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Journeying out of silenced familial spaces in Chimamanda Ngozi Adichie's Purple hibiscusOuma, Chrispher Ernest Werimo 09 December 2008 (has links)
This study explores the silencing of familial spaces in Chimamanda Ngozi Adichie’s
Purple Hibiscus. It probes into how the familial space is invested with religiosity: how
ritual and norm structure and silence familial spaces and how transcendence from these
spaces can be achieved through elements of laughter, music and sexuality. The study uses
post-colonial theories, concepts of familial ideology and familial theory to read the text.
The introductory chapter provides a politico-historical background of the text, then a
literary historiography of how the familial trope has been used in African literature with
special focus on Achebe. The chapter also outlines the theoretical framework of the study
while anticipating the issues to be dealt with. Chapter two focuses on how the familial
space is invested with religious rituals and how these silence the familial space. Chapter
three examines how augmentation out of the silenced familial spaces works through
elements of laughter, sexuality and music. Chapter four investigates the family as a
portrait of the state and most significantly how these two institutions are portrayed to be
in a complex relationship. The study’s conclusion is that the family can be used as an
alternative site for discourses of marginality and can give a nuanced critique of the postcolony.
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Atividade anti-inflamatória de extrato fenólico de tomate roxo (Solanum Lycopersicum L.) em camundongo em modelo de peritonite induzido pelo LPS / Anti-inflammatory activity of phenolic extract of purple tomato (Solanum lycopersicum L.) in mouse model of peritonitis induced by LPS.Maia, Afonso Pinho da Silva 11 March 2015 (has links)
Visando a produção de um alimento que possua elevados teores de compostos bioativos, a piramidação de genes é uma técnica capaz de estimular o acúmulo e a expressão de novas classes de flavonoides em tecidos vegetais, como por exemplo, o tomate roxo, rico em antocianinas. As antocianinas podem atenuar o processo inflamatório através da modulação da cascata de sinalização e da expressão de enzimas, sendo este um dos possíveis mecanismos de ação que leva a promoção da saúde, atribuído a esta classe de compostos. Assim, o objetivo deste trabalho foi avaliar a ação anti-inflamatória do extrato de tomate roxo, obtido por piramidação dos genes Anthocyanin Fruit (Aft), Aubergine (Abg) e atroviolaceum (atv), em camundongos submetidos ao modelo de peritonite induzida por lipopolissacarídeo (LPS). O fruto tomate vermelho - Micro Tom (MT) e o transformado foram caracterizados quanto ao seu perfil de compostos fenólicos. A casca do tomate roxo, rica em antocianinas, apresentou conteúdo de fenólicos totais dez vezes maior quando comparado à casca do MT, apresentando também maiores quantidades de ácido ascórbico e capacidade antioxidante avaliado nos métodos DPPH e ORAC; em relação à polpa e casca do tomate vermelho e a polpa do tomate roxo. Os principais flavonoides identificados na casca do tomate roxo, por CLAE-DAD, foram: as antocianidinas petunidina (86,5 mg/100 g b.u.), delfinidina (6,85 mg/100 g b.u.), principalmente na forma acilada, e o flavonol rutina (106,26 mg/100 g b.u.). A propriedade anti-inflamatória dos compostos fenólicos foi avaliada através de um modelo de peritonite, em camundongos, induzida por LPS. O extrato aquoso do tomate roxo, rico em antocianinas (2 e 4 mg petunidina eq./100 g peso corpóreo) foi administrado, por via oral, 30 minutos antes do estímulo inflamatório. No exsudato peritoneal, coletado após 3h do estímulo, foi observada, no grupo que recebeu 4 mg quando comparado ao grupo estimulado com LPS, uma redução significativa (p<0,05) de cerca de 37% no número de leucócitos totais e de 64% na expressão gênica de mRNA de COX-2 e na produção de citocinas pró-inflamatórias (TNF-α, IL-1β, IL-2, IL-6 e MCP-1), assim como um aumento significativo da citocina anti-inflamatória IL-10. Em estudo de absorção, os metabólitos: delfinidina aglicona (m/z 303) e malvidina aglicona (m/z 331) foram detectados, por cromatografia líquida ESI-MS/MS, nas amostras de fígado dos animais eutanasiados após 30 minutos de administração do extrato do tomate roxo. Portanto, os resultados demonstram que as antocianinas presentes no tomate roxo, por meio dos metabólitos encontrados no fígado dos animais, apresentam atividade anti-inflamatória através do controle do influxo leucocitário, da modulação da