Publications by authors named "Robin O"

50 Publications

Laboratory Test to Evaluate the Resistance of Cementitious Materials to Biodeterioration in Sewer Network Conditions.

Materials (Basel) 2021 Feb 2;14(3). Epub 2021 Feb 2.

LMDC, Université de Toulouse, UPS, INSA, 31077 Toulouse, France.

The biodeterioration of cementitious materials in sewer networks has become a major economic, ecological, and public health issue. Establishing a suitable standardized test is essential if sustainable construction materials are to be developed and qualified for sewerage environments. Since purely chemical tests are proven to not be representative of the actual deterioration phenomena in real sewer conditions, a biological test-named the Biogenic Acid Concrete (BAC) test-was developed at the University of Toulouse to reproduce the biological reactions involved in the process of concrete biodeterioration in sewers. The test consists in trickling a solution containing a safe reduced sulfur source onto the surface of cementitious substrates previously covered with a high diversity microbial consortium. In these conditions, a sulfur-oxidizing metabolism naturally develops in the biofilm and leads to the production of biogenic sulfuric acid on the surface of the material. The representativeness of the test in terms of deterioration mechanisms has been validated in previous studies. A wide range of cementitious materials have been exposed to the biodeterioration test during half a decade. On the basis of this large database and the expertise gained, the purpose of this paper is (i) to propose a simple and robust performance criterion for the test (standardized leached calcium as a function of sulfate produced by the biofilm), and (ii) to demonstrate the repeatability, reproducibility, and discriminability of the test method. In only a 3-month period, the test was able to highlight the differences in the performances of common cement-based materials (CEM I, CEM III, and CEM V) and special calcium aluminate cement (CAC) binders with different nature of aggregates (natural silica and synthetic calcium aluminate). The proposed performance indicator (relative standardized leached calcium) allowed the materials to be classified according to their resistance to biogenic acid attack in sewer conditions. The repeatability of the test was confirmed using three different specimens of the same material within the same experiment and the reproducibility of the results was demonstrated by standardizing the results using a reference material from 5 different test campaigns. Furthermore, developing post-testing processing and calculation methods constituted a first step toward a standardized test protocol.
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http://dx.doi.org/10.3390/ma14030686DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7867231PMC
February 2021

Molecular Cytogenetics (Fluorescence In Situ Hybridization - FISH and Fluorochrome Banding): Resolving Species Relationships and Genome Organization.

Methods Mol Biol 2021 ;2222:363-379

University Paris-Saclay, CNRS, AgroParisTech, Ecologie Systématique Evolution, Orsay, France.

Fluorochrome banding (chromomycin, Hoechst, and DAPI) and fluorescence in situ hybridization (FISH) are excellent molecular cytogenetic tools providing various possibilities in the study of chromosomal evolution and genome organization. The constitutive heterochromatin and rRNA genes are the most widely used FISH markers. The rDNA is organized into two distinct gene families (18S-5.8S-26S and 5S) whose number and location vary within the complex of closely related species. Therefore, they are widely used as chromosomal landmarks to provide valuable evidence concerning genome evolution at chromosomal levels.
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http://dx.doi.org/10.1007/978-1-0716-0997-2_18DOI Listing
March 2021

Recording of bruxism events in sleeping humans at home with a smart instrumented splint.

Cranio 2020 Jan 8:1-9. Epub 2020 Jan 8.

Nanotechnology Institute of Lyon, Biomedical sensors team, UMR CNRS, INSA, Lyon, France.

: The aim of this paper is to report quantitative and qualitative characteristics of bruxism events recorded in sleeping humans with a new smart ambulatory system specifically designed to measure dental clenching and grinding forces. The device is wireless and rechargeable, which enables its use over extended periods.: Thirty recordings were obtained from volunteer subjects who wore the device at home during 10 consecutive nights (Clinicaltrials.gov N° NCT03363204).: The recordings showed that the system was able to successfully monitor bruxism during 10 consecutive nights, allowing a quantitative (number, duration, intensity, distribution during the night), as well as a qualitative characterization of the bruxism events (clenching vs. grinding).: This system could offer new perspectives in the field of bruxism, either as a research tool for clinical studies or as a medical device for the ambulatory home-based monitoring of bruxism.
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http://dx.doi.org/10.1080/08869634.2019.1708608DOI Listing
January 2020

Time domain imaging of extended transient noise sources using phase coherence.

J Acoust Soc Am 2019 Dec;146(6):4851

Groupe d'Acoustique de l'Université de Sherbrooke, Faculté de Génie, J1K 2R1, Sherbrooke, Québec, Canada.

An acoustic imaging algorithm is proposed herein for transient noise source time reconstruction. Time domain formulations are not well suited for acoustic imaging because of the size of the resulting system to be inversed. Based on the phase coherence principle widely used in ultrasound imaging and image processing, the first step of the algorithm consists in proposing the phase coherence metric used to reject pixels that are unlikely to contribute to the radiated sound field. This translates in a reduction of the domain size and ill-posedness of the problem. In the second step, the inverse problem is solved using the Tikhonov regularization and the generalized cross-validation to extract the vibration field on the imaging domain. Two test cases are considered: a simulated baffled piston and a panel submitted to a mechanical impact in anechoic conditions. The actual vibration field of the panel is measured with an optical technique for reference. In both numerical and experimental cases, the reconstructed vibration field using the proposed approach compares well with their respective reference. The results confirm that transient excitations can be localized and quantified with the proposed approach, in contrast with the classical time-domain beamforming that dramatically overestimates its magnitude.
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http://dx.doi.org/10.1121/1.5138926DOI Listing
December 2019

Influence of Dissolved-Aluminum Concentration on Sulfur-Oxidizing Bacterial Activity in the Biodeterioration of Concrete.

