Comparative study of the Martian suprathermal electron depletions based on Mars Global Surveyor, Mars Express and Mars Atmosphere and Volatile EvolutioN missions observations

Nightside suprathermal electron depletions have been observed at Mars by three spacecraft to date: Mars Global Surveyor, Mars Express, and the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission. This spatial and temporal diversity of measurements allows us to propose here a comprehensive view of the Martian electron depletions through the first multispacecraft study of the phenomenon. We have analyzed data recorded by the three spacecraft from 1999 to 2015 in order to better understand the distribution of the electron depletions and their creation mechanisms. Three simple criteria adapted to each mission have been implemented to identify more than 134,500 electron depletions observed between 125 and 900 km altitude. The geographical distribution maps of the electron depletions detected by the three spacecraft confirm the strong link existing between electron depletions and crustal magnetic field at altitudes greater than ~170 km. At these altitudes, the distribution of electron depletions is strongly different in the two hemispheres, with a far greater chance to observe an electron depletion in the Southern Hemisphere, where the strongest crustal magnetic sources are located. However, the unique MAVEN observations reveal that below a transition region near 160–170 km altitude the distribution of electron depletions is the same in both hemispheres, with no particular dependence on crustal magnetic fields. This result supports the suggestion made by previous studies that these low-altitudes events are produced through electron absorption by atmospheric CO2

Altitude dependence of nightside Martian suprathermal electron depletions as revealed by MAVEN observations

The MAVEN (Mars Atmosphere and Volatile EvolutioN) spacecraft is providing new detailed observations of the Martian ionosphere thanks to its unique orbital coverage and instrument suite. During most periapsis passages on the nightside ionosphere suprathermal electron depletions were detected. A simple criterion was implemented to identify the 1742 depletions observed from 16 November 2014 to 28 February 2015. A statistical analysis reveals that the main ion and electron populations within the depletions are surprisingly constant in time and altitude. Absorption by CO2 is the main loss process for suprathermal electrons, and electrons that strongly peaked around 6 eV are resulting from this interaction. The observation of depletions appears however highly dependent on altitude. Depletions are mainly located above strong crustal magnetic sources above 170 km, whereas the depletions observed for the first time below 170 km are globally scattered onto the Martian surface with no particular dependence on crustal fields

Cross-species amplification of 41 microsatellites in European cyprinids: A tool for evolutionary, population genetics and hybridization studies

<p>Abstract</p> <p>Background</p> <p>Cyprinids display the most abundant and widespread species among the European freshwater Teleostei and are known to hybridize quite commonly. Nevertheless, a limited number of markers for conducting comparative differentiation, evolutionary and hybridization dynamics studies are available to date.</p> <p>Findings</p> <p>Five multiplex PCR sets were optimized in order to assay 41 cyprinid-specific polymorphic microsatellite loci (including 10 novel loci isolated from <it>Chondrostoma nasus nasus, Chondrostoma toxostoma toxostoma </it>and <it>Leuciscus leuciscus</it>) for 503 individuals (440 purebred specimens and 63 hybrids) from 15 European cyprinid species. The level of genetic diversity was assessed in <it>Alburnus alburnus, Alburnoides bipunctatus, C. genei, C. n. nasus, C. soetta, C. t. toxostoma, L. idus, L. leuciscus, Pachychilon pictum, Rutilus rutilus, Squalius cephalus </it>and <it>Telestes souffia</it>. The applicability of the markers was also tested on <it>Abramis brama, Blicca bjoerkna </it>and <it>Scardinius erythrophtalmus </it>specimens. Overall, between 24 and 37 of these markers revealed polymorphic for the investigated species and 23 markers amplified for all the 15 European cyprinid species.</p> <p>Conclusions</p> <p>The developed set of markers demonstrated its performance in discriminating European cyprinid species. Furthermore, it allowed detecting and characterizing hybrid individuals. These microsatellites will therefore be useful to perform comparative evolutionary and population genetics studies dealing with European cyprinids, what is of particular interest in conservation issues and constitutes a tool of choice to conduct hybridization studies.</p

Restauration morpho-dynamique et redynamisation de la section court-circuitée du Rhin en aval du barrage de Kembs (projet INTERREG / EDF)

National audienceThe Upper Rhine River has been heavily impacted by channelization for flood protection and navigation, and then by damming for hydropower generation. In normal non flooding conditions, most of the flows are diverted in a canalized section whereas the regulated “old Rhine” bypassed reach runs a minimum flow. Between Huningue and Neuf-Brisach, engineering works induced simplification and stabilization of the channel pattern from a formerly braiding sector to a single incised channel, hydrological modifications, bottom armouring due to bedload decrease, and thus ecological alterations. Two complementary and interdisciplinary projects have been initiated to restore alluvial morphodynamics: i) the international “INTERREG IV - Redynamisation of the old Rhine” project (2009-2012) coordinated by the Alsace region, France; ii) the left bank “controlled erosion” project launched by Electricité de France (EDF) within Kembs hydroelectric station relicensing process since 2003-2004. The purpose of these projects is to evaluate the feasibility of an important hydro-morphological and ecological restoration plan on a 45 km long reach, through both field testing of bank erosion techniques at favourable locations, and artificial sediments input from right bank excavations. This will help define possible long term prospective scenarios, in order to restore sustainable sediment transport, morphodynamics variability and associated ecological functions. The study will involve historical analysis, hydro-morphological / hydraulic physical and numerical modelling, physical and ecological monitoring, and sociological aspectsLe Rhin alsacien-allemand a enregistré de profondes modifications morphologiques et hydrologiques à la suite de sa correction et de sa régularisation pour la protection contre les crues et la navigation, puis après la construction de barrages hydro-électriques. Les aménagements réalisés entre Huningue et Neuf-Brisach ont engendré une simplification et une stabilisation du style fluvial. Un fleuve en tresses a cédé la place à un chenal unique incisé. Le fond de chenal est devenu pavé à cause d’une diminution des apports de charge de fond et des altérations écologiques ont été observées (simplification des habitats aquatiques et riverains). Deux projets complémentaires et interdisciplinaires ont été engagés afin de restaurer une dynamique des formes alluviales : i) le projet international INTERREG IV – Redynamisation du Vieux Rhin (2009-2012) sous l’impulsion de la région Alsace ; ii) le projet d’érosion maitrisée des berges de la rive gauche conduit par Electricité de France (EDF) dans le cadre du renouvellement de la concession de l’aménagement de Kembs. L’objectif des deux projets est de définir un plan de restauration hydro-morphologique et écologique conduisant à la redynamisation d’un tronçon de 45 km. L’étude repose sur une analyse historique, l’exploitation de modèles à la fois physiques et numériques, et les suivis morphologiques in situ d’une recharge artificielle en sédiments et d’érosions de berge contrôlées. Ces études de faisabilité sont complétées par des analyses écologique et sociologique pour apprécier l’impact socio-environnemental de ces projets