expressão gênica de COX-2 e da produção citocinas. / Aiming to produce a food having high contents of bioactive compounds, the gene pyramiding is a technique capable of stimulating the expression and accumulation of new classes of flavonoids in plant tissues, such as purple tomato, rich in anthocyanins. Anthocyanins may attenuate the inflammatory process by modulating the signaling cascade and expression of enzymes, which is one of the possible mechanisms of action that leads to health promotion, assigned to this class of compounds. The objective of this study was to evaluate the anti-inflammatory action of the purple tomato paste, obtained by pyramiding of genes Fruit Anthocyanin (Aft), Aubergine (Abg) and atroviolaceum (atv) in mice submitted to peritonitis model induced by lipopolysaccharide (LPS). The tomato fruit - Micro Tom (MT) and the transformed were characterized according to their profile of phenolic compounds. The purple tomato peel, rich in anthocyanins, phenolics content presented ten times higher compared to the shell of the MT, and also provides increased amounts of ascorbic acid and antioxidant activity in the DPPH rated and the ORAC methods; than the pulp and peel the tomato pulp and purple tomatoes. The main flavonoids identified in tomato peel purple, by HPLC-DAD were: petunidin the anthocyanidins (86.5 mg / 100 g wb), delphinidin (6.85 mg / 100 g wb), especially in the acylated form, and flavonol rutin (106.26 mg / 100 g bu). The anti-inflammatory properties of the phenolic compounds was evaluated through a model of peritonitis in mice induced by LPS. The extract of purple tomato, rich in anthocyanins (2 and 4 petunidin mg eq. / 100 g body weight) was administered orally 30 minutes before the inflammatory stimulus. In the peritoneal exudate collected after 3 h of stimulation was observed in the group receiving 4 mg as compared to the LPS stimulated group, a significant reduction (p <0.05) of about 37% in the number of total leukocytes and 64 % mRNA gene expression of COX-2 and production of proinflammatory cytokines (TNF-α, IL-1β, IL-2, IL-6 and MCP-1), as well as a significant increase of the anti-inflammatory cytokine IL-10. In a study of absorption, the metabolites: aglycone delphinidin (m / z 303) and malvidin aglycone (m / z 331) were detected by HPLC - ESI-MS / MS, in liver samples from animals euthanized 30 minutes after administration the purple tomato extract. Therefore, the results show that anthocyanins present in the purple tomato, through the metabolites found in animal liver, exhibit anti-inflammatory activity by controlling the leukocyte influx, the modulation of gene expression of COX-2 and production cytokines.
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TARGETED ILLUMINATION STRATEGIES FOR HYDROGEN PRODUCTION FROM PURPLE NON-SULFUR BACTERIACraven, John D. 01 January 2019 (has links)
The movement towards a more sustainable energy economy may require not only the generation of cleaner fuel sources, but the conversion of waste streams into value-added products. Phototrophic purple non-sulfur bacteria are capable of metabolizing VFAs (volatile fatty acids)and generate hydrogen as a byproduct of nitrogen fixation using energy absorbed from light. VFAs are easily produced from dark anaerobic fermentation of food, agricultural, and municipal wastes, which could then be fed into photobioreactors of purple bacteria for hydrogen production.
The process of photofermentation by purple bacteria for hydrogen production remains attractive due to the capability of reaching high substrate conversions under mild operating conditions, but increasing the efficiency of converting light energy into hydrogen remains challenging. Purple bacteria cannot utilize the entire solar spectrum, and the dominant region of absorption lies in the near-infrared region above 800 nm.
In this work, the model purple non-sulfur bacteria Rhodopseudomonas palustris was used to study different strategies to increase light utilization and hydrogen production. Near-infrared LED arrays were selected to match the target bacteriochlorophyll absorption range, and were tested to be used as a sole illumination source for photofermentation. Additionally, plasmonic nanoparticles with resonant frequencies matching bacterial absorbance were added in solution to increase light utilization through scattering and near field electric enhancement effects at intensities around 100 W/m2 . Both of these approaches proved to increase cellular growth rate and hydrogen production, which opens the door to utilizing more advanced photonic structures for use in bacterial phototrophic processes.
