Observations of the Structure and Dynamics of the Inner M87 Jet

M87 is the best source in which to study a jet at high resolution in gravitational units because it has a very high mass black hole and is nearby. The angular size of the black hole is second only to Sgr A*, which does not have a strong jet. The jet structure is edge brightened with a wide opening angle base and a weak counterjet. We have roughly annual observations for 17 years plus intensive monitoring at three week intervals for a year and five day intervals for 2.5 months made with the Very Long Baseline Array (VLBA) at 43 GHz. The inner jet shows very complex dynamics, with apparent motions both along and across the jet. Speeds from zero to over 2c are seen, with acceleration observed over the first 3 milli-arcseconds. The counterjet decreases in brightness much more rapidly than the main jet, as is expected from relativistic beaming in an accelerating jet oriented near the line-of-sight. Details of the structure and dynamics are discussed. The roughly annual observations show side-to-side motion of the whole jet with a characteristic time scale of about 9 years.Comment: 11 pages, 7 figures. Published in a special issue of Galaxies which is the proceedings of "Blazars through Sharp Multi-Wavelength Eyes" edited by J. L. Gomez, A. P. Marscher, and S. G. Jorsta

The Future Evolution of White Dwarf Stars Through Baryon Decay and Time Varying Gravitational Constant

Motivated by the possibility that the fundamental ``constants'' of nature could vary with time, this paper considers the long term evolution of white dwarf stars under the combined action of proton decay and variations in the gravitational constant. White dwarfs are thus used as a theoretical laboratory to study the effects of possible time variations, especially their implications for the future history of the universe. More specifically, we consider the gravitational constant $G$ to vary according to the parametric relation $G = G_0 (1 + t/t_\ast)^{-p}$, where the time scale $t_\ast$ is the same order as the proton lifetime. We then study the long term fate and evolution of white dwarf stars. This treatment begins when proton decay dominates the stellar luminosity, and ends when the star becomes optically thin to its internal radiation.Comment: 12 pages, 10 figures, accepted to Astrophysics and Space Scienc

Water molecules in the antibody朼ntigen interface of the structure of the Fab HyHEL-5杔ysozyme complex at 1.7 A? resolution: comparison with results from isothermal titration calorimetry

The structure of the complex between hen egg-white lysozyme and the Fab HyHEL-5 at 2.7 A? resolution has previously been reported [Cohen et al. (1996), Acta Cryst. D52, 315�6]. With the availability of recombinant Fab, the X-ray structure of the complex has been re-evaluated at 1.7 A? resolution. The refined structure has yielded a detailed picture of the Fab� lysozyme interface, showing the high complementarity of the protein surfaces as well as several water molecules within the interface that complete the good fit. The model of the full complex has improved significantly, yielding an Rwork of 19.5%. With this model, the structural results can be compared with the results of isothermal titration calorimetry. An attempt has been made to estimate the changes in bound waters that accompany complex formation and the difficulties inherent in using the crystal structures to provide the information necessary to make this calculation are discussed

Spectral Irradiance Calibration in the Infrared

We present five new absolutely calibrated continuous stellar spectra constructed as far as possible from spectral fragments observed from the ground, the Kuiper Airborne Observatory (KAO), and the IRAS Low Resolution Spectrometer. These stars-alpha Boo, gamma Dra, alpha Cet, gamma Cru, and mu UMa-augment our six, published, absolutely calibrated spectra of K and early-M giants. All spectra have a common calibration pedigree. A revised composite for alpha Boo has been constructed from higher quality spectral fragments than our previously published one. The spectrum of gamma Dra was created in direct response to the needs of instruments aboard the Infrared Space Observatory (ISO); this star's location near the north ecliptic pole renders it highly visible throughout the mission. We compare all our low-resolution composite spectra with Kurucz model atmospheres and find good agreement in shape, with the obvious exception of the SiO fundamental, still lacking in current grids of model atmospheres. The CO fundamental seems slightly too deep in these models, but this could reflect our use of generic models with solar metal abundances rather than models specific to the metallicities of the individual stars. Angular diameters derived from these spectra and models are in excellent agreement with the best observed diameters. The ratio of our adopted Sirius and Vega models is vindicated by spectral observations. We compare IRAS fluxes predicted from our cool stellar spectra with those observed and conclude that, at 12 and 25 microns, flux densities measured by IRAS should be revised downwards by about 4.1% and 5.7%, respectively, for consistency with our absolute calibration. We have provided extrapolated continuum versions of these spectra to 300 microns, in direct support of ISO (PHT and LWS instruments). These spectra are consistent with IRAS flux densities at 60 and 100 microns

Sweeping away barriers to interdisciplinary research:recommendations based on X-Net project outcomes - March 2024

