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Although Abdellah Taïa has often been celebrated for his queer positioning and the boldness with which he discusses dissident forms of sexuality in Morocco, little critical attention has been given to his ingenious use of food practices as tools for reconfiguring desires and instruments of domination. Through the study of three novels figuring his subjugation to expressions of power both in Morocco and in France, this essay examines the culinary discourse as a forceful narrative in the service of the expansion of notions of conviviality and of belonging. A close look at his rerouting of gender and sexual borders from the centre to the periphery will also unearth in the suburbs of Paris the existence of interstitial spaces fraught with tensions between solidarity and destruction, where queer and transnational connections to the world can be reformulated. [ABSTRACT FROM AUTHOR]

This article describes out method for "scaffolding expertise" that we used in our team-taught critical food studies course. We believe this technique allows students to not only gain knowledge about a particular food, but also models scholarly production of expertise on a small scale. It gives students an idea of what it means to be "experts" helping them to develop a more critical eye toward those who claim that title in other contexts. [ABSTRACT FROM AUTHOR]

Abstract It has been argued that concentration of major metallic ions such as Mg2+ and Ca2+ plays a role in determining the composition of the echinoderm skeleton. Consequently, in several studies Mg/Ca ratio from modern and fossil echinoderm ossicles was used as a proxy of secular Mg2+/Ca2+ changes of Phanerozoic seawater. However, although significant progress has been made in understanding biomineralization of echinoderms, it is still largely unknown what are the sources and physiological pathways of major ions that contribute to skeleton formation. Herein we tested the effects of modifications of ambient seawater Mg2+/Ca2+ ratio (which is typically ∼5) and Mg-enrichment of the diet on the Mg/Ca ratio in regenerating spines of sea urchin Paracentrotus lividus under experimental conditions. We found that sea urchins cultured in seawater with Mg2+/Ca2+ ratio decreased to ∼1.9 produced a skeleton with also decreased Mg/Ca ratio. However, the skeleton of specimens fed on a Mg-enriched diet showed significantly higher Mg/Ca ratio. This suggests that the seawater is an important but not the only source of ions that contributes to the Mg/Ca ratio of the skeleton. Consequently, the reliability of geochemical models that link directly seawater chemistry with the Mg/Ca ratio of the skeleton should be reevaluated. Highlights • Sea urchins fed on Mg-enriched diet display higher skeletal Mg content. • Seawater is not the only source of ions in echinoderm biomineralization. • Effect of diet should be taken into account when reconstructing seawater Mg/Ca ratio. [ABSTRACT FROM AUTHOR]

Résumé: Cet article étudie la stratégie de communication gouvernementale lors du mouvement de grève étudiante de 2012 au Québec. Six ans après la fin du conflit, et malgré la production d'un volume important d'analyses et de réflexions sur cette crise sociale, aucune étude empirique n'a recensé systématiquement le contenu de la stratégie communicationnelle du gouvernement. Par le biais d'une analyse de contenu quantitative des interventions publiques des membres de l'exécutif, cette étude relève les cadres argumentaires au cœur de la stratégie de communication gouvernementale. S'inspirant de la théorie de l'activation en cascade d'Entman, l'analyse montre comment le gouvernement a tenté de définir les problèmes, les solutions et les protagonistes impliqués dans le conflit sociétal qu'a traversé le Québec en 2012. Notre analyse met en lumière l'échec gouvernemental à maintenir au fil des évènements l'initiative du cadrage de la crise, et le changement de stratégie communicationnelle qui en résulte. This article examines how the government framed its communications during the so-called "Printemps érable" (Maple Spring), a historic student protest movement that took place in Quebec in 2012. Six years after the end of the conflict, and despite the production of a significant volume of analysis and reflections on this social crisis, no empirical work had been dedicated yet to the study of the government's communication strategy. Following a quantitative content analysis of 424 public interventions from cabinet members, this study raises the argumentative frameworks at the heart of the government's communication strategy. Drawing on Entman's cascading activation model (2004), the analysis shows how the government tried to define the problems, solutions and protagonists involved in this societal conflict. Our study highlights the government's failure to maintain the framing initiative of the crisis, and the change in communication strategy that resulted. [ABSTRACT FROM AUTHOR]

Local thermal environment has a strong influence on the physiology of marine ectotherms. This is particularly relevant for tropical organisms living close to their thermal optimum, well exemplified by the increasing frequency of bleaching occurrence in shallow-water corals. Mesophotic Coral Ecosystems (MCEs) were suggested as potential oases, especially when they are submitted to internal waves inducing short-term cooling events. Indeed, probability of bleaching occurrence in scleractinians was reported to decrease with depth in Mo'orea as temperature variability increases. However, ecophysiological data are currently lacking to understand the cause of lower susceptibility/increased plasticity of deeper corals. A growing interest has been devoted the last decade to MCEs, but our understanding of the physiological performance of benthic organisms living in this environment remains relatively unexplored. To tackle that question, we first compared the metabolic responses (dark respiration, net photosynthesis and photosynthetic efficiency) of the depth-generalist scleractinian Pachyseris speciosa from two heterogeneous thermal environment (25 and 85 m depths) to acute heat stress to determine if the local thermal environment could predict coral response to warming. Then, we tested the thermal performance of two sympatric species (the scleractinian P. speciosa and the antipatharian Stichopathes sp.) to determine if there are inter-species differences in performances in species experiencing identical levels of temperature variability, at mesophotic depths (85 m). Results revealed broader thermal performances in the mesophotic P. speciosa compared to mid-depth ones, and constrained performances in the mesophotic antipatharian compared to the scleractinian species. We hypothesize that the high fluctuations in temperature due to internal waves in deeper areas contribute to the broader thermal performances of mesophotic P. speciosa. However, the constrained performances of the mesophotic antipatharian compared to P. speciosa suggests that other processes than the symbiosis with zooxanthellae also influence thermal performances of these mesophotic organisms. Our results supported that Stichopathes sp. lives close to its thermal optimum, suggesting a (relatively) cold thermal specialist strategy. In this context, composition of MCEs in the future is unlikely to shift to antipatharian-dominated landscape and will remain coral-dominated landscape. [Display omitted] • P. speciosa has broader thermal performance at 85 than 25 m. • Thermal regime likely explains depth-specific thermal performance for P. speciosa. • At 85 m depth, thermal performance is narrower for Stichopathes sp. than for P. speciosa. • Cooling events generated by internal waves do not always improve thermotolerance. • Stichopathes sp. at 85 m lives close to its thermal optimum. [ABSTRACT FROM AUTHOR]

