Holonomic quantum computation using rf superconducting quantum interference devices coupled through a microwave cavity

We propose a different scheme to realize holonomic quantum computation with rf superconducting quantum interference device (SQUID) qubits in a microwave cavity. In this scheme associated with the non-Abelian holonomies, the single-qubit gates and a two-qubit controlled-PHASE gate as well as a controlled-NOT gate can be easily constructed by tuning adiabatically the Rabi frequencies of classical microwave pulses coupled to the SQUIDs. The fidelity of these gates is estimated to be possibly higher than 90% with the current technology. © 2005 The American Physical Society.published_or_final_versio

Theoretical basis and practical aspects of small specimen creep testing

Interest in and the application of small specimen creep test techniques are increasing. This is because it is only possible to obtain small samples of material in some situations, for example, the scoop samples that are removed from in-service components, the heat-affected zones that are created when welds are used to join components and the desire to produce only small amounts of material in alloy development programmes. It is therefore important to review and compare the theoretical basis and practical aspects of each of the small specimen creep testing methods, in order to clearly understand which of the methods is the best for any specific application. This article provides the theoretical basis for each commonly used test method

Helicases as antiviral drug targets.

1. We have demonstrated for the first time that the helicase of a ribonucleic acid virus, the SARS coronavirus (SARS-CoV), is a valid target for drug development. 2. Using high throughput screen and chemical synthesis, several lead compounds targeting the SARS-CoV helicase have been identified. We have shown that these compounds can inhibit SARS-CoV helicase activity and viral growth in cell culture systems. These compounds can potentially be used to target other viruses.published_or_final_versio

Determination of the functions of the putative metal-binding domain of the SCV helicase.

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Expression and characterization of a histidine-rich protein, Hpn: Potential for Ni2+ storage in Helicobacter pylori

Hpn is a small cytoplasmic protein found in Helicobacter pylori, which binds Ni2+ ions with moderate affinity. Consisting of 60 amino acids, the protein is rich in histidine (28 residues, 46.7%), as well as glutamate, glycine and serine residues (in total 31.7%), and contains short repeating motifs. In the present study, we report the detailed biophysical characterization of the multimeric status and Ni2+-binding properties of purified recombinant Hpn under physiologically relevant conditions. The protein exists as an equilibration of multimeric forms in solution, with 20-mers (approx. 136 kDa) being the predominant species. Using equilibrium dialysis, ICP-MS (inductively coupled plasma MS) and UV/visible spectroscopy, Hpn was found to bind five Ni2+ ions per monomer at pH 7.4, with a dissociation constant (Kd) of 7.1 μM. Importantly, Ni2+ binding to Hpn is reversible: metal is released either in the presence of a chelating ligand such as EDTA, or at a slightly acidic pH (pH for half dissociation, pH1/2 ∼6.3). Ni2+ binding induces conformational changes within the protein, increasing β-sheet and reducing α-helical content, from 22% to 37%, and 20% to 10% respectively. Growth curves of Escherichia coli BL21(DE3) both with and without the hpn gene performed under Ni2+ pressure clearly implied a role for Hpn to protect the cells from higher concentrations of external metal ions. Similarly, the accumulation of Ni2+ in these cells expressing Hpn from a plasmid was approx. 4-fold higher than in uninduced controls or control cultures that lacked the plasmid. Similarly, levels of Ni2+ in wild-type H. pylori 26695 cells were higher than those in H. pylori hpn-deletion mutant strains. Hpn may potentially serve multiple roles inside the bacterium: storage of Ni 2+ ions in a 'reservoir'; donation of Ni2+ to other proteins; and detoxification via sequestration of excess Ni2+. © 2006 Biochemical Society.published_or_final_versio

Children at Risk in the Child Welfare System: Collaborations to Promote School Readiness - Final Report

