Words derivated from Sturmian words

AbstractA return word of a factor of a Sturmian word starts at an occurrence of that factor and ends exactly before its next occurrence. Derivated words encode the unique decomposition of a word in terms of return words. Vuillon has proved that each factor of a Sturmian word has exactly two return words. We determine these two return words, as well as their first occurrence, for the prefixes of characteristic Sturmian words. We then characterize words derivated from a characteristic Sturmian word and give their precise form. Finally, we apply our results to obtain a new proof of the characterization of characteristic Sturmian words which are fixed points of morphisms

Nitric Oxide Regulates Neurogenesis in the Hippocampus following Seizures

Hippocampal neurogenesis is changed by brain injury. When neuroinflammation accompanies injury, activation of resident microglial cells promotes the release of inflammatory cytokines and reactive oxygen/nitrogen species like nitric oxide (NO). In these conditions, NO promotes proliferation of neural stem cells (NSC) in the hippocampus. However, little is known about the role of NO in the survival and differentiation of newborn cells in the injured dentate gyrus. Here we investigated the role of NO following seizures in the regulation of proliferation, migration, differentiation, and survival of NSC in the hippocampus using the kainic acid (KA) induced seizuremouse model. We show that NO increased the proliferation of NSC and the number of neuroblasts following seizures but was detrimental to the survival of newborn neurons. NO was also required for the maintenance of long-term neuroinflammation. Taken together, our data show that NO positively contributes to the initial stages of neurogenesis following seizures but compromises survival of newborn neurons.Foundation for Science and Technology (FCT, Portugal); COMPETE; FEDER [PTDC/SAU-NEU/102612/2008, PTDC/NEU-OSD/0473/2012, PEst-C/SAU/LA0001/2013-2014, PEst-OE/EQB/LA0023/2013-2014]; FCT, Portugal [SFRH/BPD/78901/2011, SFRH/BD/77903/2011

Venenos e panaceias do vinho tinto

É o propósito dos autores apresentar nesta comunicação uma reflexão crítica, com base nos dados disponíveis até à data, sobre os fundamentos dos debates recentes sobre segurança alimentar no vinho, bem como sobre o papel do vinho na saúde, usando como caso de estudo dados conjuntos sobre a casta Vinhão, quanto à presença da toxina ocratoxina A e antocianas. Aspectos como a avaliação e gestão do risco quanto à ocratoxina A, em termos de estabelecimento de limites máximos recomendados, e comunicação do risco ao consumidor serão aqui debatidos dos pontos de vista científicos, políticos e económicos, tendo a saúde do consumidor em vista final. Os mesmos pontos são focados na visão inversa, dos compostos com efeito benéficos para a saúde, quanto às antocianas. Um balanço final é apresentado

Soil and climatic influence on the free and glycosidically bound volatiles of grapes from two white varieties from vinhos verdes region

The Vinhos Verdes Region is situated in the northwest of Portugal. The Atlantic Ocean and the relief markedly influence the climate. This region is in Viticultural Zone C I a) of the Winegrowing Regions of the European Communities. The produced wine is unique and its specific characteristics are mainly due to the climate and soil. The white Vinho Verde is softly alcoholic, with a delicate, fresh and fruity bouquet. In this work we investigated the influence of the climate and the soil on the volatile compounds of grapes from two autochthonous white grape varieties, Alvarinho and Loureiro, in two sub-regions for each one of them (Alvarinho - Monção and Lima; Loureiro - Lima and Cávado). The research was carried out during three years: 1996, 1997 and 1998. We found out that the global characteristics of the grapes from the two varieties depend on the harvest factor (climate) rather than on the sub-region where the vine is planted. The characteristics of the soil have an even lesser influence on the variableness of the samples, although the Alvarinho variety picked in the Lima sub-region seems to have different characteristics