Negative capacitance (NC), already observed in conducting polymer-based nanocomposites, was recently reported and evidenced at low frequencies (<10 kHz) in non-conducting polymer-based nanocomposites containing conductive particles. In this contribution, we demonstrate that it is possible to produce economic high-density polyethylene (HDPE) nanocomposites exhibiting an NC effect at low frequencies via a convenient and environmentally friendly extrusion-like process by only adjusting the duration of melt-mixing. Nanocomposite materials are produced by confining a limited quantity, i.e., 4.6 wt.%, of multiwalled carbon nanotubes (CNTs) within semi-crystalline HDPE to reach the percolation threshold. With increasing melt processing time, crystallites of HDPE developing at the surface of CNTs become bigger and perturbate the connections between CNTs leading to a dramatic change in the electrical behavior of the systems. More specifically, the link between NC and current oscillations is stressed while the dependence of NC with the size of polymer crystallites is evidenced. NC tends to appear when space charge effects take place in HDPE/MWCNT interfaces, in structures with convenient crystallite sizes corresponding to 10 min of melt-mixing. [ABSTRACT FROM AUTHOR]

Starting from the ontological theories from the 80's about the image-printing (the index, the "isto foi"), we will remont the moviments of thoughts that led the theories of the photography, to beyound the tecnogical mutations, towards a more pragmatic thought, attached to the use of the images and, above all, inforrmed by the "theory of the possible worlds", applied to the visual field. The photo less like a fictional image of a possible world, "a-referencial" and "plausible". We will study the implications of this thought about the questions of the document and the file, the stock and flow, the image space-time unit and its non-fixity. [ABSTRACT FROM AUTHOR]

Poly(lactic acid) or polylactide (PLA), a biodegradable polyester produced from renewable resources, is used for various applications (biomedical, packaging, textile fibers and technical items). Due to its inherent properties, PLA has a key-position in the market of biopolymers, being one of the most promising candidates for further developments. Unfortunately, PLA suffers from some shortcomings, whereas for the different applications specific end-use properties are required. Therefore, the addition of reinforcing fibers, micro- and/or nanofillers, and selected additives within PLA matrix is considered as a powerful method for obtaining specific end-use characteristics and major improvements of properties. This review highlights recent developments, current results and trends in the field of composites based on PLA. It presents the main advances in PLA properties and reports selected results in relation to the preparation and characterization of the most representative PLA composites. To illustrate the possibility to design the properties of composites, a section is devoted to the production and characterization of innovative PLA-based products filled with thermally-treated calcium sulfate, a by-product from the lactic acid production process. Moreover, are emphasized the last tendencies strongly evidenced in the case of PLA, i.e., the high interest to diversify its uses by moving from biomedical and packaging (biodegradation properties, “ disposables ”) to technical applications (“ durables ”). [ABSTRACT FROM AUTHOR]

The article offers information on the theories of photography from the 80's to the present. Topics discussed include impact of the posthumous publication of Roland Barthes's "Camera Lucida" in 1980; works of artists such as Franco Vaccari's "La photographie et l'inconscient technologique," Susan Sontag's "On Photography," and Denis Roche's "The disappearance of fireflies"; and aspects of the change in the regime of photographic visuality such as the matter of the document as archieve, matter of stock flow and matter of the spatiotemporal process of the image.

The ionic nucleophilic character of ammonium betaine catalysts allows for controlling the ROP of L-LA for DP as high as 750 with very narrow dispersity values (≤1.18). Compared to ionic nucleophilic and hydrogen-bonding based catalysts for ROP, meta-betaine combines the positive aspects of both processes in terms of kinetics and selectivity. The versatility of ammonium betaines was evidenced by varying the nature of the initiating alcohol and monomer used. [ABSTRACT FROM AUTHOR]

Available evidence on the impact of acidification and its interaction with warming on the skeleton of postmetamorphic (juvenile and adult) echinoderms is reviewed. Data are available on sea urchins, starfish, and brittle stars in 33 studies. Skeleton growth of juveniles of all sea urchin species studied so far is affected from pH 7.8 to 7.6 in seawater, values that are expected to be reached during the 21st century. Growth in adult sea urchins (six species studied) is apparently only marginally affected at seawater pH relevant to this century. The interacting effect of temperature differed according to studies. Juvenile starfish as well as adults seem to be either not impacted or even boosted by acidification. Brittle stars show moderate effects at pH below or equal to 7.4. Dissolution of the body wall skeleton is unlikely to be a major threat to sea urchins. Spines, however, due to their exposed position, are more prone to this threat, but their regeneration abilities can probably ensure their maintenance, although this could have an energetic cost and induce changes in resource allocation. No information is available on skeleton dissolution in starfish, and the situation in brittle stars needs further assessment. Very preliminary evidence indicates that mechanical properties in sea urchins could be affected. So, although the impact of ocean acidification on the skeleton of echinoderms has been considered as a major threat from the first studies, we need a better understanding of the induced changes, in particular the functional consequences of growth modifications and dissolution related to mechanical properties. It is suggested to focus studies on these aspects. [ABSTRACT FROM AUTHOR]

Skeletal Mg/Ca in echinoderms is thought to be related to ambient seawater Mg2+/Ca2+ ratio, which prompts the use of well-preserved fossil echinoderms as paleoseawater Mg2+/Ca2+ proxies. Nonetheless, experimental studies testing the effect of seawater Mg2+/Ca2+ ratio on echinoderm skeleton are limited to one echinoderm class, i.e., sea urchins (echinoids). Here, we investigated the effect of decreased seawater Mg2+/Ca2+ ratio on skeletal composition (Mg/Ca ratio) of a sea star Asterias rubens and a brittle star Ophiocomina nigra. Specimens were tagged with manganese and then cultured under three different Mg2+/Ca2+ molar ratios (~5.2, ~2.5, ~1.5 mol/mol) in order to simulate variations of ambient seawater Mg2+/Ca2+ ratio that existed throughout the Phanerozoic. Decreased Mg2+/Ca2+ in seawater did not affect the respiration rates or inhibit calcification of sea stars, which suggests that they were not significantly stressed by the treatment. It did, however, clearly affect growth and mortality in brittle stars, for which reliable geochemical data could not be obtained. Under decreased seawater Mg2+/Ca2+ sea stars produced a skeleton with decreased Mg/Ca ratio. This is consistent with the hypothesis that the skeletal chemistry in echinoderms is influenced by seawater chemistry and, consequently, that fossil echinoderms may preserve a record of paleoseawater Mg2+/Ca2+. Although our data from well-preserved fossil sea stars from the Middle Jurassic and Miocene are consistent with low Mg2+/Ca2+ ratio of the Jurassic "calcite sea" and high Mg2+/Ca2+ ratio of the Miocene "aragonite sea", the accuracy of paleoseawater Mg2+/Ca2+ reconstructions from fossil echinoderms is limited by the fact that Mg partition coefficients vary significantly between different echinoderm species. [ABSTRACT FROM AUTHOR]

