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See detailEvolution of metal hyperaccumulation in Arabidopsis halleri
Hanikenne, Marc ULg; Kroymann, Juergen; Talke, Ina N. et al

Conference (2009, March 04)

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See detailThe evolution of metal hyperaccumulation in Arabidopsis halleri
Hanikenne, Marc ULg

Scientific conference (2015, August 07)

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See detailEvolution of metal hyperaccumulation required cis-regulatory changes and triplication of HMA4
Hanikenne, Marc ULg; Talke, Ina N.; Haydon, Michael J. et al

in Nature (2008), 453

Little is known about the types of mutations underlying the evolution of species-specific traits. The metal hyperaccumulator Arabidopsis halleri has the rare ability to colonize heavy-metal-polluted soils ... [more ▼]

Little is known about the types of mutations underlying the evolution of species-specific traits. The metal hyperaccumulator Arabidopsis halleri has the rare ability to colonize heavy-metal-polluted soils, and, as an extremophile sister species of Arabidopsis thaliana, it is a powerful model for research on adaptation. A. halleri naturally accumulates and tolerates leaf concentrations as high as 2.2% zinc and 0.28% cadmium in dry biomass. On the basis of transcriptomics studies, metal hyperaccumulation in A. halleri has been associated with more than 30 candidate genes that are expressed at higher levels in A. halleri than in A. thaliana. Some of these genes have been genetically mapped to broad chromosomal segments of between 4 and 24 cM co-segregating with Zn and Cd hypertolerance. However, the in planta loss-of-function approaches required to demonstrate the contribution of a given candidate gene to metal hyperaccumulation or hypertolerance have not been pursued to date. Using RNA interference to downregulate HMA4 (HEAVY METAL ATPASE 4) expression, we show here that Zn hyperaccumulation and full hypertolerance to Cd and Zn in A. halleri depend on the metal pump HMA4. Contrary to a postulated global trans regulatory factor governing high expression of numerous metal hyperaccumulation genes, we demonstrate that enhanced expression of HMA4 in A. halleri is attributable to a combination of modified cis-regulatory sequences and copy number expansion, in comparison to A. thaliana. Transfer of an A. halleri HMA4 gene to A. thaliana recapitulates Zn partitioning into xylem vessels and the constitutive transcriptional upregulation of Zn deficiency response genes characteristic of Zn hyperaccumulators. Our results demonstrate the importance of cis-regulatory mutations and gene copy number expansion in the evolution of a complex naturally selected extreme trait. The elucidation of a natural strategy for metal hyperaccumulation enables the rational design of technologies for the clean-up of metal-contaminated soils and for bio-fortification. [less ▲]

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See detailEvolution of methanol (CH3OH) above the Jungfraujoch station (46.5°N) : Variability, seasonal modulation and long-term trend.
Bader, Whitney ULg; Mahieu, Emmanuel ULg; Lejeune, Bernard ULg et al

Poster (2013, April 09)

Methanol (CH3OH) is the second most abundant organic compound in the Earth’s atmosphere with concentrations close to a few ppbv, after methane, despite a short lifetime of a few days (Jacob et al., 2005 ... [more ▼]

