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See detailOrigin and immunoescape of uterine cervical cancer
Van hede, Dorien ULg; Langers, Inge ULg; DELVENNE, Philippe ULg et al

in Presse Médicale (2014)

Human papillomavirus associated uterine cervical cancer is an important public health problem since it is classified as the fourth most common cancer in women worldwide with more than 500 000 recorded ... [more ▼]

Human papillomavirus associated uterine cervical cancer is an important public health problem since it is classified as the fourth most common cancer in women worldwide with more than 500 000 recorded cases. This review is focused on where and why HPV infection induces cervical cancers and how this virus avoids the host immune response. Immunological therapeutic approaches are also addressed. [less ▲]

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See detailLe nouveau cadre d’action en matière de climat et d’énergie à l’horizon 2030
Habran, Maxime ULg

E-print/Working paper (2014)

Cette note a pour but de fournir un éclairage sur le nouveau cadre d'action européen en matière de climat et d'énergie

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See detailLes formations cambro-ordoviciennes du Massif de Stavelot et le conglomérat permien (Poudingue de Malmedy), sur les cartes Harzé- La Gleize et Stavelot - Malmedy.
Lamberty, Pauline ULg; Marion, Jean-Marc ULg

Diverse speeche and writing (2014)

Livret-guide de l'excursion réalisée dans le cadre du Programme* de Révision de la carte géologique de la Wallonie (*commandé par le SPW). La journée est dédiée aux formations cambriennes (Wanne, La Venne ... [more ▼]

Livret-guide de l'excursion réalisée dans le cadre du Programme* de Révision de la carte géologique de la Wallonie (*commandé par le SPW). La journée est dédiée aux formations cambriennes (Wanne, La Venne et La Gleize), ordoviciennes (Jalhay et Ottré), ainsi qu'aux dépôts conglomératiques permiens, connus sous le nom de "Poudingue de Malmedy" qui affleurent dans le Massif de Stavelot (localités de Trois-Ponts, Stavelot, Basse-Bodeux, Stoumont, ainsi que la vallée de la Lienne). [less ▲]

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See detailOccurence of Satellite RNAs associated with Cucumber mosaic virus isolated from banana (Musa sp.) in Ivory Coast
Kouadio, Kouakou Théodore; De Clerck, Caroline ULg; Agneroh, TA et al

in British Society for Plant Pathology - New Disease Reports (2014), 30

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See detailA Phylogenomic analysis of the origin of plastids
Cornet, Luc ULg; Javaux, Emmanuelle ULg; Wilmotte, Annick ULg et al

Conference (2014, November 03)

Cyanobacteria are a morphologically diverse phylum, with their first occurrence dating from the Precambrian. Oxygenic photosynthesis appeared in this group during the same geological period. Several ... [more ▼]

Cyanobacteria are a morphologically diverse phylum, with their first occurrence dating from the Precambrian. Oxygenic photosynthesis appeared in this group during the same geological period. Several publications have established, without any doubt, that plastids (both primary and complex) form a monophyletic ensemble emerging from Cyanobacteria. However, the exact position of plastids within Cyanobacteria is still uncertain, with several recent papers leading to very different hypotheses. Here we present a phylogenomic analysis of the origin of plastids. Our study takes advantage of all the available genomes and thus represents the best taxonomic sampling seen so far: 140 genomes of Cyanobacteria, 101 genomes of plastids and 27 outgroups taken in Melainabacteria and Chloroflexi. It esults in an analysis using state-of- the-art methods (e.g., orthology assessment using USEARCH and rthoMCL, phylogenetic inference using CAT and CAT-GTR models) based on more than 160 protein alignments totalizing over 20,000 unambiguously aligned amino acids. To confirm our results, we performed gene jackknife inferences and gene reconciliation analyses on the same dataset. We expect that out approach accounts for potential phylogenetic artefacts due to changes in the evolutionary process having occurred when the guest cyanobacterium became an endosymbiont and eventually a plastid. Meanwhile, we improve the phylogeny of Cyanobacteria per se, notably because of the presence of Melainabacteria in our dataset. [less ▲]

