Indicateurs de qualité de prise en charge du cancer du corps de l’utérus : méthodologie et liste pour le projet EFFECT

Poster (2012)

Etude des feux d'aménagement en zone tropicale semi-aride: cas du Parc Régional du W du Niger

Poster (2012)

Anthropisation et effets de lisière: impacts sur la diversité des rongeurs dans la réserve forestière de Masako (Kisangani, RDC)

Poster (2012)

Study of the forbidden oxygen lines in a sample of cometary spectra obtained at the VLT (ESO)

Poster (2012)

Effect of aerobic training on cardiorespiratory fitness, gait, quality of life and psychometric outcomes in Parkinson’s disease patients

Poster (2012)

Neural correlates of hypokinetic gait in Parkinson’s disease: An fMRI study

Poster (2012)

Objective: To investigate the neural correlates of hypokinetic gait in Parkinson’s disease (PD) using functional magnetic resonance imaging (fMRI). Background: Although hypokinetic gait is frequent and ... [more ▼]

Objective: To investigate the neural correlates of hypokinetic gait in Parkinson’s disease (PD) using functional magnetic resonance imaging (fMRI). Background: Although hypokinetic gait is frequent and has a negative impact on quality of life in PD, its underlying mechanisms remain poorly understood. Assuming that the brain regions recruited during real and imagined gait strongly overlap, mental imagery of brisk gait may be a successful approach to study hypokinetic gait in PD. Methods: Fifteen ‘‘on-drugs’’ PD patients (8 males; mean age 5 65.1 6 9.4 years) and fifteen controls matched for age, gender and mental imagery skills were trained to perform video-taped trials of comfortable and brisk gait on a 25 meter-path. The study was organ- ized as a block-design fMRI experiment where subjects were instructed to rehearse themselves performing comfortable and brisk gait and to press a key to indicate when they completed each 25 meter-imagined gait trial. The imagined speed reserve (ISR) defined as the difference between imagined brisk and comfortable gait speeds was measured as a control of behavioral performance. Imaging data processing and analyses were performed using SPM8. The first-level individual contrast images representing the comparison between brisk and comfortable gait were entered as two separate groups (controls vs patients) in an ANOVA with the corresponding ISRs as correlation regressors. Results: Compared with controls, patients showed hypokinetic gait during real gait training as their increase in speed during brisk relatively to comfortable gait was related to an increase in step ca- dence (r50.87; p<0.001) but not in step length (r50.11). ISRs meas- ured during fMRI and their real counterparts measured offline strongly correlated in patients (r50.88; p<0.001) and controls (r50.59; p50.02). Between-group comparison (p<0.001, uncorrected) of fMRI data showed that increasing imagined gait speed was strongly associated with increased activity of the left posterior parietal cortex in controls and with decreased activity of this region in patients. Conclusions: Our findings suggest that hypokinetic gait in PD is related to the impaired functioning of the left posterior parietal cortex. This area may represent a target for therapeutic interventions aimed at alleviating gait disturbances in PD. [less ▲]

Surface and bio-adhesion properties of new hydrophobic and current materials for artificial intraocular lens

Poster (2012)

A high bio-adhesion appears to be one of the key factor for posterior capsular opacification (PCO) prevention. Indeed, the proteins adsorption and the lens epithelial cells (LEC) adhesion both contribute ... [more ▼]

A high bio-adhesion appears to be one of the key factor for posterior capsular opacification (PCO) prevention. Indeed, the proteins adsorption and the lens epithelial cells (LEC) adhesion both contribute to PCO development. We present in this work the comparison of a new glistening free hydrophobic material (GF® from Physiol) with benchmark hydrophobic and hydrophilic materials regarding their chemicophysical properties and their respective ability to interact with lens epithelial cells and proteins. For this purpose, we determined the hydrophobicity by contact angle measurement (assessed by water drop and air bubble methods), the surface adhesiveness by atomic force microscopy (AFM), the proteins adsorption by fluorescent measurement and the LEC adhesion by the determination of cell density. The new hydrophobic material presents comparable hydrophobicity, proteins adsorption and LEC adhesion to current commercial hydrophobic material. Its adhesiveness, measured with the AFM, is intermediate between hydrophilic and hydrophobic materials. In conclusion, the bio-adhesion properties of this new glistening free hydrophobic IOL material are similar to generic hydrophobic acrylic materials and therefore should to the same extent prevent PCO. [less ▲]

