488 research outputs found

    Geomorphological reconnaissance of the Psathopyrgos and Rion-Patras Fault zones (Achaia, NW Peloponnesus).

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    Στην εργασία αυτή συζητώνται γεωμορφολογικές παρατηρήσεις κατά μήκος των ενεργών ρηξιγενών ζωνών Ψαθοιτύργου και Ρίου-Πατρών (ΒΑ τμήμα). Οι ρηξιγενείς ζώνες αυτές αντιστοιχούν σε ρηξιγενή μέτωπα περισσότερο ή λιγότερο πολύπλοκης μορφολογίας. Τα γεωμορφολογικά χαρακτηριστικά των μετώπων δίδουν πληροφορίες για την γεωμετρία των ζωνών αυτών, συμπληρωματικές των ήδη υπαρχόντων δεδομένων από γεωλογικές έρευνες. Στοχεύοντας στην αναγνώριση θέσεων δυνητικά κατάλληλων για γεωμορφολογικές και γεωλογικές έρευνες για την εκτίμηση των ρυθμών ολίσθησης ρηγμάτων αυτών των ζωνών κατά το Ολόκαινο, περιγράφονται περιπτώσεις ρηγματωμένων ολοκαινικών γεωμορφών και σχετιζόμενων με αυτές επιφανειακών αποθέσεων. Επι πλέον, συζητώνται τα προβλήματα ανεύρεσης θέσεων κατάλληλων για γεωλογικές/γεωμορφολογικές έρευνες γαι τον χρονικό προσδιορισμό πρόσφατων σεισμικών διαρήξεων (παλαιοσεισμολογία), προβλήματα που οφείλονται τόσο σε ανθρώπινες επεμβάσεις, όσο και σε φυσικές γεωμορφολογικές διεργασίες.In this communication we discuss reconnaissance geomorphological observations along the active Psathopyrgos and Rion-Patras (NE part) fault zones. These fault zones correspond to more or less complex rangefronts, the geomorphic characteristics of which provide hints on the details of the fault zone geometries, adding to the existing geological data in the bibliography. Aiming at the identification of locations suitable or potentially suitable for geomorphological and geological studies for the determination of fault slip rates in the Holocene, we describe cases of faulted Holocene landforms and associated surficial deposits. We also discuss problems involved in finding locations suitable for geological (paleoseismological) studies for the determination of the timing of recent earthquake ruptures, problems due to both man-made and natural causes

    Long-Lived Time-Dependent Remnants During Cosmological Symmetry Breaking: From Inflation to the Electroweak Scale

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    Through a detailed numerical investigation in three spatial dimensions, we demonstrate that long-lived time-dependent field configurations emerge dynamically during symmetry breaking in an expanding de Sitter spacetime. We investigate two situations: a single scalar field with a double-well potential and the bosonic sector of an SU(2) non-Abelian Higgs model. For the single scalar, we show that large-amplitude oscillon configurations emerge spontaneously and persist to contribute about 1.2% of the energy density of the universe. We also show that for a range of parameters, oscillon lifetimes are enhanced by the expansion and that this effect is a result of parametric resonance. For the SU(2) case, we see about 4% of the final energy density in oscillons.Comment: 10 pages, RevTex4, 6 figures; v2: expanded SU(2) model section, added 2 figures, added one section, improved overall presentation and updated references, accepted for publication in Phys. Rev. D. Results remain the sam

    Management of multiple, late onset complications in a 33-year-old female, with a ventriculoperitoneal shunt and crohn\u27s disease

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    Numerous complications can occur after the placement of a venticuloperitoneal shunt. The late onset of an autoimmune disease such as Crohn\u27s disease can be the disruptive factor for a previously well functioning shunt. A 33-year-old female with a ventriculo-peritoneal shunt since the age of 7, as well as Crohn\u27s disease since the age of 25, presented in the ER with dysuria, long-lasting fever and intermittent severe headache. The patient underwent a CT scan of the chest, abdomen and brain. An enlargement of the ventricular system was revealed, suggesting malfunction of the shunt. Simultaneously, the abdominal scan revealed an abnormal course of the peritoneal catheter of the shunt in the lower abdomen, inside the bladder. The existence of the catheter inside the bladder was confirmed and filmed during a cystoscopy and was attributed to the several inflammations and surgeries performed for the treatment of Crohn\u27s disease.The absence of an obvious stenosis of the aqueduct, the early immunodeficiency due to Azathioprine and the multiple abdominal surgeries made the treatment selection a complex algorithm for the neurosurgeon

