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Abstract
Ambient noise polarizes inside fault zones, yet the spatial and temporal resolution of polarized noise on gas-bearing fluids migrating through stressed volcanic systems is unknown. Here we show that high polarization marks a transfer structure connecting the deforming centre of the caldera to open hydrothermal vents and extensional caldera-bounding faults during periods of low seismic release at Campi Flegrei caldera (Southern Italy). Fluids pressurize the Campi Flegrei hydrothermal system, migrate, and increase stress before earthquakes. The loss of polarization (depolarization) of the transfer and extensional structures maps pressurized fluids, detecting fluid migrations after seismic sequences. After recent intense seismicity (December 2019-April 2020), the transfer structure appears sealed while fluids stored in the east caldera have moved further east. Our findings show that depolarized noise has the potential to monitor fluid migrations and earthquakes at stressed volcanoes quasi-instantaneously and with minimum processing.
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Affiliation(s)
- S Petrosino
- Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Napoli - Osservatorio Vesuviano, Napoli, 80124, Italy
| | - L De Siena
- Institute of Geosciences, Johannes Gutenberg University, Mainz, 55128, Germany.
- TeMaS - Terrestrial Magmatic Systems Research Area, Johannes Gutenberg University, Mainz, 55128, Germany.
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Chiodini G, Selva J, Del Pezzo E, Marsan D, De Siena L, D'Auria L, Bianco F, Caliro S, De Martino P, Ricciolino P, Petrillo Z. Clues on the origin of post-2000 earthquakes at Campi Flegrei caldera (Italy). Sci Rep 2017; 7:4472. [PMID: 28667256 PMCID: PMC5493613 DOI: 10.1038/s41598-017-04845-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 05/19/2017] [Indexed: 11/19/2022] Open
Abstract
The inter-arrival times of the post 2000 seismicity at Campi Flegrei caldera are statistically distributed into different populations. The low inter-arrival times population represents swarm events, while the high inter-arrival times population marks background seismicity. Here, we show that the background seismicity is increasing at the same rate of (1) the ground uplift and (2) the concentration of the fumarolic gas specie more sensitive to temperature. The seismic temporal increase is strongly correlated with the results of recent simulations, modelling injection of magmatic fluids in the Campi Flegrei hydrothermal system. These concurrent variations point to a unique process of temperature-pressure increase of the hydrothermal system controlling geophysical and geochemical signals at the caldera. Our results thus show that the occurrence of background seismicity is an excellent parameter to monitor the current unrest of the caldera.
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Affiliation(s)
- G Chiodini
- Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Bologna, via D. Creti 12, 40128, Bologna, Italy.
| | - J Selva
- Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Bologna, via D. Creti 12, 40128, Bologna, Italy
| | - E Del Pezzo
- Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Napoli Osservatorio Vesuviano, via Diocleziano 328, 80124, Napoli, Italy.,Istituto Andalùz de Geofisica, Università de Granada, C/ Profesor Clavera Nº12, Granada, 18071, Spain
| | - D Marsan
- ISTerre, CNRS, Université de Savoie Mont Blanc, Campus Scientifique, 73376, Le Bourget du Lac, France
| | - L De Siena
- School of Geosciences, Geology and Petroleum Geology, King's College, University of Aberdeen, Aberdeen, UK
| | - L D'Auria
- Instituto Volcanológico de Canarias (INVOLCAN), 38400, Puerto de la Cruz, Tenerife, Spain
| | - F Bianco
- Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Napoli Osservatorio Vesuviano, via Diocleziano 328, 80124, Napoli, Italy
| | - S Caliro
- Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Napoli Osservatorio Vesuviano, via Diocleziano 328, 80124, Napoli, Italy
| | - P De Martino
- Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Napoli Osservatorio Vesuviano, via Diocleziano 328, 80124, Napoli, Italy
| | - P Ricciolino
- Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Napoli Osservatorio Vesuviano, via Diocleziano 328, 80124, Napoli, Italy
| | - Z Petrillo
- Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Napoli Osservatorio Vesuviano, via Diocleziano 328, 80124, Napoli, Italy
