164 research outputs found

    Architecture and permeability structure of the Sibillini Mts. Thrust and influence upon recent, extension-related seismicity in the central Apennines (Italy) through fault-valve behavior

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    The central Apennines are a fold-thrust belt currently affected by post-orogenic ex-tensional seismicity. To constrain the influ-ence that the inherited thrust-related struc-tures exert on the present seismic behavior of the belt, we provide the high-resolution structural and hydraulic characterization of one of the most external exposed thrust fault systems of the central Apennines, the Sibil-lini Mts. Thrust Front (STF). We integrate structural mapping, multiscale structural analysis, and in situ air permeability on the brittle structural facies of the thrust zone. We also performed K-Ar dating of selected fault rocks to better constrain structural in-heritance. The STF is defined by a complex, similar to 300-m-thick deformation zone involving Meso-Cenozoic marl and limestone that re-sults from the accommodation of both seis-mic and aseismic slip during shortening. Permeability measurements indicate that the low permeability (10-2 divided by 10-3 D) of the marly rich host rock diminishes within the thrust zone, where the principal slip surfaces and associated S-C structures represent efficient hydraulic barriers (permeability down to similar to 3 x 10-10 D) to sub-vertical fluid flow. Field data and K-Ar dating indicate that the STF began its evolution ca. 7 Ma (early Messin-ian). We suggest that the studied thrust zone may represent a barrier for the upward migration of deep fluids at the hypocentral depth of present-day extensional earth-quakes. We also speculate on the influence that similar deformation zones may have at depth on the overall regional seismotectonic pattern by causing transient fluid overpres-sures and, possibly, triggering cyclic exten-sional earthquakes on normal faults prone to slip while crosscutting the earlier thrust zones (as per a classic fault valve behavior). This mechanism may have controlled the ori-gin of the 2016-2017 central Apennines dev-astating earthquakes

    Erythromycin-resistant lactic acid bacteria in the healthy gut of vegans, ovo-lacto vegetarians and omnivores

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    Diet can affect the diversity and composition of gut microbiota. Usage of antibiotics in food production and in human or veterinary medicine has resulted in the emergence of commensal antibiotic resistant bacteria in the human gut. The incidence of erythromycin-resistant lactic acid bacteria (LAB) in the feces of healthy vegans, ovo-lacto vegetarians and omnivores was analyzed. Overall, 155 LAB were isolated and characterized for their phenotypic and genotypic resistance to erythromycin. The isolates belonged to 11 different species within the Enterococcus and Streptococcus genera. Enterococcus faecium was the dominant species in isolates from all the dietary categories. Only 97 out of 155 isolates were resistant to erythromycin after Minimum Inhibitory Concentration (MIC) determination; among them, 19 isolates (7 from vegans, 4 from ovo-lacto vegetarians and 8 from omnivores) carried the erm(B) gene. The copresence of erm(B) and erm(A) genes was only observed in Enterococcus avium from omnivores. Moreover, the transferability of erythromycin resistance genes using multidrug-resistant (MDR) cultures selected from the three groups was assessed, and four out of six isolates were able to transfer the erm(B) gene. Overall, isolates obtained from the omnivore samples showed resistance to a greater number of antibiotics and carried more tested antibiotic resistance genes compared to the isolates from ovo-lacto vegetarians and vegans. In conclusion, our results show that diet does not significantly affect the occurrence of erythromycin-resistant bacteria and that commensal strains may act as a reservoir of antibiotic resistance (AR) genes and as a source of antibiotic resistance spreading

    ATLAS Z Excess in Minimal Supersymmetric Standard Model

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    Recently the ATLAS collaboration reported a 3 sigma excess in the search for the events containing a dilepton pair from a Z boson and large missing transverse energy. Although the excess is not sufficiently significant yet, it is quite tempting to explain this excess by a well-motivated model beyond the standard model. In this paper we study a possibility of the minimal supersymmetric standard model (MSSM) for this excess. Especially, we focus on the MSSM spectrum where the sfermions are heavier than the gauginos and Higgsinos. We show that the excess can be explained by the reasonable MSSM mass spectrum.Comment: 13 pages, 7 figures; published versio

