3,836 research outputs found
Ambient noise and ERT data provide insights into the structure of co-seismic rock avalanche deposits in Sichuan (China)
AbstractThe post-seismic history of the 2008 Mw7.9 Wenchuan earthquake shows that marginally stable deposits of large co-seismic landslide dams can pose persistent debris flow hazards for the downstream areas. Here, we combine analyses of single-station recordings of ambient noise with electrical resistivity tomography (ERT) surveys to explore the potential of drawing information on structure and geometry of the deposit of a large rock avalanche triggered by the Mw 7.9 2008 Wenchuan earthquake, which dammed the Yangjia stream in the Sichuan Province (China). The substantial thickness and heterogeneity of this kind of deposits limit the application of standard geophysical techniques, like active seismic surveys, which require highly energetic sources and long linear geophone arrays to reach adequate investigation depths. Passive single-station methods, relying on ambient noise recordings to determine site resonance properties, controlled by the contrast between soft surface layers and a stiffer substratum, offer the opportunity of investigating subsoil properties down to larger depths. In particular, we use a recently developed technique, which isolates the contribution of Rayleigh waves to ambient noise and draws information on sub-soil properties from the inversion of Rayleigh wave ellipticity curves plotted as function of frequency. In this framework, the ERT data can support the ellipticity curve inversion, typically affected by highly non-univocal solutions, by providing constraints for defining of the thickness of the uppermost surficial layers. The results allowed inferring the overlap of different layers within the 2008 rock avalanche deposit, as well as estimating lateral variations in their thickness and S-wave (Vs) velocities
Current-induced spin polarization in InGaAs and GaAs epilayers with varying doping densities
The current-induced spin polarization and momentum-dependent spin-orbit field
were measured in InGaAs epilayers with varying indium
concentrations and silicon doping densities. Samples with higher indium
concentrations and carrier concentrations and lower mobilities were found to
have larger electrical spin generation efficiencies. Furthermore,
current-induced spin polarization was detected in GaAs epilayers despite the
absence of measurable spin-orbit fields, indicating that the extrinsic
contributions to the spin polarization mechanism must be considered.
Theoretical calculations based on a model that includes extrinsic contributions
to the spin dephasing and the spin Hall effect, in addition to the intrinsic
Rashba and Dresselhaus spin-orbit coupling, are found to qualitatively agree
with the experimental results.Comment: 16 pages, 8 figure
Lo studio delle deformazioni del suolo nell'area di Bojano nel periodo 2004-2006
In questa nota sono riportati i risultati ottenuti da indagini geodetiche effettuate nellâarea del Sannio-Matese nellâambito di una Convenzione triennale perfezionata tra lâAssessorato ai Lavori Pubblici della
Regione Molise e lâINGV-OV, rivolta allâindividuazione di eventuali fenomeni deformativi del suolo in atto nel comune di Bojano (CB). Lo studio, condotto nel periodo 2004-2006, ha visto la progettazione di
una rete geodetica nellâarea del Comune di Bojano, avente come riferimento il Cs 104 della Linea 80 IGMI corrispondente al Cs LBO/AIGM in Carta, e la materializzazione di vertici GPS, caposaldi di livellazione
e lâinstallazione di Dry Tilt. Le misure di livellazione sullâintera rete, relative al caposaldo di riferimento, hanno evidenziato un generale trend in subsidenza nel bacino di Bojano connesso, con buona probabilitĂ ,
alle oscillazioni stagionali della falda. I risultati dellemisure sui vertici della rete GPS sono in buon accordo con quelli ottenuti dalle misure di livellazione, evidenziando un trend in subsidenza nella piana di Bojano
e nellâarea delle sorgenti del Biferno. Le stime dellâinclinazione del suolo ottenute attraverso lâapplicazione della tecnica dei dry-tilt hanno delineato un quadro deformativo relativo alla zona cittadina di Bojano consistente in una inclinazione del suolo nel quadrante ENE
MULTIDISCIPLINARY STUDY OF SUBSIDENCE AND SINKHOLE OCCURRENCES IN THE ACQUE ALBULE BASIN (ROMA, ITALY)
