G2-structures for N=1 supersymmetric AdS4 solutions of M-theory

We study the N=1 supersymmetric solutions of D=11 supergravity obtained as a warped product of four-dimensional anti-de-Sitter space with a seven-dimensional Riemannian manifold M. Using the octonion bundle structure on M we reformulate the Killing spinor equations in terms of sections of the octonion bundle on M. The solutions then define a single complexified G2-structure on M or equivalently two real G2-structures. We then study the torsion of these G2-structures and the relationships between them.Comment: 48 pages, updated references, corrected minor errors and typos, Class. Quantum Grav. (2018

The parasporal crystals of Bacillus pumilus strain 15.1: a potential virulence factor?

Bacillus pumilus strain 15.1 was previously found to cause larval mortality in the Med-fly 27 Ceratitis capitata and was shown to produce crystals in association with the spore. As 28 parasporal crystals are well-known as invertebrate-active toxins in entomopathogenic 29 bacteria such as Bacillus thuringiensis (Cry and Cyt toxins) and Lysinibacillus sphaericus (Bin 30 and Cry toxins), the B. pumilus crystals were characterised. The crystals were composed of a 31 45 kDa protein that was identified as an oxalate decarboxylase by peptide mass 32 fingerprinting, N-terminal sequencing and by comparison with the genome sequence of strain 33 15.1. Synthesis of crystals by a plasmid-cured derivative of strain 15.1 (produced using a 34 novel curing strategy), demonstrated that the oxalate decarboxylase was encoded 35 chromosomally. Crystals spontaneously solubilized when kept at low temperatures and the 36 protein produced was resistant to trypsin treatment. The insoluble crystals produced by 37 B. pumilus 15.1 did not show significant toxicity when bioassayed against C. capitata larvae, 38 but once the OxdD protein was solubilized, an increase of toxicity was observed. We also 39 demonstrate that the OxdD present in the crystals has oxalate decarboxylate activity as the 40 formation of formate was detected, which suggests a possible mechanism for B. pumilus 15.1 41 activity. To our knowledge, the characterization of the B. pumilus crystals as oxalate 42 decarboxylase is the first report of the natural production of parasporal inclusions of an 43 enzyme

O conhecimento docente de licenciandos em química no contexto de um programa de iniciação à docência brasileiro

Neste trabalho apresentam-se resultados relacionados ao Conhecimento Base e ao Conhecimento Pedagógico do Conteúdo (PCK) do tema redox de três bolsistas do Programa de Iniciação à Docência (PIBID) e a percepção dos alunos da Educação Básica sobre o conhecimento docente desses futuros professores. Os resultados revelaram que os bolsistas tinham conhecimento sobre o tem, apesar de terem apresentado dificuldades com a gestão da classe e na seleção do conteúdo. Dois bolsistas não demonstraram ter conhecimento sobre o currículo oficial. De modo geral, os participantes investigados revelaram um conhecimento docente adequado e os alunos da Educação Básica tiveram a percepção desse conhecimento

Synthesis of temperature-responsive Dextran-MA/PNIPAAm particles for controlled drug delivery using superhydrophobic surfaces

Purpose: To implement a bioinspired methodology using superhydrophobic surfaces suitable for producing smart hydro- gel beads in which the bioactive substance is introduced in the particles during their formation. Methods: Several superhydrophobic surfaces, including polystyrene, aluminum and copper, were prepared. Polymeric solutions composed by photo-crosslinked dextran-methacrylated and thermal responsive poly(N-isopropylacrylamide) mixed with a protein (insulin or albumin) were dropped on the superhydrophobic surfaces, and the obtained millimetric spheres were hardened in a dry environment under UV light. Results: Spherical and non-sticky hydrogels particles were formed in few minutes on the superhydrophobic surfaces. The proteins included in the liquid formulation were homogeneously distributed in the particle network. The particles exhibited temperature-sensitive swelling, porosity and protein release rate, with the responsiveness tunable by the dextran-MA/PNIPAAm weight ratio.Conclusions: The proposed method permitted the preparation of smart hydrogel particles in one step with almost 100% encapsulation yield. The temperature-sensitive release profiles suggest that the obtained spherical-shaped biomaterials are suitable as protein carriers. These stimuli-responsive beads could have potential to be used in pharmaceutical or other biomedical applications, including tissue engineering and regenerative medicine.The authors acknowledge funding from the project: PTDC/QUI/68804/2006 (FCT), IBEROMARE-Procept, FEDER and MICINN (SAF2008-01679). The research leading to these results has also received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement #NMP4-SL-2009-229292. The authors are grateful to project DISC REGENERATION, Collaborative Project-Large-scale integrating project, NMP3-LA-2008-213904 for the use of the UV lamp

