111 research outputs found

    Fisheye Photogrammetry to Survey Narrow Spaces in Architecture and a Hypogea Environment

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    Nowadays, the increasing computation power of commercial grade processors has actively led to a vast spreading of image-based reconstruction software as well as its application in different disciplines. As a result, new frontiers regarding the use of photogrammetry in a vast range of investigation activities are being explored. This paper investigates the implementation of fisheye lenses in non-classical survey activities along with the related problematics. Fisheye lenses are outstanding because of their large field of view. This characteristic alone can be a game changer in reducing the amount of data required, thus speeding up the photogrammetric process when needed. Although they come at a cost, field of view (FOV), speed and manoeuvrability are key to the success of those optics as shown by two of the presented case studies: the survey of a very narrow spiral staircase located in the Duomo di Milano and the survey of a very narrow hypogea structure in Rome. A third case study, which deals with low-cost sensors, shows the metric evaluation of a commercial spherical camera equipped with fisheye lenses

    Minimal auxiliary basis set for time-dependent density functional theory and comparison with tight-binding approximations: Application to silver nanoparticles

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    The modeling of optical spectra of plasmonic nanoparticles via first-principles approaches is computationally expensive; thus, methods with high accuracy/computational cost ratio are required. Here, we show that the Time-Dependent Density Functional Theory (TDDFT) approach can be strongly simplified if only one s-type function per atom is employed in the auxiliary basis set, with a properly optimized exponent. This approach (named TDDFT-as, for auxiliary s-type) predicts excitation energies for silver nanoparticles with different sizes and shapes with an average error of only 12 meV compared to reference TDDFT calculations. The TDDFT-as approach resembles tight-binding approximation schemes for the linear-response treatment, but for the atomic transition charges, which are here computed exactly (i.e., without approximation from population analysis). We found that the exact computation of the atomic transition charges strongly improves the absorption spectra in a wide energy range

    an application of cosmo sky med to coastal erosion studies

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    AbstractStarted in 2009, the COSMOCoast project aims to the investigation of the potential of Remote Sensing in support to the management of coastal areas. Particular attention is paid to the contribution of data acquired from the COSMO-SkyMed constellation, in view of their frequency of acquisitions and ground resolution; in particular this paper aims at assessing the potential of COSMO-SkyMed data for coastline delineation. The results are conceived to be of particular interest for public administration bodies in charge of coastal defense. Keywords: Remote Sensing, Coastal Zones Management, COSMO-SkyMed

    Surgical Models of Liver Regeneration in Pigs. A Practical Review of the Literature for Researchers

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    The remarkable capacity of regeneration of the liver is well known, although the involved mechanisms are far from being understood. Furthermore, limits concerning the residual functional mass of the liver remain critical in both fields of hepatic resection and transplantation. The aim of the present study was to review the surgical experiments regarding liver regeneration in pigs to promote experimental methodological standardization. The Pubmed, Medline, Scopus, and Cochrane Library databases were searched. Studies evaluating liver regeneration through surgical experiments performed on pigs were included. A total of 139 titles were screened, and 41 articles were included in the study, with 689 pigs in total. A total of 29 studies (71% of all) had a survival design, with an average study duration of 13 days. Overall, 36 studies (88%) considered partial hepatectomy, of which four were an associating liver partition and portal vein ligation for staged hepatectomy (ALPPS). Remnant liver volume ranged from 10% to 60%. Only 2 studies considered a hepatotoxic pre-treatment, while 25 studies evaluated additional liver procedures, such as stem cell application, ischemia/reperfusion injury, portal vein modulation, liver scaffold application, bio-artificial, and pharmacological liver treatment. Only nine authors analysed how cytokines and growth factors changed in response to liver resection. The most used imaging system to evaluate liver volume was CT-scan volumetry, even if performed only by nine authors. The pig represents one of the best animal models for the study of liver regeneration. However, it remains a mostly unexplored field due to the lack of experiments reproducing the chronic pathological aspects of the liver and the heterogeneity of existing studies

    Inflammation-related prognostic markers in resected hepatocellular carcinoma.