Appl Environ Microbiol 2019 08 18;85(15). Epub 2019 Jul 18.

LISBP, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France

Several studies undertaken on the biodeterioration of concrete sewer infrastructures have highlighted the better durability of aluminate-based materials. The bacteriostatic effect of aluminum has been suggested to explain the increase in durability of these materials. However, no clear demonstration of the negative effect of aluminum on cell growth has been yet provided in the literature. In the present study, we sought to investigate the inhibitory potential of dissolved aluminum on nonsterile microbial cultures containing sulfur-oxidizing microorganisms. Both kinetic (maximum specific growth rate) and stoichiometric (oxygen consumption yield) parameters describing cells activity were accurately determined by using respirometry measurements coupled with modeled data obtained from fed-batch cultures run for several days at pH below 4 and with increasing total aluminum (Al) concentrations from 0 to 100 mM. Short-term inhibition was observed for cells poorly acclimated to high salinity. However, inhibition was significantly attenuated for cells grown on mortar substrate. Moreover, after a rapid adaptation, and for an Al concentration up to 100 mM, both kinetic and stoichiometric growth parameters remained similar to those obtained in control culture conditions where no aluminum was added. This argued in favor of the impact of ionic strength change on the growth of sulfur-oxidizing microorganism rather than an inhibitory effect of dissolved aluminum. Other assumptions must therefore be put forward in order to explain the better durability of cement containing aluminate-based materials in sewer networks. Among these assumptions, the influence of physical or chemical properties of the material (phase reactivity, porosity, etc.) might be proposed. Biodeterioration of cement infrastructures represents 5 to 20% of observed deteriorations within the sewer network. Such biodeterioration events are mainly due to microbial sulfur-oxidizing activity which produces sulfuric acid able to dissolve cementitious material. Calcium aluminate cement materials are more resistant to biodeterioration compared to the commonly used Portland cement. Several theories have been suggested to describe this resistance, and the bacteriostatic effect of aluminum seems to be the most plausible explanation. However, results reported by the several studies on this exact topic are highly controversial. This present study provides a comprehensive analysis of the influence of dissolved aluminum on growth parameters of long-term cultures of sulfur-oxidizing bacterial consortia sampled from different origins. Kinetic and stoichiometric parameters estimated by respirometry measurements and modeling showed that total dissolved-aluminum concentrations up to 100 mM were not inhibitory, but it is more likely that a sudden increase in the ionic strength affects cell growth. Therefore, it appears that the bacteriostatic effect of aluminum on microbial growth cannot explain the better durability of aluminate based cementitious materials.
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http://dx.doi.org/10.1128/AEM.00302-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6643239PMC
August 2019

Biomass segregation between biofilm and flocs improves the control of nitrite-oxidizing bacteria in mainstream partial nitritation and anammox processes.

Water Res 2019 05 7;154:104-116. Epub 2019 Jan 7.

Eawag: Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, 8600, Dübendorf, Switzerland.

The control of nitrite-oxidizing bacteria (NOB) challenges the implementation of partial nitritation and anammox (PN/A) processes under mainstream conditions. The aim of the present study was to understand how operating conditions impact microbial competition and the control of NOB in hybrid PN/A systems, where biofilm and flocs coexist. A hybrid PN/A moving-bed biofilm reactor (MBBR; also referred to as integrated fixed film activated sludge or IFAS) was operated at 15 °C on aerobically pre-treated municipal wastewater (23 mg L). Ammonium-oxidizing bacteria (AOB) and NOB were enriched primarily in the flocs, and anammox bacteria (AMX) in the biofilm. After decreasing the dissolved oxygen concentration (DO) from 1.2 to 0.17 mg L - with all other operating conditions unchanged - washout of NOB from the flocs was observed. The activity of the minor NOB fraction remaining in the biofilm was suppressed at low DO. As a result, low effluent NO concentrations (0.5 mg L) were consistently achieved at aerobic nitrogen removal rates (80 mg L d) comparable to those of conventional treatment plants. A simple dynamic mathematical model, assuming perfect biomass segregation with AOB and NOB in the flocs and AMX in the biofilm, was able to qualitatively reproduce the selective washout of NOB from the flocs in response to the decrease in DO-setpoint. Similarly, numerical simulations indicated that flocs removal is an effective operational strategy to achieve the selective washout of NOB. The direct competition for NO between NOB and AMX - the latter retained in the biofilm and acting as a "NO-sink" - was identified by the model as key mechanism leading to a difference in the actual growth rates of AOB and NOB (i.e., μ < μ in flocs) and allowing for the selective NOB washout over a broad range of simulated sludge retention times (SRT = 6.8-24.5 d). Experimental results and model predictions demonstrate the increased operational flexibility, in terms of variables that can be easily controlled by operators, offered by hybrid systems as compared to solely biofilm systems for the control of NOB in mainstream PN/A applications.
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http://dx.doi.org/10.1016/j.watres.2018.12.051DOI Listing
May 2019

Improving sound transmission loss at ring frequency of a curved panel using tunable 3D-printed small-scale resonators.

