1,439 research outputs found
Equilibria and catalytic properties of a chloro-bridged Diimine copper(II) complex in the N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD) oxidation
1-Ethyl 2-methyl 3,4-bis(acetyloxy)pyrrolidine-1,2-dicarboxylate: crystal structure, Hirshfeld surface analysis and computational chemistry
The title compound, C13H19NO8, is based on a tetra-substituted pyrrolidine ring, which has a twisted conformation about the central C—C bond; the Cm—Ca—Ca—Cme torsion angle is 38.26 (15)° [m = methylcarboxylate, a = acetyloxy and me = methylene]. While the N-bound ethylcarboxylate group occupies an equatorial position, the remaining substituents occupy axial positions. In the crystal, supramolecular double-layers are formed by weak methyl- and methylene-C—H...O(carbonyl) interactions involving all four carbonyl-O atoms. The two-dimensional arrays stack along the c axis without directional interactions between them. The Hirshfeld surface is dominated by H...H (55.7%) and H...C/C...H (37.0%) contacts; H...H contacts are noted in the inter-double-layer region. The interaction energy calculations point to the importance of the dispersion energy term in the stabilization of the crystal
U-Pb zircon dating of ash fall deposits from the paleozoic paran? basin of Brazil and Uruguay: A reevaluation of the stratigraphic correlations
Ash fall layers and vitroclastic-carrying sediments distributed throughout the entire Permian stratigraphic range of the Paraná Basin (Brazil and Uruguay) occur in the Tubarão Supergroup (Rio Bonito Formation) and the Passa Dois Group (Irati, Estrada Nova/Teresina, Corumbataí, and Rio do Rasto Formations), which constitute the Gondwana 1 Supersequence. U-Pb zircon ages, acquired by SHRIMP and isotope-dissolution thermal ionization mass spectrometer (IDTIMS) from tuffs within the Mangrullo and Yaguari Formations of Uruguay, are compatible with a correlation with the Irati and parts of the Teresina and Rio do Rasto Formations, respectively, of Brazil. U-Pb zircon ages suggest maximum depositional ages for the samples: (1) Rio Bonito Formation: ages ranging from 295:8 5 3:1 to 304:0 5 5:6 Ma (Asselian, lowermost Permian), consistent with the age range of the Protohaploxypinus goraiensis subzone; (2) Irati Formation:
ages ranging from 279:9 5 4:8 to 280:0 5 3:0 Ma (Artinskian, middle Permian), consistent with the occurrence of species of the Lueckisporites virkkiae zone; (3) Rio do Rasto Formation: ages ranging from 266:7 5 5:4 to 274:6 5 6:3Ma (Wordian to Roadian, middle Permian). All the SHRIMP U-Pb zircon ages are consistent with their superimposition order in the stratigraphy, the latest revisions to the Permian timescale (International Commission of Stratigraphy, 2018 version), and the most recent appraisals of biostratigraphic data. The ID-TIMS U-Pb zircon ages from the Corumbataí Formation suggest that U-Pb ages may be 110% younger than interpreted biostratigraphic ages
Ethyl 3,4-bis(acetyloxy)-2-(4-methoxyphenyl)pyrrolidine-1-carboxylate
The title pyrrolidine compound, C18H23NO7, is a tetra-substituted species in which the five-membered ring has a twisted conformation with the twist occurring in the C—C bond bearing the adjacent acetyloxy substituents; the Cm—Ca—Ca—Cp torsion angle is −40.76 (18)° [m = methylene, a = acetyloxy and p = phenyl]. The N atom, which is sp2-hybridized [sum of bond angles = 359.4°], bears an ethylcarboxylate substitutent and is connected to a methylene-C atom on one side and a carbon atom bearing a 4-methoxyphenyl group on the other side. Minor disorder is noted in the ethylcarboxylate substituent as well as in one of the acetyloxy groups; the major components of the disorder have site occupancies of 0.729 (9) and 0.62 (3), respectively. The most notable feature of the molecular packing is the formation of helical, supramolecular chains aligned along the b-axis direction whereby the carbonyl-O atom not involved in a disordered residue accepts C—H...O interactions from methylene-H and two-C atom separated methine-H atoms to form a six-membered {...HCCCH...O} synthon
O comportamento do consumidor de vinho no mercado português
A presente investigação resultou da necessidade de perceber as razões que motivam e que
eventualmente poderão condicionar a frequência de consumo de vinho em Portugal. Deste
modo, o principal objetivo deste trabalho é compreender as motivações de compra e
consumo, dependendo da situação de uso e de caraterísticas pessoais. A literatura existente
sobre as motivações de consumo de vinho salienta a existência de efeitos diretos sobre as
motivações do género do comprador e da ocasião de consumo. Este estudo introduz uma
formulação alternativa destes efeitos, considerando-os indiretos, i.e. completamente
mediados pelo conhecimento subjetivo do comprador e pelas emoções que ele associa ao
respetivo consumo.
