Exponential Mixing for a Stochastic PDE Driven by Degenerate Noise

We study stochastic partial differential equations of the reaction-diffusion type. We show that, even if the forcing is very degenerate (i.e. has not full rank), one has exponential convergence towards the invariant measure. The convergence takes place in the topology induced by a weighted variation norm and uses a kind of (uniform) Doeblin condition.Comment: 10 pages, 1 figur

Roscoe Reid Graham (1890 to 1948): a Canadian pioneer in general surgery.

Roscoe Reid Graham, a Canadian surgeon trained at the University of Toronto, was a true pioneer in the field of general surgery. Although he may be best known for his omental patch repair of perforated duodenal ulcers-often referred to as the Graham patch -he had a number of other significant accomplishments that decorated his surgical career. Dr. Graham is credited with being the first surgeon to successfully enucleate an insulinoma. He ventured to do an essentially brand new operation based solely on his patient\u27s symptoms and physical findings, a courageous move that even some of the most talented surgeons would shy away from. He also spent a large portion of his career dedicated to the study of rectal prolapse, working tirelessly to rid his patients of this awful affliction. He was recognized by a number of different surgical associations for his operative successes and was awarded membership to those both in Canada and the United States. Despite all of these accolades, Dr. Graham remained grounded and always fervent in his dedication to the patient and their presenting symptom(s), reminding us that to do anything more would be meddlesome. In an age when medical professionals are often all too eager to make unnecessary interventions, it is imperative that we look back at our predecessors such as Roscoe Reid Graham, for they will continually redirect us toward our one and only obligation: the patient

The implementation of a radiographic reporting service for trauma examinations of the skeletal system in 4 NHS trusts. NHS Executive South Thames funded research project

Executive Summary The implementation of a Radiographic Reporting Service for trauma examinations of the skeletal system, in 4 National Health Service Trusts Project Reference: SPGS 438 Project Dates: 1 September 1997 (project start) 30 November 1998 (project end) 31 March 1999: Date of report submission Project Leader: Mr Keith Piper, Senior Lecturer and Programme Director, PgD Clinical Reporting * Research Assistant: Ms Carol Ryan, Department of Radiography * Project Supervisor: Mrs Audrey Paterson, Dean of Faculty of Health and Sciences and Head of Department of Radiography * * Canterbury Christ Church University College Main Research Objectives The purpose of the study was to evaluate the implementation of a Radiographic Reporting Service (RRS) in four NHS Trusts in the United Kingdom with specific reference to the reporting by radiographers of musculo-skeletal trauma examinations. The research investigated the accuracy of radiographers’ written reports in terms of sensitivity and specificity; the impact on patient care and management as measured by the volume of reporting activity undertaken and the speed with which reports became available; costs related to the implementation of an RRR, and satisfaction of the users of the service. Methodology and Sample Size A longitudinal study design was used to measure the productivity and effectiveness of radiographic reporting in four NHS Trusts and five clinical sites in England. Data were collected by direct measure, report pro-forma, semi-structured questionnaires and interviews. A series of base line measurements were made at the commencement of the project. These were the volume of reporting activity prior to implementation of an RRS and the speed with which the reports became available. The satisfaction of the users of the reporting service prior to the implementation of an RRS was also gauged. Three measures (volume, speed, satisfaction of users) were repeated after the RRS had been implemented. Longitudinal data on the accuracy of the radiographers’ reports in terms of sensitivity and specificity were also collected at each site. Finally, some cost information related to the introduction and provision of an RRS was gathered. Four NHS Trusts and 10 radiographers participated in the study. Radiographers completed 10275 reports and 7179 were used to assess accuracy, sensitivity and specificity. Volume and speed data were obtained from the normal workload in each Trust. Four radiology services managers provided the cost data, while 26 staff took part in the initial survey and 12 in the final survey. Problems The major problem with this study was the fact that it was investigating the implementation into practice of a new and controversial service. It was beset, therefore, with the difficulties of aligning a research project to practice and this was only possible imperfectly. Points of implementation of the new service varied considerably, workload of key staff made verification of reports difficult and information systems within Trusts proved problematic. Findings Radiographers’ reports were accurate and consistently so over time. Significant improvements in the volume of reporting activity were found post-implementation at 2 of the 4 clinical sites in which this was measured. Additionally, the speed with which reports became available was shown to have improved significantly in all 4 NHS Trusts (but not at one clinical site). Cost data was not considered to be reliable and more evaluation of costs is required. Users of the radiographic reporting services were extremely or very satisfied with the quality of reports produced by the radiographers and also satisfied with the nature of the service implemented. Finally, a range of organisational issues were seen to affect the implementation of these services, at times quite inappropriately. Conclusion NHS Trusts that are unable to provide a full and/or timely musculo-skeletal trauma reporting service should implement a radiographic reporting service but must ensure that this is properly planned, funded, implemented and managed. Monitoring of service effectiveness and auditing of reporting standards should take place periodically. Acknowledgements The four collaborating NHS Trusts and their staff; Expert panel members; Members of the Steering Group; Colleagues at Canterbury Christ Church University College, and the Research and Development Directorate at South Thames Regional Office (NHSE)

