Bostonia. Volume 5

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

Rationale and design of the Clinical Evaluation of Magnetic Resonance Imaging in Coronary heart disease 2 trial (CE-MARC 2): a prospective, multicenter, randomized trial of diagnostic strategies in suspected coronary heart disease

Background: A number of investigative strategies exist for the diagnosis of coronary heart disease (CHD). Despite the widespread availability of noninvasive imaging, invasive angiography is commonly used early in the diagnostic pathway. Consequently, approximately 60% of angiograms reveal no evidence of obstructive coronary disease. Reducing unnecessary angiography has potential financial savings and avoids exposing the patient to unnecessary risk. There are no large-scale comparative effectiveness trials of the different diagnostic strategies recommended in international guidelines and none that have evaluated the safety and efficacy of cardiovascular magnetic resonance.<p></p> Trial Design: CE-MARC 2 is a prospective, multicenter, 3-arm parallel group, randomized controlled trial of patients with suspected CHD (pretest likelihood 10%-90%) requiring further investigation. A total of 1,200 patients will be randomized on a 2:2:1 basis to receive 3.0-T cardiovascular magnetic resonance–guided care, single-photon emission computed tomography–guided care (according to American College of Cardiology/American Heart Association appropriate-use criteria), or National Institute for Health and Care Excellence guidelines–based management. The primary (efficacy) end point is the occurrence of unnecessary angiography as defined by a normal (>0.8) invasive fractional flow reserve. Safety of each strategy will be assessed by 3-year major adverse cardiovascular event rates. Cost-effectiveness and health-related quality-of-life measures will be performed.<p></p> Conclusions: The CE-MARC 2 trial will provide comparative efficacy and safety evidence for 3 different strategies of investigating patients with suspected CHD, with the intension of reducing unnecessary invasive angiography rates. Evaluation of these management strategies has the potential to improve patient care, health-related quality of life, and the cost-effectiveness of CHD investigation

American College of Obstetricians and Gynecologists practice bulletins: An overview

Objective The purpose of this study was to review the American College of Obstetricians and Gynecologists practices bulletins to quantify the type of recommendations and references and determining whether there are any differences between obstetric and gynecologic bulletins. Study design All practice bulletins published from June 1998 to December 2004 were reviewed. Odds ratios and 95% confidence intervals were calculated. Results The 55 practice bulletins contained 438 recommendations of which 29% are level A, 33% level B, and 38% level C. The 55 bulletins cite 3953 references of which 17% are level I, 46% level II, 34% level III, and 3% others. Level A recommendations were significantly more likely among the 23 gynecologic than 32 obstetric bulletins (37% versus 23%, odds ratios 1.95, 95% confidence intervals 1.28, 2.96). The study types referenced in obstetric and gynecologic bulletins were similar (P \u3e .05 for comparison of levels I, II, and III and meta-analysis references). Conclusion Only 29% of the American College of Obstetricians and Gynecologists recommendations are level A, based on good and consistent scientific evidence

The medical student

The Medical Student was published from 1888-1921 by the students of Boston University School of Medicine

Scalable accelerated decentralized multi-robot policy search in continuous observation spaces

This paper presents the first ever approach for solving continuous-observation Decentralized Partially Observable Markov Decision Processes (Dec-POMDPs) and their semi-Markovian counterparts, Dec-POSMDPs. This contribution is especially important in robotics, where a vast number of sensors provide continuous observation data. A continuous-observation policy representation is introduced using Stochastic Kernel-based Finite State Automata (SK-FSAs). An SK-FSA search algorithm titled Entropy-based Policy Search using Continuous Kernel Observations (EPSCKO) is introduced and applied to the first ever continuous-observation Dec-POMDP/Dec-POSMDP domain, where it significantly outperforms state-of-the-art discrete approaches. This methodology is equally applicable to Dec-POMDPs and Dec-POSMDPs, though the empirical analysis presented focuses on Dec-POSMDPs due to their higher scalability. To improve convergence, an entropy injection policy search acceleration approach for both continuous and discrete observation cases is also developed and shown to improve convergence rates without degrading policy quality.Boeing Compan

