Does the Budyko curve reflect a maximum power state of hydrological systems? A backward analysis
Westhoff, Martijn ; ; Archambeau, Pierre et al
Conference (2016, April)
Almost all catchments plot within a small envelope around the Budyko curve. This apparent behaviour suggests that organizing principles may play a role in the evolution of catchments. In this paper we ... [more ▼]
Almost all catchments plot within a small envelope around the Budyko curve. This apparent behaviour suggests that organizing principles may play a role in the evolution of catchments. In this paper we applied the thermodynamic principle of maximum power as the organizing principle. In a top-down approach we derived mathematical formulations of the relation between relative wetness and gradients driving runoff and evaporation for a simple one-box model. We did this in an inverse manner such that when the conductances are optimized with the maximum power principle, the steady state behaviour of the model leads exactly to a point on the asymptotes of the Budyko curve. Subsequently, we added dynamics in forcing and actual evaporations, causing the Budyko curve to deviate from the asymptotes. Despite the simplicity of the model, catchment observations compare reasonably well with the Budyko curves subject to observed dynamics in rainfall and actual evaporation. Thus by constraining the – with the maximum power principle optimized – model with the asymptotes of the Budyko curve we were able to derive more realistic values of the aridity and evaporation index without any parameter calibration. [less ▲]Detailed reference viewed: 17 (3 ULg)
Does the circadian modulation of dream recall modify with age?
Chellappa, Sarah Laxhmi ; ; et al
in Sleep (2009), 32(9), 1201-9
STUDY OBJECTIVES: The ultradian NREM-REM sleep cycle and the circadian modulation of REM sleep sum to generate dreaming. Here we investigated age-related changes in dream recall, number of dreams, and ... [more ▼]
STUDY OBJECTIVES: The ultradian NREM-REM sleep cycle and the circadian modulation of REM sleep sum to generate dreaming. Here we investigated age-related changes in dream recall, number of dreams, and emotional domain characteristics of dreaming during both NREM and REM sleep. DESIGN: Analysis of dream recall and sleep EEG (NREM/REM sleep) during a 40-h multiple nap protocol (150 min of wakefulness and 75 min of sleep) under constant routine conditions. SETTING: Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland. PARTICIPANTS: Seventeen young (20-31 years) and 15 older (57-74 years) healthy volunteers INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: Dream recall and number of dreams varied significantly across the circadian cycle and between age groups, with older subjects exhibiting fewer dreams (P < 0.05), particularly after naps scheduled during the biological day, closely associated with the circadian rhythm of REM sleep. No significant age differences were observed for the emotional domain of dream content. CONCLUSIONS: Since aging was associated with attenuated amplitude in the circadian modulation of REM sleep, our data suggest that the age-related decrease in dream recall can result from an attenuated circadian modulation of REM sleep. [less ▲]Detailed reference viewed: 43 (0 ULg)
Does the community-based management of the sacred crocodiles pond of Bazoulé ensure the Nile crocodile conservation ?
; Vermeulen, Cédric
Conference (2012)Detailed reference viewed: 45 (2 ULg)
Does the cover crop residue management affect the soil water availability for plants?
