Subaqueous volcaniclastic successions in the Middle Triassic of Western Hungary

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Középső-triász platformkarbonátok és vulkanitok vizsgálata a Latemar környékén (Dolomitok, Olaszország) [Middle Triassic platform carbonates and volcanites in the Latemar area (Dolomites, Italy)]

Sponsored by the T043341 project of the Hungarian Research Found (OTKA) we have investigated the buildup of the Middle Triassic Latemar platform (Western Dolomites), its volcanic stuctures and also basinal successions of the surrounding area. Our leader on the field trip was Nereo Preto from the Padova University. The relatively small isolated Middle Triassic carbonate platform of the Latemar is one of the most famous Triassic platform of the Dolomites. It is surrounded by pelagic sediments of coeval interplatform basins. The main part of the platform is built up by cyclic peritidal to subtidal lagoon facies. Within this succession more than 600 shallowing upward basic cycles were reconstructed and several higher cyclostratigraphic units were defined. These cycles have been interpreted as orbitally forced Milankovič cycles. Based on their concept therefore 14 My were estimated for the duration of the deposition of the whole carbonate sequence. However, on the basis of new biostratigraphic and radiometric data that yielded a duration only between 2 and 4,7 My a group of researchers questioned this interpretation. The Sciliar (Schlern) Formation has been only slightly dolomitized on the Latemar, this causes unique preservation of the fossils. Dasycladacean algae and ammonoids occure together in the platform succession. Correlation of algae and ammonoid zonation can give a chance to use a more accurate and detailed chronostratigraphic chart within the Middle Triassic platforms not only in the Dolomites but in the whole area of the Western Tethys. Ammonite bearing limestone lying above the "lower edifice" belongs to the Avisianum Subzone of the Reitzi Zone (sensu VÖRÖS 1998). Based on our field observations this facies can be interpreted as infilling of a channel which connected the platform-lagoon with the pelagic basin. Within the overlying platform carbonate succession the Crassus and Serpianensis Subzone (sensu MIETTO, MANFRIN 1995) can be detected while in the uppermost part of the section the basal Curionii Zone was also indicated. Preliminary investigations of algae-assemblage show (Fig. 5) that the last occurence of Diplopora annulatissima can be correlated with the base of Secedensis (Nevadites) Zone, while the first occurence of Teutloporella herculea fits to the base of Curionii Zone. The later change in the flora may give the opportunity to fix the newly difined Anisian/Ladinian boundary within thick platform carbonate successions, as well. Being calibrated with ammonite zones the Dasycladacean zonation of the Latemar provides useful tool for chronostratigraphic subdivision of the Budaörs Dolomite (lithostratigraphic counterpart of the Schlern Formation) and for reconstruction of the evolution of Middle Triassic platforms in the Transdanubian Range. A series of dyke swarm cross cuts the carbonate platform of the Latemar. The individual dykes are mafic, aphanitic to microholocrystalline, and they vary in thickness between dm to tens of metres. The dyke margins are generally straight, however, long wavelength and small amplitude undulations have been recognized in case of thick dykes. The dykes have chilled margin up to 10 cm in width. Quench crystals of plagioclase are common in mm-size range and their size increases toward the centre of the dykes. The dykes are more weathered than the surrounding carbonate material, and therefore their location is represented by sharp irregularities in the otherwise flat top of the platform. Along the dyke strikes in the centre of the Latemar three pyroclastic breccia zone have been identified. The southernmost is a complex association of tilted limestone beds that are surrounded by a coarse-grained pyroclastic breccia. They form funnel shape disturbed zone in the carbonate platform with an average width of 150 m. In the pyroclastic breccia, angular shape basaltoid lapilli are common. Basaltoid lapilli are abundant in lherzolite nodules with angular shape and few cm in diameter. Similar, but larger nodules form cumulate zones in the basal region of the exposed volcaniclastic succession. The volcanic clasts are generally altered, but their shape is still angular, and closely resembling their non-abraded, primary origin due to fragmentation of the magma by an explosive volcanic eruption. The volcanic clasts, as well as the intruded irregularly shaped dykes in the lower part of the volcanic pipe are chilled indicating sudden cooling by magma-water interaction as an inferred fragmentation process. In the pyroclastic breccia hosts there are large angular shape blocks of debris that have been derived from the surrounding carbonate platform units. These clasts range cm to few m size in diameter and they are always angular, indicating that they must have been consolidated and hard by the time they have been disrupted by an eruption. In the upper part of the volcanic breccia pipe mega-blocks up to few tens of metres across have been identified. They are tilted, rotated, and form a chaotic zone in the pyroclastic breccia host all indicates that they have been derived from a former conduit/crater wall. The general architecture of the volcanic breccia pipe is inferred to be a diatreme that is an exposed and exhumed volcanic conduit of a former phreatomagmatic volcano. North of the above described diatreme two other pyroclastic breccia body forms a few tens of metres wide semicircular zone. Each of them is rich in angular limestone fragments, gravels, and bedded red lapilli tuff fragments. Carbonate clasts often form trains of clasts indicative of some sort of movement through the pyroclastic breccia zone inferred to be a result of a fluidization through the volcanic pipe. Each pyroclastic breccia pipe shows angularity, chilled margins, microlite-free textural features on the juvenile clasts that are indicative for fragmentation by sudden cooling of magma by magma/water interaction. The identified three pyroclastic breccia pipes are inferred to be diatremes, root zones of former small to medium volume, mafic, phreatomagmatic volcanoes. K/Ar dating of the sample from the diatreme gave an age of 204±7.8 My (Balogh Kadosa pers. comm.). Near to the Latemar on the Dos Capel, a thick succession of pelagic basin fcies (Livinallongo Formation, partly heteropic with the Sciliar Formation) crops out which is interbedded with several dm thick pyroclastic beds of typical "pietra verde". The grading, sorting, lower and upper bed contacts indicate that these beds were predominantly deposited by ash turbidites that carried volcanic material into the basin. Thin layers of fall beds also exist. Near the top of the Dos Capel sequence a well-exposed thickly to thinly bedded, accidental lithic-rich, cross-bedded or stratified, occasionally dune-bedded lapilli tuff and tuff succession crops out. These beds are rich in angular limestone clasts that occasionally form shallow impact sags on the underlying bed surface. The juvenile clasts are angular, chilled, and low in vesicularity, characteristic for juvenile fragments fragmented by phreatomagmatic explosive interaction of melt and water. The large volume of the accidental lithic clasts in the pyroclastic rock units indicates that the magma fragmentation must have occurred in subsurface environment and/or the volcanic conduit was partially closed. On the basis of the preliminary field study and comparison of different volcanic facies in and around the Latemar highlight the possible facies relationships between diatremes that cut through the platform and their eruption fed tephra falls deposited in the pelagic basin and/or produced pyroclastic density currents that may initiated volcaniclastic turbidites transported pyroclasts deep into the basin around the platforms. It is also inferred that in a shallow water environment pyroclastic mounds and associated tuff cones may have produced volcanic islands on top of platforms and an entire lateral facies transition could be expected to be identified in the near future via systematic mapping and interpretation of the pyroclastic successions in the region

