16 research outputs found
Age of the Jurassic hemipelagic sediments from the Ljubiš area (Zlatibor Mt., SW Serbia)
The type section of the Ljubiš Formation, (Djokov Potok, Zlatibor area, western Serbia) is characterized by abundant poorly-to-moderately preserved radiolarians. The lower part of the type section is characterized by Middle Jurassic (?Bajocian to Bathonian) radiolarian assemblages with Japonocapsa fusiformis (YAO), Takemuraella weghae (GRILL & KOZUR), Eoxitus hungaricus KOZUR, E. baloghi KOZUR, Helvetocapsa matsuokai (SASHIDA), Quarkus japonicus (YAO), Hexasaturnalis suboblongus (YAO), H. tetraspinus (YAO). Taking into account previous data from the upper part of the Ljubiš Formation, the age of the formation can be estimated to be in the interval from the ?Bajocian to Bathonian-Oxfordian. The new biostratigraphic data clearly show the onset of tectonic motion in the Middle Jurassic, documented by the presence of mass transport deposits intercalated in the radiolarite successions. This suggests a Middle Jurassic onset of ophiolite obduction which triggered the rapid deepening of the Adria margin, documented by the abrupt change from carbonate to radiolarite deposition.</p
The radiolarian age and petrographic composition of a block of the Lower Jurassic volcaniclastic breccia and chert of the Mamonia Complex, SW Cyprus
An exceptional exposure of volcaniclastic breccia intercalated with radiolarian cherts and limestones was studied which constitutes a unique block within the Upper Cretaceous Mamonia Mélange in the Akamas Peninsula of southwestern Cyprus. This breccia, represents the lower part of the sedimentary cover of the Upper Triassic Phasoula Formation volcanics. The breccia mainly consists of clasts of metabasalts, diabases, metagabbros, hyaloclastites and quartz-albite-chlorite-epidote aggregates, which have been metamorphosed at greenschist facies, and subordinate siltstones. The thin-bedded cherts intercalated between breccia levels, yielded radiolarian assemblages, which indicate an Early Jurassic age (Sinemurian to Pliensbachian) for the sequence
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Application of optical coherence tomography for in vivo monitoring of the meningeal lymphatic vessels during opening of blood–brain barrier: mechanisms of brain clearing
The meningeal lymphatic vessels were discovered 2 years ago as the drainage system involved in the mechanisms underlying the clearance of waste products from the brain. The blood–brain barrier (BBB) is a gatekeeper that strongly controls the movement of different molecules from the blood into the brain. We know the scenarios during the opening of the BBB, but there is extremely limited information on how the brain clears the substances that cross the BBB. Here, using the model of sound-induced opening of the BBB, we clearly show how the brain clears dextran after it crosses the BBB via the meningeal lymphatic vessels. We first demonstrate successful application of optical coherence tomography (OCT) for imaging of the lymphatic vessels in the meninges after opening of the BBB, which might be a new useful strategy for noninvasive analysis of lymphatic drainage in daily clinical practice. Also, we give information about the depth and size of the meningeal lymphatic vessels in mice. These new fundamental data with the applied focus on the OCT shed light on the mechanisms of brain clearance and the role of lymphatic drainage in these processes that could serve as an informative platform for a development of therapy and diagnostics of diseases associated with injuries of the BBB such as stroke, brain trauma, glioma, depression, or Alzheimer disease
Biological Earth observation with animal sensors
Space-based tracking technology using low-cost miniature tags is now delivering data on fine-scale animal movement at near-global scale. Linked with remotely sensed environmental data, this offers a biological lens on habitat integrity and connectivity for conservation and human health; a global network of animal sentinels of environmen-tal change
Abstracts from the 20th International Symposium on Signal Transduction at the Blood-Brain Barriers
https://deepblue.lib.umich.edu/bitstream/2027.42/138963/1/12987_2017_Article_71.pd
Radiolaires triasiques non téthysiens de Nouvelle-Zélande et du Nord-Est de la Sibérie
Des radiolaires bien conservés du Trias moyen ont été découverts dans des nodules phosphatés provenant des formations Waipapa, en Nouvelle-Zélande et du massif Omolon, au Nord-Est de la Sibérie. Les deux faunes comprennent de nombreuses espèces bien connues en Europe de la zone téthysienne, incluant Silicarmiger costatus costatus Dumitrica, Kozur & Mostler, 1980 qui indiquent un âge Ladinien inférieur. Ces espèces Téthysiennes existent avec de nombreux radiolaires non-téthysiens, caractéristiques de ces faunes. Parmi eux des spumellaires à pylome sont décrits dont le nouveau genre Glomeropyle Aita & Bragin. Ce genre n\u27avait pas encore été trouvé dans les séries du Trias moyen d\u27Europe, du Japon, d\u27Asie du Sud-Est et d\u27Amérique du Nord. Sept nouvelles espèces du Trias moyen sont décrites : Glomeropyle aurora, G. boreale, G. poinui, G. (?) galagala, G. grantmackiei, G. mahinepuaensis, G. waipapaensis. Elles n\u27ont pas d\u27affinités téthysiennes et sont seulement connues dans les hautes latitudes (Nord et Sud). Ces faunes triasiques ont donc une distribution bipolaire.Well-preserved Middle Triassic radiolarian faunas have been documented from phosphatic nodules collected from the Waipapa Terrane, New Zealand and the Omolon Massif, northeastern Siberia, respectively. Both New Zealand and northeastern Siberia faunas include many species that are well-known from European Tethys area, including Silicarmiger costatus costatus Dumitrica, Kozur & Mostler, 1980 which indicates an early Ladinian age. These Tethyan species occur with abundant non-Tethyan radiolarians that are characteristic of these faunas. Distinctive pylomate spumellarians are described herein as a new genus Glomeropyle Aita & Bragin. This genus has not been recognized in Middle Triassic sequences of Europe, Japan, Southeast Asia or North America. Seven new Middle Triassic species are described: Glomeropyle aurora, Glomeropyle boreale, Glomeropyle poinui, Glomeropyle (?) galagala, Glomeropyle grantmackiei, Glomeropyle mahinepuaensis, Glomeropyle waipapaensis. They do not haveTethyan affinities and are only known from northern and southern high latitudes. They are Triassic Radiolaria with a bipolar distribution pattern.