Slow quench dynamics of Mott-insulating regions in a trapped Bose gas

We investigate the dynamics of Mott-insulating regions of a trapped bosonic gas as the interaction strength is changed linearly with time. The bosonic gas considered is loaded into an optical lattice and confined to a parabolic trapping potential. Two situations are addressed: the formation of Mott domains in a superfluid gas as the interaction is increased, and their melting as the interaction strength is lowered. In the first case, depending on the local filling, Mott-insulating barriers can develop and hinder the density and energy transport throughout the system. In the second case, the density and local energy adjust rapidly whereas long range correlations require longer time to settle. For both cases, we consider the time evolution of various observables: the local density and energy, and their respective currents, the local compressibility, the local excess energy, the heat and single particle correlators. The evolution of these observables is obtained using the time-dependent density-matrix renormalization group technique and comparisons with time-evolutions done within the Gutzwiller approximation are provided.Comment: 15 pages, 13 figure

Downregulation of Tumor Necrosis Factor Expression in the Human Mono-Mac-6 Cell Line

Mono-Mac-6 cells, but not U937 cells, can be Induced to rapidly express tumor necrosis factor (TNF) mRNA and protein when triggered with Ilpopolysaccharlde (LPS) at 1 pg/mI. Preincubatlon of the cells for 3 d with low amounts of LPS (10 ng/mI) results In nearly complete suppression of TNF secretion. This downreguiatlon appears to occur at the pretranslational level since specIfIc mRNA is virtually undetectable under these conditions. By contrast, the same prelncubatlon with 10 ng/mI LPS results in enhanced phagocytosls (28.6-67.2% for Staphylococcus aureus), demonstrating that not all monocyte functions are suppressed. While these results show that only stringent exclusion of LPS from culture media allows for Induction of TNF In the Mono-Mac-6 cell line, the pronounced effect of LPS preincubatlon may also provide a suitable model with which to study the mechanisms of LPS-lnduced desensitizatIon

Real-time dynamics in spin-1/2 chains with adaptive time-dependent DMRG

We investigate the influence of different interaction strengths and dimerizations on the magnetization transport in antiferromagnetic spin-1/2 XXZ-chains. We focus on the real-time evolution of the inhomogeneous initial state with all spins pointing up along the z axis in the left half and down in the right half of the chain, using the adaptive time-dependent density-matrix renormalization group (adaptive t-DMRG). We find on time-scales accessible to us ballistic magnetization transport for small Sz-Sz-interaction and arbitrary dimerization, but almost no transport for stronger Sz-Sz-interaction, with a sharp crossover at Jz=1. At Jz=1 results indicate superdiffusive transport. Additionally, we perform a detailed analysis of the error made by the adaptive time-dependent DMRG using the fact that the evolution in the XX-model is known exactly. We find that the error at small times is dominated by the error made by the Trotter decomposition, whereas for longer times the DMRG truncation error becomes the most important, with a very sharp crossover at some "runaway" time.Comment: 13 pages, 20 figure

Werbenutzen einer unterhaltenden Website : eine Untersuchung am Beispiel der Moorhuhnjagd

Jedes Jahr steigt die Zahl der Internet-Nutzer, in Deutschland sind es mittlerweile 19,5 Millionen. Als Konsequenz können immer mehr Menschen von Unternehmen über das Internet erreicht werden. Das Schlagwort des e-Commerce beherrscht die Diskussion. Aber auch Unternehmen, die das Internet nicht als Handelsplattform verwenden, sind im Internet mit eigenen Homepages präsent. Sie nutzen es zur Kommunikationspolitik. Dabei ist bei zu Werbezwecken designten Homepages der werbliche Kommunikationsprozess im Vergleich zu den klassischen Medien umgedreht. Der User wird nicht passiv von einem Unternehmen mit Werbung "berieselt", sondern muss eine Seite aktiv aufrufen. Dies tut er nur, wenn er sich hiervon einen Nutzen verspricht. Im Fall von High-Involvement Produkten zieht er einen Informationsnutzen aus einer entsprechend informativen Homepage. Bei Low-Involvement Produkten sucht der Konsument nicht nach Informationen. Er besucht eine Homepage nur, wenn er einen Unterhaltungsnutzen erwartet. Wechselt man die Perspektive vom Nachfrager zum Anbieter, stellt sich die bis dato noch nicht durch eine empirische Untersuchung beantwortete Frage, was für Vorteile ein Unternehmen aus der Bereitstellung einer unterhaltenden Werbe­homepage ziehen kann. Als relevante Werbeziele wurden die Steigerung der aktiven Markenbekanntheit, die Veränderung des Image, der Aufbau neuer und lebendiger Markenbilder sowie eine Erhöhung der Kaufabsicht untersucht. Um Veränderungen nachweisen zu können, wurden zwei Gruppen befragt. Eine Gruppe hatte das Internet-Spiel Moorhuhnjagd von Johnnie Walker, das als beispielhafter Inhalt einer unterhaltenden Werbehomepage gelten kann, gespielt, die andere nicht. Spieler nehmen das Image dieser Marke signifikant trendgemäßer wahr und haben lebendigere innere Bilder zu Johnnie Walker als Nicht-Spieler. Das Moorhuhn konnte innerhalb kurzer Zeit als neues Markenbild etabliert werden

