Made available in DSpace on 2014-12-17T15:01:25Z (GMT). No. of bitstreams: 1 NataliaFO_DISSERT_Partes autorizadas.pdf: 162419 bytes, checksum: df1688a55f3602778175a9d04e3bc026 (MD5) Previous issue date: 2011-02-17 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Algaroba (Prosopis juliflora) is a typical legume from arid and semi arid regions, which is composed by sugar-rich pods and high protein seeds. Phenolic compounds are secondary metabolites recognized as potent bioactive compounds, found in several vegetables.Therefore, the objective of this work is to characterize the algaroba flour in terms of its physicalchemical composition, total phenolic content, antioxidant activity by DPPH and ABTS methods, a-amylase and a-glycosidase inhibition, as well as to analyze its organic compounds by high performance liquid chromatography (HPLC). Three experimental groups were investigated (seeds, seeds and pod together and only pod), which were prepared by oven drying and posterior grinding. Water and ethanol extracts (70, 80, 100% v/v) were prepared and used for functional studies. Organic compounds were detected by using HPLC equipment coupled to mass spectrometer. Results show important physical-chemical differences among the experimental groups, seeds, seeds and pod together and only pod. The algarroba seed flour is high in protein (49.49%) and fat (3.10%), while the pod flour is especially rich in sugar (60.3% to 67.9%). Algaroba phenolics are concentrated in pod flour, mainly in water extracts (1.30 mg GAEQ/100g sample). All seed extracts showed high DPPH activity and maximum antioxidant activity was registered for ethanol 80% extracts (19.81 ?M Trolox/g sample). The ABTS activity ranged from 9.73 to 12.74 ?M Trolox/g sample. Nearly all the extracts were able to inhibit ?-amylase activity mildly (30.50% to 48.80%), while the maximum ?-glycosidase inhibition was observed for pod water extracts (81.03%). Algaroba water extracts proven to be especially rich in organic compounds, observed by the high number of chromatographic peaks. Results demonstrate that algaroba is a potential candidate for further investigations concerning its possible functional applications / A algaroba (Prosopis juliflora) ? uma leguminosa t?pica de regi?es ?ridas e semi-?ridas constitu?da por vagem rica em a??cares e sementes de elevado teor prot?ico. Os compostos fen?licos s?o metab?litos secund?rios reconhecidos como importantes compostos bioativos, presentes em grande n?mero de vegetais. O objetivo do presente trabalho foi caracterizar a farinha de algaroba quanto ? composi??o f?sico-qu?mica, concentra??o fen?lica total, atividade antioxidante pelos m?todos DPPH e ABTS, capacidade de inibi??o das enzimas ?-amilase e ?-glicosidase, bem como analisar a presen?a de compostos org?nicos por cromatografia l?quida. Foram analisados tr?s grupos experimentais (semente, vagem inteira e vagem sem semente), os quais foram secos em estufa e mo?dos, obtendo-se a farinha de cada um dos grupos. A partir disso, foram elaborados extratos aquosos e etan?licos (70, 80, 100% v/v) para a an?lise da funcionalidade. Para a determina??o de compostos org?nicos foi utilizado cromatografia l?quida de alta efici?ncia acoplada a espectr?metro de massas. Os resultados da presente pesquisa permitem inferir que existem diferen?as importantes entre a composi??o f?sico-quimica das farinhas da semente, vagem inteira e vagem sem semente de algaroba. A farinha da semente se destacou por sua elevada concentra??o de prote?nas (49,49%) e gordura (3,10%), ao passo que a farinha das vagens mostrou-se especialmente rica em a??cares (60,3 a 67,9%). Os compostos fen?licos da algaroba est?o em maior concentra??o na vagem sem semente, sobretudo para os extratos aquosos (1,30 mg GAEQ/100g amostra). Todos os extratos da semente de algaroba apresentaram elevada capacidade antoxidante pelo m?todo DPPH, com m?ximo registrado para extratos etan?licos 80% (19,81?M Trolox/g amostra). A atividade antioxidante medida pelo m?todo ABTS dos extratos estudados estiveram entre 9,73 e 12,74 ?M Trolox/g amostra. Praticamente todos os extratos obtidos foram capazes de inibir moderadamente a atividade da enzima ?-amilase (30,50% a 48,80%), sendo que a m?xima inibi??o da ?-glicosidase foi observada para os extratos aquosos da vagem sem semente (81,03%). A algaroba apresentou variedade de compostos org?nicos detectados por cromatografia l?quida, sobretudo os extratos aquosos que demonstraram grande n?mero de picos. Sugere-se a algaroba como poss?vel candidata para futuras investiga??es visando sua utiliza??o como alimento funcional

