Publications
1046 results found
Horsager J, Andersen KB, Knudsen K, et al., 2020, Brain-first versus body-first Parkinson's disease: a multimodal imaging case-control study, BRAIN, Vol: 143, Pages: 3077-3088, ISSN: 0006-8950
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- Citations: 271
Brooks DJ, 2020, PET imaging of translocator protein expression in neurological disorders, PET and SPECT of Neurobiological Systems, Pages: 1021-1040, ISBN: 9783030531751
Microglia provide the intrinsic immune defence of the brain and are activated by any injurious process. As such they provide a non-specific marker of disease activity. Their function can be both detrimental and beneficial as they release cytokines which drive disease progression but also release restorative growth factors, help clear cellular debris and abnormal protein aggregations and can remodel connections as an adaptive response to brain damage. Activated microglia express translocator protein (TSPO), and this allows them to be imaged in vivo with positron emission tomography (PET) radioligands which are substrates. In this review the role of TSPO imaging with PET is discussed in neurodegenerative and inflammatory brain diseases and in focal brain injury due to trauma or stroke.
Palmese A, Devicente J, Pereira MES, et al., 2020, A Statistical Standard Siren Measurement of the Hubble Constant from the LIGO/Virgo Gravitational Wave Compact Object Merger GW190814 and Dark Energy Survey Galaxies, Astrophysical Journal Letters, Vol: 900, ISSN: 2041-8205
We present a measurement of the Hubble constant H 0 using the gravitational wave (GW) event GW190814, which resulted from the coalescence of a 23 M o˙ black hole with a 2.6 M o˙ compact object, as a standard siren. No compelling electromagnetic counterpart has been identified for this event; thus our analysis accounts for thousands of potential host galaxies within a statistical framework. The redshift information is obtained from the photometric redshift (photo-z) catalog from the Dark Energy Survey. The luminosity distance is provided by the LIGO/Virgo gravitational wave sky map. Since this GW event has the second-smallest localization volume after GW170817, GW190814 is likely to provide the best constraint on cosmology from a single standard siren without identifying an electromagnetic counterpart. Our analysis uses photo-z probability distribution functions and corrects for photo-z biases. We also reanalyze the binary black hole GW170814 within this updated framework. We explore how our findings impact the H 0 constraints from GW170817, the only GW merger associated with a unique host galaxy. From a combination of GW190814, GW170814, and GW170817, our analysis yields uniform between. The addition of GW190814 and GW170814 to GW170817 improves the 68% HDI from GW170817 alone by ∼18%, showing how well-localized mergers without counterparts can provide a significant contribution to standard siren measurements, provided that a complete galaxy catalog is available at the location of the event.
Yang Q, Shen Y, Liu X, et al., 2020, Dust Reverberation Mapping in Distant Quasars from Optical and Mid-infrared Imaging Surveys, Astrophysical Journal, Vol: 900, ISSN: 0004-637X
The size of the dust torus in active galactic nuclei (AGNs) and their high-luminosity counterparts, quasars, can be inferred from the time delay between UV/optical accretion disk continuum variability and the response in the mid-infrared (MIR) torus emission. This dust reverberation mapping (RM) technique has been successfully applied to ∼70 z ≲ 0.3 AGNs and quasars. Here we present first results of our dust RM program for distant quasars covered in the Sloan Digital Sky Survey Stripe 82 region combining ∼20 yr ground-based optical light curves with 10 yr MIR light curves from the WISE satellite. We measure a high-fidelity lag between W1 band (3.4 μm) and g band for 587 quasars over 0.3 ≲ z ≲ 2 (« z» ∼ 0.8) and two orders of magnitude in quasar luminosity. They tightly follow (intrinsic scatter ∼0.17 dex in lag) the IR lag-luminosity relation observed for z < 0.3 AGNs, revealing a remarkable size-luminosity relation for the dust torus over more than four decades in AGN luminosity, with little dependence on additional quasar properties such as Eddington ratio and variability amplitude. This study motivates further investigations in the utility of dust RM for cosmology and strongly endorses a compelling science case for the combined 10 yr Vera C. Rubin Observatory Legacy Survey of Space and Time (optical) and 5 yr Nancy Grace Roman Space Telescope 2 μm light curves in a deep survey for low-redshift AGN dust RM with much lower luminosities and shorter, measurable IR lags. The compiled optical and MIR light curves for 7384 quasars in our parent sample are made public with this work.
