Electrical properties of BaTiO3 based ferroelectric capacitors grown on oxide sacrificial layers for micro-cantilevers applications

An investigation of all oxides ferroelectric capacitors based on $SrRuO_3/BaTiO_3/SrRuO_3$ multi-layers grown on sacrificial oxide layers of $YBa_2Cu_3O_7$\ud and MgO for Micro-Electo-Mechanical systems applications is reported. By insertion of additional MgO or $SrTiO_3$ buffer layers the orientation of the $BaTiO_3$ film can be controlled allowing the fabrication of suspended cantilevers using the 31 and the 33 piezoelectric modes. The electrical properties of $SrRuO_3/BaTiO_3/SrRuO_3$ capacitors are changed compared with those grown directly on a single crystal substrate by the introduction of sacrificial layers. Circuit modeling of the electrical characteristics of these devices shows that a reduction of the deposition pressure for $BaTiO_3$ produces a decrease of the parasitic shunting conductance (modeled with a resistor in parallel to the capacitance of the device) which reduces the resistive loss present in the $BaTiO_3$ film. However for extremely low deposition pressure the quality of the polarization hysteresis loops is compromised.\ud Particulates present on the surface of the $YBa_2Cu_3O_7$increases the parasitic conductance at low frequency in the capacitive structure grown on this sacrificial layer. Good electrical properties are obtained for the capacitive structures grown on top of the MgO sacrificial layers at pressures equal or lower than 8 Pa.\u

The multifunctional NS1 protein of influenza A viruses

The non-structural (NS1) protein of influenza A viruses is a non-essential virulence factor that has multiple accessory functions during viral infection. In recent years, the major role ascribed to NS1 has been its inhibition of host immune responses, especially the limitation of both interferon (IFN) production and the antiviral effects of IFN-induced proteins, such as dsRNA-dependent protein kinase R (PKR) and 2'5'-oligoadenylate synthetase (OAS)/RNase L. However, it is clear that NS1 also acts directly to modulate other important aspects of the virus replication cycle, including viral RNA replication, viral protein synthesis, and general host-cell physiology. Here, we review the current literature on this remarkably multifunctional viral protein. In the first part of this article, we summarize the basic biochemistry of NS1, in particular its synthesis, structure, and intracellular localization. We then discuss the various roles NS1 has in regulating viral replication mechanisms, host innate/adaptive immune responses, and cellular signalling pathways. We focus on the NS1-RNA and NS1-protein interactions that are fundamental to these processes, and highlight apparent strain-specific ways in which different NS1 proteins may act. In this regard, the contributions of certain NS1 functions to the pathogenicity of human and animal influenza A viruses are also discussed. Finally, we outline practical applications that future studies on NS1 may lead to, including the rational design and manufacture of influenza vaccines, the development of novel antiviral drugs, and the use of oncolytic influenza A viruses as potential anti-cancer agents.Publisher PDFPeer reviewe

Strongly coupled plasma with electric and magnetic charges

A number of theoretical and lattice results lead us to believe that Quark-Gluon Plasma not too far from $T_c$ contains not only electrically charged quasiparticles -- quarks and gluons -- but magnetically charged ones -- monopoles and dyons -- as well. Although binary systems like charge-monopole and charge-dyon were considered in details before in both classical and quantum settings, it is the first study of coexisting electric and magnetic particles in many-body context. We perform Molecular Dynamics study of strongly coupled plasmas with $\sim 1000$ particles and different fraction of magnetic charges. Correlation functions and Kubo formulae lead to such transport properties as diffusion constant, shear viscosity and electric conductivity: we compare the first two with empirical data from RHIC experiments as well as results from AdS/CFT correspondence. We also study a number of collective excitations in these systems.Comment: 2nd version, 22 pages, 32 figures: two important new figures have been included to compare our results with RHIC experiments and AdS/CFT results; a few new references and comments are added as wel

Using prototyping to choose a bioinformatics workflow management system

Workflow management systems represent, manage, and execute multistep computational analyses and offer many benefits to bioinformaticians. They provide a common language for describing analysis workflows, contributing to reproducibility and to building libraries of reusable components. They can support both incremental build and re-entrancy-the ability to selectively re-execute parts of a workflow in the presence of additional inputs or changes in configuration and to resume execution from where a workflow previously stopped. Many workflow management systems enhance portability by supporting the use of containers, high-performance computing (HPC) systems, and clouds. Most importantly, workflow management systems allow bioinformaticians to delegate how their workflows are run to the workflow management system and its developers. This frees the bioinformaticians to focus on what these workflows should do, on their data analyses, and on their science. RiboViz is a package to extract biological insight from ribosome profiling data to help advance understanding of protein synthesis. At the heart of RiboViz is an analysis workflow, implemented in a Python script. To conform to best practices for scientific computing which recommend the use of build tools to automate workflows and to reuse code instead of rewriting it, the authors reimplemented this workflow within a workflow management system. To select a workflow management system, a rapid survey of available systems was undertaken, and candidates were shortlisted: Snakemake, cwltool, Toil, and Nextflow. Each candidate was evaluated by quickly prototyping a subset of the RiboViz workflow, and Nextflow was chosen. The selection process took 10 person-days, a small cost for the assurance that Nextflow satisfied the authors' requirements. The use of prototyping can offer a low-cost way of making a more informed selection of software to use within projects, rather than relying solely upon reviews and recommendations by others

