Last 7 days     Results 1821-1840 of 44021.   87 88 89 90 91 92 93 94 95 96 97   Alternatives to traditional valorisation ways for brewer’s spent grainsVillani, Nicolas ; Aguedo, Mario ; Richel, Aurore Poster (2015, August 05)Brewer’s Spent Grains (BSG) are a highly available and cheap food supply chain waste (FSCW) that is mainly used in low-valued feed applications. This residue represents around 85 % of the total amount of ... [more ▼]Brewer’s Spent Grains (BSG) are a highly available and cheap food supply chain waste (FSCW) that is mainly used in low-valued feed applications. This residue represents around 85 % of the total amount of waste produced by breweries with an annual tonnage of 3.4 million tons (on a dry basis) in the European Union. Based on its composition, BSG could be valorised in a wide variety of value-added products. For example, cellulose and remaining starch could easily be turned into ethanol or used as solid state fermentation media or as platform molecules for further chemical synthesis. These alternative valorisation ways could lead to an important economic relief through the whole brewery industry. Herein is described a multistep fractionation of BSG into cellulosic pulp, free sugars, proteins, germs and lignin using an Organosolv acidic pretreatment. This extraction procedure has been optimised in order to allow the most efficient and complete valorisation of BSG. [less ▲]Detailed reference viewed: 92 (10 ULg) Evidence of a fine-scale genetic structure for the endangered Pyrenean desman (Galemys pyrenaicus) in the French PyreneesGillet, François ; Cabria Garrido, Maria Teresa; Blanc, Frédéric et alPoster (2015, August 05)Detailed reference viewed: 27 (0 ULg) Jouer avec les mots, pourquoi et comment ?Rigo, Michel Scientific conference (2015, August 04)A l'instar de Raymond Queneau et ses cent mille milliards de poèmes, cet exposé a pour but de compter et de construire des mots aux propriétés parfois surprenantes. Les premiers résultats en combinatoire ... [more ▼]A l'instar de Raymond Queneau et ses cent mille milliards de poèmes, cet exposé a pour but de compter et de construire des mots aux propriétés parfois surprenantes. Les premiers résultats en combinatoire des mots remontent au début du siècle précédent, avec les travaux du mathématicien norvégien Axel Thue. Cette branche des mathématiques étudie la structure et les arrangements apparaissant au sein de suites finies, ou infinies, de symboles appartenant à un ensemble fini. Donnons un exemple rudimentaire. Un carré est la juxtaposition de deux répétitions d'un mot, ainsi "coco" ou "bonbon" sont des carrés. On dira alors qu'un mot comme "taratata" contient un carré. Il est aisé de vérifier que, si on dispose uniquement de deux symboles "a" et "b", alors tout mot de longueur au moins 4 contient un des carrés "aa", "bb", "abab" ou encore "baba". On dira donc que, sur deux symboles, les carrés sont inévitables. Cette observation pose des questions intéressantes et simples à formuler : Avec trois symboles, peut-on construire un mot arbitrairement long ne contenant pas de carré ? Si on se limite à deux symboles, peut-on construire un mot arbitrairement long sans cube, i.e., évitant la juxtaposition de trois répétitions d'un même mot ? En fonction de la taille de l'alphabet, quels motifs doivent nécessairement apparaître et quels sont ceux qui sont évitables ? Que se passe-t-il si on autorise certaines permutations ? etc. Dans cet exposé, on passera en revue quelques constructions simples de mots finis ou infinis : mot de Thue-Morse, mot de Fibonacci, mots Sturmiens. Nous montrerons aussi que les applications sont nombreuses : arithmétique, transcendance en théorie des nombres, informatique mathématique et théorie des automates, pavages du plan, dynamique symbolique et codage de rotations, infographie, géométrie discrète et représentation de segment de droites à l'écran, bio-informatique, ... [less ▲]Detailed reference viewed: 57 (9 ULg) Quadratic reformulations of nonlinear binary optimization problemsAnthony, Martin; Boros, Endre; Crama, Yves et alE-print/Working paper (2015)Very large nonlinear unconstrained binary optimization problems arise in a broad array of applications. Several exact or heuristic techniques have proved quite successful for solving many of these ... [more ▼]Very large nonlinear unconstrained binary optimization problems arise in a broad array of applications. Several exact or heuristic techniques have proved quite successful for solving many of these problems when the objective function is a quadratic polynomial. However, no