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See detailDynamics of greenhouse gases (CO2, CH4, N2O) along the Zambezi River and major tributaries, and their importance in the riverine carbon budget
Teodoru, C. R.; Nyoni, F. C.; Borges, Alberto ULg et al

in Biogeosciences (2015), 12(8), 2431-2453

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See detailDynamics of H+ fluxes in mitochondrial membrane.
Sluse, Francis ULg; Jarmuszkiewicz, W.

in Rengel, Z. (Ed.) Handbook of plan growth : pH as the master variable (2001)

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See detailDynamics of hybrid switching diffusions SIRS model
Settati, Adel; Lahrouz, Aadil; El Jarroudi, Mustapha et al

in Journal of Applied Mathematics and Computing (2015)

The main aim of this paper is to study the effect of the environmental noises in the asymptotic properties of a stochastic version of the classical SIRS epidemic model. The model studied here include ... [more ▼]

The main aim of this paper is to study the effect of the environmental noises in the asymptotic properties of a stochastic version of the classical SIRS epidemic model. The model studied here include white noise and telegraph noise modeled by Markovian switching. We obtained conditions for extinction both in probability one and in pth moment. We also established the persistence of disease under different conditions on the intensities of noises, the parameters of the model and the stationary distribution of the Markov chain. The highlight point of our work is that our conditions are sufficient and almost necessary for extinction and persistence of the epidemic. The presented results are demonstrated by numerical simulations. [less ▲]

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See detailThe dynamics of inequality in Katanga, D.R.Congo. A conversation with Bourdieu
Rubbers, Benjamin ULg

Conference (2016, February 10)

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See detailDynamics of inorganic carbon in surface waters off the Galician coast
Borges, Alberto ULg; Keir, R.; Larsen, S. E. et al

Conference (2000)

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See detailDynamics of Internalization and Recycling of the Pro-Metastatic Membrane Type 4-Matrix Metalloproteinase (MT4-MMP) in Breast Cancer Cells
Truong, Alice ULg; Yip, Cassandre ULg; PAYE, Alexandra ULg et al

in FEBS Journal (2016), 283(4), 704-22

MT4-MMP (MMP17) is a glycosylphosphatidyl inositol (GPI)-anchored membrane-type MMP expressed on the cell surface of human breast cancer cells. In triple negative breast cancer cells, MT4-MMP promotes ... [more ▼]

MT4-MMP (MMP17) is a glycosylphosphatidyl inositol (GPI)-anchored membrane-type MMP expressed on the cell surface of human breast cancer cells. In triple negative breast cancer cells, MT4-MMP promotes primary tumor growth and lung metastases. Although trafficking and internalization of the transmembrane MT1-MMP have been extensively investigated, little is known about the regulatory mechanisms of the GPI-anchored MT4-MMP. Here, we investigated the fate and cellular trafficking of MT4-MMP by analyzing its homophilic complex interactions, internalization and recycling dynamics compared to an inert form, MT4-MMP-E249A. Oligomeric and dimeric complexes were analyzed by co-transfection of cells with FLAG- or Myc-tagged MT4-MMP by reducing and non-reducing immunoblots and co-immunoprecipitation experiments. The trafficking of MT4-MMP was studied using an antibody feeding assay and confocal microscopy analysis or cell surface protein biotinylation and Western blot analysis. We demonstrate that MT4-MMP forms homophilic complexes at the cell surface, internalizes in early endosomes, and some of the enzyme is either auto-degraded or recycled to the cell surface. Our data indicate that MT4-MMP is internalized by the CLIC/GEEC pathway, a mechanism that differs from other MT-MMP members. Although MT4-MMP localizes with caveolin-1, MT4-MMP internalization was not affected by inhibitors of caveolin-1 or clathrin endocytosis pathways but was reduced by cdc42 or RhoA silencing with siRNA. We provide a new mechanistic insight into the regulatory mechanisms of MT4-MMP, which may have implications in the design of novel therapeutic strategies for metastatic breast cancer. This article is protected by copyright. All rights reserved. [less ▲]

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See detailDynamics of Internalization and Recycling of the pro-Metastatic Membrane Type 4-Matrix Metalloproteinase (MT4-MMP) in Breast Cancer cells
Truong, Alice ULg; Yip, Cassandre ULg; PAYE, Alexandra ULg et al

