Global climate change is predicted to affect timing and severity of disturbance events (e.g., fire, drought, hurricanes, wind storms, and inundation), but the extent of these disturbance events and their impacts on natural ecosystems may vary regionally. Rising sea level, increased frequency and intensity of tropical storms, and altered inundation regimes are likely to create changing environmental conditions in low-lying coastal ecosystems. These large scale disturbances may increase resource availability and regeneration spaces, reduce competition, and possibly increase community vulnerability to invasion. Shifting disturbance regimes and invasion together are predicted to drive long-term shifts in coastal plant community structure and ecosystem processes. However, impacts of altered environmental conditions on native and invasive plant species and the species responses to changed environmental conditions are poorly understood. The aims of this study were: (i) to assess the probability of occurrence of juveniles of the invasive exotic Triadica sebifera and co-occurring native species, Baccharis halimifolia, Ilex vomitoria, and Morella cerifera in the field in relation to surrounding environmental factors, (ii) to assess the effects of elevated salinity across a typical coastal transition on germination of T. sebifera, B. halimifolia and M. cerifera, using controlled growth chamber and greenhouse experiments, (iii) to assess the effects of climate change and shifting inundation and tropical storms regimes on T. sebifera, B. halimifolia and M. cerifera, and (iv) to evaluate the role of vesicular arbuscular mycorrhizae (VAM) on spread of invasive T. sebifera in coastal transition ecosystems at the Grand Bay National Estuarine Research Reserve (GBNERR), Coastal Mississippi, southeastern USA. Results from assessing the probability of occurrence of juveniles of invasive and co-occurring native species showed that soil water conductivity (i.e., salinity) was the major factor related to the occurrence of invasive T. sebifera and native B. halimifolia, I. vomitoria and M. cerifera along the coastal transitions. Probability of occurrence of the invasive T. sebifera was significantly related to landscape factors and occurrence was highest in close proximity to roads, trails, power lines, and recreational sites, and water bodies. These results imply that future increases in salinity will negatively impact I. vomitoria, M. cerifera, and T. sebifera, leading to range contraction of these species away from the coast. However, natural and anthropogenic disturbances that often increase resource pulses and reduce competition, likely increase the dominance of T. sebifera in already invaded areas. Positive effects of landscape structures on T. sebifera occupancy highlight the role of landscape variables in promoting new invasions in coastal forests of the southeastern USA. Controlled growth chamber and greenhouse germination experiments demonstrated that germination of all species (i.e., T. sebifera, B. halimifolia, and M. cerifera) decreased with elevated salinity and that the reduction was most pronounced in soils from the most seaward zones along the coastal transition. Although native B. halimifolia was least sensitive to elevated salinity, invasive T. sebifera displayed plasticity of germination trait across different salinity levels in most inland soils. These results suggest that the phenotypic plasticity may facilitate spread of Triadica sebifera under some degree of salinity stress in more inland section of the coastal transition. A manipulative greenhouse experiment demonstrated that simulated canopy damage from intense hurricane winds and associated storm surge produced differential effects on survival and growth of native (B. halimifolia and M. cerifera) and invasive (T. sebifera) species at simulated different forest conditions common in the GBNERR. Invasive T. sebifera was by far the most shade tolerant of the three species and seedling survival under highly shaded conditions may provide it with a competitive edge over native species during community reassembly following tropical storms. T. sebifera may better utilize post-hurricane conditions (e.g., resource-rich empty spaces) and potentially increase its dominance in coastal forested ecosystems. The last experimental study revealed that invasive T. sebifera had higher VAM colonization compared to co-occurring native species both in controlled greenhouse and field experiments, and that the higher colonization leads to significant increases in aboveground biomass, supporting the hypothesis that VAM fungi strongly benefit the invasive species. These results suggest that the VAM colonization may be necessary for the initial establishment of T. sebifera along the coastal transitions. Furthermore, my research also suggested that T. sebifera was not allelopathic and did not interfere with growth of native species. Overall, the findings of this research provide insight into the impacts of climate change related shifts on performance of invasive and co-occurring native species across coastal transitions of the southeastern USA. Variation in invasive and co-occurring native species' performances under changed environmental conditions (e.g., elevated salinity and increased light availability) and improved mutualistic association between invasive T. sebifera and VAM fungi may drive increased invasion with frequent community reassembly of low-lying coastal ecosystems undergoing rapid climate change.

