scholarly journals VRTBY ICHNORODU GASTROCHAENOLITES JAKOŽTO ŽIVOTNÍ PROSTOR MLŽŮ Z LOKALITY BORAČ-PODOLÍ (KARPATSKÁ PŘEDHLUBEŇ, ČESKÁ REPUBLIKA)

2018 ◽  
Vol 25 (1-2) ◽  
Author(s):  
Jaroslav Šamánek ◽  
Radek Mikuláš ◽  
Nela Doláková ◽  
Šářka Hladilová

In 2015 the locality Borač-Podolí was newly examined. The locality is situated 8 km NW from the town of Tišnov. A large amount of shallow-water fossils of middle Miocene (Badenian) age was collected. The state of preservation of the material enabled us bivalve borings of ichnogenus Gastrochaenolites which were bored into colonies of hermatype corals and other calcareous hard substrates. In some of these borings, bivalves were found in situ. The borings were determined as Gastrochaenolites isp., Gastrochaenolites orbicularis, Gastrochaenolites lapidicus, Gastrochaenolites dijugus and Gastrochaenolites torpedo. The in situ bivalves were determined as Gastrochaena cf. intermedia, Rocellaria cf. dubia, Hiatella arctica and Cardita calyculata. The first three species probably represent primary borers while Cardita calyculata is probably a secondary user (squatter). Based on an analysis of fossil material, we can assume that borings were created aft er the death of corals during the repeated transport of these bioclasts. It led to colonizing of the whole surface of coral bioclasts. The bioclasts were then moved to deeper water. Transport to water with clay sedimentation enabled the preservation of the bivalves in situ in borings.

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Adnan Kadić ◽  
Anikó Várnai ◽  
Vincent G. H. Eijsink ◽  
Svein Jarle Horn ◽  
Gunnar Lidén

Abstract Background Biochemical conversion of lignocellulosic biomass to simple sugars at commercial scale is hampered by the high cost of saccharifying enzymes. Lytic polysaccharide monooxygenases (LPMOs) may hold the key to overcome economic barriers. Recent studies have shown that controlled activation of LPMOs by a continuous H2O2 supply can boost saccharification yields, while overdosing H2O2 may lead to enzyme inactivation and reduce overall sugar yields. While following LPMO action by ex situ analysis of LPMO products confirms enzyme inactivation, currently no preventive measures are available to intervene before complete inactivation. Results Here, we carried out enzymatic saccharification of the model cellulose Avicel with an LPMO-containing enzyme preparation (Cellic CTec3) and H2O2 feed at 1 L bioreactor scale and followed the oxidation–reduction potential and H2O2 concentration in situ with corresponding electrode probes. The rate of oxidation of the reductant as well as the estimation of the amount of H2O2 consumed by LPMOs indicate that, in addition to oxidative depolymerization of cellulose, LPMOs consume H2O2 in a futile non-catalytic cycle, and that inactivation of LPMOs happens gradually and starts long before the accumulation of LPMO-generated oxidative products comes to a halt. Conclusion Our results indicate that, in this model system, the collapse of the LPMO-catalyzed reaction may be predicted by the rate of oxidation of the reductant, the accumulation of H2O2 in the reactor or, indirectly, by a clear increase in the oxidation–reduction potential. Being able to monitor the state of the LPMO activity in situ may help maximizing the benefit of LPMO action during saccharification. Overcoming enzyme inactivation could allow improving overall saccharification yields beyond the state of the art while lowering LPMO and, potentially, cellulase loads, both of which would have beneficial consequences on process economics.


