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See detailA tailored two-phase constructive heuristic for the three-dimensional Multiple Bin Size Bin Packing Problem with transportation constraints
Paquay, Célia ULg; Limbourg, Sabine ULg; Schyns, Michael ULg

E-print/Working paper (2017)

This paper considers the three-dimensional Multiple Bin Size Bin Packing Problem which consists in packing a set of cuboid boxes into containers of various shapes with minimising unused space. The problem ... [more ▼]

This paper considers the three-dimensional Multiple Bin Size Bin Packing Problem which consists in packing a set of cuboid boxes into containers of various shapes with minimising unused space. The problem is extended to air cargo where bins are Unit Load Devices, especially designed for fitting in aircraft. We developed a fast constructive heuristic able to manage the different constraints met in transportation. The heuristic is split into two distinct phases. The first phase deals with the packing of boxes into identical bins using an extension of the Extreme Points. During this phase, the fragility, stability and orientations of the boxes are taken into account as well as the special shape of the bins and their weight capacity. The second phase takes into account the multiple types of available bins. If necessary, the best found loading pattern is finally enhanced with respect to weight distribution in a post processing. After parametrisation, computational experiments have been performed on data sets especially designed for this application. The heuristic requires really short computational times to achieve promising results. [less ▲]

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See detailNumerical modelling of microscopic lubricant flow in sheet metal forming. Application to plane strip drawing
Carretta, Yves; Bech, Jacob; Legrand, Nicolas et al

in International Journal for Numerical Methods in Engineering (2017)

This paper presents a numerical investigation of microscopic lubricant flows from the cavities to the plateaus of the surface roughness of metal sheets during forming processes. This phenomenon, called ... [more ▼]

This paper presents a numerical investigation of microscopic lubricant flows from the cavities to the plateaus of the surface roughness of metal sheets during forming processes. This phenomenon, called micro-plastohydrodynamic lubrication, was observed experimentally in various situations such as compression sliding tests, strip drawing and cold rolling. It leads to local friction drop and wear reduction. It is therefore critical to achieve a good understanding of this phenomenon. As to move towards that goal, a multiscale fluid–structure interaction model is developed to model lubricant flows at the microscopic scale. These simulations are made possible through the use of the Arbitrary Lagrangian Eulerian (ALE) formalism. In this paper, this methodology is used to study plane strip drawing. The numerical model is able to predict the onset of lubricant escape and the amount of lubricant flowing on the plateaus. Numerical results exhibit good agreement with experimental measurements. [less ▲]

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See detailThe need for careful data collection for pattern recognition in digital pathology
Marée, Raphaël ULg

in Journal of Pathology Informatics (2017)

Effective pattern recognition requires carefully designed ground-truth datasets. In this technical note, we first summarize potential data collection issues in digital pathology and then propose ... [more ▼]

Effective pattern recognition requires carefully designed ground-truth datasets. In this technical note, we first summarize potential data collection issues in digital pathology and then propose guidelines to build more realistic ground-truth datasets and to control their quality. We hope our comments will foster the effective application of pattern recognition approaches in digital pathology. [less ▲]

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See detailNovel genetic loci associated with hippocampal volume.
Hibar, Derrek P.; Adams, Hieab H. H.; Jahanshad, Neda et al

in Nature Communications (2017), 8

The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are ... [more ▼]

The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer's disease (rg=-0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness. [less ▲]

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See detailReproducibility of tract-based white matter microstructural measures using the ENIGMA-DTI protocol.
Acheson, Ashley; Wijtenburg, S. Andrea; Rowland, Laura M. et al

in Brain and Behavior (2017), 7(2), 00615

BACKGROUND: In preparation for longitudinal analyses of white matter development in youths with family histories of substance use disorders (FH+) or without such histories (FH-), we examined the ... [more ▼]