SILVA, Jorge Roberto Pereira da. Invasões múltiplas em meios porosos desordenados. 2013. 73 f. Dissertação (Mestrado em Física) - Programa de Pós-Graduação em Física, Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2013. / Submitted by francisco lima (admir@ufc.br) on 2014-03-20T13:24:31Z No. of bitstreams: 1 2013_dis_jrpdasilva.pdf: 6783022 bytes, checksum: 56a0994d2bd89d4081cf4955dce1d3dc (MD5) / Approved for entry into archive by Edvander Pires(edvanderpires@gmail.com) on 2014-05-16T21:51:28Z (GMT) No. of bitstreams: 1 2013_dis_jrpdasilva.pdf: 6783022 bytes, checksum: 56a0994d2bd89d4081cf4955dce1d3dc (MD5) / Made available in DSpace on 2014-05-16T21:51:28Z (GMT). No. of bitstreams: 1 2013_dis_jrpdasilva.pdf: 6783022 bytes, checksum: 56a0994d2bd89d4081cf4955dce1d3dc (MD5) Previous issue date: 2013 / In this dissertation, we investigate by means of numerical simulations geometrical and transport properties related with the invasion phenomena through disordered porous media in a very slow invasion regime, using two and three dimensions porous medias. Here, the porous media is modeling by means of a random structure, where each pore is represented by a random number comes from a uniform distribution. We assume that the invasion process occurs in the limit of very low viscous force, which means that the invasion process is controlled by capillary force. In this limit the invasion percolation model without trap is suitable. The new aspect incorporated here, consists basically of a multiple invasion process, where after the first invasion takes place only part of the structure of the porous, that was invaded previous, can be invaded again. We study, how the multiple invasion changes the fractal dimension of the invaded cluster. Estimated values for the fractal dimension of the invaded region reveal that the critical exponents vary as a function of the generation number G, i.e., where the number of times the invasion takes place. On base in numerical datas, we show the averaged mass M of the invaded region decreases with a power law as a function of G, M ∼ G{−β} , where the exponents β ≈ 0.59 (2D) and β ≈ 0.73 (3D). We also investigated, how the fractal dimension changes as a function of G, find that the fractal dimension of the invaded cluster changes from df = 1.89 ± 0.02 to ds = 1.22 ± 0.02 and df = 2.52 ± 0.02 to ds = 1.46 ± 0.02 for (2D) and (3D), respectively. These results confirm that the multiple invasion process follows a continuous transition from one universality class (nontrapping invasion percolation) to another (optimal path), furthermore these change are continuos for both dimensionality. Another aspect investigated, was the avalanche distribution in the invasion process. We analyzed how the distribution of avalanche changes as function of G, more precisely, how the multiple invasion process changes the exponent τ of the power law distribution. Regardless the values, we find that the behaviour of the exponents τ looks like the same for both dimensions studied. The exponents τ , initially change in a very slow way until reach a region, of certain value of G which depend on the dimension, they start to decrease in a deep way until reach the saturation value. The saturation value is close, for (2D), to one-dimension cas / Nesta dissertação, investigamos por meio de simulação computacional propriedades geométricas e de transportes relacionadas ao fenômeno de invasão em meios porosos desordenados no regime de invasão muito lento em sistemas bidimensionais e tridimensionais. O meio poroso considerado aqui é representado por meio de uma estrutura desordenada onde a cada poro que compõe este meio se associa um número aleatório obtido a partir de uma distribuição uniforme. Considerando o regime lento de invasão, onde as forças capilares dominam o escoamento em relação as forças viscosas, utilizando para a dinâmica de invasão o modelo de percolação invasiva sem aprisionamento. Introduzimos um variante no modelo de percolação invasiva, assumindo o aspecto de múltiplas invasões, onde a cada nova invasão apenas parte do substrato utilizado na invasão anterior pode ser invadido novamente. Em