695 research outputs found
Un artesonado poliédrico manierista en Castroverde de Campos (Zamora, España)
This paper analyses an outstanding case in the field of historic Spanish carpentry. Built in the sixteenth century, the fivepanel wood coffered ceiling in the church of Santa María del Río in Castroverde de Campos (Zamora, Spain) shows a Renaissance layout with polygonal coffers. It combines Hispano–Islamic technological heritage with some innovative features, including singular disposition of timber, duplicity of structures and unorthodox carpentry joints. Furthermore, convex coffers are introduced among traditional concave ones giving it a marked Mannerist appearance. The likely double role of the author as designer and contractor explains the relevance of prefabricated elements in the construction process of the ceiling, since this effort for modulation and systematization rationalizes procedures and reduces labour costs.Este artículo analiza un caso excepcional en la carpintería de armar en España. Se trata del artesonado de cinco paños de la iglesia de Santa María del Río, en Castroverde de Campos (Zamora). Construido en el s. XVI, con una trama de artesones poligonales en su intradós, combina el diseño renacentista con la tradición técnica hispano-musulmana de estructuras de madera, y presenta aportaciones novedosas como la inusual disposición de escuadrías, la duplicidad de estructuras y las poco ortodoxas uniones carpinteras utilizadas. Además, la introducción de artesones convexos junto a los convencionales artesones cóncavos le confiere un marcado aspecto manierista y resuelve ingeniosamente el encuentro entre paños. La muy posible coincidencia de diseñador y constructor en la misma persona explicaría un proceso de construcción con módulos prefabricados, con el consiguiente ahorro de costes y riesgos laborales
La triple escalera de caracol en el Convento de Santo Domingo de Bonaval (Santiago, España): hipótesis de diseño y construcción
By 1700 Domingo de Andrade, at that time master builder of the Santiago de Compostela cathedral (North-west of Spain), built a unique spiral staircase in the Santo Domingo de Bonaval’s Convent, on the outskirts of the city. This paper provides a construction process hypothesis based on the available knowledge and technical resources at that time, involving the geometry, layout, stonework of the steps and their positioning on the site. A 1:5 scale model has been made to demonstrate that the staircase could have been built with no scaffolding at all. That would have meant for Andrade, architect and builder, an important cost reduction. Moreover been a masterpiece with an undeniable show of prowess, it is quite possible that economic reasons had driven the master to this bold design.Hacia 1700, en los últimos años de su carrera, el maestro mayor de la catedral de Santiago de Compostela, Domingo de Andrade, realizó un alarde técnico sin precedentes al construir una singular escalera de caracol en el Convento de Santo Domingo de Bonaval. El presente trabajo ofrece una hipótesis constructiva de la obra en base a los conocimientos y medios disponibles en la época, atendiendo a su geometría, trazado, labra de los peldaños y puesta en obra en condiciones de estabilidad estructural. Se ha realizado una maqueta a escala 1:5, que ha permitido demostrar la hipótesis de que la escalera pudo ser levantada sin necesidad alguna de apeos. Tal circunstancia habría supuesto para Andrade, arquitecto y contratista, una reducción importante de los costes de construcción. Más allá de la indudable demostración de pericia, es muy posible que motivaciones económicas animaran al maestro en su audacia
Dark matter searches using superheated liquids
Direct detection of dark matter is one of the most important
topics in modern physics. It is estimated that 22% of universe matter is
composed by dark matter in front of 0.4% of ordinary matter like stars,
galaxies planets and all kind of known astrophysical objects. Several kinds of
experiments are nowadays involved in detection of one of the more accepted
particle candidates to be dark matter: WIMPs (Weakly Interacting Massive
Particles). These detectors, using several kinds of techniques: Cryogenic
semiconductors, scintillation materials like I Na or noble gas chambers
among others, are reporting very interesting but inconclusive results. In this
paper a review of detectors that are using the superheated liquid technique
in bubble chambers in order to detect WIMPs is reported. Basically, we
will report about Coupp (Chicagoland observatory for underground particle
physics), PICO that is composed by Coupp and Picasso researchers having
the aim to build a ton experiment and also about a new detector named
MOSCAB (Materia oscura a bolle) that recently published a first results of
a test chamber that uses also superheated liquid technique but as a Geyser
