Do Complexity Measures of Frontal EEG Distinguish Loss of Consciousness in Geriatric Patients Under Anesthesia?

While geriatric patients have a high likelihood of requiring anesthesia, they carry an increased risk for adverse cognitive outcomes from its use. Previous work suggests this could be mitigated by better intraoperative monitoring using indexes defined by several processed electroencephalogram (EEG) measures. Unfortunately, inconsistencies between patients and anesthetic agents in current analysis techniques have limited the adoption of EEG as standard of care. In attempts to identify new analyses that discriminate clinically-relevant anesthesia timepoints, we tested 1/f frequency scaling as well as measures of complexity from nonlinear dynamics. Specifically, we tested whether analyses that characterize time-delayed embeddings, correlation dimension (CD), phase-space geometric analysis, and multiscale entropy (MSE) capture loss-of-consciousness changes in EEG activity. We performed these analyses on EEG activity collected from a traditionally hard-to-monitor patient population: geriatric patients on beta-adrenergic blockade who were anesthetized using a combination of fentanyl and propofol. We compared these analyses to traditional frequency-derived measures to test how well they discriminated EEG states before and after loss of response to verbal stimuli. We found spectral changes similar to those reported previously during loss of response. We also found significant changes in 1/f frequency scaling. Additionally, we found that our phase-space geometric characterization of time-delayed embeddings showed significant differences before and after loss of response, as did measures of MSE. Our results suggest that our new spectral and complexity measures are capable of capturing subtle differences in EEG activity with anesthesia administration-differences which future work may reveal to improve geriatric patient monitoring

An identeification guide to the Mosquitoes of Utah

journal articleThe first detailed report on the mosquito fauna of Utah was published by pees (1943). In this bulletin Rees reported the occurrence in the state of 31 species, representing 4 genera, and discussed their biology, distribution, life history and importance. Subsequent publications by Rees (1944), Rees and Nielsen (1951, 1955), Nielsen and Rees (1959) and Richards et al. (1956) have added to the knowlgdge of the mosquito fauna of this state. A total of 45 species has been reported in the literature as occurring in Utah. Of this number five are records which the authors consider invalid or of uncertain status. These are discussed by Nielsen and Rees (1959). At present the known Utah mosquito fauna consists of 40 species, representing 6 genera. A list of the Utah species with their relative abundance is presented in Table I

An identification guide to the mosquitoes of Utah

journal articleThe first detailed report on the mosquito fauna of Utah was published by pees (1943). In this bulletin Rees reported the occurrence in the state of 31 s p e c ie s , representing 4 genera, and discussed their biology, distribution, life history and importance. Subsequent publications by Rees (1944), Rees and Nielsen (1951, 1955), Nielsen and Rees (1959) and Richards et al. (1956) have added to the knowlgdge of the mosquito fauna of this state. A total of 45 species has been reported in the literature as occurring in Utah. Of this number five are records which the authors consider invalid or of uncertain status. These are discussed by Nielsen and Rees (1959). At present the known Utah mosquito fauna consists of 40 species, representing 6 genera. A list of the Utah species with their relative abundance is presented in Table I

The Raman Spectra of Carbon and Silicon Tetrafluorides

We have photographed the Raman spectra for the tetrafluorides of carbon and silicon in both the liquid and gaseous states. The results are presented in Table I together with the Raman frequencies for CCl4 for purposes of comparison

TEACHING MARKETING AND MANAGEMENT TO AN EXTENSION AUDIENCE IN AN INTER-DISCIPLINARY SETTING

This paper discusses how economists utilize an inter-disciplinary workshop to teach marketing and management concepts to beef cattle producers and beef industry advisors. Range and animal scientists along with economists teach concepts in the classroom and then demonstrate these concepts with hands-on field activities in an 8-day Ranch Practicum, spread over an 8-month period.Teaching/Communication/Extension/Profession,

Recording seismic reflections using rigidly interconnected geophones

This is the publisher's version, also available electronically from "http://library.seg.org".Ultrashallow seismic reflection surveys require dense spatial sampling during data acquisition, which increases their cost. In previous efforts to find ways to reduce these costs, we connected geophones rigidly to pieces of channel iron attached to a farm implement. This method allowed us to plant the geophones in the ground quickly and automatically. The rigidly interconnected geophones used in these earlier studies detected first‐arrival energy along with minor interfering seismic modes, but they did not detect seismic reflections. To examine further the feasibility of developing rigid geophone emplacement systems to detect seismic reflections, we experimented with four pieces of channel iron, each 2.7 m long and 10 cm wide. Each segment was equipped with 18 geophones rigidly attached to the channel iron at 15‐cm intervals, and the spikes attached to all 18 geophones were pushed into the ground simultaneously. The geophones detected both refracted and reflected energy; however, no significant signal distortion or interference attributable to the rigid coupling of the geophones to the channel iron was observed in the data. The interfering seismic modes mentioned from the previous experiments were not detected, nor was any P‐wave propagation noted within the channel iron. These results show promise for automating and reducing the cost of ultrashallow seismic reflection and refraction surveys

Treatment of Ion-Atom Collisions using a Partial-Wave Expansion of the Projectile Wavefunction

We present calculations of ion-atom collisions using a partial-wave expansion of the projectile wavefunction. Most calculations of ion-atom collisions have typically used classical or plane-wave approximations for the projectile wavefunction, since partial-wave expansions are expected to require prohibitively large numbers of terms to converge scattering quantities. Here we show that such calculations are possible using modern high-performance computing. We demonstrate the utility of our method by examining elastic scattering of protons by hydrogen and helium atoms, problems familiar to undergraduate students of atomic scattering. Application to ionization of helium using partial-wave expansions of the projectile wavefunction, which has long been desirable in heavy-ion collision physics, is thus quite feasible