La morphologie des os humains varie en fonction du sexe, de l'âge et de l'ethnie. Cette variabilité de l'anatomie humaine peut aider à déterminer le sexe, l'âge et l'ethnie. Les outils utilisés pour de telles analyses sont classiquement des méthodes ostéométriques (longueur, angle, rapport de longueur) qui peuvent être sujettes à des biais d'analyse ou d'interprétation. L'analyse morphométrique géométrique 3D (MG) permet de limiter ces biais. Elle étudie et compare la forme d'un ou plusieurs objets en éliminant les effets liés à la taille de celui-ci. Nous n'avons pas retrouvé d'analyse du dimorphisme sexuel, ethnique et lié à l'âge de l'extrémité distale du fémur à l'aide de cette méthode. Le fémur est pourtant un des plus gros os du corps et il est souvent bien conservé dans les restes humains. L'objectif de ce travail était de montrer qu'il existe une différence de forme du fémur distal en fonction de l'âge, du sexe et de l'ethnie visualisable grâce à MG. Nous avons réalisé une MG de 482 scanners d'extrémité distale de fémur de sujets vivant dans le sud de la France et dans la région de Chongqing (chine). Les sujets présentant une pathologie osseuse ou articulaires ont été exclus. Dix landmarks ont été positionnés sur des reconstructions tridimentionelles. Nous avons également réalisé une analyse ostéométrique " classique " en plus de MG afin d'évaluer la vraisemblance de nos résultats. Les données ont été analysées par deux observateurs à deux temps différents. Nous avons calculé pour chaque landmark la variabilité inter et intraobservateur. Les landmarks choisis permettaient de caractériser la forme de l'extrémité distale du fémur. La première étape a consisté en la réalisation d'une analyse généralisée procrustre (GPA). Les coordonnées dans l'espace des landmarks ont été analysées en utilisant une analyse en composant principal (PCA). Une analyse discriminante a permis de vérifier le pourcentage de cas dans lequel le sexe, l'âge ou l'ethnie estimés étaient les bons. GPA retrouve une différence de forme statistiquement significative entre les sexes, en fonction de l'âge et entre les ethnies. PCA retrouve une différence de forme en fonction de l'âge, du sexe ou de l'ethnie qui représente respectivement 54,4 ;58,6 et 61,9% de la variabilité observée. Les taux d'assignement correct avec cette méthode étaient de 80% (âge) ; 77,3% (sexe) et 82 % (l'ethnie). L'analyse ostéométrique " classique " retrouvait des valeurs comparables à celles retrouvées dans la littérature. Le pourcentage d'erreur intra et inter observateur pour l'ensemble des landmarks n'excédait jamais 2%. Nous avons démontré que l'analyse MG du fémur distal permettait de mettre en évidence une variabilité en fonction du sexe, de l'âge et de l'ethnie de ce segment osseux. La reproductibilité élevée et la vraisemblance des résultats valident notre méthodologie. Cette différence de forme a des retombées directes en anthropobiologie mais aussi en orthopédie. Cette méthode d'assignation ne donne pas de résultats suffisamment précis pour être utilisée seule. Cependant, elle a l'avantage de pouvoir être utilisée dans des contextes d'autopsie virtuelle ou in vivo. Par ailleurs, par la présente étude nous réactualisons les données morphométriques de population contemporaine du sud de la France et aussi de la région de Chongqing en chine. Cette méthodologie adéquate et reproductible va permettre de réaliser des comparaisons diachroniques ainsi qu'inter ethnique. La validation de l'utilisation d'examen d'imagerie médicaux ouvre un champ nouveau en anthropologie physique. En ce qui concerne l'aspect orthopédique, cette variabilité questionne sur la nécessité ou non d'implant spécifique et surtout sur la nécessité de réévaluer de manière régulière la forme des prothèses de genou. / The shape of human bones varies based on age, sex and ethnicity. This variability in human anatomy can be used to determine a person's age, sex and ethnicity. Historically, the tools used for such analyses are osteometric methods (length, angle, length ratio) that can be plagued by analysis or interpretation biases. Three-dimensional geometric morphometric analysis (3D GM) can limit the impact of these biases. It is used to describe and compare the general shape of one or more objects by eliminating any size-related effects. To the best of our knowledge, this method has never been used to analyse the sexual dimorphism, ethnicity-related and age-related differences in the distal