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A novel probabilistic methodology for regional seismic site characterization is proposed and applied to a region with highly heterogeneous surficial geology and varying soil sediment thickness and stiffness. The method combines various sources of geological and geotechnical uncertainties to develop a three-dimensional (3D) shear-wave velocity ( Vs) model and evaluate the associated uncertainties. A 3D geological model of the unconsolidated deposits was developed using geostatistical interpolation and simulation methods. Sequential indicator simulations produced a quantitative geologic model that explicitly quantified geological uncertainties based on the likelihood of specific soil types occurring. In situ measurements and multivariate statistical analysis allowed the development of empirical correlations between Vs, geotechnical parameters, depth, and soil types. The resulting 3D Vs values were estimated on the basis of Vs-depth correlations and the probability of occurrence of each soil type. In this approach, the propagated uncertainty was also quantified by considering the combined variance. Seismic microzonation mapping was then conducted by transforming the 3D Vs model into two-dimensional (2D) maps that represent the spatial distributions of the time-averaged shear-wave velocity of the top 30 m ( Vs,30) and the fundamental site period ( T0), along with their respective uncertainties using Monte Carlo simulations. The results indicate that microzonation maps and their uncertainties are influenced by the thickness, occurrence probability, and geotechnical properties of soils. The proposed method can be used to assess the probabilistic seismic risk at local and regional scales in areas with geologically and geotechnically complex soil properties.

The textural characteristics of rocks influence their petrophysical and mechanical properties. Such parameters largely control rock mass stability. The ability to evaluate both immediate and long-term rock behaviors based on the interaction between various parameters of rock texture, petrophysical and mechanical properties is therefore crucial to many geoengineering facilities. However, due to the common lack of high-quality core samples for geomechanics and rock texture laboratory tests, single and multivariable regression analyses are conducted between mechanical properties and textural characteristics based on experimental test data. This study presents a review of how rock texture characteristics influence the geomechanical properties of a rock, and summarizes the regression equations between two aspects. More specifically, a review of the available literature on the effects of mineralogy, grain size, grain shape, packing density, foliation index, porosity, degree of weathering, and other rock physical characteristics on geomechanics is presented. Similarly, a review of the literature discussing the failure criteria of anisotropic rocks, both continuous and discontinuous, is also presented. These reviews are accompanied by a comparison of the fundamentals of these methods, describing their equations and discussing their advantages and disadvantages. This exercise has the objective of providing better guidelines on how to use these criteria, allowing for safer underground excavations via an improved understanding of how rock texture parameters affects the mechanical behavior of rocks.

Despite numerous innovations, measuring bacteria concentrations on a routine basis is still time consuming and ensuring accurate measurements requires careful handling. Furthermore, it often requires sampling small volumes of bacteria suspensions which might be poorly representative of the real bacteria concentration. In this paper, we propose a spectroscopy measurement method based on a description of the absorption/attenuation spectra of ESKAPEE bacteria. Concentrations were measured with accuracies less than 2%. In addition, mixing the mathematical description of the absorption/attenuation spectra of mammalian T-cells and bacteria allows for the simultaneous measurements of both species’ concentrations. This method allows real-time, sampling-free and seeder-free measurement and can be easily integrated into a closed-system environment.

Landslide risk analysis is a common geotechnical evaluation and it aims to protect life and infrastructure. In the case of sensitive clay zones, landslides can affect large areas and are difficult to predict. Here we propose a methodology to determine the landslide hazard across a large territory, and we apply our approach to the Saint-Jean-Vianney area, Quebec, Canada. The initial step consists of creating a 3D model of the surficial deposits of the target area. After creating a chart of the material electrical resistivity adapted for eastern Canada, we applied electric induction to interpret the regional soil. We transposed parameter values obtained from the laboratory to a larger scale, that is to a regional slope using the results of a back analysis undertaken earlier, on a smaller slide within the same area. The regional 3D model of deposits is then used to develop a zonation map of slopes that are at risk and their respective constraint areas with the study region. This approach allowed us to target specific areas where a more precise stability analysis would be required. Our methodology offers an effective tool for stability analysis in territories characterized by the presence of sensitive clays.

The relationship between the inflow rate to a rocky tunnel and the effective parameters controlling the inflow rate (e.g. aperture, spacing, orientation, tunnel radius and water head) is investigated by numerical modelling. Response surface methodology is adopted to optimize the number of simulations and their meaningful interpretation, and Design-Expert software is used for this purpose. Consequently, numerical simulations are performed, using 3DEC version 7 software, for 88 scenarios based on different values for the parameters related to the fracture-system geometry and boundary conditions. Accordingly, the relations between the inflow rate to the tunnel and the effective parameters, as well as their interactions, are determined and presented in the form of empirical equations. In addition, the mean value of each parameter is used to develop another equation for calculating the inflow rate. Specifically, the aperture and spacing, as well as the interaction between these parameters and other effective parameters, have the most important impact on the value of the inflow rate. Furthermore, the impact of the tunnel radius on the unit inflow rate is negligible. Using numerical simulations, two empirical equations have been developed for the calculation of the unit inflow rate to the tunnel: one for exact values of parameters and another for their mean values. Supplementary material: Supplementary information on the interaction between the parameters and the statistical analysis are available at https://doi.org/10.6084/m9.figshare.c.6292560