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See detailDisentangling the sources of phenotypic variation in Ambrosia artemisiifolia L.: the role of seed traits
Ortmans, William ULg; Monty, Arnaud ULg; Mahy, Grégory ULg

Poster (2014, November 03)

When invading new environments, a plant invader may express new phenotypes as a result of different ecological and genetic processes. It includes phenotypic plasticity, local adaptation, environmental ... [more ▼]

When invading new environments, a plant invader may express new phenotypes as a result of different ecological and genetic processes. It includes phenotypic plasticity, local adaptation, environmental maternal effects, and genetic drift. The quantification of each of these factors is crucial in the study of biological invasions. Ambrosia artemisiifolia L. invasion success is strongly linked to seed characteristics (dispersal by human activities, long-lived soil seed bank, etc.). Known as an opportunist and a colonizer, the species is often limited by the competition from other plants. In the early stages of development, the seedlings can be quickly outcompeted and a rapid growth is therefore a major advantage. First, this study aims to analyze the seed traits variation, and to detect an impact of these traits on the early development of the seedling (environmental maternal effect). Second, we aimed to quantify the respective role of phenotypic plasticity, environmental maternal effect, local adaptation and genetic drift on seedlings phenotype. Variability of seeds from 3 geographical zones (Belgium – Centre of France – South of France) was assessed. We measured the seed variation in mass, length, width, circularity, and pigmentation. Seeds were disposed in growth chamber under two temperature treatments. After two months, we compared seedling phenotypic variation in germination time, height, aboveground biomass, belowground biomass, early competitive performance, and the final leaf area. We found a high variability of seed traits. Seeds were varying significantly among zones, populations, and parents, with more than 30% of the variation attributable to the mother plant identity. The main sources of seedling phenotypic variation appeared to be phenotypic plasticity and environmental maternal effect. No genetic differentiation was detected in this study. Seed mass was positively correlated to seedling biomass, early competitive performance, and the final leaf area. The relevance of traits reflecting environmental maternal effect is discussed. Phenotypic plasticity and seed characteristics appear to play a major role in the invasion success. [less ▲]

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See detailSearching for faint companions with VLTI/PIONIER. II. 92 main sequence stars from the Exozodi survey
Marion, Lindsay ULg; Absil, Olivier ULg; Ertel, S. et al

in Astronomy and Astrophysics (2014), 570

Context. The Exozodi survey aims to determine the occurrence rate of bright exozodiacal discs around nearby main sequence stars using infrared interferometry. Although the Exozodi survey targets have been ... [more ▼]

Context. The Exozodi survey aims to determine the occurrence rate of bright exozodiacal discs around nearby main sequence stars using infrared interferometry. Although the Exozodi survey targets have been carefully selected to avoid the presence of binary stars, the results of this survey can still be biased by the presence of unidentified stellar companions. <BR /> Aims: Using the PIONIER data set collected within the Exozodi survey in 2012, we aim to search for the signature of point-like companions around the Exozodi target stars. <BR /> Methods: We make use of both the closure phases and squared visibilities collected by PIONIER to search for companions within the ~100 mas interferometric field of view. The presence of a companion is assessed by computing the goodness of fit to the data for a series of binary models with various separations and contrasts. <BR /> Results: Five stellar companions are resolved for the first time around five A-type stars: HD 4150, HD 16555, HD 29388, HD 202730, and HD 224392 (although the companion to HD 16555 was independently resolved by speckle interferometry while we were carrying out the survey). In the most likely case of main sequence companions, their spectral types range from A5V to K4V. Three of these stars were already suspected to be binaries from Hipparcos astrometric measurements, although no information was available on the companions themselves so far. In addition to debiasing the statistics of the Exozodi survey, these results can also be used to revise the fraction of visual binaries among A-type stars, suggesting that an extra ~13% A-type stars are visual binaries in addition to the ones detected in previous direct imaging surveys. <BR /> Conclusions: We estimate that about half the population of nearby A-type stars could be resolved as visual binaries using a combination of state-of-the-art interferometry and single-aperture imaging, and we suggest that a significant fraction of these binaries remains undetected to date. [less ▲]

