On the context-free ambiguity of emoji

Due to their pictographic nature, emojis come with baked-in, grounded semantics. Although this makes emojis promising candidates for new forms of more accessible communication, it is still unknown to what degree humans agree on the inherent meaning of emojis when encountering them outside of concrete textual contexts. To bridge this gap, we collected a crowdsourced dataset (made publicly available) of one-word descriptions for 1,289 emojis presented to participants with no surrounding text. The emojis and their interpretations were then examined for ambiguity. We find that, with 30 annotations per emoji, 16 emojis (1.2%) are completely unambiguous, whereas 55 emojis (4.3%) are so ambiguous that the variation in their descriptions is as high as that in randomly chosen descriptions. Most emojis lie between these two extremes. Furthermore, investigating the ambiguity of different types of emojis, we find that emojis representing symbols from established, yet not cross-culturally familiar code books (e.g., zodiac signs, Chinese characters) are most ambiguous. We conclude by discussing design implications

A Prokaryotic S1P Lyase Degrades Extracellular S1P In Vitro and In Vivo: Implication for Treating Hyperproliferative Disorders

Sphingosine-1-phosphate (S1P) regulates a broad spectrum of fundamental cellular processes like proliferation, death, migration and cytokine production. Therefore, elevated levels of S1P may be causal to various pathologic conditions including cancer, fibrosis, inflammation, autoimmune diseases and aberrant angiogenesis. Here we report that S1P lyase from the prokaryote Symbiobacterium thermophilum (StSPL) degrades extracellular S1P in vitro and in blood. Moreover, we investigated its effect on cellular responses typical of fibrosis, cancer and aberrant angiogenesis using renal mesangial cells, endothelial cells, breast (MCF-7) and colon (HCT 116) carcinoma cells as disease models. In all cell types, wild-type StSPL, but not an inactive mutant, disrupted MAPK phosphorylation stimulated by exogenous S1P. Functionally, disruption of S1P receptor signaling by S1P depletion inhibited proliferation and expression of connective tissue growth factor in mesangial cells, proliferation, migration and VEGF expression in carcinoma cells, and proliferation and migration of endothelial cells. Upon intravenous injection of StSPL in mice, plasma S1P levels rapidly declined by 70% within 1 h and then recovered to normal 6 h after injection. Using the chicken chorioallantoic membrane model we further demonstrate that also under in vivo conditions StSPL, but not the inactive mutant, inhibited tumor cell-induced angiogenesis as an S1P-dependent process. Our data demonstrate that recombinant StSPL is active under extracellular conditions and holds promise as a new enzyme therapeutic for diseases associated with increased levels of S1P and S1P receptor signaling

Understanding and facilitating positive group dynamics in education

The project aims to advance our understanding of group dynamics in educational contexts. Among other things, we want to understand how children shape their impressions of social relationships during group interactions and how positive cognitions and emotions might arise through social interactions. To this end, we examine the conditions under which both positive and negative group dynamics arise, extending previous research projects involving subjective measures in the form of questionnaire data to also include objective measures such as movement data and physiological marker

On the Context-Free Ambiguity of Emoji

Due to their pictographic nature, emojis come with baked-in, grounded semantics. Although this makes emojis promising candidates for new forms of more accessible communication, it is still unknown to what degree humans agree on the inherent meaning of emojis when encountering them outside of concrete textual contexts. To bridge this gap, we collected a crowdsourced dataset (made publicly available) of one-word descriptions for 1,289 emojis presented to participants with no surrounding text. The emojis and their interpretations were then examined for ambiguity. We find that, with 30 annotations per emoji, 16 emojis (1.2%) are completely unambiguous, whereas 55 emojis (4.3%) are so ambiguous that the variation in their descriptions is as high as that in randomly chosen descriptions. Most emojis lie between these two extremes. Furthermore, investigating the ambiguity of different types of emojis, we find that emojis representing symbols from established, yet not cross-culturally familiar code books (e.g., zodiac signs, Chinese characters) are most ambiguous. We conclude by discussing design implications

Effect of StSPL on S1P-stimulated MAPK phosphorylation, cell proliferation and migration of endothelial cells.