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Improving Spectrophotometric Carbon System MeasurementsPatsavas, Mark 03 April 2014 (has links)
This work provides improved procedures for spectrophotometric carbon system measurements. Indicator dyes used for routine spectrophotometric pH measurements in seawater suffer from impurity issues, which introduce vendor-specific systematic errors in pH determinations. The magnitude of these errors for several vendors was investigated for meta Cresol Purple (mCP) and Cresol Red (CR). Flash chromatography procedures were developed to obtain purified mCP and CR on a bulk scale in order to supply the oceanographic research community with the indicators. Easy access to the purified indicators ensures global intercomparability of spectrophotometric pH determinations.
Internal consistency of marine inorganic carbon system measurements was studied using datasets obtained on two large coastal ocean acidification research cruises. In both cases, purified mCP was used to obtain the pH measurements, thereby improving accuracy relative to previous studies in which measurements were obtained with unrefined mCP. Based on this internal consistency study, recommendations are made for selecting the parameter pairs used for saturation state calculations.
Direct spectrophotometric methods for measuring carbonate ion concentrations in seawater were improved by (a) using a higher concentration of lead as the carbonate indicator and (b) altering the carbonate computational algorithm based on high quality field data. Measurements of DIC and pH (using purified mCP) were used to calculate carbonate ion concentrations for comparison with spectrophotometrically measured carbonate ion concentrations (i.e., via spectrophotometric measurements of Pb(II) spectra in the ultraviolet). Minor changes in the computational algorithm substantially improved agreement between measured and calculated carbonate ion concentrations.
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Etudes de systèmes organométalliques et biologiques par des méthodes hybrides mécanique quantique/mécanique moléculaireRetegan, Marius 27 February 2009 (has links) (PDF)
Ces dernières années, les méthodes hybrides QM/MM combinant la mécanique quantique (QM) et la mécanique moléculaire (MM) se sont revélées des méthodes de choix pour l'étude de systèmes chimiques et biochimiques contenant plus d'une centaine d'atomes. Nous avons mis en évidence les apports et difficultés liés à leur utilisation à travers des systèmes variés: modélisation de ligands phosphines, réactivité d'une protéine de type acide phosphatase pourpre, modélisation de l'interaction protéine-ligand.
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Biological Hydrogen Production By Using Co-cultures Of Pns BacteriaBaysal, Gorkem 01 October 2012 (has links) (PDF)
Biological hydrogen production is a renewable, carbon-neutral and clean route for hydrogen production. Purple non-sulfur (PNS) bacteria have the ability to produce biohydrogen via photofermentation process. The type of the bacterial strain used in photofermentation is known to have an important effect on hydrogen yield. In this study, the effect of different co-cultures of PNS bacteria on photofermentation process was investigated in search of improving the hydrogen yield.
For this purpose, growth, hydrogen production and substrate utilization of single and co-cultures of different PNS bacteria (R. capsulatus (DSM 1710), R. capsulatus hup-
v
(YO3), R. palustris (DSM 127) and R. sphaeroides O.U.001 (DSM 5864)) were compared on artificial H2 production medium in 150 mL photobioreactors under continuous illumination and anaerobic conditions.
In general, higher hydrogen yields were obtained via co-cultivation of two different PNS bacteria when compared with single cultures. Further increase in hydrogen yield was observed with co-cultivation of three different PNS bacteria.
Co-cultures of two different PNS bacteria have resulted in up to 1.4 and 2.1 fold increase in hydrogen yield and hydrogen productivity.
Whereas co-cultures of three different PNS bacteria have resulted in up to 1.6 and 2.0 fold increase in hydrogen yield and hydrogen productivity compared to single cultures.
These results indicate that, defined co-cultures of PNS bacteria produce hydrogen at a higher yield and productivity, due most probably to some synergistic relationship. Further studies regarding the physiological and molecular changes need to be carried out for deeper understanding of the mechanism of hydrogen production in co-cultures.
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Surveillance and Rebellion : A Foucauldian Reading of Chimamanda Ngozi Adichie’s Purple HibiscusLarsson, Charlotte January 2013 (has links)
In Purple Hibiscus, Adichie describes what happens in a family when one person, Papa Eugene, takes control and completely subjugates other family members to his wishes and demands. The author shows the dire consequences his actions have on his family but also how those actions ultimately lead to his own destruction. This essay links the restrictions and abuse suffered by Kambili and her family to Michel Foucault’s theories on torture and surveillance as detailed in Discipline and Punish. Foucault’s theories are linked to Jeremy Bentham’s Panopticon in order to further introduce the concept of surveillance. The essay describes the physical and psychological abuse suffered by the family and also details the surveillance and torture techniques used by Papa Eugene to stay in control. Moreover, it argues that power can be lost through applying too much control and by metering out punishment that is too harsh and it shows how such actions ultimately lead to rebellion.
