28 research outputs found
Combination of 3D Scanning, Modeling and Analyzing Methods around the Castle of Coatfrec Reconstitution
International audienceThe castle of Coatfrec is a medieval castle in Brittany constituting merely a few remaining ruins currently in the process of restoration. Beyond its great archeological interest, it has become, over the course of the last few years, the subject of experimentation in digital archeology. Methods of 3D scanning were implored in order to gauge comparisons between the remaining structures and their absent hypothetical ones, resulting in the first quantitative results of its kind. This paper seeks to introduce the methods which carried out said research, as well as to present the subsequent results obtained using these new digital tools
Clinically Meaningful <scp>Magnetic Resonance</scp> Endpoints Sensitive to Preataxic Spinocerebellar Ataxia Types <scp>1</scp> and <scp>3</scp>
International audienceObjective: This study was undertaken to identify magnetic resonance (MR) metrics that are most sensitive to early changes in the brain in spinocerebellar ataxia type 1 (SCA1) and type 3 (SCA3) using an advanced multimodal MR imaging (MRI) protocol in the multisite trial setting. Methods: SCA1 or SCA3 mutation carriers and controls (n = 107) underwent MR scanning in the US-European READISCA study to obtain structural, diffusion MRI, and MR spectroscopy data using an advanced protocol at 3T. Morphometric, microstructural, and neurochemical metrics were analyzed blinded to diagnosis and compared between preataxic SCA (n = 11 SCA1, n = 28 SCA3), ataxic SCA (n = 14 SCA1, n = 37 SCA3), and control (n = 17) groups using nonparametric testing accounting for multiple comparisons. MR metrics that were most sensitive to preataxic abnormalities were identified using receiver operating characteristic (ROC) analyses
A complete processing chain for ship detection using optical satellite imagery
International audienceShip detection from remote sensing imagery is a crucial application for maritime security, which includes among others traffic surveillance, protection against illegal fisheries, oil discharge control and sea pollution monitoring. In the framework of a European integrated project Global Monitoring for Environment and Security (GMES) Security/Land and Sea Integrated Monitoring for European Security (LIMES), we developed an operational ship detection algorithm using high spatial resolution optical imagery to complement existing regulations, in particular the fishing control system. The automatic detection model is based on statistical meth- ods, mathematical morphology and other signal-processing techniques such as the wavelet analysis and Radon transform. This article presents current progress made on the detection model and describes the prototype designed to classify small targets. The prototype was tested on panchromatic Satellite Pour l'Observation de la Terre (SPOT) 5 imagery taking into account the environmental and fishing context in French Guiana. In terms of automatic detection of small ship targets, the proposed algorithm performs well. Its advantages are manifold: it is simple and robust, but most of all, it is efficient and fast, which is a crucial point in performance evaluation of advanced ship detection strategies
Natura 2000 forest habitats: climatic debt in lowlands and thermophilization in highlands
International audienceNatura 2000 is a European network of sites dedicated to the conservation of vulnerable habitats. The definitions of Natura 2000 habitats are mainly based on plant communities. We investigated if the increase of the dominance of warm-adapted species observed in plant communities, described as thermophilization, had already led to measurable changes in Natura 2000 forest habitats. We created 5701 pairs of neighboring forest plots by gathering plots surveyed before 1987 and after 1997 to reflect historical and recent climatic conditions. A Natura 2000 habitat type was assigned to each vegetation plot using an automatic classification program. We calculated a temperature index that synthesized the temperature range of each habitat, and compared the habitat temperature indexes of the recent and historical plots of each pair. We highlighted a significant overall shift of 4.8% ± 1.78 (CI 95%) of the pairs toward warmer habitats over the studied period. While the shift was not significant in lowlands, 11.1% ± 3.0 (CI 95%) of the pairs evolved toward warmer habitats in highlands. The excess of pairs with a warmer habitat in the recent period was interpreted as thermophilization of Natura 2000 forest habitats. Therefore, global warming has been strong enough to induce actual changes at the coarse-grained habitat resolution specifically targeted by public policies. The absence of significant results in lowlands suggests the existence of unrealized potential habitat changes, which can be considered as a climatic debt. These results call for differential prioritization levels and implementations of public policies for nature conservation in lowlands and highlands
Ceramics Fragments Digitization by Photogrammetry, Reconstructions and Applications
