403 research outputs found
When is a face a face? Schematic faces, emotion, attention and the N170
Emotional facial expressions provide important non-verbal cues as to the imminent behavioural intentions of a second party. Hence, within emotion science the processing of faces (emotional or otherwise) has been at the forefront of research. Notably, however, such research has led to a number of debates including the ecological validity of utilising schematic faces in emotion research, and the face-selectively of N170. In order to investigate these issues, we explored the extent to which N170 is modulated by schematic faces, emotional expression and/or selective attention. Eighteen participants completed a three-stimulus oddball paradigm with two scrambled faces as the target and standard stimuli (counter-balanced across participants), and schematic angry, happy and neutral faces as the oddball stimuli. Results revealed that the magnitude of the N170 associated with the target stimulus was: (i) significantly greater than that elicited by the standard stimulus, (ii) comparable with the N170 elicited by the neutral and happy schematic face stimuli, and (iii) significantly reduced compared to the N170 elicited by the angry schematic face stimulus. These findings extend current literature by demonstrating N170 can be modulated by events other than those associated with structural face encoding; i.e. here, the act of labelling a stimulus a ‘target’ to attend to modulated the N170 response. Additionally, the observation that schematic faces demonstrate similar N170 responses to those recorded for real faces and, akin to real faces, angry schematic faces demonstrated heightened N170 responses, suggests caution should be taken before disregarding schematic facial stimuli in emotion processing research per se
The effect of manual handling training on transferring knowledge, employee s behaviour change and subsequent reduction of work-related musculoskeletal disorders: a systematic review
peer-reviewedThis systematic review investigated the effectiveness of manual handling training at transferring knowledge, leading to a positive change in employee’s manual handling behaviour and a reduction of WRMSDs following training. Six electronic databases were searched for randomised controlled trials, non-randomised controlled trials or cohort studies with a control and/or comparison group which investigated the effectiveness of manual handling training. Thirteen articles met the inclusion and exclusion criteria. Following quality assessment, nine of the included articles were found to be high quality. This systematic review suggests that there has been very little research focusing on the effectiveness of manual handling training on transferring knowledge to employee’s and behavioural change. This review indicates that whilst employees report understanding and awareness following training, this does not always lead to the expected behavioural change. This review also suggests it cannot be demonstrated that transferring knowledge to employees will lead to a reduction of WRMSDs.ACCEPTEDpeer-reviewe
Introduction to Magnetic Monopoles
One of the most basic properties of magnetism is that a magnet always has two
poles, north and south, which cannot be separated into isolated poles, i.e.,
magnetic monopoles. However, there are strong theoretical arguments why
magnetic monopoles should exist. In spite of extensive searches they have not
been found, but they have nevertheless played a central role in our
understanding of physics at the most fundamental level.Comment: 22 pages, 7 figures. To be published in Contemporary Physic
Quasiclassical Theory of Spontaneous Currents at Surfaces and Interfaces of d-Wave Superconductors
We investigate the properties of spontaneous currents generated at surfaces
and interfaces of d-wave superconductors using the self-consistent
quasiclassical Eilenberger equations. The influence of the roughness and
reflectivity of the boundaries on the spontaneous current are studied. We show
that these have very different effects at the surfaces compared to the
interfaces, which reflects the different nature of the time reversal symmetry
breaking states in these two systems. We find a signature of the ``anomalous
proximity effect'' at rough d-wave interfaces. We also show that the existence
of a subdominant order parameter, which is necessary for time reversal symmetry
breaking at the surface, suppresses the spontaneous current generation due to
proximity effect at the interface between two superconductors. We associate
orbital moments to the spontaneous currents to explain the ``superscreening''
effect, which seems to be present at all ideal d-wave surfaces and interfaces,
where d_{xy} is the favorite subdominant symmetry.Comment: 13 pages, 17 postscript figure
Epistemic and social scripts in computer-supported collaborative learning
