Decoherence of geometric phase gates

We consider the effects of certain forms of decoherence applied to both adiabatic and non-adiabatic geometric phase quantum gates. For a single qubit we illustrate path-dependent sensitivity to anisotropic noise and for two qubits we quantify the loss of entanglement as a function of decoherence.Comment: 4 pages, 3 figure

Dynamical equations for high-order structure functions, and a comparison of a mean field theory with experiments in three-dimensional turbulence

Two recent publications [V. Yakhot, Phys. Rev. E {\bf 63}, 026307, (2001) and R.J. Hill, J. Fluid Mech. {\bf 434}, 379, (2001)] derive, through two different approaches that have the Navier-Stokes equations as the common starting point, a set of steady-state dynamic equations for structure functions of arbitrary order in hydrodynamic turbulence. These equations are not closed. Yakhot proposed a "mean field theory" to close the equations for locally isotropic turbulence, and obtained scaling exponents of structure functions and an expression for the tails of the probability density function of transverse velocity increments. At high Reynolds numbers, we present some relevant experimental data on pressure and dissipation terms that are needed to provide closure, as well as on aspects predicted by the theory. Comparison between the theory and the data shows varying levels of agreement, and reveals gaps inherent to the implementation of the theory.Comment: 16 pages, 23 figure

Multimode solutions of first-order elliptic quasilinear systems obtained from Riemann invariants

Two new approaches to solving first-order quasilinear elliptic systems of PDEs in many dimensions are proposed. The first method is based on an analysis of multimode solutions expressible in terms of Riemann invariants, based on links between two techniques, that of the symmetry reduction method and of the generalized method of characteristics. A variant of the conditional symmetry method for constructing this type of solution is proposed. A specific feature of that approach is an algebraic-geometric point of view, which allows the introduction of specific first-order side conditions consistent with the original system of PDEs, leading to a generalization of the Riemann invariant method for solving elliptic homogeneous systems of PDEs. A further generalization of the Riemann invariants method to the case of inhomogeneous systems, based on the introduction of specific rotation matrices, enables us to weaken the integrability condition. It allows us to establish a connection between the structure of the set of integral elements and the possibility of constructing specific classes of simple mode solutions. These theoretical considerations are illustrated by the examples of an ideal plastic flow in its elliptic region and a system describing a nonlinear interaction of waves and particles. Several new classes of solutions are obtained in explicit form, including the general integral for the latter system of equations

Neoplastic transformation of mouse C3H 10T1/2 and Syrian hamster embryo cells by heavy ions

C3H 10T1/2 mouse-embryo fibroblasts were used for transformation experiments to study the effectiveness of various heavy ions with energies up to 20 MeV/u and LET values from 170 to 16.000 keV/μm. The transformation frequency per unit absorbed dose decreased with increasing ionization density; at the highest values of LET we found a decrease even of the transformation efficiency per unit fluence. Uranium ions at energies of 5, 9, and 16.3 MeV/u did not induced any transformation. In additional studies piimary Syrian hamster embryo cells (SHE) were exposed to heavy ions in order to characterize cytological and molecular changes which may be correlated with neoplastic transformation. Growth behaviour, chromosomal status, tumorigenicity in nude mice, and expression of oncogenes of transformed cell lines were examined

Molecular diversity within clonal complex 22 methicillin-resistant Staphylococcus aureus encoding Panton–Valentine leukocidin in England and Wales

AbstractPanton–Valentine leukocidin (PVL)-positive methicillin-resistant Staphylococcus aureus (MRSA) that are multi-locus sequence type clonal complex 22 (CC22) comprise a significant public health problem in the UK. In the present study we sought to determine the genetic diversity, and the respective patient demographics, among 47 PVL-MRSA with a CC22 pulsotype that occurred sporadically or in clusters in community and healthcare settings in eight of nine geographic regions in England and Wales between January 2005 and September 2007. Patient demographics and disease presentations were typical for PVL-S. aureus infections (mostly skin and soft tissue infections in individuals <40 years old); one patient with community-acquired pneumonia died. Although the isolates were closely genotypically related by spa typing and pulsed field gel electrophoresis, at least two variant groups were suggested. PCR detections demonstrated that the majority of the CC22 PVL-MRSA identified (n = 42; 89%) harboured SCCmecIVc, three had SCCmecIVd, one had SCCmecIV but was non-subtypeable, and one isolate harboured SCCmecV. At least three different PVL-encoding phages were detected: ΦPVL, Φ108PVL and an unidentified icosahedral phage. Agar dilution MIC determinations showed that the CC22 PVL-MRSA identified were typically resistant to gentamicin and trimethoprim (43 of 47 isolates) and ciprofloxacin resistance was also noted in six isolates. In conclusion, the CC22 PVL-MRSA tested were geographically disseminated but highly genetically related. The observed variances in acquired elements (most notably SCCmec and PVL-encoding phages) suggested that CC22 PVL-MRSA in England and Wales have evolved on multiple occasions

Racial/Ethnic Differences in Diet Quality and Eating Habits Among WIC Pregnant Women: Implications for Policy and Practice

Purpose: One of the major federal food assistance programs, the Special Supplemental Program for Women, Infants, and Children (WIC), serves approximately 1.5 million low-income pregnant women per year; however, limited information is available on their dietary habits. This is critical because low-income women are at higher risk of gaining excess weight during pregnancy. Thus, the study objectives were to (1) determine the overall diet quality of WIC pregnant women and (2) examine diet quality and eating behaviors by race/ethnicity and other sociodemographics. Design: This was a cross-sectional study. Setting: One of the 3 WIC offices in a north-central county in North Carolina, USA. Sample: Pregnant women (n = 198) in the second trimester. Measures: Interviews included sociodemographics, food security, diet, and eating behaviors. Diet quality was assessed by the Healthy Eating Index (HEI) 2010 scores. Analysis: Descriptives, bivariate analysis, and multivariate analysis. Results: Average participant age was 26 years, and the mean HEI-2010 score was 56 of maximum score of 100. Specifically, African American women consumed significantly lower servings of whole grains (β = −1.71; 95% CI: −3.10 to −0.32; P <.05) and dairy (β = −1.42; 95% CI: −2.51 to −0.33; P <.05) compared with non-Hispanic white women. Hispanic women scored higher in daily intake of fruits (β = 0.98; 95% CI: 0.17-1.79; P <.05) and for consuming empty calories in moderation (β = 1.57; 95% CI: 0.06-3.09; P <.05). Frequency of intake of fast foods/outside meals was higher among African American women (57%, P =.025). Conclusion: Efforts are warranted to promote optimal nutrition among WIC pregnant women. Specifically, African American women are highly vulnerable to poor dietary habits during pregnancy. Further investigation of barriers/facilitators for healthy eating is necessary to address nutrition disparities among WIC pregnant women