Moonraker -- Enceladus Multiple Flyby Mission

Enceladus, an icy moon of Saturn, possesses an internal water ocean and jets expelling ocean material into space. Cassini investigations indicated that the subsurface ocean could be a habitable environment having a complex interaction with the rocky core. Further investigation of the composition of the plume formed by the jets is necessary to fully understand the ocean, its potential habitability, and what it tells us about Enceladus' origin. Moonraker has been proposed as an ESA M-class mission designed to orbit Saturn and perform multiple flybys of Enceladus, focusing on traversals of the plume. The proposed Moonraker mission consists of an ESA-provided platform, with strong heritage from JUICE and Mars Sample Return, and carrying a suite of instruments dedicated to plume and surface analysis. The nominal Moonraker mission has a duration of 13.5 years. It includes a 23-flyby segment with 189 days allocated for the science phase, and can be expanded with additional segments if resources allow. The mission concept consists in investigating: i) the habitability conditions of present-day Enceladus and its internal ocean, ii) the mechanisms at play for the communication between the internal ocean and the surface of the South Polar Terrain, and iii) the formation conditions of the moon. Moonraker, thanks to state-of-the-art instruments representing a significant improvement over Cassini's payload, would quantify the abundance of key species in the plume, isotopic ratios, and physical parameters of the plume and the surface. Such a mission would pave the way for a possible future landed mission.Comment: Accepted for publication in The Planetary Science Journa

Moonraker: Enceladus Multiple Flyby Mission

Enceladus, an icy moon of Saturn, possesses an internal water ocean and jets expelling ocean material into space. Cassini investigations indicated that the subsurface ocean could be a habitable environment having a complex interaction with the rocky core. Further investigation of the composition of the plume formed by the jets is necessary to fully understand the ocean, its potential habitability, and what it tells us about Enceladus’s origin. Moonraker has been proposed as an ESA M-class mission designed to orbit Saturn and perform multiple flybys of Enceladus, focusing on traversals of the plume. The proposed Moonraker mission consists of an ESA-provided platform with strong heritage from JUICE and Mars Sample Return and carrying a suite of instruments dedicated to plume and surface analysis. The nominal Moonraker mission has a duration of ∼13.5 yr. It includes a 23-flyby segment with 189 days allocated for the science phase and can be expanded with additional segments if resources allow. The mission concept consists of investigating (i) the habitability conditions of present-day Enceladus and its internal ocean, (ii) the mechanisms at play for the communication between the internal ocean and the surface of the South Polar Terrain, and (iii) the formation conditions of the moon. Moonraker, thanks to state-of-the-art instruments representing a significant improvement over Cassini's payload, would quantify the abundance of key species in the plume, isotopic ratios, and the physical parameters of the plume and the surface. Such a mission would pave the way for a possible future landed mission

Antiretroviral-naive and -treated HIV-1 patients can harbour more resistant viruses in CSF than in plasma

Objectives The neurological disorders in HIV-1-infected patients remain prevalent. The HIV-1 resistance in plasma and CSF was compared in patients with neurological disorders in a multicentre study. Methods Blood and CSF samples were collected at time of neurological disorders for 244 patients. The viral loads were >50 copies/mL in both compartments and bulk genotypic tests were realized. Results On 244 patients, 89 and 155 were antiretroviral (ARV) naive and ARV treated, respectively. In ARV-naive patients, detection of mutations in CSF and not in plasma were reported for the reverse transcriptase (RT) gene in 2/89 patients (2.2%) and for the protease gene in 1/89 patients (1.1%). In ARV-treated patients, 19/152 (12.5%) patients had HIV-1 mutations only in the CSF for the RT gene and 30/151 (19.8%) for the protease gene. Two mutations appeared statistically more prevalent in the CSF than in plasma: M41L (P = 0.0455) and T215Y (P = 0.0455). Conclusions In most cases, resistance mutations were present and similar in both studied compartments. However, in 3.4% of ARV-naive and 8.8% of ARV-treated patients, the virus was more resistant in CSF than in plasma. These results support the need for genotypic resistance testing when lumbar puncture is performe

TRY plant trait database – enhanced coverage and open access

Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Moonraker: enceladus multiple flyby mission

Stars and planetary system