similarly efficient methods are available for the higher degree case. Since high degree objectives are becoming increasingly important in certain application areas, such as computer vision, various techniques have been recently developed to reduce the general case to the quadratic one, at the cost of increasing the number of variables. In this paper we initiate a systematic study of these quadratization approaches. We provide tight lower and upper bounds on the number of auxiliary variables needed in the worst-case for general objective functions, for bounded-degree functions, and for a restricted class of quadratizations. Our upper bounds are constructive, thus yielding new quadratization procedures. Finally, we completely characterize all minimal'' quadratizations of negative monomials. [less ▲]Detailed reference viewed: 63 (4 ULg) A next-generation approach to assess the cyanobacterial diversity and biogeography in the High Arctic (Svalbard)Laughinghouse, Haywood Dail; Stelmach Pessi, Igor ; Velazquez, David et alPoster (2015, August 03)Polar ecosystems are extremely sensitive to global climate changes and human activities. Cyanobacteria are key photosynthetic organisms in these latitudes, due to their roles in soil aggregation, nitrogen ... [more ▼]Polar ecosystems are extremely sensitive to global climate changes and human activities. Cyanobacteria are key photosynthetic organisms in these latitudes, due to their roles in soil aggregation, nitrogen fixation, carbon cycles, and secondary metabolite production, among others. Previous works indicate that different cyanobacterial taxa/communities have different impacts on the environment, in both biogeochemical cycles and bioactive compound productions. Furthermore, the presence of biogeographical patterns in microorganisms, as found in macroorganisms, is an ongoing debate. In this study, during the 2013 MicroFun expedition, we sampled 72 locations around Svalbard including diverse biotopes such as glacial forefields, tundra soils, hot springs, soil crusts, microbial mats, wet walls, cryoconites, plankton and periphyton, in order to (1) assess the biodiversity of cyanobacteria around Svalbard, (2) verify the existence of biogeographical trends around the archipelago, and (3) compare these data with other polar (cold) areas, especially Antarctica. We used a pyrosequencing approach targeting cyanobacteria-specific 16S rRNA gene sequences to deeply study the cyanobacterial communities. [less ▲]Detailed reference viewed: 53 (0 ULg) Development of cryopreservation methods for long-term preservation of cyanobacterial strains in the BCCM/ULC collectionCrahay, Charlotte ; Renard, Marine ; Mari, Maud et alPoster (2015, August 03)Long-term genetic and functional stability is a fundamental requirement for the maintenance of microorganisms and cryopreservation is the preferred method for the long-term storage of many micro-organisms ... [more ▼]Long-term genetic and functional stability is a fundamental requirement for the maintenance of microorganisms and cryopreservation is the preferred method for the long-term storage of many micro-organisms, including cyanobacteria. The BCCM/ULC collection currently holds 200 cyanobacterial strains, but only 62 are cryo-preserved. The main limiting factors are the low levels of survival of some strains and the long periods required to recover from cryopreservation, and thus the inability to deliver rapidly cryopreserved strains to the user community. The devel-opment of improved cryopreservation protocols is therefore required for the future expansion and valorization of the collection. The BRAIN-be project PRESPHOTO (preservation of photosynthetic micro-algae in the BCCM collections) (www.presphoto.ulg.ac.be) aims to improve the preservation of cyanobacterial and diatoms in the BCCM/ULC and BCCM/DCG collections, respectively. [less ▲]Detailed reference viewed: 33 (2 ULg) The BCCM/ULC collection : a Biological Ressource Center for polar cyanobacteriaWilmotte, Annick ; Renard, Marine ; Lara, Yannick et alPoster (2015, August 03)In this study, during the 2013 MicroFun expedition, we sampled 72 locations around Svalbard including diverse biotopes such as glacial forefields, tundra soils, hot springs, soil crusts, microbial mats ... [more ▼]In this study, during the 2013 MicroFun expedition, we sampled 72 locations around Svalbard including diverse biotopes such as glacial forefields, tundra soils, hot springs, soil crusts, microbial mats, wet walls, cryoconites, plankton and periphyton, in order to (1) assess the biodiversity of