Orientador: Carlos Alberto Vogt / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Estudos da Linguagem / Made available in DSpace on 2018-08-20T01:42:51Z (GMT). No. of bitstreams: 1 Antenor_Samuel_M.pdf: 885883 bytes, checksum: 3e5b1d6900e0337ab0e2cc9dab068a00 (MD5) Previous issue date: 2012 / Resumo: O presente trabalho tem por objetivo investigar o papel da interatividade na constituição de um modelo de percepção pública da ciência e da tecnologia (C&T), com vistas a uma análise da divulgação científica da saúde em mídias digitais. Para tanto, partimos do pressuposto de que os usuários dessas mídias, valendo-se de recursos que considerem a troca de informações e a interação entre diferentes agentes, mediada por recursos tecnológicos como a Internet, possam tomar parte na constituição de um modelo participativo de divulgação científica, com a ampla partilha de conteúdos científico-culturais. Como metodologia, buscamos estudar um caso específico de divulgação científica da saúde via Internet, com base no conceito de Cultura Científica, o qual considera o percurso que envolve o desenvolvimento científico como um processo cultural, do ponto de vista de sua produção, da difusão entre pares, do ensino e da educação, ou ainda de sua divulgação na sociedade. Nesse sentido, como primeira hipótese, pensamos que a divulgação científica via Internet poderia permitir a adoção de uma posição que considerasse a participação dos cidadãos nesse processo, de modo a tornar possível a troca de informações em diferentes esferas de espaço-tempo e de forma multidirecional. Por conseguinte, nossa escolha investigativa difere dos estudos sobre comunicação pública da ciência que definiram esse enfoque como modelo de déficit, o qual pressupõe o conhecimento como parte do domínio dos que fazem ciência e a aplicam, limitando a maneira como essas informações chegam ao público ? hierarquicamente e numa única direção ?, conjugando uma suposta superioridade de quem detém o conhecimento científico com a suposta incapacidade ou limitação de compreensão e interpretação das demais pessoas. Em nossa segunda hipótese, pensamos que, na medida em que se abandone a noção de déficit de conhecimento, poder-se-ia promover não só a participação e a interatividade entre as várias esferas da sociedade, mas também uma profunda reflexão da parte de todos os envolvidos com a produção e divulgação científicas. Para tanto, buscamos analisar se ? e em que medida ? esta participação permite que os cidadãos usuários das mídias digitais "interajam" não apenas com instâncias diversas, mas também entre si; se essa participação contribui ou não para o processamento crítico de informações; e se pode ou não reorientar os processos comunicacionais. Para desenvolver nosso trabalho, dividimos o texto em cinco partes, compostas por quatro capítulos e uma conclusão. Na primeira parte, buscaremos tratar, em linhas gerais, do campo da percepção pública da ciência e da tecnologia, discorrendo sobre os modelos de percepção, estabelecendo contrapontos entre o modelo de déficit e o modelo participativo, a partir de pressupostos metodológicos da Cultura Científica, com base em autores como Carlos Vogt e Carmelo Polino. Na segunda parte, buscaremos discutir um ideal filosófico para a área, o qual teria na crítica ao positivismo, feita por Walter Benjamin, as bases de uma possível crítica que o modelo participativo dirige ao cientificismo. Em nossa terceira parte, propomos discutir o papel da interatividade na constituição dos modelos de percepção, para o que trabalharemos com a visão de Marshall Mcluhan, sobre os meios de comunicação como extensões do homem, e de Pierre Lévy, sobre virtualidade e ciberespaço. Para tanto, buscaremos exemplificar e discutir, na quarta parte desta dissertação, mecanismos e experiências de divulgação científica dos temas da saúde via Internet, mais especificamente em um recorte sobre questões retratadas pelo Canal Saúde, da Fundação Oswaldo Cruz (Fiocruz). Por fim, uma quinta parte fecha o trabalho, com as principais conclusões a que chegamos durante nossa pesquisa de Mestrado / Abstract: This study aims to investigate the role of interactivity in building a model of public perception of science and technology (S&T), with a view to an analysis of scientific health in digital media. For this purpose, we assume that users of these media, using resources that consider the exchange of information and interaction between different agents, mediated by technological resources like the Internet, can take part in the establishment of a participatory model of scientific with wide sharing of scientific and cultural content. As a methodology, we study a specific case of scientific health in the Internet, based on the concept of scientific culture, which considers the route that