Chelin, Marie ; Parvin, Nargish ; Hiel, Marie-Pierre et al
Poster (2014, December 05)
Hydraulic processes and soil storage capacity may be affected by the crop residue management. Thus, a better understanding of the spatial and temporal distribution of water as a consequence of different ... [more ▼]
Hydraulic processes and soil storage capacity may be affected by the crop residue management. Thus, a better understanding of the spatial and temporal distribution of water as a consequence of different tillage methods is needed. The distribution of soil water content is basically studied thanks to soil moisture sensors such as time domain reflectometry (TDR) probes. However, this method requires the disturbance of the soil and only provides local information. Comparatively, electrical resistivity tomography (ERT) slightly alters the soil structure. It has been considered as a proxy to assess the spatial and temporal variability of the soil water content. This study aims at assessing whether and to which extent the crop residue management influences soil water dynamics and the water availability for maize. Water content will be monitored from March to October 2014, under three crop residue managements: conventional tillage realized in the end of autumn, conventional tillage realized just before sowing, and strip tillage. A bare soil under conventional tillage will also be monitored so as to better understand the influence of the plant over the growing season. So as to better understand the dynamics of water in the soil-water-continuum, the influence of the crop residue management on the soil structure and the plant development will also be investigated. The soil water pattern will be daily monitored on a surface of two square meters through surface stainless steel electrodes, corresponding to three rows of seven maize plants. Five additional sticks with buried electrodes will be setup to get more detailed information near to the maize row. For each of the monitored zone, two TDR probes will help validating the data. In order to calibrate the relationship between electrical resistivity and soil water content, a dig will be dug, in which a set of four electrodes, one TDR probe and one temperature sensor will be placed at four different depths. Two suction cups placed on each of the monitoring zone will help getting the electrical conductivity of the soil solution. [less ▲]Detailed reference viewed: 89 (10 ULg)
Does the Debris Disk around HD 32297 Contain Cometary Grains?
; ; et al
in Astrophysical Journal (2014), 783
We present an adaptive optics imaging detection of the HD 32297 debris disk at L' (3.8 μm) obtained with the LBTI/LMIRcam infrared instrument at the Large Binocular Telescope. The disk is detected at ... [more ▼]
We present an adaptive optics imaging detection of the HD 32297 debris disk at L' (3.8 μm) obtained with the LBTI/LMIRcam infrared instrument at the Large Binocular Telescope. The disk is detected at signal-to-noise ratio per resolution element ~3-7.5 from ~0.''3 to 1.''1 (30-120 AU). The disk at L' is bowed, as was seen at shorter wavelengths. This likely indicates that the disk is not perfectly edge-on and contains highly forward-scattering grains. Interior to ~50 AU, the surface brightness at L' rises sharply on both sides of the disk, which was also previously seen at Ks band. This evidence together points to the disk containing a second inner component located at lsim50 AU. Comparing the color of the outer (50 <r/AU <120) portion of the disk at L' with archival Hubble Space Telescope/NICMOS images of the disk at 1-2 μm allows us to test the recently proposed cometary grains model of Donaldson et al. We find that the model fails to match this disk's surface brightness and spectrum simultaneously (reduced chi-square = 17.9). When we modify the density distribution of the model disk, we obtain a better overall fit (reduced chi-square = 2.87). The best fit to all of the data is a pure water ice model (reduced chi-square = 1.06), but additional resolved imaging at 3.1 μm is necessary to constrain how much (if any) water ice exists in the disk, which can then help refine the originally proposed cometary grains model. Based on observations made at the Large Binocular Telescope (LBT). The LBT is an international collaboration among institutions in the United States, Italy, and Germany. LBT Corporation partners are: the University of Arizona on behalf of the Arizona University system; Istituto Nazionale di Astrosica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, the Astrophysical Institute Potsdam, and Heidelberg University; the Ohio State University, and the Research Corporation, on behalf of the University of Notre Dame, University of Minnesota and University of Virginia. Based on observations made using the Large Binocular Telescope Interferometer (LBTI). LBTI is funded by the National Aeronautics and Space Administration as part of its Exoplanet Exploration program. [less ▲]Detailed reference viewed: 23 (4 ULg)
Does the Direction of Ductal Blood Flow Affect Regional Circulatory Hemodynamics in Duct Dependent Congenital Heart Disease?
; Rigo, Vincent ;
in Pediatric Research (2003, April), 53(4 Part 2/2), 471Detailed reference viewed: 26 (10 ULg)
Does the facultative bacteria Serratia symbiotica influence the foraging strategies of aphid parasitoids?
