Multimodal Differential Emission Measure in the Solar Corona

The Atmospheric Imaging Assembly (AIA) telescope on board the Solar Dynamics Observatory (SDO) provides coronal EUV imaging over a broader temperature sensitivity range than the previous generations of instruments (EUVI, EIT, and TRACE). Differential emission measure tomography (DEMT) of the solar corona based on AIA data is presented here for the first time. The main product of DEMT is the three-dimensional (3D) distribution of the local differential emission measure (LDEM). While in previous studies, based on EIT or EUVI data, there were 3 available EUV bands, with a sensitivity range $\sim 0.60 - 2.70$ MK, the present study is based on the 4 cooler AIA bands (aimed at studying the quiet sun), sensitive to the range $\sim 0.55 - 3.75$ MK. The AIA filters allow exploration of new parametric LDEM models. Since DEMT is better suited for lower activity periods, we use data from Carrington Rotation 2099, when the Sun was in its most quiescent state during the AIA mission. Also, we validate the parametric LDEM inversion technique by applying it to standard bi-dimensional (2D) differential emission measure (DEM) analysis on sets of simultaneous AIA images, and comparing the results with DEM curves obtained using other methods. Our study reveals a ubiquitous bimodal LDEM distribution in the quiet diffuse corona, which is stronger for denser regions. We argue that the nanoflare heating scenario is less likely to explain these results, and that alternative mechanisms, such as wave dissipation appear better supported by our results.Comment: 52 pages, 18 figure

Estimating the mass of CMEs from the analysis of EUV dimmings

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

The WHI Corona from Differential Emission Measure Tomography

A three dimensional (3D) tomographic reconstruction of the local differential emission measure (LDEM) of the global solar corona during the whole heliosphere interval (WHI, Carrington rotation CR-2068) is presented, based on STEREO/EUVI images. We determine the 3D distribution of the electron density, mean temperature, and temperature spread, in the range of heliocentric heights 1.03 to 1.23 Rsun. The reconstruction is complemented with a potential field source surface (PFSS) magnetic-field model. The streamer core, streamer legs, and subpolar regions are analyzed and compared to a similar analysis previously performed for CR-2077, very near the absolute minimum of the Solar Cycle 23. In each region, the typical values of density and temperature are similar in both periods. The WHI corona exhibits a streamer structure of relatively smaller volume and latitudinal extension than during CR-2077, with a global closed-to-open density contrast about 6% lower, and a somewhat more complex morphology. The average basal electron density is found to be about 2.23 and 1.08 x 10^8 cm^-3, in the streamer core and subpolar regions, respectively. The electron temperature is quite uniform over the analyzed height range, with average values of about 1.13 and 0.93 MK, in the streamer core and subpolar regions, respectively. Within the streamer closed region, both periods show higher temperatures at mid-latitudes and lower temperatures near the equator. Both periods show beta>1 in the streamer core and beta<1 in the surrounding open regions, with CR-2077 exhibiting a stronger contrast. Hydrostatic fits to the electron density are performed, and the scale height is compared to the LDEM mean electron temperature. Within the streamer core, the results are consistent with an isothermal hydrostatic plasma regime, with the temperatures of ions and electrons differing by up to about 10% .. (continues)..Comment: 13 Figure

Barriers to the care of febrile patients in a malaria endemic area : El Bagre (Antioquia, Colombia) 2016.

Objetivo: Identificar limitaciones de los pacientes con síndrome febril agudo para acceder a los servicios de atención institucional, con énfasis en la identificación de barreras de comunicación.Método: Estudio descriptivo que involucra técnicas de investigación cualitativa con pacientes de los servicios de atención de la malaria y con personal asistencial y administrativo del municipio de El Bagre Antioquia, Colombia en el 2016. Se aplicaron encuestas semiestructuradas individuales, entrevistas y grupos focales. Los usuarios señalaron dificultades con el transporte, insuficiente número de citas y falta de personal para acceder a la atención. Resultados: Las dificultades de comunicación se relacionaron con la información suministrada sobre trámites y documentación para asistir a los puestos de salud, poca información sobre el diagnóstico, control y adherencia al tratamiento antimalárico y el no uso de algunos pacientes del español para comunicarse en forma verbal o escrita. Conclusiones: Esto exige crear modelos de salud basados en transformaciones estructurales que abarquen las necesidades de los actores del sistema de salud y las comunidades, permitiendo establecer las bases para un proyecto multicultural de sociedad.Objective: identify constraints of patients with acute febrile syndrome to institutional care services access, emphasizing the identification of communication barriers. Method: this is a descriptive study that involves qualitative research techniques including malaria care service patients as well as assistance and administrative personnel of El Bagre town in Antioquia, Colombia in 2016. Semi-structured individual surveys, interviews and focus groups were used. Results: users listed difficulties including transportation, insufficient number of appointments and absence of personnel to access healthcare. Communication difficulties were related to the information provided in the paperwork and documents filled out to attend healthcare facilities, scarce information about diagnostic, control, and adherence to antimalarial treatment; additionally some patients did not use Spanish to communicate in oral or write form. Conclusion: the creation of health models based on structural transformations that encompass the needs of Healthcare System actors and communities is a must, which allows the establishment of foundations for a multicultural society Project