Nanoindentation induced deformation anisotropy in WC, β-Si3N4 and ZrB2 crystals

The influence of crystal orientation on elastic and plastic response of WC, β-Si3N4 and ZrB2 ceramic grains is important to understand, model and enhance its composite mechanical properties. In order to investigate this, nanoindentation testing was carried out using Berkovich tip on selected surface areas which were mapped by electron backscatter diffraction (EBSD) prior to the tests. To study the surface morphology after nanoindentation and to characterize the resulted deformation fields around the imprints additional EBSD, atomic force microscopy (AFM) and scanning electron microscopy (SEM) investigations were performed. Considerable elastic and plastic anisotropy was found is WC and β-Si3N4 (Fig. 1a,b) crystals while the orientation dependence of ZrB2 grains exhibited slight influence on hardness and indentation modulus. The measured indentation modulus, as the elastic response, was compared with the model proposed by Vlassak and Nix and our finite element model (FEM) calculations using single crystal elastic constants, as it is shown for β-Si3N4 in Fig. 1c. To explain the obtained hardness anisotropy, as the plastic response, a theoretical model is proposed in which the critical force for slip activation is determined as a function of crystal orientation, based on the possible slip systems of materials. The predictions of the applied models describing both elastic and plastic behaviors are in good agreement with the experimental results, (for β-Si3N4 see in Fig. 1d

Life Predicted in a Probabilistic Design Space for Brittle Materials With Transient Loads