Hypoxia signaling and cholesterol/steroidogenic acute regulatory protein 1 axis: interplay and role in alcohol and non-alcohol-related liver diseases

Metabolic zonation in the liver carries out the maintenance of organ and body homeostasis. Hypoxia is an inherent physiological feature of the liver and contributes to the zonal properties of the hepatic parenchyma. As a master regulator of hypoxia, the transcription factor hypoxia-inducing factor (HIF) is stabilized primarily by oxygen availability, and it is thought to contribute to steatohepatitis due to alcohol-related (ASH) and non-alcohol-related liver disease (NASH). Cholesterol has emerged as an important player in both diseases, and hypoxia increases hepatic cholesterol levels. Steroidogenic acute regulatory protein 1 (STARD1) is a mitochondrial outer membrane protein that transfers cholesterol to mitochondrial inner membrane for metabolic processing and acts as the rate-limiting step in the alternative pathway of bile acid synthesis in hepatocytes. STARD1 expression increases in ASH and NASH and determines the accumulation of cholesterol in mitochondria, which impacts the physico-chemical mitochondrial membranes properties and as a consequence impairs the activity of specific mitochondrial solute carriers, such as the 2-oxoglutarate carrier (2-OGC), limiting the exchange between cytosolic glutathione and mitochondrial 2-oxoglutarate (2-OG). Although HIF-1 is stabilized in hypoxia largely due to the requirement of prolylhydroxylases (PHDs) for oxygen to signal HIF degradation, PHDs are also dependent on 2-OG, and therefore it is conceivable that impairment of 2-OGC by STARD1-mediated cholesterol accumulation may contribute to HIF-1 stabilization due in part to decreased availability of cytosolic 2-OG. In this perspective, this review explores the interplay between HIF-1 stabilization and STARD1 induction and the potential contribution of this functional relationship to ASH and NASH

IDENTIFICATION OF VOLATILE FLAVOUR COMPOUNDS OF HOKI (Macruronus novaezelandiae) AND ORANGE ROUGHY (Hoplostethus atlanticus) OILS

Identification of volatile flavour compounds of hoki (Macruronus novaezelandiae) and orange roughy (Hoplostethus atlanticus) oils has been carried out.  Flavour compounds were extracted by a purging system and collected using a porous polymer Tenax TA trap.  The gas chromatography-mass spectrometry (GC-MS) was used to identify the volatile flavour compounds.  The predominant compounds contributing to the volatile flavour of hoki oil were methyl ethyl benzoate, ethyl benzoate and 1,1-dimethylethyl-2-propionic acid.  Meanwhile, the main volatile flavour components of orange roughy oil were toluene, cyclohexane, 1,1-dimethylethyl-2-methyl propionic acid and tetrachloroethane

As limitações de ensino-aprendizagem associadas ao conteúdo redox nos eventos brasileiros

Este trabalho apresenta os desdobramentos de um estudo que mapeou as pesquisas entre os anos de 2000 a 2016 nos eventos científicos brasileiros ENEQ, EPPEQ, ENPEC e RASBQ que tiveram o conteúdo redox como foco de investigação. Nesta segunda etapa aqui apresentada analisaramse os trabalhos catalogados, no sentido de mapear as dificuldades identificadas por seus autores em relação aos alunos, aos problemas presentes em livros didáticos e às limitações dos professores com o tema oxirredução. Em apenas 42 de 138 trabalhos os autores evidenciaram as limitações conceituais, entre elas compreender a simultaneidade das reações redox, diferenciar pilha de eletrólise, transpor os conceitos redox para outros temas. O principal público das investigações eram alunos do Ensino Médio e a estratégia de ensino mais adotada foi a experimentação