10,777 research outputs found
Protocol for electrophysiological monitoring of carotid endarterectomies.
Near zero stroke rates can be achieved in carotid endarterectomy (CEA) surgery with selective shunting and electrophysiological neuromonitoring. though false negative rates as high as 40% have been reported. We sought to determine if improved training for interpretation of the monitoring signals can advance the efficacy of selective shunting with electrophysiological monitoring across multiple centers, and determine if other factors could contribute to the differences in reports. Processed and raw beta band (12.5-30 Hz) electroencephalogram (EEG) and median and tibial nerve somatosensory evoked potentials (SSEP) were monitored in 668 CEA cases at six surgical centers. A decrease in amplitude of 50% or more in any EEG or SSEP channel was the criteria for shunting or initiating a neuroprotective protocol. A reduction of 50% or greater in the beta band of the EEG or amplitude of the SSEP was observed in 150 cases. No patient showed signs of a cerebral infarct after surgery. Selective shunting based on EEG and SSEP monitoring can reduce CEA intraoperative stroke rate to a near zero level if trained personnel adopted standardized protocols. We also found that the rapid administration of a protective stroke protocol by attending anesthesiologists was an important aspect of this success rate
A Configurable Matchmaking Framework for Electronic Marketplaces
E-marketplaces constitute a major enabler of B2B and B2C e-commerce activities. This paper proposes a framework for one of the central activities of e-marketplaces: matchmaking of trading intentions lodged by market participants. The framework identifies a core set of concepts and functions that are common to all types of marketplaces and can serve as the basis for describing the distinct styles of matchmaking employed within various market mechanisms. A prototype implementation of the framework based on Web services technology is presented, illustrating its ability to be dynamically configured to meet specific market needs and its potential to serve as a foundation for more fully fledged e-marketplace frameworks
Lepton Asymmetry of the Universe and Charged Quark-Gluon Plasma
The lepton asymmetry of order one is not excluded experimentally and, if
present, can lead to interesting phenomena in the early Universe. It is shown
that, when the temperature is above the quark-hadron transition, the lepton
asymmetry induces chemical potentials for electric charge and for baryon
number, and makes the quark-gluon plasma electrically charged.Comment: 7 pages, 2 figures; v2: misprints in eqs. 10 and 13 correcte
Environmental research on the new Lincoln University dairy farm
A major challenge to the New Zealand’s growing dairy industry is to achieve an annual
productivity gain of 4% in order to remain internationally competitive. However, it is important
to ensure that this productivity gain is achieved without significantly comprising the quality and
integrity of New Zealand’s “clean and green” environment.
There is increasing public concern about the effects of dairying on the environment, both
within New Zealand and by our overseas customers. One of the main concerns is the possible
threat to the quality of groundwater and surface water, particularly by nitrate, phosphate and
microbial contaminants.
Nitrate leaching from soil is of concern because of its impact on drinking water quality
and the effects that nitrate can have on rivers and lakes. A high nitrate concentration in drinking
water is a recognised health hazard and a high concentration in rivers and lakes can cause
excessive growth of algae and weeds, which may reduce the fish population. Nitrate leaching
also represents a financial cost to the farmer and a loss in soil fertility.
The establishment of the new Lincoln University dairy farm is designed to enable us to
develop and test practical methods to improve productivity and at the same time protect the
environment.
The objective of the environmental project on the new Lincoln University dairy farm is to
develop best management practices under irrigation which will ensure that the dairy
industry’s 4% productivity gain is achieved in a sustainable way, and that the wider
environment is protected
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Effects of the glial modulator palmitoylethanolamide on chronic pain intensity and brain function.
Background: Chronic neuropathic pain (NP) is a complex disease that results from damage or presumed damage to the somatosensory nervous system. Current treatment regimens are often ineffective. The major impediment in developing effective treatments is our limited understanding of the underlying mechanisms. Preclinical evidence suggests that glial changes are crucial for the development of NP and a recent study reported oscillatory activity differences within the ascending pain pathway at frequencies similar to that of cyclic gliotransmission in NP. Furthermore, there is evidence that glial modifying medications may be effective in treating NP. The aim of this Phase I open-label clinical trial is to determine whether glial modifying medication palmitoylethanolamide (PEA) will reduce NP and whether this is associated with reductions in oscillatory activity within the pain pathway. Methods: We investigated whether 6 weeks of PEA treatment would reduce pain and infra-slow oscillatory activity within the ascending trigeminal pathway in 22 individuals (17 females) with chronic orofacial NP. Results: PEA reduced pain in 16 (73%) of the 22 subjects, 11 subjects showed pain reduction of over 20%. Whilst both the responders and non-responders showed reductions in infra-slow oscillatory activity where orofacial nociceptor afferents terminate in the brainstem, only responders displayed reductions in the thalamus. Furthermore, functional connections between the brainstem and thalamus were altered only in responders. Conclusion: PEA is effective at relieving NP. This reduction is coupled to a reduction in resting oscillations along the ascending pain pathway that are likely driven by rhythmic astrocytic gliotransmission
Hiding relativistic degrees of freedom in the early universe
We quantify the extent to which extra relativistic energy density can be
concealed by a neutrino asymmetry without conflicting with the baryon asymmetry
measured by the Wilkinson Microwave Anisotropy Probe (WMAP). In the presence of
a large electron neutrino asymmetry, slightly more than seven effective
neutrinos are allowed by Big Bang Nucleosynthesis (BBN) and WMAP at 2\sigma.