Abstract: In this work, we evaluate the exploration of the Solar system by ad hoc wireless sensor networks (WSN), i.e., networks where all nodes (either moving or stationary) can both provide and relay data. The two aspects of self-organization and localization are the major challenges to achieve a reliable network for a variety of missions. We point out the diversity of environmental and operational constrains that WSN used for space exploration would face. We evaluate two groups of scenarios consisting in static or moving sensing nodes that can be either located on the ground or in the atmosphere of a Solar-system object. These scenarios enable collecting data simultaneously over a large surface or volume. We consider physical and chemical sensing of the atmosphere, surface and soil using such networks. Emerging technologies such as nodes localization techniques are reviewed. Finally, we compare the specific requirements of WSN for space exploration with those of WSN designed for terrestrial applications. [Copyright &y& Elsevier]

We report on the characterization, active tuning, and modeling of the first mode resonance frequency of dielectric electroactive polymer (DEAP) membranes. Unlike other resonance frequency tuning techniques, the tuning procedure presented here requires no external actuators or variable elements. Compliant electrodes were sputtered or implanted on both sides of 20-35-µm-thick and 2-4-mm-diameter polydimethylsiloxane membranes. The electrostatic force from an applied voltage adds compressive stress to the membrane, effectively softening the device and reducing its resonance frequency, in principle to zero at the buckling threshold. A reduction in resonance frequency up to 77% (limited by dielectric breakdown) from the initial value of 1620 Hz was observed at 1800 V for ion-implanted membranes. Excellent agreement was found between our measurements and an analytical model we developed based on the Rayleigh-Ritz theory. This model is more accurate in the tensile domain than the existing model for thick plates applied to DEAPs. By varying the resonance frequency of the membranes (and, hence, their compliance), they can be used as frequency-tunable attenuators. The same technology could also allow the fine-tuning of the resonance frequencies in the megahertz range of devices made from much stiffer polymers. [ABSTRACT FROM AUTHOR]

Soualili, D., Dubois, P., Gosselin, P., Pernet, P., and Guillou, M. 2008 Assessment of seawater pollution by heavy metals in the neighbourhood of Algiers: use of the sea urchin, Paracentrotus lividus, as a bioindicator. – ICES Journal of Marine Science, 65: 132–139.The objective of the study was to assess the levels of contamination by heavy metals near the Algiers metropolis, using a combination of chemical and toxicological data gained from analyses of sediments and biological parameters characteristic of the sea urchin, Paracentrotus lividus. Zinc, lead, cadmium, copper, and iron concentrations were determined in sediments and in sea urchin gonads. Sediment toxicity was assessed by bioassay based on the larval development of sea urchins. The most numerous larval abnormalities were found in a site near Algiers identified as highly polluted by lead. The levels of the other metals across the study area fell within the background concentrations reported in the literature for the Mediterranean Sea, with the exception of zinc, which showed high values in female gonads. [ABSTRACT FROM PUBLISHER]

Abstract: The minimum and maximum actuation voltages in electrowetting actuated microsystems are investigated in this paper. The minimum actuation voltage corresponds to the electric potential required to obtain motion of a droplet between two electrodes. Below this threshold, a droplet cannot be displaced due to contact angle hysteresis. The maximum actuation voltage corresponds to the electric potential above which there is no more gain in capillary forces because of the saturation effect. Based on the calculation of the electrocapillary forces on a drop in an EWOD system, and taking into account the contact angle hysteresis, an analytical relation is derived for the minimum actuation potential. On the other hand, the Peykov–Quinn–Ralston–Sedev model produces an approximate value of the maximum actuation voltage. Thus, a range of actuation potentials can be predicted depending on the liquid of the droplet, the surrounding gas or fluid and the nature of the solid substrate. The results of the two models are favorably compared with experimental results obtained using different liquids and substrates. [Copyright &y& Elsevier]

Abstract: We report on the first successfully microfabricated and tested ion implanted dielectric electroactive polymer (DEAP) actuators. Dielectric EAP (DEAP) actuators combine exceptionally high energy–density with large amplitude displacements [S. Ashley, Artificial muscles, Sci. Am. 289 (2003) 52–59; R. Pelrine, R. Kornbluh, J. Joseph, R. Heydt, Q. Pei, S. Chiba, High field deformation of elastomeric dielectrics for actuators, Mater. Sci. Eng. C 11 (2000) 89–100]. Scaling DEAPs down to the millimeter and micron scale requires patterning compliant electrodes on such a scale on the surfaces of the polymer. We used ion implantation to make the surfaces of the polymer locally conducting. Implanting the compliant electrodes solves the problem of microfabricating patterned electrodes whose elasticity is close to that of the insulating elastomer, thus avoiding the deposition of metal electrodes on the polymer which leads to significant stiffening of the membrane [A. Pimpin, Y. Suzuki, N. Kasagi, Micro electrostrictive actuator with metal compliant electrodes for flow control applications, in: MEMS 04, Maastricht, The Netherlands, 25–29 January, 2004, pp. 478–481]. Several techniques based on ion implantation for chip level and wafer level fabrication are presented. Ion implanted DEAP membranes were both simulated (FEM) and characterized. We report measurements on an actuator consisting of a 30-μm-thick ion implanted PDMS membrane bonded to a silicon chip into which a cavity had been etched. We measured 110μm vertical displacements for a 0.72mm2 membrane, achieving for the first time the same percent displacement in microscopic DEAPs as in macroscopic devices. These observations show that ion implantation allows the patterning of electrodes on PDMS membranes with negligible increase in stiffness. [Copyright &y& Elsevier]

A powerful approach combining a droplet-based, open digital microfluidic lab-on-a-chip using task-specific ionic liquids as soluble supports to perform solution-phase synthesis is reported as a new tool for chemical applications. The negligible volatility of ionic liquids enables their use as stable droplet reactors on a chip surface under air. The concept was validated with different ionic liquids and with a multicomponent reaction. Indeed, we showed that different ionic liquids can be moved by electrowetting on dielectric (EWOD), and their displacement was compared with aqueous solutions. Furthermore, we showed that mixing ionic liquids droplets, each containing a different reagent, in ‘open’ systems is an efficient way of carrying supported organic synthesis. This was applied to Grieco's tetrahydroquinolines synthesis with different reagents. Analysis of the final product was performed off-line and on-line, and the results were compared with those obtained in a conventional reaction flask. This technology opens the way to easy synthesis of minute amounts of compounds ad libitum without the use of complex, expensive, and bulky robots and allows complete automation of the process for embedded chemistry in a portable device. It offers several advantages, including simplicity of use, flexibility, and scalability, and appears to be complementary to conventional microfluidic lab-on-a-chip devices usually based on continuous-flow in microchannels. [ABSTRACT FROM AUTHOR]