, 2020, Abstracts of the MDS Virtual Congress 2020., Mov Disord, Vol: 35 Suppl 1, Pages: S1-S702
Nicholas R, Brooks D, Owen D, 2020, 18F-GE180, a radioligand for the TSPO protein: not ready for clinical trials in multiple sclerosis, EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING, Vol: 47, Pages: 2242-2243, ISSN: 1619-7070
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- Citations: 2
Kinnerup M, Doppler C, Farrher E, et al., 2020, Noradrenergic terminal and locus coeruleus cell loss may be uncoupled in Parkinson's disease - a PET and MRI multi-modal imaging study, Movement-Disorder-Society (MDS) International Virtual Congress, Publisher: WILEY, Pages: S251-S251, ISSN: 0885-3185
Pagano G, Molloy S, Bain P, et al., 2020, Levodopa-induced dyskinesias and substantia nigra dopamine D3 receptor availability in Parkinson's disease, Movement-Disorder-Society (MDS) International Virtual Congress, Publisher: WILEY, Pages: S261-S261, ISSN: 0885-3185
Pagano G, Molloy S, Bain P, et al., 2020, Impulse control disorder and ventral striatum dopamine D3 receptor availability in Parkinson's disease, Movement-Disorder-Society (MDS) International Virtual Congress, Publisher: WILEY, Pages: S261-S261, ISSN: 0885-3185
Staer K, Iranzo A, Stokholm M, et al., 2020, Microglial activation associated with a faster progression of nigrostriatal dysfunction in patients with isolated REM sleep behavior disorder, Movement-Disorder-Society (MDS) International Virtual Congress, Publisher: WILEY, Pages: S283-S283, ISSN: 0885-3185
Sigurdsson H, Yarnall A, Galna B, et al., 2020, Identifying neural signatures of Parkinson's disease that predict decline in gait and postural control, Movement-Disorder-Society (MDS) International Virtual Congress, Publisher: WILEY, Pages: S281-S282, ISSN: 0885-3185
Pasquini J, Ceravolo R, Brooks DJ, et al., 2020, Progressive loss of raphe nuclei serotonin transporter in early Parkinson's disease: A longitudinal <SUP>123</SUP>I-FP-CIT SPECT study, PARKINSONISM & RELATED DISORDERS, Vol: 77, Pages: 170-175, ISSN: 1353-8020
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- Citations: 13
Stokholm MG, Garrido A, Tolosa E, et al., 2020, Imaging dopamine function and microglia in asymptomatic LRRK2 mutation carriers, JOURNAL OF NEUROLOGY, Vol: 267, Pages: 2296-2300, ISSN: 0340-5354
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- Citations: 10
Edison P, Femminella GD, Livingston NR, et al., 2020, Influence of cerebral glucose metabolic rate on cognitive function in Alzheimer's subjects., 2020 Alzheimer's Association International Conference
Edison P, Calsolaro V, Hinz R, et al., 2020, Microglial activation evaluated using Flutriciclamide (11F-GE180) in subjects with cognitive impairment, 2020 Alzheimer's Association International Conference
Edison P, Leng F, Hinz R, et al., 2020, Tau formation is associated with microglial activation in more widespread cortical areas than amyloid deposition does, 2020 Alzheimer's Association International Conference
Edison P, Femminella GD, Livingston NR, et al., 2020, Influence of cerebral glucose metabolic rate on cognitive function in Alzheimer's subjects, 2020 Alzheimer's Association International Conference
Femminella GD, Frangou E, Love SB, et al., 2020, Evaluating the effects of the novel GLP-1 analogue liraglutide in Alzheimer's disease: study protocol for a randomised controlled trial (ELAD study) (vol 20, 191, 2019), TRIALS, Vol: 21
Edison P, Femminella GD, Frangou E, et al., 2020, Evaluating the effects of the novel GLP-1 analogue liraglutide in Alzheimer's Disease: study protocol for a randomised controlled trial (ELAD study) (vol 20,191,2019), Trials, ISSN: 1745-6215
Hansen TT, Marshall JL, Simon JD, et al., 2020, Chemical Analysis of the Ultrafaint Dwarf Galaxy Grus II. Signature of High-mass Stellar Nucleosynthesis, Astrophysical Journal, Vol: 897, ISSN: 0004-637X
