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See detailWill Big Data Deliver its Promised Productivity Growth?
Artige, Lionel ULg

E-print/Working paper (2015)

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See detailLes carrières en fin d'activités: un potentiel paysager?
Joris, Alicia ULg

Master's dissertation (2015)

The present study focuses on the landscape concept and evaluations and is based on some issues related to the impact, restoration and ecological potential of the abandoned quarries. It proposes a ... [more ▼]

The present study focuses on the landscape concept and evaluations and is based on some issues related to the impact, restoration and ecological potential of the abandoned quarries. It proposes a landscape character assessment for non active limestone quarries resulting from the spontaneous succession. Taking into account the guidelines of the European Landscape Convention (Conseil de l'Europe, 2000) , this work has for objectives (1) to describe these landscape areas and (2) to assess the landscape aesthetic quality. To achieve these goals, two methods inspired by the Landscape Character Assessment (LCA) were tested. The first one is a field sheet and the second one a landscape perception survey with stakeholders. The results have emphasized the natural, harmonious and unique character of these landscapes. The key characteristics are the visual importance of cliffs, water bodies, vegetation forms and the landform in bleachers. Furthermore, color contrast and textures from vegetation, rock and water were also relevant. An apparent aesthetic landscape quality was perceived and the study showed that respondents are feeling good in the site surveyed. The quarryscape can be characterized of challenging, attractive, wild with an important degree of naturality but not really safe. Cultural, historic, symbolic and ecological values were also highlighted as a potential. These later observations take part in a landscape dynamic and allow to open the debate concerning the need for landscape interventions within these sites and the profit we could benefit from if security issues were well-managed. [less ▲]

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See detailThe impact of ageing on episodic memory encoding: an fMRI study
François, Sarah ULg; Angel, Lucie; SALMON, Eric ULg et al

Poster (2015, September 04)

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See detailUne féminité en métamorphose: Représentation de la féminité noire dans le cinéma black-British
Herbert, Emilie ULg

Conference (2015, September 03)

Le long-métrage "Burning an illusion", réalisé par Menelik Shabazz, met en scène l'éveil politique d'une jeune femme noire, Pat (Cassie McFarlane) lorsqu'elle fait l'expérience du racisme et de la ... [more ▼]

Le long-métrage "Burning an illusion", réalisé par Menelik Shabazz, met en scène l'éveil politique d'une jeune femme noire, Pat (Cassie McFarlane) lorsqu'elle fait l'expérience du racisme et de la violence dans les rues de Londres. "Burning an illusion" est l'un des premiers films black British à prendre pour personnage principal une femme et Shabazz décrit la conscientisation politique de Pat en termes ouvertement féminins : sa transformation intellectuelle passe en effet par une métamorphose physique. A travers une africanisation de son apparence (son maquillage disparaît, ses vêtements changent et ses cheveux, soigneusement lissés au début du film, reprennent leur apparence naturelle), Pat manifeste son rejet des codes de beauté occidentaux qui annihilent les femmes noires en imposant la blancheur comme point de référence. Ce long-métrage, réalisé en 1981, met en avant une notion développée par un féminisme noir qui s'éveille à la même époque en Grande-Bretagne : celle de la (re)conquête de la féminité noire à travers la création d'une identité black British fluide qui reconnaît la nature fragmentée des identitées hybrides, racialisées et genrées (Mirza, 1997). L'analyse d'un corpus de plusieurs films du mouvement du black British Cinema des années 1980 et 90 à travers une approche intersectionnelle, féministe et de genre nous permettra de comprendre ce processus de redéfinition de la féminité noire, jusqu'alors rendue invisible au sein du cinéma britannique blanc (Bourne, 2001). Les films étudiés encouragent en effet la revalorisation de la beauté naturelle du corps féminin noir, permettant ainsi son mouvement d'objet à sujet (Weekes, 1997), en passant par un processus de métamorphose physique. Le corps y est fragmenté (Coly, 2010) afin d'en déconstruire l'image socialement et culturellement produite (Jordan-Zachery, 2013) et de créer ainsi une nouvelle syntaxe qui permet d'articuler et de comprendre le corps féminin noir différemment (Doane, 1981). [less ▲]

