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See detailUnexpected sensitivity of the annual net ecosystem exchange to the high frequency loss corrections in a grazed grassland site in Belgium
Mamadou, Ossénatou ULg; Gourlez de la Motte, Louis ULg; De Ligne, Anne ULg et al

Poster (2016)

The eddy covariance technique is widely used to measure CO2 and other gas fluxes. However, eddy covariance fluxes are affected by systematic errors that must be corrected. Among them, high frequency loss ... [more ▼]

The eddy covariance technique is widely used to measure CO2 and other gas fluxes. However, eddy covariance fluxes are affected by systematic errors that must be corrected. Among them, high frequency loss corrections are particularly important in this regard, especially when using a closed-path infrared gas analyzer. In this study, we compared three approaches to do these corrections for CO2 fluxes and evaluated their impact on the carbon balance an intensively grazed grassland site in Belgium . In the first approach, the computation of correction factors was based on the measured sensible heat cospectra (‘local’ cospectra), whereas the other two were based on theoretical models (Kaimal et al., 1972). The correction approaches were validated by comparing the nighttime eddy covariance CO2 fluxes corrected with each approach and in situ soil respiration measurements. We found that the local cospectra differed from the Kaimal theoretical shape, although the site could not be considered ‘difficult’ (i.e., fairly flat, homogeneous, low vegetation, sufficient measurement height), appearing less peaked in the inertial subrange. This difference greatly affected the correction factor, especially for night fluxes. Night fluxes measured by eddy covariance were found to be in good accord with in situ soil respiration measurements when corrected with local cospectra and to be overestimated when corrected with Kaimal cospectra. As the difference between correction factors was larger in stable than unstable conditions, this acts as a selective systematic error and has an important impact on annual fluxes. On the basis of a 4-year average, at DTO the errors reach 71-150 g C m-2 y-1 for net ecosystem exchange (NEE), 280-562 g C m-2 y-1 for total ecosystem respiration (TER) and 209-412 g C m-2 y-1 for gross primary productivity (GPP), depending on the approach used. We finally encourage site PIs to check the cospectrum shape at their sites and, if necessary, compute frequency correction factors on the basis of local cospectra rather than on Kaimal cospectra. [less ▲]

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See detailResting-state test-retest reliability over different preprocessing steps
Varikuti, Deepthi; Hoffstaedter, Felix; Genon, Sarah ULg et al

Poster (2016)

Introduction: Resting-state (RS) functional connectivity (FC) analysis has become a widely used method for the investigation of human brain connectivity and pathology. While most of the current ... [more ▼]

Introduction: Resting-state (RS) functional connectivity (FC) analysis has become a widely used method for the investigation of human brain connectivity and pathology. While most of the current applications are based on data-driven analyses, the use of functionally specific, a priori defined networks provided by neuroimaging meta-analyses represent an important alternative to these, as they allow the standardized assessment of connectivity patterns. Neuronal activity as measured by functional MRI is influenced by various nuisance signals including system noise, thermal noise, and noise induced by physiological processes of the participant. The presence of these confounds in turn have an impact on the estimation of functional connectivity. Several methods exist to deal with this predicament, but little consensus has yet been reached on the most appropriate approach. Given the crucial importance of reliability for the development of clinical applications, we investigated the test-retest reliability of FC analyses in meta-analytically defined networks after removing confounding noise regressors. Methods: RS-fMRI data of 42 healthy subjects with an average age of 42 ± 20 years were obtained in two sessions with an average time interval of 175 ± 75 days. A seed-based FC analysis was conducted after spatial preprocessing, approach specific confound-regression, and band-pass filtering [0.01-0.08 Hz]. We focused on the effects of various commonly used confound removals in the resting state studies such as PCA de-noising, global mean signal regression, and removal of tissue-class specific mean signals (in particular, white matter (WM) + cerebrospinal fluid (CSF) and WM + CSF + grey matter (GM)) [2,3,4,5,7]. Additionally, we examined GM specific time-series extraction from seed regions. In order to compute the seed based FC, a priori defined networks were analyzed (extended socio-affective default mode [1] and working-memory [6]). Both networks show robust within network resting state connectivity as well as anti-correlation between each other. The reliability of FC was measured using two different measures Spearman correlations and the absolute differences of functional connectivity scores. The different approaches defined by the combination of different masking / confound removal approaches were compared using a non-parametric Friedman ANOVA. Results: The summary ranking across both indices of reliability (Spearman correlations and absolute differences) reflects the major patterns noted in the individual analyses (Fig.1). GM masking, in particular using the group-mean segmentation, improves reliability. PCA denoising in turn reduces it. Within-network connections are most reliably estimated when not using any global or tissue-class specific signal regression, with removing the global WM and CSF signals representing the next-best approach. In contrast, between-network connections are most reliably measured by linear and second order removal of global signals of all three-tissue classes. Conclusion: Our results show that GM masking of the seed regions based on the group-average GM probabilities is advisable when investigating meta-analytically defined networks. In turn, PCA de-noising reduces the reliability of connectivity estimates. Finally, with respect to global signal regression, we observe that refraining from this approach enhances reliability, but comes at the expense of potentially poorer biological validity, indicated by missing anti-correlations between what has been previously described as antagonistic networks. Here, removal of global WM and CSF signals seems to provide a good compromise, as this approach yielded reliable and meaningful estimates of within and between-network connections (Fig.2). We noted that reliability is proportional to the retained variance, presumably including structured noise. Consequently, we would argue that compromises are needed between maximizing reliability and removing variance that may be attributable to non-neuronal sources. [less ▲]

