On the origin of cavities in extraterrestrial magnetic spherules

It was discovered that extraterrestrial magnetic spherules larger than 10 μm in diameter contain internal cavities. The possible origin of cavities is discussed. It is suggested that the primary particles contain ferrous carbonate or ferric hydroxide that upon heating during entry of micrometeorite releases carbon dioxide or water vapor that produces cavity in the molten spherule. The chemical composition of magnetic spherules is similar to that of the crust of the Earth

Tetrapolar Heterothallism in the Basidiomycete, Lentodium Squamulosum

Lentodium squamulosum has been shown to be tetrapolarly heterothallic. The 4 predicted mating reactions can be recognized by gross characters on Potato dextrose agar, but not on other media tested. Three sectors were found, 2 of which do not seem to dikaryotize with any of the 4 established mating types. Malt extract would appear to yield more consistent fruiting than Oat flake agar

Nanostructured targets for TNSA laser ion acceleration

Abstract Nanostructured targets, based on hydrogenated polymers with embedded nanostructures, were prepared as thin micrometric foils for high-intensity laser irradiation in TNSA regime to produce high-ion acceleration. Experiments were performed at the PALS facility, in Prague, by using 1315 nm wavelength, 300 ps pulse duration and an intensity of 1016 W/cm2 and at the IPPLM, in Warsaw, by using 800 nm wavelength, 40 fs pulse duration, and an intensity of 1019 W/cm2. Forward plasma diagnostic mainly uses SiC detectors and ion collectors in time of flight (TOF) configuration. At these intensities, ions can be accelerated at energies above 1 MeV per nucleon. In presence of Au nanoparticles, and/or under particular irradiation conditions, effects of resonant absorption can induce ion acceleration enhancement up to values of the order of 4 MeV per nucleon

Top-down and bottom-up approach to competence management implementation: A case of two central banks Abordagem top-down (de cima para baixo) e bottom-up (de baixo para cima) para a implementação de gestão de competências: O caso de dois bancos centrais

Abstract The primary aim of this paper is to evaluate the contribution that competence based approaches to staff management can and ought to make to the overall effectiveness of organisations. The importance of competencies and their proper management is broadly acknowledged in the literature, and the first part of the paper is a literature review. This is followed with a comparison of the design and implementation of two competence management projects that were introduced in two central banks, one of a western European nation, and the other of a central European nation. There is a brief presentation of two fundamental approaches to competence management implementation in organization (top-down (directive) and bottom-up (participative)), and this is juxtaposed with the actual implementation of competence management model that took place in two central banks. What ensues from the comparison is the identification of potential threats to the implementation of competence management models in organizations, accompanied by suggestions on how to counteract them. Keywords: Strategic HRM, competencies, competence management, organisation development, HR development strategies. Resumo O objetivo principal deste trabalho é avaliar o contributo que as abordagens baseadas nas competências na gestão do pessoal pode e deve dar para a eficácia global das organizações. A primeira parte do artigo faz uma revisão da literatura, na qual a importância das competências e da sua correta gestão é amplamente reconhecida. Segue-se uma comparação entre o desenho e implementação de dois projetos de gestão de competências que foram introduzidas em dois bancos centrais, um de um país da Europa Ocidental e outro de um país da Europa Central. Há uma breve apresentação de duas abordagens fundamentais para a implementação da gestão de competências numa organização (topdown (diretiva) e bottom-up (participativa)), sendo isto justaposto com a implementação do modelo de gestão de competências que ocorreu em dois bancos centrais

Protons accelerated in the target normal sheath acceleration regime by a femtosecond laser

Advanced targets based on thin films of graphene oxide covered by metallic layers have been irradiated at high laser intensity (∼1019 W/cm2) with 40 fs laser pulses to investigate the forward ion acceleration in the target normal sheath acceleration regime. A time-of-flight technique was employed with silicon-carbide detectors and ion collectors as fast on-line plasma diagnostics. At the optimized conditions of the laser focus position with respect to the target surface was measured the maximum proton energy using Au metallic films. A maximum proton energy of 2.85 MeV was measured using the Au metallization of 200 nm. The presence of graphene oxide facilitates the electron crossing of the foil minimizing the electron scattering and increasing the electric field driving the ion acceleration. The effect of plasma electron density control using the graphene oxide is presented and discussed

Resampling U-statistics using p-stable laws

It is well known that symmetric statistics based on a kernel with finite second moment have a limit law which can be described by a multiple Wiener-Ito integral. However, if the kernel has less than second moments, no weak limit law holds in general. In the present paper we show that by a suitable change of the empirical process this process has a p-stable multiple integral as its limit

Multi-dimensional parameter estimation of heavy-tailed moving averages

In this paper we present a parametric estimation method for certain multi-parameter heavy-tailed L\'evy-driven moving averages. The theory relies on recent multivariate central limit theorems obtained in [3] via Malliavin calculus on Poisson spaces. Our minimal contrast approach is related to the papers [14, 15], which propose to use the marginal empirical characteristic function to estimate the one-dimensional parameter of the kernel function and the stability index of the driving L\'evy motion. We extend their work to allow for a multi-parametric framework that in particular includes the important examples of the linear fractional stable motion, the stable Ornstein-Uhlenbeck process, certain CARMA(2, 1) models and Ornstein-Uhlenbeck processes with a periodic component among other models. We present both the consistency and the associated central limit theorem of the minimal contrast estimator. Furthermore, we demonstrate numerical analysis to uncover the finite sample performance of our method

Study of shock waves generation, hot electron production and role of parametric instabilities in an intensity regime relevant for the shock ignition

We present experimental results at intensities relevant to Shock Ignition obtained at the sub-ns Prague Asterix Laser System in 2012 . We studied shock waves produced by laser-matter interaction in presence of a pre-plasma. We used a first beam at 1ω (1315 nm) at 7 × 10 13 W/cm 2 to create a pre-plasma on the front side of the target and a second at 3ω (438 nm) at ∼ 10 16 W/cm 2 to create the shock wave. Multilayer targets composed of 25 (or 40 μm) of plastic (doped with Cl), 5 μm of Cu (for Kα diagnostics) and 20 μm of Al for shock measurement were used. We used X-ray spectroscopy of Cl to evaluate the plasma temperature, Kα imaging and spectroscopy to evaluate spatial and spectral properties of the fast electrons and a streak camera for shock breakout measurements. Parametric instabilities (Stimulated Raman Scattering, Stimulated Brillouin Scattering and Two Plasmon Decay) were studied by collecting the back scattered light and analysing its spectrum. Back scattered energy was measured with calorimeters. To evaluate the maximum pressure reached in our experiment we performed hydro simulations with CHIC and DUED codes. The maximum shock pressure generated in our experiment at the front side of the target during laser-interaction is 90 Mbar. The conversion efficiency into hot electrons was estimated to be of the order of ∼ 0.1% and their mean energy in the order ∼50 keV. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distributio

Breast lesion classification based on absorption and composition parameters: a look at SOLUS first outcomes

A machine learning classification algorithm is applied to the SOLUS database to discriminate benign and malignant breast lesions, based on absorption and composition properties retrieved through diffuse optical tomography. The Mann-Whitney test indicates oxy-hemoglobin (p-value = 0.0007) and lipids (0.0387) as the most significant constituents for lesion classification, but work is in progress for further analysis. Together with sensitivity (91%), specificity (75%) and the Area Under the ROC Curve (0.83), special metrics for imbalanced datasets (27% of malignant lesions) are applied to the machine learning outcome: balanced accuracy (83%) and Matthews Correlation Coefficient (0.65). The initial results underline the promising informative content of optical data