Wellington : a novel method for the accurate identification of digital genomic footprints from DNase-seq data

The expression of eukaryotic genes is regulated by cis-regulatory elements such as promoters and enhancers, which bind sequence-specific DNA-binding proteins. One of the great challenges in the gene regulation field is to characterise these elements. This involves the identification of transcription factor (TF) binding sites within regulatory elements that are occupied in a defined regulatory context. Digestion with DNase and the subsequent analysis of regions protected from cleavage (DNase footprinting) has for many years been used to identify specific binding sites occupied by TFs at individual cis-elements with high resolution. This methodology has recently been adapted for high-throughput sequencing (DNase-seq). In this study, we describe an imbalance in the DNA strand-specific alignment information of DNase-seq data surrounding protein–DNA interactions that allows accurate prediction of occupied TF binding sites. Our study introduces a novel algorithm, Wellington, which considers the imbalance in this strand-specific information to efficiently identify DNA footprints. This algorithm significantly enhances specificity by reducing the proportion of false positives and requires significantly fewer predictions than previously reported methods to recapitulate an equal amount of ChIP-seq data. We also provide an open-source software package, pyDNase, which implements the Wellington algorithm to interface with DNase-seq data and expedite analyses

Lack of Effect of Murine Norovirus Infection on a Mouse Model of Bacteria-Induced Colon Cancer

Murine norovirus (MNV) is endemic in mouse research facilities in the United States and Europe, with a prevalence as high as 58% to 64%. Because of MNV's orofecal route of infection, clinically silent persistent infections in some mouse strains, and proclivity for macrophage and dendritic cells, its presence in mouse colonies has potential to alter phenotypes in experimental mouse models, particularly those involving inflammation and immunologic responses. Although MNV is subclinical, not causing overt disease in immunocompetent mice, we found that MNV infection can accelerate bacteria-induced inflammatory bowel disease (IBD) progression in Mdr1a^(-/-) mice. The studies presented here examined whether MNV infection also affects the phenotype of a bacterially driven mouse model of inflammation-associated colon cancer in genetically susceptible Smad3^(-/-) mice. In vitro culture of bone-marrow—derived macrophages (BMDM) was used to determine whether MNV4 influenced macrophage cytokine production. For in vivo studies, Smad3-/- mice were infected with MNV4 one week prior to infection with Helicobacter. Mice were monitored for 17 to 32 wk for development of IBD and colon cancer, and tissues were analyzed histopathologically. Although in vitro infection of BMDM with MNV4 led to increased inflammatory cytokine production, infection with MNV4 in vivo did not result in any statistically significant differences in survival, IBD scores, tumor incidence, or tumor phenotype in Smad3^(-/-) mice. In addition, MNV infection alone did not result in IBD or colon cancer. Therefore MNV infection alone or in conjunction with Helicobacter does not alter the development or progression of IBD or colon cancer in Smad3^(-/-) mice