Prevalence and correlates of mild cognitive impairment among diverse Hispanics/Latinos: Study of Latinos-Investigation of Neurocognitive Aging results.

IntroductionWe estimated the prevalence and correlates of mild cognitive impairment (MCI) among middle-aged and older diverse Hispanics/Latinos.MethodsMiddle-aged and older diverse Hispanics/Latinos enrolled (n = 6377; 50-86 years) in this multisite prospective cohort study were evaluated for MCI using the National Institute on Aging-Alzheimer's Association diagnostic criteria.ResultsThe overall MCI prevalence was 9.8%, which varied between Hispanic/Latino groups. Older age, high cardiovascular disease (CVD) risk, and elevated depressive symptoms were significant correlates of MCI prevalence. Apolipoprotein E4 (APOE) and APOE2 were not significantly associated with MCI.DiscussionMCI prevalence varied among Hispanic/Latino backgrounds, but not as widely as reported in the previous studies. CVD risk and depressive symptoms were associated with increased MCI, whereas APOE4 was not, suggesting alternative etiologies for MCI among diverse Hispanics/Latinos. Our findings suggest that mitigating CVD risk factors may offer important pathways to understanding and reducing MCI and possibly dementia among diverse Hispanics/Latinos

Newly Discovered Global Temperature Structures in the Quiet Sun at Solar Minimum

Magnetic loops are building blocks of the closed-field corona. While active region loops are readily seen in images taken at EUV and X-ray wavelengths, quiet Sun loops are seldom identifiable and therefore difficult to study on an individual basis. The first analysis of solar minimum (Carrington Rotation 2077) quiet Sun (QS) coronal loops utilizing a novel technique called the Michigan Loop Diagnostic Technique (MLDT) is presented. This technique combines Differential Emission Measure Tomography (DEMT) and a potential field source surface (PFSS) model, and consists of tracing PFSS field lines through the tomographic grid on which the Local Differential Emission Measure (LDEM) is determined. As a result, the electron temperature Te and density Ne at each point along each individual field line can be obtained. Using data from STEREO/EUVI and SOHO/MDI, the MLDT identifies two types of QS loops in the corona: so-called "up" loops in which the temperature increases with height, and so-called "down" loops in which the temperature decreases with height. Up loops are expected, however, down loops are a surprise, and furthermore, they are ubiquitous in the low-latitude corona. Up loops dominate the QS at higher latitudes. The MLDT allows independent determination of the empirical pressure and density scale heights, and the differences between the two remain to be explained. The down loops appear to be a newly discovered property of the solar minimum corona that may shed light on the physics of coronal heating. The results are shown to be robust to the calibration uncertainties of the EUVI instrument.Comment: Accepted for publication in The Astrophysical Journal, waiting for the full biblio inf

POSTUPAK KOD KOMPLICIRANE PLUĆNE SEKVESTRACIJE U BLIZANAČKOJ TRUDNOĆI

It is well established that fetal pulmonary sequestration complicated by non-immune hydrops fetalis is associated with a high risk of mortality; however, antenatal management remains controversial in these rare cases. The main therapeutic strategies aim to drain the effusions in utero, although there is still debate as to the most adequate drainage route. The two main options are thoracoamniotic shunting and serial thoracocentheses. Others include medical inotropic therapy, alcohol ablation of the vascular pedicle, open fetal surgery and ablation of the feeding vessel with laser surgery. We report the case of a twin pregnancy in which one of the fetuses was affected by an extralobar pulmonary sequestration with large hydrothorax that was successfully treated with serial thoracocentheses.Poznato je da je fetalna plućna sekvestracija komplicirana neimunološkim hidropsom povezana s visokim rizikom mortaliteta; prenatalni postupak je u tim rijetkim slučajevima proturječan. Glavna terapijska strategija je u in utero drenaži izljeva, a još se raspravlja o najprikladnijem načinu drenaže. Dvije su glavne mogućnosti: torako-amnionska prijemosnica i ponovljene serijske torakocenteze. Druge mogućnosti su medikamentozna inotropna terapija, ablacija vaskularne peteljke alkoholom, otvorena fetalna kirurgija i laserska ablacija opskrbne krvne žile. Prikazana je blizanačka trudnoća s ekstralobarnom plućnom sekvestracijom i jakim hidrotoraksom u jednoga fetusa, uspješno liječena serijskom torakocentezom. U 35. tjednu trudnoće je počeo spontani porod, dovršen carskim rezom. Nezahvaćeni fetus je bio težine 1800 grama, a zahvaćeni 2700 grama. Zahvaćeno novorođenče je trebalo ventilatornu potporu, a s 26 dana života učinjen je kirurški zahvat. Nakon jedne godine života oba su novorođenčeta zdrava

