Determining predictors of underlying etiology and clinical deterioration in patients with physiologic instability in the emergency department

Thesis (M.A.)--Boston UniversityShock is a critical state defined by inadequate oxygen delivery to tissues. It is well known in the critical care community that early diagnosis and treatment of shock are crucial to improving patient outcomes. However, in many cases, when a state of circulatory shock has been reached, irreversible damage already occurred. In the present study, we broadened our patient cohort from those with shock to those with physiologic instability with the intent of finding predictive factors that allow us to recognize when a patient is at risk for deterioration or when it is already occurring. These patients included patients with pre-shock, shock, and other forms of dysfunction. The purpose of this study was to determine the predictors of underlying etiology of physiologic instability as well as the likelihood of clinical deterioration in these various states, using elements from the physical exam, history, laboratory values, and vital sign measurements. This study was a prospective observational study of patients, from November 15, 2012 to March 1, 2013, found to have physiologic instability in the emergency department at an urban, academic tertiary-care hospital with 55,000 annual visits. Physiologic instability was defined as any one of the following abnormalities: heart rate (HR) > 130, respiratory rate (RR>24), shock index (SI) > 1, systolic blood pressure (SBP) 4.0 mmol/L, for a time period of more than five minutes. We identified 540 patients, 74.8% of which were included. Data describing epidemiology, and elements from the patient history and physical exam were abstracted from physician charts and the final etiology of physiologic instability, defined as septic, cardiogenic, hypovolemic, hemorrhagic, or other, was adjudicated by a physician. Blood samples from a subset of our patient group were collected from the hospital hematology laboratory and sent to the Wyss Institute to be analyzed using a novel bacterial detection assay. All of the covariates that data was collected for were analyzed to determine their diagnostic and prognostic value. [TRUNCATED

Voltage regulator/amplifier is self-regulated

Signal modulated, self-regulating voltage regulator/amplifier controls the output b-plus voltage in modulated regulator systems. It uses self-oscillation with feedback to a control circuit with a discontinuous amplitude action feedback loop

Mitchell and Seiden\u27s Reviewing the academic library: A guide to selfstudy and external review (Book Review)

A review of Mitchell, E., & Seiden, P. (Eds.) (2015). Reviewing the academic library: A guide to selfstudy and external review. Chicago: ACRL. 334 pp. $65.00. ISBN 978083898783

Effective classroom practice: a mixed-method study of influences and outcomes: a research paper

This brief paper reports findings from a two-year research project, funded by the ESRC, which identified, described and analyzed variation in effective primary and secondary school teachers’ classroom practice. The study also explored these practices in relation to different school contexts and teachers’ professional life phases in order to draw out relevant implications for policy and practice

Critical mutation rate has an exponential dependence on population size in haploid and diploid populations

Understanding the effect of population size on the key parameters of evolution is particularly important for populations nearing extinction. There are evolutionary pressures to evolve sequences that are both fit and robust. At high mutation rates, individuals with greater mutational robustness can outcompete those with higher fitness. This is survival-of-the-flattest, and has been observed in digital organisms, theoretically, in simulated RNA evolution, and in RNA viruses. We introduce an algorithmic method capable of determining the relationship between population size, the critical mutation rate at which individuals with greater robustness to mutation are favoured over individuals with greater fitness, and the error threshold. Verification for this method is provided against analytical models for the error threshold. We show that the critical mutation rate for increasing haploid population sizes can be approximated by an exponential function, with much lower mutation rates tolerated by small populations. This is in contrast to previous studies which identified that critical mutation rate was independent of population size. The algorithm is extended to diploid populations in a system modelled on the biological process of meiosis. The results confirm that the relationship remains exponential, but show that both the critical mutation rate and error threshold are lower for diploids, rather than higher as might have been expected. Analyzing the transition from critical mutation rate to error threshold provides an improved definition of critical mutation rate. Natural populations with their numbers in decline can be expected to lose genetic material in line with the exponential model, accelerating and potentially irreversibly advancing their decline, and this could potentially affect extinction, recovery and population management strategy. The effect of population size is particularly strong in small populations with 100 individuals or less; the exponential model has significant potential in aiding population management to prevent local (and global) extinction events

Containerless processing of glass forming melts: D-1, MEA/A-2 experiment 81F01 conducted on STS-61A flight, October 1985

Results of experiment 81F01, which was conducted in the Material Experiment Assembly MEA/A-2 on the D-1 Spacelab Mission (STS-61A), are presented. The general plan of the experiment was to heat, melt, and quench six spherical samples of different glass forming compositions while they were levitated in a single axis acoustic levitator furnace (SAAL). In addition, two non-melting sintered alumina samples were used to check the operational characteristics of the SAAL under reduced gravity conditions. Three of the eight samples were levitated between 1250 and 1500 C before the lack of coolant created an over-temperature condition that caused the SAAL to shut down prematurely. Two of the three samples processed were calcia-gallia-silica and soda-lime-silica glass forming compositions. Evidence of a two to three times increase in the tendency for glass formation was obtained for the calcia-gallia-silica. The final glass appeared reasonably homogeneous even though it was made from hot pressed powders containing deliberate heterogeneities. A photographic record was obtained of the microgravity sample processing sequences

OPERATIONS - FLIGHT CREW REQUIREMENTS

Flight simulation in crew training - manned space fligh

Alternative determinism principle for topological analysis of chaos

The topological analysis of chaos based on a knot-theoretic characterization of unstable periodic orbits has proved a powerful method, however knot theory can only be applied to three-dimensional systems. Still, the core principles upon which this approach is built, determinism and continuity, apply in any dimension. We propose an alternative framework in which these principles are enforced on triangulated surfaces rather than curves and show that in dimension three our approach numerically predicts the correct topological entropies for periodic orbits of the horseshoe map.Comment: Accepted for publication as Rapid Communication in Physical Review

Is simultaneous yy and ξ\xi--scaling in the quasi-elastic region accidental?

We study the $y$ and $\xi$--scaling of the nuclear response at large momentum transfer in order to understand how scaling based on very different descriptions of the elementary interaction can occur simultaneously. We find that the approximate validity of $\xi$-scaling at low energy loss arises from the coincidental behavior of the quasielastic and deep inelastic cross sections.Comment: 4 pages, 3 Postscript figure

Carbonate Formation in Non-Aqueous Environments by Solid-Gas Carbonation of Silicates

We have produced synthetic analogues of cosmic silicates using the Sol Gel method, producing amorphous silicates of composition Mg(x)Ca(1-x)SiO3. Using synchrotron X-ray powder diffraction on Beamline I11 at the Diamond Light Source, together with a newly-commissioned gas cell, real-time powder diffraction scans have been taken of a range of silicates exposed to CO2 under non-ambient conditions. The SXPD is complemented by other techniques including Raman and Infrared Spectroscopy and SEM imaging.Comment: 5 pages, 3 figures. Contribution to the Proceedings of the First European Conference on Laboratory Astrophysics (ECLA