Modélisation par Eléments Finis d'une Ligne à Retard à Ondes de Love

Les microcapteurs acoustiques à ondes de surface ont largement démontré leurs performances pour détecter des composés chimiques et biologiques en milieux gazeux et liquides. Plus précisément, les dispositifs à onde de Love font l’objet d’une attention particulière en raison de leurs bons résultats en milieux liquides notamment. La conception de ces dispositifs nécessite une phase de modélisation et de simulation indispensable à leur mise en œuvre opérationnelle. Cependant, à ce jour, en raison de la complexité de ces dispositifs, la plupart des modèles présentés simulent quelques caractéristiques de propagation de l’onde. La vitesse de phase est plus particulièrement calculée afin de permettre l’estimation de la sensibilité à l’effet de masse des capteurs. Nous proposons dans cette communication d’aller au-delà des modélisations classiques en présentant l’utilisation d’un logiciel à éléments finis pour un dispositif à ondes de Love. Nous présentons ainsi une modélisation globale permettant l’estimation d’un large champ de paramètres lors du fonctionnement du dispositif. Les premiers résultats seront présentés et analysés. Les perspectives et potentialités de l’utilisation de ce logiciel pour les capteurs à ondes de Love seront également abordées

Frequency dependence of viscous and viscoelastic dissipation in coated micro-cantilevers from noise measurement

We measure the mechanical thermal noise of soft silicon atomic force microscopy cantilevers. Using an interferometric setup, we have a resolution down to 1E-14 m/rtHz on a wide spectral range (3 Hz to 1E5 Hz). The low frequency behavior depends dramatically on the presence of a reflective coating: almost flat spectrums for uncoated cantilevers versus 1/f like trend for coated ones. The addition of a viscoelastic term in models of the mechanical system can account for this observation. Use of Kramers-Kronig relations validate this approach with a complete determination of the response of the cantilever: a power law with a small coefficient is found for the frequency dependence of viscoelasticity due to the coating, whereas the viscous damping due to the surrounding atmosphere is accurately described by the Sader model

Russian roulette with unlicensed fat-burner drug 2,4-dinitrophenol (DNP) : evidence from a multidisciplinary study of the internet, bodybuilding supplements and DNP users

BACKGROUND: 2,4-Dinitrophenol (DNP) poses serious health-risks to humans. The aims of this three-stage multidisciplinary project were, for the first time, to assess the risks to the general public from fraudulent sale of or adulteration/contamination with DNP; and to investigate motives, reasons and risk-management among DNP-user bodybuilders and avid exercisers. METHODS: Using multiple search-engines and guidance for Internet research, online retailers and bodybuilding forums/blogs were systematically explored for availability of DNP, advice offered on DNP use and user profiles. Ninety-eight pre-workout and weight-loss supplements were purchased and analysed for DNP using liquid-chromatography-mass-spectrometry. Psychosocial variables were captured in an international sample of 35 DNP users (26.06 ± 6.10 years, 94.3 % male) with an anonymous, semi-qualitative self-reported survey. RESULTS: Although an industrial chemical, evidence from the Internet showed that DNP is sold 'as is', in capsules or tablets to suit human consumption, and is used 'uncut'. Analytical results confirmed that DNP is not on the supplement market disguised under fictitious supplement names, but infrequently was present as contaminant in some supplements (14/98) at low concentration (<100mcg/kg). Users make conscious and 'informed' decisions about DNP; are well-prepared for the side-effects and show nonchalant attitude toward self-experimentation with DNP. Steps are often taken to ensure that DNP is genuine. Personal experience with performance- and appearance enhancing substances appears to be a gateway to DNP. Advice on DNP and experiences are shared online. The significant discrepancy between the normative perception and the actual visibility suggests that DNP use is-contrary to the Internet accounts-a highly concealed and lonesome activity in real life. Positive experiences with the expected weight-loss prevail over the negative experiences from side effects (all but two users considered using DNP again) and help with using DNP safely is considered preferable over scare-tactics. CONCLUSION: Legislation banning DNP sale for human consumption protects the general public but DNP is sold 'as is' and used 'uncut' by determined users who are not dissuaded from experimenting with DNP based on health threats. Further research with stakeholders' active participation is imperative for targeted, proactive public health policies and harm-reduction measures for DNP, and other illicit supplements

