétés d'écoulements diphasiques (perméabilités relatives) dans des milieux poreux carbonatés représentatifs de la zone de transition de réservoirs pétroliers carbonatés. Notre étude expérimentale a porté sur deux roches carbonatées de même minéralogie mais de propriétés pétrophysiques différentes (unimodale et bimodale). Les fluides utilisés sont une saumure, une huile minérale pour les expériences en mouillabilité franche à l'eau et une huile brute pour les expériences en mouillabilité altérée (obtenue par macération). Durant les expériences en « écoulements permanents », la perte de charge est mesurée continûment et le champ de saturation locale est mesuré en fin d'expérience par atténuation gamma. Les principaux résultats expérimentaux de cette étude sont les suivantes :- La mouillabilité dépend de la saturation initiale en huile et donc de la hauteur de la zone de transition. Elle a une influence sur les perméabilités relatives à l'huile ET à l'eau.- L'hystérésis des perméabilités relatives à l'eau est d'autant plus prononcée que la saturation initiale en huile augmente. Une observation similaire est faite sur la courbure des perméabilités relatives à l'huile.- Les évolutions des Sorw en fonction des Soi ne vérifient pas toutes, une loi monotone de type Land. Leur évolution dépend aussi de la structure poreuse.- Les deux types de roches carbonatés présentent une altération de mouillabilité différente, la structure vacuolaire favorisant l'altération de mouillabilité. Nos données expérimentales ont été interprétées en utilisant différents modèles d'hystérésis de la littérature. Il apparait clairement des différences entre les prédictions numériques et nos données expérimentales car ces modèles ne prennent pas en compte l'évolution de la mouillabilité. Nous avons proposé un modèle de calcul des perméabilités relatives qui décrit nos données expérimentales de manière satisfaisante. / In this work, we take an interest in measuring and modeling the multiphase flow properties (relative permeabilities) in different carbonate rock types that are representative of the transition zone of carbonate reservoirs. Our experimental study focused on two different carbonate rock types, with almost the same mineralogy, but different petrophysical properties (bimodal and unimodal). The system of fluids used is composed of brine, a mineral oil (for experiments at water-wet conditions), and a crude oil (for experiments including wettability alteration after an ageing process at high temperature). During the experiments performed by the steady-state core flooding method, the pressure drop is continuously measured along the core, and the saturation profiles are obtained at the end of the flooding, by gamma ray measurements. The main results of this study are as follows:- Wettability depends on the initial oil saturation and hence the heights above the oil-water contact. It affects the oil relative permeabilities AND water relative permeabilities- The hysteresis observed on water relative permeability is even more pronounced that the initial oil saturation increases. A similar observation is made on the curvatures of the oil relative permeability.- The evolution of Sorw as function of Soi does not always follow a classical Land correlation. Their evolution also depends on the pore structure.- The two rock types exhibit different responses to wettability alteration. The vuggy structure might promote oil-wetness.Our experimental data were interpreted using different hysteretic models of the literature. We observed significant differences between the results predicted by the models and our experimental observations which are attributed mainly to the failures to take into account the change in wettability. We proposed an improved hysteresis model, which described our experimental data satisfactorily.

No description available.

Deep-water strata of the Neoproterozoic Kaza Group and Isaac Formation (Cariboo Group) in the southern Canadian Cordillera (B.C.) were deposited in a passive-margin basin during the break-up of supercontinent Rodinia. At the Castle Creek and Mount Quanstrom study areas, a remarkably continuous stratigraphic interval throughout these units preserves a record of basin-floor overlain by strata deposited in the lowermost part of the slope. Although similar stratal intervals have been described from ancient and modern deep-marine settings, they still remain poorly understood. Three main stratal units are recognized within the study areas. The lower unit consists of three channel-lobe systems formed in the basin floor to slope transition. Uniquely, siliciclastic-dominated strata here consist of a variety of small- and few large-scale scour elements, indicating transport bypass along the channel-lobe transition zone, in addition to detached or attached depositional lobes composed mostly of distributary channels, fine-grained deposits, and uncommon splays, and a rare slope leveed channel complex. The middle unit is a siliciclastic-dominated succession of stacked, km-scale mass-transport deposits (i.e. debrites and slides), which indicates the more frequent emplacement of increasingly larger mass failures on a prograding slope, and are overlain by fine-grained, splay deposits that are successively overlain by channel, ponded and fine-grained deposits. In contrast, the upper unit is a mixed siliciclastic-carbonate slope succession of the first Isaac carbonate, a regional marker horizon that comprises mostly carbonate-rich and siliciclastic-rich fine-grained strata intercalated with channel and gully complexes that are mostly filled with coarser-grained strata. Abrupt changes in facies trends, stratal stacking patterns and depositional styles throughout these units are largely linked to long-term changes in relative sea level and its control on sediment supply, namely sediment caliber, volume and mineralogy. Notably, in the upper unit, small-scale changes in sediment source and supply are related to shorter sea-level variations superimposed on the long-term eustatic change.

