Collaboration network of applied linguistics research articles with different methodological orientations

The current study draws on synthetic techniques and bibliometric analysis to explore the patterns of scientific collaboration in light of methodological orientations. We examined 3,992 applied linguistics (AL) articles published in 18 top-tier journals from 2009 to 2018 and analyzed their methodological orientations and scientific collaboration. Considering that the number of co-authored papers outweighs single-authored counterparts, our results revealed that the overall degree of collaboration for AL journals was moderate-to-high (57.7%). In particular, quantitative studies contained the highest degree of collaboration (66.8%). This was followed by systematic reviews (60.9%), and mixed-methods approach (55.7%). Country-wise, our overall findings further indicated that the United States and the United Kingdom were the two main hubs of collaborative activities for quantitative, qualitative, and mixed-methods research. While the USA was the top country in systematic reviews like all other research approaches, the UK was the fifth country in systematic reviews. As for collaborating authors, our findings demonstrated that the most influential quantitative researchers had collaborated on Natural Language Processing (NLP) and data mining. While the mixed-methods researchers had a tendency to collaborate on conceptual issues subscribing to the language testing and assessment strand, the most productive qualitative researchers had collaborated on L2 writing issues. Implications for applied linguistics research are further discussed

Efficient Computation of Distance Labeling for Decremental Updates in Large Dynamic Graphs

Since today's real-world graphs, such as social network graphs, are evolving all the time, it is of great importance to perform graph computations and analysis in these dynamic graphs. Due to the fact that many applications such as social network link analysis with the existence of inactive users need to handle failed links or nodes, decremental computation and maintenance for graphs is considered a challenging problem. Shortest path computation is one of the most fundamental operations for managing and analyzing large graphs. A number of indexing methods have been proposed to answer distance queries in static graphs. Unfortunately, there is little work on answering such queries for dynamic graphs. In this paper, we focus on the problem of computing the shortest path distance in dynamic graphs, particularly on decremental updates (i.e., edge deletions). We propose maintenance algorithms based on distance labeling, which can handle decremental updates efficiently. By exploiting properties of distance labeling in original graphs, we are able to efficiently maintain distance labeling for new graphs. We experimentally evaluate our algorithms using eleven real-world large graphs and confirm the effectiveness and efficiency of our approach. More specifically, our method can speed up index re-computation by up to an order of magnitude compared with the state-of-the-art method, Pruned Landmark Labeling (PLL)

Extracellular NAD and ATP: Partners in immune cell modulation

Extracellular NAD and ATP exert multiple, partially overlapping effects on immune cells. Catabolism of both nucleotides by extracellular enzymes keeps extracellular concentrations low under steady-state conditions and generates metabolites that are themselves signal transducers. ATP and its metabolites signal through purinergic P2 and P1 receptors, whereas extracellular NAD exerts its effects by serving as a substrate for ADP-ribosyltransferases (ARTs) and NAD glycohydrolases/ADPR cyclases like CD38 and CD157. Both nucleotides activate the P2X7 purinoceptor, although by different mechanisms and with different characteristics. While ATP activates P2X7 directly as a soluble ligand, activation via NAD occurs by ART-dependent ADP-ribosylation of cell surface proteins, providing an immobilised ligand. P2X7 activation by either route leads to phosphatidylserine exposure, shedding of CD62L, and ultimately to cell death. Activation by ATP requires high micromolar concentrations of nucleotide and is readily reversible, whereas NAD-dependent stimulation begins at low micromolar concentrations and is more stable. Under conditions of cell stress or inflammation, ATP and NAD are released into the extracellular space from intracellular stores by lytic and non-lytic mechanisms, and may serve as ‘danger signals–to alert the immune response to tissue damage. Since ART expression is limited to naïve/resting T cells, P2X7-mediated NAD-induced cell death (NICD) specifically targets this cell population. In inflamed tissue, NICD may inhibit bystander activation of unprimed T cells, reducing the risk of autoimmunity. In draining lymph nodes, NICD may eliminate regulatory T cells or provide space for the preferential expansion of primed cells, and thus help to augment an immune response

Argumentative writing behavior of graduate EFL learners

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.This study analyzed the argumentative writing behavior of Iranian graduate learners of English as Foreign Language in their English essays. Further, the correlations between the use of argument elements and overall writing quality as well as soundness of produced arguments were investigated. To this end, 150 essays were analyzed. The sample essays were found to be predominantly deductive in terms of rhetorical pattern. Moreover, they mainly utilized ‘data’ and ‘claim’ most frequently with secondary elements of argument (i.e., counterargument claim, counterargument data, rebuttal claim, and rebuttal data) as the least produced elements. Overall writing quality co-varied significantly positively with the uses of claims, data, counterargument claims, counterargument data, rebuttal claims, and rebuttal data. Essays rated high in terms of overall writing quality were further rated for soundness and relevance of the arguments. The results demonstrate that even for advanced language learners good surface structure cannot necessarily guarantee well thought-out logical structure. The pedagogical implications for writing instruction and research are discussed