    Predicting Landslide Risk Combining Space Measurements and Geotechnical Modeling: Application at Kerasia Slide

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    The work developed and applied a methodology combining (a) space measurement of past displacement and (b) geotechnical modelling of displacement to predict and mitigate the risk of ground displacement cased by progressive slope instability. The area of study is in Kerasea village in Plastiras Lake Municipality. The problem under treatment is a creeping landslide in an inhabited area. Mitigation measures were analyzed

    Unnatural Oscillon Lifetimes in an Expanding Background

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    We consider a classical toy model of a massive scalar field in 1+1 dimensions with a constant exponential expansion rate of space. The nonlinear theory under consideration supports approximate oscillon solutions, but they eventually decay due to their coupling to the expanding background. Although all the parameters of the theory and the oscillon energies are of order one in units of the scalar field mass mm, the oscillon lifetime is exponentially large in these natural units. For typical values of the parameters, we see oscillon lifetimes scaling approximately as τexp(kE/m)/m\tau \propto \exp(k E/m)/m where EE is the oscillon energy and the constant kk is on the order of 5 to 15 for expansion rates between H=0.02mH=0.02m and H=0.01mH=0.01m.Comment: 7 pages, 2 .eps figures; v2: expanded discussion of decay, fixed typos; version to appear in Physics Letters

    Emergence of Oscillons in an Expanding Background

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    We consider a (1+1) dimensional scalar field theory that supports oscillons, which are localized, oscillatory, stable solutions to nonlinear equations of motion. We study this theory in an expanding background and show that oscillons now lose energy, but at a rate that is exponentially small when the expansion rate is slow. We also show numerically that a universe that starts with (almost) thermal initial conditions will cool to a final state where a significant fraction of the energy of the universe -- on the order of 50% -- is stored in oscillons. If this phenomenon persists in realistic models, oscillons may have cosmological consequences.Comment: 13 pages, 4 .eps figures, uses RevTeX4; v2: clarified details of expansion, added reference

    Aging of bone marrow mesenchymal stromal cells: Hematopoiesis disturbances and potential role in the development of hematologic cancers

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    Aging of bone marrow is a complex process that is involved in the development of many diseases, including hematologic cancers. The results obtained in this field of research, year after year, underline the important role of cross-talk between hematopoietic stem cells and their close environment. In bone marrow, mesenchymal stromal cells (MSCs) are a major player in cell-to-cell communication, presenting a wide range of functionalities, sometimes opposite, depending on the environmental conditions. Although these cells are actively studied for their therapeutic properties, their role in tumor progression remains unclear. One of the reasons for this is that the aging of MSCs has a direct impact on their behavior and on hematopoiesis. In addition, tumor progression is accompanied by dynamic remodeling of the bone marrow niche that may interfere with MSC functions. The present review presents the main features of MSC senescence in bone marrow and their implications in hematologic cancer progression

    Measurement of the neutron-induced fission cross section of Th 230 at the CERN n_TOF facility

