J-type Carbon Stars in the Large Magellanic Cloud

A sample of 1497 carbon stars in the Large Magellanic Cloud has been observed in the red part of the spectrum with the 2dF facility on the AAT. Of these, 156 have been identified as J-type (i.e. 13C-rich) carbon stars using a technique which provides a clear distinction between J stars and the normal N-type carbon stars that comprise the bulk of the sample, and yields few borderline cases. A simple 2-D classification of the spectra, based on their spectral slopes in different wavelength regions, has been constructed and found to be related to the more conventional c- and j-indices, modified to suit the spectral regions observed. Most of the J stars form a photometric sequence in the K - (J-K) colour magnitude diagram, parallel to and 0.6 mag fainter than the N star sequence. A subset of the J stars (about 13 per cent) are brighter than this J star sequence; most of these are spectroscopically different from the other J stars. The bright J stars have stronger CN bands than the other J stars and are found strongly concentrated in the central regions of the LMC. Most of the rather few stars in common with Hartwick and Cowley's sample of suspected CH stars are J stars. Overall, the proportion of carbon stars identified as J stars is somewhat lower than has been found in the Galaxy. The Na D lines are weaker in the LMC J stars than in either the Galactic J stars or the LMC N stars, and do not seem to depend on temperature.Comment: 19 pages, 21 figures, Latex; in press, MNRA

The Different Artificial Sweeteners and Their Effects on Endothelial Cell/Blood Vessel Health: Possible Implications for Ringing in the Ear

Abstract: Background: Tinnitus, a condition whose remarkable symptom is ringing in the ear (RIE), is a problem plaguing people all around the world in varying degrees of severity, though it is most common and severe in older populations. Literature is lacking on its etiology. Therefore, it is difficult to diagnose and treat. Several possible components could play a role in the development of tinnitus including neurological, physiological, traumatic, dietary and vascular factors. No factor has yet been definitively linked to the development of tinnitus. Vascular health can be significantly impacted by diet- especially in regard to sugars. As artificial sweeteners are used widely in the American diet, they may play a significant role in vascular health. Objective: This project aims to investigate a possible connection between artificial sugars’ impact on vascular health and complaints of RIE among age groups through a patient survey and laboratory experiments. Methods: A survey assessing individuals’ demographic information, subjective severity of RIE and reported artificial sweetener consumption will be distributed to audiologists’ offices in major Ohio cities, via Qualtrics, where patients will complete them. Data collected will be analyzed for interrelationships among sugar intake, age and severity of RIE. In the laboratory, an ELISA assay will evaluate the effects of artificial sweeteners on endothelial cells- the same cells that comprise blood vessels- through quantifying stimulation of the Tie-2 survival and angiogenesis pathway via the cellular messenger pAKT

Test of CPT and Lorentz invariance from muonium spectroscopy

Following a suggestion of Kostelecky et al. we have evaluated a test of CPT and Lorentz invariance from the microwave spectroscopy of muonium. Hamiltonian terms beyond the standard model violating CPT and Lorentz invariance would contribute frequency shifts $\delta\nu_{12}$ and $\delta\nu_{34}$ to $\nu_{12}$ and $\nu_{34}$, the two transitions involving muon spin flip, which were precisely measured in ground state muonium in a strong magnetic field of 1.7 T. The shifts would be indicated by anti-correlated oscillations in $\nu_{12}$ and $\nu_{34}$ at the earth's sidereal frequency. No time dependence was found in $\nu_{12}$ or $\nu_{34}$ at the level of 20 Hz, limiting the size of some CPT and Lorentz violating parameters at the level of $2\times10^{-23}$ GeV, representing Planck scale sensitivity and an order of magnitude improvement in sensitivity over previous limits for the muon.Comment: 4 pages, 4 figures, uses REVTeX and epsf, submitted to Phys. Rev. Let

3D ToF-SIMS imaging of polymer multilayer films using argon cluster sputter depth profiling

ToF-SIMS imaging with argon cluster sputter depth profiling has provided detailed insight into the three-dimensional (3D) chemical composition of a series of polymer multilayer structures. Depths of more than 15 μm were profiled in these samples while maintaining uniform sputter rates. The 3D chemical images provide information regarding the structure of the multilayer systems that could be used to inform future systems manufacturing and development. This also includes measuring the layer homogeneity, thickness, and interface widths. The systems analyzed were spin-cast multilayers comprising alternating polystyrene (PS) and polyvinylpyrrolidone (PVP) layers. These included samples where the PVP and PS layer thickness values were kept constant throughout and samples where the layer thickness was varied as a function of depth in the multilayer. The depth profile data obtained was observed to be superior to that obtained for the same materials using alternative ion sources such as C60 n+. The data closely reflected the “as manufactured” sample specification, exhibiting good agreement with ellipsometry measurements of layer thickness, while also maintaining secondary ion intensities throughout the profiling regime. The unprecedented quality of the data allowed a detailed analysis of the chemical structure of these systems, revealing some minor imperfections within the polymer layers and demonstrating the enhanced capabilities of the argon cluster depth profiling technique

