The effect of new oral anticoagulants and extended thromboprophylaxis policy on hip and knee arthroplasty outcomes: observational study

The efficacy and safety of the new oral anticoagulants (NOAC) and the benefits of extended duration thromboprophylaxis following hip and knee replacements remain uncertain. This observational study describes the relations between thromboprophylaxis policies following hip and knee replacements across England's NHS and patient outcomes between January 2008 and December 2011. From the national administrative database, we analyzed mortality, thromboembolic complications, emergency readmission, and bleeding rates for 201,418 hip and 230,282 knee replacements. There were no differences in outcomes for either LMWH or NOAC. We found no advantage in favor of any single anticoagulation policy or in changing policy. This study supports the American Academy of Orthopaedic Surgeons' recommendation that the choice and duration of thromboprophylaxis prophylaxis be decided by the treating surgeon

The effects of ordinal data on coefficient alpha

Given coefficient alpha’s wide prevalence as a measure of internal reliability, it is important to know the conditions under which it is an appropriate estimate of reliability. The present paper explores alpha’s assumption of uncorrelated errors when used with ordinal data. Alpha overestimates true reliability when correlated errors are present. In this paper, I use a simulation study to recreate three mechanisms proposed to create correlated errors in ordinal data. The first mechanism, misclassification error, occurs when there are correlated measurement errors present in the data. The second mechanism, grouping error, occurs when there are not enough categories to represent the construct in question. The final mechanism is transformation error, which occurs when observed data do not match the distribution of true scores. Results indicated that misclassification and transformation error caused correlated errors, but only misclassification error caused correlated errors that were large enough for alpha to overestimate true reliability. Researchers should consider the assumption of correlated errors when reporting and making decisions based on alpha’s value alone

Linking Chapter I and regular classroom programs in an urban elementary school through curriculum redesign : a case study, 1986-1989, Roosevelt, New York.

This case study documented the process of designing, implementing, and accessing a low-cost, school-based staff development project. The principal objective of the study was to help a group of elementary school teachers serving African-American students seek alternative means of instructing those students not reached through traditional channels. In addition, it sought to expand teaching repertories; build stronger ties between the regular classroom and Chapter I programs; incorporate the tenets of action research in conjunction with sound staff development procedures; and to keep restructuring to a minimum. To facilitate and achieve these aims, the Chapter I curriculum was redesigned and linked to the regular classroom program. This case study also demonstrated a comprehensive collection of school improvement activities. The Chapter I staff, in concert with the classroom teachers, designed, implemented, and evaluated student activity modules. The modules focused on building positive self-image, cultural diversity, congruence, cultural heritage, and cooperative learning. Lessons learned from the activity modules promoted teacher interaction and feedback. In addition, the modules provided the Chapter I staff and teacher participants an avenue for connecting two disparate entities through planned staff development. The project succeeded as a result of the support garnered from administrators, the building principal, auxiliary staff, and community volunteers. Sound staff development processes permitted (1) the involvement of those persons most directly affected by the restructuring, (2) teachers to expand their repertoire of teaching strategies, (3) an increase in the level of optimism and resolve among teachers, administrators, and Chapter I staff, (4) time for teachers to explore new concepts and curriculum, (5) flexibility within the parameters of the project, (6) the undertaking of activities that permitted the linkage of the Chapter I curriculum to the regular classroom program, (7) opportunities for teachers/staff to plan collaboratively, and (8) teachers to grow professionally

Identification of masses in digital mammograms with MLP and RBF Nets

Copyright © 2000 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.IEEE-INNS-ENNS International Joint Conference on Neural Networks 2000 (IJCNN 2000), Como, Italy, 24-27 July 2000We study the identification of masses in digital mammograms using texture analysis. A number of texture measures are calculated for bilateral difference images showing regions of interest. The measurements are made on co-occurrence matrices in four different direction giving a total of seventy features. These features include the ones proposed by Haralick et al. (1973) and Chan et al. (1997). We study a total of 144 breast images from the MIAS database. The dimensionality of the dataset is reduced using principal components analysis (PCA), PCA components are classified using both multilayer perceptron networks using backpropagation (MLP) and radial basis functions based on Gaussian kernels (RBF). The two methods are compared on the same data across a ten fold cross-validation. The results are generated on the average recognition rate over these folds on correctly recognising masses and normal regions. Further analysis is based on the receiver operating characteristic (ROC) plots. The best results show recognition rates of 77% correct recognition and an area under the ROC curve value Az of 0.7

How to find an attractive solution to the liar paradox

The general thesis of this paper is that metasemantic theories can play a central role in determining the correct solution to the liar paradox. I argue for the thesis by providing a specific example. I show how Lewis’s reference-magnetic metasemantic theory may decide between two of the most influential solutions to the liar paradox: Kripke’s minimal fixed point theory of truth and Gupta and Belnap’s revision theory of truth. In particular, I suggest that Lewis’s metasemantic theory favours Kripke’s solution to the paradox over Gupta and Belnap’s. I then sketch how other standard criteria for assessing solutions to the liar paradox, such as whether a solution faces a so-called revenge paradox, fit into this picture. While the discussion of the specific example is itself important, the underlying lesson is that we have an unused strategy for resolving one of the hardest problems in philosophy

An immune response gene expression module identifies a good prognosis subtype in estrogen receptor negative breast cancer

A feature selection method was used in an analysis of three major microarray expression datasets to identify molecular subclasses and prognostic markers in estrogen receptor-negative breast cancer, showing that it is a heterogeneous disease with at least four main subtypes