uma primeira parte, estudamos como o processo de múltipla invasão altera as características do agregado invadido. Valores estimados para a dimensão fractal da região invadida revelam que os expoentes críticos variam em função do número de geração G, isto é, o número de vezes que o processo de invasão foi repetido. Com base em dados numéricos, mostramos que a massa média do agregado invadido decresce na forma de uma lei de potência como função de G, M ~ G^{-β}, com o expoente β = 0.59 (2D) e 0.73 (3D). Investigamos como a dimensão fractal do agregado invadido varia em função dos repetitivos processo de invasão, mostrando que as mesmas variam de df = 1.89 ± 0.02 até ds = 1.22 ± 0.02 para o caso (2D) e df = 2.52 ± 0.02 até ds = 1.46 ± 0.02 para o caso (3D). Os resultados confirmam que o processo de múltiplas invasões segue uma transição continua entre as classes de universalidade do modelo de percolação invasiva sem aprisionamento e ótimo caminho, sendo este comportamento observado em duas e três dimensões. Um outro aspecto investigado nessa dissertação, foi o fenômeno de avalanche que ocorre durante o processo de invasão. Investigamos como a distribuição de tamanhos de avalanche, que se comporta na forma de uma lei de potência P(S, L) ~ S^{-τ} , altera-se em função das múltiplas invasões. Mais precisamente, calculamos como o expoente que governa o comportamento das avalanches se altera em função do número de geração G. Verificamos que este comportamento do expoente em função de G é semelhante para duas e três dimensões, apresentando uma região de mudança suave seguida por uma mudança mais acentuada até atingir um limite de saturação, onde o sistema se comporta de maneira parecida com o caso unidimensional.

Ampliar nosso conhecimento sobre a biologia do carcinoma espinocelular bucal é fundamental para o desenvolvimento de novas estratégias terapêuticas e para melhorar a sobrevida dos pacientes acometidos por essa patologia. Para tanto, compreender as contribuições do microambiente tumoral à carcinogênese é muito importante. Um característica importante a ser avaliada do microambiente tumoral é a acidificação do meio extracelular. Considerando que o pH ácido tumoral está relacionado à maior agressividade da lesão, o objetivo deste projeto é estudar os efeitos de um microambiente ácido na biologia de células de carcinoma espinocelular bucal. Para tanto, foram realizadas duas revisões da literatura, nas quais foram avaliados os seguintes temas: influência da acidez extracelular na invasão e migração; e os mecanismos moleculares envolvidos na resistência ao tratamento quimioterápico, induzida pela acidez do microambiente tumoral. Tais revisões embasaram a construção do terceiro artigo desta tese, o qual se propôs a comparar o comportamento de células linhagens de carcinoma espinocelular bucal (SCC-4 e SCC-9) e queratinócitos (HaCat) cultivadas em meio de cultura de pH 6.8 com células mantidas em meio neutro pH 7.4. As células foram expostas de forma contínua ou intermitente ao pH 6.8 e a adaptação das células foi avaliada pelo ensaio clonogênico. Além disso, as células foram avaliadas quanto à sua capacidade migratória pelo ensaio de cicatrização de feridas e de time lapse. A expressão gênica relacionada à indiferenciação e pluripotência foi investigada por PCR em tempo real com os marcadores Bmi-1 e CD44, assim como pelo ensaio de orosferas. A resistência desses grupos de células ao tratamento anti-câncer foi avaliada pelo ensaio de viabilidade celular da sulforodamina B após o tratamento com Cisplatina. Para a análise estatística, inicialmente foi realizada a distribuição dos dados, seguido da comparação estatística dos grupos utilizando, para distribuição normal, os testes ANOVA e ANOVA de duas vias. Toda a análise foi realizada no programa GraphPad Prism 5.0 e o nível de significância considerado foi de p< 0.05.Observamos que ambas as linhagens mudaram sua morfologia para um aspecto mesenquimal. Ao avaliar o perfil migratório observou-se que as células SCC-9 apresentaram maior capacidade de migração após a exposição ao pH6.8. O aumento da migração celular pode ser causado pela indução da