Methanol (CH3OH) is the second most abundant organic compound in the Earth’s atmosphere with concentrations close to a few ppbv, after methane, despite a short lifetime of a few days (Jacob et al., 2005). Natural sources of CH3OH include plant growth, oceans, decomposition of plant matter, oxidation of methane and other VOCs,. . . while anthropogenic sources are from vehicles, industry,. . . biomass burning completes the emission budget. The main sink is the oxidation by hydroxyl radical, leading to the formation of carbon monoxide (CO) and formaldehyde (H2CO). The retrieval of methanol is very challenging due to the presence of strong absorption of ozone and its isotopologues in addition to water vapour and carbon dioxide in the region of the selected strong nu8 band of CH3OH. First retrievals from satellite observations using the Atmospheric Chemistry Experiment infrared Fourier Transform Spectrometer (ACE-FTS) on board the SCISAT satellite have been performed by Dufour et al. (2007 and references therein) using a spectral interval going from 995.5 to 1008.3 cm-1. In 2009, first retrievals from a ground-based FTS, using spectra recorded at Kitt Peak (31.9°N) and a window going from 992 to 999 cm-1 have been reported by Rinsland et al. (2009), followed by Vigouroux et al. (2012 and references therein) who used yet another spectral interval going from 1029 to 1037cm-1. From those former retrieval strategies and also considering the Mahieu et al. (2012) contribution, we redefined our spectral intervals to maximize the information content. Indeed, our first window, starting from 992 to 1008.3 cm-1, is issued from the merge of Rinsland et al. and Dufour et al. windows while our second, going from 1029 to 1037 cm-1, is the one used by Vigouroux et al.With this new combination of windows, we were able to enlarge the range of zenith angles providing robust results while maintaining good correlation between our two windows; this also resulted in an improvement of the fitting residuals and of the information content. We used the 2008 HITRAN compilation (Rothman et al., 2009) for spectroscopic parameters. However, systematic residuals still remain in the 1033 cm-1 region which are attributed to unsatisfactory line parameters for methanol. New cross sections recorded at the Molecular Spectroscopy Facility of the Rutherford Appleton Laboratory (Harrison et al. 2012) and calibrated in intensity by using the reference spectra from the Pacific Northwest National Laboratory (PNNL) IR database will be tested as soon as converted into pseudolines. In this work, we will present the first long-term time series of methanol total columns, resulting from the implementation of our new retrieval strategy. All retrievals have been performed with the SFIT2 algorithm (v 3.91) (Rinsland et al., 1998) using a series of about 7 000 spectra recorded between 1995 and 2012, with zenith angles between 60 and 85°. These solar absorption observations have been recorded with a high-resolution FTIR Bruker 120HR instrument, at the high altitude station of the Jungfraujoch (46.5°N, 8°E, 3580 m asl), within the framework of the Network for the Detection of Atmospheric Composition Change (NDACC, visit http://www.ndacc.org). [less ▲]

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See detailEvolution of microstructure during creep of thermally treated Zn-Al-Cu alloy
Lecomte-Beckers, Jacqueline ULg; Terziev, L.; Wegria, J.

in Proceedings of the 13th International Congress on Electron Microscopy (1994)

This paper illustrates the modifications of the structure induced by creep treatments. The aim of this study is to compare the evolution of the structure after creep tests on samples treated at 100°C and ... [more ▼]

This paper illustrates the modifications of the structure induced by creep treatments. The aim of this study is to compare the evolution of the structure after creep tests on samples treated at 100°C and 250°C. Creep tests have been carried out at 120°C with a tensile stress of 40MPa and at 20°C with a tensile stress of 100MPa. [less ▲]

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See detailEvolution of multiple paralogous adenosine kinase genes in the moss genus Hygroamblystegium: phylogenetic implications
Vanderpoorten, Alain ULg; Shaw, A. J.; Cox, C. J.

in Molecular Phylogenetics and Evolution (2004), 31(2), 505-516

Maximum likelihood analyses of DNA sequences from two chloroplast regions, trnL-trnF and atpB-rbcL, and the internal transcribed spacers of ISS-5.8S-26S rRNA gene array, were performed to resolve species ... [more ▼]

Maximum likelihood analyses of DNA sequences from two chloroplast regions, trnL-trnF and atpB-rbcL, and the internal transcribed spacers of ISS-5.8S-26S rRNA gene array, were performed to resolve species relationships within the moss genus Hygroamblystegium. Constraining morphospecies to monophyly resulted in significantly less likely trees for H. tenax, but not for the other species. The lack of support for most clades and the partial incongruence among topologies necessitated the use of another independent, more variable region, namely the adenosine kinase gene (adk). Sequences for adk were polymorphic but were present as multiple copies within individuals. making parology a problem for phylogenetic analyses. Adk evolution was reconstructed using a reconciled gene tree approach in which duplications and losses were minimized in the context of ail estimate of the species tree derived from the analysis of the cp and nrDNA sequence data. Additional resolution of the species tree was then obtained by searching for reconstructions that further reduced adk duplications and losses. All the traditionally recognized morphospecies appeared to be polyphyletic in the resulting tree. Together with previous data from different molecular markers, the results Support the interpretation that Hygroamblystegium represents a recent radiation in which molecular and morphological evolution have been uncoupled. (C) 2003 Elsevier Inc. All rights reserved. [less ▲]