Poster (2015, October 26)

MT4-MMP (MMP17) is a glycosyl-phosphatidyl inositol-anchored membrane-type matrix metalloproteinase expressed at the cell surface of human breast cancer cells. In triple negative breast cancer, MT4-MMP ... [more ▼]

MT4-MMP (MMP17) is a glycosyl-phosphatidyl inositol-anchored membrane-type matrix metalloproteinase expressed at the cell surface of human breast cancer cells. In triple negative breast cancer, MT4-MMP promotes primary tumor growth and lung metastases. Recently, we demonstrated that EGFR activation and signaling are enhanced by MT4-MMP in a non-proteolytic dependent manner. While trafficking and internalization of EGFR was extensively investigated, little is known about MT4-MMP. Here, we investigated the dimerization, internalization and recycling dynamics of MT4-MMP and its mutated inactive form MT4-MMP-E249A. We demonstrate that MT4-MMP forms dimers and oligomers at the cell surface, a process that was not inhibited neither by broad-spectrum MMP inhibitors (GM6001 and BB94) nor TIMP-2. MT4-MMP is internalized in early endosomes from 10 minutes to 60 minutes. Once internalized, some amount of MT4-MMP is auto-degraded, whereas its inert form E249A was found intact. Large part of the internalized enzyme was recycled intact at the cell surface. By exploring its endocytosis, we found that MT4-MMP is internalized by the CLIC/GEEC pathway, a mechanism that differs from other MT-MMP members. Overall, we provided a new mechanistic insight on the regulatory mechanisms of MT4-MMP in human breast cancer cells. We also, highlighted unique features of MT4-MMP among membrane-associated MMPs, which may be useful for the design of novel therapeutic strategies for metastatic breast cancer. [less ▲]

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See detailDynamics of ligands on gold surface to obtain Janus nanoclusters: A theoretical and experimental investigation
Lugo Preciado, Jesús Gustavo ULg

Doctoral thesis (2016)

We performed a joint computational – experimental investigation of the dynamics of ligand exchange on gold nanoclusters (GNC) surface with the aim to understand how to control the structural and optical ... [more ▼]

We performed a joint computational – experimental investigation of the dynamics of ligand exchange on gold nanoclusters (GNC) surface with the aim to understand how to control the structural and optical properties of GNC through the design of their ligand shell. Our computational studies were carried out in the framework of the Kohn – Sham implementation of density functional theory in quantum chemistry. We analyzed the main features of UV – Vis spectra computed at the TD – DFT / CAM – B3LYP level for the Au13, Au25, and Au28 metallic cores protected by thiolate, chloride, and phosphine ligands. Our results show that it is possible to tune the energy of the lowest absorption band of gold clusters by ligand shell engineering in order to control the charge redistribution between ligand shell and metallic core. In parallel we synthesized a set of Au25(ATP)x(TP)18 – x clusters with different ATP/TP ratios using an adapted Demessence protocol by combining 4ATP (4 – aminothiophenol) and TP (thiophenol) ligands. ESI – MS measurements evidence that for these mixed ligand shells the Au25 nuclearity is preserved. However, the addition of the DDT (1 – dodecanethiol) ligand in the mixture leads to nanoparticle formation. FT – IR spectroscopy confirms the absorption of two different ligands on the gold surface and SAXS shows that we have a good correlation between the distance between two clusters and the length of the ligand protecting them. Furthermore, we collaborated with the Institut Charles Gerhardt in the Université de Montpellier, France whose experimental results show that several n – heterocyclic carbenes (NHC) bearing different groups on the N atoms exhibit similar reactivity when protecting a gold nanosurface. The formation of the bis(NHC) AuI gold complexes is evidenced by 13C NMR. In order to complement and interpret the experimental results, we carried out a computational study of the adsorption of a single NHC on Au38 which acts as a model for the gold surface, as well as of the fully NHC ligated Au38 cluster. The joint experimental – theoretical study, in particular the comparison between computed and 13C NMR spectra allows proposing a possible mechanism explaining the formation of [NHC – Au – NHC]+ complexes and the erosion experienced by the nanoparticle. Finally, we carried out a comparison of the mode of binding and the structural and optical properties of the fully ligated PH3 and NHC GNC with metallic cores of different nuclearities. Our computations show that the Au – P bond is weaker than the Au – NHC one. Additionally, our study confirms that the ligand – to – metal charge transfer is an important parameter for understanding the electronic transitions and the UV – Vis spectra in these clusters. Our computations on the PH3 – Au38 set of complexes show that there is a site selectivity for the reactivity for the PH3 interacting on the Au38 surface which allows predicting where the PH3 is likely to be adsorbed. This selectivity is not observed in the case of the binding of a single NHC ligand on the surface of the Au38 cluster. [less ▲]