Transition zone biopsies have been found to increase the detection rates of cancer of the prostate in patients with negative digital rectal examination. There are however no data available whether the higher biopsy rate is associated with greater morbidity. The present study was therefore designed to evaluate the complication rate of extended sextant biopsy. In this prospective study, 162 consecutive patients who presented for prostatic evaluation were included. After starting prophylactic antibiotic treatment 48 h prior to the procedure, transrectal ultrasound-guided core biopsies were obtained from each lobe: three each from the peripheral zone (apex, mid-zone and base) and two from the transition zone of each prostatic lobe. In all patients a questionnaire was obtained 10–12 days after the procedure. Major complications occurred in 3 patients. In 2 of the 3 cases major macroscopic hematuria was treated by an indwelling catheter for 1 or 2 days and 1 patient developed fever >38.5°C for 1 day. Minor macroscopic hematuria was present in 68.5% of the patients. In 17.9% of these cases, the hematuria lasted for more than 3 days. Hematospermia was observed in 19.8% and minor rectal bleeding occurred in 4.9%. Ten-core biopsies did not lead to an increase in adverse effects or complications when compared to the results of sextant biopsies reported in the literature. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

A multi-scale high-resolution geophysical and geological study was conducted in the Sevier Desert, central Utah, found within the Colorado Plateau-Basin and Range Transition Zone. The region is marked by with Quaternary volcanics and faulting as young as 660 yr B.P., with many fault scarps thought to have the potential for 7+ magnitude earthquakes. Three locations within the Sevier Desert which represent three different tectonic expressions of possible faulting at the surface were selected. These include a location found within surface sedimentation, a location with surface sedimentation and sub-surface basalts and a location with basalts, at the surface with very limited sedimentation. A suite of geophysical data were obtained including the use of P-wave, SH-wave, ground-penetrating radar (GPR). Auger holes, microprobe glass analysis, and mapping information were also completed in order to constrain and gain a more complete understanding of the sub-surface structure. These data were used to determine if there are sub-surface expressions of the possible surface scarps and if all the faults within the fault zone have the same structural style. The possible surface fault expressions were found to be connected to sub-surface fault expressions but with differing results within both sediments and basalts. Our data show that a multi-scale approach is needed to obtain a complete view of tectonic activity. The area faulting in the Sevier Desert penetrates at depth involving multiple complex styles that include some faulting that cuts recent lava flows and some that do not. The evidence also indicates that in at least some area faulting was episodic and others may be single events having implications on level of activity and hazard.

No description available.

Plants are exposed to various external stresses influencing physiology, anatomy, and morphology. Shape, geometry, and size of shoots and leaves are particularly affected. Among the latter, peltate leaves are not very common and so far, only few studies focused on their properties. In this case study, four Begonia species with different leaf shapes and petiole attachment points were analyzed regarding their leaf morphology, anatomy, and biomechanical properties. One to two plants per species were examined. In all four species, the petiole showed differently sized vascular bundles arranged in a peripheral ring and subepidermal collenchyma. These anatomical characteristics, low leaf dry mass, and low amount of lignified tissue in the petiole point toward turgor pressure as crucial for leaf stability. The petiole-lamina transition zone shows a different organization in leaves with a more central (peltate) and lateral petiole insertion. While in non-peltate leaves simple fiber branching is present, peltate leaves show a more complex reticulate fiber arrangement. Tensile and bending tests revealed similar structural Young’s moduli in all species for intercostal areas and venation, but differences in the petiole. The analysis of the leaves highlights the properties of petiole and the petiole-lamina transition zone that are needed to resist external stresses.