Decay rate measurement of the first vibrationally excited state of MgH+^+ in a cryogenic Paul trap

We present a method to measure the decay rate of the first excited vibrational state of simple polar molecular ions being part of a Coulomb crystal in a cryogenic linear Paul trap. Specifically, we have monitored the decay of the $|\nu$=$1,J$=$1 \rangle_X$ towards the $|\nu$=$0,J$=$0 \rangle_X$ level in MgH$^+$ by saturated laser excitation of the $|\nu$=$0,J$=$2 \rangle_X$-$|\nu$=$1,J$=$1 \rangle_X$ transition followed by state selective resonance enhanced two-photon dissociation out of the $|\nu$=$0,J$=$2 \rangle_X$ level. The technique enables the determination of decay rates, and thus absorption strengths, with an accuracy at the few percent level.Comment: 5 pages, 4 figure

Imaging of cell membrane topography using Tamm plasmon coupled emission

Imaging of the cell membrane topography is important for a clear understanding of various biological activities of cells. We propose a technique for imaging the cell membrane topography that uses a metal-photonic crystal structure instead of a glass-water interface used in conventional polarized total internal reflection fluorescence microscopy (pTIRFM) techniques. Through the metal-photonic crystal of the proposed technique, the fluorophore labels on the cell membrane can be excited by both the p- and s-polarized excitation light, and in each case, the p- and s-polarized radiation from the excited fluorophores can be separated to form an image. We calculate the images of the cell membrane topography that is fusing a granule using the proposed technique and pTIRFM. The image obtained by the proposed technique shows a much greater contrast with respect to the background than that of the image obtained by pTIRFM. We also find that the structural similarity index of the image obtained by the proposed technique to a reference image is ~77%, which is only ~16% for the image obtained by pTIRFM. The proposed technique will help to obtain a clearer and more accurate image of the cell membrane topography, and hence, a deeper understanding of different biological activities

The unacknowledged legacy

This paper presents a critical discussion of the treatment of mimetic art, and particularly poetry and the theatre, in the work of the Athenian philosopher Plato (427-347 BC). It centres on Plato's discussion of the corrupting powers of the arts in the Republic, and the implications that his fierce attack on poetry and theatre have for his construction of the ideal polity. The legacy of Platonic ideas in later elaborations of the corrupting power of the arts is discussed. Furthermore, the paper investigates the relationship between current debates on cultural policy and the Platonic idea that the transformative powers of the arts ought to be harnessed by the state to promote a just society. The conclusion thus reached is that “instrumental cultural policy”, rather then being a modern invention, was in fact first theorized precisely in Plato's Republic

MULTIPLE CURRENT SHEET SYSTEMS IN THE OUTER HELIOSPHERE: ENERGY RELEASE AND TURBULENCE

Accepted for publication in The Astrophysical Journal, March 21, 201

Pre-transplant CDKN2A expression in kidney biopsies predicts renal function and is a future component of donor scoring criteria

CDKN2A is a proven and validated biomarker of ageing which acts as an off switch for cell proliferation. We have demonstrated previously that CDKN2A is the most robust and the strongest pre-transplant predictor of post- transplant serum creatinine when compared to “Gold Standard” clinical factors, such as cold ischaemic time and donor chronological age. This report shows that CDKN2A is better than telomere length, the most celebrated biomarker of ageing, as a predictor of post-transplant renal function. It also shows that CDKN2A is as strong a determinant of post-transplant organ function when compared to extended criteria (ECD) kidneys. A multivariate analysis model was able to predict up to 27.1% of eGFR at one year post-transplant (p = 0.008). Significantly, CDKN2A was also able to strongly predict delayed graft function. A pre-transplant donor risk classification system based on CDKN2A and ECD criteria is shown to be feasible and commendable for implementation in the near future

THE THREE-DIMENSIONAL EVOLUTION OF ION-SCALE CURRENT SHEETS: TEARING AND DRIFT-KINK INSTABILITIES IN THE PRESENCE OF PROTON TEMPERATURE ANISOTROPY

