368 research outputs found
Functional Brain Signals: A photon counting system for brain activity monitoring
A simplified in vivo near infrared spectroscopy
(NIRS) system for functional brain analysis and a protocol for the
study of visual evoked potentials in the human brain is presented.
A novel NIRS system bases on a simple photon counting technique
using a CW light source (laser diode at 780 nm), fibre optodes
delivering light to the subject and from the subject to detector, a
photomultiplier tube (PMT) for high infra-red (IR) response and
the 800 MHz Gated Photon Counter/multichannel scaler (MCS) for
data acquisition. A chequerboard stimulus was used to elicit a
response signal from the visual cortex. This photon signal arising
from the cortical systems of the brain was processed to detect
features indicative of the neural processing systems involved
Functional Brain Signals: A photon counting system for brain activity monitoring
A simplified in vivo near infrared spectroscopy
(NIRS) system for functional brain analysis and a protocol for the
study of visual evoked potentials in the human brain is presented.
A novel NIRS system bases on a simple photon counting technique
using a CW light source (laser diode at 780 nm), fibre optodes
delivering light to the subject and from the subject to detector, a
photomultiplier tube (PMT) for high infra-red (IR) response and
the 800 MHz Gated Photon Counter/multichannel scaler (MCS) for
data acquisition. A chequerboard stimulus was used to elicit a
response signal from the visual cortex. This photon signal arising
from the cortical systems of the brain was processed to detect
features indicative of the neural processing systems involved
A Dual-Channel Optical Brain-Computer Interface In A Gaming Environment
This paper explores the viability of using a novel optical
Brain-Computer Interface within a gaming environment.
We describe a system that incorporates a 3D gaming
engine and an optical BCI. This made it possible to
classify activation in the motor cortex within a synchronous
experimental paradigm. Detected activations were
used to control the arm movement of a human model in
the graphical engine
The effect of poloidal velocity shear on the local development of current-driven instabilities
We perform a local (short-wavelength) linear stability analysis of an
axisymmetric column of magnetized plasma with a nearly toroidal magnetic field
and a smooth poloidal velocity shear by perturbing the equations of
relativistic magnetohydrodynamics. We identify two types of unstable modes,
which we call 'exponential' and 'overstable', respectively. The exponential
modes are present in the static equilibria and their growth rates decrease with
increasing velocity shear. The overstable modes are driven by the effects of
velocity shear and dominate the exponential modes for sufficiently high shear
values. We argue that these local instabilities can provide an important energy
dissipation mechanism in astrophysical relativistic jets. Strong co-moving
velocity shear arises naturally in the magnetic acceleration mechanism,
therefore it may play a crucial role in converting Poynting-flux-dominated jets
into matter-dominated jets, regulating the global acceleration and collimation
processes, and producing the observed emission of blazars and gamma-ray bursts.Comment: 8 pages, 5 figures, submitted to MNRA
A Dual-Channel Optical Brain-Computer Interface In A Gaming Environment
This paper explores the viability of using a novel optical Brain-Computer Interface within a gaming environment. We describe a system that incorporates a 3D gaming engine and an optical BCI. This made it possible to classify activation in the motor cortex within a synchronous experimental paradigm. Detected activations were used to control the arm movement of a human model in the graphical engine
4,7-Dichloroquinoline
The two molecules in the asymmetric unit of the title compound, C9H5Cl2N, are both essentially planar (r.m.s. deviations for all non-H atoms = 0.014 and 0.026 Å). There are no close C—H⋯Cl contacts
Nuclear transparencies in relativistic A(e,e'p) models
Relativistic and unfactorized calculations for the nuclear transparency
extracted from exclusive A(e,e'p) reactions for 0.3 \leq Q^2 \leq 10 (GeV/c)^2
are presented for the target nuclei C, Si, Fe and Pb. For Q^2 \geq 0.6
(GeV/c)^2, the transparency results are computed within the framework of the
recently developed relativistic multiple-scattering Glauber approximation
(RMSGA). The target-mass and Q^2 dependence of the RMSGA predictions are
compared with relativistic distorted-wave impulse approximation (RDWIA)
calculations. Despite the very different model assumptions underlying the
treatment of the final-state interactions in the RMSGA and RDWIA frameworks,
they predict comparable nuclear transparencies for kinematic regimes where both