</p
Increasing the efficiency of highly concentrated coal-water fuel based on the simulation of non-Newtonian fluid flow
The analysis of further prospects for increasing the efficiency of transportation of coal-water fuel in hydro-transport systems of industrial enterprises is carried out. The mathematical model of the spatial three-dimensional flow of coal-water fuel was developed on the basis of SST turbulence model based on the solution of Navier-Stokes equation. As a result of the calculation, the values of pressure loss, flow rate and velocity distribution over the cross section of the pipeline in the straight section and in the turn were determined, which allowed determining the energy consumption during coal-water fuel transportation in the industrial hydro-transport system. The performed studies allowed us to refine the mathematical model of water-coal suspension flow and, thus, improve the patterns of influence of hydro-transportation scheme and parameters of coal-water fuel on energy consumption for its supply to enterprise consumers. By means of mathematical model of non-Newtonian fluids flow, the patterns of influence of hydro-transport system parameters and transportation modes of coal-water fuel on its energy indicators in industrial hydro-transport systems are determined. The obtained results are related to reduction of energy consumption, optimization of enterprise transport network configuration and increase of efficiency of coal-water fuel transportation to enterprise energy facilities
Age and microfacies of oceanic Upper Triassic radiolarite components from the Middle Jurassic ophiolitic mélange in the Zlatibor Mountains (Inner Dinarides, Serbia) and their provenance
Oceanic radiolarite components from the Middle Jurassic ophiolitic mélange between Trnava and Rožanstvo in the Zlatibor Mountains (Dinaridic Ophiolite Belt) west of the Drina–Ivanjica unit yield Late Triassic radiolarian ages. The microfacies characteristics of the radiolarites show pure ribbon radiolarites without crinoids or thin-shelled bivalves. Beside their age and the preservation of the radiolarians this points to a deposition of the radiolarites on top of the oceanic crust of the Neo-Tethys, which started to open in the Late Anisian. South of the study area the ophiolitic mélange (Gostilje–Ljubiš–Visoka–Radoševo mélange) contains a mixture of blocks of 1) oceanic crust, 2) Middle and Upper Triassic ribbon radiolarites, and 3) open marine limestones from the continental slope. On the basis of this composition we can conclude that the Upper Triassic radiolarite clasts derive either from 1) the younger parts of the sedimentary succession above the oceanic crust near the continental slope or, more convincingly 2) the sedimentary cover of ophiolites in a higher nappe position, because Upper Triassic ribbon radiolarites are only expected in more distal oceanic areas. The ophiolitic mélange in the study area overlies different carbonate blocks of an underlying carbonate-clastic mélange (Sirogojno mélange). We date and describe three localities with different Upper Triassic radiolarite clasts in a mélange, which occurs A) on top of Upper Triassic fore-reef to reefal limestones (Dachstein reef), B) between an Upper Triassic reefal limestone block and a Lower Carnian reef limestone (Wetterstein reef), and C) in fissures of an Upper Triassic lagoonal to back-reef limestone (Dachstein lagoon). The sedimentary features point to a sedimentary and not to a tectonic emplacement of the ophiolitic mélange (= sedimentary mélange) filling the rough topography of the topmost carbonate-clastic mélange below. The block spectrum of the underlying and slightly older carbonate-clastic mélange points to a deposition of the sedimentary ophiolitic mélange east of or on top of the Drina–Ivanjica unit
Macro- vs Microcrystalline Wax: Interplay of Evaporation and Decomposition under Pressure Variation
Thermal behavior of two principally different wax materials (viz., paraffin Russian grade P-2 and microcrystalline Sasol 0907) has been investigated using thermogravimetry and differential scanning calorimetry at atmospheric and elevated pressure. The variation of experimental conditions during thermoanalytical studies highly affects the kinetics and highlights the interplay between evaporation and decomposition processes. It is revealed that vaporization kinetics is defined by the amount of the linear and branched hydrocarbons and under low confinement takes place with an enthalpy of δHev(298 K) = 79 ± 7 kJ mol-1. In turn, thermal decomposition with the activation energy equal to 236 ± 4 kJ mol-1 is shown to follow the random-scission reaction mechanism. The simultaneous consideration of obtained kinetic data reveals the general kinetic compensation trend and elucidates the unified underlying nature of the wax thermal response