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See detailEvolution of municipal waste management in Belgium (Liège) for the last thirty years
Belboom, Sandra ULg; Renzoni, Roberto ULg; Digneffe, Jean-Marc et al

in SETAC Europe 17th LCA Case Studies Symposium : "Sustainable lifestyles", Budapest 28 February - 1 March 2011 (2011)

Waste is considered as a major concern of our century. Management tools were provided to help municipalities to reduce their emissions and to find the best way to valorize their waste. Life cycle ... [more ▼]

Waste is considered as a major concern of our century. Management tools were provided to help municipalities to reduce their emissions and to find the best way to valorize their waste. Life cycle assessment methodology was used jointly by the University of Liège and by Intradel, inter-municipal of the region of Liège (Belgium) to evaluate the impact of their activities and their improvement through years. [less ▲]

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See detailEvolution of Native Kidney Function After Pancreas Transplantation Alone
LE DINH, Hieu; DE ROOVER, Arnaud ULg; COIMBRA MARQUES, Carla ULg et al

in Transplantation Proceedings (2012), 44

Introduction. This study investigated changes in kidney function over time among a cohort of patients undergoing pancreas transplantation alone (PTA) from January 2002 to December 2011. Patients and ... [more ▼]

Introduction. This study investigated changes in kidney function over time among a cohort of patients undergoing pancreas transplantation alone (PTA) from January 2002 to December 2011. Patients and Methods. Ten of eighteen PTA patients bearing functioning grafts for at least 1 year were recruited for the analysis. Primary endpoints were changes in mean serum creatinine (SCr, mg/L) and mean estimated glomerular filtration rate (eGFR) using the 4-variable Levey-MDRD equation (mL/min/1.73 m2) comparing baseline (pretransplantation) to 6-month, 1-year, 3-year, and 5-year posttransplantation values. Mean follow-up time was 75.7 20.5 months (range, 46–106.5). Results. Baseline eGFR was 89.3 27.9 (range, 58–145). eGFR decreased to 75.7 26.2, 71 20.6, 66.5 14.8, and 62.1 11.2 at 6 months, 1, 3, and 5 years representing 15.2%, 20.5%, 15.8%, and 22.6% percentage decreases respectively (P .05 for all pairwise comparisons). The Baseline SCr was 8.6 2.3 mg/L (range, 5–13). SCr progressively increased to 10.1 3, 10.5 3.1, 10.9 3.1, and 11.3 1.7 at 6 months, 1, 3, and 5 years a 17.1%, 22%, 16.6%, and 19.9% increase respectively (P .05 for all pairwise comparisons). One of ten, 2/8, and 3/7 patients displayed an eGFR 60 at transplantation versus 3 and 5 years thereafter, respectively. No patient developed a SCr 25 mg/L or eGFR 30 or needed dialysis or kidney transplantation. Five of ten patients had micro-albuminuria or proteinuria before transplantation. Tacrolimus levels were within recommended therapeutic ranges over time. Conclusion. Kidney function deteriorated significantly after PTA. Understanding of risk factors for the development of renal impairment is important to preserve kidney function and to select appropriate candidates for PTA. [less ▲]

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See detailEvolution of nuclear shells with the Skyrme density dependent interaction
Brink, D. M.; Stancu, Floarea ULg

in Physical Review C (2007), 75(6), 064311

We present the evolution of the shell structure of nuclei in Hartree-Fock calculations using Skyrme's density-dependent effective nucleon-nucleon interaction. The role of the tensor part of the Skyrme ... [more ▼]

