The Effect of Local Galaxy Surface Density on Star Formation for HI selected galaxies

We present the result of investigations into two theories to explain the star formation rate-density relationship. For regions of high galaxy density, either there are fewer star forming galaxies, or galaxies capable of forming stars are present but some physical process is suppressing their star formation. We use HI Parkes All Sky Survey's (HIPASS) HI detected galaxies and infrared and radio fluxes to investigate star formation rates and efficiencies with respect to local surface density. For nearby (vel<10000 km\s) HI galaxies we find a strong correlation between HI mass and star formation rate. The number of HI galaxies decreases with increasing local surface density. For HI galaxies (1000<vel<6000 km\s) there is no significant change in the star formation rate or the efficiency of star formation with respect to local surface density. We conclude the SFR-density relation is due to a decrease in the number of HI star forming galaxies in regions of high galaxy density and not to the suppression of star formation.Comment: 17 pages, 16 figures, Accepted for publication by MNRAS 2 August 200

The magnitude distribution of earthquakes near Southern California faults

We investigate seismicity near faults in the Southern California Earthquake Center Community Fault Model. We search for anomalously large events that might be signs of a characteristic earthquake distribution. We find that seismicity near major fault zones in Southern California is well modeled by a Gutenberg-Richter distribution, with no evidence of characteristic earthquakes within the resolution limits of the modern instrumental catalog. However, the b value of the locally observed magnitude distribution is found to depend on distance to the nearest mapped fault segment, which suggests that earthquakes nucleating near major faults are likely to have larger magnitudes relative to earthquakes nucleating far from major faults

Verification of mesoscale objective analyses of VAS and rawinsonde data using the March 1982 AVE/VAS special network data

Various combinations of VAS (Visible and Infrared Spin Scan Radiometer Atmospheric Sounder) data, conventional rawinsonde data, and gridded data from the National Weather Service's (NWS) global analysis, were used in successive-correction and variational objective-analysis procedures. Analyses are produced for 0000 GMT 7 March 1982, when the VAS sounding distribution was not greatly limited by the existence of cloud cover. The successive-correction (SC) procedure was used with VAS data alone, rawinsonde data alone, and both VAS and rawinsonde data. Variational techniques were applied in three ways. Each of these techniques was discussed

The Large Peculiar Velocity of the cD Galaxy in Abell 3653

We present a catalogue of galaxies in Abell 3653 from observations made with the 2dF spectrograph at the Anglo-Australian Telescope. Of the 391 objects observed, we find 111 are bone-fide members of Abell 3653. We show that the cluster has a velocity of cz = 32214 +/- 83 km/s (z=0.10738 +/- 0.00027), with a velocity dispersion typical of rich, massive clusters of sigma_{cz} = 880^{+66}_{-54}. We find that the cD galaxy has a peculiar velocity of 683 +/- 96 km/s in the cluster restframe - some 7sigma away from the mean cluster velocity, making it one of the largest and most significant peculiar velocities found for a cD galaxy to date. We investigate the cluster for signs of substructure, but do not find any significant groupings on any length scale. We consider the implications of our findings on cD formation theories.Comment: 16 pages, including 7 figures and a long table. Accepted for publication in MNRA

Yoga use, physical and mental health, and quality of life in adults with irritable bowel syndrome: A mixed-methods study

Introduction Intervention studies show yoga has several physical and psychological benefits for Irritable Bowel Syndrome (IBS), however few studies have explored yoga use in everyday life amongst people with IBS. This study explored yoga use as a predictor of IBS-related quality of life (QoL) in relation to other physical and psychological factors. It also utilized the Capability, Opportunity, Motivation-Behaviour (COM-B) model to investigate predictors of yoga practice, with a qualitative exploration of perceived IBS-related benefits and barriers to yoga. Methods A cross-sectional, mixed-methods survey was used. 219 adults with IBS (86.3% female, 32% yoga practitioners, mean age 46.42 years) completed a questionnaire battery to assess symptom severity, psychological symptoms, general health, QoL, COM-B constructs in relation to yoga, and perceived effectiveness of yoga for IBS. Open-ended responses assessing perceptions of yoga in relation to IBS were analysed using thematic analysis. Results In hierarchical linear regression, education, yoga use, symptom severity, anxiety, depression, and general health explained 64.6% of variance in QoL (p<.001). Yoga use explained 6.1% after controlling for education. In hierarchical logistic regression, COM-B constructs explained 37.5% of the variance in yoga use (p<.001). In the final model, only Opportunity (p<.05) and Motivation (p<.001) significantly predicted yoga practice. Qualitative analysis identified three themes reflecting perceived benefits of yoga (IBS Relief, A Valuable Self-Management Tool, Holistic Wellbeing), and three reflecting perceived barriers/limitations (Lack of Physical Capability, Need for a Tailored Approach, Limited Motivation). Conclusion This study identifies significant relationships between yoga use in everyday life, physical and mental health, and IBS-related QoL, and identifies the COM-B model as a useful framework for understanding yoga practice amongst people with IBS. The findings demonstrate that practicing yoga as part of daily life may positively impact both physical and mental health of IBS patients. Furthermore, the findings can be used to inform more targeted yoga interventions and increase accessibility of yoga for this group

The Pathogenesis of Atherosclerosis and Coronary Heart Disease

Fifty-five percent of all deaths in the United States are ascribed to cardiovascular disease. The vast majority of these deaths are due directly or indirectly to atherosclerosis and its ischemic complications (Am. Heart Assoc., 1965; U.S. President\u27s Commission on Heart Disease, Cancer and Stroke, 1964). Atherosclerosis is defined in Dorland\u27s dictionary (24th edition) as a lesion of large and medium-sized arteries with deposits in the intima of yellowish plaques containing cholesterol, lipoid material and lipophages. Typical atherosclerotic lesions of the coronary arteries are shown in figure 1. Even a casual inspection of these lesions shows the incompleteness of this conventional definition. It is obvious that thrombosis accounts for the occlusive terminal phase of atherosclerosis and, indeed, is supposed by some to initiate atherosclerosis

Chromospheric Inversions of a Micro-flaring Region

We use spectropolarimetric observations of the Ca II 8542~\AA\ line, taken from the Swedish 1-m Solar Telescope (SST), in an attempt to recover dynamic activity in a micro-flaring region near a sunspot via inversions. These inversions show localized mean temperature enhancements of $\sim$1000~K in the chromosphere and upper photosphere, along with co-spatial bi-directional Doppler shifting of 5 - 10 km s$^{-1}$. This heating also extends along a nearby chromospheric fibril, co-spatial to 10 - 15 km s$^{-1}$ down-flows. Strong magnetic flux cancellation is also apparent in one of the footpoints, concentrated in the chromosphere. This event more closely resembles that of an Ellerman Bomb (EB), though placed slightly higher in the atmosphere than is typically observed.Comment: 9 pages, 9 figures, accepted in ApJ. Movies are stored here: https://star.pst.qub.ac.uk/webdav/public/areid/Microflare