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    Hepatocellular carcinoma is usually detected late and therapeutic options are unsatisfactory. Despite marked progress in patient care, HCC remains among the deadliest cancers world-wide. While surgical resection remains a key option for early-stage HCC, the 5-year survival rates after surgical resection are limited. One reason for limited outcomes is the lack of reliable prognostic biomarkers to predict HCC recurrence. HCC prognosis has been shown to correlate with different systemic and pathological markers which are associated with patient survival and HCC recurrence. Liver inflammatory processes offer a large variety of systemic and pathological markers which may be exploited to improve the reliability of prognosis and decision making of liver surgeons and hepatologists. The following review aims to dissect the potential tools, targets and prognostic meaning of inflammatory markers in patients with resectable HCC. We analyze changes in circulant cellular populations and assess inflammatory biomarkers as a surrogate of impaired outcomes and provide an overview on predictive gene expression signatures including inflammatory transcriptional patterns, which are representative of poor survival in these patients.journal articlereview20232023 12 07importe

    ANDES, the high-resolution spectrograph for the ELT: RIZ Spectrograph preliminary design

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    We present here the preliminary design of the RIZ module, one of the visible spectrographs of the ANDES instrument 1. It is a fiber-fed high-resolution, high-stability spectrograph. Its design follows the guidelines of successful predecessors such as HARPS and ESPRESSO. In this paper we present the status of the spectrograph at the preliminary design stage. The spectrograph will be a warm, vacuum-operated, thermally controlled and fiber-fed echelle spectrograph. Following the phase A design, the huge etendue of the telescope will be reformed in the instrument with a long slit made of smaller fibers. We discuss the system design of the spectrographs system.Comment: Paper submitted to the SPIE astronomical telescope and instrumentation 2024, conference title : Ground-based and Airborne Instrumentation for Astronomy X, paper reference number : 13096-17

    An Information Theoretic Criterion for Empirical Validation of Time Series Models

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    Simulated models suffer intrinsically from validation and comparison problems. The choice of a suitable indicator quantifying the distance between the model and the data is pivotal to model selection. However, how to validate and discriminate between alternative models is still an open problem calling for further investigation, especially in light of the increasing use of simulations in social sciences. In this paper, we present an information theoretic criterion to measure how close models' synthetic output replicates the properties of observable time series without the need to resort to any likelihood function or to impose stationarity requirements. The indicator is sufficiently general to be applied to any kind of model able to simulate or predict time series data, from simple univariate models such as Auto Regressive Moving Average (ARMA) and Markov processes to more complex objects including agent-based or dynamic stochastic general equilibrium models. More specifically, we use a simple function of the L-divergence computed at different block lengths in order to select the model that is better able to reproduce the distributions of time changes in the data. To evaluate the L-divergence, probabilities are estimated across frequencies including a correction for the systematic bias. Finally, using a known data generating process, we show how this indicator can be used to validate and discriminate between different models providing a precise measure of the distance between each of them and the data

    Stratégies périopératoires multidisciplinaires pour améliorer les résultats à court et à long terme dans les cancers hépato-biliaires et pancréatiques

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    Cette thèse est une exploration complète de la prise en charge multidisciplinaire des tumeurs hépato-biliopancréatiques (HBP), et de la manière dont cette approche peut améliorer les résultats oncologiques pour le patient. Ce travail est développé en trois chapitres, chacun couvrant un domaine spécifique de cette discipline. Chaque chapitre révèle également une collaboration importante entre chirurgiens, oncologues, chercheurs et diverses personnalités médicales, ouvrant la voie à l'avancement de la prise en charge des tumeurs HBP. Les stratégies de traitement affinées et les approches de médecine personnalisée décrites dans cette thèse ne sont pas des constructions théoriques mais des outils prêts à être intégrés dans les soins aux patients. L'esprit de collaboration soutenu tout au long de ce travail résonne dans l'amélioration des soins aux patients atteints de tumeurs HBP, garantissant que les progrès de la recherche se traduisent par des améliorations cliniques tangibles.This thesis is a comprehensive exploration of the multidisciplinary management of hepatobiliarypancreatic tumors (HBP), and how this approach can improve oncological outcomes for the patient.This work is developed in three chapters, each covering a specific domain of this discipline. Each chapter also reveals significant collaboration between surgeons, oncologists, researchers, and various medical personalities, paving the way for the advancement of HBP tumor management. The refined treatment strategies and personalized medicine approaches described in this thesis are not theoretical constructs but tools ready to be integrated into patient care. The spirit of collaboration sustained throughout this work resonates in the improvement of care for patients with HBP tumors, ensuring that research advancements translate into tangible clinical improvements
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