The Size Distribution of the Neptune Trojans and the Missing Intermediate Sized Planetesimals

We present an ultra-deep survey for Neptune Trojans using the Subaru 8.2-m and Magellan 6.5-m telescopes. The survey reached a 50% detection efficiency in the R-band at 25.7 magnitudes and covered 49 square degrees of sky. This depth corresponds to Neptune Trojans that are about 16 km in radius (assuming an albedo of 0.05). A paucity of smaller Neptune Trojans (radii < 45 km) compared to larger ones was found. The brightest Neptune Trojans appear to follow a steep power-law slope (q = 5+-1) similar to the brightest objects in the other known stable reservoirs such as the Kuiper Belt, Jupiter Trojans and main belt asteroids. We find a roll-over for the Neptune Trojans that occurs around a radii of r=45+-10 km (23.5+-0.3 mags), which is also very similar to the other stable reservoirs. All the observed stable regions in the the solar system show evidence for Missing Intermediate Sized Planetesimals (MISPs). This indicates a primordial and not collisional origin, which suggests planetesimal formation proceeded directly from small to large objects. The scarcity of intermediate and smaller sized Neptune Trojans may limit them as being a strong source for the short period comets.Comment: Accepted for publication in Astrophysical Journal Letter

Analysis of a long-duration AR throughout five solar rotations: Magnetic properties and ejective events

Coronal mass ejections (CMEs), which are among the most magnificent solar eruptions, are a major driver of space weather and can thus affect diverse human technologies. Different processes have been proposed to explain the initiation and release of CMEs from solar active regions (ARs), without reaching consensus on which is the predominant scenario, and thus rendering impossible to accurately predict when a CME is going to erupt from a given AR. To investigate AR magnetic properties that favor CMEs production, we employ multi-spacecraft data to analyze a long duration AR (NOAA 11089, 11100, 11106, 11112 and 11121) throughout its complete lifetime, spanning five Carrington rotations from July to November 2010. We use data from the Solar Dynamics Observatory to study the evolution of the AR magnetic properties during the five near-side passages, and a proxy to follow the magnetic flux changes when no magnetograms are available, i.e. during far-side transits. The ejectivity is studied by characterizing the angular widths, speeds and masses of 108 CMEs that we associated to the AR, when examining a 124-day period. Such an ejectivity tracking was possible thanks to the multi-viewpoint images provided by the Solar-Terrestrial Relations Observatory and Solar and Heliospheric Observatory in a quasi-quadrature configuration. We also inspected the X-ray flares registered by the GOES satellite and found 162 to be associated to the AR under study. Given the substantial number of ejections studied, we use a statistical approach instead of a single-event analysis. We found three well defined periods of very high CMEs activity and two periods with no mass ejections that are preceded or accompanied by characteristic changes in the AR magnetic flux, free magnetic energy and/or presence of electric currents. Our large sample of CMEs and long term study of a single AR, provide further evidence relating AR magnetic activity to CME and Flare production.Fil: Iglesias, Francisco Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina. Universidad Tecnológica Nacional. Facultad Regional de Mendoza; ArgentinaFil: Cremades Fernandez, Maria Hebe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina. Universidad Tecnológica Nacional. Facultad Regional de Mendoza; ArgentinaFil: Merenda, Luciano A.. Universidad Tecnológica Nacional. Facultad Regional de Mendoza; ArgentinaFil: Mandrini, Cristina Hemilse. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Lopez Fuentes, Marcelo Claudio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Lopez Fuentes, Marcelo Claudio. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Ugarte Urra, Ignacio. Spece Sciences División. Naval Research Laboratory; Estados Unido

Food Safety Management in a Global Environment: The Role of Risk Assessment Models

Quantitative risk assessment models are playing a minor role in the development of the new EU legal framework for food safety. There is a tendency of the EU institutions to apply the precautionary principle versus the predisposition of the USA institutions to rely on risk analysis. This paper provides a comparison of the role played by quantitative risk assessment models in the development of new policies on food safety in the EU and in the USA, focusing on a study case: the supply chain of shell eggs. We suggest that EU regulatory bodies should reconsider the role that quantitative risk assessment models have to play in order to design more effective food safety management systems.Food safety policy, food safety assurance, risk analysis, risk assessment, precautionary principle, Food Consumption/Nutrition/Food Safety,

Influencia del ACPA en la resolución y estabilidad de redes holográficas almacenadas en fotopolímeros basados en PVA/Acrilamida

Este trabajo presenta los resultados obtenidos después de almacenar redes holográficas por transmisión con una frecuencia espacial de 2663 líneas/mm, en un material basado en PVA/AA. A la composición del material se le ha incorporado un agente acortador de cadenas para mejorar su resolución espacial. Además, se ha aplicado un proceso de curado a las redes almacenadas para fijar el rendimiento en difracción y que no disminuya con el paso del tiempo.Este trabajo ha sido subvencionado por el Ministerio de Economía y Competitividad (proyectos FIS2011-29803-C02-01 y FIS2011-29803-C02-02), por la Generalitat Valenciana (proyecto PROMETEO/2011/021) y por la Universidad de Alicante (proyecto GRE09-10)

