1,429 research outputs found
Attentional capture by deviant sounds: A non-contingent form of auditory distraction?
The occurrence of an unexpected, infrequent sound in an otherwise homogeneous auditory background tends to disrupt the ongoing cognitive task. This ‘deviation effect’ is typically explained in terms of attentional capture whereby the deviant sound draws attention away from the focal activity, regardless of the nature of this activity. Yet, there is theoretical and empirical evidence suggesting that the attention-capture mechanism underlying this form of distraction could rather be triggered in a task-contingent fashion. The present study aimed at determining whether the auditory deviation effect reflects the action of either a stimulus-driven or a task-contingent orienting mechanism. To do so, we conducted a systematic investigation whereby the impact of verbal deviants—a letter embedded in the repetition of another letter—and spatial deviants—a sound presented contralaterally to the other sounds—on verbal and spatial short-term memory was assessed. This study established that both verbal and spatial deviants can hinder both verbal and spatial order-reconstruction (Experiment 1) and missing-item tasks (Experiment 2). Such results demonstrate that the deviation effect reflects a general form of auditory distraction as interference took place both within and across domains and regardless of the processes engaged in the focal tas
Private Businesses Predict Limited Growth for 2013
The quarterly private capital access (PCA) index and the private capital demand (PCD) index, economic indicators published by the Pepperdine Private Capital Markets Project, predict continued low levels of both demand and access in the near future. Thus the near-term prospects for robust economic growth are restricted. The implied policy recommendation for national and local governments is to enhance loan guarantee programs for private firms with revenues of less than five million USD ($5M)
Acceleration and Substructure Constraints in a Quasar Outflow
We present observations of probable line-of-sight acceleration of a broad
absorption trough of C IV in the quasar SDSS J024221.87+004912.6. We also
discuss how the velocity overlap of two other outflowing systems in the same
object constrains the properties of the outflows. The Si IV doublet in each
system has one unblended transition and one transition which overlaps with
absorption from the other system. The residual flux in the overlapping trough
is well fit by the product of the residual fluxes in the unblended troughs. For
these optically thick systems to yield such a result, at least one of them must
consist of individual subunits rather than being a single structure with
velocity-dependent coverage of the source. If these subunits are identical,
opaque, spherical clouds, we estimate the cloud radius to be r = 3.9 10^15 cm.
If they are identical, opaque, linear filaments, we estimate their width to be
w = 6.5 10^14 cm. These subunits are observed to cover the Mg II broad emission
line region of the quasar, at which distance from the black hole the above
filament width is equal to the predicted scale height of the outer atmosphere
of a thin accretion disk. Insofar as that scale height is a natural size scale
for structures originating in an accretion disk, these observations are
evidence that the accretion disk can be a source of quasar absorption systems.
Based on data from ESO program 075.B-0190(A).Comment: 14 emulateapj pages, 7 figures, ApJ in pres
Metabolic Rate and Ground Reaction Force During Motorized and Non-Motorized Treadmill Exercise
PURPOSE: To measure vertical ground reaction force (vGRF) and oxygen consumption (VO2) at several velocities during exercise using a ground-based version of the ISS treadmill in the M and NM modes. METHODS: Subjects (n = 20) walked or ran at 0.89, 1.34, 1.79, 2.24, 2.68, and 3.12 m/s while VO2 and vGRF data were collected. VO2 was measured using open-circuit spirometry (TrueOne 2400, Parvo-Medics). Data were averaged over the last 2 min of each 5-min stage. vGRF was measured in separate 15-s bouts at 125 Hz using custom-fitted pressure-sensing insoles (F-Scan Sport Sensors, Tekscan, Inc). A repeated-measures ANOVA was used to test for differences in VO2 and vGRF between M and NM and across speeds. Significance was set at P < 0.05. RESULTS: Most subjects were unable to exercise for 5 min at treadmill speeds above 1.79 m/s in the NM mode; however, vGRF data were obtained for all subjects at each speed in both modes. VO2 was approx.40% higher during NM than M exercise across treadmill speeds. vGRF increased with treadmill speed but was not different between modes. CONCLUSION: Higher VO2 with no change in vGRF suggests that the additional metabolic cost associated with NM treadmill exercise is accounted for in the horizontal forces required to move the treadmill belt. Although this may limit the exercise duration at faster speeds, high-intensity NM exercise activates the hamstrings and plantarflexors, which are not specifically targeted or well protected by other in-flight countermeasures
65-micron thin monocrystalline silicon solar cell technology allowing 12-fold reduction in silicon usage
Thin (<70 micron) single crystal silicon solar cells have been manufactured through the use of a novel process involving selective etching. Narrow grooves are micromachined through the wafer using a standard micromachining technique with cells manufactured on the resulting silicon strips. These bifacial cells have a much greater surface area than the original wafer, leading to dramatic decreases in processing effort and silicon usage. Individual cells fabricated using the new process have displayed efficiencies up to 17.5% while a 560cm2 prototype module has displayed an efficiency of 12.3%. The size, thickness and bifacial nature of the cells offer the opportunity for a wide variety of module architectures and applications
Epidemiology, genetics, and subtyping of preserved ratio impaired spirometry (PRISm) in COPDGene.
