20 research outputs found
The LAUE project for broadband gamma-ray focusing lenses
We present the LAUE project devoted to develop an advanced technology for
building a high focal length Laue lens for soft gamma--ray astronomy (80-600
keV). The final goal is to develop a focusing optics that can improve the
current sensitivity in the above energy band by 2 orders of magnitude.Comment: 7 pages, 6 figures, presented at the SPIE conference on "Optics for
EUV, X-ray, and Gamma-ray Astronomy". To be published in the Proceedings of
SPIE, vol.8147, 201
Genetic variation in neotropical butterflies is associated with sampling scale, species distributions, and historical forest dynamics
Previous studies of butterfly diversification in the Neotropics have focused on Amazonia and the tropical Andes, while southern regions of the continent have received little attention. To address the gap in knowledge about the Lepidoptera of temperate South America, we analysed over 3000 specimens representing nearly 500 species from Argentina for a segment of the mitochondrial cytochrome c oxidase subunit I (COI) gene. Representing 42% of the country's butterfly fauna, collections targeted species from the Atlantic and Andean forests, and biodiversity hotspots that were previously connected but are now isolated. We assessed COI effectiveness for species discrimination and identification and how its performance was affected by geographic distances and taxon coverage. COI data also allowed to study patterns of genetic variation across Argentina, particularly between populations in the Atlantic and Andean forests. Our results show that COI discriminates species well, but that identification success is reduced on average by ~20% as spatial and taxonomic coverage rises. We also found that levels of genetic variation are associated with species' spatial distribution type, a pattern which might reflect differences in their dispersal and colonization abilities. In particular, intraspecific distance between populations in the Atlantic and Andean forests was significantly higher in species with disjunct distributions than in those with a continuous range. All splits between lineages in these forests dated to the Pleistocene, but divergence dates varied considerably, suggesting that historical connections between the Atlantic and Andean forests have differentially affected their shared butterfly fauna. Our study supports the fact that large-scale assessments of mitochondrial DNA variation are a powerful tool for evolutionary studies.Fil: Attiná, Natalí. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Núñez Bustos, Ezequiel Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Lijtmaer, Dario Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Hebert, Paul David Neil. University of Guelph; CanadáFil: Tubaro, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Lavinia Oblanca, Pablo Damián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina. Universidad Nacional de Río Negro; Argentin
Relevance of donated and confiscated materials for biological collections: Avian tissue samples as a study case
A pesar de su importancia, el aporte de decomisos y donaciones a las colecciones biológicas ha sido muy poco cuantificado. El objetivo de este análisis fue evaluar la relevancia de las donaciones y los decomisos de material ornitológico a la Colección Nacional de Tejidos Ultracongelados del Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”. De los 10 288 tejidos de aves depositados en la colección desde su establecimiento en 2003, más de un tercio corresponde a donaciones (22% en total, 13% de particulares y 9% institucionales) y decomisos (12%). Dichos tejidos pertenecen a 28 órdenes y representan más del 50% del total de muestras de 15 de ellos. Passeriformes, Anseriformes y Procelariiformes son los grupos más representados en las donaciones y/o decomisos, aunque hay varios otros órdenes en los que este tipo de muestras son la principal fuente de tejidos, dado que se recolectan pocos ejemplares de manera activa. De las 871 especies presentes en la colección, 156 (18%) están representadas únicamente por muestras provenientes de donaciones y/o decomisos, resaltándose así su notoria relevancia. De hecho, más de la mitad de los tejidos de donaciones y alrededor de un cuarto de los decomisados han sido incorporados en al menos 46 estudios científicos. Este análisis evidencia la importancia de las donaciones y los decomisos para las colecciones biológicas y hace hincapié en la necesidad de un trabajo conjunto con instituciones públicas y privadas y de la concientización de la sociedad sobre la significancia de donar materiales biológicos a los museos.In spite of their relevance, the contribution of donated and confiscated materials to biological collections has been poorly quantified. The objective of this analysis was to evaluate the significance of donated and confiscated ornithological materials in the National Ultrafrozen Tissue Collection of the Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”. Out of the 10 288 avian tissues deposited at the collection since its establishment in 2003, over one third correspond to donations (22% in total, 13% from individuals and 9% from Institutions) and confiscated specimens (12%). These tissues belong to 28 avian orders and represent over 50% of the