234 research outputs found

    The effect of light intensity and temperature on berry growth and sugar accumulation in Vitis vinifera 'Shiraz' under vineyard conditions

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    Temperature and light are key climatic factors which affect grapevine physiology in the growing season. Our aim was to investigate the interactive effects of temperature and light intensity on reproductive growth responses of 'Shiraz' vines in vineyard conditions. Well-watered vines were covered with no shade, light, medium and heavy shade covers in a vineyard over three consecutive seasons. Several heat events, i.e., air temperatures exceeding 40 °C for several days, occurred in two of the seasons. Heavy shade reduced canopy temperatures by 3.2-6 °C in the cooler season and by 4-6 °C in the warmer seasons, relative to air temperature and compared with the open canopy. The onset of berry growth was delayed by the heavy shade but the rate of sugar accumulation was not affected. During the season with the most severe heat events, berry dry matter accumulation was significantly higher in the shaded treatments compared to the unshaded vines. The hypothesis was confirmed that medium and heavy shade conferred high levels of protection on the berry ripening process from high summer temperatures and the concurrent exposure to light intensities

    Towards relating delivery methods and examination success: lessons learned from the VALO LLP project case study

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    Didactic, teacher-centred approaches and rote learning have long been discredited and gradually replaced by participative, interactive and creative learning sessions. Formal classroom sessions are being replaced or augmented by self-directed study increasingly in distance mode. The evolution and affordability of technologies enables massive participation in studies, not only for short training for professional updating but also for longer study periods and attainment of qualifications. The rapid changes in society and technology demand that everybody continuously updates their knowledge and skills in their area of expertise and gain knowledge, skills and competencies in other areas for a successful life of careers and not necessarily a career for life as was the norm in the past. It is important to safeguard the quality of independent assessment and certification methods. In this paper we consider the main delivery methods and their impact on assessment methods and associated results. With reference to the ECQA framework and the recently completed EU co-funded Lifelong Learning Programme project VALO we juxtapose the delivery methods used and the examination results at different partner institutions. We extract observed issues and trends, which could be principles to be adopted by future projects with regards to process improvement and performance enhancement

    Refinement of the taxonomic structure of 16SrXI and 16SrXIV phytoplasmas of gramineous plants using multilocus sequence typing

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    Phytoplasmas that infect gramineous plants, including Napier grass stunt, sugarcane whiteleaf, sugarcane grassy shoot, and Bermuda grass whiteleaf, have been classified into two closely related groups, 16SrXI and 16SrXIV, based on the 16S ribosomal RNA (rRNA) gene. Subsequently, phytoplasmas associated with coconut and Areca palm in southern India and Sri Lanka have been added into the 16SrXI group. However, the 16S rRNA gene gives relatively poor resolution between these phytoplasmas. In this study, a new set of universal phytoplasma primers that amplify approximately 1 kb of the leucyl transfer RNA synthetase (leuS) gene have been validated on a broad range of phytoplasma taxonomic groups. These have been used along with partial sequences of the secA gene to clarify the taxonomic classification of 16SrXI and 16SrXIV phytoplasmas. Based on this data, the sugarcane whiteleaf and grassy shoot phytoplasmas appear to be the same phytoplasma. The Napier grass stunt phytoplasma forms a distinct group from the Bermuda grass whiteleaf and sugarcane phytoplasmas, suggesting that Napier grass stunt should be in its own ‘Candidatus Phytoplasma sp.’. The phytoplasmas associated with coconut and arecanut in southern India and Sri Lanka, which are in the same 16SrXI group, appear in different groups based on secA analysis

    Investigation of shock waves in explosive blasts using fibre optic pressure sensors