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See detailA near-infrared interferometric survey of debris-disk stars. IV. An unbiased sample of 92 southern stars observed in H band with VLTI/PIONIER
Ertel, S.; Absil, Olivier ULg; Defrere, D. et al

in Astronomy and Astrophysics (2014), 570

Context. Detecting and characterizing circumstellar dust is a way to study the architecture and evolution of planetary systems. Cold dust in debris disks only traces the outer regions. Warm and hot ... [more ▼]

Context. Detecting and characterizing circumstellar dust is a way to study the architecture and evolution of planetary systems. Cold dust in debris disks only traces the outer regions. Warm and hot exozodiacal dust needs to be studied in order to trace regions close to the habitable zone. <BR /> Aims: We aim to determine the prevalence and to constrain the properties of hot exozodiacal dust around nearby main-sequence stars. <BR /> Methods: We searched a magnitude-limited (H <= 5) sample of 92 stars for bright exozodiacal dust using our VLTI visitor instrument PIONIER in the H band. We derived statistics of the detection rate with respect to parameters, such as the stellar spectral type and age or the presence of a debris disk in the outer regions of the systems. We derived more robust statistics by combining our sample with the results from our CHARA/FLUOR survey in the K band. In addition, our spectrally dispersed data allowed us to put constraints on the emission mechanism and the dust properties in the detected systems. <BR /> Results: We find an overall detection rate of bright exozodiacal dust in the H band of 11% (9 out of 85 targets) and three tentative detections. The detection rate decreases from early type to late type stars and increases with the age of the host star. We do not confirm the tentative correlation between the presence of cold and hot dust found in our earlier analysis of the FLUOR sample alone. Our spectrally dispersed data suggest that either the dust is extremely hot or the emission is dominated by the scattered light in most cases. The implications of our results for the target selection of future terrestrial planet-finding missions using direct imaging are discussed. [less ▲]

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See detailBiostratigraphic and chemostratigraphic constraints of the Mbuji-Mayi Supergroup (Meso-Neoproterozoic age), Democratic Republic of Congo.
Kabamba Baludikay, Blaise ULg; Bekker, Andrey; Baudet, Daniel et al

Conference (2014, November 03)

The Mbuji-Mayi Supergroup is a sedimentary sequence unaffected by regional metamorphism [1]. It was deposited between 1174 ± 22 Ma and ca. 800 Ma in the intracratonic failed-rift SMLL “Sankuru-Mbuji-Mayi ... [more ▼]