transição epitélio-mesênquima, visto que observamos o aumento da expressão de N-caderina (SCC-4:p<0.05) concomitante à diminuição de E-caderina (SCC-4: p<0.05). A exposição à acidez também provocou, em ambas as linhagens, aumento da capacidade de formar orosferas em placa de baixa aderência, denotando um fenótipo pluripotente (SCC-4: p=0.007/ SCC-9: p= 0.1202). Tal resultado foi reforçado com aumento da expressão gênica do marcador de célula-tronco tumoral CD44 (p= 0.0325). na linhagem SCC-4. No entanto, observamos diminuição da expressão de Bmi-1(p=0.0572) em relação ao controle. A resistência à Cisplatina aumentou nos casos de exposição contínua à acidez (SCC-4: p<0,05). O recondicionamento em meio neutro reverteu a sensibilidade celular (SCC-4: p>0,05). Concluímos que a acidez extracelular no carcinoma espinocelular bucal aumenta a capacidade de migração, induz o fenótipo de células tronco-tumorais e aumenta a resistência a quimioterápicos. / To expand our knowledge about the biology of oral squamous cell carcinoma is crucial for the development of new therapeutic strategies and to improve the survival of the patients affected by this pathology. Therefore, understanding the contributions of the tumor microenvironment to carcinogenesis is very important. An important feature to be evaluated of the tumor microenvironment is the acidification of the extracellular medium. Considering that acidic pH is related to the greater aggressiveness of the tumor, the aim of this study is to analyze the effects of an acidic microenvironment on the biology of oral squamous cell carcinoma cells. We realized two reviews of the literature, in which the following themes were evaluated: the influence of extracellular acidity on the invasion and migration; and the molecular mechanisms involved in the resistance to chemotherapeutic treatment, induced by the acidity of the tumor microenvironment. These revisions helped to construct the third article of this thesis, which proposed to compare the behavior of squamous cell carcinoma lines (SCC-4 and SCC-9) and keratinocytes (HaCat), cultured under pH 6.8 was compared to cells maintained at pH 7.4. For the statistical analysis, the data distribution was initially performed, followed by the statistical comparison of the groups using, for normal distribution, ANOVA and ANOVA two-way tests. All analysis was performed in the GraphPad Prism 5.0 program and the level of significance considered was p <0.05.After continuous or intermittent exposure to pH 6.8, cell adaptation was assessed by the clonogenic assay. In addition, the migratory capacity of the cells was evaluated by the wound healing and time-lapse assays. The gene expression related to undifferentiation and pluripotency was assessed by real-time PCR analysis of the Bmi-1 and CD44 markers, as well as by the orosphere assay. The resistance of these cell groups to anti-cancer treatment was assessed by the sulforhodamine B cell viability assay after treatment with Cisplatin. We observed that both cell lines changed their morphology to a mesenchymal aspect. When assessed the migratory profile, it was observed that SCC-9 cells showed higher migration capacity after exposure to pH6.8. Increased cell migration may be caused by the induction of the epithelial-mesenchymal transition, as we observed increased N-cadherin (SCC-4:p<0.05) expression concomitant with decreased E-cadherin (SCC-4: p<0.05). Exposure to acidity also led to increased ability to form orospheres on low-attachment dishes, denoting a pluripotent phenotype in both strains (SCC-4: p=0.007/ SCC-9: p= 0.1202). This result was reinforced by increased expression of the CD44 (p= 0.0325) tumor cell marker in the SCC- 4 cells. However, we observed a decrease in the expression of Bmi-1(p=0.0572) in relation to the control. Resistance to Cisplatin increased when cells were continuously exposed to acidity(SCC-4: p<0,05). Neutral reconditioning reversed cell sensitivity (SCC-4: p>0,05). We conclude that extracellular acidity in oral squamous cell carcinoma increases the migration capacity, induces the cancer stem cell phenotype and increases resistance to chemotherapy.