Determination of seven azole antifungal drugs in human serum by UHPLC-DAD and its clinical application

Poster (2012)

Utilisation du propeptide N-terminal du procollagène de type 1 (P1NP) comme marqueur de formation osseuse chez le patient insuffisant rénal : différence entre le dosage total et le dosage « intact ».

Poster (2012)

Blue... is a bad sign

Poster (2012)

X-ray Dose Quantification for Various Scanning Protocols with the GE eXplore 120 micro-CT

Poster (2012)

Le débit de filtration glomérulaire est-il un déterminant de la concentration plasmatique du NGAL aux soins intensifs ?

Poster (2012)

Assessing the role of porosity in composite electrodes through model thin film electrode studies

Poster (2012)

Variation in TGF-BETA 1 blood levels in healthy dogs according to the breed predisposition to canine idiopathic pulmonary fibrosis

Poster (2012)

Pharmacological evaluation of succinic acid receptor (SUCNR1) small molecule modulators with an intracellular calcium biosensor.

Poster (2012)

Advanced genetic models for Piétrain boars involved in crossbreeding in the Walloon Region using test station and on-farm phenotypic and genomic data

Poster (2012)

Since 2007 the Walloon Region is acquiring a new advanced genetic evaluation program for Piétrain boars. Comprehensive models for routine genetic evaluation of boars involved in crossbreeding programs ... [more ▼]

Since 2007 the Walloon Region is acquiring a new advanced genetic evaluation program for Piétrain boars. Comprehensive models for routine genetic evaluation of boars involved in crossbreeding programs, using simultaneously data recorded on crossbred progeny at central test station and data recorded on-farm on purebred or crossbred pigs, are under development. Traits evaluated include growth, carcass quality traits and feed intake. Estimated breeding values allow breeders to select the best boars according to their selection objectives. But to have comprehensive models for crossbreeding performances, more advanced modelling of non-additive and crossbreeding effects will be added to current models. Additionally potential use of genomic information will be explored. [less ▲]

Fire promotes downy brome (Bromus tectorum L.) seed dispersal

Poster (2012)

Particularly well-known among the many impacts of the invasive annual grass downy brome (Bromus tectorum, Poaceae) is its ability to alter fire cycles and increase in abundance after fire. However, little ... [more ▼]

Particularly well-known among the many impacts of the invasive annual grass downy brome (Bromus tectorum, Poaceae) is its ability to alter fire cycles and increase in abundance after fire. However, little is known about how fire influences B. tectorum dispersal. We quantified fire effects on B. tectorum dispersal using three recently burned areas in the western region of the Colorado Rocky Mountains by marking diaspores (seeds) with fluorescent powder, and then recovering them at night using ultraviolet lights. Diaspores were of two types: with and without sterile florets attached. We also characterized vegetation cover and near-surface wind speed in burned and unburned areas. Diaspores travelled much farther in burned areas than in nearby unburned areas (means ± standard error at the end of the experiment: 209 ± 16 cm and 38 ± 1 cm, respectively; maximal distance at the end of the experiment: 2274 cm and 150 cm, respectively), indicating an increase in dispersal distance after fire. Diaspores with sterile florets attached dispersed longer distances than those without sterile florets (means ± standard error at the end of the experiment: 141 ± 14 cm and 88 ± 7 cm, respectively). Vegetation cover was lower and wind speeds were higher in the burned areas. Our results indicate that at least one of the mechanisms by which the spread of B. tectorum is promoted by fire is through increased seed dispersal distance. Preventing movement of seeds from nearby infestations into burned areas may help avoid the rapid population expansion often observed. [less ▲]

Anisotropy of magnetic susceptibility in the giant Lac Tio hemo-ilmenite ore body (Quebec Province, Canada): source and geological implications