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See detailMultimodal evidence of a rostro-caudal and ventro-dorsal organization in the dorsal premotor cortex
Genon, Sarah ULg; Li, Hai; Fan, Lingzhong et al

Poster (2016)

Introduction Different methods for in-vivo characterization have resulted in different maps of the human dorsal premotor cortex (PMd): Task-based functional studies suggested a rostro-caudal gradient ... [more ▼]

Introduction Different methods for in-vivo characterization have resulted in different maps of the human dorsal premotor cortex (PMd): Task-based functional studies suggested a rostro-caudal gradient corresponding to a cognitive-motor gradient1,2 and mapping based on resting-state functional connectivity (RSFC) likewise suggested a subdivision along the rostro-caudal axis3. In contrast, mapping based on structural connectivity as assessed by probabilistic diffusion tractography (PDT) provided evidence that the dorsal part of the precentral gyrus (PG) is organized along a ventro-dorsal axis4. However, there is currently no multimodal mapping of a broadly defined PMd. The present study used a multimodal approach to (1) identify a robust topographical organization of the right PMd by using connectivity-based parcellation (CBP) applied to a meta-analytic approach of task-related coactivation data (i.e. meta-analytic connectivity modeling, MACM5,6), and (2) examine whether the thus obtained parcellation pattern would be reproduced by CBP based on two other connectivity modalities: unconstrained functional (as reflected by RSFC) and structural as measured by PDT based on diffusion-weighted imaging (DWI). Methods A volume of interest (VOI) was defined by merging PMd activation sites from several meta-analyses serving as robust functional localizers of the PMd while excluding primary sensorimotor areas. MACM-CBP6 was performed using Brainmap database. RSFC-CBP and PDT-CBP were performed on distinct datasets to ensure independent parcellation7. RSFC-CBP was computed on RS data of 124 healthy subjects (age: 39.5 ± 11.5 yrs., 66 males) from the 1000BRAINS project8. The voxels’ time series (TS) were first cleaned from confounding effects using PCA denoising and global signal regression. RSFC was then computed by Pearson correlations between the TS of the VOI voxels and those of the rest of the brain. PDT-CBP9 was performed on DWI data of 20 healthy subjects (age: 18.5 ± .76, 10 males) using FSL. Several cluster solutions (k solution) were examined with k-means for MACM- and RSFC-CBP and spectral clustering for PDT-CBP. The choice of the k solution was driven by task-based functional data (MACM) based on three criteria: variation of information, percentage of deviants, and silhouette value6. Results The selected criteria jointly identified the 5-cluster (5k) solution as optimal across the range of functional studies from Brainmap database (Figure 1). Examination of stability across subjects following PDT-CBP further suggested that k=5 may be considered a local optimum within 2 ≤ k ≤ 6. This solution revealed a similar pattern of topographical organization across modalities (Figure 2) with a subdivision along both rostro-caudal and ventro-dorsal axes, including a rostral cluster lying mainly anteriorly to the PG, a central one at the intersection of the precentral sulcus and the superior frontal gyrus, a caudal one in the posterior part of the PG, a ventral one adjacent to ventral PM, and a dorsal one adjacent to the inter-hemispheric premotor areas. Discussion For the first time our study revealed that the PMd could be divided along two axes: rostro-caudal and ventro-dorsal. This is consistent with previous functional2 and microstructure studies10 in humans and non-human primates suggesting a rostro-caudal distinction and with a previous PDT-CBP of the (dorsal) precentral gyrus4 showing that it could be subdivided in the ventro-dorsal direction. Importantly, this topographical organization was found in the independent analysis of three different connectivity aspects: task functional, unconstrained functional and structural, each based on different datasets. In sum, different modalities consistently show that the PMd can be subdivided into 5 subregions organized along both rostro-caudal and ventro-dorsal axes, comprehensively integrating patterns previously revealed by different methods. [less ▲]

