Karotten von der Saat bis zum Teller - Einfluss von Sorte, Standort, Jahr, Anbauweise und Lagerung auf den Carotingehalt

Karotten sind ergiebige Quellen an a- und ß-Carotin und weiterer sekundärer Pflanzenstoffe (SPS). Es ist bekannt, dass viele SPS auch für Geschmack, Aroma und Farbe eine Rolle spielen. Der Einfluss von Vorernte- und Nacherntefaktoren auf den Gehalt an SPS gewinnt deshalb zunehmend an Bedeutung. Für die Entwicklung eines Qualitätssicherungskonzepts sind die Kenntnisse über die Auswirkung dieser Faktoren unumgänglich

Mid-Pleistocene and Holocene demographic fluctuation of Scots pine (Pinus sylvestris L.) in the Carpathian Mountains and the Pannonian Basin: Signs of historical expansions and contractions

Climate fluctuations of the Quaternary caused radical changes in distribution of tree species and resulted in large-scale range shifts, population contractions and expansions. Scots pine (Pinus sylvestris L.) a widely distributed conifer of the boreal regions underwent spatio-temporal changes, which shaped the modern-day genetic structure and phylogeographic pattern of the species. By applying independent approaches, including molecular genetic data and historical climate models we aimed to describe demography and past distribution patterns of Scots pine populations from the highly fragmented southern periphery, the Carpathians and the Pannonian Basin. We used Approximate Bayesian Computation (ABC) approach based on nuclear microsatellite markers (nSSRs) and Maximum Entropy distribution modelling (MaxEnt) with temperature- and precipitation-related bioclimatic data. ABC results indicated that from an ancestral Scots pine population two genetic lineages have diverged that in the Mid-Pleistocene due to the favourable climatic conditions underwent population expansion leading to an admixture event. The outcome of the hindcasting confirmed the expansion that leaded to the admixture event revealed by the ABC analysis. This can be dated to the Late Glacial period (14,160–11,800 yrs BP), in which widespread distribution of Scots pine in accordance with palynological proxies was detected. Predictions for the Mid-Holocene period have shown large-scale reduction in distribution of Scots pine and low probability of its occurrence, leading to disjunction and population fragmentation

Atomic scale analysis of the GaP Si 100 heterointerface by in situ reflection anisotropy spectroscopy and ab initio density functional theory

A microscopic understanding of the formation of polar on nonpolar interfaces is a prerequisite for well defined heteroepitaxial preparation of III V compounds on 100 silicon for next generation high performance devices. Energetically and kinetically driven Si 100 step formations result in majority domains of monohydride terminated Si dimers oriented either parallel or perpendicular to the step edges. Here, the intentional variation of the Si 100 surface reconstruction controls the sublattice orientation of the heteroepitaxial GaP film, as observed by in situ reflection anisotropy spectroscopy RAS in chemical vapor ambient and confirmed by benchmarking to surface science analytics in ultrahigh vacuum. Ab initio density functional calculations of both abrupt and compensated interfaces are carried out. For P rich chemical potentials at abrupt interfaces, Si P bonds are energetically favored over Si Ga bonds, in agreement with in situ RAS experiments. The energetically most favorable interface is compensated with an intermixed interfacial layer. In situ RAS reveals that the GaP sublattice orientation depends on the P chemical potential during nucleation, which agrees with a kinetically limited formation of abrupt interface

(Broken) Gauge Symmetries and Constraints in Regge Calculus

We will examine the issue of diffeomorphism symmetry in simplicial models of (quantum) gravity, in particular for Regge calculus. We find that for a solution with curvature there do not exist exact gauge symmetries on the discrete level. Furthermore we derive a canonical formulation that exactly matches the dynamics and hence symmetries of the covariant picture. In this canonical formulation broken symmetries lead to the replacements of constraints by so--called pseudo constraints. These considerations should be taken into account in attempts to connect spin foam models, based on the Regge action, with canonical loop quantum gravity, which aims at implementing proper constraints. We will argue that the long standing problem of finding a consistent constraint algebra for discretized gravity theories is equivalent to the problem of finding an action with exact diffeomorphism symmetries. Finally we will analyze different limits in which the pseudo constraints might turn into proper constraints. This could be helpful to infer alternative discretization schemes in which the symmetries are not broken.Comment: 32 pages, 15 figure

Role of Gd in Enhancing the Charge Carrier Mobility of Spray Deposited BiVO4 Photoanodes

The emergence of bismuth vanadate BiVO4 as one of the most promising photoanodes for solar water splitting is largely driven by the successful efforts of dopant introduction and optimization to improve its photoelectrochemical PEC performance. To this end, although less commonly used, several trivalent ions e.g., Sm3 , In3 , Gd3 that substitute Bi3 have also been demonstrated to be effective dopants, which can increase the photocurrent density of BiVO4 photoanodes. However, the main factor behind such improvement is still unclear, as various explanations have been proposed in the literature. Herein, Gd3 is introduced to substitute Bi3 in spray deposited BiVO4 films, which enables up to a 2 fold increase in the photocurrent density. Further PEC analysis suggests that Gd doping enhances the charge carrier separation in the BiVO4 films and does not affect the catalytic and optical properties. Indeed, time resolved microwave conductivity TRMC measurements reveal that the charge carrier mobility of BiVO4 is increased by 50 with the introduction of Gd while the charge carrier lifetime is unaffected. This increase of mobility is rationalized to be a result of a higher degree of monoclinic lattice distortion in Gd doped BiVO4, as evident from the X ray diffraction and Raman spectroscopy data. Overall, these findings provide important insights into the nature and the underlying role of Gd in improving the photoelectrochemical performance of BiVO4 photoanode

Interfering Doorway States and Giant Resonances. I: Resonance Spectrum and Multipole Strengths

A phenomenological schematic model of multipole giant resonances (GR) is considered which treats the external interaction via common decay channels on the same footing as the coherent part of the internal residual interaction. The damping due to the coupling to the sea of complicated states is neglected. As a result, the formation of GR is governed by the interplay and competition of two kinds of collectivity, the internal and the external one. The mixing of the doorway components of a GR due to the external interaction influences significantly their multipole strengths, widths and positions in energy. In particular, a narrow resonance state with an appreciable multipole strength is formed when the doorway components strongly overlap.Comment: 20 pages, LaTeX, 3 ps-figures, to appear in PRC (July 1997