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Computational Methods to Study Diversification in Pathogens, and Invertebrate and Vertebrate Immune SystemsMunshaw, Supriya Shaunak January 2010 (has links)
<p>Pathogens and host immune systems use strikingly similar methods of diversification. Mechanisms such as point mutations and recombination help pathogens escape the host immune system and similar mechanisms help the host immune system attack rapidly evolving pathogens. Understanding the interplay between pathogen and immune system evolution is crucial to effective drug and vaccine development. In this thesis we employ various computational methods to study diversification in a pathogen, an invertebrate and a vertebrate immune system.</p>
<p>First, we develop a technique for phylogenetic inference in the presence of recombination based on the principle of minimum description length, which assigns a cost-the description length-to each network topology given the observed sequence data. We show that the method performs well on simulated data and demonstrate its application on HIV <italic>env</italic> gene sequence data from 8 human subjects.</p>
<p>Next, we demonstrate via phylogenetic analysis that the evolution of repeats in an immune-related gene family in <italic>Strongylocentrotus purpuratus</italic> is the result of recombination and duplication and/or deletion. These results support the evidence suggesting that invertebrate immune systems are highly complex and may employ similar mechanisms for diversification as higher vertebrates.</p>
<p>Third, we develop a probabilistic model of the immunoglobulin (Ig) rearrangement process and a Bayesian method for estimating posterior probabilities for the comparison of multiple plausible rearrangements. We validate the software using various datasets and in all tests, SoDA2 performed better than other available software.</p>
<p>Finally, we characterize the somatic population genetics of the nucleotide sequences of >1000 recombinant Ig pairs derived from the blood of 5 acute HIV-1 infected (AHI) subjects. We found that the Ig genes from the 20 day AHI PC showed extraordinary clonal relatedness among themselves; a single clone comprised of 52 members, with observed and inferred precursor antibodies specific for HIV-1 Env gp41. Antibodies from AHI patients show a decreased CDR3H length and an increased mutation frequency when compared to influenza vaccinated individuals. The high mutation frequency is coupled with a comparatively low synonymous to non-synonymous mutation ratio in the heavy chain. Our results may suggest presence of positive antigenic selection in previously triggered non-HIV-1 memory B cells in AHI.</p>
<p>Taken together, the studies presented in this thesis provide methods to study diversification in pathogens, and invertebrate and vertebrate immune systems.</p> / Dissertation
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Photobiological Hydrogen Production From Sugar Beet MolassesSagir, Emrah 01 February 2012 (has links) (PDF)
The main aim of this study was to investigate biological hydrogen production from sucrose and molasses by purple non-sulphur bacteria (PNS). The hydrogen production capacities of four different PNS bacteria (Rhodobacter capsulatus (DSM 1710), Rhodobacter capsulatus YO3 (Hup-), Rhodopseudomonas palustris (DSM 127) and Rhodobacter sphaeroides O.U.001 (DSM 5864)) were tested on sucrose and molasses. The photobiological hydrogen production were performed in 50 ml and 150 ml small scale photobioreactors, in batch mode. The produced hydrogen quantities, bacterial growth profiles and pH of the media were recorded through the
photobiological hydrogen production processes. Organic acids and sucrose consumption rates were determined by HPLC during the experiments. The maximum hydrogen productivitiy of 0.78 (mmol/lc.h) and 0.55 (mmol/lc.h) was obtained by R. palustris (DSM 127) on sucrose and molasses, respectively. Secondly, co-cultivation of these bacterial strains was studied. The maximum hydrogen productivity by co-cultivation of R. sphaeroides O.U.001 (DSM 5864) and R. palustris (DSM 127) was found as 1.0 (mmol/lc.h).
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Invasive species and compensatory wetland mitigation successEhorn, Casey H. January 2006 (has links) (PDF)
Thesis (M.E.S.)--The Evergreen State College, 2006. / Title from title screen (viewed 3/11/2010). Includes bibliographical references (leaves 41-53).
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