2,684 research outputs found

    A Dynamic CGE Model: An Application of R&D- Based Endogenous Growth Model Theory

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    An R&D based endogenous growth - applied general equilibrium model is developed from an underlying analytical model which combines Romer's capital variety with Grossman and Helpman's multi-sector open economy model. The transitional dynamics of the analytical model are derived. For numerical implementation, a time discrete empirical model, with an Armington structure, is fit to East Asian data of the social accounting matrix variety. Simulations of trade reform are performed and their static and dynamic effects compared. The transition paths of the state variables are found to have a half-life of five to six periods. A solution of the Social Planner's problem, and interventions which seek to obtain this outcome from the decentralized model are also obtained'.Applied General Equilibrium, Trade, Growth, International Relations/Trade, F11, 031, 041,

    MACRO-MICRO FEEDBACK LINKS OF IRRIGATION WATER MANAGEMENT IN TURKEY

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    Agricultural production is heavily dependent on water availability in Turkey, where half the crop production relies on irrigation. Irrigated agriculture consumes about 75 percent of total water used, which is about 30 percent of renewable water availability. This study analyzes the likely effects of increased competition for water resources and changes in the Turkish economy. The analysis uses an economy-wide Walrasian Computable General Equilibrium model with a detailed account of the agricultural sector. The study investigated the economy-wide effects of two external shocks, namely a permanent increase in the world prices of agricultural commodities and climate change, along with the impact of the domestic reallocation of water between agricultural and non-agricultural uses. It was also recognized that because of spatial heterogeneity of the climate, the simulated scenarios have differential impact on the agricultural production and hence on the allocation of factors of production including water. The greatest effects on major macroeconomic indicators occur in the climate change simulations. As a result of the transfer of water from rural to urban areas, overall production of all crops declines. Although production on rainfed land increases, production on irrigated land declines, most notably the production of maize and fruits. The decrease in agricultural production, coupled with the domestic price increase, is further reflected in net trade. Agricultural imports increase with a greater decline in agricultural exports.Computable General Equilibrium; Feedback links; Irrigation Water; Turkey

    Determination of Chemical Constituents of the Marine Pulmonate Slug, Paraoncidium reevesii

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    Purpose: To isolate and identify the chemical components of Paraoncidium reevesii.Methods: Silica gel column chromatography was used to isolate the components from petroleum ether and ethyl acetate fractions of the acetone extract, and the structures of the compounds were derived from 1H-nuclear magnetic resonance (1H-NMR), 13C-nuclear magnetic resonance (13C-NMR) and mass spectrometry (MS) analyses and also with the aid of literature data for authenticated samples.Results: Cholesterol (1), baconipyrone D (2), chimyl alcohol (3), batyl alcohol (4), á-monpalmitin (5), stearic acid (6), 3-indolecarboxylic acid (7), uracil (8), thymine (9), uridine (10), thymidine (11) were isolated from the marine slug (Paraoncidium reevesii).Conclusion: All the isolated compounds are being reported here for Paraoncidium reevesii for the first time. The results provide base data for further study of the Onchidiidae as a Chinese traditional remedy for asthma and athlete’s foot.Keywords: Mollusk, Paraoncidium reevesii, Baconipyrone D, Batyl alcohol, Chimyl alcohol Onchidiidae, Marine Pulmonate, Slug, Asthma, Athlete’s foo

    Expression of Caveolin-1 in tongue squamous cell carcinoma by quantum dots

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    Quantum dots (QDs) are a new class of fluorescent probes to detect biomarker expression. The role of caveolin-1 (Cav-1) in tongue squamous cell carcinoma (TSCC) is still unknown. This study aimed to investigate the expression profile of Cav-1 in carcinogenesis and development of TSCC by QDs immunofluorescence histochemistry (QDs-IHC) and discuss the relationship between the Cav-1 expression and the clinicopathological outcomes. QDs-IHC was used to detect Cav-1 expression in tissue microarrays including normal tongue mucosa (NTM; n=10), hyperplastic tongue mucosa (HTM; n=10), tongue pre-cancer lesions (TPL; n=15) and primary tongue squamous cell carcinoma (PTSCC; n=61). Correlations between the Cav-1 expression and clinicopathologic variables were evaluated statistically. Cells positive for Cav-1 were clearly detected and bright images were obtained in a fine, granular pattern at the cell membrane and cytoplasm using QDs-IHC. The rate of Cav-1 immunoreactivity increased progressively from NTM (0%), HTM (0%), TPL (36%) to PTSCC (74%). When compared with each other, there was statistical significance among PTSCC, TPL and NTM as well as among PTSCC, TPL and HTM. Moreover, Cav-1 expression level in PTSCC was correlated positively with clinical stage and histologic grade. QDs-IHC could accurately detect protein location in tongue mucosa. An increased expression of Cav-1 in the stepwise carcinogenesis from NTM, HTM, TPL to PTSCC suggested that Cav-1 might be an oncogene in the development of tongue squamous cell carcinoma

    Plug-and-play genetic access to drosophila cell types using exchangeable exon cassettes.

