77 research outputs found
An alginate-confined peroxygenase-CLEA for styrene epoxidation
No full textOxyfunctionalisation reactions in neat substrate still pose a challenge for biocatalysis. Here, we report an alginate-confined peroxygenase-CLEA to catalyse the enantioselective epoxidation of cis-β-methylstyrene in a solvent-free reaction system achieving turnover numbers of 96 000 for the biocatalyst and epoxide concentrations of 48 mM. </p
Clea: an isiac priestess with philosophical knowledge of Plutarch's works
No full textO objetivo principal neste artigo é analisar o papel do conhecimento filosófico na piedade religiosa segundo Plutarco de Queronéia, usando a educação da sacerdotisa Cléa como exemplo. Plutarco dedicou dois textos a Cléa: Sobre Ísis e Osíris e Sobre as virtudes das mulheres. O bom comportamento religioso, para Plutarco, baseia-se na compreensão adequada da filosofia e na aplicação desse conhecimento nos ensinamentos religiosos, o que nos parece evidente em Sobre Ísis e Osíris. Nesse tratado, o autor grego ensina Cléa a interpretar os mitos e os preceitos egípcios de maneira filosoficamente correta, visando torná-la uma "verdadeira" isíaca, especialmente após sua iniciação nos mistérios dessa divindade.Recibido: 30/09/2023 - Aceptado: 19/10/2023The main objective is to analyze the role of philosophical knowledge in religious piety according to Plutarch of Chaeronea, using the education of Clea as an example. Plutarch dedicated two texts to Clea: "On Isis and Osiris'' and "On the Virtues of Women." For Plutarch, proper religious conduct is based on a thorough understanding of philosophy and the application of this knowledge to religious teachings, which is evident in "On Isis and Osiris." In this treatise, the Greek author teaches Clea how to interpret Egyptian myths and precepts in a philosophically correct manner, aiming to make her a "true" Isiac, especially after her initiation into the mysteries of these deities
Série professor artista: uma experiência em ensino-aprendizagem em arte
No full textThe Professor Artist series is a set of films with a duration of approximately 15 minutes, prepared for the Specialization Course in Teaching Visual Arts, distance learning modality, which is part of the Graduate Program in Arts of the School of Fine Arts of Federal University of Minas Gerais (UFMG), Brasil. The films deal with the work of artist teachers and their propositions in the two fields of action: in the poetics of creation and in the actions in teaching-learning. As one of the objectives, it aims to bring art students and
teachers closer to the universe of contemporary artistic production, aiming to broaden artistic thinking and the understanding of artistic creation processes that can stimulate author production and professional performance in teaching-learning.A série Professor Artista é um conjunto de filmes com duração aproximada de 15 minutos, elaborado para o Curso de Especialização em Ensino de Artes Visuais, modalidade educação a distância, que faz parte do Programa de Pós-Graduação em Artes da Escola de Belas Artes da Universidade Federal de Minas Gerais (EBA/UFMG), Brasil. Os filmes mostram o trabalho de professores artistas e suas proposições nos dois campos de atuação: nas poéticas de criação e nas ações no ensino-aprendizagem. Com isso propõe, como
um dos objetivos, aproximar alunos e professores de Arte do universo da produção artística contemporânea visando ampliar o pensamento artístico e o entendimento de processos de criações artísticas que possam estimular a produção autoral e a atuação profissional no ensino-aprendizagem
Book Review: The Disability Rights Movement: From Deinstitutionalization to Self-Determination
No full textAuthor: Duane F. Stroman
Publisher: University Press of America, 2003
Cost: Paperback - $37.00 USD
Reviewer: Mike Clea
Open data and Earth observations
No full textAbstract
Earth observations (EO) represent a growing and valuable resource for many scientific, research and practical applications carried out by users around the world. Access to EO data for some applications or activities, like climate change research or emergency response activities, becomes indispensable for their success. However, often EO data or products made of them are (or are claimed to be) subject to intellectual property law protection and are licensed under specific conditions regarding access and use. Restrictive conditions on data use can be prohibitive for further work with the data. Global Earth Observation System of Systems (GEOSS) is an initiative led by the Group on Earth Observations (GEO) with the aim to provide coordinated, comprehensive, and sustained EO and information for making informed decisions in various areas beneficial to societies, their functioning and development. It seeks to share data with users world-wide with the fewest possible restrictions on their use by implementing GEOSS Data Sharing Principles adopted by GEO. The Principles proclaim full and open exchange of data shared within GEOSS, while recognizing relevant international instruments and national policies and legislation through which restrictions on the use of data may be imposed. The proposed paper focuses on the issue of the legal-interoperability of data that are shared with varying restrictions on use with the aim to explore the options of making data interoperable. The paper analyses legal protection regimes and their norms applicable to EO data. Based on the findings, it highlights the existing public law statutory, regulatory, and policy approaches, as well as private law instruments, such as waivers, licenses and contracts, that may be used to place the datasets in the public domain, or otherwise make them publicly available for use and re-use without restrictions. It uses GEOSS and the particular characteristics of it as a system to identify the ways to reconcile the vast possibilities it provides through sharing of data from various sources and jurisdictions on the one hand, and the restrictions on the use of the shared resources on the other. On a more general level the paper seeks to draw attention to the obstacles and potential regulatory solutions for sharing factual or research data for the purposes that go beyond research and education
