Discontinuous Galerkin approximation of the Maxwell eigenproblem

A theoretical framework for the analysis of discontinuous Galerkin approximations of the Maxwell eigenproblem with discontinuous coefficients is presented. Necessary and sufficient conditions for a spurious-free approximation are established, and it is shown that, at least on conformal meshes, basically all the discontinuous Galerkin methods in the literature actually fit into this framework. Relations with the classical theory for conforming approximations are also discussed

Cross-habitat usage by crop aphids and their parasitoids in the cropnoncrop interface in an organic vegetable farm.

Plant-aphid-parasitoid interactions and parasitism rates were assessed in adjacent cultivated and noncultivated habitats in an organic vegetable farm in a chaco serrano woodland, Córdoba, Argentina. Seven aphid species on eight vegetable species were found in the cultivated habitat. Macrosiphum euphorbiae was present on all vegetable species. Four parasitoid species were recorded, of which Diaretiella rapae was the most common. It provided 21.32% of parasitism on Brevicoryne brassicae. In the non-cultivated habitat, 36 plant species hosted 22 aphid species and five parasitoid species. The aphid Myzus persicae was present on 17 plant species of eight different families. Macrosiphoniella artemisiae was the most abundant aphid species, with the associated Aphidius sp. being the most abundant parasitoid. Aphidius polygonaphis provided 10% of parasitism on Uroleucon aeneus. We report several wild plant species as important reservoirs of parasitoids, which are potential controllers of many pest aphid species

Investigating the high-frequency spectral features of SNRs Tycho, W44 and IC443 with the Sardinia Radio Telescope

The main characteristics in the radio continuum spectra of Supernova Remnants (SNRs) result from simple synchrotron emission. In addition, electron acceleration mechanisms can shape the spectra in specific ways, especially at high radio frequencies. These features are connected to the age and the peculiar conditions of the local interstellar medium interacting with the SNR. Whereas the bulk radio emission is expected at up to $20-50$ GHz, sensitive high-resolution images of SNRs above 10 GHz are lacking and are not easily achievable, especially in the confused regions of the Galactic Plane. In the framework of the early science observations with the Sardinia Radio Telescope in February-March 2016, we obtained high-resolution images of SNRs Tycho, W44 and IC443 that provided accurate integrated flux density measurements at 21.4 GHz: 8.8 $\pm$ 0.9 Jy for Tycho, 25 $\pm$ 3 Jy for W44 and 66 $\pm$ 7 Jy for IC443. We coupled the SRT measurements with radio data available in the literature in order to characterise the integrated and spatially-resolved spectra of these SNRs, and to find significant frequency- and region-dependent spectral slope variations. For the first time, we provide direct evidence of a spectral break in the radio spectral energy distribution of W44 at an exponential cutoff frequency of 15 $\pm$ 2 GHz. This result constrains the maximum energy of the accelerated electrons in the range $6-13$ GeV, in agreement with predictions indirectly derived from AGILE and \textit{Fermi}-LAT gamma-ray observations. With regard to IC443, our results confirm the noticeable presence of a bump in the integrated spectrum around $20-70$ GHz that could result from a spinning dust emission mechanism.Comment: 12 pages, 9 figure

Los estudios afroamericanos y africanos en América Latina: herencia, presencia y visiones del otro

