The Church in Andalusia during the Franco regime.

SIGLELD:D48057/83 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

A Dark Matter Hurricane: Measuring the S1 Stream with Dark Matter Detectors

The recently discovered S1 stream passes through the Solar neighbourhood on a low inclination, counter-rotating orbit. The progenitor of S1 is a dwarf galaxy with a total mass comparable to the present-day Fornax dwarf spheroidal, so the stream is expected to have a significant DM component. We compute the effects of the S1 stream on WIMP and axion detectors as a function of the density of its unmeasured dark component. In WIMP detectors the S1 stream supplies more high energy nuclear recoils so will marginally improve DM detection prospects. We find that even if S1 comprises less than 10% of the local density, multi-ton xenon WIMP detectors can distinguish the S1 stream from the bulk halo in the relatively narrow mass range between 5 and 25 GeV. In directional WIMP detectors such as CYGNUS, S1 increases DM detection prospects more substantially since it enhances the anisotropy of the WIMP signal. Finally, we show that axion haloscopes possess by far the greatest potential sensitivity to the S1 stream. Once the axion mass has been discovered, the distinctive velocity distribution of S1 can easily be extracted from the axion power spectrum.Comment: 21 pages, 11 figure

The relationship between visual discomfort and cortical excitability in cone-opponent stimuli

Increased colour contrast can induce visual discomfort, but there is little research on the effect of hue. Colour is processed via one or more information streams or channels. We hypothesized that hues which activate more than one channel would induce greater visual discomfort, as they will demand greater neural resources. Normally-sighted young observers made discomfort judgments of isoluminant stimuli of varying hue and contrast whilst EEG was recorded. As predicted, stimuli recruiting more than one channel were more uncomfortable, and this increased with contrast. Uncomfortable stimuli showed increased N2 event-related potentials and decreased alpha-band oscillations, potentially indicating increased neural excitability. This is evidence that increased neural responses are related to visual discomfort for chromatic stimuli. Furthermore, it suggests that the origins of visual discomfort are in early visual areas, when colour is represented in a cone-opponent space, rather than later areas where colour representation is determined by perceptual similarity

Guidelines for type 2 diabetes: keeping a finger on the pulse

Cardiovascular disease remains the biggest cause of morbidity and mortality in patients with type 2 diabetes.1 Individual drugs from two classes of glucose-lowering agents, glucagon-like peptide-1 (GLP-1)receptor agonists and sodium-glucose cotransporter-2 (SGLT2) inhibitors, have been shown in recent clinical trials to improve cardiovascular outcomes in patients with type 2 diabetes at high risk of cardiovascular disease. These new data are reflected in guidelines from several professional associations, but not in the National Institute for Health and Care Excellence (NICE) guidelines in the UK.2 We believe that NICE and other national and international health authorities should respond rapidly to new data, particularly when there is potential to improve outcomes and save lives

Axion minicluster streams in the solar neighbourhood

A consequence of QCD axion dark matter being born after inflation is the emergence of ultra-small-scale substructures known as miniclusters. Although miniclusters merge to form minihalos, this intrinsic granularity is expected to remain imprinted on small scales in our galaxy, leading to potentially damning consequences for the campaign to detect axions directly on Earth. This picture, however, is modified when one takes into account the fact that encounters with stars will tidally strip mass from the miniclusters, creating pc-long tidal streams that act to refill the dark matter distribution. Here we ask whether or not this stripping rescues experimental prospects from the worst-case scenario in which the majority of axions remain bound up in unobservably small miniclusters. We find that the density sampled by the Earth on mpc-scales will be, on average, around 70-90% of the known local DM density, and at a typical point in the solar neighbourhood, we expect most of the dark matter to be comprised of debris from $\mathcal{O}(10^2$-$10^3)$ overlapping streams. If haloscopes can measure the axion signal with high-enough frequency resolution, then these streams are revealed in the form of an intrinsically spiky lineshape, in stark contrast with the standard assumption of a smooth, featureless Maxwellian distribution -- a unique prediction that constitutes a way for experiments to distinguish between pre and post-inflationary axion cosmologies.Comment: 5 + 8 page

Simultaneous differential scanning calorimetry – synchrotron X-ray powder diffraction : a powerful technique for physical form characterisation in pharmaceutical materials

© 2016 American Chemical Society. We report a powerful new technique: hyphenating synchrotron X-ray powder diffraction (XRD) with differential scanning calorimetry (DSC). This is achieved with a simple modification to a standard laboratory DSC instrument, in contrast to previous reports which have involved extensive and complex modifications to a DSC to mount it in the synchrotron beam. The high-energy X-rays of the synchrotron permit the recording of powder diffraction patterns in as little as 2 s, meaning that thermally induced phase changes can be accurately quantified and additional insight on the nature of phase transitions obtained. Such detailed knowledge cannot be gained from existing laboratory XRD instruments, since much longer collection times are required. We demonstrate the power of our approach with two model systems, glutaric acid and sulfathiazole, both of which show enantiotropic polymorphism. The phase transformations between the low and high temperature polymorphs are revealed to be direct solid-solid processes, and sequential refinement against the diffraction patterns obtained permits phase fractions at each temperature to be calculated and unit cell parameters to be accurately quantified as a function of temperature. The combination of XRD and DSC has further allowed us to identify mixtures of phases which appeared phase-pure by DSC