Feasibility of Focused Cardiac Ultrasound in Pre-participation Screening

Objective: Current American Heart Association (AHA) guidelines for pre-participation athletic screening recommend a 12-point history and exam to minimize the risk of sudden cardiac death. We tested the hypothesis that focused cardiac ultrasound (FCU) performed and simultaneously interpreted by a cardiologist using a handheld ultrasound device would be a feasible addition. Methods: We performed pre-participation screening according to AHA recommendations on high school athletes in a multi-purpose room at their school. In addition to the standard 12-point assessment, a cardiologist simultaneously performed and interpreted a FCU on each athlete using a handheld ultrasound. Results: The mean age of the athletes was 16.6 ± 3.4 years; 68% were male. No evidence of left ventricular hypertrophy, cardiomyopathy, bicuspid aortic valve, or aortopathy was identified. Coronary ostia could not be visualized. Echocardiography added 1.35 ± 0.51 minutes to the standard exam. Conclusion: This feasibility study suggests that the addition of handheld echocardiography with real-time interpretation performed by a cardiologist to a standard AHA pre-participation screening adds less than two minutes of time to the assessment. While the study is not as comprehensive as an office based echocardiogram, it can provide valuable information which may be useful in ruling out some of the most common causes of sudden cardiac death in the young athlete or in selecting those who would benefit from further testing

Results from GROCSE I: A real-time search for gamma ray burst optical counterparts

The GROCSE I experiment (Gamma-Ray Optical Counterpart Search Experiment) is a rapid slewing wide field of view optical telescope at Lawrence Livermore National Laboratory, which responds to triggers from the BATSE GRB data telemetry stream that have been processed and distributed by the BACODINE network. GROCSE I has been in continuous automated operation since January 1994. As of October 1995, sky images for 22 GRB triggers have been recorded, in some cases while the burst was still in progress. The preliminary analysis of eight of these events are presented here. No optical counterparts have yet been detected. Limits for optical emission are given. © 1996 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87367/2/671_1.pd

LMDA Review, volume 10, issue 1

Contents include: Photo of Conference Participants Annual Conference 1999, Send in your Ballot, A Note to Ourselves, Increase in Dues and New Annual Membership Expiration Date, LMDA Archive, LMDA Administrator; LMDA Interns, Mid-Year Meeting, Early Career Dramaturg Program, Elliot Hayes Award 2000, Report on Canadian Caucus, Script Exchange, Report on the Dramaturgy Focus Group ATHE 1999, Elliot Hayes Award Winners Lue Douthit and Michel Volansky, Acceptance Speech Lue Morgan Douthit, Elliot Hayes Award Presentation to Michele Volansky for Space, On the Elliot Hayes Award Michele Volansky, Day One of the Conference, Day Two of the Conference, Day Three of the Conference, Day Four of the Conference, The Advocacy Caucus Presentation at the Conference, Final Thoughts, Conference 1999 Many Thanks, Arthur Ballet and the Office for Advanced Drama Research, Spotlight on Early Career Dramaturg Vanessa Porteous, A Working History of LMDA The Early Years, From Academia to Arena A Dramaturg\u27s Education in the Real World, Tony Creamer and Death of a Salesman, Two Moments, Jobs and Projects, Scriptseeker.com, LMDA Online Listserv Instructions, Note from James Magruder, Literary Managers and Dramaturgs of the Americas Bibliography 1999, Noted with Pleasure, and Internship Questionnaire.https://soundideas.pugetsound.edu/lmdareview/1020/thumbnail.jp

Gamma ray burst optical counterpart search experiment (GROCSE)

GROCSE (Gamma-Ray Optical Counterpart Search Experiment) is a system of automated telescopes that search for simultaneous optical activity associated with gamma ray bursts in response to real-time burst notifications provided by the BATSE/BACODINE network. The first generation system, GROCSE I, is sensitive down to MV ∼ 8.5MV∼8.5 and requires an average of 12 seconds to obtain the first images of the gamma ray burst error box defined by the BACODINE trigger. The collaboration is now constructing a second generation system which has a 4 second slewing time and can reach MV ∼ 14MV∼14 with a 5 second exposure. GROCSE II consists of 4 cameras on a single mount. Each camera views the night sky through a commercial Canon lens (f/1.8,(f/1.8, focal length 200 mm) and utilizes a 2K×2K2K×2K Loral CCD. Light weight and low noise custom readout electronics were designed and fabricated for these CCDs. The total field of view of the 4 cameras is 17.6×17.6°.17.6×17.6°. GROCSE II will be operating by the end of 1995. In this paper, we present an overview of the GROCSE system and the results of measurements with a GROCSE II prototype unit. © 1996 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87369/2/861_1.pd

