References of "2012"
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See detailEncoded haplotype data as input to ipPCA can better resolve population clustering
Chaichoompu, Kridsadakorn ULg; Pongsakorn, Wangkumhang; Anunchai, Assawamakin et al

Poster (2012, October)

Background Studies in population genetics are mainly based on the analysis of genetic variations among different populations. With the advent of advanced genotyping technology, large number of Single ... [more ▼]

Background Studies in population genetics are mainly based on the analysis of genetic variations among different populations. With the advent of advanced genotyping technology, large number of Single Nucleotide Polymorphisms (SNPs) can be used to capture the underlying population variations. Iterative pruning principal component analysis (ipPCA) is a very powerful tool to cluster subpopulations based on their SNP profiles. However, when several similar populations are considered in the analysis, differentiating these populations can become very challenging. Haplotype has been known to capture more segregation information and higher power than SNP but due to high inference complexity, this concept has not been widely used. Recently, haplotype sharing (HS) was reported as a good alternative method to evaluate variation among populations. HS interrogates the entire genotyping without estimating haplotype block, making it computational efficient, yet retaining population profile. Adopting HS technique and introducing a new haplotype encoding as the input to ipPCA to perform population clustering can yield very good outcomes. Results In this study we transformed an indigenous Thai SNP genotyping data, obtained from Pan Asian SNP consortium, into encoded haplotype profiles. The dataset include 13 indigenous populations (245 individuals) composing of approximately 54K SNPs for each individual. To do this, an encoded haplotype matrix was constructed by inferring overlapping haplotype based on sliding window approach in BEAGLE, an efficient haplotype inference tool. We fed this encoded haplotype matrix to ipPCA to cluster these individuals into sub-groups using only their genetic profiles. We compared the results obtained from standard protocol of ipPCA with the one that use the encoded haplotype matrix in terms of numbers of clustered subpopulations as well as the accuracy to correctly assign an individual to a correct subpopulation. Using the encoded haplotype matrix as input to ipPCA rendered the exact 13 subpopulations to be clustered with 99.18% of individual assignment accuracy, whereas the conventional ipPCA identified only 10 subpopulations with 93.47% of individual assignment accuracy. Conclusions Our result demonstrated the great potential of using the encoded haplotype matrix with ipPCA for population genetics studies. This new protocol can promote the clustering of individuals using only their genetic profiles. [less ▲]

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See detailDe la réciprocité des échanges aux dettes d’alliance : L’anti-Œdipe et l’économie politique des sociétés “primitives”
Janvier, Antoine ULg

in Actuel Marx (2012), 52

The present article aims at pinpointing the issues involved in the analysis of the economy of ‘primitive’ societies carried out by Deleuze and Guattari in Anti-Oedipus by relying on a logic of debt ... [more ▼]

The present article aims at pinpointing the issues involved in the analysis of the economy of ‘primitive’ societies carried out by Deleuze and Guattari in Anti-Oedipus by relying on a logic of debt (Nietzsche) rather than on a logic of reciprocity (Lévi-Strauss). Deleuze and Guattari’s critical discussion of Lévi-Strauss’s ethnology should related to the problematization of kinship as a system of alliance and filiation relationships suggested by French Marxist anthropology (E. Terray, C. Meillassoux) on the one hand, and to Edmund Leach’s critical anthropology on the other. This double mediation helps to show that in Anti-Oedipus, Deleuze and Guattari seek to identify the political strategies which are at work in economic relationships, that is to say, in the present case, the finite alliance strategies in ‘primitive’ societies, which are deeper than trade and production relationships. [less ▲]

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See detailEUV high resolution imager on-board Solar Orbiter: optical design and detector performances.
Halain, Jean-Philippe ULg; Mazzoli, Alexandra ULg; Rochus, Pierre ULg et al

Poster (2012, October)

The EUV high resolution imager (HRI) channel of the Extreme Ultraviolet Imager (EUI) on-board Solar Orbiter will observe the solar atmospheric layers at 17.4 nm wavelength with a 200 km resolution. The ... [more ▼]

