11 research outputs found

    Restriction semigroups and λ -Zappa-Szép products

    Get PDF
    The aim of this paper is to study λ-semidirect and λ-Zappa-Szép products of restriction semigroups. The former concept was introduced for inverse semigroups by Billhardt, and has been extended to some classes of left restriction semigroups. The latter was introduced, again in the inverse case, by Gilbert and Wazzan. We unify these concepts by considering what we name the scaffold of a Zappa-Szép product S⋈ T where S and T are restriction. Under certain conditions this scaffold becomes a category. If one action is trivial, or if S is a semilattice and T a monoid, the scaffold may be ordered so that it becomes an inductive category. A standard technique, developed by Lawson and based on the Ehresmann-Schein-Nambooripad result for inverse semigroups, allows us to define a product on our category. We thus obtain restriction semigroups that are λ-semidirect products and λ-Zappa-Szép products, extending the work of Billhardt and of Gilbert and Wazzan. Finally, we explicate the internal structure of λ-semidirect products

    Presentations for singular wreath products

    Get PDF
    For a monoid M and a subsemigroup S of the full transformation semigroup Tn, the wreath product M≀S is defined to be the semidirect product Mn ⋊S, with the coordinatewise action of S on Mn. The full wreath product M≀T n is isomorphic to the endomorphism monoid of the free M-act on n generators. Here we are particularly interested in the case that S=Sing n is the singular part of Tn, consisting of all non-invertible transformations. Our main results are presentations for M≀Sing n in terms of certain natural generating sets, and we prove these via general results on semidirect products and wreath products. We re-prove a classical result of Bulman-Fleming that M≀Sing n is idempotent-generated if and only if the set M/L of L-classes of M forms a chain under the usual ordering of L-classes, and we give a presentation for M≀Sing n in terms of idempotent generators for such a monoid M. Among other results, we also give estimates for the minimal size of a generating set for M≀Sing n, as well as exact values in some cases (including the case that M is finite and M/L is a chain, in which case we also calculate the minimal size of an idempotent generating set). As an application of our results, we obtain a presentation (with idempotent generators) for the idempotent-generated subsemigroup of the endomorphism monoid of a uniform partition of a finite set

    Quality standards for the management of alcohol-related liver disease: consensus recommendations from the British Association for the Study of the Liver and British Society of Gastroenterology ARLD special interest group

    Get PDF
    Objective Alcohol-related liver disease (ALD) is the most common cause of liver-related ill health and liver-related deaths in the UK, and deaths from ALD have doubled in the last decade. The management of ALD requires treatment of both liver disease and alcohol use; this necessitates effective and constructive multidisciplinary working. To support this, we have developed quality standard recommendations for the management of ALD, based on evidence and consensus expert opinion, with the aim of improving patient care.Design A multidisciplinary group of experts from the British Association for the Study of the Liver and British Society of Gastroenterology ALD Special Interest Group developed the quality standards, with input from the British Liver Trust and patient representatives.Results The standards cover three broad themes: the recognition and diagnosis of people with ALD in primary care and the liver outpatient clinic; the management of acutely decompensated ALD including acute alcohol-related hepatitis and the posthospital care of people with advanced liver disease due to ALD. Draft quality standards were initially developed by smaller working groups and then an anonymous modified Delphi voting process was conducted by the entire group to assess the level of agreement with each statement. Statements were included when agreement was 85% or greater. Twenty-four quality standards were produced from this process which support best practice. From the final list of statements, a smaller number of auditable key performance indicators were selected to allow services to benchmark their practice and an audit tool provided.Conclusion It is hoped that services will review their practice against these recommendations and key performance indicators and institute service development where needed to improve the care of patients with ALD

    REQUITE: A prospective multicentre cohort study of patients undergoing radiotherapy for breast, lung or prostate cancer

    Get PDF
    Purpose: REQUITE aimed to establish a resource for multi-national validation of models and biomarkers that predict risk of late toxicity following radiotherapy. The purpose of this article is to provide summary descriptive data. Methods: An international, prospective cohort study recruited cancer patients in 26 hospitals in eight countries between April 2014 and March 2017. Target recruitment was 5300 patients. Eligible patients had breast, prostate or lung cancer and planned potentially curable radiotherapy. Radiotherapy was prescribed according to local regimens, but centres used standardised data collection forms. Pre-treatment blood samples were collected. Patients were followed for a minimum of 12 (lung) or 24 (breast/prostate) months and summary descriptive statistics were generated. Results: The study recruited 2069 breast (99% of target), 1808 prostate (86%) and 561 lung (51%) cancer patients. The centralised, accessible database includes: physician-(47,025 forms) and patient-(54,901) reported outcomes; 11,563 breast photos; 17,107 DICOMs and 12,684 DVHs. Imputed genotype data are available for 4223 patients with European ancestry (1948 breast, 1728 prostate, 547 lung). Radiation-induced lymphocyte apoptosis (RILA) assay data are available for 1319 patients. DNA (n = 4409) and PAXgene tubes (n = 3039) are stored in the centralised biobank. Example prevalences of 2-year (1-year for lung) grade >= 2 CTCAE toxicities are 13% atrophy (breast), 3% rectal bleeding (prostate) and 27% dyspnoea (lung). Conclusion: The comprehensive centralised database and linked biobank is a valuable resource for the radiotherapy community for validating predictive models and biomarkers. Patient summary: Up to half of cancer patients undergo radiation therapy and irradiation of surrounding healthy tissue is unavoidable. Damage to healthy tissue can affect short-and long-term quality-of-life. Not all patients are equally sensitive to radiation "damage" but it is not possible at the moment to identify those who are. REQUITE was established with the aim of trying to understand more about how we could predict radiation sensitivity. The purpose of this paper is to provide an overview and summary of the data and material available. In the REQUITE study 4400 breast, prostate and lung cancer patients filled out questionnaires and donated blood. A large amount of data was collected in the same way. With all these data and samples a database and biobank were created that showed it is possible to collect this kind of information in a standardised way across countries. In the future, our database and linked biobank will be a resource for research and validation of clinical predictors and models of radiation sensitivity. REQUITE will also enable a better understanding of how many people suffer with radiotherapy toxicity