Made available in DSpace on 2014-12-17T15:14:46Z (GMT). No. of bitstreams: 1 AntonioSAF.pdf: 1214999 bytes, checksum: c500092609bb7d7681af9a0f37dcaf88 (MD5) Previous issue date: 2008-11-14 / High-precision calculations of the correlation functions and order parameters were performed in order to investigate the critical properties of several two-dimensional ferro- magnetic systems: (i) the q-state Potts model; (ii) the Ashkin-Teller isotropic model; (iii) the spin-1 Ising model. We deduced exact relations connecting specific damages (the difference between two microscopic configurations of a model) and the above mentioned thermodynamic quanti- ties which permit its numerical calculation, by computer simulation and using any ergodic dynamics. The results obtained (critical temperature and exponents) reproduced all the known values, with an agreement up to several significant figures; of particular relevance were the estimates along the Baxter critical line (Ashkin-Teller model) where the exponents have a continuous variation. We also showed that this approach is less sensitive to the finite-size effects than the standard Monte-Carlo method. This analysis shows that the present approach produces equal or more accurate results, as compared to the usual Monte Carlo simulation, and can be useful to investigate these models in circumstances for which their behavior is not yet fully understood / Atrav?s de c?lculos de alta precis?o das fun??es de correla??o e dos par?metros de ordem, investigamos as propriedades cr?ticas de v?rios modelos ferromagn?ticos bidimensionais, a saber: (i) Potts q-estados; (ii) Ashkin-Teller isotr?pico; (iii) Ising de spin-1. Utilizamos simula??es computacionais, obtidas a partir de rela??es anal?ticas exatas, conectando as quantidades acima mencionadas e certas combina??es de Danos (diferen?as entre duas configura??es microsc?picas de um modelo), que s?o v?lidas para qualquer din?mica erg?dica. Todos os resultados encontrados (temperaturas e expoentes cr?ticos) concordam com os valores conhecidos, em v?rias casas decimais, destacando-se em particular a reprodu??o da linha de Baxter (no caso ii) onde os expoentes variam continuamente, resultado de dif?cil obten??o por m?todos tradicionais. Tamb?m mostramos que este m?todo ? menos sens?vel aos efeitos de tamanho finito que aqueles baseados no procedimento usual de simula??o de Monte-Carlo. Tais fatos indicam a potencialidade desta abordagem para investigar situa??es ainda insuficientemente exploradas, nos modelos acima analisados e em outros semelhantes

The palaeoecological development of alum mire since early Eneolithic on the basis of the results of macro-remains, pollen, and chemical analysis. The developement of local vegetation and nearest surrounding area was studied.

The distribution and occurrence of plant species within a given region provides insight into the many environmental properties of that region. Although much research has been conducted on plant communities and associated environmental properties, few studies have been conducted on the characteristics of individual plants within those communities. Calcareous fens are wetlands formed by the upwelling of mineral-rich groundwater and often are associated with many unique plant communities and rare species of flora and fauna. Although many studies have documented the vegetation patterns and associated environmental gradients of these fens, none have isolated the specific hydrogeochemical conditions associated with individual species, nor have any studies attempted to document and compare the individual physiological response of species to elevated environmental calcium levels. This research was conducted to estimate environmental calcium requirements for rare as well as common indicator species of calcareous fens of Massachusetts and to examine the relationship between the accumulation of calcium in the tissues of these species to calcium availability in their environment. These factors will be important when determining required conditions for fen restoration and will further the understanding of why these species often only occur in calcareous fens. Eight calcareous fen study sites at three different locations were established where calciphiles occur in western Massachusetts. In each site, data were collected on the vegetation patterns and associated soil chemistry, water chemistry, and hydrology. In addition, plant tissues were collected and analyzed for calcium. Species distributions were evaluated as to whether they increased in abundance as environmental calcium did or whether they appeared to occur only once a specific calcium threshold was met. In addition, the concentrations of calcium in the tissues were used to determine the extent to which those plants accumulated calcium and how those levels related to levels of calcium in the substrate environment and to their overall distributions. It was found that certain calciphiles are calcium specialists, i.e. they are more abundant when environmental calcium levels are elevated, absorb greater quantities of calcium and those quantities correlate to the available environmental supply. These species include Parnassia glauca, Packera aurea, Geum rivale and Carex granularis. Of these, Geum rivale and Carex granularis, as well as Carex sterilis, did not occur below calcium concentrations of 48 mg.L-1. However, other calciphiles are calcium generalists, i.e. they are tolerant of elevated calcium levels but show no other relationship with respect to growth or accumulation. These species include Carex flava, Carex hystericina, Juncus nodosus, Solidago patula, Solidago uliginosa, and Symphyotrichum puniceum. In addition, some wetland generalists maintain elevated calcium levels (Symplocarpus foetidus and Mentha arvensis) whereas most others do not (Thelypteris palustris and Fragaria vesca). Of the calciphile and wetland generalist species, some appear to increase in abundance in calcareous fens in relation to increases in accessory benefits (Dasiphora fruticosa and Juncus brachycephalus with pH; Thelypteris palustris and Carex flava with magnesium and possibly Equisetum fluviatile with iron). Combined, these findings characterize the growth habits and calcium accumulation of species that grow in calcareous fens and indicate that calciphiles have varying degrees of dependence on calcium.

