Dynamics of charge-displacement channeling in intense laser-plasma interactions

The dynamics of transient electric fields generated by the interaction of high intensity laser pulses with underdense plasmas has been studied experimentally with the proton projection imaging technique. The formation of a charged channel, the propagation of its front edge and the late electric field evolution have been characterised with high temporal and spatial resolution. Particle-in-cell simulations and an electrostatic, ponderomotive model reproduce the experimental features and trace them back to the ponderomotive expulsion of electrons and the subsequent ion acceleration.Comment: 5 figures, accepted for publication in New Journal of Physic

Population structure of Atlantic swordfish (Xiphias gladius L. 1758) (Teleostea, Xiphiidae) using mitochondrial DNA analysis: implications for fisheries management

Recent studies on Atlantic swordfish (Xiphias gladius L. 1758) genetic structure have demonstrated significant heterogeneity but the precise boundary between populations remains to be identified. In this context, genetic diversity was investigated by PCR–RFLP analysis at the control region of mitochondrial DNA (D–loop) from 274 swordfish specimens collected from five different areas of the Atlantic Ocean. The analysis of molecular variance (AMOVA) showed that genetic variation was mainly due to differences within rather than between the studied areas. Additionally, the phylogenetic analysis did not show evident relationships among haplotypes from all areas. However, low but significant FST values were recorded when comparing Equatorial samples with those from the north central and north tropical Atlantic. These results do not support a need for changing the current management boundary for the Atlantic fishery. Key words: Xiphiidae, Swordfish, Xiphias gladius, Mitochondrial DNA, Genetic variability, Atlantic Ocean.Estudios recientes sobre la estructura genética del pez espada del Atlántico (Xiphias gladius L. 1758) han demostrado una heterogeneidad significativa, pero los límites precisos entre poblaciones no han sido identificados. En este contexto, la diversidad genética se ha investigado mediante análisis PCR–RFLP en la región control de ADN mitocondrial (bucle D) de 274 peces espada recolectados en cinco zonas diferentes del océano Atlántico. El análisis de la varianza molecular (AMOVA) mostró que la variación genética se debía a diferencias en cada zona y no entre las zonas estudiadas. Además, los análisis filogenéticos no muestran relaciones evidentes entre los haplotipos de todas las zonas. A pesar de ello, al comparar las muestras ecuatoriales con las de zonas más al norte, se obtienen valores de FST bajos pero significativos. Estos resultados indican que no es necesario cambiar los límites de las zonas de gestión para la pesquería del Atlántico. Palabras clave: Xiphiidae, Pez espada, Xiphias gladius, ADN mitocondrial, Variabilidad genética, Océano Atlántico.Recent studies on Atlantic swordfish (Xiphias gladius L. 1758) genetic structure have demonstrated significant heterogeneity but the precise boundary between populations remains to be identified. In this context, genetic diversity was investigated by PCR–RFLP analysis at the control region of mitochondrial DNA (D–loop) from 274 swordfish specimens collected from five different areas of the Atlantic Ocean. The analysis of molecular variance (AMOVA) showed that genetic variation was mainly due to differences within rather than between the studied areas. Additionally, the phylogenetic analysis did not show evident relationships among haplotypes from all areas. However, low but significant FST values were recorded when comparing Equatorial samples with those from the north central and north tropical Atlantic. These results do not support a need for changing the current management boundary for the Atlantic fishery. Key words: Xiphiidae, Swordfish, Xiphias gladius, Mitochondrial DNA, Genetic variability, Atlantic Ocea

Biomarkers of oxidative and nitrosative damage in Alzheimer's disease and mild cognitive impairment

Alzheimer's disease (AD) is the most common type of dementia in the elderly. Products of oxidative and nitrosative stress (OS and NS, respectively) accumulate with aging, which is the main risk factor for AD. This provides the basis for the involvement of OS and NS in AD pathogenesis. OS and NS occur in biological systems due to the dysregulation of the redox balance, caused by a deficiency of antioxidants and/or the overproduction of free radicals. Free radical attack against lipids, proteins, sugars and nucleic acids leads to the formation of bioproducts whose detection in fluids and tissues represents the currently available method for assessing oxidative/nitrosative damage. Post-mortem and in-vivo studies have demonstrated an accumulation of products of free radical damage in the central nervous system and in the peripheral tissues of subjects with AD or mild cognitive impairment (MCI). In addition to their individual role, biomarkers for OS and NS in AD are associated with altered bioenergetics and amyloid-beta (Aβ) metabolism. In this review we discuss the main results obtained in the field of biomarkers of oxidative/nitrosative stress in AD and MCI in humans, in addition to their potential role as a tool for diagnosis, prognosis and treatment efficacy in AD. © 2009 Elsevier Ireland Ltd. All rights reserved

