This study examines the relationship between principals’ leadership and student achievement. Based on the Programme for International Student Assessment 2015 United States data, a two-level...

A stock divestment campaign is a common strategy used by social activists to pressure corporations to abandon undesirable practices. However, evidence on the effectiveness of the strategy remains mixed. In this paper, we examine the effectiveness of an international stock boycott by studying a large sample of institutional investor transactions in four emerging market stocks targeted by the Sudan divestment campaign from 2001 to 2012. We find evidence of a negative relationship between the intensity of the campaign and the ownership (...) breadth of the stocks, suggesting the effectiveness of the campaign in encouraging investors to divest from targeted companies. Additional analysis indicates that investors in countries that are sympathetic towards CSR activities are more responsive to the divestment campaign. Further, we find evidence consistent with higher campaign intensity being associated with more depressed stock prices. Finally, when performing qualitative content analyses of the annual reports and CSR reports, we find evidence about the effects of the campaign on the targeted companies’ corporate policies and activities in Sudan. In sum, our results support the effectiveness of the stock boycott. (shrink)

The fifth base in human DNA, 5‐methylcytosine, is inherently mutagenic. This has led to marked changes in the distribution of the CpG methyl acceptor site and an 80% depletion in its frequency of occurrence in vertebrate DNA. The coding regions of many genes contain CpGs which are methylated in sperm and serve as hot spots for mutation in human genetic diseases. Fully 30–40% of all human germline point mutations are thought to be methylation induced even though the CpG dinucleotide is (...) under‐represented and efficient cellular repair systems exist. Importantly, tumor suppressor genes such as p53 also contain methylated CpGs and these serve as hot spots for mutations in some, but not all, human cancers. Comparison of the spectrum of mutations present in this gene in different human cancers allows for predictions to be made on the molecular mechanisms of tumorigenesis. (shrink)

In this study, we developed and validated an instrument that researchers can use to measure the collective effort of principals and teachers who excise their own unique leadership to genera...

Diffusion plays an essential role in the distribution of predator and prey. We mainly research the diffusion network’s effect on the predator-prey model through bifurcation. First, it is found that the link probability and diffusion parameter can cause Turing instability in the network-organized predator-prey model. Then, the Turing stability region is obtained according to the sufficient condition of Turing instability and the eigenvalues’ distribution. Finally, the biological mechanism is explained through our theoretical results, which are also illustrated by numerical simulation.

Articles from the semiotic point of view, through the "Poems" and "easy" comparison, discusses the "Book" class artistic features. Integrated in the form of symbols, in the chapter structure, sentence use of the phrase, in the selection and deep implication on the images, the "easy" and "poetry" with isomorphic relationship. Appear in later works of art similar images, the prototype can be traced back to the "poetry" is more-resort "easy." The essay discuss the characteristic of analogous art in the Book (...) of Changes in terms of semeiology through comparing the Book of Songs with the Book of Changes. By comparison the writer draw a conclusion that they were in the relation of heterogeneity and homoorganicity in the comprehensiveness of constructing symbol, in the structure of sections and chapters, in the use of lexical and sentential expressions, in the choice of images and deep signification. The heterogeneous images appear in the art pieces of later ages, and its protomodel could be found in the Book of Changes more than in the Book of Songs. (shrink)