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See detailMars’ seasonal mesospheric transport seen through nitric oxide nightglow
Milby, Zachariah; Stiepen, Arnaud ULiege; Jain, Sonal et al

Conference (2017, October 01)

We analyze the ultraviolet nightglow in the atmosphere of Mars through nitric oxide (NO) δ and γ band emissions as observed by the Imaging UltraViolet Spectrograph (IUVS) instrument onboard the Mars ... [more ▼]

We analyze the ultraviolet nightglow in the atmosphere of Mars through nitric oxide (NO) δ and γ band emissions as observed by the Imaging UltraViolet Spectrograph (IUVS) instrument onboard the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft when it is at apoapse and periapse.In the dayside thermosphere of Mars, solar extreme-ultraviolet radiation dissociates CO[SUB]2[/SUB] and N[SUB]2[/SUB] molecules. O([SUP]3[/SUP]P) and N([SUP]4[/SUP]S) atoms are carried from the dayside to the nightside by the day-night hemispheric transport process, where they descend through the nightside mesosphere and can radiatively recombine to form NO(C[SUP]2[/SUP]Π). The excited molecules rapidly relax by emitting photons in the UV δ and γ bands. These emissions are indicators of the N and O atom fluxes from the dayside to Mars’ nightside and the descending circulation pattern from the nightside thermosphere to the mesosphere (e.g. Bertaux et al., 2005 ; Bougher et al., 1990 ; Cox et al., 2008 ; Gagné et al., 2013 ; Gérard et al., 2008 ; Stiepen et al., 2015, 2017).Observations of these emissions are gathered from a large dataset spanning different seasonal conditions.We present discussion on the variability in the brightness and altitude of the emission with season, geographical position (longitude), and local time, along with possible interpretation by local and global changes in the mesosphere dynamics. We show the possible impact of atmospheric waves forcing longitudinal variability and data-to-model comparisons indicating a wave-3 structure in Mars’ nightside mesosphere. Quantitative comparison with calculations of the Laboratoire de Météorologie Dynamique-Mars Global Climate Model (LMD-MGCM) suggests the model reproduces both the global trend of NO nightglow emission and its seasonal variation. However, it also indicates large discrepancies, with the emission up to a factor 50 times fainter in the model, suggesting that the predicted transport is too efficient toward the night winter pole in the thermosphere by ˜20° latitude to the north.These questions are now addressed through an extensive dataset of disk images, in complement to improved simulations of the LMD-MGCM and the Mars Global Ionosphere-Thermosphere Model (MGITM) models. [less ▲]

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See detailFirst Retrieval of Thermospheric Carbon Monoxide From Mars Dayglow Observations
Evans, J. Scott; Stevens, Michael H.; Jain, Sonal et al

Conference (2017, October 01)

As a minor species in the Martian thermosphere, Carbon Monoxide (CO) is a tracer that can be used to constrain changing circulation patterns between the lower thermosphere and upper mesosphere of Mars. By ... [more ▼]

As a minor species in the Martian thermosphere, Carbon Monoxide (CO) is a tracer that can be used to constrain changing circulation patterns between the lower thermosphere and upper mesosphere of Mars. By linking CO density distributions to dynamical wind patterns, the structure and variability of the atmosphere will be better understood. Direct measurements of CO can therefore provide insight into the magnitude and pattern of winds and provide a metric for studying the response of the atmosphere to solar forcing. In addition, CO measurements can help solve outstanding photochemical modeling problems in explaining the abundance of CO at Mars. CO is directly observable by electron impact excitation and solar resonance fluorescence emissions in the far-ultraviolet (FUV). The retrieval of CO from solar fluorescence was first proposed over 40 years ago, but has been elusive at Mars due to significant spectral blending. However, by simulating the spectral shape of each contributing emission feature, electron impact excitation and solar fluorescence brightnesses can be extracted from the composite spectrum using a multiple linear regression approach. We use CO Fourth Positive Group (4PG) molecular band emission observed on the limb (130 - 200 km) by the Imaging Ultraviolet Spectrograph (IUVS) on NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft over both northern and southern hemispheres from October 2014 to December 2016. We present the first direct retrieval of CO densities by FUV remote sensing in the upper atmosphere of Mars. Atmospheric composition is inferred using the terrestrial Atmospheric Ultraviolet Radiance Integrated Code adapted to the Martian atmosphere. We investigate the sensitivity of CO density retrievals to variability in solar irradiance, solar longitude, and local time. We compare our results to predictions from the Mars Global Ionosphere-Thermosphere Model as well as in situ measurements by the Neutral Gas and Ion Mass Spectrometer on MAVEN and quantify any differences. [less ▲]