This study examines the degree to which key players in the child welfare, early intervention/preschool special education (EI/Preschool SPED) and early care and education (ECE) systems (e.g. Head Start, preschool, child care centers, family child care homes) collaborate to meet the developmental needs of children ages 0 to 5 who are involved in the child welfare system. This research includes an analysis of data from the National Survey of Child and Adolescent Wellbeing (NSCAW) as well as a case study in Colorado involving interviews with key stakeholders and statewide surveys of caseworkers and foster parents

Investigation of Alternative Work Zone Merging Sign Configurations

This study investigated the effect of an alternative merge sign configuration within a freeway work zone. In this alternative configuration, the graphical lane closed sign from the MUTCD was compared with a MERGE/arrow sign on one side and a RIGHT LANE CLOSED sign on the other side. The study measured driver behavior characteristics including speeds and open lane occupancies. The measurements were taken at two identical work zones on I-70 in Missouri, one with the new test sign and the other with the standard MUTCD sign. The study found that the open lane occupancy upstream of the merge sign was higher for the test sign in comparison to the MUTCD sign. Occupancy values at different distances between the merge sign and the taper were similar for both signs. The test sign had 11% more traffic in the open lane upstream of the merge sign. In terms of safety, it is desirable for vehicles to occupy the open lane as far upstream from the taper as possible to avoid conflicts due to the lane drop. Thus, the test sign proved to be a good alternative to the MUTCD sign. The analysis of speed characteristics did not reveal substantial differences between the two sign configurations. The 85th percentile speeds with the MUTCD sign were 1 mph and 2 mph lower than the test sign at the merge sign and taper locations, respectively

Evaluation of J-turn Intersection Design Performance in Missouri, Final Report

Research shows that a high percentage of crashes that take place on high-speed rural expressways occur at intersections with minor roads. One low-cost alternative design for improving the safety of at-grade intersections on such expressways is the J-turn. In the last few years, the Missouri Department of Transportation has converted some two-way stop controlled (TWSC) intersections into J-turns. This study evaluated the effectiveness of the J-turn intersection design in Missouri utilizing field studies, a public survey, crash analysis, and traffic conflict analysis. The field studies collected detailed video data at a J-turn site and a control site. The crash analysis included a statistically rigorous empirical Bayes before-after safety evaluation of five J-turn sites in Missouri. The J-turn design resulted in a 34.8% reduction in crash frequency for all crashes and a 53.7% reduction in crash frequency for all injury and fatal crashes. Both reductions were significant at the 95% confidence level. Annual disabling injury crashes and minor injury crashes decreased by 86% and 50%, respectively. None of the five sites exhibited a fatal crash following J-turn implementation. This five-site analysis showed that annual right angle crashes decreased from 6.3 to 1.3, a 80% reduction. One of the most severe crash types, the left turn, right angle crash, was completely eliminated by the J-turn. One conflict measure, average time to collision, was found to be four times higher at the J-turn site compared to the control TWSC site among minor road turning vehicles, indicating greater safety at the J-turn site. The average wait time at the J-turn site was half the wait time at the control site, while the average travel time at the J-turn site was approximately one minute greater than at the TWSC site. When the public was surveyed regarding trip time perceptions resulting from the J-turn, the majority said there was no adverse effect. A high percentage of minor road left turning and through movements at the J-turn site merged into the travel lanes within the first 400 feet of the acceleration lane. Public opinion regarding the J-turn at US 63 and Deer Park Rd was mixed. Frequent concerns raised by respondents included difficulty merging following the U-turn, improper use of acceleration and deceleration lanes, insufficient U-turn radius to accommodate large vehicles, and driver confusion

Full Elite Sets for Multi-Objective Optimisation

Copyright © 2002 Springer. The final publication is available at link.springer.com5th International Conference on Adaptive Computing in Design and Manufacture (ACDM 2002), Exeter, UK, 16-18 April, 2002Multi-objective evolutionary algorithms frequently use an archive of non-dominated solutions to approximate the Pareto front. We show that the truncation of this archive to a limited number of solutions can lead to oscillating and shrinking estimates of the Pareto front. New data structures to permit efficient query and update of the full archive are proposed, and the superior quality of frontal estimates found using the full archive is illustrated on test problems