The Application of Nitrile Hydratases in Organic Synthesis
No full textNitrile hydratases (NHases, E.C. 4.2.1.84) catalyse the transformation of nitriles into the corresponding amides and were first discovered 30 years ago in studies on the microbial degradation of toxic cyano-group-containing compounds. The use of NHases in synthetic chemistry is especially interesting in conversions where the substrate or the product is labile at the high temperature or extreme pH employed in chemical nitrile hydration. However, also in the production of bulk chemicals like acrylamide, NHases offer a green alternative to chemical hydration. Besides mild reaction conditions, the potential advantage of using a nitrile hydratase as a catalyst is a high chemo-, regio-, and enantioselectivity. In this thesis new NHase containing organisms from soda lakes and soda soils in Mongolia and Russia were isolated. One of the NHases from these organisms was characterized in detail and subsequently it was demonstrated that it was possible to significantly increase the stability of this NHase by immobilisation in the form of a cross-linked enzyme aggregate (CLEA). Combining the aforementioned NHase CLEA with a CLEA of the hydroxynitrile lyase (HnL, E.C. 4.1.2.37) from Manihot esculenta enabled an efficient one-pot bienzymatic cascade for the production of enantiomerically enriched aliphatic ?-hydroxycarboxylic amides from the corresponding aldehydes and HCN. Finally, a small library of five purified NHases was screened on their enantioselectivity for several structurally different chiral nitriles. Some of these NHases were shown to have promising enantioselectivities (E > 100).BiotechnologyApplied Science
Audio Interview with Mrs. Dorothy (Bellerose) Chartrand
No full textAudio - Mrs. Dorothy Chartrand discusses her family history which includes her grandfather, Octave, and his son Pierre setting up the Bellerose Livery Stable in Athabasca in 1898. She talks about her family's short sojourn in Colinton near the Athabasca Landing Trail. Mrs. Chartrand mentions early businesses and settlers in the Athabasca area and discusses freighting, lumbering and the railway (20 minutes)very clea
An Artist\u27s Confrontations with Selected Fictions of Love
No full textLawrence Durrell\u27s Alexandria Quartet consists of four novels: Justine, Balthazar, Mounolive, and Clea, generally concerned with the same characters, experiences, and events in and around Alexandria, Egypt. The author has designated one character, L.G. Darley as the writer-protagonist of three of the novels. Mountolive, the single exception, presents an omniscient author\u27s view in which Darley is a minor, third person figure
Activity and Enantioselectivity of the Hydroxynitrile Lyase MeHNL in Dry Organic Solvents
No full textWater concentration affects both the enantioselectivity and activity of enzymes in dry organic media. Its influence has been investigated using the hydrocyanation of benzaldehyde catalyzed by hydroxynitrile lyase cross-linked enzyme aggregate (MeHNL-CLEA) as a model reaction. The enzyme displayed higher enantioselectivity at higher water concentration, thus suggesting a positive effect of enzyme flexibility on selectivity. The activity increased on reducing the solvent water content, but drastic dehydration of the enzyme resulted in a reversible loss of activity.DelftChemTechApplied Science
Hydroxynitrile Lyase-Catalyzed Enantioselective Conversion of Ketones into Cyanohydrins
No full textIn this thesis I have addressed several issues related to the HNL-catalyzed preparation of cyanohydrins. I first demonstrated in Chapter 2 that immobilized HNL as sol-gels and as commercially available Cross Linked Enzyme Aggregates (CLEA®) improved several features of the biocatalyst such as solvent stability, and substrate or product inhibition/deactivation. In particular, MeCLEA was remarkably stable towards the deleterious effect of organic solvent and the enzymatic reaction could be carried out in organic media. The CLEA immobilization strategy is nonetheless enzyme-dependent and I successfully developed the biocatalyst LuCLEA for optimum catalytic performances in organic media as described in Chapter 3. This enantioselective and recyclable biocatalyst appeared to be particularly effective for the preparation of 2-butanone cyanohydrin. In Chapter 4, I used benzaldehyde as a model substrate to develop multistep strategies towards cyanohydrin derivatives based on HNL-CLEA catalysis in organic solvents. The reaction could be carried out in one pot or with limited downstream processing/purification of the cyanohydrin intermediate. In the case of ketones such as acetophenone where unfavourable thermodynamics limit the practical conversion, all attempts to derivatize the cyanohydrin in situ in order to shift the equilibrium were not successful. Cyanohydrins from ketones can indeed be considered as tertiary alcohols which require relatively reactive reagents for derivatization. Under these conditions the biocatalyst was rendered inactive. Since no in situ derivatization method could de designed to enable complete conversion of unreactive ketones, kinetic resolution as a means to produce chiral cyanohydrin was explored in Chapter 5. I established enzymatic activity for a previously unreported ?,?-unsaturated ketone and showed that kinetic resolution was more suitable than the direct synthetic route for the preparation of the corresponding chiral cyanohydrin. As an extension of this work I also described the rearrangement of a similar ?,?-unsatuared cyanohydrin acetate into the corresponding tetronic acid derivative. Chapter 6 concludes this thesis with straightforward synthetic procedures towards racemic cyanohydrins from unreactive ketones in order to improve the overall cost efficiency of the kinetic resolution approach.Biocatalysis and Orgnanic ChemistryApplied Science
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