207 research outputs found
The Quadratic Shortest Path Problem and its Genetic Algorithm
The quadratic shortest path (QSP) problem is to find a path from a node to another node in a given network such that the total cost includes two kinds of costs, say direct cost and interactive cost, is minimum. The direct cost is the cost associated with each arc and the interactive cost occurs when two arcs appear simultaneously in the shortest path. In this paper, the concept of the quadratic shortest path is initialized firstly. Then a spanning tree-based genetic algorithm is designed for solving the quadratic shortest path problem. Finally, a numerical example is given
Politeness Strategies of Chinese in A Talk Show “If You Are The One”
Based on discourse of a Chinese talk show, this study aims to test and verify Brown & Levinson’s (hereafter B&L) theory of politeness. Politeness is culture specific, and in this respect, the term of “face” provides more evidence. Adopting descriptive text analysis, this study analysed the transcriptions of a popular Chinese TV show If You Are the One on a rhetorical level in the context of Chinese culture. The present study reveals that politeness strategies are prevalent in If You Are the One, with the majority of them being positive politeness strategies, which contradict with B&L’s claim that people tend to select negative politeness as their preference, while bald on-record and off-record ones occurring rarely among the texts. The result shows that B&L’s politeness model provides us directions about the affecting elements of Chinese interaction on its validity. Under positive politeness, the author added three subcategories, namely speaking, “approbation of L”, “showing gratitude”, and “saving face for L”. The original typology presented by B&L may reflect a western cultural bias, but necessitating validation efforts for each culture is research worthy. Chinese peculiar culture contributes a lot to the result, which hints a further research in the future
Demonstration of Functional Coupling between Dopamine Synthesis and Its Packaging into Synaptic Vesicles
Demonstration of functional coupling between dopamine synthesis and its packaging into synaptic vesicles
This is the publisher's version, also available electronically from "http://link.springer.com".We have previously shown that the membrane-associated form of the GABA-synthesizing enzyme, glutamate decarboxylase 65 (GAD65), is activated by synaptic vesicle proton gradient-mediated protein phosphorylation. We now report that the rate-limiting enzyme in dopamine (DA) biosynthesis, tyrosine hydroxylase (TH), is regulated similarly to GAD65. The membrane-associated form of TH (MTH) was activated by conditions favoring protein phosphorylation (e.g. ATP) and was inhibited by phosphatase (e.g. calf intestine phosphatase). Furthermore, the ATP-mediated activation of MTH was abolished by conditions that disrupted the proton gradient of synaptic vesicles, e.g. the presence of carbonyl cyanidem-chorophenylhydrazone, gramicidin, or the V-type ATPase inhibitor (bafilomycin), but not the P-type ATPase inhibitor (vanadate). Moreover, DA newly synthesized from tyrosine by MTH and membrane-associated aromatic amino acid decarboxylase was taken up preferentially rather than pre-existing DA. Therefore, the previously proposed model showing close coupling between GABA synthesis and GABA packaging into synaptic vesicles by vesicular GABA transporters is also applicable to the DA system. Hence, it is concluded that there is a general coupling mechanism between neurotransmitter synthesis and packaging of transmitter into synaptic vesicles
Stellar Parameters of Main Sequence Turn-off Star Candidates Observed with the LAMOST and Kepler
Main sequence turn-off (MSTO) stars have advantages as indicators of Galactic
evolution since their ages could be robustly estimated from atmospheric
parameters. Hundreds of thousands of MSTO stars have been selected from the
LAMOST Galactic sur- vey to study the evolution of the Galaxy, and it is vital
to derive accurate stellar parameters. In this work, we select 150 MSTO star
candidates from the MSTO stars sample of Xiang that have asteroseismic
parameters and determine accurate stellar parameters for these stars combing
the asteroseismic parameters deduced from the Kepler photometry and atmospheric
parameters deduced from the LAMOST spectra.With this sample, we examine the age
deter- mination as well as the contamination rate of the MSTO stars sample. A
comparison of age between this work and Xiang shows a mean difference of 0.53
Gyr (7%) and a dispersion of 2.71 Gyr (28%). The results show that 79 of the
candidates are MSTO stars, while the others are contaminations from either main
sequence or sub-giant stars. The contamination rate for the oldest stars is
much higher than that for the younger stars. The main cause for the high
contamination rate is found to be the relatively large systematic bias in the
LAMOST surface gravity estimates.Comment: accepted by RA
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