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See detailDynamics of livestock production systems during the economic transformation period in Northern Vietnam : case study in Cam Giang District, Hai Duong Province
Han Quang, Hanh ULg; Vu Dinh, Ton; Lebailly, Philippe ULg

in Koonawootrittriron, S.; Suwanasopee, T.; Jattawa, D. (Eds.) et al The 15th AAAP Animal Science Congress "Improving Smallholder and Industrial Livestock Production for Enhancing Food Security, Environment and Human Welfare" : Proceedings, Vol. II. Abstracts (2012)

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See detailThe dynamics of lysozyme from bacteriophage lambda in solution probed by NMR and MD simulations.
Smith, Lorna J.; Bowen, Alice M.; Di Paolo, Alexandre et al

in Chembiochem : a European journal of chemical biology (2013), 14(14), 1780-8

(15) N NMR relaxation studies, analyses of NMR data to include chemical shifts, residual dipolar couplings (RDC), NOEs and H(N) -H(alpha) coupling constants, and molecular dynamics (MD) simulations have ... [more ▼]

(15) N NMR relaxation studies, analyses of NMR data to include chemical shifts, residual dipolar couplings (RDC), NOEs and H(N) -H(alpha) coupling constants, and molecular dynamics (MD) simulations have been used to characterise the behaviour of lysozyme from bacteriophage lambda (lambda lysozyme) in solution. The lower and upper lip regions in lambda lysozyme (residues 51-60 and 128-141, respectively) show reduced (1) H-(15) N order parameters indicating mobility on a picosecond timescale. In addition, residues in the lower and upper lips also show exchange contributions to T2 indicative of slower timescale motions. The chemical shift, RDC, coupling constant and NOE data for lambda lysozyme indicate that two fluctuating beta-strands (beta3 and beta4) are populated in the lower lip region while the N terminus of helix alpha6 (residues 136-139) forms dynamic helical turns in the upper lip region. This behaviour is confirmed by MD simulations that show hydrogen bonds, indicative of the beta-sheet and helical secondary structure in the lip regions, with populations of 40-60 %. Thus in solution lambda lysozyme adopts a conformational ensemble that will contain both the open and closed forms observed in the crystal structures of the protein. [less ▲]

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See detailThe dynamics of market, credit and liquidity risk in the US corporate bond market
Heck, Stéphanie ULg

Doctoral thesis (2016)

Market, credit and liquidity constitute important risk factors in financial markets. Investors looking for optimal combinations of risk and return have to monitor their portfolios with regard to each of ... [more ▼]

Market, credit and liquidity constitute important risk factors in financial markets. Investors looking for optimal combinations of risk and return have to monitor their portfolios with regard to each of those factors. This work brings answers to some of the challenges presented by these three risk factors in the US corporate bond market. Market risk is the earliest and most widely acknowledged risk factor, affecting all financial securities. The risk that the issuer of the bond might go bankrupt introduces credit risk for corporate bonds. Finally, these securities are also characterized by a low trading frequency. Liquidity in this market has been severely affected by the recent global financial crisis as well as by the regulatory changes that followed the crisis. The first part of this dissertation studies the return premium investors require in compensation for undertaking credit risk. It is shown that distributional characteristics of individual assets and in particular the contribution of an asset’s return to the market portfolio’s skewness and kurtosis are important determinants of these premiums. The second part explores commonality in individual bond liquidity levels. It is shown that the pricing of liquidity in yield spreads is essentially due to this commonality. The final part of this dissertation designs a corporate bond market index based on the repeat-sales technique. The index adequately captures aggregate market dynamics and contributes to the explanation of the cross-section of individual corporate bond returns. [less ▲]

