Open FRW model in Loop Quantum Cosmology

Open FRW model in Loop Quantum Cosmology is under consideration. The left and right invariant vector fields and holonomies along them are studied. It is shown that in the hyperbolic geometry of $k=-1$ it is possible to construct a suitable loop which provides us with quantum scalar constraint originally introduced by Vandersloot. The quantum scalar constraint operator with negative cosmological constant is proved to be essentially self-adjoint.Comment: 12 pages, no figures, late

Effective dynamics of the closed loop quantum cosmology

In this paper we study dynamics of the closed FRW model with holonomy corrections coming from loop quantum cosmology. We consider models with a scalar field and cosmological constant. In case of the models with cosmological constant and free scalar field, dynamics reduce to 2D system and analysis of solutions simplify. If only free scalar field is included then universe undergoes non-singular oscillations. For the model with cosmological constant, different behaviours are obtained depending on the value of $\Lambda$. If the value of $\Lambda$ is sufficiently small, bouncing solutions with asymptotic de Sitter stages are obtained. However if the value of $\Lambda$ exceeds critical value $\Lambda_{\text{c}} =\frac{\sqrt{3}m^2_{\text{Pl}}}{2\pi\gamma^3} \simeq 21 m^2_{\text{Pl}}$ then solutions become oscillatory. Subsequently we study models with a massive scalar field. We find that this model possess generic inflationary attractors. In particular field, initially situated in the bottom of the potential, is driven up during the phase of quantum bounce. This subsequently leads to the phase of inflation. Finally we find that, comparing with the flat case, effects of curvature do not change qualitatively dynamics close to the phase of bounce. Possible effects of inverse volume corrections are also briefly discussed.Comment: 18 pages, 11 figure

Eber und Börge im Vergleich – Auswirkungen der Kastration auf agonistisches und sexuell motiviertes Verhalten unter ökologischen Haltungsbedingungen

Nach dem Verbot der betäubungslosen Ferkelkastration nach VO (EG) 889 (2008) zum 01.01.2012 stellt die Ebermast eine mögliche Alternative für die ökologische Schweinefleischerzeugung dar. Im Rahmen des Projektes „Ebermast im Verbund: Entwicklung eines Konzepts für die Produktion, Schlachtung, Verarbeitung und Vermarktung ökologisch erzeugter Eber entlang der Wertschöpfungskette“ ist es ein Ziel, das Ausmaß möglichen unerwünschten Verhaltens, wie agonistische Interaktionen und Aufreitverhalten der Eber, mit dem von Börgen unter praxisüblichen ökologischen Haltungsbedingungen zu vergleichen und wichtige Einflussfaktoren hierauf zu identifizieren. Auch mögliche Verletzungsfolgen sollen einbezogen werden. Aus einer Zwischenauswertung werden hier erste Ergebnisse zum Ausmaß des genannten Verhaltens und der Verletzungsfolgen vorgestellt. 9 Gruppen Eber und 7 Gruppen Börge wurden mit einem Lebendgewicht von etwa 80 kg auf vier ökologischen Praxisbetrieben beobachtet. Agonistische Interaktionen (Kopfschlagen, Beißen, Kampf und Besteigen ohne sexuelle Motivation) und Besteigen mit sexueller Motivation wurden mittels kontinuierlicher Verhaltenszählung (continuous behaviour sampling) jeweils über die ersten 15 Minuten einer jeden Lichtstunde von zusammenhängenden 48h-Aufnahmen ausgewertet. Zum selben Zeitpunkt wurden zusätzlich die Verletzungen bei den 109 Ebern und 91 Börgen gezählt. Eber zeigten bezüglich aller erhobener Verhaltensparameter gegenüber den Börgen signifikant höhere Häufigkeiten bzw. Dauern. Dagegen konnten hinsichtlich der Verletzungsscores zwischen Ebern und Börgen keine signifikanten Unterschiede festgestellt werden. Die Untersuchung wird fortgesetzt

The status of Quantum Geometry in the dynamical sector of Loop Quantum Cosmology

This letter is motivated by the recent papers by Dittrich and Thiemann and, respectively, by Rovelli discussing the status of Quantum Geometry in the dynamical sector of Loop Quantum Gravity. Since the papers consider model examples, we also study the issue in the case of an example, namely on the Loop Quantum Cosmology model of space-isotropic universe. We derive the Rovelli-Thiemann-Ditrich partial observables corresponding to the quantum geometry operators of LQC in both Hilbert spaces: the kinematical one and, respectively, the physical Hilbert space of solutions to the quantum constraints. We find, that Quantum Geometry can be used to characterize the physical solutions, and the operators of quantum geometry preserve many of their kinematical properties.Comment: Latex, 12 page

A Common Precursor Approach to Structurally Diverse Natural Products: The Synthesis of the Core Structure of (±)-Clausenamide and the Total Synthesis of (±)-Hyalodendrin

Structurally diverse natural products from unrelated sources typically require the development of individual synthetic routes. In a novel approach, we have shown that the epidithiodiketopiperazine-derived natural product (±)-hyalodendrin and the core structure of the unrelated pyrrolidine-derived natural product clausenamide can be synthesised from a common synthetic precursor in good yield by simple variation of the reaction conditions

Loop Quantum Cosmology corrections to inflationary models

In the recent years the quantization methods of Loop Quantum Gravity have been successfully applied to the homogeneous and isotropic Friedmann-Robertson-Walker space-times. The resulting theory, called Loop Quantum Cosmology (LQC), resolves the Big Bang singularity by replacing it with the Big Bounce. We argue that LQC generates also certain corrections to field theoretical inflationary scenarios. These corrections imply that in the LQC the effective sonic horizon becomes infinite at some point after the bounce and that the scale of the inflationary potential implied by the COBE normalisation increases. The evolution of scalar fields immediately after the Bounce becomes modified in an interesting way. We point out that one can use COBE normalisation to establish an upper bound on the quantum of length of LQG.Comment: 16 pages, 1 figure, plain Late

Beyond deficiency:Potential benefits of increased intakesof vitamin K for bone and vascular health

Vitamin K is wellknown for its role in the synthesisof a number of blood coagulationfactors.During recent years vitaminK-dependent proteins werediscovered to be of vital importancefor bone and vascular health.Recommendations for dietary vitaminK intake have been made onthe basis of the hepatic requirementsfor the synthesis of bloodcoagulation factors.Accumulatingevidence suggests that the requirementsfor other functions thanblood coagulation may be higher.This paper is the result of a closedworkshop (Paris,November 2002)in which a number of Europeanvitamin K experts reviewed theavailable data and formulated theirstandpoint with respect to recommendeddietary vitamin K intakeand the use of vitamin K-containingsupplements