Linear optics substituting scheme for multi-mode operations

We propose a scheme allowing a conditional implementation of suitably truncated general single- or multi-mode operators acting on states of traveling optical signal modes. The scheme solely relies on single-photon and coherent states and applies beam splitters and zero- and single-photon detections. The signal flow of the setup resembles that of a multi-mode quantum teleportation scheme thus allowing the individual signal modes to be spatially separated from each other. Some examples such as the realization of cross-Kerr nonlinearities, multi-mode mirrors, and the preparation of multi-photon entangled states are considered.Comment: 11 pages, 4 eps-figures, using revtex

From bi-layer to tri-layer Fe nanoislands on Cu3Au(001)

Self assembly on suitably chosen substrates is a well exploited root to control the structure and morphology, hence magnetization, of metal films. In particular, the Cu3Au(001) surface has been recently singled out as a good template to grow high spin Fe phases, due to the close matching between the Cu3Au lattice constant (3.75 Angstrom) and the equilibrium lattice constant for fcc ferromagnetic Fe (3.65 Angstrom). Growth proceeds almost layer by layer at room temperature, with a small amount of Au segregation in the early stage of deposition. Islands of 1-2 nm lateral size and double layer height are formed when 1 monolayer of Fe is deposited on Cu3Au(001) at low temperature. We used the PhotoElectron Diffraction technique to investigate the atomic structure and chemical composition of these nanoislands just after the deposition at 140 K and after annealing at 400 K. We show that only bi-layer islands are formed at low temperature, without any surface segregation. After annealing, the Fe atoms are re-aggregated to form mainly tri-layer islands. Surface segregation is shown to be inhibited also after the annealing process. The implications for the film magnetic properties and the growth model are discussed.Comment: Revtex, 5 pages with 4 eps figure

A European perspective on alternatives to animal testing for environmental hazard identification and risk assessment

Tests with vertebrates are an integral part of environmental hazard identification and risk assessment of chemicals, plant protection products, pharmaceuticals, biocides, feed additives and effluents. These tests raise ethical and economic concerns and are considered as inappropriate for assessing all of the substances and effluents that require regulatory testing. Hence, there is a strong demand for replacement, reduction and refinement strategies and methods. However, until now alternative approaches have only rarely been used in regulatory settings. This review provides an overview on current regulations of chemicals and the requirements for animal tests in environmental hazard and risk assessment. It aims to highlight the potential areas for alternative approaches in environmental hazard identification and risk assessment. Perspectives and limitations of alternative approaches to animal tests using vertebrates in environmental toxicology, i.e. mainly fish and amphibians, are discussed. Free access to existing (proprietary) animal test data, availability of validated alternative methods and a practical implementation of conceptual approaches such as the Adverse Outcome Pathways and Integrated Testing Strategies were identified as major requirements towards the successful development and implementation of alternative approaches. Although this article focusses on European regulations, its considerations and conclusions are of global relevanc

The International Criteria for Behçet's Disease (ICBD): a collaborative study of 27 countries on the sensitivity and specificity of the new criteria

Behçet's disease (BD) is a chronic, relapsing, inflammatory vascular disease with no pathognomonic test. Low sensitivity of the currently applied International Study Group (ISG) clinical diagnostic criteria led to their reassessment

Stent-assisted Woven EndoBridge device for the treatment of intracranial aneurysms: an international multicenter study.

The Woven EndoBridge (WEB) device is an intrasaccular flow disruptor designed for wide-necked bifurcation aneurysms. These aneurysms may require the use of a concomitant stent. The objective of this study was to determine the clinical and radiological outcomes of patients undergoing stent-assisted WEB treatment. In addition, the authors also sought to determine the predictors of a concomitant stent in aneurysms treated with the WEB device. The data for this study were taken from the WorldWideWEB Consortium, an international multicenter cohort including patients treated with the WEB device. Aneurysms were classified into two groups based on treatment: stent-assisted WEB and WEB device alone. The authors compared clinical and radiological outcomes of both groups. Univariable and multivariable binary logistic regression analyses were performed to determine factors that predispose to stent use. The study included 691 intracranial aneurysms (31 with stents and 660 without stents) treated with the WEB device. The adequate occlusion status did not differ between the two groups at the latest follow-up (83.3% vs 85.6%, p = 0.915). Patients who underwent stenting had more thromboembolic (32.3% vs 6.5%, p < 0.001) and procedural (16.1% vs 3.0%, p < 0.001) complications. Aneurysms treated with a concomitant stent had wider necks, greater heights, and lower dome-to-neck ratios. Increasing neck size was the only significant predictor for stent use. This study demonstrates that there is no difference in the degree of aneurysm occlusion between the two groups; however, complications were more frequent in the stent group. In addition, a wider aneurysm neck predisposes to stent assistance in WEB-treated aneurysms