femur. The femur is one of the longest human bones and is often well preserved in human remains. The goal of this study was to demonstrate differences in the shape of the distal femur according to age, sex and ethnicity using GM. We carried out 3D GM on 482 CT scans of the distal femur of adults living in the South of France and in the Chongqing region of China. Subjects with bone or joint pathologies were excluded. Ten landmarks were defined on 3D reconstructions of the distal femur. A standard osteometric analysis was performed in addition to the GM analysis to evaluate the plausibility of our results. The data were analysed by two observers at two different times. This allowed us to calculate the inter- and intra-observer variability for each landmark. The chosen landmarks were used to characterise the shape of the distal femur. The first step consisted of a generalized Procrustes analysis (GPA). The landmarks' coordinates in space were analysed using a principal component analysis (PCA). A discriminant analysis was performed to determine the percentage of cases in which the sex, age or ethnicity was correctly estimated. The GPA found a statistically significant difference in the distal femur shape between different sexes, ethnicity groups and age groups. The PCA found that age, sex and ethnicity accounted for 54.4%, 58.6% and 61.9% of the observed variability in distal femur shape, respectively. Using this method, 80% of cases were assigned the correct age, 77.3% the correct sex and 82% the correct ethnic group. The results of the osteometric analysis were comparable to published values. The percentage error for the intra- and interobserver comparisons for all the landmarks was always less than 2%. In this study, MG analysis of the distal femur revealed age-related, sex-related and ethnicity-related variability in the distal femur. The high reproducibility and plausibility of our results validate our methodology. These shape differences have direct implications for anthropobiology and also orthopaedics. Although this method is not sufficiently accurate to be used alone, it has the advantage of being usable in the context of virtual or in vivo autopsy cases. Moreover, this study has updated the morphometric data for a modern population in the south of France and the Chongqing region of China. This reliable and accurate methodology can be used to perform diachronic and interethnic comparisons. Validation of this medical imaging modality opens new avenues in physical anthropology research. In the orthopaedics field, this variability means that the shape of implants used for knee arthroplasty should be re-assessed regularly and brings into question the need for gender-specific or ethnicity-specific implants.

La sclérose en plaques est une maladie inflammatoire et démyélinisante chronique du système nerveux central présentant une expression clinique très variable d'un patient à l'autre. Face à cette hétérogénéité, l'identification de biomarqueurs issus de la neuro-imagerie capables de refléter les dommages responsables des déficits cognitifs et moteurs retrouvés chez ces patients est cruciale pour l'évaluation de l'efficacité de nouvelles thérapies. Lors de ce travail de thèse, nous avons étudié et mis en avant l'atteinte morphologique (changements de volume et de forme) du thalamus, structure cérébrale centrale, au travers de populations représentant l'ensemble des formes cliniques de la maladie. Nous avons ensuite évalué l'effet d'un traitement lors d'une analyse volumétrique longitudinale menée sur 12 mois. La répétabilité des résultats concernant la mesure du volume thalamique atteste alors de la qualité de la méthode utilisée. / Multiple sclerosis is a chronic inflammatory and demyelinating disease of the central nervous system having a highly variable clinical expression from patient to another. Given this heterogeneity, the identification of neuroimaging biomarkers able to reflect damages responsible for cognitive and motor deficits found in these patients is crucial for evaluating the efficacy of new therapies. In this thesis, we studied and highlighted the morphological damages (changes in volume and shape) of the thalamus , a central brain structure, through populations representing all clinical forms of the disease. We then evaluated the effect of treatment in a longitudinal volumetric analysis conducted over 12 months. Repeatability of thalamic volume results attests the quality of the method used.

