Alien Registration- Thomas, Blanche F. (Portland, Cumberland County)

https://digitalmaine.com/alien_docs/31419/thumbnail.jp

Alien Registration- Wilder, Blanche F. (Portland, Cumberland County)

https://digitalmaine.com/alien_docs/31421/thumbnail.jp

Concordance Among Extension Workers, Researchers, and Professional Arborists in Rating Landscape Trees

Formulas developed to determine the monetary value of landscape trees require a species rating value. Polling Extension professionals, researchers, and arborists is a common procedure to derive species rating value. Due to differences in professional training and background, and the variability of landscapes in any given area, professional agreement on the rating of a species is difficult to reach but is necessary to be useful. The Delphi method and W criterion were used to determine the strength of concordance among extension professionals. We hope that other Extension professionals can use this method in developing species rating in their respective areas

Time- and rate-dependent alterations of the QT interval precede the onset of torsade de pointes in patients with acquired QT prolongation.

Abstract Objectives. The purpose of this study was to determine whether the QT interval dynamics that precede torsade de pointes are consistent with the initiation of this arrhythmia by early afterdepolarization-induced triggered activity. Background. Early afterdepolarization-induced triggered activity has been suggested as an electrophysiologic mechanism for torsade de pointes. Consequently, the initiation of torsade de pointes should involve time- and rate-dependent alterations of ventricular repolarization similar to those known to modulate the development of early afterdepolarizations. Methods. RR and QT intervals were measured in digitized 24-h ambulatory electrocardiographic recordings obtained from seven patients with acquired prolongation of ventricular repolarization. Each patient had one or more episodes of torsade de pointes. The relation between RR and QT intervals was determined before, during and after multiple episodes of torsade de pointes. Results. In patients with multiple episodes of ventricular arrhythmias, the onset of the arrhythmias was associated with a critical prolongation of the QT interval. In some episodes, prolongation of the QT interval was associated with sudden prolongation of the sinus cycle length, whereas in other episodes, the QT interval prolonged progressively at a constant cycle length. Conclusions. The association between a critically prolonged QT interval and the onset of ventricular arrhythmias suggests that the initial complex of torsade de pointes is an early afterdepolarization-induced triggered response. However, prolongation of the QT interval itself was not sufficient to account for the initiation of torsade de pointes, suggesting that other, as yet unidentified factors are required. (J Am Coll Cardiol 1997;30:209–17

Lead-Free Experiment in a Space Environment

This Technical Memorandum addresses the Lead-Free Technology Experiment in Space Environment that flew as part of the seventh Materials International Space Station Experiment outside the International Space Station for approximately 18 months. Its intent was to provide data on the performance of lead-free electronics in an actual space environment. Its postflight condition is compared to the preflight condition as well as to the condition of an identical package operating in parallel in the laboratory. Some tin whisker growth was seen on a flight board but the whiskers were few and short. There were no solder joint failures, no tin pest formation, and no significant intermetallic compound formation or growth on either the flight or ground units

Propensity score weighting plus an adjusted proportional hazards model does not equal doubly robust away from the null

Recently it has become common for applied works to combine commonly used survival analysis modeling methods, such as the multivariable Cox model, and propensity score weighting with the intention of forming a doubly robust estimator that is unbiased in large samples when either the Cox model or the propensity score model is correctly specified. This combination does not, in general, produce a doubly robust estimator, even after regression standardization, when there is truly a causal effect. We demonstrate via simulation this lack of double robustness for the semiparametric Cox model, the Weibull proportional hazards model, and a simple proportional hazards flexible parametric model, with both the latter models fit via maximum likelihood. We provide a novel proof that the combination of propensity score weighting and a proportional hazards survival model, fit either via full or partial likelihood, is consistent under the null of no causal effect of the exposure on the outcome under particular censoring mechanisms if either the propensity score or the outcome model is correctly specified and contains all confounders. Given our results suggesting that double robustness only exists under the null, we outline two simple alternative estimators that are doubly robust for the survival difference at a given time point (in the above sense), provided the censoring mechanism can be correctly modeled, and one doubly robust method of estimation for the full survival curve. We provide R code to use these estimators for estimation and inference in the supplementary materials

Pi‐29

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110026/1/cptclpt200664.pd