C6-alcohols as varietal markers for assessment of wine origin

A significant part of the compounds present in wines having six carbon atoms, the C6-compounds, derive from grape polyunsaturated fatty acids (primarily originated from membrane lipids), namely linoleic and α-linolenic acids, through a cascade of enzymatic reactions. This biochemical pathway yield C6-aldehydes, which are subsequently reduced to C6-alcohols, which can, in turn, be esterified to produce esters. As the C6- compounds derive from varietal precursors, they could hypothetically contribute to judge wine origin and affiliation. In this way, two C6-alcohols, (E)-3-hexenol and (Z)-3-hexenol, have been referred as the most important because its ratio can act as an indicator of the variety of origin. This study presents the results, concerning the concentration of the three main C6-alcohols, 1-hexanol, (E)-3-hexenol and (Z)-3-hexenol, as well as ratios between them, for 43 monovarietal wines from Vinhos Verdes demarcated region, belonging to six white – Alvarinho (8), Arinto (1), Avesso (9), Azal (1), Loureiro (17) and Trajadura (4) – and three red – Amaral (1), Borra¸cal (1) and Vinh˜ao (1) – grape varieties. Wines were produced at experimental scale using slightly different winemaking practices and representing various terroirs and vintages, being analyzed after different conservation periods. The results showed that (E)-3-hexenol/(Z)-3-hexenol ratio clearly discriminates Loureiro wines from those of Alvarinho, Avesso and Trajadura. Moreover, 1-hexanol/(E)-3-hexenol and 1-hexanol/(Z)-3-hexenol ratios may also be able to discriminate Vinhos Verdes monovarietal wines, and can act on a second level differentiation. The remaining monovarietal wines produced results which may be observed as indicative, since only one sample of each was analysed.Comissão de Viticultura da Região dos Vinhos Verdes—EVAG, the Direcção Regional de Agricultura de Entre Douro e Minho—DVF, the Solar de Serrade and the Casa da Tapada Sociedade Agrícola Lda. PO AGRO

Estratégia de implementação do REACH

O regulamento (CE) nº1907/2006 do Parlamento estabelece o registo, avaliação autorização e restrição das substâncias químicas (REACH - Registration, evaluation, authorization and restriction of chemicals) (1) e tem como principais objetivos introduzir restrições quanto à exposição a substâncias químicas com vista a proteção da saúde humana e do ambiente e melhorar a competitividade da indústria química na União Europeia, bem como dar conhecimento dos produtos que circulam (2). O REACH é aplicado não só às substâncias químicas, mas também aos produtos e artigos que as comportam. É direcionado com maior impacto aos fabricantes e importadores de substâncias químicas, no entanto abrange todas as categorias da cadeia de abastecimento das substâncias, misturas ou artigos, incluindo distribuidores e utilizadores a jusante. Importa referir que cada cadeia de abastecimento é distinta e cada categoria pode ter um ou mais agentes. A aplicação do Regulamento está a cargo das empresas associadas a cada substância abrangida, tendo a obrigação de atribuir a cada substância os riscos associados ao seu uso, as aplicações para as quais são criadas e qualquer informação importante para o seu manuseamento. Para casos em que a previsão de riscos possa não ser fiável a substância pode estar sujeita a restrições ou autorização. Após a validação do registo, é partilhada a informação em fóruns, de modo a criar uma partilha de informação entre empresas associadas às mesmas substâncias, incluindo as várias categorias da cadeia de abastecimento (2) . Este trabalho pretende ser um contributo para facilitar a implementação do REACH nas empresas, sendo importante conhecer os vários passos que o Regulamento impõe de acordo com as diversas funções de fabricante, importador ou utilizador à jusante

Stimuli-sensitive self-assembled tubules based on lysine-derived surfactants as nanocarriers for proteins