Analytical techniques have progressively become more sophisticated, and now we can consider the probabilistic nature of the entire space of random input variables on the lifetime reliability of brittle structures. This was demonstrated with NASA s CARES/Life (Ceramic Analysis and Reliability Evaluation of Structures/Life) code combined with the commercially available ANSYS/Probabilistic Design System (ANSYS/PDS), a probabilistic analysis tool that is an integral part of the ANSYS finite-element analysis program. ANSYS/PDS allows probabilistic loads, component geometry, and material properties to be considered in the finite-element analysis. CARES/Life predicts the time dependent probability of failure of brittle material structures under generalized thermomechanical loading--such as that found in a turbine engine hot-section. Glenn researchers coupled ANSYS/PDS with CARES/Life to assess the effects of the stochastic variables of component geometry, loading, and material properties on the predicted life of the component for fully transient thermomechanical loading and cyclic loading

Nanoindentation, micropillar compression and nanoscratch testing of ZrB2 grains

The mechanical response under nanoindentation, micropillar compression and nanoscratch tests of ultra-high temperature ZrB2 ceramic grains were investigated. The tests were carried on selected surface areas where the grain orientations were mapped by electron backscatter diffraction (EBSD) prior to the measurements (Fig.1a). Instrumented indentation were applied for compression using flat punch tip for nanoindentation and nanoscratch tests Berkovich tips were used. Scanning electron microscopy (SEM), atomic force microscopy (AFM) and additional EBSD were performed to study the surface morphology and to characterize the deformations. Strong influence of crystal orientation was observed during micropillar compression while nanoindentation and nanoscratch tests revealed smaller anisotropy. Considerable plastic deformation is revealed under pillar compression, as it is shown in Fig. 1b,c, but indentation and scratch tests showed detectable plasticity, as well. Uniformly, basal oriented grains exhibited higher hardness, yield stress and rupture stress values compared to the prismatic orientation. The elastic anisotropy showed reversed tendency with lower indentation and Young’s modulus values corresponding to the basal orientation in comparison with the prismatic. To describe the elastic anisotropy, the Vlassak-Nix model and finite element model (FEM) calculations were performed based on the single crystal elastic constants of ZrB2. To explain the obtained hardness anisotropy, a theoretical model was proposed in which the critical force for slip activation is determined as a function of crystal orientation, based on the possible slip systems of materials. The calculated results shows similar tendency as the experimental values

Regional effect on urban atmospheric nucleation

Secondary aerosol particle production via new particle formation (NPF) has been shown to be a major contributor to the global aerosol load. NPF has also been observed frequently in urban environments. Here, we investigate the effect of regional NPF on urban aerosol load under well-defined atmospheric conditions. The Carpathian Basin, the largest orogenic basin in Europe, represents an excellent opportunity for exploring these interactions. Based on long-term observations, we revealed that NPF seen in a central large city of the basin (Budapest) and its regional background occur in a consistent and spatially coherent way as a result of a joint atmospheric phenomenon taking place on large horizontal scales. We found that NPF events at the urban site are usually delayed by > 1 h relative to the rural site or even inhibited above a critical condensational sink level. The urban processes require higher formation rates and growth rates to be realized, by mean factors of 2 and 1.6, respectively, than the regional events. Regional-and urban-type NPF events sometimes occur jointly with multiple onsets, while they often exhibit dynamic and timing properties which are different for these two event types.Peer reviewe

Probabilistic Prediction of Lifetimes of Ceramic Parts

ANSYS/CARES/PDS is a software system that combines the ANSYS Probabilistic Design System (PDS) software with a modified version of the Ceramics Analysis and Reliability Evaluation of Structures Life (CARES/Life) Version 6.0 software. [A prior version of CARES/Life was reported in Program for Evaluation of Reliability of Ceramic Parts (LEW-16018), NASA Tech Briefs, Vol. 20, No. 3 (March 1996), page 28.] CARES/Life models effects of stochastic strength, slow crack growth, and stress distribution on the overall reliability of a ceramic component. The essence of the enhancement in CARES/Life 6.0 is the capability to predict the probability of failure using results from transient finite-element analysis. ANSYS PDS models the effects of uncertainty in material properties, dimensions, and loading on the stress distribution and deformation. ANSYS/CARES/PDS accounts for the effects of probabilistic strength, probabilistic loads, probabilistic material properties, and probabilistic tolerances on the lifetime and reliability of the component. Even failure probability becomes a stochastic quantity that can be tracked as a response variable. ANSYS/CARES/PDS enables tracking of all stochastic quantities in the design space, thereby enabling more precise probabilistic prediction of lifetimes of ceramic components