involves the scientific development as a cultural process, in terms of its production, dissemination peer, teaching, education and outreach in society. In this sense, in a first hypothesis, we think science communication in the Internet could allow the adoption of a position to consider the participation of citizens in this process in order to make possible the exchange of information in different spheres of space-time and in a multidirectional form. Therefore, our choice differs from investigative studies of public communication of science that defined this approach as a deficit model, which assumes knowledge as part of the field of science and apply that are limiting the way that information reach the public, combining supposed superiority of one who has the scientific knowledge with the alleged incapacity or limitation of understanding and interpretation of others. As a second hypothesis, we think, in that it abandons the notion of lack of knowledge, we would not only promote the participation and interactivity between the various spheres of society, but also a reflection on the part of everyone involved with the production and dissemination of science. For this, we examine whether - and to what extent - this participation enables citizens of digital media users "interact" with not only several instances, but also among themselves; if such participation will contribute or not to process critical information; and whether you can redirect the communication processes. To develop our work, we divide the text into five parts, consisting of four chapters and a conclusion. In the first part, we try to treat the field of public perception of science and technology, discussing models of perception, providing counterpoints between the deficit model and the participatory model, from the methodological assumptions of Scientific Culture, based on authors such as Carlos Vogt and Carmelo Polino. In the second part, we try to discuss a philosophical ideal for the area, which would have the critique of positivism, made by Walter Benjamin, the groundwork for a possible criticism that the participatory model runs to scientism. In our third part, we propose to discuss the role of interactivity in the constitution of perception models, for which work with the vision of Marshall McLuhan on the media as extensions of man, and Pierre Lévy on virtuality and cyberspace. For this, we will seek to exemplify and discuss, in the fourth part of this thesis, mechanisms and experiences of scientific disclosure of health issues in the Internet, a clipping issues portrayed by Canal Saúde, an IPTV produced by Fundação Oswaldo Cruz (Fiocruz). Finally, a fifth part closes this work with the main conclusions reached during our master research / Mestrado / Divulgação Científica e Cultural / Mestre em Divulgação Científica e Cultural

Stallgödsel består av spillning, gödselvatten, urin och strömaterial. Miljö- och hälsoskadliga ämnen kan också förekomma i form av antibiotikarester eller patogener. Det är därför viktigt att gödselhanteringen sköts på korrekt sätt för att undvika att de skadliga ämnena vållar miljö- och hälsoproblem. Naturliga ämnen som kväve och fosfor förekommer också i stallgödsel bidrar till miljöeffekter som övergödning eller försurning vid felaktig gödselhantering. Miljöeffekterna drabbar i sin tur ekosystem och de konsekvenser som uppstår är bland andra fiskdöd och giftalgblomningar i vattendrag. Examensarbetet kommer att belysa de ekologiska och sociala fördelarna som Kolmården skulle kunna erhålla om de byter gödselhanteringssystem från gödselspridning till rötning. Dessutom kommer Kolmårdens nuvarande stallgödselhantering att beskrivas, aspekter som kan påverka biogaspotentialen att presenteras och den teoretiska mängden biogas som kan utvinnas ur stallgödseln att beräknas. Det första som genomfördes i examensarbetet var att dela in Kolmårdens djur i olika djurgrupper för att kunna utföra beräkningar på biogaspotentialen. Totalt tre djurgrupper figurerar i examensarbetet och de är: fågel, icke-idisslare och idisslare samt allätare och rovdjur När djuruppdelningen var slutförd påbörjades litteraturstudien för att få fram aktuellt material att använda i studien och förbereda de intervjufrågor som sedan användes i samband med ett studiebesök på Kolmården. Stallgödseln som uppkommer i djurparken mockas från djurens hägn och stall varje dag för att sedan lagras på mindre gödselplattor. Dessa töms sedan tre gånger i veckan av entreprenörer som fraktar stallgödseln till en central gödselplatta innan den sprids på arrenderad mark eller överförs till en lantbruksentreprenör. Stallgödseln på Kolmården har teoretisk sett en potential att kunna täcka nära hälften av djurparkens årliga energibehov. Aspekter som påverkar biogasutbytet är