We present a detailed abundance analysis of the three brightest member stars at the top of the giant branch of the ultrafaint dwarf (UFD) galaxy Grus II. All stars exhibit a higher than expected [Mg/Ca] ratio compared to metal-poor stars in other UFD galaxies and in the Milky Way (MW) halo. Nucleosynthesis in high-mass (20 M o) core-collapse supernovae has been shown to create this signature. The abundances of this small sample (three) stars suggests the chemical enrichment of Grus II could have occurred through substantial high-mass stellar evolution, and is consistent with the framework of a top-heavy initial mass function. However, with only three stars it cannot be ruled out that the abundance pattern is the result of a stochastic chemical enrichment at early times in the galaxy. The most metal-rich of the three stars also possesses a small enhancement in rapid neutron-capture (r-process) elements. The abundance pattern of the r-process elements in this star matches the scaled r-process pattern of the solar system and r-process enhanced stars in other dwarf galaxies and in the MW halo, hinting at a common origin for these elements across a range of environments. All current proposed astrophysical sites of r-process element production are associated with high-mass stars, thus the possible top-heavy initial mass function of Grus II would increase the likelihood of any of these events occurring. The time delay between the and r-process element enrichment of the galaxy favors a neutron star merger as the origin of the r-process elements in Grus II.
Morbelli S, Esposito G, Arbizu J, et al., 2020, EANM practice guideline/SNMMI procedure standard for dopaminergic imaging in Parkinsonian syndromes 1.0, EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING, Vol: 47, Pages: 1885-1912, ISSN: 1619-7070
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- Citations: 91
Dafsari HS, Ray-Chaudhuri K, Ashkan K, et al., 2020, Beneficial effect of 24-month bilateral subthalamic stimulation on quality of sleep in Parkinson's disease., J Neurol, Vol: 267, Pages: 1830-1841
BACKGROUND: Subthalamic nucleus (STN) deep brain stimulation (DBS) improves quality of life (QoL), motor, and sleep symptoms in Parkinson's disease (PD). However, the long-term effects of STN-DBS on sleep and its relationship with QoL outcome are unclear. METHODS: In this prospective, observational, multicenter study including 73 PD patients undergoing bilateral STN-DBS, we examined PDSleep Scale (PDSS), PDQuestionnaire-8 (PDQ-8), Scales for Outcomes in PD-motor examination, -activities of daily living, and -complications (SCOPA-A, -B, -C), and levodopa-equivalent daily dose (LEDD) preoperatively, at 5 and 24 months follow-up. Longitudinal changes were analyzed with Friedman-tests or repeated-measures ANOVA, when parametric tests were applicable, and Bonferroni-correction for multiple comparisons. Post-hoc, visits were compared with Wilcoxon signed-rank/t-tests. The magnitude of clinical responses was investigated using effect size. RESULTS: Significant beneficial effects of STN-DBS were observed for PDSS, PDQ-8, SCOPA-A, -B, and -C. All outcomes improved significantly at 5 months with subsequent decrements in gains at 24 months follow-up which were significant for PDSS, PDQ-8, and SCOPA-B. Comparing baseline and 24 months follow-up, we observed significant improvements of PDSS (small effect), SCOPA-A (moderate effect), -C, and LEDD (large effects). PDSS and PDQ-8 improvements correlated significantly at 5 and 24 months follow-up. CONCLUSIONS: In this multicenter study with a 24 months follow-up, we report significant sustained improvements after bilateral STN-DBS using a PD-specific sleep scale and a significant relationship between sleep and QoL improvements. This highlights the importance of sleep in holistic assessments of DBS outcomes.
