Interplay between a hydrodynamic instability and a phase transition: the Faraday instability in dispersions of rodlike colloids

Strong effects of the Faraday instability on suspensions of rodlike colloidal particles are reported through measurements of the critical acceleration and of the surface wave amplitude. We show that the transition to parametrically excited surface waves displays discontinuous and hysteretic features. This subcritical behaviour is attributed to the shear-thinning properties of our colloidal suspensions thanks to a phenomenological model based on rheological data under large amplitude oscillatory shear. Birefringence measurements provide direct evidence that Faraday waves induce local nematic ordering of the rodlike colloids. While local alignment simply follows the surface oscillations for dilute, isotropic suspensions, permanent nematic patches are generated by surface waves in samples close to the isotropic-to-nematic transition and above the transition large domains align in the flow direction. This strong coupling between the fluid microstructure and a hydrodynamic instability is confirmed by numerical computations based on the microstructural response of rodlike viruses in shear flow.Comment: 8 pages, 6 figure

Signature of elasticity in the Faraday instability

We investigate the onset of the Faraday instability in a vertically vibrated wormlike micelle solution. In this strongly viscoelastic fluid, the critical acceleration and wavenumber are shown to present oscillations as a function of driving frequency and fluid height. This effect, unseen neither in simple fluids nor in previous experiments on polymeric fluids, is interpreted in terms of standing elastic waves between the disturbed surface and the container bottom. It is shown that the model of S. Kumar [Phys. Rev. E, {\bf 65}, 026305 (2002)] for a viscoelastic fluid accounts qualitatively for our experimental observations. Explanations for quantitative discrepancies are proposed, such as the influence of the nonlinear rheological behaviour of this complex fluid.Comment: 4 pages, 4 figure

Taking stock of Roma health policies in Spain: lessons for health governance

Roma health inequities are a wicked problem. Despite concerted efforts to reduce them under the Decade of Roma Inclusion initiative, the health gap between Roma and non-Roma populations in Europe persists. To address this problem, the European Commission devised the National Roma Integration Strategies (NRIS). This paper provides a critical assessment of the implementation of the NRIS’ health strand (NRIS-H) in Spain and proposes an evaluation tool to monitor Roma health policies – the Roma Health Integration Policy Index (RHIPEX). It also makes recommendations to promote Roma health governance. To achieve these goals, four community forums, 33 stakeholder interviews and a scoping review were conducted. Results show that the NRIS-H implementation is hindered by lack of political commitment and poor resource allocation. This has a negative impact on Roma’s entitlement to healthcare and on their participation in decision-making processes, jeopardising the elimination of the barriers that undermine their access to healthcare and potentially contributing to reproduce inequalities. These unintended effects point out the need to rethink Roma health governance by strengthening intersectional and intersectoral policies, enabling transformative Roma participation in policymaking and guaranteeing shared socio-political responsibility and accountability.info:eu-repo/semantics/acceptedVersio

Superposition rheology of shear-banding wormlike micelles

Wormlike micelle solutions are submitted to small-amplitude oscillatory shear superimposed to steady shear in the shear banding regime. By imposing a shear oscillation, the interface between high- and low-shear regions oscillates in time. A two-fluid semi-phenomenological model is proposed for superposition rheology in the shear banding regime, which allows us to extract a characteristic velocity for the interface dynamics from experiments involving only a standard rheometer. Estimates of the stress diffusion coefficient ${\cal D}$ can also be inferred from such superposition experiments. The validity of our model is confirmed by directly recording the interface displacement using ultrasonic velocimetry.Comment: 24 pages, 13 figure

Fusión hueso grande-trapezoide: caso clínico

La sinostosis de los huesos del carpo puede ser una anomalía congénita o adquirida que puede presentarse tanto como un cuadro aislado, como parte de un síndrome de malformaciones congénitas, ó, en el seno de enfermedades metabólicas. La mayor parte de las veces es un hallazgo radiológico casual. Presentamos el caso de una fusión entre hueso grande y trapezoide. La fusión entre hueso grande y trapezoide se ha descrito en muy pocos casos.Synostosis of carpal bones is a congenital or acquired anomaly seen as an isolated entity or as part of a syndrome of congenital malformations or metabolic disorders. Almost always it is an incidental radiological finding. A case of fused capitate and trapezoid is reported

Expression Profiles and DNA-Binding Affinity of Five ERF Genes in Bunches of Vitis vinifera cv. Cardinal Treated with High Levels of CO2 at Low Temperature

Ethylene response factors (ERFs) play an important role in plants by regulating defense response through interaction with various stress pathways. After harvest, table grapes (Vitis vinifera L.) are subject to a range of problems associated with postharvest storage at 0°C, such as fungal attack, water loss and rachis browning. The application of a 3-day high CO2 treatment maintained fruit quality and activated the induction of transcription factors belonging to different families such as ERF. In this paper, we have isolated five VviERFs from table grapes cv. Cardinal, whose deduced amino acid sequence contained the conserved apetalous (AP2)/ERF domain. The phylogeny and putative conserved motifs in VviERFs were analyzed and compared with those previously reported in Vitis. VviERFs-c gene expression was studied by quantitative real-time RT-PCR in the different tissues of bunches stored at low temperature and treated with high levels of CO2. The results showed that in most of the tissues analyzed, VviERFs-c gene expression was induced by the storage under normal atmosphere although the application of high levels of CO2 caused a greater increase in the VviERFs-c transcript accumulation. The promoter regions of two PRs (pathogenesis related proteins), Vcchit1b and Vcgns1, were obtained and the in silico analysis revealed the presence of a cis-acting ethylene response element (GCC box). In addition, expression of these two PR genes was analyzed in the pulp and rachis of CO2-treated and non-treated table grapes stored at 0°C and results showed significant correlations with VviERF2-c and VviERF6L7-c gene expression in rachis, and between VviERF11-c and Vcchit1b in pulp. Finally by using electro mobility shift assays, we denoted differences in binding of VviERFs to the GCC sequences present in the promoters of both PRs, with VviERF6L7-c being the only member which did not bind to any tested probe. Overall, our results suggest that the beneficial effect of high CO2 treatment maintaining table grape quality seems to be mediated by the regulation of ERFs and in particular VviERF2-c might play an important role by modulating the expression of PR genes.This work was supported by the European Union under the 7th Framework Programme FP7-PEOPLE-2012-CIG no. 321694 and by CICYT projects AGL2011-26742 and AGL2014-53081-R. IR and MV-H were supported by a postdoctoral Juan de la Cierva contract from the MICINN and a predoctoral contract from the MEC, respectively.USD 2,116.5 APC fee funded by the EC FP7 Post-Grant Open Access PilotPeer reviewe

Screening, characterization and the novo sequencing of broccoli plasma membrane aquaporins by high resolution mass spectrometry

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A proteomic approach to study the low temperature stress induction in bell pepper fruit

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