Identidade vs. características da planta hospedeira : o que importa mais para a diversidade funcional de aranhas?

Diversidade taxonômica é a variedade de espécies presentes em uma determinada comunidade, enquanto a diversidade funcional é a variedade de atributos que tem relação com o funcionamento dessa comunidade. Abordagens baseadas exclusivamente na identidade das espécies têm sido complementadas por estudos visando os atributos funcionais das espécies, já que a primeira possui certas limitações em estudos de comunidades. No presente estudo, testamos se a diversidade taxonômica e funcional de aranhas respondia mais significativamente a variação intraespecífica ou interespecífica de atributos de bromélias, sendo estas hospedeiras das espécies de aranhas estudadas. Lançamos mão de um método estatístico que quantifica a beta-diversidade de aranhas em resposta a variação intraespecífica e interespecífica de bromélias. Fizemos também uma decomposição dos atributos de bromélias na sua filogenia a fim de investigar se existia algum nó que contribuía desproporcionalmente para a diversidade de aranhas atual naquele local. Os dados deste estudo foram obtidos em uma área de Floresta Atlântica Neotropical localizada no estado do Espírito Santo, sudeste do Brasil. A diversidade funcional de aranhas foi obtida por meio de atributos relacionados ao uso do hábitat (atributos de resposta), enquanto os atributos das bromélias foram obtidos a partir da possibilidade de uso do hábitat pelas aranhas (atributos de efeito). Buscamos estudos filogenéticos recentes para decompor os atributos das bromélias na filogenia. Utilizamos a contribuição proporcional de variação intraespecífica e interespecífica dos atributos das bromélias como variáveis preditoras da diversidade de aranhas. Nossos resultados mostraram que a variação interespecífica de um dos atributos de bromélias afetou positivamente a diversidade beta de aranhas (P < 0.05), reafirmando a necessidade de se utilizar abordagens que extrapolem a identidade de espécies como medida única ou principal de diversidade.Taxonomic diversity is the variety of species present in a given community, while functional diversity is the variety of attributes that relates to the functioning of that community. Approaches based exclusively on species identity have been complemented by studies aiming at the functional attributes of the species, since the former has certain limitations in studies of Community Ecology. In the present study, we tested whether the taxonomic and functional diversity of spiders responded more significantly to intraspecific or interspecific variation of their host plants, bromeliads. We used a statistical method that quantified beta-diversity of spiders in response to intraspecific and interspecific variation of bromeliads. We also did a decomposition of the bromeliad attributes in the phylogeny in order to investigate if there was any node that contributed disproportionately to the current diversity of spiders. The data of this study were obtained in an area of Neotropical Atlantic Forest located in the state of Espírito Santo, southeastern Brazil. The functional diversity of spiders was obtained through traits related to habitat use (response traits), while the traits of bromeliads were obtained from the possibility of habitat use by spiders (effect traits). We searched recent phylogenetic studies to decompose bromeliad traits into their phylogeny. We used the proportional contribution of intraspecific and interspecific variation of bromeliad traits as predictors of spider diversity. Our results showed that the interspecific variation of one of the bromeliad traits positively affected spider beta diversity (P < 0.05), reinforcing the necessity to use approaches that extrapolate species identity as a single or main measure of diversity