In situ measurements of soil nitrogen dynamics is a potential method for evaluating the health of constructed wetlands following oil sands mining. The objective of this study is to measure and compare the soil nitrogen availability of a reclaimed fen (Sandhill fen) with a nutrient-rich reference fen (Poplar fen) and a nutrient-poor reference fen (Pauciflora fen) in the Athabasca oil sands region of northern Alberta. Total Nitrogen (TN), Nitrate (NO3-) and Ammonium (NH4+) supply rates were determined along wetland hillslope transects using Western Ag Innovations Plant Root Simulator (PRSTM) probes at all three sites in 2014. Net N mineralization, net nitrification and net ammonification were determined simultaneously using the buried polyethylene bag sampling method. Overall, TN supply rates were greatest at the poor fen and least at the constructed Sandhill fen. In contrast, mineralization was greatest at the rich fen but again least at the Sandhill fen. Mineralization at the Sandhill fen was controlled evenly by ammonification and nitrification, whereas the two natural sites were controlled by ammonification. Relatively low N supply rates and mineralization at the Sandhill fen were likely due to lower soil organic matter and limited soil moisture in these newly constructed substrates. Spatial differences along the hillslopes also varied among sites. The Sandhill fen had higher TN supply rates at the upslope positions but no significant differences in net N mineralization rates along the hillslopes. The rich fen also had higher TN supply rates at the upslope but greatest mineralization rates downslope. These results highlight the importance of N storage and transport processes and offer insight into the N status of a constructed fen. / Thesis / Master of Science (MSc)