Arabidopsis RETINOBLASTOMA RELATED directly regulates DNA damage responses through functions beyond cell cycle control

The rapidly proliferating cells in plant meristems must be protected from genome damage. Here, we show that the regulatory role of the Arabidopsis RETINOBLASTOMA RELATED (RBR) in cell proliferation can be separated from a novel function in safeguarding genome integrity. Upon DNA damage, RBR and its binding partner E2FA are recruited to heterochromatic γH2AX-labelled DNA damage foci in an ATM- and ATR-dependent manner. These γH2AX-labelled DNA lesions are more dispersedly occupied by the conserved repair protein, AtBRCA1, which can also co-localise with RBR foci. RBR and AtBRCA1 physically interact in vitro and in planta. Genetic interaction between the RBR-silenced amiRBR and Atbrca1 mutants suggests that RBR and AtBRCA1 may function together in maintaining genome integrity. Together with E2FA, RBR is directly involved in the transcriptional DNA damage response as well as in the cell death pathway that is independent of SOG1, the plant functional analogue of p53. Thus, plant homologs and analogues of major mammalian tumour suppressor proteins form a regulatory network that coordinates cell proliferation with cell and genome integrity

The SP2 SCOPES Project on Speech Prosody

This is an overview of a Joint Research Project within the Scientific co-operation between Eastern Europe and Switzerland (SCOPES) Program of the Swiss National Science Foundation (SNFS) and Swiss Agency for Development and Cooperation (SDC). Within the SP2 SCOPES Project on Speech Prosody, in the course of the following two years, the four partners aim to collaborate on the subject of speech prosody and advance the extraction, processing, modeling and transfer of prosody for a large portfolio of European languages: French, German, Italian, English, Hungarian, Serbian, Croatian, Bosnian, Montenegrin, and Macedonian. Through the intertwined four research plans, synergies are foreseen to emerge that will build a foundation for submitting strong joint proposals for EU funding

T cell immune response predicts survival in severely ill COVID-19 patients requiring venovenous extracorporeal membrane oxygenation support

IntroductionThere is a critical gap in understanding which SARS-CoV-2 patients would benefit most from venovenous extracorporeal membrane oxygenation (VV-ECMO) support. The potential role of a dysregulated immune response is still unclear in this patient population.ObjectivesTo assess the potential predictive value of SARS-CoV-2 specific cellular and humoral immune responses for survival in critically ill COVID-19 patients requiring VV-ECMO.MethodsWe conducted a prospective single-center observational study of unvaccinated patients requiring VV-ECMO support treated at the intensive care unit of Semmelweis University Heart and Vascular Center between March and December 2021. Peripheral blood samples were collected to measure the humoral and cellular immune statuses of the patients at the VV-ECMO cannulation. Patients were followed until hospital discharge.ResultsOverall, 35 COVID-19 patients (63% men, median age 37 years) on VV-ECMO support were included in our study. The time from COVID-19 verification to ECMO support was a median (IQR) of 10 (7-14) days. Of the patients, 9 (26%) were discharged alive and 26 (74%) died during their hospital stay. Immune tests confirmed ongoing SARS-CoV-2 infection in all the patients, showing an increased humoral immune response. SARS-CoV-2-specific cellular immune response was significantly higher among survivors compared to the deceased patients. A higher probability of survival was observed in patients with markers indicating a higher T cell response detected by both QuantiFeron (QF) and flow cytometry (Flow) assays. (Flow S1 CD8+ ≥ 0.15%, Flow S1 CD4+ ≥ 0.02%, QF CD4 ≥ 0.07, QF whole genome ≥ 0.59). In univariate Cox proportional hazard regression analysis BMI, right ventricular (RV) failure, QF whole genome T cell level, and Flow S1 CD8+ T cell level were associated with mortality, and we found that an increased T cell response showed a significant negative association with mortality, independent of BMI and RV failure.ConclusionEvaluation of SARS-CoV-2 specific T cell response before the cannulation can aid the risk stratification and evaluation of seriously ill COVID-19 patients undergoing VV-ECMO support by predicting survival, potentially changing our clinical practice in the future