International audienceThis paper presents an application of photogrammetry on ceramic fragments from two excavation sites located north-west of France. The restitution by photogrammetry of these different fragments allowed reconstructions of the potteries in their original state or at least to get to as close as possible. We used the 3D reconstructions to compute some metrics and to generate a presentation support by using a 3D printer. This work is based on affordable tools and illustrates how 3D technologies can be quite easily integrated in archaeology process with limited financial resources. 1. INTRODUCTION Today, photogrammetry and 3D modelling are an integral part of the methods used in archeology and heritage management. They provide answers to scientific needs in the fields of conservation, preservation, restoration and mediation of architectural, archaeological and cultural heritage [2] [6] [7] [9]. Photogrammetry on ceramic fragments was one of the first applications contemporary of the development of this technique applied in the archaeological community [3]. More recently and due to its democratization, it was applied more generally to artifacts [5]. Finally joined today by the rise of 3D printing [8] [10], it can restore fragmented artifacts [1] [12]. These examples target one or several particular objects and use different types of equipment that can be expensive. These aspects can put off uninitiated archaeologists. So it would be appropriate to see if these techniques could be generalized to a whole class of geometrically simple and common artifacts, such as ceramics. From these observations, associated to ceramics specialists with fragments of broken ceramics, we aimed at arranging different tools and methods, including photogrammetry, to explore opportunities for a cheap and attainable reconstruction methodology and its possible applications. Our first objective was to establish a protocol for scanning fragments with photogrammetry, and for reconstruction of original ceramics. We used the digital reconstitutions of the ceramics we got following our process to calculate some metrics and to design and 3D print a display for the remaining fragments of one pottery
Ceramics Fragments Digitization by Photogrammetry, Reconstructions and Applications
International audienceThis paper presents an application of photogrammetry on ceramic fragments from two excavation sites located north-west of France. The restitution by photogrammetry of these different fragments allowed reconstructions of the potteries in their original state or at least to get to as close as possible. We used the 3D reconstructions to compute some metrics and to generate a presentation support by using a 3D printer. This work is based on affordable tools and illustrates how 3D technologies can be quite easily integrated in archaeology process with limited financial resources. 1. INTRODUCTION Today, photogrammetry and 3D modelling are an integral part of the methods used in archeology and heritage management. They provide answers to scientific needs in the fields of conservation, preservation, restoration and mediation of architectural, archaeological and cultural heritage [2] [6] [7] [9]. Photogrammetry on ceramic fragments was one of the first applications contemporary of the development of this technique applied in the archaeological community [3]. More recently and due to its democratization, it was applied more generally to artifacts [5]. Finally joined today by the rise of 3D printing [8] [10], it can restore fragmented artifacts [1] [12]. These examples target one or several particular objects and use different types of equipment that can be expensive. These aspects can put off uninitiated archaeologists. So it would be appropriate to see if these techniques could be generalized to a whole class of geometrically simple and common artifacts, such as ceramics. From these observations, associated to ceramics specialists with fragments of broken ceramics, we aimed at arranging different tools and methods, including photogrammetry, to explore opportunities for a cheap and attainable reconstruction methodology and its possible applications. Our first objective was to establish a protocol for scanning fragments with photogrammetry, and for reconstruction of original ceramics. We used the digital reconstitutions of the ceramics we got following our process to calculate some metrics and to design and 3D print a display for the remaining fragments of one pottery
Ceramics Fragments Digitization by Photogrammetry, Reconstructions and Applications
International audienceThis paper presents an application of photogrammetry on ceramic fragments from two excavation sites located north-west of France. The restitution by photogrammetry of these different fragments allowed reconstructions of the potteries in their original state or at least to get to as close as possible. We used the 3D reconstructions to compute some metrics and to generate a presentation support by using a 3D printer. This work is based on affordable tools and illustrates how 3D technologies can be quite easily integrated in archaeology process with limited financial resources. 1. INTRODUCTION Today, photogrammetry and 3D modelling are an integral part of the methods used in archeology and heritage management. They provide answers to scientific needs in the fields of conservation, preservation, restoration and mediation of architectural, archaeological and cultural heritage [2] [6] [7] [9]. Photogrammetry on ceramic fragments was one of the first applications contemporary of the development of this technique applied in the archaeological community [3]. More recently and due to its democratization, it was applied more generally to artifacts [5]. Finally joined today by the rise of 3D printing [8] [10], it can restore fragmented artifacts [1] [12]. These examples target one or several particular objects and use different types of equipment that can be expensive. These aspects can put off uninitiated archaeologists. So it would be appropriate to see if these techniques could be generalized to a whole class of geometrically simple and common artifacts, such as ceramics. From these observations, associated to ceramics specialists with fragments of broken ceramics, we aimed at arranging different tools and methods, including photogrammetry, to explore opportunities for a cheap and attainable reconstruction methodology and its possible applications. Our first objective was to establish a protocol for scanning fragments with photogrammetry, and for reconstruction of original ceramics. We used the digital reconstitutions of the ceramics we got following our process to calculate some metrics and to design and 3D print a display for the remaining fragments of one pottery