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See detailLa fonction publique régionale wallonne: Réflexions et balises pour un projet de recherche prospective
Claisse, Frédéric ULg; Guyot, Jean-Luc

Scientific conference (2015, September 03)

Évolution du cadre institutionnel, contraintes budgétaires, transferts de compétences, instauration de nouveaux modes de gestion, vieillissement du personnel, recomposition du métier de fonctionnaire ... [more ▼]

Évolution du cadre institutionnel, contraintes budgétaires, transferts de compétences, instauration de nouveaux modes de gestion, vieillissement du personnel, recomposition du métier de fonctionnaire : tels sont quelques-uns des défis, tendances lourdes ou incertitudes auxquels la fonction publique régionale sera confrontée à plus ou moins brève échéance. Pour répondre à ce questionnement, l’IWEPS a décidé de développer une réflexion prospective sur le(s) futur(s) du SPW et des OIP à l’horizon 2030-2040. La présentation se centrera sur la méthodologie du projet, les variables et composantes de l’analyse systémique et de la base prospective. [less ▲]

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See detailImportance des résidus lysine 70 et tryptophane 154 sur la structure, la stabilité, la carbonatation et l'activité de la béta-lactamase OXA-10 de Pseudomonas aeruginosa
Baurin, Stéphane ULg

Doctoral thesis (2015)

SUMMARY : This thesis was conducted to highlight the biochemical and structures impact of conserved residues of the beta-lactamase OXA-10 isolated from P. aeruginosa. The beta-lactamase OXA-10 production ... [more ▼]

SUMMARY : This thesis was conducted to highlight the biochemical and structures impact of conserved residues of the beta-lactamase OXA-10 isolated from P. aeruginosa. The beta-lactamase OXA-10 production is one of the main responsible to the beta-lactam antibiotics resistance of Pseudomonas strains. This work is subdivided in five chapters. The first is focused on the organization of class D beta-lactamase in sub classes. We have created by identity analysis, 21 sub classes that reflect an easy discrimination between proteins variability and mutants. This methodology is able to organize the enzymes as function of a parental enzyme but also based on the substrate profiles. The second chapter regroups the studies that target the importance of the residue tryptophan 154 carried by the Omega loop. The substitution of the residue tryptophan 154 by an alanine, a glycine or an phenylalanine leads to a large decrease of i) the catalytic activity, ii) of the affinity toward to CO2 and iii) on the enzyme stability. The structural data show an absence of lysine 70 modification and a large modification of the hydrogen network throughout the mutants structures. The various complexes resolved by R-x diffraction of the W154A mutant indicate that the deacylation rate is the most impacted. The third chapter makes an analogy between the available structural informations of others proteins characterized by a carboxylation modification. Others serine enzymes known to be not modified were also integrated in the analysis. The data reveal that the presence of a tryptophan residue seems to be necessary. We notice the presence of a large hydrophobic area with various shape near of the modified lysines. The calculation of the theoretical pKa values of the lysines seems to indicate a large decrease of the values that lead to an unprotonated form at physiological pH. The fourth chapter describes, the role of the lysine 70. The substitution of the lysine by a cysteine or a glutamate leads to a large decrease of the catalytic activity and an absence of carboxylation. At the opposite, the protein stability is not impacted, and an increase of stability is observed for the K70C mutant. The structural data show that the overall fold and structures localization are conserved. The complex obtained with the nitrocefin proves that the mutant is always able to react with the beta-lactams compounds and show that the deacylation step is rate limiting. Finally, the last chapter regroups the effect of pH on the structure, the dimerization, the stability and the catalytic activity. The data show that in the tested conditions the OXA-10 beta-lactamase is in a dimeric form at physiological pH. The addition of CO2, leads the formation of a more compact enzyme form. At high pH (10), the monomer is observed, while a fast equilibrium between the monomer and the dimer is observed between the pH 7.5 and 10. The enzyme is characterized with similar stability as function of pH. The addition of CO2 leads an increase of the stabilities. In tested conditions, the OXA-10 beta-lactamase is characterized by two optimum pH in presence or not of CO2. The CO2 addition leads to a large increase of the catalytic constant. The biophysics' studies reveal that in absence of CO2, subtle modifications are observed as function of pH, but that the addition of CO2 leads theirs disappearance. [less ▲]

