Gut-seeded α-synuclein fibrils promote gut dysfunction and brain pathology specifically in aged mice

Parkinson’s disease is a synucleinopathy that is characterized by motor dysfunction, death of midbrain dopaminergic neurons and accumulation of α-synuclein (α-Syn) aggregates. Evidence suggests that α-Syn aggregation can originate in peripheral tissues and progress to the brain via autonomic fibers. We tested this by inoculating the duodenal wall of mice with α-Syn preformed fibrils. Following inoculation, we observed gastrointestinal deficits and physiological changes to the enteric nervous system. Using the AAV-PHP.S capsid to target the lysosomal enzyme glucocerebrosidase for peripheral gene transfer, we found that α-Syn pathology is reduced due to the increased expression of this protein. Lastly, inoculation of α-Syn fibrils in aged mice, but not younger mice, resulted in progression of α-Syn histopathology to the midbrain and subsequent motor defects. Our results characterize peripheral synucleinopathy in prodromal Parkinson’s disease and explore cellular mechanisms for the gut-to-brain progression of α-Syn pathology

Bragg scattering of Cooper pairs in an ultra-cold Fermi gas

We present a theoretical treatment of Bragg scattering of a degenerate Fermi gas in the weakly interacting BCS regime. Our numerical calculations predict correlated scattering of Cooper pairs into a spherical shell in momentum space. The scattered shell of correlated atoms is centered at half the usual Bragg momentum transfer, and can be clearly distinguished from atoms scattered by the usual single-particle Bragg mechanism. We develop an analytic model that explains key features of the correlated-pair Bragg scattering, and determine the dependence of this scattering on the initial pair correlations in the gas.Comment: Manuscript substantially revised. Version 2 contains a more detailed discussion of the collisional interaction used in our theory, and is based on three-dimensional solution

An ultraviolet excess in the superluminous supernova Gaia16apd reveals a powerful central engine

Since the discovery of superluminous supernovae (SLSNe) in the last decade, it has been known that these events exhibit bluer spectral energy distributions than other supernova subtypes, with significant output in the ultraviolet. However, the event Gaia16apd seems to outshine even the other SLSNe at rest-frame wavelengths below $\sim 3000$ \AA. Yan et al (2016) have recently presented HST UV spectra and attributed the UV flux to low metallicity and hence reduced line blanketing. Here we present UV and optical light curves over a longer baseline in time, revealing a rapid decline at UV wavelengths despite a typical optical evolution. Combining the published UV spectra with our own optical data, we demonstrate that Gaia16apd has a much hotter continuum than virtually any SLSN at maximum light, but it cools rapidly thereafter and is indistinguishable from the others by $\sim 10$-15 days after peak. Comparing the equivalent widths of UV absorption lines with those of other events, we show that the excess UV continuum is a result of a more powerful central power source, rather than a lack of UV absorption relative to other SLSNe or an additional component from interaction with the surrounding medium. These findings strongly support the central-engine hypothesis for hydrogen-poor SLSNe. An explosion ejecting $M_{\rm ej} = 4 (0.2/\kappa)$ M$_\odot$, where $\kappa$ is the opacity in cm$^2$g$^{-1}$, and forming a magnetar with spin period $P=2$ ms, and $B=2\times10^{14}$ G (lower than other SLSNe with comparable rise-times) can consistently explain the light curve evolution and high temperature at peak. The host metallicity, $Z=0.18$ Z$_\odot$, is comparable to other SLSNe.Comment: Updated to match accepted version (ApJL

Designing for Musical Play

Though sensory spaces are a common feature within many special needs schools, the way in which they are designed and resourced varies greatly between provisions as do the types of activities that take place within them. A short series of case studies has been carried out across a cross section of UK special needs schools to demonstrate this contrast whilst also attempting to better understand the reasoning and motivation behind their design and usage. In 2012, eight schools were visited in England and Wales with the aim of documenting the types of sensory space that were available, the resources that were featured within each space and the types of sensory activities that were being used. The key themes that emerged during the case studies are discussed alongside an historical overview of the conception and evolution of the multisensory environment

