Europawahl 2009 : Erwartungen – Programme – Visionen

Zwischen 4. und 7. Juni 2009 sind fast eine halbe Milliarde Unionsbürgerinnen und -bürger dazu aufgerufen, ein neues Europäisches Parlament zu wählen. Doch auch 30 Jahre nach der ersten Direktwahl hat sich das Europäische Parlament nicht als politischer Bezugspunkt der Bürger etabliert. Seit 1979 sinkt die Wahlbeteiligung kontinuierlich, 2004 gingen durchschnittlich nur 45,6 Prozent der EU-Bürger zur Wahl. Die Debatte um das Demokratiedefizit der Europäischen Union nimmt gerade an diesem Punkt immer wieder Anstoß

La reproduction assistée chez les rhinocérotidés

Les espèces représentant la famille des rhinocérotidés sont toutes sévèrement menacées par le braconnage et la destruction de leur habitat. Les quatre espèces présentes en captivité, le rhinocéros blanc (Ceratotherium simum), le rhinocéros noir (Diceros bicornis), le rhinocéros indien (Rhinoceros unicornis) et le rhinocéros de Sumatra (Dicerorhinus sumatrensis) ont des taux de reproduction inférieurs à celui des individus sauvages. Certaines caractéristiques de la reproduction sont sensiblement différentes d’une espèce à l’autre (ovulation provoquée ou spontanée, durée du cycle, principales affections). La durée de la gestation, qui est la deuxième plus longue parmi les mammifères terrestres, est de 15 à 16 mois. Les techniques de reproduction assistée utilisées chez les rhinocérotidés sont celles communément utilisées chez les animaux de rente. Des cathéters d’insémination ont été spécialement conçus en raison des spécificités anatomiques du tractus génital de la femelle. Les perspectives envisagées en matière de reproduction assistée ont toutes pour but la préservation du potentiel génétique à long terme des espèces de rhinocéros

Generation of strongly-coupled plasma using Argon-based capillary discharge lasers

Argon based capillary discharge lasers operate in the extreme ultra violet (EUV) at 46.9 nm with an output of up to 0.5 mJ energy per pulse and up to a 10 Hz repetition rate. Focussed irradiances of up to 1012 W cm-2 are achievable and can be used to generate plasma in the warm dense matter regime by irradiating solid material. To model the interaction between such an EUV laser and solid material, the 2D radiative-hydrodynamic code POLLUX has been modified to include absorption via direct photo-ionisation, a super-configuration model to describe the ionisation dependant electronic configurations and a calculation of plasma refractive indices for ray tracing of the incident EUV laser radiation. A simulation study is presented, demonstrating how capillary discharge lasers of 1.2ns pulse duration can be used to generate strongly coupled plasma at close to solid density with temperatures of a few eV and energy densities up to 1×105 J cm-3. Plasmas produced by EUV laser irradiation are shown to be useful for examining the equation-of-state properties of warm dense matter. One difficulty with this technique is the reduction of the strong temperature and density gradients which are produced during the interaction. Methods to inhibit and control these gradients will be examined

The application of extreme ultra-violet lasers in plasma heating and diagnosis

Laser-plasma studies have been undertaken for 50 years using infra-red to ultra-violet lasers. We show that a new regime of laser-produced plasmas can be created with capillary discharge and free electron lasers operating in the extreme ultra-violet (EUV). For example, EUV radiation (wavelength <50 nm) has a critical electron density above electron densities formed by ionization at solid material density and so potentially can penetrate to large depth into a solid density plasma. We explore here the importance of this penetration in ablating solid targets, in creating novel warm dense matter and in the diagnosis of plasmas

The French National 3D Data Repository for Humanities: Features, Feedback and Open Questions

We introduce the French National 3D Data Repository for Humanities designed for the conservation and the publication of 3D research data in the field of Humanities and Social Sciences. We present the choices made for the data organization, metadata, standards and infrastructure towards a FAIR service. With 437 references at the time of the writing, we have feedback on some challenges to develop such a service and to make it widely used. This leads to open questions and future developments.Comment: CAA 2021 - "Digital Crossroads" full paper version (in review

Control of excitation selectivity in pulse EPR on spin-correlated radical pairs with shaped pulses

Spin-correlated radical pairs generated by photoinduced electron transfer are characterised by a distinctive spin polarisation and a unique behaviour in pulse Electron Paramagnetic Resonance (EPR) spectroscopy. Under non-selective excitation, an out-of-phase echo signal modulated by the dipolar and exchange coupling interactions characterising the radical pair is observed and allows extraction of geometric information in the two-pulse out-of-phase Electron Spin Echo Envelope Modulation (ESEEM) experiment. The investigation of the role of spin-correlated radical pairs in a variety of biological processes and in the fundamental mechanisms underlying device function in optoelectronics as well as their potential use in quantum information science relies on the ability to precisely address and manipulate the spins using microwave pulses. Here, we explore the use of shaped pulses for controlled narrowband selective and broadband non-selective excitation of spin-correlated radical pairs in two model donor-bridge-acceptor triads, characterised by different spectral widths, at X- and Q-band frequencies. We demonstrate selective excitation with close to rectangular excitation profiles using BURP (Band-selective, Uniform Response, Pure phase) pulses and complete non-selective excitation of both spins of the radical pair using frequency-swept chirp pulses. The use of frequency-swept pulses in out-of-phase ESEEM experiments enables increased modulation depths and, combined with echo transient detection and Fourier transformation, correlation of the dipolar frequencies with the EPR spectrum and therefore the potential to extract additional information on the donor-acceptor pair geometry