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Electrophysiological evidence for changes in attentional orienting and selection in functional somatic symptoms
Neurophysiology Objective: We investigated changes in attention mechanisms in people who report a high number of somatic symptoms which cannot be associated with a physical cause. Method: Based on scores on the Somatoform Disorder Questionnaire (SDQ-20; Nijenhuis et al., 1996) we compared two non-clinical groups, one with high symptoms on the SDQ-20 and a control group with low or no symptoms. We recorded EEG whilst participants performed an exogenous tactile attention task where they had to discriminate between tactile targets following a tactile cue to the same or opposite hand. Results: The neural marker of attentional orienting to the body, the Late Somatosensory Negativity (LSN), was diminished in the high symptoms group and attentional modulation of touch processing was prolonged at mid and enhanced at later latency stages in this group. Conclusion: These results confirm that attentional processes are altered in people with somatic symptoms, even in a non-clinical group. Furthermore, the observed pattern fits explanations of changes in prior beliefs or expectations leading to diminished amplitudes of the marker of attentional orienting to the body (i.e. the LSN) and enhanced attentional gain of touch processing. Significance: This study shows that high somatic symptoms are associated with neurocognitive attention changes
Application to rotary wings of a simplified aerodynamic lifting surface theory for unsteady compressible flow
A general method of predicting airloads is applied to helicopter rotor blades on a full three-dimensional basis using the general theory developed for a rotor blade at the psi = pi/2 position where flutter is most likely to occur. Calculations of aerodynamic coefficients for use in flutter analysis are made for forward and hovering flight with low inflow. The results are compared with values given by two-dimensional strip theory for a rigid rotor hinged at its root. The comparisons indicate the inadequacies of strip theory for airload prediction. One important conclusion drawn from this study is that the curved wake has a substantial effect on the chordwise load distribution
A study of some reactor shielding problems for spacecraft applications
Programs to calculate single-scattered neutron and gamma fluxes from reactor-powered spacecraft radiators and sample calculations from unshielded SNAP-
Gallium Arsenide preparation and QE Lifetime Studies using the ALICE Photocathode Preparation Facility
In recent years, Gallium Arsenide (GaAs) type photocathodes have become
widely used as electron sources in modern Energy Recovery Linac based light
sources such as the Accelerators and Lasers in Combined Experiments (ALICE) at
Daresbury Laboratory and as polarised electron source for the proposed
International Linear Collider (ILC). Once activated to a Low Electron Affinity
(LEA) state and illuminated by a laser, these materials can be used as a
high-brightness source of both polarised and un-polarised electrons. This paper
presents an effective multi-stage preparation procedure including heat
cleaning, atomic hydrogen cleaning and the activation process for a GaAs
photocathode. The stability of quantum efficiency (QE) and lifetime of
activated to LEA state GaAs photocathode have been studied in the ALICE
load-lock photocathode preparation facility which has a base pressure in the
order of 10^-11 mbar. These studies are supported by further experimental
evidence from surface science techniques such as X-ray Photoelectron
Spectroscopy (XPS) to demonstrate the processes at the atomic level.Comment: Presented at First International Particle Accelerator Conference,
IPAC'10, Kyoto, Japan, from 23 to 28 May 201
The Fornax Spectroscopic Survey --- Low Surface Brightness Galaxies in Fornax
The Fornax Spectroscopic Survey is a large optical spectroscopic survey of
ALL 14,000 objects with 16.5<Bj<19.7 in a 12 sq.deg area of sky centered on the
Fornax Cluster. We are using the 400-fibre Two Degree Field spectrograph on the
Anglo-Australian Telescope: the multiplex advantage of this system allows us to
observe objects conventionally classified as `stars' as well as `galaxies'.
This is the only way to minimise selection effects caused by image
classification or assessing cluster membership.
In this paper we present the first measurements of low surface brightness
(LSB) galaxies we have detected both in the Fornax Cluster and among the
background field galaxies. The new cluster members include some very low
luminosity (M_B approx -11.5 mag) dwarf ellipticals, whereas the background LSB
galaxies are luminous (-19.6<M_B<-17.0 mag) disk-like galaxies.Comment: To appear in "The Low Surface Brightness Universe", IAU Coll 171,
eds. J.I. Davies et al., A.S.P. Conference Series. 8 pages, LaTex, 6
encapsulated ps-figures, requires paspconf.st
Molecular Evolution in Time Dependent Environments
The quasispecies theory is studied for dynamic replication landscapes. A
meaningful asymptotic quasispecies is defined for periodic time dependencies.
The quasispecies' composition is constantly changing over the oscillation
period. The error threshold moves towards the position of the time averaged
landscape for high oscillation frequencies and follows the landscape closely
for low oscillation frequencies.Comment: 5 pages, 3 figures, Latex, uses Springer documentclass llncs.cl
Obstetrician-Gynecologistsâ Knowledge of Health Disparities and Barriers among American Indian/Alaska Native Women in Washington State
Background: Health disparities between American Indian/Alaska Native (AI/AN) women and other races/ethnicities have long been noted. Obstetricians-Gynecologists (Ob-Gyn) play a significant role in well-woman care and are often the first and most frequent point of medical contact for women, particularly among minority and low-income women.
Objective: This study aimed to assess Ob-Gynsâ knowledge, beliefs, and practices related to health disparities among AI/AN women.
Method: A self-administered questionnaire, consisting of questions about knowledge, beliefs, and practices of health disparities among AI/AN women, was mailed to 722 members of The American College of Obstetricians and Gynecologists (ACOG) practicing in the state of Washington in September 2013-February 2014.
Results: The majority of respondents were knowledgeable about numerous health care disparities among non-pregnant AI/AN women, while slightly fewer were aware of disparities among pregnant AI/AN patients. Ob-Gyns reported low confidence in their training and knowledge of AI/AN culture and health disparities, but high confidence in their ability to treat AI/AN patients. Participants reported dissatisfaction with their AI/AN patientsâ breastfeeding rates.
Conclusion: Ob-Gyn knowledge of health disparities among AI/AN women is adequate. In spite of this, barriers to quality care are still present and increased identification and implementation of effective resources is needed
Flux Expulsion - Field Evolution in Neutron Stars
Models for the evolution of magnetic fields of neutron stars are constructed,
assuming the field is embedded in the proton superconducting core of the star.
The rate of expulsion of the magnetic flux out of the core, or equivalently the
velocity of outward motion of flux-carrying proton-vortices is determined from
a solution of the Magnus equation of motion for these vortices. A force due to
the pinning interaction between the proton-vortices and the neutron-superfluid
vortices is also taken into account in addition to the other more conventional
forces acting on the proton-vortices. Alternative models for the field
evolution are considered based on the different possibilities discussed for the
effective values of the various forces. The coupled spin and magnetic evolution
of single pulsars as well as those processed in low-mass binary systems are
computed, for each of the models. The predicted lifetimes of active pulsars,
field strengths of the very old neutron stars, and distribution of the magnetic
fields versus orbital periods in low-mass binary pulsars are used to test the
adopted field decay models. Contrary to the earlier claims, the buoyancy is
argued to be the dominant driving cause of the flux expulsion, for the single
as well as the binary neutron stars. However, the pinning is also found to play
a crucial role which is necessary to account for the observed low field binary
and millisecond pulsars.Comment: 23 pages, + 7 figures, accepted for publication in Ap
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