605 research outputs found

    Editorial: The Interplay Between Immune Activation and Cardiovascular Disease During Infection, Autoimmunity and Aging: The Role of T Cells

    Get PDF
    Chronic activation of cells of the immune system including T cells and systemic inflammation are well known risk factors for cardiovascular disease (CVD). Many human pathological conditions including viral infections, autoimmune diseases and aging are recognized drivers of increased risk of CVD. Among viral infections, Cytomegalovirus (CMV) infection is a contributing risk element to the existing traditional risk factors of atherogenesis; Influenza infection is correlated with ncreased the risk of cardiovascular events leading to deaths and HIV infection is an independent predictor of cardiovascular risk. The pandemic of SARS-COV2 infection showed that the severe presentation of the disease manifests with vascular damage and cardiovascular events. Autoimmune and chronic inflammatory diseases, including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and psoriatic disease are also associated with cardiovascular disease. Lastly, in adults over 65 years, the accumulation of age-related phenotypic and functional alterations in immune cells parallels with a decline of the cardiovascular system with an increased incidence of cardiovascular disease. The mechanisms behind are not well defined, and while the role of innate immune cells has been established, the involvement of T cells in promoting vascular pathology and cardiovascular disease has emerged more recently (1). Chronic systemic inflammation and increased circulating levels of cytokines and chemokines can indeed contribute to vascular damage by promoting endothelial cell activation and oxidative stress thus linking to the increased risk of CVD (2, 3). Activation of endothelial cells promotes recruitment of circulating immune cells including T cells that will be activated and differentiate into distinct effector cells contributing to the pathology of the disease (4–6). Endothelial cells in this context have also been proposed to act as “semiprofessional” antigen presenting cells (APC) presenting antigens and providing several costimulatory signals to T cells leading to T cell activation especially at sites defined as endothelium-dependent microvascular reactivity sites by Laser Doppler Flowmetry Assessment (7). A milestone in the understanding the role of T cells in promoting vascular inflammation has been reached with the characterization of the immune cell infiltrate in human atherosclerotic plaque by scRNA-seq technology which defined the main subsets of T cells in atherosclerosis (8). This data paved the way for further investigations about the role of T cells as a putative mechanistic link in pathologies associated with an increased risk of CVD. The proposed mechanisms by which T cells contribute to the pathology of the disease include dysregulated T helper and CD8 T cell function, expansion of terminally differentiated cytotoxic effectors CD4+ CD28- T cells and impaired Tregs function. This Research Topic has the aim to provide an overview of the latest advances in the study of the role of T cell activation and endothelial inflammation in cardiovascular risk and disease in the context of infection, autoimmunity and aging. The Research Topic highlights the emerging common and distinctive features of the putative immune mechanistic links between the pathophysiological conditions and the associated cardiovascular disease. The Research Topic comprises 11 articles, original research articles, 5 review and one systematic review and was divided into 3 sections. 1. Endothelial inflammation and T cell activation in CVD associated with infection. 2. T cell mechanisms involved in CVD associated with autoimmune diseases. 3. The immunology of cardiovascular disease during aging

