Searching for the dual of the Maxwell-Chern-Simons model minimally coupled to dynamical U(1) charged matter

The possibility of dual equivalence between the self-dual and the Maxwell-Chern-Simons (MCS) models when the latter is coupled to dynamical, U(1) fermionic charged matter is examined. The proper coupling in the self-dual model is then disclosed using the iterative gauge embedding approach. We found that the self-dual potential needs to couple directly to the Chern-Kernel of the source in order to establish this equivalence besides the need for a self-interaction term to render the matter sector unchanged.Comment: 4 pages, RevTeX, new references, accepted for publication on Phys. Lett.

The S2 VLBI Correlator: A Correlator for Space VLBI and Geodetic Signal Processing

We describe the design of a correlator system for ground and space-based VLBI. The correlator contains unique signal processing functions: flexible LO frequency switching for bandwidth synthesis; 1 ms dump intervals, multi-rate digital signal-processing techniques to allow correlation of signals at different sample rates; and a digital filter for very high resolution cross-power spectra. It also includes autocorrelation, tone extraction, pulsar gating, signal-statistics accumulation.Comment: 44 pages, 13 figure

Phase-space Analysis by Multiple Resonance-Frequency Identification: Applications to the LHC and LEP

Many beam-dynamical phenomena are studied, experimentally or computationally, by means of spectral analysis of a time-series of values of a dynamical variable. When the underlying dynamics is regular, the frequencies appearing in the spectrum are integer combinations of a small set of basic frequencies, e.g., the three tunes in the case of single-particle orbital dynamics. For well-known reasons, identification of the frequencies can be ambiguous or subjective in practice. We present an algorithm that overcomes these difficulties by exploiting theoretical bounds on the spectral power density to transform time series into sets of labelled resonance lines. In our examples, the time series are orbits obtained by tracking single particles from many initial conditions. The method has been applied to off-momentum LHC injection optics. This is a deterministic Hamiltonian system. A second application, to orbits with strong quantum fluctuations in LEP2, shows that it also works well in a noisy, dissipative system

Laser frequency modulation with electron plasma

When laser beam passes through electron plasma its frequency shifts by amount proportional to plasma density. This density varies with modulating signal resulting in corresponding modulation of laser beam frequency. Necessary apparatus is relatively inexpensive since crystals are not required

Cervico-mandibular muscle activity in females with chronic cervical pain

Pathophysiological mechanisms behind pain in chronic cervical musculoskeletal conditions (MSC) in office workers remain unclear. Chronic cervical pain has established links with temporomandibular (TM) disorders. Yet there is no current published evidence to report whether individuals with cervical dysfunction exhibit altered masseter and cervical extensor (CE) muscle activity. Objective: To explore CE and masseter surface electromyographic (sEMG) activity and teeth clenching habits in females with chronic cervical dysfunction and no TM disorder. Design: Descriptive cross-sectional correlational study with single-blinding. Participants: University students and staff with or without chronic cervical pain and no TM involvement. Methods: Descriptive and pain data captured from Research Diagnostic Criteria for TM disorders, Neck Disability Index, Computer Usage, Brief Pain Inventory, and EuroQoL-5D questionnaires. Female participants allocated to a chronic cervical (n = 20) and a control group (n = 22). Investigator blinded to the study groups recorded sEMG of bilateral masseter and CE muscles (C4/5 level) at rest and during light teeth clenching. Results: No differences in socio-demographic profile; or in masseter or CE sEMG activity at rest or during light clench between groups. The pain group had higher scores for pain, reported a daytime teeth clenching habit, and had worse scores for the health-related quality of life (HRQoL) sub-sections for pain, anxiety/depression, and lower scores for perceived health status. Conclusion: No relationship established between cervico-mandibular sEMG activity and reported disability in females with chronic cervical dysfunction and no TM disorder. Association between biopsychosocial factors of teeth clenching and anxiety/depression highlights complex pathophysiological mechanisms in chronic recurrent cervical pain

Operational experience and design recommendations for teleoperated flight hardware

Teleoperation (remote manipulation) will someday supplement/minimize astronaut extravehicular activity in space to perform such tasks as satellite servicing and repair, and space station construction and servicing. This technology is being investigated by NASA with teleoperation of two space-related tasks having been demonstrated at the Oak Ridge National Lab. The teleoperator experiments are discussed and the results of these experiments are summarized. The related equipment design recommendations are also presented. In addition, a general discussion of equipment design for teleoperation is also presented

Finding agency in limbo: a qualitative investigation into the impact of occupational engagement on mental health and wellbeing of asylum seekers in the U.K.

The process of seeking asylum is complex, and often leads to extended periods of limbo for millions of people awaiting decisions on their status. Engagement in occupation – defined as meaningful activities and roles that bring purpose and agency to one’s life- is suggested as a key driver for mental health recovery for marginalised populations, including asylum seekers with traumatic experiences pre- and post-migration. How does occupational engagement impact one’s mental health and wellbeing while existing in the asylum system? How do asylum seekers maintain engagement in occupation in the context of socio-political constraints of the asylum process? We explored the occupational experiences of 12 clients of one human-rights charity, utilising community-based participatory research methods. Participants completed group mapping sessions (n =4 sessions with 11 total participants) where participants depicted routine journeys taken to perform occupations in London, which included discussion around the significance of their journeys. Four participants also completed additional “walking maps” - semi-structured interviews which occurred along a selected “occupational journey” self-identified as meaningful to their wellbeing. All Data were analysed using thematic network analysis. Findings revealed that engagement in routine occupations within safe, social spaces positively affects the mental wellbeing of asylum seekers by promoting competence, agency and feelings of belonging. The liminal space of the asylum process meant that participants’ occupational engagement was limited to ‘leisure’ activities but were still critical to establishing forms of agency associated with their wellbeing. Implications for programmes and interventions responding to the needs of asylum seekers are discusse

Neural signatures of strategic types in a two-person bargaining game

The management and manipulation of our own social image in the minds of others requires difficult and poorly understood computations. One computation useful in social image management is strategic deception: our ability and willingness to manipulate other people's beliefs about ourselves for gain. We used an interpersonal bargaining game to probe the capacity of players to manage their partner's beliefs about them. This probe parsed the group of subjects into three behavioral types according to their revealed level of strategic deception; these types were also distinguished by neural data measured during the game. The most deceptive subjects emitted behavioral signals that mimicked a more benign behavioral type, and their brains showed differential activation in right dorsolateral prefrontal cortex and left Brodmann area 10 at the time of this deception. In addition, strategic types showed a significant correlation between activation in the right temporoparietal junction and expected payoff that was absent in the other groups. The neurobehavioral types identified by the game raise the possibility of identifying quantitative biomarkers for the capacity to manipulate and maintain a social image in another person's mind

Cosmology and two-body problem of D-branes

In this paper, we investigate the dynamics and the evolution of the scale factor of a probe Dp-brane which move in the background of source Dp-branes. Action of the probe brane is described by the Born-Infeld action and the interaction with the background R-R field. When the probe brane moves away from the source branes, it expands by power law, whose index depends on the dimension of the brane. If the energy density of the gauge field on the brane is subdominant, the expansion is decelerating irrespective of the dimension of the brane. On the other hand, when the probe brane is a Nambu-Goto brane, the energy density of the gauge field can be dominant, in which case accelerating expansion occurs for $p \leq 4$. The accelerating expansion stops when the brane has expanded sufficiently so that the energy density of the gauge field become subdominant.Comment: 6 pages, 7 figures, reference added, accepted for publication in PR