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See detailDynamics of mitotic activity and expression of viral proteins gp51 and p24 of Bovine Leukemia Virus producing cells.
Roussev, Roussi; Polianova, M.; Portetelle, Daniel ULg et al

in Folia Biologica (1993), 39

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See detailDynamics of mononuclear cadmium beta-lactamase revealed by the combination of NMR and PAC spectroscopy.
Hemmingsen, L.; Damblon, Christian ULg; Antony, J. et al

in Journal of the American Chemical Society (2001), 123(42), 10329-35

The two metal sites in cadmium substituted beta-lactamase from Bacillus cereus 569/H/9 have been studied by NMR spectroscopy ((1)H, (15)N, and (113)Cd) and PAC spectroscopy ((111m)Cd). Distinct NMR ... [more ▼]

The two metal sites in cadmium substituted beta-lactamase from Bacillus cereus 569/H/9 have been studied by NMR spectroscopy ((1)H, (15)N, and (113)Cd) and PAC spectroscopy ((111m)Cd). Distinct NMR signals from the backbone amides are identified for the apoenzyme and the mononuclear and binuclear cadmium enzymes. For the binuclear cadmium enzyme, two (113)Cd NMR signals (142 and 262 ppm) and two (111m)Cd PAC nuclear quadrupole interactions are observed. Two nuclear quadrupole interactions are also observed, with approximately equal occupancy, in the PAC spectra at cadmium/enzyme ratios < 1; these are different from those derived for the binuclear cadmium enzyme, demonstrating interaction between the two metal ion binding sites. In contrast to the observation from PAC spectroscopy, only one (113)Cd NMR signal (176 ppm) is observed at cadmium/enzyme ratios < 1. The titration of the metal site imidazole (N)H proton signals as a function of cadmium ion-to-enzyme ratio shows that signals characteristic for the binuclear cadmium enzyme appear when the cadmium ion-to-enzyme ratio is between 1 and 2, whereas no signals are observed at stoichiometries less than 1. The simplest explanation consistent with all data is that, at cadmium/enzyme ratios < 1, the single Cd(II) is undergoing exchange between the two metal sites on the enzyme. This exchange must be fast on the (113)Cd NMR time scale and slow on the (111m)Cd PAC time scale and must thus occur in a time regime between 0.1 and 10 micros. [less ▲]

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See detailDynamics of organic and inorganic carbon across contiguous mangrove and seagrass systems (Gazi bay, Kenya)
Bouillon, Steven; Dehairs, Frank; Velimirov, Branko et al

in Journal of Geophysical Research. Biogeosciences (2007), 112(G02018),

We report on the water column biogeochemistry in adjacent mangrove and seagrass systems in Gazi Bay (Kenya), with a focus on assessing the sources and cycling of organic and inorganic carbon. Mangrove and ... [more ▼]

We report on the water column biogeochemistry in adjacent mangrove and seagrass systems in Gazi Bay (Kenya), with a focus on assessing the sources and cycling of organic and inorganic carbon. Mangrove and seagrass-derived material was found to be the dominant organic carbon sources in the water column, and could be distinguished on the basis of their d13C signatures and particulate organic carbon:total suspended matter (POC/TSM) ratios. Spatially, a distinct boundary existed whereby the dominance of mangrove-derived material decreased sharply close to the interface between the mangrove forest and the dense seagrass beds. The latter is consistent with the reported export of mangrove-derived material, which is efficiently trapped in the adjacent seagrass beds. There were significant net inputs of POC and dissolved organic carbon (DOC) along the Kidogoweni salinity gradient, for which the d13CPOC signatures were consistent with those of mangroves. DOC was the dominant form of organic carbon in both mangrove and seagrass beds, with DOC/POC ratios typically between 3 and 15. Dynamics of dissolved inorganic carbon in the creeks were strongly influenced by diagenetic C degradation in the intertidal mangrove areas, resulting in significant CO2 emission from the water column to the atmosphere. Although highest partial pressure of CO2 (pCO2) values and areal CO2 flux rates were observed in the mangrove creeks, and the water column above the seagrass beds was in some locations a net sink of CO2, most of the ecosystems’ emission of CO2 to the atmosphere occurred in the seagrass beds adjacent to the mangrove forest. The presence of dense seagrass beds thus had a strong effect on the aquatic biogeochemistry, and resulted in trapping and further mineralization of mangrove-derived POC, intense O2 production and CO2 uptake. The adjacent seagrass beds provide a large area with conditions favorable to exchange of CO2 with the atmosphere, thereby limiting export of mangrove-derived organic and inorganic carbon toward the coastal ocean. [less ▲]