Réseau de suivi pérenne de la température des plans d'eau à l'échelle nationale

[Departement_IRSTEA]Eaux [TR1_IRSTEA]QUASARE [Relecteur_IRSTEA]Daufresne, M. ; Baudoin, J.M.The project of developing a protocol to establish a sustainable network for water bodies temperature comes to its end. After testing the protocol in real conditions upon 9 pilot sites over the 2013/2014 period, a methodological guide (Rebiere et al., 2015) about implementing monitoring devices was written and is presented in this report (&2). It is hardly possible to equip all the territory water bodies in the network because of financial constraints related to the implementation of national monitoring programs. The sites to be equipped were prioritized depending on their environmental and socio-economic stakes through a questionnaire, sent during the first 2015 quarter to key water stakeholders in France. This work is the subject of this document second part. Despite the low return rate of the questionnaire, 109 water bodies were submitted by organizations. This report describes a classification proposal for 109 water bodies in descending order of their stakes "importance"; this should allow an objective selection of water bodies to be equipped first, for example by ONEMA, as part of a permanent monitoring network potential. To be refined, this proposed classification will have to take into account the water bodies typological classification results achieved in parallel by Prats and Danis (2015).Le projet de développement d'un protocole pour la mise en place d'un réseau de suivi pérenne de la température des plans d'eau arrive à terme. Suite au test du protocole en conditions réelles sur 9 sites pilotes sur la période 2013/2014, un guide méthodologique (Rebiere, Peroux, Dublon et Danis, 2015) de réalisation des dispositifs de suivi a été rédigé et est présenté dans ce rapport (&2). Il est difficilement envisageable d'équiper l'ensemble des plans d'eau du territoire dans le cadre du réseau du fait des contraintes financières liées à la mise en oeuvre des programmes de surveillance nationaux. Les sites à équiper ont été priorisés selon leurs enjeux environnementaux et socio-économiques par l'intermédiaire d'un questionnaire, envoyé le premier trimestre 2015 aux principaux acteurs de l'eau en France. Ce travail fait l'objet de la seconde partie du présent document. Malgré le faible taux de retour du questionnaire, 109 plans d'eau ont été proposés par des organismes. Ce rapport décrit une proposition de classement de ces 109 plans d'eau par ordre décroissant de l' « importance » de leurs enjeux afin de permettre une sélection objective des plans d'eau à équiper prioritairement, par exemple par l'ONEMA , dans le cadre d'un potentiel réseau de suivi pérenne. Pour être affinée, cette proposition de classement devra prendre en compte les résultats de classement typologique des plans d'eau réalisée en parallèle par Prats et Danis (2015)

Caractérisation environnementale de la retenue des Bariousses (Treignac, Corrèze)

[Departement_IRSTEA]Eaux [TR1_IRSTEA]QUASAREThe present study aims at (i) identify and describe the driving forces that are exerted on the watershed and riparian corridor, (ii) describe the state of the banks and the coast and (iii) characterize the shape of the bowl, can influence biological communities and in particular fish communities. The watershed and riparian zone of the Bariousses are characterized by a predominance of forest areas, a low level of urbanization, a few meadows. We can thus expect a low intake of heavy metals, pesticides and other contaminants in the reservoir due to the low pollution sources, the role of riparian scrubber and reservoir of Viam further upstream that intercepts some of the water runoff. Coastal habitats are dominated by overhanging vegetation and woody emerging alive. We also note the presence of helophytes and root hairs. These habitats are necessary components of biological communities throughout their development cycle. These habitats are subject to fluctuations in water level. This results in a significant loss of vegetation on the coastal zone, which is essential to biological communities (breeding area, refuge, feeding). Recreation on the lake also generate habitat alterations. This translates, on Bariousses, by strengthening and compaction of embankments, the presence of facilities and the addition of sand (beaches). These changes represent a small linear, but their impact can be significant. Bariousses is characterized by a concave bowl type with a linear cut of shoreline bit. This limits the availability of habitats within the coastal zone.La présente étude s’attache à (i) identifier et décrire les forces motrices qui s’exercent sur le bassin versant et dans le corridor rivulaire, (ii) qualifier l’état des berges et du littoral et (iii) caractériser la forme de la cuvette, à même d’influencer les biocénoses et en particulier les communautés piscicoles. Le bassin versant et la zone rivulaire des Bariousses sont caractérisés par une forte dominance des surfaces forestières, un faible taux d’urbanisation, quelques prairies. On peut ainsi s’attendre à un apport faible en métaux lourds, pesticides et autres contaminants dans la retenue du fait des faibles sources de pollutions, du rôle épurateur de la ripisylve et de la retenue de Viam plus en amont qui intercepte une partie des eaux de ruissellement. Les habitats littoraux sont dominés par de la végétation surplombante et des ligneux émergents vivants. On note aussi la présence d’hélophytes et de chevelu racinaire. Ces composantes d’habitats sont nécessaires aux communautés biologiques tout au long de leur cycle de développement. Ces habitats sont soumis à des fluctuations du niveau d’eau. Cela se traduit par une perte importante de la végétation sur la zone littorale, qui est essentielle aux communautés biologiques (zone de reproduction, de refuge, de nourrissage). Les activités récréatives sur le lac génèrent également des altérations des habitats. Cela se traduit, sur les Bariousses, par le renforcement et le compactage des berges, la présence d’aménagements et par l’apport de sable (plages). Ces altérations ne représentent qu’un faible linéaire, mais leurs impacts peuvent être importants. La retenue des Bariousses est caractérisée par une cuvette de type concave avec un linéaire de rives peu découpé. Cela limite la disponibilité en habitats au sein de la zone littorale