Efficient Algorithms for Moral Lineage Tracing

Lineage tracing, the joint segmentation and tracking of living cells as they move and divide in a sequence of light microscopy images, is a challenging task. Jug et al. have proposed a mathematical abstraction of this task, the moral lineage tracing problem (MLTP), whose feasible solutions define both a segmentation of every image and a lineage forest of cells. Their branch-and-cut algorithm, however, is prone to many cuts and slow convergence for large instances. To address this problem, we make three contributions: (i) we devise the first efficient primal feasible local search algorithms for the MLTP, (ii) we improve the branch-and-cut algorithm by separating tighter cutting planes and by incorporating our primal algorithms, (iii) we show in experiments that our algorithms find accurate solutions on the problem instances of Jug et al. and scale to larger instances, leveraging moral lineage tracing to practical significance.Comment: Accepted at ICCV 201

Interaction-induced impeding of decoherence and anomalous diffusion

We study how the interplay of dissipation and interactions affects the dynamics of a bosonic many-body quantum system. In the presence of both dissipation and strongly repulsive interactions, observables such as the coherence and the compressibility display three dynamical regimes: an initial exponential variation followed by a power-law regime and finally a slow exponential convergence to their asymptotic values corresponding to the infinite temperature state. These very long-time scales arise as dissipation forces the population of states disfavored by interactions. The long-time, strong coupling dynamics are understood by performing a mapping onto a classical diffusion process displaying non-Brownian behavior. While both dissipation and strong interactions tend to suppress coherence when acting separately, we find that strong interaction impedes the decoherence process generated by the dissipation.Comment: 5 pages, 3 figure

Controllable manipulation and detection of local densities and bipartite entanglement in a quantum gas by a dissipative defect

We study the complex dynamics of a one-dimensional Bose gas subjected to a dissipative local defect which induces one-body atom losses. In experiments these atom losses occur, for example, when a focused electron or light beam or a single trapped ion is brought into contact with a quantum gas. We discuss how within such setups one can measure or manipulate densities locally and specify the excitations that are induced by the defect. In certain situations the defect can be used to generate entanglement in a controlled way despite its dissipative nature. The careful examination of the interplay between hole excitations and the collapse of the wave function due to nondetection of loss is crucial for the understanding of the dynamics we observe.Comment: 4+ pages, 3 figure

Examining the Preparedness of Educational Diagnosticians in Texas

This study examined the extent to which educational diagnosticians in Texas perceived their certification program prepared them with the professional knowledge recommended by the Council for Exceptional Children’s Advanced Preparation Standards Specialty Set: Special Education Diagnostician Specialist (CEC, 2015). A total of 113 currently practicing educational diagnosticians in Texas responded to a 28-item survey based on the CEC standards for educational diagnosticians. Participants reported being less prepared to meet standards related to collaboration, vocational and assessment measures, behavior assessment measures, and language assessment measures. Diagnosticians working in urban school districts reported lower levels of preparation as compared to those working in suburban and rural school districts on standards related to assessment. Recommendations for educator preparation programs for educational diagnosticians are discussed

Ergodic directions for billiards in a strip with periodically located obstacles

We study the size of the set of ergodic directions for the directional billiard flows on the infinite band $\R\times [0,h]$ with periodically placed linear barriers of length $0<\lambda<h$. We prove that the set of ergodic directions is always uncountable. Moreover, if $\lambda/h\in(0,1)$ is rational the Hausdorff dimension of the set of ergodic directions is greater than 1/2. In both cases (rational and irrational) we construct explicitly some sets of ergodic directions.Comment: The article is complementary to arXiv:1109.458

Structural characterization and photochemical properties of mono-and bimetallic Cu-Mabiq complexes

A series of mono- and bimetallic copper-Mabiq complexes is described. One-electron reduction of the CuII and CuICuII complexes is ligand-centered, yielding the (Mabiq•) form of the macrocycle. Both bimetallic compounds are thus mixed-valent with respect to the metal ions. The influence of the outer copper ion on the redox, spectroscopic, and photochemical properties of the central ion was examined. The two metals ions interact weakly, such that the photoactivity of the central Cu-Mabiq unit is retained