Collaborative learning in computer-supported learning environments typically means that learners work on tasks together, discussing their individual perspectives via text-based media or videoconferencing, and consequently acquire knowledge. Collaborative learning, however, is often sub-optimal with respect to how learners work on the concepts that are supposed to be learned and how learners interact with each other. One possibility to improve collaborative learning environments is to conceptualize epistemic scripts, which specify how learners work on a given task, and social scripts, which structure how learners interact with each other. In this contribution, two studies will be reported that investigated the effects of epistemic and social scripts in a text-based computer-supported learning environment and in a videoconferencing learning environment in order to foster the individual acquisition of knowledge. In each study the factors ‘epistemic script’ and ‘social script’ have been independently varied in a 2×2-factorial design. 182 university students of Educational Science participated in these two studies. Results of both studies show that social scripts can be substantially beneficial with respect to the individual acquisition of knowledge, whereas epistemic scripts apparently do not to lead to the expected effects
Nonlinear coupled Alfv\'{e}n and gravitational waves
In this paper we consider nonlinear interaction between gravitational and
electromagnetic waves in a strongly magnetized plasma. More specifically, we
investigate the propagation of gravitational waves with the direction of
propagation perpendicular to a background magnetic field, and the coupling to
compressional Alfv\'{e}n waves. The gravitational waves are considered in the
high frequency limit and the plasma is modelled by a multifluid description. We
make a self-consistent, weakly nonlinear analysis of the Einstein-Maxwell
system and derive a wave equation for the coupled gravitational and
electromagnetic wave modes. A WKB-approximation is then applied and as a result
we obtain the nonlinear Schr\"{o}dinger equation for the slowly varying wave
amplitudes. The analysis is extended to 3D wave pulses, and we discuss the
applications to radiation generated from pulsar binary mergers. It turns out
that the electromagnetic radiation from a binary merger should experience a
focusing effect, that in principle could be detected.Comment: 20 pages, revtex4, accepted in PR
Tilt Grain-Boundary Effects in S- and D-Wave Superconductors
We calculate the s- and d-wave superconductor order parameter in the vicinity
of a tilt grain boundary. We do this self-consistently within the Bogoliubov de
Gennes equations, using a realistic microscopic model of the grain boundary. We
present the first self-consistent calculations of supercurrent flows in such
boundaries, obtaining the current-phase characteristics of grain boundaries in
both s-wave and d-wave superconductors
The phase-space structure of a dark-matter halo: Implications for dark-matter direct detection experiments
We study the phase-space structure of a dark-matter halo formed in a high
resolution simulation of a Lambda CDM cosmology. Our goal is to quantify how
much substructure is left over from the inhomogeneous growth of the halo, and
how it may affect the signal in experiments aimed at detecting the dark matter
particles directly. If we focus on the equivalent of ``Solar vicinity'', we
find that the dark-matter is smoothly distributed in space. The probability of
detecting particles bound within dense lumps of individual mass less than 10^7
M_\sun h^{-1} is small, less than 10^{-2}. The velocity ellipsoid in the Solar
neighbourhood deviates only slightly from a multivariate Gaussian, and can be
thought of as a superposition of thousands of kinematically cold streams. The
motions of the most energetic particles are, however, strongly clumped and
highly anisotropic. We conclude that experiments may safely assume a smooth
multivariate Gaussian distribution to represent the kinematics of dark-matter
particles in the Solar neighbourhood. Experiments sensitive to the direction of
motion of the incident particles could exploit the expected anisotropy to learn
about the recent merging history of our Galaxy.Comment: 13 pages, 13 figures, Phys. Rev. D in press. Postscript version with
high resolution figures available from
http://www.mpa-garching.mpg.de/~ahelmi/research/lcdm_dm.html; some changes in
the text; constraints on the effect of bound dark-matter lumps revised;
remaining conclusions unchange
Molecular epidemiology and extended-spectrum β-lactamases production of Klebsiella pneumoniae isolated from three dairy herds
The objectives of this study were to isolate Klebsiella pneumoniae from different sources in three dairy cattle herds, to use the pulsed-field gel electrophoresis (PFGE) to measure genotypic similarities between isolates within a dairy herd, to verify the production of extended-spectrum β-lactamases (ESBLs) by the double-disk synergy test (DDST), and to use the PCR to detect the main ESBLs subgroups genes. Three dairy farms were selected based on previous mastitis outbreaks caused by K. pneumoniae. Milk samples were collected from lactating cows and from the bulk tank. Swabs were performed in different locations, including milking parlors, waiting room, soil, animal's hind limbs and rectum. K. pneumoniae was isolated from 27 cases of intramammary infections (IMI) and from 41 swabs. For farm A isolates from IMI and bulk tank were considered of the same PGFE subtype. One isolate from a bulk tank, three from IMI cases and four from environmental samples were positive in the DDST test. All eight DDST positive isolates harbored the bla shv gene, one harbored the bla tem gene, and three harbored the bla ctx-m gene, including the bulk tank isolate. Our study confirms that ESBL producing bacteria is present in different locations in dairy farms, and may be responsible for IMI. The detection of ESBLs on dairy herds could be a major concern for both public and animal health
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