The dust environment of comet 67P/Churyumov–Gerasimenko: results from Monte Carlo dust tail modelling applied to a large ground-based observation data set

We present an extensive data set of ground-based observations and models of the dust environment of comet 67P/Churyumov–Gerasimenko covering a large portion of the orbital arc from about 4.5 au pre-perihelion through 3.0 au post-perihelion, acquired during the current orbit. In addition, we have also applied the model to a dust trail image acquired during this orbit, as well as to dust trail observations obtained during previous orbits, in both the visible and the infrared. The results of the Monte Carlo modelling of the dust tail and trail data are generally consistent with the in situ results reported so far by the Rosetta instruments Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) and Grain Impact Analyser and Dust Accumulator (GIADA). We found the comet nucleus already active at 4.5 au pre-perihelion, with a dust production rate increasing up to ∼3000 kg s−1 some 20 d after perihelion passage. The dust size distribution at sizes smaller than r = 1 mm is linked to the nucleus seasons, being described by a power law of index −3.0 during the comet nucleus southern hemisphere winter but becoming considerably steeper, with values between −3.6 and −4.3, during the nucleus southern hemisphere summer, which includes perihelion passage (from about 1.7 au inbound to 2.4 au outbound). This agrees with the increase of the steepness of the dust size distribution found from GIADA measurements at perihelion showing a power index of −3.7. The size distribution at sizes larger than 1 mm for the current orbit is set to a power law of index −3.6, which is near the average value of in situ measurements by OSIRIS on large particles. However, in order to fit the trail data acquired during past orbits previous to the 2009 perihelion passage, a steeper power-law index of −4.1 has been set at those dates, in agreement with previous trail modelling. The particle sizes are set at a minimum of r = 10 μm, and a maximum size, which increases with decreasing heliocentric distance, in the 1–40 cm radius domain. The particle terminal velocities are found to be consistent with the in situ measurements as derived from the instrument GIADA on board Rosetta

The Agilkia boulders/pebbles size-frequency distributions: OSIRIS and ROLIS joint observations of 67P surface

By using the images acquired by the OSIRIS (Optical, Spectroscopic and Infrared Remote Imaging System) and ROLIS (ROsetta Lander Imaging System) cameras, we derive the size¿ frequency distribution (SFD) of cometary pebbles and boulders covering the size range 0.05¿ 30.0 m on the Agilkia landing site. The global SFD measured on OSIRIS images, reflects the different properties of the multiple morphological units present on Agilkia, combined with selection effects related to lifting, transport and redeposition. Contrarily, the different ROLIS SFD derived on the smooth and rough units may be related to their different regolith thickness present on Agilkia. In the thicker, smoother layer, ROLIS mainly measures the SFD of the airfall population which almost completely obliterates the signature of underlying boulders up to a size of the order of 1 m. This is well matched by the power-law index derived analysing coma particles identified by the grain analyser Grain Impact Analyser and Dust Accumulator. This result confirms the important blanketing dynamism of Agilkia. The steeper SFD observed in rough terrains from 0.4 to 2 m could point out intrinsic differences between northern and southern dust size distributions, or it may suggest that the underlying boulders `peek through¿ the thinner airfall layer in the rough terrain, thereby producing the observed excess in the decimetre size range. Eventually, the OSIRIS SFD performed on the Philae landing unit may be due to water sublimation from a static population of boulders, affecting smaller boulders before the bigger ones, thus shallowing the original SFD.The support of the national funding agencies of Germany (DLR), France(CNES), Italy(ASI), Spain(MEC), Sweden(SNSB) and the ESA Technical Directorate is gratefully acknowledged.Peer Reviewe

Influencia del entorno donde se habita (rural vs

Introducción El objetivo de este estudio fue valorar la influencia del entorno donde se habita (rural vs urbano) sobre la condición física y parámetros antropométricos en estudiantes de educación primaria. Material y método Se seleccionaron 509 sujetos (290 urbanos y 219 rurales) de entre 8 y 11 años, a los que se les realizó una valoración antropométrica (masa, talla, IMC, ratio cintura/cadera) y de la condición física (fuerza de prensión manual, salto vertical, flexibilidad y fitness cardiorrespiratorio). Resultados Los resultados muestran que la población urbana obtiene valores más bajos en parámetros antropométricos, y la población rural mejores resultados en condición física: fuerza de prensión manual (15,72 ± 4,10 vs 19,78 ± 5,20 kg), flexibilidad (8,38 ± 4,59 vs 17,08 ± 6,24 cm) y fitness cardiorrespiratorio (46,00 ± 4,19 vs 46,79 ± 4,49 ml/kg/min), no existiendo diferencias para el salto vertical. Conclusiones Se pone de manifiesto que el lugar de residencia (rural vs urbano) se debe tener en cuenta a la hora de aplicar programas de intervención para la promoción de la actividad física

