In Silico and Biochemical Analysis of Physcomitrella patens Photosynthetic Antenna: Identification of Subunits which Evolved upon Land Adaptation

Background. In eukaryotes the photosynthetic antenna system is composed of subunits encoded by the light harvesting complex (Lhc) multigene family. These proteins play a key role in photosynthesis and are involved in both light harvesting and photoprotection. The moss Physcomitrella patens is a member of a lineage that diverged from seed plants early after land colonization and therefore by studying this organism, we may gain insight into adaptations to the aerial environment. Principal Findings. In this study, we characterized the antenna protein multigene family in Physcomitrella patens, by sequence analysis as well as biochemical and functional investigations. Sequence identification and analysis showed that some antenna polypeptides, such as Lhcb3 and Lhcb6, are present only in land organisms, suggesting they play a role in adaptation to the sub-aerial environment. Our functional analysis which showed that photo-protective mechanisms in Physcomitrella patens are very similar to those in seed plants fits with this hypothesis. In particular, Physcomitrella patens also activates Non Photochemical Quenching upon illumination, consistent with the detection of an ortholog of the PsbS protein. As a further adaptation to terrestrial conditions, the content of Photosystem I low energy absorbing chlorophylls also increased, as demonstrated by differences in Lhca3 and Lhca4 polypeptide sequences, in vitro reconstitution experiments and low temperature fluorescence spectra. Conclusions. This study highlights the role of Lhc family members in environmental adaptation and allowed proteins associated with mechanisms of stress resistance to be identified within this large family

Analysis of LhcSR3, a Protein Essential for Feedback De-Excitation in the Green Alga Chlamydomonas reinhardtii

To prevent photodamage by excess light, plants use different proteins to sense pH changes and to dissipate excited energy states. In green microalgae, however, the LhcSR3 gene product is able to perform both pH sensing and energy quenching functions

Platform-Independent Modelling in MDA: Supporting Abstract Platforms

An MDA-based design approach should be able to accommodate designs at different levels of platform-independence. We have previously proposed a design approach, which allows these levels to be identified. An important feature of this approach is the notion of abstract platform. An abstract platform is determined by considering the platform characteristics that are relevant for applications at a certain level of platform-independence as well as the various design goals. In this paper, we discuss how our design approach can be supported using the MDA standards UML 2.0 and MOF 2.0. Since our methodological framework is based on the notion of abstract platform, we pay particular attention to the representation of abstract platforms and the language requirements to specify abstract platforms

Systematic review and characterization of experimental hydroxyapatite front simulation processing variables

Bone tissue has regenerative capacity, directly dependent on the size of the bone injury, and in cases of more extensive lesions, there may be need to use bone graft materials that may contribute to this property. We can cite various types of materials, natural or synthetic. Each has advantages and disadvantages in its use, currently the calcium phosphate has excelled, especially hydroxyapatite, which can be used alone or as support for tissue engineering. Thus, this study aimed to evaluate the biocompatibility of the hydroxyapatite in study animals through a systematic review and characterize and evaluate previously synthesized hydroxyapatite microfibers. For the systematic review, the same search strategy was used in the following databases: PubMed (Medline), ISI Web of Science, Lilacs, IBECS, BBO, Scopus and Scielo. Initially they found 4101 potential articles and after removing duplicates and reading the titles and abstracts remaining 75 to read in its entirety. Of these, 35 were included in the review. In the second study, a previously developed hydroxyapatite has been characterized chemically and biologically after being subjected to sterilization processes and inducing metal contamination. Hydroxyapatite has shown satisfactory results in the studies included in the review, particularly when used in larger defects than the critical size. The repair and bone regeneration have significant challenges, making it clear that the successful development of materials for this field of research behind lasting benefits that outweigh potential risks. The hydroxyapatite tested demonstrated chemical stability and ease of sterilization, without contamination present in the composition, which allows the next step of the research animal testing.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESO tecido ósseo apresenta capacidade regenerativa, diretamente dependente do tamanho da lesão óssea, sendo que em casos de lesões mais extensas, pode haver necessidade de utilização de materiais para enxerto ósseo que possam contribuir com esta propriedade. Podemos citar diversos tipos destes materiais, sejam naturais ou sintéticos. Cada um apresentando vantagens e desvantagens na sua utilização, atualmente os fosfatos de cálcio tem se destacado, principalmente a hidroxiapatita, que pode ser utilizado de forma isolada ou como suporte na engenharia tecidual. Dessa forma, o presente trabalho objetivou avaliar a resposta tecidual da hidroxiapatita em estudos animais através de uma revisão sistemática, bem como caracterizar e avaliar microfibras de hidroxiapatita previamente sintetizadas. Para realização da revisão sistemática, a mesma estratégia de busca foi utilizada nas seguintes bases de dados: PubMed (MedLine), ISI Web of Science, Lilacs, Ibecs, BBO, Scopus and Scielo. Inicialmente foram encontrados 4101 potenciais artigos e após remoção de duplicatas e leitura dos títulos e abstracts restaram 75 para leitura na íntegra. Destes, 35 foram incluídos na revisão. No segundo trabalho, uma hidroxiapatita previamente desenvolvida foi caracterizada química e biologicamente após ser submetida a processos de esterilização e indução de contaminação por metais. A hidroxiapatita demonstrou resultados satisfatórios nos trabalhos incluídos na revisão, principalmente quando é utilizada em defeitos maiores que o tamanho crítico. O reparo e regeneração ósseo possuem significativos desafios, tornando-se evidente que o sucesso no desenvolvimento de materiais para este campo de pesquisa trás benefícios duradouros que superam potenciais riscos. Sendo que a hidroxiapatita testada demonstrou estabilidade química e facilidade de esterilização, sem apresentar contaminações em sua composição, o que possibilita o passo seguinte da pesquisa com teste em animais