2,934 research outputs found
Maltreated and non-maltreated children's true and false memories of neutral and emotional word lists in the DRM task
Maltreated (n = 26) and non - maltreated (n = 31) 7 - to 12 - year - old children were tested on the Deese/Roediger - McDermot (DRM) false memory task using emotional and neutral word lists. True recall was significantly better for non - maltreated than maltreated children regardless of list valence. The proportion of false recall for neutral lists was comparable regardless of maltreatment status. However, maltreated children showed a significantly higher false recall rate for the emotional lists than non - maltreated children. Together, these results provide new evidence that maltreated children could be more prone to false memory illusions for negatively - valenced information than their non - maltreated counterparts
Validation of the Human Ozone Challenge Model as a Tool for Assessing Anti-Inflammatory Drugs in Early Development
This study aimed to test the utility of the ozone challenge model for profiling novel compounds designed to reduce airway inflammation. The authors used a randomized, doubledummy, double-blind, placebo-controlled 3-period crossover design alternating single orally inhaled doses of fluticasone propionate (inhaled corticosteroids, 2mg), oral prednisolone (oral corticosteroids, 50mg), ormatched placebo. At a 2-week interval, 18 healthy ozone responders (>10% increase in sputum neutrophils) underwent a 3-hour ozone (250 ppb)/intermittent exercise challenge starting 1 hour after drug treatment. Airway inflammation was assessed at 2 hours (breath condensate) and 3 hours (induced sputum) after ozone challenge. Compared to placebo, pretreatment with inhaled corticosteroids or oral corticosteroids resulted in a significant reduction (mean [95% confidence interval]) of sputum neutrophils by 62% (35%, 77%) and 64% (39%, 79%) and of sputum supernatant myeloperoxidase by 55% (41%, 66%) and 42% (25%, 56%), respectively. The authors conclude that an optimized ozone challenge model (including ozone responders and ensuring adequate drug levels during exposure) may be useful for testing novel anti-inflammatory compounds in early development
The influence of spatial pattern on visual short-term memory for contrast
Several psychophysical studies of visual short-term memory (VSTM) have shown high-fidelity storage capacity for many properties of visual stimuli. On judgments of the spatial frequency of gratings, for example, discrimination performance does not decrease significantly, even for memory intervals of up to 30 s. For other properties, such as stimulus orientation and contrast, however, such “perfect storage” behavior is not found, although the reasons for this difference remain unresolved. Here, we report two experiments in which we investigated the nature of the representation of stimulus contrast in VSTM using spatially complex, two-dimensional random-noise stimuli. We addressed whether information about contrast per se is retained during the memory interval by using a test stimulus with the same spatial structure but either the same or the opposite local contrast polarity, with respect to the comparison (i.e., remembered) stimulus. We found that discrimination thresholds got steadily worse with increasing duration of the memory interval. Furthermore, performance was better when the test and comparison stimuli had the same local contrast polarity than when they were contrast-reversed. Finally, when a noise mask was introduced during the memory interval, its disruptive effect was maximal when the spatial configuration of its constituent elements was uncorrelated with those of the comparison and test stimuli. These results suggest that VSTMfor contrast is closely tied to the spatial configuration of stimuli and is not transformed into a more abstract representation
Treatment of Advanced Emphysema with Emphysematous Lung Sealant (AeriSeal (R))
Background: This report summarizes initial tests of an emphysematous lung synthetic polymer sealant (ELS) designed to reduce lung volume in patients with advanced emphysema. Objectives: The primary study objective was to define a therapeutic strategy to optimize treatment safety and effectiveness. Methods: ELS therapy was administered bronchoscopically to 25 patients with heterogeneous emphysema in an open-label, noncontrolled study at 6 centers in Germany. Treatment was performed initially at 2-4 subsegments. After 12 weeks, patients were eligible for repeat therapy to a total of 6 sites. Safety and efficacy were assessed after 6 months. Responses were evaluated in terms of changes from baseline in lung physiology, functional capacity, and health-related quality of life. Follow-up is available for 21 of 25 patients. Results: Treatment was well tolerated. There were no treatment-related deaths (i.e. within 90 days of treatment), and an acceptable short-and long-term safety profile. Physiological and clinical benefits were observed at 24 weeks. Efficacy responses were better among Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage III patients {[}n = 14; change in residual volume/total lung capacity (Delta RV/TLC) = -7.4 +/- 10.3%; Delta forced expiratory volume in 1 s (Delta FEV(1)) = +15.9 +/- 22.6%; change in forced vital capacity (Delta FVC) = +24.1 +/- 22.7%; change in carbon monoxide lung diffusion capacity (Delta DLCO) = +19.3 +/- 34.8%; change in 6-min walk test (Delta 6MWD) = +28.7 +/- 59.6 m; change in Medical Research Council Dyspnea (Delta MRCD) score = -1.0 +/- 1.04 units; change in St. George's Respiratory Questionnaire (Delta SGRQ) score = -9.9 +/- 15.3 units] than for GOLD stage IV patients (n = 7; Delta RV/TLC = -0.5 +/- 6.4%; Delta FEV 1 = +2.3 +/- 12.3%; Delta FVC = +2.6 +/- 21.1%; Delta DLCO = -2.8 +/- 17.2%; Delta 6MWD = +28.3 +/- 58.4 m; Delta MRCD = 0.3 +/- 0.81 units; Delta SGRQ = -6.7 +/- 7.0 units). Conclusions: ELS therapy shows promise for treating patients with advanced heterogeneous emphysema. Additional studies to assess responses in a larger cohort with a longer follow-up are warranted. Copyright (C) 2011 S. Karger AG, Base
