7,383 research outputs found

    Evaluation of Aglianico grape skin and seed polyphenols astringency by SDS-PAGE electrophoresis of salivary proteins after the binding reaction

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    SDS–PAGE electrophoresis and densitometry analysis were carried out to evaluate the reactivity of Aglianico red grape skin and seed polyphenols with human salivary proteins in order to find a method able to assess their astringency. Analysis of the supernatant obtained after a tannin/human salivary protein binding assay and sensorial analysis showed that four proteins, lactoferrin, PRPbg1, PRPbg2 and a-amylase, were the proteins best able to distinguish tannin solutions characterised by different levels of astringency. A correlation between densitometric data and tannin concentration was plotted in order to give an indirect measure of astringency. The two sources of Aglianico grape polyphenols differed from each other in astringency power; the seed extract solution was about two-fold more tannic than the skin one. The difference in astringency was also perceived by sensorial analysis. The results from this study show that SDS–PAGE electrophoresis of human salivary proteins after the binding reaction with grape polyphenol extracts, coupled with densitometric analysis and the use of a calibration curve, looks extremely promising as a new approach to evaluate polyphenol astringency

    Cheating and the evolutionary stability of mutualisms

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    Interspecific mutualisms have been playing a central role in the functioning of all ecosystems since the early history of life. Yet the theory of coevolution of mutualists is virtually nonexistent, by contrast with well-developed coevolutionary theories of competition, predator–prey and host–parasite interactions. This has prevented resolution of a basic puzzle posed by mutualisms: their persistence in spite of apparent evolutionary instability. The selective advantage of 'cheating', that is, reaping mutualistic benefits while providing fewer commodities to the partner species, is commonly believed to erode a mutualistic interaction, leading to its dissolution or reciprocal extinction. However, recent empirical findings indicate that stable associations of mutualists and cheaters have existed over long evolutionary periods. Here, we show that asymmetrical competition within species for the commodities offered by mutualistic partners provides a simple and testable ecological mechanism that can account for the long-term persistence of mutualisms. Cheating, in effect, establishes a background against which better mutualists can display any competitive superiority. This can lead to the coexistence and divergence of mutualist and cheater phenotypes, as well as to the coexistence of ecologically similar, but unrelated mutualists and cheaters

    Analisis Perkembangan Produksi Perikanan Budidaya di Kabupaten Rokan Hulu Provinsi Riau

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    The Research on Analysis of Aquaculture Production Development wasconducted in 31 May – 16 June 2014 at Rokan Hulu Regency of Riau Province.The aims of the study were to determine the aquaculture resource potentialthrough the production development analysis, includes the effect of theaquaculture production and also production estimate for the next five years. Themethod used in this study is a Survey Research Development to view theproduction progress each year to support district development.The result showed that the progress of aquaculture production increasedannually with average of 25% per year, and the impact of aquaculture toproduction about 80,8 %, as well as production estimate for 5 years

    Brane World in a Topological Black Hole Bulk

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    We consider a static brane in the background of a topological black hole, in arbitrary dimensions. For hyperbolic horizons, we find a solution only when the black hole mass assumes its minimum negative value. In this case, the tension of the brane vanishes, and the brane position coincides with the location of the horizon. For an elliptic horizon, we show that the massless mode of Randall-Sundrum is recovered in the limit of large black hole mass.Comment: Latex, 8 pages, v2: Additional references, to appear in MPL

    Exploiting exciton-exciton interactions in semiconductor quantum dots for quantum-information processing

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    We propose an all-optical implementation of quantum-information processing in semiconductor quantum dots, where electron-hole excitations (excitons) serve as the computational degrees of freedom (qubits). We show that the strong dot confinement leads to an overall enhancement of Coulomb correlations and to a strong renormalization of the excitonic states, which can be exploited for performing conditional and unconditional qubit operations.Comment: 5 pages revtex, 2 encapsulated postscript figures. Accepted for publication in Phys. Rev. B (Rapid Communication

    Analisis Kapasitas Drainase Jalan BTN Lago Permai Kota Pangkalan Kerinci Kabupaten Pelalawan

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    The effect of residential areas development in the city of Pangkalan Kerinci causing a land conversion thus, increasing of surface waters flow due to rain. Surface runoff caused a flood inundation in Jalan Permai BTN Lago. Therefore we need an analyz to reduce flood inundation by analyzing the capacity of drainage channels ranging from the most upstream channel to the final disposal site gas pipeline passing through the country. The existing drainage channels compared with the discharge channel plan with return period of 5 years. Results of comparative analysis is 17.48% drainage channel had width modified (b), 35.92% had modified the width (b) and height (h), 44.66% of drainage channels are not modified, and 1.94% are the new channel. The most downstream channel passes through a gas pipeline that takes cross-sectional modification into reservoir. It required help of a pump for pumping water from the reservoir into the exhaust channel / outlet. reservoir accept 5.63 m3 / sec discharge for the return period of 5 years. Modified existing drainage channels into reservoir withsize (2m x 5m x 230m) using a pump with a capacity of 5 m3 / sec