models are applicable.Comment: 15 pages, 4 figure
Pit Crew Approach to Pre Hospital Trauma Resuscitation
IntroductionPre hospital trauma care is often delivered by dual crewed ambulances supported by additional resources as necessary and available. Coordinating resuscitation of a critically injured patient may require multiple simultaneous actions. Equally, a large number of practitioners can hinder patient care if not coordinated.AimsTo describe a multi disciplinary, scaleabe approach to pre hospital trauma care suitable for small and large multi disciplinary teams. Methods The MCI medical team (as part of Motorsport Rescue Services) is a PHECC-registered multidisciplinary team, which provides medical cover at Motorcycle road racing events in Ireland. The MCI medical team has significant experience of major trauma and routinely performs prehospital anaesthesia for trauma patients. We have evolved a pit crew approach to trauma care with pre defined roles and interventions assigned to a five person team, three clinical members, a scribe and a team lead. The approach is both scalable and collapsible, meaning that if multiple patients are present, roles can be merged; if additional clinical input is required, roles can also be supplemented. Each team member carries equipment and medications specific to their role, allowing efficiencies at the patients side.ResultsThe pit crew approach to pre hospital trauma care has evolved over a decade and is routinely implemented at motorcycle road races in Ireland.ConclusionsThe pit crew trauma approach, although applicable to a pre defined five person team in unique circumstances, may also be applicable to ad hoc clinical teams that typically form in the pre hospital arena
Conservative versus liberal oxygenation targets in critically ill children: the randomised multiple-centre pilot Oxy-PICU trial
BACKGROUND: Oxygen saturation monitoring for children receiving respiratory support is standard worldwide. No randomised clinical trials have compared peripheral oxygen saturation (SpO_{2}) targets for critically ill children. The harm of interventions to raise SpO_{2} to > 94% may exceed their benefits. METHODS: We undertook an open, parallel-group randomised trial of children > 38 weeks completed gestation and 94%) or a conservative oxygenation group (SpO_{2} = 88–92% inclusive). Outcomes were measures of feasibility: recruitment rate, protocol adherence and acceptability, between-group separation of SpO_{2} and safety. The Oxy-PICU trial was registered before recruitment: ClinicalTrials.gov identifier NCT03040570. RESULTS: A total of 159 children met the inclusion criteria, of whom 119 (75%) were randomised between April and July 2017, representing a rate of 10 patients per month per site. The mean time to randomisation from first contact with an intensive care team was 1.9 (SD 2.2) h. Consent to continue in the study was obtained in 107 cases (90%); the children’s parents/legal representatives were supportive of the consent process. The median (interquartile range, IQR) of time-weighted individual mean SpO_{2} was 94.9% (92.6–97.1) in the conservative oxygenation group and 97.5% (96.2–98.4) in the liberal group [difference 2.7%, 95% confidence interval (95% CI) 1.3–4.0%, p < 0.001]. Median (IQR) time-weighted individual mean FiO_{2} was 0.28 (0.24–0.37) in the conservative group and 0.37 (0.30–0.42) in the liberal group (difference 0.08, 95% CI 0.03–0.13, p < 0.001). There were no significant between-group differences in length of stay, duration of organ support or mortality. Two prespecified serious adverse events (cardiac arrests) occurred, both in the liberal oxygenation group. CONCLUSION: A definitive clinical trial of peripheral oxygen saturation targets is feasible in critically ill children
On the linear stability of magnetized jets without current sheets - non-relativistic case
In this paper we consider stability of magnetized jets that carry no net electric current and do not have current sheets. The non-relativistic magnetohydrodynamics equations are linearized around the background velocity and the magnetic field structure of the jet. The resulting linear equations are solved numerically inside the jet. We find that introduction of current-sheet-free magnetic field significantly improves jet stability relative to unmagnetized jets or magnetized jets with current sheets at their surface. This particularly applies to the fundamental pinch and kink modes – they become completely suppressed in a wide range of long wavelengths that are known to become most pernicious to jet stability when the evolution enters the non-linear regime. The reflection modes, both for the pinch and kink instability, also become progressively more stable with increased magnetization
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