300 research outputs found

    Catálogo de Melastomataceae de Guinea Ecuatorial

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    A chec klist of the Melastomataceae of Equatorial Guinea is presented with 57 taxa. Three species were accepted based only on literature records, their distribution área strongly suggests their presence in Equatorial Guinea. Six species are known from Annobón, 23 from Bioko and 49 from Río Muni. Best-represented genera are Memecylon (10), Calvoa (10) and Tristemma (7). Twenty-six taxa are newly recorded for the country. Heterotis obamae Lejoly & Lisowski is set in synonymy with the previously described Heterotis arenaria Jacq.-Fél.Se presenta el catálogo florístico de la familia Melastomataceae en Guinea Ecuatorial. Se recogen un total de 57 táxones. Tres especies fueron aceptadas teniendo en cuenta solamente la literatura. Su distribución sugiere que su presencia en Guinea Ecuatorial es muy probable. En Annobón están presentes 6 especies, 23 en Bioko y 49 en Río Muni. Los géneros mejor representados son Memecylon (10 especies), Calvoa (10) y Tristemma (7).Veintiséis táxones son citados por primera vez en Guinea Ecuatorial. Se propone Heterotis obamae Lejoly & Lisowski como sinónimo de Heterotis arenaria Jacq.-Fél

    Fully embedded optical and electrical interconnections in flexible foils

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    This paper presents the development of a technology platform for the full integration of opto-electronic and electronic components, as well as optical interconnections in a flexible foil. A technology is developed to embed ultra thin (20 μ m) VCSEL's and Photodiodes in layers of optical transparent material. These layers are sandwiched in between two Polyimide layers to get a flexible foil with a final stack thickness of 150 μ m. Optical waveguides are structured by photolithography in the optical layers and pluggable mirror components couple the light from the embedded opto-electronics in and out of the waveguides. Besides optical links and optoelectronic components, electrical circuitry is also embedded by means of embedded copper tracks and thinned down Integrated Circuits (20 μ m). Optical connection towards the outer world is realized by U-groove passive alignment coupling of optical fibers with the embedded waveguides

    Development and characterization of composites consisting of woven fabrics with integrated prismatic shaped cavities

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    Composites are extensively used in automotive, construction, airplanes, wind turbines etc. because of their good mechanical properties such as high specific stiffness, high specific strength and resistance against fatigue. The main issues with composites are delamination and the manual labour in the production process. If hollow structures like stiffeners need to be manufactured, these problems become even more apparent. As a result, there is a lot of interest in woven fabrics with integrated prismatic shaped cavities for composites as they reduce the manual labour, have a higher resistance against delamination and can lead to special properties and applications. In this work several of these woven fabrics with integrated prismatic shaped cavities are designed and produced in high-tenacity polyester yarns. Then, the possibility to use these fabrics in composites is explored: reproducibility of the production process is assessed and static testing is performed. A reproducible production process is developed and static testing shows promising results

    Mutation of the inducible ARABIDOPSIS THALIANA CYTOCHROME P450 REDUCTASE2 alters lignin composition and improves saccharification

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    ARABIDOPSIS THALIANA CYTOCHROME P450 REDUCTASE1 (ATR1) and ATR2 provide electrons from NADPH to a large number of CYTOCHROME P450 (CYP450) enzymes in Arabidopsis (Arabidopsis thaliana). Whereas ATR1 is constitutively expressed, the expression of ATR2 appears to be induced during lignin biosynthesis and upon stresses. Therefore, ATR2 was hypothesized to be preferentially involved in providing electrons to the three CYP450s involved in lignin biosynthesis: CINNAMATE 4-HYDROXYLASE (C4H), p-COUMARATE 3-HYDROXYLASE1 (C3H1), and FERULATE 5-HYDROXYLASE1 (F5H1). Here, we show that the atr2 mutation resulted in a 6% reduction in total lignin amount in the main inflorescence stem and a compositional shift of the remaining lignin to a 10-fold higher fraction of p-hydroxyphenyl units at the expense of syringyl units. Phenolic profiling revealed shifts in lignin-related phenolic metabolites, in particular with the substrates of C4H, C3H1 and F5H1 accumulating in atr2 mutants. Glucosinolate and flavonol glycoside biosynthesis, both of which also rely on CYP450 activities, appeared less affected. The cellulose in the atr2 inflorescence stems was more susceptible to enzymatic hydrolysis after alkaline pretreatment, making ATR2 a potential target for engineering plant cell walls for biofuel production
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