cyanobacteria around Svalbard, (2) verify the existence of biogeographical trends around the archipelago, and (3) compare these data with other polar (cold) areas, especially Antarctica. We used a pyrosequencing approach targeting cyanobacteria-specific 16S rRNA gene sequences to deeply study the cyanobacterial communities. [less ▲]Detailed reference viewed: 17 (1 ULg) Genome sequencing of an endemic filamentous Antarctic cyanobacteriumLara, Yannick ; Verlaine, Olivier ; Kleinteich, Julia et alPoster (2015, August 03)The strain Phormidium priestleyi ULC007 was isolated from a benthic mat located in a shallow freshwater pond in the Larsemann Hills (69°S), Western Antarctica. This strain belongs to a cyanobacterial ... [more ▼]The strain Phormidium priestleyi ULC007 was isolated from a benthic mat located in a shallow freshwater pond in the Larsemann Hills (69°S), Western Antarctica. This strain belongs to a cyanobacterial cluster that appeared as potentially endemic (Taton et al. 2006). After obtaining an axenic isolate, we sequenced the genome of this strain in the frame of the BELSPO CCAMBIO project, in order to better understand the functioning, metabolism and adaptative strategies of cyanobacteria to the extreme Antarctic environment. [less ▲]Detailed reference viewed: 30 (4 ULg) Contribution of cyanobacteria to the building of travertines in a calcareous streamWilmotte, Annick ; Golubic, Stjepko; Kleinteich, Julia et alPoster (2015, August 03)The ambient temperature travertine deposits of the calcareous Hoyoux River (Modave, Belgium) and several tributaries are organized and promoted by the filamentous cyanobacterium identified by its ... [more ▼]The ambient temperature travertine deposits of the calcareous Hoyoux River (Modave, Belgium) and several tributaries are organized and promoted by the filamentous cyanobacterium identified by its morphotype and ecological properties as Phormidium cf. incrustatum. A combination of techniques was used to study this biotope: physico-chemical parameters and CO2 measurements, Scanning and Transmission Electron Microscopy, RAMAN microspectroscopy. A molecular diversity study with pyrosequencing of the cyanobacterial 16S rRNA is in progress. A potential candidate was isolated in culture. [less ▲]Detailed reference viewed: 33 (1 ULg) A propos des fonctions continues qui ne sont dérivables en aucun pointEsser, Céline Conference (2015, August 03)En 1872, Karl Weierstrass présenta non seulement une, mais toute une famille de fonctions continues et nulle part dérivables. Après la publication de ce résultat, beaucoup d'autres mathématiciens ... [more ▼]En 1872, Karl Weierstrass présenta non seulement une, mais toute une famille de fonctions continues et nulle part dérivables. Après la publication de ce résultat, beaucoup d'autres mathématiciens apportèrent leur propre contribution en construisant d'autres fonctions continues et nulle part dérivables. Dans cet exposé, nous présenterons les fonctions de Weierstrass et nous montrerons que le théorème de Baire permet d'affirmer que l'ensemble des fonctions nulle part dérivables est dense dans l'ensemble des fonctions continues. Nous étudierons également la régularité ponctuelle des fonctions de Weierstrass en introduisant la notion d'exposant de Hölder. [less ▲]Detailed reference viewed: 31 (6 ULg) Time series of high-resolution spectra of SN 2014J observed with the TIGRE telescopeJack, D.; Mittag, M.; Schröder, K.-P. et alin Monthly Notices of the Royal Astronomical Society (2015), 451We present a time series of high-resolution spectra of the Type Ia supernova 2014J, which exploded in the nearby galaxy M82. The spectra were obtained with the HEROS échelle spectrograph installed at the ... [more ▼]We present a time series of high-resolution spectra of the Type Ia supernova 2014J, which exploded in the nearby galaxy M82. The spectra were obtained with the HEROS échelle spectrograph installed at the 1.2-m TIGRE telescope. We present a series of 33 spectra with a resolution of R ≈ 20 000, which covers the important bright phases in the evolution of SN 2014J during the period from 2014 January 24 to April 1. The spectral evolution of SN 2014J is derived empirically. The expansion velocities of the Si II P-Cygni features were measured and show the expected decreasing behaviour, beginning with a high velocity of 14 000 km s[SUP]-1[/SUP] on January 24. The Ca II infrared triplet feature shows a high-velocity component with expansion velocities of >20 000 km s[SUP]-1[/SUP] during the early evolution apart from the normal component showing similar