Accelerating Wilson Fermion Matrix Inversions by Means of the Stabilized Biconjugate Gradient Algorithm

The stabilized biconjugate gradient algorithm BiCGStab recently presented by van der Vorst is applied to the inversion of the lattice fermion operator in the Wilson formulation of lattice Quantum Chromodynamics. Its computational efficiency is tested in a comparative study against the conjugate gradient and minimal residual methods. Both for quenched gauge configurations at beta= 6.0 and gauge configurations with dynamical fermions at beta=5.4, we find BiCGStab to be superior to the other methods. BiCGStab turns out to be particularly useful in the chiral regime of small quark masses.Comment: 25 pages, WUB 94-1

Quality, Stability, and Safety Data of Packed Red Cells and Plasma Processed by Gravity Separation Using a New Fully Integrated Hollow-Fibre Filter Device

Background. We developed a completely closed system based on gravity separation without centrifugation steps for separation of whole blood. With this new system we compared quality and stability of the processed blood components (PRC and plasma) with respect to classical preparation. Furthermore the cost-effectiveness of this hollow fibre system was evaluated. Study Design and Methods. Whole blood collections of 15 regular blood donors were used for component preparation using the U shaped hollow fibre filter device. Results were compared to 15 whole blood preparations using centrifugation. The following parameters were evaluated: total hemoglobin, leukocyte counts, the serum concentration of total protein, lactate dehydrogenase (LDH) and potassium. Furthermore ATIII, vWF and F VIII were analyzed at different timepoints. Results. packed red cells: the data directly after separation and after 42 days of storage are in line with the guidelines of the council of Europe. Plasma. all plasma quality data are in line with the guidelines of the council of Europe for quality assurance of plasma, except for a low protein amount (factor 0.75). Conclusion. Separation of whole blood on a clinical scale in this new closed system is feasible, however the plasma protein content must be optimized

Colored Non-Crossing Euclidean Steiner Forest

Given a set of $k$-colored points in the plane, we consider the problem of finding $k$ trees such that each tree connects all points of one color class, no two trees cross, and the total edge length of the trees is minimized. For $k=1$, this is the well-known Euclidean Steiner tree problem. For general $k$, a $k\rho$-approximation algorithm is known, where $\rho \le 1.21$ is the Steiner ratio. We present a PTAS for $k=2$, a $(5/3+\varepsilon)$-approximation algorithm for $k=3$, and two approximation algorithms for general~$k$, with ratios $O(\sqrt n \log k)$ and $k+\varepsilon$

Evolution of magnetic and microstructural properties of thick sputtered NdFeB films with processing temperature

Ta (100 nm) / NdFeB (5 $\mu$m) / Ta (100 nm) films have been deposited onto Si substrates using triode sputtering (deposition rate ~ 18 $\mu$m/h). A 2-step procedure was used : deposition at temperatures up to 400 C followed by ex-situ annealing at higher temperatures. Post-deposition annealing temperatures above 650 C are needed to develop high values of coercivity. The duration of the annealing time is more critical in anisotropic samples deposited onto heated substrates than in isotropic samples deposited at lower temperatures. For a given set of annealing conditions (750 C/ 10'), high heating rates (≥ 2000 C / h) favour high coercivity in both isotropic and anisotropic films. The shape and size of Nd2Fe14B grains depend strongly on the heating rate

Mental Health Service Utilization before and after Receipt of a Service‐Connected Disability Award for PTSD: Findings from a National Sample

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146624/1/hesr12859.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146624/2/hesr12859-sup-0001-AppendixSA1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146624/3/hesr12859_am.pd

Characterization of cytochrome P450 CYP109E1 from Bacillus megaterium as a novel vitamin D3 hydroxylase

In this study the ability of CYP109E1 from Bacillus megaterium to metabolize vitamin D3 (VD3) was investigated. In an in vitro system using bovine adrenodoxin reductase (AdR) and adrenodoxin (Adx4-108), VD3 was converted by CYP109E1 into several products. Furthermore, a whole-cell system in B. megaterium MS941 was established. The new system showed a conversion of 95% after 24h. By NMR analysis it was found that CYP109E1 catalyzes hydroxylation of VD3 at carbons C-24 and C-25, resulting in the formation of 24(S)-hydroxyvitamin D3 (24S(OH)VD3), 25-hydroxyvitamin D3 (25(OH)VD3) and 24S,25-dihydroxyvitamin D3 (24S,25(OH)2VD3). Through time dependent whole-cell conversion of VD3, we identified that the formation of 24S,25(OH)2VD3 by CYP109E1 is derived from VD3 via the intermediate 24S(OH)VD3. Moreover, using docking analysis and site-directed mutagenesis, we identified important active site residues capable of determining substrate specificity and regio-selectivity. HPLC analysis of the whole-cell conversion with the I85A-mutant revealed an increased selectivity towards 25-hydroxylation of VD3 compared with the wild type activity, resulting in an approximately 2-fold increase of 25(OH)VD3 production (45mgl(-1)day(-1)) compared to wild type (24.5mgl(-1)day(-1))

Understanding Design Patterns Density with Aspects: A Case Study in JHotDraw using AspectJ

International audienceDesign patterns offer solutions to common engineering prob- lems in programs [1]. In particular, they shape the evolution of program elements. However, their implementations tend to vanish in the code: thus it is hard to spot them and to understand their impact. The prob- lem becomes even more difficult with a "high density of pattern": then the program becomes easy to evolve in the direction allowed by patterns but hard to change [2]. Aspect languages offer new means to modular- ize elements. Implementations of object-oriented design patterns with AspectJ have been proposed [3]. We aim at testing the scalability of such solutions in the JHotDraw framework. We first explore the impact of density on pattern implementation. We show how AspectJ helps to reduce this impact. This unveils the principles of aspects and AspectJ to control pattern density

Phase Synchronization in Railway Timetables

Timetable construction belongs to the most important optimization problems in public transport. Finding optimal or near-optimal timetables under the subsidiary conditions of minimizing travel times and other criteria is a targeted contribution to the functioning of public transport. In addition to efficiency (given, e.g., by minimal average travel times), a significant feature of a timetable is its robustness against delay propagation. Here we study the balance of efficiency and robustness in long-distance railway timetables (in particular the current long-distance railway timetable in Germany) from the perspective of synchronization, exploiting the fact that a major part of the trains run nearly periodically. We find that synchronization is highest at intermediate-sized stations. We argue that this synchronization perspective opens a new avenue towards an understanding of railway timetables by representing them as spatio-temporal phase patterns. Robustness and efficiency can then be viewed as properties of this phase pattern

Collective vs local measurements in qubit mixed state estimation

We discuss the problem of estimating a general (mixed) qubit state. We give the optimal guess that can be inferred from any given set of measurements. For collective measurements and for a large number $N$ of copies, we show that the error in the estimation goes as 1/N. For local measurements we focus on the simpler case of states lying on the equatorial plane of the Bloch sphere. We show that standard tomographic techniques lead to an error proportional to $1/N^{1/4}$, while with our optimal data processing it is proportional to $1/N^{3/4}$.Comment: 4 pages, 1 figure, minor style changes, refs. adde