    Mental Imagery to Reduce Alcohol-related harm in patients with alcohol dependence and alcohol-related liver damaGE: the MIRAGE pilot trial protocol.

    No full text
    INTRODUCTION: In the UK, alcohol use is the main driver of chronic liver disease and each year results in over 1 million unplanned hospital admissions and over 25 000 deaths from alcohol-related liver disease (ArLD). The only effective treatment to prevent progression of liver damage is reducing or ceasing alcohol consumption. Psychological and pharmacological therapies for alcohol misuse are ineffective in patients with ArLD. Functional imagery training (FIT) is a novel psychological therapy that builds on motivational interviewing techniques with multisensory imagery. This pilot trial aims to test the feasibility of training alcohol liaison nurses to deliver FIT therapy and of recruiting and retaining patients with ArLD and alcohol dependence to a randomised trial of FIT and treatment as usual (TAU) versus TAU alone. METHODS AND ANALYSIS: This is a randomised pilot trial of FIT and TAU versus TAU alone in 90 patients with ArLD and alcohol dependence admitted to one of four UK centres. The primary objectives are to estimate rates of screening, recruitment, randomisation, retention, adherence to FIT/TAU and a preliminary assessment of the FIT intervention in the ArLD population. Data from the pilot study will be used to finalise the design of a definitive randomised controlled trial to assess the effectiveness and cost-effectiveness of FIT. The proposed primary outcome measure for the definitive trial is self-reported alcohol use assessed using timeline follow-back. ETHICS AND DISSEMINATION: Research ethics approval was given by the Yorkshire and Humber-Bradford Leeds Research Ethics Committee (reference: 21/YH/0044). Eligible patients will be approached and written informed consent obtained prior to participation. Results will be disseminated through peer-reviewed open access journals, international conferences and a lay summary published on the Trials Unit website and made available to patient groups

    Quality standards for the management of alcohol-related liver disease: consensus recommendations from the British Association for the Study of the Liver and British Society of Gastroenterology ARLD special interest group

    No full text
    Objective Alcohol-related liver disease (ALD) is the most common cause of liver-related ill health and liver-related deaths in the UK, and deaths from ALD have doubled in the last decade. The management of ALD requires treatment of both liver disease and alcohol use; this necessitates effective and constructive multidisciplinary working. To support this, we have developed quality standard recommendations for the management of ALD, based on evidence and consensus expert opinion, with the aim of improving patient care.Design A multidisciplinary group of experts from the British Association for the Study of the Liver and British Society of Gastroenterology ALD Special Interest Group developed the quality standards, with input from the British Liver Trust and patient representatives.Results The standards cover three broad themes: the recognition and diagnosis of people with ALD in primary care and the liver outpatient clinic; the management of acutely decompensated ALD including acute alcohol-related hepatitis and the posthospital care of people with advanced liver disease due to ALD. Draft quality standards were initially developed by smaller working groups and then an anonymous modified Delphi voting process was conducted by the entire group to assess the level of agreement with each statement. Statements were included when agreement was 85% or greater. Twenty-four quality standards were produced from this process which support best practice. From the final list of statements, a smaller number of auditable key performance indicators were selected to allow services to benchmark their practice and an audit tool provided.Conclusion It is hoped that services will review their practice against these recommendations and key performance indicators and institute service development where needed to improve the care of patients with ALD

    La evaluación colegiada de las competencias básicas en la Comunidad Autónoma de Canarias : hacia un modelo de escuela inclusiva y sostenible

    No full text
    Precede al título: Educación Primaria y Educación Secundaria ObligatoriaLa Ley Orgánica de Educación (LOE) introduce el concepto de «competencias básicas» como eje articulador del currículo, conectando de pleno con las reflexiones y las estrategias que se están desarrollando en otros sistemas educativos internacionales a la luz del informe Delors (1996), el documento DeSeCo (Definición y Selección de Competencias fundamentales) elaborado por la OCDE, de las evaluaciones PISA (Programa para la Evaluación Internacional del Alumnado), etc. Esta propuesta centra el foco en la dimensión formativa de la «evaluación», aspecto inacabado con la LOGSE (Ley Orgánica General del Sistema Educativo), a pesar de los esfuerzos realizados en esa dirección. Trabajar en las aulas para la consecución de las «competencias básicas» lleva ineludiblemente al problema de cómo evaluarlas de forma colegiada —cuando la propia ordenación del sistema educativo fragmenta cada una de las enseñanzas en diferentes áreas o materias— y de cómo emplear la información que proporciona esta labor para hacer valer el sentido formativo y regulador que debe tener la evaluación de las competencias básicas.Consejería de Educación y Universidades. Dirección General de Ordenación, Innovación y Promoción Educativa; Avda. Buenos Aires, 5; 38071 Tenerife; Tel. +34922592592; Fax +34922592570; [email protected]
    corecore