A comparative analysis of the pairing of two critical texts on food, the 1839 edition of Jean-Anthelme Brillat-Savarin's 'Physiologie du Goût' and Honoré de Balzac's 'Traité sur les Excitants Modernes,' which was published appended to Brillat-Savarin's text in the 1839 republication. Situated within the burgeoning gastronomic context of the time, Balzac's renowned obsession with the culinary is examined as a creative decoction made at the intersection of eating, generation, and textual production. [ABSTRACT FROM AUTHOR]

Polyethylene-layered silicate nanocomposites were prepared by the in situ intercalative polymerization of ethylene by the so-called polymerization-filling technique and analyzed by transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), differential scanning calorimetry, dynamic mechanical analysis and tensile testing. Non-modified montmorillonite and hectorite were first treated by trimethylaluminum-depleted methylaluminoxane before being contacted by a Ti-based constrained geometry catalyst. The nanocomposite was formed by addition and polymerization of ethylene. In the absence of a chain transfer agent, ultra high molecular weight polyethylene was produced. The tensile properties of these nanocomposites were poor and essentially independent of the nature and content of the silicate. Upon hydrogen addition, the molecular weight of the polyethylene was decreased with parallel improvement of the tensile and shear moduli, in relation to the filler content. The exfoliation of the layered silicates was confirmed by XRD analysis and TEM observation. The mechanical kneading of the molten nanocomposites resulted in the partial collapse of the exfoliated structure driven by the thermodynamic stability of the layered filler. [Copyright &y& Elsevier]

Focuses on dual multimodular class A, penicillin binding proteins in Mycobacterium leprae. Discussion on the pon A gene of cosmid L222 of the Mycobacterium leprae genome library; Indepth look at the modular design of M. leprae pencillin binding proteins (PBP1).

The immune precipitates of high-density lipoprotein of duck serum with rabbit antisera are active on an esterase substrate, while the high-density lipoprotein itself is not active. The immune precipitates formed by high-density lipoprotein with isolated immunoglobulins, either in agar gel or in liquid medium, were also shown to be inactive, Such inactive immune precipitates can become active through interaction with a component of rabbit serum. Investigations on the conditions of the reaction and first observations concerning the nature of the activating component are reported. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented which discusses the securing of gastronomy in France.

An interview with Institut Européen d'Histoire et des Cultures de I'Alimentation (IEHCA) director Francis Chevrier is presented. When asked about the IEHCA's mission, he says that the agency promotes research, training, and acknowledgement of food culture in universities in France. He notes that the Ministry of Culture should also be concerned with promoting gastronomy as popular culture.

Solute exchange between the sediment and the water column strongly influences water quality in aquatic ecosystems. Among the techniques available for in situ observation, only aquatic eddy covariance (AEC) can resolve the hourly dynamics of benthic fluxes, but only for few substances like oxygen. In micrometeorology, relaxed eddy accumulation (REA), a technique based on high‐frequency sampling conditioned by current direction, overcomes this limitation. We developed a portable prototype instrumentation platform to transfer REA to the sediment‐water interface of shallow aquatic ecosystems. In order to evaluate the sampling system, we configured the prototype for measuring oxygen fluxes and comparing them to simultaneous AEC measurements. In a river and two artificial lakes, at depths 1–3 m and 0.2 m above the sediment, we measured 15 oxygen flux pairs in fully developed turbulence during 8–15 min periods, ranging from −150 to 50 mmol m−2 day−1. The good agreement between REA and AEC fluxes (R2 = 0.94) shows the reliability of the conditional sampling system. REA represents a promising technique for exploring the sediment contribution to biogeochemical cycles in aquatic ecosystems. Plain Language Summary: Microbial activity at the bottom boundary of aquatic ecosystems, such as lakes, rivers and coastal areas, influences their water quality. Microorganisms decompose organic matter and release nutrients and greenhouse gases to the overlying open water. In shallow aquatic ecosystems, the release from the sediment surface can vary rapidly, especially with currents, but so far, no technique succeeds in monitoring dynamic fluxes at hourly timescales for a broad range of substances. In micrometeorology, relaxed eddy accumulation is a well‐established technique for monitoring the turbulent exchange of all kinds of compounds between land and atmosphere (including gas, aerosols and particles). Air is sampled conditionally for downward or upward motions and accumulated in separate containers. Concentration differences between sample pairs provide information on the fluxes. We developed a portable prototype, transferring this technique to quantify the exchange of nutrients and other compounds at the bottom boundary of shallow aquatic ecosystems. For its evaluation, we adapted the prototype to measure dissolved oxygen fluxes. The agreement of its measurements with fluxes measured by aquatic eddy covariance, our reference, shows the potential of this technique. It can now be used to quantify the exchange of major ions and of other substances including dissolved gases. Key Points: We developed a portable instrumentation platform for measuring benthic fluxes in shallow aquatic environments by relaxed eddy accumulationSimultaneous measurements of dissolved oxygen fluxes by aquatic eddy covariance showed the reliability of the conditional sampling techniqueThis work paves the way for exploring the dynamics of biogeochemical cycles in aquatic ecosystems at hourly time scales [ABSTRACT FROM AUTHOR]

To develop novel mineral-filled composites and assess their enhanced properties (stiffness, a good balance between mechanical strength and impact resistance, greater temperature stability), a high-impact polypropylene copolymer (PPc) matrix containing an elastomeric discrete phase was melt mixed with natural CaSO4 β-anhydrite II (AII) produced from gypsum rocks. First, in a prior investigation, the PPc composites filled with AII (without any modification) displayed enhanced stiffness, which is correlated with the relative content of the filler. The tensile and impact strengths dramatically decreased, especially at high filling (40 wt.%). Therefore, two key methods were considered to tune up their properties: (a) the ionomeric modification of PPc composites by reactive extrusion (REx) with zinc diacrylate (ZA), and (b) the melt mixing of PPc with AII surface modified with ethylenebis(stearamide) (EBS), which is a multifunctional processing/dispersant additive. The properties of composites produced with twin-screw extruders (TSEs) were deeply assessed in terms of morphology, mechanical, and thermal performance, including characterizations under dynamic mechanical solicitations at low and high temperatures. Two categories of products with distinct properties are obtained. The ionomeric modification by Rex (evaluated by FTIR) led to composites characterized by remarkable thermal stability, a higher temperature of crystallization, stronger interfacial interactions, and therefore noticeable mechanical properties (high tensile strength (i.e., 28 MPa), increased stiffness, moderate (3.3 kJ/m2) to good (5.0 kJ/m2) impact resistance) as well as advanced heat deflection temperature (HDT). On the other hand, the surface modification of AII with EBS facilitated the dispersion and debonding of microparticles, leading to composites revealing improved ductility (strain at break from 50% to 260%) and enhanced impact properties (4.3–5.3 kJ/m2), even at high filling. Characterized by notable mechanical and thermal performances, high whiteness, and a good processing ability, these new PPc–AII composites may be tailored to meet the requirements of end-use applications, ranging from packaging to automotive components. [ABSTRACT FROM AUTHOR]

