698 research outputs found

    Development and Testing of a Green Monopropellant Ignition System

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    This paper will detail the development and testing of a "green" monopropellant booster ignition system. The proposed booster ignition technology eliminates the need for a pre-heated catalyst bed, a high wattage power source, toxic pyrophoric ignition fluids, or a bi-propellant spark ignitor. The design offers the simplicity of a monopropellant feed system features non-hazardous gaseous oxygen (GOX) as the working fluid. The approach is fundamentally different from all other "green propellant" solutions in the aerospace in the industry. Although the proposed system is more correctly a "hybrid" rocket technology, since only a single propellant feed path is required, it retains all the simple features of a monopropellant system. The technology is based on the principle of seeding an oxidizing flow with a small amount of hydrocarbon.1 The ignition is initiated electrostatically with a low-wattage inductive spark. Combustion gas byproducts from the hydrocarbon-seeding ignition process can exceed 2400 C and the high exhaust temperature ensures reliable main propellant ignition. The system design is described in detail in the Hydrocarbon-Seeded Ignition System Design subsection

    Scenario-based MUVE for Science Inquiry

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    The development of scientific inquiry skills is a core element of the draft national science curriculum for secondary school students. Yet, despite the prominence of inquiry learning in the curriculum, research has shown that student understanding of and interest in engaging in scientific inquiry is lacking in Australian secondary schools. The purpose of the Virtual Worlds project, which commenced this year, is to conduct learning and cognitive sciences-based research into the potential of scenario-based Multi-User Virtual Environment systems to promote and perhaps enhance secondary school learning experiences. In this paper we consider a number of existing science education-based multi-user virtual environments and introduce our project including our goals, approach and scenario underpinning the virtual world

    A Comparison of Embedded and Nonembedded Print Coverage of the U.S. Invasion and Occupation of Iraq

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    This study examines the impact of embedded versus nonembedded (unilateral) news coverage during the U.S. invasion and occupation of Iraq. A content analysis was conduycted of the Washington Post, New York Times, Los Angeles Times, and Chicago Tribune news coverage of the invasion and occupation examining whether embedded and nonembedded new reports were different and, if so, how. News reports were examined for differences in tone toward the military, trust in the military, framing, and authoritativeness. The results of the study revealed significant differences in overall tone toward the military, trust in military personnel, framing, and authoritativeness between embedded and nonembedded articles.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    Association between circulating levels of sex steroid hormones and esophageal adenocarcinoma in the FINBAR Study

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    Funding: The study was supported by NIH Intramural Research Program, National Cancer Institute; Cancer Focus Northern Ireland (formerly the Ulster Cancer Foundation); the Northern Ireland R&D office; and the Health Research Board, Ireland. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

    Treg depletion potentiates checkpoint inhibition in claudin-low breast cancer

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    Claudin-low breast cancer is an aggressive subtype that confers poor prognosis and is found largely within the clinical triple-negative group of breast cancer patients. Here, we have shown that intrinsic and immune cell gene signatures distinguish the claudin-low subtype clinically as well as in mouse models of other breast cancer subtypes. Despite adaptive immune cell infiltration in claudin-low tumors, treatment with immune checkpoint inhibitory antibodies against cytotoxic T lymphocyte–associated protein 4 (CTLA-4) and programmed death receptor 1 (PD-1) were ineffective in controlling tumor growth. CD4+FoxP3+ Tregs represented a large proportion of the tumor-infiltrating lymphocytes (TILs) in claudin-low tumors, and Tregs isolated from tumor-bearing mice were able to suppress effector T cell responses. Tregs in the tumor microenvironment highly expressed PD-1 and were recruited partly through tumor generation of the chemokine CXCL12. Antitumor efficacy required stringent Treg depletion combined with checkpoint inhibition; delays in tumor growth were not observed using therapies that modestly diminished the number of Tregs in the tumor microenvironment. This study provides evidence that the recruitment of Tregs to the tumor microenvironment inhibits an effective antitumor immune response and highlights early Treg recruitment as a possible mechanism for the lack of response to immune checkpoint blockade antibodies in specific subtypes of cancer that are heavily infiltrated with adaptive immune cells