föda, strömaterial, näringsinnehåll och antibiotika. / Manure consist of feces, manure water, urine and stray material. Environmental and health harmful substances can also occur in manure. That is why it is important that the manure management is handled in a correct way to avoid the harmful substances that are likely to cause environmental and health problems. Natural substances are also a part of the manure and those are nitrogen and phosphorus and they could cause environmental effects as eutrophication and acidification with insufficient manure management. The environmental effects could affect ecosystems and the consequences could appear as that fishes are dying and poisonous algal blooms in watercourses. The bachelor thesis will illustrate the ecological and social benefits that Kolmården could achieve if they are replacing the current manure management which is manure spreading with anaerobic digestion. Besides that the current manure management will be described in more depth, aspects that could affect the biogas potential will be presented and the theoretical amount of biogas of the manure will be calculated. The first step that was completed in the thesis were to divide Kolmården’s animals into different animal groups that later could be used in the calculations of the biogas potential. Totally there are three animal groups in this thesis and they are: fowl, non-ruminant and omnivore and beast of prey. When dividing the animals was completed the search for literature began with the purpose to get up-to-date material that could be used in the thesis and to prepare the interview questions for the study visit at Kolmården. The amount of manure that emerge in the zoo is mucked from the animal’s pens and stables every day to be stored in small manure storage places. Those are emptied three times a week and freighted to a central storage place before the manure is spread on tenancy land or transferred to a farmer. The theoretical biogas potential from the manure at Kolmården can cover almost half of the energy need in a year. Aspects as food, straw material, nutrition content and antibiotics can affect the biogas yield.

Abstract Multicarrier and multiple input–multiple output (MIMO) techniques have become popular in wireless communications over multipath fading channels in recent years. This thesis firstly considers the characterization and simulation of fading mobile radio channels for MIMO multicarrier systems. Secondly, the performance of spread-spectrum multicarrier (MC) code-division multiple-access (CDMA) with multirate transmission is analyzed. Thirdly, the analysis is applied to ultra-wideband (UWB) orthogonal frequency-division multiplexing (OFDM) systems enhanced with frequency-domain code-division multiplexing (CDM). The response of a small-scale fading channel is derived as a function of time, transmit and receive antenna positions, and subcarrier frequency, which leads to a tapped delay-line model with time-, space-, and frequency-selective taps. The taps are modeled as a sum of a deterministic line-of-sight or dominant scattered path and a zero-mean Gaussian part composed of a number of unresolvable scattered paths and, therefore, are Rice fading. The Gaussian parts have the desired temporal and spatiospectral correlations generated by time-correlation shaping filtering and a space-frequency correlation transformation, respectively. The simulator achieves a good accuracy while retaining a reasonable computational complexity. The generic performance analysis of MC-CDMA includes both the multicode and variable spreading factor (VSF) multirate schemes that are inherent for CDMA and capable of providing efficient support for services of different required data rates. The analysis also takes into account the intersymbol interference caused by the multipath delay components exceeding a guard interval, which is commonly omitted in the literature by assuming the guard interval to be longer than the maximum delay spread. Results comparing and pointing out notable differences in the error rate performance of the two multirate schemes in conjunction with six different combining techniques are presented for a synchronous downlink and both a synchronous and asynchronous uplink. The analysis of CDM-enhanced OFDM-UWB involves first a single piconet with different combinations of the VSF and multicode schemes. Frequency-domain spreading is found to improve the performance remarkably when a sufficient spreading factor and a suitable subcarrier combining method are used. Subsequently, CDMA of simultaneously operating piconets (SOPs) with either the VSF or multicode scheme is considered. While both multirate schemes result in a similar performance when the number of SOPs is large, notable differences arise when there are only a few SOPs.

