Quantitative monitoring of surface movements on active landslides by multi-temporal, high-resolution X-Band SAR amplitude information: Preliminary results

Multi-temporal image cross-correlation is a method for tracking moving features and can there-fore be used for quantitative assessments of surface displacements. Accuracies of up to 1/8th of the original image geometric resolution can be achieved. We present the results of an analysis car- ried out on Corvara landslide located in the Italian Dolomites. Image offset-tracking was applied to CosmoSky-Med amplitude images acquired between October 2013 and August 2015. The presence of a validation dataset consisting of periodical GPS surveys carried out on 16 benchmarks represents an ideal opportunity to test the applicability of SAR-based image cross-correlation for landslide moni- toring. Despite the relative low accuracy of the results amplitude-based offset-tracking proved to be beneficial due to the ability of this method to capture large displacements. In particular the results evidence its complementarity with respect to multi-temporal interferometry that is confined to slow displacements along E-W directions

Multi-Temporal X-Band Radar Interferometry Using Corner Reflectors: Application and Validation at the Corvara Landslide (Dolomites, Italy)

From the wide range of methods available to landslide researchers and practitioners for monitoring ground displacements, remote sensing techniques have increased in popularity. Radar interferometry methods with their ability to record movements in the order of millimeters have been more frequently applied in recent years. Multi-temporal interferometry can assist in monitoring landslides on the regional and slope scale and thereby assist in assessing related hazards and risks. Our study focuses on the Corvara landslides in the Italian Alps, a complex earthflow with spatially varying displacement patterns. We used radar imagery provided by the COSMO-SkyMed constellation and carried out a validation of the derived time-series data with differential GPS data. Movement rates were assessed using the Permanent Scatterers based Multi-Temporal Interferometry applied to 16 artificial Corner Reflectors installed on the source, track and accumulation zones of the landslide. The overall movement trends were well covered by Permanent Scatterers based Multi-Temporal Interferometry, however, fast acceleration phases and movements along the satellite track could not be assessed with adequate accuracy due to intrinsic limitations of the technique. Overall, despite the intrinsic limitations, Multi-Temporal Interferometry proved to be a promising method to monitor landslides characterized by a linear and relatively slow movement rates

Comparative Analysis of RNA-seq transcriptomes in aging and non-aging Hydra

The cnidarian Hydra exhibits extremely low senescence when maintained in homeostatic conditions. However H. oligactis animals that undergo sexual differentiation upon transfer from 18°C to 10°C, exhibit a visible aging. Our laboratory characterized two H. oligactis male strains that exhibit different phenotypes once they enter gametogenesis: the cold-sensitive strain (Ho_CS) that exhibits a typical cold-induced degenerative phenotype, and the cold-resistant strain (Ho_CR) that returns to homeostasis. In this study, we performed a large-scale comparative transcriptomic analysis to identify structural as well as regulatory genetic differences between these two strains. We identified a TNF receptor-associated factor (TRAF) that shows a series of deletions in Ho_CS when compared to Ho_CR. We also characterized genes differentially expressed over time between the two strains, such as CIRBP, IMPDH1, TRPA1 and TRPM3, which are orthologs to human proteins involved in response to cold or sensory perception of temperature stimulus, as well as sequences that encode uncharacterized proteins. Moreover, we characterized genes reported in the Human Ageing Genomic Resources (HAGR) GenAge database revealed supplementary interesting candidates such as orthologs for AIFM1, EIF5A2, ERCC4, GCLC, GSK3A, HDAC, HSPD1, MLH1, MAPK3, SOCS2, TRAP1, UCHL1 and ZMPSTE24, which are temporarily differentially expressed between the two strains. TRAP1 and HSPD1 are heat shock proteins, the latter being also involved in the response to cold. We thus retrieved interesting genes candidates that may influence aging phenotype following exposure to cold in Hydra

Human-Robot Collaboration Using Fuzzy Adaptive Virtual Fixture Method for Dental Implant Surgery

The purpose of this work is to develop a methodology to improve human-robot collaboration for robot-aided dental implant placement. In this study, a human-robotic implant system (HRIS) is designed according to a hand-guiding control to increase the accuracy and stability of osteotomy drilling based on the surgeon's decision, and robot motion during the implant placement. The proposed method is able to guide the surgeon's hand according to the pose of the desired placement. To guide and modify the pose of the surgeon's hand, the virtual fixture method is used as the main control approach. To verify the performance of the introduced method, the KUKA MED robot is used to perform the dental implant placement using the presented approach on a phantom head with a 3D jaw bone model. Additionally, the results between free-hand drilling and HRIS controlled drilling according to the apical center and head center of the implant placement are compared to evaluate the performance of the introduced method

Integration of X-band SAR interferometry , continuous and periodic D-GPS and in-place inclinometers to characterize and monitor a deep-seated earthslide in the Dolomites ( Italy )

The Corvara landslide is an active, large-scale, deep-seated and slow moving earthslide of about 30 Mm3 located in the Dolomites (Italy). It is frequently damaging a national road and, occasionally, isolated buildings and recreational ski facilities. Since the mid ‘90s it has been mapped, dated and monitored thanks to field surveys, boreholes, radiocarbon dating, inclinometers, piezometers and periodic D-GPS measurements, carried out by the Geology and the Forestry Planning offices of the Autonomous Province of Bolzano, the Municipality of Corvara in Badia, the University of Modena and Reggio Emilia, the IRPI-CNR of Padua. In 2013, a new phase of characterization and monitoring has started which also involves the EURAC’s Institute for Applied Remote Sensing, the geodesy group of University La Sapienza, the CNR-IREA of Naples and the Leica Geosystems office in Italy. This new phase of characterization and monitoring is meant to investigate the opportunities of innovative SAR interferometry, D-GPS and in-place inclinometers techniques to provide for a high frequency monitoring of the study site in support to the analysis of the investigation of forcing factors leading unsteady, nonuniform landslide motion through different seasons of the year. Monitoring results are also expected to provide a validation of innovative interferometric techniques so to fully evaluate their conformity to be used as a long-term monitoring system in land-use planning and risk management procedures. The monitoring infrastructure now integrates: 16 Corner Reflector for satellite X-Band SAR interferometric products, 13 benchmarks for D-GPS periodic surveys, three on-site GPS receivers for continuous positioning and remote ftp data pushing, two in-place inclinometers and a pressure transducer to record pore-pressure variations. The coupling of SAR-based products with GPS records is achieved using especially designed Corner Reflectors having an appendix dedicated to hold Dual-Frequency GPS antennas. COSMO-SkyMed X-Band SAR acquisitions started on October 2013 and are ongoing with a temporal resolution of 16 days using STRIPMAP (HIMAGE) measuring mode. Discontinuous D-GPS Fast-Static surveys are scheduled with a triple frequency: annual for 24 points outside recent activation areas, monthly for 13 points in the active zone and a bi-weekly for 6 points located in the most active zone. Displacement high-frequency data are acquired thank to the installation of 3 Dual-Frequency GPS in permanent acquisition that have been located in the accumulation, track and source zone of the active portion of the landslide. High frequency data are also obtained by the two inclinometers operating in continuous acquisition located across the main slide surface at 48 m depth into a 90 m borehole drilled in the accumulation zone. A piezometer installed in the source zone and the meteorological station of Piz La Ila (3 km far away) of the Autonomous Province of Bolzano complete the system