285 research outputs found

    Estimating the mass of CMEs from the analysis of EUV dimmings

    Get PDF
    Context. Reliable estimates of the mass of coronal mass ejections (CMEs) are required to quantify their energy and predict how they affect space weather. When a CME propagates near the observer's line of sight, these tasks involve considerable errors, which motivated us to develop alternative means for estimating the CME mass. Aims. We aim at further developing and testing a method that allows estimating the mass of CMEs that propagate approximately along the observer's line of sight. Methods. We analyzed the temporal evolution of the mass of 32 white-light CMEs propagating across heliocentric heights of 2.5-15 R, in combination with that of the mass evacuated from the associated low coronal dimming regions. The mass of the white-light CMEs was determined through existing methods, while the mass evacuated by each CME in the low corona was estimated using a recently developed technique that analyzes the dimming in extreme-UV (EUV) images. The combined white-light and EUV analyses allow the quantification of an empirical function that describes the evolution of CME mass with height. Results. The analysis of 32 events yielded reliable estimates of the masses of front-side CMEs. We quantified the success of the method by calculating the relative error with respect to the mass of CMEs determined from white-light STEREO data, where the CMEs propagate close to the plane of sky. The median for the relative error in absolute values is ≈30%; 75% of the events in our sample have an absolute relative error smaller than 51%. The sources of uncertainty include the lack of knowledge of piled-up material, subsequent additional mass supply from the dimming region, and limitations in the mass-loss estimation from EUV data. The proposed method does not rely on assumptions of CME size or distance to the observer's plane of sky and is solely based on the determination of the mass that is evacuated in the low corona. It therefore represents a valuable tool for estimating the mass of Earth-directed events.Fil: López, F. M.. 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: Cremades Fernandez, Maria Hebe. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Tecnológica Nacional; ArgentinaFil: Balmaceda, Laura Antonia. George Mason University; Estados Unidos. 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: Nuevo, Federico Alberto. 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: Vásquez, A. M.. 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; Argentina. Universidad Nacional de Tres de Febrero; Argentin

    Exposure to selected pathogens in Geoffroy's cats and domestic carnivores from central Argentina

    Get PDF
    Wild carnivores share a high percentage of parasites and viruses with closely related domestic carnivores. Because of increased overlap and potential contact with domestic species, we conducted a retrospective serosurvey for 11 common carnivore pathogens in 40 Geoffroy's cats (Leopardus geoffroyi) sampled between 2000 and 2008 within or near two protected areas in central Argentina (Lihué Calel National Park, La Pampa, and Campos del Tuyú National Park, Buenos Aires), as well as five domestic cats and 11 domestic dogs from cattle ranches adjacent to Lihué Calel Park. Geoffroy's cats had detectable antibody to canine distemper virus (CDV), feline calicivirus (FCV), feline coronavirus, feline panleukopenia virus (FPV), Toxoplasma gondii, Leptospira interrogans (serovars Ictero/Icter and Ballum), and Dirofilaria immitis. None of the wild cats had antibodies to feline herpesvirus, feline immunodeficiency virus (FIV), feline leukemia virus, or rabies virus. Domestic dogs had antibodies to CDV, canine adenovirus, canine herpesvirus, and canine parvovirus. Antibodies to FPV, FCV, FIV, and T. gondii were found in domestic cats.We provide the first data on exposure of free-ranging Geoffroy's cats to pathogens at two sites within the core area of the species distribution range, including the first report of antibodies to CDV in this species. We encourage continued monitoring for diseases in wild and domestic carnivores as well as preventive health care for domestic animals, particularly in park buffer zones where overlap is greatest.Fil: Uhart, Marcela María. ildlife Conservation Society; ArgentinaFil: Rago, María Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Marull, Carolina A.. ildlife Conservation Society; ArgentinaFil: Ferreyra, Hebe del Valle. ildlife Conservation Society; ArgentinaFil: Pereira, Javier Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentin

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

    Get PDF
    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

    Plant regeneration of tea (Camellia sinensis) by in vitro culture of meristems, axillary buds and uninodal segments