Drug delivery vectors based on amphiphilic molecules present considerable advantages, namely versatility in physicochemical properties and sensitivity to stimuli. Amino acid-based surfactants, in particular, are rather promising amphiphiles for this purpose1 because of their enhanced biocompatibility compared to conventional surfactants. In addition to forming micelles and vesicles, they can self-organize into other complex supramolecular structures, such as fibers, twisted ribbons, helical tapes and nanotubes.2,3 Herein, we have studied a family of novel anionic double-chained lysine-based surfactants, with variable degree of chain length mismatch. Because of their peculiar structure, these compounds are able to form in water tubular structures with assorted morphologies, as evidenced by video-enhanced light microscopy (VELM), scanning electron microscopy (SEM and cryo-SEM), cryogenic transmission electron microscopy (cryo-TEM) and atomic force microscopy (AFM).3 The loading ability of the tubules towards lysozyme, under varying experimental conditions, has been investigated inter alia by differential scanning microcalorimetry, gel electrophoresis and UV/VIS spectroscopy, with the goal of assessing the efficiency of these aggregates as pH- and temperature-sensitive nanocarriers for a model biomolecule. Results on the stability of the native and loaded tubules when in contact with different fluids (serum, artificial saliva, artificial sweat, blood), and on their toxicity in human cells, are also presented and discussed.FCT is gratefully acknowledged for financial support through Ph.D. grant SFRH/BD/108629/2015. CIQUP acknowledges financial support from FEDER/COMPETE and FCT through grants UID/QUI/00081/2013, POCI-01-0145-FEDER- 006980 and NORTE-01-0145-FEDER-000028

Characterization and differentiation of five “vinhos verdes” grape varieties on the basis of monoterpenic compounds

The aromatic profiles of three white grape varieties (Alvarinho, Loureiro, and Avesso) and two red varieties (Amaral and Vinhão) from the Vinhos Verdes region have been established with respect to the monoterpenic compounds, present either in free and in glycosidically bound fractions. Seventeen compounds have been identified and quantified in the free form and 21 in the glycosidically bound form. Loureiro variety is characterized by important levels of linalool in the free fraction, above the odour perception threshold; in contrast, Alvarinho and Avesso varieties do not contain compounds above the perception threshold. For Alvarinho, geraniol prevails, followed by linalool, while Avesso only has, in much low concentration, geraniol, nerol and citronellol; red varieties do not contain terpenic compounds. Loureiro and Alvarinho are still the richer varieties with regard to the glycosylated fraction; linalool and 3,7-dimethylocta-1,5-dien-3,7-diol have equivalent concentrations, and linalool is around the odour perception threshold; Avesso does not contain linalool. The isomers (Z) and (E) of 8-hydroxylinalool seem to differentiate white varieties; they are similar in Loureiro but the (Z) isomer prevails in Avesso and especially in Alvarinho; Avesso has a more balanced distribution. Amaral only contains α-terpineol, nevertheless of similar concentrator found in Loureiro; Vinhão has a more balanced distribution of isomers but the concentrations are very low. The results show that profiles of the terpenic compounds vary to a significant degree for the grape varieties studied and as is already known empirically, the white varieties are richer than red varieties, especially Loureiro.União Europeia - Fundo Social Europeu (FSE) - Programa Operacional Agricultura e Desenvolvimento Rural (PO AGRO) - Project no. 202

Economia colaborativa e contratação pública: rumo a um modelo aquisitivo mais eficiente e sustentável?

A prossecução da eficiência e da sustentabilidade nas aquisições públicas apelam crescentemente a instrumentos conducentes a sinergias e a ganhos de escala que se cruzam com os propósitos da economia colaborativa, sob um pano de fundo marcadamente inovador e digital. No entanto, esta rota dogmática, em prol da otimização dos escassos recursos de que a comunidade dispõe, corre o risco de ficar aquém dos méritos que lhe estariam subjacentes se a lei portuguesa não contornar algumas das suas debilidades para o efeito.The pursuit of efficiency and sustainability within the scope of public procurement increasingly requires approaches leading to synergies and economies of scale, as advocated by the collaborative economy. Nevertheless, such expectations towards the most fruitful management of resources may also face some risks, which are exacerbated by the Portuguese legal framework