961 research outputs found
Building a taxonomy for understanding knowledge management
As an interdisciplinary research field emerging recently, Knowledge Management (KM) has been given many different definitions. This paper introduces two studies we carried out to provide a holistic and better understanding of KM. By applying the methodology of domain analysis to investigate leading peer-reviewed journals regarding KM, the first study explores six fundamental issues regarding KM, which are: why is KM necessary; what enables the birth of KM and triggers actions on KM; what does KM deal with; how to implement KM; how to support KM by information technology; and where has KM been applied. By building an ontology structure of research topics within the community of the Graduate School of Knowledge Science at Japan Advanced Institute of Science and Technology (JAIST), the second study examines KM within a more general disciplinary called Knowledge Science, which gives a description of how KM is related to other research topics
X-ray and Radio Follow-up Observations of High-Redshift Blazar Candidates in the Fermi-LAT Unassociated Source Population
We report on the results of X-ray and radio follow-up observations of two GeV
gamma-ray sources 2FGL J0923.5+1508 and 2FGL J1502.1+5548, selected as
candidates for high-redshift blazars from unassociated sources in the {\it
Fermi} Large Area Telescope Second Source Catalog. We utilize the Suzaku
satellite and the VLBI Exploration of Radio Astrometry (VERA) telescopes for
X-ray and radio observations, respectively. For 2FGL J0923.5+1508, a possible
radio counterpart NVSS J092357+150518 is found at 1.4 GHz from an existing
catalog, but we do not detect any X-ray emission from it and derive a flux
upper limit 1.37 10 erg cm
s. Radio observations at 6.7 GHz also result in an upper limit of
19 mJy, implying a steep radio spectrum that is not
expected for a blazar. On the other hand, we detect X-rays from NVSS
J150229+555204, the potential 1.4 GHz radio counterpart of 2FGL J1502.1+5548.
The X-ray spectrum can be fitted with an absorbed power-law model with a photon
index =1.8 and the unabsorbed flux is =4.3 10 erg cm s. Moreover,
we detect unresolved radio emission at 6.7 GHz with flux =30.1
mJy, indicating a compact, flat-spectrum radio source. If NVSS J150229+555204
is indeed associated with 2FGL J1502.1+5548, we find that its multiwavelength
spectrum is consistent with a blazar at redshift .Comment: 24 pages, 7 figures, 6 tables, accepted for publication in Ap
Magnetization measurements on Li2Pd3B superconductor
Magnetization in DC magnetic fields and at different temperatures have been
measured on the Li2Pd3B compound. This material was recently found to show
superconductivity at 7-8K. Critical fields Hc1(0) and Hc2(0) have been
determined to be 135Oe and 4T, respectively. Critical current density, scaling
of the pinning force within the Kramer model and the irreversibility field data
are presented. Several superconductivity parameters were deduced: x(csi)=9.1
nm, l(lamda)=194nm and k=21. The material resembles other boride
superconductors from the investigated points of view.Comment: 10 pages, 5 figure
Raft-derived tau-associated vesicles
Aims: Neurofibrillary tangles (NFTs), a cardinal pathological feature of neurodegenerative disorders, such as Alzheimer's disease (AD) are primarily composed of hyper‐phosphorylated tau protein. Recently, several other molecules, including flotillin‐1, phosphatidylinositol‐4,5‐bisphosphate [PtdIns(4,5)P2] and cyclin‐dependent kinase 5 (CDK5), have also been revealed as constituents of NFTs. Flotillin‐1 and PtdIns(4,5)P2 are considered markers of raft microdomains, whereas CDK5 is a tau kinase. Therefore, we hypothesized that NFTs have a relationship with raft domains and the tau phosphorylation that occurs within NFTs. Methods: We investigated six cases of AD, six cases of other neurodegenerative diseases with NFTs and three control cases. We analysed the PtdIns(4,5)P2‐immunopositive material in detail, using super‐resolution microscopy and electron microscopy to elucidate its pattern of expression. We also investigated the spatial relationship between the PtdIns(4,5)P2‐immunopositive material and tau kinases through double immunofluorescence analysis. Results: Pretangles contained either paired helical filaments (PHFs) or PtdIns(4,5)P2‐immunopositive small vesicles (approximately 1 μm in diameter) with nearly identical topology to granulovacuolar degeneration (GVD) bodies. Various combinations of these vesicles and GVD bodies, the latter of which are pathological hallmarks observed within the neurons of AD patients, were found concurrently in neurons. These vesicles and GVD bodies were both immunopositive not only for PtdIns(4,5)P2, but also for several tau kinases such as glycogen synthase kinase‐3β and spleen tyrosine kinase. Conclusions: These observations suggest that clusters of raft‐derived vesicles that resemble GVD bodies are substructures of pretangles other than PHFs. These tau kinase‐bearing vesicles are likely involved in the modification of tau protein and in NFT formation
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