Mechanisms of thyristor turn-on wore studied. An attempt was made to relate the ‘on’ plasma spreading velocity to the small signal current gain value of the n-p-n transistor section of the thyristor. The extent to which the thyristor turns on initially largely affects the speed of turning-on the device. A model is proposed to calculate the initial turned-on area of thyristors.

Social media is a big part of today’s society. But how do we know where the information we put out on the internet end up? This bachelor thesis is part of a bigger project where first year students at the cognitive science program at Linköping University will be taught about modeling of a social phenomenon. A lot can be learned about a phenomenon through modeling and simulation and that was the motivation for this bachelor thesis – to try to make a simulation of the spreading of information on social media. The social media platform that was selected was Twitter and the information spreading was narrowed down to retweeting of a tweet. The simulation was implemented in NetLogo – a modeling and simulation program. The simulation was based on important factors that contribute to a person’s willingness to retweet. The factors were found in published research reports. The result was a simulation of retweeting on Twitter that in some aspects resemble the real world phenomenon as it is depicted in published research reports. Towards the end of the report there is a discussion about what factors contributed to the resemblance or the difference between the world depicted in the published research reports and the simulation.

Ce travail de thèse s’inscrit dans la problématique générale du projet ECODEFI - ECOconception et Développement de méthodologies de Fabrication Innovante de machines d’épandage financé par l’Agence Nationale de la Recherche (ANR) dans le cadre du PRogramme ECOtechnologies et Développement Durable (PRECODD). Le projet ECODEFI porte sur l’écoconception et l’éco-innovation appliquées aux technologies de l’épandage, pour répondre à deux enjeux majeurs : (i) le recyclage des effluents organiques issus de l’industrie et de l’épuration des eaux et (ii) réduire à la source les risques de pollution des agro-écosystèmes. Face au besoin de prise en compte de l’environnement dans le développement des machines d’épandage, nous avons proposé une démarche d’éco-innovation qui permet d’aboutir à des véritables percées technologiques. Cette approche présente une synergie entre l’Analyse du Cycle de Vie (ACV), la matrice de non-qualité, la Théorie de Résolution des Problèmes Inventifs (TRIZ), l’analyse morphologique et le Processus d’Analyse Hiérarchique (Analytical Hierarchy Process – AHP). Dans l’enchaînement de ces outils, l’ACV évalue les impacts environnementaux générés par le système. Puis, pour une meilleure prise en considération des aspects écologiques, nous avons développé un nouvel outil, la matrice de non-qualité, qui définit, à partir des résultats de l’ACV, le problème à résoudre en priorité du point de vue environnemental. La méthode TRIZ permet la génération de nouveaux concepts et la résolution des contradictions. Ensuite, l’analyse morphologique offre la possibilité d’étendre l’espace de recherche des solutions d’un problème de conception de manière systématique. Enfin l’AHP identifie la ou les solution(s) prometteuse(s) en fournissant une logique claire pour les choix réalisés. Dans notre étude, nous nous sommes principalement intéressés aux problèmes rencontrés sur la machine PROLOG lors de la phase d’épandage des produits compostés. En effet, l'épandage du compost se développe fortement et l'entreprise SIRTEC souhaite pouvoir réaliser cette tâche avec leurs machines conçues initialement pour des matériaux granulaires. L’approche a été appliquée pour résoudre le problème d’extraction de ces produits suite à la formation de voûtes à l’intérieur de la trémie de l’épandeur. / This thesis is part of the ECODEFI project (ECOconception et DEveloppement de méthodologies de Fabrication Innovante de machines d’épandage – Ecodesign and development of innovative production methods of spreading machines) funded by the French National Research Agency within the framework of Eco-technologies and sustainable development programme (PRECODD) The ECODEFI project focuses on ecodesign and eco-innovation applied to spreading technologies, to address two major issues : (i) recycling of organic waste from industry and sewage and (ii) reducing the source of pollution risk of agro-ecosystems. Facing the need to take into account the environment in developing spreading machines, we proposed an eco-innovation design approach that can lead to real breakthroughs. This approach provides a synergy between the LCA, the non-quality matrix, TRIZ method, the morphological analysis and the AHP. In the sequence of these tools, LCA (Life Cycle Assessment) assesses the environmental impacts generated by the system. Then, for a better consideration of environmental aspects, we developed a new tool, the non-quality matrix, which defines the problem requiring solving first from an environmental point of view, from the LCA results. The TRIZ method allows the generation of new concepts and contradiction resolution. Then, the morphological analysis offers the possibility of extending the search space of solutions of a design problem in a systematic way. Finally, the AHP (Analytical Hierarchy Process) identifies the promising solution(s) by providing a clear logic for the choice made. In our study, we are mainly interested in problems on the PROLOG machine during the phase of composted products application. Indeed, compost application is strongly growing and the SIRTEC Company hopes to accomplish this task with their machines which were initially designed for granular materials. The approach has been applied to solve the problem of extraction of these products due to the formation of arches inside the spreader hopper.