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    The neutron-induced fission cross section of 230 Th has been measured at the neutron time-of-flight facility n_TOF located at CERN. The experiment was performed at the experimental area EAR-1 with a neutron flight path of 185 m, using Micromegas detectors for the detection of the fission fragments. The 230 Th(n, f ) cross section was determined relative to the 235 U(n, f ) one, covering the energy range from the fission threshold up to 400 MeV. The results from the present work are compared with existing cross-section datasets and the observed discrepancies are discussed and analyzed. Finally, using the code EMPIRE 3.2.3 a theoretical study, based on the statistical model, was performed leading to a satisfactory reproduction of the experimental results with the proper tuning of the respective parameters, while for incident neutron energy beyond 200 MeV the fission of 230 Th was described by Monte Carlo simulations.This project received funding from the Euratom “Support safe operation of nuclear systems” program 2014–2018 under Grant Agreement No. 847552 (SANDA) and by the funding agencies of the participating institutes. This research is imple- mented through the IKY scholarships program and cofinanced by the European Union (European Social Fund ’ESF) and Greek national funds through the action entitled “Reinforce- ment of Postdoctoral Researchers - 2nd call (MIS 5033021)”, in the framework of the Operational Programme “Human Resources Development Program, Education and Lifelong Learning” of the National Strategic Reference Framework.Article signat per 137 autors/es: V. Michalopoulou, A. Stamatopoulos, M. Diakaki, A. Tsinganis, R. Vlastou, M. Kokkoris, N. Patronis, Z. Eleme, D. Macina, L. Tassan-Got, N. Colonna, E. Chiaveri, A. Ventura, P. Schillebeeckx, J. Heyse, G. Sibbens, G. Alaerts, A. Borella, A. Moens, D. Vanleeuw, O. Aberle, V. Alcayne, S. Amaducci, J. Andrzejewski, L. Audouin, V. Babiano-Suarez, M. Bacak, M. Barbagallo, S. Bennett, E. Berthoumieux, J. Billowes, D. Bosnar, A. Brown, M. Busso, M. Caamaño, L. Caballero, F. Calviño, M. Calviani, D. Cano-Ott, A. Casanovas, F. Cerutti, G. Cortés, M. A. Cortés-Giraldo, L. Cosentino, S. Cristallo, L. A. Damone, P. J. Davies, M. Dietz, C. Domingo-Pardo, R. Dressler, Q. Ducasse, E. Dupont, I. Durán, B. Fernández-Domínguez, A. Ferrari, P. Finocchiaro, V. Furman, K. Göbel, R. Garg, A. Gawlik-Ramiega, S. Gilardoni, I. F. Gonçalves, E. González-Romero, C. Guerrero, F. Gunsing, H. Harada, S. Heinitz, D. G. Jenkins, A. Junghans, F. Käppeler, Y. Kadi, A. Kimura, I. Knapová, Y. Kopatch, M. Krticka, D. Kurtulgil, I. Ladarescu, C. Lederer-Woods, H. Leeb, J. Lerendegui-Marco, S. J. Lonsdale, A. Manna, T. Martínez, A. Masi, C. Massimi, P. Mastinu, M. Mastromarco, E. A. Maugeri, A. Mazzone, E. Mendoza, A. Mengoni, P. M. Milazzo, F. Mingrone, J. Moreno-Soto, A. Musumarra, A. Negret, R. Nolte, F. Ogállar, A. Oprea, A. Pavlik, J. Perkowski, C. Petrone, L. Piersanti, E. Pirovano, I. Porras, J. Praena, J. M. Quesada, D. Ramos-Doval, T. Rauscher, R. Reifarth, D. Rochman, Y. Romanets, C. Rubbia, M. Sabaté-Gilarte, A. Saxena, D. Schumann, A. Sekhar, A. G. Smith, N. V. Sosnin, P. Sprung, G. Tagliente, J. L. Tain, A. Tarifeño-Saldivia, Th. Thomas, P. Torres-Sánchez, J. Ulrich, S. Urlass, S. Valenta, G. Vannini, V. Variale, P. Vaz, D. Vescovi, V. Vlachoudis, A. Wallner, P. J. Woods, T. Wright, and P. Žugec.Postprint (published version

    First results of the 241Am(n,f) cross section measurement at the Experimental Area 2 of the n_TOF facility at CERN

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    Feasibility, design and sensitivity studies on innovative nuclear reactors that could address the issue of nuclear waste transmutation using fuels enriched in minor actinides, require high accuracy cross section data for a variety of neutron-induced reactions from thermal energies to several tens of MeV. The isotope 241Am (T1/2= 433 years) is present in high-level nuclear waste (HLW), representing about 1.8 % of the actinide mass in spent PWR UOx fuel. Its importance increases with cooling time due to additional production from the β-decay of 241Pu with a half-life of 14.3 years. The production rate of 241 Am in conventional reactors, including its further accumulation through the decay of 241Pu and its destruction through transmutation/incineration are very important parameters for the design of any recycling solution. In the present work, the 241 Am(n,f) reaction cross-section was measured using Micromegas detectors at the Experimental Area 2 of the n_TOF facility at CERN. For the measurement, the 235U(n,f) and 238U(n,f) reference reactions were used for the determination of the neutron flux. In the present work an overview of the experimental setup and the adopted data analysis techniques is given along with preliminary results
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