1,721,868 research outputs found
Replication Data for: "A Ramsey Theory of Financial Distortions"
No full textThis is the replication package for "A Ramsey Theory of Financial Distortions," accepted in 2023 by the Journal of Political Economy.Matlab (and AMPL) code of producing the Figures and Tables in the paper
Characterization of neural progenitor/stem cells derived from human embryonic stem cells
Full text linkHuman embryonic stem cells (hESCs) are able to proliferate indefinitely without losing their ability to differentiate into multiple cell types of all three germ layers. Due to these fascinating properties, hESCs have promise as a robust cell source for regenerative medicine and as an in vitro model for the study of human development. In my PhD study, I have investigated the neural differentiation process of hESCs using our established protocol, identified characteristics associated with each stage of the differentiation and explored possible signalling pathways underlying these dynamic changes.
It was found that neural differentiation of hESCs could be divided into 5 stages according to their morphology, marker expression and differentiation potencies: hESCs, neural initiation, neural epithelium/rosette, neuronal progenitor cells and neural progenitor/stem cells (NPSCs) and 4 of these stages have been studied in more detail. At the neural initiation, hESCs firstly lose TRA-1-81 expression but retain SSEA4 expression. This transient cell population shows several similar properties to the primitive ectoderm. After neural-tube like structure/neural rosette formation, neural progenitor cells appear as typical bipolar structures and exhibit several properties of radial glial cells, including gene expression and pro-neuronal differentiation. The neural progenitor cells are able to grow in culture for a long time in the presence of growth factors bFGF and EGF. However, they gradually lose their bipolar morphology to triangular cell type and become pro-glial upon further differentiation. In addition, the state of neural progenitor and stem cells can be distinguished by their differential response to canonical Notch effector, C protein-binding factor 1. It was also found that delta like1 homolog (DLK-1) is temporally upregulated upon initial neural differentiation, but becomes undetectable after the neural progenitor stage. Overexpression of DLK-1 in NPSCs enhances neuronal differentiation in the presence of serum by blocking BMP and Notch pathways. These results show that neural differentiation of hESCs is a dynamic process in which cells go through sequential changes, and the events are reminiscent of the in vivo neurodevelopment process.
Moreover, I have characterized stably transfected nestin-GFP reporter hESC lines and found that the cell lines maintained the features of hESCs and the expression of GFP is restricted to the neural lineage after differentiation. Therefore, these reporter lines will be useful for the study of factors that regulate neural differentiation and for the enrichment of neural progenitors from other lineages.
Taken together, this study has demonstrated that hESCs are a good in vitro model to study the mechanisms and pathways that are involved in neural differentiation. The availability of hESCs allows us to explore previously inaccessible processes that occur during human embryogenesis, such as gastrulation and neurogenesis
An analysis of price impact functions of individual trades on the London stock exchange
No full textPrice impact is an important area of research in market microstructure. Previous studies have examined the relationship between trade size and price impact on a number of equity markets. In this study, using recent order book data from the London Stock Exchange, we examine the immediate price impact function for all stocks from FTSE 100 and novelly we investigate whether the function displays time-of-day effects. The results show that price impact exhibits a power-law scaling that price impact is highest in the first hour of the trading day, and lowest in the 90 minutes before market close
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
The intergenerational transmission of anxiety in a Chinese population: the mediating effect of parental control
No full textObjectivesAnxiety aggregates in families. The key putative environmental mediators of risk transmission from parents to children include parental psychological control and behavioral control, which are important features of parenting in Chinese culture. It is unclear, however, whether Chinese parents’ own anxiety is associated with their partners’ controlling behaviors and whether control mediates the transmission of anxiety. This study aimed to examine whether and how anxiety is transmitted from parents to children with a mediation model incorporating an actor–partner interdependent model.MethodsWe conducted a prospective longitudinal study with parents of Chinese children aged 7–12 years old (N = 651).ResultsOur results found the intergenerational transmission of anxiety from parents to children and maternal transmission of anxiety was mediated by maternal psychological control. Parental anxiety was positively associated with parents’ own psychological, but not behavioral, control. The data showed no association between parents’ own anxiety and their partners’ psychological or behavioral control.ConclusionsThese findings support parental anxiety and maternal psychological control as critical risk factors in children’s development of anxiety in Chinese families
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
FIGURES 1–2 in A new genus and species of Old World Opsiini (Hemiptera: Cicadellidae: Deltocephalinae), with a key to genera and species checklist for the tribe
No full textFIGURES 1–2. Introrsa yaoquensis sp. nov. 1. Habitus, dorsal view; 2. Habitus, lateral view.Published as part of Dai, Wu, Cui, Wei, Xiao, Bin & Zhang, Yalin, 2010, A new genus and species of Old World Opsiini (Hemiptera: Cicadellidae: Deltocephalinae), with a key to genera and species checklist for the tribe, pp. 55-68 in Zootaxa 2607 on page 59, DOI: 10.5281/zenodo.19772
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
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