Poster (2012)

Bone marrow-derived mesenchymal stromal cells failed to prevent experimental xenogeneic graft-versus-host disease

Poster (2012)

Assessing the role of porosity in composite electrodes through model thin film electrode studies

Poster (2012)

Characterization of T-helper lymphocytes in peripheral blood and bronchoalveolar lavage of healthy horses with recurrent airway obstruction

Poster (2012)

Combining in vivo and in silico experiments to unravel root water uptake dynamics

Poster (2012)

Genetic variation in heat stress tolerance of Holsteins producing under a continental temperate environment

Poster (2012)

Under projected climate changes, considerations for heat stress tolerance but also for genotype by environment interactions should enter breeding decisions, both for importing, but also exporting ... [more ▼]

Under projected climate changes, considerations for heat stress tolerance but also for genotype by environment interactions should enter breeding decisions, both for importing, but also exporting countries. Most studies concerning the breeding strategies on heat stress tolerance used the temperature humidity index (THI) to assess the thermal stress in a given environment and assumed a specific threshold to each studied population with the same response to each individual above this threshold. Recently new comprehensive thermal indices (TI) integrating radiation solar, wind speed, in addition to temperature and relative humidity were developed. Therefore, the aim of this study is advanced modelling of milk yield trait to evaluate the genetic variation in heat stress tolerance of Holsteins in a temperate environment using random regressions models and six new comprehensive TI. A total of 107,350 test day milk records were available for 12,099 primiparous Holsteins calving from 2000 to 2010. Test-day milk records were merged with meteorological data from 14 public weather stations across Luxembourg. Daily values of 6 new comprehensive TI (3 THI and 3 apparent temperature indices) were calculated by averaging hourly TI over 24 hours. The average distance between herds and their meteorological reference station was of 16 km. Sensitivity of cows to the climate environmental conditions was modelled by applying a reaction norm for each animal, representing its EBV for milk yield on values of the TI on the day in milk (DIM). Six separate random regression models were applied using time-dependent (DIM) and specific TI-dependent covariates. Random effects were additive genetic, permanent environmental, and herd year modelled with Legendre polynomials of order 2 for both DIM and TI. Genetic variances of the different TI evaluated in this study represent 27 to 30% of their correspondent variances for DIM effect. Permanent environmental and genetic variances of TI effect were in the same range. Additive genetic variances and heritabilities for daily milk yield slightly decreased with increasing degrees of the different THI and apparent temperature indices. The average daily milk heritability overall the lactation at the mean of each of the six TI was of 0.28. Genetic correlations between adjacent points across the lactation were > 0.90. Correlations between extreme distant DIM (e.g. early and late lactation stage) were reduced at 0.38 to 0.52. The overall genetic correlations between the different values of each TI remain high (> 0.85). EBV’s summing regular additive effect (DIM effect) and tolerance to heat stress (TI effect) were computed for several combinations of DIM and TI values. Ranking for sires and cows did not change among the 6 heat stress indicators. The correlations between EBVs estimated with the six models were greater than 0.90. In conclusion, the different models depicted genetic variation of milk yield among combinations of DIM and TI levels without defining thresholds in advance. Genetic variation was slightly lower when TI values exceed the thermoneutral zone. Breeding for reduced thermal sensitivity using any of the six indicators of heat stress evaluated in this study is possible. The indicator TI2 representing the adjusted THI for radiation solar and wind speed is favoured because it was the indicator that did identify the highest yearly milk losses under this continental temperate environment. [less ▲]

Oncogenic human papillomavirus could directly interact with natural killer cells

Poster (2012)

New surgical options in the management of menometrorrhagia: an overview

Poster (2012)

Impact de la réforme de la PAC sur le secteur de la viande bovine dans le sud de la Belgique

Poster (2012)

En 2010, en Wallonie, région occupant le sud de la Belgique, les aides directes représentaient, en moyenne près de 103 % du revenu agricole familial par unité de travail familial (RAF/UTF) des ... [more ▼]

