The University of Western Brittany (French: Université de Bretagne-Occidentale; UBO) is a French university, located in Brest, in the Academy of Rennes. On a national scale, in terms of graduate employability, the university oscillates between 18th and 53rd out of 69 universities depending on fields of study. Overall, the University is ranked 12th out of 76 universities in France.
Granitoids and volcanic rocks of hybrid composition between mantle and crustal components are common in various tectonic settings and contribute to both the growth and differentiation of the continental crust. However, the mechanisms by which such hybrid magmas are produced are debated. We focus on a key lower crustal exposure of the Permian Sesia Magmatic System located in the Ivrea-Verbano Zone—IVZ, Italy, allowing to directly investigate the deep roots of a hybrid magmatic system. Integrating multi-scale field observations and bulk-rock data with zircon and apatite petrochronology (U–Pb dating, trace elements, Lu–Hf and Sm–Nd isotopes respectively), we show that lower-crustal orthopyroxene-bearing rocks associated to migmatites in a ‘frozen’ hybridization zone, correspond to hybrid cumulates from which melts were extracted to form upper crustal granitic plutons. Igneous zircon records at least three crystallization stages: (i) initial low-crystallinity hybridization phase at lower-crustal scale; (ii) subsequent chemical differentiation in a mush system, driven by reactive porous flow at the 102–103 m scale; and (iii) final crystallization after significant melt extraction and subsequent, smaller-scale (100–10−1 m) chemical equilibration. Apatite, on the other hand, is fully homogenized at the sample scale but chemical differences between samples preserve the first-order hybridization trends. While crustal-scale differentiation (melt extraction, transfer and cooling) took place in a short time span (ca. 2–4 Ma) as previously suggested in the IVZ, our zircon U–Pb data are permissive of the construction and equilibration of the lower crustal system over a longer period of ca. 15 Myr minimum. Our study also reveals the potential of accessory minerals, in particular zircon, to preserve the successive steps involved in the complex history of the lower crust, even at high temperatures.
Cone-beam computed tomography (CBCT) is a imaging modality widely used in head and neck diagnostics due to its accessibility and lower radiation dose. However, its relatively long acquisition times make it susceptible to patient motion, especially under sparse-view settings used to reduce dose, which can result in severe image artifacts. In this work, we propose a novel framework, joint reconstruction and motion estimation (JRM) with adaptive diffusion model (ADM), that simultaneously addresses motion compensation and sparse-view reconstruction in head CBCT. Leveraging recent advances in diffusion-based generative models, our method integrates a wavelet-domain diffusion prior into an iterative reconstruction pipeline to guide the solution toward anatomically plausible volumes while estimating rigid motion parameters in a blind fashion. We evaluate our method on simulated motion-affected CBCT data derived from real clinical computed tomography (CT) volumes. Experimental results demonstrate that JRM-ADM substantially improves reconstruction quality over traditional model-based and learning-based baselines, particularly in highly undersampled scenarios. Our approach enables motion-robust and low-dose CBCT imaging, paving the way for improved clinical viability.
PURPOSE:Ten years after the first Global Consensus on Keratoconus and Ectatic Diseases, this updated edition revisits key issues, incorporates advances in new technologies, and integrates the expertise of corneal and refractive surgeons from 12 international societies. This initiative aimed to establish a consensus among global ophthalmology experts, including corneal and refractive specialists from 6 continents, on the definition, diagnosis, staging, clinical management, and surgical treatment of keratoconus and ectatic corneal diseases. METHODS:The Delphi method consisted of 4 rounds of questionnaires, supplemented by a face-to-face meeting. A total of 128 ophthalmologists participated, with 3 main coordinators and 125 keratoconus experts distributed across 7 panels: definition/diagnosis/staging, clinical treatment and noninvasive visual rehabilitation, cross-linking for progression, and invasive visual rehabilitation (including therapeutic approaches, improved corrected distance visual acuity, keratoplasty techniques, and cataract surgery in keratoconus). The consensus threshold was defined as at least two-thirds agreement. RESULTS:A significant consensus was reached on topics such as definitions, diagnostic and progression criteria, and management strategies for keratoconus and other ectatic corneal disorders. A comprehensive approach was outlined, encompassing both nonsurgical and surgical treatments, organized in a group-based approach. In addition, major agreements and disagreements across the 7 subcommittees are outlined in individual tables. CONCLUSIONS:This updated Global Consensus provides revised definitions, expert statements, and recommendations for diagnosing and managing keratoconus and other ectatic corneal diseases. It benefits from broader participation, with more refractive surgeons and greater representation from major ophthalmic societies across 6 continents, capturing a wider range of global clinical perspectives than the prior report.
Many papers refer in a revised way to the two-step scenario of the Messinian Crisis conceived by Clauzon et al. (1996). The present paper recalls the basis for the two-step scenario and discrepancies with the later modified version, completed by new data supported by extensive micropaleontological analyses. Our interpretation of the Sicilian Eraclea Minoa section as belonging to a peripheral basin is the centre of the debate. We show the great amplitude of fluvial erosion during the peak of the crisis, which for the Rhône River, exceeded 400 km upstream of the present shoreline. Based on dinoflagellate cysts, we also recall the reasons for supporting the occurrence of three successive Lago Mare episodes of two different origins. The first and third episodes constitute phases of high sea-level exchanges between the Mediterranean and the Paratethys respectively just before the onset of paroxysm and after it. The second episode is due to overflowing Paratethyan waters from the Aegean Basin just before the end of paroxysm. Similarly, the demonstration of the marine reflooding of the Mediterranean Basin prior to the Zanclean is repeated. We emphasize dissimilarity between basins, focussing in particular on those, isolated or perched ones, which were continuously filled by waters during the desiccation phase: western part of the Alboran Sea and southeastern part of the Levantine Basin (marine waters), Apennine Foredeep (fresh waters), and Aegean Basin (brackish waters). The Apennine Foredeep cannot be the reference for the entire Mediterranean with respect to its evolution during the crisis. During the crisis, water exchanges between the Aegean Basin and the Eastern Paratethys (Dacic Basin, Black Sea) were impossible through the Marmara region because of the development of two opposed fluvial networks. Such exchanges existed thanks to a gateway that was probably located within the Balkans. Investigations around the Levantine Basin point to areas submitted to fluvial erosion during the crisis paroxysm and nearby areas, which might have received marine waters from the Red Sea. Much information is still to be discovered and that more progress is still needed in order to fully decipher this outstanding event.
This paper explores the problem of the paving of the union of adjacent contractors. The focus is first put on the analysis of the topology of a set operator, which can be stable or not stable. Then, depending on the stability of the union operator, solutions are proposed to avoid fake boundaries in stable and non-stable union of sets. For stable unions of sets, a boundary preserving form will be developed to add a set overlapping the fake boundary in the expression of the union, whereas for non-stable union of sets, a boundary approach will be developed to avoid fake boundaries. Some problem-specific solutions are also developed to avoid fake boundaries. As an example, an enhancement of the separator on the visibility constraint is proposed. This avoids fake boundaries while characterizing the set of non-visible points from an observation point relative to a polygon.