Influència de l’entorn on es viu (rural vs urbà) sobre la condició

Introducció L’objectiu d’aquest estudi fou valorar la influència de l’entorn en què es viu (rural vs urbà) en la condició física i els paràmetres antropomètrics d’escolars d’educació primària. Material i mètode Es seleccionaren 509 subjectes (290 urbans i 219 rurals) de 8 a 11 anys, als quals es féu una valoració antropomètrica (massa, talla, IMC, ràtio cintura/maluc) i de la condició física (força de prensió manual, salt vertical, flexibilitat i fitnes cardiorespiratori). Resultats Els resultats mostren que la població urbana obté valors més baixos en els paràmetres antropomètrics i la població rural millors resultats en la condició física: força de prensió manual (15,72 ± 4,10 vs 19,78 ± 5,20 kg), flexibilitat (8,38 ± 4,59 vs 17,08 ± 6,24 cm) i fitnes cardiorespiratori (46,00 ± 4,19 vs 46,79 ± 4,49 ml/kg/min), i no es trobaren diferències en el salt vertical. Conclusions Es posa de manifest que cal tenir en compte el lloc de residència (rural vs urbà) a l’hora d’aplicar programes d’intervenció de promoció de l’activitat física

Depth of faulting and ancien theat flows in the Kuiper region of Mercury from lobate scarp topography

Mercurian lobate scarp sare interpreted to be the surface expressions of thrust faults formed by planetary cooling and contraction, which deformed the crust downto the brittle–ductile transition (BDT) dep that the time of faulting. In this work we have used a for ward modeling procedure in order to analyze the relation be tweens carptopography and fault geometrie sand dep thsas sociated with a group of prominent lobate scarps (Santa Maria Rupes and twoun named scarps) located inthe Kuiper region of Mercury for which Earth-based radar altimetry is available. Also aback thrust associated with one of the lobate scarps has been included in this study. We have obtained best fits for depthsof faul ting between 30 and 39 km; the results are consistent with the previous results for o ther lobate scarps on Mercury. The so-derived fault depths have been used to calculate surface heat flows for the time of faulting, taking into account crustal heat source sand a heterogeneous surface temperature due to the variable in solation pattern. Deduced surface heat flow sare be tween 19 and 39m Wm-2 for the Kuiper region, and between 22 and 43 mWm-2 for Discovery Rupes. Both BDT depth sand heat flows are consistent with the predictions of thermal history models for the range of time relevant for scarp formation

Regional surface morphology of comet 67P/Churyumov-Gerasimenko from Rosetta/OSIRIS images: The southern hemisphere

Aims. The OSIRIS camera on board the Rosetta spacecraft has been acquiring images of the comet 67P/Churyumov-Gerasimenko (67P)'s nucleus since August 2014. Starting in May 2015, the southern hemisphere gradually became illuminated and was imaged for the first time. Here we present the regional morphology of the southern hemisphere, which serves as a companion to an earlier paper that presented the regional morphology of the northern hemisphere. Methods. We used OSIRIS images that were acquired at orbits ~45-125 km from the center of the comet (corresponding to spatial resolutions of ~0.8 to 2.3 m/pixel) coupled with the use of digital terrain models to define the different regions on the surface, and identify structural boundaries accurately. Results. Seven regions have been defined in the southern hemisphere bringing the total number of defined regions on the surface of the nucleus to 26. These classifications are mainly based on morphological and/or topographic boundaries. The southern hemisphere shows a remarkable dichotomy with its northern counterpart mainly because of the absence of wide-scale smooth terrains, dust coatings and large unambiguous depressions. As a result, the southern hemisphere closely resembles previously identified consolidated regions. An assessment of the overall morphology of comet 67P suggests that the comet's two lobes show surface heterogeneities manifested in different physical/mechanical characteristics, possibly extending to local (i.e., within a single region) scales.© 2016 ESO.The support of the national funding agencies of Germany (DLR), France (CNES), Italy (ASI), Spain (MEC), Sweden (SNSB), and the ESA Technical Directorate is gratefully acknowledged.Peer Reviewe

A novel synthetic approach to tyrosine dimers based on pterin photosensitization

[EN] Oxidative damage to proteins leads to a variety of modifications that are markers of pathogenesis. One of the most important modifications is the dityrosine (Tyr(2)) cross-link, resulting from an oxidative covalent bond between two tyrosines (Tyr). An optimized methodology for preparation of pure Tyr(2) is important to investigate in detail its physicochemical properties and reactivity. Pterin (Ptr), the parent and unsubstituted compound of oxidized pterins, is able to photosensitize the cross-linking of free tyrosine (Tyr) and tyrosine residues of peptides and proteins through a photoinduced electron transfer mechanism. We have optimized a simple, one-step photocatalyzed formation of Tyr(2), using Ptr as photocatalyst. Our procedure is carried out in aqueous solutions under UV-A radiation for few minutes. The purification of Tyr(2) is performed by reverse-phase chromatography. The obtained highly pure solution is used to fully characterize the Tyr(2) (exact mass and H-1, H-1-H-1 COSY; DEPT; HSQC and HMBC NMR experiments) and to deeper study its fluorescence properties. (C) 2017 Elsevier Ltd. All rights reserved.The present work was partially supported by Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET; Grant PIP 0304), Agencia de Promocion Cientifica y Tecnologica (ANPCyT; Grants PICT 2012-0508), and Universidad Nacional de La Plata (UNLP; Grant X586 and X712). L.O.R. and C.C. thanks CONICET for doctoral research fellowships. Funding from the Programa CSIC de Cooperacion Cientifica para el Desarrollo (iCOOPLight project ref 20105CD0017) is gratefully acknowledged. A.H.T. and M.L.D are research members of CONICET. The authors thank Dr. Mariana Vignoni (INIFTA, CONICET) and Nathalie Martins-Froment of the Service Commun de Spectrometrie de Masse (FR2599), Universite de Toulouse III (Paul Sabatier) for their crucial contributions in mass spectrometry measurements.Reid, LO.; Castaño, C.; Dantola, ML.; Lhiaubet ., VL.; Miranda Alonso, MÁ.; Marín García, ML.; Thomas, AH. (2017). A novel synthetic approach to tyrosine dimers based on pterin photosensitization. Dyes and Pigments. 147:67-74. https://doi.org/10.1016/j.dyepig.2017.07.058S677414

