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See detailLong-wave infrared digital holographic interferometry for deformation measurement of the segmented detector array of the space EUCLID mission
Vandenrijt, Jean-François ULg; Thizy, Cédric ULg; Beaumont, Florent et al

in Digital Holography and Three-Dimensional Imaging (2015, May)

Digital holographic interferometry in LWIR is used for following the deformation and relative movement of an assembly of detectors to be used in space. The setup is incorporated in a vacuum chamber for ... [more ▼]

Digital holographic interferometry in LWIR is used for following the deformation and relative movement of an assembly of detectors to be used in space. The setup is incorporated in a vacuum chamber for cryogenic testing. [less ▲]

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See detailLong-wave infrared digital holographic interferometry with diffuser or point source illuminations for measuring deformations of aspheric mirrors
Vandenrijt, Jean-François ULg; Thizy, Cédric ULg; Queeckers, Patrick et al

in Optical Engineering : The Journal of the Society of Photo-Optical Instrumentation Engineers (2014), 53(11), 112309

Long-wave infrared digital holographic interferometry with CO2 laser and microbolometer arrays has been developed for testing the large deformations of space reflectors. The setup considered is a ... [more ▼]

Long-wave infrared digital holographic interferometry with CO2 laser and microbolometer arrays has been developed for testing the large deformations of space reflectors. The setup considered is a Mach–Zehnder, associated to the digital holography reconstruction of the wavefront in the inline configuration with phase shifting. Two possibilities exist for illuminating the tested reflector: either with a point source (similarly to classical interferometry) or an extended source (with a diffuser). This paper presents the development of a modular setup which allows comparing both in the case of a parabolic mirror [less ▲]

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See detailLong-wave infrared digital holography
Georges, Marc ULg

in Picart, Pascal (Ed.) New Techniques in Digital Holography (2015)

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See detailLong-wave infrared digital holography for the qualification of large space reflectors
Vandenrijt, Jean-François ULg; Thizy, Cédric ULg; Georges, Marc ULg et al

Conference (2012, October 09)

Deformation metrology of complex and large space reflectors is a recurrent problem addressed by ESA. The challenging tasks of on-ground qualification and verification testing are to achieve the required ... [more ▼]

Deformation metrology of complex and large space reflectors is a recurrent problem addressed by ESA. The challenging tasks of on-ground qualification and verification testing are to achieve the required accuracy in the measurement of these reflectors deformation and to verify their performance under simulated space conditions (vacuum, low temperature). A long-wave infrared digital holographic interferometer for the verification and validation of this type of reflector in a space environment is presented. It has been developed to fill the gap between holography/interferometry techniques in the visible wavelengths and methods based on structured light illumination like videogrammetry, stereocorrelation, and fringe/pattern projection. The former provide a good measurement uncertainty but the displacements are often too large to be measured and they require a very stable environment, while the latter provide large measurement range but with higher measurement uncertainty. The new instrument is based on digital holography and uses a CO2 lasers emitting at 10.6 µm combined with a commercial thermographic camera. A diffuser is illuminated by the laser beam, producing a speckle wavefront which is observed after reflection on the reflector surface. This reflected speckle wavefront behaves exactly as if the reflector was a diffusive surface, producing its own speckle, allowing the measurement of its deformation. The advantage of this configuration compared to a classical interferometer working at 10.6 µm, is that it requires no specific optics such as a null lens (in the case of parabola) or expensive illumination/collection optics (in the case of ellipse). The metrological certification of the system was performed in the laboratory by measuring the tilts of a 1.1 meter diameter parabolic reflector. The displacements are measured in parallel with a Doppler effect interferometer and the measurement uncertainty is estimated. The application of the new interferometer to the measurement of an elliptic reflector is also presented. The technique has been certified during a thermal-vacuum test. The deformation of the parabolic reflector is measured for a temperature variation from 288 K down to 113 K. The results are compared to previous results obtained on the same reflector with a high spatial resolution infrared interferometer, also developed at CSL. [less ▲]