J Acoust Soc Am 2019 Jan;145(1):EL72

Groupe d'acoustique de l'Université de Sherbrooke, Faculté de génie, Département de génie mécanique, 2500, boulevard de l'université, Sherbrooke J1K 2R1,

An important dip in the sound transmission loss of curved panels occurs at the ring frequency. The relevance of using small-scale resonators to solve this issue is experimentally demonstrated on an aircraft sidewall panel. The effect of varying the spatial distribution of single frequency resonators (including combination with a broadband soundproofing treatment), as well as using multi-frequency resonators with a fixed spatial distribution is studied. Large improvement of the measured sound transmission loss under a diffuse acoustic field excitation is obtained around the ring frequency with limited added mass and very small alteration of the overall sound insulation performance.
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http://dx.doi.org/10.1121/1.5088036DOI Listing
January 2019

Experimental prediction of the vibration response of panels under a turbulent boundary layer excitation from sensitivity functions.

J Acoust Soc Am 2018 May;143(5):2954

Groupe d'Acoustique de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, J1K 2R1, Canada.

This study aims at validating an experimental method for characterizing the vibration behavior of panels excited by a turbulent boundary layer (TBL) excitation as a possible alternative to standard means like wind tunnels or in situ tests. The approach takes advantage of an explicit separation of the excitation contribution from the dynamic behavior of the panel. Based on the measurement of deterministic transfer functions on the panel, called "sensitivity functions," which are then combined with either measurements or a model of the wall-pressure fluctuations induced by the TBL excitation, the vibration response under such an excitation can be retrieved. For validation purposes, the wall-pressure fluctuations of the turbulent flow generated in an anechoic wind tunnel are measured with a flush-mounted microphone array. The decay rates and the convection velocity, which mainly characterize the excitation, are extracted from these measurements. The plate velocity response to this excitation is estimated following the proposed method using the measured sensitivity functions and the model of Mellen fed with experimentally estimated decay rates and convection velocity. A comparison between a directly measured vibration auto-spectrum under the actual flow and the one predicted following the suggested method shows satisfactory agreement.
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http://dx.doi.org/10.1121/1.5037362DOI Listing
May 2018

Epigenetic Differentiation of Natural Populations of Lilium bosniacum Associated with Contrasting Habitat Conditions.

Genome Biol Evol 2018 01;10(1):291-303

Laboratory for Research and Protection of Endemic Resources, Department of Biology, Faculty of Sciences, University of Sarajevo, Bosnia and Herzegovina.

Epigenetic variation in natural populations with contrasting habitats might be an important element, in addition to the genetic variation, in plant adaptation to environmental stress. Here, we assessed genetic, epigenetic, and cytogenetic structure of the three Lilium bosniacum populations growing on distinct habitats. One population was growing under habitual ecological conditions for this species and the other two were growing under stress associated with high altitude and serpentine soil. Amplified fragment length polymorphism and methylation-sensitive amplification polymorphism analyses revealed that the three populations did not differentiate genetically, but were clearly separated in three distinct clusters according to DNA methylation profiles. Principal coordinate analysis showed that overall epigenetic variation was closely related to habitat conditions. A new methylation-sensitive amplification polymorphism scoring approach allowed identification of mainly unmethylated (φST = 0.190) and fully CpG methylated (φST = 0.118) subepiloci playing a role in overall population differentiation, in comparison with hemimethylated sites (φST = 0.073). In addition, unusual rDNA repatterning and the presence of B chromosomes bearing 5S rDNA loci were recorded in the population growing on serpentine soil, suggesting dynamic chromosome rearrangements probably linked to global genome demethylation, which might have reactivated some mobile elements. We discuss our results considering our earlier data on morphology and leaf anatomy of several L. bosniacum populations, and suggest a possible role of epigenetics as a key element in population differentiation associated with environmental stress in these particular lily populations.
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http://dx.doi.org/10.1093/gbe/evy010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5786246PMC
January 2018

Vibroacoustic response of panels under diffuse acoustic field excitation from sensitivity functions and reciprocity principles.

J Acoust Soc Am 2017 06;141(6):4508

Groupe d'Acoustique de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, J1K 2R1, Canada.

This paper aims at developing an experimental method to characterize the vibroacoustic response of a panel to a diffuse acoustic field (DAF) excitation with a different laboratory setup than those used in standards (i.e., coupled rooms). The proposed methodology is based on a theoretical model of the DAF and on the measurement of the panel's sensitivity functions, which characterize its vibroacoustic response to wall plane waves. These functions can be estimated experimentally using variations of the reciprocity principle, which are described in the present paper. These principles can either be applied for characterizing the structural response by exciting the panel with a normal force at the point of interest or for characterizing the acoustic response (radiated pressure, acoustic intensity) by exciting the panel with a monopole and a dipole source. For both applications, the validity of the proposed approach is numerically and experimentally verified on a test case composed of a baffled simply supported plate. An implementation for estimating the sound transmission loss of the plate is finally proposed. The results are discussed and compared with measurements performed in a coupled anechoic-reverberant room facility following standards.
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http://dx.doi.org/10.1121/1.4985126DOI Listing
June 2017

Estimating transmission loss in coupled reverberant-anechoic rooms by measuring sound intensity with and without a test specimen.

