154 research outputs found
Electroencephalogram findings in patients with posterior cortical atrophy
Aim of the study: The aim of this study is to evaluate standard scalp EEG findings in patients with posterior cortical atrophy (PCA), an atypical variant of Alzheimer's disease (AD).
Clinical rationale: PCA is a topographically selective variant of AD. Patients with typical AD have an increased likelihood of seizures, which may negatively impact overall functional performance and cognition. It is currently unknown what the typical EEG findings are for patients with PCA.
Materials and methods: A retrospective chart review was performed on patients identified either with autopsy confirmed (n = 13) or clinically (n = 126) as PCA.
Results: 139 patients were included though only 23 (16.5%) had undergone EEG recording. The EEG was normal in 6 (26%), while an abnormal EEG was present in 17 (74%). Interictal epileptic discharges (IEDs) were found in 2 of the 23 patients (9%).
Conclusions: This study of limited sample size suggests that there may be an increased predilection to find IEDs within PCA when compared to typical AD. Larger cohorts are required to determine frequency of abnormal EEGs in PCA, roles of AEDs in therapy, and in the selection of preferred AED.
Clinical implications: Patients with PCA would potentially benefit from an EEG for assessment of IEDs which may provide the clinician with a therapeutic opportunity
PAR Proteins Regulate Microtubule Dynamics at the Cell Cortex in C. elegans
BACKGROUND: The PAR proteins are known to be localized asymmetrically in polarized C. elegans, Drosophila, and human cells and to participate in several cellular processes, including asymmetric cell division and spindle orientation. Although astral microtubules are known to play roles in these processes, their behavior during these events remains poorly understood.
RESULTS: We have developed a method that makes it possible to examine the residence time of individual astral microtubules at the cell cortex of developing embryos. Using this method, we found that microtubules are more dynamic at the posterior cortex of the C. elegans embryo compared to the anterior cortex during spindle displacement. We further observed that this asymmetry depends on the PAR-3 protein and heterotrimeric G protein signaling, and that the PAR-2 protein affects microtubule dynamics by restricting PAR-3 activity to the anterior of the embryo.
CONCLUSIONS: These results indicate that PAR proteins function to regulate microtubule dynamics at the cortex during microtubule-dependent cellular processes
Instabilities in a Two-Component, Species Conserving Condensate
We consider a system of two species of bosons of equal mass, with
interactions and for bosons of the same and different
species respectively. We present a rigorous proof -- valid when the Hamiltonian
does not include a species switching term -- showing that, when
, the ground state is fully "polarized" (consists of
atoms of one kind only). In the unpolarized phase the low energy excitation
spectrum corresponds to two linearly dispersing modes that are even a nd odd
under species exchange. The polarization instability is signaled by the vani
shing of the velocity of the odd modes.Comment: To appear in Phys. Rev.
Primeval Corrections to the CMB Anisotropies
We show that deviations of the quantum state of the inflaton from the thermal
vacuum of inflation may leave an imprint in the CMB anisotropies. The quantum
dynamics of the inflaton in such a state produces corrections to the
inflationary fluctuations, which may be observable. Because these effects
originate from IR physics below the Planck scale, they will dominate over any
trans-Planckian imprints in any theory which obeys decoupling. Inflation sweeps
away these initial deviations and forces its quantum state closer to the
thermal vacuum. We view this as the quantum version of the cosmic no-hair
theorem. Such imprints in the CMB may be a useful, independent test of the
duration of inflation, or of significant features in the inflaton potential
about 60 e-folds before inflation ended, instead of an unlikely discovery of
the signatures of quantum gravity. The absence of any such substructure would
suggest that inflation lasted uninterrupted much longer than
e-folds.Comment: 17 pages, latex, no figures; v3: added references and comments, final
version to appear in Phys. Rev.
Spinor condensates and light scattering from Bose-Einstein condensates
These notes discuss two aspects of the physics of atomic Bose-Einstein
condensates: optical properties and spinor condensates. The first topic
includes light scattering experiments which probe the excitations of a
condensate in both the free-particle and phonon regime. At higher light
intensity, a new form of superradiance and phase-coherent matter wave
amplification were observed. We also discuss properties of spinor condensates
and describe studies of ground--state spin domain structures and dynamical
studies which revealed metastable excited states and quantum tunneling.Comment: 58 pages, 33 figures, to appear in Proceedings of Les Houches 1999
Summer School, Session LXXI
Evaluation of basil extract ( Ocimum basilicum L.) on oxidative, anti-genotoxic and anti-inflammatory effects in human leukocytes cell cultures exposed to challenging agents
Superimposed Oscillations in the WMAP Data?
The possibility that the cosmic variance outliers present in the recently
released WMAP multipole moments are due to oscillations in the primordial power
spectrum is investigated. Since the most important contribution to the WMAP
likelihood originates from the outliers at relatively small angular scale
(around the first Doppler peak), special attention is paid to these in contrast
with previous studies on the subject which have concentrated on the large
scales outliers only (i.e. the quadrupole and octupole). As a physically
motivated example, the case where the oscillations are of trans-Planckian
origin is considered. It is shown that the presence of the oscillations causes
an important drop in the WMAP chi square of about fifteen. The F-test reveals
that such a drop has a probability less than 0.06% to occur by chance and can
therefore be considered as statistically significant.Comment: 9 pages, 3 figures, uses RevTex 4, references added, matches
published versio
A joint Fermi-GBM and Swift-BAT analysis of gravitational-wave candidates from the third gravitational-wave observing run
We present Fermi Gamma-ray Burst Monitor (Fermi-GBM) and Swift Burst Alert Telescope (Swift-BAT) searches for gamma-ray/X-ray counterparts to gravitational-wave (GW) candidate events identified during the third observing run of the Advanced LIGO and Advanced Virgo detectors. Using Fermi-GBM onboard triggers and subthreshold gamma-ray burst (GRB) candidates found in the Fermi-GBM ground analyses, the Targeted Search and the Untargeted Search, we investigate whether there are any coincident GRBs associated with the GWs. We also search the Swift-BAT rate data around the GW times to determine whether a GRB counterpart is present. No counterparts are found. Using both the Fermi-GBM Targeted Search and the Swift-BAT search, we calculate flux upper limits and present joint upper limits on the gamma-ray luminosity of each GW. Given these limits, we constrain theoretical models for the emission of gamma rays from binary black hole mergers
Britain prepares for peace British preparations for the Paris Peace Conference, 1916-1919
SIGLEAvailable from British Library Lending Division - LD:D55563/85 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
The added value of advanced neuro-imaging (MR diffusion, perfusion and proton spectroscopy) in diagnosis of primary CNS lymphoma
- âŠ