28 research outputs found

    The demand for hydrographic surveyors in the Benelux

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    In February 2015, the Hydrographic Society Benelux (HSB) sent an extended questionnaire to 77 of the most important hydrographic companies in the Benelux (Belgium, The Netherlands and Luxemburg). The organization of this questioning was in cooperation with the Department of Geography of Ghent University (Belgium). The purpose was to inquire the demand for hydrographic surveyors during the next 5 years in the Benelux. The Benelux is hosting the four biggest dredging companies in the world, so the demand for hydrographic surveyors is usually fairly high and a good parameter for the general demand in the West of Europe. On the one hand, the aim of the questionnaire was to research the demand for the preferred level of hydrographic surveyor, allowing a concise estimation of the demand for IHO category-A and category-B certified hydrographic surveyors. On the other hand, the required balance between hydrographic surveyors with a Bachelor versus Master degree was questioned. As a similar questionnaire and analysis has been performed in 2009, trends over the past 6 years can be discerned and analyzed. The results are important, not only for the private companies, but also for the higher education institutes. In the Benelux, but also outside the Benelux, one can find hydrographic institutes delivering cat. A and cat. B. IHO certified hydrographic surveyors, combined or not with a Bachelor and/or Master diploma. It is generally assumed that there is a shortage of hydrographic surveyors and/or of hydrographical educated employees in the Benelux. Currently, part of the active hydrographic surveyors in the Benelux are engineers, geologists and other non-specifically hydrographic trained people, who received additional bathymetric trining within private companies. But does this hypothesis withstands a scientific analysis? This will be critically analyzed in this paper

    Towards cost-efficient prospection and 3D visualization of underwater structures using compact ROVs

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    The deployment of Remotely Operated Vehicles (ROV) for underwater prospection and 3D visualization has grown significantly in civil applications for a few decades. The demand for a wide range of optical and physical parameters of underwater environments is explained by an increasing complexity of the monitoring requirements of these environments. The prospection of engineering constructions (e.g. quay walls or enclosure doors) and underwater heritage (e.g. wrecks or sunken structures) heavily relies on ROV systems. Furthermore, ROVs offer a very flexible platform to measure the chemical content of the water. The biggest bottleneck of currently available ROVs is the cost of the systems. This constrains the availability of ROVs to a limited number of companies and institutes. Fortunately, as with the recent introduction of cost-efficient Unmanned Aerial Vehicles on the consumer market, a parallel development is expected for ROVs. The ability to participate in this new field of expertise by building Do It Yourself (DIY) kits and by adapting and adding on-demand features to the platform will increase the range of this new technology. In this paper, the construction of a DIY OpenROV kit and its implementation in bathymetric research projects are elaborated. The original platform contains a modified webcam for visual underwater prospection and a Micro ElectroMechanical System (MEMS) based depth sensor, allowing relative positioning. However, the performance of the standard camera is limited and an absolute positioning system is absent. It is expected that 3D visualizations with conventional photogrammetric qualities are limited with the current system. Therefore, modifications to improve the standard platform are foreseen, allowing the development of a cost-efficient underwater platform. Preliminary results and expectations on these challenges are reported in this paper

    Applied surveying education : documenting cultural heritage in 3D in the city of Ghent (Belgium) using laser scanning and photo modelling

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    For several years the city of Ghent (Belgium) and the Ghent University, Department of Geography have been working together to document and measure important cultural heritage sites in 3D. The partnership enables master students in Geomatics and Surveying at the Ghent University to take part in a project driven measuring campaign. During the project, students use and compare several 3D data acquisition methods. This allows the students to implement their theoretical knowledge in the field. The used methods are analysed and critically compared by the students. Through this hands-on-training, students are encouraged to think ‚Äúoutside the box‚ÄĚ. When problems occur, they are stimulated to think how these problems could have happened and most importantly how they can solve them. The documentation of these historic monuments in Ghent will be used during future renovation works and archaeological research. This paper will discuss the measurements in the Ghent City Museum (Stadsmuseum or STAM). The following methods are applied during the extensive field work: engineering surveying using total station and GNSS, photo modelling and laser scanning. The deliverables are created in a CAD or GIS environment. After successful completion of the course, students have gained a significant expertise concerning the processing of topographic data, 3D point clouds and imagery in an integrated way. This knowledge can be used after their studies to assess which equipment is most suitable for any given survey project. The final products of the photo modelling and the laser scanning process is a 3D model. Furthermore, digital elevation models and orthorectified images of the historic monument can be created. The orthorectified images are visualised and processed into high resolution orthophoto plans, in a CAD or GIS environment

    Using 3D modelling in the Valley or Turu Alty (Siberia, Russia) for research and conservational purposes

