Using asymptotic methods to compute diffracted pressure by curved surfaces

13 pagesInternational audienceThis article presents an original and efficient method to compute acoustic pressure diffracted by curved surfaces. Our approach is perfectly suited to be integrated into ray of beam tracing softwares

Diffraction d'une onde acoustique (ou électromagnétique) par un plateau rigide (ou parfaitement conducteur)

National audienceL'objectif des travaux brièvement présentés dans ce papier était d'implémenter au sein de deux logiciels considérant la propagation en 3D d'ondes acoustiques et électromagnétiques à lancer de faisceaux (ICARE **) et tracé de rayons (CRT *) un modèle asymptotique (TUD) permettant de prendre en compte les phénomènes de double diffraction par un écran d'épaisseur donnée. Nous l'avons ensuite mis en œuvre dans différentes configurations afin d'en étudier le comportement. La dernière étape de ce travail a consisté à valider la formulation choisie en comparéléments finis de frontière (B.E.M) [JEA

Complement System Part II: Role in Immunity

International audienceThe complement system has been considered for a long time as a simple lytic cascade, aimed to kill bacteria infecting the host organism. Nowadays, this vision has changed and it is well accepted that complement is a complex innate immune surveillance system, playing a key role in host homeostasis, inflammation, and in the defense against pathogens. This review discusses recent advances in the understanding of the role of complement in physiology and pathology. It starts with a description of complement contribution to the normal physiology (homeostasis) of a healthy organism, including the silent clearance of apoptotic cells and maintenance of cell survival. In pathology, complement can be a friend or a foe. It acts as a friend in the defense against pathogens, by inducing opsonization and a direct killing by C5b–9 membrane attack complex and by triggering inflammatory responses with the anaphylatoxins C3a and C5a. Opsonization plays also a major role in the mounting of an adaptive immune response, involving antigen presenting cells, T-, and B-lymphocytes. Nevertheless, it can be also an enemy, when pathogens hijack complement regulators to protect themselves from the immune system. Inadequate complement activation becomes a disease cause, as in atypical hemolytic uremic syndrome, C3 glomerulopathies, and systemic lupus erythematosus. Age-related macular degeneration and cancer will be described as examples showing that complement contributes to a large variety of conditions, far exceeding the classical examples of diseases associated with complement deficiencies. Finally, we discuss complement as a therapeutic target

Estimación de la composición botánica del área de influencia de un apiario sobre monte natural en Portezuelo (La Rioja). Reporte de una jornada interactiva

El objetivo del presente artículo fue dar a conocer el trabajo realizado durante el encuentro inicial de una capacitación sobre “Estimación de la composición botánica del área de influencia de un apiario demostrativo”, desarrollado en la localidad de El Portezuelo y sus inmediaciones.EEA La RiojaFil: Biurrun, Fernando Noe. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Rioja. Laboratorio de Diversidad Vegetal y Fitosociología; ArgentinaFil: Biurrun, Fernando Noe. Universidad Nacional de La Rioja Sede Chamical. Herbario Regional; ArgentinaFil: Agüero, Walter Damian. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Rioja. Laboratorio de Diversidad Vegetal y Fitosociología; ArgentinaFil: Riva De Neyra, Leonardo Atilio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Rioja. Laboratorio de Diversidad Vegetal y Fitosociología; ArgentinaFil: Riva De Neyra, Leonardo Atilio. Universidad Nacional de La Rioja Sede Chamical. Herbario Regional; ArgentinaFil: Serrano, Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Rioja. Laboratorio de Diversidad Vegetal y Fitosociología; ArgentinaFil: Serrano, Maria. Universidad Nacional de La Rioja Sede Chamical. Herbario Regional; ArgentinaFil: Pizarro, Nicolas Santos. Instituto Nacional de Tecnología Agropecuaria. Agencia de Extensión Rural Portezuelo; ArgentinaFil: Luna Toledo, Emanuel Santiago. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Rioja. Laboratorio de SIG y Teledetección; ArgentinaFil: Gomez, Raul. Asociación Apícola Guasamayo; Argentin

Terahertz Faraday and Kerr rotation spectroscopy of Bi1−x_{1-x}Sbx_x films in high magnetic fields up to 30 Tesla