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See detailMars topographic clouds: MAVEN/IUVS observations and LMD MGCM predictions
Schneider, Nicholas M.; Connour, Kyle; Forget, Francois et al

Conference (2017, October 01)

The Imaging Ultraviolet Spectrograph (IUVS) instrument on the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft takes mid-UV spectral images of the Martian atmosphere. From these apoapse disk ... [more ▼]

The Imaging Ultraviolet Spectrograph (IUVS) instrument on the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft takes mid-UV spectral images of the Martian atmosphere. From these apoapse disk images, information about clouds and aerosols can be retrieved and comprise the only MAVEN observations of topographic clouds and cloud morphologies. Measuring local time variability of large-scale recurring cloud features is made possible with MAVEN’s ~4.5-hour elliptical orbit, something not possible with sun-synchronous orbits. We have run the LMD MGCM (Mars global circulation model) at 1° x 1° resolution to simulate water ice cloud formation with inputs consistent with observing parameters and Mars seasons. Topographic clouds are observed to form daily during the late mornings of northern hemisphere spring and this phenomenon recurs until late summer (Ls = 160°), after which topographic clouds wane in thickness. By northern fall, most topographic clouds cease to form except over Arsia Mons and Pavonis Mons, where clouds can still be observed. Our data show moderate cloud formation over these regions as late as Ls = 220°, something difficult for the model to replicate. Previous studies have shown that models have trouble simulating equatorial cloud thickness in combination with a realistic amount of water vapor and not-too-thick polar water ice clouds, implying aspects of the water cycle are not fully understood. We present data/model comparisons as well as further refinements on parameter inputs based on IUVS observations. [less ▲]

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See detailFirst Detection of the Nitric Oxide Dayglow on Mars
Stevens, Michael H.; Siskind, David E.; Evans, J. Scott et al

Conference (2017, October 01)

Nitric oxide (NO) is a well-known indicator of solar and auroral activity in the terrestrial upper atmosphere. Direct measurements of NO on Mars can therefore constrain studies of energetic processes ... [more ▼]

Nitric oxide (NO) is a well-known indicator of solar and auroral activity in the terrestrial upper atmosphere. Direct measurements of NO on Mars can therefore constrain studies of energetic processes controlling the composition and structure of its upper atmosphere (80-200 km). Identifying and quantifying these processes is one of the science objectives of NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) mission currently orbiting Mars. NO can be observed directly by solar resonance fluorescence in the mid-ultraviolet (MUV). Indeed, this approach has routinely been used to measure terrestrial NO for 50 years. On Mars, this “dayglow” emission is very weak relative to other bright MUV features and thus has confounded attempts at its detection there for nearly the same amount of time. Here, we report the first detection of the NO dayglow in the Martian atmosphere using limb observations by the Imaging Ultraviolet Spectrograph (IUVS) on the MAVEN spacecraft. The detection is enabled by the spectral modeling and removal of the carbon monoxide Cameron bands, which dominate the MUV limb spectra. We focus on the spectral region between 213.0-225.5 nm, where three NO gamma bands emit. We will infer NO densities from the dayglow spectra and compare our observations with predictions from a photochemical model. We will discuss the implications, particularly in the context of previous in situ measurements. [less ▲]

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See detailOptical linear polarization measurements of quasars obtained with the 3.6 m telescope at the La Silla Observatory
Hutsemekers, Damien ULiege; Hall, P.; Sluse, Dominique ULiege

in Astronomy and Astrophysics (2017), 606

We report 192 previously unpublished optical linear polarization measurements of quasars obtained in April 2003, April 2007, and October 2007 with the European Southern Observatory Faint Object ... [more ▼]

We report 192 previously unpublished optical linear polarization measurements of quasars obtained in April 2003, April 2007, and October 2007 with the European Southern Observatory Faint Object Spectrograph and Camera (EFOSC2) instrument attached to the 3.6 m telescope at the La Silla Observatory. Each quasar was observed once. Among the 192 quasars, 89 have a polarization degree p ≥ 0.6%, 18 have p ≥ 2%, and two have p ≥ 10%. Based on observations made with the ESO 3.6 m Telescope at the La Silla Observatory under program ID 071.B-0460, 079.A-0625, 080.A-0017.Full Table 4 is only available at the CDS via anonymous ftp to <A href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A> (<A href="http://130.79.128.5">http://130.79.128.5</A>) or via <A href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/606/A101">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/606/A101</A> [less ▲]