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See detailImpact of a one-day preventive voice program for teachers : A longitudinal study
Remacle, Angélique ULg; Gerber, Silvain; David, Claire et al

Conference (2015, September 02)

I. INTRODUCTION Teachers are professional voice users, i.e. people who rely on a consistent, special, or appealing voice quality to achieve their job. If afflicted with dysphonia or aphonia, they would ... [more ▼]

I. INTRODUCTION Teachers are professional voice users, i.e. people who rely on a consistent, special, or appealing voice quality to achieve their job. If afflicted with dysphonia or aphonia, they would generally loose motivation at work and seek alternative employment [1]. Teachers represent the largest group of professionals complaining of dysphonia: they represent 20% to 25% of the treatment-seeking workers [2, 3]. Voice disorders impact both physical and psychological health. They represent a public health problem, since they have considerable economic consequences in terms of treatment and replacement of professionals who suffer from these problems [4]. Moreover, they have been shown to interfere with quality of life, emotional state, job satisfaction, performance and attendance [4, 5]. Finally, a teacher’s dysphonia adversely impacts students’ comprehension and learning [6]. These negative effects of teachers’ voice disorders motivate to develop prevention programs and test their efficacy. This study aims to evaluate the impact over a five-month period of a one-day prevention program for female teachers. This program includes both direct and indirect methods. II. METHODS A. Participants Twenty-two female kindergarten and elementary schoolteachers with less than 5 years of experience participated in this study. Half of them (test group) took part in a one-day prevention program in October, while the other half (control group) received no counseling on the use of the voice. B. Assessments For each participant, five sustained /a/ vowels and the reading of a text were recorded (1) at two times of the workday (morning and evening), and (2) at three times of the year: October (T0), December (T1) and February (T2). For the sustained vowels, we measured maximum phonation time (MPT), mean fundamental frequency (F0), values of jitter, shimmer and harmonics-to-noise ratio (HNR). For the texts, we measured mean F0, standard deviation in F0 and intensity, and parameters related to speech rate (number of syllables per second, number of pauses and mean duration of pauses). For each parameter, a repeated-measures ANOVA (2 groups * 2 times of day * 3 times of year) was carried out. Participants also completed a questionnaire on voice use and comfort at the three test sessions. III. RESULTS A. Time of day effect The main effect of time of day showed an increase in the mean F0 of the vowels and the text following a workday (p<.01). MPT and HNR also increased (p<.01), while jitter and shimmer decreased at the end of the day (p<.05). The speech rate measures showed that the teachers tended to pause less often while reading the text at the end of the day, and their pauses were shorter (p<.05). B. Time of year effect The main effect of time of year showed an increase in the mean F0 of the vowels and the text during the year (p<.01), with the highest values observed in December (T1). The speech rate measures also showed an increase in the number of syllables per second (p<.01) and a tendency for speakers to pause less often later in the year. C. Group effect Several acoustic parameters showed that voice changed during the day and during the year in significantly different ways in the two groups. Thus, the MPT increased more during the year for the control group than for the test group. The elevation of mean F0 during the day increased to a similar degree for both groups between T0 and T1, but continued to increase until T2 for the control group, while it decreased for the test group. Jitter and shimmer decreased significantly following a workday for both groups at T0, and this decrease was more marked for the test group at T1 and T2. Finally, analysis of the questionnaires showed a very strong deterioration in teachers’ self-evaluations of vocal comfort and control at T1; nevertheless there were significantly fewer complaints from the group that received the prevention program. IV. DISCUSSION AND CONCLUSION For both groups, the changes in the observed parameters suggested an increase in vocal fatigue and hyperfunctional phonation during the day and during the year. The results showed greater vocal deterioration in December than at the other points in the school year (October and February). For several acoustic parameters, the comparison of the two groups showed a less severe vocal deterioration for subjects who received the preventive program. Moreover, the questionnaires showed that the prevention program had a significantly positive impact on the changes in the teachers’ perception during the year. These results encourage to offer such preventive interventions to teachers before or during their career, since they have a positive impact on teachers’ perception and vocal comfort. V. REFERENCES [1] Titze IR, Lemke J, Montequin D. (1997). Populations in the U.S. workforce who rely on voice as a primary tool of trade: A preliminary report. Journal of Voice, 11(3), 254-259. [2] Van Houtte, E., Van Lierde, K., D'Haeseleer, E., & Claeys, S. (2010). The prevalence of laryngeal pathology in a treatment-seeking population with dysphonia. Laryngoscope, 120(2), 306-312. [3] Remacle, A., Petitfils, C., Lejeune, L., Finck, C., & Morsomme, D. (2014). Quel est le profil professionnel des patients consultant en phoniatrie ? 70e Congrès de la Société Française de Phoniatrie, Paris, France. (October 13, 2014). [4] Roy, N., Merrill, R. M., Thibeault, S., Parsa, R. A., Gray, S. D., & Smith, E. M. (2004). Prevalence of voice disorders in teachers and the general population. Journal of Speech, Language, and Hearing Research, 47(2), 281-293. [5] Chen, S. H., Chiang, S.-C., Chung, Y.-M., Hsiao, L.-C., & Hsiao, T.-Y. (2010). Risk factors and effects of voice problems for teachers. Journal of Voice, 24(2), 183-190. [6] Morsomme, D., Minel, L., & Verduyckt, I. (2011). Impact of teachers’ voice quality on children’s language processing skills. Vocologie: Stem en Stemstoornissen, 4, 9-15. [less ▲]

