1,697 research outputs found
An inside-out origin for the eukaryotic cell.
Although the origin of the eukaryotic cell has long been recognized as the single most profound change in cellular organization during the evolution of life on earth, this transition remains poorly understood. Models have always assumed that the nucleus and endomembrane system evolved within the cytoplasm of a prokaryotic cell
Patentes pipeline e seus reflexos no desenvolvimento econômico
Após 21 (vinte e um) anos da promulgação da Lei de Propriedade Industrial de nº 9.279, de 14 de maio de 1996, as patentes pipeline continuam trazendo debates sobre sua validade ou não. Trata-se de um mecanismo temporário que concede patentes referentes a uma série de produtos e processos ligados à área químico-farmacêutica e mesmo especialistas da área afirmam ser um mecanismo inconstitucional por não cumprir com o requisito da novidade, necessário a todas patentes, e retirar do domínio público tais produtos.After 21 years of the promulgation of industrial property law nº. 9.279 of May 14th, 1996, pipeline patents continue to bring debates about its validity or not. It is a temporary mechanism granting patents relating to a number of products and processes related to the chemical-pharmaceutical area, where even experts in the field claim to be an unconstitutional mechanism for failing to meet the novelty requirement (needed for all patents) and to remove such products from the public domain
Annexins as cell-type-specific markers in the developing chicken chorionallantoic membrane
Between day E8 and E12 of embryonic development, the chicken chorioallantoic membrane (CAM) undergoes massive structural rearrangement enabling calcium-uptake from the eggshell to supply the growing embryo. However, the contribution of the various cell types of the chorionic epithelium including the capillary covering (CC) cells, villus cavity (VC) cells, endothelial-like cells, and basal cells to this developmental program is largely unknown. In order to obtain markers for the different cell types in the chorionic epithelium, we determined the expression patterns of various calcium-binding annexins in the developing chicken CAM. By reverse transcription/polymerase chain reaction with primers deduced from nucleotide sequences available in various databases, the presence of annexin (anx)-1, anx-2, anx-5, and anx-6 was demonstrated at days E8 and E12. Quantitative immunoblotting with novel antibodies raised against the recombinant proteins revealed that anx-1 and anx-5 were significantly up-regulated at day E12, whereas anx-2 and anx-6 expression remained almost unchanged in comparison to levels at day E8. Immunohistochemistry of paraffin-embedded sections of E12 CAM revealed anx-1 in CC cells and VC cells. Anx-2 was localized in capillaries in the chorionic epithelium and in basal cells of the allantoic epithelium, whereas anx-6 was detected in basal cells or endothelial-like cells of the chorionic epithelium and in the media of larger vessels in the mesenchyme. A 2-day exposure of the CAM to a tumor cell spheroid resulted in strong proliferation of anx-1-expressing CC cells suggesting that these cells participate in the embryonic response to experimental intervention. Thus, annexins exhibit complementary expression patterns and represent appropriate cell markers for the further characterization of CAM development and the interpretation of results obtained when using CAM as an experimental mode
Enaction : introductory concepts and contemporary contributions
O presente artigo se propõe a ser uma introdução ao estudo dos processos cognitivos segundo uma perspectiva incorporada da cognição. Para isso, abordamos a teoria enativa, do biólogo chileno Francisco Varela, a partir de cinco conceitos principais: autonomia, adaptatividade, incorporação, emergência e experiência. Destacamos a forma como esses conceitos se alinham de modo a contrapor proposições hegemônicas no campo dos estudos cognitivos, tais como a metáfora do funcionamento da mente como um processamento computacional e a redução dos processos cognitivos à atividade neuronal.The following article presents an introdutory study of cognitive processes from an incorporated cognition perspective. The Enactive Theory, from the Chilean biologist Francisco Varela, is then approached in five of its main concepts: autonomy, adaptivity, incorporation, emergency and experience. We bring forth the way these concepts are aligned in countering hegemonic propositions in the cognitive studies field, such as the metaphor of mind functioning as a computational process and the reduction of cognitive processes to neural activity
“Battle Arena”: o videogame como um contexto inventivo
Then aim of this article is to discuss the relation between video games and cognition analyzing the first author’s experience with the game “Defence of the Ancients”. This online game is cooperative and competitive. The playing experience is discussed through the Ian Bogost’s method of Procedural Rhetoric analysis, considering not only the elements of the game, but a broader process involving actions from software and player. By this research it was possible to build tools to think about this game as an invention space focusing its description on the functionality that the games require of their players. In this perspective, the set of symbols arranged by the game only acquire meaning through the action of the player and are not properly interpreted from the spectator’s point of view. The rules, in turn, do not determine action, but define the player’s conditions of a possible experience. These features allow the operator to create a less descriptive and more operational type of knowledge, a more embodied know-how, which is configured from the rules of the game, but that is not so destitute of thought.O presente artigo busca discutir a relação entre