Nonlinear atom-optical delta-kicked harmonic oscillator using a Bose-Einstein condensate

We experimentally investigate the atom-optical delta-kicked harmonic oscillator for the case of nonlinearity due to collisional interactions present in a Bose-Einstein condensate. A Bose condensate of rubidium atoms tightly confined in a static harmonic magnetic trap is exposed to a one-dimensional optical standing-wave potential that is pulsed on periodically. We focus on the quantum anti-resonance case for which the classical periodic behavior is simple and well understood. We show that after a small number of kicks the dynamics is dominated by dephasing of matter wave interference due to the finite width of the condensate's initial momentum distribution. In addition, we demonstrate that the nonlinear mean-field interaction in a typical harmonically confined Bose condensate is not sufficient to give rise to chaotic behavior.Comment: 4 pages, 3 figure

An Atlas of Spectrophotometric Landolt Standard Stars

We present CCD observations of 102 Landolt standard stars obtained with the R-C spectrograph on the CTIO 1.5 m telescope. Using stellar atmosphere models we have extended the flux points to our six spectrophotometric secondary standards, in both the blue and the red, allowing us to produce flux-calibrated spectra that span a wavelength range from 3050 \AA to 1.1 \micron. Mean differences between UBVRI spectrophotometry computed using Bessell's standard passbands and Landolt's published photometry is found to be 1% or less. Observers in both hemispheres will find these spectra useful for flux-calibrating spectra and through the use of accurately constructed instrumental passbands be able to compute accurate corrections to bring instrumental magnitudes to any desired standard photometric system (S-corrections). In addition, by combining empirical and modeled spectra of the Sun, Sirius and Vega, we calculate and compare synthetic photometry to observed photometry taken from the literature for these three stars.Comment: Added referee's comments, minor corrections, replaced Table 1

Defining digital-Foley for live performance

Using a series of reflective case-studies, the role of the Foley artist is reconsidered alongside technological innovations in both digital sound manipulation and physical computing. Through a series of theatrical productions and collaborations Challis and Dean have explored the sonic and dramatic possibilities created by the utilisation of digital technology in a live performance context. In this article, a variety of approaches to electronic sound-production and control are described along with first-hand reflections on the expressivity and control that are offered by each within a context of live drama. Their current project is a multimedia adaptation of the novel and film Metropolis where the aural accompaniment will be performed live using a range of adapted and purpose built sonic triggers. In defining digital-Foley, design considerations and key principles are outlined that can enhance the connectivity between the sound-artist and the sonic-landscapes they create

Metropolis raised her voice: Live digital-foley & multimedia accompaniment

Since sound was first recorded on a cylinder wrapped in tin foil by Edison in 1877, technology has steadily evolved to allow an ever increasing level of sonic mutability. Gradually, pre-recorded sounds (or 'inputs') which where once fixed could be increasingly manipulated both before and during playback. While early gramophones and tape players afforded the operator very few parameters to experiment within, the development of digital technology transformed sound into a fully plastic medium. As such, sound in the age of digital reproduction has achieved a level of playability more commonly associated with the performance of live music. The sound-operator is now able to react to events unfolding in a live environment and adjust both subtle and prominent aspects of the sound in many of the same ways a musician can. Through a series of theatrical productions and collaborations Challis & Dean have explored the sonic and dramatic possibilities created by the utilization of digital technology in a live performance context. Their current project is a multimedia adaptation of the novel and film Metropolis (Harbou & Lang, 1927). The aural accompaniment for this project will be performed live using a range of adapted and purpose built sonic triggers (such as accelerometers, gyroscopes, tilt switches, and proximity sensors). This paper will outline the processes and techniques adopted in this production and consider how this way of working has altered the interactional relationship between those that perform sound and those that receive it