The shape, the volume, and the distribution of the rock blocks represent important geomechanical factors of a rock mass behavior in engineering works. Several methods have been developed for estimating these parameters, including numerical models, as well as analytical and empirical methods. However, their determination in actual in-situ conditions can be quite challenging. The existing analytical methods show limitations in determining the in-situ rock blocks volume. Numerical models provide more reliable estimates of these parameters, but they are not accessible to all, and they require a good working knowledge. Increasing the accuracy of existing analytical methods, or developing more reliable and accessible methods, are more realistic approaches to obtain better estimates of rock block volumes. This paper presents a new method to obtain more accurate estimates of in-situ rock block volume. The method is developed for rock a mass consisting of three persistent joint sets, each set having constant spacing and orientation values. It is based on vector products to obtain exact block volumes, an improvement as compared to previous methods. The volumes of the rock blocks are calculated through the multiplication of the blocks’ edge vector. The results of the developed equation are validated with the output of numerical simulations using 3DEC version 7.0 software, and the results indicate that the developed method makes it possible to determine in-situ rock block volume more reliably than the existing methods.

Advanced Therapy Medicinal Products are promising drugs for patients in therapeutic impasses. Their complex fabrication process implies regular quality controls to monitor cell concentration. Among the different methods available, optical techniques offer several advantages. Our study aims to measure cell concentration in real time in a potential closed-loop environment using white light spectroscopy and to test the possibility of simultaneously measuring concentrations of several species. By analyzing the shapes of the absorption spectra, this system allowed the quantification of T-cells with an accuracy of about 3% during 30 h of cultivation monitoring and 26 h of doubling time, coherent with what is expected for normal cell culture. Moreover, our system permitted concentration measurements for two species in reconstructed co-cultures of T-cells and Candida albicans yeasts. This method can now be applied to any single or co-culture, it allows real-time monitoring, and can be easily integrated into a closed system.

Due to inherent variability arising from unpredictable geological depositional and post-depositional processes, the geotechnical parameters of Laflamme sea clay deposits remain highly uncertain. This study aims to develop and apply a methodology to assess the uncertainties of geotechnical parameters using statistical distributions for a landslide-prone Saguenay Lac-Saint-Jean (SLSJ) region. We used the measured physical and mechanical parameters of Laflamme Sea clays of various locations in the SLSJ region to characterize the geotechnical parameters in a representative manner. Goodness-of-fit tests assign each physical and mechanical parameter a distribution function for their descriptive analysis. We found that the quality of these tests is significantly influenced by outliers. The detected outliers in the dataset considerably impact the distribution type and the uncertainties of the specific geotechnical parameter. Subsequently, appropriate distribution functions for each parameter were assigned after treating the outliers. The derived coefficient of variability values for the SLSJ region were significantly high in comparison to the literature with cone penetration test data being only the exception. Finally, the results indicated that the uncertainties of geotechnical parameters of the Saguenay-Lac-Saint-Jean region marine clays are high as compared to Scandinavian clays and are relatively comparable to other eastern Canadian clays.

International audience; Breast cancer is one of the leading causes of cancer-related death among females worldwide. A major challenge is to develop innovative therapy in order to treat breast cancer subtypes resistant to current treatment. In the present study, we examined the effects of two Troglitazone derivatives Δ2-TGZ and AB186. Previous studies showed that both compounds induce apoptosis, nevertheless AB186 was a more potent agent. The kinetic of cellular events was investigated by real-time cell analysis system (RTCA) in MCF-7 (hormone dependent) and MDA-MB-231 (triple negative) breast cancer (TNBC) cells, followed by cell morphology analysis by immuno-localization. Both compounds induced a rapid modification of both impedance-based signals and cellular morphology. This process was associated with an inhibition of cell migration measured by wound healing and transwell assays in TNBC MDA-MB-231 and Hs578T cells. In order to identify cytoplasmic targets of AB186, we performed surface plasmon resonance (SPR) and pull-down analyses. Subsequently, 6 cytoskeleton components were identified as potential targets. We further validated α-tubulin as one of the direct targets of AB186. In conclusion, our results suggested that AB186 could be promising to develop novel therapeutic strategies to treat aggressive forms of breast cancer such as TNBC.

International audience; For the last 30 years, molecular surveys have shown that human norovirus (HuNoV), predominantly the GII.4 genotype, is one of the main causative agents of gastroenteritis. However, epidemiological surveys have revealed the worldwide emergence of GII.17 HuNoVs. Genetic analysis confirmed that GII.17 strains are distributed into three variants (i.e., Kawasaki 308, Kawasaki 323, and CS-E1). Here, virus-like particles (VLPs) were baculovirus-expressed from these variants to study putative interactions with HBGA. Qualitative analysis of the HBGA binding profile of each variant showed that the most recent and predominant GII.17 variant, Kawasaki 308, possesses a larger binding spectrum. The retrospective study of GII.17 strains documented before the emergence of the dominant Kawasaki 308 variant showed that the emergence of a new GII.17 variant could be related to an increased binding capacity toward HBGA. The use of duodenal histological sections confirmed that recognition of enterocytes involved HBGA for the three GII.17 variants. Finally, we observed that the relative affinity of recent GII.17 VLPs for HBGA remains lower than that of the GII.4-2012 variant. These observations suggest a model whereby a combination of virological factors, such as polymerase fidelity and increased affinity for HBGA, and immunological factors was responsible for the incomplete and non-persistent replacement of GII.4 by new GII.17 variants.