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See detailIn vivo quantification of dopaminergic terminals loss in Parkinson’s Disease rat model: comparison between [18F]FMT and [18F]FDOPA.
Becker, Guillaume ULg; Bahri, Mohamed Ali ULg; Michel, Anne et al

Poster (2015, September 02)

Objectives: Rat models of Parkinson’s disease (PD), such as unilaterally lesioned rats with 6-hydroxydopamine (6-OHDA), are useful to evaluate novel antiparkinsonian therapies. MicroPET imaging, using L-3 ... [more ▼]

Objectives: Rat models of Parkinson’s disease (PD), such as unilaterally lesioned rats with 6-hydroxydopamine (6-OHDA), are useful to evaluate novel antiparkinsonian therapies. MicroPET imaging, using L-3,4-dihydroxy-6-[18F]-fluoro-phenylalanine ([18F]FDOPA) allows longitudinal evaluations of DA terminals loss. However, chemical structure of [18F]FDOPA leads to suboptimal PET imaging. 18F-fluoro-m-tyrosine ([18F]FMT) is an effective PET tracer to evaluate DA terminals integrity and L-aromatic amino acid decarboxylase (AAAD) metabolic pathway. So far, there are no available quantitative PET studies comparing the two methods in hemiparkinsonian rats. In this study, we compare imaging data provided by [18F]FMT PET and [18F]FDOPA PET in 6-OHDA-lesioned rats. Methods: 10 µg of 6-OHDA were injected into the right medial forebrain bundle (MFB) of male Sprague-Dawley rats (n=8). As control, sham-treated rats (n=8) were injected with vehicle only but otherwise treated identically. Striatal DA presynaptic activity was assessed by dynamic PET with both [18F]FMT and [18F]FDOPA. Structural T2-weighted brain images were acquired on a 9.4T MRI and were used for co-registration. After normalization on a MRI template, kinetic analysis was performed by “Patlak Reference” model, using PMOD software. Six days after the last PET scan, rats were sacrificed, and striatum were rapidly removed for striatal DA and metabolites quantification. Results: Striatal accumulation was observed for both tracers. However, while the administration of [18F]FDOPA required two peripheral inhibitors (benserazide and entacapone), only benserazide is needed with [18F]FMT. As consequence of the 6-OHDA-lesion, significant decrease of both [18F]FMT and [18F]DOPA accumulation was recorded in the striatum ipsilateral to the lesion. Lesioned rats had dramatically reduced uptake constant Ki in the ipsilateral striatum compared to the contralateral striatum (p<0.001 for [18F]FMT and p<0.05 for [18F]DOPA) and to the ipsilateral striatum of sham-treated rats (p<0.001 for both tracers). The DA content in the ipsilateral striatum was significantly lower (p<0.001) than in the contralateral striatum in the 6-OHDA-injected group, whereas such difference was not measured with the sham group. This indicate that [18F]FMT PET is as effective as [18F]DOPA PET to quantify loss of DA presynaptic function in unilaterally 6-OHDA lesioned rats. Conclusions: Our results are in agreement with data reporting correlation between these two tracers in a Non-human primate model of PD. The sensitivity of the data quantification obtained in this study, confirms the interest to pursue longitudinal investigations with [18F]FMT to monitor dopaminergic dysfunction in a more progressive preclinical model of PD. [less ▲]