En 2010, en Wallonie, région occupant le sud de la Belgique, les aides directes représentaient, en moyenne près de 103 % du revenu agricole familial par unité de travail familial (RAF/UTF) des exploitations agricoles professionnelles de type « bovins à viande ». De plus, ce type d’exploitation est dépendant du dernier régime d’aide couplée à la production en Wallonie, la prime à la vache allaitante, qui représente plus de la moitié de leur revenu (55 %). Cette étude s’inscrit dans le cadre de la réflexion actuellement menée en Belgique sur les répercussions de la future réforme de la PAC et les effets de la diminution budgétaire combinée au passage du modèle historique au modèle régional ainsi qu’à la possible suppression de la prime à la vache allaitante. [less ▲]

The sheepshead minnow Cyprinodon variegatus as a marine vertebrate model for investigating endocrine disrupting effects of triclosan

Poster (2012)

Zebrafish (Danio rerio) has been a prominent model in toxicology. This freshwater species present many advantages both in identifying endpoints of toxicity and in elucidating mechanisms of toxicity ... [more ▼]

Zebrafish (Danio rerio) has been a prominent model in toxicology. This freshwater species present many advantages both in identifying endpoints of toxicity and in elucidating mechanisms of toxicity. However, marine toxicologists lack such omnipotent model displaying similar advantages to zebrafish: small size, rapid breeding, and easy maintenance. We propose here the use of the sheepshead minnow Cyprinodon variegatus to define thyroid-disrupting effects of triclosan during pre-hatching development. Three females and two males were placed in each of the three breeding chambers designed for this experiment. More than 300 eggs were collected over three days and maintained in seawater with triclosan concentrations at 0, 100 ng.L-1, and 100 µg.L-1. Exposure of larvae to triclosan lasted until hatching. After hatching (six days post-spawning), 5 larvae per condition were placed in Bouin’s fixative for brain and thyroid histology. Length and body mass were measured. The body was frozen at -80oC to determine muscle thyroid hormone levels (T3 and T4), using radio-immunoassay techniques. Hatching success, in vivo observations, gross observation, thyroid hormone levels, histology will be determined and discussed in the framework of whether or not triclosan may alter thyroid metabolism during pre-hatching period of the sheepshead minnow. [less ▲]

Benevolent sexism leads women's self-concept be closely related to warmth and it strikes hard for their self-promotion and career orientation

Poster (2012)

Development of an automatic drowsiness monitoring system based on EEG and EOG signals, and preliminary tests in a professional driving simulator

Poster (2012)

Magnetostructural effects in ligand stabilized Pd13 cluster: a density functional theory study.

Poster (2012)

Geoarcheological aspects of new excavations at the Palaeolithic site of Kulbulak (Uzbekistan)

Poster (2012)

Precisely controlled mesoporous films to assess the role of architecture in Li‐ion batteries

Poster (2012)

Analyse sensorielle et biochimique du Tilapia du Nil (Oreochromis niloticus) conservé à température ambiante (30°C) et à 4°C

Poster (2012)

Impact of sequencing design on missing marker imputation and genomic selection in cattle

Poster (2012)

KINETICS OF QUINALPHOS RESIDUES ELIMINATION IN WATER AND FISH TISSUES FROM TANK CULTURED SILVER BARB (Barbonymus gonionotus)

Poster (2012)

A descriptive study of physico-chemical characteristics of Posidonia oceanica litter accumulation

Poster (2012)

The Mediterranean seagrass Posidonia oceanica meadow losses every fall the major part of its leaf biomass after senescing. These phytodetritus may decay within the meadow, be buried or be exported to ... [more ▼]

