7 resultados para Modalities of representation

em Digital Commons at Florida International University


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Hyperthermia is usually used at a sub-lethal level in cancer treatment to potentiate the effects of chemotherapy. The purpose of this study is to investigate the role of heating rate in achieving synergistic cell killing by chemotherapy and hyperthermia. For this purpose, in vitro cell culture experiments with a uterine cancer cell line (MES-SA) and its multidrug resistant (MDR) variant MES-SA/Dx5 were conducted. The cytotoxicity, mode of cell death, induction of thermal tolerance and P-gp mediated MDR following the two different modes of heating were studied. Doxorubicin (DOX) was used as the chemotherapy drug. Indocyanine green (ICG), which absorbs near infrared light at 808nm (ideal for tissue penetration), was chosen for achieving rapid rate hyperthermia. A slow rate hyperthermia was provided by a cell culture incubator. The results show that the potentiating effect of hyperthermia to chemotherapy can be maximized by increasing the rate of heating as evident by the results from the cytotoxicity assay. When delivered at the same thermal dose, a rapid increase in temperature from 37°C to 43°C caused more cell membrane damage than gradually heating the cells from 37°C to 43°C and thus allowed for more intracellular accumulation of the chemotherapeutic agents. Different modes of cell death are observed by the two hyperthermia delivery methods. The rapid rate laser-ICG hyperthermia @ 43°C caused cell necrosis whereas the slow rate incubator hyperthermia @ 43°C induced very mild apoptosis. At 43°C a positive correlation between thermal tolerance and the length of hyperthermia exposure is identified. This study shows that by increasing the rate of heating, less thermal dose is needed in order to overcome P-gp mediated MDR.

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The reinforcing effects of diverse tactile stimuli were examined in this study. The study had two purposes. First, this study expanded on the Pelaez-Nogueras, Field, Gewirtz, Cigales, Gonzalez, Sanchez and Clasky (1997) finding that stroking increases infants' gaze duration, and smiling and vocalization frequencies more than tickling/poking. Instead of presenting poking and tickling as a single stimulus combination, this study separated poking and tickling in order to measure the effects of each component separately. Further, the effects of poking, tickling/tapping and stroking intensity (i.e., tactile pressure) were compared by having both mild and intense conditions. Second, this study compared the reinforcing efficacy of mother-delivered tactile stimulation to that of infant-originated tactile exploration. Twelve infants from 2- to 5-months of age participated in this study. The experiment was conducted using a repeated measures A-B-A-C-A-D reversal design. The A phases signified baselines and reversals. The B, C, and D phases consisted of alternating treatments (either mild stroking vs. mild poking vs. mild tickling/tapping, intense stroking vs. intense poking vs. intense tickling/tapping, or mother-delivered tactile stimulation vs. infant-originated tactile exploration). Three experimental hypotheses were assessed: (1) infant leg kick rate would be greater when it produced stroking or tickling/tapping (presumptive positive reinforcers), than when it produced poking (a possible punisher), regardless of tactile pressure; (2) infant leg kick rate would be greater when it produced a more intense level of stroking or tickling/tapping and lower when it produced intense poking compared to mild poking; (3) infant leg-kick rate would be greater for mother-delivered tactile stimulation than for infant-originated tactile exploration. Visual inspection and inferential statistical methods were used to analyze the results. The data supported the first two hypotheses. Mixed support emerged for the third hypothesis. This study made several important contributions to the field of psychology. First, this was the first study to quantify the pressure of tactile stimulation, via a pressure meter developed by the researcher. Additionally, the results of this study yielded valuable information about the effects of different modalities of touch. ^

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Majority of the microbial activity in humans is in the form of biofilms i.e. an Exopolysaccharide-enclosed bacterial mass. Unlike planktonic cells and the cells on the surface of the biofilm, the biofilm-embedded cells are more resistant to the effects of the antibiotics and the host cellular defense mechanisms. A combination of biofilm growth and inherent resistance prevents effective antibiotics treatment of Pseudomonas aeruginosa infections including those in patients with cystic fibrosis. This has lead to an increasing interest in alternative modalities of treatment. Thus, phages that multiply in situ, only in the presence of susceptible hosts can be used as natural, self-limiting, and deeply penetrating antibacterial agents. The objective of this study is to identify effective phages against a collection of P. aeruginosa isolates (PCOR strains) including the prototype PAOl and the isogenic constitutively alginate-producing PD0300 strains.These PCOR strains were tested against six phages (P105, P134, P140, P168, P175B and P182). Analysis shows 69 % of the PCOR isolates are sensitive and the rest are resistant to all six phages. These phages were then tested for their ability to inhibit biofilm formation using a modified biofilm assay. The analysis demonstrated that the sensitive strains showed increased resistance but none of the sensitive strains from the initial screening were resistant. Using the minimum biofilm eradication concentration (MBEC) assay for biofilm formation, the biofilm eradication ability of the phages was tested. The data showed that a higher volume of phage was required to eradicate preformed biofilms than the volume required to prevent colonization of planktonic cells. This data supports the idea of phage therapy more as a prophylactic treatment.