J Acoust Soc Am 2017 03;141(3):1896

Groupe d'Acoustique de l'Université de Sherbrooke, Faculté de Génie Mécanique, Université de Sherbrooke, Sherbrooke J1K 2R1, Canada.

A method for estimating the sound transmission loss of partitions in coupled reverberant-anechoic rooms is proposed, using two sound intensity measurements made before and after a test specimen is installed between the two rooms. Laboratory tests performed following a standard procedure and the suggested method with three different panels provide comparable transmission loss values.
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http://dx.doi.org/10.1121/1.4978039DOI Listing
March 2017

Mainstream partial nitritation and anammox: long-term process stability and effluent quality at low temperatures.

Water Res 2016 09 3;101:628-639. Epub 2016 May 3.

Eawag: Swiss Federal Institute of Aquatic Science and Technology, Überlandstr. 133, 8600 Dübendorf, Switzerland.

The implementation of autotrophic anaerobic ammonium oxidation processes for the removal of nitrogen from municipal wastewater (known as "mainstream anammox") bears the potential to bring wastewater treatment plants close to energy autarky. The aim of the present work was to assess the long-term stability of partial nitritation/anammox (PN/A) processes operating at low temperatures and their reliability in meeting nitrogen concentrations in the range of typical discharge limits below 2  [Formula: see text] and 10 mgNtot·L(-1). Two main 12-L sequencing batch reactors were operated in parallel for PN/A on aerobically pre-treated municipal wastewater (21 ± 5 [Formula: see text] and residual 69 ± 19 mgCODtot·L(-1)) for more than one year, including over 5 months at 15 °C. The two systems consisted of a moving bed biofilm reactor (MBBR) and a hybrid MBBR (H-MBBR) with flocculent biomass. Operation at limiting oxygen concentrations (0.15-0.18 [Formula: see text] ) allowed stable suppression of the activity of nitrite-oxidizing bacteria at 15 °C with a production of nitrate over ammonium consumed as low as 16% in the MBBR. Promising nitrogen removal rates of 20-40 mgN·L(-1)·d(-1) were maintained at hydraulic retention times of 14 h. Stable ammonium and total nitrogen removal efficiencies over 90% and 70% respectively were achieved. Both reactors reached average concentrations of total nitrogen below 10 mgN·L(-1) in their effluents, even down to 6 mgN·L(-1) for the MBBR, with an ammonium concentration of 2 mgN·L(-1) (set as operational threshold to stop aeration). Furthermore, the two PN/A systems performed almost identically with respect to the biological removal of organic micropollutants and, importantly, to a similar extent as conventional treatments. A sudden temperature drop to 11 °C resulted in significant suppression of anammox activity, although this was rapidly recovered after the temperature was increased back to 15 °C. Analyses of 16S rRNA gene-targeted amplicon sequencing revealed that the anammox guild of the bacterial communities of the two systems was composed of the genus "Candidatus Brocadia". The potential of PN/A systems to compete with conventional treatments for biological nutrients removal both in terms of removal rates and overall effluent quality was proven.
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http://dx.doi.org/10.1016/j.watres.2016.05.005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5250802PMC
September 2016

Activity and growth of anammox biomass on aerobically pre-treated municipal wastewater.

Water Res 2015 Sep 1;80:325-36. Epub 2015 May 1.

Eawag: Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, CH-8600 Dübendorf, Switzerland.

Direct treatment of municipal wastewater (MWW) based on anaerobic ammonium oxidizing (anammox) bacteria holds promise to turn the energy balance of wastewater treatment neutral or even positive. Currently, anammox processes are successfully implemented at full scale for the treatment of high-strength wastewaters, whereas the possibility of their mainstream application still needs to be confirmed. In this study, the growth of anammox organisms on aerobically pre-treated municipal wastewater (MWW(pre-treated)), amended with nitrite, was proven in three parallel reactors. The reactors were operated at total N concentrations in the range 5-20 mg(N)∙L(-1), as expected for MWW. Anammox activities up to 465 mg(N)∙L(-1)∙d(-1) were reached at 29 °C, with minimum doubling times of 18 d. Lowering the temperature to 12.5 °C resulted in a marked decrease in activity to 46 mg(N)∙L(-1)∙d(-1) (79 days doubling time), still in a reasonable range for autotrophic nitrogen removal from MWW. During the experiment, the biomass evolved from a suspended growth inoculum to a hybrid system with suspended flocs and wall-attached biofilm. At the same time, MWW(pre-treated) had a direct impact on process performance. Changing the influent from synthetic medium to MWW(pre-treated) resulted in a two-month delay in net anammox growth and a two to three-fold increase in the estimated doubling times of the anammox organisms. Interestingly, anammox remained the primary nitrogen consumption route, and high-throughput 16S rRNA gene-targeted amplicon sequencing analyses revealed that the shift in performance was not associated with a shift in dominant anammox bacteria ("Candidatus Brocadia fulgida"). Furthermore, only limited heterotrophic denitrification was observed in the presence of easily biodegradable organics (acetate, glucose). The observed delays in net anammox growth were thus ascribed to the acclimatization of the initial anammox population or/and the development of a side population beneficial for them. Additionally, by combining microautoradiography and fluorescence in situ hybridization it was confirmed that the anammox organisms involved in the process did not directly incorporate or store the amended acetate and glucose. In conclusion, these investigations strongly support the feasibility of MWW treatment via anammox.
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http://dx.doi.org/10.1016/j.watres.2015.04.026DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5250675PMC
September 2015

Experimental evidence of modal wavenumber relation to zeros in the wavenumber spectrum of a simply supported plate.