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See detailDynamics of PCB transfer from mother to pup during lactation in UK grey seals Halichoerus grypus: differences in PCB profile between compartments of transfer and changes during the lactation period
Debier, Cathy; Pomeroy, Paddy P.; Dupont, Cédric et al

in Marine Ecology-Progress Series (2003), 247

The composition of the PCB mixture which is transferred from mother to pup in grey seals Halichoerus grypus throughout lactation was measured in the successive compartments of transfer: maternal blubber ... [more ▼]

The composition of the PCB mixture which is transferred from mother to pup in grey seals Halichoerus grypus throughout lactation was measured in the successive compartments of transfer: maternal blubber, maternal serum, milk and pup serum. Mother-pup pairs were captured regularly between birth and weaning on the Isle of May, Scotland. The PCB profiles of the different compartments of transfer consisted mainly of congeners 153, 138, 180, 187, 170 and 101, which made up 85% of the total PCB burden. Outer blubber contained higher relative concentrations (R-153) Of hepta-, octa-, and nona-chlorinated congeners (higher chlorinated congeners) than inner blubber, at both early (less than or equal to 5 d) and late (greater than or equal to 11 d) lactation. There was no change in the composition of the outer blubber layer between early and late lactation, while in the inner blubber, there was a slight increase in the R153 of higher chlorinated congeners at late lactation. In maternal serum, profiles changed towards having a higher proportion of higher chlorinated congeners as lactation progressed, but in milk, the PCB pattern stayed constant throughout lactation. Surprisingly, in pup serum profiles also changed towards higher R153 of higher chlorinated congeners at late lactation compared to early lactation, which was different to the pattern observed in milk. In all body compartments, higher proportions of higher chlorinated congeners were associated with higher concentrations of total PCBs. Maternal blubber and pup serum contained a higher R153 of higher chlorinated congeners than milk and, to a lesser extent, maternal serum. Thus biomagnification of the higher chlorinated congeners was recorded in pup serum. [less ▲]

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See detailDynamics of pCO2 and related air-ice CO2 fluxes in the Arctic coastal zone (Amundsen Gulf, Beaufort Sea)
Geilfus, Nicolas-Xavier ULg; Carnat, G.; Papakyriakou, T. et al

in Journal of Geophysical Research. Oceans (2012), 117(C00G10),

We present an Arctic seasonal survey of carbon dioxide partial pressure (pCO2) dynamics within sea ice brine and related air-ice CO2 fluxes. The survey was carried out from early spring to the beginning ... [more ▼]

We present an Arctic seasonal survey of carbon dioxide partial pressure (pCO2) dynamics within sea ice brine and related air-ice CO2 fluxes. The survey was carried out from early spring to the beginning of summer in the Arctic coastal waters of the Amundsen Gulf. High concentrations of pCO2 (up to 1834 matm) were observed in the sea ice in early April as a consequence of concentration of solutes in brines, CaCO3 precipitation and microbial respiration. CaCO3 precipitation was detected through anomalies in total alkalinity (TA) and dissolved inorganic carbon (DIC). This precipitation seems to have occurred in highly saline brine in the upper part of the ice cover and in bulk ice. As summer draws near, the ice temperature increases and brine pCO2 shifts from a large supersaturation (1834 matm) to a marked undersaturation (down to almost 0 matm). This decrease was ascribed to brine dilution by ice meltwater, dissolution of CaCO3 and photosynthesis during the sympagic algal bloom. The magnitude of the CO2 fluxes was controlled by ice temperature (through its control on brine volume and brine channels connectivity) and the concentration gradient between brine and the atmosphere. However, the state of the ice-interface clearly affects air-ice CO2 fluxes. [less ▲]

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