A condição do hábitat local em riachos é determinada por fatores naturais e antrópicos, em escala regional e separar a influência relativa desses fatores é difícil, pois geralmente a sua distribuição espacial encontra-se sobreposta. Neste sentido, este estudo tem por objetivo determinar a influência relativa das características naturais e de usos do solo, em escala regional, sobre a condição do hábitat, em escala de trecho de riacho, na bacia hidrográfica do Arroio Candiota, sul do Rio Grande do Sul. Para isso, as características naturais (de relevo e de rede de drenagem) e as atividades antrópicas (usos do solo) foram avaliadas em 26 sub-bacias. Em escala de trecho de riacho, os atributos avaliados foram agrupados em condição do hábitat físico no canal fluvial, qualidade da zona ripária e qualidade da água. Por meio de análise de redundância parcial, determinou-se a percentagem da variação, na condição de cada grupo atributos do hábitat, explicada pelos fatores naturais, pelos fatores antrópicos e pelo seu efeito compartilhado. As sub-bacias maiores tendem a apresentar maior textura no relevo, formato menos circular e menor declive. As sub-bacias com relevo mais acidentado tendem a apresentar maior densidade de drenagem. A vegetação natural ocupa a maior parte da bacia, principalmente as regiões de relevo mais acidentado, porém atividades como agricultura, pecuária, silvicultura e mineração de carvão estão distribuídas pela bacia, principalmente em áreas de relevo mais suave e próximo aos riachos. A maior parte dos riachos apresenta boa qualidade do hábitat, porém em riachos com baixa qualidade observa-se gado na zona ripária ou grande aporte de rejeitos da mineração de carvão. As principais alterações do hábitat físico no canal são assoreamento, dragagem e represamento. Em relação à qualidade da água, pH e condutividade apresentam valores extremos nos riachos associados à mineração de carvão. A condição do hábitat físico no canal é mais influenciada pelas características naturais das sub-bacias, enquanto a qualidade da água está mais associada aos usos do solo. A qualidade da zona ripária, por sua vez, é determinada pelo efeito compartilhado dos fatores naturais e antrópicos. Dessa forma, as atividades antrópicas na bacia hidrográfica exercem maior efeito sobre os atributos mais dinâmicos do hábitat, tendo influência menor sobre processos mais lentos, como alteração no hábitat físico do canal. / The stream local habitat condition is determined by natural and anthropogenic regional characteristics and to determine the relative influence of these factors is difficult because their spatial distribution is usually superimposed. Thus, this study aims to determine the relative influence of natural characteristics and land use, in regional scale, on the the stream local habitat condition in the Arroio Candiota watershed. For this, natural characteristics (relief and drainage network) and human activities (land uses) were evaluated in 26 sub-catchments. In the reach scale, the stream habitat attributes were grouped into stream physical habitat, riparian zone quality and water quality. Using partial redundancy analysis, the percentage of variation in the condition of each group of habitat attributes, explained by natural factors, by human factors and by their shared effect was determined. The major catchments tend to have higher texture in relief, less circular shape and lower slope while catchments with steeper relief tend to have higher drainage density. Most of the Arroio Candiota watershed are occupied by natural vegetation, especially the regions of steeper relief. Agriculture, livestock, forestry and mining are distributed throughout the basin, especially in areas of gentle relief and close to streams. Most streams has good habitat quality, but in streams where quality is low there is livestock in the riparian zone or large supply of wastes from coal mining. The main changes in the physical habitat channel are siltation, dredging and damming. Regarding water quality, pH and conductivity have extreme values in streams associated with coal mining. The condition of physical habitat in the channel is more influenced by the natural characteristics of the catchments, while water quality is more associated with land use. The quality of the riparian zone, in turn, is determined by the shared effect of natural and anthropogenic factors. Thus , the anthropogenic activities in the watershed exert greater effect on the more dynamic attributes of habitat, having less influence on slower processes, such as changes in physical habitat of the channel.

