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See detailCore cross-linked micelles of polyphosphoester containing amphiphilic block copolymers as drug nanocarriers
Ergül, Zeynep ULg; Vanslambrouck, Stéphanie; Cajot, Sébastien et al

in RSC Advances (2016), 6(48), 42081-42088

Poly(ethylene oxide)-b-polyphosphoester amphiphilic block copolymers are known to self-assemble into polymer micelles when dissolved into water. This work aims at reporting on the improvement of the ... [more ▼]

Poly(ethylene oxide)-b-polyphosphoester amphiphilic block copolymers are known to self-assemble into polymer micelles when dissolved into water. This work aims at reporting on the improvement of the stability of the micelles at high dilution by crosslinking the hydrophobic polyphosphoester micellar core. Typically, an unsaturated alkene side-chain was introduced on the cyclic phosphate monomer according to a one-step reaction followed by its organocatalyzed polymerization initiated by a poly(ethylene oxide) macroinitiator. This strategy avoids the use of any organometallic compounds in order to facilitate the purification and meet the stringent requirements of biomedical applications. After self-assembly into water, the micelles were cross-linked by simple UV irradiation. These cross-linked micelles have then been loaded by doxorubicin to evaluate their potential as drug nanocarriers and monitor the impact of crosslinking on the release profile. [less ▲]

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See detailReview of Véronique Maisier’s Violence in Caribbean Literature: Stories of Stones and Blood
Ledent, Bénédicte ULg

in Nieuwe West-Indische Gids = New West Indian Guide (2016), 90(3&4),

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See detailHidden Markov Model-based population synthesis
Saadi, Ismaïl ULg; El Saeid Mustafa, Ahmed Mohamed ULg; Teller, Jacques ULg et al

in Transportation Research. Part B : Methodological (2016), 90

Micro-simulation travel demand and land use models require a synthetic population, which consists of a set of agents characterized by demographic and socio-economic attributes. Two main families of ... [more ▼]

Micro-simulation travel demand and land use models require a synthetic population, which consists of a set of agents characterized by demographic and socio-economic attributes. Two main families of population synthesis techniques can be distinguished: (a) fitting methods (iterative proportional fitting, updating) and (b) combinatorial optimization methods. During the last few years, a third outperforming family of population synthesis procedures has emerged, i.e., Markov process-based methods such as Monte Carlo Markov Chain (MCMC) simulations. In this paper, an extended Hidden Markov Model (HMM)-based approach is presented, which can serve as a better alternative than the existing methods. The approach is characterized by a great flexibility and efficiency in terms of data preparation and model training. The HMM is able to reproduce the structural configuration of a given population from an unlimited number of micro-samples and a marginal distribution. Only one marginal distribution of the considered population can be used as a boundary condition to “guide” the synthesis of the whole population. Model training and testing are performed using the Survey on the Workforce of 2013 and the Belgian National Household Travel Survey of 2010. Results indicate that the HMM method captures the complete heterogeneity of the micro-data contrary to standard fitting approaches. The method provides accurate results as it is able to reproduce the marginal distributions and their corresponding multivariate joint distributions with an acceptable error rate (i.e., SRSME=0.54 for 6 synthesized attributes). Furthermore, the HMM outperforms IPF for small sample sizes, even though the amount of input data is less than that for IPF. Finally, simulations show that the HMM can merge information provided by multiple data sources to allow good population estimates. [less ▲]

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See detailSurfactant-assisted ultrasonic spray pyrolysis of hematite mesoporous thin films
Henrist, Catherine ULg; Toussaint, Caroline ULg; De Vroede, Jordan et al

in Microporous and Mesoporous Materials (2016), 221

Mesoporous crystalline hematite is a material difficult to prepare by soft-templating with conventional techniques, because of its high crystallization temperature associated to the crystal-to-crystal ... [more ▼]

Mesoporous crystalline hematite is a material difficult to prepare by soft-templating with conventional techniques, because of its high crystallization temperature associated to the crystal-to-crystal goethiteto-hematite phase transition. In a previous work, it has been reported that with very careful calcination steps, it is possible to prepare mesoporous hematite films with the spin-coating technique. However, with less conventional techniques such as surfactant-assisted ultrasonic spray pyrolysis, the deposition usually leads to non-porous oxide films or to films with interstitial porosity. In this work, we demonstrate for the first time the proof-of-concept of block-copolymer templating of hematite thin films by the ultrasonic spray pyrolysis technique. Despite the fast thermal decomposition during spray deposition, a regular, monodisperse packing of spherical pores is observed after deposition on pre-heated substrates (250 C) and after a careful post-annealing step at 470 C. Moreover, with the use of a silica scaffold, we successfully preserved porosity up to a temperature as high as 800 C. These films are highly crystalline and they are composed by randomly oriented nanocrystallites with sizes as small as 25 nm. Furthermore, we show that the crystallization evolution with temperature is influenced by the presence of the templating agent and also by the preparation technique. [less ▲]