; ; et al
Poster (2014)Detailed reference viewed: 77 (12 ULg)
Does the local embeddedness of energy production contribute to sustainable rural development? Some evidence and propositions concerning the spreading of wind energy parks in Belgium
Schmitz, Serge ; Vanderheyden, Vincent
in Ecological and Social innovation - 9th International conference of territorial intelligence, ENTI, Strasbourg 2010., Strasbourg : France (2010) - (2010, November)
Parce que l’énergie éolienne prend place à l’échelle locale, il semble important de penser aussi son développement à ce niveau. Quand le développement éolien est globalement perçu comme positif, des ... [more ▼]
Parce que l’énergie éolienne prend place à l’échelle locale, il semble important de penser aussi son développement à ce niveau. Quand le développement éolien est globalement perçu comme positif, des problèmes apparaissent au niveau local. Basée sur une revue de la littérature et sur cinq études de cas en Belgique, la communication souligne la transition spatiale de la production d’énergie suite à la multiplication des sites éoliens. Elle propose des pistes afin de mieux inclure la société locale dans le développement éolien [less ▲]Detailed reference viewed: 22 (7 ULg)
Does the metabolic syndrome help to select patients requiring high statin dose?
in Lancet (2006), 368(9539), 893-4Detailed reference viewed: 27 (0 ULg)
Does the mission of providers matter on a quasi-market? The case of the Belgian "service voucher" scheme
Defourny, Jacques ; ; et al
in Annals of Public and Cooperative Economics = Annales de l'Economie Publique, Sociale et Coopérative (2010), 81(4), 583-610
In 2001, the Belgian government introduced a ‘service voucher’ scheme in the field of domestic (housework) services, following a quasi-market mechanism which fosters competition between providers of ... [more ▼]
In 2001, the Belgian government introduced a ‘service voucher’ scheme in the field of domestic (housework) services, following a quasi-market mechanism which fosters competition between providers of different types as regards sector (for-profit, public, third sector) and mission (seeking profits, home care provision to vulnerable groups and work integration of the unemployed). Empirical evidence suggests that third sector organizations focusing on a social mission recognized by a tutelary regulation are the best performing with regards to the quality of jobs and service organization, leading to a better ‘triangulation’ of the service relationship. On the other hand, for-profit providers, especially temporary work agencies, seem to favour their capacity of adaptation to the desiderata of their clients and costs’ minimization to the detriment of the quality of jobs which are made as flexible as possible. [less ▲]Detailed reference viewed: 200 (30 ULg)
Does the new water-soluble form of curcumin(NDS27) inhibit the oxidant response of stimulated neutrophils and HL-60 cells?
Derochette, Sandrine ; Franck, Thierry ; et al
Poster (2012, September 07)
Neutrophils (PMNs) are involved in host defense against infections through the production of reactive oxygen species (ROS) and the release of an oxidant enzyme, myeloperoxidase (MPO), to kill pathologic ... [more ▼]
Neutrophils (PMNs) are involved in host defense against infections through the production of reactive oxygen species (ROS) and the release of an oxidant enzyme, myeloperoxidase (MPO), to kill pathologic agents. But, an excessive stimulation of PMNs is associated with development of inflammatory diseases. Neutrophils are prime targets to control inflammatory events and the therapeutic use of polyphenols is proposed to lower oxidative stress. The aim of this work was to study antioxidant effect of NDS27, a water-soluble form of curcumin, on stimulated equine PMNs and human promyelocytic leukemia cells (HL-60) which are less differenciated. 2',7'-Dichlorofluorescin diacetate and lucigenin were used to measure ROS production by activated HL-60 cells or PMNs. NDS27 (10-6 to 10-4 M) was pre-incubated with cells and eliminated before their activation to study its intracellular effects on ROS production. The effect of NDS27 on MPO activity released by the cells was determined by SIEFED. Likewise, the ability of NDS27 to enter into the cells was checked by HPLC on the cellular extracts.NDS27 significantly and dose-dependently inhibited the ROS production in both cell types without affecting their viability. Its intracellular effect showed higher efficiency for PMNs while its interaction with HL-60 cells remained better. The activity of MPO released by PMNs and HL-60 cells was decreased by NDS27 with a more efficient effect for PMNs. Our findings suggest that the greater efficiency of NDS27 in mature PMNs is not due to a better membrane permeability or a better interaction between membrane and NDS27, but rather to an inhibitory effect on the ROS production by the more mature cells, probably by targeting the enzymes implied in respiratory burst like MPO and NADPH oxidase. The modulatory effect of NDS27 towards oxidant activity of cells involved in immune and inflammatory response opens therapeutic perspectives to control pathologies with excessive inflammatory reactions. [less ▲]Detailed reference viewed: 73 (8 ULg)
Does the orbital degeneracy play any role in the high thermopower of lamellar cobaltites?
