1,721,102 research outputs found
Integrated Communication and Navigation Based on LEO Satellite Networks: A Survey
Full text linkAdvancements in communication, manufacturing, and launch technologies have significantly accelerated the development of Low-Earth orbit (LEO) satellite communication constellations. Simultaneously, the rapid expansion of LEO satellite platforms presents new opportunities for navigation enhancements and substantial benefits for internet of things (IoT) applications. This survey highlights the latest advancements in the integrated communication and navigation (ICAN) technologies, emphasizing key research issues. Specifically, we discuss the motivation and feasibility of integrating communication and navigation on LEO satellite platforms, analyzing various LEO-based navigation paradigms while assessing their respective advantages and limitations. We further explore the mutual promotion of navigation and communication under the ICAN paradigm and discuss waveform design, analyzing the characteristics of different waveform design approaches. Finally, we highlight the unique challenges and identify open research topics within the ICAN framework for future exploration
Enhanced vasorin signaling mitigates adverse cardiovascular remodeling
Full text linkArterial stiffening is a critical risk factor contributing to the exponential rise in age-associated cardiovascular disease incidence. This process involves age-induced arterial proinflammation, collagen deposition, and calcification, which collectively contribute to arterial stiffening. The primary driver of proinflammatory processes leading to collagen deposition in the arterial wall is the transforming growth factor-beta1 (TGF-β1) signaling. Activation of this signaling is pivotal in driving vascular extracellular remodeling, eventually leading to arterial fibrosis and calcification. Interestingly, the glycosylated protein vasorin (VASN) physically interacts with TGF-β1, and functionally restraining its proinflammatory fibrotic signaling in arterial walls and vascular smooth muscle cells (VSMCs). Notably, as age advances, matrix metalloproteinase type II (MMP-2) is activated, which effectively cleaves VASN protein in both arterial walls and VSMCs. This age-associated/MMP-2-mediated decrease in VASN levels exacerbates TGF-β1 activation, amplifying arterial fibrosis and calcification in the arterial wall. Importantly, TGF-β1 is a downstream molecule of the angiotensin II (Ang II) signaling pathway in the arterial wall and VSMCs, which is modulated by VASN. Indeed, chronic administration of Ang II to young rats significantly activates MMP-2 and diminishes the VASN expression to levels comparable to untreated older control rats. This review highlights and discusses the role played by VASN in mitigating fibrosis and calcification by alleviating TGF-β1 activation and signaling in arterial walls and VSMCs. Understanding these molecular physical and functional interactions may pave the way for establishing VASN-based therapeutic strategies to counteract adverse age-associated cardiovascular remodeling, eventually reducing the risk of cardiovascular diseases.This research was supported by the Intramural Research Program of the National Institute on Aging, National Institutes of Health.Scopu
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
意大利主流媒体有关“一带一路”报道中“中国形象”分析 (Yidali zhuliu meiti youguan yidaiyilu baodao zhong zhongguo xingxiang fenxi, Analysis of "China's image" in Italian mainstream media reports on "One Belt One Road")
No full text意大利是G7成员国之一,也是欧盟的创始成员国,在地中海沿岸地区有着举足轻重的地位。因此,意大利国内媒体的涉华报道理应视为观察西方世界对华态度的窗口。结合2019年3月国家主席习近平对意大利进行国事访问并签订中意两国“一带一路”谅解备忘录这一重大历史事件为背景,本文选择2019年3月至12月间意大利两家发行量最大的主流纸质媒体有关“一带一路”的报道为研究对象,运用定量与定性的研究方法对相关新闻文本进行深入分析,从而探讨中国在海外的国家形象与影响力。研究发现,虽然意大利主流媒体对中国国家形象的塑造趋于公正客观,但仍然带有传统西方社会固有的偏见,这类偏见不仅来源于中西方意识形态领域的客观差异,更有意大利自身发展道路上独特因素的影响。Italy is a member of the G7 and a founding member of the European Union, and has a pivotal position in the Mediterranean coastal region. Italian domestic media coverage of China should be seen as a window into the Western world's attitude towards China. Based on the background of Chinese President Xi Jinping's state visit to Italy in March 2019 and the signing of the Memorandum of Understanding on the Belt and Road between Italy and China, this article selects the reports on the Belt and Road by the two largest Italian mainstream media outlets between March and December 2019. This paper uses quantitative and qualitative research methods to analyze the relevant news texts, in order to explore China's national image and influence abroad. The study found that although the Italian mainstream media tends to portray China in an impartial and objective manner, it still carries the bias inherent in traditional Western society, not only due to the objective differences between the ideological spheres of China and the West, but also due to factors unique to Italy's own development path
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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