BACKGROUND: In preparation for longitudinal analyses of white matter development in youths with family histories of substance use disorders (FH+) or without such histories (FH-), we examined the reproducibility and reliability of global and regional measures of fractional anisotropy (FA) values, measured using the Enhancing Neuro Imaging Genetics Through Meta Analysis (ENIGMA)-diffusion tensor imaging (DTI) protocol. Highly reliable measures are necessary to detect any subtle differences in brain development. METHODS: First, we analyzed reproducibility data in a sample of 12 healthy young adults (ages 20-28) imaged three times within a week. Next, we calculated the same metrics in data collected 1-year apart in the sample of 68 FH+ and 21 FH- adolescents. This is a timeframe where within subject changes in white matter microstructure are small compared to between subject variance. Reproducibility was estimated by examining mean coefficients of variation (MCV), mean absolute differences (MAD), and intraclass correlations (ICC) for global and tract-specific FA values. RESULTS: We found excellent reproducibility for whole-brain DTI-FA values and most of the white matter tracts, except for the corticospinal tract and the fornix in both adults and youths. There was no significant effect of FH-group on reproducibility (p = .4). Reproducibility metrics were not significantly different between adolescents and adults (all p > .2). In post hoc analyses, the reproducibility metrics for regional FA values showed a strong positive correlation (r = .6) with the regional FA heritability measures previously reported by ENIGMA-DTI. CONCLUSION: Overall, this study demonstrated an excellent reproducibility of ENIGMA-DTI FA, positing it as viable analysis tools for longitudinal studies and other protocols that repeatedly assess white matter microstructure. [less ▲]

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See detailTime related effects on functional brain connectivity after serotonergic and cholinergic neuromodulation.
Klaassens, Bernadet L.; Rombouts, Serge A. R. B.; Winkler, Anderson ULg et al

in Human Brain Mapping (2017), 38(1), 308-325

Psychopharmacological research, if properly designed, may offer insight into both timing and area of effect, increasing our understanding of the brain's neurotransmitter systems. For that purpose, the ... [more ▼]

Psychopharmacological research, if properly designed, may offer insight into both timing and area of effect, increasing our understanding of the brain's neurotransmitter systems. For that purpose, the acute influence of the selective serotonin reuptake inhibitor citalopram (30 mg) and the acetylcholinesterase inhibitor galantamine (8 mg) was repeatedly measured in 12 healthy young volunteers with resting state functional magnetic resonance imaging (RS-fMRI). Eighteen RS-fMRI scans were acquired per subject during this randomized, double blind, placebo-controlled, crossover study. Within-group comparisons of voxelwise functional connectivity with 10 functional networks were examined (P < 0.05, FWE-corrected) using a non-parametric multivariate approach with cerebrospinal fluid, white matter, heart rate, and baseline measurements as covariates. Although both compounds did not change cognitive performance on several tests, significant effects were found on connectivity with multiple resting state networks. Serotonergic stimulation primarily reduced connectivity with the sensorimotor network and structures that are related to self-referential mechanisms, whereas galantamine affected networks and regions that are more involved in learning, memory, and visual perception and processing. These results are consistent with the serotonergic and cholinergic trajectories and their functional relevance. In addition, this study demonstrates the power of using repeated measures after drug administration, which offers the chance to explore both combined and time specific effects. Hum Brain Mapp 38:308-325, 2017. (c) 2016 Wiley Periodicals, Inc. [less ▲]

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See detailInvestigating resting-state functional connectivity in the cervical spinal cord at 3T.
Eippert, Falk; Kong, Yazhuo; Winkler, Anderson ULg et al

in NeuroImage (2017), 147

The study of spontaneous fluctuations in the blood-oxygen-level-dependent (BOLD) signal has recently been extended from the brain to the spinal cord. Two ultra-high field functional magnetic resonance ... [more ▼]

The study of spontaneous fluctuations in the blood-oxygen-level-dependent (BOLD) signal has recently been extended from the brain to the spinal cord. Two ultra-high field functional magnetic resonance imaging (fMRI) studies in humans have provided evidence for reproducible resting-state connectivity between the dorsal horns as well as between the ventral horns, and a study in non-human primates has shown that these resting-state signals are impacted by spinal cord injury. As these studies were carried out at ultra-high field strengths using region-of-interest (ROI) based analyses, we investigated whether such resting-state signals could also be observed at the clinically more prevalent field strength of 3T. In a reanalysis of a sample of 20 healthy human participants who underwent a resting-state fMRI acquisition of the cervical spinal cord, we were able to observe significant dorsal horn connectivity as well as ventral horn connectivity, but no consistent effects for connectivity between dorsal and ventral horns, thus replicating the human 7T results. These effects were not only observable when averaging along the acquired length of the spinal cord, but also when we examined each of the acquired spinal segments separately, which showed similar patterns of connectivity. Finally, we investigated the robustness of these resting-state signals against variations in the analysis pipeline by varying the type of ROI creation, temporal filtering, nuisance regression and connectivity metric. We observed that - apart from the effects of band-pass filtering - ventral horn connectivity showed excellent robustness, whereas dorsal horn connectivity showed moderate robustness. Together, our results provide evidence that spinal cord resting-state connectivity is a robust and spatially consistent phenomenon that could be a valuable tool for investigating the effects of pathology, disease progression, and treatment response in neurological conditions with a spinal component, such as spinal cord injury. [less ▲]

