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Bingen am Rhein, Germany

Yurova A.Y.,Russian Academy of Sciences | Volodin E.M.,Hydrometcentre of Russia | Agren G.I.,Swedish University of Agricultural Sciences | Chertov O.G.,Bingen University of Applied Sciences | Komarov A.S.,Russian Academy of Sciences
Global Change Biology | Year: 2010

Climatic variables have major effects on all components and processes of the global carbon (C) cycle, including soil C contents and dynamics, which in turn have significant feedback effects on the global climate. We have investigated the interactive effects between soil C and projected climatic changes using the Institute of Numerical Mathematics Climate Model (INMCM) climate-C cycle model coupled to three soil organic matter dynamics models [the Lund-Potsdam-Jena (LPJ) soil biogeochemistry, ROMUL and Q models] based on three markedly differing conceptual interpretations of soil organic matter transformation (biochemical, discrete succession and continuous quality, respectively). According to simulations using all these couplings the positive effect of CO2 fertilization on plant productivity outweighed the negative effects of increased soil temperature on soil C, consequently soils were projected to contain 10-104 Pg more C in 2100 than in the preindustrial period. However, the projected soil respiration rates tended to be higher and additional C storage lower when the LPJ soil biochemistry model was used rather than either the ROMUL or Q models. Global temperatures for 2100 predicted by the INMCM coupled to either the ROMUL or Q models were almost identical, but 0.4 °C lower than those predicted by the INMCM coupled to the LPJ soil biochemistry model. The differences in global predictions obtained with the ROMUL and Q models were smaller than expected given the fundamental difference in their formulations of the relationship between the quality and temperature sensitivity of soil organic matter decomposition. © 2009 Blackwell Publishing Ltd. Source

Winkel R.,Bingen University of Applied Sciences
Computer Aided Geometric Design | Year: 2016

The investigation of a--Bernstein polynomials and a--Bézier curves is continued in this paper. It is shown that convolution of the parameters a-=(a-1,...,a-n) is fundamental for (1) the definition of a--Bernstein polynomials, (2) a simplified derivation of the a--de Casteljau algorithm, (3) the recurrences that give the blossoming of a--Bernstein polynomials and a--Bézier curves, (4) the dual functional property and the a--dual functional property for an a--Bézier curve - it is necessary to make this distinction - and (5) the a--degree elevation. © 2016 Elsevier B.V. Source

Czemmel S.,Center for Organismal Studies Heidelberg Heidelberg | Heppel S.C.,Center for Organismal Studies Heidelberg Heidelberg | Bogs J.,German Aerospace Center | Bogs J.,Bingen University of Applied Sciences
Protoplasma | Year: 2012

Flavonoids compose one of the most abundant and important subgroups of secondary metabolites with more than 6,000 compounds detected so far in higher plants. They are found in various compositions and concentrations in nearly all plant tissues. Besides the attraction of pollinators and dispersers to fruits and flowers, flavonoids also protect against a plethora of stresses including pathogen attack, wounding and UV irradiation. Flavonoid content and composition of fruits such as grapes, bilberries, strawberries and apples as well as food extracts such as green tea, wine and chocolate have been associated with fruit quality including taste, colour and health-promoting effects. To unravel the beneficial potentials of flavonoids on fruit quality, research has been focused recently on the molecular basis of flavonoid biosynthesis and regulation in economically important fruit-producing plants such as grapevine (Vitis vinifera L.). Transcription factors and genes encoding biosynthetic enzymes have been characterized, studies that set a benchmark for future research on the regulatory networks controlling flavonoid biosynthesis and diversity. This review summarizes recent advances in the knowledge of regulatory cascades involved in flavonoid biosynthesis in grapevine. Transcriptional regulation of flavonoid biosynthesis during berry development is highlighted, with a particular focus on MYB transcription factors as molecular clocks, key regulators and powerful biotechnological tools to identify novel pathway enzymes to optimize flavonoid content and composition in grapes. © 2012 Springer-Verlag. Source

Winkel R.,Bingen University of Applied Sciences
Computer Aided Geometric Design | Year: 2014

In Winkel (2001) a generalization of Bernstein polynomials and Bézier curves based on umbral calculus has been introduced. In the present paper we describe new geometric and algorithmic properties of this generalization including: (1) families of polynomials introduced by Stancu (1968) and Goldman (1985), i.e., families that include both Bernstein and Lagrange polynomial, are generalized in a new way, (2) a generalized de Casteljau algorithm is discussed, (3) an efficient evaluation of generalized Bézier curves through a linear transformation of the control polygon is described, (4) a simple criterion for endpoint tangentiality is established. © 2014 Elsevier B.V. Source

Hichri I.,Institut Universitaire de France | Hichri I.,Catholic University of Louvain | Barrieu F.,Institut Universitaire de France | Bogs J.,German Aerospace Center | And 4 more authors.
Journal of Experimental Botany | Year: 2011

Flavonoids are secondary metabolites involved in several aspects of plant development and defence. They colour fruits and flowers, favouring seed and pollen dispersal, and contribute to plant adaptation to environmental conditions such as cold or UV stresses, and pathogen attacks. Because they affect the quality of flowers (for horticulture), fruits and vegetables, and their derivatives (colour, aroma, stringency, etc.), flavonoids have a high economic value. Furthermore, these compounds possess pharmaceutical properties extremely attractive for human health. Thanks to easily detectable mutant phenotypes, such as modification of petal pigmentation and seeds exhibiting transparent testa, the enzymes involved in the flavonoid biosynthetic pathway have been characterized in several plant species. Conserved features as well as specific differences have been described. Regulation of structural gene expression appears tightly organized in a spatial and temporal way during plant development, and is orchestrated by a ternary complex involving transcription factors from the R2R3-MYB, basic helix-loop-helix (bHLH), and WD40 classes. This MYB-bHLH-WD40 (MBW) complex regulates the genes that encode enzymes specifically involved in the late steps of the pathway leading to the biosynthesis of anthocyanins and condensed tannins. Although several genes encoding transcription factors from these three families have been identified, many gaps remain in our understanding of the regulation of this biosynthetic pathway, especially about the respective roles of bHLH and WD40 proteins. A better knowledge of the regulatory mechanisms of the flavonoid pathway is likely to favour the development of new biotechnological tools for the generation of value-added plants with optimized flavonoid content. © The Author [2011]. Source

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