We report results of terahertz Faraday and Kerr rotation spectroscopy measurements on thin films of $\text{Bi}_{1-x}\text{Sb}_{x}$, an alloy system that exhibits a semimetal-to-topological-insulator transition as the Sb composition $x$ increases. By using a single-shot time-domain terahertz spectroscopy setup combined with a table-top pulsed mini-coil magnet, we conducted measurements in magnetic fields up to 30~T, observing distinctly different behaviors between semimetallic ($x < 0.07$) and topological insulator ($x > 0.07$) samples. Faraday and Kerr rotation spectra for the semimetallic films showed a pronounced dip that blue-shifted with the magnetic field, whereas spectra for the topological insulator films were positive and featureless, increasing in amplitude with increasing magnetic field and eventually saturating at high fields ($>$20~T). Ellipticity spectra for the semimetallic films showed resonances, whereas the topological insulator films showed no detectable ellipticity. To explain these observations, we developed a theoretical model based on realistic band parameters and the Kubo formula for calculating the optical conductivity of Landau-quantized charge carriers. Our calculations quantitatively reproduced all experimental features, establishing that the Faraday and Kerr signals in the semimetallic films predominantly arise from bulk hole cyclotron resonances while the signals in the topological insulator films represent combined effects of surface carriers originating from multiple electron and hole pockets. These results demonstrate that the use of high magnetic fields in terahertz magnetopolarimetry, combined with detailed electronic structure and conductivity calculations, allows us to unambiguously identify and quantitatively determine unique contributions from different species of carriers of topological and nontopological nature in Bi$_{1-x}$Sb$_x$.Comment: 17 pages, 22 figure

Androgen receptor expresion in breast cancer: Relationship with clinicopathological characteristics of the tumors, prognosis, and expression of metalloproteases and their inhibitors

<p>Abstract</p> <p>Background</p> <p>In the present study we analyze, in patients with breast cancer, the tumor expression of androgen receptors (AR), its relationship with clinicopathological characteristics and with the expression of several matrix metalloproteases (MMPs) and their inhibitors (TIMPs), as well as with prognosis.</p> <p>Methods</p> <p>An immunohistochemical study was performed using tissue microarrays and specific antibodies against AR, MMPs -1, -2, -7, -9, -11, -13, -14, and TIMPs -1, -2 and -3. More than 2,800 determinations on tumor specimens from 111 patients with primary invasive ductal carcinoma of the breast (52 with axillary lymph node metastases and 59 without them) and controls were performed. Staining results were categorized using a score based on the intensity of the staining and a specific software program calculated the percentage of immunostained cells automatically.</p> <p>Results</p> <p>A total of 83 cases (74.8%) showed a positive immunostaining for AR, but with a wide variation in the staining score values. There were no significant associations between the total immunostaining scores for AR and any clinicopathological parameters. However, score values for MMP-1, -7 and -13, were significantly higher in AR-positive tumors than in AR-negative tumors. Likewise, when we considered the cellular type expressing each factor, we found that AR-positive tumors had a higher percentage of cases positive for MMP-1, -7, -11, and TIMP-2 in their malignant cells, as well as for MMP-1 in intratumoral fibroblasts. On the other hand, multivariate analysis demonstrated that patients with AR-positive tumors have a significant longer overall survival than those with AR-negative breast carcinomas (<it>p </it>= 0.03).</p> <p>Conclusion</p> <p>Our results confirm that AR are commonly expressed in breast cancer, and are correlated with the expression of some MMPs and TIMP-2. Although we found a specific value of AR expression to be a prognostic indicator in breast cancer, the functional role of AR in these neoplasms is still unclear and further data are needed in order to clarify their biological signification in breast cancer.</p

La vacuna de ARNm para el tratamiento del cáncer de páncreas llegó para quedarse

El adenocarcinoma ductal pancreáticoEl adenocarcinoma ductal pancreático (PDAC) es una enfermedad letal, destacada por la altísima semejanza entre su incidencia y mortalidad1, 2. La supervivencia a 5 años de los pacientes con PDAC sigue siendo tan baja como hace 30 años. La baja tasa de supervivencia se atribuye a varios factores, siendo el más importante el diagnóstico tardío3. Esto se debe a que los pacientes con PDAC son generalmente asintomáticos hasta etapas avanzadas de la enfermedad y casi siempre presentan metástasis al momento del diagnóstico, por lo que solo el 15% es apto para la cirugía de resección. Sin embargo, incluso después de este intento de resección curativa, la mayoría de los pacientes presentan una recurrencia, y la supervivencia a los 5 años de éstos será solo del 25%4. Debido a ello, la opción terapéutica restante es la administración de agentes quimioterapéuticos en forma de monoterapia o terapias combinadas. Entre los regímenes combinados, el FOLFIRINOX modificado (mFFX) mejora la evolución de los pacientes en comparación con la gemcitabina5,6. Sin embargo, el tratamiento con mFFX está asociado a una alta toxicidad5,6, limitando su administración a enfermos con buen estado general.Fil: Chuluyan, Hector Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Davio, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Dusetti, Nelson. No especifíca;Fil: Fraunhoffer Navarro, Nicolas Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Garcia, Maria Noe. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Garona, Juan. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gonzalez, Betina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gottardo, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Grasso, Daniel Hector. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Iovanna, Juan Lucio. No especifíca;Fil: Kohan, Gustavo Ariel. No especifíca;Fil: Lada, Paul Eduardo. No especifíca;Fil: Mazza, Oscar. No especifíca;Fil: Monte, Martin. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Papademetrio, Daniela Laura. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pascualini, María Eugenia. No especifíca;Fil: Sahores, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Santofimia, Patricia. No especifíca;Fil: Yaneff, Agustín. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

