2,522 research outputs found

    Oxidative Coupling of Methane for Ethylene Production: Reviewing Kinetic Modelling Approaches, Thermodynamics and Catalysts

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    Ethylene production via oxidative coupling of methane (OCM) represents an interesting route for natural gas upscaling, being the focus of intensive research worldwide. Here, OCM developments are analysed in terms of kinetic mechanisms and respective applications in chemical reactor models, discussing current challenges and directions for further developments. Furthermore, some thermodynamic aspects of the OCM reactions are also revised, providing achievable olefins yields in a wide range of operational reaction conditions. Finally, OCM catalysts are reviewed in terms of respective catalytic performances and thermal stability, providing an executive summary for future studies on OCM economic feasibility

    Limited Knowledge About Hydatidosis Among Farmers in Northwest Portugal: A Pressing Need for a One Health Approach

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    Hydatidosis is a re-emerging disease. Farmers are a vulnerable population; however, little is known about their awareness of this disease. The purpose of this study was two-fold: (1) to assess sheep and goat farmers' awareness of, perceptions of, and attitudes towards parasitic zoonoses and hydatidosis and (2) to identify the preferred means for promotion of information about hydatidosis. A cross-sectional study was conducted. An in-person questionnaire was constructed and administered to 279 individuals. A coprological survey in shepherd dogs was performed using 88 faecal samples. SPSS version 18.0 was used for statistical analysis. Farmers reported several risk practices (69% practice home slaughtering, 46% do not deworm the dogs, 58% of these dogs have contact with other animals) and very little knowledge about hydatidosis (97% have never heard about it). Nevertheless, 75% of the farmers demonstrated interest in receiving information, mainly from a veterinarian. A wide diversity of potentially zoonotic parasites (Trichuris spp., Ancylostomatidae, Toxocara spp., Taeniidae) was found in 61% of the dogs. This survey revealed farmers' lack of knowledge in relation to hydatidosis and a high prevalence of potentially zoonotic parasites in dogs, thus pointing to the need for health education and a closer collaboration between veterinarian and public health professionals

    Pro-inflammatory polarization and colorectal cancer modulate alternative and intronic polyadenylation in primary human macrophages

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    Macrophages are essential cells of the immune system that alter their inflammatory profile depending on their microenvironment. Alternative polyadenylation in the 3'UTR (3'UTR-APA) and intronic polyadenylation (IPA) are mechanisms that modulate gene expression, in particular in cancer and activated immune cells. Yet, how polarization and colorectal cancer (CRC) cells microenvironment affect 3'UTR-APA and IPA in primary human macrophages remains unknown. Here, primary human monocytes were isolated from healthy donors, differentiated and polarized into a pro-inflammatory state and ChrRNA-Seq and 3'RNA-Seq were performed to quantify gene expression and characterize new 3’UTR-APA and IPA mRNA isoforms. Our results show that polarization of human macrophages from naïve to a pro-inflammatory state causes a marked increase both in proximal polyA site selection in the 3'UTR and in IPA events, in genes relevant for macrophage functions. Additionally, we found a negative correlation between differential gene expression and IPA during pro-inflammatory polarization of primary human macrophages. As macrophages are abundant immune cells in the CRC microenvironment that either promote or abrogate cancer progression, we investigated how indirect exposure to CRC cells affects macrophage gene expression and 3'UTR-APA and IPA mRNA events. Co-culture with CRC cells alters the inflammatory phenotype of macrophages, increases the expression of pro tumoral genes and induce 3’UTR-APA alterations. Notably, some of these gene expression differences were also found in tumour-associated macrophages of CRC patients, indicating that they are physiological relevant. Upon macrophage pro inflammatory polarization SRSF12 is the pre-mRNA processing gene that is most upregulated. After SRSF12 knockdown in M1 macrophages there is a global downregulation of gene expression, in particular in genes involved in gene expression regulation and in immune responses. Our results reveal new 48 3’UTR-APA and IPA mRNA isoforms produced during pro-inflammatory polarization of primary human macrophages and CRC co-culture that may be used in the future as diagnostic or therapeutic tools

    Closed-loop separation control over a sharp edge ramp using Genetic Programming

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    We experimentally perform open and closed-loop control of a separating turbulent boundary layer downstream from a sharp edge ramp. The turbulent boundary layer just above the separation point has a Reynolds number Reθ3500Re_{\theta}\approx 3\,500 based on momentum thickness. The goal of the control is to mitigate separation and early re-attachment. The forcing employs a spanwise array of active vortex generators. The flow state is monitored with skin-friction sensors downstream of the actuators. The feedback control law is obtained using model-free genetic programming control (GPC) (Gautier et al. 2015). The resulting flow is assessed using the momentum coefficient, pressure distribution and skin friction over the ramp and stereo PIV. The PIV yields vector field statistics, e.g. shear layer growth, the backflow area and vortex region. GPC is benchmarked against the best periodic forcing. While open-loop control achieves separation reduction by locking-on the shedding mode, GPC gives rise to similar benefits by accelerating the shear layer growth. Moreover, GPC uses less actuation energy.Comment: 24 pages, 24 figures, submitted to Experiments in Fluid

    Macro level factors influencing strategic responses to emergent pandemics: A scoping review

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    Copyright (c) 2021 The Authors. Background Strategic planning is critical for successful pandemic management. This study aimed to identify and review the scope and analytic depth of situation analyses conducted to understand their utility, and capture the documented macro-level factors impacting pandemic management. Methods To synthesise this disparate body of literature, we adopted a two-step search and review process. A systematic search of the literature was conducted to identify all studies since 2000, that have 1) employed a situation analysis; and 2) examined contextual factors influencing pandemic management. The included studies are analysed using a seven-domain systems approach from the discipline of strategic management. Results Nineteen studies were included in the final review ranging from single country (6) to regional, multi-country studies (13). Fourteen studies had a single disease focus, with 5 studies evaluating responses to one or more of COVID-19, Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS), Influenza A (H1N1), Ebola virus disease, and Zika virus disease pandemics. Six studies examined a single domain from political, economic, sociological, technological, ecological or wider industry (PESTELI), 5 studies examined two to four domains, and 8 studies examined five or more domains. Methods employed were predominantly literature reviews. The recommendations focus predominantly on addressing inhibitors in the sociological and technological domains with few recommendations articulated in the political domain. Overall, the legislative domain is least represented. Conclusions Ex-post analysis using the seven-domain strategic management framework provides further opportunities for a planned systematic response to pandemics which remains critical as the current COVID-19 pandemic evolves.This study did not receive any external funding
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