; ; et al
in Journal of Applied Physics (2007), 101(8),
This article investigates the role of the CoO6 octahedron distortion on the electronic properties and more particularly on the high value of the Seebeck coefficient in the BiCaCoO lamellar cobaltites. Our ... [more ▼]
This article investigates the role of the CoO6 octahedron distortion on the electronic properties and more particularly on the high value of the Seebeck coefficient in the BiCaCoO lamellar cobaltites. Our measurements provide clues indicating that the t2g orbital degeneracy lifting has to be considered to account for the observed high temperature limit of the thermopower. They also provide experimental arguments for locating the a1g and eg′ orbitals levels on the energy scale, through the compression of the octahedron. These results are in agreement with recent ab initio calculation including the electronic correlations and concluding for the inversion of these levels as compared to the expectation from the crystal field theory. © 2007 American Institute of Physics. [less ▲]Detailed reference viewed: 19 (1 ULg)
Does the P(2X1del) variant lacking 17 amino acids in its extracellular domain represent a relevant functional ion channel in platelets?
Oury, Cécile ; ; et al
in Blood (2002)
In this letter, we questionned the existence of a ADP responsive P2X1 protein variant in platelets.Detailed reference viewed: 4 (0 ULg)
Does the phenotype at diagnosis (e.g., fibrostenosing, inflammatory, perforating) predict the course of Crohn's disease?
Louis, Edouard ; Reenaers, Catherine ; Belaiche, Jacques
in Inflammatory Bowel Diseases (2008), 14Detailed reference viewed: 20 (2 ULg)
Does the production of Belgian bioethanol fit with European requirements on GHG emissions? Case of wheat
Belboom, Sandra ; Bodson, Bernard ; Léonard, Angélique
in Biomass & Bioenergy (2015), 74
This paper undertakes an environmental evaluation of bioethanol production, using wheat cultivated in Belgium. Cultivation steps are modelled using Belgian specific data. Wheat transformation in ethanol ... [more ▼]
This paper undertakes an environmental evaluation of bioethanol production, using wheat cultivated in Belgium. Cultivation steps are modelled using Belgian specific data. Wheat transformation in ethanol relies on industrial data. GHG emissions of the whole life cycle are calculated and compared with the default values given by the European Renewable Energy Directive. Belgian wheat bioethanol achieves a 5% higher GHG reduction than the one mentioned in the European directive but impact repartition is different with a higher importance of cultivation step in our case. Belgian wheat bioethanol complies with the current sustainability criteria but is also able to conform to further ones. Sensitivity analyses are performed on the importance of N fertilizers and associated emissions known as main important parameters. These analyses reveal non negligible variations and then a range of available GHG reduction when using wheat bioethanol. [less ▲]Detailed reference viewed: 49 (12 ULg)
Does the self-face grab and/or retain attention? An eye movement study
Devue, Christel ; ; Brédart, Serge et al
in Perception (2008), 37(Suppl. S), 94
Previous studies that investigated the ability of high priority stimuli to grab attention reported contradictory results. In the present study, eye tracking was used to examine the effect of the presence ... [more ▼]
Previous studies that investigated the ability of high priority stimuli to grab attention reported contradictory results. In the present study, eye tracking was used to examine the effect of the presence of the self-face among unfamiliar faces in a visual search task in which face identity was task-irrelevant. We evaluated whether the self-face (i) received prioritized selection, (ii) retained attention, and (iii) whether its status as target or distractor had a differential effect. Another highly familiar face was included to control whether possible effects were specific to the self-face or could be explained by high familiarity. We found that the presence of the self-face affected performance on the search task. This was not due to a prioritized processing but rather to a difficulty to disengage attention. Crucially, this effect seemed due to self-face familiarity. Indeed, similar results were obtained with the other familiar face. Moreover, the effect of the self-face was stronger when it was presented as the target than when it was a distractor. [less ▲]Detailed reference viewed: 112 (11 ULg)
Does the self-referential stimuli percpetion decrease with diminished level of consciousness?