Este libro se propone reflejar el estado de la cuestión acerca de la enseñanza y la investigación sobre África y su diáspora en América Latina. Producto de un encuentro convocado por el Programa Sur-Sur de CLACSO en Salvador de Bahía en el año 2006, donde académicos de muy diversas áreas y de diferentes países de América Latina debatieron sobre nuevos abordajes y líneas de investigación, y sobre la enseñanza y difusión de estas temáticas. Esta obra nos introduce desde una perspectiva pluralista y multifocal de la realidad en campos no tradicionales de la academia, identificando trayectorias, impulsos renovadores, influencias externas y paradigmas propios.Indice Prefacio Maria José Becerra y Diego Buffa Los estudios sobre África y Afroamérica en América Latina. El estado del arte. Gladis Lechini Parte I Estudios Afroamericanos O racismo brasileiro em questão: temas relevantes no debate recente Paula Cristina da Silva Barreto História e historiografia do trabalhador esclavizado no RS: 1819-2006 Mario Maestri A abolição do Comércio Atlãntico de Escravos e os Africanos Livres no Brasil. Ana Flavio Cicchelli Pires De la desaparición de los negros a la reaparición de los afrodescendientes:comprendiendo las políticas de las identidades negras, las clasificaciones raciales y de su estudio en Argentina. Alejandro Frigerio Estudios sobre esclavitud en Córdoba: análisis y perspectivas. Maria José Becerra La historiografía paraguaya y los afrodescendientes. Ignacio Telesca Las raíces del olvido. Un estado de la cuestión sobre el estudio de las poblaciones de origen africano en México. Salvador Vásquez Fernández El que no tiene de inga tiene de mandinga. Género, Etnicidad y Sexualidad en los Estudios Históricos-Antropológicos Afroperuanos. Fátima Valdivia del Río Música, artes performáticas y el campo de las relaciones raciales. Área de estudios de la presencia africana en América Latina. Luis Ferreira Makl Parte II. Estudios sobre África O Ensino e a Pesquisa sobre África no Brasil e a Lei 10.639 Luena Nascimento Nunes Pereira Os estudos africanos no Brasil Um estudo de caso: o CEAA José María Nunes Pereira La enseñanza de la historia de África en Cuba. Aproximación a sus presupuestos teóricos y metodológicos. M. Elena Álvarez Acosta Estudios africanos en Colombia desde Ciencias Políticas y Sociales. Maguemati Wabgou Pasado y presente en los estudios e investigaciones sobre África en Argentina. Diego Buffa Estudios sobre África desde Argentina. Los aportes de la Universidad de Buenos Aires y de la Universidad Nacional del Luján. Marisa Pineau La enseñanza y la investigación sobre África y Afroamérica de la Universidad Nacional de La Plata-Argentina. Marta Maffia Los estudios sobre el Norte de África en Brasil y Argentina: reflexiones en torno a un espacio residual. Juan José Vagni La perspectiva Iberoamericana Consideraciones sobre estudios afroamericanos y africanos en Iberoamérica. Luis Beltrá

Imaging of SNR IC443 and W44 with the Sardinia Radio Telescope at 1.5 GHz and 7 GHz

Observations of supernova remnants (SNRs) are a powerful tool for investigating the later stages of stellar evolution, the properties of the ambient interstellar medium, and the physics of particle acceleration and shocks. For a fraction of SNRs, multi-wavelength coverage from radio to ultra high-energies has been provided, constraining their contributions to the production of Galactic cosmic rays. Although radio emission is the most common identifier of SNRs and a prime probe for refining models, high-resolution images at frequencies above 5 GHz are surprisingly lacking, even for bright and well-known SNRs such as IC443 and W44. In the frameworks of the Astronomical Validation and Early Science Program with the 64-m single-dish Sardinia Radio Telescope, we provided, for the first time, single-dish deep imaging at 7 GHz of the IC443 and W44 complexes coupled with spatially-resolved spectra in the 1.5-7 GHz frequency range. Our images were obtained through on-the-fly mapping techniques, providing antenna beam oversampling and resulting in accurate continuum flux density measurements. The integrated flux densities associated with IC443 are S_1.5GHz = 134 +/- 4 Jy and S_7GHz = 67 +/- 3 Jy. For W44, we measured total flux densities of S_1.5GHz = 214 +/- 6 Jy and S_7GHz = 94 +/- 4 Jy. Spectral index maps provide evidence of a wide physical parameter scatter among different SNR regions: a flat spectrum is observed from the brightest SNR regions at the shock, while steeper spectral indices (up to 0.7) are observed in fainter cooling regions, disentangling in this way different populations and spectra of radio/gamma-ray-emitting electrons in these SNRs.Comment: 13 pages, 9 figures, accepted for publication to MNRAS on 18 May 201

Evaluation of mucosal adjuvants and immunization routes for the induction of systemic and mucosal humoral immune responses in macaques

