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ABSTRACT: We consider the pickup and delivery problem with time windows as a general model of the practical transportation problems in automated guided vehicle systems, logistic systems, etc. The problem requires that any paired pickup and delivery locations have to be served by one vehicle and the pickup location has to be scheduled before the corresponding delivery location in the route. In this paper, to search a set of routes close to the optimal one, we propose the autonomous distributed genetic approach based on the search space decomposition for the problem. In this approach, first, the search space is divided into sub-spaces based on the number of customers loaded in each vehicle. Then, GA is applied in each sub-space. In addition, the dynamic separation is applied for an efficient search. The effectiveness of the search space decomposition is evaluated by computational experiments
SICE-ICASE, 2006. International Joint Conference; 11/2006
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ABSTRACT: Three tachykinins, substance P (SP), neurokinin A (NKA), and neurokinin B (NKB), have been isolated from the mammalian nervous system. In accordance with the presence of multiple tachykinins, the existence of multiple tachykinin receptors has been suggested. These receptors differ in binding specificities for different tachykinins. However, it is not known whether these receptors are indeed made of different molecules or whether the same receptor molecule undergoes posttranslational modification at different destination tissues, thereby altering its binding specificity. We examined whether mRNAs isolated from different tissues may synthesize different types of tachykinin receptors in the same expression system. For this purpose, Xenopus oocytes were injected with poly (A)+ RNAs extracted from rat brain or bovine stomach, and their responses to different tachykinins were examined under voltage-clamp. On the basis of potency ranking of 6 tachykinin agonists, the receptor induced by rat brain mRNA was found to correspond to a tachykinin receptor subtype currently classified as the NK-1 (SP-P) receptor, whereas that synthesized by bovine stomach mRNA corresponded to the NK-2 (NK-A) receptor. Thus, each of the 2 receptors can be induced in the same expression system, depending upon the source of exogenous mRNA injected. Therefore, the difference in the nature of the 2 receptors does not seem to be due to the possible posttranslational modification alone. However, the ionic mechanisms underlying activation of the 2 receptors translated in oocytes were similar. It is likely that activation of the 2 receptors uses the same internal mediator in oocytes.
Journal of Neuroscience 11/1987; 7(10):3265-73. · 7.11 Impact Factor
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ABSTRACT: The neuropeptide receptors which are present in very small quantities in the cell and are embedded tightly in the plasma membrane have not been well characterized. Mammals contain three distinct tachykinin neuropeptides, substance P, substance K and neuromedin K, and it has been suggested that there are multiple tachykinin receptors. By electrophysiological measurement, we have previously shown that Xenopus oocytes injected with brain and stomach mRNAs faithfully express mammalian substance-P and substance-K receptors, respectively. Here we report the isolation of the cDNA clone for bovine substance-K receptor (SKR) by extending this method to develop a new cloning strategy. We constructed a stomach cDNA library with a cloning vector that allowed in vitro synthesis of mRNAs and then identified a particular cDNA clone by testing for receptor expression following injection of the mRNAs synthesized in vitro into the oocyte system. Because oocytes injected with exogenous mRNAs can express numerous receptors and channels, our new strategy will be applicable in the general molecular cloning of these proteins. The result provides the first indication that the neuropeptide receptor has sequence similarity with rhodopsin-type receptors (the G-protein-coupled receptor family) and thus possesses multiple membrane-spanning domains.
Nature 329(6142):836-8. · 36.28 Impact Factor