Generic and homophobic bullying in school context

Objetivo: Tendo em conta a reduzida literatura sobre o bullying homofóbico em Portugal, os objetivos deste estudo foram descrever a sua prevalência, comparativamente ao bullying genérico, na perspetiva das vítimas; comparar as diferenças de género e compreender a relação entre o bullying homofóbico e os sentimentos de infelicidade e humilhação e a denúncia por parte das vítimas. Método: Participaram 171 (7º ano), 160 (8º) e 156 (9º) alunos (52.0% feminino e 48.0% masculino), entre os 11 e os 17 anos, aos quais foi aplicado um questionário de autorrelato em formato digital, avaliando-se: género, vitimação, sentimentos infelicidade/humilhação e denúncia. Resultados: Um total de 33.0% dos alunos foram vítimas de bullying genérico, maioritariamente no 8º ano. Rapazes e raparigas registaram índices de vitimação semelhantes. Quanto ao bullying homofóbico, a prevalência aumentou do 7º para o 9º ano e os rapazes apresentaram maior frequência de vitimação comparativamente às raparigas, havendo diferenças estatisticamente significativas no 9º ano. À medida que as situações de vitimação homofóbica aumentam, maior foi o sentimento de infelicidade e humilhação nas vítimas e maior a denúncia. Conclusão: Estes dados reforçam a necessidade de ações e programas de prevenção nas escolas, enquadrados numa perspetiva sistémica, privilegiando a intervenção dos observadores de situações de bullying.Aim: Given the little scientific information about homophobic bullying in Portugal, the purpose of this study was to assess its prevalence, in comparison to generic bullying, from the perspective of the victims; to compare differences related to gender and to understand the association between homophobic bullying and feelings of unhappiness and humiliation and victim’s reporting. Method: A total of 171 (7th grade), 160 (8th) and 156 (9th) students (52.0% female/48.0% male), between 11 and 17 years old, completed a self-report questionnaire in digital format, assessing: gender, victimization, feelings of unhappiness and humiliation and victim’s reporting. Results: Of these students 33.0% were victims of bullying, mostly in the 8th grade. Boys and girls were equally likely to be victims. On the other hand, homophobic bullying situations in school increased from the 7th to the 9th grade and male students were more frequently bullied than females, showing statistically significant differences in the 9th grade. The more frequent the homophobic bullying episodes became, the greater the feelings of unhappiness and humiliation and more frequent the reporting. Conclusion: These findings strengthen the need to promote actions and programs aiming at prevention in schools, from a systemic perspective, emphasizing the intervention of observers of bullying episodes.CIEC - Centro de Investigação em Estudos da Criança, IE, UMinho (UI 317 da FCT), Portugal. Projeto Estratégico UID/CED/00317/2013, financiado através dos Fundos Nacionais da FCT (Fundação para a Ciência e a Tecnologia), cofinanciado pelo Fundo Europeu de Desenvolvimento Regional (FEDER) através do COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) com a referência POCI-01-0145-FEDER-007562info:eu-repo/semantics/publishedVersio

7-ketocholesterol stimulates differentiation of lens epithelial cells

PURPOSE: To establish if oxysterols stimulate differentiation of lens epithelial cells (LEC). METHODS: Primary cultures of lens epithelial cells were incubated with 7-ketocholesterol (7-keto), 25-hydroxycholesterol (25-OH) or cholesterol at 10 microg/ml for 10 days. Cells incubated with 100 ng/ml basic fibroblast growth factor (b-FGF) were used as positive controls for differentiation. The expression of the differentiation marker p57KIP2, proliferation marker PCNA (Proliferating Cell Nuclear Antigen) and fibers specific proteins gamma-crystallin, CP49, MIP26 following treatment with oxysterols was determined by western blot. Differentiation into fiber cells was further confirmed by counting the number of lentoid bodies formed following incubation with 7-keto. RESULTS: LEC incubated with 7-keto presented higher levels of p57KIP2 and showed expression of fiber specific proteins such as MIP26 and CP49, compared to cells incubated with 25-OH or cholesterol. The differentiation marker p57KIP2 increased over time for cells incubated with 7-keto while there was a decline on the amount of the proliferation marker PCNA. The expression of the fiber specific proteins gamma-crystallin, MIP26 and CP49 was detected after 5 days of incubation with 7-keto. Differentiation was accompanied by a seven-fold increase in the number of lentoid bodies formed. CONCLUSIONS: Results show for the first time that 7-keto inhibits proliferation and stimulates differentiation of lens epithelial cells into fiber cells. The presence of 7-keto in the lens may disrupt the highly regulated differentiation program of LEC, compromising normal lens growth and transparenc

High glucose down-regulates intercellular communication in retinal endothelial cells by enhancing degradation of connexin 43 by a proteasome-dependent mechanism

Intercellular communication through gap junctions (GJIC) is most likely relevant to maintaining the integrity of the blood-retinal barrier. In this study, we investigated the mechanism whereby high glucose enhances degradation of connexin 43 (Cx43), thus contributing to a decrease in GJIC. The levels of Cx43 in bovine retinal endothelial cells exposed to high glucose (25 mm) decreased about 50% as compared with controls (5.5 mm glucose). Consistently, the half-life of the protein decreased from 2.3 to 1.9 h. The proteasome inhibitors MG132 and lactacystin prevented the loss of Cx43 induced by high glucose and extended Cx43 half-life. The amount of phosphorylated Cx43 increased in high glucose and after proteasome inhibition. Scrape-loading dye transfer experiments show that high glucose is associated to a decrease of 40% in GJIC. Significantly, this reduction can be reversed by proteasome inhibitors. The decrease in GJIC in cells exposed to high glucose is associated with a loss of Cx43 from the plasma membrane, as demonstrated by immunofluorescence and biotinylation of cell-surface proteins. Results indicate that increased phosphorylation of Cx43 under high glucose is the mechanism targeting Cx43 for degradation by a proteasome-dependent mechanism. Increased degradation of Cx43 and reduction of GJIC in high glucose may be of physiological importance by contributing to endothelial cell dysfunction associated with the breakdown of the blood-retinal barrier in diabetic retinopath