Ex vivo uranium decontamination efficiency on wounded skin and in vitro skin toxicity of a calixarene-loaded nanoemulsion

International audienceThe present work aims at studying the decontamination efficacy of a calixarene-loaded nanoemulsion on two ex vivo wounded skin models mimicking superficial stings or cuts contaminated with uranium, and on a third model using excoriation. The decontaminating formulation was compared with the currently used radio-decontaminating soapy water (Trait rouge®) treatment. Moreover, to assess skin damage potentially induced by the undiluted nanoemulsion, in vitro toxicity studies were conducted on an in vitro reconstructed human epidermis, coupled with three different toxicity tests [3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide, lactate dehydrogenase, and interleukin-1-α]. This work demonstrated not only a significant decontamination activity of the calixarene nanoemulsion on wounded skin, ranging from 92% to 94% of the applied uranium solution according to the ex vivo model used, but also the absence of side effects of this promising treatment. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association

UNEQUAL PATTERNS OF DEVELOPMENT OF SUCCINATE-DEHYDROGENASE and ACETYLCHOLINESTERASE IN PURKINJE CELL BODIES and GRANULE CELLS ISOLATED IN BULK FROM THE CEREBELLAR CORTEX OF THE IMMATURE RAT 1

–A preparative procedure for the isolation in bulk of two cellular populations of the cerebellar cortex of the immature rat, the granule cells and the Purkinje cell bodies, is described. The procedure is used to delineate the developmental pattern of succinate-INT-reduclase (EC 1.3.99.1) and acetylcholinesterase (EC 3.1.1.7) in the crucial period of cerebellar maturation, i.e. between 12 and 19 days postnatally. Although the overall yield of neuronal RNA diminished with age, the proportion of RNA in the Purkinje cell body fraction increased while that in the granule cells decreased and microscopic examination of the fractions confirmed this result. The yields of succinate-INT-reductase and of acetylcholinesterase in the fractions paralleled the yields of RNA. A significant finding was the trend toward diminishing specific activities (units/Μg of RNA) with age of both enzymes in the Purkinje cell bodies as against the opposite, upward trend of their specific activities in the granule cells. An additional finding of interest was the different ratio of true acetylcholinesterase/total cholinesterase activity in the two cell types, with the granule cells consistently exhibiting higher true acetylcholinesterase values than the Purkinje cell bodies. The present report thus supplements the histoenzymological data on the developing rat cerebellum in that it reveals specific differences in the enzymatic development of two different cerebellar types, a finding which was greatly facilitated by the availability of the procedure for their bulk isolation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66200/1/j.1471-4159.1974.tb12210.x.pd

Association of a Love wave sensor to thin film molecularly imprinted polymers for nucleosides analogs detection

International audienceThe overall objective of this work is to develop and validate a quantitative, non-invasive therapeutic tool to detect selected urinary modified nucleosides as biomarkers of colorectal cancer chemotherapy and to monitor in fine the efficiency of the chemotherapy. Our methodology takes the advantage of high sensitivity of acoustic biosensor combined with high selectivity and robustness of thin molecularly imprinted polymer (MIP) film. In this paper we present a process based on a thin film of a MIP of adenosine 5'-monophosphate (AMP) coating on the sensor surface which is compatible with the acoustic wave propagation. Detection tests of AMP have been performed in aqueous media. The sensor response was recorded in terms of synchronous frequency and total insertion losses after both steps: extraction from, rebinding by the MIP layer. A frequency decrease of 6.875 Hz was recorded for 25μg/mL AMP concentration