velocities as Si II. Further broad P-Cygni profiles are exhibited by the principal lines of Ca II, Mg II and Fe II. The TIGRE SN 2014J spectra also resolve several very sharp Na I D doublet absorption components. Our analysis suggests interesting substructures in the interstellar medium of the host galaxy M82, as well as in our Milky Way, confirming other work on this SN. We were able to identify the interstellar absorption of M82 in the lines of Ca II H & K at 3933 and 3968 Å as well as K I at 7664 and 7698 Å. Furthermore, we confirm several diffuse interstellar bands, at wavelengths of 6196, 6283, 6376, 6379and 6613 Å and give their measured equivalent widths. [less ▲]Detailed reference viewed: 15 (0 ULg) A Coordinated X-Ray and Optical Campaign of the Nearest Massive Eclipsing Binary, δ Orionis Aa. II. X-Ray VariabilityNichols, J.; Huenemoerder, D. P.; Corcoran, M. F. et alin Astrophysical Journal (2015), 809We present time-resolved and phase-resolved variability studies of an extensive X-ray high-resolution spectral data set of the δ Ori Aa binary system. The four observations, obtained with Chandra ACIS ... [more ▼]We present time-resolved and phase-resolved variability studies of an extensive X-ray high-resolution spectral data set of the δ Ori Aa binary system. The four observations, obtained with Chandra ACIS HETGS, have a total exposure time of ≈ 479 ks and provide nearly complete binary phase coverage. Variability of the total X-ray flux in the range of 5–25 Å is confirmed, with a maximum amplitude of about ±15% within a single ≈ 125 ks observation. Periods of 4.76 and 2.04 days are found in the total X-ray flux, as well as an apparent overall increase in the flux level throughout the nine-day observational campaign. Using 40 ks contiguous spectra derived from the original observations, we investigate the variability of emission line parameters and ratios. Several emission lines are shown to be variable, including S xv, Si xiii, and Ne ix. For the first time, variations of the X-ray emission line widths as a function of the binary phase are found in a binary system, with the smallest widths at ϕ = 0.0 when the secondary δ Ori Aa2 is at the inferior conjunction. Using 3D hydrodynamic modeling of the interacting winds, we relate the emission line width variability to the presence of a wind cavity created by a wind–wind collision, which is effectively void of embedded wind shocks and is carved out of the X-ray-producing primary wind, thus producing phase-locked X-ray variability. Based on data from the Chandra X-ray Observatory and the MOST satellite, a Canadian Space Agency mission, jointly operated by Dynacon Inc., the University of Toronto Institute of Aerospace Studies, and the University of British Columbia, with the assistance of the University of Vienna. [less ▲]Detailed reference viewed: 24 (1 ULg) A Coordinated X-Ray and Optical Campaign of the Nearest Massive Eclipsing Binary, δ Orionis Aa. IV. A Multiwavelength, Non-LTE Spectroscopic AnalysisShenar, T.; Oskinova, L.; Hamann, W.-R. et alin Astrophysical Journal (2015), 809Eclipsing systems of massive stars allow one to explore the properties of their components in great detail. We perform a multi-wavelength, non-LTE analysis of the three components of the massive multiple ... [more ▼]Eclipsing systems of massive stars allow one to explore the properties of their components in great detail. We perform a multi-wavelength, non-LTE analysis of the three components of the massive multiple system δ Ori A, focusing on the fundamental stellar properties, stellar winds, and X-ray characteristics of the system. The primary’s distance-independent parameters turn out to be characteristic for its spectral type (O9.5 II), but usage of the Hipparcos parallax yields surprisingly low values for the mass, radius, and luminosity. Consistent values follow only if δ Ori lies at about twice the Hipparcos distance, in the vicinity of the σ-Orionis cluster. The primary and tertiary dominate the spectrum and leave the secondary only marginally detectable. We estimate the V-band magnitude difference between primary and secondary to be {{Δ }}V≈ 2\buildrel{{m}}\over{.