Coach development through collaborative action research: enhancing the learning environment within a national talent development system

Motivation to learn is an essential factor of talent being realised , which throws into light the essential role that the motivational climate plays in developing talent. Through collaborative action research, the aim of this study was to develop coaches’ learning to enhance the learning environment within a national talent development system, utilising the) TARGET framework (task, authority, recognition, grouping, evaluation and time). Results revealed that participatory collaborative action research is an effective coach development tool for coaches in order to enhance their learning and the motivational climate within their sessions. The study identified the benefits of coach development through participatory action research, revealing a highly positive response to the role that collaborative learning played in pedagogical developmen

Kepler photometry of RRc stars: peculiar double-mode pulsations and period doubling

We present the analysis of four first overtone RR Lyrae stars observed with the Kepler space telescope, based on data obtained over nearly 2.5 yr. All four stars are found to be multiperiodic. The strongest secondary mode with frequency f2 has an amplitude of a few mmag, 20–45 times lower than the main radial mode with frequency f1. The two oscillations have a period ratio of P2/P1 = 0.612–0.632 that cannot be reproduced by any two radial modes. Thus, the secondary mode is non-radial. Modes yielding similar period ratios have also recently been discovered in other variables of the RRc and RRd types. These objects form a homogenous group and constitute a new class of multimode RR Lyrae pulsators, analogous to a similar class of multimode classical Cepheids in the Magellanic Clouds. Because a secondary mode with P2/P1 ∼ 0.61 is found in almost every RRc and RRd star observed from space, this form of multiperiodicity must be common. In all four Kepler RRc stars studied, we find subharmonics of f2 at ∼1/2f2 and at ∼3/2f2. This is a signature of period doubling of the secondary oscillation, and is the first detection of period doubling in RRc stars. The amplitudes and phases of f2 and its subharmonics are variable on a time-scale of 10–200 d. The dominant radial mode also shows variations on the same time-scale, but with much smaller amplitude. In three Kepler RRc stars we detect additional periodicities, with amplitudes below 1 mmag, that must correspond to non-radial g-modes. Such modes never before have been observed in RR Lyrae variables

Lowering of blood pressure after nitrate-rich vegetable consumption is abolished with the co-ingestion of thiocyanate-rich vegetables in healthy normotensive males

A diet rich in vegetables is known to provide cardioprotection. However, it is unclear how the consumption of different vegetables might interact to influence vascular health. This study tested the hypothesis that nitrate-rich vegetable consumption would lower systolic blood pressure but that this effect would be abolished when nitrate-rich and thiocyanate-rich vegetables are co-ingested. On four separate occasions, and in a randomised cross-over design, eleven healthy males reported to the laboratory and consumed a 750 mL vegetable smoothie that was either: low in nitrate (~ 0.3 mmol) and thiocyanate (~ 5 μmol), low in nitrate and high in SCN- (~ 72 μmol), high in nitrate (~ 4 mmol) and low in SCN- and high in nitrate and SCN-. Blood pressure as well as plasma and salivary [thiocyanate], [nitrate] and [nitrite] were assessed before and 3 hours after smoothie consumption. Plasma [nitrate] and [nitrite] and salivary [nitrate] were not different after consuming the two high-nitrate smoothies, but salivary [nitrite] was higher after consuming the high-nitrate low-thiocyanate smoothie (1183 ± 625 µM) compared to the high-nitrate high-thiocyanate smoothie (941 ± 532 µM; P<0.001). Systolic blood pressure was only lowered after consuming the high-nitrate low-thiocyanate smoothie (-3 ± 5 mmHg; P<0.05). The acute consumption of vegetables high in nitrate and low in thiocyanate lowered systolic blood pressure. However, when the same dose of nitrate-rich vegetables was co-ingested with thiocyanate-rich vegetables the increase in salivary [nitrite] was smaller and systolic blood pressure was not lowered. These findings might have implications for optimising dietary guidelines aimed at improving cardiovascular health