Questioning the relationship between the χ\chi4 susceptibility and the dynamical correlation length in a glass former

Clusters of fast and slow correlated particles, identified as dynamical heterogeneities (DHs), con-stitute a central aspect of glassy dynamics. A key ingredient of the glass transition scenario is asignificant increase of the cluster size $\xi$4 as the transition is approached. In need of easy-to-computetools to measure $\xi$4 , the dynamical susceptibility $\chi$4 was introduced recently, and used in various ex-perimental works to probe DHs. Here, we investigate DHs in dense microgel suspensions using imagecorrelation analysis, and compute both $\chi$4 and the four-point correlation function G4 . The spatialdecrease of G4 provides a direct access to $\xi$4 , which is found to grow significantly with increasingvolume fraction. However, this increase is not captured by $\chi$4 . We show that the assumptions thatvalidate the connection between $\chi$4 and $\xi$4 are not fulfilled in our experiments.Comment: The present version was accepted for publication in Soft Matter (http://pubs.rsc.org/en/journals/journalissues/sm

Non-linear oscillatory rheological properties of a generic continuum foam model: comparison with experiments and shear-banding predictions

The occurence of shear bands in a complex fluid is generally understood as resulting from a structural evolution of the material under shear, which leads (from a theoretical perspective) to a non-monotonic stationnary flow curve related to the coexistence of different states of the material under shear. In this paper we present a scenario for shear-banding in a particular class of complex fluids, namely foams and concentrated emulsions, which differs from other scenarii in two important ways. First, the appearance of shear bands is shown to be possible both without any intrinsic physical evolution of the material (e.g. via a parameter coupled to the flow such as concentration or entanglements) and without any finite critical shear rate below which the flow does not remain stationary and homogeneous. Secondly, the appearance of shear bands depends on the initial conditions, i.e., the preparation of the material. In other words, it is history dependent. This behaviour relies on the tensorial character of the underlying model (2D or 3D) and is triggered by an initially inhomogeneous strain distribution in the material. The shear rate displays a discontinuity at the band boundary, whose amplitude is history dependent and thus depends on the sample preparation.Comment: 18 pages - 17 figure

B Mixing

The neutral $B$ mesons, $B^0$ and $B_s$, can oscillate between their particle and antiparticle states owing to flavor-changing weak interactions. In recent years, techniques to detect these oscillations as a function of the meson's decay time have been developed. In this article the physics of flavor oscillations is reviewed and theoretical predictions are summarized. The many observations that demonstrate the time-dependence of B^0-\B0bar oscillations are presented along with a combined measurement of its frequency, $\delta m_d$. The attempts to measure the $B_s$ oscillation frequency, both directly and indirectly, are then summarized. Finally, values for the CKM elements $|V_{td}|$ and $|V_{ts}/V_{td}|$ are extracted

AntagomiR directed against miR-20a restores functional BMPR2 signalling and prevents vascular remodelling in hypoxia-induced pulmonary hypertension

Aims Dysregulation of the bone morphogenetic protein receptor type 2 (BMPR2) is a hallmark feature that has been described in several forms of pulmonary hypertension. We recently identified the microRNA miR-20a within a highly conserved pathway as a regulator of the expression of BMPR2. To address the pathophysiological relevance of this pathway in vivo, we employed antagomiR-20a and investigated whether specific inhibition of miR-20a could restore functional levels of BMPR2 and, in turn, might prevent pulmonary arterial vascular remodelling. Methods and results For specific inhibition of miR-20a, cholesterol-modified RNA oligonucleotides (antagomiR-20a) were synthesized. The experiments in mice were performed by using the hypoxia-induced mouse model for pulmonary hypertension and animal tissues were analysed for right ventricular hypertrophy and pulmonary arterial vascular remodelling. Treatment with antagomiR-20a enhanced the expression levels of BMPR2 in lung tissues; moreover, antagomiR-20a significantly reduced wall thickness and luminal occlusion of small pulmonary arteries and reduced right ventricular hypertrophy. To assess BMPR2 signalling and proliferation, we performed in vitro experiments with human pulmonary arterial smooth muscle cells (HPASMCs). Transfection of HPASMCs with antagomiR-20a resulted in activation of downstream targets of BMPR2 showing increased activation of Id-1 and Id-2. Proliferation of HPASMCs was found to be reduced upon transfection with antagomiR-20a. Conclusion This is the first report showing that miR-20a can be specifically targeted in an in vivo model for pulmonary hypertension. Our data emphasize that treatment with antagomiR-20a restores functional levels of BMPR2 in pulmonary arteries and prevents the development of vascular remodellin

