The creation and testing of a mock functional magnetic resonance imaging facility for pain patients

Unfamiliarity with functional Magnetic Resonance Imaging (fMRI) facilities leads to unwanted stress-related disturbances in the processing of fMRI data. A mock fMRI facility was developed to increase familiarization among subjects participating in fiviRI studies and to alleviate the time and cost of familiarizing each subject in an actual fMRI facility. A decommissioned Magnetic Resonance Imaging (MRI) unit was remodeled to visually and aurally resemble the Siemens Magnetom Allegra 3 Telsa fMRI machine currently used at the University of Medicine and Dentistry of New Jersey (UMDNJ), Newark, New Jersey. Instrumentation was developed using LabVIEW software which presented subjects with recreated sounds of the UMDNJ fMRI unit, displayed interactive Pain Descriptor Differential Scales to the subject, collected and displayed electrocardiogram (ECG), blood pressure (BP), and questionnaire data to the operator. In addition to these tasks, the LabVIEW program triggered the Medoc Neuro-Sensory Analyzer to begin producing warm stimuli to patient\u27s forearm, in synchrony with the order of the study. A pilot experiment was conducted to assess if subjects became more habituated to the fMRI environment after two mock fMRI experiences. ECG, BP, and questionnaire data for two subjects in the mock fMRI unit for two sessions were compared. The results support that the subjects were more comfortable, relaxed, and familiar with the experiment and the fMRI environment during the second session

Optimizing multi-dimensional terahertz imaging analysis for colon cancer diagnosis

Peer reviewedPublisher PD

Mesospheric turbulent velocity estimation using the Buckland Park MF radar

Copyright © 2001 European Geosciences UnionThis paper investigates turbulent velocity estimation using the full correlation analysis (FCA) of spaced antenna (SA) data, and its application to the routine FCA observations of the Buckland Park MF (BPMF) radar. The effects of transmitter beamwidths are investigated, confirming the suggestions of previous authors that wide transmit beam widths lead to an overestimation of the turbulent velocity. The annual variation of the turbulent velocity is investigated, revealing an increase in turbulent velocity with height, and equinoctal minima and solstice maxima observed below 80 km. Investigations of the turbulent velocities about the March diurnal tide maximum reveals a diurnal variation in phase with the zonal velocity. Harmonic analysis reveals this relationship exists between February and September. Descending power layers are also observed during this period. A number of mechanisms are proposed to describe these observations.D. A. Holdsworth, R. A. Vincent, and I. M. Rei

The fixation distance to the stimulus influences ERP quality:an EEG and eye tracking N400 study

In a typical visual Event Related Potential (ERP) study, the stimulus is presented centrally on the screen. Normally an ERP response will be measured provided that the participant directs their gaze towards the stimulus. The aim of this study was to assess how the N400 component of an ERP was affected when the stimulus was presented in the foveal, parafoveal or peripheral vision of the participant’s visual field. Utilizing stimuli that have previously produced an N400 response to action incongruities, the same stimuli sequences were presented at 0º, 4º, 8º and 12º of visual angle from a fixation location. In addition to the EEG data, eye tracking data were recorded to act as a fixation control method and to allow for eye artifact detection. The results show a significant N400 effect in the right parieto-temporal electrodes within the 0º visual angle condition. For the other conditions, the N400 effect was reduced (4º) or not present (8º and 12º). Our results suggest that the disappearance of the N400 effect with eccentricity is the fixation distance to the stimulus. However, variables like attentional allocation could have also had an impact on the results. This study highlights the importance of presenting a stimulus within the foveal vision of the participant in order to maximize ERP effects related to higher order cognitive processes

Large Magnetic Fields and Motions of OH Masers in W75 N

We report on a second epoch of VLBA observations of the 1665 and 1667 MHz OH masers in the massive star-forming region W75 N. We find evidence to confirm the existence of very strong (~40 mG) magnetic fields near source VLA 2. The masers near VLA 2 are dynamically distinct and include a very bright spot apparently moving at 50 km/s relative to those around VLA 1. This fast-moving spot may be an example of a rare class of OH masers seen in outflows in star-forming regions. Due to the variability of these masers and the rapidity of their motions, tracking these motions will require multiple observations over a significantly shorter time baseline than obtained here. Proper motions of the masers near VLA 1 are more suggestive of streaming along magnetized shocks rather than Keplerian rotation in a disk. The motions of the easternmost cluster of masers in W75 N (B) may be tracing slow expansion around an unseen exciting source.Comment: 7 pages including 4 figures (2 color) & 3 tables, to appear in Ap

Magnetic Field Clumping in Massive Star-Forming Regions as Determined from Excited-State OH Absorption and Maser Emission

We have observed six high-mass star-forming regions in the 2 Pi 3/2, J = 7/2 lines of OH using the GBT in order to investigate whether the magnetic field, and hence the density, measured in absorption differs from that implied by maser Zeeman splitting. We detect absorption in both the 13441 and 13434 MHz main lines in all six sources. Zeeman splitting in the F = 3-3 absorption line in W3(OH) implies a line-of-sight magnetic field strength of 3.0 +/- 0.3 mG. This is significantly less than full magnetic field strengths detected from OH maser Zeeman splitting, suggesting that OH maser regions may be denser than the non-masing OH material by a factor of several. Zeeman splitting is not detected in other sources, but we are able to place upper limits on B_parallel of 1.2 mG in G10.624-0.385 and 2.9 mG in K3-50. These results are consistent with a density enhancement of the masers, but other explanations for the lower magnetic field in absorption compared to maser emission are possible for these two sources. Absorption in one or both of the 13442 and 13433 MHz satellite lines is also seen in four sources. This is the very first detection of the 2 Pi 3/2, J = 7/2 satellite lines. Ratios of satellite-line to main-line absorption suggest enhancement of the satellite lines from local thermodynamic equilibrium values. Masers are seen in the F = 4-4 and 3-3 transitions of W3(OH) and the 4-4 transition of ON 1. A previously undetected 4-4 maser is seen near -44.85 km/s in W3(OH).Comment: 29 pages, 22 figures, scheduled to be published in 20 April 2005 issue of ApJ (vol 623, no 2