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See detailIntroduction
Henneau, Marie-Elisabeth ULg

in Henneau, Marie-Elisabeth; Dubois-Nayt, Armel; von Kulessa, Rotraud (Eds.) Revisiter la Querelle des femmes : les discours sur l’égalité/inégalité des sexes à l’échelle européenne, 4. 1400-1800 (2016)

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See detailRevisiter la Querelle des femmes : les discours sur l’égalité/inégalité des sexes à l’échelle européenne, 4. 1400-1800
Henneau, Marie-Elisabeth ULg; Dubois-Nayt, Armel; von Kulessa, Rotraud

Book published by Publications de l'Université de Saint-Etienne (2016)

Dernier des quatre volumes consacrés à la gigantesque polémique qui agita la France durant de longs siècles sur la place et le rôle des femmes dans la société, ce recueil d'articles se concentre sur les ... [more ▼]

Dernier des quatre volumes consacrés à la gigantesque polémique qui agita la France durant de longs siècles sur la place et le rôle des femmes dans la société, ce recueil d'articles se concentre sur les développements de cette controverse en Europe. Il mesure ainsi l’influence de la France, considérée comme le berceau et l’épicentre de la Querelle, sur les autres nations, notamment à travers la diffusion d’œuvres d’une importance majeure, comme La Cité des dames de Christine de Pizan. Mais il déplace également cette problématique, en étudiant le rôle joué par des œuvres phares issues d’autres pays, comme le célébrissime De mulieribus claris de l'Italien Boccacio, en s'intéressant à l'adaptation de la controverse aux contextes locaux. Attentif à ses modalités d’expression, il parcourt les supports traditionnels empruntés par les protagonistes, tels les traités philosophiques et politiques ou les dictionnaires des femmes, mais il met également à jour d'autres genres moins convenus, comme les autobiographies, les correspondances, les romans et discours imaginaires, l'histoire de la musique… Enfin, il révèle l'existence de la Querelle dans des lieux plus inattendus comme l'espace clos des couvents ou le discours des mystiques [less ▲]

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See detailEffects of fish predation on Posidonia oceanica amphipod assemblages
Sturaro, Nicolas ULg; Gobert, Sylvie ULg; Pérez-Perera, Amanda et al

in Marine Biology (2016), 163

Amphipod assemblages that inhabit Posidonia oceanica seagrass meadows are potentially relevant trophic resources for ichthyofauna. However, the effects of fish predation on amphipod assemblages in this ... [more ▼]

Amphipod assemblages that inhabit Posidonia oceanica seagrass meadows are potentially relevant trophic resources for ichthyofauna. However, the effects of fish predation on amphipod assemblages in this system have received little attention. To address this gap in knowledge, experimental manipulations of predation intensity (exclusion and inclusion cages) were conducted at two sites in a Mediterranean marine protected area, where different levels of fish predation were expected to occur. We found that in the absence of predatory fishes (exclusion cages), total amphipod density and biomass were higher than in uncaged areas and partially controlled cages. At the species level, Caprella acanthifera and Iphimedia minuta responded to caging with increased abundance, while in most cases different species did not exhibit differences in density or biomass between treatments. The presence of one enclosed labrid fish predator (inclusion cages) resulted in a lower density and biomass of Aora spinicornis and a lower biomass of Phtisica marina, although total amphipod density and biomass were unchanged. In the inclusion cages, a size-frequency analysis revealed that predators mainly targeted large A. spinicornis and Apherusa chiereghinii individuals. Our results suggest that predation by fish may be an important factor in controlling amphipod abundances and biomasses in P. oceanica meadows. Overall, amphipod community composition was not affected by exclusion or inclusion of fish predators. However, some significant effects at the species level point to more complex interactions between some amphipods and fish. [less ▲]

