Imprints of the QCD Phase Transition on the Spectrum of Gravitational Waves

We have investigated effects of the QCD phase transition on the relic GW spectrum applying several equations of state for the strongly interacting matter: Besides the bag model, which describes a first order transition, we use recent data from lattice calculations featuring a crossover. Finally, we include a short period of inflation during the transition which allows for a first order phase transition at finite baryon density. Our results show that the QCD transition imprints a step into the spectrum of GWs. Within the first two scenarios, entropy conservation leads to a step-size determined by the relativistic degrees of freedom before and after the transition. The inflation of the third scenario much stronger attenuates the high-frequency modes: An inflationary model being consistent with observation entails suppression of the spectral energy density by a factor of ~10^(-12).Comment: 11 pages, 13 figure

A Practical Algorithm with Performance Guarantees for the Art Gallery Problem

Given a closed simple polygon P, we say two points p,q see each other if the segment seg(p,q) is fully contained in P. The art gallery problem seeks a minimum size set G ? P of guards that sees P completely. The only currently correct algorithm to solve the art gallery problem exactly uses algebraic methods. As the art gallery problem is ? ?-complete, it seems unlikely to avoid algebraic methods, for any exact algorithm, without additional assumptions. In this paper, we introduce the notion of vision-stability. In order to describe vision-stability consider an enhanced guard that can see "around the corner" by an angle of ? or a diminished guard whose vision is by an angle of ? "blocked" by reflex vertices. A polygon P has vision-stability ? if the optimal number of enhanced guards to guard P is the same as the optimal number of diminished guards to guard P. We will argue that most relevant polygons are vision-stable. We describe a one-shot vision-stable algorithm that computes an optimal guard set for vision-stable polygons using polynomial time and solving one integer program. It guarantees to find the optimal solution for every vision-stable polygon. We implemented an iterative vision-stable algorithm and show its practical performance is slower, but comparable with other state-of-the-art algorithms. The practical implementation can be found at: https://github.com/simonheng/AGPIterative. Our iterative algorithm is inspired and follows closely the one-shot algorithm. It delays several steps and only computes them when deemed necessary. Given a chord c of a polygon, we denote by n(c) the number of vertices visible from c. The chord-visibility width (cw(P)) of a polygon is the maximum n(c) over all possible chords c. The set of vision-stable polygons admit an FPT algorithm when parameterized by the chord-visibility width. Furthermore, the one-shot algorithm runs in FPT time when parameterized by the number of reflex vertices

Untersuchungen zur transkriptionellen Regulation des Chromogranin A Gens und seine Anwendung zum zellspezifischen therapeutischen Gentransfer in neuroendokrine Pankreastumorzellen

Die Therapieoptionen zur Behandlung metastasierter neuroendokriner Tumore sind bisher ineffektiv. Der regulierte Gentransfer könnte eine weitere Möglichkeit eröffnen, metastasierte neuroendokrine Tumore zu behandeln. In der vorliegenden Arbeit wurde daher die transkriptionelle Regulation von Chromogranin A als Basis zur Gentherapie durch eine regulierte Genexpression in neuroendokrinen Tumorzellen untersucht. Chromogranin A (CgA) besitzt vielfältige Funktionen in der regulierten Sekretion von Peptidhormonen und Neurotransmittern. Es wird spezifisch in nahezu allen endokrinen und neuroendokrinen Zellen exprimiert und diagnostisch als Marker bei neuroendokrinen Tumorerkrankungen eingesetzt. Zur Identifizierung wichtiger cis-regulatorischer Elemente im humanen Chromogranin A Promotor wurde die 5'-flankierende Sequenz des hCgA Gens auf putative Transkriptionsfaktorbindungsseiten untersucht und eine Interspezieshomologie des humanen, bovinen, murinen und des Rattenchromogranin A Promotors erstellt. Es fand sich eine konservierte Sequenzhomologie in den proximalen Chromogranin A Promotorbereichen mit den putativen Transkriptionsfaktor-Bindungsseiten Egr-1/Sp1, CRE und TATA-Box. Untersuchungen zur zelltypspezifischen Regulation des Chromogranin A Promotors ergaben eine starke Expression von Chromogranin A in neuroendokrinen Pankreastumorzellen BON-1 und der Lungenkarzinomzelllinie EPLC 32M1, während sich nur eine geringe Expression in nicht neuroendokrinen Zelllinien wie z.B. der Fibroblastenzelllinie MSTO-211H zeigte. Die neuroendokrin-spezifische Regulation wurde im hCgA Promotor durch das im proximalen Promotorbereich gelegene CRE vermittelt. Ebenso konnte gezeigt werden, dass Gastrin und cAMP den hCgA Promotor über das CRE regulieren. Unter Anwendung des charakterisierten hCgA Promotors konnte die funktionelle Expression des Natriumjodidsymporters unter der Kontrolle des humanen CgA Promotors in BON 1 Zellen nachgewiesen werden. Dies bildet einen vielversprechenden neuen Therapieansatz, durch einen regulierten Gentransfer neuroendokrine Tumorzellen mittels einer Radiojodtherapie in Analogie zu Schilddrüsenkarzinomen zu behandeln

Lower Bounds for Ground States of Condensed Matter Systems

Standard variational methods tend to obtain upper bounds on the ground state energy of quantum many-body systems. Here we study a complementary method that determines lower bounds on the ground state energy in a systematic fashion, scales polynomially in the system size and gives direct access to correlation functions. This is achieved by relaxing the positivity constraint on the density matrix and replacing it by positivity constraints on moment matrices, thus yielding a semi-definite programme. Further, the number of free parameters in the optimization problem can be reduced dramatically under the assumption of translational invariance. A novel numerical approach, principally a combination of a projected gradient algorithm with Dykstra's algorithm, for solving the optimization problem in a memory-efficient manner is presented and a proof of convergence for this iterative method is given. Numerical experiments that determine lower bounds on the ground state energies for the Ising and Heisenberg Hamiltonians confirm that the approach can be applied to large systems, especially under the assumption of translational invariance.Comment: 16 pages, 4 figures, replaced with published versio

Measuring children’s harmonic knowledge with implicit and explicit tests

We uses implicit and explicit tasks to measure knowledge of Western harmony in musically trained and untrained Canadian children. Younger children were 6-7 years of age; older children were 10-11. On each trial, participants heard a sequence of five piano chords. The first four chords established a major-key context. The final chord was the standard, expected tonic of the context or one of two deviant endings: the highly unexpected flat supertonic or the moderately unexpected subdominant. In the implicit task, children identified the timbre of the final chord (guitar or piano) as quickly as possible. Response times were faster for the tonic ending than for either deviant ending, but the magnitude of the priming effect was similar for the two deviants, and the effect did not vary as a function of age or music training. In the explicit task, children rated how good each chord sequence sounded. Ratings were highest for sequences with the tonic ending, intermediate for the subdominant, and lowest for the flat supertonic. Moreover, the difference between the tonic and deviant sequences was larger for older children with music training. Thus, the explicit task provided a more nuanced picture of musical knowledge than did the implicit task.info:eu-repo/semantics/acceptedVersio