High-order stroboscopic averaging methods for highly oscillatory delay problems

We introduce and analyze a family of heterogeneous multiscale methods for the numerical integration of highly oscillatory systems of delay differential equations with constant delays. The methodology suggested provides algorithms of arbitrarily high accuracy.The authors are indebted to A. Murua for the discussion that started this project. M.P.C and J.M.S. were supported by project MTM2016-77660-P (AEI/FEDER, UE) funded by MINECO (Spain). M.P.C. was also supported by project VA024P17 (Consejería de Educación, Junta de Castilla y León, ES, cofinanced by FEDER funds). B.Z. was supported by the National Center for Mathematics and Interdisciplinary Sciences, CAS and the National Natural Science Foundation of China (Grant No. 11771438 and Grant No. 11901564) and by China Postdoctoral Science Foundation (Grant No. 2018M641505)

Symmetrically processed splitting integrators for enhanced hamiltonian monte carlo sampling

We construct integrators to be used in Hamiltonian (or Hybrid) Monte Carlo sampling. The new integrators are easily implementable and, for a given computational budget, may deliver five times as many accepted proposals as standard leapfrog/Verlet without impairing in any way the quality of the samples. They are based on a suitable modification of the processing technique first introduced by Butcher. The idea of modified processing may also be useful for other purposes, like the construction of high-order splitting integrators with positive coefficients

Anti-tumour necrosis factor discontinuation in inflammatory bowel disease patients in remission: study protocol of a prospective, multicentre, randomized clinical trial

Background: Patients with inflammatory bowel disease who achieve remission with anti-tumour necrosis factor (anti-TNF) drugs may have treatment withdrawn due to safety concerns and cost considerations, but there is a lack of prospective, controlled data investigating this strategy. The primary study aim is to compare the rates of clinical remission at 1?year in patients who discontinue anti-TNF treatment versus those who continue treatment. Methods: This is an ongoing, prospective, double-blind, multicentre, randomized, placebo-controlled study in patients with Crohn?s disease or ulcerative colitis who have achieved clinical remission for ?6?months with an anti-TNF treatment and an immunosuppressant. Patients are being randomized 1:1 to discontinue anti-TNF therapy or continue therapy. Randomization stratifies patients by the type of inflammatory bowel disease and drug (infliximab versus adalimumab) at study inclusion. The primary endpoint of the study is sustained clinical remission at 1?year. Other endpoints include endoscopic and radiological activity, patient-reported outcomes (quality of life, work productivity), safety and predictive factors for relapse. The required sample size is 194 patients. In addition to the main analysis (discontinuation versus continuation), subanalyses will include stratification by type of inflammatory bowel disease, phenotype and previous treatment. Biological samples will be obtained to identify factors predictive of relapse after treatment withdrawal. Results: Enrolment began in 2016, and the study is expected to end in 2020. Conclusions: This study will contribute prospective, controlled data on outcomes and predictors of relapse in patients with inflammatory bowel disease after withdrawal of anti-TNF agents following achievement of clinical remission. Clinical trial reference number: EudraCT 2015-001410-1

Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

Adelante / Endavant

Séptimo desafío por la erradicación de la violencia contra las mujeres del Institut Universitari d’Estudis Feministes i de Gènere "Purificación Escribano" de la Universitat Jaume

Numerical solution of isospectral flows

Abstract. In this paper we are concerned with the problem of solving numerically isospectral flows. These flows are characterized by the differential equation L ′ =[B(L),L], L(0) = L0, where L0 is a d × d symmetric matrix, B(L) is a skew-symmetric matrix function of L and [B, L] is the Lie bracket operator. We show that standard Runge–Kutta schemes fail in recovering the main qualitative feature of these flows, that is isospectrality, since they cannot recover arbitrary cubic conservation laws. This failure motivates us to introduce an alternative approach and establish a framework for generation of isospectral methods of arbitrarily high order. 1. Background and notation 1.1. Introduction. The interest in solving isospectral flows is motivated by their relevance in a wide range of applications, from molecular dynamics to micromagnetics to linear algebra. The general form of an isospectral flow is the differentia

Multi-center study of noise in patients from hospitals in Spain: A questionnaire survey

To identify the most annoying noises in the hospital environment. One hundred and ninety-three patients took part in the study. A questionnaire collected the perceptions of patients from four hospitals in Spain, with three distinct units. The most annoying noises were the repetitive ones and the most unbearable source was the people who talk loudly. The daily hours were the noisiest and the most annoying, especially when patients wanted to rest and indicated that noise was annoying for them to get to sleep. Our results demonstrate how sensitive patients are toward noise in Spain. We also suggest some strategies to reduce the noise and the harmful physiological effects of increased sound levels in order to improve the quality of life in a healthcare environment