First direct observation of muon antineutrino disappearance

This Letter reports the first direct observation of muon antineutrino disappearance. The MINOS experiment has taken data with an accelerator beam optimized for ν(μ) production, accumulating an exposure of 1.71 × 102? protons on target. In the Far Detector, 97 charged current ν(μ) events are observed. The no-oscillation hypothesis predicts 156 events and is excluded at 6.3σ. The best fit to oscillation yields |Δm2| = [3.36(-0.40)(+0.46)(stat) ± 0.06(syst)] × 10?3 eV2, sin2(2θ) = 0.86(-0.12)(+0.11)(stat) ± 0.01(syst). The MINOS ν(μ) and ν(μ) measurements are consistent at the 2.0% confidence level, assuming identical underlying oscillation parameters.     

Segmental dynamics in poly(ε‐caprolactone)/poly(L‐lactide) copolymer networks

Poly(ε‐caprolactone) (PCL) and poly(lactic acid) (PLA) networks were prepared from macromonomer diols functionalized with methacrylic anhydride, which allows one to get self‐crosslinkable polymers. Besides, both macromonomers were copolymerized to get copolymer networks with different compositions (namely, PCL/PLA: 0/100, 70/30, 50/50, 30/70, 100/0). Dielectric and calorimetric experiments allow one to conclude the microphase separation of the system: one phase made of pure PCL domains while the second one consists of caprolactone units, which somehow plasticize PLA and moves its main relaxation (glass transition) to lower temperatures. The effect of crosslinking PLA on the dynamics of the system was further investigated by comparing with the dynamics for linear PLA. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 183–193, 2009     

Conformal metrics on the ball with zero scalar curvature and prescribed mean curvature on the boundary

This paper considers the prescribed zero scalar curvature and mean curvature problem on the n-dimensional Euclidean ball for n?3. We consider the limits of solutions of the regularization obtained by decreasing the critical exponent. We characterize those subcritical solutions which blow-up at the least possible energy level, determining the points at which they can concentrate, and their Morse indices. We show that when n=3 this is the only blow-up which can occur for solutions. We use this in combination with the Morse inequalities for the subcritical problem to obtain a general existence theorem for the prescribed zero scalar curvature and mean curvature on the three-dimensional Euclidean ball. In the higher-dimensional case n?4, we give conditions on the function h to guarantee there is only one simple blow-up point.     

Dynamics of GDOES-induced surface roughening in metal interfaces

The roughness induced during glow-discharge optical-emission spectroscopy (GDOES) measurements has been reported to cause a loss of resolution during GDOES depth-profiling analysis. In this paper, we undertake for the first time a study of the dynamics of the surface morphology of chromium and titanium thin films (designed in mono and multilayer structures) under the impinging of GDOES incoming ions. We performed this study under the theoretical framework of the dynamic scaling theory, by analysing surface morphology changes, as measured ex-situ by AFM, with irradiation time. For single metal layers it was found that, after an initial surface smoothening, the surface undergoes a rapid steep roughening for both systems, with quite similar quantitative dynamics. Once this roughening ends a second temporal scaling regime arises, operating for long length scales with dynamics depending on the sputtering rate of the material. For the chromium layer, with a very high sputtering rate of 5.5 μm min^?1, this regime is consistent with the KPZ model, whereas for the titanium layer an EW scaling regime is indicated. These different scaling regimes are consistent with the development of larger surface slopes for the Cr system. In the multilayer systems, the initial roughness induced on the top Cr layer by GDOES has similar dynamics to that for single-layer Cr. However, a clear decrease in the roughness was observed once the underlying Ti layer, with a lower sputtering rate, was reached. This decrease in the induced roughness is maintained while the Ti layer is eroded. Therefore, choice of appropriate material (i.e. sputtering yield values) combinations and of their depth of location can enable tuning of GDOES-induced roughness and achieve substantial control over the depth profiling process.     

Grid‐based algorithm to search critical points,in the electron density,accelerated by graphics processing units

Using a grid‐based method to search the critical points in electron density, we show how to accelerate such a method with graphics processing units (GPUs). When the GPU implementation is contrasted with that used on central processing units (CPUs), we found a large difference between the time elapsed by both implementations: the smallest time is observed when GPUs are used. We tested two GPUs, one related with video games and other used for high‐performance computing (HPC). By the side of the CPUs, two processors were tested, one used in common personal computers and other used for HPC, both of last generation. Although our parallel algorithm scales quite well on CPUs, the same implementation on GPUs runs around 10× faster than 16 CPUs, with any of the tested GPUs and CPUs. We have found what one GPU dedicated for video games can be used without any problem for our application, delivering a remarkable performance, in fact; this GPU competes against one HPC GPU, in particular when single‐precision is used. © 2014 Wiley Periodicals, Inc.     