} 8. The inferred parameters suggest that the secondary is an early B-type dwarf (≈B1 V), while the tertiary is an early B-type subgiant (≈B0 IV). We find evidence for rapid turbulent velocities (∼200 km s[SUP]‑1[/SUP]) and wind inhomogeneities, partially optically thick, in the primary’s wind. The bulk of the X-ray emission likely emerges from the primary’s stellar wind ({log}{L}[SUB]{{X[/SUB]}}/{L}[SUB]{Bol[/SUB]}≈ -6.85), initiating close to the stellar surface at {R}[SUB]0[/SUB]∼ 1.1 {R}[SUB]*[/SUB]. Accounting for clumping, the mass-loss rate of the primary is found to be {log}\dot{M}≈ -6.4 ({M}[SUB]ȯ [/SUB] {{yr}}[SUP]-1[/SUP]), which agrees with hydrodynamic predictions, and provides a consistent picture along the X-ray, UV, optical, and radio spectral domains. [less ▲]Detailed reference viewed: 14 (1 ULg) A Coordinated X-Ray and Optical Campaign of the Nearest Massive Eclipsing Binary, δ Orionis Aa. I. Overview of the X-Ray SpectrumCorcoran, M. F.; Nichols, J. S.; Pablo, H. et alin The Astrophysical Journal (2015), 809We present an overview of four deep phase-constrained Chandra HETGS X-ray observations of δ Ori A. Delta Ori A is actually a triple system that includes the nearest massive eclipsing spectroscopic binary ... [more ▼]We present an overview of four deep phase-constrained Chandra HETGS X-ray observations of δ Ori A. Delta Ori A is actually a triple system that includes the nearest massive eclipsing spectroscopic binary, δ Ori Aa, the only such object that can be observed with little phase-smearing with the Chandra gratings. Since the fainter star, δ Ori Aa2, has a much lower X-ray luminosity than the brighter primary (δ Ori Aa1), δ Ori Aa provides a unique system with which to test the spatial distribution of the X-ray emitting gas around δ Ori Aa1 via occultation by the photosphere of, and wind cavity around, the X-ray dark secondary. Here we discuss the X-ray spectrum and X-ray line profiles for the combined observation, having an exposure time of nearly 500 ks and covering nearly the entire binary orbit. The companion papers discuss the X-ray variability seen in the Chandra spectra, present new space-based photometry and ground-based radial velocities obtained simultaneously with the X-ray data to better constrain the system parameters, and model the effects of X-rays on the optical and UV spectra. We find that the X-ray emission is dominated by embedded wind shock emission from star Aa1, with little contribution from the tertiary star Ab or the shocked gas produced by the collision of the wind of Aa1 against the surface of Aa2. We find a similar temperature distribution to previous X-ray spectrum analyses. We also show that the line half-widths are about 0.3‑0.5 times the terminal velocity of the wind of star Aa1. We find a strong anti-correlation between line widths and the line excitation energy, which suggests that longer-wavelength, lower-temperature lines form farther out in the wind. Our analysis also indicates that the ratio of the intensities of the strong and weak lines of Fe xvii and Ne x are inconsistent with model predictions, which may be an effect of resonance scattering. [less ▲]Detailed reference viewed: 9 (1 ULg) A Coordinated X-Ray and Optical Campaign of the Nearest Massive Eclipsing Binary, δ Orionis Aa. III. Analysis of Optical Photometric (MOST) and Spectroscopic (Ground-based) VariationsPablo, Herbert; Richardson, Noel D.; Moffat, Anthony F. J. et alin Astrophysical Journa (2015), 809We report on both high-precision photometry from the Microvariability and Oscillations of Stars (MOST) space telescope and ground-based spectroscopy of the triple system δ Ori A, consisting of a binary O9 ... [more ▼]We report on both high-precision photometry from the Microvariability and Oscillations of Stars (MOST) space telescope and ground-based spectroscopy of the triple system δ Ori A, consisting of a binary O9.5II+early-B (Aa1 and Aa2) with P = 5.7 days, and a more distant tertiary (O9 IV P\gt 400 years). This data was collected in concert with X-ray spectroscopy from the Chandra X-ray Observatory. Thanks to continuous coverage for three weeks, the MOST light curve reveals clear eclipses between Aa1 and Aa2 for the first time in non-phased data. From the spectroscopy, we have a well-constrained radial velocity (RV) curve of Aa1. While we are unable to recover RV variations of the secondary star, we are able to constrain several fundamental parameters of this system and determine an approximate mass of the primary using apsidal motion. We also detected second order modulations at 12 separate frequencies with spacings indicative of tidally influenced oscillations. These spacings have never been seen in a massive binary, making this system one of only a handful of such binaries that show evidence for tidally induced pulsations. [less ▲]Detailed reference viewed: 15 (1 ULg) A force sensor based on three weakly coupled resonators with ultrahigh sensitivityZhao, Chun; Wood, Graham; Xie, J.B. et alin