Study of influence of ACPA in PVA/AA photopolymer for holographic reflection gratings

This work pretends to optimize the standard composition of the PVA/Acrylamide photopolymer, changing its composition in order to improve its spatial resolution. To do this, a chain transfer agent, 4,4'-azobis (4-cyanopentanoic acid) (ACPA) was introduced in the photopolymer and its concentration was modified. Thus, the optimal concentration which gets obtain the maximum diffraction efficiency for high spatial frequencies was found. To quantify the improvement that occurs with the inclusion of the ACPA in the PVA/Acrylamide photopolymer, holographic reflexion gratings of 4553 lines/mm were stored. Moreover, diffraction efficiency obtained with the different concentrations of ACPA was measured to compare the obtained results.This work was supported by the “Generalitat Valenciana” (Spain) under project PROMETEO/2011/021, ISIC/2012/013 and GV/2012/099 and by “Ministerio de Ciencia e Innovación” (Spain) under projects FIS2011-29803-C02-01 and FIS2011-29803-C02-02

Influence of 4,4’-azobis (4-cyanopentanoic acid) in Transmission and Reflection Gratings Stored in a PVA/AA Photopolymer

Holographic transmission gratings with a spatial frequency of 2658 lines/mm and reflection gratings with a spatial frequency of 4553 lines/mm were stored in a polyvinyl alcohol (PVA)/acrylamide (AA) based photopolymer. This material can reach diffraction efficiencies close to 100% for spatial frequencies about 1000 lines/mm. However, for higher spatial frequencies, the diffraction efficiency decreases considerably as the spatial frequency increases. To enhance the material response at high spatial frequencies, a chain transfer agent, the 4,4’-azobis (4-cyanopentanoic acid), ACPA, is added to the composition of the material. Different concentrations of ACPA are incorporated into the main composition of the photopolymer to find the concentration value that provides the highest diffraction efficiency. Moreover, the refractive index modulation and the optical thickness of the transmission and reflection gratings were obtained, evaluated and compared to procure more information about the influence of the ACPA on them.This work was supported by the “Generalitat Valenciana” (Spain) under projects PROMETEOII/2015/015 and ISIC/2012/013 and by “Ministerio de Ciencia e Innovación” (Spain) under projects FIS2014-56100-C2-1-P and FIS2015-66570-P

Identidad, patrimonio y desarrollo territorial en la Provincia de Arauco-Chile

Se presenta el proyecto Identidad, patrimonio y desarrollo territorial en la provincia de Arauco, Chile, proyecto desarrollado el año 2012 por un equipo de arquitectos/as de la Universidad del Bío-Bío en Concepción-Chile, en convenio con la Asociación de Municipalidades de la Provincia de Arauco-Chile. El proyecto tuvo como objetivo la investigación, reconocimiento y valoración de los espacios públicos de valor patrimonial de la Provincia de Arauco-Chile, haciendo una propuesta de diseño a nivel de imagen objetivo para 40 espacios públicos deteriorados pero de gran valor patrimonial en las localidades involucradas. Se trabajó con lugares degradados y/o poco consolidados pero de una gran potencialidad urbana, con el propósito de desarrollar propuestas de recuperación que valoren el patrimonio cultural, urbano, arquitectónico y paisajístico de 6 pequeñas localidades del sur de Chile.We present the project Identity, heritage and territorial development in Arauco province, Chile, a project developed in 2012by a team of architects of the University of Bío-Bío in Concepción, Chile, in agreement with the Association of Municipalities in the Province of Arauco, Chile. The project aims to research, recognition and appreciation of the public spaces of the equity value of Arauco Province, Chile, with a design proposal in terms of image target damaged 40 public spaces but of great historical value in the localities involved. Worked with degraded sites or poorly consolidated but a large urban potential, in order develop proposals for recovery that value cultural heritage, urban, architectural and landscape of six small towns in southern Chile.Peer Reviewe

Binary Intensity Modulation and Hybrid Ternary Modulation Applied to Multiplexing Objects Using Holographic Data Storage on a PVA/AA Photopolymer

Holographic data pages were multiplexed in a polyvinyl alcohol/acrylamide photopolymer and a liquid crystal device was used to modify the object beam and store objects in the material. A peristrophic multiplexing method was used to store a large number of objects in the same spot of the material. The objects were stored using two different modulations: binary intensity modulation and hybrid ternary modulation. Moreover, the bit error rate (BER) of the images was calculated in order to compare which modulation is most appropriate to be used for holographic data storage.This work was supported by the “Generalitat Valenciana” (Spain) under Projects PROMETEO/2011/021 and ISIC/2012/013 and by “Ministerio de Ciencia e Innovación” (Spain) under Projects FIS2011-29803-C02-01 and FIS2011-29803-C02-02