Andersen KB, Hansen AK, Sommerauer M, et al., 2020, Altered sensorimotor cortex noradrenergic function in idiopathic REM sleep behaviour disorder - A PET study, PARKINSONISM & RELATED DISORDERS, Vol: 75, Pages: 63-69, ISSN: 1353-8020
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- Citations: 20
Ismail R, Parbo P, Madsen LS, et al., 2020, The relationships between neuroinflammation, beta-amyloid and tau deposition in Alzheimer's disease: a longitudinal PET study, JOURNAL OF NEUROINFLAMMATION, Vol: 17
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- Citations: 92
Burke CJ, Baldassare VF, Liu X, et al., 2020, The Curious Case of PHL 293B: A Long-lived Transient in a Metal-poor Blue Compact Dwarf Galaxy, Astrophysical Journal Letters, Vol: 894, ISSN: 2041-8205
We report on small-amplitude optical variability and recent dissipation of the unusually persistent broad emission lines in the blue compact dwarf galaxy PHL 293B. The galaxy's unusual spectral features (P Cygni-like profiles with ∼800 km s-1 blueshifted absorption lines) have resulted in conflicting interpretations of the nature of this source in the literature. However, analysis of new Gemini spectroscopy reveals the broad emission has begun to fade after being persistent for over a decade prior. Precise difference imaging light curves constructed with the Sloan Digital Sky Survey and the Dark Energy Survey reveal small-amplitude optical variability of ∼0.1 mag in the g band offset by 100 21 pc from the brightest pixel of the host. The light curve is well-described by an active galactic nuclei (AGN)-like damped random walk process. However, we conclude that the origin of the optical variability and spectral features of PHL 293B is due to a long-lived stellar transient, likely a Type IIn supernova or nonterminal outburst, mimicking long-term AGN-like variability. This work highlights the challenges of discriminating between scenarios in such extreme environments, relevant to searches for AGNs in dwarf galaxies. This is the second long-lived transient discovered in a blue compact dwarf, after SDSS1133. Our result implies such long-lived stellar transients may be more common in metal-deficient galaxies. Systematic searches for low-level variability in dwarf galaxies will be possible with the upcoming Legacy Survey of Space and Time at the Vera C. Rubin Observatory.
Fox T, Siderowf AD, Fernandez HH, et al., 2020, Baseline Characteristics of Participants of the SPARK Trial, a Phase 2 Study of the anti-alpha-synuclein antibody Cinpanemab (BIIB054) in Parkinson's Disease, Annual Meeting of the American-Academy-of-Neurology, Publisher: LIPPINCOTT WILLIAMS & WILKINS, ISSN: 0028-3878
Drlica-Wagner A, Bechtol K, Mau S, et al., 2020, Milky Way Satellite Census. I. The Observational Selection Function for Milky Way Satellites in des Y3 and Pan-STARRS DR1, Astrophysical Journal, Vol: 893, ISSN: 0004-637X
We report the results of a systematic search for ultra-faint Milky Way satellite galaxies using data from the Dark Energy Survey (DES) and Pan-STARRS1 (PS1). Together, DES and PS1 provide multi-band photometry in optical/near-infrared wavelengths over ∼80% of the sky. Our search for satellite galaxies targets ∼25,000 deg2 of the high-Galactic-latitude sky reaching a 10σ point-source depth of ⪆22.5 mag in the g and r bands. While satellite galaxy searches have been performed independently on DES and PS1 before, this is the first time that a self-consistent search is performed across both data sets. We do not detect any new high-significance satellite galaxy candidates, recovering the majority of satellites previously detected in surveys of comparable depth. We characterize the sensitivity of our search using a large set of simulated satellites injected into the survey data. We use these simulations to derive both analytic and machine-learning models that accurately predict the detectability of Milky Way satellites as a function of their distance, size, luminosity, and location on the sky. To demonstrate the utility of this observational selection function, we calculate the luminosity function of Milky Way satellite galaxies, assuming that the known population of satellite galaxies is representative of the underlying distribution. We provide access to our observational selection function to facilitate comparisons with cosmological models of galaxy formation and evolution.