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    Genetically encoded effectors are important tools for probing cellular function in living animals, but improved methods for directing their expression to specific cell types are required. Here, we introduce a simple, versatile method for achieving cell-type-specific expression of transgenes that leverages the untapped potential of "coding introns" (i.e., introns between coding exons). Our method couples the expression of a transgene to that of a native gene expressed in the cells of interest using intronically inserted "plug-and-play" cassettes (called "Trojan exons") that carry a splice acceptor site followed by the coding sequences of T2A peptide and an effector transgene. We demonstrate the efficacy of this approach in Drosophila using lines containing suitable MiMIC (Minos-mediated integration cassette) transposons and a palette of Trojan exons capable of expressing a range of commonly used transcription factors. We also introduce an exchangeable, MiMIC-like Trojan exon construct that can be targeted to coding introns using the Crispr/Cas system.This work was supported by the Intramural Research Program of the National Institute of Mental Health (B.H.W.) and by grants from the Whitehall Foundation (C.J.P.), NIH (R01DC013070, C.J.P.), the Wellcome Trust (H.I. and M.L.), and the Sir Isaac Newton Trust, Cambridge (M.L.). J.E. was supported by FONDECYT #1141278 and the CINV, which is supported by the Millennium Scientific Initiative of the Ministerio de Economía, Fomento y Turismo. We thank the Bellen laboratory and the Drosophila Gene Disruption Project at Baylor College of Medicine, the Bloomington Stock Center (NIH P40OD018537), and Julie Simpson for fly lines. Thanks also to Aaron DiAntonio, Aaron Hsueh, and John Reinitz for antibodies and the NINDS Sequencing Core Facility for DNA sequencing. Finally, thanks to Sarah Naylor for technical help and Grace Gray, Herman Dierick, Koen Venken, and Hugo Bellen for comments on the manuscript and productive discussions.This is the final published version. It first appeared at http://www.ncbi.nlm.nih.gov/pubmed/25732830

    The effect of calcium nitrate on the hydration of calcium aluminate cement at different curing temperatures

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    Phase conversion in calcium aluminate cements (CAC) induces significant volumetric instability; it would result in an increase in porosity and decrease in strength in CAC. In this study, calcium nitrate (CN) as a phase conversion inhibitor, the effect of CN on the hydration of CAC at different curing temperatures was studied. Xray diffraction, thermal analysis, SEM, isothermal calorimetry and the compressive strength were conducted on the CAC dosages of 0%, 5%, 10% and 15%CN cured at 20�, 30�, 40� and 50�. The results show CN can retard CAC hydration, alter the characters of the hydrates of CAC systems and avoid the conversion process. With increasing dosage of CN and curing temperature, the hydration products formed is different.in CAC systems with CN, NO3-AFm and NO3-AFt are more preferred than CAH10 and C2AH8 and are more thermostable than those typically hydrates. In the presence of CN, The phase conversion to a large extent can be avoided and the compressive strength is significantly improved. The CN dosage has a very important effect on CAC systems with CN. In this study, the optimum dosage for CN is 10 percent. This study may provide a new insight into avoiding the unstable phase conversion in calcium aluminate cements

    Cooperative inter-vehicle communication protocol with low cost differential GPS

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    This paper describes a cooperative MANET protocol dedicated to intelligent transport systems, named CIVIC (Communication Inter Véhicule Intelligente et Coopérative). The CIVIC protocol is an auto-configuration inter-vehicle communication protocol, which supports adhoc and infrastructure networks, contains reactive and proactive routing components, and adapts different wireless standards. It is a context-aware protocol reacting to vehicle status, road traffic, and geographic environment. It supports location-based communication. To improve the accuracy of GPS, it integrates a localization solution called LCD-GPS (Low Cost Differential GPS). It has been implemented and experimented on the LiveNode sensor developed by our lab. At the end of this paper, an application project MobiPlus is introduced

    Local control of intestinal stem cell homeostasis by enteroendocrine cells in the adult <i>Drosophila</i> midgut

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    Background: Enteroendocrine cells populate gastrointestinal tissues and are known to translate local cues into systemic responses through the release of hormones into the bloodstream.&lt;p&gt;&lt;/p&gt; Results: Here we report a novel function of enteroendocrine cells acting as local regulators of intestinal stem cell (ISC) proliferation through modulation of the mesenchymal stem cell niche in the &lt;i&gt;Drosophila&lt;/i&gt; midgut. This paracrine signaling acts to constrain ISC proliferation within the epithelial compartment. Mechanistically, midgut enteroendocrine cells secrete the neuroendocrine hormone Bursicon, which acts—beyond its known roles in development—as a paracrine factor on the visceral muscle (VM). Bursicon binding to its receptor, DLGR2, the ortholog of mammalian leucine-rich repeat-containing G protein-coupled receptors (LGR4-6), represses the production of the VM-derived EGF-like growth factor Vein through activation of cAMP.&lt;p&gt;&lt;/p&gt; Conclusions: We therefore identify a novel paradigm in the regulation of ISC quiescence involving the conserved ligand/receptor Bursicon/DLGR2 and a previously unrecognized tissue-intrinsic role of enteroendocrine cells.&lt;p&gt;&lt;/p&gt
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