The EUV high resolution imager (HRI) channel of the Extreme Ultraviolet Imager (EUI) on-board Solar Orbiter will observe the solar atmospheric layers at 17.4 nm wavelength with a 200 km resolution. The HRI channel is based on a compact two mirrors off-axis design. The spectral selection is obtained by a multilayer coating deposited on the mirrors and by redundant Aluminum filters rejecting the visible and infrared light. The detector is a 2k x 2k array back-thinned silicon CMOS-APS with 10 µm pixel pitch, sensitive in the EUV wavelength range. Due to the instrument compactness and the constraints on the optical design, the channel performance is very sensitive to the manufacturing, alignments and settling errors. A trade-off between two optical layouts was therefore performed to select the final optical design and to improve the mirror mounts. The effect of diffraction by the filter mesh support and by the mirror diffusion has been included in the overall error budget. Manufacturing of mirror and mounts has started and will result in thermo-mechanical validation on the EUI instrument structural and thermal model (STM). Because of the limited channel entrance aperture and consequently the low input flux, the channel performance also relies on the detector EUV sensitivity, readout noise and dynamic range. Based on the characterization of a CMOS-APS back-side detector prototype, showing promising results, the EUI detector has been specified and is under development. These detectors will undergo a qualification program before being tested and integrated on the EUI instrument. [less ▲]

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See detailApplication of a new thermo-mechanical model for the study of the nuclear waste disposal in clay rocks
Dizier, A.; François, B.; Collin, Frédéric ULg et al

Poster (2012, October)

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See detailHigh precision astrometry mission for the detection and characterization of nearby habitable planetary systems with the Nearby Earth Astrometric Telescope (NEAT)
Malbet, Fabien; Léger, Alain; Shao, Michael et al

in Experimental Astronomy (2012), 34(2), 385-413

A complete census of planetary systems around a volume-limited sample of solar-type stars (FGK dwarfs) in the Solar neighborhood (d ≤ 15 pc) with uniform sensitivity down to Earth-mass planets within ... [more ▼]

A complete census of planetary systems around a volume-limited sample of solar-type stars (FGK dwarfs) in the Solar neighborhood (d ≤ 15 pc) with uniform sensitivity down to Earth-mass planets within their Habitable Zones out to several AUs would be a major milestone in extrasolar planets astrophysics. This fundamental goal can be achieved with a mission concept such as NEAT—the Nearby Earth Astrometric Telescope. NEAT is designed to carry out space-borne extremely-high-precision astrometric measurements at the 0.05 μas (1 σ) accuracy level, sufficient to detect dynamical effects due to orbiting planets of mass even lower than Earth's around the nearest stars. Such a survey mission would provide the actual planetary masses and the full orbital geometry for all the components of the detected planetary systems down to the Earth-mass limit. The NEAT performance limits can be achieved by carrying out differential astrometry between the targets and a set of suitable reference stars in the field. The NEAT instrument design consists of an off-axis parabola single-mirror telescope (D = 1 m), a detector with a large field of view located 40 m away from the telescope and made of 8 small movable CCDs located around a fixed central CCD, and an interferometric calibration system monitoring dynamical Young's fringes originating from metrology fibers located at the primary mirror. The mission profile is driven by the fact that the two main modules of the payload, the telescope and the focal plane, must be located 40 m away leading to the choice of a formation flying option as the reference mission, and of a deployable boom option as an alternative choice. The proposed mission architecture relies on the use of two satellites, of about 700 kg each, operating at L2 for 5 years, flying in formation and offering a capability of more than 20,000 reconfigurations. The two satellites will be launched in a stacked configuration using a Soyuz ST launch vehicle. The NEAT primary science program will encompass an astrometric survey of our 200 closest F-, G- and K-type stellar neighbors, with an average of 50 visits each distributed over the nominal mission duration. The main survey operation will use approximately 70% of the mission lifetime. The remaining 30% of NEAT observing time might be allocated, for example, to improve the characterization of the architecture of selected planetary systems around nearby targets of specific interest (low-mass stars, young stars, etc.) discovered by Gaia, ground-based high-precision radial-velocity surveys, and other programs. With its exquisite, surgical astrometric precision, NEAT holds the promise to provide the first thorough census for Earth-mass planets around stars in the immediate vicinity of our Sun. [less ▲]

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See detailApprentissage et contenus en fonction de l’âge
Jidovtseff, Boris ULg; Theunissen, Catherine ULg

Learning material (2012)

Ces notes présentent l'évolution de l'apprentissage en fonction de l'âge.