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Many U.S. students do not perform well on mathematics assessments with respect to algebra topics such as linear functions, a building-block for other functions. Poor achievement of U.S. middle school students in this topic is a problem. U.S. eighth graders have had average mathematics scores on international comparison tests such as Third International Mathematics Science Study, later known as Trends in Mathematics and Science Study, (TIMSS)-1995, -99, -03, while Singapore students have had highest average scores. U.S. eighth grade average mathematics scores improved on TIMMS-2007 and held steady onTIMMS-2011. Results from national assessments, PISA 2009 and 2012 and National Assessment of Educational Progress of 2007, 2009, and 2013, showed a lack of proficiency in algebra. Results of curriculum studies involving nations in TIMSS suggest that elementary textbooks in high-scoring countries were different than elementary textbooks and middle grades texts were different with respect to general features in the U.S. The purpose of this study was to compare treatments of linear functions in Singapore and U.S. middle grades mathematics textbooks. Results revealed features currently in textbooks. Findings should be valuable to constituencies who wish to improve U.S. mathematics achievement. Portions of eight Singapore and nine U.S. middle school student texts pertaining to linear functions were compared with respect to 22 features in three categories: (a) background features, (b) general features of problems, and (c) specific characterizations of problem practices, problem-solving competency types, and transfer of representation. Features were coded using a codebook developed by the researcher. Tallies and percentages were reported. Welch's t-tests and chi-square tests were used, respectively, to determine whether texts differed significantly for the features and if codes were independent of country. U.S. and Singapore textbooks differed in page appearance and number of pages, problems, and images. Texts were similar in problem appearance. Differences in problems related to assessment of conceptual learning. U.S. texts contained more problems requiring (a) use of definitions, (b) single computation, (c) interpreting, and (d) multiple responses. These differences may stem from cultural differences seen in attitudes toward education. Future studies should focus on density of page, spiral approach, and multiple response problems.

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From the multitudinous streets of Mexico City through the lonely highways of the United States, this collection of poetry charts strategies of representation across complex territories of culture and gender. These poems represent dialogues and negotiations with popular and poetic narratives of the Americas, as well as individual quests for identification against a backdrop of postmodern and postcolonial concerns. The effect is like that of a collage that elicits the reader's participation in order to produce individual signification. The figures alluded to in these pieces enact the struggle to situate the self within multiple registers of discourse and identity, as well as to establish a site from which to speak.

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This dissertation examines the discursive practice of Argentine costumbrista texts from a novel perspective. In (re)reading the works of selected prominent writers from the late colonial period to the end of the Nineteenth Century, including those of Alonso Carrió de la Vandera, Emeric Essex Vidal, León Pallière, Lucio Vicente López, Lucio V. Mansilla, and Pastor Obligado we focus on the presence of ekphrastic enunciations with a view toward linking the plastic, painterly dimensions of the prose to parallel representations by artists of the same period. Thus the costumbristas are studied in tandem with the watercolors, oil paintings and lithographic compositions of artists such as Carlos Enrique Pellegrim, César Hipólito Bacle, Raymond Monvoisin and Hipólito Moulin. The resulting comparative study of the two arts---the verbal and the pictorial---illustrates the notion described by W. J. T. Mitchell that a literary text may well "represent a work of visual or graphic art." And thus, it provides us with visual, spatial motifs that enhance its powers of representation. ^ In developing our focus on ekphrastic representations we have followed the theoretic studies of Murray Krieger, Jean H. Hagstrum, James Hefferman, John Hollander, W. J. T. Mitchell, Johann Gottfried Herder, and Wendy Steiner among others, all of whom in various ways take their cue from Horace's Ut pictura poesis and the notion that poetry, that is literary discourse, can be likened to a panting and that in both arts there is a refractive quality that makes literature a spoken vehicle of expression and painting a silent, complementary voice. ^ In studying the literary and plastic discourses comparatively what becomes evident is that they share cultural and ideological concerns that center around the notion of self-definition, national identity, and the relation of the individual to the incipient national community (Benedict Anderson). These concerns are highlighted via the depiction of customs, mores, dress, work habits, professions, and social classes. In late colonial literature and painting and especially in the Nineteenth Century, which constitutes the defining period of Argentine political independence, the confluence of the two disciplinary discourses addresses, and underscores the issues of socio-political empowerment in the new Argentine nation. ^

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The purpose of this dissertation is to investigate the reasons for the under-representation of women in politics in Lebanon, and the role of international norms of gender equality in bringing about change. For those questions, I examined the particular relevance of confessionalism arguing that a confessional social structure and political system empower patriarchal forms of organization with detrimental effects to women's political participation. This dissertation makes innovative contributions to two types of literature. First, literature on the barriers to women being elected into political office has put strong emphasis on electoral systems of representation, but has rarely addressed the way in which electoral systems that seek to ensure minority representation – such as the confessional system in Lebanon – operate to keep women out of politics. This study provides an important corrective to this literature by exploring a non-Western case and broadening theorizing on the issue. Second, constructivist literature in the field of International Relations has argued that international norms of gender equality – including gender quotas – have diffused throughout the 20th century. This research illustrates the mechanisms that counteract international diffusion, and adds to our understanding of how international norms are translated into domestic contexts.