Testing a new intervention to enhance road safety

By 2020, it is estimated that road accidents will have moved from ninth to third in the worldwide ranking of burden of disease, as assessed in the disability adjusted life years (DALY)^1,2^. Therefore, it is vital to find effective methods to enhance road safety. Speed limits and traffic calming have the potential to reduce injuries due to road accidents^3,4^. Many drivers, however, do not adhere to speed limits^1-7^. Several studies have shown that adherence to speed limits can be explained by the theory of planned behaviour ^5-7^ and that it is possible to focus on drivers' intentions via self-report questionnaires. It is often difficult, however, to reach the majority of drivers on accident-prone locations with self-report questionnaires. This paper demonstrates an intervention that can be interpreted in the light of two of the theory's key variables^8^. It also has the potential to reach a large number of drivers on such locations. It is a speed-displaying device mounted next to the road (especially in villages). It tells drivers their actual speed (which is publicly visible). The measurement takes place continuously, giving the driver the chance to adjust speed and see the new speed shortly thereafter. The results show that the feedback about the current speed is associated with a significant speed reduction relative to a Control condition

Sphingosine kinase and sphingosine-1-phosphate in liver pathobiology

Over 20 years ago, sphingosine-1-phosphate (S1P) was discovered to be a bioactive signaling molecule. Subsequent studies later identified two related kinases, sphingosine kinase 1 and 2, which are responsible for the phosphorylation of sphingosine to S1P. Many stimuli increase sphingosine kinase activity and S1P production and secretion. Outside the cell, S1P can bind to and activate five S1P-specific G protein-coupled receptors (S1PR1–5) to regulate many important cellular and physiological processes in an autocrine or paracrine manner. S1P is found in high concentrations in the blood where it functions to control vascular integrity and trafficking of lymphocytes. Obesity increases blood S1P levels in humans and mice. With the world wide increase in obesity linked to consumption of high-fat, high-sugar diets, S1P is emerging as an accomplice in liver pathobiology, including acute liver failure, metabolic syndrome, control of blood lipid and glucose homeostasis, nonalcoholic fatty liver disease, and liver fibrosis. Here, we review recent research on the importance of sphingosine kinases, S1P, and S1PRs in liver pathobiology, with a focus on exciting insights for new therapeutic modalities that target S1P signaling axes for a variety of liver diseases

Polar confinement of the Sun's interior magnetic field by laminar magnetostrophic flow

The global-scale interior magnetic field needed to account for the Sun's observed differential rotation can be effective only if confined below the convection zone in all latitudes, including the polar caps. Axisymmetric nonlinear MHD solutions are obtained showing that such confinement can be brought about by a very weak downwelling flow U~10^{-5}cm/s over each pole. Such downwelling is consistent with the helioseismic evidence. All three components of the magnetic field decay exponentially with altitude across a thin "magnetic confinement layer" located at the bottom of the tachocline. With realistic parameter values, the thickness of the confinement layer ~10^{-3} of the Sun's radius. Alongside baroclinic effects and stable thermal stratification, the solutions take into account the stable compositional stratification of the helium settling layer, if present as in today's Sun, and the small diffusivity of helium through hydrogen, chi. The small value of chi relative to magnetic diffusivity produces a double boundary-layer structure in which a "helium sublayer" of smaller vertical scale is sandwiched between the top of the helium settling layer and the rest of the confinement layer. Solutions are obtained using both semi-analytical and purely numerical, finite-difference techniques. The confinement-layer flows are magnetostrophic to excellent approximation. More precisely, the principal force balances are between Lorentz, Coriolis, pressure-gradient and buoyancy forces, with relative accelerations and viscous forces negligible. This is despite the kinematic viscosity being somewhat greater than chi. We discuss how the confinement layers at each pole might fit into a global dynamical picture of the solar tachocline. That picture, in turn, suggests a new insight into the early Sun and into the longstanding enigma of solar lithium depletion.Comment: Accepted by JFM. 36 pages, 10 figure

A study of hypertension screening by optometry

A study of hypertension screening by optometr

Generation of human antibody fragments against Streptococcus mutans using a phage display chain shuffling approach