The Mbuji-Mayi Supergroup is a sedimentary sequence unaffected by regional metamorphism [1]. It was deposited between 1174 ± 22 Ma and ca. 800 Ma in the intracratonic failed-rift SMLL “Sankuru-Mbuji-Mayi- Lomami- Lovoy” basin [2] which extends from SE to NW between Katanga and Kasai Provinces. And overlies the Mesoproterozoic Kibaran Belt Supergroup (in the eastern part of SMLL basin) while in the Western part, where we focused our work, it rests unconformably upon Archean Dibaya Granitic Complex [3]. The amygdaloidal basaltic pillow lavas (948 ± 20 Ma) overlie the Mbuji-Mayi Supergroup, at the confluence of Mbuji-Mayi and Sankuru rivers [4]. Lithostratigraphically, this Supergroup consists in two distinct successions: a lower siliciclastic sequence (~500m) of BI Group and an upper carbonatic sequence (~1000m) with stromatolitic build-ups and black shales of BII Group [2]. Our own and previous sedimentological observations [5] indicate facies ranging from subtidal, low-energy stromatolitic environments to overlying intertidal to supratidal evaporitic settings of lagoon and sabkha. Here we present data on microfossil diversity and carbon isotope chemostratigraphy from the Kanshi, Lubi and Kafuku drillholes. The well-preserved and diverse assemblage of acritarchs and filamentous forms includes prokaryotes and eukaryotes, and is similar to other coeval assemblages described worldwide outside of Africa. The presence of the acanthomorph acritarch Trachyhystrichosphaera aimika is significant as it is indicative of the late Meso- to early Neoproterozoic age elsewhere, and is reported for the first time in Central Africa. So far, 56 species belonging to 31 genera were identified, dramatically increasing the previously reported diversity [6, 7]. Chemostratigraphy based on δ13Ccarb values for 290 samples, records, for the BI Group, predominantly negative values down to -8 to -9 ‰ VPDB with few samples having more positive, up to +3 ‰, values. Although the siliciclastics-rich sediments in the lower part of the BI Group likely record early diagenetic signal, carbonates in the upper part of the BI Group show similar patterns in both the Lubi and Kafuku drill cores with the sharp fall from +1 to +3 ‰ values to -8 to -7 ‰ and recovery back to +1 ‰ values over 40 to 70 m of section. The BII Group shows a less dramatic rise from -1 ‰ to +4 to +5 ‰ over more than 150 m of section. These large-scale variations differ from the steady-state carbon cycle of the late Mesoproterozoic [8] and are typical of the early Neoproterozoic record [9]. The project is supported by the EU FP7 ERC Stg ELITE. [less ▲]

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See detailEconomic Statistical Design of the VP( X) ̅ Control Charts for Monitoring a Process under Non-normality
Seif, Asghar; Faraz, Alireza ULg; Saniga, Erwin

in International Journal of Production Research (2014)

Recent studies proved that variable parameters (VP) X ̅ control charts not only detects process mean shifts quicker than the classical X ̅ control chart but also has better economic properties ... [more ▼]

Recent studies proved that variable parameters (VP) X ̅ control charts not only detects process mean shifts quicker than the classical X ̅ control chart but also has better economic properties. Furthermore, like most papers in control chart design, the fundamental assumption is that process data are normally distributed. Nevertheless, process quality variables may not be normal in application. In this paper, we investigate the economic statistical design of the VP X ̅ control chart when the underlying process distribution is non-normal. We illustrate the design procedure and perform a sensitivity analysis on the process and cost parameters based upon the degrees of skewness and kurtosis of the population using an industrial application. [less ▲]

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See detailTRAPPIST monitoring of comet C/2013 A1 (Siding Spring)
Opitom, Cyrielle ULg; Jehin, Emmanuel ULg; Manfroid, Jean ULg et al

in Bulletin of the American Astronomical Society (2014, November 01), 46

C/2013 A1 (Siding Spring) is a long period comet discovered by Robert H McNaught at Siding Spring Observatory in Australia on January 3, 2013 at 7.2 au from the Sun. This comet will make a close encounter ... [more ▼]

C/2013 A1 (Siding Spring) is a long period comet discovered by Robert H McNaught at Siding Spring Observatory in Australia on January 3, 2013 at 7.2 au from the Sun. This comet will make a close encounter with Mars on October 19, 2014. At this occasion the comet will be extensively observed both from Earth and from several orbiters around Mars.On September 20, 2013 when the comet was around 5 au from the Sun, we started a monitoring with the TRAPPIST robotic telescope installed at La Silla observatory [1]. A set of narrowband cometary filters designed by the NASA for the Hale-Bopp Observing Campaign [2] is permanently mounted on the telescope along with classic Johnson-Cousins B, V, Rc, and Ic filters.We observed the comet continuously at least once a week from September 20, 2013 to April 6, 2014 with broad band filters. We then recovered the comet on May 20. At this time we could detect the gas and started the observations with narrow band filters until early November, covering the close approach to Mars and the perihelion passage.We present here our first results about comet Siding Springs. From the images in the broad band filters and in the dust continuum filters we derived A(θ)fρ values [3] and studied the evolution of the comet activity with the heliocentric distance from September 20, 2013 to early November 2014. We could also detect gas since May 20, 2014. We thus derived gas production rates using a Haser model [4]. We present the evolution of gas production rates and gas production rates ratios with the heliocentric distance.Finally, we discuss the dust and gas coma morphology. [less ▲]