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See detailSHIP2 controls plasma membrane PI(4,5)P2 thereby participating in the control of cell migration in 1321 N1 glioblastoma.
Edimo, William S Elong; Ghosh, Somadri; Derua, Rita et al

in Journal of cell science (2016)

Phosphoinositides, particularly PI(3,4,5)P3, and PI(4,5)P2, are recognized by SHIP2 a member of the inositol polyphosphate 5-phosphatase family. SHIP2 dephosphorylates PI(3,4,5)P3 to form PI(3,4)P2; the ... [more ▼]

Phosphoinositides, particularly PI(3,4,5)P3, and PI(4,5)P2, are recognized by SHIP2 a member of the inositol polyphosphate 5-phosphatase family. SHIP2 dephosphorylates PI(3,4,5)P3 to form PI(3,4)P2; the latter interacts with specific target proteins (e.g. lamellipodin). Although the SHIP2 preferred substrate is PI(3,4,5)P3, PI(4,5)P2 could also be dephosphorylated to PI4P. Through depletion of SHIP2 in a glioblastoma cell line 1321 N1 cells, we show that SHIP2 inhibits cell migration. In different glioblastoma cell lines and primary cultures, SHIP2 staining at the plasma membrane partly overlaps with PI(4,5)P2 immunoreactivity. PI(4,5)P2 was upregulated in SHIP2-deficient N1 cells as compared to control cells; in contrast, PI4P was very much decreased in SHIP2-deficient cells. Therefore, SHIP2 controls both PI(3,4,5)P3 and PI(4,5)P2 levels in intact cells. In N1 cells, the PI(4,5)P2 binding protein myosin-1c was identified as a new interactor of SHIP2. Regulation of PI(4,5)P2 and PI4P content by SHIP2 controls N1 cell migration through the organization of focal adhesions. Thus, our results reveal a novel role of SHIP2 in the control of PI(4,5)P2, PI4P and cell migration in PTEN-deficient glioblastoma N1 cells. [less ▲]

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See detailPerformance and Robustness of Nonlinear Systems Using Bifurcation Analysis
Detroux, Thibaut ULg

Doctoral thesis (2016)

Nonlinear vibrations can be frequently encountered in engineering applications, and take their origin from different sources including contact, friction or large displacements. Other manifestations of ... [more ▼]

Nonlinear vibrations can be frequently encountered in engineering applications, and take their origin from different sources including contact, friction or large displacements. Other manifestations of nonlinearities are peculiar phenomena such as amplitude jumps, quasi-periodic oscillations and isolated response curves. These phenomena are closely related to the presence of bifurcations in the frequency response, which dictate the system's dynamics. While recent progress has been achieved to develop tools for nonlinear modal analysis of industrial applications, bifurcation analysis was still limited to reduced models and academic case studies. Along with the lack of an efficient algorithm to detect and study bifurcations, bifurcation analysis for design purposes also remained unexplored. The fundamental contribution of this doctoral thesis is the development of a new methodology for the detection, characterization and tracking of bifurcations of large-scale mechanical systems. To this end, an extension of the harmonic balance (HB) method is proposed. Taking advantage of the efficiency of the HB method for the continuation of nonlinear normal modes and frequency responses, this extension allows for robust computation of bifurcation curves in the system's parameter space. A validation of the methodology is performed on the strongly nonlinear model of an Airbus Defence & Space spacecraft, which possesses an impact-type nonlinear device consisting of multiple mechanical stops limiting the motion of an inertia wheel mounted on an elastomeric interface. The second main contribution is the development of a new vibration absorber, the nonlinear tuned vibration absorber (NLTVA), which generalizes Den Hartog's equal-peak method to nonlinear systems. The absorber is demonstrated to exhibit unprecedented performance for the mitigation of nonlinear resonances. In a second step, the HB-based bifurcation methodology is utilized to characterize the performance regions of the NLTVA, and to ensure its robustness with respect to parameter uncertainties. [less ▲]

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See detailMultivariate ARMA Based Modal Identification of a Time-varying Beam
Bertha, Mathieu ULg; Golinval, Jean-Claude ULg

in Proceedings of the International Modal Analysis Conference (IMAC) XXXIV (2016)

The present paper addresses the problem of modal identification of time-varying systems. The identification is based on a multivariate autoregressive moving-average model in which the time variability of ... [more ▼]