Sensors and Actuators. A, Physical (2015), 232A proof-of-concept force sensor based on three degree-of-freedom (DoF) weakly coupled resonatorswas fabricated using a silicon-on-insulator (SOI) process and electrically tested in 20 Torr vacuum.Compared ... [more ▼]A proof-of-concept force sensor based on three degree-of-freedom (DoF) weakly coupled resonatorswas fabricated using a silicon-on-insulator (SOI) process and electrically tested in 20 Torr vacuum.Compared to the conventional single resonator force sensor with frequency shift as output, by measuringthe amplitude ratio of two of the three resonators, the measured force sensitivity of the 3DoF sensor was4.9 × 106/N, which was improved by two orders magnitude. A bias stiffness perturbation was applied toavoid mode aliasing effect and improve the linearity of the sensor. The noise floor of the amplitude ratiooutput of the sensor was theoretically analyzed for the first time, using the transfer function model ofthe 3DoF weakly coupled resonator system. It was shown based on measurement results that the outputnoise was mainly due to the thermal–electrical noise of the interface electronics. The output noise spectraldensity was measured, and agreed well with theoretical estimations. The noise floor of the force sensoroutput was estimated to be approximately 1.39nN for an assumed 10 Hz bandwidth of the output signal,resulting in a dynamic range of 74.8 dB. [less ▲]Detailed reference viewed: 25 (2 ULg) What effects do rater bias and assessment method haveon disease severity estimation with regard to hypothesis testing?Chiang, Kuo-Szu; Bock, Clive; El Jarroudi, Moussa et alin Plant Pathology (2015)Detailed reference viewed: 15 (1 ULg) Disease Severity Estimates – Effects of Rater Accuracy and Assessment Methods for Comparing TreatmentsBock, Clive; El Jarroudi, Moussa ; Kouadio, Louis et alin Plant Disease (2015), 99(1104-1112), Assessment of disease severity is required for several purposes in plant pathology; most often the estimates are made visually. It is established that visual estimates can be inaccurate and unreliable ... [more ▼]Assessment of disease severity is required for several purposes in plant pathology; most often the estimates are made visually. It is established that visual estimates can be inaccurate and unreliable. The ramifications of biased or imprecise estimates by raters have not been fully explored using empirical data; partly because of the logistical difficulties involved in different raters assessing the same leaves for which actual disease has been measured in a replicated experiment with multiple treatments. In this study nearest percent estimates (NPEs) of Septoria leaf blotch (SLB) on leaves of winter wheat from non-treated and fungicide treated plots were assessed in both 2006 and 2007 by four raters and compared to assumed true values measured using image analysis. Lin’s concordance correlation (LCC, ρc) was used to assess agreement between the two approaches. NPEs were converted to Horsfall-Barratt (HB) mid-points and again compared for agreement with true values. The estimates of SLB severity from fungicide-treated and non-treated plots were analyzed using generalized linear mixed modeling to ascertain effects of rater using both the NPE and HB values. Rater 1 showed good agreement with image analysis (ρc = 0.986 to 0.999), while raters 3 and 4 had less good agreement (ρc = 0.205 to 0.936). Conversion to the HB scale had little effect on bias or accuracy, but reduced both precision and agreement for most raters on most assessment dates (precision, r = -0.001 to -0.132; and agreement, ρc = -0.003 to -0.468). Inter-rater reliability was also reduced slightly by conversion of estimates to HB midpoint values. Estimates of mean SLB severity were significantly different between image analysis and raters 2, 3 and 4, and there were frequently significant differences among raters (F=151 to 1260, P=0.001 to <0.0001). Conversion to the HB scale changed the means separation ranking of rater estimates on 26 June 2007. Nonetheless, image analysis and all raters were able to differentiate control and treated plots treatments (F=116 to 1952, P=0.002 to <0.0001, depending on date and rater). Conversion of NPEs to the HB scale tended to reduce F-values slightly (2006: NPEs, F=116 to 276, P=0.002 to 0.0005, and for the HB converted values F=101 to 270, P=0.002 to 0.0005, and in 2007, NPEs, F=164 to 1952 P=0.001 to <0.0001, and for HB converted values F=126 to 1633 P=0.002 to <0.0001). The results demonstrated the need for accurate and reliable disease