The same electron neutrino degeneracy that reconciles the BBN prediction for
the primordial helium abundance with the observationally inferred value also
reconciles the LSND neutrino with BBN by suppressing its thermalization prior
to BBN.Comment: 5 pages, 5 figure
HST Grism Observations of a Gravitationally Lensed Redshift 10 Galaxy
We present deep spectroscopic observations of a Lyman-break galaxy candidate
(hereafter MACS1149-JD) at with the Space
Telescope () WFC3/IR grisms. The grism observations were taken at
4 distinct position angles, totaling 34 orbits with the G141 grism, although
only 19 of the orbits are relatively uncontaminated along the trace of
MACS1149-JD. We fit a 3-parameter (, F160W mag, and Ly equivalent
width) Lyman-break galaxy template to the three least contaminated grism
position angles using an MCMC approach. The grism data alone are best fit with
a redshift of ( confidence), in
good agreement with our photometric estimate of
( confidence). Our analysis
rules out Lyman-alpha emission from MACS1149-JD above a equivalent
width of 21 \AA{}, consistent with a highly neutral IGM. We explore a scenario
where the red /IRAC color of the galaxy
previously pointed out in the literature is due to strong rest-frame optical
emission lines from a very young stellar population rather than a 4000 \AA{}
break. We find that while this can provide an explanation for the observed IRAC
color, it requires a lower redshift (), which is less preferred
by the imaging data. The grism data are consistent with both
scenarios, indicating that the red IRAC color can still be explained by a 4000
\AA{} break, characteristic of a relatively evolved stellar population. In this
interpretation, the photometry indicate that a Myr stellar
population is already present in this galaxy only after
the Big Bang.Comment: Accepted to ApJ. This is the accepted versio
Technical Performance Reduces during the Extra-Time Period of Professional Soccer Match-Play
Despite the importance of extra-time in determining progression in specific soccer tournament matches, few studies have profiled the demands of 120-minutes of soccer match-play. With a specific focus on the extra-time period, and using a within-match approach, we examined the influence of prolonged durations of professional soccer match-play on markers of technical (i.e., skilled) performance. In 18 matches involving professional European teams played between 2010 and 2014, this retrospective study quantified the technical actions observed during eight 15-minute epochs (E1: 00:00–14:59 min, E2: 15:00-29:59 min, E3: 30:00-44:59 min, E4: 45:00-59:59 min, E5: 60:00-74:59 min, E6: 75:00-89:59 min, E7: 90:00-104:59 min, E8: 105:00-119:59 min). Analysis of players who completed the demands of the full 120 min of match-play revealed that the cumulative number of successful passes observed during E8 (61±23) was lower than E1-4 (E1: 88±23, P=0.001; E2: 77±21, P=0.005; E3: 79±18, P=0.001; E4: 80±21, P=0.001) and E7 (73±20, P=0.002). Similarly, the total number of passes made in E8 (71±25) was reduced when compared to E1 (102±22, P=0.001), E3 (91±19, P=0.002), E4 (93±22, P≤0.0005) and E7 (84±20, P=0.001). The cumulative number of successful dribbles reduced in E8 (9±4) when compared to E1 (14±4, P=0.001) and E3 (12±4, P≤0.0005) and the total time the ball was in play was less in E8 (504±61 s) compared to E1 (598±70 s, P≤0.0005). These results demonstrate that match-specific factors reduced particular indices of technical performance in the second half of extra-time. Interventions that seek to maintain skilled performance throughout extra-time warrant further investigation
Big Bang Nucleosynthesis with Gaussian Inhomogeneous Neutrino Degeneracy
We consider the effect of inhomogeneous neutrino degeneracy on Big Bang
nucleosynthesis for the case where the distribution of neutrino chemical
potentials is given by a Gaussian. The chemical potential fluctuations are
taken to be isocurvature, so that only inhomogeneities in the electron chemical
potential are relevant. Then the final element abundances are a function only
of the baryon-photon ratio , the effective number of additional neutrinos
, the mean electron neutrino degeneracy parameter , and
the rms fluctuation of the degeneracy parameter, . We find that for
fixed , , and , the abundances of helium-4,
deuterium, and lithium-7 are, in general, increasing functions of .
Hence, the effect of adding a Gaussian distribution for the electron neutrino
degeneracy parameter is to decrease the allowed range for . We show that
this result can be generalized to a wide variety of distributions for .Comment: 9 pages, 3 figures, added discussion of neutrino oscillations,
altered presentation of figure
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