X-Net is an interdisciplinary research network whose main aim is to understand barriers to interdisciplinary research, before offering solutions to overcome them. X-Net recommends a 13-step programme of targeted multi-level interventions drawn from evidence gathered by the network in 2022- 2023. The 13 interventions would deeply weave interdisciplinarity into UK scientific research culture and free the flow of ideas and expertise across traditional disciplinary boundaries and sectors

Intimal smooth muscle cells are a source but not a sensor of anti-inflammatory CYP450 derived oxylipins

AbstractVascular pathologies are associated with changes in the presence and expression of morphologically distinct vascular smooth muscle cells. In particular, in complex human vascular lesions and models of disease in pigs and rodents, an intimal smooth muscle cell (iSMC) which exhibits a stable epithelioid or rhomboid phenotype in culture is often found to be present in high numbers, and may represent the reemergence of a distinct developmental vascular smooth muscle cell phenotype. The CYP450-oxylipin - soluble epoxide hydrolase (sEH) pathway is currently of great interest in targeting for cardiovascular disease. sEH inhibitors limit the development of hypertension, diabetes, atherosclerosis and aneurysm formation in animal models. We have investigated the expression of CYP450-oxylipin-sEH pathway enzymes and their metabolites in paired intimal (iSMC) and medial (mSMC) cells isolated from rat aorta. iSMC basally released significantly larger amounts of epoxy-oxylipin CYP450 products from eicosapentaenoic acid > docosahexaenoic acid > arachidonic acid > linoleic acid, and expressed higher levels of CYP2C12, CYP2B1, but not CYP2J mRNA compared to mSMC. When stimulated with the pro-inflammatory TLR4 ligand LPS, epoxy-oxylipin production did not change greatly in iSMC. In contrast, LPS induced epoxy-oxylipin products in mSMC and induced CYP2J4. iSMC and mSMC express sEH which metabolizes primary epoxy-oxylipins to their dihydroxy-counterparts. The sEH inhibitors TPPU or AUDA inhibited LPS-induced NFκB activation and iNOS induction in mSMC, but had no effect on NFκB nuclear localization or inducible nitric oxide synthase in iSMC; effects which were recapitulated in part by addition of authentic epoxy-oxylipins. iSMCs are a rich source but not a sensor of anti-inflammatory epoxy-oxylipins. Complex lesions that contain high levels of iSMCs may be more resistant to the protective effects of sEH inhibitors

The association between exaggeration in health related science news and academic press releases: retrospective observational study

Objective To identify the source (press releases or news) of distortions, exaggerations, or changes to the main conclusions drawn from research that could potentially influence a reader’s health related behaviour. Design Retrospective quantitative content analysis. Setting Journal articles, press releases, and related news, with accompanying simulations. Sample Press releases (n=462) on biomedical and health related science issued by 20 leading UK universities in 2011, alongside their associated peer reviewed research papers and news stories (n=668). Main outcome measures Advice to readers to change behaviour, causal statements drawn from correlational research, and inference to humans from animal research that went beyond those in the associated peer reviewed papers. Results 40% (95% confidence interval 33% to 46%) of the press releases contained exaggerated advice, 33% (26% to 40%) contained exaggerated causal claims, and 36% (28% to 46%) contained exaggerated inference to humans from animal research. When press releases contained such exaggeration, 58% (95% confidence interval 48% to 68%), 81% (70% to 93%), and 86% (77% to 95%) of news stories, respectively, contained similar exaggeration, compared with exaggeration rates of 17% (10% to 24%), 18% (9% to 27%), and 10% (0% to 19%) in news when the press releases were not exaggerated. Odds ratios for each category of analysis were 6.5 (95% confidence interval 3.5 to 12), 20 (7.6 to 51), and 56 (15 to 211). At the same time, there was little evidence that exaggeration in press releases increased the uptake of news. Conclusions Exaggeration in news is strongly associated with exaggeration in press releases. Improving the accuracy of academic press releases could represent a key opportunity for reducing misleading health related news

Reflections on Sculptural Thinking in Fashion Design

This paper explores three-dimensional thinking in fashion design; it does this by engaging with theories, concepts and philosophies related to thought and the experience of creating three-dimensional artifacts, which are common to both sculpture and fashion. Central to this relationship is the employment of the senses with respect to perception and cognition. Of particular interest is the sense of touch,and how sensory experience encounters notions of empathy and mimicry in a phenomenological encounter with others: whether animate or inanimate. The research emerged through conversations between a fashion designer, Kevin Almond and a contemporary artist, Stephen Swindells. The sensibility of the paper, and much ofthe analysis and debates, thus adopt a creative practitioners perspective. A conceptual current running through the conversation, and subsequently the paper, touched upon whether following a line of thought becomes analogous to visually and mentally tracing a human form in a psychological space – and what is the significance for fashion of the interrelationships between sculptural thinking and phenomenological encounters with others within urban environments