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See detailOrganocatalytic promoted coupling of carbon dioxide with epoxides: a rational investigation of the cocatalytic activity of various hydrogen bond donors
Alves, Margot ULg; Grignard, Bruno ULg; Gennen, Sandro ULg et al

in Catalysis Science & Technology (2015), 5(9), 4636-4643

A catalytic platform based on an onium salt used in combination with organic cocatalysts of various structures was developed for the efficient CO2/epoxide coupling under mild conditions. Through detailed ... [more ▼]

A catalytic platform based on an onium salt used in combination with organic cocatalysts of various structures was developed for the efficient CO2/epoxide coupling under mild conditions. Through detailed kinetic studies by in-situ FT-IR spectroscopy, a rational investigation of the efficiency of a series of commercially available hydrogen bond donors co-catalysts was realized and the influence of different parameters such as the pressure, the temperature, the catalyst loading, and the nature of the epoxide on the reaction kinetics was evaluated. Fluorinated alcohols were found to be more efficient than other hydrogen bond donor activators proposed previously in the literature under similar conditions. [less ▲]

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See detailFirst-Principles Study on the Lattice Dynamics and Thermoelectric Properties of Materials
Miao, Naihua ULg

Doctoral thesis (2015)

Thermoelectricity has been regarded as one of the most promising strategies for clean, low-cost and environmental friendly sustainable energy for several decades. Perovskite oxides, like SrRuO3, are ... [more ▼]

Thermoelectricity has been regarded as one of the most promising strategies for clean, low-cost and environmental friendly sustainable energy for several decades. Perovskite oxides, like SrRuO3, are considered as a potential thermoelectric material for low-cost and large-scale thermoelectric applications due to their good thermal and chemical stability in a wide temperature range, great flexibility for structural and compositional manipulating, and environmental friendliness. This thesis is devoted to a theoretical study of the lattice dynamics and thermoelectric properties of materials, like SrRuO3 perovskite and MgAgSb-based materials. Firstly, to obtain insight into the lattice dynamics of the SrRuO3, the phonon-related properties are presented and contributes to rationalize better why many ABO3 perovskites, including metallic compounds, exhibit an orthorhombic ground state. Then the thermoelectric properties of SrRuO3 are investigated by combining first-principles calculations and Boltzmann transport theory, revealing the relationship between the exchange-correlation functionals and the thermoelectric quantities. Furthermore, based on the first-principles calculations, effective model potentials for SrRuO3 are constructed providing access to the finite-temperature properties and phase-transitions. Additionally, the electronic structure and thermoelectric properties of a class of new emerging MgAgSb-based materials, which are promising for room-temperature thermoelectric applications, are also studied and the optimization strategies are proposed for the improvement of thermoelectric performance. [less ▲]

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See detailThe changing UV and X-ray properties of the Of?p star CPD -28°2561
Nazé, Yaël ULg; Sundqvist, Jon O.; Fullerton, Alex W. et al

in Monthly Notices of the Royal Astronomical Society (2015), 452

The Of?p star CPD -28°2561 was monitored at high energies with XMM-Newton and HST. In X-rays, this magnetic oblique rotator displays bright and hard emission that varies by ~55 per cent with rotational ... [more ▼]