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See detailPartial ages: diagnosing transport processes by means of multiple clocks.
Mouchet, Anne ULg; Cornaton, Fabien; Deleersnijder, Eric et al

in Ocean Dynamics (2016), 66

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See detailImproving properties of recycled concrete aggregates by accelerated carbonation
Zhao, Zengfeng ULg; Remond, Sébastien; Damidot, Denis et al

in Proceedings of the 4th International Conference on Sustainability Construction Materials and Technologies (2016)

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See detailVolcanic eruptions boost tropical Pacific biological productivity
Chikamoto, Megumi O.; Timmermann, Axel; Yoshimori, Masakazu et al

in Geophysical Research Letters (2016), 43

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See detailOld‐Age Employment and Hours of Work Trends: Empirical Analysis for Four European Countries
Jousten, Alain ULg; Perelman, Sergio ULg; Flawinne, Xavier ULg et al

E-print/Working paper (2016)

For the last two decades, the increase of employment among cohorts of individuals aged 50+ has been a policy objective on the European employment agenda. The present paper takes stock of the situation as ... [more ▼]

For the last two decades, the increase of employment among cohorts of individuals aged 50+ has been a policy objective on the European employment agenda. The present paper takes stock of the situation as observed in Belgium over the time period 1997-2011. First, we provide analysis on the evolution of older workers’ employment in Belgium and its neighboring countries Germany, France and the Netherlands using the EU Labour Force Survey. Second, we characterize the different employment and hours of work patterns for different age sub‐groups (50‐54, 55‐59, 60‐64) and provide evidence on their respective evolution. The results show that employment rates among older workers started to catch‐up with employment rates of younger cohorts as of 2001, and with more acuity after 2006. This effect dominates the observed negative effect on hours of work and hence leads to an increase in total hours of work of the cohort – net of any purely demographic effects. [less ▲]

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See detailMaximum entropy properties of discrete-time first-order stable spline kernel
Chen, Tianshi; Ardeshiri, Tohid; Carli, Francesca Paola ULg et al

in Automatica (2016), 66

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See detailOn-demand continuous flow production of pharmaceuticals in a compact, reconfigurable system
Adamo, Andrea; Beingessner, Rachel L.; Behnam, Mohsen et al

in Science (2016), 352

Pharmaceutical manufacturing typically uses batch processing at multiple locations. Disadvantages of this approach include long production times and the potential for supply chain disruptions. As a ... [more ▼]

Pharmaceutical manufacturing typically uses batch processing at multiple locations. Disadvantages of this approach include long production times and the potential for supply chain disruptions. As a preliminary demonstration of an alternative approach, we report here the continuous-flow synthesis and formulation of active pharmaceutical ingredients in a compact, reconfigurable manufacturing platform. Continuous end-to-end synthesis in the refrigerator-sized [1.0 meter (width) × 0.7 meter (length) × 1.8 meter (height)] system produces sufficient quantities per day to supply hundreds to thousands of oral or topical liquid doses of diphenhydramine hydrochloride, lidocaine hydrochloride, diazepam, and fluoxetine hydrochloride that meet U.S. Pharmacopeia standards. Underlying this flexible plug-and-play approach are substantial enabling advances in continuous-flow synthesis, complex multistep sequence telescoping, reaction engineering equipment, and real-time formulation. [less ▲]

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See detailMaximum Entropy Kernels for System Identification
Carli, Francesca Paola ULg; Chen, Tianshi; Ljung, Lennart

in IEEE Transactions on Automatic Control (2016)

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See detailUne présentation rare de craniosténose associée à un crâne lacunaire
Vaessen, françois; Thimmesch, Mathieu; BORN, Jacques et al

in Revue Médicale de Liège (2016), 71(3), 120-123

A rare case of lacunar skull deformity associated with craniosynostosis Summary : The lacunar skull is a radiologic description characterised by the presence of lacunae in the cranial vault. Its ... [more ▼]

A rare case of lacunar skull deformity associated with craniosynostosis Summary : The lacunar skull is a radiologic description characterised by the presence of lacunae in the cranial vault. Its physiopathology remains up to now poorly understood; it is mostly associated with neural tube defects. The association of a lacunar skull with a craniosynostosis has rarely been described in the literature. The case of a 9-month-old patient presenting a multisutural craniosynostosis with a lacunar skull is reported in this article. The surgical treatment allowed to remodel the skull and to hope for a spontaneous regression of the lacunae. [less ▲]