Abordo nesta tese a invasão / ocupação da Universidade Federal do Rio Grande do Sul – UFRGS, desde o seu surgimento, por pessoas negras. Trago como objetivo principal o registro da percepção de seis docentes de três cursos de licenciatura: História, Letras e Pedagogia, sobre modificações ocorridas na universidade, considerando a adoção do Programa de Ações Afirmativas, inserido a partir de 2008. No trabalho utilizo o método da entrevista compreensiva, para conhecer o posicionamento do grupo de docentes frente à adoção do Programa de Ações Afirmativas, do desempenho do alunado cotista e de possíveis alterações na grade curricular, levando em conta o disposto na legislação referente à Educação das Relações Étnico-Raciais - ERER. Busquei destacar a permanente presença de mulheres negras e de homens negros na UFRGS. Contei com grupo de pessoas negras e não negras que invadiram / ocuparam a tese com escritos. São textos que denotam o compromisso da população negra com a educação em seus diversos níveis. Referem também o compromisso com a mudança da sociedade Cabe evidenciar que a tese foi efetivada após passados 30 anos da elaboração da dissertação de mestrado intitulada ¿A Exclusão da Cultura Negra dos Currículos Escolares: uma questão só de desconhecimento histórico?, na qual entrevistei docentes de escolas públicas estaduais. Naquele período inexistia legislação determinando o ensino da cultura e da história africana, afro-brasileira e indígena. A possível originalidade esboçada na tese referiu-se à investigação do compromisso de docentes de licenciaturas da UFRGS no tocante ao ingresso de alunos pelo Programa de Ações Afirmativas, como também pela valorização das culturas africana / afro-brasileira e indígena, tendo em vista a invasão / ocupação da UFRGS por alunos autodeclarados pretos, pardos e indígenas, que trazem em seus corpos marcas inalienáveis de outras culturas. / I approach on this thesis the invasion / occupation by black people of the Universidade Federal do Rio Grande do Sul – UFRGS since the beginning of this institution. I bring as main objective the registration of the perception of six different professors from three teaching courses: History, Languages and Pedagogy, about the modifications within the university, considering the adoption of the Affirmative Actions Program, founded in 2008. In the study, I use the method of comprehensive interview, in order to get to know the perspective of this group of professors about the adoption of the Affirmative Actions Program, the performance of students who are a part of the Affirmative Action Program and possible alterations in the curricular schedule, taking into consideration the legislation regarding the Education of Ethnic-Racial Relations - ERER. I seeked to highlight the permanent presence of black women and men at UFRGS. Black and non-black people had also invaded/occupied the thesis with written pieces. They are texts that denote the commitment of the black population with the education in its different levels. They also refer the commitment with the change in society It is important to highlight that the thesis was made 30 years after the elaboration of the dissertation of master’s called The Exclusion of the Black Culture from School Schedule: a mere issue of historical ignorance? in which I interviewed teachers of public schools within the state. In that period, there wasn't any law determining the teaching of African, Afro-brazilian and indigenous culture and history. The possible originality sketched in the thesis referred the investigation of the commitment of professors of teaching courses at UFRGS in regards to the ingression of students of the Program of Affirmative Actions, as well as for the valuation of the African/afro-Brazilian and indigenous cultures, taking into consideration the invasion/occupation of UFRGS by self-declared black, brown and indigenous students, who bring in their bodies inalienable marks of other cultures.

The spread of invasive plant species in natural habitats has become a worldwide problem with negative environmental and economic impacts. An increasing number of invasive organisms are responsible for adverse environmental and economic impacts worldwide, including species extinction, crop failures, reduced water supply, and damage to industrial infrastructures (KERCHER et al., 2007). Phalaris arundinacea L. is widespread throughout the world, except Antarctica and Greenland. Center of diversity of this genus is in the Mediterranean. Members of the genus Phalaris occurs in moist habitats from lower to alpine altitudes (ANDERSON, 1997). Phalaris has a plethora of uses. Its most frequent use is as the root wastewater treatment plants. Phalaris grown as feed for livestock and is also used as an ornamental grass. Phalaris have recently received a lot of attention as a new biomass source for the production of renewable energy in USA. In recent years there has been a massive spread of P. arundinacea across North America (currently occurs in 43 states) and Canada (ZEDLER & KERCHER, 2004). Phalaris represents a significant threat to its original wetland vegetation and is classified as a harmful agens in nine state of U.S. states (LAVERGNE & MOLOFSKY, 2004). It is believed that these aggressive population have European origin.