The Mediterranean seagrass Posidonia oceanica meadow losses every fall the major part of its leaf biomass after senescing. These phytodetritus may decay within the meadow, be buried or be exported to other habitats. They form large litter accumulations, notably on shallow water sand patches. Such accumulation host many organisms which participate to the degradation of this material. In a first step to understand the dynamics of these accumulations and of their associated biota, we have characterised their physico-chemical heterogeneity at different seasons. We measured the dissolved oxygen, nutrients and sulphide concentrations in interstitial waters from litter accumulations varying regarding their phytodetritus composition, fragmentation level and thickness. Results show that oxygen conditions were highly variable depending on litter thickness but also on local hydrodynamics. Anoxic conditions and presence of sulphide were sometimes measured, particularly in very thick litter or in degraded litter at the end of summer. Colonies of sulphur-oxidising bacteria were observed. Litter accumulations were also often enriched in ammonium and, sometimes, in dissolved phosphorus. It is not clear whether this results from the litter degradation within the accumulation or whether this is a consequence of a barrier effect between sediment and water column. Nevertheless, this makes litter accumulations particularly attractive for micro-phytobenthic producers. Litter accumulations appear as key habitats both to understand the dead-face of seagrass dynamics and its consequence for C cycle in coastal areas and to study the consequence of hypoxia on biodiversity in a natural context. [less ▲]

Belgian experience of robot assisted laparoscopic para – aortic lymphadenectomy for staging of locally advanced cervical carcinoma. A multicentric study.

Poster (2012)

Objectives: FIGO clinical staging, imaging techniques sometimes underestimate extension of locally advanced cervical cancer (LACC). The presence of para-aortic lymph node (LN) metastases in LACC ... [more ▼]

Objectives: FIGO clinical staging, imaging techniques sometimes underestimate extension of locally advanced cervical cancer (LACC). The presence of para-aortic lymph node (LN) metastases in LACC identifies patients with poor prognosis. Laparoscopic para-aortic lymphadenectomy is now proposed as a diagnostic tool. Feasibility and safety of robot assisted laparoscopic para-aortic lymphadenectomy has been reported. We collected data from different Belgian centers to assess its oncological safety and complication rate. Study design: Three centers participated in the study. Thirty seven patients with LACC underwent a pre treatment robot assisted laparoscopic para-aortic lymphadenectomy. Data was prospectively collected. Results: The median number of LN collected was 27.5 (1-54) per patient. Five out of 37 patients had para-aortic node metastasis. The false negative rate for PET CT diagnosing para- aortic node metastasis was 10.8% (4/37). We encountered 2 major intra operative complications (5.4%). Post operative morbidity was low (13.5%). Median follow up was 27 months (95% CI 24–30). Median disease free survival (DFS) was 16 months (95% CI 2.4- 29.6). Patients with negative LN had a median DFS of 24 months (NA) although patients with positive LN had a median DFS of 9 months (95% CI 6.9-11.9). Conclusions: In this series we report that robot assisted laparoscopic para-aortic lymphadencetomy provided the surgeon with useful information to avoid understaging in 10.8% of women with LACC, at the expense of low morbidity (13.5%). Presence of microscopic para-aortic LN metastasis is correlated with shorter DFS. The number of patients with positive LN doesn’t allow us to draw any firm conclusion. [less ▲]

Integrated crisis management to mitigate storm impacts for the forest sector in Wallonia (Belgium)

Poster (2012)

Massive stars' nebulae, as seen through Herschel's eyes

Poster (2012)

HDAC5 depletion modulates heterochromatin plasticity and triggers programmed cell death of human cancer cells

Poster (2012)

A Novel Image Analysis Toolbox Enabling Quantitative Analysis of Root System Architecture.

Poster (2012)

Association entre le contrôle de la pression artérielle et le rapport sodium/potassium urinaire chez les transplantés rénaux hypertendus

Poster (2011, December 15)

Design and method : Office blood pressure (OBP) and home BP (HBP) were measured in 70 kidney transplant patients (KT) (43 men/27 women;KT>1 year), all were treated with antihypertensive drugs (mean number ... [more ▼]