We present the evolution of the shell structure of nuclei in Hartree-Fock calculations using Skyrme's density-dependent effective nucleon-nucleon interaction. The role of the tensor part of the Skyrme interaction to the Hartree-Fock spin-orbit splitting in spherical spin unsaturated nuclei is reanalyzed. The contribution of a finite range tensor force to the spin-orbit splitting in closed shell nuclei is calculated. It is found that the exact matrix elements of a Gaussian and of a one-pion exchange tensor potential could be written as a product Skyrme's short range expression times a suppression factor which is almost constant for closed shell nuclei with mass number A >= 48. The suppression factor is similar to 0.15 for the one-pion exchange potential. [less ▲]

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See detailEvolution of ontogenetic allometry shaping giant species: a case study from the damselfish genus Dascyllus (Pomacentridae)
Frederich, Bruno ULg; Sheets, David

in Biological Journal of the Linnean Society (2010), 99(1), 99-117

The evolution of body size, the paired phenomena of giantism and dwarfism, has long been studied by biologists and paleontologists. However, detailed investigations devoted to the study of the evolution ... [more ▼]

The evolution of body size, the paired phenomena of giantism and dwarfism, has long been studied by biologists and paleontologists. However, detailed investigations devoted to the study of the evolution of ontogenetic patterns shaping giant species are scarce. The damselfishes of the genus Dascyllus appear as an excellent model for such a study. Their well understood phylogeny reveals that large-bodied species have evolved in two different clades. Geometric morphometric methods were used to compare the ontogenetic trajectories of the neurocranium and the mandible in both small-bodied (Dascyllus aruanus and Dascyllus carneus; maximum size: 50–65 mm standard length) and giant (Dascyllus trimaculatus and Dascyllus flavicaudus; maximum size: 90–110 mm standard length) Dascyllus species. At their respective maximum body size, the neurocranium of the giant species is significantly shorter and have a higher supraoccipital crest relative to the small-bodied species, whereas mandible shape variation is more limited and is not related to the ‘giant’ trait. The hypothesis of ontogenetic scaling whereby the giant species evolved by extending the allometric trajectory of the small-bodied ones (i.e. hypermorphosis) is rejected. Instead, the allometric trajectories vary among species by lateral transpositions. The rate of shape changes and the type of lateral transposition also differ according to the skeletal unit among Dascyllus species. Differences seen between the two giant species in the present study demonstrate that giant species may appear by varied alterations of the ancestor allometric pattern. [less ▲]

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See detailEvolution of organic debris and palynomorph preservation in two late middle Frasnian sections, southern Dinant Synclinorium border, Belgium
Vanguestaine, M.; Pardo-Trujillo, A.; Coen-Aubert, M. et al

in Bollettino della Società Paleontologica Italiana (1999), 38(2-3), 317-330

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See detailEvolution of paleoclimatic conditions and vegetation change in Himalaya from compound specific hydrogen and carbon analyses
Palhol, F.; Galy, V.; France-Lanord, C. et al

in Geochimica et Cosmochimica Acta (2006), 70(18), 468-468

Supplied by the Ganga–Brahmaputra fluvial system, the Bengal Fan provides an integrated record of the Himalayan basin history through time. The active channel-levee system of the middle fan documents the ... [more ▼]

Supplied by the Ganga–Brahmaputra fluvial system, the Bengal Fan provides an integrated record of the Himalayan basin history through time. The active channel-levee system of the middle fan documents the last glacial/interglacial cycle. Organic geochemistry studies have shown that the organic matter contained in the Bengal Fan sediments is mainly of terrestrial origin. We analysed terrestrial n-alkanes (C27–C33) from Bengal Fan sediments and modern Ganga–Brahmaputra sediments. Comparison of compound specific hydrogen and carbon isotopic ratios in these samples allow us to follow the evolution of paleoenvironmental conditions since the Last Glacial Maximum. Carbon molecular isotopic data on the odd-HMW n-alkanes show a shift of 4&, corresponding to an evolution in the Himalayan system from a C4-dominated vegetation at LGM to a C3- dominated vegetation during the Holocene. It is now well known that C4 plants are more adapted than C3 plants to low atmospheric CO2 concentrations and to relatively hot and dry climate. In the same time, molecular D/H isotopic ratios measured on the same samples show an increase of the deuterium content of about 20& during the Holocene, which is consistent with lower temperature at the end of the LGM in the Himalaya. As low temperature should favored C3 plants, the predominance of a C4 vegetation have to be linked with dryer conditions at the end of the LGM. Afterwards, the increase of the C3/C4 ratio in the Himalayan system is related to a concomitant increase of humidity and pCO2 during the Holocene. [less ▲]