Landslide risk analysis is a common geotechnical evaluation and aims to protect life and infrastructure. In the case of sensitive clay zones, landslides can affect large areas and are difficult to predict. Here we propose a methodology to determine the landslide hazard across a large territory, and we apply our approach to the Saint-Jean-Vianney area, Quebec, Canada. The initial step consists of creating a 3D model of the surficial deposits of the target area. After creating a chart of the material electrical resistivity adapted for eastern Canada, we applied electric induction to interpret the regional soil. We collected samples from the main lithologies and estimated selected soil geotechnical parameters in laboratory tests. We transposed parameter values obtained from the samples to a larger scale that of a slope using the results of a back analysis undertaken on an earlier, smaller slide within the same area. The regional 3D model of deposits is then used to develop a zonation map of at-risk slopes and their respective constraint areas with the study region. This approach allowed us to target specific areas where a more precise stability analysis would be required. Our methodology offers an effective tool for stability analysis in territories characterized by the presence of sensitive clays.

Background The 5-years survival rate of breast cancer patients is around 90%. Unfortunately, some types of tumors, especially the triple negative breast cancer (TNBC), present chemo-resistance and have a higher relapse 5 years post-treatment due to metastasis. These challenges highlight the need for the development of new drugs for these tumors. In this context, we developed new troglitazone derivatives as support for such potential new treatment.Methods The kinetic of early cellular events was investigated after Δ2-TGZ and AB186 treatment by real-time cell analysis system (RTCA) in MCF-7 and MDA-MB-231 breast cancer cells, followed by cell morphology analysis by immuno-localization. Then, we characterized the action of both compounds on the cell migration by wound healing and transwell assays in TNBC MDA-MB-231 and Hs578T cell lines. Finally, we performed surface plasmon resonance (SPR) analysis and pull-down assay using biotinylated AB186 to identify cytoplasmic targets.Results Δ2-TGZ and AB186 induced a rapid modification of impedance-based signals and morphology in MCF7 and MDA-MB-231 breast cancer cell lines. This process was associated with an inhibition of cell migration in MDA-MB-231 and Hs578T cell lines. Subsequently, 6 cytoskeleton components have been identified as potential targets of AB186 in MDA-MB-231 cytoplasmic fraction. We further validated α-tubulin as one of the direct targets of AB186.Conclusion New troglitazone derivatives, Δ2-TGZ and AB186, induced early cell morphological changes and showed anti-migratory effects on TNBC cells suggesting that these drugs could be proposed as novel candidates to treat TNBC patients.

Um dos procedimentos mais adotados para o estudo de redes de fraturas são as linhas de levantamento estrutural, tanto em trabalhos de Geologia como de Engenharia. Os dados coletados através desse método necessitam ser corrigidos para viés de orientação, sendo a correção proposta por Ruth Terzaghi a mais empregada e amplamente reconhecida. Uma vez que a correção originalmente era feita através de ábacos manuais, e que muitos dos programas atualmente disponíveis para realizá-la não são de acesso livre, este trabalho propõe a execução da correção de viés de orientação de linhas de levantamento através de planilhas eletrônicas, visando tornar o procedimento mais acessível e difundido entre os profissionais brasileiros.

The inherent variability of the geomechanical parameters of a rock mass plays a critical role in affecting underground mine stability. Neglecting this characteristic of a rock mass oversimplifies stability assessment and provides potentially inaccurate results as the actual behavior of rock mass is not considered. Use of probabilistic methods in conjunction with numerical analysis is a reliable approach for evaluating the effect of geomechanical parameter variability on the different modes of underground instability. The degree of stability can be expressed by the probability of failure for different stress-induced instability modes. Here, we use probabilistic methods (random Monte Carlo and Monte Carlo simulations) coupled with the finite difference code FLAC3D to incorporate the variability of rock mass geomechanical parameters into numerical analysis. We assess the stability of seven existing primary open stopes at mining levels V and VI at the Niobec Mine, Quebec, Canada. The stability around each open stope is evaluated by calculating the tensile and compressive probabilities of failure, based on the Hoek–Brown tensile and compressive safety factor, and the probability of brittle damage initiation (PDI), via the brittle shear ratio. For the evaluated open stopes, tensile and compressive failures share similar probabilities of occurrence. Considering the PDI values around all the open stopes, no brittle failure is expected to occur under the existing conditions of rock mass quality and in situ stress regime at the Niobec Mine. Comparison of these probabilistic numerical model results with those run using a deterministic numerical approach highlights the effect of variability of rock mass geomechanical parameters on stope stability.

Stress-induced failure is among the most common causes of instability in Canadian deep underground mines. Open stoping is the most widely practiced underground excavation method in these mines, and creates large stopes which are subjected to stress-induced failure. The probability of failure (POF) depends on many factors, of which the geometry of an open stope is especially important. In this study, a methodology is proposed to assess the effect of stope geometrical parameters on the POF, using numerical modelling. Different ranges for each input parameter are defined according to previous surveys on open stope geometry in a number of Canadian underground mines. A Monte-Carlo simulation technique is combined with the finite difference code FLAC3D, to generate model realizations containing stopes with different geometrical features. The probability of failure (POF) for different categories of stope geometry, is calculated by considering two modes of failure; relaxation-related gravity driven (tensile) failure and rock mass brittle failure. The individual and interactive effects of stope geometrical parameters on the POF, are analyzed using a general multi-level factorial design. Finally, mathematical optimization techniques are employed to estimate the most stable stope conditions, by determining the optimal ranges for each stope’s geometrical parameter. Keywords: Stope stability, Stope geometrical parameters, Probability of failure, General factorial design, Numerical modeling, Sublevel open stoping