La recuperación mutua en personas con trastornos psicológicos o diversidad funcional a través de la práctica creativa

In this paper we introduce the concept of “mutual recovery” and we propose creative practices as efficient recovery tools people with both mental health problems as some sort of functional diversity. Compared with the traditional concept of “art therapy” we propose the concept of “creative practice” as more consistent with the model of “mutual recovery.” To do this, we first make a brief critical review of the relationship between art and madness. Next, we present the related concepts of “recovery” and “mutual recovery” in the context of what has become known as the “health humanities”. Finally, we describe two creative practices currently being tested in Spain in the context of the a international research project about mutual recovery:Creative workshops with people with serious mental illness at the Museum of Contemporary Art of Seville and the theater group of people with diverse functionality with the Down Syndrome Association of Seville.En el presente artículo introducimos el concepto de “recuperación mutua” y proponemos las prácticas creativas como herramientas eficientesde recuperación de personas tanto con problemas de salud mental como con algún tipo de diversidad funcional. Frente al concepto clásico de “arte-terapia” nosotros proponemos el concepto de “práctica creativa” como más compatible con el modelo de “recuperación mutua”. Para ello, en primer lugar realizamos un breve repaso crítico a la relación del arte con la locura. Seguidamente, presentamos los conceptos hermanos de “recuperación” y “recuperación mutua” en el marco de lo que se ha venido a denominar las “health humanities”. Para finalizar, describimos dos prácticas creativas que en la actualidad están siendo evaluadas en España en el contexto de un proyecto de investigacióninternacional en recuperación mutua: Los seminarios creativos con personas con trastorno mental grave en el Museo de Arte Contemporáneo de Sevilla y el grupo de teatro con personas con diversidad funcional de la Asociación Síndrome de Down-Sevill

Low levels of few micronutrients may impact COVID-19 disease progression : an observational study on the first wave

We report an observational study performed between March and May 2020 in a Spanish university hospital during the SARS-CoV-2 pandemic. The main objective was to analyse the association between the levels of micronutrients in severe Covid-19 patients and their outcome. Adult patients with a positive polymerase-chain-reaction (PCR) for SARS-CoV-2 in the nasopharyngeal swab or in tracheal aspirate culture in the case of intubation were included. Micronutrient data were obtained from plasma analysis of a standard nutritional assessment performed within the first 24 h of hospital admission. Vitamins A, B6, C and E were analysed with HPLC methods; 25-OH-vitamin D by immunoassay and zinc by colorimetric measurements. One hundred and twenty patients were included. We found that 74.2% patients had low levels of zinc (normal levels >84 µg/dL) with a mean value of 63.5 (SD 13.5); 71.7% patients had low levels of vitamin A (normal levels >0.3 mg/L) with a mean value of 0.17 (SD 0.06); 42.5% patients had low levels of vitamin B6 (normal levels >3.6 ng/mL) with a mean value of 2.2 (SD 0.9); 100% patients had low levels of vitamin C (normal levels >0.4 mg/dL) with a mean value of 0.14 (SD 0.05); 74.3% patients had low values of vitamin D (normal levels >20 ng/mL) with mean value of 11.4 (SD 4.3); but only 5.8% of patients had low levels of vitamin E (normal levels >5 mg/L) with a mean value of 3.95 (SD 0.87). The variables associated with the need for ICU admission were low levels of zinc (standard error 0.566, 95% CI 0.086 to 0.790, p = 0.017), low levels of vitamin A (standard error 0.582, 95% CI 0.061 to 0.594, p = 0.004), age over 65 (standard error 0.018, 95% CI 0.917 to 0.985, p = 0.005) and male gender (standard error 0.458, 95% CI 1.004 to 6.040, p = 0.049). The only variable that was independently associated with the need for orotracheal intubation was low levels of vitamin A (standard error 0.58, 95% CI 0.042 to 0.405, p = 0.000). Conclusions: Low levels of vitamin A and zinc are associated with a greater need for admission to the ICU and orotracheal intubation. Patients older than 65 years had higher mortality. Randomized clinical trials are needed to examine whether micronutrient supplementation could be beneficial as an adjunctive treatment in COVID-19