2016 ◽  
Vol 61 (1) ◽  
pp. 199-216 ◽  
Author(s):  
Marilena Cardu ◽  
Sergio Dipietromaria ◽  
Pierpaolo Oreste

Abstract The aim of this study was to evaluate the state of stress of a „voids-pillar“ structure excavated by means of the sub-level stoping method in an underground limestone quarry near Bergamo (Italy). Both the current structure of the quarry (i.e. the rooms exploited till now) and a possible future scenario were analysed using the (FDM) FLAC 2D code. The quarry has been in operation since 1927; at present, exploitation is carried out underground via the sub-level stoping method. Exploitation involves two levels, with 5 rooms on the upper level and 9 rooms on the lower level. After analysing data obtained from laboratory and in situ tests carried out on rock samples and natural discontinuities, the geomechanical properties of the medium, knowledge of which is essential in order to establish the parameters that must be included in the numerical model, were evaluated. The implementation of three numerical models made it possible to study both the present conditions of quarry exploitation and the evolution of the exploited rooms, as well as a possible expansion involving a third level of rooms. Using the results obtained regarding the stress-strain present in the pillars, a potential change in room geometry was proposed aimed at reducing the stress state inside the pillars, decreasing plasticity and increasing overall quarry safety.


2020 ◽  
Vol 40 (04) ◽  
pp. 524-535
Author(s):  
Dmitry Y. Nechipurenko ◽  
Aleksey M. Shibeko ◽  
Anastasia N. Sveshnikova ◽  
Mikhail A. Panteleev

AbstractComputational physiology, i.e., reproduction of physiological (and, by extension, pathophysiological) processes in silico, could be considered one of the major goals in computational biology. One might use computers to simulate molecular interactions, enzyme kinetics, gene expression, or whole networks of biochemical reactions, but it is (patho)physiological meaning that is usually the meaningful goal of the research even when a single enzyme is its subject. Although exponential rise in the use of computational and mathematical models in the field of hemostasis and thrombosis began in the 1980s (first for blood coagulation, then for platelet adhesion, and finally for platelet signal transduction), the majority of their successful applications are still focused on simulating the elements of the hemostatic system rather than the total (patho)physiological response in situ. Here we discuss the state of the art, the state of the progress toward the efficient “virtual thrombus formation,” and what one can already get from the existing models.


2019 ◽  
Vol 48 (21) ◽  
pp. 7122-7129 ◽  
Author(s):  
Chia-Jui Chang ◽  
You-Chiuan Chu ◽  
Hao-Yu Yan ◽  
Yen-Fa Liao ◽  
Hao Ming Chen

The state-of-art RuO2 catalyst for the oxygen evolution reaction (OER) is measured by using in situ X-ray absorption spectroscopy (XAS) to elucidate the structural transformation during catalyzing the reaction in acidic and alkaline conditions.


2017 ◽  
Vol 72 (1) ◽  
pp. 101-111
Author(s):  
Florian Mazel

Dominique Iogna-Prat’s latest book, Cité de Dieu, cité des hommes. L’Église et l’architecture de la société, 1200–1500, follows on both intellectually and chronologically from La Maison Dieu. Une histoire monumentale de l’Église au Moyen Âge (v. 800–v. 1200). It presents an essay on the emergence of the town as a symbolic and political figure of society (the “city of man”) between 1200 and 1700, and on the effects of this development on the Church, which had held this function before 1200. This feeds into an ambitious reflection on the origins of modernity, seeking to move beyond the impasse of political philosophy—too quick to ignore the medieval centuries and the Scholastic moment—and to relativize the effacement of the institutional Church from the Renaissance on. In so doing, it rejects the binary opposition between the Church and the state, proposes a new periodization of the “transition to modernity,” and underlines the importance of spatial issues (mainly in terms of representation). This last element inscribes the book in the current of French historiography that for more than a decade has sought to reintroduce the question of space at the heart of social and political history. Iogna-Prat’s stimulating demonstration nevertheless raises some questions, notably relating to the effects of the Protestant Reformation, the increasing power of states, and the process of “secularization.” Above all, it raises the issue of how a logic of the polarization of space was articulated with one of territorialization in the practices of government and the structuring of society—two logics that were promoted by the ecclesial institution even before states themselves.


2018 ◽  
Vol 127 (2) ◽  
pp. 371-389 ◽  
Author(s):  
Tyler Oesch ◽  
Frank Weise ◽  
Dietmar Meinel ◽  
Christian Gollwitzer

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