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See detailMurray Bail's Eucalyptus: An Australian Fairy-Tale?
Herbillon, Marie ULg

in Collier, Gordon; Davis, Geoff; Delrez, Marc (Eds.) et al The Invention of Legacy: Essays in Memory of Hena Maes-Jelinek (2016)

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See detailPhage therapy against antimicrobial resistance, design of the first clinical study Phagoburn.
Jault, Patrick; Gabard, Jérôme; Leclerc, Thomas et al

in Critical Care (2016), 20(Suppl 2), 109

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See detailInformation behaviour of French-speaking speech–language therapists in Belgium: results of a questionnaire survey
Durieux, Nancy ULg; Pasleau, Françoise ULg; Piazza, Aurélie ULg et al

in Health Information and Libraries Journal (2016), 33

BACKGROUND: Speech–language therapists (SLTs) are encouraged to implement evidence-based practice (EBP). Nevertheless, EBP use by practitioners can be questioned. OBJECTIVES: The objective of this study ... [more ▼]

BACKGROUND: Speech–language therapists (SLTs) are encouraged to implement evidence-based practice (EBP). Nevertheless, EBP use by practitioners can be questioned. OBJECTIVES: The objective of this study was to explore Belgian French-speaking SLTs’ information behaviour and their awareness of EBP. The collected data allow one to determine how far they have embraced this approach. METHODS: The two Belgian French-speaking SLT professional associations promoted an online questionnaire survey by email. Additionally, clinical supervisors of students were asked to participate. In March 2012, 2068 emails were sent. RESULTS: The participation rate was at least 20% (n = 415). The reported information needs mainly concerned treatment or diagnosis. Most of the time, to attempt to fulfil their information needs, SLTs relied on their own resources (personal experience and libraries) and on colleagues in the workplace. When they searched on the Internet, they preferred to use a general search engine rather than a specialised bibliographic database. Barriers to obtaining scientific information are highlighted. Only 12% of the respondents had already heard about EBP. CONCLUSION: This study provides the first overview of the information behaviour of SLTs working in the French community of Belgium. Several recommendations are suggested for SLTs and librarians. [less ▲]

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See detailUn diplomate allemand en Belgique. Werner von Bargen (1898-1975) dans le débat autour de l’Auswärtiges Amt durant le « Troisième Reich » et dans la jeune République fédérale d’Allemagne
Brüll, Christoph ULg

in Dumoulin, Michel; Lanneau, Catherine (Eds.) La biographie individuelle et collective dans le champ des relations internationales (2016)

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See detailTowards an Australian Philosophy. Constructive Appropriation of Enlightenment Thinking in Murray Bail's The Pages
Herbillon, Marie ULg

in Tunca, Daria; Wilson, Janet (Eds.) Under Construction. Postcolonial Gateways and Walls (2016)

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See detailKinetic Study of Laboratory Mutants of NDM-1 Metallo-beta-Lactamase and the Importance of an Isoleucine at Position 35.
Marcoccia, Francesca; Bottoni, Carlo; Sabatini, Alessia et al

in Antimicrobial agents and chemotherapy (2016), 60(4), 2366-72

Two laboratory mutants of NDM-1 were generated by replacing the isoleucine at position 35 with threonine and serine residues: the NDM-1(I35T)and NDM-1(I35S)enzymes. These mutants were well characterized ... [more ▼]

Two laboratory mutants of NDM-1 were generated by replacing the isoleucine at position 35 with threonine and serine residues: the NDM-1(I35T)and NDM-1(I35S)enzymes. These mutants were well characterized, and their kinetic parameters were compared with those of the NDM-1 wild type. Thekcat,Km, andkcat/Kmvalues calculated for the two mutants were slightly different from those of the wild-type enzyme. Interestingly, thekcat/Kmof NDM-1(I35S)for loracarbef was about 14-fold higher than that of NDM-1. Far-UV circular dichroism (CD) spectra of NDM-1 and NDM-1(I35T)and NDM-1(I35S)enzymes suggest local structural rearrangements in the secondary structure with a marked reduction of alpha-helix content in the mutants. [less ▲]

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