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See detailHyperinsulinemia and elevated systolic blood pressure independently predict white matter hyperintensities with associated cognitive decrement in the middle-aged offspring of dementia patients.
Hawkins, Keith A.; Emadi, Nazli; Pearlson, Godfrey D. et al

in Metabolic Brain Disease (2017)

Cerebrovascular disease is an independent risk factor for dementia that may also be synergistic with Alzheimer's disease. In recent years attention has switched from cerebral infarcts to microvascular ... [more ▼]

Cerebrovascular disease is an independent risk factor for dementia that may also be synergistic with Alzheimer's disease. In recent years attention has switched from cerebral infarcts to microvascular disease as the primary cause of cerebrovascular cognitive decline, with damage to the white matter the primary mechanism. Uncertainties remain regarding the risks posed by different types vascular threat, the extent to which cerebrovascular damage occurs in middle age, and whether relatively "normal" amounts of white matter damage are accompanied by meaningful degrees of cognitive decline. We explored these issues via laboratory, cardiovascular, cognitive, and magnetic resonance imaging (MRI) data in 67 middle-aged cognitively normal offspring of dementia patients. The sample was enriched for vascular risk. Plasma insulin, 24-h systolic blood pressure, body mass index, age, and % small dense LDL cholesterol were the strongest correlates of MRI white matter hyperintensity (WMH) volume. With shared variance controlled for, 24 h systolic BP, plasma insulin, and age remained as significant predictors of WMH volume. An interaction variable (24 h BP * insulin) did not improve the prediction of WMH. WMH volume correlated negatively with cognition. No evidence for an ApoE epsilon4 effect emerged for either WMH or cognition. Hypertension and hyperinsulinemia appear to pose independent, consequential threats to the cerebral small vessel vasculature in middle age, reflected in the presence of areas of WMH on MRI scans. Our data show that even modest WMH volumes in middle age are associated with cognitive decrement, underscoring the importance of aggressive treatment and lifestyle modifications to address vascular risk throughout adulthood. [less ▲]

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See detailLes genres médiatiques de l'anticipation: des usages comiques du futur
Stienon, Valérie ULg

in Médias19 (2017)

La petite presse multiplie les usages comiques de la prédiction, tantôt en empruntant ses effets à l’almanach, tantôt en traitant au second degré les marronniers trop familiers, tantôt encore en ... [more ▼]

La petite presse multiplie les usages comiques de la prédiction, tantôt en empruntant ses effets à l’almanach, tantôt en traitant au second degré les marronniers trop familiers, tantôt encore en infléchissant vers la prospective le principe de la revue de fin d’année. Il est fréquent que les petits journaux satiriques feignent d’imaginer les événements à venir sous la forme de « prédictions pour l’année » et de « coups d’œil prophétiques ». Si de telles éphémérides parodiques ne bénéficient pas de la stabilité d’une rubrique spécifique, elles sont toutefois appelées, au siècle suivant, à prendre l’ampleur de numéros complets qui témoignent d’une postérité intéressante (Illustration, Lectures pour tous, VU, Sciences et voyages) et d’une créativité iconotextuelle qui peut aller jusqu’au faux reportage photographique d’anticipation. Cet article propose de cerner dans sa variété une microforme médiatique inhérente à la modernité de la petite presse. D’une part, sa discursivité porte sur des données socioculturelles présentées comme remarquables et novatrices, censées incarner la quintessence de leur époque tout entière tendue vers l’avenir. D’autre part, sa poétique affiche une temporalité méta-médiatique renvoyant aux fonctions rituelles et référentielles du périodique. [less ▲]

