8 research outputs found

    Ontwikkeling epifauna, infauna en kreeften (T0, T1, T2) op een ecologisch aantrekkelijke vooroeverbestorting (Schelphoek, Oosterschelde) : monitoring Building for Nature proefvak Schelphoek

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    Rijkswaterstaat voert vooroeverbestortingen uit op het deel van de dijk dat onder water ligt in de Oosteren Westerschelde. Dit is nodig om de stabiliteit van de dijk en daarmee de waterveiligheid te kunnen blijven garanderen. Eerst werd hierbij alleen op veiligheidsdoelen gelet. Nieuw inzicht is dat je door gebruik van bepaalde materialen ook de natuur kunt faciliteren, dit principe wordt ‘Building for Nature’ genoemd. In 2014 is bij de oostelijke strekdam van locatie Schelphoek in de Oosterschelde een bestorting van zeegrind uitgevoerd. In het oorspronkelijke ontwerp was een basis van staalslakken voorzien, maar bij de uitvoering van het werk is vanwege beperkte beschikbaarheid van staalslakken voor zeegrind gekozen. Op het zeegrind zijn riffen van twee verschillende typen breuksteen gestort: kalksteen en zandsteen. Er is gekozen voor deze aangepaste bestorting om de ecologische meerwaarde van dit ontwerp te kunnen onderzoeken. Doel van dit onderzoek is om de rekolonisatie en ontwikkeling van hardsubstraatsoorten (epifauna) en soorten die leven in het sediment (infauna), en het voorkomen van kreeften op de nieuwe bestorting van kalksteen, zandsteen en zeegrind bij de locatie Schelphoek gedurende twee jaar na bestorting te volgen (T1-2015 en T2-2016) en te vergelijken met de situatie voor bestorten (T0-situatie in 2014)

    Система управління оборотним капіталом підприємства: елементна структура та ефектівність

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    Метою дослідження є створення комплексної сістеми менеджменту оборотним капіталом та забезпечення її ефективного функціонування. В цьому зв’язку необхідно управляти не лише окремими елементами оборотного капіталу, але і всіма бізнес – процесами підприємства з інтегруванням у стратегічне управління. Це зумовлено тим, що систему управління оборотним капіталом не доцільно розглядати відокремлено від всього підприємства, а її варто досліджувати у комплексі з іншими підсистемами

    Genetic complexity of miscanthus cell wall composition and biomass quality for biofuels

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    BACKGROUND: Miscanthus sinensis is a high yielding perennial grass species with great potential as a bioenergy feedstock. One of the challenges that currently impedes commercial cellulosic biofuel production is the technical difficulty to efficiently convert lignocellulosic biomass into biofuel. The development of feedstocks with better biomass quality will improve conversion efficiency and the sustainability of the value-chain. Progress in the genetic improvement of biomass quality may be substantially expedited by the development of genetic markers associated to quality traits, which can be used in a marker-assisted selection program. RESULTS: To this end, a mapping population was developed by crossing two parents of contrasting cell wall composition. The performance of 182 F1 offspring individuals along with the parents was evaluated in a field trial with a randomized block design with three replicates. Plants were phenotyped for cell wall composition and conversion efficiency characters in the second and third growth season after establishment. A new SNP-based genetic map for M. sinensis was built using a genotyping-by-sequencing (GBS) approach, which resulted in 464 short-sequence uniparental markers that formed 16 linkage groups in the male map and 17 linkage groups in the female map. A total of 86 QTLs for a variety of biomass quality characteristics were identified, 20 of which were detected in both growth seasons. Twenty QTLs were directly associated to different conversion efficiency characters. Marker sequences were aligned to the sorghum reference genome to facilitate cross-species comparisons. Analyses revealed that for some traits previously identified QTLs in sorghum occurred in homologous regions on the same chromosome. CONCLUSION: In this work we report for the first time the genetic mapping of cell wall composition and bioconversion traits in the bioenergy crop miscanthus. These results are a first step towards the development of marker-assisted selection programs in miscanthus to improve biomass quality and facilitate its use as feedstock for biofuel production