BackgroundPreserved Ratio Impaired Spirometry (PRISm), defined as a reduced FEV1 in the setting of a preserved FEV1/FVC ratio, is highly prevalent and is associated with increased respiratory symptoms, systemic inflammation, and mortality. Studies investigating quantitative chest tomographic features, genetic associations, and subtypes in PRISm subjects have not been reported.MethodsData from current and former smokers enrolled in COPDGene (n = 10,192), an observational, cross-sectional study which recruited subjects aged 45-80 with ≥10 pack years of smoking, were analyzed. To identify epidemiological and radiographic predictors of PRISm, we performed univariate and multivariate analyses comparing PRISm subjects both to control subjects with normal spirometry and to subjects with COPD. To investigate common genetic predictors of PRISm, we performed a genome-wide association study (GWAS). To explore potential subgroups within PRISm, we performed unsupervised k-means clustering.ResultsThe prevalence of PRISm in COPDGene is 12.3%. Increased dyspnea, reduced 6-minute walk distance, increased percent emphysema and decreased total lung capacity, as well as increased segmental bronchial wall area percentage were significant predictors (p-value <0.05) of PRISm status when compared to control subjects in multivariate models. Although no common genetic variants were identified on GWAS testing, a significant association with Klinefelter's syndrome (47XXY) was observed (p-value < 0.001). Subgroups identified through k-means clustering include a putative "COPD-subtype", "Restrictive-subtype", and a highly symptomatic "Metabolic-subtype".ConclusionsPRISm subjects are clinically and genetically heterogeneous. Future investigations into the pathophysiological mechanisms behind and potential treatment options for subgroups within PRISm are warranted.Trial registrationClinicaltrials.gov Identifier: NCT000608764
A Search for Variable Stars and Planetary Occultations in NGC 2301 II: Variability
We performed R-band time series observations of the young, metal rich open
cluster NGC 2301 for 12 nights in Feb. 2004. B images were also obtained and
color magnitude diagrams, having limits of R=19.5 and B=21.5, were produced.
Only asmall effort was made to determine cluster membership as our magnitude
limits are far deeper than previously published values. Our photometric
precision, for the brightest 5 magnitudes of sources, is 1-2 mmag. We determine
that for the 4000 stars which have time-series data, 56% are variable and
of these, approximately 13% are observed to exhibit periodic light curves
ranging from tens of minutes to days. We present some examples of the light
curves obtained and produce cuts in variability space based on parameters such
as color and amplitude. The percentage of variability is approximately equal
across all colors with the majority of variables having amplitudes of 0.15
magnitudes or less. In general, redder stars show larger variability
amplitudes. We find a smooth decline in the number of periodic variables toward
longer period. This decline is probably due to a transition from intrinsic to
extrinsic variability and, in part, to our limited observing period of 12
nights. Essentially all the A and F main sequence stars in our sample are
variable (2 mmag and larger) and most present complex light curves
containing multiple periods suggestive of their inclusion in the Sct
and Dor classes. A variable non-cluster member giant and two variable
white dwarf candidates are discussed. Our equational description of variability
is shown to be an excellent predictive tool for determining the cumulative
fraction of variables that will be observed in a photometric survey. Our entire
dataset is available electronically.Comment: 25 pages, 21 figures Accepted to PAS
Does Method of Placental Removal or Site of Uterine Incision Repair Alter Endometritis After Cesarean Delivery?
ABSTRACT Objective: his investigation was undertaken to evaluate the relationship between postcesarean endometritis and (1) method of placental removal an
NLTT 41135: a field M-dwarf + brown dwarf eclipsing binary in a triple system, discovered by the MEarth observatory
We report the discovery of an eclipsing companion to NLTT 41135, a nearby M5
dwarf that was already known to have a wider, slightly more massive common
proper motion companion, NLTT 41136, at 2.4 arcsec separation. Analysis of
combined-light and radial velocity curves of the system indicates that NLTT
41135B is a 31-34 +/- 3 MJup brown dwarf (where the range depends on the
unknown metallicity of the host star) on a circular orbit. The visual M-dwarf
pair appears to be physically bound, so the system forms a hierarchical triple,
with masses approximately in the ratio 8:6:1. The eclipses are grazing,
preventing an unambiguous measurement of the secondary radius, but follow-up
observations of the secondary eclipse (e.g. with the James Webb Space
Telescope) could permit measurements of the surface brightness ratio between
the two objects, and thus place constraints on models of brown dwarfs.Comment: 15 pages, 6 figures, 10 tables, emulateapj format. Accepted for
publication in Ap
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