Abstract We present the results of a combined analysis of remote sensing and geophysicalâgeotechnical data carried out in the Acque Albule Basin, a sinkhole prone area located close to the city of Roma, where a wide travertine wedge is present. We carried out geophysical measurements and borehole drillings over two test areas to image the subsoil where paroxysmal surficial dynamics occur. One site is marked by subsidence occurring at least since the early 2000s, whereas the other site hosts the "La Regina" and "Colonnelle" sinkhole lakes, which discharge sulfurâcarbonated waters. The stability of these two sites threatens highway, railway, and airport facilities, and this study helps to assess the geological hazard. For example, InSAR and LiDAR data helped define wide scale subsidence over the last 20 years and previously undetected smallâscale morphologies. Geophysical measurements of the latter revealed shallow and deep dissolution affecting the travertine and driving surficial paroxysmal events. Both study sites were found to lie inside a large depression located at the junction between Jurassic carbonate and PlioâPleistocene units in association with paleo karst morphologies in the travertine deposits and affected by the presentâpast spillage of sulfurous waters. Given these elements, multidisciplinary geophysical observations are crucial for assessing and mitigating the geological risk and guiding land use planning and management
Paratesticular Mesenchymal Malignancies: A Single-Center Case Series, Clinical Management, and Review of Literature
Background: Primary soft tissue sarcomas arising from the male urinary and genital tract are rare tumors, only accounting for 1% to 2% of all malignancies of the genitourinary tract. Clinical management of advanced disease is lacking in standardized recommendations due to the rarity of the disease. To date, complete and extensive surgery represents the only curative and standardized approach for localized disease, while the impact of retroperitoneal lymphadenectomy and adjuvant treatments on clinical outcomes are still unclear. Similarly, a standardized systemic treatment for advanced metastatic disease is still missing. Cases Presentation: Four out of 274 patients have been identified in our sarcoma population. The mean age was 54 years (range = 45-73). The histotypes showed liposarcoma in 2 cases and leiomyosarcoma in the remaining 2 cases. In all 4 cases, the disease was localized at presentation, patients underwent complete surgery, and no adjuvant treatments were done. Three cases presented a recurrence of disease at a mean follow-up of 86 months (range = 60-106 months), more than 7 years. Two cases were treated with a second surgery and chemotherapy and 1 case only with chemotherapy. Discussion and Conclusions: Sharing data about clinical management of paratesticular mesenchymal tumors is a key issue due to the rarity of this tumor\u2019s subtype. In this article, we report the clinical history of 4 patients affected by paratesticular mesenchymal tumor. In particular, main issues of interest are the decision of postoperative treatment and systemic treatment at time of disease recurrence
Hypothermic Oxygenated New Machine Perfusion System in Liver and Kidney Transplantation of Extended Criteria Donors:First Italian Clinical Trial
With the aim to explore innovative tools for organ preservation, especially in marginal organs, we hereby describe a clinical trial of ex-vivo hypothermic oxygenated perfusion (HOPE) in the field of liver (LT) and kidney transplantation (KT) from Extended Criteria Donors (ECD) after brain death. A matched-case analysis of donor and recipient variables was developed: 10 HOPE-ECD livers and kidneys (HOPE-L and HOPE-K) were matched 1:3 with livers and kidneys preserved with static cold storage (SCS-L and SCS-K). HOPE and SCS groups resulted with similar basal characteristics, both for recipients and donors. Cumulative liver and kidney graft dysfunction were 10% (HOPE L-K) vs. 31.7%, in SCS group (p = 0.05). Primary non-function was 3.3% for SCS-L vs. 0% for HOPE-L. No primary non-function was reported in HOPE-K and SCS-K. Median peak aspartate aminotransferase within 7-days post-LT was significantly higher in SCS-L when compared to HOPE-L (637 vs.344 U/L, p = 0.007). Graft survival at 1-year post-transplant was 93.3% for SCS-L vs. 100% of HOPE-L and 90% for SCS-K vs. 100% of HOPE-K. Clinical outcomes support our hypothesis of machine perfusion being a safe and effective system to reduce ischemic preservation injuries in KT and in LT
âI luoghi di Mercalliâ: a travelling exhibition as a tool for scientists to dialogue with the public on volcanoes and earthquakes
On March 19, 1914 Giuseppe Mercalli, a seismologist and volcanologist, well-known around the world for the
Intensity scale of earthquakes bearing his name, died tragically. A hundred years after, the Istituto Nazionale di
Geofisica e Vulcanologia (INGV) has promoted a variety of activities and cultural events that will take place under the
Patronage of the President of the Italian Republic within a year, the so called âAnno Mercallianoâ (the Year of
Mercalli).
The opening ceremony took place in Naples, Italy, on March 19, 2014, in the Convitto Nazionale Vittorio Emanuele
II. A scientific conference was held with the participation of experts from INGV and the university of Milano â
Bicocca, and presentations of students. On that day the exhibition entitled âI luoghi di Mercalliâ (Mercalli's places) was
also inaugurated, at the presence of local authorities.