    Erythromycin-resistant lactic acid bacteria in the healthy gut of vegans, ovo-lacto vegetarians and omnivores

    Get PDF
    Diet can affect the diversity and composition of gut microbiota. Usage of antibiotics in food production and in human or veterinary medicine has resulted in the emergence of commensal antibiotic resistant bacteria in the human gut. The incidence of erythromycin-resistant lactic acid bacteria (LAB) in the feces of healthy vegans, ovo-lacto vegetarians and omnivores was analyzed. Overall, 155 LAB were isolated and characterized for their phenotypic and genotypic resistance to erythromycin. The isolates belonged to 11 different species within the Enterococcus and Streptococcus genera. Enterococcus faecium was the dominant species in isolates from all the dietary categories. Only 97 out of 155 isolates were resistant to erythromycin after Minimum Inhibitory Concentration (MIC) determination; among them, 19 isolates (7 from vegans, 4 from ovo-lacto vegetarians and 8 from omnivores) carried the erm(B) gene. The copresence of erm(B) and erm(A) genes was only observed in Enterococcus avium from omnivores. Moreover, the transferability of erythromycin resistance genes using multidrug-resistant (MDR) cultures selected from the three groups was assessed, and four out of six isolates were able to transfer the erm(B) gene. Overall, isolates obtained from the omnivore samples showed resistance to a greater number of antibiotics and carried more tested antibiotic resistance genes compared to the isolates from ovo-lacto vegetarians and vegans. In conclusion, our results show that diet does not significantly affect the occurrence of erythromycin-resistant bacteria and that commensal strains may act as a reservoir of antibiotic resistance (AR) genes and as a source of antibiotic resistance spreading

    Top Partner Discovery in the TtZT\to tZ channel at the LHC

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    In this paper we study the discovery potential of the LHC run II for heavy vector-like top quarks in the decay channel to a top and a ZZ boson. Despite the usually smaller branching ratio compared to charged-current decays, this channel is rather clean and allows for a complete mass reconstruction of the heavy top. The latter is achieved in the leptonic decay channel of the ZZ boson and in the fully hadronic top channel using boosted jet and jet substructure techniques. To be as model-independent as possible, a simplified model approach with only two free parameters has been applied. The results are presented in terms of parameter space regions for 3σ3\sigma evidence or 5σ5\sigma discovery for such new states in that channel.Comment: 24 pages, 8 figures, version 2 updated to JHEP 01 (2015) 08

    Heavy-light decay topologies as a new strategy to discover a heavy gluon

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    We study the collider phenomenology of the lightest Kaluza-Klein excitation of the gluon, G*, in theories with a warped extra dimension. We do so by means of a two-site effective lagrangian which includes only the lowest-lying spin-1 and spin-1/2 resonances. We point out the importance of the decays of G* to one SM plus one heavy fermion, that were overlooked in the previous literature. It turns out that, when kinematically allowed, such heavy-light decays are powerful channels for discovering the G*. In particular, we present a parton-level Montecarlo analysis of the final state Wtb that follows from the decay of G* to one SM top or bottom quark plus its heavy partner. We find that at \sqrt{s} = 7 TeV and with 10 fb^{-1} of integrated luminosity, the LHC can discover a KK gluon with mass in the range M_{G*} = (1.8 - 2.2) TeV if its coupling to a pair of light quarks is g_{G*qqbar} = (0.2-0.5) g_3. The same process is also competitive for the discovery of the top and bottom partners as well. We find, for example, that the LHC at \sqrt{s} = 7 TeV can discover a 1 TeV KK bottom quark with an integrated luminosity of (5.3 - 0.61) fb^{-1} for g_{G*qqbar} = (0.2-0.5) g_3.Comment: 36 pages, 13 figures. v2: a few typos corrected, comments added, version published in JHE

    Physics at a 100 TeV pp collider: beyond the Standard Model phenomena

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    This report summarises the physics opportunities in the search and study of physics beyond the Standard Model at a 100 TeV pp collider.Comment: 196 pages, 114 figures. Chapter 3 of the "Physics at the FCC-hh" Repor
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