The cell differentiation process is associated with activation and repression of different genes, whereby the formation of heterochromatin is mediated by spreading of repressor proteins along large chromatin domains. Some of these proteins are methyltransferases, including GLP and G9a that are implicated in the addition of mono- and dimethyl groups to lysine 9 at Histone 3. Despite extensive research the exact mechanism of binding and spreading of G9a and GLP is unclear. To better understand the molecular mechanisms through which G9a and GLP bind to chromatin we tested the in vivo binding of a mutant G9a that is unable to bind to H3K9me2 histone marks via its Ankyrin domain. Murine erythroleukemia (MEL) cell line with expression of mutant G9a was generated using recombinant DNA technologies; G9a binding targets genome-wide were detected by the analysis of ChIP-sequencing data. We validated ChIP-sequencing data providing a reliable tool to visualize G9a targets in MEL cells. We also found that G9a Ankyrin mutant bound to all tested regions suggesting that the Ankyrin domain is not the only factor that contributes to the binding of G9a on chromatin in vivo.

The complex network theory has been extensively used to understand various natural and artificial phenomena made of interconnected parts. This representation enables the study of dynamical processes running on complex systems, such as epidemics and rumor spreading. The evolution of these dynamical processes is influenced by the organization of the network. The size of some real world networks makes it prohibitive to analyse the whole network computationally. Thus it is necessary to represent it by a set of topological measures or to reduce its size by means of sampling. In addition, most networks are samples of a larger networks whose structure may not be captured and thus, need to be inferred from samples. In this work, we study both problems: the influence of the structure of the network in spreading processes and the effects of sampling in the structure of the network. Our results suggest that it is possible to predict the final fraction of infected individuals and the final fraction of individuals that came across a rumor by modeling them with a beta regression model and using topological measures as regressors. The most influential measure in both cases is the average search information, that quantifies the ease or difficulty to navigate through a network. We have also shown that the structure of a sampled network differs from the original network and that the type of change depends on the sampling method. Finally, we apply four sampling methods to study the behaviour of the epidemic threshold of a network when sampled with different sampling rates and found out that the breadth-first search sampling is most appropriate method to estimate the epidemic threshold among the studied ones. / Vários fenômenos naturais e artificiais compostos de partes interconectadas vem sendo estudados pela teoria de redes complexas. Tal representação permite o estudo de processos dinâmicos que ocorrem em redes complexas, tais como propagação de epidemias e rumores. A evolução destes processos é influenciada pela organização das conexões da rede. O tamanho das redes do mundo real torna a análise da rede inteira computacionalmente proibitiva. Portanto, torna-se necessário representá-la com medidas topológicas ou amostrá-la para reduzir seu tamanho. Além disso, muitas redes são amostras de redes maiores cuja estrutura é difícil de ser capturada e deve ser inferida de amostras. Neste trabalho, ambos os problemas são estudados: a influência da estrutura da rede em processos de propagação e os efeitos da amostragem na estrutura da rede. Os resultados obtidos sugerem que é possível predizer o tamanho da epidemia ou do rumor com base em um modelo de regressão beta com dispersão variável, usando medidas topológicas como regressores. A medida mais influente em ambas as dinâmicas é a informação de busca média, que quantifica a facilidade com que se navega em uma rede. Também é mostrado que a estrutura de uma rede amostrada difere da original e que o tipo de mudança depende do método de amostragem utilizado. Por fim, quatro métodos de amostragem foram aplicados para estudar o comportamento do limiar epidêmico de uma rede quando amostrada com diferentes taxas de amostragem. Os resultados sugerem que a amostragem por busca em largura é a mais adequada para estimar o limiar epidêmico entre os métodos comparados.