deposited samples in 15 of them. Passeriformes, Anseriformes, and Procelariiformes are the most represented groups in donated and confiscated material, but there are other orders for which this source of samples is also the main contribution to the collection because they are not commonly captured in the field. Of the 871 species present in the collection, 156 (18%) are represented only by samples that come from donations and confiscated material. In fact, over half of the donated tissues and more than one quarter of the samples that come from confiscated specimens have been used in at least 46 different research projects. This analysis visualizes the importance that donated and confiscated specimens have for biological collections and highlights the need for joint work with private and public organizations, as well as the awareness of the society regarding the significance of donating biological materials to museums.Fil: Barone, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Vilacoba, Elisabet. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Davies, Yolanda Ester. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Attiná, Natalí. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Estalles, María Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Tubaro, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Lijtmaer, Dario Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin
XIPE: the X-ray imaging polarimetry explorer
Abstract X-ray polarimetry, sometimes alone, and sometimes coupled to spectral and temporal variability measurements and to imaging, allows a wealth of physical phenomena in astrophysics to be studied. X-ray polarimetry investigates the acceleration process, for example, including those typical of magnetic reconnection in solar flares, but also emission in the strong magnetic fields of neutron stars and white dwarfs. It detects scattering in asymmetric structures such as accretion disks and columns, and in the so-called molecular torus and ionization cones. In addition, it allows fundamental physics in regimes of gravity and of magnetic field intensity not accessible to experiments on the Earth to be probed. Finally, models that describe fundamental interactions (e.g. quantum gravity and the extension of the Standard Model) can be tested. We describe in this paper the X-ray Imaging Polarimetry Explorer (XIPE), proposed in June 2012 to the first ESA call for a small mission with a launch in 2017. The proposal was, unfortunately, not selected. To be compliant with this schedule, we designed the payload mostly with existing items. The XIPE proposal takes advantage of the completed phase A of POLARIX for an ASI small mission program that was cancelled, but is different in many aspects: the detectors, the presence of a solar flare polarimeter and photometer and the use of a light platform derived by a mass production for a cluster of satellites. XIPE is composed of two out of the three existing JET-X telescopes with two Gas Pixel Detectors (GPD) filled with a He-DME mixture at their focus. Two additional GPDs filled with a 3-bar Ar-DME mixture always face the Sun to detect polarization from solar flares. The Minimum Detectable Polarization of a 1 mCrab source reaches 14 % in the 2-10 keV band in 105 s for pointed observations, and 0.6 % for an X10 class solar flare in the 15-35 keV energy band. The imaging capability is 24 arcsec Half Energy Width (HEW) in a Field of View of 14.7 arcmin × 14.7 arcmin. The spectral resolution is 20 % at 6 keV and the time resolution is 8 mus. The imaging capabilities of the JET-X optics and of the GPD have been demonstrated by a recent calibration campaign at PANTER X-ray test facility of the Max-Planck-Institut für extraterrestrische Physik (MPE, Germany). XIPE takes advantage of a low-earth equatorial orbit with Malindi as down-link station and of a Mission Operation Center (MOC) at INPE (Brazil). The data policy is organized with a Core Program that comprises three months of Science Verification Phase and 25 % of net observing time in the following 2 years. A competitive Guest Observer program covers the remaining 75 % of the net observing time
Amplitude da autonomia dos entes federados quanto à disciplina jurídica da participação e compensação financeira pela exploração de recursos naturais
The butterfly effect: geographic patterns of DNA barcode variation in subtropical Lepidoptera
Forest dynamics, spatial distribution patterns, and sampling scale are associated with mitochondrial DNA variation in Argentinian butterflies.Fil: Attiná, Natalí. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Núñez Bustos, Ezequiel Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Lijtmaer, Dario Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Tubaro, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Lavinia Oblanca, Pablo Damián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin
THE LAUE PROJECT FOR BROADBAND GAMMA-RAY FOCUSING LENSES
We present the LAUE project devoted to develop an advanced technology for building a high focal length Laue lens for hard X and soft gamma–ray astronomy (80-600 keV). The final goal of the project, supported by the Italian Space Agency, is to build and test a focusing optics that can improve the current sensitivity in the above energy band by 2 orders of magnitude