chamber.Bou Cabo, M.; Ardid Ramírez, M.; Felis-Enguix, I. (2016). Dark matter searches using superheated liquids. EPJ Web of Conferences. 121(06007):1-8. doi:10.1051/epjconf/201612106007S1812106007Rayleigh L., On the pressure developed in a liquid during the collapse of a spherical cavity (Philos. Mag34, 94, 1917)Plesset M.S., The growth of vapor bubbles in superheated liquid (J. Appl. Phys.25, 9493, 1954)Forster H.K., Growth of vapor bubbles in superheated liquid (J. Appl. Phys.05, 474, 1954)Seitz F. (Phys. Fluids1, 2, 1958)Behnke E. et al., Coupp Collaboration, First dark matter search results from a 4-kg CF3I bubble chamber operated in a deep underground site (Phys. Rev. D86, 2012)Behnke et al., Coupp Collaboration, Direct measurement of the bubble-nucleation energy threshold in a CF3I bubble chamber (Phys. Rev. D88, 2013)Archambault S., Picasso Collaboration, Dark Matter Spin-Dependent Limits for WIMPs Interactions on19F by PICASSO(Phys. Lett. B, 2009)Bertoni R. et al., A new technique for direct investigation of dark matter (Nuclear Instruments and Methods in Physics Research, A, 61–68, 2014)Bou-Cabo M. et al., LOW Radioactivity Techniques 2013 (LRT 2013): Proceedings of the IV International Workshop in Low Radioactivity Techniques, V:1549, 142 – 147Ardid M. et al., MOSCAB: Direct dark matter search using the Geyser technique, Proc. ICHEP 2014 Conf., Nucl. Phys. B: Proc. Supp. (in press
Comparative Proteomic Analyses of the Parietal Lobe from Rhesus Monkeys Fed a High-Fat/Sugar Diet With and Without Resveratrol Supplementation, Relative to a Healthy Diet: Insights Into the Roles of Unhealthy Diets and Resveratrol on Function
A diet consisting of a high intake of saturated fat and refined sugars is characteristic of a Western-diet and has been shown to have a substantial negative effect on human health. Expression proteomics were used to investigate changes to the parietal lobe proteome of rhesus monkeys consuming either a high fat and sugar (HFS) diet, a HFS diet supplemented with resveratrol (HFS+RSV), or a healthy control diet for 2 years. Here we discuss the modifications in the levels of 12 specific proteins involved in various cellular systems including metabolism, neurotransmission, structural integrity, and general cellular signaling following a nutritional intervention. Our results contribute to a better understanding of the mechanisms by which resveratrol functions through the up- or down-regulation of proteins in different cellular sub-systems to affect the overall health of the brain
Anyon in External Electromagnetic Field: Hamiltonian and Lagrangian Formulations
We propose a simple model for a free relativistic particle of fractional spin
in 2+1 dimensions which satisfies all the necessary conditions. The canonical
quantization of the system leads to the description of one- particle states of
the Poincare group with arbitrary spin. Using the Hamil- tonian formulation
with the set of constraints, we introduce the electro- magnetic interaction of
a charged anyon and obtain the Lagrangian. The Casimir operator of the extended
algebra, which is the first-class constraint, is obtained and gives the
equation of motion of the anyon. In particular, from the latter it follows that
the gyromagnetic ratio for a charged anyon is two due to the parallelness of
spin and momentum of the particle in 2+1 dimensions. The canonical quantization
is also considered in this case.Comment: 9 pages, Latex, HU-SEFT R 1993-1
Status and Recent Results of the Acoustic Neutrino Detection Test System AMADEUS
The AMADEUS system is an integral part of the ANTARES neutrino telescope in
the Mediterranean Sea. The project aims at the investigation of techniques for
acoustic neutrino detection in the deep sea. Installed at a depth of more than
2000m, the acoustic sensors of AMADEUS are based on piezo-ceramics elements for
the broad-band recording of signals with frequencies ranging up to 125kHz.
AMADEUS was completed in May 2008 and comprises six "acoustic clusters", each
one holding six acoustic sensors that are arranged at distances of roughly 1m
from each other. The clusters are installed with inter-spacings ranging from
15m to 340m. Acoustic data are continuously acquired and processed at a
computer cluster where online filter algorithms are applied to select a
high-purity sample of neutrino-like signals. 1.6 TB of data were recorded in
2008 and 3.2 TB in 2009. In order to assess the background of neutrino-like
signals in the deep sea, the characteristics of ambient noise and transient
signals have been investigated. In this article, the AMADEUS system will be
described and recent results will be presented.Comment: 7 pages, 8 figures. Proceedings of ARENA 2010, the 4th International
Workshop on Acoustic and Radio EeV Neutrino Detection Activitie
Search for muon-neutrino emission from GeV and TeV gamma-ray flaring blazars using five years of data of the ANTARES telescope
The ANTARES telescope is well-suited for detecting astrophysical transient
neutrino sources as it can observe a full hemisphere of the sky at all times
with a high duty cycle. The background due to atmospheric particles can be
drastically reduced, and the point-source sensitivity improved, by selecting a
narrow time window around possible neutrino production periods. Blazars, being
radio-loud active galactic nuclei with their jets pointing almost directly
towards the observer, are particularly attractive potential neutrino point
sources, since they are among the most likely sources of the very high-energy
cosmic rays. Neutrinos and gamma rays may be produced in hadronic interactions
with the surrounding medium. Moreover, blazars generally show high time
variability in their light curves at different wavelengths and on various time
scales. This paper presents a time-dependent analysis applied to a selection of
flaring gamma-ray blazars observed by the FERMI/LAT experiment and by TeV
Cherenkov telescopes using five years of ANTARES data taken from 2008 to 2012.
