417 research outputs found
Influence of initiators on the tipping point in the extended Watts model
In this paper, we study how the influence of initiators (seeds) affects the
tipping point of information cascades in networks. We consider an extended
version of the Watts model, in which each node is either active (i.e., having
adopted an innovation) or inactive. In this extended model, the adoption
threshold, defined as the fraction of active neighbors required for an inactive
node to become active, depends on whether the node is a seed neighbor (i.e.,
connected to one or more initiators) or an ordinary node (i.e., not connected
to any initiators). Using the tree approximation on random graphs, we determine
the tipping point, at which the fraction of active nodes in the final state
increases discontinuously with an increasing seed fraction. The occurrence of a
tipping point and the scale of cascades depend on two factors: whether a giant
component of seed neighbors is formed when the seed fraction is large enough to
trigger cascades among seed neighbors, and whether the giant component of
ordinary nodes is maintained when newly activated nodes trigger further
activations among ordinary nodes. The coexistence of two giant components
suggests that a tipping point can appear twice. We present an example
demonstrating the existence of two tipping points when there is a gap between
the adoption thresholds of seed neighbors and ordinary nodes. Monte Carlo
simulations clearly show that the first cascade, occurring at a small tipping
point, occurs in the giant component of seed neighbors, while the second
cascade, occurring at a larger tipping point, extends into the giant component
of ordinary nodes.Comment: 10 pages, 5 figure
Content-Based Instruction (CBI) for the Social Future: A Recommendation for Critical Content-Based Language Instruction (CCBI)
In this article, we seek to reconceptualize content-based instruction (CBI) curricula and practices from a critical perspective. Further, we propose developing criticality as an essential component of CBI, advocating for an approach we call critical content-based instruction (CCBI). While the importance of CBI has long been recognized, previous discussions predominantly focused on its effectiveness for language learning (and content learning to a lesser degree), and overlooked its fundamental linkage and relevance to broader educational missions. In order to fully maximize the potential of CBI and envision language education as integral to the advancement of society, we argue that a critical approach to CBI should be considered. First, we lay out how CBI came to be and how it has been treated in language pedagogy. We believe CBI is indeed a suitable forum for introducing and implementing a critical perspective because of its original contribution of broadening language education to meet societal needs. Second, we provide an overview of recent discourse surrounding world language education. Based on these reviews, we lastly and most importantly delineate directions for CCBI by presenting examples and possible challenges
A RecA-mediated exon profiling method
We have developed a RecA-mediated simple, rapid and scalable method for identifying novel alternatively spliced full-length cDNA candidates. This method is based on the principle that RecA proteins allow to carry radioisotope-labeled probe DNAs to their homologous sequences, resulting in forming triplexes. The resulting complex is easily detected by mobility difference on electrophoresis. We applied this exon profiling method to four selected mouse genes as a feasibility study. To design probes for detection, the information on known exonic regions was extracted from public database, RefSeq. Concerning the potentially transcribed novel exonic regions, RNA mapping experiment using Affymetrix tiling array was performed. As a result, we were able to identify alternative splice variants of Thioredoxin domain containing 5, Interleukin1β, Interleukin 1 family 6 and glutamine-rich hypothetical protein. In addition, full-length sequencing demonstrated that our method could profile exon structures with >90% accuracy. This reliable method can allow us to screen novel splice variants from a huge number of cDNA clone set effectively
Discovery of the Pigtail Molecular Cloud in the Galactic Center
This paper reports the discovery of a helical molecular cloud in the central
molecular zone (CMZ) of our Galaxy. This "pigtail" molecular cloud appears at
(l, b, V_LSR) ~ (-0.7deg, +0.0deg, -70 to -30 km/s), with a spatial size of ~
(20 pc)^2 and a mass of (2-6) 10^5 solar masses. This is the third helical
gaseous nebula found in the Galactic center region to date. Line intensity
ratios indicate that the pigtail molecular cloud has slightly higher
temperature and/or density than the other normal clouds in the CMZ. We also
found a high-velocity wing emission near the footpoint of this cloud. We
propose a formation model of the pigtail molecular cloud. It might be
associated with a magnetic tube that is twisted and coiled because of the
interaction between clouds in the innermost x_1 orbit and ones in the outermost
x_2 orbit.Comment: 15 pages, 6 figures, accepted for publication in Astrophysical
Journa
A Study on Assessment of Physical Activity in Workers
In this study, we calculated physical activity scores, according to the time spent and energy expenditure in daily life. The subjects were 290 volunteers who were 53 students of the University, and 237 workers. Examinations were made twice at an interval of about 6 months in a test-retest examination. Physical activity scores were calculated from the life activity index of the "Japanese Nutritive Requirement". The amount of energy expenditure was calculated from the time spent, and base metabolism during activity of each subject. The physical activity scores obtained in the test and retest examinations showed a high correlation (r=0.86), confirming our recently developed questionnaire's ability to yield reproducible results. Our results show no sex difference in energy expenditure and Japanese Nutritive Requirement. Therefore, the method of calculation of energy expended per day (according to physical activity score) is highly objective and great deal of confidence can be placed in it
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