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    [EN] Since 1999 the Department of Archeology and the Department of Geography of Ghent University undertake field surveys to the Altai Region in Siberia, Russia. This region is a very important archaeological heritage area in the world. Scattered throughout the region are hundreds of frozen tombs, ritual monuments and petroglyphs. Research of these relics helps to understand the life of Eurasian nomads in the 4th century BC. Even more important, due to upcoming touristic activities and climate change, the documentation of the frozen tombs is imperative. A traditional archaeological survey consists out of a basic description, a drawing, one or two pictures and the GNSS location of each monument. With support of the department of Geography several topographical maps are created based on satellite images (IKONOS, Pleiades) and measurement of Ground Control Points (GCP) on site. Furthermore, since 2012 the use of 3D realistic photo modelling is being applied to survey the monuments in higher detail. The method of photo modelling proves to be successful and cost-effective. Besides their high detail, the almost real-life virtual representation of the monuments makes these techniques less abstract than a traditional archaeological survey. During the field campaigns in the summer of 2014 and 2015 this method was implied to record hundreds of monuments in the valley of Turu Alty (Siberia, Russia). Using 3D modelling software the models are created to document the monuments and petroglyphs of the study area for research and conservational purposes.Vandenbulcke, A.; Stal, C.; Lonneville, B.; Bourgeois, J.; De Wulf, A. (2016). Using 3D modelling in the Valley or Turu Alty (Siberia, Russia) for research and conservational purposes. En 8th International congress on archaeology, computer graphics, cultural heritage and innovation. Editorial Universitat Politècnica de València. 408-411. https://doi.org/10.4995/arqueologica8.2015.3787OCS40841

    BUILDING A VIRTUAL TIME MACHINE FOR THE ANCIENT RUINS OF JIAOHE

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    [EN] The goal of this work in progress is the virtual 3D reconstruction of one of the temples of the Ancient Ruins of Jiaohe (China). This site, considered as one of the key locations on the Silk Road, is slowly deteriorating due to erosion and human activity. One of its buildings, the Northwest Small Temple, was partially reconstructed as part of the Master plan for preservation and restoration as proposed by the UNESCO/Japan Trust Fund. Furthermore, a replica of the temple was built at the site entrance. The UNESCO master plan serves as the starting point for the 3D reconstruction, which is performed in three phases. The first phase comprises an initial 3D reconstruction of the temple based on floor plans and sections, and the placement of this reconstruction in a low-resolution 3D model of Jiaohe. The second phase consists of a field campaign at the site, in order to acquire the necessary data to complement the initial reconstruction: a high-resolution 3D model of the current state of the Northwest Small Temple, 3D models of the statues inside the replica of the temple and imagery of the murals inside the replica. After combining the data from phase one and two, a 3D model of the Northwest Small Temple, completed with textures and statues inside, will be placed on a 3D model of its surroundings. This final 3D model will then be made available to a broad audience as a virtual time machine, allowing the visitors to both experience the site as it is today, as the way it used to be at the peak of the site’s civilisation.Lonneville, B.; Vanhaeren, N.; Vandenbulcke, A.; De Wulf, A.; De Maeyer, P. (2016). BUILDING A VIRTUAL TIME MACHINE FOR THE ANCIENT RUINS OF JIAOHE. En 8th International congress on archaeology, computer graphics, cultural heritage and innovation. Editorial Universitat Politècnica de València. 400-403. https://doi.org/10.4995/arqueologica8.2015.3741OCS40040

    DEVELOPMENT OF AN EFFICIENT APPROACH OF ARCHAEOLOGICAL HERITAGE IN THE INTERTIDAL ZONE OF THE BELGIAN NORTH SEA

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    [EN] The knowledge of the submerged cultural heritage in the North Sea is rather limited. The Belgian North Sea is being used for a lot of different purposes, such as fishing, aggregate extraction, wind farms, dredging, etc. Due to these increasing economic activities, the underwater archive is in danger. In the context of the UNESCO Convention on the Protection of the Underwater Cultural Heritage of 2001, gathering more information about the submerged cultural heritage in the intertidal zones of the North Sea is one of the main objectives of the Belgian scientific project ‚ÄėSeArch‚Äô. It will give a clearer picture of the broader cultural and archaeological heritage in the region and it can be used as a basis for a sustainable management by government agencies. The Department of Geography (Ghent University, Belgium) contributes to the SeArch project in two ways. First, an innovative survey methodology has been developed which allows an accurate and cost-efficient evaluation of the archaeological potential in the intertidal zones of the Belgian beaches. Secondly, the Department of Geography is developing an interactive webGIS platform, which makes it possible to share, integrate and visualize the gathered archaeological and environmental data and information in a user-friendly way. Hereby, the total potential of this project is fully exploited in a time-efficient manner. To create an interactive webGIS platform, a good structured spatial database is needed. It enables manipulation of a wide variety of georeferenced information in both raster and vector formats. This paper provides more information about the configuration and application of the spatial database. Moreover, it focusses on the development of a fully functional Spatial Data Infrastructure (SDI) using the most reliable, powerful and state-of-the-art technological components. Besides, a new way of collecting geomatic data in a fast and accurate manner will be discussed. Some processing results will show the possibilities for detecting and visualizing underground structures and archaeological objects.Decock, M.; Stal, C.; Van Ackere, S.; Vandenbulcke, A.; De Maeyer, P.; De Wulf, A. (2016). DEVELOPMENT OF AN EFFICIENT APPROACH OF ARCHAEOLOGICAL HERITAGE IN THE INTERTIDAL ZONE OF THE BELGIAN NORTH SEA. En 8th International congress on archaeology, computer graphics, cultural heritage and innovation. Editorial Universitat Polit√®cnica de Val√®ncia. 138-145. https://doi.org/10.4995/arqueologica8.2015.3554OCS13814

