93 research outputs found

    Semantic annotations on heritage models: 2D/3D approaches and future research challenges

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    Research in the field of Cultural Heritage is increasingly moving towards the creation of digital information systems, in which the geometric representation of an artifact is linked to some external information, through meaningful tags. The process of attributing additional and structured information to various elements in a given digital model is customarily identified with the term semantic annotation; the added contextual information is associated, for instance, to analysis and conservation terms. Starting from the existing literature, aim of this work is to discuss how semantic annotations are used, in digital architectural heritage models, to link the geometrical representation of an artefact with knowledge-related information. Most consolidated methods -such as traditional mapping on 2D media, are compared with more recent approaches making the most of 3D representation. Reference is made, in particular, to Heritage-BIM techniques and to collaborative reality-based platforms, such as Aïoli (http://aioli.cloud). Potentialities and limits of the different solutions proposed in literature are critically discussed, also addressing future research challenges in Cultural Heritage application fields

    From the semantic point cloud to heritage-building information modeling: A semiautomatic approach exploiting machine learning

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    This work presents a semi-automatic approach to the 3D reconstruction of Heritage-Building Information Models from point clouds based on machine learning techniques. The use of digital information systems leveraging on three-dimensional (3D) representations in architectural heritage documentation and analysis is ever increasing. For the creation of such repositories, reality-based surveying techniques, such as photogrammetry and laser scanning, allow the fast collection of reliable digital replicas of the study objects in the form of point clouds. Besides, their output is raw and unstructured, and the transition to intelligible and semantic 3D representations is still a scarcely automated and time-consuming process requiring considerable human intervention. More refined methods for 3D data interpretation of heritage point clouds are therefore sought after. In tackling these issues, the proposed approach relies on (i) the application of machine learning techniques to semantically label 3D heritage data by identification of relevant geometric, radiometric and intensity features, and (ii) the use of the annotated data to streamline the construction of Heritage-Building Information Modeling (H-BIM) systems, where purely geometric information derived from surveying is associated with semantic descriptors on heritage documentation and management. The “Grand-Ducal Cloister” dataset, related to the emblematic case study of the Pisa Charterhouse, is discussed

    Iperparatiroidismo ipercalcemico post-trapianto renale: un problema per il nefrologo

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    Descriviamo un caso di una paziente dializzata, sottoposta a paratiroidectomia pre-trapianto: la PTX non è stata risolutiva per mancato reperimento della IV ghiandola; a 6 mesi dall'intervento si è manifestata, infatti, una recidiva dell'iperparatiroidismo. Nel frattempo si è presentata la possibilità di eseguire un trapianto renale. Nonostante la "recidiva" dell'IPT, è stato deciso di optare per il trapianto renale che è stato effettuato con successo e con recupero precoce della funzione renale: si è manifestato, però, nel post-trapianto, un iperparatiroidismo residuale ipercalcemico. Di fronte al rischio di rendere aparatiroidea la paziente con una nuova PTX, si è optato per una terapia farmacologica. Per 6 anni la paziente trattata con calcitriolo (0,5–0,25 mcg a giorni alterni, con periodiche interruzioni dovute all'ipercalcemia) e difosfonati a cicli, ha mantenuto livelli di calcemia e di paratormone al di sopra dei valori di normalità senza raggiungere livelli di rischio, mentre il VFG si è mantenuto stabilmente nella norma. Nel dicembre 2008 a seguito di una frattura della branca ischio-pubica e per un progressivo incremento nell'ultimo anno dei livelli di calcemia e del PTH viene deciso di iniziare la somministrazione "off label" di Cinacalcet, di sospendere gradualmente lo steroide e di sostituire la ciclosporina con il Tacrolimus. Nei 3 anni di trattamento abbiamo notato, mantenendo costante la dose somministrata di Cinacalcet (30 mg/die), una riduzione significativa e persistente nel tempo dei livelli di calcemia e del PTH e un incremento della fosforemia. La funzione renale è persistita stabile senza episodi di rigetto. Indagini tomodensitometriche ripetute hanno rilevato un quadro di osteopenia sostanzialmente invariato. La nostra singola ma prolungata esperienza conferma in accordo con dati recenti della letteratura e in attesa dei risultati di uno studio RCT attualmente in corso, che questo farmaco può rappresentare una reale alternativa alla PTX mostrando grande efficacia e mancanza di effetti collaterali

