The purpose of this investigation was to determine and characterise the anti-oxidant activity of the methanol extract of the leaves of Halleria lucida utilizing the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay. The methanol extract of the leaves of H. lucida displayed promising anti-oxidant activity with an IC50 value of 8.49±0.12 μg/ml and was subsequently subjected to activity-guided fractionation resulting in the isolation of a flavone-type flavonoid and phenylpropanoid glycoside, namely luteolin-5-O-β-D-glucoside and verbascoside (acteoside), respectively. Both compounds displayed promising anti-oxidant activities with IC50 values of 6.12±0.40 and 7.18±0.08 μg/ml for luteolin-5-O-β-D-glucoside and verbascoside, respectively. Furthermore, isobologram construction was undertaken to determine pharmacological interactions between the isolated molecules resulting in a concentration-dependent additive and antagonistic interaction being recognised.

Made available in DSpace on 2015-03-26T13:42:03Z (GMT). No. of bitstreams: 1 texto completo.pdf: 3514431 bytes, checksum: 363b70b87828ee72684cb0b0718115ca (MD5) Previous issue date: 2008-02-25 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Dinoponera lucida (Formicidae: Ponerinae) is a ant of black color and large size, up to four cm, with apterous females and smaller, winged males. There are no morphologically differentiated castes and the reproduction is carried out by fertilized workers known as gamergates . The species is on the Brazilian list of fauna threatened with extinction. Its distribution is restricted to the south of Bahia and to Espírito Santo in the Central Corridor of the Mata Atlântica. As a contribution to the elucidation of the type of geopgraphic distribution and population structure of the species, the phylogeography of D. lucida was studied from mitochondrial DNA. 1149 bp of the COI, COII and Cytb genes were sequenced. Phylogenetic trees were constructed by Bayesian Inference. Molecular variation, fixation indices, nucleotide and haplotype diversity indices were estimated. Haplotype networks were reconstructed by median-joining network. The type of phylogeography observed was phylogeographic structure with discontinuous genetic divergence and loss of intermediate haplotypes and populations with limited gene flow. The area of occurrence of the species has been intensely impacted by habitat loss and consequently isolation of remaining populations and preserved forests that represent modern ecological refuges for the species. The loss of the habitat also represents loss of intermediate haplotypes and the remaining populations presented exclusive haplotypes. The loss of any of these can not be replaced or compensated for by the conservation of any other. This implies the necessity of conservation efforts aiming to preserve as many as possible of the remaining areas that still harbour population of the D. lucida. / Dinoponera lucida (Formicidae: Ponerinae) é uma formiga de coloração preta e grande porte, até 4 cm, com fêmeas ápteras e machos alados e menores. Não há castas morfologicamente diferenciadas e a reprodução é feita por operárias fertilizadas conhecidas como gamergates . A espécie consta na lista brasileira da fauna ameaçada de extinção. Sua distribuição está restrita ao sul da Bahia e ao Espírito Santo no Corredor Central da Mata Atlântica. Como contribuição para a elucidação do padrão de distribuição geográfica e estruturação populacional da espécie, a filogeografia de D. lucida foi estudada a partir de seqüências do DNA mitocondrial. Foram seqüenciados 1149 pb dos genes COI, COII e Cytb. Árvores filogenéticas foram construídas por Inferência Bayesiana. Variância molecular, índices de fixação, índices de diversidade nucleotídica e haplotípica foram estimados. Redes de haplótipos foram reconstruídas por median-joining network. Os índices de diversidade e fixação indicaram a estruturação das populações. O padrão filogeográfico observado foi a estruturação filogeográfica com padrão descontínuo de divergência genética e perda de haplótipos intermediários em populações com limitado fluxo gênico. A área de ocorrência da espécie tem sido intensamente impactada com perda de habitat e conseqüente isolamento das populações remanescentes em fragmentos florestais preservados que representam refúgios ecológicos modernos para a espécie. A perda de habitat representa também a perda haplótipos intermediários e as populações remanescentes apresentaram haplótipos exclusivos. A perda de qualquer uma delas não pode ser substituída ou compensada pela conservação de nenhuma outra. Isto implica a necessidade de esforços conservacionistas que visem preservar o máximo possível das áreas remanescentes que ainda abrigam populações de D. lucida.

Much like a photograph, a casts creates a replica of its referent, thereby immobilising the subject in time. While the subject continues in time and hence ages and inevitably dies the replica does not. With this basic notion of fixing a subject, I have built an argument to contextualise my sculptures, which are made using casts of elderly people. In this discussion I have looked at my works through the ideas of different theorists. The main theorist I have cited is Roland Barthes, specifically with regards to his notion of the photograph as discussed in his book Camera Lucida. I have also referenced three particular artists: Rachel Whiteread, Diane Arbus and Churchill Madikida, as I have found each of their works relate to my work in various ways, creating a different reading from each viewpoint.

I studied the habitat characteristics of Mexican Spotted Owls (Strix occidentalis lucida), a federally threatened species, in the canyonlands region of southern Utah. Vegetative and geologic features were measured within 10m wide belt plots at each current or historic nest/roost site. Based on our findings, past research, and species life history characteristics, I constructed a species distribution model (SDM) predicting Mexican Spotted Owl distribution in Utah for the Colorado Plateau region. The SDM was generated using the following inputs as important habitat variables: elevation, aspect, surface ratio, curvature, slope, geology, and vegetation. Program R was used for model development and generation. The SDM was generated using an ensemble model approach by combining three modeling techniques: random forest, logistic regression, and maximum entropy. This study combines measured habitat characteristics, with sophisticated geographic information system (GIS) tools and SDMs to provide managers with an informative and useful toolkit for Mexican Spotted Owl conservation. Chapter 2 discusses modeling techniques and SDM development. I detail how individual models were constructed using random forest, logistic regression, and maximum entropy and how these were combined into an ensemble model. Final models indicated that several vegetative and geologic characteristics were considered important habitat characteristics for predicting Mexican Spotted Owl presence within the Colorado Plateau. The SDMs produced eight distribution maps predicting Mexican Spotted Owl presence and probability of occurrence in Utah for the Colorado Plateau region. Chapter 3 explains the use of SDMs by managers and synthesizes findings of measured habitat characteristics for southern Utah. For habitat characteristics I measured a combination of vegetative and geologic features within 10m wide belts at current and historic Mexican Spotted Owl sites. Vegetative features measured included: height and species of all trees and shrubs, position of tree or shrub within plot, presence of canopy cover, and tree diameter at breast height (DBH). Geologic features measured included: geologic formation type, wall height, structure type, number of caves, and number of solution cavities. I found that canyon width and density of vegetation > 2.5 m tall were significantly correlated with Mexican Spotted Owl presence.

This historical work focuses on the theory of photography. It is divided into three autonomous episodes chronologically correspond to three historical stages. These parts are connected with one genealogies of one possible reading of the photography. The first part deals with the historical circumstances and causes of the birth of photography. The second phase describes the later period of history of the Weimar Republic and photographic movement of Neue Sachlichkeit. The last part concentrates on Düsseldorf School of Photography and its current followers. These historical eras combines the aesthetic issues of cult and conceptual values, which is demonstrated on the way how read the photographic medium as a specific aesthetic phenomenon.