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See detailLong-wavelength behavior of the exchange-correlation kernel in the Kohn-Sham theory of periodic systems
Ghosez, Philippe ULg; Gonze, X.; Godby, R. W.

in Physical Review. B : Condensed Matter (1997), 56(20), 12811-12817

The polarization dependence of the exchange-correlation (re) energy functional of periodic insulators within Kohn-Sham (KS) density-functional theory requires a O(1/q(2)) divergence in the re kernel for ... [more ▼]

The polarization dependence of the exchange-correlation (re) energy functional of periodic insulators within Kohn-Sham (KS) density-functional theory requires a O(1/q(2)) divergence in the re kernel for small vectors q. This behavior, exemplified for a one-dimensional model semiconductor, is also observed when an insulator happens to be described asa KS metal, or vice versa. Although it can occur in the exchange-only kernel, it is not found in the usual local, semilocal, or even nonlocal approximations to KS theory. We also show that the test-charge and. electronic definitions of the macroscopic dielectric constant differ from one another in exact KS theory, but are equivalent in the above-mentioned approximations. [less ▲]

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See detailLongevity and annuities: an introduction
Cremer, Helmuth; Pestieau, Pierre ULg

in Journal of Public Economic Theory (2010), (12), 1-5

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See detailA longirostrine Temnodontosaurus (Ichthyosauria) with comments on Early Jurassic ichthyosaur niche partitioning and disparity
Martin, Jeremy; Fischer, Valentin ULg; Vincent, Peggy et al

in Palaeontology (2012), 55(1), 9951005

We describe an almost complete ichthyosaur skeleton from the middle Toarcian (Lower Jurassic) of the Beaujolais foothills near Lyon, France, and assign it to Temnodontosaurus azerguensis sp. nov. This new ... [more ▼]

We describe an almost complete ichthyosaur skeleton from the middle Toarcian (Lower Jurassic) of the Beaujolais foothills near Lyon, France, and assign it to Temnodontosaurus azerguensis sp. nov. This new species exhibits cranial peculiarities such as a thin, elongated and possibly edentulous rostrum, as well as a reduced quadrate. These characters indicate dietary preferences that markedly differ from other species referred to Temnodontosaurus, a genus previously considered as the top predator of the Early Jurassic seas. Despite a conservative postcranial skeleton, we propose that Temnodontosaurus is one of the most ecologically disparate genera of ichthyosaurs, including apex predators and now a soft prey longirostrine hunter. Ammonites collected from the same stratigraphic level as the described specimen indicate that the new species is somewhat younger (bifrons ammonite zone) than the most known Toarcian ichthyosaurs and therefore slightly postdates the interval of severe environmental changes and marine invertebrate extinctions known as the Toarcian Oceanic Anoxic Event. The present study therefore raises the question of whether postcrisis recovery of vertebrate faunas, including the radiation of Temnodontosaurus into a new ecological niche, may have been a consequence of marine ecosystem reorganization across this event. [less ▲]

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See detailLongitudinal analysis of ordinal data
Donneau, Anne-Françoise ULg; Mauer, M

Conference (2009, June 30)

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See detailLongitudinal assessment of progress in reasoning capacity and relation with self-estimation of knowledge base
Collard, Anne ULg; Mélot, France ULg; Bourguignon, Jean-Pierre ULg

in Assessment & Evaluation in Higher Education (2014)

The aim of the study was to investigate progress in reasoning capacity and knowledge base appraisal in a longitudinal analysis of data from summative evaluation throughout a medical problem-based learning ... [more ▼]

The aim of the study was to investigate progress in reasoning capacity and knowledge base appraisal in a longitudinal analysis of data from summative evaluation throughout a medical problem-based learning curriculum. The scores in multidisciplinary discussion of a clinical case and multiple choice questionnaires (MCQs) were studied longitudinally for 213 students from years 2 to 5. The capacity of core knowledge delimitation was calculated as the difference between the levels of average ascertainment degrees given for correct and incorrect answers at MCQ. For both multidisciplinary discussion of a clinical case evaluation and self-estimation of core knowledge, the capacity increases throughout the curriculum. The reasoning capacity assessed through multidisciplinary discussion of a clinical case is positively correlated with MCQ scores and the capacity to discriminate the mastered core knowledge. In conclusion, this study indicates that self-estimation of core knowledge is associated with an increase in reasoning performance through a well-organised knowledge base. Since that ability is related to success or failure, it is suggested that student awareness about delimitation of mastered core knowledge is considered as part of learning. [less ▲]