A global observational analysis to understand changes in air quality during exceptionally low anthropogenic emission

This global study, which has been coordinated by the World Meteorological Organization Global Atmospheric Watch (WMO/GAW) programme, aims to understand the behaviour of key air pollutant species during the COVID-19 pandemic period of exceptionally low emissions across the globe. We investigated the effects of the differences in both emissions and regional and local meteorology in 2020 compared with the period 2015–2019. By adopting a globally consistent approach, this comprehensive observational analysis focuses on changes in air quality in and around cities across the globe for the following air pollutants PM2.5, PM10, PMC (coarse fraction of PM), NO2, SO2, NOx, CO, O3 and the total gaseous oxidant (OX = NO2 + O3) during the pre-lockdown, partial lockdown, full lockdown and two relaxation periods spanning from January to September 2020. The analysis is based on in situ ground-based air quality observations at over 540 traffic, background and rural stations, from 63 cities and covering 25 countries over seven geographical regions of the world. Anomalies in the air pollutant concentrations (increases or decreases during 2020 periods compared to equivalent 2015–2019 periods) were calculated and the possible effects of meteorological conditions were analysed by computing anomalies from ERA5 reanalyses and local observations for these periods. We observed a positive correlation between the reductions in NO2 and NOx concentrations and peoples’ mobility for most cities. A correlation between PMC and mobility changes was also seen for some Asian and South American cities. A clear signal was not observed for other pollutants, suggesting that sources besides vehicular emissions also substantially contributed to the change in air quality. As a global and regional overview of the changes in ambient concentrations of key air quality species, we observed decreases of up to about 70% in mean NO2 and between 30% and 40% in mean PM2.5 concentrations over 2020 full lockdown compared to the same period in 2015–2019. However, PM2.5 exhibited complex signals, even within the same region, with increases in some Spanish cities, attributed mainly to the long-range transport of African dust and/or biomass burning (corroborated with the analysis of NO2/CO ratio). Some Chinese cities showed similar increases in PM2.5 during the lockdown periods, but in this case, it was likely due to secondary PM formation. Changes in O3 concentrations were highly heterogeneous, with no overall change or small increases (as in the case of Europe), and positive anomalies of 25% and 30% in East Asia and South America, respectively, with Colombia showing the largest positive anomaly of ~70%. The SO2 anomalies were negative for 2020 compared to 2015–2019 (between ~25 to 60%) for all regions. For CO, negative anomalies were observed for all regions with the largest decrease for South America of up to ~40%. The NO2/CO ratio indicated that specific sites (such as those in Spanish cities) were affected by biomass burning plumes, which outweighed the NO2 decrease due to the general reduction in mobility (ratio of ~60%). Analysis of the total oxidant (OX = NO2 + O3) showed that primary NO2 emissions at urban locations were greater than the O3 production, whereas at background sites, OX was mostly driven by the regional contributions rather than local NO2 and O3 concentrations. The present study clearly highlights the importance of meteorology and episodic contributions (e.g., from dust, domestic, agricultural biomass burning and crop fertilizing) when analysing air quality in and around cities even during large emissions reductions. There is still the need to better understand how the chemical responses of secondary pollutants to emission change under complex meteorological conditions, along with climate change and socio-economic drivers may affect future air quality. The implications for regional and global policies are also significant, as our study clearly indicates that PM2.5 concentrations would not likely meet the World Health Organization guidelines in many parts of the world, despite the drastic reductions in mobility. Consequently, revisions of air quality regulation (e.g., the Gothenburg Protocol) with more ambitious targets that are specific to the different regions of the world may well be required.Peer reviewedFinal Published versio