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See detailThe TRAPPIST comet survey in 2014
Jehin, Emmanuel ULg; Opitom, Cyrielle ULg; Manfroid, Jean ULg et al

in Bulletin of the American Astronomical Society (2014, November 01), 46

TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) is a 60-cm robotic telescope that has been installed in June 2010 at the ESO La Silla Observatory [1]. Operated from Liège (Belgium) it is ... [more ▼]

TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) is a 60-cm robotic telescope that has been installed in June 2010 at the ESO La Silla Observatory [1]. Operated from Liège (Belgium) it is devoted to the detection and characterisation of exoplanets and to the study of comets and other small bodies in the Solar System. A set of narrowband cometary filters designed by the NASA for the Hale-Bopp Observing Campaign [2] is permanently mounted on the telescope along with classic Johnson-Cousins filters. We describe here the hardware and the goals of the project. For relatively bright comets (V < 12) we measure several times a week the gaseous production rates (using a Haser model) and the spatial distribution of several species among which OH, NH, CN, C2 and C3 as well as ions like CO+. The dust production rates (Afrho) and color of the dust aredetermined through four dust continuum bands from the UV to the red (UC, BC, GC, RC filters). We will present the dust and gas production rates of the brightest comets observed in 2014: C/2012 K1 (PANSTARRS), C/2014 E2 (Jacques), C/2013 A1 (Siding Springs) and C/2013 V5 (Oukaimeden). Each of these comets have been observed at least once a week for several weeks to several months. Light curves with respect to the heliocentric distance will be presented and discussed. [1] Jehin et al., The Messenger, 145, 2-6, 2011.[2] Farnham et al., Icarus, 147, 180-204, 2000. [less ▲]

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See detailMagnetic fields in O stars
Nazé, Yaël ULg

in Mathys, Gauthier; Griffin, E.; Kochukhov, O. (Eds.) et al Putting A Stars into Context: Evolution, Environment, and Related Stars (2014, November 01)

During the last decade, large-scale, organized (generally dipolar) magnetic fields with strengths between 0.1 and 20 kG have been detected in dozens of OB stars. This contribution reviews the impact of ... [more ▼]

During the last decade, large-scale, organized (generally dipolar) magnetic fields with strengths between 0.1 and 20 kG have been detected in dozens of OB stars. This contribution reviews the impact of such fields on the stellar winds of O-type stars, with emphasis on variability and X-ray emission. [less ▲]

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See detailX-Ray Emission from Magnetic Massive Stars
Nazé, Yaël ULg; Petit, Véronique; Rinbrand, Melanie et al

in The Astrophysical Journal Supplement Series (2014), 215

Magnetically confined winds of early-type stars are expected to be sources of bright and hard X-rays. To clarify the systematics of the observed X-ray properties, we have analyzed a large series of ... [more ▼]

Magnetically confined winds of early-type stars are expected to be sources of bright and hard X-rays. To clarify the systematics of the observed X-ray properties, we have analyzed a large series of Chandra and XMM-Newton observations, corresponding to all available exposures of known massive magnetic stars (over 100 exposures covering ~60% of stars compiled in the catalog of Petit et al.). We show that the X-ray luminosity is strongly correlated with the stellar wind mass-loss rate, with a power-law form that is slightly steeper than linear for the majority of the less luminous, lower-{\dot{M}} B stars and flattens for the more luminous, higher-{\dot{M}} O stars. As the winds are radiatively driven, these scalings can be equivalently written as relations with the bolometric luminosity. The observed X-ray luminosities, and their trend with mass-loss rates, are well reproduced by new MHD models, although a few overluminous stars (mostly rapidly rotating objects) exist. No relation is found between other X-ray properties (plasma temperature, absorption) and stellar or magnetic parameters, contrary to expectations (e.g., higher temperature for stronger mass-loss rate). This suggests that the main driver for the plasma properties is different from the main determinant of the X-ray luminosity. Finally, variations of the X-ray hardnesses and luminosities, in phase with the stellar rotation period, are detected for some objects and they suggest that some temperature stratification exists in massive stars' magnetospheres. Based on data collected with XMM-Newton and Chandra. [less ▲]