Linguistic representations of agency in discourse on the Fukushima nuclear disaster

This Modular PhD thesis argues for a more detailed treatment of agency than has previously been employed in critical linguistics. I present a framework for analysing four aspects of the linguistic representation of agency. The framework classifies the strengths of the different possible representations of agency in each of these four aspects. This framework is then applied to three areas of discourse concerning the 2011 Fukushima nuclear disaster. First, I compare domestic and foreign reporting of the disaster, and argue the less critical stance of domestic reporting is due to a greater emphasis on technological rather than human agency. I then examine representations of responsibility in three official reports into the causes of the Fukushima disaster, and argue that each report diffuses responsibility in different ways, according to their institutional aims. Finally, I look at the kinds of agency attributed to Fukushima in pro and anti-nuclear media opinion pieces, and argue these reflect an interpretation of the disaster as a unique event in pro- nuclear arguments, and as evidence of the inherent danger of nuclear power in anti- nuclear arguments

Bichromatic Local Oscillator for Detection of Two-Mode Squeezed States of Light

We present a new technique for the detection of two-mode squeezed states of light that allows for a simple characterization of these quantum states. The usual detection scheme, based on heterodyne measurements, requires the use of a local oscillator with a frequency equal to the mean of the frequencies of the two modes of the squeezed field. As a result, unless the two modes are close in frequency, a high-frequency shot-noise-limited detection system is needed. We propose the use of a bichromatic field as the local oscillator in the heterodyne measurements. By the proper selection of the frequencies of the bichromatic field, it is possible to arbitrarily select the frequency around which the squeezing information is located, thus making it possible to use a low-bandwidth detection system and to move away from any excess noise present in the system.Comment: 11 pages, 3 figure

Theta- and alpha-band EEG activity in response to eye gaze cues in early infancy

In order to elucidate the development of how infants use eye gaze as a referential cue, we investigated theta and alpha oscillations in response to object-directed and object-averted eye gaze in infants aged 2, 4, 5, and 9 months. At 2 months of age, no difference between conditions was found. In 4- and 9-month-olds, alpha-band activity desynchronized more in response to faces looking at objects compared to faces looking away from objects. Theta activity in 5-month-old infants differed between conditions with more theta synchronization for object-averted eye gaze. Whereas alpha desynchronization might reflect mechanisms of early social object learning, theta is proposed to imply activity in the executive attention network. The interplay between alpha and theta activity represents developmental changes in both kinds of processes during early infancy

Differential Processing of Gaze Cueing from a Congruent and Incongruent Informant

Infants are known to be sensitive to, and be capable of, processing social information from birth. However, less is known about abilities related to actively choosing the information source on which to rely, over passively processing all available information. A recent study showed that 8-month-olds’ gaze following behaviour was influenced by the reliability of the informant (Tummeltshammer et al., 2014), suggesting that infants as young as 8 months of age might recognize whether the person in front of them is trustworthy. To better understand this discriminative ability of infants, the current study utilizes event-related potentials (ERPs), to investigate whether infants’ neural activity indicates the differentiation of a congruent informant (who always gives the correct gaze cue to the object location) from an incongruent informant (who only gives the correct gaze cue on 25% of trials). 9-month-old infants (N = 21) were presented with 32 static images in total which showed two female experimenters (16 images for each), one of whom looked at the object appearing on one of the corners 100% of the time (i.e. congruent informant) and the other only looked at the object 25 % of the time and looked away from the object 75% of the time (i.e. incongruent informant). A paired-sample t-test comparing between the congruent and incongruent informants showed that the amplitude of the negative deflection occurring at approximately 275ms post-stimuli over fronto-central regions was enhanced while infants were processing information given by a congruent informant (M= -15.05[µV], SD= 4.56), compared to when the information was given by an incongruent informant (M= -12.35[µV], SD= 3.79) (t= -2.49, p= .002). Previous studies have shown that a negative amplitude component occurring at around 400ms post-stimuli in 9-month infants (the negative component, or the Nc), has been associated with infants’ attentional allocation (e.g. Striano et al., 2006; Parise et al., 2008). While the negative peak observed in the present study is at an earlier latency than the Nc, this indicates a difference in neural processing of congruent and incongruent informants in 9-month-old infants. Furthermore, an enhanced positive slow wave (PSW) over fronto-temporal regions was observed for an incongruent informant (M= 9.27[µV], SD= 5.32) compared to a congruent informant (M= 6.12[µV], SD= 5.63) (t= -2.309, p=.003). As the PSW has been thought to reflect memory updating (Snyder, Webb & Nelson, 2002; Reid et al. 2004), this might reflect how infants alter their perception about the congruency of gaze cues during the short exposure to the information (16 per condition). In sum, the result demonstrates how quickly young infants can recognize the congruency of other people’s gaze cues. This study extends our understanding forward on how infants collect and process social information, as the current study offers evidence that infants as young as 9 months of age selectively process sources of information differentially in the social domain, which might enable them to learn efficiently at a social situation despite ample and complex information present