Este trabalho se inscreve na interface entre Geografia, História e Política. Apesar do amplo debate que cerca a Geografia Histórica e sua definição, como o apresentado por Chris Philo (1996) quando coloca a impossibilidade de existir esta área de especialização, uma vez que tanto a Geografia quanto a História são ciências horizontais, o mistério da Geografia Histórica, várias pesquisas têm sido realizadas na Geografia, pelo menos nos últimos 20 anos no Brasil, fortalecendo esta entrada de investigação. A importância do Rio de Janeiro desde o início do século XVI ocorre como um dos pontos estratégicos do Atlântico Sul. Por esta ocasião, as expedições de Solis e Fernão Magalhães nos idos da década de 1530 já utilizavam este ponto do território para fazer aguada e descansar antes de partirem para a tão cobiçada bacia do Rio da Prata. Na análise preliminar pode-se verificar que as invasões francesas de 1710 e 1711 serviram como um importante evento para o controle territorial da América Portuguesa. A pesquisa bibliográfica e documental realizada, conforme poderá ser verificada ao longo dessa dissertação, confirma também a importância dessas invasões no controle militar mais efetivo na porção sul da colônia. Objetivo deste trabalho é mostrar como essas duas invasões francesas impactaram na organização do sistema defensivo do Rio de Janeiro e de sua hinterlândia, contribuindo para repensar a reorganização desse sistema. Vale ressaltar que essas invasões francesas tiveram impactos diferentes. A invasão de 1710, comandada por Duclerc foi um evento no qual os portugueses saíram vencedores, impedindo que a guarnição francesa tomasse e saqueasse cidade. Enquanto, que a invasão liderada por Trouin, em 1711, obteve maior sucesso, seqüestrando a cidade e mantendo-a como refém, exigindo dos portugueses o pagamento para reintegrá-la a jurisdição lusitana. / This work is part of the interface between geography, history and politics. Despite the extensive debate surrounding the Historical Geography and definition, as presented by Chris Philo (1996) when placing the impossibility of this area of expertise, as both geography and history are horizontal sciences, "the mystery of Historical Geography, "several studies have been performed in Geography, at least the last 20 years in Brazil, strengthening this entry research.The importance of Rio de Janeiro since the beginning of the sixteenth century is one of the strategic points in the South Atlantic On this occasion, the expeditions of Solis and Ferdinand Magellan back in the 1530s have used this point in the territory to take in water and rest before departing for the much coveted basin of the River Plate. In the preliminary analysis can be seen that the French invasion of 1710 and 1711 served as an important event for territorial control of Portuguese America. The bibliographic and documental research, as can be found throughout this thesis, also confirms the importance of these invasions in the most effective military control in the southern portion of the colony. This paper aims to show how these two French invasions impacted the organization of the defensive system of Rio de Janeiro and its hinterland, contributing to rethink the reorganization of the system. It is noteworthy that these French invasion had different impacts. The invasion of 1710, led by Duclerc was an event in which the Portuguese came out winners, preventing the French garrison to take and loot the city. While the invasion led Duguay in 1711, enjoyed success, seized the city and holding it hostage, demanding the payment of the Portuguese to reinstate the jurisdiction Lusitanian.