An adaptive solar radiation numerical model

A numerical model for the evaluation of solar radiation in different locations is presented. The solar radiation model is implemented taking into account the terrain surface using two-dimensional adaptive meshes of triangles that are constructed using a refinement/derefinement procedure in accordance with the variations of terrain surface and albedo. The selected methodology defines the terrain characteristics with a minimum number of points so that the computational cost is reduced for a given accuracy. The model can be used in atmospheric sciences as well as in other fields such as electrical engineering, since it allows the user to find the optimal location for maximum power generation in photovoltaic or solar thermal power plants. For this purpose, the effect of shadows is considered in each time step. The solar radiation is first computed for clear sky conditions considering the different components of the radiation. The real sky radiation is computed daily, starting from the results of clear sky radiation, in terms of the clear sky index. Maps for the clear sky index are obtained from a spatial interpolation of observational data that are available for each day at several points of the region under consideration. Finally, the solar radiation maps for a month are calculated from the daily results. The model can also be applied in solar radiation forecasting with the help of a forecasting meteorological model. This model takes into account the shadows cast, and allows the user to make a better estimation of the amount of solar power generation. Some numerical experiments related to the generation of solar radiation maps in Gran Canaria Island (Canary Islands, Spain) are presented.     

Incorporation of silver/carbon nanoparticles into poly(methyl methacrylate) via in situ miniemulsion polymerization and its influence on the glass‐transition temperature

Silver/carbon nanoparticles (9 nm) were incorporated, as reinforcements, into a matrix of poly(methyl methacrylate) via in situ miniemulsion polymerization. It was found by differential scanning calorimetry that the glass‐transition temperature of the poly(methyl methacrylate) showed an improvement of 14 °C with only 0.5 wt % nanoparticles in comparison with a pure poly(methyl methacrylate) control, which was also obtained by miniemulsion polymerization under the same conditions. This increase was related to a polymer chain mobility restriction due to a combination of bound plastic and joint plastic shell effects at the interphase and the surrounding regions. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 511–518, 2007.     

THE PEROXIDATIVE METABOLISM OF TENOXICAM PRODUCES EXCITED SPECIES

The peroxidative metabolism of the nonsteroid anti-inflammatory oxicams generates metabolites of the type expected from a dioxetane intermediae. Therefore, electronically excited metabolites may be expected. Consistent with this possibility, both direct and sensitized light emission are observed when tenoxicam is exposed to horseradish peroxidase or when added to leukocytes, where it undergoes a myeloperoxidase-catalyzed aerobic oxidation. The similarity between peroxidative metabolism with concomitant oxygen uptake and photodegrdation brought about by singlet oxygen addition to the substrate is pointed out. As a whole, the results strengthen the view that electronically excited species should also be considered when analyzing the effect(s) of xenobiotics.     

Antiviral effect and mode of action of methanolic extract of Verbascum thapsus L. on pseudorabies virus (strain RC/79)

The methanolic extract of Verbascum thapsus was evaluated for its antiviral activity against the pseudorabies virus strain RC/79 (PrV), and also for its cytotoxic activity on Vero cells. The extract showed CC?? values of 1100?μg?mL?1 and 1426?μg?mL?1 by NRU and MTT assays, respectively. The 50% inhibitory concentration of the extract for PrV plaque formation was determined at 35?μg?mL?1, and selectivity indices were 31.4 (NRU) and 40.7 (MTT). When cells were pre-treated with the extract prior to virus infection, the inhibition in plaque formation was 70%. PrV was highly inhibited when it was incubated with plant extract or when the extract was added during the adsorption phase (99%). However, no inhibitory effect was observed when the extract was added to the cells after the adsorption period. Thus, these results suggest that the methanolic extract of Verbascum thapsus may contain bioactive compound(s) that affect PrV mostly in the adsorption phase.     

Stochastic Correlation and Volatility Mean-reversion – Empirical Motivation and Derivatives Pricing via Perturbation Theory

Abstract

The dependence structure is crucial when modelling several assets simultaneously. We show for a real-data example that the correlation structure between assets is not constant over time but rather changes stochastically, and we propose a multidimensional asset model which fits the patterns found in the empirical data. The model is applied to price multi-asset derivatives by means of perturbation theory. It turns out that the leading term of the approximation corresponds to the Black–Scholes derivative price with correction terms adjusting for stochastic volatility and stochastic correlation effects. The practicability of the presented method is illustrated by some numerical implementations. Furthermore, we propose a calibration methodology for the considered model.