1,386 research outputs found

    Some solutions to the multivariate Behrens-Fisher problem for dissimilarity-based analyses

    Get PDF
    The essence of the generalised multivariate Behrens–Fisher problem (BFP) is how to test the null hypothesis of equality of mean vectors for two or more populations when their dispersion matrices differ. Solutions to the BFP usually assume variables are multivariate normal and do not handle high‐dimensional data. In ecology, species' count data are often high‐dimensional, non‐normal and heterogeneous. Also, interest lies in analysing compositional dissimilarities among whole communities in non‐Euclidean (semi‐metric or non‐metric) multivariate space. Hence, dissimilarity‐based tests by permutation (e.g., PERMANOVA, ANOSIM) are used to detect differences among groups of multivariate samples. Such tests are not robust, however, to heterogeneity of dispersions in the space of the chosen dissimilarity measure, most conspicuously for unbalanced designs. Here, we propose a modification to the PERMANOVA test statistic, coupled with either permutation or bootstrap resampling methods, as a solution to the BFP for dissimilarity‐based tests. Empirical simulations demonstrate that the type I error remains close to nominal significance levels under classical scenarios known to cause problems for the un‐modified test. Furthermore, the permutation approach is found to be more powerful than the (more conservative) bootstrap for detecting changes in community structure for real ecological datasets. The utility of the approach is shown through analysis of 809 species of benthic soft‐sediment invertebrates from 101 sites in five areas spanning 1960 km along the Norwegian continental shelf, based on the Jaccard dissimilarity measure

    Late-onset Lennox-Gastaut syndrome as a phenotype of 15q11.1q13.3 duplication

    Get PDF
    The clinical symptoms associated with chromosome 15q duplication syndrome manifest through a heterogeneous group of symptoms characterised by hypotonia, delay in motor skills and language development, cognitive and learning disabilities, autism spectrum disorder and refractory epilepsy. The late development of Lennox-Gastaut syndrome in patients with 15q11q13 duplication is a possibility that physicians should be aware of. We report the case of a 27-year-old man with a neurodevelopmental syndrome due to a 15q duplication, with intellectual disability, psychiatric disturbances, and an epileptic phenotype diagnosed as late-onset Lennox-Gastaut syndrome

    Key factors for effective implementation of healthcare workers support interventions after patient safety incidents in health organisations: a scoping review

    Get PDF
    Objectives: This study aims to map and frame the main factors present in support interventions successfully implemented in health organisations in order to provide timely and adequate response to healthcare workers (HCWs) after patient safety incidents (PSIs). Design: Scoping review guided by the six-stage approach proposed by Arksey and O'Malley and by PRISMA-ScR. Data sources: CINAHL, Cochrane Library, Embase, Epistemonikos, PsycINFO, PubMed, SciELO Citation Index, Scopus, Web of Science Core Collection, reference lists of the eligible articles, websites and a consultation group. Eligibility criteria for selecting studies: Empirical studies (original articles) were prioritised. We used the Mixed Methods Appraisal Tool Version 2018 to conduct a quality assessment of the eligible studies. Data extraction and synthesis: A total of 9766 records were retrieved (last update in November 2022). We assessed 156 articles for eligibility in the full-text screening. Of these, 29 earticles met the eligibility criteria. The articles were independently screened by two authors. In the case of disagreement, a third author was involved. The collected data were organised according to the Organisational factors, People, Environment, Recommendations from other Audies, Attributes of the support interventions. We used EndNote to import articles from the databases and Rayyan to support the screening of titles and abstracts. Results: The existence of an organisational culture based on principles of trust and non-judgement, multidisciplinary action, leadership engagement and strong dissemination of the support programmes' were crucial factors for their effective implementation. Training should be provided for peer supporters and leaders to facilitate the response to HCWs' needs. Regular communication among the implementation team, allocation of protected time, funding and continuous monitoring are useful elements to the sustainability of the programmes. Conclusion: HCWs' well-being depends on an adequate implementation of a complex group of interrelated factors to support them after PSIs.info:eu-repo/semantics/publishedVersio

    Sarcoidosis or Tuberculosis? Difficulties in Diagnosis

    Get PDF
    A sarcoidose é uma doença multissistémica rara, caracterizada por granulomas não caseosos. A clínica e os testes diagnósticos são pouco sensíveis e específicos, dificultando o diagnóstico diferencial, particularmente com a tuberculose. Relata-se o caso clínico de um rapaz de 17 anos com nódulos cutâneos dolorosos, astenia, hipersudorese e uveíte recorrente com dois anos de evolução. Apresentava prova tuberculínica e interferon gamma release assay positivos, anemia e velocidade de sedimentação elevada, hipergamaglobulinemia, lisozima e enzima de conversão de angiotensina elevadas. A tomografia computorizada torácica mostrava opacidades micronodulares centrilobulares, gânglios mediastinicos e hilares calcificados; a broncofibroscopia e o teste de difusão de monóxido de carbono foram normais. A biópsia de nódulo cutâneo revelou paniculite septolobular. A cintigrafia das glândulas lacrimal e salivar sugeriu sarcoidose. Não se podendo excluir tuberculose concomitante, iniciou antibacilares. Dois meses depois, foram associados prednisolona e metotrexato. Seis meses depois verificou-se remissão dos sintomas e normalização dos exames laboratoriais. Este caso mostra as dificuldades no diagnóstico de sarcoidose e tuberculose na ausência dos achados microbiológicos e histológicos típicos e a possibilidade da coexistência destas entidades.info:eu-repo/semantics/publishedVersio