Distraction Control Processes in Free Recall: Costs and Benefits to Performance

How is semantic memory influenced by individual differences under conditions of distraction? This question was addressed by observing how visual target words—drawn from a single category—were recalled whilst ignoring spoken distracter words that were either members of the same, or members of a different (single) category. Distracter words were presented either synchronously or asynchronously with target words. Recall performance was correlated with participants’ working memory capacity (WMC), which was taken to be an index of the capacity for distracter inhibition. Distraction was greater from semantically similar words and distraction was greater when the words were presented synchronously. WMC was related to disruption only with synchronous, not asynchronous, presentation. Subsequent experiments found more distracter inhibition – as measured by subsequent negative priming of distracters – amongst individuals with higher WMC but this may be dependent on targets and distracters being comparable category exemplars: With less dominant category members as distracters, target recall was impaired – relative to control – only amongst individuals with low WMC. The results demonstrate distracter inhibition occurring only in conditions where target-distracter selection is challenging. Inhibition incurs costs to subsequent performance, but there is an immediate price for not inhibiting

Quantum Correlations in Two-Boson Wavefunctions

We present the Schmidt decomposition for arbitrary wavefunctions of two indistinguishable bosons, extending the recent studies of entanglement or quantum correlations for two fermion systems [J. Schliemann et al., Phys. Rev. B {\bf 63}, 085311 (2001) and quant-ph/0012094]. We point out that the von Neumann entropy of the reduced single particle density matrix remains to be a good entanglement measure for two identical particles.Comment: in press at Phys. Rev.

Predicting cannabis cultivation on national forests using a rational choice framework

Government agencies in the United States eradicated 10.3 million cannabis plants in 2010. Most (94%) of these plants were outdoor-grown, and 46% of those were discovered on federal lands, primarily on national forests in California, Oregon, and Washington. We developed models that reveal how drug markets, policies, and environmental conditions affect grow siting decisions. The models were built on a rational choice theoretical structure, and utilized data describing 2322 cannabis grow locations (2004–2012) and 9324 absence locations in the states\u27 national forests. Predictor variables included cannabis market prices, law enforcement density, and socioeconomic, demographic, and environmental variables.We also used the models to construct regional maps of grow site likelihood. Significant predictors included marijuana street price and variables associated with grow site productivity (e.g., elevation and proximity to water), production costs, and risk of discovery. Overall, the pattern of grow site establishment on national forests is consistent with rational choice theory. In particular, growers consider cannabis prices and law enforcement when selecting sites. Ongoing adjustments in state cannabis laws could affect cultivation decisions on national forests. Any changes in cannabis policies can be reflected in our models to allow agencies to redirect interdiction resources and potentially increase discovery success

Predicting cannabis cultivation on national forests using a rational choice framework

Government agencies in the United States eradicated 10.3 million cannabis plants in 2010. Most (94%) of these plants were outdoor-grown, and 46% of those were discovered on federal lands, primarily on national forests in California, Oregon, and Washington. We developed models that reveal how drug markets, policies, and environmental conditions affect grow siting decisions. The models were built on a rational choice theoretical structure, and utilized data describing 2322 cannabis grow locations (2004–2012) and 9324 absence locations in the states\u27 national forests. Predictor variables included cannabis market prices, law enforcement density, and socioeconomic, demographic, and environmental variables.We also used the models to construct regional maps of grow site likelihood. Significant predictors included marijuana street price and variables associated with grow site productivity (e.g., elevation and proximity to water), production costs, and risk of discovery. Overall, the pattern of grow site establishment on national forests is consistent with rational choice theory. In particular, growers consider cannabis prices and law enforcement when selecting sites. Ongoing adjustments in state cannabis laws could affect cultivation decisions on national forests. Any changes in cannabis policies can be reflected in our models to allow agencies to redirect interdiction resources and potentially increase discovery success