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See detailA Stochastic Multi-scale Model For Predicting MEMS Stiction Failure
Hoang Truong, Vinh ULg; Wu, Ling ULg; Paquay, Stéphane et al

in Starman, La Vern; Hay, Jennifer; Karanjgaokar, Nikhil (Eds.) Micro and Nanomechanics, Volume 5: Proceedings of the 2016 Annual Conference on Experimental and Applied Mechanics (2017)

Adhesion is an important phenomenon in the context of MEMS for which the surface forces become dominant in comparison with the body forces. Because the magnitudes of the adhesive forces strongly depend on ... [more ▼]

Adhesion is an important phenomenon in the context of MEMS for which the surface forces become dominant in comparison with the body forces. Because the magnitudes of the adhesive forces strongly depend on the surface interaction distances, which in turn evolve with the roughness of the contacting surfaces, the adhesive forces cannot be determined in a deterministic way. To quantify the uncertainties on the structural stiction behavior of a MEMS, this work proposes a “stochastic multi-scale methodology”. The key ingredient of the method is the evaluation of the random meso-scale apparent contact forces, which homogenize the effect of the nano-scale roughness and are integrated into a numerical model of the studied structure as a random contact law. To obtain the probabilistic behavior at the structural MEMS scale, a direct method needs to evaluate explicitly the meso-scale apparent contact forces in a concurrent way with the stochastic multi-scale approach. To reduce the computational cost, a stochastic model is constructed to generate the random meso-scale apparent contact forces. To this end, the apparent contact forces are parameterized by a vector of parameters before applying a polynomial chaos expansion in order to construct a mathematical model representing the probability of the random parameters vector. The problem of micro-beam stiction is then studied in a probabilistic way. [less ▲]

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See detailLes circuits courts : organisations hybrides sous haute(s) tension(s) ?
Maréchal, Kevin ULg; Plateau, Lou; Holzemer, Laurence

Conference (2017)

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See detailFormaliser le trope : De la subjectivité linguistique à la subjectivité épilinguistique
Mathy, Adrien ULg

in Signata. Annales des Sémiotiques = Annals of Semiotics (2017)

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See detailLa mise en œuvre du droit de plainte en Belgique francophone. Observation des processus de médiation en soins de santé
Dubois, Christophe ULg; Vandeninden, Elise ULg

in Revue Française des Affaires Sociales (2017), 1(1), 79-96

This article concerns the treatment of patients’ rights cases in French‐speaking Belgian hospitals by the “mediator”, that is, the person who has the legal duty of dealing with grievances arising from the ... [more ▼]

This article concerns the treatment of patients’ rights cases in French‐speaking Belgian hospitals by the “mediator”, that is, the person who has the legal duty of dealing with grievances arising from the application of this right of complaint. What happens to a patient’s complaint? This is the question that this article attempts to answer through a report on the “local” organization of mediation ser‐ vices within the hospital. It thus clari es the links and divergences between the formal discourses accompanying the implementation of the mediation function in health care on the one hand, and, on the other hand, the actual practices of media‐ tion determined by the work of mediators in the hospital. [less ▲]

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See detailA generic wear prediction procedure based on the Discrete Element Method for ball mill liners in the cement industry
Boemer, Dominik ULg; Ponthot, Jean-Philippe ULg

in Minerals Engineering (2017)

generic procedure to predict the wear evolution of lining surfaces, namely the spatial distribution of wear and the progressive modification of the geometry due to wear, is introduced in the context of ... [more ▼]

generic procedure to predict the wear evolution of lining surfaces, namely the spatial distribution of wear and the progressive modification of the geometry due to wear, is introduced in the context of shell liners in ball mills. The wear data is accumulated on the surface of the liner by 3D discrete element method (DEM) simulations of the ball charge in an axial slice of the mill, which is either closed by a periodic boundary condition or by frictionless end walls. The calibration of this wear data with the measured wear profiles of the shell liner in a 5.8 m diameter industrial cement tube mill shows that the tangential damping energy defined by the linear spring-slider-damper DEM contact law is the best fitting wear model of 6 different models. The gradual update of the liner shape delivers adequate results for liners without an axial height variation, while the accuracy of fully variable geometrical modifications is limited by the computation time. Nevertheless, detailed phenomena, like the creation of grooves in the liner, were for the first time numerically modeled. [less ▲]