This article investigates the extent to which provincial political parties made use of social media in their strategy, organization and communication in order to achieve their electoral goals during the Quebec 2012 general election. Using data from a series of 19 interviews conducted with online strategists and campaign directors from the five leading parties active in the 2012 election, we identify the strategic objectives these organizations followed when developing their social media campaigns. The strategists' narratives reveal that social media became a central component of electioneering and that parties were carrying out, in various forms, hybrid campaigns that combined traditional and emergent communication technologies and employed both old and new types of organizational principles. [ABSTRACT FROM AUTHOR]

• PLA and ABS were mixed by reactive extrusion with epoxidized cardanol compounds. • Epoxidized cardanol and its mixture with raw cardanol were tested. • Both approach led a substantial increase of the compatibility of PLA and ABS. • The mixture led a synergistic effect on the mechanical properties. • Impact strength increased of 172% and strain at break more than 1000% vs PLA. With the aim to reinforce polylactide (PLA) mechanical properties, poly(acrylonitrile-butadienestyrene) (ABS) is considered as a polymer of choice. However, PLA and ABS are immiscible, leading to blends with weak properties. Cardanol is a lipid phenolic known to compatibilize these two polymers thanks to its reaction with ABS, but does not react with PLA and restricts its use to the modification of ABS. In this work, we investigated the effect of cardanol-based compatibilizers able to react by reactive extrusion with both PLA and ABS. In a first approach, cardanol unsaturations were epoxidized (CardE), hoping to react with PLA, while cardanol phenolic group would react with ABS. This compatibilizer was efficient as attested by ABS nodules size reduction and dispersion within PLA, in addition to the merging of the relaxation temperatures of both polymers at 69.5 °C when 5 wt% CardE was used. In addition, it led to a substantial improvement of PLA/ABS impact strength and elongation at break. In a second approach, we used of a mixture of compatibilizers, containing raw and epoxidized cardanol, both of them reacting either with PLA or with ABS. Here, a clear synergistic effect was observed, as attested by the exceptional increases of both impact strength (+172% compared to neat PLA) and elongation at break (+1000% compared to neat PLA). We assumed modified chains of both PLA and ABS with cardanol derivatives during reactive extrusion would intersperse between PLA and ABS, reducing the interfacial tension and improving the interfacial adhesion, leading to the outstanding compatibilization of the blend. [ABSTRACT FROM AUTHOR]

Development of appropriate models, based on an in-depth understanding of the wash-off process, is essential to accurately estimating pollutant loads transported by stormwater, thereby minimizing environmental contamination. To this end, we developed an innovative rainfall simulator, which simulated an intense rainfall (120 mm/h) and permitted the acquisition of runoff samples as well as the in situ monitoring of continuous flow and turbidity dynamics. Relationships between deposited sediments and total suspended solids in simulated runoff were thus investigated on two different types of surfaces within the Paris region in terms of loads and particle size distribution. Results demonstrate the occurrence of first flush phenomenon on the sidewalks even under constant flow. Results also show that the highest fraction conveyed by runoff consisted of fine (< 16 μm) and medium-sized (< 100 μm) particles, whose detachment was more favorable from smooth surfaces than from rougher ones. In terms of stormwater quality modelling, results suggest that the integration of a wash-off fraction based on both particle size and rainfall intensity could be an entrance for a better prediction of stormwater pollution. [ABSTRACT FROM AUTHOR]

Halloysite nanotubes (HNT) and polylactide (PLA) were dry-mixed and melt-compounded to produce PLA nanocomposites with up to 12 wt-% nanofiller. The key characteristics of PLA-HNT nanocomposites were evidenced as follows: good nanofiller distribution and dispersion assessed by transmission electron microscopy (TEM), high tensile strength (values above 60 MPa) and mechanical rigidity, with Young's modulus increasing with HNT loading. The impact resistance of PLA is not decreased, whereas as it was revealed under dynamic solicitation (DMA), addition of HNT led to the notable enhancement of storage modulus. The degradation by photooxidation of PLA-HNT nanocomposites was compared to pristine PLA. The chemical modifications were evidenced by infrared (IR) and UV–visible spectroscopy, whereas from IR absorbance at 1845 cm -1 was determined the rate of degradation. Like in the case of other natural clays, HNT had a dramatic pro-degradant effect on the photooxidation of PLA, ascribed to the presence of chromophoric groups and/or iron impurities. Indeed, by comparing nanofillers of different purity, the photooxidation of PLA was found significantly reduced using HNT having about four times lower traces of iron. The choice of HNT of adequate purity or/and its purification is looked as powerful method to reduce the photooxidative degradation of PLA nanocomposites. [ABSTRACT FROM AUTHOR]

Background: Fluorochrome staining is among the most widely used techniques to study growth dynamics of echinoderms. However, it fails to detect fine-scale increments because produced marks are commonly diffusely distributed within the skeleton. In this paper we investigated the potential of trace element (manganese) labeling and subsequent cathodoluminescence (CL) imaging in fine-scale growth studies of echinoderms. Results: Three species of sea urchins (Paracentrotus lividus, Echinometra sp. and Prionocidaris baculosa) were incubated for different periods of time in seawater enriched in different Mn2+ concentrations (1 mg/L; 3 mg/L; 61.6 mg/L). Labeling with low Mn2+ concentrations (at 1 mg/L and 3 mg/L) had no effect on behavior, growth and survival of sea urchins in contrast to the high Mn2+ dosage (at 61.6 mg/L) that resulted in lack of skeleton growth. Under CL, manganese produced clearly visible luminescent growth fronts in these specimens (observed in sectioned skeletal parts), which allowed for a determination of the average extension rates and provided direct insights into the morphogenesis of different types of ossicles. The three species tend to follow the same patterns of growth. Spine growth starts with the formation of microspines which are simultaneously becoming reinforced by addition of thickening layers. Spine septa develop via deposition of porous stereom that is rapidly (within less than 2 days) filled by secondary calcite. Development of the inner cortex in cidaroids begins with the formation of microspines which grow at ~3.5 μm/day. Later on, deposition of the outer polycrystalline cortex with spinules and protuberances proceeds at ~12 μm/day. The growth of tooth can be rapid (up to ~1.8 mm/day) and starts with the formation of primary plates (pp) in plumula. Later on, during the further growth of pp in aboral and lateral directions, secondary extensions develop inside (in chronological order: lamellae, needles, secondary plate, prisms and carinar processes), which are increasingly being solidified towards the incisal end. Interradial growth in the ambital interambulacral test plates exceeds meridional growth and inner thickening. Conclusions: Mn2+ labeling coupled with CL imaging is a promising, low-cost and easily applicable method to study growth dynamics of echinoderms at the micro-length scale. The method allowed us to evaluate and refine models of echinoid skeleton morphogenesis. [ABSTRACT FROM AUTHOR]

