593 research outputs found
"Digitaria sanguinalis - Ustilago syntherismae" pathosystem: changes in the reproductive development of plants due to fungal infection
El objetivo del estudio fue conocer cómo la infección por carbón causado por “Ustilago syntherismae” afecta al número de ápices reproductivos (NAR) que forman las plantas de garranchuelo (Digitaria sanguinalis) en una generación. Se marcaron 24 cuadrados de 0,25m2, se escardaron manualmente para dejar únicamente plantas de garranchuelo, y se registraron la densidad y NAR de cada planta. El NAR se sometió a un análisis de la covarianza que contempló el efecto principal tipo de individuo (con carbón o sin carbón), la densidad, y su interacción. El tipo de ápice reproductivo y la interacción fueron muy significativos en el rango de densidades registrado (de 12 a 156 pl m-2). A densidades elevadas, la media del NAR de las plantas con carbón casi dobló la de las plantas aparentemente sanas, es decir las plantas enfermas desarrollaron más soros que inforescencias se hubieran formado en plantas sanas.The main objective of our study was to evaluate how the infection by “Ustilago syntherismae” (loose smut) can affect the number of apical reproductive buds (NAR) formed in Digitaria sanguinalis plants during one generation. The study was performed using 24 quadrats of 0.25m2 in which seedlings of other species were removed. The large crabgrass densities and the NAR of each plant were obtained. The NAR was subjected to an analysis of covariance considering the type of plant (smutted or non-smutted) as a principal effect, the plant density, and their interaction. The type of reproductive bud and the interaction were highly significant sources of variance at the observed densities (ranging from 12 to 156 pl m-2). At high plant densities, NAR of smutted plants was, on average, near to the double of that non-smutted plants. The number of sori registered in smutted plants was much higher than the expected number of inflorescences if they would not have been infected
High-power test results of a 3 GHz single-cell cavity
Compact, reliable and little consuming accelerators are required for the
treatment of tumours with ions. TERA proposes the "cyclinac", composed of a
high-frequency, fast-cycling linac which boosts the energy of the particles
previously accelerated in a cyclotron. The dimensions of the linac can be
reduced if high gradients are used. TERA initiated a high-gradient test program
to understand the operational limit of such structures. The program foresees
the design, prototyping and high-power test of several high-gradient structures
operating at 3 and 5.7 GHz. The high-power tests of the 3 GHz single-cell
cavity were completed in Winter 2012. The maximum BDR threshold measured for
Emax of 170 MV/m and RF pulses of 2.5 \mu s was 3 x 10-6 bpp/m
Factores psicosociales influyentes en la ocurrencia de accidentes laborales
El objetivo del trabajo es la presentación de un modelo de predicción de la siniestralidad laboral basado en datos empíricos en
un conjunto de variables susceptibles de intervención. El método empleado es un diseño transversal y correlacional, en el que
a partir de una muestra representativa de más de 500 trabajadores de diferentes sectores de actividad de la provincia de Valencia,
se cuantifica la importancia relativa de cada uno de los aspectos definidos como relevantes para predecir la ocurrencia
de accidentes. El uso metodológico de modelos de ecuaciones estructurales permite la consideración simultánea de un gran
número de variables, junto con un adecuado control estadístico, reflejando así con mayor fidelidad la problemática de la siniestralidad
laboral. Los resultados muestran el impacto de la variables organizacionales y los riesgos sobre variables del trabajador,
la importancia de éstas en la predicción de accidentes, junto con su papel mediador en los efectos de las variables organizacionales
(clima de seguridad, formación en seguridad, sobrecarga de trabajo, etc.) sobre la ocurrencia de accidentes laborales.
La conclusión es que los aspectos psicosociales son claves en la explicación de los accidentes laborales y abren vías para
una intervención efica
Break location influence in pressure vessel SBLOCA scenarios
[EN] The inspections performed in Davis Besse and the South Texas Project Unit-I reactors pointed out safety issues
regarding the structural integrity of the Pressure Vessel (PV). In these inspections, two anomalies were found: a
wall thinning and degradation in the PV upper head of the Davis Besse reactor and a small amount of residue
around two instrument-tube penetration nozzles located in the PV lower plenum of the South Texas Project
Unit-I reactor. The evolution of these defects could have resulted in Small Break Loss-Of-Coolant Accidents
(SBLOCA) if they had not been detected in time. In this frame, the OECD/NEA considered the necessity to simulate these accidental sequences in the OECD/NEA ROSA Project using the Large Scale Test Facility (LSTF).