    Get PDF
    Tres tipos de explantes de dos clones ( C H 1 4 I N TA y C H 3 1 8 I N TA ) d e t é (Camellia sinensis (L.) O. Kuntze) fueron evaluados para su regeneración in vitro, bajo la influencia de dos citocininas (BAP y CIN) y una giberelina (AG3). Previa desinfección, con etanol 70% (1 minuto) e hipoclorito de sodio 1,5% (20 minutos) y tres enjuagues con agua destilada estéril, los explantes fueron aislados y cultivados en los distintos medios de cultivo. Las mejores respuestas en formación de vástagos se registraron con los segmentos uninodales de ambos clones cultivados en el medio ½ MS + 1 mg/L de BAP o con el cultivo de yemas axilares del clon CH 14 INTA en el medio ½ MS + 1 mg/L de BAP o del clon CH 318 INTA en el medio ½ MS + 1 mg/L BAP + 1 mg/L AG3. Los mejores resultados con el empleo de meristemas caulinares se obtuvieron en el medio ½ MS + 1 mg/L de CIN y 1 mg/L de AG3. Los vástagos obtenidos fueron enraizados mediante su cultivo en ¼ MS + 6 mg/L de IBA.Plants of two clones (CH 14 INTA and CH 318 INTA) of tea (Camellia sinensis (L.) O. Kuntze) were regenerated by in vitro culture of three types of explants disinfected by immersion in 70% ethanol (1 min) and 1.5% sodium hypochlorite (20 min). The best medium for shoot regeneration from uninodal segments, for both clones, as well as for axillary buds of CH 14 INTA clone was ½ MS + 1 mg/L BAP. While the best medium for axillary buds of CH 318 clone was ½ MS + 1 mg/L BAP + 1 mg/L AG3. For meristems culture, the best medium, for both clones was ½ MS + 1 mg/L KIN + 1 mg/L AG3. Rooting of regenerated shoots were achieved by culture them on ¼ MS + 6 mg/L IBA.Fil: Molina, Sandra P.. Instituto Nacional de Tecnología Agropecuaria (Argentina). Estación Experimental Agropecuaria Cerro AzulFil: Pérez, María Laura. Universidad Nacional del Nordeste. Facultad de Ciencias AgrariasFil: Rey, Hebe Y.. Universidad Nacional del Nordeste. Facultad de Ciencias AgrariasFil: Mroginski, Luis A.. Universidad Nacional del Nordeste. Facultad de Ciencias Agraria

    Functional ingredients from Brassicaceae species: overview and perspectives

    Get PDF
    Brassicaceae vegetables are important crops consumed worldwide due to their unique flavor, and for their broadly recognized functional properties, which are directly related to their phytochemical composition. Isothiocyanates (ITC) are the most characteristic compounds, considered responsible for their pungent taste. Besides ITC, these vegetables are also rich in carotenoids, phenolics, minerals, and vitamins. Consequently, Brassica’s phytochemical profile makes them an ideal natural source for improving the nutritional quality of manufactured foods. In this sense, the inclusion of functional ingredients into food matrices are of growing interest. In the present work, Brassicaceae ingredients, functionality, and future perspectives are reviewed.Fil: Ramirez, Daniela Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: Abellán Victorio, Angel. Consejo Superior de Investigaciones Científicas; EspañaFil: Beretta, Hebe Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: Camargo, Alejandra Beatriz. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Ciencias Enológicas y Agroalimentarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: Moreno, Diego A.. Consejo Superior de Investigaciones Científicas; Españ

    Daytime Sky Quality at El Leoncito, Argentina

    Get PDF
    We characterize the daytime sky quality in terms of brightness, cloud coverage, and main weather variables at the Carlos Ulrico Cesco station of the Felix Aguilar Astronomical Observatory (OAFA), located in El Leoncito National Park, San Juan, Argentina. We have collected more than 15 years of daily observations from the auxiliary sky brightness detectors of the Mirror Coronagraph for Argentina (MICA, in operations from 1997 to 2012), including daily observing reports. We additionally present data from two meteorological stations operated at the site from 2000 to 2020. We determine the main statistical properties and seasonal variability of daytime sky brightness, clear sky time fraction (CSTF), precipitable water vapor (WV), temperature, humidity, and wind speed, which are relevant for solar, particularly coronal observations. Our results confirm that El Leoncito is an excellent place to perform daytime astronomical observations. We measure a median sky brightness of 15.8 ppm, estimated at 526.0 ± 1.0 nm and 6 solar radii from the solar disk center; a median CSTF of 0.7; and a median WV below 6 mm. These values, and those of other relevant weather variables, are comparable to the levels found among the best astronomical observing sites in the world. Due to the extended period of time analyzed and high sampling frequency, the novel data and results presented in this report contribute to the analysis and interpretation of historical sky brightness data and are of great value for the future planning of daytime astronomical instrumentation at El Leoncito.Fil: Iglesias, F. A.. Universidad de Mendoza. Facultad de Ingenieria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Francile, Carlos Natale. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Departamento de Informática. Observatorio Astronómico Félix Aguilar; ArgentinaFil: Lazarte Gelmetti, J.. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Balmaceda, L. A.. George Mason University. School Of Physics. Astronomy And Computational Sciences; Estados Unidos. National Aeronautics and Space Administration; Estados UnidosFil: Cremades Fernandez, Maria Hebe. Universidad de Mendoza; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cisterna, F.. Universidad de Mendoza. Facultad de Ingenieria; Argentin

    Prenatal sonographic detection of birth defects in 18 hospitals from South America

