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991.
We evaluate author impact indicators and ranking algorithms on two publication databases using large test data sets of well-established researchers. The test data consists of (1) ACM fellowship and (2) various life-time achievement awards. We also evaluate different approaches of dividing credit of papers among co-authors and analyse the impact of self-citations. Furthermore, we evaluate different graph normalisation approaches for when PageRank is computed on author citation graphs.We find that PageRank outperforms citation counts in identifying well-established researchers. This holds true when PageRank is computed on author citation graphs but also when PageRank is computed on paper graphs and paper scores are divided among co-authors. In general, the best results are obtained when co-authors receive an equal share of a paper's score, independent of which impact indicator is used to compute paper scores. The results also show that removing author self-citations improves the results of most ranking metrics. Lastly, we find that it is more important to personalise the PageRank algorithm appropriately on the paper level than deciding whether to include or exclude self-citations. However, on the author level, we find that author graph normalisation is more important than personalisation. 相似文献
992.
Scientific research is increasingly relying on collaborations to address complex real-world problems. Many researchers, policymakers, and administrators consider a multidisciplinary environment an important factor for fostering research collaborations, especially interdisciplinary ones that involve researchers from different disciplines. However, it remains unknown whether a higher level of multidisciplinarity within an academic institution is associated with internal collaborations that are more prevalent and more interdisciplinary. Analyzing 90,000 publications by 2500 faculty members in over 100 academic institutions from three multidisciplinary areas, information, public policy, and neuroscience, we investigated the connection between multidisciplinarity and research collaborations. Based on social network analysis and text mining, our analysis suggests that more multidisciplinary institutions are not necessarily more collaborative, although they do feature collaborations that are more interdisciplinary. Our findings provide implications for academic administrators and policymakers to promote research collaborations and interdisciplinarity in academic institutions. 相似文献
993.
Mike Thelwall 《Journal of Informetrics》2018,12(2):430-435
Dimensions is a partly free scholarly database launched by Digital Science in January 2018. Dimensions includes journal articles and citation counts, making it a potential new source of impact data. This article explores the value of Dimensions from an impact assessment perspective with an examination of Food Science research 2008–2018 and a random sample of 10,000 Scopus articles from 2012. The results include high correlations between citation counts from Scopus and Dimensions (0.96 by narrow field in 2012) as well as similar average counts. Almost all Scopus articles with DOIs were found in Dimensions (97% in 2012). Thus, the scholarly database component of Dimensions seems to be a plausible alternative to Scopus and the Web of Science for general citation analyses and for citation data in support of some types of research evaluations. 相似文献
994.
Facebook is challenging professional journalism. These challenges were evident in three incidents from 2016: the allegation that Facebook privileged progressive-leaning news on its trending feature; Facebook’s removal of the Pulitzer Prize-winning “Napalm Girl” photo from the pages of prominent users; and the proliferation of “fake news” during the US presidential election. Using theoretical concepts from the field of boundary work, this paper examines how The Guardian, The New York Times, Columbia Journalism Review and Poynter editorialized Facebook’s role in these three incidents to discursively construct the boundary between the value of professional journalism to democracy and Facebook’s ascendant role in facilitating essential democratic functions. Findings reveal that these publications attempted to define Facebook as a news organization (i.e., include it within the boundaries of journalism) so that they could then criticize the company for not following duties traditionally incumbent upon news organizations (i.e., place it outside the boundaries of journalism). This paper advances scholarship that focuses on both inward and outward conceptions of boundary work, further explores the complex challenge of defining who a journalist is in the face of rapidly changing technological norms, and advances scholarship in the field of media ethics that positions ethical analysis at the institutional level. 相似文献
995.
查代春 《江西广播电视大学学报》2006,31(4):88-90
广告效果下降是当前广告业的一种普遍现象,成为困扰广告商和广告公司的一个难题。如何创制更有新意、更有效果的广告,使广告传递的商品信息让受众注意、形成记忆、产生行动是广告人努力的方向。本文通过时广告效果下降原因的剖析,提出了相应的对策和措施。 相似文献
996.
当前,面临转型期的图书馆事业存在着一系列的问题,解决的途径和对策需要我们从技术、经济、人才三方面进行认真研究。 相似文献
997.
998.
关于学习控制的定量分析 总被引:3,自引:0,他引:3
本文根据著名教育技术学家瑞奇鲁斯 (C .M .Reigeluth)的影响学习控制的主要因素 ,将其进行量化处理 ,并设计出相应的计算公式 ,然后根据学习控制定量分析调查结果 ,计算学习控制的量化数据 ,利用定量分析的方法 ,指导教师制定和实施相应的教学策略。 相似文献
999.
BackgroundPlanctomycetes is a phylum of biofilm-forming bacteria with numerous biosynthetic gene clusters, offering a promising source of new bioactive secondary metabolites. However, the current generation of chemically defined media achieves only low biomass yields, hindering research on these species. We therefore developed a chemically defined medium for the model organism Planctopirus limnophila to increase biomass production.ResultsWe found that P. limnophila grows best with a 10 mM sodium phosphate buffer. The replacement of complex nitrogen sources with defined amino acid solutions did not inhibit growth. Screening for vitamin requirements revealed that only cyanocobalamin (B12) is needed for growth. We used response surface methodology to optimize the medium, resulting in concentrations of 10 g/L glucose, 34 mL/L Hutner’s basal salts, 23.18 mM KNO3, 2.318 mM NH4Cl and 0.02 mg/L cyanocobalamin. The analysis of amino acid consumption allowed us to develop a customized amino acid solution lacking six of the amino acids present in Aminoplasmal 10%. Fed-batch cultivation in a bioreactor using the optimized medium achieved a final ΔOD600 of 46.8 ± 0.5 after 108 h, corresponding to a cell dry weight of 13.6 ± 0.7 g/L.ConclusionsThe optimized chemically defined medium allowed us to produce larger amounts of biomass more quickly than reported in earlier studies. Further research should focus on triggering P. limnophila biofilm formation to activate the gene clusters responsible for secondary metabolism.How to cite: Kruppa OC, Gerlach D, Fan R, et al. Development of a chemically defined medium for Planctopirus limnophila to increase biomass production. Electron J Biotechnol 2021;54. https://doi.org/10.1016/j.ejbt.2021.09.002. 相似文献
1000.
ABSTRACT This study used the 2017 Las Vegas and 2016 Orlando mass shootings as case studies to explore alleged double standards in reporting of events featuring Muslim and non-Muslim mass perpetrators of violence. The study used framing theory and content analysis to examine Los Angeles Times and New York Times coverage of the shootings during the one week immediately following each event. Findings are consistent with previous literature and the researchers’ expectations. The Orlando shooting, carried out by a Muslim, was allotted more coverage despite the fact that it produced nine fewer fatalities than the Las Vegas shooting, perpetrated by a white non-Muslim. The analysis also showed that the examined newspapers were more likely to employ a “terrorism” frame in their coverage of the Orlando shooting than in their coverage of the Las Vegas shooting; link the Orlando mass shooting with the global war on terrorism; and to humanize Stephen Paddock, the white perpetrator of the Las Vegas shooting. Framing differences found in this study may contribute to downplaying the threat of white male gun violence, and to reinforcing fears of Islam and Muslims. 相似文献