The exhibition, organized by INGV, was realized in collaboration with the high school Vittorio Emanuele II, where
Mercalli has been teaching for 19 years, and the UniversitĂ degli Studi Suor Orsola Benincasa, where he was professor
of natural sciences.
A biographical and geographical description of the places where Mercalli operated introduces the exhibition, which
is organized in sections:
- Mercalli educator (he taught at high schools in Reggio Calabria and Naples);
- Mercalli volcanologist (Mercalli studied Vesuvius volcanic activity for more than twenty years, he was a scientific
witness of the Vesuvius 1906 eruption, and of the eruptions occurred at Vulcano (1888-90) and Stromboli (1891)
islands.
- Mercalli seismologist (Mercalli Intensity scale definition, based on his experience as witness of catastrophic
earthquakes, such as Casamicciola in 1883 and Messina in 1908).
Another section deals with the Vesuvius Observatory, directed by Mercalli between 1911 and 1914, and the
description of the three active volcanoes of the Campania region (Vesuvius, Campi Flegrei and Ischia island), which
have been the subject of studies by the well-known scientist. The exhibition is enriched by documents, manuscripts,
photos and field notebooks of Mercalli.
It is not intended to be only a celebratory exhibition; rather it is designed as a tool for dissemination of scientific
culture and to raise awareness about seismic and volcanic hazards.
In the exhibition path a continuous thread between the figure of Mercalli as a researcher and the role of an Earth
Science researcher today is highlighted, pointing to the development of scientific knowledge in the past century. The
goal is to improve the capability of learning from the disasters occurred in the past to implement preventive actions to
safely deal with future events.
The exhibition is travelling and will be provided on request to institutions and schools.PublishedMilano, Italia1V. Storia e struttura dei sistemi vulcaniciope
Participation in medical decision-making across Europe: an international longitudinal multicenter study
Background: The purpose of this paper was to examine national differences in the desire to participate in decision-making of people with severe mental illness in six European countries.
Methods: The data was taken from a European longitudinal observational study (CEDAR; ISRCTN75841675). A sample of 514 patients with severe mental illness from the study centers in Ulm, Germany, London, England, Naples, Italy, Debrecen, Hungary, Aalborg, Denmark and Zurich, Switzerland were assessed as to desire to participate in medical decision-making. Associations between desire for participation in decision-making and center location were analyzed with generalized estimating equations.
Results: We found large cross-national differences in patientsâ desire to participate in decision-making, with the center explaining 40% of total variance in the desire for participation (p<0.001). Averaged over time and independent of patient characteristics, London (mean=2.27), Ulm (mean=2.13) and Zurich (mean=2.14) showed significantly higher scores in desire for participation, followed by Aalborg (mean=1.97), where scores were in turn significantly higher than in Debrecen (mean=1.56). The lowest scores were reported in Naples (mean=1.14). Over time, desire for participation in decision-making increased significantly in Zurich (b=0.23) and decreased in Naples (b=-0.14). In all other centers, values remained stable.
Conclusions: This study demonstrates that patientsâ desire for participation in decisionmaking varies by location. We suggest that more research attention be focused on identifying specific cultural and social factors in each country to further explain observed differences across Europe
Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC
The uncertainty on the calorimeter energy response to jets of particles is
derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the
calorimeter response to single isolated charged hadrons is measured and
compared to the Monte Carlo simulation using proton-proton collisions at
centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009
and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter
response to specific types of particles (positively and negatively charged
pions, protons, and anti-protons) is measured and compared to the Monte Carlo
predictions. Finally, the jet energy scale uncertainty is determined by
propagating the response uncertainty for single charged and neutral particles
to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3%
for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table,
submitted to European Physical Journal
Expedition 391 Preliminary Report : Walvis Ridge Hotspot: drilling Walvis Ridge, Southeast Atlantic Ocean, to test models of ridge hotspot interaction, isotopic zonation, and the hotspot reference frame