    Get PDF
    Objective. The purpose of this study was to assess the accuracy of prenatal sonographic diagnosis of birth defects and the gestational age at detection according to the health insurance schemes of mothers in 450 malformed neonates from 18 South American hospitals on the basis of prenatal sonographic records. Methods. Between July 2000 and December 2003, 18 hospitals included in the Latin American Collaborative Study of Congenital Malformations (13 from Argentina [8 public and 5 nonpublic], 3 from Brazil [2 public and 1 nonpublic], 1 from Chile [nonpublic], and 1 from Venezuela [public]) voluntarily participated in this prospective observational study, recording fetuses with sonographically detected malformations. Prenatal sonographic descriptions of anomalies were compared with those recorded at birth. Results. Of 812 anomalies detected at birth, 457 had been prenatally detected (detection rate, 56.3%; 95% confidence interval, 52.8%-59.8%). Before 24 gestational weeks, anencephaly had the highest detection rate. Cleft lip and clubfoot were more easily detected when associated with other anomalies. The detection rates for central nervous system and renourinary malformations were greater than 80%. Detection rates between both health insurance schemes (public and nonpublic) did not show significant differences, but anencephaly, spina bifida, renourinary defects, and cleft lip with or without cleft palate were detected earlier in patients from nonpublic rather than in public hospitals. Conclusions. For specific anomalies, South America shows similar levels of prenatal sonographic detection as developed countries. Detection rates during pregnancy were similar for public and nonpublic hospitals, whereas cases were diagnosed earlier in patients from nonpublic hospitals.Instituto Multidisciplinario de Biología Celula

    Novel aromatic ring-hydroxylating dioxygenase genes from coastal marine sediments of Patagonia

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Polycyclic aromatic hydrocarbons (PAHs), widespread pollutants in the marine environment, can produce adverse effects in marine organisms and can be transferred to humans through seafood. Our knowledge of PAH-degrading bacterial populations in the marine environment is still very limited, and mainly originates from studies of cultured bacteria. In this work, genes coding catabolic enzymes from PAH-biodegradation pathways were characterized in coastal sediments of Patagonia with different levels of PAH contamination.</p> <p>Results</p> <p>Genes encoding for the catalytic alpha subunit of aromatic ring-hydroxylating dioxygenases (ARHDs) were amplified from intertidal sediment samples using two different primer sets. Products were cloned and screened by restriction fragment length polymorphism analysis. Clones representing each restriction pattern were selected in each library for sequencing. A total of 500 clones were screened in 9 gene libraries, and 193 clones were sequenced. Libraries contained one to five different ARHD gene types, and this number was correlated with the number of PAHs found in the samples above the quantification limit (<it>r </it>= 0.834, <it>p </it>< 0.05). Overall, eight different ARHD gene types were detected in the sediments. In five of them, their deduced amino acid sequences formed deeply rooted branches with previously described ARHD peptide sequences, exhibiting less than 70% identity to them. They contain consensus sequences of the Rieske type [2Fe-2S] cluster binding site, suggesting that these gene fragments encode for ARHDs. On the other hand, three gene types were closely related to previously described ARHDs: archetypical <it>nahAc</it>-like genes, <it>phnAc</it>-like genes as identified in <it>Alcaligenes faecalis </it>AFK2, and <it>phnA1</it>-like genes from marine PAH-degraders from the genus <it>Cycloclasticus</it>.</p> <p>Conclusion</p> <p>These results show the presence of hitherto unidentified ARHD genes in this sub-Antarctic marine environment exposed to anthropogenic contamination. This information can be used to study the geographical distribution and ecological significance of bacterial populations carrying these genes, and to design molecular assays to monitor the progress and effectiveness of remediation technologies.</p

    Cirurgia estapédica na otosclerose: análise retrospectiva de resultados

    Get PDF
    Objectivo: Relatar os resultados auditivos da cirurgia estapédica na otosclerose numa serie consecutiva de 99 ouvidos. Materiais e métodos: Revisão retrospectiva dos processos clínicos de 84 pacientes consecutivos, submetidos a estapedectomia (99 ouvidos) num Hospital Distrital. Resultados: O gap aero-ósseo(AO) médio de 4 frequências (0.5, 1, 2 e 4 KHz) no pós-operatório foi de 5,4 dB. O gap AO pre-operatório menos o gap AO pós-operatório (ganho auditivo) foi de 23,1 dB. Obteve-se um gap AO pós-operatório <10 dB em 87,5% dos casos. Ocorreu uma perda auditiva sensorioneural pós-operatória significativa(>15 dB) em 5,9% dos caso. Conclusão: Os nossos resultados confirmam a eficácia e segurança da cirurgia estapédica na otosclerose

    Circulando conocimientos desde las asimetrías : el papel de los actores académicos en la producción y circulación del debate sobre multiculturalismo en Chile

    Get PDF
    ¿Qué papel cumplen los actores del campo académico en los procesos de producción y circulación de conocimiento a nivel internacional y local? ¿Qué asimetrías son inherentes a estos procesos? Estas son las preguntas que dirigen la investigación de doctorado de Sabina García Peter, quien argumenta que la circulación de conocimientos es un proceso complejo y multidimensional e introduce la noción de agentes de la circulación para su estudio. A partir del caso de la producción y circulación del debate sobre multiculturalismo en Chile, desde el retorno a la democracia en los años noventa, la autora plantea que los actores académicos no sólo han sido relevantes a la hora de producir y circular aquellos conceptos y teorías que dan forma al debate teórico sobre multiculturalismo, sino que también han asumido otros roles en la implementación y puesta en marcha de este debate en otros campos, como el político-estatal
    corecore