    Oxidative Stress, DNA, Cell Cycle/Cell Cycle Associated Proteins and Multidrug Resistance Proteins: Targets of Human Amniotic Membrane in Hepatocellular Carcinoma

    Get PDF
    The anticancer effects of human amniotic membrane (hAM) have been studied over the last decade. However, the action mechanisms responsible for these effects are not fully understood until now. Previously results reported by our team proved that hAM is able to induce cytotoxicity and cell death in hepatocellular carcinoma (HCC), a worldwide high incident and mortal cancer. Therefore, this experimental study aimed to investigate the cellular targets of hAM protein extracts (hAMPE) in HCC through in vitro studies. Our results showed that hAMPE is able to modify oxidative stress environment in all HCC cell lines, as well as its cell cycle. hAMPE differently targets deoxyribonucleic acid (DNA), P21, P53, β-catenin and multidrug resistance (MDR) proteins in HCC cell lines. In conclusion, hAMPE has several targets in HCC, being clear that the success of this treatment depends of a personalized therapy based on the biological and genetic characteristics of the tumor

    Leg length, skull circumference, and the incidence of dementia in Latin America and China: A 10/66 population-based cohort study

    Get PDF
    \ua9 2018 Prince et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Background Adult leg length is influenced by nutrition in the first few years of life. Adult head circumference is an indicator of brain growth. Cross-sectional studies indicate inverse associations with dementia risk, but there have been few prospective studies. Methods Population-based cohort studies in urban sites in Cuba, Dominican Republic Puerto Rico and Venezuela, and rural and urban sites in Peru, Mexico and China. Sociodemographic and risk factor questionnaires were administered to all participants, and anthropometric measures taken, with ascertainment of incident dementia, and mortality, three to five years later. Results Of the original at risk cohort of 13,587 persons aged 65 years and over, 2,443 (18.0%) were lost to follow-up; 10,540 persons with skull circumference assessments were followed up for 40,466 person years, and 10,400 with leg length assessments were followed up for 39,954 person years. There were 1,009 cases of incident dementia, and 1,605 dementia free deaths. The fixed effect pooled meta-analysed adjusted subhazard ratio (ASHR) for leg length (highest vs. lowest quarter) was 0.80 (95% CI, 0.66–0.97) and for skull circumference was 1.02 (95% CI, 0.84–1.25), with no heterogeneity of effect between sites (I2 = 0%). Leg length measurements tended to be shorter at follow-up, particularly for those with baseline cognitive impairment and dementia. However, leg length change was not associated with dementia incidence (ASHR, per cm 1.006, 95% CI 0.992–1.020), and the effect of leg length was little altered after adjusting for baseline frailty (ASHR 0.82, 95% CI 0.67–0.99). A priori hypotheses regarding effect modification by gender or educational level were not supported. However, the effect of skull circumference was modified by gender (M vs F ASHR 0.86, 95% CI 0.75–0.98), but in the opposite direction to that hypothesized with a greater protective effect of larger skull dimensions in men. Conclusions Consistent findings across settings provide quite strong support for an association between adult leg length and dementia incidence in late-life. Leg length is a relatively stable marker of early life nutritional programming, which may confer brain reserve and protect against neu-rodegeneration in later life through mitigation of cardiometabolic risk. Further clarification of these associations could inform predictive models for future dementia incidence in the context of secular trends in adult height, and invigorate global efforts to improve childhood nutrition, growth and development

    Recent advances on information transmission and storage assisted by noise

    Full text link
    The interplay between nonlinear dynamic systems and noise has proved to be of great relevance in several application areas. In this presentation, we focus on the areas of information transmission and storage. We review some recent results on information transmission through nonlinear channels assisted by noise. We also present recent proposals of memory devices in which noise plays an essential role. Finally, we discuss new results on the influence of noise in memristors.Comment: To be published in "Theory and Applications of Nonlinear Dynamics: Model and Design of Complex Systems", Proceedings of ICAND 2012 (Springer, 2014

    Intraventricular Pressure Gradients in Heart Failure

    Get PDF
    The aim of the present study was to characterize intraventricular pressure gradients (IVPGs) in an animal model of chronic heart failure. New Zealand rabbits were treated with doxorubicin (heart failure group, n=5) or saline (control group, n=5) and instrumented with pressure catheters placed in the apex and outflow-tract of left ventricle (LV) and with sonomicrometer crystals placed in the apex and base of the LV free wall. In heart failure animals, ventricular filling was delayed and slower when compared with control animals. Moreover, the physiological nonuniformity observed between apical and basal segments in normal hearts was abolished in failing hearts. Simultaneously, physiological IVPGs observed during normal ventricular filling were entirely lost in heart failure animals. During ventricular emptying physiological nonuniformity between apical and basal segments observed in control animals was also abolished in heart failure animals. In failing hearts minimal length occurred later and almost at same time both in apical and in basal myocardial segments. Simultaneously, the characteristic IVPG pattern observed in healthy hearts during systole, which promotes ventricular emptying, was not observed in failing hearts. The present study showed that diastolic IVPGs, a marker of normal ventricular filling, and systolic IVPGs, a marker of normal ventricular emptying, are abolished in heart failure
    corecore