BACKGROUND: Common oral diseases and dental caries can be prevented effectively by passive immunization. In humans, passive immunotherapy may require the use of humanized or human antibodies to prevent adverse immune responses against murine epitopes. Therefore we generated human single chain and diabody antibody derivatives based on the binding characteristics of the murine monoclonal antibody Guy's 13. The murine form of this antibody has been used successfully to prevent Streptococcus mutans colonization and the development of dental caries in non-human primates, and to prevent bacterial colonization in human clinical trials. RESULTS: The antibody derivatives were generated using a chain-shuffling approach based on human antibody variable gene phage-display libraries. Like the parent antibody, these derivatives bound specifically to SAI/II, the surface adhesin of the oral pathogen S. mutans. CONCLUSIONS: Humanization of murine antibodies can be easily achieved using phage display libraries. The human antibody fragments bind the antigen as well as the causative agent of dental caries. In addition the human diabody derivative is capable of aggregating S. mutans in vitro, making it a useful candidate passive immunotherapeutic agent for oral diseases

Homotopical Foundations of Parametrized Quantum Spin Systems

In this paper, we present a homotopical framework for studying invertible gapped phases of matter from the point of view of infinite spin lattice systems, using the framework of algebraic quantum mechanics. We define the notion of quantum state types. These are certain lax-monoidal functors from the category of finite dimensional Hilbert spaces to the category of topological spaces. The universal example takes a finite dimensional Hilbert space to the pure state space of the quasi-local algebra of the quantum spin system with this Hilbert space at each site of a specified lattice. The lax-monoidal structure encodes the tensor product of states, which corresponds to stacking for quantum systems. We then explain how to formally extract parametrized phases of matter from quantum state types, and how they naturally give rise to $\mathscr{E}_\infty$-spaces for an operad we call the "multiplicative" linear isometry operad. We define the notion of invertible quantum state types and explain how the passage to phases for these is related to group completion. We also explain how invertible quantum state types give rise to loop-spectra. Our motivation is to provide a framework for constructing Kitaev's loop-spectrum of bosonic invertible gapped phases of matter. Finally, as a first step towards understanding the homotopy types of the loop-spectra associated to invertible quantum state types, we prove that the pure state space of any UHF algebra is simply connected.Comment: Minor revisions from v1 and a new appendix with background on operads, E infinity spaces and simplicial sets, as well as additional functional analytic background in section

Continuous Dependence on the Initial Data in the Kadison Transitivity Theorem and GNS Construction

We consider how the outputs of the Kadison transitivity theorem and Gelfand-Naimark-Segal construction may be obtained in families when the initial data are varied. More precisely, for the Kadison transitivity theorem, we prove that for any nonzero irreducible representation $(\mathcal{H}, \pi)$ of a $C^*$-algebra $\mathfrak{A}$ and $n \in \mathbb{N}$, there exists a continuous function $A:X \rightarrow \mathfrak{A}$ such that $\pi(A(\mathbf{x}, \mathbf{y}))x_i = y_i$ for all $i \in \{1, \ldots, n\}$, where $X$ is the set of pairs of $n$-tuples $(\mathbf{x}, \mathbf{y}) \in \mathcal{H}^n \times \mathcal{H}^n$ such that the components of $\mathbf{x}$ are linearly independent. Versions of this result where $A$ maps into the self-adjoint or unitary elements of $\mathfrak{A}$ are also presented. Regarding the Gelfand-Naimark-Segal construction, we prove that given a topological $C^*$-algebra fiber bundle $p:\mathfrak{A} \rightarrow Y$, one may construct a topological fiber bundle $\mathscr{P}(\mathfrak{A}) \rightarrow Y$ whose fiber over $y \in Y$ is the space of pure states of $\mathfrak{A}_y$ (with the norm topology), as well as bundles $\mathscr{H} \rightarrow \mathscr{P}(\mathfrak{A})$ and $\mathscr{N} \rightarrow \mathscr{P}(\mathfrak{A})$ whose fibers $\mathscr{H}_\omega$ and $\mathscr{N}_\omega$ over $\omega \in \mathscr{P}(\mathfrak{A})$ are the GNS Hilbert space and closed left ideal, respectively, corresponding to $\omega$. When $p:\mathfrak{A} \rightarrow Y$ is a smooth fiber bundle, we show that $\mathscr{P}(\mathfrak{A}) \rightarrow Y$ and $\mathscr{H}\rightarrow \mathscr{P}(\mathfrak{A})$ are also smooth fiber bundles; this involves proving that the group of $*$-automorphisms of a $C^*$-algebra is a Banach-Lie group. In service of these results, we review the geometry of the topology and pure state space. A simple non-interacting quantum spin system is provided as an example