Prospect for Charge Current Neutrino Interactions Measurements at the CERN-PS

Tensions in several phenomenological models grew with experimental results on neutrino/antineutrino oscillations at Short-Baseline (SBL) and with the recent, carefully recomputed, antineutrino fluxes from nuclear reactors. At a refurbished SBL CERN-PS facility an experiment aimed to address the open issues has been proposed [1], based on the technology of imaging in ultra-pure cryogenic Liquid Argon (LAr). Motivated by this scenario a detailed study of the physics case was performed. We tackled specific physics models and we optimized the neutrino beam through a full simulation. Experimental aspects not fully covered by the LAr detection, i.e. the measurements of the lepton charge on event-by-event basis and their energy over a wide range, were also investigated. Indeed the muon leptons from Charged Current (CC) (anti-)neutrino interactions play an important role in disentangling different phenomenological scenarios provided their charge state is determined. Also, the study of muon appearance/disappearance can benefit of the large statistics of CC muon events from the primary neutrino beam. Results of our study are reported in detail in this proposal. We aim to design, construct and install two Spectrometers at "NEAR" and "FAR" sites of the SBL CERN-PS, compatible with the already proposed LAr detectors. Profiting of the large mass of the two Spectrometers their stand-alone performances have also been exploited.Comment: 70 pages, 38 figures. Proposal submitted to SPS-C, CER

The PLASMONX Project for advanced beam physics experiments

The Project PLASMONX is well progressing into its design phase and has entered as well its second phase of procurements for main components. The project foresees the installation at LNF of a Ti:Sa laser system (peak power > 170 TW), synchronized to the high brightness electron beam produced by the SPARC photo-injector. The advancement of the procurement of such a laser system is reported, as well as the construction plans of a new building at LNF to host a dedicated laboratory for high intensity photon beam experiments (High Intensity Laser Laboratory). Several experiments are foreseen using this complex facility, mainly in the high gradient plasma acceleration field and in the field of mono- chromatic ultra-fast X-ray pulse generation via Thomson back-scattering. Detailed numerical simulations have been carried out to study the generation of tightly focused electron bunches to collide with laser pulses in the Thomson source: results on the emitted spectra of X-rays are presented

Why are Prices Sticky? Evidence from Business Survey Data

This paper offers new insights on the price setting behaviour of German retail firms using a novel dataset that consists of a large panel of monthly business surveys from 1991-2006. The firm-level data allows matching changes in firms' prices to several other firm-characteristics. Moreover, information on price expectations allow analyzing the determinants of price updating. Using univariate and bivariate ordered probit specifications, empirical menu cost models are estimated relating the probability of price adjustment and price updating, respectively, to both time- and state- dependent variables. First, results suggest an important role for state-dependence; changes in the macroeconomic and institutional environment as well as firm-specific factors are significantly related to the timing of price adjustment. These findings imply that price setting models should endogenize the timing of price adjustment in order to generate realistic predictions concerning the transmission of monetary policy. Second, an analysis of price expectations yields similar results providing evidence in favour of state-dependent sticky plan models. Third, intermediate input cost changes are among the most important determinants of price adjustment suggesting that pricing models should explicitly incorporate price setting at different production stages. However, the results show that adjustment to input cost changes takes time indicating "additional stickiness" at the last stage of processing

Multi-GeV Electron Spectrometer

The advance in laser plasma acceleration techniques pushes the regime of the resulting accelerated particles to higher energies and intensities. In particular the upcoming experiments with the FLAME laser at LNF will enter the GeV regime with almost 1pC of electrons. From the current status of understanding of the acceleration mechanism, relatively large angular and energy spreads are expected. There is therefore the need to develop a device capable to measure the energy of electrons over three orders of magnitude (few MeV to few GeV) under still unknown angular divergences. Within the PlasmonX experiment at LNF a spectrometer is being constructed to perform these measurements. It is made of an electro-magnet and a screen made of scintillating fibers for the measurement of the trajectories of the particles. The large range of operation, the huge number of particles and the need to focus the divergence present unprecedented challenges in the design and construction of such a device. We will present the design considerations for this spectrometer and the first results from a prototype.Comment: 7 pages, 6 figures, submitted to NIM

Prospects for K+→π+ννˉK^+ \to \pi^+ \nu \bar{ \nu } at CERN in NA62

The NA62 experiment will begin taking data in 2015. Its primary purpose is a 10% measurement of the branching ratio of the ultrarare kaon decay $K^+ \to \pi^+ \nu \bar{ \nu }$, using the decay in flight of kaons in an unseparated beam with momentum 75 GeV/c.The detector and analysis technique are described here.Comment: 8 pages for proceedings of 50 Years of CP

States, Banks and the Financing of the Economy: Monetary Policy and Regulatory Perspectives

On 5-6 September 2012 SUERF held its 30th Colloquium “States, Banks, and the Financing of the Economy” at the University of Zürich, Switzerland. The papers included in this SUERF Study are based on contributions to the Colloquium. All the papers in this publication discuss from different angles the complex interrelations between states and financial systems, which have developed in recent years with economic, financial and sovereign debt crises. The contributions look primarily on the monetary policy and financial regulation and supervision perspectives. In the preceding SUERF Study (2013/2), the focus of the contributions also delivered at the 30th SUERF Colloquium is on fiscal policy and sovereign debt perspectives