Static QˉQ\bar Q Q Potentials and the Magnetic Component of QCD Plasma near TcT_c

Static quark-anti-quark potential encodes important information on the chromodynamical interaction between color charges, and recent lattice results show its very nontrivial behavior near the deconfinement temperature $T_c$. In this paper we study such potential in the framework of the ``magnetic scenario'' for the near Tc QCD plasma, and particularly focus on the linear part (as quantified by its slope, the tension) in the potential as well as the strong splitting between the free energy and internal energy. By using an analytic ``ellipsoidal bag'' model, we will quantitatively relate the free energy tension to the magnetic condensate density and relate the internal energy tension to the thermal monopole density. By converting the lattice results for static potential into density for thermal monopoles we find the density to be very large around Tc and indicate at quantum coherence, in good agreement with direct lattice calculation of such density. A few important consequences for heavy ion collisions phenomenology will also be discussed.Comment: 10 pages, 6 figure

Healthcare professionals’ assertions and women's responses during labour: A conversation analytic study of data from One born every minute

© 2016 Elsevier Ireland Ltd Objective Communication during labour is consequential for women's experience yet analyses of situated labour-ward interaction are rare. This study demonstrates the value of explicating the interactional practices used to initiate ‘decisions’ during labour. Methods Interactions between 26 labouring women, their birth partners and HCPs were transcribed from the British television programme, One Born Every Minute. Conversation analysis was used to examine how decisions were initiated and accomplished in interaction. Findings HCPs initiate decision-making using interactional practices that vary the ‘optionality’ afforded labouring women in the responsive turn. Our focus here is on the minimisation of optionality through ‘assertions’. An ‘assertive’ turn-design (e.g. ‘we need to…’) conveys strong expectation of agreement. HCPs assert decisions in contexts of risk but also in contexts of routine activities. Labouring women tend to acquiesce to assertions. Conclusion The expectation of agreement set up by an assertive initiating turn can reduce women's opportunities to participate in shared decision-making (SDM). Practice implications When decisions are asserted by HCPs there is a possible dissonance between the tenets of SDM in British health policy and what occurs in situ. This highlights an educational need for HCPs in how best to afford labouring women more optionality, particularly in low-risk contexts

Structure of the regulatory hyaluronan binding domain in the inflammatory leukocyte homing receptor CD44

Adhesive interactions involving CD44, the cell surface receptor for hyaluronan, underlie fundamental processes such as inflammatory leukocyte homing and tumor metastasis. Regulation of such events is critical and appears to be effected by changes in CD44 N-glycosylation that switch the receptor "on" or "off" under appropriate circumstances. How altered glycosylation influences binding of hyaluronan to the lectin-like Link module in CD44 is unclear, although evidence suggests additional flanking sequences peculiar to CD44 may be involved. Here we show using X-ray crystallography and NMR spectroscopy that these sequences form a lobular extension to the Link module, creating an enlarged HA binding domain and a formerly unidentified protein fold. Moreover, the disposition of key N-glycosylation sites reveals how specific sugar chains could alter both the affinity and avidity of CD44 HA binding. Our results provide the necessary structural framework for understanding the diverse functions of CD44 and developing novel therapeutic strategies

Making Sense of the Legendre Transform

The Legendre transform is an important tool in theoretical physics, playing a critical role in classical mechanics, statistical mechanics, and thermodynamics. Yet, in typical undergraduate or graduate courses, the power of motivation and elegance of the method are often missing, unlike the treatments frequently enjoyed by Fourier transforms. We review and modify the presentation of Legendre transforms in a way that explicates the formal mathematics, resulting in manifestly symmetric equations, thereby clarifying the structure of the transform algebraically and geometrically. Then we bring in the physics to motivate the transform as a way of choosing independent variables that are more easily controlled. We demonstrate how the Legendre transform arises naturally from statistical mechanics and show how the use of dimensionless thermodynamic potentials leads to more natural and symmetric relations.Comment: 11 pages, 3 figure