The Mars Environmental Dynamics Analyzer, MEDA. A Suite of Environmental Sensors for the Mars 2020 Mission

86 pags., 49 figs., 24 tabs.NASA’s Mars 2020 (M2020) rover mission includes a suite of sensors to monitor current environmental conditions near the surface of Mars and to constrain bulk aerosol properties from changes in atmospheric radiation at the surface. The Mars Environmental Dynamics Analyzer (MEDA) consists of a set of meteorological sensors including wind sensor, a barometer, a relative humidity sensor, a set of 5 thermocouples to measure atmospheric temperature at ∼1.5 m and ∼0.5 m above the surface, a set of thermopiles to characterize the thermal IR brightness temperatures of the surface and the lower atmosphere. MEDA adds a radiation and dust sensor to monitor the optical atmospheric properties that can be used to infer bulk aerosol physical properties such as particle size distribution, non-sphericity, and concentration. The MEDA package and its scientific purpose are described in this document as well as how it responded to the calibration tests and how it helps prepare for the human exploration of Mars. A comparison is also presented to previous environmental monitoring payloads landed on Mars on the Viking, Pathfinder, Phoenix, MSL, and InSight spacecraft.This work has been funded by the Spanish Ministry of Economy and Competitiveness, through the projects No. ESP2014-54256-C4-1-R (also -2-R, -3-R and -4-R) and AYA2015-65041-P; Ministry of Science, Innovation and Universities, projects No. ESP2016-79612-C3-1-R (also -2-R and -3-R), ESP2016-80320-C2-1-R, RTI2018-098728-B-C31 (also -C32 and -C33) and RTI2018-099825-B-C31; Instituto Nacional de Técnica Aeroespacial; Ministry of Science and Innovation’s Centre for the Development of Industrial Technology; Grupos Gobierno Vasco IT1366-19; and European Research Council Consolidator Grant no 818602. The US co-authors performed their work under sponsorship from NASA’s Mars 2020 project, from the Game Changing Development program within the Space Technology Mission Directorate and from the Human Exploration and Operations Directorate

Observation of inverse Compton emission from a long γ-ray burst.

Long-duration γ-ray bursts (GRBs) originate from ultra-relativistic jets launched from the collapsing cores of dying massive stars. They are characterized by an initial phase of bright and highly variable radiation in the kiloelectronvolt-to-megaelectronvolt band, which is probably produced within the jet and lasts from milliseconds to minutes, known as the prompt emission1,2. Subsequently, the interaction of the jet with the surrounding medium generates shock waves that are responsible for the afterglow emission, which lasts from days to months and occurs over a broad energy range from the radio to the gigaelectronvolt bands1-6. The afterglow emission is generally well explained as synchrotron radiation emitted by electrons accelerated by the external shock7-9. Recently, intense long-lasting emission between 0.2 and 1 teraelectronvolts was observed from GRB 190114C10,11. Here we report multi-frequency observations of GRB 190114C, and study the evolution in time of the GRB emission across 17 orders of magnitude in energy, from 5 × 10-6 to 1012 electronvolts. We find that the broadband spectral energy distribution is double-peaked, with the teraelectronvolt emission constituting a distinct spectral component with power comparable to the synchrotron component. This component is associated with the afterglow and is satisfactorily explained by inverse Compton up-scattering of synchrotron photons by high-energy electrons. We find that the conditions required to account for the observed teraelectronvolt component are typical for GRBs, supporting the possibility that inverse Compton emission is commonly produced in GRBs

Immunisation of sheep against heartwater in The Gambia using inactivated and attenuated Ehrlichia ruminantium vaccines

Heartwater (cowdriosis) is a disease of ruminants caused by a rickettsial pathogen Ehrlichia ruminantium and transmitted by ticks of the genus Amblyomma. The purpose of this work was to evaluate the protective efficacies of inactivated and attenuated vaccines to protect sheep against heartwater in The Gambia. An inactivated vaccine, prepared from E. ruminantium (Gardel stock), and a live attenuated vaccine from E. ruminantium (Senegal stock), were evaluated in two independent on-station trials. A local stock of E. ruminantium (Kerr Seringe) was used as challenge material. Inactivated and live attenuated vaccines provided 43% and 100% protection, respectively, against virulent needle challenge. In a subsequent field trial, the attenuated vaccine protected 75% of sheep against virulent tick challenge, which was fatal for all control sheep. Quantification by real-time PCR showed that an immunising dose of approximately 23,000 attenuated E. ruminantium organisms was sufficient. Moreover, restriction fragment length polymorphism (RFLP) analysis indicated that the local Kerr Seringe genotype caused mortality amongst control sheep, whereas fatalities in the vaccinated group could be attributed to a different genotype

Activity of Thymus capitellatus volatile extract, 1,8-cineoleand borneol against Leishmania species

In the search for new leishmanicidal agents, Thymus capitellatus Hoffmanns. & Link (familyLamiaceae) volatile extract and its major compounds, 1,8-cineole and borneol, were testedagainst Leishmania infantum, Leishmania tropica and Leishmania major. Plant volatile extract(essential oil) was analysed by GC and GC–MS and the activity of essential oil on Leishmaniapromastigotes viability was assessed using tetrazolium-dye colorimetric method (MTT).The MTT test was also used to assess the cytotoxicity of essential oil on macrophages andbovine aortic endothelial cells. Effects on parasites were also analyzed by flow cytometryin order to assess mitochondrial transmembrane electrochemical gradient (JC-1), analyzephosphatidylserine externalization (annexin V–FITC, propidium iodide) and evaluate cellcycle (DNase-free, RNase, PI). Morphological and ultrastructural studies were performedby light, scanning and transmission electron microscopy. T. capitellatus volatile extractexhibited anti-parasite activity on Leishmania species, with IC50values ranging from 35to 62 g/ml. However, major compounds 1,8-cineole and borneol did not showed biologi-cal activity suggesting that these monoterpenes are not responsible for the antileishmanialactivity of T. capitellatus essential oil. Appearance of aberrant-shaped cells, mitochondrialswelling and autophagosomal structures were some of the ultrastructural alterations exhib-ited among treated promastigote cells. T. capitellatus promoted leishmanicidal effect bytriggering a programmed cell death as evidenced by externalization of phosphatidylserine,loss of mitochondrial membrane potential, and cell-cycle arrest at the G(0)/G(1) phase. Thevolatile extract did not induced cytotoxic effects on mammalian cells. Taken together, theseresults suggest that T. capitellatus may represent a valuable source for therapeutic controlof leishmaniasis in humans and animals.This work was supported by “Programa Opera-cional Ciência e Inovacão 2010 (POCI)/FEDER” da Fundac¸ ãopara a Ciência e Tecnologia (FCT)