312 research outputs found
Testing for Asymmetric Employer Learning and Statistical Discrimination
No full textWe test the implications of a statistical discrimination model with asymmetric learning. Firms receive signals of productivity over time and may use race to infer worker's productivity. Incumbent employers have more information about workers productivity than outside employers. Using data from the NLSY79, we find evidence of asymmetric learning. In addition, employers statistically discriminate against non-college educated black workers at time of hiring. We also find that employers directly observe most of the productivity of college graduates at hiring, and learn very little over time about these workers
Rhizosphere bacteria show a stronger response to antibiotic-based biopesticide than to conventional pesticides
No full textThe plant microbiota can substantially contribute to various functions related to host health, fitness, and productivity. Therefore, maintaining the integrity of the microbiota is beginning to be seen as a crucial factor in modern agriculture. Here, we evaluated the effects of two chemical pesticides (azoxystrobin and carbendazim) and an antibiotic-based biopesticide (wuyiencin) on the rhizosphere microbiome of tomato plants. It was found that all treatments resulted in changes in the bacterial community structure to varying degrees. The most pronounced changes were observed with the biopesticide, which resulted in an enrichment of Streptomyces in the microbiome. In contrast, the relative abundance of Actinobacteria decreased in samples that were treated with low and high dosages of carbendazim. Clostridia were enriched after the applications of azoxystrobin and wuyiencin. When functioning of the microbiome was assessed, it was shown that genes encoding multidrug efflux pumps and ABC transporters related to nutrient uptake were enriched. This enrichment is likely to overcome potentially negative effects linked to the exposure to the employed substances. The study provides new insights into the potential of different pesticides to modulate native plant microbiomes, and thus highlights the importance to include such evaluations when new active agents are developed
sj-docx-1-dhj-10.1177_20552076241239182 - Supplemental material for Comparative effectiveness of interventions on promoting physical activity in older adults: A systematic review and network meta-analysis
No full textSupplemental material, sj-docx-1-dhj-10.1177_20552076241239182 for Comparative effectiveness of interventions on promoting physical activity in older adults: A systematic review and network meta-analysis by Shuang Wu, Guangkai Li, Beibei Shi, Hongli Ge, Si Chen, Xianliang Zhang and Qiang He in DIGITAL HEALTH</p
sj-tif-1-ear-10.1177_0145561320963627 – Supplemental Material for Predictive Significance of Enhanced Level of Angiogenesis and Tissue Neutrophils for Antrochoanal Polyps Recurrence in Children
No full textSupplemental Material, sj-tif-1-ear-10.1177_0145561320963627 for Predictive Significance of Enhanced Level of Angiogenesis and Tissue Neutrophils for Antrochoanal Polyps Recurrence in Children by Yeran Yang, Beibei Song, Xiaojian Yang, Chunju Zhou, Lixing Tang, Jie Lu, Pengpeng Wang, Ping Chu, Shujing Han, Yongli Guo and Wentong Ge in Ear, Nose & Throat Journal</p
Guan yu gong ren he gong si jin rong de yan jiu
No full textShen, Beibei.Thesis Ph.D. Chinese University of Hong Kong 2015.Includes bibliographical references.Abstracts also in Chinese.Title from PDF title page (viewed on 02, November, 2016).Shen, Beibei
Constructing an expeditious and durable composite as an air electrode of solid oxide cells through synergistic phase transformation and phase segregation engineering
No full textThe sluggish catalytic activity of iron-rich perovskite-based air electrodes at low temperatures (<650 degrees C) is a common problem faced by solid oxide cells (SOCs). Herein, an expeditious and durable iron-rich, multifunctional, composite material is reported as an outstanding air electrode for SOCs. Such a composite consists of a dominant cubic single perovskite (SP) phase, SrFe1-x(Ta,Nb)(x)O3-delta, and a minor oxygen vacancy-rich double perovskite (DP) phase, Sr2FeNbO6-delta. The incorporation of pentavalent Ta and Nb effectively inhibits the formation of tetragonal SP and induces phase transformation to a cubic SP with high symmetry, while the in-situ separated DP phase synergistically boosts the performance of oxygen activation. Such multiple benefits result in the generation of an oxygen-ion conductor-based solid oxide fuel cell (O-SOFC) with the developed composite electrode that yields a superb maximum power density (P-max) of 1259 mW cm(-2) at 600 degrees C, similar to 2.1 times that of an O-SOFC with SrFeO3-delta parent electrode (595 mW cm(-2)). A reversible protonic ceramic cell (R-PCC) with such composite air electrode delivers a remarkable electrochemical performance, e.g., a P-max of 844 mW cm(-2) and an electrolysis current density of -957 mA cm(-2) @ 1.3 V at 650 degrees C. More attractively, the resulting cell exhibits an outstanding operating endurance of 500 h in fuel cell mode and 210 h in cycle mode (i.e., alternating between fuel cell and electrolysis cell modes).
