Survey of Beam Optics Solutions for the MLS Lattice

The Metrology Light Source MLS is an electron storage ring containing 24 quadrupole magnets which can be powered individually. Fully exploring the capabilities of the machine optics by tracking or experiment would be very time consuming. Therefore the quadrupoles were combined in five families and a numerical brute force approach was used to scan for areas of stable solutions in the scope of linear beam optics. In order to get information on the expected beam lifetimes for each generated optics, a model for the Touschek lifetime was implemented. Simulation results as well as experimental tests of selected optics will be presente

Lifetime Studies at Metrology Light Source and ANKA

The Metrology Light Source MLS , situated in Berlin Germany is an electron storage ring operating from 105 MeV to 630 MeV and is serving as the national primary radiation source standard from the near infrared to the extrem ultraviolet spectral region [1]. In its standard user mode, the lifetime is dominated by the Touschek effect. Measurements and analysis of the Touschek lifetime as a function of beam current and RF Voltage will be presented and compared to measurements done at the A amp; 730; ngstro mquelle Karlsruhe ANKA electron storage ring Karlsruhe, Germany which operates at 0.5 to 2.5 GeV [2

Cat States and Single Runs for the Damped Harmonic Oscillator

We discuss the fate of initial states of the cat type for the damped harmonic oscillator, mostly employing a linear version of the stochastic Schr\"odinger equation. We also comment on how such cat states might be prepared and on the relation of single realizations of the noise to single runs of experiments.Comment: 18, Revte

Cdc53p acts in concert with Cdc4p and Cdc34p to control the G1 to S phase transition and identifies a conserved family of proteins

Regulation of cell cycle progression occurs in part through the targeted degradation of both activating and inhibitory subunits of the cyclin-dependent kinases. During G1, CDC4, encoding a WD-40 repeat protein, and CDC34, encoding a ubiquitin-conjugating enzyme, are involved in the destruction of these regulators. Here we describe evidence indicating that CDC53 also is involved in this process. Mutations in CDC53 cause a phenotype indistinguishable from those of cdc4 and cdc34 mutations, numerous genetic interactions are seen between these genes, and the encoded proteins are found physically associated in vivo. Cdc53p defines a large family of proteins found in yeasts, nematodes, and humans whose molecular functions are uncharacterized. These results suggest a role for this family of proteins in regulating cell cycle proliferation through protein degradation

Optimal control of entanglement via quantum feedback

It has recently been shown that finding the optimal measurement on the environment for stationary Linear Quadratic Gaussian control problems is a semi-definite program. We apply this technique to the control of the EPR-correlations between two bosonic modes interacting via a parametric Hamiltonian at steady state. The optimal measurement turns out to be nonlocal homodyne measurement -- the outputs of the two modes must be combined before measurement. We also find the optimal local measurement and control technique. This gives the same degree of entanglement but a higher degree of purity than the local technique previously considered [S. Mancini, Phys. Rev. A {\bf 73}, 010304(R) (2006)].Comment: 10 pages, 5 figure

Damped Bloch oscillations of cold atoms in optical lattices

The paper studies Bloch oscillations of cold neutral atoms in the optical lattice. The effect of spontaneous emission on the dynamics of the system is analyzed both analytically and numerically. The spontaneous emission is shown to cause (i) the decay of Bloch oscillations with the decrement given by the rate of spontaneous emission and (ii) the diffusive spreading of the atoms with a diffusion coefficient depending on {\em both} the rate of spontaneous emission and the Bloch frequency.Comment: 10 pages, 8 figure

State and dynamical parameter estimation for open quantum systems

Following the evolution of an open quantum system requires full knowledge of its dynamics. In this paper we consider open quantum systems for which the Hamiltonian is ``uncertain''. In particular, we treat in detail a simple system similar to that considered by Mabuchi [Quant. Semiclass. Opt. 8, 1103 (1996)]: a radiatively damped atom driven by an unknown Rabi frequency $\Omega$ (as would occur for an atom at an unknown point in a standing light wave). By measuring the environment of the system, knowledge about the system state, and about the uncertain dynamical parameter, can be acquired. We find that these two sorts of knowledge acquisition (quantified by the posterior distribution for $\Omega$, and the conditional purity of the system, respectively) are quite distinct processes, which are not strongly correlated. Also, the quality and quantity of knowledge gain depend strongly on the type of monitoring scheme. We compare five different detection schemes (direct, adaptive, homodyne of the $x$ quadrature, homodyne of the $y$ quadrature, and heterodyne) using four different measures of the knowledge gain (Shannon information about $\Omega$, variance in $\Omega$, long-time system purity, and short-time system purity).Comment: 14 pages, 18 figure

Impact of \u3cem\u3eMYH6\u3c/em\u3e Variants in Hypoplastic Left Heart Syndrome

Hypoplastic left heart syndrome (HLHS) is a clinically and anatomically severe form of congenital heart disease (CHD). Although prior studies suggest that HLHS has a complex genetic inheritance, its etiology remains largely unknown. The goal of this study was to characterize a risk gene in HLHS and its effect on HLHS etiology and outcome. We performed next-generation sequencing on a multigenerational family with a high prevalence of CHD/HLHS, identifying a rare variant in the α-myosin heavy chain (MYH6) gene. A case-control study of 190 unrelated HLHS subjects was then performed and compared with the 1000 Genomes Project. Damaging MYH6 variants, including novel, missense, in-frame deletion, premature stop, de novo, and compound heterozygous variants, were significantly enriched in HLHS cases (P \u3c 1 × 10−5). Clinical outcomes analysis showed reduced transplant-free survival in HLHS subjects with damaging MYH6 variants (P \u3c 1 × 10−2). Transcriptome and protein expression analyses with cardiac tissue revealed differential expression of cardiac contractility genes, notably upregulation of the β-myosin heavy chain (MYH7) gene in subjects with MYH6 variants (P \u3c 1 × 10−3). We subsequently used patient-specific induced pluripotent stem cells (iPSCs) to model HLHS in vitro. Early stages of in vitro cardiomyogenesis in iPSCs derived from two unrelated HLHS families mimicked the increased expression of MYH7 observed in vivo (P \u3c 1 × 10−2), while revealing defective cardiomyogenic differentiation. Rare, damaging variants in MYH6 are enriched in HLHS, affect molecular expression of contractility genes, and are predictive of poor outcome. These findings indicate that the etiology of MYH6-associated HLHS can be informed using iPSCs and suggest utility in future clinical applications