The DRASTIC index used to assess the vulnerability of aquifers to contamination, has been subject to various adjustments to improve its reliability. These adjustments include adding and/or eliminating certain aquifer factors and modifying the factor weights. Nonetheless, there is no consensus about which factors, or their respective weights, are most important for assessing aquifer vulnerability. In the present study, we propose an operational methodology that: (1) identifies the relevant factors for assessing aquifer vulnerability to contamination; and (2) determines the relative importance of the selected factors. We applied this approach to a large data set of granular aquifers from a region in Canada, which includes information for DRASTIC factors, combined with groundwater quality and land-use data. We found that for our study region, topography (terrain-slope) is an irrelevant factor for assessing the vulnerability of aquifers to contamination. On the other hand, the relevant factors ranked according to their relative importance (from highest to lowest), are (1) water table depth; (2) hydraulic conductivity; (3) characteristics of vadose zone materials; and (4) recharge. Our approach can serve as an initial step for identifying the relevant aquifer factors when assessing aquifer vulnerability and determining the relative importance of the relevant factors to validate weights attributed to these factors. Our methodology can help adapt index-based methods of aquifer vulnerability assessment to a range of study regions.

Recent hydrogeological mapping throughout the Saguenay-Lac-Saint-Jean region in Quebec, Canada, has yielded a very comprehensive geodatabase (GDB) on groundwater and aquifer systems, designed to fulfil the requirements of groundwater management at the regional level. The high density of observed hydrogeological data points also makes the GDB useful for many local or sub-regional applications. Recently acquired data from continuing geotechnical or groundwater-related activities must be integrated into the GDB in order to maintain its relevance for a variety of problems concerning groundwater quality, its management and its protection. When it is consistently updated, such a hydrogeological (HG) GDB also stands as a critical and constantly evolving link between the scientific community, government agencies, regional and municipal authorities, and ultimately the population who draw upon the groundwater resource. The HG-GDB represents a central hub of effective collaboration between scientists and data users, and the intent is that it may lead to more appropriate decision-making when faced with different issues and/or when taking actions that may include applied groundwater research projects. Groundwater data transfer becomes an information exchange process, an essential tool facilitating the sustainable management of groundwater resources.

Primary haemostasis is a complex dynamic process, which involves in-flow interactions between platelets and sub-endothelial matrix at the area of the damaged vessel wall. It results in a first haemostatic plug, which stops bleeding, before coagulation ensues and consolidates it. The diagnosis of primary haemostasis defect would benefit from evaluation of the whole sequence of mechanisms involved in platelet plug formation in flow. This work proposes a new approach that is based on characterization of the shear-dependent kinetics that enables the evaluation of the early stages of primary haemostasis. We used a label-free method with a quartz crystal microbalance (QCM) biosensor to measure the platelet deposits over time onto covalently immobilized type I fibrillar collagen. We defined three metrics: total frequency shift, lag time, and growth rate. The measurement was completed at four predefined shear rates prevailing in small vessels (500, 770, 1000 and 1500 s−1) during five minutes of perfusion with anticoagulated normal whole blood. The rate of the frequency shift over the first five minutes was strongly influenced by shear rate conditions, presenting a maximum around 770 s−1, and varying by a factor larger than three in the studied shear rate range. To validate the biosensor signal, the total frequency shift was compared to results obtained by atomic force microscopy (AFM) on final platelet deposits. The results show that shear-dependent kinetic assays are promising as an advanced method for screening of primary haemostasis.

Abstract To conduct a successful geomechanical characterization of rock masses, an appropriate interpretation of lithological heterogeneity should be attained by considering both the geological and geomechanical data. In order to clarify the reliability and applicability of geological surveys for rock mechanics purposes, a geomechanical characterization study is conducted on the heterogeneous rock mass of Niobec Mine (Quebec, Canada), by considering the characteristics of its various identified lithological units. The results of previous field and laboratory test campaigns were used to quantify the variability associated to intact rock geomechanical parameters for the different present lithological units. The interpretation of geomechanical similarities between the lithological units resulted in determination of three main rock units (carbonatite, syenite, and carbonatite-syenite units). Geomechanical parameters of these rock units and their associated variabilities are utilized for stochastic estimation of geomechanical parameters of the heterogeneous rock mass using the Monte Carlo Simulation method. A comparison is also made between the results of probabilistic and deterministic analyses to highlight the presence of intrinsic variability associated with the heterogeneous rock mass properties. The results indicated that, for the case of Niobec Mine, the carbonatite-syenite rock unit could be considered as a valid representative of the entire rock mass geology since it offers an appropriate geomechanical approximation of all the present lithological units at the mine site, in terms of both the magnitude and dispersion of the strength and deformability parameters. Article Highlights Evaluating the reliability and applicability of geological survey outcomes for rock mechanics purposes. A geomechanical characterization study is conducted on the heterogeneous rock mass by considering the various identified rock lithotypes. The geomechanical parameters of intact units and their associated variabilities are used to stochastically estimate the geomechanical parameters of the heterogeneous rock mass by employing the Monte Carlo Simulation. A comparison is also made between the results of probabilistic and deterministic geomechanical analyses. The results indicate that, in the case of Niobec Mine, the combined syenite-carbonatite rock unit could be considered as a valid representative of the entire rock mass.

• An assessment has been made on the effect of open stope geometry on rock mass brittle damage.