The Of?p star CPD -28°2561 was monitored at high energies with XMM-Newton and HST. In X-rays, this magnetic oblique rotator displays bright and hard emission that varies by ~55 per cent with rotational phase. These changes occur in phase with optical variations, as expected for magnetically confined winds; there are two maxima and two minima in X-rays during the 73 d rotational period of CPD -28°2561. However, contrary to previously studied cases, no significant hardness variation is detected between minima and maxima, with the exception of the second minimum which is slightly distinct from the first one. In the UV domain, broad-band fluxes remain stable while line profiles display large variations. Stronger absorptions at low velocities are observed when the magnetic equator is seen edge-on, which can be reproduced by a detailed 3D model. However, a difference in absorption at high velocities in the C IV and N V lines is also detected for the two phases where the confined wind is seen nearly pole-on. This suggests the presence of strong asymmetries about the magnetic equator, mostly in the free-flowing wind (rather than in the confined dynamical magnetosphere). [less ▲]

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See detailOrbivirus screening on dried blood spots from captive oryx in United Arab Emirates stresses the importance of pre-import measures
Martinelle, Ludovic ULg; Haegeman, Andy; Lignereux, Louis et al

Poster (2015, September 01)

Objective: Following reintroduction and conservation programs of the Arabian oryx (Oryx leucoryx) and the scimitar horned oryx (SHO, Oryx dammah) in the United Arab Emirates (UAE), import of animals from ... [more ▼]

Objective: Following reintroduction and conservation programs of the Arabian oryx (Oryx leucoryx) and the scimitar horned oryx (SHO, Oryx dammah) in the United Arab Emirates (UAE), import of animals from wild game ranches in the United States of America (USA) is not uncommon. Bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV) are orbiviruses that are the causative agents of bluetongue disease (BT) and epizootic hemorrhagic disease (EHD), respectively. BTV and EHDV are endemic in the UAE and the USA. Sheep and some wild ruminant species are usually severely affected by BT whereas EHD mostly affects wild animals and sometimes cattle. The objective of this study was to estimate the prevalence of these orbiviruses in Arabian and SHO from captive herds in the UAE using serology and molecular virology. Dry blood spot sampling for orbivirus screening is also discussed. Methods: A total of 175 SHO and 16 Arabian oryx were sampled. The latters were imported from Texas (USA) two weeks before sampling. All sampled animals belonged to captive herds spread over the Al Wathba area. For biosecurity reasons and to simplify blood storage, elutes from dried blood spot were used for serological and virological tests. Drops of about 80 µl of blood were dispensed on Whatman protein saver cards, and then allowed to dry in the dark at room temperature for 48 hours. Blood spots were punched out in paper discs with a 6 mm diameter punch and diluted in 250 µl PBS and Tween 20 0.05%. Eluted samples were incubated overnight at room temperature and then used immediately or stored at -80°C. To assess the most suitable ELISA kit to detect anti-BTV antibodies from the oryx discs, similar discs were prepared using blood issued from BTV seropositive and viremic as well as seronegative and non-viremic cattle. Elutes from discs with dried-blood from cattle were tested by BTV competitive ELISA (cELISA), sandwich ELISA (sELISA) and indirect ELISA (iELISA) and compared to cELISA performed directly on the serum of the same animals. iELISA on cattle paper discs gave the best correspondence with cELISA on cattle serum and was therefore used to test the oryx paper discs. Subsequently oryx paper discs were tested to detect antibodies against EHDV by cELISA. All the paper discs elutes from Arabian oryx and ELISA positive elutes from SHO were also tested by pan-BTV RTqPCR targeting a fragment of BTV segment 5 and detecting all BTV serotypes. Serotype specific end-point RT-PCR targeting a fragment of segment 2 of BTV2, BTV8, BTV10, BTV11, BTV13 and BTV17 were performed on pan-BTV positive samples. Results: Three out of 175 SHO and eight out of 16 Arabian oryx were found BTV seropositive by iELISA. None of the animals could be found seropositive against EHDV. BTV genome was detected in 1/3 seropositive SHO and in 5/16 of the Arabian oryx, amongst those 2/5 were seronegative. Overall Cq values were high (33-39). End point PCR failed to detect positive samples for any of the tested serotypes. Conclusion: BTV seroprevalence and RNA detection in SHO was very limited. By contrast BTV could be demonstrated in 5/16 imported Arabian oryx by molecular virology and in 8/16 by serology. The sampling was realized two weeks after the animals arrived in UAE and some oryx were viremic and seronegative, possibly suggesting a recent infection. Among the local SHO a low BTV seroprevalence was observed (3/175) and no animals were found positive to EHDV. This result was quite surprising because previous studies showed a higher BTV seroprevalence in domestic and wild ruminants of the Arabian Peninsula with wide local variations. In addition, dried blood spot testing has been demonstrated being a convenient and reliable method of sampling when storage conditions are hazardous. BTV serotypes could not be determined by end-point RT-PCR. At least 15 different BTV serotypes were reported in the USA and at least 10 in the Middle East, thus the oryx could be infected by a serotype not tested so far. Since RTqPCR positive values were high, the sensitivity of end-point RT-PCR might be insufficient to detect BTV out of eluted blood spots. Additional testing will be performed to identify the virus on the serotype level and therefore provide new insights to clarify the origin of the infection of the oryx. These results stress the need for pre-import risk assessment, precaution and implementation of biosecurity measures when considering translocation of wild ruminant species susceptible to BTV and EHDV. [less ▲]