Determinación del valor nutritivo del fríjol canavalia (Canavalia ensiformis) utilizando bolsas de dacrón móviles.

El ensayo se realizó en el Centro Nacional de Investigaciones Agropecuarias Tibaitatá del Instituto Colombiano Agropecuario (ICA), con la finalidad de determinar la calidad nutritiva del grano de fríjol canavalia por medio de la técnica de la bolsa de dacrón móvil, con un cerdo castrado de 90 kg al cual se le había implantado una cánula duodenal. El diseño estadístico fue completamente al azar con 2 tratamientos: fríjol canavalia crudo y tratado (remojado, cocido y secado). A cada tratamiento se le ejecutaron 4 procedimientos para estimar las pérdidas ocurridas durante las digestiones en agua, estomacal, intestinal y total. El fríjol canavalia fue molido y luego se pesaron 2 gr de muestra que se colocaron en las bolsas de dacrón de 3.5 x 6.0 cm. El residuo que quedó después de atravesar todo el tracto gastrointestinal, representa la fracción indigerible de la materia seca. Estos se analizaron para determinar el porcentaje de digestibilidad de la materia seca, proteína cruda, fibra cruda, extracto etéreo, ureasa, cenizas y energía, mostrando en todos los casos excepto en proteína cruda y ureasa, diferencias estadísticamente significativas (P menor que 0.01) entre el fríjol crudo y el tratado. Se encontró que los principios nutritivos del fríjol canavalia en general son altamente solubles en agua, encontrándose para este procedimiento diferencias altamente significativas (P menor que 0.01) para la desaparición de proteína cruda, extracto etéreo y cenizas. En la digestión estomacal, se encontraron diferencias significativas (P menor que 0.01) para coeficientes de digestibilidad de materia seca, cenizas y fibra cruda entre los tratamientos. Se encontraron diferencias significativas (P menor que 0.01) para los porcentajes de desaparición total de materia seca, extrato etéreo, cenizas, fibra y energía.;En la digestión intestinal se encontraron diferencias altamente significativas (P menor que 0.01) para materia seca, cenizas, extracto etéreo, fibra cruda y energía. Los resultados permitieron determinar un mejor valor nutritivo del fríjol tratado con respecto al crudo sin que por ello se pueda llegar a concluír que sea benéfica su utilización en la alimentación de cerdos por la presencia de factores tóxicos no inhibidos con el tratamiento efectuado al granoFríjol-Phaseolus vulgari

Study of the spatial association between an active region jet and a nonthermal type III radio burst

Aims: We aim to investigate the spatial location of the source of an active region (AR) jet and its relation with associated nonthermal type III radio emission. Methods: An emission measure (EM) method was used to study the thermodynamic nature of the AR jet. The nonthermal type III radio burst observed at meterwavelength was studied using the Murchison Widefield Array (MWA) radio imaging and spectroscopic data. The local configuration of the magnetic field and the connectivity of the source region of the jet with open magnetic field structures was studied using a nonlinear force-free field (NLFFF) extrapolation and potential field source surface (PFSS) extrapolation respectively. Results: The plane-of-sky velocity of the AR jet was found to be ∼136 km s−1. The EM analysis confirmed the presence of low temperature 2 MK plasma for the spire, whereas hot plasma, between 5 and 8 MK, was present at the footpoint region which also showed the presence of Fe XVIII emission. A lower limit on the electron number density was found to be 1.4 × 108 cm−3 for the spire and 2.2 × 108 cm−3 for the footpoint. A temporal and spatial correlation between the AR jet and nonthermal type III burst confirmed the presence of open magnetic fields. An NLFFF extrapolation showed that the photospheric footpoints of the null point were anchored at the location of the source brightening of the jet. The spatial location of the radio sources suggests an association with the extrapolated closed and open magnetic fields although strong propagation effects are also present. Conclusions: The multi-scale analysis of the field at local, AR, and solar scales confirms the interlink between different flux bundles involved in the generation of the type III radio signal with flux transferred from a small coronal hole to the periphery of the sunspot via null point reconnection with an emerging structure