    On the Analysis of a Wave Energy Farm with Focus on Maintenance Operations

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    Wave energy has a promising technical potential that could contribute to the future energy mix. However, costs related to the deployment of wave energy converters (WECs) are still high compared to other technologies. In order to reduce these costs, two principle options are available, a reduction in cost and an increase in productivity. This paper presents a reliability-based computational tool to identify typical decision problems and to shed light on the complexity of optimising a wave power farm. The proposed tool is used to investigate productivity and availability of a wave energy farm during 10 years of operational life. A number of optimization possibilities to improve productivity, namely vessel choice, maintenance regime, failure rate and component redundancy, are then explored in order to assess their effectiveness. The paper quantifies the yield increase and provides a practical approach to evaluate the effectiveness of strategic and operational decision options. Results, in terms of the variations in productivity and availability of the farm, are analysed and discussed. Conclusions highlight the importance of reliability-centred simulations that consider the specific decision parameters throughout the operational life to find suitable solutions that increase the productivity and reduce the running cost for offshore farms.The work in this paper has been conducted within the multinational Initial Training Network (ITN) OceaNET, funded under the PEOPLE Programme (Marie Curie Actions) of European Union’s FP7. Mojo Maritime have provided access to Mermaid to support, and for integration with, this research

    A decision support model to optimise the operation and maintenance strategies of an offshore renewable energy farm

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    This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.In order to accelerate the access into the energy market for ocean renewables, the operation and maintenance (O & M) costs for these technologies must be reduced. In this paper a reliability-based simulation tool for the optimization of the management of an offshore renewable energy (ORE) farm is presented. The proposed tool takes into account the reliability data of the simulated devices and estimations on the energy produced to create a series of results in terms of availability and maintainability of the farm. The information produced supports operational and strategic decision making regarding the O & M for offshore farms. A case study simulating a conceptual tidal energy project, consisting of an array of two tidal turbines located off the north coast of Scotland, is presented to show some of the results achievable with this model. The proposed methodology, although ado pted for a tidal farm here, is generally applicable to other kinds of ORE farms.This research has been conducted within the multinational Initial Training Network (ITN) OceaNET, funded under the People Programme (Marie Curie Actions) of the European Union's Seventh Framework ProgrammeFP7/2007-2013/under REA grant agreement no 607656. Mojo Maritime have provided access to Mermaid to support, and for integration with, this research

    The O&M driven design of a multi-row platform tidal project

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    This is the author accepted manuscript. The final version is available from EWTEC via the link in this recordA number of tidal projects with different design, sizes and conceptual approaches, have been developed in recent years. While the technology has proven to be effective in converting tidal streams into electric energy, the economic viability is still far from being achieved due to unforeseen complications following the installation of the devices. In this paper, the authors provide an overview of the major challenges tidal energy developers should consider in order to design a viable tidal energy device. In addition, based on past field experiences, the typical issues encountered by offshore contractors during the deployment of one or an array of devices are presented. Therefore, paying special attention to the operational requirements of the devices, the solutions to these offshore challenges are proposed. Hence, a novel tidal concept is presented, using lifecycle O&M costs as a top driver for the development of the device. Subsequently, the iterative improvement of the project is achieved by means of a verified and calibrated integrated framework, based on Monte Carlo simulation and evolutionary algorithms, in order to support the decision-making process and management of the assets. Thus, the pivotal role of computational tools to improve the profitability of the project while ensuring satisfactory levels of availability and reliability is highlighted, and the potential for cost reduction in the design of a tidal energy project, in order to achieve financial viability, is shown.European Regional Development Fund (ERDF

    Some Biological Aspects of Freshwater Lobsters, Cherax Quadricarinatus, in Ralik River of Southeast Minahasa and in Tondano Lake of Minahasa

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    Hasil yang didapat dari penelitian ini yakni persamaan linier hubungan panjang berat di sungai untuk jantan W = -1,761049+ 3.1153 log L, dan W = -1,647836 + 2,957268 log L untuk betina; di danau W = -1,494 + 2,8495 log L untuk jantan dan betina W = -1,388 + 2,7198 log L. Pola pertumbuhan lobster jantan dan betina di sungai dan jantan di danau adalah isometrik; sedangkan betina di danau allometrik. Nilai faktor kondisi biologis lobster jantan sungai berkisar antara 0,90-1,14 dengan nilai rata- rata 1,004±0,06, sedangkan lobster jantan danau berkisar antara 0,83-1,23 dengan nilai rata-rata 1,004±0,09. Nilai faktor kondisi lobster betina sungai berkisar antara 0.82-1.18 dengan nilai rata-rata 1,004±0,89 dan lobster betina danau berkisar antara 0,90-1,11 dengan nilai rata-rata 1,001±0,06. Hal ini menunjukkan bahwa kondisi badan lobster cukup baik
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