Polypropylene (PP) is one of the most versatile polymers widely used in packaging, textiles, automotive, and electrical applications. Melt blending of PP with micro- and/or nano-fillers is a common approach for obtaining specific end-use characteristics and major enhancements of properties. The study aims to develop high-performance composites by filling PP with CaSO4 β-anhydrite II (AII) issued from natural gypsum. The effects of the addition of up to 40 wt.% AII into PP matrix have been deeply evaluated in terms of morphology, mechanical and thermal properties. The PP–AII composites (without any modifier) as produced with internal mixers showed enhanced thermal stability and stiffness. At high filler loadings (40% AII), there was a significant decrease in tensile strength and impact resistance; therefore, custom formulations with special reactive modifiers/compatibilizers (PP functionalized/grafted with maleic anhydride (PP-g-MA) and zinc diacrylate (ZnDA)) were developed. The study revealed that the addition of only 2% ZnDA (able to induce ionomeric character) leads to PP–AII composites characterized by improved kinetics of crystallization, remarkable thermal stability, and enhanced mechanical properties, i.e., high tensile strength, rigidity, and even rise in impact resistance. The formation of Zn ionomers and dynamic ionic crosslinks, finer dispersion of AII microparticles, and better compatibility within the polyolefinic matrix allow us to explain the recorded increase in properties. Interestingly, the PP–AII composites also exhibited significant improvements in the elastic behavior under dynamic mechanical stress and of the heat deflection temperature (HDT), thus paving the way for engineering applications. Larger experimental trials have been conducted to produce the most promising composite materials by reactive extrusion (REx) on twin-screw extruders, while evaluating their performances through various methods of analysis and processing. [ABSTRACT FROM AUTHOR]

Nowadays, due to their natural availability, renewability, biodegradability, nontoxicity, light weight and relatively low cost, natural fibers, especially lignocellulosic fibers, present attractive potential to substitute non-eco-friendly synthetic fibers. In this study, Ziziphus jujuba fibers were used, thanks to their low lignin content, as an alternative of renewable resource for the production of cellulosic fibers with suitable characteristics and minimal time and energy consumption. In fact, due to their valuable chemical composition, it was possible to remove the amorphous fractions and impurities from the fiber surface by applying ultrasounds coupled with alkaline treatment (80 °C, 5 wt.% NaOH), followed by a bleaching step. The efficient dissolution of the noncellulosic compounds was confirmed by Fourier Transform Infrared Spectroscopy (FTIR). The resulted increase in the crystallinity index (from 35.7% to 57.5%), occurred without impacting the crystalline structure of the fibers. The morphological analysis of the fibers evidences the higher surface area of the obtained fibers. Based on the obtained results, Ziziphus jujuba fibers were found to present a suitable sustainable source for the production of cellulosic fibers. [ABSTRACT FROM AUTHOR]

Echinoderms are considered particularly sensitive to ocean acidification (OA) as their skeleton is made of high-magnesium calcite, one of the most soluble forms of calcium carbonate. Recent studies have investigated effects of OA on the skeleton of "classical" sea urchins (euechinoids), but the impact of etching on skeleton mechanical properties is almost unknown. Furthermore, the integrity of the skeleton of cidaroids has never been assessed, although their extracellular fluid is under-saturated with respect to their skeleton, and the skeleton of their primary spines is in direct contact with seawater. In this study, we compared the dissolution of test plates and spines as well as the spine mechanical properties (two-points bending tests) in a cidaroid (Eucidaris tribuloides) and a euechinoid (Tripneustes ventricosus) submitted to a 5 week acidification experiment (pHT of 8.1, 7.7, and 7.4). Test plates of both species were not affected by dissolution. The spines of E. tribuloides showed no mechanical effects at pHSW-T 7.4 despite having traces of corrosion on secondary spines. On the contrary, spines of the T. ventricosus were significantly etched at both pHSW-T 7.7 and 7.4 and their fracture force reduced by 16 to 35%, respectively. This increased brittleness is probably of little significance with regards to predation protection but has consequences in terms of energy allocation. [ABSTRACT FROM AUTHOR]

Coating Nitinol (NiTi) surfaces with a polymer layer has become very appealing in the past few years owing to its increased attraction in the biomedical field. Although its intrinsic properties helped ensure its popularity, its extensive implementation is still hampered by its nickel inclusion, making it sensitive to pitting corrosion and therefore leading to the release of carcinogenic Ni2+ ions. Among all recent ways to modify NiTi surfaces, elaboration of self-assembled monolayers is of great interest as their high order confers a reinforcement of the metal surface corrosion resistance and brings new functionalities to the metal for postmodification processes. In this work, we compare the electroassisted and thermally assisted self-assembling of 11-(2-bromoisobutyrate)-undecyl-1-phosphonic acid (BUPA) to the classical immersion process on NiTi surfaces initially submitted to a hydrothermal treatment. Among all tested conditions, the electroassisted grafting of BUPA at room temperature appears to be the most promising alternative, as it allows grafting in very short times (5-10 min), thus preventing its degradation. The thus-formed layer has been proven to be sufficient to enable the surface-initiated atom transfer radical polymerization (SI-ATRP) of 2-(dimethylamino)ethyl methacrylate. [ABSTRACT FROM AUTHOR]

Shape-memory polymers (SMPs) as stimuli-responsive shape-changing polymers are of great interest for fundamental research and technological innovation. In this contribution, a brief review of the recent trends in the field of SMPs is presented with particular focus on their structure, shape-memory effects and working mechanism. A special attention is paid to smart multi-responsive and multi-functional SMP materials as emerging technological class. They are mainly described as shape-memory nanocomposites (SMCs) where the incorporation of functional (in)organic nanofillers in the SMP matrices is purposely carried out. Potential applications of the SMCs-based materials as medical and biomimetic devices, self-healing systems, self-deployable structures, actuators, sensors, etc. or their direct implementation in the industry are finally outlined. [ABSTRACT FROM AUTHOR]

