The Nature of Nearby Counterparts to Intermediate Redshift Luminous Compact Blue Galaxies I. Optical/H I Properties and Dynamical Masses

We present single-dish H I spectra obtained with the Green Bank Telescope, along with optical photometric properties from the Sloan Digital Sky Survey, of 20 nearby (D < 70 Mpc) Luminous Compact Blue Galaxies (LCBGs). These ~L*, blue, high surface brightness, starbursting galaxies were selected with the same criteria used to define LCBGs at higher redshifts. We find these galaxies are gas-rich, with M(HI) ranging from 5*10^8 to 8*10^9 M_sun, and M(HI)/L_B ranging from 0.2 to 2 M_sun/L_sun, consistent with a variety of morphological types of galaxies. We find the dynamical masses (measured within R_25) span a wide range, from 3*10^9 to 1*10^11 M_sun. However, at least half have dynamical mass-to-light ratios smaller than nearby galaxies of all Hubble types, as found for LCBGs at intermediate redshifts. By comparing line widths and effective radii with local galaxy populations, we find that LCBGs are consistent with the dynamical mass properties of Magellanic (low luminosity) spirals, and the more massive irregulars and dwarf ellipticals, such as NGC 205.Comment: 33 pages, 8 figures, accepted by Ap

Point of care blood tests during home visits by out-of-hours primary care clinicians; a mixed methods evaluation of a service improvement

Objectives We aimed to evaluate test usage and patient and clinician experience following the introduction of point-of-care (POC) blood tests into a primary care out-of-hours service. Design A mixed methods service evaluation comprising quantitative records of the clinical contexts of tests taken and qualitative interviews with clinicians. Research permissions and governance were obtained for patient interviews. Setting Out-of-hours primary care. Participants All patients requiring home visits from the service during the implementation period. Interventions The i-STAT POC blood test platform was introduced to two bases providing home visits for a period of 8 months. Venous blood samples were used and two cartridges were available. The CHEM8 cartridge measures sodium, potassium, chloride, total carbon dioxide (TCO2), anion gap, ionised calcium, glucose, urea, creatinine, haematocrit and haemoglobin. The CG4 cartridge measures lactate, pH, PaO2 and PCO2, TCO2, bicarbonate, base excess and oxygen saturation. Primary and secondary outcome measures The proportion of home visits where tests were taken, the clinical contexts of those tests, the extent to which clinicians felt the tests had influenced their decisions, time taken to perform the test and problems encountered. Clinician and patient experiences of using POC tests. Results i-STAT POC tests were infrequently used, with successful tests taken at just 47 contacts over 8 months of implementation. The patients interviewed felt that testing had been beneficial for their care. Clinician interviews suggested barriers to POC tests, including practical challenges, concerns about time, doubt over whether they would improve clinical decision making and concern about increased medicolegal risk. Suggestions for improving adoption included sharing learning, adopting a whole team approach and developing protocols for usage. Conclusions POC tests were not successfully adopted by an out-of-hours home visiting service in Oxfordshire. While some clinicians felt they could not add value, in other cases they resulted in improved patient experience. Adoption could be promoted by improving technical, team and education factors

Invariants of Lie algebras extended over commutative algebras without unit

We establish results about the second cohomology with coefficients in the trivial module, symmetric invariant bilinear forms and derivations of a Lie algebra extended over a commutative associative algebra without unit. These results provide a simple unified approach to a number of questions treated earlier in completely separated ways: periodization of semisimple Lie algebras (Anna Larsson), derivation algebras, with prescribed semisimple part, of nilpotent Lie algebras (Benoist), and presentations of affine Kac-Moody algebras.Comment: v3: added a footnote on p.10 about a wrong derivation of the correct statemen

Smectic ordering in liquid crystal - aerosil dispersions I. X-ray scattering

Comprehensive x-ray scattering studies have characterized the smectic ordering of octylcyanobiphenyl (8CB) confined in the hydrogen-bonded silica gels formed by aerosil dispersions. For all densities of aerosil and all measurement temperatures, the correlations remain short range, demonstrating that the disorder imposed by the gels destroys the nematic (N) to smectic-A (SmA) transition. The smectic correlation function contains two distinct contributions. The first has a form identical to that describing the critical thermal fluctuations in pure 8CB near the N-SmA transition, and this term displays a temperature dependence at high temperatures similar to that of the pure liquid crystal. The second term, which is negligible at high temperatures but dominates at low temperatures, has a shape given by the thermal term squared and describes the static fluctuations due to random fields induced by confinement in the gel. The correlation lengths appearing in the thermal and disorder terms are the same and show strong variation with gel density at low temperatures. The temperature dependence of the amplitude of the static fluctuations further suggests that nematic susceptibility become suppressed with increasing quenched disorder. The results overall are well described by a mapping of the liquid crystal-aerosil system into a three dimensional XY model in a random field with disorder strength varying linearly with the aerosil density.Comment: 14 pages, 13 figure