Bog turtles (Glyptemys muhlenbergii) are a small freshwater turtle ranging east of the Appalachian Mountains from New York to Georgia, in small, patchily distributed (<10ha) groundwater fed wetlands. Despite their name, these wetlands are more appropriately identified as seep meadows or fens owing to their reliance on groundwater, with bogs being typified by precipitation as the major hydrologic input. Groundwater inputs are not only important in taxonomically classifying wetland type, but also contribute in important ways to bog turtle natural history. Bog turtles ectothermically regulate body temperature by utilizing thermally buffered groundwater inputs during seasonal extremes. Perennially saturated wetland areas disrupt the establishment of facultative wetland vegetation or woody vegetation that may induce wetland succession, maintaining adequate bog turtle habitat. Further, groundwater input mechanistically contributes to microtopographic variation, providing viable nesting locations. Hydrologic studies pertaining to these wetland habitats has been limited in scope, and often attempts to define hydrologic regimes by use of a centrally placed monitoring well. Several studies that have comprehensively monitored these seep meadow wetlands show hydrologic regime variability at intrasite scales. In this thesis, I sought to confirm the spatially variable nature of hydrologic regimes in bog turtle wetlands. Finding that hydrologic conditions were location-dependent, I then tested whether a seep to non-seep hydrologic gradient, or the defining physical components therein, explained variation in bog turtle population density across a wetland. In Chapter II, I observed wetland conditions in summer extremes to categorize wetland areas based on surface saturation into seep, always wet, and sometimes wet locations. I placed multiple water level monitoring wells within these categories at six bog turtle wetlands and used observed water level data to test for spatial hydrologic variability at within- and across-site scales, finding that hydrologic regime can vary at short distances (<10m), and that alike categorized wells differed in groundwater inputs across-sites. I then used observed water level monitoring data during the growing season to test initial observer-based classifications. These classifications were then reorganized using the amount of time water remained near the soil surface, the degree of fluctuation that water level experienced, and differences in thermal exchange with ambient air temperature and thermally buffered groundwater input. I created a method to delineate spatially variable hydrologic regimes based on groundwater discharge by using several seep-associated features. Soil water temperature, depth to resistive soil layer, and specific conductivity were tested for sampling applicability across seasonal extremes, and for co-occurrence in constrained ordination with spatially explanatory covariates. I found that spatial gradients for relative measures of each seep-associated feature were largely consistent across seasons and that all seep-associated features were more often correlated than any other spatial arrangement. Constrained ordination model results were visualized to depict the seep to non-seep hydrologic gradients found within these wetlands. These gradients were then tested against observed water level data for their predictive capability, finding mixed results across seasons and that hydrologic gradients as modeled could likely be improved with additional explanatory information. Depending on where groundwater is entering a wetland, habitat conditions might vary for bog turtles. Seep areas create perennially saturated or mucky soil conditions, with locations further from groundwater discharge experiencing total or some degree of drying out in the growing season. Bog turtle habitat associations recorded in literature suggest that bog turtles are typically found in or near these soft mud or open water areas. Constant groundwater input near these seeps also leads to rivulet formation. Cool, gently flowing water weaves between hummocks of vegetation near these locations, creating pathways for easy movement, elevated platforms for turtles to bask, and muddy substrates to which turtles can retreat to. Because of the habit conditions afforded by these seep areas, I hypothesized that turtle density might be higher with seep occurrence as influenced by the underlying wetland hydrologic gradient. In Chapter III, I tested whether bog turtle population density was a function of hydrologic features across seep to non-seep gradients, relative soil water temperatures, the depth of substrate above a consolidated soil layer, and relative soil moisture conditions. In the summer of 2022, I trapped at six bog turtle wetlands and tracked 24 bog turtles with radiotelemetry. I used a spatially explicit capture mark recapture framework to estimate density and used data developed for hydrologic datasets in Chapter II to examine density associations. Bog turtle density relationships to hydrologic covariates varied across wetlands and supports the view that bog turtles in their active season are not particularly sensitive to specific hydrologic regime conditions, but rather utilize the entirety of wetland conditions. / Master of Science / Bog turtles (Glyptemys muhlenbergii) are a small freshwater turtle ranging east of the Appalachian Mountains from New York to Georgia, in small, patchily distributed (<10ha) groundwater-fed seep meadows and fens. Groundwater inputs create these wetlands and conditions necessary for bog turtle survival. Hydrologic studies in these wetland types are limited but hint towards a reliance on groundwater input as contributing to hydrologic regimes that are locationally dependent. In this thesis, I sought to confirm the spatially variable nature of hydrologic conditions in these wetlands by focusing on ground water entry points and testing whether seeps, or associated seep characteristics, influenced bog turtle population density across a wetland. In Chapter II, I used water level monitoring wells to establish that hydrologic regimes in bog turtle wetlands are spatially variable and characterized these regimes by the resulting saturated to dry surface conditions. I then selected wetland features hypothesized to be associated with groundwater discharge locations and provided evidence that these features occur together and are seasonally constant. These features were then used to delineate hydrologic gradients and tested for whether they could predict conditions observed in water level monitoring. Hydrologic gradients drawn from seep to non-seep locations had limited ability to predict observed hydrologic regimes. Ground water seeps are considered to contain necessary habitat conditions for bog turtles as thermal and predatory refugia, a mechanistic disturbance favoring herbaceous vegetation over woody vegetation, and provide processes that establish microtopographic variation favorable to bog turtle nesting behavior. In Chapter III, I used delineated gradients from the preceding chapter to assess underlying hydrologic conditions that explain where turtles are more likely to be found within their habitat, and whether these associations were shared across bog turtle populations. Bog turtle density across wetlands differed by hydrologic-associated features, and findings suggest that site-wide variability in conditions is the more important aspect of bog turtle wetlands than a specific hydrologic regime.

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Made available in DSpace on 2014-12-17T15:14:47Z (GMT). No. of bitstreams: 1 DarlanAM.pdf: 1159480 bytes, checksum: d201bf0e3558be6b14b14c9a86a46f20 (MD5) Previous issue date: 2005-03-10 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / In this work we have studied the problem of percolation in a multifractal geometric support, in its di&#64256;erent versions, and we have analysed the conection between this problem and the standard percolation and also the connection with the critical phenomena formalism. The projection of the multifractal structure into the subjacent regular lattice allows to map the problem of random percolation in the multifractal lattice into the problem of correlated percolation in the regular lattice. Also we have investigated the critical behavior of the invasion percolation model in this type of environment. We have discussed get the &#64257;nite size e&#64256;ects / Nesta disserta??o estudamos o problema da percola??o num suporte geom?trico multifractal, em suas diferentes vers?es, e analisamos a conex?o deste problema com a percola??o convencional e com o formalismo dos fen?menos cr?ticos. A proje??o da estrutura multifractal numa rede regular subjacente permite mapear o problema da percola??o aleat?ria no multifractal num problema de percola??o correlacionada numa rede regular. Tamb?m investigamos o comportamento cr?tico do modelo da percola??o por invas?o neste tipo de ambiente e discutimos a quest?o do efeito de tamanho &#64257;nito

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