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See detailLe langage et l’homme
Dubuisson, Francois ULg

in Bulletin d'Analyse Phénoménologique [En ligne] (2014), 10(11),

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See detailBuilding galaxies, stars, planets and the ingredients for life between the stars. The science behind the European Ultraviolet-Visible Observatory
Gómez de Castro, Ana I.; Appourchaux, Thierry; Barstow, Martin A. et al

in Astrophysics and Space Science (2014), 354

This contribution gathers the contents of the white paper submitted by the UV community to the Call issued by the European Space Agency in March 2013, for the definition of the L2 and L3 missions in the ... [more ▼]

This contribution gathers the contents of the white paper submitted by the UV community to the Call issued by the European Space Agency in March 2013, for the definition of the L2 and L3 missions in the ESA science program. We outlined the key science that a large UV facility would make possible and the instrumentation to be implemented. The growth of luminous structures and the building blocks of life in the Universe began as primordial gas was processed in stars and mixed at galactic scales. The mechanisms responsible for this development are not well-understood and have changed over the intervening 13 billion years. To follow the evolution of matter over cosmic time, it is necessary to study the strongest (resonance) transitions of the most abundant species in the Universe. Most of them are in the ultraviolet (UV; 950 Å-3000 Å) spectral range that is unobservable from the ground. A versatile space observatory with UV sensitivity a factor of 50-100 greater than existing facilities will revolutionize our understanding of the Universe. Habitable planets grow in protostellar discs under ultraviolet irradiation, a by-product of the star-disk interaction that drives the physical and chemical evolution of discs and young planetary systems. The electronic transitions of the most abundant molecules are pumped by this UV field, providing unique diagnostics of the planet-forming environment that cannot be accessed from the ground. Earth's atmosphere is in constant interaction with the interplanetary medium and the solar UV radiation field. A 50-100 times improvement in sensitivity would enable the observation of the key atmospheric ingredients of Earth-like exoplanets (carbon, oxygen, ozone), provide crucial input for models of biologically active worlds outside the solar system, and provide the phenomenological baseline to understand the Earth atmosphere in context. [less ▲]

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See detailJupiter’s polar auroral dynamics
Grodent, Denis ULg; Bonfond, Bertrand ULg

in AAS/Division for Planetary Sciences Meeting Abstracts (2014, November 01)

The morphology of Jupiter’s ultraviolet aurora is commonly described in terms of components located inside (poleward of) or outside (equatorward of) the main oval emission. These components may also be ... [more ▼]

The morphology of Jupiter’s ultraviolet aurora is commonly described in terms of components located inside (poleward of) or outside (equatorward of) the main oval emission. These components may also be discriminated by their temporal behaviour, where the narrowest parts of the main “oval” remain relatively stable over time periods of several hours, and the satellite footprints show large variability with timescales of minutes. Inside the main emission the so-called polar aurora, presumably corresponding to the polar cap mixing open and closed magnetic field lines, is characterized by rapid motions taking the form of swirls, giving rise to the “swirl region” and by intermittent brightenings in the “active region”. Coarse analysis of these motions suggests that they are too fast to respond to an equatorial magnetospheric forcing. Instead, they appear to be related to processes taking place in or above the ionosphere where distances travelled by plasma waves match those of the subtended auroral emission. Here, we present a preliminary improved analysis of the auroral motion in the polar region based on the application of an iterative “Advection Corrected Correlation Image Velocimetry” (ACCIV) method (Asay-Davis et al., 2009). This method allows one to build velocity fields quantifying local and overall auroral motions which may then be used to constrain their origin. [less ▲]

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