in Vanhaudenhuyse, Audrey; BOVEROUX, Pierre; Bruno, Marie-Aurélie (Eds.) et al Journal of Neurology (2012)Detailed reference viewed: 33 (0 ULg)
Does the soil’s effective hydraulic conductivity adapt in order to obey the Maximum Entropy Production principle? A lab experiment
Westhoff, Martijn ; ; Erpicum, Sébastien et al
Conference (2015, April)
The Maximum Entropy Production (MEP) principle is a conjecture assuming that a medium is organized in such a way that maximum power is subtracted from a gradient driving a flux (with power being a flux ... [more ▼]
The Maximum Entropy Production (MEP) principle is a conjecture assuming that a medium is organized in such a way that maximum power is subtracted from a gradient driving a flux (with power being a flux times its driving gradient). This maximum power is also known as the Carnot limit. It has already been shown that the atmosphere operates close to this Carnot limit when it comes to heat transport from the Equator to the poles, or vertically, from the surface to the atmospheric boundary layer. To reach this state close to the Carnot limit, the effective thermal conductivity of the atmosphere is adapted by the creation of convection cells (e.g. wind). The aim of this study is to test if the soil’s effective hydraulic conductivity also adapts itself in such a way that it operates close to the Carnot limit. The big difference between atmosphere and soil is the way of adaptation of its resistance. The soil’s hydraulic conductivity is either changed by weathering processes, which is a very slow process, or by creation of preferential flow paths. In this study the latter process is simulated in a lab experiment, where we focus on the preferential flow paths created by piping. Piping is the process of backwards erosion of sand particles subject to a large pressure gradient. Since this is a relatively fast process, it is suitable for being tested in the lab. In the lab setup a horizontal sand bed connects two reservoirs that both drain freely at a level high enough to keep the sand bed always saturated. By adding water to only one reservoir, a horizontal pressure gradient is maintained. If the flow resistance is small, a large gradient develops, leading to the effect of piping. When pipes are being formed, the effective flow resistance decreases; the flow through the sand bed increases and the pressure gradient decreases. At a certain point, the flow velocity is small enough to stop the pipes from growing any further. In this steady state, the effective flow resistance of the sand bed will be compared with the theoretical optimal flow resistance obtained with the MEP principle. For this study, different magnitudes of the forcing will be tested, while also the effect of dry spells will be explored. [less ▲]Detailed reference viewed: 54 (6 ULg)
Does the surgical treatment for lumbar radiculopathy fulfil patients preoperative expectations?
Demoulin, Christophe ; ; Martin, Didier et al
in Abstract book of the 8th Interdisciplinary World Congress on Low Back and Pelvic Pain (2013, October)Detailed reference viewed: 19 (2 ULg)
Does the surgical treatment for lumbar radiculopathy fulfill patients preoperative expectations? A one-year follow-up study
Demoulin, Christophe ; ; Martin, Didier et al
in WIP 2014 Abstract Book (2014, May)Detailed reference viewed: 43 (5 ULg)