Tumour dissemination is a major reason for failure of therapy for many tumour types therefore there is a requirement for novel targets & therapies. The αIIbβ3 and αvβ3 integrins have been demonstrated to have significant involvement at many stages of the tumour dissemination process including, tumour cell adhesion, migration, metastasis and angiogenesis, and thus the β3 integrins are a potential target for therapeutic antagonism with small molecules. Because of the clear interaction between the different integrin types, targeting integrins as a therapeutic strategy requires targeting more than one integrin type. Consequently, the ICT is developing a group of novel new αIIbβ3 and αvβ3 integrin dual antagonists. One of the main challenges is having a relevant, validated experimental model that expresses these integrins. The aim of the work presented here is to develop and validate an in vitro αIIbβ3 and αvβ3 integrin expressing assay of tumour cell invasion. The spheroid invasion assay has the advantage over standard monolayer transwell chamber invasion assays of being a 3-dimensional assay, and thus mimics better the cell-cell interactions and architecture that are present in a tumour compared to the monolayer-based assay. A panel of human cancer cell lines known to express one of the molecular targets of interest, αvβ3 integrin was evaluated for the ability to form spheroids and to invade through collagen matrices. One glioma cell line, U87-MG, demonstrated consistent spheroid formation and invasion and was thus selected for further studies. Optimum conditions were established for use of U87-MG in the invasion assay, and the assay was validated using a known inhibitor of invasion, LiCl and known β3 antagonist, cRGDfV. Subsequently a group of novel small molecule β3 antagonists were evaluated at nontoxic concentrations using the assay. Both LiCl and cRGDfV inhibited spheroid invasion through the gel in a dose-dependent manner, thus validating the assay. Furthermore, when the novel small molecule β3 antagonists were evaluated using the model, a dose and time dependent reduction in U87-MG spheroids invasion in collagen was observed. In further work initial steps were taken to construct a cell line which expresses both αIIbβ3 and αvβ3 integrin to use in the model to assess for dual integrin antagonism. In conclusion, this work has established a validated assay which has been utilised for some compounds to evaluate a group of novel small molecule β3 integrin antagonists with encouraging results.

abstract: Mechanical properties (e.g. deformability or stiffness) are critical to a cancer cell's ability to maneuver through and exert forces upon the extracellular matrix, and thus affect its ability to metastasize. §3.1 introduces the experimental method combining atomic force microscope (AFM) based indentation and confocal laser scanning microscopy (CLSM). §3.2 presents a method combining AFM and confocal microscopy (AFM stiffness nanotomography), and results on normal and pre-cancerous esophageal cells which indicate that even in the earliest stages, cancer cells exhibit increased deformability. §3.3 presents experimental results on weakly metastatic breast cancer cells that compare well with values obtained from other experimental methods and demonstrates that the mechanical response of cells to sharp and mesoscale probes differ significantly. §3.4 presents experimental results indicating that metastatic breast cancer cells are more deformable than normal counterparts, and demonstrates that indentation measurements with sharp probes are capable of identifying mechanical differences between cytoplasmic, nuclear and nucleolar regions of the cell. §3.5 presents results on weakly metastatic breast cancer cells sensitive and resistant to tamoxifen (an estrogen antagonist), and demonstrate that estrogen has a significant effect on cell stiffness. §3.6 applies stiffness nanotomography to study metastatic breast cancer cells allowed to invade 3D collagen gels, demonstrating the ability to use AFM indentation on heterogeneous samples, and shows that cell stiffness increases during the invasion process for partially and fully embedded metastatic breast cancer cells. / Dissertation/Thesis / Doctoral Dissertation Physics 2014