The specific length of a tunnel (STL) and a new analytical model for calculating the block surface area of the rock mass are introduced. First, a method for determining the appropriate length of a tunnel for a numerical simulation is described. The length is then used to examine the correlation between the inflow rate to the tunnel and the block volume, the block surface area, and the fracture intensity (P32) through analytical and numerical modeling. The results indicate that the length of the tunnel should at least be equal to the least common multiple (LCM) of the apparent spacings of the joint sets at the wall of the tunnel to obtain the more reliable and immediate results for the inflow rate to a tunnel that is excavated in a fractured rock mass. A new analytical model was developed to calculate the block surface area and determine the essential joint set parameters, which include the dip, dip direction, and spacing. The determination of the rock block characteristics through numerical modeling requires considering the intact block for calculations. The results indicated that the inflow rate to the tunnel increased with an increase in fracture intensity and a decrease in block volume and surface area. The STL and the analytical model used for calculating the block surface area are validated through numerical simulations with 3DEC software version 7.0.

The rock mass erosion of dam spillways, a phenomenon involving the interaction between the hydraulic load of water and the capability of the rock mass to resist its destruction, remains a critical safety issue. The erosion resistance of a rock mass can be estimated through several erodibility indices, including those of Kirsten, Pells or Bollaert. Several indices have been developed to link rock resistance to the hydraulic parameters of water, i.e., the hydraulic load applied on a rock mass. The developed indices use the average flow velocity, the average shear stress on the bottom of the flow channel, the stress applied to the internal joints of fractured rock mass, the dynamic impulse force, and the power dissipation of water to represent the erosive force of water. From these indices, several methods of assessing hydraulic erosion have been developed, and all use the threshold line concept. Nonetheless, several uncertainties are associated with these methods. This paper presents and discusses the various means of calculating the erosive force of water as a hazard parameter for predicting potential rock erosion. The representativeness of these approaches is also discussed, and we clarify nuances associated with each method. We then provide guidelines for future research aimed at improving estimates of the erosive force of the water within spillway flow channels.

The backfilling of underground stopes in mines has become common practice in the mining industry as it increases the stability of mine excavations and reduces environmental problems. The backfilling process involves several technical aspects that must be assessed to ensure that the backfilling objectives are achieved. The horizontal stress exerted by backfill on excavation walls must be estimated accurately to avoid the failure of mine pillars. The analytical Marston method is often used for evaluating this stress as it takes into consideration an earth pressure coefficient (K) that is dependent on the geotechnical properties of the backfill. This paper demonstrates that the accuracy of the Marston method for predicting horizontal earth pressure would be improved by using K values that are determined as a function of backfill geotechnical parameters and also excavation geometry. Both components vary inevitably from one backfilled site to another. A methodology is developed to adjust the K value to be a function of these parameters for its application within the Marston analytical method thereby providing a more accurate prediction of earth pressure. Based on various geometric and geomechanical parameters, two graphs are developed to evaluate proper earth pressure values. These graphs can be used for estimating more accurate K values that are based on the characteristics of the stope and the backfill material.

The spatial distribution of soil shear-wave velocity and the fundamental period of vibration were selected as input parameters for the determination of potential seismic site effects in the Saguenay region, Canada. The methodology used in this study involved three clear steps. First, a 3D geological model of the surficial deposits was built taking into consideration the type, spatial distribution and thickness of the deposits. Second, representative average Vs values were determined for each of the major soil units. Finally, the average shear-wave velocity from the ground surface to bedrock (Vsav), the shear-wave velocity of the upper 30 m (Vs30) and the fundamental site resonance period (T0) were calculated over a regular grid for the study area. The results include the spatial distribution of the fundamental site resonance period, the average shear-wave velocity in the first 30 m of the ground and the spatial distribution of National Building Code of Canada seismic soil classes for the Saguenay region.

Many geology, mining, and geotechnical applications require or depend upon some form of modeling of bedrock topography. Optimizing the manner with which bedrock topography is modeled poses a significant challenge because of the unpredictable or erratic presentation of the surface shape of bedrock. Unlike surface topography, bedrock topography is more difficult to determine because direct observation points are often not readily or directly accessible, unless the bedrock outcrops at the surface and is exposed, a relatively rare occurrence. When bedrock is covered by granular deposits, the only methods that allow practitioners to objectively establish the location of the top of the bedrock are to drill boreholes or conduct geophysical surveys. This makes the determination of bedrock topography not only difficult but also expensive. This study proposes a new approach for optimizing the modeling of complex bedrock topography, whose originality is based on the addition of “virtual” data points derived from cross-sections located between known boreholes. The proposed methodology is thus composed of four steps: gathering the maximum amount of relevant surface and subsurface data (from observation points), selecting the most appropriate technique for interpolating the observed bedrock elevations that will be entered into the dataset to be modeled, enriching the quantity of modeling data by adding “virtual” data elements based on geological interpretations of cross-sections (inserted into the model alongside the original objective data), and finally the modeling itself. The proposed approach is illustrated using data from a study area located in the Canadian Shield. Thousands of borehole records and surficial geological data as well as geological cross-section records were integrated to construct a three-dimensional bedrock topography model. The new proposed methodology can be applied to other regions worldwide.