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See detailMagnetic fields in O-, B- and A-type stars on the main sequence
Briquet, Maryline ULg

in European Physical Journal Web of Conferences (2015, September 01)

In this review, the latest observational results on magnetic fields in main-sequence stars with radiative envelopes are summarised together with the theoretical works aimed at explaining them.

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See detailDevelopment of photo- or thermo-reversible cross-linked recyclable shape-memory materials
Defize, Thomas ULg; Riva, Raphaël ULg; Thomassin, Jean-Michel ULg et al

Conference (2015, September 01)

Shape-memory polymers (SMPs) are remarkable materials able to switch from a stressed deformed state (temporary shape) to their initial relaxed state (permanent shape) by the application of a stimulus ... [more ▼]

Shape-memory polymers (SMPs) are remarkable materials able to switch from a stressed deformed state (temporary shape) to their initial relaxed state (permanent shape) by the application of a stimulus, such as heat or light. Typically, the shape-memory property is generally observed for chemically or physically cross-linked polymers that exhibit an elastomeric behavior above a phase transition, e.g. glass or melting transition. As an example, cross-linked semi-crystalline poly(ε-caprolactone) (PCL) is widely studied for the development of SMPs. As most of SMPs are irreversibly cross-linked material, their reprocessing is impossible preventing any recycling. Thereby, reversible reactions, allowing the formation/cleavage of the network, raise tremendous interest for the development of new SMPs. Recently, we reported the preparation reversibly cross-linked PCL-based SMP using the Diels-Alder (DA) reaction between furan and maleimide end-groups of 4-arm star-shaped PCL, well-known to create reversible bonds. After implementation, this shape-memory material was demonstrated to be recyclable, and was characterized by excellent fixity and recovery before and after recycling experiments. However, the relatively low retro DA temperature of the furan-maleimide adducts led to an inelastic deformation during shape-memory tensile cycles. In order to get rid of this drawback, an alternative approach was investigated. The substitution of the DA reaction by a photo-reversible reaction, typically the photo-induced (2+2) cycloaddition of coumarins, was proposed to prepare cross-linked PCL matrix presenting one-way and two-way memory properties, since photolabile adducts are supposed to be stable during shape-memory tensile cycles. [less ▲]

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See detailLamost Observations in the Kepler Field. I. Database of Low-resolution Spectra
De Cat, P.; Fu, J. N.; Ren, A. B. et al

in Astrophysical Journal Supplement Series (2015), 220

The nearly continuous light curves with micromagnitude precision provided by the space mission Kepler are revolutionizing our view of pulsating stars. They have revealed a vast sea of low-amplitude ... [more ▼]

The nearly continuous light curves with micromagnitude precision provided by the space mission Kepler are revolutionizing our view of pulsating stars. They have revealed a vast sea of low-amplitude pulsation modes that were undetectable from Earth. The long time base of Kepler light curves allows for the accurate determination of the frequencies and amplitudes of pulsation modes needed for in-depth asteroseismic modeling. However, for an asteroseismic study to be successful, the first estimates of stellar parameters need to be known and they cannot be derived from the Kepler photometry itself. The Kepler Input Catalog provides values for the effective temperature, surface gravity, and metallicity, but not always with sufficient accuracy. Moreover, information on the chemical composition and rotation rate is lacking. We are collecting low-resolution spectra for objects in the Kepler field of view with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (lamost, Xinglong observatory, China). All of the requested fields have now been observed at least once. In this paper, we describe those observations and provide a useful database for the whole astronomical community. ) located at the Xinglong observatory, China. [less ▲]