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See detailLongitudinal effects of muscular hypertrophy allele on milk production traits during the lactation using a novel equivalent model when molecular information is limited
Colinet, Frédéric ULg; Gengler, Nicolas ULg

in Proceedings of the 9th World Congress on Genetics Applied to Livestock Production (2010, August)

Given that the mh allele causes the double muscling phenotype, this allele could also influence milk production traits of the dual purpose Belgian Blue cattle. However, all dual purpose Belgian Blue ... [more ▼]

Given that the mh allele causes the double muscling phenotype, this allele could also influence milk production traits of the dual purpose Belgian Blue cattle. However, all dual purpose Belgian Blue animals could not be genotyped. So, a new alternative strategy for the prediction of gene effects and especially their smooth integration into genetic evaluations based on an equivalent method was developed from existing theory. Developed equations were modified to allow that not all animals were genotyped. As expected, the mh allele had negative effects on milk production traits. For the first three lactations, the average estimated allelic substitution effects were -0.074 % fat content and -158.7 kg milk per lactation (305 days). Moreover, effects of mh allele were not constant during the lactation. [less ▲]

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See detailLongitudinal effects of muscular hypertrophy allele on milk production traits during the lactation using a novel equivalent model when molecular information is limited
Colinet, Frédéric ULg; Gengler, Nicolas ULg

Conference (2010, August)

Given that the mh allele causes the double muscling phenotype, this allele could also influence milk production traits of the dual purpose Belgian Blue cattle. However, all dual purpose Belgian Blue ... [more ▼]

Given that the mh allele causes the double muscling phenotype, this allele could also influence milk production traits of the dual purpose Belgian Blue cattle. However, all dual purpose Belgian Blue animals could not be genotyped. So, a new alternative strategy for the prediction of gene effects and especially their smooth integration into genetic evaluations based on an equivalent method was developed from existing theory. Developed equations were modified to allow that not all animals were genotyped. As expected, the mh allele had negative effects on milk production traits. For the first three lactations, the average estimated allelic substitution effects were -0.074 % fat content and -158.7 kg milk per lactation (305 days). Moreover, effects of mh allele were not constant during the lactation. [less ▲]

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See detailA longitudinal epidemiological survey of bovine trypanosomosis and its vectors in the White Volta river basin of Northern Ghana
Mahama, C. I.; Desquesnes, M.; Dia, M. L. et al

in Veterinary Parasitology (2005), 128(3-4), 201-208

A longitudinal epidemiological survey of bovine trypanosomosis and its vectors was carried out in the Volta river basin of Northern Ghana to determine the relationship between cattle management and the ... [more ▼]

A longitudinal epidemiological survey of bovine trypanosomosis and its vectors was carried out in the Volta river basin of Northern Ghana to determine the relationship between cattle management and the incidence of bovine trypanosomosis. Two groups of sentinel cattle under different systems of management, classified as "fully-sedentary" and "partially-sedentary" (depending on the type of management) were followed over a 1-year period starting from March 2003 onwards. Cattle were screened at intervals of 3 months using the huffy coat technique (BCT). Buffy coat specimen from animals that were positive for the BCT and those that were negative, but with a packed cell volume (PCV) of less than 21% were further tested using the polymerase chain reaction (PCR). Plasma from all animals were tested for antibody using the indirect antibody enzyme-linked immunosorbent assay (ELISA). Trypanosomosis challenge was determined in tandem with the epidemiological survey with watering sites of sentinel cattle being the foci of interest. The parasitological prevalence at the start of the survey was higher in the fully-sedentary group (9%) than in the partially-sedentary group (3%). In subsequent visits, however, the parasitological incidence was consistently higher in the partially-sedentary group than in the fully-sedentary group. The mean seroprevalence (ELISA) of both groups increased from 3% in March to 54% in December. Statistical analysis of the serological results using a random effect logistic regression, showed a significant difference in incidence of bovine trypanosomosis between the two groups. There was also a significant effect of time. The influence of cattle herding on host-vector-parasite interface and its consequence on the incidence of trypanosomosis are discussed. (c) 2004 Elsevier B.V. All rights reserved. [less ▲]