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See detailOptimization and validation of a fast Supercritical Fluid Chromatography method for the quantitative determination of vitamin D3 and its related impurities.
Andri, Bertyl ULg; Lebrun, Pierre ULg; Dispas, Amandine ULg et al

in Journal of Chromatography. A (2017)

In the uprising context of green analytical chemistry, Supercritical Fluid Chromatography (SFC) is often suggested as an alternative to Normal Phase Liquid Chromatography. Indeed, SFC provides fast ... [more ▼]

In the uprising context of green analytical chemistry, Supercritical Fluid Chromatography (SFC) is often suggested as an alternative to Normal Phase Liquid Chromatography. Indeed, SFC provides fast, efficient and green separations. In this report, the quantitative performances of SFC were challenged on a real-life case study: the Quality Control (QC) of vitamin D3. A rapid and green SFC method was optimized thanks to the Design of Experiments–Design Space (DoE–DS) methodology. It provided robust and high quality separation of the compounds within a 2 min timeframe, using a gradient of ethanol as co-solvent of the carbon dioxide. The analytical method was fully validated according to the total error approach, demon- strating the compliance of the method to the specifications of U.S. Pharmacopeia (USP: 97.0–103.0%) and European Pharmacopeia (EP: 97.0–102.0%) for an interval of [50–150%] of the target concentration. In order to allow quantification of impurities using vitamin D3 as an external standard in SFC-UV, correction factors were determined and verified during method validation. Thus, accurate quantification of impu- rities was demonstrated at the specified levels (0.1 and 1.0% of the main compound) for a 70.0–130.0% dosing range. This work demonstrates the validity of an SFC method for the QC of vitamin D3 raw material and its application to real samples. Therefore, it supports the switch to a greener and faster separative technique as an alternative to NPLC in the pharmaceutical industry. [less ▲]

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See detailRoad and intermodal transport performance: the impact of operational costs and air pollution external costs
Mostert, Martine ULg; Caris, An; Limbourg, Sabine ULg

in Research in Transportation Business & Management (2017)

The transportation of goods is essential for the economy, but it also contributes to air pollution which, in turn, affects human health. These negative impacts generate additional costs for society that ... [more ▼]

The transportation of goods is essential for the economy, but it also contributes to air pollution which, in turn, affects human health. These negative impacts generate additional costs for society that are not necessarily taken into account in public transportation policies and in private transportation decisions of companies and individuals. This leads to inefficient transportation systems where the social equilibrium is not reached. Intermodal transport is promoted by the European Commission to reduce these negative externalities. The objective of this paper is to analyze at a strategic level the effect on modal split between road, intermodal rail and intermodal inland waterway transport of several economic or environmental policies. An intermodal allocation model is applied to the Belgian case in order to identify the modal split changes between the single minimization of costs (operational or health-related external) and the introduction of additional road taxes. [less ▲]

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See detailRectal cancer treatment in a teaching hospital
Verdin, Vanessa; Weerts, Joseph; Francart, David et al

in Acta Chirurgica Belgica (2017), 117

Background: Rectal adenocarcinomas surgery morbidity and mortality might be impaired by neoadjuvant therapy. We performed this retropsective study to be compared with the PROCARE study running afterwards ... [more ▼]

Background: Rectal adenocarcinomas surgery morbidity and mortality might be impaired by neoadjuvant therapy. We performed this retropsective study to be compared with the PROCARE study running afterwards. Methods: We performed a retrospective study of 95 patients operated on for rectal denocarcinoma in a single institution during the period 2007-2009. We used logistic regression to estimate the relationship between possible predictive parameters of AL. Results: The laparoscopic approach is favored in 63.1% of the cases with a conversion rate of 11.6%, mainly in man (6 out of 7). For low rectal cancer though, laparotomy was the first choice (92.3%). From a carcinological point of view, laparoscopy allowed a complete tumor resection according to the PME (n=27) and TME (n=26) standards. Multivariate analysis revealed that women, lower BMI, lower rectum tumor, laparoscopic surgery, neoadjuvant treatment and anal suture were associated with higher risk of AL. The mean hospital stay was 15.4 days (3 – 46 days). In-hospital mortality was 3.1%. Adjuvant chemotherapy was completed in 42.1% of the patients. Despite these treatments, we registered a recurrence rate of 26.6%. Of these, 72% were distally localized and 12% exclusively locally. Among the patients operated on by laparoscopy, there was one local recurrence and one local with distant metastases (3.7%). The one- and three-years survival rates were 91.5% and 80.4% respectively. Conclusions: Our study showed a higher rate of AL than expected (18%). In our series recorded in PROCARE-Home, our leak rate has dropped to 10%. It may be indicating a positive effect of PROCARE. [less ▲]