Convective injection and photochemical decay of peroxides in the tropical upper troposphere: Methyl iodide as a tracer of marine convection

The convective injection and subsequent fate of the peroxides H2O2 and CH3OOH in the upper troposphere is investigated using aircraft observations from the NASA Pacific Exploratory Mission‐Tropics A (PEM‐Tropics A) over the South Pacific up to 12 km altitude. Fresh convective outflow is identified by high CH3I concentrations; CH3I is an excellent tracer of marine convection because of its relatively uniform marine boundary layer concentration, relatively well‐defined atmospheric lifetime against photolysis, and high sensitivity of measurement. We find that mixing ratios of CH3OOH in convective outflow at 8–12 km altitude are enhanced on average by a factor of 6 relative to background, while mixing ratios of H2O2 are enhanced by less than a factor of 2. The scavenging efficiency of H2O2 in the precipitation associated with deep convection is estimated to be 55–70%. Scavenging of CH3OOH is negligible. Photolysis of convected peroxides is a major source of the HOx radical family (OH + peroxy radicals) in convective outflow. The timescale for decay of the convective enhancement of peroxides in the upper troposphere is determined using CH3I as a chemical clock and is interpreted using photochemical model calculations. Decline of CH3OOH takes place on a timescale of a 1–2 days, but the resulting HOx converts to H2O2, so H2O2 mixing ratios show no decline for ∼5 days following a convective event. The perturbation to HOx at 8–12 km altitude from deep convective injection of peroxides decays on a timescale of 2–3 days for the PEM‐Tropics A conditions

Anarchy's anatomy : two-tiered security systems and Libya’s civil wars

No issue deserves more scrutiny than the mechanisms whereby popular unrest unleashes civil wars. We argue that one institution — two-tiered security systems — is particularly pernicious in terms of the accompanying civil war risk. These systems’ defining characteristic is the juxtaposition of small communally stacked units that protect regimes from internal adversaries with larger regular armed forces that deter external opponents. These systems aggravate civil war risks because stacked security units lack the size to repress widespread dissent, but inhibit rapid regime change through coup d’état. Regular militaries, meanwhile, fracture when ordered to employ force against populations from which they were recruited.PostprintPeer reviewe

Photochemistry in biomass burning plumes and implications for tropospheric ozone over the tropical South Atlantic

Photochemistry occuring in biomass burning plumes over the tropical south Atlantic is analyzed using data collected during the Transport and Atmospheric Chemistry Near the Equator‐Atlantic aircraft expedition conducted during the tropical dry season in September 1992 and a photochemical point model. Enhancement ratios (ΔY/ΔX, where Δ indicates the enhancement of a compound in the plume above the local background mixing ratio, Y are individual hydrocarbons, CO, O3, N2O, HNO3, peroxyacetyl nitrate (PAN), CH2O, acetone, H2O2, CH3OOH, HCOOH, CH3COOH or aerosols and X is CO or CO2) are reported as a function of plume age inferred from the progression of Δnon‐methane hydrocarbons/ΔCO enhancement ratios. Emission, formation, and loss of species in plumes can be diagnosed from progression of enhancement ratios from fresh to old plumes. O3 is produced in plumes over at least a 1 week period with mean ΔO3/ΔCO = 0.7 in old plumes. However, enhancement ratios in plumes can be influenced by changing background mixing ratios and by photochemical loss of CO. We estimate a downward correction of ∼20% in enhancement ratios in old plumes relative to ΔCO to correct for CO loss. In a case study of a large persistent biomass burning plume at 4‐km we found elevated concentrations of PAN in the fresh plume. The degradation of PAN helped maintain NOx mixing ratios in the plume where, over the course of a week, PAN was converted to HNO3. Ozone production in the plume was limited by the availability of NOx, and because of the short lifetime of O3 at 4‐km, net ozone production in the plume was negligible. Within the region, the majority of O3 production takes place in air above median CO concentration, indicating that most O3 production occurs in plumes. Scaling up from the mean observed ΔO3/ΔCO in old plumes, we estimate a minimum regional O3 production of 17×1010molecules O3 cm−2 s−1. This O3 production rate is sufficient to fully explain the observed enhancement in tropospheric O3 over the tropical South Atlantic during the dry season