550 research outputs found

    On the frequency sweep rate estimation in airborne fmcw sar systems

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    Use of Frequency Modulated Continuous Wave (FMCW) Synthetic Aperture Radar (SAR) systems requires to accurately know the electronic parameters of the system. In particular, the use of an incorrect value of the Frequency Sweep Rate (FSR) introduces geometric distortions in the focused images. Recently, a method, that we name FSR Estimate Through Corner reflectors (FSRETC), has been proposed to estimate the FSR value actually employed by the radar. The method is based on the use of the SAR image focused with the available erroneous FSR. Moreover, it exploits a number of Corner Reflectors (CRs) deployed over the illuminated area. In this work, we provide an assessment of the capabilities of the FSRETC algorithm. The overall analysis is performed through the use of a real dataset consisting of 10 acquisitions carried out in 2018 (5 acquisitions) and 2019 (5 acquisitions) with an airborne FMCW SAR system. The presented experimental analysis shows that even with a single acquisition, use of two CRs sufficiently far from each other in the range direction, allows achieving an accurate estimate of the searched FSR. Moreover, it is shown that the obtained estimate is very stable over the time. Therefore, the overall procedure can be applied only once, since the estimated values can be safely used for the subsequent missions, at least for the time interval considered in the work, that is, 14 months. In addition, the presented results pose the basis for an enhanced measurement strategy that allows effective application of the FSRETC algorithm through the use of only one CR

    Uplift and magma intrusion at Long Valley caldera from InSAR and gravity measurements

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    The Long Valley caldera (California) formed ~760,000 yr ago following the massive eruption of the Bishop Tuff. Postcaldera volcanism in the Long Valley volcanic fi eld includes lava domes as young as 650 yr. The recent geological unrest is characterized by uplift of the resurgent dome in the central section of the caldera (75 cm in the past 33 yr) and earthquake activity followed by periods of relative quiescence. Since the spring of 1998, the caldera has been in a state of low activity. The cause of unrest is still debated, and hypotheses range from hybrid sources (e.g., magma with a high percentage of volatiles) to hydrothermal fl uid intrusion. Here, we present observations of surface deformation in the Long Valley region based on differential synthetic aperture radar interferometry (InSAR), leveling, global positioning system (GPS), two-color electronic distance meter (EDM), and microgravity data. Thanks to the joint application of InSAR and microgravity data, we are able to unambiguously determine that magma is the cause of unrest

    Abstract BOOK SIAART

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    INTRODUCTION. Dental injury occurres in 0.06 - 0.13 % of general anesthesia procedures re- quiring endotracheal intubation, and it is still a reason of complaint against anesthetists. Maxil- lary central incisors are the most commonly teeth injured.1 In our center claims related to teeth damage after intubation ended with a total reimbursement of 13.000 Euros (2014-2015) and 5 patients (2014 to June 2016) were admitted for cares in Prosthodontics Implant dentistry dept. Dental School - Turin. BUCX et al.2 used a strain gauge based sensor between handle and blade of the laryngoscope to measure forces applied on the maxillary incisors to show that during routine laryngoscopy great forces are exerted on the maxillary incisor teeth with no differences based on the operator experience. OBJECTIVES.The aim of this study is to measure of the forces applied on teeth using a direct laryngoscope or a McGRATH¼ videolaringoscope. Many authors described how lower force on soft tissue could be applied using a VLS (GlideScope) instead of a standard laryngoscope (P=0.05).3, but no studies have ever been performed involving the use of a force sensor directly applied on teeth. The aim of our study is to measure the forces applied on teeth after the application of a cus- tomized bite (2 mm dental bite) applied on the manikin. Anesthesiologists and anesthesia residents from “Città della Salute e della Scienza”,Turin will be asked to perform 3 intubations using the standard intubation system, and other 3 using McGRATH¼ videolaringoscope in order to test the intubation forces exerted

    An oxaloacetate decarboxylase homologue protein influences the intracellular survival of Legionella pneumophila

