Asymptotic analysis of drug dissolution in two layers having widely differing diffusivities

This paper is concerned with a diffusion-controlled moving-boundary problem in drug dissolution, in which the moving front passes from one medium to another for which the diffusivity is many orders of magnitude smaller. The classical Neumann similarity solution holds while the front is passing through the first layer, but this breaks down in the second layer. Asymptotic methods are used to understand what is happening in the second layer. Although this necessitates numerical computation, one interesting outcome is that only one calculation is required, no matter what the diffusivity is for the second laye

Delayed Recognition of Acute Stroke by Emergency Department Staff Following Failure to Activate Stroke by Emergency Medical Services

Introduction: Early recognition and pre-notification by emergency medical services (EMS) improves the timeliness of emergency department (ED) stroke care; however, little is known regarding the effects on care should EMS providers fail to pre-notify. We sought to determine if potential stroke patients transported by EMS, but for whom EMS did not provide pre-notification, suffer delays in ED door-to-stroke-team activation (DTA) as compared to the other available cohort of patients for whom the ED is not pre-notified-those arriving by private vehicle. Methods: We queried our prospective stroke registry to identify consecutive stroke team activation patients over 12 months and retrospectively reviewed the electronic health record for each patient to validate registry data and abstract other clinical and operational data. We compared patients arriving by private vehicle to those arriving by EMS without pre-notification, and we employed a multivariable, penalized regression model to assess the probability of meeting the national DTA goal of \u3c /=15 minutes, controlling for a variety of clinical factors. Results: Our inclusion criteria were met by 200 patients. Overall performance of the regression model was excellent (area under the curve 0.929). Arrival via EMS without pre-notification, compared to arrival by private vehicle, was associated with an adjusted risk ratio of 0.55 (95% confidence interval, 0.27-0.96) for achieving DTA \u3c /= 15 minutes. Conclusion: Our single-center data demonstrate that potential stroke patients arriving via EMS without pre-notification are less likely to meet the national DTA goal than patients arriving via other means. These data suggest a negative, unintended consequence of otherwise highly successful EMS efforts to improve stroke care, the root of which may be ED staff over-reliance on EMS for stroke recognition

Emergency Medicine Providers Systematically Underestimate Their Opioid Prescribing Practices

Background: Opioid misuse is a known public health problem, nationwide and in Massachusetts. The Massachusetts Hospital Association (MHA) developed recommendations to address opioid prescribing in the ED setting, and UMassMemorial Health Care recently implemented a system-wide opioid practice guideline mirroring the MHA policy. Little is known about methods to influence behavior change among ED providers related to opioid prescribing practices. Guideline implementation provided a unique opportunity for a natural experiment related to prescribing patterns, and we hypothesized that a simultaneous experimental intervention to provide clinicians with their individual prescribing data would alter their practices beyond any effect achieved solely by being subject to the new guidelines. Methods: As part of an ongoing, prospective, randomized trial of an intervention hypothesized to influence providers’ opioid prescribing, we developed a survey instrument consisting of graphical depictions of the distributions of three measures of opioid prescribing among all ED providers at four UMass-affiliated EDs (attending and resident physicians and advanced practice providers). Clinicians randomized to the intervention arm were asked to identify his/her perceived position on each distribution. We compared each provider’s self-perception to their actual decile. Results: Fifty-one providers were randomized to the intervention arm. Forty-eight completed the survey (94%). Providers underestimated their decile of opioid prescriptions per hundred total prescriptions by a median of one decile (p=0.0399 for difference from zero). Attendings underestimated their decile of percentage of patients dispositioned with an opioid prescription by a median of two deciles (p=0.0292), while residents did not exhibit a significant difference. Providers showed systematic disagreement with their raw number of prescriptions for extended-release opioid formulations (kappa -0.18), underestimating by a median of one. Conclusions: Based upon three measures of ED opioid prescribing, providers’ self-perceptions of their practices systematically underestimated their actual prescribing, which likely has implications related to efforts to influence clinician behavior change

Alcohol intoxication progressively impairs drivers' capacity to detect important environmental stimuli

Rationale Alcohol intoxication impairs driving skills, leading to an increased frequency of accidents and crash fatalities. Inebriation may specifically impair environmental vigilance, reducing the driver's capacity for attention to stimuli that are relevant to successful navigation. Objectives We examined the separate and interactive effects of breath alcohol concentration (BrAC) and simulated driving scenario on the capacity to correctly identify visual stimuli embedded in the environment. Methods Ten healthy young adult drivers (6 males; 4 females) each performed 4 driving scenarios at each of 3 steady breath alcohol concentration levels (0, 60 and 100 mg/dl). Scenarios were based on speed or distance keeping while navigating a rural 2-lane road in daytime or nighttime conditions. Drivers pressed a button on the steering wheel corresponding to the direction of an arrow (up or down) which appeared briefly on road signs embedded in the environment, either overhead or on the roadside. Results Increasing level of BrAC and subjective scenario difficulty manifested significant, separate, but not interactive influences in association with the number of arrows correctly identified. Significant impairments could be detected at a level of BrAC below the current American limit for legal operation of a motor vehicle. Conclusions Environmental vigilance is subject to impairment by either/both alcohol intoxication and driving conditions

Marshall University Music Department Presents Bluetrane, Faculty Jazz Ensemble, Featuring, Ed Bingham, saxophone, Mike Stroeher, trombone, Steve Hall, percussion Sean Parsons, piano, Martin Saunders, trumpet, Mark Zanter, guitar

https://mds.marshall.edu/music_perf/1498/thumbnail.jp

A Necessary and Sufficient Timing Assumption for Speed-Independent Circuits

This paper presents a proof that the adversary path timing assumption is both necessary and sufficient for correct SI circuit operation. This assumption requires that the delay of a wire on one branch of a fork be less than the delay through a gate sequence beginning at another branch in the same fork. Both the definition of the timing assumption and the proof build on a general, formal notion of computation given with respect to production rule sets. This underlying framework can be used for a variety of proof efforts or as a basis for defining other useful notions involving asynchronous computation