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See detailIsotopic Ratios in a Peculiar Outbursting Comet
Yang, Bin; Hutsemekers, Damien ULiege; Shinnaka, Yoshiharu et al

in Bulletin of the American Astronomical Society (2017, October 01), 49

Isotopic ratios in comets provide keys for the understanding of the origin of cometary material, and the physical and chemical conditions in the early Solar Nebula. A newly discovered peculiar comet, C ... [more ▼]

Isotopic ratios in comets provide keys for the understanding of the origin of cometary material, and the physical and chemical conditions in the early Solar Nebula. A newly discovered peculiar comet, C/2015 ER61, underwent an outburst with a total brightness increase of 2 magnitudes on the night of April 4th, 2017. The sharp increase in brightness offers a rare opportunity to measure the isotopic ratios of the light elements of this comet. We obtained two high-resolution spectra of C/2015 ER61 with UVES on Apr. 13 and Apr. 17 respectively. At the time of our observations, the comet was fading gradually since the outburst. We measured the 12C/13C and 14N/15N isotopic ratios from the CN Violet (0,0) band. In addition, we determined the 14N/15N ratio in NH2 for C/2015 ER61 from four pairs of NH2 isotopologue lines. Some 18OH lines were detected but the S/N of these lines is too low to derive a reliable 18O/16O estimate. We will present our UVES spectra of C/2015 ER61, obtained shortly after the outburst. We will also present the comparison of the Isotopic ratios of C/2015 ER61 with those of other comets. [less ▲]

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See detailRAPPORT SUR L’ÉGALITÉ ENTRE LES FEMMES ET LES HOMMES À L’UNIVERSITÉ DE LIÈGE 2017 - rapport genre 2017
Cornet, Annie ULiege

E-print/Working paper (2017)

this report present the statistical data of University de Liège (student and personal) for the year 2016-2017. Similar report in 2016 and 2014.

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See detailA model-based approach to characterize individual inbreeding at both global and local genomic scales.
Druet, Tom ULiege; Gautier, M.

in Molecular Ecology (2017), 26

Inbreeding results from the mating of related individuals and may be associated with reduced fitness because it brings together deleterious variants in one individual. In general, inbreeding is estimated ... [more ▼]

Inbreeding results from the mating of related individuals and may be associated with reduced fitness because it brings together deleterious variants in one individual. In general, inbreeding is estimated with respect to an arbitrary base population consisting of ancestors that are assumed unrelated. We herein propose a model-based approach to estimate and characterize individual inbreeding at both global and local genomic scales by assuming the individual genome is a mosaic of homozygous-by-descent (HBD) and non-HBD segments. The HBD segments may originate from ancestors tracing back to different periods in the past defining distinct age-related classes. The lengths of the HBD segments are exponentially distributed with class-specific parameters reflecting that inbreeding of older origin generates on average shorter stretches of observed homozygous markers. The model is implemented in a hidden Markov model framework that uses marker allele frequencies, genetic distances, genotyping error rates and the sequences of observed genotypes. Note that genotyping errors, low-fold sequencing or genotype-by-sequencing data are easily accommodated under this framework. Based on simulations under the inference model, we show that the genomewide inbreeding coefficients and the parameters of the model are accurately estimated. In addition, when several inbreeding classes are simulated, the model captures them if their ages are sufficiently different. Complementary analyses, either on data sets simulated under more realistic models or on human, dog and sheep real data, illustrate the range of applications of the approach and how it can reveal recent demographic histories among populations (e.g., very recent bottlenecks or founder effects). The method also allows to clearly identify individuals resulting from extreme consanguineous matings. [less ▲]

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See detailHera
Pirenne-Delforge, Vinciane ULiege; Pironti, Gabriella

in Oxford Classical Dictionary (2017)

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See detailQuestions choisies de droit des sociétés (2012-2017)
Caprasse, Olivier ULiege; Aydogdu, Roman ULiege; Léonard, Laura ULiege

in Chroniques notariales (2017)