Design and method : Office blood pressure (OBP) and home BP (HBP) were measured in 70 kidney transplant patients (KT) (43 men/27 women;KT>1 year), all were treated with antihypertensive drugs (mean number: 2±1). Mean age: 56±11 years, mean graft survival: 7±6.6 years, mean GFR: 65.6±24 ml/min, diabetes:27% and current smoking:11.5%. HBP (Omron M6) was measured during 7 days following the OBP measurement, mean HBP was calculated from day 2 to day 7. Uncontrolled BP was defined by OBP>=140-90 (>=130-80 when diabetes) and HBP>=135-85 (>=130-80 when diabetes). The day of the OBP measurement and the last day of HBP, patients collected 24h- urine and recorded at the same time their food and beverage consumption. Sodium and potassium were measured in urines and their intakes were quantified through food records. Urinary and diet Na+, K+ did not differ between the two urine collections 7 days apart. Results: 16 patients(23%) had controlled BP (OBP and HBP) while 34 (49%) remained with sustained hypertension (SHT) despite treatment, 14 (20%) had masked uncontrolled hypertension (MHT, OBP<140-90 and HBP>=135-85,130-80 if diabetes for both).When comparing the controlled and SHT, no differences were found with age, graft survival, BMI, GFR, calcineurin inhibitors or number and type of antihypertensive drugs. The groups did not differ by their sodium excretion (154±93 vs 162±88 mmol/24h) but well by their K excretion significantly higher in controlled patients (68±17 vs 53±20 mmol/24h,p=0.018) giving a Na/K ratio higher in SHT (3.2±1.3 vs2.2±1.2,p=0.03). Diet analysis showed significantly higher intakes of K (fruits, vegetables) in controlled patients (3279±753 vs 2208±720 mg/24h,p=0.010) whereas both groups consumed on average 9 g/24h of salt. When controlled for age, BMI and Na excretion, Home systolic BP was inversely and significantly correlated with urinary potassium (- 0.46;P=0.002) while no correlation was found with urinary Na.Conclusions: KT patients remaining hypertensive and well controlled patients had both high salt consumption. However, well controlled patients differed by significant higher potassium intakes and excretion. Urinary Na/K ratio could be a useful tool contributing to an optimal BP control in KT patients. However, impact of increasing potassium intakes on uncontrolled BP in KT has to be validated by prospective randomized studies [less ▲]

Characterization of the inhibition of metallo-β-lactamases of subclass B1 by VHHs cAbVIM4 and cAbBCII10

Poster (2011, December 10)

Zoonotic diseases in pet birds -a short review

Poster (2011, December 09)

The term « Pet bird » designates birds housed and breeded for an exclusively ornamental use. This category includes mainly Passeriformes (canaries, finches…) and Psittaciformes (parrots, parakeets…), and ... [more ▼]

The term « Pet bird » designates birds housed and breeded for an exclusively ornamental use. This category includes mainly Passeriformes (canaries, finches…) and Psittaciformes (parrots, parakeets…), and is a not-so-well known vet’s clientship fraction. Many families indeed own their « kitchen canary », which represent a lucrative business for pet shops or local breeders (e.a. via birds fairs and markets). Besides, some birds are bred for their very high value; for example, in the case of canaries, male and female reproductors with recognized genetic potential are presented in international contests for their posture (the Bossu Belge : fig 1a), their colour (red mosaic: fig 1b) and for their song (Harzer: fig 1c) and sold for rising prices. Finally, exotic birds like parrots (ara, cockatoo…), legally or illegaly traded from Asia, are however very popular pets and profusely represented in zoos and parks. Notwithstanding these economic facts, these animals are potential carriers and/or transmitters of zoonotic diseases. Some of them could have an important impact on human health, like ornithosis, salmonellosis or even H5N1 high pathogenic avian influenza. This review, although non exhausive, has as aim to enlighten, by the description of several cases of birds-humans transmission the risks encountered by birds owners, including children, and on another point of view to assess the potential economic consequences. [less ▲]

Gestion des ressources génétiques animales par les éleveurs de dromadaires de la région d’Ansongo (Mali).