Hotspot tracks (quasilinear chains of seamounts, ridges, and other volcanic structures) provide important records of plate motions, as well as mantle geodynamics, magma flux, and mantle source compositions. The Tristan-Gough-Walvis Ridge (TGW) hotspot track, extending from the active volcanic islands of Tristan da Cunha and Gough through a province of guyots and then along Walvis Ridge to the Etendeka flood basalt province, forms one of the most prominent and complex global hotspot tracks. The TGW hotspot track displays a tight linear age progression in which ages increase from the islands to the flood basalts (covering ~135 My). Unlike Pacific tracks, which are simple chains of seamounts that are often compared to chains of pearls, the TGW track is alternately a steep-sided narrow ridge, an oceanic plateau, subparallel linear ridges and chains of seamounts, and areas of what appear to be randomly dispersed seamounts. The track displays isotopic zonation over the last ~70 My. The zonation appears near the middle of the track just before it splits into two to three chains of ridge- and guyot-type seamounts. The older ridge is also overprinted with age-progressive late-stage volcanism, which was emplaced ~30â40 My after the initial eruptions and has a distinct isotopic composition. The plan for Expedition 391 was to drill at six sites, three along Walvis Ridge and three in the seamount (guyot) province, to gather igneous rocks to better understand the formation of track edifices, the temporal and geochemical evolution of the hotspot, and the variation in paleolatitudes at which the volcanic edifices formed. After a delay of 18 days to address a shipboard outbreak of the coronavirus disease 2019 (COVID-19) virus, Expedition 391 proceeded to drill at four of the proposed sites: three sites on the eastern Walvis Ridge around Valdivia Bank, an ocean plateau within the ridge, and one site on the lower flank of a guyot in the Center track, a ridge located between the Tristan subtrack (which extends from the end of Walvis Ridge to the island of Tristan da Cunha) and the Gough subtrack (which extends from Walvis Ridge to the island of Gough). One hole was drilled at Site U1575, located on a low portion of the northeastern Walvis Ridge north of Valdivia Bank. At this location, 209.9 m of sediments and 122.4 m of igneous basement were cored. The latter comprised 10 submarine lava units consisting of pillow, lobate, sheet, and massive lava flows, the thickest of which was ~21 m. Most lavas are tholeiitic, but some alkalic basalts were recovered. A portion of the igneous succession consists of low-Ti basalts, which are unusual because they appear in the Etendeka flood basalts but have not been previously found on Walvis Ridge. Two holes were drilled at Site U1576 on the west flank of Valdivia Bank. The first hole was terminated because a bit jammed shortly after penetrating igneous basement. Hole U1576A recovered a remarkable ~380 m thick sedimentary section consisting mostly of chalk covering a nearly complete sequence from Paleocene to Late Cretaceous (Campanian). These sediments display short and long cyclic color changes that imply astronomically forced and longer term paleoenvironmental changes. The igneous basement yielded 11 submarine lava units ranging from pillows to massive flows, which have compositions varying from tholeiitic basalt to basaltic andesite, the first occurrence of this composition recovered from the TGW track. These units are separated by seven sedimentary chalk units that range in thickness from 0.1 to 11.6 m, implying a long-term interplay of sedimentation and lava eruptions. Coring at Site U1577, on the extreme eastern flank of Valdivia Bank, penetrated a 154 m thick sedimentary section, the bottom ~108 m of which is MaastrichtianâCampanian (possibly Santonian) chalk with vitric tephra layers. Igneous basement coring progressed only 39.1 m below the sediment-basalt contact, recovering three massive submarine tholeiite basalt lava flows that are 4.1, 15.5, and >19.1 m thick, respectively. Paleomagnetic data from Sites U1577 and U1576 indicate that their volcanic basements formed just before the end of the Cretaceous Normal Superchron and during Chron 33r, shortly afterward, respectively. Biostratigraphic and paleomagnetic data suggest an eastâwest age progression across Valdivia Bank, becoming younger westward. Site U1578, located on a Center track guyot, provided a long and varied igneous section. After coring through 184.3 m of pelagic carbonate sediments mainly consisting of Eocene and Paleocene chalk, Hole U1578A cored 302.1 m of igneous basement. Basement lavas are largely pillows but are interspersed with sheet and massive flows. Lava compositions are mostly alkalic basalts with some hawaiite. Several intervals contain abundant olivine, and some of the pillow stacks consist of basalt with remarkably high Ti content. The igneous sequence is interrupted by 10 sedimentary interbeds consisting of chalk and volcaniclastics and ranging in thickness from 0.46 to 10.19 m. Paleomagnetic data display a change in basement magnetic polarity ~100 m above the base of the hole. Combining magnetic stratigraphy with biostratigraphic data, the igneous section is inferred to span >1 My. Abundant glass from pillow lava margins was recovered at Sites U1575, U1576, and U1578. Although the igneous penetration was only two-thirds of the planned amount, drilling during Expedition 391 obtained samples that clearly will lead to a deeper understanding of the evolution of the Tristan-Gough hotspot and its track. Relatively fresh basalts with good recovery will provide ample samples for geochemical, geochronologic, and paleomagnetic studies. Good recovery of Late Cretaceous and early Cenozoic chalk successions provides samples for paleoenvironmental study
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