628 research outputs found

    Environments for sonic ecologies

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    This paper outlines a current lack of consideration for the environmental context of Evolutionary Algorithms used for the generation of music. We attempt to readdress this balance by outlining the benefits of developing strong coupling strategies between agent and en- vironment. It goes on to discuss the relationship between artistic process and the viewer and suggests a placement of the viewer and agent in a shared environmental context to facilitate understanding of the artistic process and a feeling of participation in the work. The paper then goes on to outline the installation ‘Excuse Me and how it attempts to achieve a level of Sonic Ecology through the use of a shared environmental context

    Comparative genomics suggests primary homothallism of Pneumocystis species.

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    UNLABELLED: Pneumocystis species are fungal parasites of mammal lungs showing host specificity. Pneumocystis jirovecii colonizes humans and causes severe pneumonia in immunosuppressed individuals. In the absence of in vitro cultures, the life cycle of these fungi remains poorly known. Sexual reproduction probably occurs, but the system of this process and the mating type (MAT) genes involved are not characterized. In the present study, we used comparative genomics to investigate the issue in P. jirovecii and Pneumocystis carinii, the species infecting rats, as well as in their relative Taphrina deformans. We searched sex-related genes using 103 sequences from the relative Schizosaccharomyces pombe as queries. Genes homologous to several sex-related role categories were identified in all species investigated, further supporting sexuality in these organisms. Extensive in silico searches identified only three putative MAT genes in each species investigated (matMc, matMi, and matPi). In P. jirovecii, these genes clustered on the same contig, proving their contiguity in the genome. This organization seems compatible neither with heterothallism, because two different MAT loci on separate DNA molecules would have been detected, nor with secondary homothallism, because the latter involves generally more MAT genes. Consistently, we did not detect cis-acting sequences for mating type switching in secondary homothallism, and PCR revealed identical MAT genes in P. jirovecii isolates from six patients. A strong synteny of the genomic region surrounding the putative MAT genes exists between the two Pneumocystis species. Our results suggest the hypothesis that primary homothallism is the system of reproduction of Pneumocystis species and T. deformans. IMPORTANCE: Sexual reproduction among fungi can involve a single partner (homothallism) or two compatible partners (heterothallism). We investigated the issue in three pathogenic fungal relatives: Pneumocystis jirovecii, which causes severe pneumonia in immunocompromised humans; Pneumocystis carinii, which infects rats; and the plant pathogen Taphrina deformans. The nature, the number, and the organization within the genome of the genes involved in sexual reproduction were determined. The three species appeared to harbor a single genomic region gathering only three genes involved in sexual differentiation, an organization which is compatible with sexual reproduction involving a single partner. These findings illuminate the strategy adopted by fungal pathogens to infect their hosts

    The role of HKT transporters in salinity tolerance of tomato

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    Lill, H. [Promotor]Boer, A.H. de [Copromotor

    Liver bioengineering using decellularized whole-liver scaffolds

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    Currently, due to the progress made in the field of regenerative medicine, whole-organ bioengineering is becoming a valid alternative to cope with the shortages of organs for transplantation. In this chapter, we describe the main techniques carried out for pig liver bioengineering, which serves as an essential model for future human liver bioengineering. These include porcine whole-liver decellularization, endothelial and mesenchymal stem cell isolation, porcine ES-derived hepatoblasts, and scaffold recellularization using a bioreactor perfusion system

    Scientific journalism characteristics in reading of popular science texts by undergraduate students of physics

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    In this article we synthesize some specific aspects of scientific journalism and identified the presence of some of these elements in the interpretations of physics undergraduates acquired while reading popular scientific texts from the journals Ciência Hoje and Pesquisa Fapesp. We believe that the relationship between undergraduates interpretation and some journalism characteristics seem to suggest that the potentialities and limits in the use of scientific popularization magazines for teaching effective situations could be linked to conditions in which those texts are produced.Neste artigo fazemos uma síntese sobre elementos específicos do jornalismo científico e identificamos a presença de alguns desses elementos nas interpretações de licenciandos em física ao lerem textos de divulgação científica das revistas Ciência Hoje e Pesquisa Fapesp. Consideramos que o relacionamento entre a interpretação dos licenciandos e algumas especificidades do campo jornalístico, que fazem parte das revistas lidas, parece sugerir que a investigação de potencialidades e limites na utilização de revistas de divulgação científica em situações efetivas de ensino estaria vinculada às condições em que esses textos são produzidos.44014412Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

    Can a restocking event with European (glass) eels cause early changes in local biological communities and its ecological status?

