Electro-optic bunch diagnostics on ALICE

An electro-optic longitudinal bunch profile monitor has been implemented on ALICE (Accelerators and Lasers in Combined Experiments) at the Daresbury Laboratories and will be used both to characterise the electron bunch and to provide a testbed for electro-optic techniques. The electro-optic station is located immediately after the bunch compressor, within the FEL cavity; its location allows nearby OTR, beam profile monitors and Coherent Synchrontron Radiation (CSR) diagnostics to be used for calibration and benchmarking. We discuss the implementation and the planned studies on electro-optic diagnostics using this diagnostic station

Robust Trapped-Ion Quantum Logic Gates by Continuous Dynamical Decoupling

We introduce a novel scheme that combines phonon-mediated quantum logic gates in trapped ions with the benefits of continuous dynamical decoupling. We demonstrate theoretically that a strong driving of the qubit decouples it from external magnetic-field noise, enhancing the fidelity of two-qubit quantum gates. Moreover, the scheme does not require ground-state cooling, and is inherently robust to undesired ac-Stark shifts. The underlying mechanism can be extended to a variety of other systems where a strong driving protects the quantum coherence of the qubits without compromising the two-qubit couplings.Comment: Slightly longer than the published versio

EFFECT OF THE 1985 FARM BILL PROVISIONS ON FARMERS' SOIL CONSERVATION DECISIONS

Conservation initiatives in the 1985 Farm Bill affected farmers' decisions regarding soil conservation. A farmer survey was conducted and a multiperiod mixed-integer programming model was developed to determine an optimal farm plan with choice of crop-tillage combinations and land retirement. Results indicate that farmers' incentives to reduce soil loss in the Sand Mountain region in Alabama are not substantially affected by provisions of the 1985 Farm Bill. The bid price for the Conservation Reserve Program will have to be considerably higher than 1988 levels to provide an incentive to remove land from production.Agricultural and Food Policy,

Upconversion of a relativistic Coulomb field terahertz pulse to the near infrared

We demonstrate the spectral upconversion of a unipolar subpicosecond terahertz (THz) pulse, where the THz pulse is the Coulomb field of a single relativistic electron bunch. The upconversion to the optical allows remotely located detection of long wavelength and nonpropagating components of the THz spectrum, as required for ultrafast electron bunch diagnostics. The upconversion of quasimonochromatic THz radiation has also been demonstrated, allowing the observation of distinct sum- and difference-frequency mixing components in the spectrum. Polarization dependence of first and second order sidebands at ωopt±ωTHz, and ωopt±2ωTHz, respectively, confirms the χ(2) frequency mixing mechanism

Stronger computational modelling of signalling pathways using both continuous and discrete-state methods

Starting from a biochemical signalling pathway model expresses in a process algebra enriched with quantitative information, we automatically derive both continuous-space and discrete-space representations suitable for numerical evaluation. We compare results obtained using approximate stochastic simulation thereby exposing a flaw in the use of the differentiation procedure producing misleading results

Thermal noise of a plano-convex mirror

We study theoretically the internal thermal noise of a mirror coated on a plano-convex substrate. The comparison with a cylindrical mirror of the same mass shows that the effect on a light beam can be reduced by a factor 10, improving the sensitivity of high-precision optical experiments such as gravitational-wave interferometers.Comment: 5 pages, 5 figures, RevTe

StochKit-FF: Efficient Systems Biology on Multicore Architectures

The stochastic modelling of biological systems is an informative, and in some cases, very adequate technique, which may however result in being more expensive than other modelling approaches, such as differential equations. We present StochKit-FF, a parallel version of StochKit, a reference toolkit for stochastic simulations. StochKit-FF is based on the FastFlow programming toolkit for multicores and exploits the novel concept of selective memory. We experiment StochKit-FF on a model of HIV infection dynamics, with the aim of extracting information from efficiently run experiments, here in terms of average and variance and, on a longer term, of more structured data.Comment: 14 pages + cover pag

Long term response of loblolly pine to colloidal phosphate

Three or six ounces of colloidal phosphate were applied either in planting hole or on soil surface while planting loblolly pine in East Texas. Combination of phosphate in the planting hole with NK on soil surface increased diameter growth for four years and the height growth for 18 years after planting

Meningitis in an Irish community

A series of 26 cases of meningitis occurring in one year in a defined area is presented. The clinical features, and complications are reviewed. Neisseria meningitidis occurred twice as commonly as Haemophilus influenzae, suggesting that the pattern of infection differs from that reported in England and Wales. An incidence of 4·6/100,000 for N. meningitidis is reported exceeding rates of infection in previous UK “epidemics”