    La novella del buon pastore: continuare a raccontarla per non rischiare di dimenticarla

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    Viene descritta una paziente affetta da insufficienza renale rapidamente progressiva. Il caso appare interessante soprattutto perché mette in evidenza come una condizione patologica potenzialmente letale possa manifestarsi nel paziente per lungo tempo in forma oligo-asintomatica, e quindi più facilmente aggredibile se riconosciuta precocemente, prima di manifestarsi in tutta la sua esplosività

    SEMANTIC ANNOTATIONS ON HERITAGE MODELS: 2D/3D APPROACHES AND FUTURE RESEARCH CHALLENGES

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    Abstract. Research in the field of Cultural Heritage is increasingly moving towards the creation of digital information systems, in which the geometric representation of an artifact is linked to some external information, through meaningful tags. The process of attributing additional and structured information to various elements in a given digital model is customarily identified with the term semantic annotation; the added contextual information is associated, for instance, to analysis and conservation terms. Starting from the existing literature, aim of this work is to discuss how semantic annotations are used, in digital architectural heritage models, to link the geometrical representation of an artefact with knowledge-related information. Most consolidated methods -such as traditional mapping on 2D media, are compared with more recent approaches making the most of 3D representation. Reference is made, in particular, to Heritage-BIM techniques and to collaborative reality-based platforms, such as Aïoli (http://aioli.cloud). Potentialities and limits of the different solutions proposed in literature are critically discussed, also addressing future research challenges in Cultural Heritage application fields

    5-fluorouracil modulated by leucovorin, methotrexate and mitomycin: highly effective, low-cost chemotherapy for advanced colorectal cancer

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    We have reported that an alternating regimen of bolus and continuous infusion 5-fluorouracil (FU) was superior to bolus FU in terms of response rate and progression-free survival in advanced colorectal cancer. Biochemical modulation was an essential part of this regimen and it was selective for the schedule of FU administration: bolus FU was in fact modulated by methotrexate (MTX) while continuous infusion FU was potentiated by 6-s-leucovorin (LV). Considering the low cost and the favourable report on the activity of mitomycin C (mito) added to CI FU, we have incorporated this agent in the infusional part of our treatment programme. 105 patients with untreated, advanced, measurable colorectal cancer were accrued from 13 Italian centres and treated with the following regimen. 2 biweekly cycles of FU bolus (600 mg/m2), modulated by MTX (24 h earlier, 200 mg/m2) were alternated with a 3-week continuous infusion of FU (200 mg/m2daily), modulated by LV (20 mg/m2weekly bolus). Mito, 7 mg/m2, was given on the first day of the infusional period. After a 1 week rest, the whole cycle (8 weeks) was repeated, if indicated. 5 complete and 34 partial responses were obtained (response rate, 37% on the intention to treat basis; 95% confidence limits, 28–46%). After a median follow-up time of 26 months, 37 patients are still alive. The median progression-free survival is 7.7 months with an overall survival of 18.8 months and a 2-year survival rate of 30%. The regimen was very well tolerated with fewer than 13% of patients experiencing WHO grade III–IV toxicity. These results are consistent with those obtained by our group in 3 previous trials of schedule specific biochemical modulation of FU. They also indicate a highly active, little toxic, inexpensive regimen of old drugs to be used (a) as an alternative to the more expensive combinations including CPT-11 or oxaliplatin or (b) as the basis for combination programmes with these agents. © 2001 Cancer Research Campaign http://www.bjcancer.co
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