Os stents são dispositivos intravasculares implantados com o objetivo de dilatar ou fixar a placa de colesterol contra a parede arterial. O objetivo avaliar dois tipos de stents de aço inoxidável, um recoberto com poliéster (dacron) e outro não recoberto, implantados na aorta infra-renal de suínos jovens, foram avaliados por morfometria digital para medir o espessamento intimal. Foi realizado um estudo experimental randomizado, separados em dois grupos(stents não revestidos e revestidos com dacron) e duas fases (I e II). Oito stents recobertos com dacron e oito stents de aço inoxidável (30mm de extensão e 8 mm de diâmetro), não revestidos, foram implantados através de abordagem retroperitoneal na aorta infrarenal normal de 16 suínos normolipêmicos. Para a passagem do sistema de implante, foi necessário uma pequena arteriotomia na aorta distal (fase I). Após quatro semanas, a aorta com os stents foram removidas em monoblocos (fase II). Os valores de hematimetria e do lipidograma foram coletados nas duas fases e não apresentaram alterações que pudessem influenciar o estudo. Amostras de tecido dos sítios de fixação (proximal e distal) dos stents foram retiradas, confeccionadas lâminas, que foram coradas pelas técnicas de hematoxilina e eosina de Verhoeff e enviadas para análise morfométrica digital. A camada intima distal não apresentou diferença estatística significativa. A camada média proximal das porções proximal e da porção distal não apresentaram diferença entre os grupos. Os dois tipos de stents apresentaram 100% de perviedade, boa biocompatibilidade e boa incorporação a parede aórtica de suínos normolipêmicos. A camada íntima proximal do grupo de stents revestidos com dacron apresentou espessura maior do que os stents não revestidos, mas com significância estatísitica limítrofe. / Stents are intravascular devices implanted with the objective of dilating or fixing the cholesterol plate against the arterial wall. To evaluate, by digital morphometry, the intimal thickening after the placement of two different kinds of stents: polyester covered stainless steel stents (Dacron) and non-covered stents implanted in young pigs’ infrarenal aortas. The stents were made at the Biotransformation Laboratory of Federal University of Rio Grande do Sul. The experiment was performed at the Biotério of University of Caxias do Sul, carried out on two separate groups of pigs. Eight polyester-covered stainless steel stents (Dacron) and eight stainless steel stents (30-mm long, 8-mm diameter) were deployed through extraperitoneal approach in the normal infrarenal aorta of 16 normolipemic pigs. To allow the passage of the delivery system, a small arteriotomy was performed (phase I). After four weeks, the aorta with the stent was removed en bloc. (phase II). The values of the hematimetric and lipid analysis did not show any changes that could influence the study. Tissue samples of the fixing sites (proximal and distal) of the stents were taken. Microscope slices were prepared and submitted to Verhoeff’s hematoxilin and eosin techniques and sent to morphometric analysis.The intima immediately proximal to the device was thicker in the group of covered stents with marginal significance. The distal intimal layer, proximal medial layer of the proximal portion and distal portion did not present statistical difference between the two groups. Patency was 100% in both groups of these normolipemic pigs. After four weeks the intimal layer immediately proximal to the covered stents was ticker when compared to uncovered stents, but this had a borderline significance. The intimal layer distal to covered stents and the media proximal or distal to the devices had similar morphometric features when covered and uncovered stents where compared.

A condição do hábitat local em riachos é determinada por fatores naturais e antrópicos, em escala regional e separar a influência relativa desses fatores é difícil, pois geralmente a sua distribuição espacial encontra-se sobreposta. Neste sentido, este estudo tem por objetivo determinar a influência relativa das características naturais e de usos do solo, em escala regional, sobre a condição do hábitat, em escala de trecho de riacho, na bacia hidrográfica do Arroio Candiota, sul do Rio Grande do Sul. Para isso, as características naturais (de relevo e de rede de drenagem) e as atividades antrópicas (usos do solo) foram avaliadas em 26 sub-bacias. Em escala de trecho de riacho, os atributos avaliados foram agrupados em condição do hábitat físico no canal fluvial, qualidade da zona ripária e qualidade da água. Por meio de análise de redundância parcial, determinou-se a percentagem da variação, na condição de cada grupo atributos do hábitat, explicada pelos fatores naturais, pelos fatores antrópicos e pelo seu efeito compartilhado. As sub-bacias maiores tendem a apresentar maior textura no relevo, formato menos circular e menor declive. As sub-bacias com relevo mais acidentado tendem a apresentar maior densidade de drenagem. A vegetação natural ocupa a maior parte da bacia, principalmente as regiões de relevo mais acidentado, porém atividades como agricultura, pecuária, silvicultura e mineração de carvão estão distribuídas pela bacia, principalmente em áreas de relevo mais suave e próximo aos riachos. A maior parte dos riachos apresenta boa