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See detailDessine-moi un Hôpital de jour : dessein du cadre thérapeutique
Close, mireille; Landauer, valérie; Noirfalise, Stéphanie et al

in Revue des Hôpitaux de Jour Psychiatriques et des Thérapies Institutionnelles (2012), 14

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See detailFamilial Pituitary Syndromes
Beckers, Albert ULg

Scientific conference (2012, October)

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See detailPoly-SiGe-based MEMS Xylophone Bar Magnetometer
Rochus, Véronique; Jansen, R.; Tilmans, H. A. C. et al

in IEEE SENSORS 2012 (2012, October)

This paper presents the design, fabrication and preliminary characterization of highly sensitive MEMS-based Xylophone Bar Magnetometers (XBMs) realized in imec’s poly-SiGe MEMS technology. Key for our ... [more ▼]

This paper presents the design, fabrication and preliminary characterization of highly sensitive MEMS-based Xylophone Bar Magnetometers (XBMs) realized in imec’s poly-SiGe MEMS technology. Key for our Lorentz force driven capacitively sensed resonant sensor are the combination of reasonably high Q-factor and conductivity of imec’s poly-SiGe, our optimized multiphysics sensor design targeting the maximization of the Q-factor in a wide temperature range as well as our proprietary monolithic above-CMOS integration and packaging schemes. Prototypes 3-axis devices were fabricated and characterized. We present optical vibrometer and electrical S-parameter measurements of XBMs performed in vacuum with a reference magnet at increasing sensor separation. The optical oscillation amplitude is well correlated with the magnetic field amplitude. The electrical 2-port measurements, 1st port as Lorentz force actuator and 2nd port as capacitive sensor, also reproduces the designed magnetic field dependence. This opens the way towards the on-chip integration of small footprint extremely sensitive magnetometers. [less ▲]

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See detailFamilial Isolated Pituitary Adenomas
Beckers, Albert ULg

Scientific conference (2012, October)

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See detailStudy of the Boettcher cells along their development: Junctions and expression of the urea-transporter B (UT-B)
Cloes, Marie ULg; Renson, Thomas; Johnen, Nicolas ULg et al

Poster (2012, September 30)

The Boettcher cells (BC) lie on the sensory epithelium of the cochlea. Their function has never been clearly defined. However it has been suggested that they may influence the ionic composition of the ... [more ▼]

The Boettcher cells (BC) lie on the sensory epithelium of the cochlea. Their function has never been clearly defined. However it has been suggested that they may influence the ionic composition of the fluids of the inner ear, which play a central role in the conduction of the sensory information. In this context the compartimentating function of the BC around and after the onset of hearing may influence the subsequent refining of hearing. We collected ultrastructural and immunohistological data during the final maturation stage of the sensory epithelium. In particular the cell junctions were investigated to clarify the compartimentating function of the BC at early stages. As a potential actor in the ion flow in the sensory epithelium, the urea transporter-B (UT-B) was also immunolocalised during the development of the BC. At the mature stage (P25) the BC are linked to the adjacent cells by numerous adherens and non-adherens junctions. They rest on a basilar membrane to which they are attached by hemidesmosomes. They typically exhibit large basolateral interdigitations. We found that, at the 8th postnatal day, the BC are separated from the neighbouring cells by wide spaces entered by scarce cytoplasmic extensions. These spaces are interrupted by areas of close contact, where adherens and non-adherens junctions may be found. Thus, although there seems to be fewer interdigitations at P8, gap junctions probably still allow easy cell-to-cell exchanges. Moreover non-adherens junctions can systematically be identified apically. Although it was impossible to differenciate tight and gap junctions without specific labeling, we postulate that these non-adherens junctions correspond to tight junctions and seal the apex of the BC. This feature is necessary to enable the control of the ion concentrations surrounding the sensory epithelium. We also found that UT-B, known for water and urea transport in red blood cells, is present in the membranes of the BC from P12 (the earliest stage tested) to P25. Thus UT-B may play a role in the regulation of the ionic concentrations of the inner ear fluids. [less ▲]

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See detailWhen should we measure Vitamin D in Clinical Practice
CAVALIER, Etienne ULg

Conference (2012, September 29)

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See detailMultimodality blood conservation strategy in cardiac surgery with cardiopulmonary bypass : the CHU of Liège experience
ERPICUM, Marie ULg; BLAFFART, Francine ULg; DEFRAIGNE, Jean ULg et al

Poster (2012, September 29)

Introduction: The aim of this study is to analyze the transfusion rates of cardiac surgery patients in a single centre following an in-house strategy of blood conservation. Methods: The data of all adult ... [more ▼]