abstract: Quiescin sulfhydryl oxidase 1 (QSOX1) is a highly conserved disulfide bond-generating enzyme that represents the ancient fusion of two major thiol-disulfide oxidoreductase gene families: thioredoxin and ERV. QSOX1 was first linked with cancer after being identified as overexpressed in pancreatic ductal adenocarcinoma (but not in adjacent normal ductal epithelia, infiltrating lymphocytes, or chronic pancreatitis). QSOX1 overexpression has been confirmed in a number of other histological tumor types, such as breast, lung, kidney, prostate, and others. Expression of QSOX1 supports a proliferative and invasive phenotype in tumor cells, and its enzymatic activity is critical for promoting an invasive phenotype. An in vivo tumor growth study utilizing the pancreatic tumor cell line MIAPaCa-2 containing a QSOX1-silencing shRNA construct revealed that QSOX1 expression supports a proliferative phenotype. These preliminary studies suggest that suppressing the enzymatic activity of QSOX1 could represent a novel therapeutic strategy to inhibit proliferation and invasion of malignant neoplasms. The goal of this research was to identify and characterize biologically active small molecule inhibitors for QSOX1. Chemical inhibition of QSOX1 enzymatic activity was hypothesized to reduce growth and invasion of tumor cells. Recombinant QSOX1 was screened against libraries of small molecules using an enzymatic activity assay to identify potential QSOX1 inhibitors. Two lead QSOX1 inhibitors were confirmed, 2-phenyl-1, 2-benzisoselenazol-3-one (ebselen), and 3-methoxy-n-[4-(1 pyrrolidinyl)phenyl]benzamide. The biological activity of these compounds is consistent with QSOX1 knockdown in tumor cell lines, reducing growth and invasion in vitro. Treatment of tumor cells with these compounds also resulted in specific ECM defects, a phenotype associated with QSOX1 knockdown. Additionally, these compounds were shown to be active in pancreatic and renal cancer xenografts, reducing tumor growth with daily treatment. For ebselen, the molecular mechanism of inhibition was determined using a combination of biochemical and mass spectrometric techniques. The results obtained in these studies provide proof-of-principle that targeting QSOX1 enzymatic activity with chemical compounds represents a novel potential therapeutic avenue worthy of further investigation in cancer. Additionally, the utility of these small molecules as chemical probes will yield future insight into the general biology of QSOX1, including the identification of novel substrates of QSOX1. / Dissertation/Thesis / Doctoral Dissertation Molecular and Cellular Biology 2015

Made available in DSpace on 2016-06-02T18:57:49Z (GMT). No. of bitstreams: 1 5843.pdf: 20411510 bytes, checksum: 6c8a32aab0699c1288fb33bf02ffdf15 (MD5) Previous issue date: 2014-03-17 / Financiadora de Estudos e Projetos / Digitonthophagus gazella is known worldwide because it has been introduced in tropical and subtropical regions of several countries. The aim of this introduction was to assist in the removal of dung pats in pasture areas and to aid in the biological control of flies of veterinary importance. Thus, although D. gazella has a preference for open and sunny habitats and herbaceous vegetation, there is evidence that it apparently has been adapting to closed-canopy areas. Therefore, this study aimed at evaluating the ability of D. gazella to develop in a forest environment. The study was conducted in 2012 and 2013 in the Farm of UNESP - Ilha Solteira in Mato Grosso do Sul, Brazil. To evaluate the presence of D. gazella in the forest were used pitfall traps and to verify its capability of develop in this habitat couples of this species were kept in pasture and forest fragment in the absence and presence of competitors. The results indicate that D. gazella is able to enter the forest fragment, but at short distances from the edge. Additionally, D. gazella was not able to develop and establishment in the forest fragment. / A espécie Digitonthophagus gazella é conhecida mundialmente pelo fato de ter sido introduzida em regiões tropicais e subtropicais de vários países. O objetivo dessas introduções foi o de auxiliar na remoção de massas fecais em áreas de pastagem e no controle biológico de moscas de importância veterinária. D. gazella apresenta preferência por habitats abertos e ensolarados e de vegetação herbácea, porém há indícios de que esta vem se adaptando a áreas fechadas. Com isso, este estudo objetivou avaliar a capacidade de D. gazella em se desenvolver em ambiente florestal. O estudo foi realizado nos anos de 2012 e 2013 na Fazenda de Pesquisa e Extensão da UNESP - campus de Ilha Solteira, em Selvíria/MS. Para avaliar a presença de D. gazella na mata foram utilizadas armadilhas pitfall e para verificar a capacidade de desenvolvimento um casal da referida espécie foi mantido no pasto e no fragmento florestal na ausência e presença de competidores. Os resultados indicam que D. gazella é capaz de entrar no fragmento florestal, porém a curtas distâncias da borda. E que de forma geral os indivíduos desta espécie não são capazes de se desenvolverem e se estabelecerem no fragmento florestal.