Braid Group Action and Quantum Affine Algebras

We lift the lattice of translations in the extended affine Weyl group to a braid group action on the quantum affine algebra. This action fixes the Heisenberg subalgebra pointwise. Loop like generators are found for the algebra which satisfy the relations of Drinfel$'$d's new realization. Coproduct formulas are given and a PBW type basis is constructed.Comment: 15 page

External-field-induced tricritical point in a fluctuation-driven nematic-smectic-A transition

We study theoretically the effect of an external field on the nematic-smectic-A (NA) transition close to the tricritical point, where fluctuation effects govern the qualitative behavior of the transition. An external field suppresses nematic director fluctuations, by making them massive. For a fluctuation-driven first-order transition, we show that an external field can drive the transition second-order. In an appropriate liquid crystal system, we predict the required magnetic field to be of order 10 T. The equivalent electric field is of order $1 V/\mu m$.Comment: revtex, 4 pages, 1 figure; revised version, some equations have been modifie

First order isotropic - smectic-A transition in liquid crystal-aerosil gels

The short-range order which remains when the isotropic to smectic-A transition is perturbed by a gel of silica nanoparticles (aerosils) has been studied using high-resolution synchrotron x-ray diffraction. The gels have been created \textit{in situ} in decylcyanobiphenyl (10CB), which has a strongly first-order isotropic to smectic-A transition. The effects are determined by detailed analysis of the temperature and gel density dependence of the smectic structure factor. In previous studies of the continuous nematic to smectic-A transition in a variety of thermotropic liquid crystals the aerosil gel appeared to pin, at random, the phase of the smectic density modulation. For the isotropic to smectic-A transition the same gel perturbation yields different results. The smectic correlation length decreases more slowly with increasing random field variance in good quantitative agreement with the effect of a random pinning field at a transition from a uniform phase directly to a phase with one-dimensional translational order. We thus compare the influence of random fields on a \textit{freezing} transition with and without an intervening orientationally ordered phase.Comment: 8 pages, 8 figure

Two Experimental Tests of the Halperin-Lubensky-Ma Effect at the Nematic-Smectic-A Phase Transition

We have conducted two quantitative tests of predictions based on the Halperin-Lubensky-Ma (HLM) theory of fluctuation-induced first-order phase transitions. First, we explore the effect of an external magnetic field on the nematic-smectic-A (NA) transition in a liquid crystal. Second, we examine the dependence of the first-order discontinuity as a function of mixture concentration in pure 8CB and three 8CB-10CB mixtures. We find the first quantitative evidence for deviations from the HLM theory.Comment: 4 pages, 2 figure

SU(2) Calorons and Magnetic Monopoles

We investigate the self-dual Yang-Mills gauge configurations on $R^3\times S^1$ when the gauge symmetry SU(2) is broken to U(1) by the Wilson loop. We construct the explicit field configuration for a single instanton by the Nahm method and show that an instanton is composed of two self-dual monopoles of opposite magnetic charge. We normalize the moduli space metric of an instanton and study various limits of the field configuration and its moduli space metric.Comment: 17 pages, RevTex, 1 Figur

Variation in referral rates to emergency departments and inpatient services from a GP out of hours service and the potential impact of alternative staffing models

Introduction Out of hours (OOHs) primary care is a critical component of the acute care system overnight and at weekends. Referrals from OOH services to hospital will add to the burden on hospital assessment in the ED and on-call specialties. Methods We studied the variation in referral rates (to the ED and direct specialty admission) of individual clinicians working in the Oxfordshire, UK OOH service covering a population of 600 000 people. We calculated the referral probability for each clinician over a 13-month period of practice (1 December 2014 to 31 December 2015), stratifying by clinician factors and location and timing of assessment. We used Simul8 software to determine the range of hospital referrals potentially due to variation in clinician referral propensity. Results Among the 119 835 contacts with the service, 5261 (4.4%) were sent directly to the ED and 3474 (3.7%) were admitted directly to specialties. More referrals were made to ED by primary care physicians if they did not work in the local practices (5.5% vs 3.5%, p=0.011). For clinicians with >1000 consultations, percentage of patients referred varied from 1% to 21% of consultations. Simulations where propensity to refer was made less extreme showed a difference in maximum referrals of 50 patients each week. Conclusions There is substantial variation in clinician referral rates from OOHs primary care to the acute hospital setting. The number of patients referred could be influenced by this variation in clinician behaviour. Referral propensity should be studied including casemix adjustment to determine if interventions targeting such behaviour are effective