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See detailHigh spectral resolution monitoring of Nova V339 Delphini with TIGRE
De Gennaro Aquino, I.; Schröder, K.-P.; Mittag, M. et al

in Astronomy and Astrophysics (2015), 581

We investigate the early development of the classical nova V339 Del (Nova Delphini 2013) through high-resolution optical spectroscopy. To study the structure of the ejecta, we focus on the evolution of ... [more ▼]

We investigate the early development of the classical nova V339 Del (Nova Delphini 2013) through high-resolution optical spectroscopy. To study the structure of the ejecta, we focus on the evolution of the absorption and emission features and the changes within the line profiles. We obtained spectra with the robotic 1.2 m telescope TIGRE equipped with the HEROS spectrograph (R = 20 000, wavelength coverage from 3800 to 8800 Å). Our data set covers the outburst from 3 until 121 days after discovery. We provide a qualitative analysis of the spectra, describing the line profiles evolution and providing a rich list of identified lines. During the optically thick phase, we detected several blue-shifted absorption features from s-processed elements, whose origin is unclear. The presence of strong lines from C/O and the absence of Neon features confirm that the nature of the central white dwarf is a CO type. The later "nebular" phase spectra show evidence of the non-spherical, inhomogeneous structure of the ejecta. The detailed evolution of the line profiles and appearance of high ionization species (e.g. N III, O III, He II, [Fe VII]) are direct consequences of the re-ionization of the ejecta during the peak of the soft X-ray emission. [less ▲]

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See detailStar Formation and Evolution as seen with Athena
Rauw, Gregor ULg; Sciortino, Salvatore; Hornschemeier, Ann et al

in Exploring the Hot and Energetic Universe: The first scientific conference dedicated to the Athena X-ray observatory. Proceedings of a conference held 8-10 September, 2015 in Madrid, Spain. Online at <A href="http://www.sciops.esa.int/index.php?project=CONF2015&page=ATHENA2015">http://www.sciops.esa.int/index.php?project=CONF2015&page=ATHENA2015</A>, p.36 (2015, September 01)

Stars over a wide range of masses and evolutionary stages are nowadays known to emit X-rays. This X-ray emission probes the most energetic phenomena occurring in the circumstellar environment of these ... [more ▼]

Stars over a wide range of masses and evolutionary stages are nowadays known to emit X-rays. This X-ray emission probes the most energetic phenomena occurring in the circumstellar environment of these stars, and provides precious insight on magnetic phenomena or hydrodynamic shocks. Owing to its unprecedented capabilities, Athena will open up an entirely new window on these phenomena. Athena will not only allow us to study many more objects with an unprecedented spectral resolution, but will also pioneer the study of the dynamics of these objects via time-resolved high-resolution spectroscopy. These studies will lead to a deeper understanding of yet poorly understood processes which have profound impact in star formation and evolution, including at earlier times in the Universe. They also are important to understanding feedback processes on Galactic scale. [less ▲]

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See detailNonlinear normal modes, modal interactions and isolated resonance curves
Kuether, Robert J.; Renson, Ludovic ULg; Detroux, Thibaut ULg et al

in Journal of Sound and Vibration (2015), 351

The objective of the present study is to explore the connection between the nonlinear normal modes of an undamped and unforced nonlinear system and the isolated resonance curves that may appear in the ... [more ▼]

The objective of the present study is to explore the connection between the nonlinear normal modes of an undamped and unforced nonlinear system and the isolated resonance curves that may appear in the damped response of the forced system. To this end, an energy balance technique is used to predict the amplitude of the harmonic forcing that is necessary to excite a specific nonlinear normal mode. A cantilever beam with a nonlinear spring at its tip serves to illustrate the developments. The practical implications of isolated resonance curves are also discussed by computing the beam response to sine sweep excitations of increasing amplitudes. [less ▲]

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