qualidade do hábitat, porém em riachos com baixa qualidade observa-se gado na zona ripária ou grande aporte de rejeitos da mineração de carvão. As principais alterações do hábitat físico no canal são assoreamento, dragagem e represamento. Em relação à qualidade da água, pH e condutividade apresentam valores extremos nos riachos associados à mineração de carvão. A condição do hábitat físico no canal é mais influenciada pelas características naturais das sub-bacias, enquanto a qualidade da água está mais associada aos usos do solo. A qualidade da zona ripária, por sua vez, é determinada pelo efeito compartilhado dos fatores naturais e antrópicos. Dessa forma, as atividades antrópicas na bacia hidrográfica exercem maior efeito sobre os atributos mais dinâmicos do hábitat, tendo influência menor sobre processos mais lentos, como alteração no hábitat físico do canal. / The stream local habitat condition is determined by natural and anthropogenic regional characteristics and to determine the relative influence of these factors is difficult because their spatial distribution is usually superimposed. Thus, this study aims to determine the relative influence of natural characteristics and land use, in regional scale, on the the stream local habitat condition in the Arroio Candiota watershed. For this, natural characteristics (relief and drainage network) and human activities (land uses) were evaluated in 26 sub-catchments. In the reach scale, the stream habitat attributes were grouped into stream physical habitat, riparian zone quality and water quality. Using partial redundancy analysis, the percentage of variation in the condition of each group of habitat attributes, explained by natural factors, by human factors and by their shared effect was determined. The major catchments tend to have higher texture in relief, less circular shape and lower slope while catchments with steeper relief tend to have higher drainage density. Most of the Arroio Candiota watershed are occupied by natural vegetation, especially the regions of steeper relief. Agriculture, livestock, forestry and mining are distributed throughout the basin, especially in areas of gentle relief and close to streams. Most streams has good habitat quality, but in streams where quality is low there is livestock in the riparian zone or large supply of wastes from coal mining. The main changes in the physical habitat channel are siltation, dredging and damming. Regarding water quality, pH and conductivity have extreme values in streams associated with coal mining. The condition of physical habitat in the channel is more influenced by the natural characteristics of the catchments, while water quality is more associated with land use. The quality of the riparian zone, in turn, is determined by the shared effect of natural and anthropogenic factors. Thus , the anthropogenic activities in the watershed exert greater effect on the more dynamic attributes of habitat, having less influence on slower processes, such as changes in physical habitat of the channel.

A condição do hábitat local em riachos é determinada por fatores naturais e antrópicos, em escala regional e separar a influência relativa desses fatores é difícil, pois geralmente a sua distribuição espacial encontra-se sobreposta. Neste sentido, este estudo tem por objetivo determinar a influência relativa das características naturais e de usos do solo, em escala regional, sobre a condição do hábitat, em escala de trecho de riacho, na bacia hidrográfica do Arroio Candiota, sul do Rio Grande do Sul. Para isso, as características naturais (de relevo e de rede de drenagem) e as atividades antrópicas (usos do solo) foram avaliadas em 26 sub-bacias. Em escala de trecho de riacho, os atributos avaliados foram agrupados em condição do hábitat físico no canal fluvial, qualidade da zona ripária e qualidade da água. Por meio de análise de redundância parcial, determinou-se a percentagem da variação, na condição de cada grupo atributos do hábitat, explicada pelos fatores naturais, pelos fatores antrópicos e pelo seu efeito compartilhado. As sub-bacias maiores tendem a apresentar maior textura no relevo, formato menos circular e menor declive. As sub-bacias com relevo mais acidentado tendem a apresentar maior densidade de drenagem. A vegetação natural ocupa a maior parte da bacia, principalmente as regiões de relevo mais acidentado, porém atividades como agricultura, pecuária, silvicultura e mineração de carvão estão distribuídas pela bacia, principalmente em áreas de relevo mais suave e próximo aos riachos. A maior parte dos riachos apresenta boa qualidade do hábitat, porém em riachos com baixa qualidade observa-se gado na zona ripária ou grande aporte de rejeitos da mineração de carvão. As principais alterações do hábitat físico no canal são assoreamento, dragagem e represamento. Em relação à qualidade da água, pH e condutividade apresentam valores extremos nos riachos associados à mineração de carvão. A condição do hábitat físico no canal é mais influenciada pelas características naturais das sub-bacias, enquanto a qualidade da água está mais associada aos usos do solo. A qualidade da zona ripária, por sua vez, é determinada pelo efeito compartilhado dos fatores naturais e antrópicos. Dessa forma, as atividades antrópicas na bacia hidrográfica exercem