The results are compatible with fluctuations of the background. Upper limits on
the neutrino fluence have been produced and compared to the measured gamma-ray
spectral energy distribution.Comment: 27 pages, 16 figure
Performance of the First ANTARES Detector Line
In this paper we report on the data recorded with the first Antares detector
line. The line was deployed on the 14th of February 2006 and was connected to
the readout two weeks later. Environmental data for one and a half years of
running are shown. Measurements of atmospheric muons from data taken from
selected runs during the first six months of operation are presented.
Performance figures in terms of time residuals and angular resolution are
given. Finally the angular distribution of atmospheric muons is presented and
from this the depth profile of the muon intensity is derived.Comment: 14 pages, 9 figure
The Pierre Auger Observatory III: Other Astrophysical Observations
Astrophysical observations of ultra-high-energy cosmic rays with the Pierre
Auger ObservatoryComment: Contributions to the 32nd International Cosmic Ray Conference,
Beijing, China, August 201
Oxidized low-density lipoprotein receptor in lymphocytes prevents atherosclerosis and predicts subclinical disease
Background: Although the role of Th17 and regulatory T cells in the progression of atherosclerosis has been highlighted in recent years, their molecular mediators remain elusive. We aimed to evaluate the association between the CD69 receptor, a regulator of Th17/regulatory T cell immunity, and atherosclerosis development in animal models and in patients with subclinical disease. Methods: Low-density lipoprotein receptor-deficient chimeric mice expressing or not expressing CD69 on either myeloid or lymphoid cells were subjected to a high fat diet. In vitro functional assays with human T cells were performed to decipher the mechanism of the observed phenotypes. Expression of CD69 and NR4A nuclear receptors was evaluated by reverse transcription-polymerase chain reaction in 305 male participants of the PESA study (Progression of Early Subclinical Atherosclerosis) with extensive (n=128) or focal (n=55) subclinical atherosclerosis and without disease (n=122). Results: After a high fat diet, mice lacking CD69 on lymphoid cells developed large atheroma plaque along with an increased Th17/regulatory T cell ratio in blood. Oxidized low-density lipoprotein was shown to bind specifically and functionally to CD69 on human T lymphocytes, inhibiting the development of Th17 cells through the activation of NR4A nuclear receptors. Participants of the PESA study with evidence of subclinical atherosclerosis displayed a significant CD69 and NR4A1 mRNA downregulation in peripheral blood leukocytes compared with participants without disease. The expression of CD69 remained associated with the risk of subclinical atherosclerosis in an adjusted multivariable logistic regression model (odds ratio, 0.62; 95% CI, 0.40-0.94; P=0.006) after adjustment for traditional risk factors, the expression of NR4A1, the level of oxidized low-density lipoprotein, and the counts of different leucocyte subsets. Conclusions: CD69 depletion from the lymphoid compartment promotes a Th17/regulatory T cell imbalance and exacerbates the development of atherosclerosis. CD69 binding to oxidized low-density lipoprotein on T cells induces the expression of anti-inflammatory transcription factors. Data from a cohort of the PESA study with subclinical atherosclerosis indicate that CD69 expression in PBLs inversely correlates with the presence of disease. The expression of CD69 remained an independent predictor of subclinical atherosclerosis after adjustment for traditional risk factors.Funding was provided by the Spanish Ministry of Economy and Competitiveness:
Plan Nacional de Salud SAF2017-82886-R to Dr Sánchez-Madrid,
SAF2015-64767-R to Dr Martínez-González; Instituto de Salud Carlos III
(AES 2016): PI16/01956 to Dr Martin, Centro de Investigación Biomédica en
Red de Enfermedades Cardiovasculares; European Research Council, ERC-
2011-AdG294340-GENTRIS to Dr Sánchez-Madrid; Proyecto Integrado de
Excelencia PIE13/041 and Fundació La Marató TV3 (20152330 31); and Comunidad
Autónoma de Madrid CAM (S2017/BMD-3671) to Drs Martin and
Sánchez-Madrid. Dr Tsilingiri is cofunded by the European Union Marie Curie
Program. M. Relaño is supported by a Contratos Predoctorales Severo Ochoa
para la formación de doctores (BES-2015–072625) from the Spanish Ministry
of Economy and Competitiveness. This research has been cofinanced by Fondo
Europeo de Desarrollo Regional. Centro Nacional de Investigaciones Cardiovasculares
(CNIC), Madrid, Spain, is supported by the Ministerio de Ciencia, Innovación
y Universidades, and the Pro CNIC Foundation and is a Severo Ochoa
Center of Excellence (SEV-2015-0505). The PESA study is cofunded equally by
the Pro CNIC Foundation and Banco Santander, Madrid, Spai
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