Concerning new polylactide (PLA) applications, the study investigates the toughening of PLA–CaSO4 β-anhydrite II (AII) composites with bio-sourced tributyl citrate (TBC). The effects of 5–20 wt.% TBC were evaluated in terms of morphology, mechanical and thermal properties, focusing on the enhancement of PLA crystallization and modification of glass transition temperature (Tg). Due to the strong plasticizing effects of TBC (even at 10%), the plasticized composites are characterized by significant decrease of Tg and rigidity, increase of ductility and impact resistance. Correlated with the amounts of plasticizer, a dramatic drop in melt viscosity is also revealed. Therefore, for applications requiring increased viscosity and enhanced melt strength (extrusion, thermoforming), the reactive modification, with up to 1% epoxy functional styrene–acrylic oligomers, was explored to enhance their rheology. Moreover, larger quantities of products were obtained by reactive extrusion (REX) and characterized to evidence their lower stiffness, enhanced ductility, and toughness. In current prospects, selected samples were tested for the extrusion of tubes (straws) and films. The migration of plasticizer was not noted (at 10% TBC), whereas the mechanical and thermal characterizations of films after two years of aging evidenced a surprising preservation of properties. [ABSTRACT FROM AUTHOR]

Biobased and biocompatible polymers, such as polyhydroxyalkanoates (PHAs), are of great interest for a large range of applications in the spirit of green chemistry and upcoming reuse and recycling strategies. Polyhydroxybutyrate (PHB), as a promising biocompatible polymer belonging to PHAs, is subject to increased research concern regarding the high degree of crystallinity and brittle behavior of the resulting materials. Therefore, the improvement of PHB's physico-mechanical properties aims to decrease the Young's modulus values and to increase the ductility of samples. Here, we proposed an ambitious approach to develop melt-processed materials, while combining PHB characteristics with the ductile properties of poly(ε-caprolactone) (PCL). In order to compatibilize the poorly miscible PHB/PCL blends, dicumyl peroxide (DCP) was used as a free-radical promotor of polyester interchain reactions via the reaction extrusion process. The resulting PHB/PCL-DCP materials revealed a slight increase in the elongation at break, and significant improvement in the impact resistance (7.2 kJ.m−2) as compared to PHB. Additional decrease in the Young's modulus values was achieved by incorporating low molecular polyethylene glycol (PEG) as a plasticizer, leading to an important improvement in the impact resistance (15 kJ.m−2). Successful 3D printing using fused deposition melting (FDM) of the resulting PHB/PCL-based blends for the design of a prosthetic finger demonstrated the great potential of the proposed approach for the development of next-generation biomaterials. [ABSTRACT FROM AUTHOR]

Aim: In the context of intensifying threats of climate change on marine communities, ecological models are widely applied for conservation strategies, though polar studies remain scarce given the limited number of datasets available. Correlative (e.g. species distribution models, SDM) and mechanistic (e.g. dynamic energy budget models, DEB) modelling approaches are usually used independently in studies. Using both approaches in integrative, hybrid models could help to better estimate the species potential ecological niche, as mechanistic and correlative models complement each other very well, giving more insights into species potential response to fast‐changing environmental conditions. Location: The study focusses on the Baie du Morbihan, a silled basin located in the east of the Kerguelen Islands (sub‐Antarctic). Methods: A hybrid, correlative‐mechanistic model was implemented to predict the response of the endemic sea urchin Abatus cordatus (Verrill, 1876). We compared the performances of classic and integrated approaches to predict A. cordatus distribution according to two dates representing seasonal contrasts. Two integrated approaches were studied and performed by either (1) including the spatial projection of the DEB model as an input layer inside the SDM ('integrated SDM‐DEB') or (2) using a Bayesian procedure to use DEB model outputs as priors of the SDM ('integrated Bayesian' approach). Results: Results show higher performances of 'integrated Bayesian' approaches to evaluate A. cordatus potential ecological niche compared with 'classic' and 'integrated SDM‐DEB' methods. The influence of environmental conditions on model predictions is further captured with these Bayesian procedures and better highlights the environmental influence on the species‐predicted distribution. Model performance is good for the different simulations, and uncertainty in predictions is well‐highlighted. Main conclusions: The good performances of 'integrated Bayesian' approaches to estimate species potential ecological niche opens perspectives for future applications to a broad panel of natural examples, noteworthy for decision‐making and conservation management purposes. [ABSTRACT FROM AUTHOR]

The development of flame retardant polymer materials has two roots, one in materials design, and the other in materials processing. Over recent decades, different types and classes of flame retardant polymer materials have been commercialized to meet safety requirements in the construction, automotive, and coatings industries. In the vast majority of cases, the design and fabrication of new materials presenting low fire hazards could be obtained through the incorporation of one, two or more flame retardants with similar or different natures into polymers. Nevertheless, the presence of these new phases, often used at high loading levels, usually impact the polymer's other functional properties, such as mechanical, aging and transparency. These limitations could be partially or totally overcome using reactive extrusion, which is a promising process for developing new polymers or modifying the chemical structure of existing ones. Amongst other possibilities, reactive extrusion can be used for enhancing the fire behavior of existing polymers or for the synthesis of new ones presenting inherent flame retardant properties. In recent years, several new flame retardant polymers have been developed by reactive extrusion, but these developments have not been systematically described with regard to their technical circumstances, properties, and commercial potential. This short review attempts to overview and classify the available reports on the development of flame-retardant polymeric materials through reactive extrusion processes. [ABSTRACT FROM AUTHOR]

Echinoids are common members of Antarctic zoobenthos, and different groups can show important trophic diversity. As part of the ANT-XXIX/3 cruise of RV Polarstern, trophic plasticity of sea urchins was studied in three neighbouring regions (Drake Passage, Bransfield Strait and Weddell Sea) featuring several depth-related habitats offering different trophic environments to benthic consumers. Three families with contrasting feeding habits (Cidaridae, Echinidae and Schizasteridae) were studied. Gut content examination and stable isotopes ratios of C and N suggest that each of the studied families showed a different response to variation in environmental and food conditions. Schizasteridae trophic plasticity was low, and these sea urchins were bulk sediment feeders relying on sediment-associated organic matter in all regions and/or depth-related habitats. Cidaridae consumed the most animal-derived material. Their diet varied according to the considered area, as sea urchins from Bransfield Strait relied mostly on living and/or dead animal material, while specimens from Weddell Sea fed on a mixture of dead animal material and other detritus. Echinidae also showed important trophic plasticity. They fed on various detrital items in Bransfield Strait, and selectivity of ingested material varied across depth-related habitats. In Weddell Sea, stable isotopes revealed that they mostly relied on highly C-enriched food items, presumably microbially reworked benthic detritus. The differences in adaptive strategies could lead to family-specific responses of Antarctic echinoids to environmental and food-related changes. [ABSTRACT FROM AUTHOR]

