Sensitivity of the Mini-Mental State Examination, Montreal Cognitive Assessment and the Addenbrooke’s Cognitive Examination III to everyday activity impairments in dementia: An exploratory study

Objective: The Mini-Mental State Examination (MMSE) is one of the most frequently used cognitive measures for dementia severity, and linked to deficits in everyday functioning. Recently, the Montreal Cognitive Assessment (MoCA) and the Addenbrooke's Cognitive Examination III (ACE-III) increasingly substitute for the MMSE. However, there are no specific cut offs in the ACE-III for mild dementia. The objectives of this exploratory study were to assess the sensitivity of each scale to everyday functioning and to examine the cut offs between mild and moderate dementia on the ACE-III. Methods: People with mild dementia completed the MMSE, MoCA and ACE-III, whilst informal carers completed the Revised Interview for Deteriorations in Daily Living Activities for Dementia to rate their relative’s initiative and performance of instrumental activities of daily living, and the Katz activities of daily living scale. Data were analysed using correlation analysis, raw score comparisons, Cohen’s kappa and Receiver Operating Characteristics analysis. Results: Thirty-three dyads completed the measures. The ACE-III was the most sensitive tool for everyday functioning performance, whilst its language sub-scale was specifically related to initiation of activities. The most suitable cut off on the ACE-III between mild and moderate dementia was 61. Conclusions: Findings suggest ACE-III more efficiently identifies everyday functional impairments. Further research is required to confirm these exploratory analyses of the cut off between mild and moderate dementia on the ACE-III. Both functional impairment and stage of dementia are needed in the diagnostic process and in the clinical assessment of people with dementia

Theory of preparation and relaxation of a p-orbital atomic Mott insulator

We develop a theoretical framework to understand the preparation and relaxation of a metastable Mott insulator state within the first excited band of a 1D optical lattice. The state is loaded by "lifting" atoms from the ground to the first excited band by means of a stimulated Raman transition. We determine the effect of pulse duration on the accuracy of the state preparation for the case of a Gaussian pulse shape. Relaxation of the prepared state occurs in two major stages: double-occupied sites occurring due to quantum fluctuations initially lead to interband transitions followed by a spreading of particles in the trap and thermalization. We find the characteristic relaxation times at the earliest stage and at asymptotically long times approaching equilibrium. Our theory is applicable to recent experiments performed with 1D optical lattices [T. M\"uller, S. F\"olling, A. Widera, and I. Bloch, Phys. Rev. Lett. \textbf{99}, 200405 (2007)].Comment: 27 pages, 23 figures: Edited figures, added reference

PS1-10jh Continues to Follow the Fallback Accretion Rate of a Tidally Disrupted Star

We present late-time observations of the tidal disruption event candidate PS1-10jh. UV and optical imaging with HST/WFC3 localize the transient to be coincident with the host galaxy nucleus to an accuracy of 0.023 arcsec, corresponding to 66 pc. The UV flux in the F225W filter, measured 3.35 rest-frame years after the peak of the nuclear flare, is consistent with a decline that continues to follow a $t^{-5/3}$ power-law with no spectral evolution. Late epochs of optical spectroscopy obtained with MMT ~ 2 and 4 years after the peak, enable a clean subtraction of the host galaxy from the early spectra, revealing broad helium emission lines on top of a hot continuum, and placing stringent upper limits on the presence of hydrogen line emission. We do not measure Balmer H\delta absorption in the host galaxy strong enough to be indicative of a rare, post-starburst "E+A" galaxy as reported by Arcavi et al. (2014). The light curve of PS1-10jh over a baseline of 3.5 yr is best modeled by fallback accretion of a tidally disrupted star. Its strong broad helium emission relative to hydrogen (He II \lambda 4686/H\alpha > 5) could be indicative of either the hydrogen-poor chemical composition of the disrupted star, or certain conditions in the tidal debris of a solar-composition star in the presence of an optically-thick, extended reprocessing envelope.Comment: Accepted for publication in ApJ Letter

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

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