assessment to minimize over or underestimates compared to actual disease, and where multiple raters are deployed, they should be assigned in a manner to reduce any potential effect of rater differences on the analysis. [less ▲]Detailed reference viewed: 16 (0 ULg) Simultaneous X-ray and optical spectroscopy of the Oef supergiant λ CepheiRauw, Grégor ; Hervé, A.; Nazé, Yaël et alin Astronomy and Astrophysics (2015), 580Probing the structures of stellar winds is of prime importance for the understanding of massive stars. Based on their optical spectral morphology and variability, it has been suggested that the stars in ... [more ▼]Probing the structures of stellar winds is of prime importance for the understanding of massive stars. Based on their optical spectral morphology and variability, it has been suggested that the stars in the Oef class feature large-scale structures in their wind. High-resolution X-ray spectroscopy and time-series of X-ray observations of presumably single O-type stars can help us understand the physics of their stellar winds. We have collected XMM-Newton observations and coordinated optical spectroscopy of the O6 Ief star λ Cep to study its X-ray and optical variability and to analyse its high-resolution X-ray spectrum. We investigate the line profile variability of the He ii λ 4686 and Hα emission lines in our time series of optical spectra, including a search for periodicities. We further discuss the variability of the broadband X-ray flux and analyse the high-resolution spectrum of λ Cep using line-by-line fits as well as a code designed to fit the full high-resolution X-ray spectrum consistently. During our observing campaign, the He ii λ 4686 line varies on a timescale of ~18 h. On the contrary, the Hα line profile displays a modulation on a timescale of 4.1 days which is likely the rotation period of the star. The X-ray flux varies on timescales of days and could in fact be modulated by the same 4.1-day period as Hα, although both variations are shifted in phase. The high-resolution X-ray spectrum reveals broad and skewed emission lines as expected for the X-ray emission from a distribution of wind-embedded shocks. Most of the X-ray emission arises within less than 2 R∗ above the photosphere. The properties of the X-ray emission of λ Cep generally agree with the expectations of the wind-embedded shock model. There is mounting evidence for the existence of large-scale structures that modulate the Hα line and about 10% of the X-ray emission of λ Cep. [less ▲]Detailed reference viewed: 17 (1 ULg) Impact of ηEarth on the Capabilities of Affordable Space Missions to Detect Biosignatures on Extrasolar PlanetsLéger, Alain; Defrère, Denis; Malbet, Fabien et alin Astrophysical Journal (2015), 808We present an analytic model to estimate the capabilities of space missions dedicated to the search for biosignatures in the atmosphere of rocky planets located in the habitable zone of nearby stars ... [more ▼]We present an analytic model to estimate the capabilities of space missions dedicated to the search for biosignatures in the atmosphere of rocky planets located in the habitable zone of nearby stars. Relations between performance and mission parameters, such as mirror diameter, distance to targets, and radius of planets, are obtained. Two types of instruments are considered: coronagraphs observing in the visible, and nulling interferometers in the thermal infrared. Missions considered are: single-pupil coronagraphs with a 2.4 m primary mirror, and formation-flying interferometers with 4 × 0.75 m collecting mirrors. The numbers of accessible planets are calculated as a function of η[SUB]Earth[/SUB]. When Kepler gives its final estimation for η[SUB]Earth[/SUB], the model will permit a precise assessment of the potential of each instrument. Based on current estimations, η[SUB]Earth[/SUB] = 10% around FGK stars and 50% around M stars, the coronagraph could study in spectroscopy only ∼1.5 relevant planets, and the interferometer ∼14.0. These numbers are obtained under the major hypothesis that the exozodiacal light around the target stars is low enough for each instrument. In both cases, a prior detection of planets is assumed and a target list established. For the long-term future, building both types of spectroscopic instruments, and using them on the same targets, will be the optimal solution because they provide complementary information. But as a first affordable space mission, the interferometer looks the more promising in terms of biosignature harvest. [less ▲]Detailed reference viewed: 24 (4 ULg)