Introduction: The aim of this study is to analyze the transfusion rates of cardiac surgery patients in a single centre following an in-house strategy of blood conservation. Methods: The data of all adult patients undergoing normothermic cardiac surgery with cardiopulmonary bypass (CPB) over a 1 year period were retrospectively collected (n=491). Management protocols were described. The transfusion rates of allogeneic blood components were recorded: red blood cells (RBC), fresh frozen plasma (FFP) and platelets (PT), as well as the number of units transfused. The timing of transfusion was categorized: during CPB (peroperative period), within the first 48 postoperative hours after wean out CPB (early postoperative period) and during the hospitalisation from surgery until discharge (hospitalisation). The hematocrit values were recorded during CPB, 10 minutes after wean out CPB, after the first 48 postoperative hours and at discharge from hospital. Results: Two hundred and forty-eight patients (50%) received an allogeneic blood component transfusion during hospitalisation. One hundred and twenty-one patients (25%) received RBC during the operative period; the median of units transfused was 2(1-2).The lowest hematocrit value during CPB was 21(19-24) % in median. A cell salvage device was used in each case: the median volume of washed red blood cells transfused was 678(512-891) mL. The median hematocrit value after CPB was 23(21-25) %. One hundred and sixty-five patients (34%) were transfused in the early postoperative period: 27% received RBC, 18% received FFP and 18% received PT. The median of units transfused was 2(1-3) for RBC, 4(2-6) for FFP and 1(1-2) for PT. The median hematocrit value after 48 hours was 32(29-34) % and 32(30-35) % at discharge. Conclusion: The transfusion rates observed in this series are relatively high compared with the literature. Improvements will be made in our practice and protocols management in order to decrease the need of transfusion. This detailed audit of the transfusion practices in our cardiac surgery centre would be helpful to value the effectiveness of further improvements. [less ▲]

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See detailHjelmslev's notion of "Participation"
Cigana, Lorenzo ULg

Conference (2012, September 29)

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See detailAbout the diagnosis of acute transfusion-related reaction during cardiopulmonary bypass
ERPICUM, Marie ULg; BLAFFART, Francine ULg; DEFRAIGNE, Jean ULg et al

Conference (2012, September 29)

Many advances have been realized in the field of blood safety during the last decade: donors’ selection, leukoreduction of packed red blood cells and platelet concentrates, genomic screening of blood ... [more ▼]

Many advances have been realized in the field of blood safety during the last decade: donors’ selection, leukoreduction of packed red blood cells and platelet concentrates, genomic screening of blood-borne diseases, viral and bacterial inactivation process,... However, transfusion of blood components remains unsafe. Therefore, detecting and reporting transfusion-related complications are still essential means for both the patients’ management and the public health approach, since these measures help to adjust preventive measures to be applied in a haemovigilance purpose. Most acute transfusion-related complications occur within minutes or hours after transfusion and require urgent medical care; delayed transfusion reactions may also develop days, even months later, implying a longer follow-up. Transfusion of red blood cells is not infrequent during cardiac surgery with cardiopulmonary bypass. Symptoms of acute transfusion-related reactions include hypotension, diffuse bleeding, hemoglobinuria and oliguria. These symptoms are identical to those that can be observed during a complicated cardiopulmonary bypass. Consequently, identification of acute transfusion-related reactions in this particular situation is quite difficult and probably leads to an under-reporting of their occurrence. In this paper, we explore how to track acute transfusion-related reactions during cardiopulmonary bypass. Any suspicion of such reactions must leads to investigations, in order to confirm the diagnosis. Their detection would allow to better focus their specific treatment and further their notification in a global blood safety policy. [less ▲]

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See detailCardiac surgery and acute kidney injury: retrospective study
LAGNY, Marc-Gilbert ULg; BLAFFART, Francine ULg; Defraigne, Jean-Olivier ULg et al

Conference (2012, September 29)

Background: In cardiac surgery, acute kidney injury (AKI) is a severe postoperative complication and associated with increased rates of mortality, morbidity, and length of stay in intensive care units ... [more ▼]

