University at Buffalo

About: University at Buffalo is a education organization based out in Buffalo, New York, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 33773 authors who have published 63840 publications receiving 2278954 citations. The organization is also known as: UB & State University of New York at Buffalo.

Generalized median filtering and related nonlinear filtering techniques

Abstract: We consider some generalizations of median filters which combine properties of both the linear and median filters. In particular, L filters and M filters are considered, motivated by robust estimators which are generalizations of the median as a location estimator. A related filter, which we call the modified trimmed mean (MTM) filter, is also described. The filters are evaluated for their performance on noisy signals containing sharp discontinuities or edges. It is shown that M filters can offer a more favorable combination of the running mean and median filters than can L filters, while MTM filters generally have better characteristics than M filters. We also show that an MTM filter is a data-dependent modification of L filters. The concept of double-window filtering is introduced as a refinement of MTM filtering. One representative set of filtered sequences of a test input using these filters are presented to illustrate the performance characterisics of these filters.

Statin Use and Risk of Diabetes Mellitus in Postmenopausal Women in the Women's Health Initiative

Abstract: Background: This study investigates whether the incidence of new-onset diabetes mellitus (DM) is associated with statin use among postmenopausal women participating in the Women’s Health Initiative (WHI). Methods: The WHI recruited 161 808 postmenopausal women aged 50 to 79 years at 40 clinical centers across the United States from 1993 to 1998 with ongoingfollow-up.Thecurrentanalysisincludesdatathrough 2005. Statin use was captured at enrollment and year 3. Incident DM status was determined annually from enrollment. Cox proportional hazards models were used to estimate the risk of DM by statin use, with adjustmentsforpropensityscoreandotherpotentialconfounding factors. Subgroup analyses by race/ethnicity, obesity status, and age group were conducted to uncover effect modification. Results: This investigation included 153840 women without DM and no missing data at baseline. At baseline,7.04%reportedtakingstatinmedication.Therewere 10242incidentcasesofself-reportedDMover1004466 person-years of follow-up. Statin use at baseline was associatedwithanincreasedriskofDM(hazardratio[HR], 1.71; 95% CI, 1.61-1.83). This association remained afteradjustingforotherpotentialconfounders(multivariateadjusted HR,1.48; 95% CI, 1.38-1.59) and was observedforalltypesofstatinmedications.Subsetanalyses evaluating the association of self-reported DM with longitudinal measures of statin use in 125575 women confirmed these findings. Conclusions: Statin medication use in postmenopausalwomenisassociatedwithanincreasedriskforDM. This may be a medication class effect. Further study by statintypeanddosemayrevealvaryingrisklevelsfornewonset DM in this population.

Clinical Mechanism of the Cystic Fibrosis Transmembrane Conductance Regulator Potentiator Ivacaftor in G551D-mediated Cystic Fibrosis

Abstract: Rationale: Ivacaftor is a cystic fibrosis transmembrane conductance regulator (CFTR) potentiator recently approved for patients with CF age 6 and older with the G551D mutation. Objectives: To evaluate ivacaftor in a postapproval setting and determine mechanism of action and response of clinically relevant markers. Methods: We conducted a longitudinal cohort study in 2012–2013 in G551D CF patients age 6 and older with no prior exposure to ivacaftor. Study assessments were performed at baseline, 1, 3, and 6 months after ivacaftor initiation. Substudies evaluated mucociliary clearance, β-adrenergic sweat secretion rate, gastrointestinal pH, and sputum inflammation and microbiology Measurements and Main Results: A total of 151 of 153 subjects were prescribed ivacaftor and 88% completed the study through 6 months. FEV1 % predicted improved from baseline to 6 months (mean absolute change, 6.7%; P < 0.001). Similarly, body mass index improved from baseline to 6 months (mean change, 0.8 kg/m2; P < 0.001). Sweat chloride decreased from baseline to 6 months (mean change, −53.8 mmol/L; 95% confidence interval, −57.7 to −49.9; P < 0.001), reflecting augmented CFTR function. There was significant improvement in hospitalization rate (P < 0.001) and Pseudomonas aeruginosa burden (P < 0.01). Significant improvements in mucociliary clearance (P < 0.001), gastrointestinal pH (P = 0.001), and microbiome were also observed, providing clinical mechanisms underlying the therapeutic benefit of ivacaftor. Conclusions: Significant clinical and physiologic improvements were observed on initiation of ivacaftor in a broad patient population, including reduced infection with P. aeruginosa. Biomarker studies substantially improve the understanding of the mechanistic consequences of CFTR modulation on pulmonary and gastrointestinal physiology.

Market Efficiency and Insider Trading: New Evidence

Abstract: It is not surprising that corporate insiders earn profits from trading their stocks, but it is surprising that outsiders can earn abnormal returns by mimicking the insider trades using publically available information. We suggest that these anomalous returns are explained by the size and price/earnings ratio effects. Controlling for these factors reduces outsider profits by one-half. The additional assumption of 2 percent transactions costs makes outsider profits zero or negative. Measured insider profits are also greatly reduced by controlling for size and price/earnings effects. Insider profits are a modest 3 percent per annum after deducting a 2 perecnt transactions costs fee.