12,060 research outputs found

    Canard Cycles and Poincar\'e Index of Non-Smooth Vector Fields on the Plane

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    This paper is concerned with closed orbits of non-smooth vector fields on the plane. For a subclass of non-smooth vector fields we provide necessary and sufficient conditions for the existence of canard kind solutions. By means of a regularization we prove that the canard cycles are singular orbits of singular perturbation problems which are limit periodic sets of a sequence of limit cycles. Moreover, we generalize the Poincar\'e Index for non-smooth vector fields.Comment: 20 pages, 25 figure

    O1-5 Digital tools for physical activity assessment and brief counselling in Primary Health Care: The Portuguese model

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    Issue/problem Implementation of national systems for patients' physical activity (PA) assessment and counselling is a cost-effective strategy recommended in the WHO Global Action Plan for PA 2018-2030. Although Primary Health Care (PHC) professionals are recognized as key agents for PA promotion, challenges remain on how to develop feasible and scalable tools to support them in promoting patients' PA. The Portuguese model could help other countries improve PA assessment and brief counselling in PHC settings. This study aims to describe the tools' development and usage. Description of the problem The Portuguese Directorate-General of Health developed two evidence-based digital tools to support PA promotion by healthcare professionals: a) PA brief assessment tool; and b) brief counselling tool. The assessment tool was incorporated within the electronic medical health record software ?SClínico? in September 2017. It includes three questions: 1) how many days per week the patient performs any kind of PA (work, commuting or leisure-time); 2) how much time per day; and 3) how many hours per day the patient spends in sedentary behaviours. The PA brief counselling tool is available through the electronic medical prescription software ?PEM? since December 2017 and consists of five inter-related self-explanatory guides that can be delivered to patients (printed or by email), according to their motivation and PA levels. They facilitate person-centered and autonomy-supportive PA counselling, targeting specific behaviour change mediators, and using validated techniques. Results From September 2017 to December 2021, 159,179 patients had their PA assessed (2235 per 100,000 users of the National Health Service) and, from these, 16133 received PA brief counselling guides (177 per 100000 residents in Portugal, ≥ 15 years old), with a six-fold and three-fold increases, respectively, between 2018 and 2019 (previous to the COVID-19 pandemic). Future actions will address cost-effectiveness of this policy. Lessons The brief assessment and brief counselling tools were well-accepted and are increasingly being used, with potential for generalized adoption within the Portuguese Health Care System. Main messages Portugal has taken a decisive action to promote PA using PHC as a priority setting. PA tools usage is increasing considerably, highlighting the importance of making available easy-to-use PA promotion tools

    Incidence of testicular germ-cell malignancies in England and Wales: trends in children compared with adults.

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    The incidence of testicular cancer has been increasing markedly in most industrialised countries. This rise is known to have affected young adults, but it is less clear whether it has affected other age groups, particularly children. We used data from the National Cancer Registry file at the Office of National Statistics (ONS) and the National Registry of Childhood Tumours to examine trends in testicular germ-cell malignancies overall in England and Wales from 1962 to 1990 and in children from 1962 to 1995. The incidence of testicular cancer at all ages rose by 3.4% (95% CI 3.3-3.6%) per annum from 1962 to 1990. A similar rise in the incidence of germ-cell malignancies occurred during the years for which histological information was available in the ONS files, 1971-1989 (3.4%; 3.1-3.6%), to which both seminomas and non-seminomas contributed equally. The incidence of non-seminomas in adults rose in men under age 55 years and declined in older men, whereas there were increases in the incidence of seminomas in both young and older men. Cohort analysis at young ages showed a marked rise in the risk of germ-cell malignancies up to the cohort born in 1955-1959 but no further rise for those born subsequently. The rise in the incidence of these tumours in young adults was paralleled by a similar trend, although less marked, in children aged under 15 years (1.3% per annum; 0.2-2.5%). The increase in risk for children in this very large data set alongside the rise in young adults is compatible with the hypothesis that childhood and adult testicular germ-cell malignancies may have some common risk factors, presumably pre-natal

    Complement Decay-Accelerating Factor is a modulator of influenza A virus lung immunopathology