A ADAM23 é uma glicoproteína transmembrana pertencente à família ADAM (A Disintegrin and Metalloprotease) que apresenta a estrutura protéica típica dos membros desta família, mas não possui atividade de metaloprotease. O gene ADAM23 apresenta três isoformas de splicing, α, β e γ, que codificam proteínas com porções C-terminais distintas. As isoformas α e β codificam proteínas com domínios transmembranas diferentes, enquanto γ provavelmente consiste em uma isoforma secretada ou citoplasmática de ADAM23. Foi demonstrado que o gene ADAM23 está epigeneticamente silenciado em tumores de mama de estágios mais avançados e que seu silenciamento está associado a um maior risco de desenvolvimento de metástases e a um pior prognóstico. Recentemente, foi descrito que a proteína ADAM23 interage diretamente com a integrina αVβ3 na linhagem tumoral de mama MDA-MB-435, sendo capaz de modular seu estado conformacional, controlando sua ativação. Utilizando RNAi, observou-se que o silenciamento completo do gene ADAM23 (i.e., as três isoformas) aumenta os níveis de αVβ3 em conformação ativa na superfície das células MDA-MB-435, promovendo um incremento de sua capacidade migratória e adesiva. No presente trabalho, avaliamos por reações de amplificação em tempo real o perfil de expressão das três isoformas de splicing do gene ADAM23 em cinco tecidos normais (mama, cólon, cérebro, próstata e pâncreas) e em doze linhagens tumorais derivadas destes tecidos. Observamos diferenças nos níveis de expressão das isoformas em todas as amostras avaliadas, tanto dentro de uma determinada amostra, como quando comparamos tecidos normais entre si ou com linhagens tumorais. A isoforma γ é a mais expressa em todos os tecidos normais (exceto em cérebro) e em todas as linhagens tumorais. Em tecido normal de mama e de próstata e nas doze linhagens tumorais, ADAM23α é a segunda isoforma mais expressa, sendo β a menos expressa. Constatamos também que a fração representada por cada isoforma, em relação à expressão total do gene ADAM23, está alterada nas linhagens tumorais, em comparação aos tecidos normais correspondentes. Com o intuito de elucidar a função das isoformas de ADAM23 separadamente, utilizamos shRNAs (short hairpin RNAs) para reduzir a expressão de cada isoforma de modo individual e específico na linhagem tumoral MDA-MB-435, e avaliamos seu efeito na proliferação, na morfologia, na adesão e no espraiamento celular. Verificamos que a redução da expressão da isoforma γ aumentou significativamente a taxa de proliferação das células MDA-MB-435 cultivadas em modelo tridimensional. Demonstramos também que ADAM23γ participa da regulação da morfologia e da capacidade de espraiamento das células MDA-MB-435 em condições padrão de cultivo (i.e., meio de cultura completo e placas não-sensibilizadas com substratos) e em componentes específicos da matriz extracelular, como fibronectina, colágeno I e matrigel. A isoforma α também está envolvida no controle da morfologia e do espraiamento da linhagem MDA-MB-435, porém, de modo distinto da isoforma γ. Já ADAM23β não interfere na morfologia das células MDA-MB-435 e tem efeito marginal no espraiamento celular apenas em condições padrão de cultivo. Em conjunto, nossos resultados demonstram que as isoformas de ADAM23 são diferencialmente expressas em tecidos normais e tumorais, e exercem funções biológicas distintas. / ADAM23 is a transmembrane glycoprotein that belongs to the ADAM (A Disintegrin and Metalloprotease) family of proteins and exhibits the typical protein structure of the family members, but it doesn\'t have metalloprotease activity. The ADAM23 gene has three splicing isoforms, α, β and γ, that code for proteins with different C-terminal regions. Isoforms α and β code for proteins with different transmembrane domains, while γ probably constitute a secreted or cytoplasmatic isoform of ADAM23. It has been demonstrated that the ADAM23 gene is epigenetically silenced in advanced stage breast tumors and that its silencing