Knowledge of the stratigraphic architecture and geotechnical properties of surficial soil sediments is essential for geotechnical risk assessment. In the Saguenay study area, the Quaternary deposits consist of a basal till layer and heterogeneous post-glacial deposits. Considering the stratigraphic setting and soil type heterogeneity, a multistep stochastic methodology is developed for 3D geological modelling and quantification of the associated uncertainties. This methodology is adopted for regional studies and involves geostatistical interpolation and simulation methods. Empirical Bayesian kriging (EBK) is applied to generate the bedrock topography map and determine the thickness of the till sediments and their uncertainties. The locally varying mean and variance of the EBK method enable accounting for data complexity and moderate nonstationarity. Sequential indicator simulation is then performed to determine the occurrence probability of the discontinuous post-glacial sediments (clay, sand and gravel) on top of the basal till layer. The individual thickness maps of the discontinuous soil layers and uncertainties are generated in a probabilistic manner. The proposed stochastic framework is suitable for heterogeneous soil deposits characterised with complex surface and subsurface datasets.

In deep underground mines, a successful development plan to exploit deeper mining levels is highly dependent on adequate consideration of the magnitude and orientation of situ stress state. However, significant uncertainties are associated with the estimation of these parameters. The in-situ stress values that are used in the evaluation of the stability of underground structures in each mine strongly depends on the results of measurement of the stresses as function of the mine depth and the methodology used for the interpretation of the data as well as engineering judgment. These interpretations could produce several scenarios for estimating the stresses in a mine. Each scenario could yield different stability assessment results some of which were not normally used in the current mine stability study. Three different scenarios for estimating stress at the Niobec underground mine (Quebec, Canada) were determined based on the data available from previous stress measurement campaigns. Numerical modeling (FLAC3D) was used to evaluate the potential of brittle, tensile and compressive failure for the vertical transverse and rib pillars. The results demonstrate that in spite of the development of extensive brittle and tensile damage zones within the rock mass, no major brittle or tensile failure is expected to occur at the considered mining levels based on all three stress scenarios. Moreover, meaningful differences in the stability analysis results between the three stress scenarios highlight the importance of appropriate selection of stress estimation approaches in planning deeper mine levels.

A preliminary conceptual model of groundwater flow was developed for the Serra Geral fractured basalt aquifer in order to assess the recharge to the underlying sandstone Guarani Aquifer System, one of the main aquifer systems in Brazil, which supplies water to millions of people. Detailed geological investigations included macroscopic description of the basalt flow units and the underlying sandstone. Petrographic and chemical analyzes were conducted on rock samples from outcrops and from five drilled boreholes. Detailed fracture surveys were accomplished at outcrops to characterize fracture sets and their potential to transmit water in the current tectonic context. Four basalt flows were identified in the Ribeirao Preto area and were named B1, B2, B3 and B4 (from oldest to youngest). The cooling process in flow B3 led to the generation of large sub-horizontal fractures at the contacts B2/B3 and B3-C/B3-E, which are the most transmissive structures. Groundwater flow in the basalt appears to be of the stratabound type because fractures, in general, do not propagate through the basalt vesicular layers, which behave as a regional hydraulic barrier for the vertical groundwater flow. However, it is proposed that the localized, continuous and closely spaced subvertical tectonic fractures, the only features that have the potential to crosscut the vesicular layers and the intertrappe sediments, can vertically connect the sub-horizontal transmissive fractures. Weathering and water seepage, observed in rock exposures, indicate that subvertical NE-trending fractures would be the most transmissive in the Ribeirao Preto area.

Failure of rock mass in deep underground excavations could be attributed to a broad range of performance malfunction, from plastic yielding of rock, generation of macro cracks on the boundary of the excavation, gravity driven rockfalls or even complete stress-induced collapse. The failure criteria determine the stress level (or strain level) at which the rock mass loses its load-carrying (or strain-carrying) capacity. Determination of the state of underground stability can be successfully achieved through implementation of appropriate failure criteria within the numerical analyses’ tools. The choice of failure criteria in numerical stability analysis plays a key role in defining the behaviour of an underground excavation. A failure criterion will be useful only if selected based on the correct mechanism of failure. Plus, a right choice of failure criterion, significantly reduces the errors of quantifying an excavations behaviour. Therefore, this paper offers a critical review of the most common stress-based and strain-based failure criteria used in numerical stability analysis of underground excavations. Particular attention is paid to characterize different mechanisms of underground failure and recommendations are formulated for each failure mode. In addition, this paper addresses the theoretical considerations for the applicability of different failure criteria and highlights the practical limitations for their numerical implementation.

Sensitive clays are known for producing retrogressive landslides, also called spread or flowslides. The key characteristics associated with the occurrence of these landslides on a sensitive clay slope must be assessed, and the potential retrogressive distance must be evaluated. Common risk analysis methods include empirical methods for estimating the distance of potential retrogression, analytical limit equilibrium methods, numerical modelling methods using the strength reduction technique, and the integration of a progressive failure mechanism into numerical methods. Methods developed for zoning purposes in Norway and Quebec provide conservative results in most cases, even if they don’t cover the worst cases scenario. A flowslide can be partially analysed using analytical limit equilibrium methods and numerical methods having strength reduction factor tools. Numerical modelling of progressive failure mechanisms using numerical methods can define the critical parameters of spread-type landslides, such as critical unloading and the retrogression distance of the failure. Continuous improvements to the large-deformation numerical modeling approach allow its application to all types of sensitive clay landslides.

International audience; A general method to develop diazonium-based biochip for SPRi analysis is presented. The electrografting of carboxybenzene diazonium salt is optimized in order to fit with the requirement of the SPR technology. The influence of the surface preparation on plasmon quality is discussed and the performance of this original modified biochip is investigated for determining the binding constants between circulating ovalbumin and spotted anti-ovalbumin antibody. The kinetic constants are calculated and compared with literature and similar performances are reached confirming that diazonium based biochip is a good complement to commercial SPRi sensor.