An elasto-visco-plastic model for immortal foams or emulsions

A variety of complex fluids consist in soft, round objects (foams, emulsions, assemblies of copolymer micelles or of multilamellar vesicles -- also known as onions). Their dense packing induces a slight deviation from their prefered circular or spherical shape. As a frustrated assembly of interacting bodies, such a material evolves from one conformation to another through a succession of discrete, topological events driven by finite external forces. As a result, the material exhibits a finite yield threshold. The individual objects usually evolve spontaneously (colloidal diffusion, object coalescence, molecular diffusion), and the material properties under low or vanishing stress may alter with time, a phenomenon known as aging. We neglect such effects to address the simpler behaviour of (uncommon) immortal fluids: we construct a minimal, fully tensorial, rheological model, equivalent to the (scalar) Bingham model. Importantly, the model consistently describes the ability of such soft materials to deform substantially in the elastic regime (be it compressible or not) before they undergo (incompressible) plastic creep -- or viscous flow under even higher stresses.Comment: 69 pages, 29 figure

Suspended particulate matter and turbidity

Suspended Particulate Matter (SPM) carries pollutants, shades light and so inhibits primary production, and embodies particulate organic matter forming part of the marine ecosystem. It is highly variable according to depth and physical processes in the area (i.e. tide and current regimes and wind). Traditional assessment methodologies are still used successfully, but various optical techniques are increasingly being used, for particle size as well as weight of SPM. This has increased understanding of the dynamics and processes associated with SPM in shelf seas, especially tidal stirring of sediments. Remote sensing measurements of ocean colour provide time series for studying variability of suspended material, phytoplankton pigments and coloured dissolved material. Trends in SPM concentrations and therefore turbidity for UK waters show no significant change over the last five years. Remote sensing measurements are still hampered by weather (especially cloud) and by a lack of understanding of optics in (turbid) coastal and shelf waters. For improved shoreline management plans there is a need for more quantitative information, especially on shoreline processes, wave interactions (inshore wave climate) and water flow along coasts. There is much interest for Integrated Coastal Zone Management

Predicting Brand Awareness of Corporate Sponsor Activation in Intercollegiate Athletics

Brand awareness is cited as the main objective of companies engaging in sponsorship agreements with collegiate athletic departments and is often used as a measurement of sponsorship effectiveness. The field of sports sponsorship has evolved from static signage advertisements and one-way messaging to include on-site displays, digital and social media, and interactive technology. Multi-media rights holders are expected to spend over $25.5 billion in rights fees to colleges and universities over the next 15 years (imgcollege.com, 2017). Brands are vying for engagement and convergence with a team and the 190 million college sports fans they reach. In 2015, Nissan signed a historic national sponsorship contract with over 100 collegiate athletic departments (Forbes, 2015). The all encompassing contract consists largely of interactive stadium displays, on-site technology, enter-to-win contests, and in-stadium LED signage. This style of sponsorship is becoming common across all levels of sport, and the effectiveness of such sponsorships in achieving consumer brand awareness should be examined. Since companies must decide whether to allocate their marketing budget for sport sponsorships, it is necessary they are aware which assets will be the most effective in achieving brand awareness. The purpose of this study was to predict the brand awareness of corporate sponsorship activation through the measurement of consumer recognition rates of athletic department sponsors at an intercollegiate football game. Corporate sponsors, athletic departments, brand marketers, and multi-media rights holders will benefit from the research in this area.Master of Art