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De Siena L, Del Pezzo E, Bianco F. Seismic attenuation imaging of Campi Flegrei: Evidence of gas reservoirs, hydrothermal basins, and feeding systems. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009jb006938] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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De Siena L, Pallavicino F, Lacilla M, Canale A, Longobardo A, Pecorari G, Albera R. Auditory-evoked potentials in general anesthesia monitoring: baseline study of availability in relation to hearing function in awake status. Acta Anaesthesiol Scand 2005; 49:774-7. [PMID: 15954958 DOI: 10.1111/j.1399-6576.2005.00719.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND It has been confirmed that middle latency auditory-evoked potentials are good indicators of the hypnotic level in patients undergoing general anesthesia. The focal point for the evocation of auditory-evoked potentials is the presence of a serviceable hearing function. The aim of the study was to evaluate the limit of hearing loss above which the test could not be applied. METHODS To determine the limit of applicability of the technique, 100 subjects were studied. Twenty of them were normally hearing and 80 were affected by sensorineural hearing loss of various degrees. Each subject was submitted to pure tone audiometry, to determine hearing threshold, and then, in awake status, to auditory-evoked potentials recording using acoustic stimuli of 85 dB HL. RESULTS All the 20 normally hearing subjects showed a reliable auditory-evoked potentials. Among the 80 subjects affected by hearing loss, only five had no potentials. These five subjects presented a pure tone audiometry threshold greater than 85 dB HL. CONCLUSION The study demonstrated that middle latency auditory-evoked potentials recorded using an A-Line (software version 1.4) AEP monitor (Danmeter, Odense, Denmark) can be carried out even in presence of hearing loss if the pure tone threshold is less than 85 dB HL.
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Affiliation(s)
- L De Siena
- Department of Medico-Surgical Disciplines, Section of Anesthesia, University of Turin, Turin, Italy
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Albera R, Ferrero V, Canale A, De Siena L, Pallavicino F, Poli L. Cochlear blood flow modifications induced by anaesthetic drugs in middle ear surgery: comparison between sevoflurane and propofol. Acta Otolaryngol 2003; 123:812-6. [PMID: 14575396 DOI: 10.1080/00016480310002230] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVE Because it is necessary to maintain controlled hypotension during middle ear surgery in order to avoid bleeding and as it is known that cochlear blood flow (CBF) is related to blood pressure (BP), it is useful to evaluate CBF modifications induced by anaesthetics in order to prevent cochlear damage. The aim of this paper is to evaluate, using laser Doppler flowmetry, which anaesthetic drug, out of sevoflurane and propofol, has the smallest effect on CBF. MATERIAL AND METHODS Twenty consenting adult patients scheduled for myringoplasty under general anaesthesia for simple tympanic membrane perforation were studied. Patients were divided into two groups: the first group was treated with sevoflurane and the second with propofol. For the first group, CBF measurement was carried out on three different occasions: (i) at a basal low drug dosage; (ii) having increased the drug dosage to a higher level; and (iii) having reduced the drug dosage to the basal low level again. For the second group, CBF measurement was carried out on three different occasions: (i) 10 min after injecting a bolus of propofol; (ii) immediately after a second propofol injection; and (iii) 10 min after a third injection of propofol. A probe was placed over the promontory in order to measure CBF levels. RESULTS In the subjects treated with sevoflurane, after having increased the drug dosage, BP decreased significantly while CBF did not change significantly. In the subjects treated with propofol we recorded a significant reduction in BP, as well as a decrease in CBF. CONCLUSION The results obtained show that sevoflurane has a hypotensive effect without modifying CBF, while propofol, although having a similar effect on BP to sevoflurane, has less of a protective effect on inner ear microcirculation.
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Affiliation(s)
- R Albera
- Department of Clinical Physiopathology, II Chair of ENT, University of Turin, Turin, Italy.