Surface Structure of Liquid Metals and the Effect of Capillary Waves: X-ray Studies on Liquid Indium
We report x-ray reflectivity (XR) and small angle off-specular diffuse
scattering (DS) measurements from the surface of liquid Indium close to its
melting point of C. From the XR measurements we extract the surface
structure factor convolved with fluctuations in the height of the liquid
surface. We present a model to describe DS that takes into account the surface
structure factor, thermally excited capillary waves and the experimental
resolution. The experimentally determined DS follows this model with no
adjustable parameters, allowing the surface structure factor to be deconvolved
from the thermally excited height fluctuations. The resulting local electron
density profile displays exponentially decaying surface induced layering
similar to that previously reported for Ga and Hg. We compare the details of
the local electron density profiles of liquid In, which is a nearly free
electron metal, and liquid Ga, which is considerably more covalent and shows
directional bonding in the melt. The oscillatory density profiles have
comparable amplitudes in both metals, but surface layering decays over a length
scale of \AA for In and \AA for Ga. Upon controlled
exposure to oxygen, no oxide monolayer is formed on the liquid In surface,
unlike the passivating film formed on liquid Gallium.Comment: 9 pages, 5 figures; submitted to Phys. Rev.
Rejection of the hypothesis that Markarian 501 TeV photons are pure Bose-Einstein condensates
The energy spectrum of the Blazar type galaxy Markarian 501 (Mrk 501) as
measured by the High-Energy-Gamma-Ray Astronomy (HEGRA) air Cerenkov telescopes
extends beyond 16 TeV and constitutes the most energetic photons observed from
an extragalactic object. A fraction of the emitted spectrum is possibly
absorbed in interactions with low energy photons of the diffuse extragalactic
infrared radiation, which in turn offers the unique possibility to measure the
diffuse infrared radiation density by TeV spectroscopy. The upper limit on the
density of the extragalactic infrared radiation derived from the TeV
observations imposes constraints on models of galaxy formation and stellar
evolution. One of the recently published ideas to overcome severe absorption of
TeV photons is based upon the assumption that sources like Mrk 501 could
produce Bose-Einstein condensates of coherent photons. The condensates would
have a higher survival probability during the transport in the diffuse
radiation field and could mimic TeV air shower events. The powerful
stereoscopic technique of the HEGRA air Cerenkov telescopes allows to test this
hypothesis by reconstructing the penetration depths of TeV air shower events:
Air showers initiated by Bose-Einstein condensates are expected to reach the
maximum of the shower development in the atmosphere earlier than single photon
events. By comparing the energy-dependent penetration depths of TeV photons
from Mrk 501 with those from the TeV standard-candle Crab Nebula and simulated
air shower events, we can reject the hypothesis that TeV photons from Mrk 501
are pure Bose-Einstein condensates.Comment: 9 pages, 2 figures, published by ApJ Letters, revised version
(simulation results added
The TeV Energy Spectrum of Mkn 501 Measured with the Stereoscopic Telescope System of HEGRA during 1998 and 1999
During 1997, the BL Lac object Mkn 501 went into an extraordinary state of
high X-ray and TeV gamma-ray activity, lasting more than 6 months. In this
paper we report on the TeV emission characteristics of the source in the
subsequent years of 1998 and 1999 as measured with the Stereoscopic Cherenkov
Telescope System of HEGRA (La Palma, Canary Islands). Our observations reveal a
1998-1999 mean emission level at 1 TeV of 1/3 of the flux of the Crab Nebula, a
factor of 10 lower than during the year of 1997. A dataset of 122 observations
hours with the HEGRA telescope system makes it possible to assess for the first
time the Mkn 501 TeV energy spectrum for a mean flux level substantially below
that of the Crab Nebula with reasonable statistical accuracy. Excluding the
data of a strong flare, we find evidence that the 1998--1999 low-flux spectrum
is substantially softer (by 0.44+-0.1(stat) in spectral index) than the 1997
time averaged spectrum. The 500 GeV to 10 TeV energy spectrum can well be
described by a power law model with exponential cutoff: dN/dE ~ E^(-alpha)
exp(-E/E0) with alpha=2.31+-0.22(stat), and E0=5.1 (-2.3+7.8)(stat) TeV. Within
statistical accuracy, also a pure power law model gives an acceptable fit to
the data: dN/dE ~ E^(-Gamma) with Gamma=2.76+-0.08(stat). After presenting the
1998-1999 TeV characteristics of the source we discuss the implications of the
results.Comment: Accepted for publication in The Astrophysical Journal, Part 1, on
August 4th, 200
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