The Relationship Between Molecular Gas Tracers and Kennicutt-Schmidt Laws

We provide a model for how Kennicutt-Schmidt (KS) laws, which describe the correlation between star formation rate and gas surface or volume density, depend on the molecular line chosen to trace the gas. We show that, for lines that can be excited at low temperatures, the KS law depends on how the line critical density compares to the median density in a galaxy's star-forming molecular clouds. High critical density lines trace regions with similar physical properties across galaxy types, and this produces a linear correlation between line luminosity and star formation rate. Low critical density lines probe regions whose properties vary across galaxies, leading to a star formation rate that varies superlinearly with line luminosity. We show that a simple model in which molecular clouds are treated as isothermal and homogenous can quantitatively reproduce the observed correlations between galactic luminosities in far infrared and in the CO(1->0) and HCN(1->0) lines, and naturally explains why these correlations have different slopes. We predict that IR-line luminosity correlations should change slope for galaxies in which the median density is close to the line critical density. This prediction may be tested by observations of lines such as HCO^+(1->0) with intermediate critical densities, or by HCN(1->0) observations of intensely star-forming high redshift galaxies with very high densities. Recent observations by Gao et al. hint at just such a change in slope. We argue that deviations from linearity in the HCN(1->0)-IR correlation at high luminosity are consistent with the assumption of a constant star formation efficiency.Comment: Accepted to ApJ. 11 pages, 4 figures, emulateapj format. This version has some additional models exploring the effects of varying metallicity and temperature. The conclusions are unchange

Multimodal Frontostriatal Connectivity Underlies Individual Differences in Self-Esteem

A heightened sense of self-esteem is associated with a reduced risk for several types of affective and psychiatric disorders, including depression, anxiety and eating disorders. However, little is known about how brain systems integrate self-referential processing and positive evaluation to give rise to these feelings. To address this, we combined diffusion tensor imaging (DTI) and functional magnetic resonance imaging (fMRI) to test how frontostriatal connectivity reflects long-term trait and short-term state aspects of self-esteem. Using DTI, we found individual variability in white matter structural integrity between the medial prefrontal cortex and the ventral striatum was related to trait measures of self-esteem, reflecting long-term stability of self-esteem maintenance. Using fMRI, we found that functional connectivity of these regions during positive self-evaluation was related to current feelings of self-esteem, reflecting short-term state self-esteem. These results provide convergent anatomical and functional evidence that self-esteem is related to the connectivity of frontostriatal circuits and suggest that feelings of self-worth may emerge from neural systems integrating information about the self with positive affect and reward. This information could potentially inform the etiology of diminished self-esteem underlying multiple psychiatric conditions and inform future studies of evaluative self-referential processing

Characterisation of damage mechanisms in oxide ceramics indented at dynamic and quasi-static strain rates

Ceramic materials are known to display rate dependent behaviour under impact. Tests to establish the strain-rate dependent variations in damage mechanisms have been carried out on debased alumina, an alumina-zirconia composite, and 3Y-TZP. Materials were indented dynamically and quasi-statically using identical sharp hardened steel projectiles while recording the load profile. Characteristics typical of both sharp and blunt indentation types were observed using scanning electron microscopy and piezospectroscopic mapping. At dynamic strain rates both the depth of the indentation and the residual stress in the material were lower than for quasi-static tests. This was attributed to temperature-induced softening of the projectile. Unusual behaviour was observed in the 3Y-TZP samples due to the reversible transformation from tetragonal to monoclinic crystal structures during mechanical loading. These effects and the observed superior mechanical strength against impact suggest that zirconia or zirconia-composite materials may have advantages over debased alumina for application as ceramic armour materials

Does current UK research address priorities in palliative and end-of-life care?

The Palliative and end of life care Priority Setting Partnership uncovered 83 unanswered research questions. Florence Todd Fordham, Bridget Candy, Stevie McMillan and Sabine Best show that, as current UK research starts to address some of these questions, UK open grant data have the potential to encourage collaboratio

Power Output Is Increased After Phosphorylation of Myofibrillar Proteins in Rat Skinned Cardiac Myocytes

This work was supported by American Heart Association Beginning Grant-in-Aid 9914291 and NIH Grant HL57852.The publisher's version may be found at http://circres.ahajournals.org/cgi/content/full/89/12/1184ß-Adrenergic stimulation increases stroke volume in mammalian hearts as a result of protein kinase A (PKA)-induced phosphorylation of several myocyte proteins. This study investigated whether PKA-induced phosphorylation of myofibrillar proteins directly affects myocyte contractility. To test this possibility, we compared isometric force, loaded shortening velocity, and power output in skinned rat cardiac myocytes before and after treatment with the catalytic subunit of PKA. Consistent with previous studies, PKA increased phosphorylation levels of myosin binding protein C and troponin I, and reduced Ca2+ sensitivity of force. PKA also significantly increased both maximal force (25.4±8.3 versus 31.6±11.3 µN [P<0.001, n=12]) and peak absolute power output (2.48±1.33 versus 3.38±1.52 µW/mg [P<0.05, n=5]) during maximal Ca2+ activations. Furthermore, PKA elevated power output at nearly all loads even after normalizing for the increase in force. After PKA treatment, peak normalized power output increased {approx}20% during maximal Ca2+ activations (n=5) and {approx}33% during half-maximal Ca2+ activations (n=9). These results indicate that PKA-induced phosphorylation of myofibrillar proteins increases the power output-generating capacity of skinned cardiac myocytes, in part, by speeding the step(s) in the crossbridge cycle that limit loaded shortening rates, and these changes likely contribute to greater contractility in hearts after ß-adrenergic stimulation

RISE: a fast-readout imager for exoplanet transit timing

By the precise timing of the low amplitude (0.005 - 0.02 magnitude) transits of exoplanets around their parent star it should be possible to infer the presence of other planetary bodies in the system down to Earth-like masses. We describe the design and construction of RISE, a fast-readout frame transfer camera for the Liverpool Telescope designed to carry out this experiment. The results of our commissioning tests are described as well as the data reduction procedure necessary. We present light curves of two objects, showing that the desired timing and photometric accuracy can be obtained providing that autoguiding is used to keep the target on the same detector pixel for the entire (typically 4 hour) observing run.Comment: Published in PROC SPIE, vol 7014, 70416

Video-based Education Ethnography Project

This article chronicles the development of a video-based ethnography project documenting daily life in a Kansas elementary and a secondary classroom. The project, which took nearly two years of planning, allows a direct link to two classrooms approximately 250 miles away to provide a virtual field experience for undergraduates and a wide array of research possibilities for faculty. Since its first semester in spring 2016, it now enables students to see the daily actions of an elementary teacher and a secondary math teacher in a live classroom setting, and various faculty and graduate student research projects are currently under way