    Adaptive implementation of turbo multi-user detection architecture

    Get PDF
    MULTI-access techniques have been adopted widely for communications in underwater acoustic channels, which present many challenges to the development of reliable and practical systems. In such an environment, the unpredictable and complex ocean conditions cause the acoustic waves to be affected by many factors such as limited bandwidth, large propagation losses, time variations and long latency, which limit the usefulness of such techniques. Additionally, multiple access interference (MAI) signals and poor estimation of the unknown channel parameters in the presence of limited training sequences are two of the major problems that degrade the performance of such technologies. In this thesis, two different single-element multi-access schemes, interleave division multiple access (IDMA) and code division multiple access (CDMA), employing decision feedback equalization (DFE) and soft Rake-based architectures, are proposed for multi-user underwater communication applications. By using either multiplexing pilots or continuous pilots, these adaptive turbo architectures with carrier phase tracking are jointly optimized based on the minimum mean square error (MMSE) criterion and adapted iteratively by exchanging soft information in terms of Log-Likelihood Ratio (LLR) estimates with the single-user’s channel decoders. The soft-Rake receivers utilize developed channel estimation and the detection is implemented using parallel interference cancellation (PIC) to remove MAI effects between users. These architectures are investigated and applied to simulated data and data obtained from realistic underwater communication trials using off-line processing of signals acquired during sea-trials in the North Sea. The results of different scenarios demonstrate the penalty in performance as the fading induces irreducible error rates that increase with channel delay spread and emphasize the benefits of using coherent direct adaptive receivers in such reverberant channels. The convergence behaviour of the detectors is evaluated using EXIT chart analyses and issues such as the adaptation parameters and their effects on the performance are also investigated. However, in some cases the receivers with partial knowledge of the interleavers’ patterns or codes can still achieve performance comparable to those with full knowledge. Furthermore, the thesis describes implementation issues of these algorithms using digital signal processors (DSPs), such as computational complexity and provides valuable guidelines for the design of real time underwater communication systems.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    If it does take a village to raise a child, how should the village do it? Insights from the kids in places initiative

    Get PDF
    Cross-sector collaborations are some of the strategies used to promote early childhood development and wellbeing. Without these collaborations, key services for families with young children may be missed or even duplicated. By drawing from experiences in Canada and Italy, we share findings from a study that aimed to understand the factors that make cross-sector collaborations (CSC) succeed or fail. Specifically, the study focused on understanding how CSC promoting early child development are created, maintained, and consolidated; and on identifying the social psychological, organizational, and economic aspects of CSC that help or hinder their functioning. Based on qualitative analysis of data gathered from four focus groups and thirteen interviews conducted across seven Canadian and Italian communities, we conclude that the success of CSC depend of a series of factors that transcend context, language and culture

    Error-estimate-based adaptive integration for immersed isogeometric analysis

    Get PDF
    The Finite Cell Method (FCM) together with Isogeometric analysis (IGA) has been applied successfully in various problems in solid mechanics, in image-based analysis, fluid–structure interaction and in many other applications. A challenging aspect of the isogeometric finite cell method is the integration of cut cells. In particular in three-dimensional simulations the computational effort associated with integration can be the critical component of a simulation. A myriad of integration strategies has been proposed over the past years to ameliorate the difficulties associated with integration, but a general optimal integration framework that suits a broad class of engineering problems is not yet available. In this contribution we provide a thorough investigation of the accuracy and computational effort of the octree integration scheme. We quantify the contribution of the integration error using the theoretical basis provided by Strang's first lemma. Based on this study we propose an error-estimate-based adaptive integration procedure for immersed isogeometric analysis. Additionally, we present a detailed numerical investigation of the proposed optimal integration algorithm and its application to immersed isogeometric analysis using two- and three-dimensional linear elasticity problems

    Elastic geobarometry for anisotropic inclusions in cubic hosts

    Get PDF
    Mineral inclusions entrapped in other minerals may record the local stresses at the moment of their entrapment in the deep Earth. When rocks are exhumed to the surface of the Earth, residual stresses and strains may still be preserved in the inclusion. If measured and interpreted correctly through elastic geobarometry, they give us invaluable information on the pressures (P) and temperatures (T) of metamorphism. Current estimates of P and T of entrapment rely on simplified models that assumes that the inclusion is spherical and embedded in an infinite host, and that their elastic properties are isotropic. We report a new method for elastic geobarometry for anisotropic inclusions in quasi-isotropic hosts. The change of strain in the inclusion is modelled with the axial equations of state of the host and the inclusion. Their elastic interaction is accounted for by introducing a 4th rank tensor, the relaxation tensor, that can be evaluated numerically for any symmetry of the host and the inclusion and for any geometry of the system. This approach can be used to predict the residual strain/stress state developed in an inclusion after exhumation from known entrapment conditions, or to estimate the entrapment conditions from the residual strain measured in real inclusions. In general, anisotropic strain and stress states are developed in non-cubic mineral inclusions such as quartz and zircon, with deviatoric stresses typically limited to few kbars. For garnet hosts, the effect of the mutual crystallographic orientation between the host and the inclusion on the residual strain and stress is negligible when the inclusion is spherical and isolated. Assuming external hydrostatic conditions, our results suggest that the isotropic and the new anisotropic models give estimations of entrapment conditions within 2%

