A Generalized Flow-Based Method for Analysis of Implicit Relationships on Wikipedia

We focus on measuring relationships between pairs of objects in Wikipedia whose pages can be regarded as individual objects. Two kinds of relationships between two objects exist: in Wikipedia, an explicit relationship is represented by a single link between the two pages for the objects, and an implicit relationship is represented by a link structure containing the two pages. Some of the previously proposed methods for measuring relationships are cohesion-based methods, which underestimate objects having high degrees, although such objects could be important in constituting relationships in Wikipedia. The other methods are inadequate for measuring implicit relationships because they use only one or two of the following three important factors: distance, connectivity, and cocitation. We propose a new method using a generalized maximum flow which reflects all the three factors and does not underestimate objects having high degree. We confirm through experiments that our method can measure the strength of a relationship more appropriately than these previously proposed methods do. Another remarkable aspect of our method is mining elucidatory objects, that is, objects constituting a relationship. We explain that mining elucidatory objects would open a novel way to deeply understand a relationship

Matrix metalloproteinase-1 up-regulation by hepatocyte growth factor in human dermal fibroblasts via ERK signaling pathway involves Ets1 and Fli1

In this study, we clarified the molecular mechanism(s) underlying the regulation of matrix metalloproteinase (MMP)-1 gene by hepatocyte growth factor (HGF) in cultured human dermal fibroblasts. HGF induced MMP-1 protein as well as mRNA at a transcriptional level via extracellular signal-regulated kinase (ERK) signaling pathway. The region in the MMP-1 promoter mediating the inducible responsiveness to HGF, defined by the transient transfection analysis of the serial 5′ deletion constructs, contained an Ets binding site. Mutation of this Ets binding site abrogated the HGF-inducible promoter activity. Ets1 up-regulated the expression of MMP-1 promoter activity, whereas Fli1 had antagonistic effects on them. After HGF treatment, the protein level and the binding activity of Ets1 was increased and those of Fli1 was decreased, which were canceled by PD98059. These results suggest that HGF up-regulates MMP-1 expression via ERK signaling pathway through the balance of Ets1 and Fli1, which may be a novel mechanism of regulating MMP-1 gene expression

Musical instrument training program improves verbal memory and neural efficiency in novice older adults

楽器訓練で高齢者の認知機能が向上することを確認 --訓練による脳活動の変化を高齢者で初報告--. 京都大学プレスリリース. 2020-12-24.Previous studies indicate that musical instrument training may improve the cognitive function of older adults. However, little is known about the neural origins of training‐related improvement in cognitive function. Here, we assessed the effects of instrumental training program on cognitive functions and neural efficiency in musically naïve older adults (61–85 years old). Participants were assigned to either the intervention group, which received a 4‐month instrumental training program using keyboard harmonica, or a control group without any alternative training. Cognitive measurements and functional magnetic resonance imaging during visual working memory (VWM) task were administered before and after the intervention in both groups. Behavioral data revealed that the intervention group significantly improved memory performance on the test that measures verbal recall compared to the control group. Neuroimaging data revealed that brain activation in the right supplementary motor area, left precuneus, and bilateral posterior cingulate gyrus (PCgG) during the VWM task decreased after instrumental training only in the intervention group. Task‐related functional connectivity (FC) analysis revealed that the intervention group showed decreased FC between the right PCgG and left middle temporal gyrus, and between the left putamen and right superior temporal gyrus (lPu‐rSTG) during a VWM task after the intervention. Furthermore, a greater improvement in memory performance in the intervention group was associated with a larger reduction in lPu‐rSTG FC, which might be interpreted as improved neural efficiency. Our results indicate that the musical instrument training program may contribute to improvements in verbal memory and neural efficiency in novice older adults

Five isoforms of the phosphatidylinositol 3-kinase regulatory subunit exhibit different associations with receptor tyrosine kinases and their tyrosine phosphorylations

AbstractThere are five isoforms of the regulatory subunit for the heterodimeric type of phosphatidylinositol 3-kinase. These five regulatory subunit isoforms were overexpressed using an adenovirus transfection system, and their own tyrosine phosphorylations and associations with various tyrosine kinase receptors were investigated. When overexpressed in CHO-PDGFR cells, the associations of these regulatory subunit isoforms with the platelet-derived growth factor receptor were similar. However, when overexpressed in CHO-IR cells, p55γ exhibited a significantly lower ability to bind with IRS-1 upon insulin stimulation, as compared with other regulatory subunit isoforms. Furthermore, p55α and p55γ were found to be tyrosine-phosphorylated. Finally, interestingly, when overexpressed in CHO-EGFR cells or A431 cells and stimulated with epidermal growth factor (EGF), phosphorylated EGF receptor was detected in p85α, p85β and p50α immunoprecipitates, but not in p55α and p55γ immunoprecipitates. In addition, EGF-induced tyrosine phosphorylation was observed in p85α, p85β, p55α and p55γ, but not in p50α, immunoprecipitates. Thus, each regulatory subunit exhibits specific responses regarding both the association with tyrosine-phosphorylated substrates and its own tyrosine phosphorylation. These results suggest that each isoform possesses specific roles in signal transduction, based on its individual tyrosine kinase receptor

A novel efficient feeder-free culture system for the derivation of human induced pluripotent stem cells

Nakagawa, M.et al. A novel efficient feeder-free culture system forthe derivation of human induced pluripotent stem cells.Sci. Rep.4, 3594; DOI:10.1038/srep03594 (2014)