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    Clearance of viral infections, such as SARS-CoV-2 and influenza A virus (IAV), must be fine-tuned to eliminate the pathogen without causing immunopathology. As such, an aggressive initial innate immune response favors the host in contrast to a detrimental prolonged inflammation. The complement pathway bridges innate and adaptive immune system and contributes to the response by directly clearing pathogens or infected cells, as well as recruiting proinflammatory immune cells and regulating inflammation. However, the impact of modulating complement activation in viral infections is still unclear. In this work, we targeted the complement decay-accelerating factor (DAF/CD55), a surface protein that protects cells from non-specific complement attack, and analyzed its role in IAV infections. We found that DAF modulates IAV infection in vivo, via an interplay with the antigenic viral proteins hemagglutinin (HA) and neuraminidase (NA), in a strain specific manner. Our results reveal that, contrary to what could be expected, DAF potentiates complement activation, increasing the recruitment of neutrophils, monocytes and T cells. We also show that viral NA acts on the heavily sialylated DAF and propose that the NA-dependent DAF removal of sialic acids exacerbates complement activation, leading to lung immunopathology. Remarkably, this mechanism has no impact on viral loads, but rather on the host resilience to infection, and may have direct implications in zoonotic influenza transmissions.This work was funded by Instituto Gulbenkian de Ciência (IGC), Fundac¸ão Calouste Gulbenkian (FCG) and Fundação para a Ciência e a Tecnologia (FCT) (PTDC/IMI-MIC/1142/2012). NBS was funded by Graduate Programme Science for Development (PGCD) and FCG. ZEVS was funded by FCT (SFRH/BD/52179/2013). CG was funded by FCT (POCI-01-0145-FEDER-29780, PTDC/MEDQUI/29780/2017). CAR was funded by FCT (POCI-01-0145-FEDER-007274, UID/BIM/04293). MJA is funded by FCT (2020.02373.CEECIND). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    The Interstitial Spaces Of Urban Sprawl: The Planning Problems And Prospects – The Case Of Santiago De Chile

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    Urban sprawl has been largely discussed as a multifaceted phenomenon mainly driven by the housing debate. Nevertheless, this debate has been strongly determined by the focus on the ‘built-up realm’ leaving aside a crucial less addressed dimension defined by the wide spectrum of undeveloped (or less developed) lands and open tracts. Indeed, these lands determine the fragmented and disperse character of sprawl, and define a parallel unbuilt geography. Pieces of countryside, farmlands, landfills, brownfields, geographical accidents, speculative lands, infrastructural areas, military facilities, buffers of security and others appear as different but nevertheless as interstitial spaces – not clearly considered as ‘urban’ – that take part in suburban transformations. Thus, the emergence of these interstitial spaces deserves a closer inspection in order to unveil their origins, role and implications in planning, and to improve the comprehension of urban sprawl and its unbuilt geography. In this vein, this thesis inspects three research questions. First, what are the interstitial spaces of urban sprawl? Second, how they emerge and participate in suburban transformations? and finally, what are their implications in planning? To answer these questions, the thesis develops the concept of ‘interstitial space’ based on a critical revision of current literature, and focused on the different interpretations of institutional actors, their relational character, impacts at different scales and implications in planning. To do so, the capital city of Chile, Santiago, is used as a context of study. Here, various interstitial spaces are analysed using a mixed methodological approach that implies secondary research, fieldwork that involved 56 semi-structured interviews, site visits, revision of representative documentation and data analysis. Evidence found suggests that interstitial spaces are active components of suburban transformations; they emerge as contested spaces and imply major revisions in planning policies aimed to accommodate population and employment growth

    Genetic and morphometric variation in Schwarziana quadripunctata and Schwarziana mourei (Hymenoptera: Apidae: Meliponini)

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    Schwarziana bees are a ground-nesting stingless bee distributed in the Neotropical region. Schwarziana quadripunctata was the first described and the most studied species of this genus. Now, there are four valid species of Schwarziana bees, but it has been suggested that the diversity of this taxon may be higher, due to undescribed cryptic species. In this study, we investigated the populational diversity of S. quadripunctata using workers collected at 11 localities in Brazil (from the Northeast to South region). We also included one population of S. mourei (collected in São Paulo state, 2 nests). We analysed the bees using geometric morphometrics and molecular analyses amplifying mtDNA cytochrome oxidase I (COI) and 16S to access the diversity among the populations. From the results of geometric morphometrics, the Mahalanobis distances between S. mourei and S. quadripunctata are greater than those distances among S. quadripunctata populations. A similar scenario can also be observed looking to the phylogenetic tree generated by the molecular markers. Morphometry and molecular markers data showed significant association with geographic distance, indicating the existence of intrapopulation variation in S. quadripunctata. Our hypothesis was supported, that the populations of S. quadripunctata showed differences in haplotypic diversity. Overall, these analyses revealed a moderate level of intraspecific variation among S. quadripunctata populations and discriminated well the species S. quadripunctata from S. mourei
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