    Repercussions of the COVID-19 pandemic on child and adolescent mental health: A matter of concern—A joint statement from EAP and ECPCP

    Get PDF
    COVID-19 pandemic and the consequent rigid social distancing measures implemented, including school closures, have heavily impacted children's and adolescents' psychosocial wellbeing, and their mental health problems significantly increased. However, child and adolescent mental health were already a serious problem before the Pandemic all over the world. COVID-19 is not just a pandemic, it is a syndemic and mentally or socially disadvantaged children and adolescents are the most affected. Non-Communicable Diseases (NCDs) and previous mental health issues are an additional worsening condition. Even though many countries have responded with decisive efforts to scale-up mental health services, a more integrated and community-based approach to mental health is required. EAP and ECPCP makes recommendations to all the stakeholders to take action to promote, protect and care for the mental health of a generation

    Subtracting Compact Binary Foregrounds to Search for Subdominant Gravitational-Wave Backgrounds in Next-Generation Ground-Based Observatories

    Full text link
    Stochastic gravitational-wave backgrounds (SGWBs) derive from the superposition of numerous individually unresolved gravitational-wave (GW) signals. Detecting SGWBs provides us with invaluable information about astrophysics, cosmology, and fundamental physics. In this paper, we study SGWBs from binary black-hole (BBH) and binary neutron-star (BNS) coalescences in a network of next-generation ground-based GW observatories (Cosmic Explorer and Einstein Telescope) and determine how well they can be measured; this then limits how well we can observe other subdominant astrophysical and cosmological SGWBs. We simulate all-Universe populations of BBHs and BNSs and calculate the corresponding SGWBs, which consist of a superposition of (i) undetected signals, and (ii) the residual background from imperfect removal of resolved sources. The sum of the two components sets the sensitivity for observing other SGWBs. Our results show that, even with next-generation observatories, the residual background is large and limits the sensitivity to other SGWBs. The main contributions to the residual background arise from uncertainties in inferring the coalescence phase and luminosity distance of the detected signals. Alternative approaches to signal subtraction would need to be explored to minimize the BBH and BNS foreground in order to observe SGWBs from other subdominant astrophysical and cosmological sources.Comment: 19 pages, 10 figures, matches the published versio

    Mechanical homeostasis regulating adipose tissue volume

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The total body adipose tissue volume is regulated by hormonal, nutritional, paracrine, neuronal and genetic control signals, as well as components of cell-cell or cell-matrix interactions. There are no known locally acting homeostatic mechanisms by which growing adipose tissue might adapt its volume.</p> <p>Presentation of the hypothesis</p> <p>Mechanosensitivity has been demonstrated by mesenchymal cells in tissue culture. Adipocyte differentiation has been shown to be inhibited by stretching in vitro, and a pathway for the response has been elucidated. In humans, intermittent stretching of skin for reconstructional purposes leads to thinning of adipose tissue and thickening of epidermis – findings matching those observed in vitro in response to mechanical stimuli. Furthermore, protracted suspension of one leg increases the intermuscular adipose tissue volume of the limb. These findings may indicate a local homeostatic adipose tissue volume-regulating mechanism based on movement-induced reduction of adipocyte differentiation. This function might, during evolution, have been of importance in confined spaces, where overgrowth of adipose tissue could lead to functional disturbance, as for instance in the turtle. In humans, adipose tissue near muscle might in particular be affected, for instance intermuscularly, extraperitoneally and epicardially. Mechanical homeostasis might also contribute to protracted maintainment of soft tissue shape in the face and neck region.</p> <p>Testing of the hypothesis</p> <p>Assessment of messenger RNA-expression of human adipocytes following activity in adjacent muscle is planned, and study of biochemical and volumetric adipose tissue changes in man are proposed.</p> <p>Implications of the hypothesis</p> <p>The interpretation of metabolic disturbances by means of adipose tissue might be influenced. Possible applications in the head and neck were discussed.</p
    • …
    corecore