    LATE-NC aggravates GVD-mediated necroptosis in Alzheimer's disease

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    It has become evident that Alzheimer's Disease (AD) is not only linked to its hallmark lesions-amyloid plaques and neurofibrillary tangles (NFTs)-but also to other co-occurring pathologies. This may lead to synergistic effects of the respective cellular and molecular players, resulting in neuronal death. One of these co-pathologies is the accumulation of phosphorylated transactive-response DNA binding protein 43 (pTDP-43) as neuronal cytoplasmic inclusions, currently considered to represent limbic-predominant age-related TDP-43 encephalopathy neuropathological changes (LATE-NC), in up to 70% of symptomatic AD cases. Granulovacuolar degeneration (GVD) is another AD co-pathology, which also contains TDP-43 and other AD-related proteins. Recently, we found that all proteins required for necroptosis execution, a previously defined programmed form of neuronal cell death, are present in GVD, such as the phosphorylated necroptosis executioner mixed-lineage kinase domain-like protein (pMLKL). Accordingly, this protein is a reliable marker for GVD lesions, similar to other known GVD proteins. Importantly, it is not yet known whether the presence of LATE-NC in symptomatic AD cases is associated with necroptosis pathway activation, presumably contributing to neuron loss by cell death execution. In this study, we investigated the impact of LATE-NC on the severity of necroptosis-associated GVD lesions, phosphorylated tau (pTau) pathology and neuronal density. First, we used 230 human post-mortem cases, including 82 controls without AD neuropathological changes (non-ADNC), 81 non-demented cases with ADNC, i.e.: pathologically-defined preclinical AD (p-preAD) and 67 demented cases with ADNC. We found that Braak NFT stage and LATE-NC stage were good predictors for GVD expansion and neuronal loss in the hippocampal CA1 region. Further, we compared the impact of TDP-43 accumulation on hippocampal expression of pMLKL-positive GVD, pTau as well as on neuronal density in a subset of nine non-ADNC controls, ten symptomatic AD cases with (ADTDP+) and eight without LATE-NC (ADTDP-). Here, we observed increased levels of pMLKL-positive, GVD-exhibiting neurons in ADTDP+ cases, compared to ADTDP- and controls, which was accompanied by augmented pTau pathology. Neuronal loss in the CA1 region was increased in ADTDP+ compared to ADTDP- cases. These data suggest that co-morbid LATE-NC in AD impacts not only pTau pathology but also GVD-mediated necroptosis pathway activation, which results in an accelerated neuronal demise. This further highlights the cumulative and synergistic effects of comorbid pathologies leading to neuronal loss in AD. Accordingly, protection against necroptotic neuronal death appears to be a promising therapeutic option for AD and LATE

    Rare mutations in SQSTM1 modify susceptibility to frontotemporal lobar degeneration

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    Mutations in the gene coding for Sequestosome 1 (SQSTM1) have been genetically associated with amyotrophic lateral sclerosis (ALS) and Paget disease of bone. In the present study, we analyzed the SQSTM1 coding sequence for mutations in an extended cohort of 1,808 patients with frontotemporal lobar degeneration (FTLD), ascertained within the European Early-Onset Dementia consortium. As control dataset, we sequenced 1,625 European control individuals and analyzed whole-exome sequence data of 2,274 German individuals (total n = 3,899). Association of rare SQSTM1 mutations was calculated in a meta-analysis of 4,332 FTLD and 10,240 control alleles. We identified 25 coding variants in FTLD patients of which 10 have not been described. Fifteen mutations were absent in the control individuals (carrier frequency < 0.00026) whilst the others were rare in both patients and control individuals. When pooling all variants with a minor allele frequency < 0.01, an overall frequency of 3.2 % was calculated in patients. Rare variant association analysis between patients and controls showed no difference over the whole protein, but suggested that rare mutations clustering in the UBA domain of SQSTM1 may influence disease susceptibility by doubling the risk for FTLD (RR = 2.18 [95 % CI 1.24-3.85]; corrected p value = 0.042). Detailed histopathology demonstrated that mutations in SQSTM1 associate with widespread neuronal and glial phospho-TDP-43 pathology. With this study, we provide further evidence for a putative role of rare mutations in SQSTM1 in the genetic etiology of FTLD and showed that, comparable to other FTLD/ALS genes, SQSTM1 mutations are associated with TDP-43 pathology
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