We present the first three-dimensional hybrid simulations of the evolution of ion-scale current sheets, with an investigation of the role of temperature anisotropy and associated kinetic instabilities on the growth of the tearing instability and particle heating. We confirm the ability of the ion cyclotron and firehose instabilities to enhance or suppress reconnection, respectively. The simulations demonstrate the emergence of persistent three-dimensional structures, including patchy reconnection sites and the fast growth of a narrow-band drift-kink instability, which suppresses reconnection for thin current sheets with weak guide fields. Potential observational signatures of the three-dimensional evolution of solar wind current sheets are also discussed. We conclude that kinetic instabilities, arising from non-Maxwellian ion populations, are significant to the evolution of three-dimensional current sheets, and two-dimensional studies of heating rates by reconnection may therefore over-estimate the ability of thin, ion-scale current sheets to heat the solar wind by reconnection

Whose knowledge, whose voices? Power, agency and resistance in disability studies for the global south

Meekosha (2011) maintains that research and theories about disability derive mainly from the global North. Disability Studies rarely include non-metropolitan thinkers. Even when they do, these studies tend to be seen as context specific, and the social theories which emanate from these studies are rarely refered to in research theorizing disability in the North. This chapter sets out to investigate how this one way transfer of knowledge affects the way Disability Studies is conceptualised - whose experiences are incorporated within these studies; and whose are left out. Multilateral debate and dialogue between Disability Studies academics and activists in different locations around the world would help add on to the knowledge already available in the field, while keeping others informed about what is taking place in 'similar' situations elsewhere.peer-reviewe

An allosteric role for receptor activity-modifying proteins in defining GPCR pharmacology

G protein-coupled receptors are allosteric proteins that control transmission of external signals to regulate cellular response. Although agonist binding promotes canonical G protein signalling transmitted through conformational changes, G protein-coupled receptors also interact with other proteins. These include other G protein-coupled receptors, other receptors and channels, regulatory proteins and receptor-modifying proteins, notably receptor activity-modifying proteins (RAMPs). RAMPs have at least 11 G protein-coupled receptor partners, including many class B G protein-coupled receptors. Prototypic is the calcitonin receptor, with altered ligand specificity when co-expressed with RAMPs. To gain molecular insight into the consequences of this protein–protein interaction, we combined molecular modelling with mutagenesis of the calcitonin receptor extracellular domain, assessed in ligand binding and functional assays. Although some calcitonin receptor residues are universally important for peptide interactions (calcitonin, amylin and calcitonin gene-related peptide) in calcitonin receptor alone or with receptor activity-modifying protein, others have RAMP-dependent effects, whereby mutations decreased amylin/calcitonin gene-related peptide potency substantially only when RAMP was present. Remarkably, the key residues were completely conserved between calcitonin receptor and AMY receptors, and between subtypes of AMY receptor that have different ligand preferences. Mutations at the interface between calcitonin receptor and RAMP affected ligand pharmacology in a RAMP-dependent manner, suggesting that RAMP may allosterically influence the calcitonin receptor conformation. Supporting this, molecular dynamics simulations suggested that the calcitonin receptor extracellular N-terminal domain is more flexible in the presence of receptor activity-modifying protein 1. Thus, RAMPs may act in an allosteric manner to generate a spectrum of unique calcitonin receptor conformational states, explaining the pharmacological preferences of calcitonin receptor-RAMP complexes. This provides novel insight into our understanding of G protein-coupled receptor-protein interaction that is likely broadly applicable for this receptor class

OpenWorm: overview and recent advances in integrative biological simulation of Caenorhabditis elegans

The adoption of powerful software tools and computational methods from the software industry by the scientific research community has resulted in a renewed interest in integrative, large-scale biological simulations. These typically involve the development of computational platforms to combine diverse, process-specific models into a coherent whole. The OpenWorm Foundation is an independent research organization working towards an integrative simulation of the nematode Caenorhabditis elegans, with the aim of providing a powerful new tool to understand how the organism's behaviour arises from its fundamental biology. In this perspective, we give an overview of the history and philosophy of OpenWorm, descriptions of the constituent sub-projects and corresponding open-science management practices, and discuss current achievements of the project and future directions. This article is part of a discussion meeting issue ‘Connectome to behaviour: modelling C. elegans at cellular resolution’