Search results for " Map"
showing 10 items of 2344 documents
Non-invasive localization of atrial ectopic beats by using simulated body surface P-wave integral maps
2017
Non-invasive localization of continuous atrial ectopic beats remains a cornerstone for the treatment of atrial arrhythmias. The lack of accurate tools to guide electrophysiologists leads to an increase in the recurrence rate of ablation procedures. Existing approaches are based on the analysis of the P-waves main characteristics and the forward body surface potential maps (BSPMs) or on the inverse estimation of the electric activity of the heart from those BSPMs. These methods have not provided an efficient and systematic tool to localize ectopic triggers. In this work, we propose the use of machine learning techniques to spatially cluster and classify ectopic atrial foci into clearly diffe…
Quasi-Conformal Technique for Integrating and Validating Myocardial Tissue Characterization in MRI with Ex-Vivo Human Histological Data
2017
Ventricular tachycardia caused by a circuit of re-entry is one of the most critical arrhythmias. It is usually related with heterogeneous scar regions where slow velocity of conduction tissue is mixed with non-conductive tissue, creating pathways (CC) responsible for the tachycardia. Pre-operative DE-MRI can provide information on myocardial tissue viability and then improve therapy planning. However, the current DE-MRI resolution is not sufficient for identifying small CCs and therefore they have to be identified during the intervention, which requires considerable operator experience. In this work, we studied the relationship of histological data (with 10 \(\mu \)m resolution), with in-vi…
Comparison of different assembly and annotation tools on analysis of simulated viral metagenomic communities in the gut
2013
Abstract Background The main limitations in the analysis of viral metagenomes are perhaps the high genetic variability and the lack of information in extant databases. To address these issues, several bioinformatic tools have been specifically designed or adapted for metagenomics by improving read assembly and creating more sensitive methods for homology detection. This study compares the performance of different available assemblers and taxonomic annotation software using simulated viral-metagenomic data. Results We simulated two 454 viral metagenomes using genomes from NCBI's RefSeq database based on the list of actual viruses found in previously published metagenomes. Three different ass…
Teachers’ beliefs about gamification and competencies development: A concept mapping approach
2020
Despite an increasing academic attention towards both gamification and competencies-based education, little is known about Higher Education teachers’ beliefs regarding the use of gamification to develop students’ competencies. To fill this research gap, concept mapping was used to cluster teachers’ beliefs in 4 dimensions regarding the use of gamification to develop students’ competencies. Our findings suggest that teachers believe that gamification encourages team working and oral communication skills. Moreover, critical thinking and social skills development were also found as some of the benefits that teachers believe the use of gamification can provide to the development of students’ co…
WebGIS Implementation for Dynamic Mapping and Visualization of Coastal Geospatial Data: A Case Study of BESS Project
2021
Within an E.U.-funded project, BESS (Pocket Beach Management and Remote Surveillance System), the notion of a geographic information system is an indispensable tool for managing the dynamics of georeferenced data and information for any form of territorial planning. This notion was further explored with the creation of a WebGIS portal that will allow local and regional stakeholders/authorities obtain an easy remote access tool to monitor the status of pocket beaches (PB) in the Maltese Archipelago and Sicily. In this paper, we provide a methodological approach for the implementation of a WebGIS necessary for very detailed dynamic mapping and visualization of geospatial coastal data
A CASE STUDY OF THE APPLICATION OF HAND-HELD MOBILE LASER SCANNING IN THE PLANNING OF AN ITALIAN FOREST (ALPE DI CATENAIA, TUSCANY)
2021
Abstract. Precision forestry is becoming a key sector for forest planning because it allows complex analyses of forest data to be carried out simply and economically. It contributes to the integration between technicians and operators in the sector by guaranteeing the transparency of the forest management operations (Corona et al., 2017). In the context of the progressive development of technology, we investigated the feasibility of using the hand-held mobile laser scanner (HMLS) system in different types of forest sites and comparison of the characteristics of individual trees (tree height, diameters at breast height) with traditional surveys, applied with the aim to validate the performan…
Identification of atrial fibrillation drivers by means of concentric ring electrodes
2022
The prevalence of atrial fibrillation (AF) has tripled in the last 50 years due to population aging. High-frequency (DFdriver) activated atrial regions lead the activation of the rest of the atria, disrupting the propagation wavefront. Fourier based spectral analysis of body surface potential maps have been proposed for DFdriver identification, although these approaches present serious drawbacks due to their limited spectral resolution for short AF epochs and the blurring effect of the volume conductor. Laplacian signals (BC-ECG) from bipolar concentric ring electrodes (CRE) have been shown to outperform the spatial resolution achieved with conventional unipolar recordings. Our aimed was to…
Three-dimensional evolution of the Keuper of the Paris basin based on detailed isopach maps of the stratigraphic cycles: tectonic influences
1997
Detailed isopach maps of the stratigraphic cycles of the Keuper of the Paris basin are used to reconstruct the 3D evolution of the basin cycle by cycle and to investigate the influence of tectonic movements. The major base-level cycles record variations in the rate of subsidence in time and space. The area of greatest subsidence, which was confined to the east of the basin during the Scythian–Carnian cycle, shifted northwestwards during the Carnian–Liassic cycle. Within the “Marnes irisees inferieures”, the E–W faults abruptly limited the extent of salt deposits to the north and south by forming a “corridor” where subsidence was greater. The westward shift of areas of subsidence induced by …
FOTOGRAMMETRIA CONVENZIONALE E SENSORE AD IM-MAGINI “CASI”: APPLICAZIONI ALLA MAPPATURA DELLA VEGETAZIONE SOMMERSA
2001
Obiettivo della ricerca è stato quello di testare l’applicabilità delle tecniche che fanno uso di dati te-lerilevati (multispettrali e da aerofotogrammetria convenzionale) da piattaforma aerea per il monito-raggio delle praterie di Posidonia oceanica. L’analisi multitemporale ha permesso di monitorare l'e-voluzione del “limite superiore” delle praterie sommerse evidenziando l'impatto della pressione an-tropica sulla componente biotica fotoautotrofa dell'ecosistema marino costiero. Dallo studio è emer-so che l'analisi dei dati telerilevati da aereo fornisce un contributo essenziale all’indagine del pae-saggio vegetale a media e piccola scala, consentendo sia un monitoraggio periodico di vast…
Monitoring fire-affected areas using Thematic Mapper data
2001
In this paper three methods for updating inventories of burned areas have been presented and examined. They include Multitemporal Principal Component Analysis (MPCA), Change Vector Analysis (CVA) a...