    The GEOTRACES Intermediate Data Product 2014

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    The GEOTRACES Intermediate Data Product 2014 (IDP2014) is the first publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2013. It consists of two parts: (1) a compilation of digital data for more than 200 trace elements and isotopes (TEIs) as well as classical hydrographic parameters, and (2) the eGEOTRACES Electronic Atlas providing a strongly inter-linked on-line atlas including more than 300 section plots and 90 animated 3D scenes. The IDP2014 covers the Atlantic, Arctic, and Indian oceans, exhibiting highest data density in the Atlantic. The TEI data in the IDP2014 are quality controlled by careful assessment of intercalibration results and multi-laboratory data comparisons at cross-over stations. The digital data are provided in several formats, including ASCII spreadsheet, Excel spreadsheet, netCDF, and Ocean Data View collection. In addition to the actual data values the IDP2014 also contains data quality flags and 1-? data error values where available. Quality flags and error values are useful for data filtering. Metadata about data originators, analytical methods and original publications related to the data are linked to the data in an easily accessible way. The eGEOTRACES Electronic Atlas is the visual representation of the IDP2014 data providing section plots and a new kind of animated 3D scenes. The basin-wide 3D scenes allow for viewing of data from many cruises at the same time, thereby providing quick overviews of large-scale tracer distributions. In addition, the 3D scenes provide geographical and bathymetric context that is crucial for the interpretation and assessment of observed tracer plumes, as well as for making inferences about controlling processes

    Ontwikkeling epifauna, infauna en kreeften (T0, T1, T2) op een ecologisch aantrekkelijke vooroeverbestorting (Schelphoek, Oosterschelde) : monitoring Building for Nature proefvak Schelphoek

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    Rijkswaterstaat voert vooroeverbestortingen uit op het deel van de dijk dat onder water ligt in de Oosteren Westerschelde. Dit is nodig om de stabiliteit van de dijk en daarmee de waterveiligheid te kunnen blijven garanderen. Eerst werd hierbij alleen op veiligheidsdoelen gelet. Nieuw inzicht is dat je door gebruik van bepaalde materialen ook de natuur kunt faciliteren, dit principe wordt ‘Building for Nature’ genoemd. In 2014 is bij de oostelijke strekdam van locatie Schelphoek in de Oosterschelde een bestorting van zeegrind uitgevoerd. In het oorspronkelijke ontwerp was een basis van staalslakken voorzien, maar bij de uitvoering van het werk is vanwege beperkte beschikbaarheid van staalslakken voor zeegrind gekozen. Op het zeegrind zijn riffen van twee verschillende typen breuksteen gestort: kalksteen en zandsteen. Er is gekozen voor deze aangepaste bestorting om de ecologische meerwaarde van dit ontwerp te kunnen onderzoeken. Doel van dit onderzoek is om de rekolonisatie en ontwikkeling van hardsubstraatsoorten (epifauna) en soorten die leven in het sediment (infauna), en het voorkomen van kreeften op de nieuwe bestorting van kalksteen, zandsteen en zeegrind bij de locatie Schelphoek gedurende twee jaar na bestorting te volgen (T1-2015 en T2-2016) en te vergelijken met de situatie voor bestorten (T0-situatie in 2014)

    Systematic Error in Lung Nodule Volumetry:Effect of Iterative Reconstruction Versus Filtered Back Projection at Different CT Parameters

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    OBJECTIVE. Iterative reconstruction potentially can reduce radiation dose compared with filtered back projection (FBP) for chest CT. This is especially important for repeated CT scanning, as is the case in patients with indeterminate lung nodules. It is currently unknown whether absolute nodule volumes measured with iterative reconstruction are comparable to those measured with FBP. We compared nodule volumes measured with iterative reconstruction and FBP at different CT parameters. MATERIALS AND METHODS. An anthropomorphic chest phantom was scanned using a 256-MDCT scanner at various tube voltages and tube current-time products. Raw data were reconstructed using FBP or a commercially available iterative reconstruction algorithm. Five inserted nodules with 100 HU radiodensity and different sizes (3, 5, 8, 10, and 12 mm) were measured by two observers using semiautomatic software. Volumetric nodule measurements were performed using thin-slice reconstructions. RESULTS. For very small nodules (volume, 14.1 mm(3); diameter, 3 mm), FBP and iterative reconstruction measurements exhibited large errors and overestimated the nodule size by up to 160%. For larger nodules (volume, >= 65.4 mm(3); diameter, >= 5 mm), CT underestimated the actual size, but errors were small (within 25%) and remained small when the tube voltage and tube current-time product were reduced, even without iterative reconstruction. CONCLUSION. In a phantom model, no clinically relevant differences beyond reported interscan variation levels between lung nodule volumes were measured in nodules 5 mm or larger at reduced tube voltage and tube current-time product, with radiation dose reductions up to 90.6% for both FBP and iterative reconstruction, suggesting that it is safe to convert FBP protocols to iterative reconstruction and reduce tube voltage and tube current-time product for lung nodule follow-up. CT appears to slightly underestimate actual nodule volume

