Free Form of the Foldy-Wouthuysen Transformation in External Electromagnetic Fields

We derive the exact Foldy-Wouthuysen transformation for Dirac fermions in a time independent external electromagnetic field in the basis of the Ritus eigenfunctions, namely the eigenfunctions of the operator $(\gamma \cdot \Pi)^2$, with $\Pi^\mu = p^\mu - e A^\mu$. In this basis, the transformation acquires a free form involving the dynamical quantum numbers induced by the field.Comment: 8 pages. Accepted in J. Phys. A: Math. and Theo. (Fast Track Communication

Ac magnetic susceptibility of a molecular magnet submonolayer directly patterned onto a microSQUID sensor

We report the controlled integration, via Dip Pen Nanolithography, of monolayer dots of ferritin-based CoO nanoparticles (12 Bohr magnetons) into the most sensitive areas of a microSQUID sensor. The nearly optimum flux coupling between these nanomagnets and the microSQUID improves the achievable sensitivity by a factor 100, enabling us to measure the linear susceptibility of the molecular array down to very low temperatures (13 mK). This method opens the possibility of applying ac susceptibility experiments to characterize two-dimensional arrays of single molecule magnets within a wide range of temperatures and frequencies.Comment: 4 pages 3 figure

The conserved transmembrane proteoglycan Perdido/Kon-tiki is essential for myofibrillogenesis and sarcomeric structure in Drosophila

This is an Open Access article distributed under the terms of the Creative Commons Attribution License.Muscle differentiation requires the assembly of high-order structures called myofibrils, composed of sarcomeres. Even though themolecular organization of sarcomeres is well known, the mechanisms underlying myofibrillogenesis are poorly understood. It has been proposed that integrin-dependent adhesion nucleates myofibrils at the periphery of the muscle cell to sustain sarcomere assembly. Here, we report a role for the gene perdido (perd, also known as kon-tiki, a transmembrane chondroitin proteoglycan) in myofibrillogenesis. Expression of perd RNAi in muscles, prior to adult myogenesis, can induce misorientation and detachment of Drosophila adult abdominal muscles. In comparison to controls, perd-depleted muscles contain fewer myofibrils, which are localized at the cell periphery. These myofibrils are detached from each other and display a defective sarcomeric structure. Our results demonstrate that the extracellular matrix receptor Perd has a specific role in the assembly of myofibrils and in sarcomeric organization. We suggest that Perd acts downstream or in parallel to integrins to enable the connection of nascent myofibrils to the Z-bands. Our work identifies the Drosophila adult abdominalmuscles as amodel to investigate in vivo the mechanisms behind myofibrillogenesis.Research was funded by the Spanish Ministry of Science and Innovation [grant number BFU2011-26745]. B.E. was funded in part by the Ramon y Cajal program by the Universidad Pablo de Olavide; J.J.P.-M. was funded by the Proyecto de Excelencia of Junta de Andalucía; M.B. was funded by a Wellcome Trust Senior Investigator Award to Peter Lawrence [grant number WT096645MA]. M.D.M.-B. is funded by the Consejo Superior de Investigaciones Científicas.Peer Reviewe

Utilización de soja integral en la ración de acabado del ternero tradicional de raza rubia gallega: I. Efecto sobre la calidad de la carne

Se utilizaron 16 terneros rubios gallegos para estudiar el efecto del aca- bado con pienso, que contiene soja integral sobre el peso y las característi- cas de la canal y de la carne del ternero tradicional producido en un siste- ma de pastoreo. Se controlo el peso vivo, el peso al sacrificio, el peso canal, la conformación y el estado de engrasamiento de la canal y en la carne a 24 horas postmorten, el pH, el color L* (luminosidad) a* (índice de rojo) y b* (índice de amarillo) (CIE 1978), la composición química por espectroscopia NIRS, las pérdidas de agua por cocción, la textura midiendo la fuerza máxi- ma de corte, resistencia al corte y trabajo total y el contenido en pigmentos hemínicos. Los resultados se analizaron mediante ANOVA con el programa SPSS 8.0. No se encontraron diferencias significativas entre tratamientos en ninguno de los parámetros estudiados de peso vivo y características de la canal y de la carne. Se concluye que la sustitución de la soja desengrasada por soja integral en la ración de acabado no afecta al crecimiento y a las características de la canal y de la carne del ternero tradicional Gallego

The conserved transmembrane proteoglycan Perdido/Kon-tiki is essential for myofibrillogenesis and sarcomeric structure in Drosophila.