A facile and rapid method to synthesize graphene/layered double hydroxide (LDH) nanohybrids by a microwave technique is demonstrated. The synthesis procedure involves hydrothermal crystallization of Zn-Al LDH at the same time in situ reduction of graphene oxide (GO) to graphene. The microstructure, composition, and morphology of the resulting graphene/LDH nanohybrids were characterized. The results confirmed the formation of nanohybrids and the reduction of graphene oxide. The growth mechanism of LDH and in situ reduction of GO were discussed. The LDH sheet growth was found to prevent the scrolling of graphene layers in resulting hybrids. The electrochemical properties exhibit superior performance for graphene/Zn-Al LDH hybrids over pristine graphene. The present approach may open a strategy in hybridizing graphene with multimetallic nano-oxides and hydroxides using microwave method. [ABSTRACT FROM AUTHOR]

The melt–mixing of polylactide (PLA) with micro- and/or nanofillers is a key method used to obtain specific end-use characteristics and improvements of properties. So-called "insoluble" CaSO4 (CS) β-anhydrite II (AII) is a mineral filler recently considered for the industry of polymer composites. First, the study proves that AII made from natural gypsum by a specifically thermal treatment is highly stable compared to other CS forms. Then, PLAs of different isomer purity and molecular weights (for injection molding (IM) and extrusion), have been used to produce "green" composites filled with 20–40 wt.% AII. The composites show good thermal and mechanical properties, accounting for the excellent filler dispersion and stability. The stiffness of composites increases with the amount of filler, whereas their tensile strength is found to be dependent on PLA molecular weights. Interestingly, the impact resistance is improved by adding 20% AII into all investigated PLAs. Due to advanced kinetics of crystallization ascribed to the effects of AII and use of a PLA grade of high L-lactic acid isomer purity, the composites show after IM an impressive degree of crystallinity (DC), i.e., as high as 50%, while their Vicat softening temperature is remarkably increased to 160 °C, which are thermal properties of great interest for applications requiring elevated rigidity and heat resistance. [ABSTRACT FROM AUTHOR]

Catalystsare commonly used in polymer synthesis. Traditionally,catalysts used to be metallic compounds but some studies have pointedout their toxicity for human health and environment, and the removalof metal impurities from synthetic polymer is quite expensive. Organocatalystshave been intensively synthesized and are now widely used in ring-openingpolymerization (ROP) reactions to address these issues. However, formost of them, there is not any evidence of their safety. The presentstudy attempts to assess whether well-established organo-based ROPcatalysts used for the preparation of FDA-approved polyesters maypresent a certain level of cytotoxicity. In vitro toxicity is evaluatedusing a methyl-thiazol-tetrazoliumcytotoxicity assay on two cell models (FHs74Int and HepaRG). Amongthe investigated organocatalysts, only functionalized thiourea showsan important cytotoxicity on both cell models. 4-Dimethylaminopyridine(DMAP), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), and meta-(trimethylammonio)phenolate betaine (m-BE) showcytotoxicity against HepaRG cell line only at a high concentration. [ABSTRACT FROM AUTHOR]

Background: Physiologic narrowing of the central airway occurs during expiration. Conditions in which this narrowing becomes excessive are referred to as expiratory central airway collapse. Expiratory central airway collapse is usually managed by applying positive pressure to the airways, which acts as a pneumatic stent. The particularity of the case reported here included the patient's left main bronchus being permeable during spontaneous breathing but collapsing during general anaesthesia, despite positive pressure ventilation and positive end-expiratory pressure. Case presentation: We present the case of a 55-year-old man admitted for the placement of a ureteral JJ stent. Rapid desaturation occurred a few minutes after the onset of anaesthesia. After excluding the most common causes of desaturation, fibreoptic bronchoscopy was performed through the tracheal tube and revealed complete collapse of the left main bronchus. The collapse persisted despite the application of positive end-expiratory pressure and several recruitment manoeuvres. After recovery of spontaneous ventilation, the collapse was lifted, and saturation increased back to normal levels. No evidence of extrinsic compression was found on chest X-rays or computed tomography scans. Conclusion: Cases of unknown expiratory central airway collapse reported in the literature were usually managed with positive pressure ventilation. This approach has been unsuccessful in the case described herein. Our hypothesis is that mechanical bending of the left main bronchus occurred due to loss of the patient's natural position and thoracic muscle tone under general anaesthesia with neuromuscular blockade. When possible, spontaneous ventilation should be maintained in patients with known or suspected ECAC. [ABSTRACT FROM AUTHOR]

New synthetic strategies for molecularly imprinted polymers (MIPs) were developed to mimic the flexibility and mobility exhibited by receptor/enzyme binding pockets. The MIPs were prepared by bulk polymerization with quercetin as template molecule, acrylamide as functional monomer, ethylene glycol dimethacrylate as cross-linker, and THF as porogen. The innovative grafting of specific oligoethylene glycol units onto the imprinted cavities allowed MIPs to be obtained that exhibit extended selectivity towards template analogues. This synthetic strategy gives promising perspectives for the design of molecular recognition of molecules based on a congruent pharmacophore, which should be of interest for drug development. [ABSTRACT FROM AUTHOR]

Abstract: Polymer blends and alloys represent an interesting approach to implement bio-based poly(l-lactic acid) (PLLA) into high-value applications. Here, a re-evaluation of the miscibility extent between both biobased PLLA and petro-based poly(methyl methacrylate) (PMMA) is proposed in order to tune morphologies and properties of resulting blends upon either a solvent-casting method or a twin-screw extrusion. The solvent-casting process proved only able to produce immiscible blends with matrix–droplet or co-continuous morphologies in function of the blend composition and the immiscibility–miscibility transition is not observed for temperature lower than 250 °C. When melt-processed via extrusion technique, only miscible PLLA/PMMA blends were recovered all over the composition range, as observed by a single glass transition and a single α-relaxation transition at intermediate temperature between pure PLLA and pure PMMA as determined by DSC and DMTA, respectively. Miscibility was also observed at low shear rate with a phase-reversibility, demonstrating the absence of any reactions between PMMA and PLLA phases and the existence of a shear-sensitive clarity point. Homogenous and transparent PLLA/PMMA blends were easily produced with tunable thermomechanical and barrier properties against the blend composition. Glass transition temperature, α-relaxation temperature, thermal resistance and gas permeability were accurately controlled by the PMMA content, while maintaining impact strength and storage modulus in the same range than PLLA itself. [Copyright &y& Elsevier]