Background: In cardiac surgery, acute kidney injury (AKI) is a severe postoperative complication and associated with increased rates of mortality, morbidity, and length of stay in intensive care units (ICU). It occurs in 5% to 30% of patients depending on the definition used [1] [2] [3]. The aim of this study is to present an overview of AKI following cardiac surgery associated or not with cardiopulmonary bypass. Methods: This retrospective study includes patients treated by cardiac surgery from April 1st, 2008 to March 31th, 2009 in a single center. We selected patients who underwent on-pump coronary artery bypass surgery (CABG), off-pump CABG (OPCAB), aortic valve replacement, mitral valve repair or replacement and aortic valve replacement combined with CABG. Patients undergoing renal replacement therapy preoperatively were excluded. The RIFLE classification (Risk, Injury, Failure, Loss and End stage kidney disease) allowed to stratify the patients into the 3 grades of AKI severity. The stratification was based on the most pejorative element observed within 7 days after surgery: increased serum creatinine level or decreased urine output, or decreased glomerular filtration rate according to criteria of Bellomo [4]. Occurrence of AKI was studied by type of cardiac surgery as its impact on the length of stay in ICU and in the hospital. Proportions were compared by the Chi-square test and median values by the Kruskal-Wallis. Results were considered significant at p < 0.05. Results: Four hundred and thirty four patients were included: median (IQR) age 69.0(60.0-76.0) year, 30.2% females, 2.76% urgent/emergent cases. Fifty-eight patients (13.4%) underwent OPCAB, 182(41.9%) on-pump CABG, 104(24.0%) aortic valve replacement, 44(10.1%) mitral valve repair or replacement and 46(10.6%) aortic valve replacement combined with CABG. AKI occurred in 213(49.1%) patients: 79(37.1%) “Risk”, 108(50.7%) “Injury” and 26(12,2%) “Failure”. Occurrence of AKI after OPCAB was 21(9.86%), CABG 80(37.6%), aortic valve replacement 51(23.9%), mitral valve surgery 23(10.8%) and aortic valve replacement combined with CABG 38(17.8%). AKI occurrences differed significantly between the different groups of surgery (p<0.0001). Lengths of stay in ICU were significantly longer (p<0.0001) in AKI group compared with non AKI group: 3(2-4) days versus 2(2-3) days. No difference (p = 0.65) was observed between the two (AKI and NON-AKI) groups in hospital length of stay: 13(10-18) days versus 12(10-16) days. Conclusions: The incidence of AKI is very high in this population as compared to the literature. This may be due to the fact that the three elements of the RIFLE classification for all the population studied have been used: serum creatinine level, urine output and glomerular filtration rate. This study emphasizes the need for clear definition of AKI in order to compare adequately different studies. AKI after cardiac surgery with cardiopulmonary bypass would be further studied in order to develop more appropriate preventive measures. [less ▲]

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See detailTransplantation et don d'organes en Belgique
DETRY, Olivier ULg

Conference (2012, September 29)

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See detailPostoperative bleeding and autotransfusion
ERPICUM, Marie ULg; BLAFFART, Francine ULg; DEFRAIGNE, Jean ULg et al

Poster (2012, September 29)

Introduction: Bleeding in the postoperative period of cardiac surgery is not infrequent. Mediastinal bleeding is usually collected in a chest drainage system and discarded. Nevertheless, this blood could ... [more ▼]

Introduction: Bleeding in the postoperative period of cardiac surgery is not infrequent. Mediastinal bleeding is usually collected in a chest drainage system and discarded. Nevertheless, this blood could potentially be managed with a cell salvage device during the first six postoperative hours. This practice is generally performed only in case of a surgical re-exploration for massive bleeding and may contribute to decreased allogeneic transfusion. But in case of postoperative coagulopathy requiring medical treatment, re-exploration is usually postponed and consequently, collected blood is discarded. Therefore, chest drainage systems combined with a cell salvage option could optimize the management of blood losses and transfusions in the postoperative period, regardless of any surgical re-exploration. The aim of this study is to assess the effectiveness of such a system during the postoperative period of cardiac surgery, in patient at high risk of bleeding. Method : During a 6 months period, the CardioPAT® (Haemonetics) device was used in all cardiac surgery patients at high risk of postoperative bleeding. The following data were prospectively collected: hemoglobin level, bleeding volume, volume of autologous washed red blood cell transfused by the CardioPAT® (WRBC), volume of allogeneic red blood cell (RBC), fresh frozen plasma (FFP) or platelets (PT) transfused and surgical re-exploration. Results : The CardioPAT® was used in 16 patients during the target period. Mean postoperative bleeding volume was 338±337mL after 1 hour and 820±727mL after 6 hours. The cell salvage option was used in 9 (56%) cases and mean WRBC transfused volume was 153±212mL. One patient required surgical re-exploration. All patients transfused by WRBC received previously an allogeneic transfusion (RBC, FFP and/or PT). The hemoglobin level of blood collected in the CardioPAT® device impacted on the delay and the blood volume required for WRBC availability; lower was the hemoglobin level, larger was the volume of blood required to obtain a concentrate of WRBC. Consequently, patients with a very low hemoglobin level were anyway transfused with RBC. Conclusion : The CardioPAT® device can reduce allogeneic blood transfusion after cardiac surgery in patients at high risk of bleeding. It gives time to treat coagulopathy, leading to a decrease of surgical re-exploration. However, a device with a larger reservoir and with a flexible processing speed would be more accurate in case of major haemorrhage. Systematic utilisation of this device at the time of FFP and/or PT transfusion is a safe but expensive strategy. It seems more accurate to use this device in a permissive bleeding strategy, waiting for the spontaneous coagulation recovery of the patient, in the first postoperative hours. [less ▲]

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