A hydrodynamic model for particle beam-driven plasmon wakefield in carbon nanotubes

Charged particles moving through a carbon nanotube may be used to excite electromagnetic modes in the electron gas produced by π and σ orbitals in the cylindrical graphene shell that makes up a nanotube wall [1]. This effect has recently been proposed as a potential novel method of short-wavelength-high-gradient particle acceleration [2, 3]. In this contribution, first we review the existing theory based on a linearised hydrodynamic model for a non-relativistic, localised point-charge propagating in a single wall nanotube (SWNT) [4]. Then we extend it to the relativistic case. In this hydrodynamic model the electron gas is treated as a plasma with additional contributions to the fluid momentum equation from specific solid- state properties of the gas. The governing set of differential equations is formed by the continuity and momentum equations for the involved species: beam charges, electrons and ions of the lattice. These equations are then coupled by Maxwell’s equations. The ions are assumed to be quasistatic and provide a neutralising background. To solve the differential equation system a modified Fourier-Bessel transform has been applied. Furthermore, a spectral analysis has been realised to determine the plasma modes able to excite a longitudinal electrical wakefield component in the SWNT to accelerate test charges. Eventually, we discuss the suitability and possible limitations of the method proposed in this study for particle acceleration

Excitation of wakefields in carbon nanotubes: a hydrodynamic model approach

The interactions of charged particles with carbon nanotubes may excite electromagnetic modes in the electron gas produced in the cylindrical graphene shell constituting the nanotube wall. This wake effect has recently been proposed as a potential novel method of short-wavelength high-gradient particle acceleration. In this work, the excitation of these wakefields is studied by means of the linearized hydrodynamic model. In this model, the electronic excitations on the nanotube surface are described treating the electron gas as a 2D plasma with additional contributions to the fluid momentum equation from specific solid-state properties of the gas. General expressions are derived for the excited longitudinal and transverse wakefields. Numerical results are obtained for a charged particle moving within a carbon nanotube, paraxially to its axis, showing how the wakefield is affected by parameters such as the particle velocity and its radial position, the nanotube radius, and a friction factor, which can be used as a phenomenological parameter to describe effects from the ionic lattice. Assuming a particle driver propagating on axis at a given velocity, optimal parameters were obtained to maximize the longitudinal wakefield amplitude.<br/

Agropiro en Patagones. Evaluación cuantitativa y cualitativa en cuatro sitios

En Patagones, sudoeste (SO) de la provincia de Buenos Aires, bajo el dominio de un ambiente semiárido, el agropiro (Thinopyrum ponticum) es una especie que se produce como alternativa forrajera perenne. La región posee precipitaciones que en promedio llegan a los 430 mm anuales, lo que determina que el abanico de especies perennes viables sea muy reducido. La difusión de esta especie en Patagones permitió dar mayor estabilidad a la cadena forrajera, aportando forraje en cantidad y calidad considerables. Su performance dentro de cada sitio está condicionado por la cantidad y distribución de las precipitaciones. Dada la importancia de esta especie como recurso forrajero para ser introducida en los sistemas ganaderos de la región, se consideró de interés el estudio de parámetros cualitativos y cuantitativos sobre esta especie.EEA Hilario AscasubiFil: Gonzalez, Guillermo Martin. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Hilario Ascasubi. Agencia De Extensión Rural Carmen de Patagones; ArgentinaFil: Luna, Martín Alejandro. Universidad Nacional de Rio Negro. Sede Atlántica; ArgentinaFil: Hernández, Héctor Javier. Universidad Nacional de Rio Negro. Sede Atlántica; Argentin

Polymorphisms associated with the number of live-born piglets in sows infected with the PRRS virus in southern Sonora Mexico

The porcine reproductive and respiratory syndrome (PRRS) is a viral disease that decreases the reproductive performance in breeding sows and leads to economic losses to the swine industry. The objective of the present study was to identify single nucleotide polymorphisms (SNP) associated to the number of live-born piglets in the first (LBP1) and second birth (LBP2) in breeding sows exposed to PRRS virus. The study included 100 pregnant females of the Landrace(¾)/ Yorkshire(¼) line, 75 of which were infected with the PRRS virus and 25 were free of PRRS. Individual blood samples (6-8 drops) were obtained and spotted onto FTA cards and subsequently processed for DNA extraction, which was genotyped using a 10,000 SNP chip for genomic profile. Resulting genotypes were analyzed using a multi-locus mixed model that detected three SNP associated to LBP1 and five SNP associated to LBP2 (P<0.001). These eight SNP were validated using an associative mixed effects model which included the terms genotype and age of dam as fixed effects, and sire as random effect. Allele substitution effects were estimated using the same model including the term genotype as covariate. The SNP rs81276080, rs81334603 and rs80947173 were associated to LBP1 (P<0.001), whereas the SNP rs81364943, rs80859829, rs80895640, rs80893794 and rs81245908 were associated to LBP2 (P<0.001). Only two SNP were in functional chromosomal regions and the remainder SNP were within an intergenic position. In conclusion, these results suggest the existence of gene variants associated with the reproductive performance of sows infected with the PRRS virus.The porcine reproductive and respiratory syndrome (PRRS) is a viral disease that decreases the reproductive performance in breeding sows and leads to economic losses to the swine industry. The objective of the present study was to identify single nucleotide polymorphisms (SNP) associated to the number of live-born piglets in the first (LBP1) and second birth (LBP2) in breeding sows exposed to PRRS virus. The study included 100 pregnant females of the Landrace(¾)/ Yorkshire(¼) line, 75 of which were infected with the PRRS virus and 25 were free of PRRS. Individual blood samples (6-8 drops) were obtained and spotted onto FTA cards and subsequently processed for DNA extraction, which was genotyped using a 10,000 SNP chip for genomic profile. Resulting genotypes were analyzed using a multi-locus mixed model that detected three SNP associated to LBP1 and five SNP associated to LBP2 (P<0.001). These eight SNP were validated using an associative mixed effects model which included the terms genotype and age of dam as fixed effects, and sire as random effect. Allele substitution effects were estimated using the same model including the term genotype as covariate. The SNP rs81276080, rs81334603 and rs80947173 were associated to LBP1 (P<0.001), whereas the SNP rs81364943, rs80859829, rs80895640, rs80893794 and rs81245908 were associated to LBP2 (P<0.001). Only two SNP were in functional chromosomal regions and the remainder SNP were within an intergenic position. In conclusion, these results suggest the existence of gene variants associated with the reproductive performance of sows infected with the PRRS virus

Towards dense people detection with deep learning and depth images

This paper describes a novel DNN-based system, named PD3net, that detects multiple people from a single depth image, in real time. The proposed neural network processes a depth image and outputs a likelihood map in image coordinates, where each detection corresponds to a Gaussian-shaped local distribution, centered at each person?s head. This likelihood map encodes both the number of detected people as well as their position in the image, from which the 3D position can be computed. The proposed DNN includes spatially separated convolutions to increase performance, and runs in real-time with low budget GPUs. We use synthetic data for initially training the network, followed by fine tuning with a small amount of real data. This allows adapting the network to different scenarios without needing large and manually labeled image datasets. Due to that, the people detection system presented in this paper has numerous potential applications in different fields, such as capacity control, automatic video-surveillance, people or groups behavior analysis, healthcare or monitoring and assistance of elderly people in ambient assisted living environments. In addition, the use of depth information does not allow recognizing the identity of people in the scene, thus enabling their detection while preserving their privacy. The proposed DNN has been experimentally evaluated and compared with other state-of-the-art approaches, including both classical and DNN-based solutions, under a wide range of experimental conditions. The achieved results allows concluding that the proposed architecture and the training strategy are effective, and the network generalize to work with scenes different from those used during training. We also demonstrate that our proposal outperforms existing methods and can accurately detect people in scenes with significant occlusions.Ministerio de Economía y CompetitividadUniversidad de AlcaláAgencia Estatal de Investigació

Progesterone receptor isoform A may regulate the effects of neoadjuvant aglepristone in canine mammary carcinoma

Background: Progesterone receptors play a key role in the development of canine mammary tumours, and recent research has focussed on their possible value as therapeutic targets using antiprogestins. Cloning and sequencing of the progesterone receptor gene has shown that the receptor has two isoforms, A and B, transcribed from a single gene. Experimental studies in human breast cancer suggest that the differential expression of progesterone receptor isoforms has implications for hormone therapy responsiveness. This study examined the effects of the antiprogestin aglepristone on cell proliferation and mRNA expression of progesterone receptor isoforms A and B in mammary carcinomas in dogs treated with 20 mg/Kg of aglepristone (n = 22) or vehicle (n = 5) twice before surgery. Results: Formalin-fixed, paraffin-embedded tissue samples taken before and after treatment were used to analyse total progesterone receptor and both isoforms by RT-qPCR and Ki67 antigen labelling. Both total progesterone receptor and isoform A mRNA expression levels decreased after treatment with aglepristone. Furthermore, a significant decrease in the proliferation index (percentage of Ki67-labelled cells) was observed in progesterone-receptor positive and isoform-A positive tumours in aglepristone-treated dogs. Conclusions: These findings suggest that the antiproliferative effects of aglepristone in canine mammary carcinomas are mediated by progesterone receptor isoform A

Validación de un método de determinación de Na, K, Cd, Pb y Hg por Espectrometría de Absorción Atómica en policosanol y extracto purificado de cera de caña