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Peer Reviewed
See detailEvolution of perinatal mortality in 4 maternal health centers in the Walloon region from 1977 to 1982]
Battisti, Oreste ULg; Adam, E.; Heusquin, A. et al

in Revue Médicale de Liège (1984), 39

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See detailEvolution of phase segregation and eutectic structures in AgPb 18SbTe20
Dadda, J.; Müller, E.; Perlt, S. et al

in Physica Status Solidi A. Applications and Materials Science (2014), 211(6), 1276-1281

The evolution of phase segregation in stoichiometric quenched AgPb mSbTe2+m (m = 18, Lead-Antimony-Silver-Tellurium - LAST-18) compounds was studied starting from the known pseudo-binary diagrams among ... [more ▼]

The evolution of phase segregation in stoichiometric quenched AgPb mSbTe2+m (m = 18, Lead-Antimony-Silver-Tellurium - LAST-18) compounds was studied starting from the known pseudo-binary diagrams among Ag2Te, PbTe, Sb2Te3 and AgSbTe 2. The compositions of secondary phases indicate that liquid phase during cooling, even under quenching conditions, follows mainly the liquidus line on the 2PbTe-Ag0.45Sb0.55Te1.05 quasi-binary section of the phase diagram until it reaches a critical point (18 mol.% of 2PbTe) and then turns to Ag2Te- and Sb2Te 3-rich sides of quasi-ternary system. This has led to the formation of various secondary phases at various stages during the solidification, whose microstructural features and morphology strongly depend upon their chemical composition. Moreover, during solidification the local compositional fluctuations of liquid phase in combination with the shift of liquid composition towards Sb-rich side of the phase diagram resulted in the development of eutectic microstructures in some regions of LAST-18 matrix phase. This suggests there exists a miscibility gap and eutectic point below 600 C on the 2PbTe-Ag0.45Sb0.55Te1.05 boundary line. These eutectic lamellar structures with a cumulative composition close to LAST-3 are on the 200-500 nm length scales and possess thermal conductivity of 0.55-0.65 W/m K at room temperature. The low thermal conductivity of lamellar eutectic structures was later confirmed on bulk samples using laser flash analysis, where the samples were synthesized by quenching and annealing. The results clearly demonstrate that one can engineer the microstructures in LAST compounds by selecting the appropriate initial composition from quasi PbTe-Ag 2Te-Sb2Te3 ternary phase diagram to lower the thermal conductivity further. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. [less ▲]

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See detailEvolution of pressure distribution during apple compression tests measured with tactile sensors
Kleynen, Olivier; de la Cierva, Sonia; Destain, Marie-France ULg

in Acta Horticulturae (2003), (604),

The paper analyses the ability of thin-film tactile sensors in providing information during static compression tests of ‘Jonagold’ apples (Malus pumila) of different ripeness stages. Such sensors are able ... [more ▼]

The paper analyses the ability of thin-film tactile sensors in providing information during static compression tests of ‘Jonagold’ apples (Malus pumila) of different ripeness stages. Such sensors are able to measure the contact surface and the interfacial pressure distribution during compression of fruits, this latter being characterised by suitable mathematical parameters. Results of compression tests between two flat steel plates are presented. The differentiated evolution of the pressure distribution according to the fruit maturity is pointed out. Ability of the sensor in evaluating the firmness is also discussed. [less ▲]

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