The present paper addresses the problem of modal identification of time-varying systems. The identification is based on a multivariate autoregressive moving-average model in which the time variability of the system is caught using a basis functions approach. In this approach, the time-varying regressive coefficients in the model are expended in the chosen basis functions and only the projection coefficients have to be identified. In that way, the initial time-varying problem then becomes a time-invariant one that can be solved. Because a multivariate model is used, in addition to the time-varying poles, the time-varying mode shapes may be identified too. The method is first presented and then applied on an experimental demonstration structure. The experimental structure consists of a supported beam on which a mass is travelling. The mass is chosen sufficiently large to have a significant influence on the dynamics of the primary system. This kind of problem is a classical example commonly used by many authors to test time-varying identification methods. [less ▲]

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See detailOrigin of dc voltage in type II superconducting flux pumps: field, field rate of change, and current density dependence of resistivity
Geng, J.; Matsuda, K.; Fu, L. et al

in Journal of Physics : D Applied Physics (2016), 49(11), 1101

Superconducting flux pumps are the kind of devices which can generate direct current into superconducting circuit using external magnetic field. The key point is how to induce a dc voltage across the ... [more ▼]

Superconducting flux pumps are the kind of devices which can generate direct current into superconducting circuit using external magnetic field. The key point is how to induce a dc voltage across the superconducting load by ac fields. Giaever (1966 IEEE Spectr . 3 [http://dx.doi.org/10.1109/MSPEC.1966.5217702] 117 ) pointed out flux motion in superconductors will induce a dc voltage, and demonstrated a rectifier model which depended on breaking superconductivity. van de Klundert et al (1981 Cryogenics 21 [http://dx.doi.org/10.1016/0011-2275(81)90195-8] 195, 267 ) in their review(s) described various configurations for flux pumps all of which relied on inducing the normal state in at least part of the superconductor. In this letter, following their work, we reveal that a variation in the resistivity of type II superconductors is sufficient to induce a dc voltage in flux pumps and it is not necessary to break superconductivity. This variation in resistivity is due to the fact that flux flow is influenced by current density, field intensity, and field rate of change. We propose a general circuit analogy for travelling wave flux pumps, and provide a mathematical analysis to explain the dc voltage. Several existing superconducting flux pumps which rely on the use of a travelling magnetic wave can be explained using the analysis enclosed. This work can also throw light on the design and optimization of flux pumps. [less ▲]

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See detailRecent advances in composite CAD/CAM blocks.
Mainjot, Amélie ULg

in International Journal of Esthetic Dentistry (2016), 11(2), 275-80

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See detailConcordance between iohexol and iothalamate plasma clearance
DELANAYE, Pierre ULg; JOURET, François ULg; LE GOFF, Caroline ULg et al

in American Journal of Kidney Diseases (2016)

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See detailEfficient standard error formulas of ability estimators with dichotomous item response models
Magis, David ULg

in Psychometrika (2016), 81

This paper focuses on the computation of asymptotic standard errors (ASE) of ability estimators with dichotomous item response models. A general framework is considered and ability estimators are defined ... [more ▼]

This paper focuses on the computation of asymptotic standard errors (ASE) of ability estimators with dichotomous item response models. A general framework is considered and ability estimators are defined from a very restricted set of assumptions and formulas. This approach encompasses most standard methods such as maximum likelihood, weighted likelihood, maximum a posteriori and robust estimators. A general formula for the ASE is derived from the theory of M-estimation. Well-known results are found back as particular cases for the maximum and robust estimators, while new ASE proposals for the weighted likelihood and maximum a posteriori estimators are presented. These new formulas are compared to traditional ones by means of a simulation study under Rasch modeling. [less ▲]

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See detailintroduction et inter-duction; les règles du jeu.
Bodart, Céline ULg

in YOUNES, Chris; BONNAUD, Xavier; Bodart, Céline (Eds.) Encore l'architecture, encore la philosophie. (2016)

The international conference « encore l'architecture – encore la philosophie » is an initiative of the GERPHAU lab, research group for Philosophy, Architecture, Urban (Architecture School of Paris La ... [more ▼]