is associated with a higher risk of developing metastases and with a worse prognosis. Recently, it was described that ADAM23 protein interacts directly with αVβ3 integrin in the breast tumor cell line MDA-MB-435, modulating its conformational state and controlling its activation. Using RNAi, it was observed that the complete silencing of ADAM23 gene (the three isoforms) raises the levels of αVβ3 in its active conformation in the surface of MDA-MB-435 cells, promoting an increase in its migratory and adhesive capacity. In the present work, we evaluated by real time PCR the expression pattern of the three splicing isoforms of ADAM23 gene in five normal tissues (breast, colon, brain, prostate and pancreas) and in twelve tumor cell lines derived from these tissues. We observed differences in the expression levels of the three isoforms in all samples, either within a specific sample or comparing normal tissues among them or with tumor cell lines. Isoform γ has the highest expression in all normal tissues (except for brain) and in all tumor cell lines evaluated. In breast and prostate normal tissues and in all tumor cell lines, ADAM23α is the second most expressed isoform, while β is the less expressed. We also noticed that the ratio represented by each isoform, relative to the total expression of ADAM23 gene, is altered in the tumor cell lines, compared to the corresponding normal tissues. With the aim to elucidate the function of ADAM23 isoforms separately, we used shRNAs (short hairpin RNAs) to reduce the expression of each isoform specifically in the MDA-MB-435 tumor cell line, and studied its effects in proliferation, morphology, adhesion and cell spreading. We observed that the reduced expression of isoform γ significantly increased the proliferation rate of MDA-MB-435 cells cultivated in tridimensional system. Also, we demonstrated that ADAM23γ participates in the regulation of cell morphology and spreading of MDA-MB-435 cells, both in standard culture conditions (cell culture media with fetal serum and in plates not sensitized with substrates) and in specific components of extracellular matrix, such as fibronectin, collagen type I and matrigel. Isoform α is also involved in the control of morphology and spreading of MDA-MB-435 cell line, although in a distinct manner from isoform γ. ADAM23β doesn\'t interfere in the morphology of MDA-MB-435 cells and plays a discrete role in cell spreading only under standard culture conditions. Together, our results demonstrate that ADAM23 isoforms are differently expressed in normal and tumoral tissue, and play distinct biological roles.

Spreading models have become fundamental to the study of asymptotic geometry in Banach spaces. The existence of spreading models in every Banach space, and the so-called good sequences which generate them, was one of the first applications of Ramsey theory in Banach space theory. We use Ramsey theory and other techniques from infinitary combinatorics to examine some old and new questions concerning spreading models and good sequences. First, we consider the lp spreading model problem which asks whether a Banach space contains lp provided that every spreading model of a normalized block basic sequence of the basis is isometrically equivalent to lp. Next, using the Hindman-Milliken-Taylor theorem, we prove a new stabilization theorem for spreading models which produces a basic sequence all of whose normalized constant coefficient block basic sequences are good. When the resulting basic sequence is semi-normalized, all the spreading models generated by the above good sequences must be uniformly equivalent to lp or c0. Finally, we investigate the assumption that every normalized block tree on a Banach space has a good branch. This turns out to be a very strong assumption and is equivalent to the space being 1-asymptotic lp. We also show that the stronger assumption that every block basic sequence is good is equivalent to the space being stabilized 1-asymptotic lp.