Delivering vaccine antigens to mucosal surfaces is potentially very attractive, especially as protection from mucosal infections may be mediated by local immune responses. However, to date mucosal immunization has had limited successes, with issues of both safety and poor immunogenicity. One approach to improve immunogenicity is to develop adjuvants that are effective and safe at mucosal surfaces. Differences in immune responses between mice and men have overstated the value of some experimental adjuvants which have subsequently performed poorly in the clinic. Due to their closer similarity, non-human primates can provide a more accurate picture of adjuvant performance. In this study we immunised rhesus macaques (Macaca mulatta) using a unique matrix experimental design that maximised the number of adjuvants screened while reducing the animal usage. Macaques were immunised by the intranasal, sublingual and intrarectal routes with the model protein antigens keyhole limpet haemocyanin (KLH), β-galactosidase (β-Gal) and ovalbumin (OVA) in combination with the experimental adjuvants Poly(I:C), Pam3CSK4, chitosan, Thymic Stromal Lymphopoietin (TSLP), MPLA and R848 (Resiquimod). Of the routes used, only intranasal immunization with KLH and R848 induced a detectable antibody response. When compared to intramuscular immunization, intranasal administration gave slightly lower levels of antigen specific antibody in the plasma, but enhanced local responses. Following intranasal delivery of R848, we observed a mildly inflammatory response, but no difference to the control. From this we conclude that R848 is able to boost antibody responses to mucosally delivered antigen, without causing excess local inflammation

Expression of calpain-calpastatin system (CCS) member proteins in human lymphocytes of young and elderly individuals; pilot baseline data for the CALPACENT project.

Ubiquitous system of regulatory, calcium-dependent, cytoplasmic proteases – calpains – and their endogenous inhibitor – calpastatin – is implicated in the proteolytic regulation of activation, proliferation, and apoptosis of many cell types. However, it has not been thoroughly studied in resting and activated human lymphocytes yet, especially in relation to the subjects’ ageing process. The CALPACENT project is an international (Polish-Italian) project aiming at verifying the hypothesis of the role of calpains in the function of peripheral blood immune cells of Polish (Pomeranian) and Italian (Sicilian) centenarians, apparently relatively preserved in comparison to the general elderly population. In this preliminary report we aimed at establishing and comparing the baseline levels of expression of μ- and m-calpain and calpastatin in various, phenotypically defined, populations of human peripheral blood lymphocytes for healthy elderly Sicilians and Poles, as compared to these values observed in young cohort

Effect of boat noise on the behaviour of bluefin tuna Thunnus thynnus in the Mediterranean Sea

The effect of boat noise on the behaviour of bluefin tuna Thunnus thynnus was investigated in the Egadi Islands, Sicily, during spring 2005 using a fixed tuna trap set near shipping routes. Tuna behaviour was observed when exposed to both natural ambient sound and sound generated by hydrofoil passenger ferries, small boats and large car ferries. Acoustical and behavioural analyses were conducted with and without extraneous sound to define a list of behavioural categories. Each vessel produced different engine sounds with regard to their composition and bandwidth, and all were distinctly different from ambient sound levels. In the absence of boat noise, tuna assumed a concentrated coordinated school structure with unidirectional swimming and without a precise shape. When a car ferry approached, tuna changed swimming direction and increased their vertical movement toward surface or bottom; the school exhibited an unconcentrated structure and uncoordinated swimming behaviour. Hydrofoils appeared to elicit a similar response, but for shorter periods. Agonistic behaviour was more evident when exposed to sounds from outboard motors of small boats. This study showed that local noise pollution generated by boats produced behavioural deviations in tuna schools. Schooling enhances tuna homing accuracy during their spawning migration, and an alteration in schooling behaviour can affect the accuracy of their migration to spawning and feeding grounds

Heat flow and calculus on metric measure spaces with Ricci curvature bounded below - the compact case

We provide a quick overview of various calculus tools and of the main results concerning the heat flow on compact metric measure spaces, with applications to spaces with lower Ricci curvature bounds. Topics include the Hopf-Lax semigroup and the Hamilton-Jacobi equation in metric spaces, a new approach to differentiation and to the theory of Sobolev spaces over metric measure spaces, the equivalence of the L^2-gradient flow of a suitably defined "Dirichlet energy" and the Wasserstein gradient flow of the relative entropy functional, a metric version of Brenier's Theorem, and a new (stronger) definition of Ricci curvature bound from below for metric measure spaces. This new notion is stable w.r.t. measured Gromov-Hausdorff convergence and it is strictly connected with the linearity of the heat flow.Comment: To the memory of Enrico Magenes, whose exemplar life, research and teaching shaped generations of mathematician