J Acoust Soc Am 2015 May;137(5):2978-81

Applied Research Laboratory, The Pennsylvania State University, P.O. Box 30, State College, Pennsylvania 16804, USA.

The modal wavenumber of rectangular, simply supported, isotropic thin plates was theoretically shown to be related to the zeros in the wavenumber spectrum and not to the peaks, resulting in an error between the actual modal wavenumber and location of the wavenumber spectrum peak for low mode orders. This theoretical proof is confirmed by experimental results reported in this letter.
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http://dx.doi.org/10.1121/1.4919334DOI Listing
May 2015

Measurement of the absorption coefficient of sound absorbing materials under a synthesized diffuse acoustic field.

J Acoust Soc Am 2014 Jul;136(1):EL13-9

Groupe d'Acoustique de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec J1K 2R1, Canada

This letter proposes an experimental method to estimate the absorption coefficient of sound absorbing materials under a synthesized diffuse acoustic field in free-field conditions. Comparisons are made between experiments conducted with this approach, the standard reverberant room method, and numerical simulations using the transfer matrix method. With a simple experimental setup and smaller samples than those required by standards, the results obtained with the proposed approach do not exhibit non-physical trends of the reverberant room method and provide absorption coefficients in good agreement with those obtained by simulations for a laterally infinite material.
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http://dx.doi.org/10.1121/1.4881321DOI Listing
July 2014

Experimental vibroacoustic testing of plane panels using synthesized random pressure fields.

J Acoust Soc Am 2014 Jun;135(6):3434-45

Groupe d'Acoustique de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke J1K 2R1, Canada.

The experimental reproduction of random pressure fields on a plane panel and corresponding induced vibrations is studied. An open-loop reproduction strategy is proposed that uses the synthetic array concept, for which a small array element is moved to create a large array by post-processing. Three possible approaches are suggested to define the complex amplitudes to be imposed to the reproduction sources distributed on a virtual plane facing the panel to be tested. Using a single acoustic monopole, a scanning laser vibrometer and a baffled simply supported aluminum panel, experimental vibroacoustic indicators such as the Transmission Loss for Diffuse Acoustic Field, high-speed subsonic and supersonic Turbulent Boundary Layer excitations are obtained. Comparisons with simulation results obtained using a commercial software show that the Transmission Loss estimation is possible under both excitations. Moreover and as a complement to frequency domain indicators, the vibroacoustic behavior of the panel can be studied in the wave number domain.
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http://dx.doi.org/10.1121/1.4872298DOI Listing
June 2014

Molecular cytogenetics (FISH and fluorochrome banding): resolving species relationships and genome organization.

Methods Mol Biol 2014 ;1115:309-23

Laboratory Ecology, Systematic and Evolution, UMR 8079, CNRS-UPS-AgroParisTech, University Paris-Sud, Orsay, France.

Fluorochrome banding (chromomycin, Hoechst, and DAPI) and fluorescence in situ hybridization (FISH) are excellent molecular cytogenetic tools providing various possibilities in the study of chromosomal evolution and genome organization. The constitutive heterochromatin and rRNA genes are the most widely used FISH markers. The rDNA is organized into two distinct gene families (18S-5.8S-26S and 5S) whose number and location vary within the complex of closely related species. Therefore, they are widely used as chromosomal landmarks to provide valuable evidence concerning genome evolution at chromosomal levels.
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http://dx.doi.org/10.1007/978-1-62703-767-9_15DOI Listing
August 2014

[Does dental class II division 2 predispose to temporomandibular disorders?].

Orthod Fr 2013 Sep 3;84(3):277-85. Epub 2013 Sep 3.

Unité fonctionnelle Algies et dysfonctions de l'appareil manducateur, Service d'Odontologie, CHU de Lyon, 6-8 place Depéret, 69007 Lyon, France.

Because of its anatomical/physiological characteristics, the Class II division 2 (class II, div. 2) is one of the malocclusions considered as a possible risk factor for Temporomandibular disorders (TMD). A literature review was conducted from the electronic databases of Medline and Elsevier Masson, through the year 2010, in order to clarify the relationships that may exist between Class II division 2 and TMD. This research helped identify 50 articles: 7 articles specifically concerned the Class II div. 2, 37 articles concerned some of the characteristics of the Class II div. 2, considered individually (Class II, deep bite, retroclined maxillary incisors, mandibular retrognathism) and 6 articles orthodontic treatment. From the conclusions of these studies, the Class II, div. 2 does not appear to represent a significant risk factor for TMD. The clearest association would involve mandibular retrognathism and the risk of articular disk displacement. However, given the low number of articles published on this topic, the methodological variability and the contradictory results, it is difficult to identify reliable conclusions and, consequently, the therapeutic indications for the treatment of Class II div. 2 patients with TMD.
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http://dx.doi.org/10.1051/orthodfr/2013052DOI Listing
September 2013

Reproduction of random pressure fields based on planar nearfield acoustic holography.