maior efeito sobre os atributos mais dinâmicos do hábitat, tendo influência menor sobre processos mais lentos, como alteração no hábitat físico do canal. / The stream local habitat condition is determined by natural and anthropogenic regional characteristics and to determine the relative influence of these factors is difficult because their spatial distribution is usually superimposed. Thus, this study aims to determine the relative influence of natural characteristics and land use, in regional scale, on the the stream local habitat condition in the Arroio Candiota watershed. For this, natural characteristics (relief and drainage network) and human activities (land uses) were evaluated in 26 sub-catchments. In the reach scale, the stream habitat attributes were grouped into stream physical habitat, riparian zone quality and water quality. Using partial redundancy analysis, the percentage of variation in the condition of each group of habitat attributes, explained by natural factors, by human factors and by their shared effect was determined. The major catchments tend to have higher texture in relief, less circular shape and lower slope while catchments with steeper relief tend to have higher drainage density. Most of the Arroio Candiota watershed are occupied by natural vegetation, especially the regions of steeper relief. Agriculture, livestock, forestry and mining are distributed throughout the basin, especially in areas of gentle relief and close to streams. Most streams has good habitat quality, but in streams where quality is low there is livestock in the riparian zone or large supply of wastes from coal mining. The main changes in the physical habitat channel are siltation, dredging and damming. Regarding water quality, pH and conductivity have extreme values in streams associated with coal mining. The condition of physical habitat in the channel is more influenced by the natural characteristics of the catchments, while water quality is more associated with land use. The quality of the riparian zone, in turn, is determined by the shared effect of natural and anthropogenic factors. Thus , the anthropogenic activities in the watershed exert greater effect on the more dynamic attributes of habitat, having less influence on slower processes, such as changes in physical habitat of the channel.

Este trabalho utilizou a rede de drenagem como geoindicador das modificações ocorridas no período de 23 anos no meio físico em três sub-bacias hidrográficas que compreendem parte do município de Monte Mor(SP) e integram a porção média da bacia hidrográfica do rio Capivari. A metodologia adotada compreendeu a caracterização conjunta dos atributos do terreno, da rede de drenagem e dos processos de ocupação antrópica das sub-bacias. Foram caracterizados os principais atributos do meio físico, tais como geologia, materiais inconsolidados, landforms e declividade. A verificação das alterações neste período foi obtida por meio das análises temporais tanto das variáveis morfométricas da rede de drenagem como da caracterização de ocupação do meio físico. Os dados foram obtidos por atividades de campo, interpretação de fotografias aéreas (escala 1:25.000) de 1972 e de 1995 e processados pelo uso dos programas ENVI e AutocadMap. Os documentos cartográficos gerados foram mapas de documentação, de drenagem, de landforms, de substrato rochoso, de materiais inconsolidados e de uso e ocupação e carta de declividade. O sistema de rede de drenagem configurou-se como um adequado indicador das alterações ambientais ocorridas na área de estudo. A análise morfométrica indicou uma diminuição no número de canais de primeira ordem e no comprimento total dos canais. Estas mudanças condicionaram as modificações dos parâmetros de densidade de drenagem e de densidade hidrográfica. A análise global das mudanças no número de canais de primeira ordem indicou que a maioria deles era de pequenas dimensões (<150m). Tais alterações foram condicionadas pela expansão urbana de Monte Mor e pelo intensivo cultivo de cana-de-açúcar e estão relacionadas às diferentes classes de declividade e aos diversos tipos de relevo, de substrato rochoso e de material inconsolidado / This work used the drainage as a geoindicator to the changes that have taken place during 23 years (1972 to 1995) in the physical environment of three hydrographic sub-basins within the Monte Mor municipal boundaries, located in the medium course of the Capivari river hydrographic basin. The methodological approach comprises a complete characterization of the land attributes, drainage network and anthropic occupation for the sub-basins. The main features of the physical environment, such as geology, unconsolidated materials, landforms and slope were characterized. In order to identify the changes, a temporal analysis of the drainage network morphometric variables and land use were made. Data was collected by field work, aerialphotointerpretation (1:25000 scale) and processed by using the softwares ENVI and AutocadMap. In this work, maps of documentation, drainage, landforms, bed rock, unconsolidated materials and use and occupation and also a slope chart were generated. The drainage systems has showed to be an appropriate indicator of the environmental changes for the studied area. The morphometric analysis indicates a decrease in the number of first-order channels and in the total length of all channels. Modifications in the drainage and hydrographic densities have also been observed. The global analysis of the changes of the number of first order channels has indicated that most of the channels had small dimensions (<150m). Such changes were induced by the urban growth of Monte Mor and by the intensive sugar cane raising. They are also related to the different slope classes and to the several types of landforms, bedrock and unconsolidated materials

