On the Hyperbolicity of Lorenz Renormalization

We consider infinitely renormalizable Lorenz maps with real critical exponent $\alpha>1$ and combinatorial type which is monotone and satisfies a long return condition. For these combinatorial types we prove the existence of periodic points of the renormalization operator, and that each map in the limit set of renormalization has an associated unstable manifold. An unstable manifold defines a family of Lorenz maps and we prove that each infinitely renormalizable combinatorial type (satisfying the above conditions) has a unique representative within such a family. We also prove that each infinitely renormalizable map has no wandering intervals and that the closure of the forward orbits of its critical values is a Cantor attractor of measure zero.Comment: 63 pages; 10 figure

Development and validation of the SIMPLE endoscopic classification of diminutive and small colorectal polyps.

BACKGROUND Prediction of histology of small polyps facilitates colonoscopic treatment. The aims of this study were: 1) to develop a simplified polyp classification, 2) to evaluate its performance in predicting polyp histology, and 3) to evaluate the reproducibility of the classification by trainees using multiplatform endoscopic systems. METHODS In phase 1, a new simplified endoscopic classification for polyps - Simplified Identification Method for Polyp Labeling during Endoscopy (SIMPLE) - was created, using the new I-SCAN OE system (Pentax, Tokyo, Japan), by eight international experts. In phase 2, the accuracy, level of confidence, and interobserver agreement to predict polyp histology before and after training, and univariable/multivariable analysis of the endoscopic features, were performed. In phase 3, the reproducibility of SIMPLE by trainees using different endoscopy platforms was evaluated. RESULTS Using the SIMPLE classification, the accuracy of experts in predicting polyps was 83 % (95 % confidence interval [CI] 77 % - 88 %) before and 94 % (95 %CI 89 % - 97 %) after training ( = 0.002). The sensitivity, specificity, positive predictive value, and negative predictive value after training were 97 %, 88 %, 95 %, and 91 %. The interobserver agreement of polyp diagnosis improved from 0.46 (95 %CI 0.30 - 0.64) before to 0.66 (95 %CI 0.48 - 0.82) after training. The trainees demonstrated that the SIMPLE classification is applicable across endoscopy platforms, with similar post-training accuracies for narrow-band imaging NBI classification (0.69; 95 %CI 0.64 - 0.73) and SIMPLE (0.71; 95 %CI 0.67 - 0.75). CONCLUSIONS Using the I-SCAN OE system, the new SIMPLE classification demonstrated a high degree of accuracy for adenoma diagnosis, meeting the ASGE PIVI recommendations. We demonstrated that SIMPLE may be used with either I-SCAN OE or NBI

Detection and Treatment of Pancreatic Cancer and High-Grade Precursor Lesions in High-Risk Individuals Undergoing Surveillance: Results From the International CAPS Consortium Registry

not availabl

Educational nurse-led telephone intervention shortly before colonoscopy as a salvage strategy after previous bowel preparation failure: a multicenter randomized trial

Background: The most important predictor of unsuccessful bowel preparation is previous failure. For those patients with previous failure, we hypothesized that a nurse-led educational intervention by telephone shortly before the colonoscopy appointment could improve cleansing efficacy. Methods: We performed a multicenter, endoscopist-blinded, randomized controlled trial. Consecutive outpatients with previous inadequate bowel preparation were enrolled. Both groups received the same standard bowel preparation protocol. The intervention group also received reinforced education by telephone within 48 hours before the colonoscopy. The primary outcome was effective bowel preparation according to the Boston Bowel Preparation Scale. Intention-to-treat (ITT) analysis included all randomized patients. Per-protocol analysis included patients who could be contacted by telephone and the control cases. Results: 657 participants were recruited by 11 Spanish hospitals. In the ITT analysis, there was no significant difference between the intervention and control groups in the rate of successful bowel preparation (77.3 % vs. 72 %; P = 0.12). In the intervention group, 267 patients (82.9 %) were contacted by telephone. Per-protocol analysis revealed significantly improved bowel preparation in the intervention group (83.5 % vs. 72.0 %; P = 0.001). Conclusion: Among all patients with previous inadequate bowel preparation, nurse-led telephone education did not result in a significant improvement in bowel cleansing. However, in the 83 % of patients who could be contacted, bowel preparation was substantially improved. Phone education may therefore be a useful tool for improving the quality of bowel preparation in those cases