J Acoust Soc Am 2013 Jun;133(6):3885-99

Groupe d'Acoustique de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, J1K 2R1, Canada.

This article discusses an open-loop approach based on planar nearfield acoustic holography (P-NAH) for the reproduction of random pressure fields, mainly intended for the measurement of vibroacoustic properties of plane panels. The main application is the simulation of turbulent boundary layer excitation in a laboratory environment, as an alternative to in-flight or wind tunnel experiments. The problem under study is the synthesis of random pressure distributions on a plane reproduction surface using acoustic monopoles distributed on a plane source surface facing the reproduction surface. The problem of reproducing a pressure distribution on a plane surface is addressed using the theoretical framework of P-NAH, which is extended to random pressure fields with corresponding imposed cross-spectral density functions. Results of numerical simulations are presented for the reproduction of a diffuse acoustic field, and a subsonic and supersonic turbulent boundary layer. The influence on the reproduction accuracy of the respective sizes of the two planes, their separation and the reproduction source separation are studied. The reproduction approach shows to be effective for the reproduction of diffuse acoustic field and turbulent boundary layer, but with different requirements in terms of plane separation and reproduction sources separation. In the specific case of subsonic turbulent boundary layer and associated sub-wavelength correlation scales reproduction, possible improvements of the method are suggested.
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http://dx.doi.org/10.1121/1.4802898DOI Listing
June 2013

[Course of action in front of children or adolescent suffering from temporomandibular disorders].

Authors:
Olivier Robin

Orthod Fr 2013 Mar 27;84(1):87-96. Epub 2013 Mar 27.

Temporomandibular disorders are described in children from the age of 4. Their prevalence and severity increase strongly during the second decade, which corresponds to the period of orthodontic treatments. At this age the most common symptoms are joint clicking sounds (more than 70% of the cases), sometimes accompanied by episodes of intermittent locking. They would be favored by oral parafunctional activities (gum chewing, biting habits, bruxism...), ligamentous hyperlaxity and modification of the intra-articular space relations during growth. The questioning of the patient and his parents and clinical examination (muscular, articular and occlusal) are essential and very often sufficient for establishing the diagnosis. Even more than in the adult, the therapeutic attitude must rely on conservative and non-irreversible methods (explanations, suppression of the parafunctions, occlusal splints in the case of severe bruxism). These considerations are illustrated by the presentation of two representative clinical cases of temporomandibular disorders frequently encountered in children and adolescents.
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http://dx.doi.org/10.1051/orthodfr/2013035DOI Listing
March 2013

Quaternary ammonium-functionalized silica sorbents for the solid-phase extraction of aromatic amines under normal phase conditions.

J Chromatogr A 2013 Apr 8;1285:7-14. Epub 2013 Feb 8.

Laboratory of Analytical Chemistry, Department of Chemistry, PO Box 55, University of Helsinki, FI-00014 Helsinki, Finland.

Quaternary ammonium-functionalized silica materials were synthesized and applied for solid-phase extraction (SPE) of aromatic amines, which are classified as priority pollutants by US Environmental Protection Agency. Hexamethylenetetramine used for silica surface modification for the first time was employed as SPE sorbent under normal phase conditions. Hexaminium-functionalized silica demonstrated excellent extraction efficiencies for o-toluidine, 4-ethylaniline and quinoline (recoveries 101-107%), while for N,N-dimethylaniline and N-isopropylaniline recoveries were from low to moderate (14-46%). In addition, the suitability of 1-alkyl-3-(propyl-3-sulfonate) imidazolium-functionalized silica as SPE sorbent was tested under normal phase conditions. The recoveries achieved for the five aromatic amines ranged from 89 to 99%. The stability of the sorbent was evaluated during and after 150 extractions. Coefficients of variation between 4.5 and 10.2% proved a high stability of the synthesized sorbent. Elution was carried out using acetonitrile in the case of hexaminium-functionalized silica and water for 1-alkyl-3-(propyl-3-sulfonate) imidazolium-functionalized silica sorbent. After the extraction the analytes were separated and detected by liquid chromatography ultraviolet detection (LC-UV). The retention mechanism of the materials was primarily based on polar hydrogen bonding and π-π interactions. Comparison made with activated silica proved the quaternary ammonium-functionalized materials to offer different selectivity and better extraction efficiencies for aromatic amines. Finally, 1-alkyl-3-(propyl-3-sulfonate) imidazolium-functionalized silica sorbent was successfully tested for the extraction of wastewater and soil samples.
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http://dx.doi.org/10.1016/j.chroma.2013.02.003DOI Listing
April 2013

Swarm of terminal 35S in Cheirolophus (Asteraceae, Centaureinae).

Genome 2012 Jul 13;55(7):529-35. Epub 2012 Jul 13.