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    Legionella pneumophila is a facultative intracellular parasite which is able to survive in various eukaryotic cells. We characterised a Tn5-mutant of the L. pneumophila Corby strain and were able to identify the insertion site of the transposon. It is localised within an open reading frame which shows high homology to the α-subunit of the oxaloacetate decarboxylase (OadA) of Klebsiella pneumoniae. The OadA homologous protein of L. pneumophila was detected in the wild-type strain by Western blotting. Since the intracellular multiplication of the oadA− mutant strain is reduced in guinea pig alveolar macrophages and human monocytes, it is concluded that the oadA gene product has an effect on the intracellular survival of L. pneumophil

    Molecular cloning, promoter analysis and SNP identification of Italian Nicastrese and Saanen lactoferrin gene

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    Lactoferrin (Lf) is an iron-binding glycoprotein found in exocrine secretions including milk. High levels of lactoferrin may have a role in the prevention of microbial infection of the mammary gland. In this report we sequenced and characterized goat lactoferrin cDNA and its promoter region in two different breeds of goat. The complete cDNA comprised 2356 nucleotides, including 38bp at the 5'-UTR and 194bp at the 3'-UTR. The open reading frame is 2127bp long and it encodes a mature protein of 689 aminoacids. A total of 19 nucleotide differences, 11 of them being responsible for 8 aminoacid changes, were identified through the comparison with French, Korean and Tibetan goat lactoferrin cDNAs. About 1700bp of the lactoferrin gene promoter were sequenced. Sequence analysis revealed a non-canonical TATA box, multiple SP1/GC elements, and other putative binding sites for transcription factors, such as NF-kappaB, STAT3 and AP2. Two SNPs were identified, one of which would seem to create a new putative AP2 consensus sequence. The presence of an additional AP2 binding site could be associated with quantitative differences of such protein fraction, which could enhance all the activities related to such protein, and improve mammary gland defence against bacterial infections

    FIFTEEN YEARS OF ERS AND ENVISAT DInSAR OBSERVATIONS AT MT. ETNA (ITALY) BY USING THE SBAS APPROACH

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    We exploited the Small BAseline Subset (SBAS) technique and computed ground displacement maps and time series by inverting 283 interferograms generated from the ascending and 289 from the descending orbits to reveal Mt. Etna surface deformation from 1992 to 2006. Our analysis shows that the volcano experienced magmatic inflation/deflation and radial spreading of the west, south and east flanks. In particular, the summit area vertical deformation inverted its sign after 2000 and clearly shows a deflation effect related to the 2001 and 2002 eruptive and seismic events. On the contrary, the horizontal signals revealed on the eastern and western flanks present significant and consistent motions toward east and west, respectively, during the investigated interval. Overall, the presented results show the complex and articulated deformation behavior of Mt. Etna and remark the possible coexistence of both gravity and magma forcing

    Recent deformation at Campi Flegrei caldera (Italy) detected by DinSar and leveling techniques

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    The Campi Flegrei caldera, a volcanic and densely populated area located to the west of Napoli (Italy), was characterized by rapid ground deformation during 1970-72 and 1982-84, for a total amount of 3.5 m in the city of Pozzuoli. Since 1985 a slow deflation was active, with episodic microcrises of uplifts. A new and consistent uplift event is now going on, beginning in November 2004, as revealed by spatial and terrestrial geodetic techniques. In particular, we adopt almost all the available ENVISAT ASAR data acquired from both ascending and descending orbits during 2002-2006, to generate mean deformation velocity maps and time series with spatial resolution of about 100 m. The maps are computed following the Small BAseline Subset (SBAS) approach (Berardino et al., 2002), that implements an appropriate combination of differential interferograms generated from SAR data pairs (60 SAR images for this work). In addition to satellite observations, we show data from the high precision levelling network of the INGV-Osservatorio Vesuviano, consisting in about 320 benchmarks. Levelling measurements are regularly carried out on both the whole network and along the coast line; in case of a bradyseismic crisis, the temporal sampling is strongly increased. Both DInSAR and levelling data evidence the maximum value of the vertical displacement near the city of Pozzuoli. We model the observed deformation by means of 3D pressurized point-source and extended source, performing inversions to constrain their shape and location. The resulting sources are also compared with that inverted for the 1982-84 unrest.UnpublishedWienope
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