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See detailLongitudinal evaluation of the bed load size and of its mobilisation in a gravel bed river
Deroanne, C.; Petit, François ULg

in Floods and Landslides, Integrated Risk Assesment (1999)

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See detailLongitudinal field study on bovine Babesia spp. and Anaplasma phagocytophilum infections during a grazing season in Belgium
Lempereur, Laetitia ULg; Lebrun, Maude; Cuvelier, Pascale et al

in Parasitology Research (2012), 110(4), 1525-1530

Anaplasmosis and babesiosis are major tick-borne diseases with a high economic impact but are also a public health concern. Blood samples collected in the spring, summer, and autumn of 2010 from 65 cows ... [more ▼]

Anaplasmosis and babesiosis are major tick-borne diseases with a high economic impact but are also a public health concern. Blood samples collected in the spring, summer, and autumn of 2010 from 65 cows in seven different farms in Belgium were monitored with an indirect immunofluorescence antibody test to assess seroprevalence against these pathogens. Seroprevalences to Babesia spp. were measured as 10.7%, 20%, and 12.3% in spring, summer, and autumn, respectively, whereas seroprevalences to Anaplasma phagocytophilum were 30.8%, 77%, and 56.9%, respectively. A total of 805 Ixodes ricinus ticks were collected at the same time from both cattle (feeding ticks) and grazed pastures (questing ticks). The infection level of ticks, assessed by PCR assay, for Babesia spp. DNA was 14.6% and 7.9% in feeding and questing ticks, respectively, whereas 21.7% and 3% of feeding and questing ticks were found be positive for A. phagocytophilum cDNA. Fifty-five PCR-positive samples were identified by sequencing as Babesia sp. EU1, of which five from feeding ticks were positive for both A. phagocytophilum and Babesia sp. EU1. The high density of wild cervids in the study area could explain these observations, as deer are considered to be the main hosts for adults of I. ricinus. However, the absence of Babesia divergens both in feeding and questing ticks is surprising, as the study area is known to be endemic for cattle babesiosis. Increasing cervid populations and comorbidity could play an import role in the epidemiology of these tick-borne diseases. [less ▲]

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See detailLongitudinal Monitoring of Immune Reconstitution After Allogeneic Peripheral Blood Stem Cell Transplantation (HSCT): Impact of T Cell Depletion of the Graft
SERVAIS, Sophie ULg; Hannon, Muriel ULg; Daulne, Coline ULg et al

in Belgian Journal of Hematology (2011), Abstracts book(Supplement of 26th General Meeting of the Belgian Hematological Society), 31

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See detailA longitudinal perspective of alcohol use among adolescents: the predictive role of peers and internalizing factors.
Schmits, Emilie ULg; Glowacz, Fabienne ULg; Quertemont, Etienne ULg

Poster (2014, July 09)

Alcohol is the most commonly used psychoactive substance among teenagers. Consumption is influenced by environmental factors and personal characteristics, events or experiences. High use can lead to ... [more ▼]