7-Ketocholesterol modulates intercellular communication through gap-junction in bovine lens epithelial cells

BACKGROUND: Connexin43 (Cx43) is an integral membrane protein that forms intercellular channels called gap junctions. Intercellular communication in the eye lens relies on an extensive network of gap junctions essential for the maintenance of lens transparency. The association of Cx43 with cholesterol enriched lipid raft domains was recently demonstrated. The objective of this study is to assess if products of cholesterol oxidation (oxysterols) affect gap junction intercellular communication (GJIC). RESULTS: Primary cultures of lens epithelial cells (LEC) were incubated with 7-ketocholesterol (7-Keto), 25-hydroxycholesterol (25-OH) or cholesterol and the subcellular distribution of Cx43 was evaluated by immunofluorescence confocal microscopy. The levels of Cx43 present in gap junction plaques were assessed by its insolubility in Triton X-100 and quantified by western blotting. The stability of Cx43 at the plasma membrane following incubation with oxysterols was evaluated by biotinylation of cell surface proteins. Gap junction intercellular communication was evaluated by transfer of the dye Lucifer yellow. The results obtained showed that 7-keto induces an accumulation of Cx43 at the plasma membrane and an increase in intercellular communication through gap junction. However, incubation with cholesterol or 25-OH did not lead to significant alterations on subcellular distribution of Cx43 nor in intercellular communication. Data further suggests that increased intercellular communication results from increased stability of Cx43 at the plasma membrane, presumably forming functional gap-junctions, as suggested by decreased solubility of Cx43 in 1% Triton X-100. The increased stability of Cx43 at the plasma membrane seems to be specific and not related to disruption of endocytic pathway, as demonstrated by dextran uptake. CONCLUSIONS: Results demonstrate, for the first time, that 7-keto induces an increase in gap junction intercellular communication, that is most likely due to an increased stability of protein at the plasma membrane and to increased abundance of Cx43 assembled in gap junction plaques

De minha convidada

Nota do editor: “Cenas Médicas” (www.facebook.com/cenasmedicas) é a apresentação de um movimento literário que registra contos do cotidiano médico, com dois autores do curso de Medicina da UFSC: Fernando Bueno Neves e Paulo Henrique Pereira. Deste último é o trecho publicado nesta edição do “Boletim”. Um doutorando está sonolento em seu plantão de emergência cirúrgica..

A demonstration of an application of the Bertrand Network: Guessing the distribution of buyers within the market

Bertrand and the Cournot model are one of the most used model for modeling competition between companies. This paper presents a work-in-progress that studies the application of the recently developed Bertrand Network model by using it in a reverse manner: first it is considered that firms are competing in equilibrium, then, after analyzing how companies are choosing prices, it is calculated which distribution of buyers would lead to that equilibrium. An unreal example is presented to help to understand the model. Furthermore, a formula is suggested to expand the networked model to allow a mix of duopolies and oligopolies

When in doubt, slave! Imprisonment of free men and women through presumption of slavery. An analysis of the applied dispositive of abandoned slave according to the Free Womb Law