    Priority strategies to improve gender equity in Canadian emergency medicine: proceedings from the CAEP 2021 Academic Symposium on leadership

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    Objectives: Gender inequities are deeply rooted in our society and have significant negative consequences. Female physicians experience numerous gender-related inequities (e.g., microaggressions, harassment, violence). These inequities have far-reaching consequences on health, well-being and career longevity and may result in the devaluing of various strengths that female emergency physicians bring to the table. This, in turn, has an impact on patient healthcare experience and outcomes. During the 2021 Canadian Association of Emergency Physicians (CAEP) Academic Symposium, a national collaborative sought to understand gender inequities in emergency medicine in Canada. Methods: We used a multistep stakeholder-engagement-based approach (harnessing both quantitative and qualitative methods) to identify and prioritize problems with gender equity in emergency medicine in Canada. Based on expert consultation and literature review, we developed recommendations to effect change for the higher priority problems. We then conducted a nationwide consultation with the Canadian emergency medicine community via online engagement and the CAEP Academic Symposium to ensure that these priority problems and solutions were appropriate for the Canadian context. Conclusion: Via the above process, 15 recommendations were developed to address five unique problem areas. There is a dearth of research in this important area and we hope this preliminary work will serve as a starting point to fuel further research. To facilitate these scholarly endeavors, we have appended additional documents identifying other key problems with gender equity in emergency medicine in Canada as well as proposed next steps for future research

    Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context

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    Long noncoding RNAs (lncRNAs) are commonly dys-regulated in tumors, but only a handful are known toplay pathophysiological roles in cancer. We inferredlncRNAs that dysregulate cancer pathways, onco-genes, and tumor suppressors (cancer genes) bymodeling their effects on the activity of transcriptionfactors, RNA-binding proteins, and microRNAs in5,185 TCGA tumors and 1,019 ENCODE assays.Our predictions included hundreds of candidateonco- and tumor-suppressor lncRNAs (cancerlncRNAs) whose somatic alterations account for thedysregulation of dozens of cancer genes and path-ways in each of 14 tumor contexts. To demonstrateproof of concept, we showed that perturbations tar-geting OIP5-AS1 (an inferred tumor suppressor) andTUG1 and WT1-AS (inferred onco-lncRNAs) dysre-gulated cancer genes and altered proliferation ofbreast and gynecologic cancer cells. Our analysis in-dicates that, although most lncRNAs are dysregu-lated in a tumor-specific manner, some, includingOIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergis-tically dysregulate cancer pathways in multiple tumorcontexts

    Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas

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    This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin

    Pan-cancer Alterations of the MYC Oncogene and Its Proximal Network across the Cancer Genome Atlas

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    Although theMYConcogene has been implicated incancer, a systematic assessment of alterations ofMYC, related transcription factors, and co-regulatoryproteins, forming the proximal MYC network (PMN),across human cancers is lacking. Using computa-tional approaches, we define genomic and proteo-mic features associated with MYC and the PMNacross the 33 cancers of The Cancer Genome Atlas.Pan-cancer, 28% of all samples had at least one ofthe MYC paralogs amplified. In contrast, the MYCantagonists MGA and MNT were the most frequentlymutated or deleted members, proposing a roleas tumor suppressors.MYCalterations were mutu-ally exclusive withPIK3CA,PTEN,APC,orBRAFalterations, suggesting that MYC is a distinct onco-genic driver. Expression analysis revealed MYC-associated pathways in tumor subtypes, such asimmune response and growth factor signaling; chro-matin, translation, and DNA replication/repair wereconserved pan-cancer. This analysis reveals insightsinto MYC biology and is a reference for biomarkersand therapeutics for cancers with alterations ofMYC or the PMN
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