<p>(A) Quiescent EA.hy 926 human endothelial cells were treated for 10 min with either vehicle (Co) or S1P (1 µM) in the absence or presence of WT StSPL (StSPL; 10 µg/ml) or the K311A mutant (10 µg/ml). Cell lysates were prepared and separated by SDS-PAGE, transferred to nitrocellulose and subjected to Western blotting using antibodies against phospho-p42/p44 (dilution of 1∶1000, upper panel) and total p42/p44-MAPK (dilution each 1∶6000, lower panel). Data are representative of four independent experiments. (B) Quiescent cells were treated for 28 h with either vehicle (-) or S1P (1 µM), which had been pretreated for 30 min at 37°C with either vehicle (-), WT StSPL (StSPL) or the K311A mutant, in the presence of [³H]thymidine. Incorporated radioactivity was measured as described in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0022436#s4" target="_blank">Materials and Methods</a> section. Results are expressed as cpm/well of incorporated [³H]thymidine and are means ±S.D. (n = 4). ***p<0.001 considered statistically significant when compared to the vehicle treated control values; ^##p<0.01, ^###p<0.001 when compared to the S1P-treated values by one-way ANOVA analysis and Bonferroni post test. (C) Quiescent cells were treated for 14 h with DMEM (Co) or S1P (1 µM) which had been pretreated for 30 min at 37°C with either vehicle (-), WT StSPL (StSPL) or the K311A mutant. Thereafter, migrated cells were analysed as described in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0022436#s4" target="_blank">Materials and Methods</a> section. Results are expressed as migrated cells per counted field and are means ±S.D. (n = 3). ***p<0.001 considered statistically significant when compared to the vehicle treated control values; ^###p<0.001 when compared to the S1P-treated values.</p

Biochemical characterization of StSPL.

<p>(A) Purity of purified WT StSPL. The molecular weight marker is shown in lane 1, the pooled fractions after size-exclusion chromatography were detected by Coomassie staining of the gel (lane 2) and by Western blotting with an antibody recognizing the C-terminal His-tag (lane 3). (B) Schematic representation of the StSPL dimer. Subunit A is depicted in grey, whereas subunit B is in black. A phosphate ion found in the active site of both subunits is depicted as a red dot, while the cofactor (PLP) is denoted by a blue hexagon. (C) Spectrophotometric activity assay of WT StSPL. The red curve represents the visible spectrum of the native protein before addition of substrate, corrected by the dilution factor. The black curves depict the visible spectra at regular intervals (1 min, 2, 4, 6, 8, 10, 12, 15, and 30 min) after addition of S1P. The transient peaks at 420 and 403 nm appearing upon addition of substrate correlate with protein activity. (D) Mass spectrometric activity assay of WT StSPL. The left panel depicts the reaction mixture measured just after mixing protein and substrate. The m/z 163.07 and 380.26 peaks correspond to the end product phosphoethanolamine and the substrate S1P, respectively. The right panel shows the reaction mixture after 75 min incubation at 20°C. No peak corresponding to S1P was detectable above background level.</p

Effect of StSPL on S1P-stimulated MAPK phosphorylation, cell proliferation and CTGF expression in renal mesangial cells.

<p>(A) Quiescent rat mesangial cells were treated for 10 min with either vehicle (DMEM, -) or S1P (1 µM) in the absence or presence of WT StSPL (StSPL; 10 µg/ml) or the K311A mutant (10 µg/ml). Thereafter, cell lysates were separated by SDS-PAGE, transferred to nitrocellulose and subjected to Western blotting using antibodies against phospho-p42/p44 (dilution of 1∶1000, upper panel) and total p42/p44-MAPK (dilution each 1∶6000, lower panel). Blots were stained by the ECL method according to the manufacturer's recommendation. Data are representative of five independent experiments. (B) Quiescent cells were treated for 28 h with either vehicle (Co) or S1P (1 µM) which had been pretreated for 30 min at 37°C with either vehicle (-), WT StSPL (StSPL; 20 µg/ml) or the K311A mutant (20 µg/ml) in the presence of [³H]thymidine. Incorporated radioactivity was measured as described in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0022436#s4" target="_blank">Materials and Methods</a> section. Results are expressed as cpm/well of incorporated [³H]thymidine and are means ±S.D. (n = 4). (C) Quiescent cells were treated for 2 h as indicated above, and proteins were precipitated from the supernatants and taken for SDS-PAGE, transfer to nitrocellulose membranes and Western blotting using a CTGF-specific antibody (dilution 1∶1000). *p<0.05 considered statistically significant when compared to the vehicle-treated control values; ^#p<0.05 when compared to the S1P-treated values (one-tailed p value).</p