252 research outputs found
Recognition of Famous Names Predicts Cognitive Decline in Healthy Elders
Objective: The ability to recognize familiar people is impaired in both Mild Cognitive Impairment (MCI) and Alzheimer’s Dementia (AD). In addition, both groups often demonstrate a time-limited temporal gradient (TG) in which well known people from decades earlier are better recalled than those learned recently. In this study, we examined the TG in cognitively intact elders for remote famous names (1950–1965) compared to more recent famous names (1995–2005). We hypothesized that the TG pattern on a famous name recognition task (FNRT) would predict future cognitive decline, and also show a significant correlation with hippocampal volume.
Method: Seventy-eight healthy elders (ages 65–90) with age-appropriate cognitive functioning at baseline were administered a FNRT. Follow-up testing 18 months later produced two groups: Declining (≥ 1 SD reduction on at least one of three measures) and Stable (\u3c 1 SD).
Results: The Declining group (N = 27) recognized fewer recent famous names than the Stable group (N = 51), although recognition for remote names was comparable. Baseline MRI volumes for both the left and right hippocampi were significantly smaller in the Declining group than the Stable group. Smaller baseline hippocampal volume was also significantly correlated with poorer performance for recent, but not remote famous names. Logistic regression analyses indicated that baseline TG performance was a significant predictor of group status (Declining vs. Stable) independent of chronological age and APOE ε4 inheritance.
Conclusions: The TG for famous name recognition may serve as an early preclinical cognitive marker of cognitive decline in healthy older individual
Design and Assembly of a Large-aperture Nb3Sn Cos-theta Dipole Coil with Stress Management in Dipole Mirror Configuration
The stress-management cos-theta (SMCT) coil is a new concept which has been
proposed and is being developed at Fermilab in the framework of US Magnet
Development Program (US-MDP) for high-field and/or large-aperture accelerator
magnets based on low-temperature and high-temperature superconductors. The SMCT
structure is used to reduce large coil deformations under the Lorentz forces
and, thus, the excessively large strains and stresses in the coil. A
large-aperture Nb3Sn SMCT dipole coil has been developed and fabricated at
Fermilab to demonstrate and test the SMCT concept including coil design,
fabrication technology and performance. The first SMCT coil has been assembled
with 60-mm aperture Nb3Sn coil inside a dipole mirror configuration and will be
tested separately and in series with the insert coil. This paper summarizes the
large-aperture SMCT coil design and parameters and reports the coil fabrication
steps and its assembly in dipole mirror configuration
Field quality of quadrupole R&D models for the LHC IR
Superconducting quadrupole magnets operating in superfluid helium at 1.9 K, with 70 mm bore and nominal field gradient of 205 T/m at collision optics, are being developed by the US LHC Accelerator Project for the Interaction Regions of the Large Hadron Collider (LHC). A magnet model program to validate and optimize the design is underway. This paper reports results of field quality measurements of four model magnets. (3 refs)
Development and Test of a Large-aperture Nb3Sn Cos-theta Dipole Coil with Stress Management
The design concept of the Electron Ion Collider (EIC), which is under
construction at BNL, considers adding a 2nd Interaction Region (IR) and
detector to the machine after completion of the present EIC project. Recent
progress with development and fabrication of large-aperture high-field magnets
based on the Nb3Sn technology for the HL-LHC makes this technology interesting
for the 2nd EIC IR. This paper summarizes the results of feasibility studies of
large-aperture high-field Nb3Sn dipoles and quadrupoles for the 2nd EIC IR.Comment: IPAC 2023. arXiv admin note: text overlap with arXiv:2304.1315
Quench performance of Fermilab high gradient quadrupole short models for the LHC Interaction Regions
Fermilab and LBNL are in the midst of superconducting magnet R&D program to test and optimize the design of quadrupoles to be used in the LHC Interaction Region inner triplets. The magnets are required to deliver a 215 T/m gradient across a 70 mm aperture. Five quadrupole short models have been fabricated and four of them have been tested. This paper describes the last model design details and reports the results of the magnet quench performance study. (5 refs)
fMRI scanner noise interaction with affective neural processes
The purpose of the present study was the investigation of interaction effects between functional MRI scanner noise and affective neural processes. Stimuli comprised of psychoacoustically balanced musical pieces, expressing three different emotions (fear, neutral, joy). Participants (N=34, 19 female) were split into two groups, one subjected to continuous scanning and another subjected to sparse temporal scanning that features decreased scanner noise. Tests for interaction effects between scanning group (sparse/quieter vs continuous/noisier) and emotion (fear, neutral, joy) were performed. Results revealed interactions between the affective expression of stimuli and scanning group localized in bilateral auditory cortex, insula and visual cortex (calcarine sulcus). Post-hoc comparisons revealed that during sparse scanning, but not during continuous scanning, BOLD signals were significantly stronger for joy than for fear, as well as stronger for fear than for neutral in bilateral auditory cortex. During continuous scanning, but not during sparse scanning, BOLD signals were significantly stronger for joy than for neutral in the left auditory cortex and for joy than for fear in the calcarine sulcus. To the authors' knowledge, this is the first study to show a statistical interaction effect between scanner noise and affective processes and extends evidence suggesting scanner noise to be an important factor in functional MRI research that can affect and distort affective brain processes
Field Quality Measurements in a Single-Aperture 11 T Nb3Sn Demonstrator Dipole for LHC Upgrades
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Quench Protection Study of a Single-Aperture 11 T Nb3Sn Demonstrator Dipole for LHC Upgrades
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Larmor Power Limit for Cyclotron Radiation of Relativistic Particles in a Waveguide
Cyclotron radiation emission spectroscopy (CRES) is a modern technique for
high-precision energy spectroscopy, in which the energy of a charged particle
in a magnetic field is measured via the frequency of the emitted cyclotron
radiation. The He6-CRES collaboration aims to use CRES to probe beyond the
standard model physics at the TeV scale by performing high-resolution and
low-background beta-decay spectroscopy of and
. Having demonstrated the first observation of individual,
high-energy (0.1 -- 2.5 MeV) positrons and electrons via their cyclotron
radiation, the experiment provides a novel window into the radiation of
relativistic charged particles in a waveguide via the time-derivative (slope)
of the cyclotron radiation frequency, . We
show that analytic predictions for the total cyclotron radiation power emitted
by a charged particle in circular and rectangular waveguides are approximately
consistent with the Larmor formula, each scaling with the Lorentz factor of the
underlying as . This hypothesis is corroborated with
experimental CRES slope data.Comment: 20 pages, 5 figure
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