This work is focused on simulating different hypothetical accidental scenarios in the PV using the thermalhydraulic code TRACE5. These simulations allow studying the break localization influence in the transient and
the effectiveness of the accident management (AM) actions considered mitigating the consequences of these hypothetical accidental scenarios.This work contains findings that were produced within the OECD-NEA ROSA Project. The authors are grateful to the Management Board of the ROSA Project for their consent to this publication and thank the Spanish Nuclear Regulatory Body (CSN) for the technical and financial support
under the agreement STN/1388/05/748Lorduy, M.; Querol, A.; Gallardo Bermell, S.; Verdú Martín, GJ. (2021). Break location influence in pressure vessel SBLOCA scenarios. Brazilian Journal of Radiation Sciences. 8(3B):1-17. http://hdl.handle.net/10251/182307S11783
Inference by replication in densely connected systems
An efficient Bayesian inference method for problems that can be mapped onto
dense graphs is presented. The approach is based on message passing where
messages are averaged over a large number of replicated variable systems
exposed to the same evidential nodes. An assumption about the symmetry of the
solutions is required for carrying out the averages; here we extend the
previous derivation based on a replica symmetric (RS) like structure to include
a more complex one-step replica symmetry breaking (1RSB)-like ansatz. To
demonstrate the potential of the approach it is employed for studying critical
properties of the Ising linear perceptron and for multiuser detection in Code
Division Multiple Access (CDMA) under different noise models. Results obtained
under the RS assumption in the non-critical regime give rise to a highly
efficient signal detection algorithm in the context of CDMA; while in the
critical regime one observes a first order transition line that ends in a
continuous phase transition point. Finite size effects are also observed. While
the 1RSB ansatz is not required for the original problems, it was applied to
the CDMA signal detection problem with a more complex noise model that exhibits
RSB behaviour, resulting in an improvement in performance.Comment: 47 pages, 7 figure
A System to Generate SignWriting for Video Tracks Enhancing Accessibility of Deaf People
Video content has increased much on the Internet during last years. In spite of the efforts of different organizations and governments to increase the accessibility of websites, most multimedia content on the Internet is not accessible. This paper describes a system that contributes to make multimedia content more accessible on the Web, by automatically translating subtitles in oral language to SignWriting, a way of writing Sign Language. This system extends the functionality of a general web platform that can provide accessible web content for different needs. This platform has a core component that automatically converts any web page to a web page compliant with level AA of WAI guidelines. Around this core component, different adapters complete the conversion according to the needs of specific users. One adapter is the Deaf People Accessibility Adapter, which provides accessible web content for the Deaf, based on SignWritting. Functionality of this adapter has been extended with the video subtitle translator system. A first prototype of this system has been tested through different methods including usability and accessibility tests and results show that this tool can enhance the accessibility of video content available on the Web for Deaf people
Composite CDMA - A statistical mechanics analysis
Code Division Multiple Access (CDMA) in which the spreading code assignment
to users contains a random element has recently become a cornerstone of CDMA
research. The random element in the construction is particular attractive as it
provides robustness and flexibility in utilising multi-access channels, whilst
not making significant sacrifices in terms of transmission power. Random codes
are generated from some ensemble, here we consider the possibility of combining
two standard paradigms, sparsely and densely spread codes, in a single
composite code ensemble. The composite code analysis includes a replica
symmetric calculation of performance in the large system limit, and
investigation of finite systems through a composite belief propagation
algorithm. A variety of codes are examined with a focus on the high
multi-access interference regime. In both the large size limit and finite
systems we demonstrate scenarios in which the composite code has typical
performance exceeding sparse and dense codes at equivalent signal to noise
ratio.Comment: 23 pages, 11 figures, Sigma Phi 2008 conference submission -
submitted to J.Stat.Mec
Evaluation of the self-energy correction to the g-factor of S states in H-like ions
A detailed description of the numerical procedure is presented for the
evaluation of the one-loop self-energy correction to the -factor of an
electron in the and states in H-like ions to all orders in .Comment: Final version, December 30, 200
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