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See detailRevue de la littérature sur les effets de la compression externe dynamique péristaltique type Normatec sur la récupération sportive
Kabore, Christophe; Kaux, Jean-François ULiege

in Science & Sports (2017), 32(5), 266-277

Aims. — Recently, several studies have emerged to evaluate the effects on sports recovery of theperistaltic dynamic pneumatic external compression device developed at Newton Center, MA,USA and marketed as ... [more ▼]

Aims. — Recently, several studies have emerged to evaluate the effects on sports recovery of theperistaltic dynamic pneumatic external compression device developed at Newton Center, MA,USA and marketed as the Normatec Pulse Recovery System, with an increased use recently inthe professional and recreational sports communities. Our objective in this review is to evaluatethe effects of Normatec on performance and sports recovery by reviewing the studies publishedto date.News. — We carried out a literature search from 1st July 2016 to 31st October 2016 on theMedline database via PubMed, Scopus and the Cochrane Central Register of Controlled Trials viaOvid, at the end of which we retained for this review the comparative studies between Normatecand placebo, between Normatec and another sports recovery techniques as well as experimentalcontrolled trials, with no restriction on sex and level of training of the participants. All studieswere conducted on healthy subjects aged 18 to 40 years. There were 67 men and 61 women fora total of 128 participants. The selected studies were heterogeneous concerning the modalitiesof exercise before treatment by Normatec, as well as the duration of treatment by Normatec.No adverse effects have been described in the studies included in this review, but without anyspecific control described regarding the potential adverse effects.Conclusion. — Current investigations concerning the sport recovery method using the Normatecdevice have shown a favorable influence on blood lactate clearance, peripheral vascular reac-tivity, post-exercise muscle pain and motion amplitude. However, it does not bring significantgain interest compared to other methods of sport recovery that are cheaper, easier to accessand currently better studied, which must be known by athletes of all levels. However, theseinvestigations provide some insights into the mechanisms underlying the positive effects of thismode of treatment and pave the way for further studies that will contribute to the scientificvalidation of the method of sports recovery by Normatec. [less ▲]

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See detailTravail et subjectivité : la conservation de l’ours brun pour métier.
Denayer, Dorothée ULiege; Collard, Damien

in Travailler : Revue Internationale de Psychopathologie et de Psychodynamique du Travail (2017)

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See detailSurveillance de l'atmosphère terrestre depuis la station du Jungfraujoch : une épopée liégeoise entamée voici plus de 65 ans !
Mahieu, Emmanuel ULiege; Bader, Whitney ULiege; Bovy, Benoît ULiege et al

in Bulletin de la Société Géographique de Liège (2017), 68

It’s in the early 1950s that researchers from the University of Liège started to investigate the Earth’s atmosphere from the Jungfraujoch scientific station, in the Swiss Alps, at a time when concerns ... [more ▼]

It’s in the early 1950s that researchers from the University of Liège started to investigate the Earth’s atmosphere from the Jungfraujoch scientific station, in the Swiss Alps, at a time when concerns related to atmospheric composition changes were nonexistent. Since then, an infrared observational data base unique worldwide has been carefully collected. The exploitation of these observations has allowed constituting multi-decadal time series crucial for the characterization of the changes that affected our atmosphere and for the identification of their causes. In this paper, we first remind about the successive steps which led to establishing the observational program of the Liège team at the Jungfraujoch and we evoke important findings which justified its continuation. Then we present some recent results relevant to the Montreal and Kyoto Protocols, or related to the monitoring of air quality. [less ▲]

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See detailUnderwater world: the end of the myth
Parmentier, Eric ULiege

Conference (2017, October)

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See detailRecent Evolutions and Trends in the Use of Computer Aided Chemical Engineering for Educational Purposes at the University of Liège
Léonard, Grégoire ULiege; Belboom, Sandra ULiege; Toye, Dominique ULiege et al

in Computer Aided Chemical Engineering (2017)

The present paper addresses the evolution and perspectives in the teaching of CAPE methods in the Department of Chemical Engineering at the University of Liège. The transition that happened in the 90ies ... [more ▼]

