Epidemiologic studies often aim to estimate the odds ratio for the association between a binary exposure and a binary disease outcome. Because confounding bias is of serious concern in observational studies, investigators typically estimate the adjusted odds ratio in a multivariate logistic regression which conditions on a large number of potential confounders. It is well known that modeling er...

We study the computational power of machines that specify their own acceptance types, and show that they accept exactly the languages that ≤ m -reduce to NP sets. A natural variant accepts exactly the languages that ≤ m -reduce to P sets. We show that these two classes coincide if and only if P = P, where the latter class denotes the sets acceptable via at most one question to #P followed by at...

BACKGROUND The impact of platelet transfusion in trauma patients undergoing a massive transfusion (MT) was evaluated. STUDY DESIGN The Institutional Trauma Registry and Blood Bank Database at a Level I trauma center was used to identify all patients requiring an MT (≥10 packed red blood cells [PRBC] within 24 hours of admission). Mortality was evaluated according to 4 apheresis platelet (aPLT...

Crop condition assessment in the early growing stage is essential for crop monitoring and crop yield prediction. A normalized difference vegetation index (NDVI)-based method is employed to evaluate crop condition by inter-annual comparisons of both spatial variability (using NDVI images) and seasonal dynamics (based on crop condition profiles). Since this type of method will generate false info...

BACKGROUND Binary outcomes are common in prospective studies such as randomized controlled trials and cohort studies. Logistic regression is the most popular regression model for binary outcomes. Logistic regression yields an odds ratio that approximates the risk ratio when the risk of outcome is low. A consensus has been reached in an extensive argument in much of the literature that the risk ...

The classical mean-variance investment model is simple, elegant, and popular. As such, it is also subject to criticisms. One unsatisfactory feature of the model is that variance treats the upside and downside equally as risks. In this regard, the downside Lower Partial Moments (LPM) are more attractive as alternative risk measures, since they only penalize the downside. In the meanwhile, consid...

BACKGROUND Automated adverse outcome surveillance tools and methods have potential utility in quality improvement and medical product surveillance activities. Their use for assessing hospital performance on the basis of patient outcomes has received little attention. We compared risk-adjusted sequential probability ratio testing (RA-SPRT) implemented in an automated tool to Massachusetts public...

Let K denote a field and let V denote a vector space over K with finite positive dimension. We consider a pair of linear transformations A : V → V and A∗ : V → V that satisfy the following conditions: (i) each of A,A∗ is diagonalizable; (ii) there exists an ordering {Vi} d i=0 of the eigenspaces of A such that A ∗Vi ⊆ Vi−1+Vi+Vi+1 for 0 ≤ i ≤ d, where V−1 = 0 and Vd+1 = 0; (iii) there exists an...