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See detailCombination of Partial Least Squares regression and Design of Experiments to model the retention of pharmaceuticals in Supercritical Fluid Chromatography
Andri, Bertyl ULg; Dispas, Amandine ULg; Marini Djang'Eing'A, Roland ULg et al

in Journal of Chromatography. A (2017)

This work presents a first attempt to establish a model of the retention behaviour for pharmaceutical compounds in gradient mode SFC. For this purpose, multivariate statistics were applied on the basis of ... [more ▼]

This work presents a first attempt to establish a model of the retention behaviour for pharmaceutical compounds in gradient mode SFC. For this purpose, multivariate statistics were applied on the basis of data gathered with the Design of Experiment (DoE) methodology. It permitted to build optimally the experiments needed, and served as a basis for providing relevant physicochemical interpretation of the effects observed. Data gathered over a broad experimental domain enabled the establishment of well-fit linear models of the retention of the individual compounds in presence of methanol as co-solvent. These models also allowed the appreciation of the impact of each experimental parameter and their factorial combinations. This approach was carried out with two organic modifiers (i.e. methanol and ethanol) and provided comparable results. Therefore, it demonstrates the feasibility to model retention in gradient mode SFC for individual compounds as a function of the experimental conditions. This approach also permitted to highlight the predominant effect of some parameters (e.g. gradient slope and pressure) on the retention of compounds. Because building of individual models of retention was possible, the next step considered the estab- lishment of a global model of the retention to predict the behaviour of given compounds on the basis of, on the one side, the physicochemical descriptors of the compounds (e.g. Linear Solvation Energy Relationship (LSER) descriptors) and, on the other side, of the experimental conditions. This global model was established by means of partial least squares regression for the selected compounds, in an experimental domain defined by the Design of Experiment (DoE) methodology. Assessment of the model’s predic- tive capabilities revealed satisfactory agreement between predicted and actual retention (i.e. R2 = 0.942, slope = 1.004) of the assessed compounds, which is unprecedented in the field. [less ▲]

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See detailA Large and Consistent Phylogenomic Dataset Supports Sponges as the Sister Group to All Other Animals.
Simion, Paul; Philippe, Herve; Baurain, Denis ULg et al

in Current Biology (2017)

Resolving the early diversification of animal lineages has proven difficult, even using genome-scale datasets. Several phylogenomic studies have supported the classical scenario in which sponges (Porifera ... [more ▼]

Resolving the early diversification of animal lineages has proven difficult, even using genome-scale datasets. Several phylogenomic studies have supported the classical scenario in which sponges (Porifera) are the sister group to all other animals ("Porifera-sister" hypothesis), consistent with a single origin of the gut, nerve cells, and muscle cells in the stem lineage of eumetazoans (bilaterians + ctenophores + cnidarians). In contrast, several other studies have recovered an alternative topology in which ctenophores are the sister group to all other animals (including sponges). The "Ctenophora-sister" hypothesis implies that eumetazoan-specific traits, such as neurons and muscle cells, either evolved once along the metazoan stem lineage and were then lost in sponges and placozoans or evolved at least twice independently in Ctenophora and in Cnidaria + Bilateria. Here, we report on our reconstruction of deep metazoan relationships using a 1,719-gene dataset with dense taxonomic sampling of non-bilaterian animals that was assembled using a semi-automated procedure, designed to reduce known error sources. Our dataset outperforms previous metazoan gene superalignments in terms of data quality and quantity. Analyses with a best-fitting site-heterogeneous evolutionary model provide strong statistical support for placing sponges as the sister-group to all other metazoans, with ctenophores emerging as the second-earliest branching animal lineage. Only those methodological settings that exacerbated long-branch attraction artifacts yielded Ctenophora-sister. These results show that methodological issues must be carefully addressed to tackle difficult phylogenetic questions and pave the road to a better understanding of how fundamental features of animal body plans have emerged. [less ▲]

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