Enhancing clustering blog documents by utilizing author/reader comments
No full textBlogs are a new form of internet phenomenon and a vast everincreasing information resource. Mining blog files for information is a very new research direction in data mining. We propose to include the title, body, and comments of the blog pages in clustering datasets from blog documents. In particular, we argue that the author/reader comments of the blog pages may have more discriminating effect in clustering blog documents. We constructed a word-page matrix by downloading blog pages from a well-known website and experimented a k-means clustering algorithm with different weights assigned to the title, body, and comment parts. Our experimental results show that assigning a larger weight value to the blog comments helps the k-means algorithm produce better clustering solutions. The experimental results confirm our hypothesis that the author/reader comments of the blog files are very useful in discriminating blog files
Question bias and biased question words in Mandarin, German and Bangla
No full textBias is a linguistic phenomenon that is primarily found in questions. Various kinds of biased questions have been studied extensively in the literature, e.g. Negative Polar Questions, Questions with Minimizers, Questions with Verum focus (Ladd 1981, Buring & Gunlogson 2000, Guerzoni 2003, Romero & Han 2004, a.o.). Aside from those biased questions, there are questions with dedicated words that can express bias (i.e. biased question words). Those words are "nandao" in Mandarin, "etwa" in German, and "naki" in Bangla. The current dissertation takes a modal approach to bias, distinct from earlier accounts of bias. In order to find out the nature of bias, e.g. how it is introduced, at which level it is interpreted, and why it is primarily found in questions, I study the three biased question words at the interface of syntax, semantics and pragmatics. Based on the analyses of the three words, I claim that bias is a not-at-issue content that is revealed via the speaker's public belief domain (i.e. Discourse commitment). Considering the phenomenon in general, I isolate three conditions for introducing bias: a preference ranking of alternatives, selection of a particular alternative as privileged, and the requirement to update the Question Under Discussion with the alternatives. Biased question words lexically satisfy all three conditions and give rise to the obligatorily biased reading of questions containing them. With these three conditions, I provide a definition for bias and explain the opening statement that "bias is a linguistic phenomenon that is primarily found in questions".Ph.D.Includes bibliographical referencesby Beibei X
Enhancing clustering blog documents by utilizing author/reader comments
No full textBlogs are a new form of internet phenomenon and a vast ever-increasing information resource. Mining blog files for information is a very new research direction in data mining. Blog files are different from standard web files and may need specialized mining strategies. We propose to include the title, body, and comments of the blog pages in clustering datasets from blog documents. In particular, we argue that the author/reader comments of the blog pages may have more discriminating effect in clustering blog documents. We constructed a word-page matrix by downloading blog pages from a well-known website and experimented a k-means clustering algorithm with different weights assigned to the title, body, and comment parts. Our experimental results show that assigning a larger weight value to the blog comments helps the k-means algorithm produce better clustering solutions. The experimental results confirm our hypothesis that the author/reader comments of the blog files are very useful in discriminating blog files
Three Essays on Employer Learning and Statistical Discrimination
No full textThis dissertation consists of three essays studying employer learning and statistical discrimination of young workers in the U.S. labor market. The first chapter outlines the dissertation by discussing the motivations, methods, and research findings.Chapter two develops a framework that nests both symmetric and asymmetric employer learning, and derives testable hypotheses on racial statistical discrimination under different processes of employer learning. Testing the model with data from the NLSY79, we find that employers statistically discriminate against black workers on the basis of both education and race in the high school market where learning appears to be mostly asymmetric. In the college market, employers directly observe most parts of the productivity of potential employees and learn very little over time.In chapter three, we investigate how the process of employer learning and statistical discrimination varies over time and across employers. The comparison between the NLSY79 and the NLSY97 cohorts reveals that employer learning and statistical discrimination has became stronger over the past decades. Using the NLSY97 data, we identify three employer- specific characteristics that influencing employer learning and statistical discrimination, the supervisor-worker race match, supervisor\'s age, and firm size. Black high school graduates face weaker employer learning and statistical discrimination if they choose to work for a black supervisor, work for an old supervisor, or work in a firm of small size.In the last chapter, we are interested in the associations between verbal and quantitative skills and individual earnings as well as the employer learning process of these two specific types of skills. There exist significant differences in both the labor market rewards and employer learning process of verbal and quantitative skills between high school and college graduates. Verbal skills are more important than quantitative skills for high school graduates, whereas college-educated workers benefit greatly from having high quantitative skills but little from having high verbal skills. In addition, employers directly learn verbal skills and continuously learn quantitative skills in the high school market, but almost perfectly observe quantitative skills in the college market.Ph. D
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