    A semi-automatic seed point-based method for separation of individual vertebrae in 3D surface meshes: a proof of principle study

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    Purpose The purpose of this paper is to present and validate a new semi-automated 3D surface mesh segmentation approach that optimizes the laborious individual human vertebrae separation in the spinal virtual surgical planning workflow and make a direct accuracy and segmentation time comparison with current standard segmentation method. Methods The proposed semi-automatic method uses the 3D bone surface derived from CT image data for seed point-based 3D mesh partitioning. The accuracy of the proposed method was evaluated on a representative patient dataset. In addition, the influence of the number of used seed points was studied. The investigators analyzed whether there was a reduction in segmentation time when compared to manual segmentation. Surface-to-surface accuracy measurements were applied to assess the concordance with the manual segmentation. Results The results demonstrated a statically significant reduction in segmentation time, while maintaining a high accuracy compared to the manual segmentation. A considerably smaller error was found when increasing the number of seed points. Anatomical regions that include articulating areas tend to show the highest errors, while the posterior laminar surface yielded an almost negligible error. Conclusion A novel seed point initiated surface based segmentation method for the laborious individual human vertebrae separation was presented. This proof-of-principle study demonstrated the accuracy of the proposed method on a clinical CT image dataset and its feasibility for spinal virtual surgical planning applications

    Starlikeness of Libera transformation (II) (Applications of Complex Function Theory to Differential Equations)

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    The GEOTRACES Intermediate Data Product 2017 (IDP2017) is the second publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2016. The IDP2017 includes data from the Atlantic, Pacific, Arctic, Southern and Indian oceans, with about twice the data volume of the previous IDP2014. For the first time, the IDP2017 contains data for a large suite of biogeochemical parameters as well as aerosol and rain data characterising atmospheric trace element and isotope (TEI) sources. The TEI data in the IDP2017 are quality controlled by careful assessment of intercalibration results and multi-laboratory data comparisons at crossover stations. The IDP2017 consists of two parts: (1) a compilation of digital data for more than 450 TEIs as well as standard hydrographic parameters, and (2) the eGEOTRACES Electronic Atlas providing an on-line atlas that includes more than 590 section plots and 130 animated 3D scenes. The digital data are provided in several formats, including ASCII, Excel spreadsheet, netCDF, and Ocean Data View collection. Users can download the full data packages or make their own custom selections with a new on-line data extraction service. In addition to the actual data values, the IDP2017 also contains data quality flags and 1-σ data error values where available. Quality flags and error values are useful for data filtering and for statistical analysis. Metadata about data originators, analytical methods and original publications related to the data are linked in an easily accessible way. The eGEOTRACES Electronic Atlas is the visual representation of the IDP2017 as section plots and rotating 3D scenes. The basin-wide 3D scenes combine data from many cruises and provide quick overviews of large-scale tracer distributions. These 3D scenes provide geographical and bathymetric context that is crucial for the interpretation and assessment of tracer plumes near ocean margins or along ridges. The IDP2017 is the result of a truly international effort involving 326 researchers from 25 countries. This publication provides the critical reference for unpublished data, as well as for studies that make use of a large cross-section of data from the IDP2017. This article is part of a special issue entitled: Conway GEOTRACES - edited by Tim M. Conway, Tristan Horner, Yves Plancherel, and Aridane G. González
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