The present paper addresses the evolution and perspectives in the teaching of CAPE methods in the Department of Chemical Engineering at the University of Liège. The transition that happened in the 90ies with the arrival of commercial software is highlighted, as the learning outcomes evolved from the ability of building programs to solve chemical engineering problems towards the ability to use complex commercial software and to understand their limitations. Moreover, CAPE methods were extended to non-dedicated CAPE courses, which is illustrated here by the goals and challenges of their use in courses like “Reactor Engineering” and “Life Cycle Analysis”. It was observed that students sometimes assume that CAPE softwares provide straightforward and trustworthy solutions without the need of understanding their mathematical bases and assumptions. Thus, solutions to make students aware of these limitations are proposed, including the creation of an integrated project focussing on complex multi-disciplinary issues, evidencing the need for critical input from the operator. [less ▲]

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See detailHighlights from the Organic and Biological Analytical Chemistry Group (OBiAChem)
Focant, Jean-François ULiege

Scientific conference (2017, October)

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See detailSoil Microbial Properties and Nutrients Content Under Exotic and Native Tree Species in Southern Rwanda
Rwibasira, Peter; Naramabuye, François Xavier; Nsabimana, Donat et al

Conference (2017, October)

Detailed reference viewed: 8 (1 ULiège)
See detailThe role of soil microbial diversity and activity in ecosystem functioning
Carnol, Monique ULiege

Conference (2017, October)

Soil microorganisms and soil organic matter availability regulate soil quality and fertility. Through their activity in biogeochemical cycling processes, soil microorganisms decompose soil organic matter ... [more ▼]

Soil microorganisms and soil organic matter availability regulate soil quality and fertility. Through their activity in biogeochemical cycling processes, soil microorganisms decompose soil organic matter and thus regulate nutrient availability and primary production. Landuse changes, such as a shift from forest to agricultural land, as well as a change in tree species composition, can modify microbial diversity and activity and consequently ecosystem funcitoning. Some parameters can be used as biological indicators, relating land use management to soil functioning and ecosystem services. New molecular tools allow now an in-depth investigation of the role of soil microbial diversity in ecosystem functioning. I will adress biogeochemical cycling processes and their relation to ecosystem functioning, with particular emphasis on forest ecosystems. Examples will be drawn from recent research projects investigating the links between tree species, tree species diversity, and soil microbial biomass, diversity and activity in temperate and tropical forests. [less ▲]

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See detailPrise en charge des tendinopathies en pratique générale
Sauvant, Céline; Kaux, Jean-François ULiege

in La Revue de la Médecine Générale (2017), 346

Tendinopathies can develop in several stages. Different therapeutic means are at our disposal. The continuum model, proposed by Cook and Purdam, provides an understanding of pathophysiology and adapts the ... [more ▼]

Tendinopathies can develop in several stages. Different therapeutic means are at our disposal. The continuum model, proposed by Cook and Purdam, provides an understanding of pathophysiology and adapts the therapeutic strategy to achieve optimal recovery and limitation of recurrences. [less ▲]

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See detailFish habitat selection in a large hydropeaking river: Strong individual and temporal variations revealed by telemetry
Capra, Hervé; Plichard, Laura; Bergé, Julien et al

in Science of the Total Environment (2017), 578

Modeling individual fish habitat selection in highly variable environments such as hydropeaking rivers is required for guiding efficient management decisions. We analyzed fish microhabitat selection in ... [more ▼]

Modeling individual fish habitat selection in highly variable environments such as hydropeaking rivers is required for guiding efficient management decisions. We analyzed fish microhabitat selection in the heterogeneous hydraulic and thermal conditions (modeled in two-dimensions) of a reach of the large hydropeaking Rhône River locally warmed by the cooling system of a nuclear power plant. We used modern fixed acoustic telemetry techniques to survey 18 fish individuals (five barbels, six catfishes, seven chubs) signaling their position every 3 s over a three-month period. Fish habitat selection depended on combinations of current microhabitat hydraulics (e.g. velocity, depth), past microhabitat hydraulics (e.g. dewatering risk or maximum velocities during the past 15 days) and to a lesser extent substrate and temperature. Mixed-effects habitat selection models indicated that individual effects were often stronger than specific effects. In the Rhône, fish individuals appear to memorize spatial and temporal environmental changes and to adopt a “least constraining” habitat selection. Avoiding fast-flowing midstream habitats, fish generally live along the banks in areas where the dewatering risk is high. When discharge decreases, however, they select higher velocities but avoid both dewatering areas and very fast-flowing midstream habitats. Although consistent with the available knowledge on static fish habitat selection, our quantitative results demonstrate temporal variations in habitat selection, depending on individual behavior and environmental history. Their generality could be further tested using comparative experiments in different environmental configurations. [less ▲]

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