Institut Botànic de Barcelona (IBB-CSIC-ICUB), Passeig del Migdia s.n., Parc de Montjuïc, 08038 Barcelona, Catalonia, Spain.

Island radiation constitutes a playground for species diversification, which has long fascinated researchers and still does today. Because only a small subset of taxa within the pool of island colonizers is concerned by this process, the question is raised on whether some factors could make a taxon prone to radiate. Cheirolophus is the only genus of Centaureinae subtribe to have experienced a radiation in the Canary Islands. Cytogenetic characterization through FISH of 5S and 35S ribosomal RNA genes in eight Cheirolophus species from continent and Canary Islands revealed an unusually high number of 35S predominantly at terminal position, together with a single interstitial 5S rDNA locus in all the studied taxa. Such an abundance of 35S rDNA signals is unique among Centaureinae and predates Cheirolophus arrival in Canary Islands. The possible link of the rDNA profile with radiation process is discussed through a comparison with two other case studies, the closely related Rhaponticum group and the genus Centaurea.
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http://dx.doi.org/10.1139/g2012-041DOI Listing
July 2012

A wave field synthesis approach to reproduction of spatially correlated sound fields.

J Acoust Soc Am 2012 Feb;131(2):1226-39

Groupe d'Acoustique de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke J1K 2R1, Canada.

This article discusses an open-loop wave field synthesis (WFS) approach for the reproduction of spatially correlated sound fields. The main application concerns laboratory reproduction of turbulent boundary layer wall pressure on aircraft fuselages and measurement of their sound transmission loss. The problem configuration involves reconstruction of random sound pressure distributions on a planar reproduction surface using a planar array of reproduction monopoles parallel to the reproduction plane. In this paper, the WFS formulation is extended to sound fields with imposed time and spatial correlation properties (or equivalently imposed cross-spectral density in the frequency and wave number domains). Numerical examples are presented for the reproduction of a propagating plane wave, diffuse acoustic field and wall pressure in subsonic or supersonic turbulent boundary layers. The reproduction accuracy is examined in terms of the size of the source plane and reproduction plane, their separation, and the number of reproduction sources required per acoustic wavelength. While the reproduction approach cannot reconstruct sub-wavelength correlation scales of subsonic turbulent boundary layers, it effectively reconstructs correlation scales larger than the acoustic wavelength, making it appropriate for diffuse acoustic field and supersonic turbulent layers.
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http://dx.doi.org/10.1121/1.3675942DOI Listing
February 2012

[Can orthodontic treatment generate temporomandibular disorders and pain? A review].

Orthod Fr 2010 Mar 1;81(1):85-93. Epub 2010 Apr 1.

Département d'Orthopédie Dento-Faciale, Faculté d'Odontologie, 11 rue Guillaume Paradin, 69372 Lyon Cedex 08, France.

While considered for years to play the primary role in the etiology of temporo-mandibular joint disturbances (TMD), occlusal discrepancies are now considered to be just one causative factor among many. Recent studies, literature reviews or meta-analyses, and longitudinal studies with follow-up of children treated for many years all conclude that there is no risk of orthodontic treatment giving rise to episodes of temporo-mandibular disorders. The signs of TMD appearing during the course of orthodontic treatment should be considered in the context of the epidemiology of the disorder, which is characterized by a strong increase in its occurrence during adolescence. In conclusion, it should be stated that if orthodontic treatment can no longer be considered as one of the etiopathogenic factors in the TMD complex, there are no scientific arguments to justify the converse, that there are indications for orthodontic treatment whose sole goal would be the treatment of TMD.
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http://dx.doi.org/10.1051/orthodfr/2010009DOI Listing
March 2010

Physical mapping of rDNA and heterochromatin in chromosomes of 16 Coffea species: a revised view of species differentiation.

Chromosome Res 2009 31;17(3):291-304. Epub 2009 Mar 31.

IRD, UMR DIAPC, 911 Av Agropolis, BP 64501, 34394, Montpellier cedex 5, France.

The chromosome organization among 15 wild diploid Coffea species and cultivated tetraploid C. arabica was determined by fluorochrome banding (CMA, DAPI) and double fluorescence in-situ hybridization (FISH) of 5S and 18S rDNA achieved on the same chromosome plates. Two to five chromosome pairs (plus one putative chromosome B) are marked. Overall, there are two SAT-chromosome pairs for East African species and one for the Malagasy and the West and Central African species. 18S rDNA loci are telomeric and strongly marked the SAT-chromosome pairs. Generally, only one pericentromeric 5S rDNA locus characterized East African species, while an additional minor locus co-localized with the 18S rDNA-SAT locus for the Malagasy species and West and Central African species. A combination of rDNA FISH plus CMA and DAPI banding patterns enables identification of almost all the species, even those for which the genetic or botanical status is still being discussed. C. arabica clearly appears to be an allotetraploid species, including one genome from East Africa and one from West and Central Africa. However, since the minor 5S rDNA-SAT locus present in West/Central African genomes is not detected, two evolutionary hypotheses could be put forward for C. arabica. Considering only the diploid species, global trends are obvious in rDNA signal patterns, genome size variations, and geographic distribution of the species, but there are no clear evolutionary trends. However, complex interactions between these factors and environmental growing conditions exist, which have resulted in loss and gain of rDNA loci and probably also in copy repeat number variations in each rDNA family.
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http://dx.doi.org/10.1007/s10577-009-9033-2DOI Listing
August 2009

Stimulated Raman scattering in an optical parametric oscillator based on periodically poled MgO-doped stoichiometric LiTaO3.