The international conference « encore l'architecture – encore la philosophie » is an initiative of the GERPHAU lab, research group for Philosophy, Architecture, Urban (Architecture School of Paris La Villette, UMR 7218 CNRS-Lavue), in partnership with Cité de l'architecture et du patrimoine, UMR-Lavue (Laboratoire Architecture, Ville, Urbanisme, Environnement) and philAU (a scientific thematic network : Philosophy, Architecture, Urban). This conference is the first ARENA conference (Architectural Research in Europe Network Association), a shared platform that aims to promote, support, develop and disseminate high-quality research in all fields of architecture in the widest sense. The network already includes researchers from leading European architecture schools. Synopsis. In Paris in 1987, a first event was held to celebrate the meeting of two disciplinary fields, entitled “Mesure pour mesure, architecture et philosophie”. Architects and philosophers were invited to discuss together how philosophy could capture better what determines architecture itself. Now, on the occasion of a new international conference, the GERPHAU Lab seeks to restate and refresh the question of the meeting of architecture and philosophy, by asking: what still remains today of our cross-over practices? ENCORE L'ARCHITECTURE, ENCORE LA PHILOSOPHIE. To build together these reflections about the future of our respective practices, why don't we hold to the hypothesis that our recent histories, in architecture as well as philosophy, could be written through the addition of a few prefixes? In linguistics, a prefix does not only serve the formation of a new word: it also regenerates the question of the meaning of the word. It is a discursive invention and its real strength lies in its ability to engage a new type of relationship with the world. Re-, alter-, eco-, co-, bio-, etc., these prefixes have clung to both our discourses as well as our disciplines. But in what way do they question the meaning of our practices? In archi-tecture as in philo-sophy, how do these successive re-definitions put the fundamentals into question, and how do they disturb their alleged unity inherited from Ancient Greece? And, moreover, how does the over-use of prefixes help us to understand what still makes sense in philosophy, or what still makes sense in architecture? The key issue of this conference, ‘Encore l'architecture, Encore la philosophie’, will be to trace backwards the stream of architectural and philosophical ideas through the thematic of the prefix as constituting a form of narrative. The conference will aim to trace the paths of their development, and other influencing factors, so as to return to those meetings between architecture and philosophy which already have oriented, re-oriented and sometimes dis-oriented our speech. It will be a meeting at which we invite participants to retell the story of our disciplines in order to grasp what it is still unique today about our practices. [less ▲]

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See detailApoptosis of Sertoli cells after conditional ablation of murine double minute 2 (Mdm2) gene is p53-dependent and results in male sterility.
Fouchecourt, S.; Livera, G.; Messiaen, S. et al

in Cell death and differentiation (2016)

Beside its well-documented role in carcinogenesis, the function of p53 family has been more recently revealed in development and female reproduction, but it is still poorly documented in male reproduction ... [more ▼]

Beside its well-documented role in carcinogenesis, the function of p53 family has been more recently revealed in development and female reproduction, but it is still poorly documented in male reproduction. We specifically tested this possibility by ablating Mdm2, an E3 ligase that regulates p53 protein stability and transactivation function, specifically in Sertoli cells (SCs) using the AMH-Cre line and created the new SC-Mdm2-/- line. Heterozygous SC-Mdm2-/+ adult males were fertile, but SC-Mdm2-/- males were infertile and exhibited: a shorter ano-genital distance, an extra duct along the vas deferens that presents a uterus-like morphology, degenerated testes with no organized seminiferous tubules and a complete loss of differentiated germ cells. In adults, testosterone levels as well as StAR, P450c17 (Cyp17a1) and P450scc (Cyp11a1) mRNA levels decreased significantly, and both plasma LH and FSH levels increased. A detailed investigation of testicular development indicated that the phenotype arose during fetal life, with SC-Mdm2-/- testes being much smaller at birth. Interestingly, Leydig cells remained present until adulthood and fetal germ cells abnormally initiated meiosis. Inactivation of Mdm2 in SCs triggered p53 activation and apoptosis as early as 15.5 days post conception with significant increase in apoptotic SCs. Importantly, testis development occurred normally in SC-Mdm2-/- lacking p53 mice (SC-Mdm2-/-p53-/-) and accordingly, these mice were fertile indicating that the aforementioned phenotypes are entirely p53-dependent. These data not only highlight the importance of keeping p53 in check for proper testicular development and male fertility but also certify the critical role of SCs in the maintenance of meiotic repression.Cell Death and Differentiation advance online publication, 16 October 2015; doi:10.1038/cdd.2015.120. [less ▲]

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See detailBrentano, la théorie des catégories et la définition de la substance
Boccaccini, Federico ULg

in Etudes Philosophiques (2016)

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See detailCombinatorics, Words and Symbolic Dynamics
Berthé, Valérie; Rigo, Michel ULg

Book published by Cambridge University Press (2016)

Internationally recognised researchers look at developing trends in combinatorics with applications in the study of words and in symbolic dynamics. They explain the important concepts, providing a clear ... [more ▼]

Internationally recognised researchers look at developing trends in combinatorics with applications in the study of words and in symbolic dynamics. They explain the important concepts, providing a clear exposition of some recent results, and emphasise the emerging connections between these different fields. Topics include combinatorics on words, pattern avoidance, graph theory, tilings and theory of computation, multidimensional subshifts, discrete dynamical systems, ergodic theory, numeration systems, dynamical arithmetics, automata theory and synchronised words, analytic combinatorics, continued fractions and probabilistic models. Each topic is presented in a way that links it to the main themes, but then they are also extended to repetitions in words, similarity relations, cellular automata, friezes and Dynkin diagrams. The book will appeal to graduate students, research mathematicians and computer scientists working in combinatorics, theory of computation, number theory, symbolic dynamics, tilings and stringology. It will also interest biologists using text algorithms. [less ▲]

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