videogames e cognição tomando em análise a experiência do primeiro autor com o jogo Defense of the Ancients. Trata-se de um jogo online cooperativo e competitivo. A experiência de jogar é discutida a partir do método de análise da Retórica Procedural de Ian Bogost, que leva em consideração não apenas os elementos do jogo, mas um processo mais amplo que envolve as ações do software e as do jogador. Esse modo de pesquisar permitiu construir ferramentas para pensar o videogame como espaço para invenção, centrando sua descrição na operatividade que os jogos exigem de quem os joga. Nessa perspectiva, o conjunto de símbolos dispostos pelo jogo só adquirem significado através da ação do jogador e não são adequadamente interpretados do ponto de vista de um espectador. As regras, por sua vez, não determinam a ação, mas definem as condições de possibilidade da experiência do jogador. Essas características permitem ao operador do jogo criar um tipo de conhecimento menos descritivo e mais operacional, um saber-fazer, mais corporificado, que se configura a partir das regras do jogo, mas que nem por isso é destituído de pensamento
ENAÇÃO: CONCEITOS INTRODUTÓRIOS E CONTRIBUIÇÕES CONTEMPORÂNEAS
O presente artigo se propõe a ser uma introdução ao estudo dos processos cognitivos segundo uma perspectiva incorporada da cognição. Para isso, abordamos a teoria enativa, do biólogo chileno Francisco Varela, a partir de cinco conceitos principais: autonomia, adaptatividade, incorporação, emergência e experiência. Destacamos a forma como esses conceitos se alinham de modo a contrapor proposições hegemônicas no campo dos estudos cognitivos, tais como a metáfora do funcionamento da mente como um processamento computacional e a redução dos processos cognitivos à atividade neuronal
Basket Cases and Breadbaskets: Sacred Rice and Agricultural Development in Postcolonial Africa
Author's final manuscript.Based on ethnographic research among rural Diola in Guinea-Bissau, I provide a broad view of the history and interpenetration of rice in social, political, religious, and ecological domains, while chronicling the current difficulties of residents in this region who are no longer able to grown enough of it. These farmers’ experiences are unfolding at a time of revitalized attention to agricultural development in Africa, particularly under the auspices of the New Green Revolution for Africa. I examine the premises that constitute the resuscitated effort to address the plight of African farmers. I argue that the totalizing quality of rice in Diola and other rice-cultivating societies requires a development approach that takes into account dimensions of agrarian life not encapsulated by the high- modernist and anti-political orientation of the New Green Revolution for Africa
The dynamic mosaic phenotypes of flowering plants
Ecological interaction and adaptation both depend on phenotypic characteristics. In contrast with the common conception of the ‘adult’ phenotype, plant bodies develop continuously during their lives. Furthermore, the different units (metamers) that comprise plant bodies are not identical copies, but vary extensively within individuals. These characteristics foster recognition of plant phenotypes as dynamic mosaics. We elaborate this conception based largely on a wide‐ranging review of developmental, ecological and evolutionary studies of plant reproduction, and identify its utility in the analysis of plant form, function and diversification. An expanded phenotypic conception is warranted because dynamic mosaic features affect plant performance and evolve. Evidence demonstrates that dynamic mosaic phenotypes enable functional ontogeny, division of labour, resource and mating efficiency. In addition, dynamic mosaic features differ between individuals and experience phenotypic selection. Investigation of the characteristics and roles of dynamic and mosaic features of plant phenotypes benefits from considering within‐individual variation as a function‐valued trait that can be analysed with functional data methods. Phenotypic dynamics and within‐individual variation arise despite an individual's genetic uniformity, and develop largely by heterogeneous gene expression and associated hormonal control. These characteristics can be heritable, so that dynamic mosaic phenotypes can evolve and diversify by natural selection.Fil: Harder, Lawrence. University of Calgary; CanadáFil: Strelin, Marina Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional Autónoma de México. Departamento de Ecología Evolutiva. Instituto de Ecología; MéxicoFil: Clocher, Ilona C.. University of Calgary; CanadáFil: Kulbaba, Mason. University of Calgary; CanadáFil: Aizen, Marcelo Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentin
Quinupristin/dalfopristin in Staphylococcus aureus endophthalmitis: a case report
<p>Abstract</p> <p>Introduction</p> <p>The intravitreal injection of antibiotics remains the mainstay of therapy for postoperative endophthalmitis. Bacterial resistance, however, is still a pitfall in achieving an adequate response to treatment. Quinupristin/dalfopristin might be a feasible therapeutic option in these cases.</p> <p>Case presentation</p> <p>A 55-year-old Hispanic man had endophthalmitis secondary to <it>Staphylococcus aureus </it>in his right eye and was treated with intravitreal 0.4 mg/0.1 ml quinupristin/dalfopristin injection. Inflammation and pain remission were observed at four days after injection. The final best-corrected visual acuity was 20/40.</p> <p>Conclusion</p> <p>Although vancomycin remains the first-line intravitreal antibiotic therapy against infectious endophthalmitis caused by Gram-positive bacteria, quinupristin/dalfopristin exhibits similar efficacy and is theoretically more active against vancomycin-resistant strains, with no apparent retinal toxicity.</p
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