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Pignataro PF, Sartini M, De Siena L, Ghetti A, Cariani S, Amenta E. [Crohn's disease of the appendix: a rare nosological entity]. Chir Ital 1993; 45:229-32. [PMID: 7923496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In this study, the authors describe a case of Crohn's disease confined to the vermiform appendix out of a total of 1,263 appendectomies performed over the past 10 years in a Clinical Surgery Department (Clinica Chirurgica III) of the Policlinico S. Orsola in Bologna. In agreement with other reports in the scientific literature, the essentially non-specific clinical picture prevents pre-operative identification of the condition, whereas a diagnosis of Crohn's disease can be reached only on the basis of histological characteristics. The extreme rarity of Crohn's disease confined to the appendix is, however, confirmed. Follow-up at 3 years revealed no involvement of other areas of the digestive tract.
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Affiliation(s)
- P F Pignataro
- Università di Bologna, Policlinico S. Orsola, Clinica Chirurgica III
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Albera R, Magnano M, De Siena L, Orecchia C, Bolognese P, Pignocchino P, Cortesina G. [The measurement of cochlear flow by laser Doppler in man: the preliminary results]. Acta Otorhinolaryngol Ital 1992; 12:553-64. [PMID: 1307446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Laser-Doppler flowmetry is presently one of the methods of choice in measuring cochlear blood flow. The techniques is non-invasive and is based on the frequency shift of the laser beam induced by the red blood cell movement. Previous studies of cochlear blood flow carried out on animals and humans demonstrated the reliability of laser-Doppler flowmetry and its usefulness in understanding inner ear microcirculation physiology. In this paper we present preliminary data obtained from three patients examined under general anesthesia while undergoing tympanoplasty. Results showed that tracings, whose baseline is proportional with the blood flow, are characterized by waves correlated to pulse beat and automatic ventilation. Moreover, intrinsic contractions of inner ear vessels (waves of vasomotion) as exist in cerebral microcirculation, were observed. Pharmacological hypotension hypocapnia and the application of epinephryne determine a significant reduction of cochlear blood flow. These results suggest that while cochlear blood flow is related to systemic pressure, it has an intrinsic control system. As well since we did not obtain any modification in bone conduction threshold after surgery, we conclude that laser-Doppler flowmetry is a safe technique.
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Affiliation(s)
- R Albera
- II Clinica ORL, Università di Torino
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De Siena L, Sartini M, Cervellera M, Cariani S, Amenta E, Conti A. [2 cases of chylothorax during total parenteral nutrition: the etiopathogenetic considerations]. G Chir 1992; 13:545-7. [PMID: 1292564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The authors report the onset of bilateral chylothorax during postoperative total parenteral nutrition. They underline the peculiar origin of the complication. Therefore, attention is payed to the possible pathogenic causes. The overload of fluids, in the elderly with minimal functional reserves, may increase central blood pressure, so to adversely affect lymphatic drainage causing chylothorax.
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Affiliation(s)
- L De Siena
- Istituto Clinico di Chirurgia, Università degli Studi di Bologna
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Fagiano G, Orecchia C, De Siena L, Pandolfi P. Prevention and treatment of emergencies in dental offices. Anesth Prog 1989; 36:221-3. [PMID: 2490042 PMCID: PMC2190693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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Fagiano G, Salamino A, Parigi L, De Siena L. [Iatrogenic hypernatremic hyperosmolar coma]. Minerva Anestesiol 1982; 48:341-5. [PMID: 6752756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Fagiano G, Ghizzoni R, Reviglio P, De Siena L. [Memories and dreams of patients under general anesthesia]. Minerva Anestesiol 1979; 45:759-62. [PMID: 553250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Fagiano G, Maggi G, Borrione A, De Siena L, Casadio C, Pischedda F. [Anesthesia and postoperative treatment in thymectomy for myasthenia gravis. Results in 190 cases]. Minerva Anestesiol 1978; 44:93-8. [PMID: 652166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Fagiano G, De Siena L, Viglino F. [Muscle relaxants and intratracheal intubation. Comparison between various methods and evaluation of the possibilities and limits in the use of pancuronium bromide]. Minerva Anestesiol 1975; 41:375-9. [PMID: 1186983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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