A Escravidão como o tema central do século XIX brasileiro apresentou profundos paradoxos no campo do direito: formalmente enfrentada através da promulgação de normas que poderiam ser lidas como construtoras de um caminho de abolição progressiva, na prática, é possível observar mecanismos e atores institucionais que trabalharam para preservá-la. Tais procedimentos deram-se, muitas vezes, através de um agir jurídico que procurava distorcer, desviar o disposto no campo da legalidade formal. Esse conjunto de práticas atingiu mulheres e homens livres, desestabilizando seus direitos, e precarizando suas expectativas de liberdade. Nesse balanço entre o direito e o avesso – entre a positivação de uma legalidade formal e a consecução de seu sentido concreto na realidade social –, o presente artigo busca analisar, sob enfoque do direito como prática linguística, parte dessas discrepâncias pela figura do escravo abandonado. Observando as disposições da Lei do Ventre Livre de 1871 sobre tal instituto, essas breves considerações almejam demonstrar a existência de usos e performances formadores de uma espécie de presunção de escravidão, que agia para preservar o escravismo, e que encontrava respaldo na consolidação de uma prática jurídica pela ilegalidade.Slavery as the main topic of the XIX century in Brazil presented profound paradoxes in the field of Law: faced in form through the promulgation of norms that could be read as pavers of a path of progressive abolition, in practice, it is possible to observe institutional mechanisms that worked to preserve it. Such procedures happened most of the times through legal action that sought to distort and deviate what was laid in the field of formal legality. This set of practices hit free women and men, destabilizing their rights and making more and more precarious their expectations of freedom. In this analysis between law and its reverse – between the positivation of a formal legality and the practice of its concrete meaning in social reality, the following article seeks to analyze, through a focus of law as linguistic practice, part of said discrepancies through the example of the abandoned slave. Looking at the dispositives of the Free Womb Law of 1871 on this institute, these brief remarks seek to show the existence of usages and performances that formed what could be known as presumption of slavery in order to preserve it as an institution, and that was aided by the consolidation of a legal practice through illegality

A liberdade na ordem escravocrata: interpretações sobre o conto Pai contra mãe, de Machado de Assis

As instituições jurídicas da escravidão deixaram um legado profundo na sociedade brasileira. Ao mesmo tempo, a literatura tem cada vez mais fornecido o subsídio para uma análise aprofundada da prática jurídica na sociedade, enxergando o direito como linguagem. O presente artigo busca, a partir dessas premissas, traçar uma análise do conto Pai contra Mãe de Machado de Assis, um raro exemplo da abordagem do escritor sobre o tema da escravidão, extraindo dela a percepção da sociedade da condição de liberto e de escravizado na ordem escravocrata, explorando os aspectos jurídicos, como a realidade pré-Lei do Ventre Livre, por meio dos diálogos das personagens. Assim, apresentando um panorama do conto, espera-se fornecer ao leitor um retrato da percepção e prática de institutos jurídicos quando sob a escravidão no Brasil do século XIX.The legal institutions of slavery have left a deep legacy in Brazilian society. At the same time, literature has increasingly provided the support for an in-depth analysis of legal practice in society, understanding law as a language. This paper seeks, based on these premises, to trace an analysis of Machado de Assis’ short story Pai contra Mãe, a rare example of writer’s approach to the slavery subject, extracting from it society’s perception of the condition of released and enslaved individuals under slave rule, exploring legal aspects, such as the pre-Free Womb Law reality, through the dialogues of the characters. Thus, by presenting an overview of the short story, it is expected to provide the reader with a portrait of the perception and practice of legal institutes when under slavery in Brazil in the 19th century

Um grito de socorro: a democracia roubada

More than three decades have passed since the end of the military regime in Brazil, and it seems that all atrocities committed by the military have been forgotten or forgiven, at least by an apparent majority. Therefore, it is necessary to remember what were the reasons that led the army to take the government for itself. It is important to know what measures were taken to ensure the coup, (titled by the military and its revolutionary supporters) how they managed to maintain the dictatorship for so long. why deceiving the population with myths and illusions was so beneficial for the military? How they managed to mask their illegitimacy through a false idea of democracy and how a coup became a "victorious revolution"? Through an interview and his research methods fulfilled with an ex-military man from the city of Três Lagoas we will try to elucidate all these crucial points. &nbsp;Mais de três décadas se passaram desde o término do regime militar no Brasil, e parece que todas as atrocidades cometidas pelos militares foram esquecidas ou perdoadas, ao menos por uma aparente maioria. Por isso, é necessário lembrar quais foram os motivos que levaram o exército a dar o golpe de Estado e tomar o governo para si. É importante saber que medidas foram tomadas para assegurar o golpe, (intitulado pelos militares e seus simpatizantes de revolução) como conseguiram manter a ditadura por tanto tempo. Por que ludibriar a população com mitos e ilusões foi tão benéfico para os militares? Como conseguiram mascarar sua ilegitimidade através de uma falsa ideia de democracia e como um golpe se tornou uma ''revolução vitoriosa''? Por meio de uma entrevista e dos seus métodos de investigação feita com um ex militar da cidade de Três Lagoas tentaremos elucidar todos estes pontos cruciais