Poster (2011, December 09)

La gouvernance environnementale au Sri Lanka

Poster (2011, December 08)

Le projet de recherches SAFE

Poster (2011, December 08)

The impact of alien fish species on feeding behavior and shelter use in Alpine newt

Poster (2011, December 08)

Assessment of Mytilus galloprovincialis to monitor 19 trace elements in the Calvi Bay

Poster (2011, December 08)

Mussel caging with Mytilus galloprovincialis has been successively used to monitor classic trace metal (Cd, Cu, Zn, Cr, Fe, Ni, Pb) pollution of Mediterranean coastal waters at spatial scales ranging from ... [more ▼]

Mussel caging with Mytilus galloprovincialis has been successively used to monitor classic trace metal (Cd, Cu, Zn, Cr, Fe, Ni, Pb) pollution of Mediterranean coastal waters at spatial scales ranging from 10 to 100km. However, its relevance as bioindicator at smaller scales (100 m - 1 km) is poorly known. Moreover, the levels of some little studied trace elements (Al, V, Mn, Sb, Sn, Ag, Mo, Se, As, Co, Be, Bi), recently identified as potential pollutants of coastal environments, have not yet been assessed in that species. In this work, M. galloprovincialis was used to monitor the 19 listed trace elements at the scale of the Calvi Bay (NW Corsica, France). Additionally, we investigated decontamination kinetics and trace element tissue speciation before and after spawning. Mytilus galloprovincialis trace element levels reflect the good water quality of the Calvi Bay, showing little spatial variations either at 100m or 1km scales. Filter feeders are only influenced by their relatively homogeneous pelagic environment (dissolved trace elements and suspended particulate matters), in contrast to organisms which inhabit typically heterogeneous benthic habitats. This bioindicator, a convincing candidate for the monitoring of the 12 little studied trace elements, effectively accumulates the 19 studied elements to 105 seawater concentrations. Mytilus galloprovincialis rapidly equilibrates (within days) with its environment, and is therefore a good indicator of chronic and stable chemical pollutions. Tissue speciation shows that the most relevant organ to monitor trace elements is the hepatopancreas. However, the important variability induced by the reproductive cycle of mussels requires using this bioindicator during its sexual dormancy. [less ▲]

Shallow heat injection and storage experiment monitored with electrical resistivity tomography and simulated with heat transport model

Poster (2011, December 06)

Groundwater resources are increasingly used around the world as geothermal systems. Understanding physical processes and quantification of parameters determining heat transport in porous media is ... [more ▼]

Groundwater resources are increasingly used around the world as geothermal systems. Understanding physical processes and quantification of parameters determining heat transport in porous media is therefore important. To monitor the geothermal behavior of groundwater systems and to estimate the governing parameters, we rely mainly on borehole observations of the temperature field at a few locations (temperature logs or thermal response test). In analogy to research in hydrogeophysics, geophysical methods may be useful in order to yield additional information for thermal properties estimation with greater coverage than conventional wells. We report a heat transport study during a shallow heat injection and storage field test. Heated water (about 50°C) was injected for 6 days at the rate of 80 l/h in 10.5°C aquifer. Since bulk electrical resistivity variations can bring important information on temperature changes in aquifers (water electrical conductivity increases about 2%/°C around 25°C), we monitored the test with surface electrical resistivity tomography and demonstrate its ability to monitor spatially temperature variations. Time-lapse electrical image clearly show the decrease and then the increase in bulk electrical resistivity of the plume of heated water, during respectively the injection and the storage phase. This information enabled to calibrate the conceptual flow and heat model used to simulate the test (using SEAWAT). Inverted resistivity values are validated with borehole electromagnetic measurements (EM39) and are in agreement with the temperature logs used to calibrate the parameters of the thermo-hydrogeological model. This field work demonstrates that surface electrical resistivity tomography can monitor heat and storage experiments in shallow aquifers. These results could potentially lead to a number of practical applications, such as the monitoring or the design of shallow geothermal systems. Moreover, sensitivity analyses and collinear diagnostic were used to assess the pertinence of the flow and heat model parameters. The most sensitive parameter is the conductivity of the solid followed by the porosity, heat capacity of the solid and the longitudinal dispersivity. This indicates the predominance of conductive transport during the storage phase over the convective transport during the injection phase. These values rely only on temperature logs and more parameters could be derived or more robust values could be achieved with the use of geophysical data in a coupled inversion scheme. [less ▲]