International audience; The contribution focuses on the development of microresonant sensor solution integrated in microfluidic platform for the haemostasis assessment at realistic rheological flow conditions similar to the one in blood vessels. A multi-parameter sensor performs real time analysis of interactions between immobilized collagen and platelets. The detection and characterization of such interactions at controlled flow rates provide information to evaluate the dynamic of each step of primary haemostasis. The microresonant sensor concept was developed and is described in the contribution.

Aquifer formations along the northern shore of the Saint-Lawrence River in Quebec (Canada) mainly consist of glacial and coastal deposits of variable thickness overlying Precambrian bedrock. These deposits are important because they provide the main water supply for many communities. As part of a continuing project aimed at developing an inventory of the groundwater resources in the Charlevoix and Haute-Cote-Nord (CHCN) regions of the province of Quebec in Canada, the central loop transient electromagnetic (TEM) method was used to map the principal hydrogeological environments in these regions. One-dimensional smooth inversion models of the TEM soundings have been used to construct two-dimensional electrical resistivity sections, which provided images for hydrogeological validation. Electrical contour lines of aquifer environments were compared against available well logs and Quaternary surface maps in order to interpret TEM soundings. A calibration table was achieved to represent common deposits and basements. The calibration table was then exported throughout the CHCN region. This paper presents three case studies; one in the Forestville site, another in the Les Escoumins site and the other in the Saint-Urbain site. These sites were selected as targets for geophysical surveys because of the general lack of local direct hydrogeological data related to them.

An improperly sealed casing can produce a direct hydraulic connection between two or more originally isolated aquifers with important consequences regarding groundwater quantity and quality. A recent study by Richard et al. (2014) investigated a monitoring well installed in a fractured rock aquifer with a defective casing seal at the soil-bedrock interface. A hydraulic short circuit was detected that produced some leakage between the rock and the overlying deposits. A falling-head permeability test performed in this well showed that the usual method of data interpretation is not valid in this particular case due to the presence of a piezometric error. This error is the direct result of the preferential flow originating from the hydraulic short circuit and the subsequent re-equilibration of the piezometric levels of both aquifers in the vicinity of the inlet and the outlet of the defective seal. Numerical simulations of groundwater circulation around the well support the observed impact of the hydraulic short circuit on the results of the falling-head permeability test. These observations demonstrate that a properly designed falling-head permeability test may be useful in the detection of defective casing seals.

The construction of 3D hydrogeological models for unconsolidated sedimentary aquifers remains particularly challenging, especially in Quaternary deposits. Simplifications at small or large scale are part of groundwater flow modeling and are often required due on the usual inherent complexity of the stratigraphic systems. This study analyzes the effects of hydrostratigraphic simplifications on the accuracy of 3D numerical groundwater flow models. Such investigation is conducted from an initial detailed model of an aquifer located in the Saguenay-Lac-St-Jean region in Canada and the considered simplifications are based on using the equivalent hydraulic conductivity concept. Different levels or approaches of simplification are applied to numerical simulated models and the results of the different scenarios are compared. A root mean square (RMS) calibration result of 3.79 m on the groundwater levels is obtained for the most detailed model, while the RMS ranges between 4.01 and 4.83 m with the simplified models. Such results illustrate a gain obtained in the calibration of the model with increasing level of hydrostratigraphic details, but that this gain is relatively limited. The proposed methodology for simplifying the hydrostratigraphic settings could be used by hydrogeological modellers for a wide variety of aquifers constituted of sedimentary granular material.

In the field of blood transfusion, there is a need to improve the bedside pre-transfusion ABO compatibility test. In France, this test is mandatory for each red cell concentrates transfusion. It is performed manually and serious transfusion accidents still occur, principally due to human errors. Therefore, an automated ABO compatibility test is required. Works concerning objective interpretation of ABO compatibility test have been reported but the proposed techniques cannot be easily translated to the patient's bedside. We propose a prototype device which demonstrates the easy use of biochip technology to perform this test: it contains a fluidic system, biochips (two to test the patient and two to test the red cell concentrates) and an optical absorbance detection module. When blood is applied to the biochips, red blood cells are trapped onto the surface if antigens and antibodies are complementary (positive chips). If they are not complementary, very little red blood cells are adsorbed (negative chips). Percentages of surface covered with red blood cells in negative biochips are 2% ± 2 (red cell concentrates) and 1% ± 1 (whole blood). This proves that the fluidic configuration leads to an optimum control of fluids flows with little retention of red blood cells in the circuitry. These percentages increase to 96% ± 3 and 82% ± 8 for red cell concentrates and whole blood respectively. This demonstrates a strong and specific immunocapture of red blood cells on positive chips. Furthermore, optical detection proves to be efficient at critical red blood cells concentrations (108 C/mL) and absorbance strongly correlates to the percentage of red blood cells captured by antibodies.

ABO mismatch between donor and patient’s blood is still the cause of accidents which are sometimes lethal. The main causes of mis-assignment are human errors and wrong identification of patients or blood product. Only a final compatibility test at the patient’s bedside can avoid these errors. In some countries, this test is performed using manual procedures. This does not prevent from human manipulation and interpretation errors. In this paper, we present a prototype able to automatically perform a final ABO compatibility test. It relies on the use of disposable antibodies grafted biochips inserted into a mobile reader/actuator. Red blood cells are selectively captured on biochips grafted with antibodies complementary of antigens present on the cells surface. Detection of captured cells is based on optical absorption techniques. So far, our device achieved blood compatibility test with 99.3% sensitivity and 97.9% specificity.

