Search results for "Ultra"
showing 10 items of 4451 documents
Experimental Evolution Reveals a Genetic Basis for Membrane-Associated Virus Release
2021
Many animal viruses replicate and are released from cells in close association to membranes. However, whether this is a passive process or is controlled by the virus remains poorly understood. Importantly, the genetic basis and evolvability of membrane-associated viral shedding have not been investigated. To address this, we performed a directed evolution experiment using coxsackievirus B3, a model enterovirus, in which we repeatedly selected the free-virion or the fast-sedimenting membrane-associated viral subpopulations. The virus responded to this selection regime by reproducibly fixing a series of mutations that altered the extent of membrane-associated viral shedding, as revealed by fu…
Ultra-high temperature metamorphism recorded in Fe-rich olivine-bearing migmatite from the Khondalite Belt, North China Craton
2018
International audience; We document the first occurrence of Fe‐rich olivine‐bearing migmatitic metapelite in the Khondalite Belt, North China Craton. Petrological analyses revealed two exotic assemblages of orthopyroxene+spinel+olivine and orthopyroxene+spinel+cordierite. Phase relation modelling suggests that these assemblages are diagnostic of ultra‐high temperature (UHT) metamorphism in the Fe‐rich system, with temperatures from 1,000 to 1,050°C at 0.6 GPa. U–Th–Pb SIMS analyses on zircon reveal a similar age of c. 1.92 Ga for the olivine‐bearing migmatite and an adjacent gabbronoritic intrusion that is therefore identified as the heat source for the UHT metamorphism. These results, coup…
Age of Information Based URLLC-enabled UAV Wireless Communications System
2022
This paper considers an unmanned aerial vehicles (UAV) communication network, where UAV operate as an aerial mobile relay between a source and a destination of the network. To capture the “timelines” of the received information at the destination node, a new performance metric named age of information (AoI) is considered. In addition, a short packet communication scheme maintains low latency in the proposed UAV wireless communication system. The finite block-length theory investigates the performances of short packet communications scheme in the UAV-assisted wireless communications system. In this paper, the Average Age of Information (AAoI) is estimated by applying the Stochastic Hybrid Sy…
Ultrafast solvent-assisted level crossing in 1-Naphthol
2013
The nonadiabatic inversion dynamics of the energetic order of the electronic excited states of the photoacid 1-naphthol have been revealed by ultrafast spectroscopy on a femtosecond timescale (see picture; IC=internal conversion). The energetic order of the excited states La and Lb of 1-naphthol is reversed in 60 fs in polar dimethyl sulfoxide solvent.
Ultrametriski algoritmi
2015
Maģistra darbā tiek pētīta ultrametriska galīga automāta un ultrametriska vaicājošā algoritma definīcija, kas paredz p-adisku skaitļu izmantošanu amplitūdu norādīšanā. Lasītājs tiek iepazīstināts ar p-adisku skaitļošanas sistēmu un absolūtās vērtības jēdzienu. Darba ietvaros tiek izstrādātas ultrametrisku automātu realizācijas dažādu valodu atpazīšanai. Ultrametrisku automātu rēķināšanas sarežģītība tiek novērtēta pēc stāvokļu skaita automātā. Tiek apskatīts ultrametrisks vaicājošais algoritms, kas pārbauda Heminga koda pareizību. Darbā tiek pētītas ultrametrisku algoritmu priekšrocības salīdzinot ar klasiskām un kvantu skaitļošanas teorijas pamatkoncepcijām.
FPGA-piirien hyödyntäminen ultranopeassa automatisoidussa kaupankäynnissä
2012
Ultranopeassa automatisoidussa kaupankäynnissä (HFT) aika on rahaa ja jo millisekunnin etu kilpailijoihin nähden voi tuottaa suurenkin voiton. Optimoinnin HFT-järjestelmän joka osissa nopeuttavat järjestelmää. FPGA-piirien käyttö voi nopeuttaa HFT-järjestelmää huomattavasti. Erityisesti FPGA-piiri soveltuu markkinasyötteen käsittelyyn. FPGA-piireillä savutetaan 5-22 kertainen nopeus yleiskäyttöiseen suorittimeen nähden markkinasyötteen käsittelyssä In high-frequency trading (HFT) time is money. Even a one millisecond advance to other traders can bring huge wins to the HFT system. