Efecto de diferentes composiciones del espesor de amortiguación en superficies ecuestres de Césped de dos sistemas constructivos

Las superficies ecuestres de césped para la práctica deportiva deben cumplir requisitos funcionales para asegurar la calidad de la performance, el bienestar animal y la seguridad del jinete. La FEI definió las características de las superficies ecuestres. Firmeza, amortiguación, rebote, agarre, uniformidad y consistencia. Los métodos constructivos deben alcanzar estas propiedades. La falta de conocimiento técnico específico en la ejecución de superficies ecuestres hace que las propiedades agronómicas prevalezcan por sobre las propiedades funcionales y no sean incluidas en las decisiones constructivas. Es necesario monitorear los aspectos críticos de la respuesta de la superficie, como así también adoptar materiales y métodos posibles de ser utilizados localmente. El objetivo del ensayo es establecer y caracterizar las propiedades funcionales de superficies ecuestres de césped diseñadas con materiales existentes en el medio local. Para ello se estableció un experimento en la localidad de Los Cardales, se dispusieron 16 cajas de 1 m2; 8 con subbase de tosca y 8 con subbase de tosca + capas drenantes, dos niveles de fibras de geotextil, la Humedad fue 25% CVH, se adicionó Hidrogel. Se realizaron mediciones de Impacto, con un dispositivo similar al Clegg Hammer. La tracción longitudinal, se midió utilizando un dispositivo según norma ASTM F2333-04, además se utilizó el dispositivo denominado Going Stick. Se realizaron ensayos de caracterización de los materiales. El Contenido Volumétrico de Humedad se monitoreó con TDR. Los datos obtenidos se analizaron mediante ANVA y test de Tuckey. Las conclusiones preliminares indican que el sistema drenante diseñado mostró diferencias significativas para el índice de Tracción del GS, el tratamiento de adición de fibras de Geotextil, fue significativo para el índice de GS, Penetración GS, Tracción ASTM e Impácto. El agregado de Hidrogel mostró valores significativos para IGS y para Penetración de G

Synthetic properties of bright metal-poor variables. II. BL Her stars

We investigate the properties of the so-called BL Her stars, i.e., Population II Cepheids with periods shorter than 8 days, using updated pulsation models and evolutionary tracks computed adopting a metal abundance in the range of Z=0.0001 to Z=0.004. We derive the predicted Period-Magnitude (PM) and Period-Wesenheit (PW) relations at the various photometric bands and we show that the slopes of these relations are in good agreement with the slopes determined by observed variables in Galactic globular clusters, independently of the adopted M_V(RR)-[Fe/H] relation to get the cluster RR Lyrae-based distance. Moreover, we show that also the distances provided by the predicted PM and PW relations for BL Her stars agree within the errors with the RR Lyrae based values. The use of the predicted relations with W Vir stars, which are Population II Cepheids with periods longer than 8 days, provides no clear evidence for or against a change in the PM and PW slopes around P~10 days.Comment: 12 pages, 6 figures, 6 tables, accepted for publication in A&A on date 16/05/200

Trans-generational epigenetic regulation associated with the amelioration of Duchenne Muscular Dystrophy

Exon skipping is an effective strategy for the treatment of many Duchenne Muscular Dystrophy (DMD) mutations. Natural exon skipping observed in several DMD cases can help in identifying novel therapeutic tools. Here, we show a DMD study case where the lack of a splicing factor (Celf2a), which results in exon skipping and dystrophin rescue, is due to a maternally inherited trans-generational epigenetic silencing. We found that the study case and his mother express a repressive long non-coding RNA, DUXAP8, whose presence correlates with silencing of the Celf2a coding region. We also demonstrate that DUXAP8 expression is lost upon cell reprogramming and that, upon induction of iPSCs into myoblasts, Celf2a expression is recovered leading to the loss of exon skipping and loss of dystrophin synthesis. Finally, CRISPR/Cas9 inactivation of the splicing factor Celf2a was proven to ameliorate the pathological state in other DMD backgrounds establishing Celf2a ablation or inactivation as a novel therapeutic approach for the treatment of Duchenne Muscular Dystrophy

A spectroscopic survey of thick disc stars outside the solar neighbourhood

We performed a spectroscopic survey of nearly 700 stars probing the galactic thick disc far from the solar neighbourhood towards the galactic coordinates (l~277, b~47). The derived effective temperatures, surface gravities and overall metallicities were then combined with stellar evolution isochrones, radial velocities and proper motions to derive the distances, kinematics and orbital parameters of the sample stars. The targets belonging to each galactic component (thin disc, thick disc, halo) were selected either on their kinematics or according to their position above the galactic plane, and the vertical gradients were also estimated. We present here atmospheric parameters, distances and kinematics for this sample, and a comparison of our kinematic and metallicity distributions with the Besancon model of the Milky Way. The thick disc far from the solar neighbourhood is found to differ only slightly from the thick disc properties as derived in the solar vicinity. For regions where the thick disc dominates, we measured vertical velocity and metallicity trends of d(V_phi)/dZ = 19 +/- 8 km/s/kpc and d[M/H]/dZ = -0.14 +/- 0.05 dex/kpc, respectively. These trends can be explained as a smooth transition between the different galactic components, although intrinsic gradients could not be excluded. In addition, a correlation d(V_phi)/d[M/H] = -45 +/- 12 km/s/dex between the orbital velocity and the metallicity of the thick disc is detected. This gradient is inconsistent with the SDSS photometric survey analysis, which did not detect any such trend, and challenges radial migration models of thick disc formation. Estimations of the scale heights and scale lengths for different metallicity bins of the thick disc result in consistent values, with hR~3.4 \pm 0.7 kpc, and hZ~694 \pm 45 pc, showing no evidence of relics of destroyed massive satellites.Comment: 19 pages, 15 figures, accepted for publication in A&

Identification of mitochondrial carriers in Saccharomyces cerevisiae by transport assay of reconstituted recombinant proteins".

The inner membranes of mitochondria contain a family of carrier proteins that are responsible for the transport in and out of the mitochondrial matrix of substrates, products, co-factors and biosynthetic precursors that are essential for the function and activities of the organelle. This family of proteins is characterized by containing three tandem homologous sequence repeats of approximately 100 amino acids, each folded into two transmembrane α-helices linked by an extensive polar loop. Each repeat contains a characteristic conserved sequence. These features have been used to determine the extent of the family in genome sequences. The genome of Saccharomyces cerevisiae contains 34 members of the family. The identity of five of them was known before the determination of the genome sequence, but the functions of the remaining family members were not. This review describes how the functions of 15 of these previously unknown transport proteins have been determined by a strategy that consists of expressing the genes in Escherichia coli or Saccharomyces cerevisiae, reconstituting the gene products into liposomes and establishing their functions by transport assay. Genetic and biochemical evidence as well as phylogenetic considerations have guided the choice of substrates that were tested in the transport assays. The physiological roles of these carriers have been verified by genetic experiments. Various pieces of evidence point to the functions of six additional members of the family, but these proposals await confirmation by transport assay. The sequences of many of the newly identified yeast carriers have been used to characterize orthologs in other species, and in man five diseases are presently known to be caused by defects in specific mitochondrial carrier genes. The roles of eight yeast mitochondrial carriers remain to be established. © 2006 Elsevier B.V. All rights reserved

Digitatio and Scientific Exploitation of the Italian and Vatican Astronomical Plate Archives

There is a widespread interest to digitize the precious information contained in the astronomical plate archives, both for the preservation of their content and for its fast distribution to all interested researchers in order to achieve their better scientific exploitation. This paper presents the first results of our large-scale project to digitize the archive of plates of the Italian Astronomical Observatories and of the Specola Vaticana. Similar systems, composed by commercial flat-bed retro-illuminated scanners plus dedicated personal computers and acquisition and analysis software, have been installed in all participating Institutes. Ad-hoc codes have been developed to acquire the data, to test the suitability of the machines to our scientific needs, and to reduce the digital data in order to extract the astrometric, photometric and spectroscopic content. Two more elements complete the overall project: the provision of high quality BVRI CCD sequences in selected fields with the Campo Imperatore telescopes, and the distribution of the digitized information to all interested researchers via the Web. The methods we have derived in the course of this project have been already applied successfully to plates taken by other Observatories, for instance at Byurakan and at Hamburg.Comment: To appear in Experimental Astronom