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    In an attempt to assist the recovery of the panmictic population of the European eel, declining since the late 1980s, the restocking of areas with low or no natural recruitment has been one of the measures adopted to reverse this trend. However, the main focus in several monitoring programmes for these actions, has been in the best interest of its viability and cost/benefit relationships and, for that, the condition of the released stocks has been the main concern. Yet, so far, no studies have assessed the potential ecological impacts that restocking might have on other biological communities. This pioneer pilot study aimed to evaluate the early ecological impact of a restocking event on other biological communities, considering inter-specific competition (other fish species) and feeding impact (macroinvertebrates).The reference condition of the biological communities of an inland tributary of the Mondego river, the River Ceira, was determined in three sites inaccessible to the natural recruitment of eels, followed by a post-stocking assessment. The results showed no significant changes in the fish assemblages in restocked areas, contrary to the macroinvertebrate community. However, the ecological status for the macroinvertebrate community showed no deleterious effects, with the results suggesting exactly the opposite. This may be related to the low density of the restocked eels and factors influencing the local trophic web. This study confirms the suitability of the habitat for restocking with glass eels, during its early stages, without disrupting the local ecological status, using densities close to those of natural recruitment

    Slowly synchronizing automata and digraphs

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    We present several infinite series of synchronizing automata for which the minimum length of reset words is close to the square of the number of states. These automata are closely related to primitive digraphs with large exponent.Comment: 13 pages, 5 figure

    Development of suported ionic liquids for the purification of antileukemic drugs

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    L-asparaginase (LA) is an antileukemic biopharmaceutical of current high-cost. LA is produced via fermentation and its purification usually comprises precipitation, liquid- liquid extraction and chromatography techniques [1]. This work aims to develop sustainable technologies to purify LA. Functionalized nanomaterials, namely supported ionic liquids (SILs), are used as cost-effective purification techniques for the target enzyme. Initially, the synthesis and modification of SILs was performed. Different SILs were obtained and used for the purification of LA. Commercial LA was used for the first purification tests, in order to understand the behavior of the enzyme in contact with the nanomaterial. Experimental conditions, such as pH, and material/LA ratio, contact time were optimized. LA activity was quantified by Nessler reaction [2]. The first results reveal a total adsorption of LA by the SILs with a recovered activity reaching 90% depending on the SILs functionalization/ treatment. The modified SILs are shown to be very promising nanomaterials for the purification of LA. The LA was easily attached to SILs by adsorption under mild conditions. SILs supports can be a real alternative for a single step immobilization/purification of LA.publishe

    Articulation of texts on nanoscience and nanotechnology for the initial training of physics teachers

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    Evidence that modern physics should be taught in high school and that many teachers do not teach this subject, among other reasons, because these teachers do not feel able to do it, led us to a proposal for a set of texts selected from a preliminary study involving 15 students in a course of teacher training in physics, with texts on nanoscience and nanotechnology. In the selection, which was based on extensive review of the subject, we focused on texts in alternative language that avoids the almost exclusive use of mathematical language and seeks also allow the study for different teaching strategies, especially with the history of science and reading popular science.Evidências de que a física moderna e contemporânea deve ser trabalhada no Ensino Médio, agregadas a indícios de que muitos professores não a ensinam, entre outros motivos, por não se sentirem aptos a fazê-lo, nos levaram a uma proposta de um conjunto de textos selecionados a partir de um trabalho preliminar, envolvendo 15 estudantes de uma disciplina de Licenciatura em Física, com textos sobre nanociência e nanotecnologia. Na seleção, que se baseou em ampla revisão sobre o tema, privilegiamos os textos em linguagens alternativas ao uso quase exclusivo da linguagem matemática e buscamos também possibilitar que o estudo ocorra a partir de diferentes estratégias de ensino, com destaque para a história da ciência e a leitura de divulgação científica.19Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    A General Backwards Calculus of Variations via Duality

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    We prove Euler-Lagrange and natural boundary necessary optimality conditions for problems of the calculus of variations which are given by a composition of nabla integrals on an arbitrary time scale. As an application, we get optimality conditions for the product and the quotient of nabla variational functionals.Comment: Submitted to Optimization Letters 03-June-2010; revised 01-July-2010; accepted for publication 08-July-201
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