Muscle differentiation requires the assembly of high-order structures called myofibrils, composed of sarcomeres. Even though the molecular organization of sarcomeres is well known, the mechanisms underlying myofibrillogenesis are poorly understood. It has been proposed that integrin-dependent adhesion nucleates myofibrils at the periphery of the muscle cell to sustain sarcomere assembly. Here, we report a role for the gene perdido (perd, also known as kon-tiki, a transmembrane chondroitin proteoglycan) in myofibrillogenesis. Expression of perd RNAi in muscles, prior to adult myogenesis, can induce misorientation and detachment of Drosophila adult abdominal muscles. In comparison to controls, perd-depleted muscles contain fewer myofibrils, which are localized at the cell periphery. These myofibrils are detached from each other and display a defective sarcomeric structure. Our results demonstrate that the extracellular matrix receptor Perd has a specific role in the assembly of myofibrils and in sarcomeric organization. We suggest that Perd acts downstream or in parallel to integrins to enable the connection of nascent myofibrils to the Z-bands. Our work identifies the Drosophila adult abdominal muscles as a model to investigate in vivo the mechanisms behind myofibrillogenesis

Model-based passive and active diagnostics strategies for diesel oxidation catalyst

[EN] This article proposes a diesel oxidation catalyst diagnostics strategy based on the exothermic process generated by exhaust gas species oxidation in the catalyst. The diagnostics strategy is designed to be applied on-board and respecting real-time electronic control unit computational limitations. Diagnostics purposes are fulfilled by means of the comparison of the passive model temperature, which represents the outlet temperature of a non-impregnated diesel oxidation catalyst, and the measurement provided by the on-board catalyst-out temperature sensor. Thus, the presented diagnostics strategy uses only two production grade temperature sensors and the measurements of air and fuel mass flows from the electronic control unit. Passive diagnostics is based on the oxidation of engine-raw emissions, whilst active diagnostics is based on the oxidation of requested post injected fuel. Post-injection strategy is also discussed for active diagnosis. Then, the diagnostics strategy is able to discern whether the diesel oxidation catalyst is able to oxidise or not. (C) 2016 Elsevier Ltd. All rights reserved.This research has been partially financed by the Spanish Ministerio de Economia y Competitividad, through project TRA2013-40853-R 'Desarrollo de nuevas tecnicas de limitacion de la perdida de presion en DPFs para reducir las emisiones y el consumo de los motores diesel (PRELIMIT)'.Guardiola, C.; Plá Moreno, B.; Piqueras, P.; Mora-Pérez, J.; Lefebvre, D. (2017). Model-based passive and active diagnostics strategies for diesel oxidation catalyst. Applied Thermal Engineering. 110:962-971. https://doi.org/10.1016/j.applthermaleng.2016.08.207S96297111

Threading Through Macrocycles Enhances the Performance of Carbon Nanotubes as Polymer Fillers

In this work we study the reinforcement of polymers by mechanically interlocked derivatives of single-walled carbon nanotubes (SWNTs). We compare the mechanical properties of fibers made of polymers and of composites with pristine single-walled carbon nanotubes (SWNTs), mechanically interlocked derivatives of SWNTs (MINTs) and the corresponding supramolecular models. Improvements of both Young's modulus and tensile strength of up to 200 % were observed for the polystyrene-MINTs samples with an optimized loading of just 0.01 wt.%, while the supramolecular models with identical chemical composition and loading showed negligible or even detrimental influence. This behavior is found for three different types of SWNTs and two types of macrocycles. Molecular dynamics simulations show that the polymer adopts an elongated conformation parallel to the SWNT when interacting with MINT fillers, irrespective of the macrocycle chemical nature, whereas a more globular structure is taken upon facing with either pristine SWNTs or supramolecular models. The MINT composite architecture thus leads to a more efficient exploitation of the axial properties of the SWNTs and of the polymer chain at the interface, in agreement with experimental results. Our findings demonstrate that the mechanical bond imparts distinctive advantageous properties to SWNT derivatives as polymer fillers.Comment: 39 pages, 19 figure

Valence band offset of the ZnO/AlN heterojunction determined by X-ray photoemission spectroscopy

The valence band offset of ZnO/AlN heterojunctions is determined by high resolution x-ray photoemission spectroscopy. The valence band of ZnO is found to be 0.43±0.17 eV below that of AlN. Together with the resulting conduction band offset of 3.29±0.20 eV, this indicates that a type-II (staggered) band line up exists at the ZnO/AlN heterojunction. Using the III-nitride band offsets and the transitivity rule, the valence band offsets for ZnO/GaN and ZnO/InN heterojunctions are derived as 1.37 and 1.95 eV, respectively, significantly higher than the previously determined values