Alcohol is the most commonly used psychoactive substance among teenagers. Consumption is influenced by environmental factors and personal characteristics, events or experiences. High use can lead to substantial problems, especially after an early consumption. Detecting and preventing an increase of alcohol use among teenagers, through the identification of risk and protective factors, seems essential in terms of public health. This study aimed to examine the progression of use in young teenagers, to identify protective and risk factors of alcohol use (including peers and internalizing factors) and to specifically focus on the influence of social anxiety. A questionnaire was administered twice to 877 teenagers (49.94% female, M=15.61) with one year interval (T1 and T2). Sex, age, alcohol use, number of friends, social comparison, trait-anxiety, social anxiety and depression were assessed through validated scales. T-test for paired sample and hierarchical regressions were performed. During the follow-up year, the average alcohol use significantly increased. A positive social comparison at T1 significantly predicted alcohol use at T2. The more teenagers positively compared themselves to their friends and felt popular, the more they consume alcohol. A similar significant effect was demonstrated for depression. The more young people manifested depressive affects at T1, the more they used alcohol at T2. However, social anxiety significantly protected from this substance use. More social anxiety at T1 was associated with less alcohol consumption at T2. The number of friends and trait-anxiety at T1 did not significantly influence alcohol use at T2. A positive social comparison and depressive affects could be considered as risk factors, whereas social anxiety could be defined as protective factor. At this developmental period, young people suffering from social anxiety symptoms subsequently use less alcohol, maybe due to the lack of contact with this substance usually socially consumed, whereas more popular and integrated teenagers are more at risk. The present results challenge the tension-reduction model according to which alcohol is consumed to reduce anxious affects and to facilitate social relationships. However, results suggest that alcohol might be used to reduce unpleasant depressive affects. [less ▲]

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See detailLongitudinal quality of life assessment in cancer trials: should data be treated as continuous or ordinal?
Donneau, Anne-Françoise ULg; Mauer, Murielle; Coens, Corneel et al

Poster (2013, October 11)

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See detailLongitudinal quality of life data: a comparison of continuous and ordinal approaches
Donneau, Anne-Françoise ULg; Mauer, Murielle; Coens, C et al

in Quality of Life Research (2014), 23(10), 2873-2881

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See detailA longitudinal study of ABC transporter expression in canine multicentric lymphoma.
Zandvliet, M.; Teske, Erik ULg; Schrickx, J. A. et al

in Veterinary journal (London, England : 1997) (2014)

Canine lymphoma is typically treated with a doxorubicin-based multidrug chemotherapy protocol. Although this is often initially successful, tumour recurrence is common and frequently refractory to ... [more ▼]

Canine lymphoma is typically treated with a doxorubicin-based multidrug chemotherapy protocol. Although this is often initially successful, tumour recurrence is common and frequently refractory to treatment. Failure to respond to chemotherapy is thought to represent drug resistance and has been associated with active efflux of cytostatic drugs by transporter proteins of the ATP-binding cassette (ABC) family, including P-glycoprotein (ABCB1), MRP1 (ABCC1) and BCRP (ABCG2). In this study, ABC transporter mRNA expression was assessed in 63 dogs diagnosed with multicentric lymphoma that were treated with a doxorubicin-based chemotherapy protocol. Expression of ABCB1, ABCB5, ABCB8, ABCC1, ABCC3, ABCC5 and ABCG2 mRNA was quantified in tumour samples (n = 107) obtained at the time of diagnosis, at first tumour relapse and when the tumour was no longer responsive to cytostatic drugs while receiving chemotherapy. Expression data were related to patient demographics, staging, treatment response and drug resistance (absent, intrinsic, acquired). ABC transporter expression was independent of sex, weight, age, stage or substage, but T cell lymphoma and hypercalcaemia were associated with increased ABCB5 and ABCC5 expression, and decreased ABCC1 mRNA expression. Drug resistance occurred in 35/63 (55.6%) dogs and was associated with increased ABCB1 mRNA expression in a subset of dogs with B cell lymphoma, and with increased ABCG2 and decreased ABCB8, ABCC1 and ABCC3 mRNA expression in T cell lymphomas. ABC transporter expression in the pre-treatment sample was not predictive of the length of the first disease-free period or overall survival. Glucocorticoids had no effect on ABC transporter mRNA expression. In conclusion, drug resistance in canine multicentric lymphoma is an important cause of treatment failure and is associated with upregulation of ABCB1 and ABCG2 mRNA. [less ▲]

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