Vibholm AK, Landau AM, Alstrup AKO, et al., 2020, Activation of NMDA receptor ion channels by deep brain stimulation in the pig visualised with [<SUP>18</SUP>F]GE-179 PET, BRAIN STIMULATION, Vol: 13, Pages: 1071-1078, ISSN: 1935-861X
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- Citations: 10
Simon JD, Li TS, Erkal D, et al., 2020, Birds of a Feather? Magellan/IMACS Spectroscopy of the Ultra-faint Satellites Grus II, Tucana IV, and Tucana v, Astrophysical Journal, Vol: 892, ISSN: 0004-637X
We present Magellan/IMACS spectroscopy of three recently discovered ultra-faint Milky Way satellites, Grus II, Tucana IV, and Tucana V. We measure systemic velocities of vhel=-110.0 ± 0.5 kms-1, vhel= 15.9-1.7+1.8kms-1 and vhel=-36.2-2.2+2.5 kms-1 for the three objects, respectively. Their large relative velocities demonstrate that the satellites are unrelated despite their close physical proximity. We determine a velocity dispersion for Tuc IV of σ = 4.3-1.0+1.7km s-1 but we cannot resolve the velocity dispersions of the other two systems. For Gru II, we place an upper limit (90% confidence) on the dispersion of σ < 1.9 kms-1 and for Tuc V, we do not obtain any useful limits. All three satellites have metallicities below, but none has a detectable metallicity spread. We determine proper motions for each satellite based on Gaia astrometry and compute their orbits around the Milky Way. Gru II is on a tightly bound orbit with a pericenter of 25-7+6 kpc and orbital eccentricity of 0.45-0.05+0.08. Tuc V likely has an apocenter beyond 100 kpc and could be approaching the Milky Way for the first time. The current orbit of Tuc IV is similar to that of Gru II, with a pericenter of 25-8+11 kpc and an eccentricity of 0.36-0.06+0.13. However, a backward integration of the position of Tuc IV demonstrates that it collided with the Large Magellanic Cloud at an impact parameter of 4 kpc ∼120 Myr ago, deflecting its trajectory and possibly altering its internal kinematics. Based on their sizes, masses, and metallicities, we classify Gru II and Tuc IV as likely dwarf galaxies, but the nature of Tuc V remains uncertain.
Khain T, Becker JC, Lin HW, et al., 2020, Dynamical Classification of Trans-Neptunian Objects Detected by the Dark Energy Survey, Astronomical Journal, Vol: 159, ISSN: 0004-6256
The outer solar system contains a large number of small bodies (known as trans-Neptunian objects or TNOs) that exhibit diverse types of dynamical behavior. The classification of bodies in this distant region into dynamical classes-subpopulations that experience similar orbital evolution- A ids in our understanding of the structure and formation of the solar system. In this work, we propose an updated dynamical classification scheme for the outer solar system. This approach includes the construction of a new (automated) method for identifying mean motion resonances. We apply this algorithm to the current data set of TNOs observed by the Dark Energy Survey (DES) and present a working classification for all of the DES TNOs detected to date. Our classification scheme yields 1 inner centaur, 19 outer centaurs, 21 scattering disk objects, 47 detached TNOs, 48 securely resonant objects, 7 resonant candidates, and 97 classical belt objects. Among the scattering and detached objects, we detect 8 TNOs with semimajor axes greater than 150 au.
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