Foram desenvolvidos dois modelos, um para explicar as motivações, outro a frequência de
consumo, os quais foram posteriormente validados numa amostra de 523 compradores
entrevistados no momento da compra em grandes superfícies retalhistas da Grande Lisboa
e do Grande Porto. Os resultados apresentados no primeiro modelo apontam para a rejeição
dos efeitos diretos, sendo o conhecimento subjetivo o mediador mais importante. Sugere-se
que a autoconfiança e a eficácia na decisão, que aparecem associadas ao conhecimento
subjetivo, justifiquem que os homens se sintam mais motivados para o consumo. Este efeito
positivo do conhecimento na motivação é ainda mais importante nas ocasiões regulares.
No segundo modelo, verificou-se que a frequência de consumo é explicada
predominantemente pela motivação por gratificação sensorial e, também, pela ocasião de
consumo no contexto de refeição normal (efetuada no dia-a-dia). O conhecimento subjetivo
revelou-se também como elemento fundamental no comportamento do consumidor, quer
pela sua influência sobre as motivações, quer pela sua influência sobre a frequência de
consumo.
As conclusões retiradas desta investigação salientam a importância do conhecimento
subjetivo no consumo de vinho. Realçam também que os efeitos de fatores como o género e
a ocasião sobre as motivações para consumir vinho, reportados na literatura, poderão
dever-se a mediadores de ordem psicográfica, como o conhecimento subjetivo. Esta
conclusão tem implicações no marketing de vinhos para compradores regulares,
nomeadamente pelo reconhecimento da necessidade de reforçar a perceção de confiança e de eficácia de decisão que costumam ser associadas aos elevados níveis de conhecimento
percebido numa categoria de produto
Alimentação popular em São Paulo (1920 a 1950): políticas públicas, discursos técnicos e práticas profissionais
This article discusses how the concept of lower-class eating habits came about and developed in the intellectual circles of São Paulo during the first half of the 20th century. It starts by reconstructing the elements of the debate around the income and ignorance of the underprivileged as the main reasons behind their bad eating habits. Then, it looks at the focal points for interventions and public policies proposed by the government to deal with the problem thus identified, namely: training methods to produce sanitation counselors capable of offering dietary guidance as well; popular educational campaigns and new learning sites in addition to schools (e.g. healthcare centers and households); lunch and other means of offering food at schools; and diagnostic studies about food intake and eating habits among laborers. Because they were translated into technical and scientific language, the proposals and policies implemented in São Paulo left traces in a variety of supporting documents and media (photographs, primers, posters, inquiry notebooks, and academic literature).O artigo discute a construção da idéia de alimentação popular nos meios intelectuais em São Paulo, na primeira metade do século XX. Para isso, reconstitui, como motivos da má alimentação, elementos do debate em torno da renda e da ignorância dos mais pobres. Identificado o problema, as propostas de intervenção e as políticas públicas concentraram-se em alguns setores, abordados neste trabalho: métodos para a formação de educadores sanitários aptos a atuar também na educação alimentar; campanhas de instrução popular e criação de novos lugares de aprendizado (além das escolas, os centros de saúde e os lares); merenda escolar e outras alternativas de alimentação nas escolas; e diagnósticos referentes ao conteúdo e à forma da alimentação dos operários. Traduzidas em discurso técnico-científicos, as propostas e políticas implementadas na cidade deixaram indícios em documentação de suporte e tipologia variados (fotografias, cartilhas, cartazes, cadernetas de inquéritos e textos acadêmicos).Universidade Federal de São Paulo (UNIFESP)UNIFESPSciEL
Physiological responses and production of 'Syrah' vines as a function of training systems
Plant architecture and its interaction with agricultural practices and environmental constraints is determinant for grapevine canopy structure, which is related to carbon assimilation, bud fertility and fruit quality. In this context, this study evaluated the performance of field-grown 'Syrah' grapevines conducted by two management systems: Vertical Shoot Position (VSP) or a modified Geneva Double Curtain (GDC), in Pirapora, state of Minas Gerais, Brazil, during the winters of 2007 and 2008. The evaluations of leaf area, water relations and net CO2 assimilation were made at the end of the ripening period. Yield per vine and per hectare were estimated and mean berry weight and diameter, total soluble solids, pH and titratable acidity were evaluated during berry ripening. The grapevines trained in VSP had higher water status as compared to GDC, shown by differences in pre-dawn leaf water potential (ψpd) and stem water potential (ψstem). However, the CO2 assimilation was similar in both training systems. Fruit exposure was higher in VSP than in GDC, which contributed to increasing berry temperature. At harvest, the berries in GDC reached values near to 23 ºBrix whereas berries in VSP showed values near 21 ºBrix
TRY plant trait database - enhanced coverage and open access
Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
Vaccines for the Leishmaniases: Proposals for a Research Agenda
The International Symposium on Leishmaniasis Vaccines, held in Olinda, Brazil, on March 9–11, 2009, congregated international experts who conduct research on vaccines against the leishmaniases. The questions that were raised during that meeting and the ensuing discussions are compiled in this report and may assist in guiding a research agenda. A group to further discussion on issues raised in this policy platform has been set up at http://groups.google.com/group/leishvaccines-l
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