Se desarrolló y validó una metodología analítica para la determinación por espectrometría de absorción atómica de los contenidos de Na, K, Cd, Pb y Hg en policosanol y extracto purificado de cera de caña. Los criterios de validación fueron los siguientes: linealidad, proporcionalidad, exactitud, especificidad y precisión en condiciones de repetibilidad y reproducibilidad. Para el Cd, Pb y Hg, se calcularon los límites de detección (LD) y cuantificación (LC) en dos espectrómetros de absorción atómica. Los criterios de aceptación en todos los casos fueron tomados de la Sección Catalana de Normas de Buena Fabricación y Control de Calidad, excepto para los límites de detección y cuantificación, donde se exige que la suma de metales pesados debe ser menor de 10 ppm, especificación de calidad del producto que aparece en el registro sanitario del medicamento. En el estudio de linealidad se encontraron coeficientes de variación de los factores de respuesta inferiores al 5 % y valores aceptables para la varianza del error experimental total y la desviación estándar de la pendiente, lo que denota una buena linealidad. En cuanto a la proporcionalidad, se comprobó que el sistema no presenta sesgo. Para los dos productos y los cinco elementos analizados la recuperación se situó entre el 97 y 103 %, lo que indicó una adecuada recuperación-exactitud del método. En cuanto a la especificidad, se verificó que en ningún caso hay interferencia de la matriz en la determinación de Na y K

Impact of Wnt/β-Catenin Inhibition on Cell Proliferation through CDC25A Downregulation in Soft Tissue Sarcomas.

The Wnt signaling pathway is an important cellular mechanism for regulating differentiation processes as well as cell cycle events, and different inhibitors of this pathway, for example, PRI-724, are showing promising results in clinical trials for treatment of advanced pancreatic adenocarcinoma or ovarian cancer. Growing evidence suggests that Wnt signaling may also be crucial for tumorigenesis and progression of soft tissue sarcomas (STS), a malignant neoplasm with few therapeutic options at an advanced state. Our study with several STS cell lines and primary cultures shows that inhibition of Wnt/β-catenin signaling with PRI-724 is able to suppress cell viability/proliferation and to increase cell death rates. TCF/β-catenin-mediated transcriptional activity is decreased in treated cells, leading to downregulation of its target genes CCND1 and CDC25A. The latter was critical because its downregulation via siRNA was able to mimic the effect of PRI-724 on cell cycle arrest and cell death induction. An evaluation of NCBI/GenBank data confirmed that CDC25A mRNA is elevated in STS patients. Importantly, PRI-724 in combination with standard STS chemotherapeutics doxorubicin or trabectedin enhanced their antitumoral effect in a synergistic manner according to isobolographic analysis, suggesting that Wnt inhibition through PRI-724 could be a beneficial combination regime in patients with advanced STS.This study was financed by Grupo Español de Investigación en Sarcomas (GEIS) and Fundación Mari PazJiménez Casado. MPC is supported by Programa Estrategia de Emprendimiento y Empleo Joven,Garantía Juvenil(Ministerio de Trabajo, Migraciones y Seguridad Social-SOIB.S

The state of art of the drought studies in Spain

Póster elaborado para el WCRP Workshop on Drought Predictability and Prediction in a Changing Climate celebrado en Barcelona del 2 al 4 de marzo de 201

Validación de la base de datos reticular de la AEMET: temperatura diaria máxima y mínima

Ponencia presentada en: VI Congreso Internacional de la Asociación Española de Climatología celebrado en Tarragona del 8 al 11 de octubre de 2008.[ES]Para cubrir la necesidad de conjuntos de datos reticulares, de alta resolución espacial y a escala temporal diaria, de elementos climatológicos tales como temperatura y precipitación, el Área de Climatología de la Agencia Estatal de Meteorología ha desarrollado una base datos reticular de temperatura máxima y mínima con un espaciado de 25x25 km y un registro temporal desde el 1 de enero de 1931 hasta el 31 de diciembre de 2006. Estos datos deben ser validados y deben ofrecerse junto con una medida de su precisión. Un método clásico consiste en eliminar del análisis espacial con el que se efectúa la interpolación unos pocos e independientes observatorios, y posteriormente utilizarlos para validar. Así, se mantienen la mayoría de las observaciones en la interpolación.[EN]In order to fulfil the necessity for climatological data onto a regular grid, the Climatic Area of Spanish Meteorological Agency (Agencia Estatal de Meteorología) has developed a regular database by spatial interpolation of maximum and minimum daily temperature. All available observed daily data for the period from 1 January 1931 to 31 December 2006 is used in the interpolation over a 25x25 km regular grid covering the Iberian Peninsula and the Balearic Islands. In order to assess estimation uncertainty, an independent validation procedure has to be carried out and a description of the precision of the grid database should be provided. A classical approach for this procedure is to split the data sample in two parts, and use those to parts for estimation and validation respectively.Este trabajo ha sido parcialmente financiado por el proyecto de investigación CGL2007- 61328/CLI