Photogrammetry Based Study of Ceramics Fragments
International audienceReconstitution of whole ceramics from fragments is a true priesthood for ceramographers. This activity remains mainly handled by manual sketching and can be very time consuming. However, more and more tools and workflows provide digital solutions, based on 3D technologies, to assist such tasks. In this paper, we present an application of photogrammetry on ceramic fragments from two excavation sites located in Brittany, France. This study was required by two ceramics specialists and conducted in CReAAH, a French research center in archaeology, archaeosciences and history. The 3D restitution by photogrammetry of these different fragments allowed reconstructions of the original shapes of the potteries or at least to get to as close as possible. We furthermore used the resulting 3D models of the ceramics to compute various metrics required by the ceramographers. In collaboration with IRISA, a French research center in computer science, we designed and generated a presentation support using a 3D printer. This work is based on affordable tools and illustrates how 3D technologies can be quite easily integrated in archaeology process with limited financial resources, to obtain useful results for the study and analysis of such artefacts
Plasma neurofilament light chain predicts cerebellar atrophy and clinical progression in spinocerebellar ataxia
International audienceNeurofilament light chain (NfL) is a marker of brain atrophy and predictor of disease progression in rare diseases such as Huntington Disease, but also in more common neurological disorders such as Alzheimer's disease. The aim of this study was to measure NfL longitudinally in autosomal dominant spinocerebellar ataxias (SCAs) and establish correlation with clinical and imaging parameters. We enrolled 62 pathological expansions carriers (17 SCA1, 13 SCA2, 19 SCA3, and 13 SCA7) and 19 age-matched controls in a prospective biomarker study between 2011 and 2015 and followed for 24 months at the Paris Brain Institute. We performed neurological examination, brain 3 T MRI and plasma NfL measurements using an ultrasensitive single-molecule array at baseline and at the two-year follow-up visit. We evaluated NfL correlations with ages, CAG repeat sizes, clinical scores and volumetric brain MRIs. NfL levels were significantly higher in SCAs than controls at both time points (p < 0.001). Age-adjusted NfL levels were significantly correlated at baseline with clinical scores (p < 0.01). We identified optimal NfL cutoff concentrations to differentiate controls from carriers for each genotype (SCA1 16.87 pg/mL, SCA2, 19.1 pg/mL, SCA3 16.04 pg/mL, SCA7 16.67 pg/mL). For all SCAs, NfL concentration was stable over two years (p = 0.95) despite a clinical progression (p < 0.0001). Clinical progression between baseline and follow-up was associated with higher NfL concentrations at baseline (p = 0.04). Of note, all premanifest carriers with NfL levels close to cut off concentrations had signs of the disease at follow-up. For all SCAs, the higher the observed NfL, the lower the pons volume at baseline (p < 0.01) and follow-up (p = 0.02). Higher NfL levels at baseline in all SCAs predicted a decrease in cerebellar volume (p = 0.03). This result remained significant for SCA2 only among all genotypes (p = 0.02). Overall, plasma NfL levels at baseline in SCA expansion carriers predict cerebellar volume change and clinical score progression. NfL levels might help refine inclusion criteria for clinical trials in carriers with very subtle signs
Disability and colonialism : (dis)encounters and anxious intersectionalities
This special issue sets out to position disability within the colonial (the real and imagined), as it explores a range of (often anxious) intesectionalities as disability is theorised, constructed, and lived as a post/neocolonial condition. The issue emerged from serious and pressing concerns from disability and other scholars engaged in a dialogical praxis that seeks to critically explore, interrogate and challenge a series of epistemic,
ontological and practical negligences. Much of this work has occurred at the margins of various disciplines and projects, in particular the intersections of disability studies and postcolonial theory, intersections that continue to be marked by ambivalence. Disability theorists who have traversed this path have mooted that, too often, disability is drawn upon as a metaphor by (post)colonial theorists, while for disability theorists, colonisation has become a key metaphor to describe experiences of oppression, marginalisation and
exclusion to which disabled people are often subjected (Barker & Murray, 2010; Sherry, 2007). This process of conflation within either field has denied the 'necessary recognition of an uneven biopolitical incorporation' (McRuer, 2010, p. 171), while the spatial, historical, temporal and geopolitical factors that emerged to govern bodies-and-minds in differential ways, are confined to silence (Soldatic & Grech, 2014)