Phacelia purshii, one of a few phacelias with fringed corolla lobes, has historically been described as a variety of Phacelia fimbriata or as a distinct species. The geographical range is centered on the Ohio River Valley extending north to Pennsylvania, east to the Blue Ridge, and south to Alabama. Two related species were described, Phacelia bicknellii and Phacelia boykinii, but these names were rarely used in floras or applied to herbarium specimens. A morphometric and geographic analysis of herbarium specimens showed that the description of P. bicknellii corresponds to male sterile plants and therefore does not warrant taxonomic recognition. In a sample of 280 specimens, latitudinal variation was evident in a suite of characters, some of which were associated with the historical distinction between P. purshii and P. boykinii. Two previously unrecognized diagnostic characters, pubescent ovaries and pubescent abaxial surfaces of corolla lobes, distinguished plants from the southern part of the geographic range. Both pubescence characters had a relatively abrupt transition from more or less present to absent and these corresponded to southern and northern localities, respectively. Pedicel length, the historical diagnostic character for P. boykinii, had a bimodal distribution. A discriminant function correctly assigned > 94% of specimens to northern and southern morphs when the morphs were defined by ovary pubescence. The morphological and geographical data provide for accurate diagnosis of specimens and therefore support taxonomic recognition of the southern form. That form is recognized not as a distinct species, but as a variety of P. purshii, Phacelia purshii var. boykinii.

We analyzed recent total suspended solids (TSS) data from 45 gages on 36 rivers throughout the state of Minnesota. Watersheds range from 32 to 14,600 km2 and represent a variety of distinct settings in terms of topography, land cover, and geologic history. Our study rivers exhibited three distinct patterns in the relationship between discharge and TSS: simple power functions, threshold power functions, and peaked or negative power functions. Differentiating rising and falling limb samples, we generated sediment rating curves (SRC) of form TSS = aQb, Q being normalized discharge. Rating parameters a and b describe the vertical offset and steepness of the relationships. We also used the fitted SRCs to estimate TSS values at low flows and to quantify event-scale hysteresis. In addition to quantifying the watershed-average topographic, climatic/hydrologic, geologic, soil and land cover conditions, we used high-resolution lidar topography data to characterize the near-channel environment upstream of gages. We used Random Forest statistical models to analyze the relationship between basin and channel features and the rating parameters. The models enabled us to identify morphometric variables that provided the greatest explanatory power and examine the direction, form, and strength of the partial dependence of the response variables on individual predictor variables. The models explained between 43% and 60% of the variance in the rating curve parameters and determined that Q-TSS relation steepness (exponent) was most related to near-channel morphological characteristics including near-channel local relief, channel gradient, and proportion of lakes along the channel network. Land use within the watershed explained most variation in the vertical offset (coefficient) of the SRCs and in TSS concentrations at low flows.

Occurrences of Phacelia dubia in the Piedmont of South Carolina have been taxonomically enigmatic. Prior work had shown that there was partial reproductive isolation when plants from South Carolina were hybridized with any of the other varieties but evidence of morphological differentiation was lacking. In this study, a new morphological analysis showed South Carolina plants differed significantly in corolla lobe size, sepal size, and leaf dissection in comparisons with neighboring varieties, P. dubia var. dubia and P. dubia var. georgiana. A preponderance of evidence showing differentiation from all other varieties supports recognition of a new variety, P. dubia var. rionensis. Field work and an updated analysis of herbarium records showed the new variety is found in nine contiguous counties in the central and northern Piedmont of South Carolina and two counties in the inner Coastal Plain. We posit a hypothesized biogeographic pathway based on migration of a P. dubia ancestor from the Great Plains or Mexico to the Nashville Basin cedar glades, then to South Carolina piedmont granite outcrops, followed by a migration south to Georgia and Alabama piedmont granite outcrops and a separate migration north to rocky woodlands in North Carolina.