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    The published version of this article may be accessed at the link below. Copyright @ IOP Publishing, 2006.We describe miniature all-optical pressure sensors, fabricated by wafer etching techniques, less than 1 mm(2) in overall cross-section with rise times in the mu s regime and pressure ranges typically 900 kPa (9 bar). Their performance is suitable for experimental studies of the pressure-time history for test models exposed to shocks initiated by an explosive charge. The small size and fast response of the sensors promises higher quality data than has been previously available from conventional electrical sensors, with potential improvements to numerical models of blast effects. Results from blast tests are presented in which up to six sensors were multiplexed, embedded within test models in a range of orientations relative to the shock front.Support from the UK Engineering&Physical Sciences Research Council and Dstl Fort Halstead through the MoD Joint Grants Scheme are acknowledged. WN MacPherson is supported by an EPSRC Advanced Research Fellowship

    Patterns of dominant flows in the world trade web

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    The large-scale organization of the world economies is exhibiting increasingly levels of local heterogeneity and global interdependency. Understanding the relation between local and global features calls for analytical tools able to uncover the global emerging organization of the international trade network. Here we analyze the world network of bilateral trade imbalances and characterize its overall flux organization, unraveling local and global high-flux pathways that define the backbone of the trade system. We develop a general procedure capable to progressively filter out in a consistent and quantitative way the dominant trade channels. This procedure is completely general and can be applied to any weighted network to detect the underlying structure of transport flows. The trade fluxes properties of the world trade web determines a ranking of trade partnerships that highlights global interdependencies, providing information not accessible by simple local analysis. The present work provides new quantitative tools for a dynamical approach to the propagation of economic crises

    IMPACT OF LAND USE CHANGES THE CATCHMENT ON THE QUALITY AND QUANT1TY OF WATER IN THE RAJANGANA RESERVOIR

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    The condition of the watershed plays an important role in the quality and quantity of thewater of reservoirs. Among the factors, which affect the health of a watershed, areclimate, geology and land use management. Rajangana watershed drains water to theRajangana reservoir, which irrigates about 5520 ha in the dry zone.In the present study, total monthly inflows to the reservoir were calculated through awater balance study and water inflows from the catchments were obtained through asensitivity analysis using past records. Land use changes were studied by using existingland use maps (1: 50,000) using GIS software. Some water quality parameters in thereservoir waters were analysed. These parameters were compared with the ones takenduring the past 10 years from past records of the MASL in order to identify any trendswith the changes of rainfall, temperature, land use etc.The results showed that the annual total water inflow and also the inflow during the dryseason decreased with time. These trends correlated with the increase in built up areas,reduction of forest cover. Further, there was a marked increase of the pH and alkalinity inthe waters with time

    Application of remote sensing and GIS techniques for exploring construction material from inaccessible terrains; case study in Eastern Province of Sri Lanka

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    Demand for construction materials in the North and Eastern provinces of Sri Lanka has risen significantly due to accelerated construction work in progress to restore the destroyed infrastructures during the civil war. Ground surveying methods to locate quarries within this area are not applicable due to security reasons and the larger area to be covered. Thus a Remote Sensing method is suitable for this task. This study introduces a methodology to locate suitable quarries and sand mines for constructions in the Eastern province. LANDSAT ETM+ images were used for classification. Feasible rocks and sand deposits for quarry operations were located using Multicriteria Analysis (AHP).The highly suitable rock quarries and sand deposits were considered in closest facility analysis. The results showed that the integration of Remote Sensing (RS) and Geographic Information System (GIS) can serve as an effective tool in demarcating suitable sites for construction material and this methodology can also be applied for projects of similar nature

    The International-Trade Network: Gravity Equations and Topological Properties

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    This paper begins to explore the determinants of the topological properties of the international - trade network (ITN). We fit bilateral-trade flows using a standard gravity equation to build a "residual" ITN where trade-link weights are depurated from geographical distance, size, border effects, trade agreements, and so on. We then compare the topological properties of the original and residual ITNs. We find that the residual ITN displays, unlike the original one, marked signatures of a complex system, and is characterized by a very different topological architecture. Whereas the original ITN is geographically clustered and organized around a few large-sized hubs, the residual ITN displays many small-sized but trade-oriented countries that, independently of their geographical position, either play the role of local hubs or attract large and rich countries in relatively complex trade-interaction patterns
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