Opt Express 2009 Mar;17(7):5912-8

Laboratoire Aimé Cotton, CNRS-Université, Paris Sud 11, Campus d'Orsay, Orsay Cedex, France.

The evolution of the spectrum of a singly resonant optical parametric oscillator based on an MgO-doped periodically poled stoichiometric lithium tantalate crystal is observed when the pump power is varied. The onset of cascade Raman lasing due to stimulated Raman scattering in the nonlinear crystal is analyzed. Spurious frequency doubling and sum-frequency generation phenomena are observed and understood. A strong reduction of the intracavity Raman scattering is obtained by a careful adjustment of the cavity losses.
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http://dx.doi.org/10.1364/oe.17.005912DOI Listing
March 2009

Recent human sexual dimorphism study using cephalometric plots on lateral teleradiography and discriminant function analysis.

J Forensic Sci 2008 Jul;53(4):786-9

UFR d'Odontologie, Université Claude Bernard Lyon 1, France.

The examination of skull sexual dimorphism has been the subject of numerous morphologic and craniometric studies, but the disadvantage of these studies is that they are dependent on the experience of the operator and involve subjectivity. In 1996, a team from Taiwan refined the methods enabling the sex of an individual to be determined using cephalometric plots made from lateral teleradiography. To validate their work using a European population, 114 dry skulls (59 men and 55 women) were examined. Cephalometric plots were made on lateral teleradiography with an orthodontic software and 18 cephalometric variables were analyzed. Sex was determined with 95.6% accuracy using the 18 variables discriminant function. A subset of eight variables was selected and could predict sex with the same accuracy. In conclusion, it can be said that skull-sexing methods using lateral teleradiography seem always suitable but the most indicative variables could differ relative to the ethnic population concerned.
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http://dx.doi.org/10.1111/j.1556-4029.2008.00759.xDOI Listing
July 2008

Autonomic nervous system responses to sweet taste: evidence for habituation rather than pleasure.

Physiol Behav 2008 Mar 12;93(4-5):994-9. Epub 2008 Jan 12.

Université de Lyon, Lyon, F-69008, France, Université Lyon 1, Faculté d'Odontologie, Lyon, F-69008, France.

Previous recordings of the variations of autonomic nervous system (ANS) parameters associated with each primary taste (sweet, salty, sour and bitter) showed that sweet taste induced very weak ANS responses, in the same range or weaker than responses evoked by mineral water. The purpose of this study was then to determine whether this weak ANS activation reflects the pleasant hedonic valence of sweet or the habituation of the organism to this innate-accepted taste. Twenty healthy volunteer subjects (8 males and 12 females, mean age=22.85 years) participated in the experiment. Taste stimuli were a solution of 0.3 M sucrose and three sweet flavours (orange juice, coke, lemonade) as "pleasant" sweet stimuli, and a solution of 0.15 M NaCl as an "unpleasant" stimulus. "Evian" mineral water served as the diluent and as a neutral stimulus. Throughout the test, five ANS parameters (skin potential and skin resistance, skin blood flow and skin temperature, instantaneous heart rate) were simultaneously and continuously recorded. After they had tasted each solution, subjects filled out a questionnaire in which they had to evaluate the hedonic dimension and the sweet intensity of each gustative stimulus. The lack of correlation between the mean hedonic scores associated with the four sweet stimuli and the mean values of the autonomic parameter variations tends to indicate that the weak ANS responses induced by the sweet gustative stimuli rather reflect the habituation of the organism to sweet taste than a gradation in sensory pleasure.
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http://dx.doi.org/10.1016/j.physbeh.2008.01.005DOI Listing
March 2008

Wrist ambulatory monitoring system and smart glove for real time emotional, sensorial and physiological analysis.

Conf Proc IEEE Eng Med Biol Soc 2004;2004:2161-4

Microcapteurs et Microsystèmes Biomédicaux, CNRS, Villeurbanne, France.

Improvement of the quality and efficiency of the quality of health in medicine, at home and in hospital becomes more and more important Designed to be user-friendly, smart clothes and gloves fit well for such a citizen use and health monitoring. Analysis of the autonomic nervous system using non-invasive sensors provides information for the emotional, sensorial, cognitive and physiological analysis. MARSIAN (modular autonomous recorder system for the measurement of autonomic nervous system) is a wrist ambulatory monitoring and recording system with a smart glove with sensors for the detection of the activity of the autonomic nervous system. It is composed of a "smart tee shirt", a "smart glove", a wrist device and PC which records data. The smart glove is one of the key point of MARSIAN. Complex movements, complex geometry, sensation make smart glove designing a challenge. MARSIAN has a large field of applications and researches (vigilance, behaviour, sensorial analysis, thermal environment for human, cognition science, sport, etc...) in various fields like neurophysiology, affective computing and health monitoring.
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http://dx.doi.org/10.1109/IEMBS.2004.1403632DOI Listing
September 2007