Field evidence of hydraulic connections between a bedrock aquifer and an overlying granular aquifer in the Canadian Shield (Grenville Province) is presented. This issue is rarely considered and investigated despite its important hydraulic and chemical consequences and its widespread occurrence worldwide. The methodology employed is based on complementary field tests conducted at specific experimental sites instrumented both in the rock and in the overlying deposits. One of the bedrock sites revealed a natural hydraulic connection with the overlying granular aquifer caused by the weathered surface of the uppermost bedrock. Another site revealed an artificial hydraulic connection between the bedrock and the granular aquifer created by an improperly sealed casing. A regional study showed that hydraulic connections yield an erroneous interpretation of the true hydraulic properties of the tested aquifer. The detection of hydraulic connections is therefore essential to properly define well-capture areas and contamination conditions. It is recommended to practitioners that pumping tests be performed as well as hydrochemical comparisons of each existing aquifer unit. Falling-head permeability tests are also helpful in verifying the quality of the seal at the bedrock–casing contact. More effective procedural controls and better well-construction practices are necessary to reduce the risks of cross-contamination induced by defective seals.

Groundwater contamination by nitrate was investigated in an agricultural area in southern Quebec, Canada, where a municipal well is the local source of drinking water. A network of 38 piezometers was installed within the capture zone of the municipal well to monitor water table levels and nitrate concentrations in the aquifer. Nitrate concentrations were also measured in the municipal well. A Water flow and Nitrate transport Global Model (WNGM) was developed to simulate the impact of agricultural activities on nitrate concentrations in both the aquifer and municipal well. The WNGM first uses the Agriflux model to simulate vertical water and nitrate fluxes below the root zone for each of the seventy agricultural fields located within the capture zone of the municipal well. The WNGM then uses the HydroGeoSphere model to simulate three-dimensional variably-saturated groundwater flow and nitrate transport in the aquifer using water and nitrate fluxes computed with the Agriflux model as the top boundary conditions. The WNGM model was calibrated by reproducing water levels measured from 2005 to 2007 in the network of piezometers and nitrate concentrations measured in the municipal well from 1997 to 2007. The nitrate concentrations measured in the network of piezometers, however, showed greater variability than in the municipal well and could not be reproduced by the calibrated model. After calibration, the model was validated by successfully reproducing the decrease of nitrate concentrations observed in the municipal well in 2006 and 2007. Although it cannot predict nitrate concentrations in individual piezometers, the calibrated and validated WNGM can be used to assess the impact of changes in agricultural practices on global nitrate concentrations in the aquifer and in the municipal well.

The study of the physical geology and geochemistry of the Ribeirão Preto basalts was part of a hydrogeologicalresearch, which aimed to investigate the recharge of the Guarani Aquifer System (SAG) through the basalts of the SerraGeral Aquifer (ASG), a project shortly named FRATASG. In addition to the hydrogeological research, a detailed geologicalinvestigation was conducted to develop a conceptual model of groundwater fl ow in complex aquifers, as is the case ofthe fractured basalts of the ASG. Therefore, this study included a thorough structural survey and analysis of horizontaland subvertical fractures, which resulted in the identifi cation of four tectonic events. It was concluded that the verticalgroundwater flow is important up to 10 m in depth and, secondarily, up to 25 m. Horizontal fl ow, more evident up to thedepth of 50 m, predominates and occurs along sub-horizontal fractures, which occur mainly at the contact between basalts2 and 3 and in its vicinity. Because the great majority of subvertical fractures do not propagate into the vesicular layers,which occur at the basalt contacts, it is suggested that these layers act as regional hydraulic barriers, and greatly hamperthe recharge of the SAG through the ASG. As a consequence, groundwater flow in the basalt stack is of stratabound type,as it occurs mainly along the basalt contacts. Based on diagnostic features of the fl ow, it is proposed in this study that the vertical flow,which crosses the basalt stack reaching the SAG, is local and probably occurs along NE structures.

A motivação que levou ao estudo da geologia física e química dos basaltos de Ribeirão Preto foi investigar a existência de recarga do Sistema Aquífero Guarani (SAG) através dos basaltos do Aquífero Serra Geral (ASG), objetivo do projeto abreviadamente denominado de FRATASG. Além de métodos hidrogeológicos, a pesquisa demandou uma investigação geológica de detalhe, a qual é essencial para a elaboração de modelos conceituais de circulação de água subterrânea em aquíferos complexos, caso dos basaltos do ASG. Assim, o estudo englobou levantamentos estruturais de detalhe e a análise de fraturas que levou à identificação de quatro eventos tectônicos. Concluiu-se que o fluxo vertical de água subterrânea é importante até a profundidade de 10 m e, secundariamente, até 25 m. O fluxo horizontal, mais importante até a profundidade de 50 m, ocorre ao longo de fraturas preferencialmente localizadas nos contatos entre os basaltos B2 e B3 ou próximas a estes. Sugere-se que a recarga do SAG através do ASG é dificultada pela não propagação de fraturas nos níveis vesiculares dos basaltos, presentes nos contatos entre derrames, que funcionariam como uma barreira hidráulica de caráter regional. Assim a circulação de água subterrânea nos basaltos é do tipo limitada por estratos (stratabound), uma vez que é muito mais intensa paralelamente aos derrames do que transversalmente a eles. Com base em feições diagnósticas de fluxo, propõe-se que o fluxo vertical, atravessando toda a pilha de basaltos e chegando ao SAG, quando presente, ocorra segundo estruturas de direção NE.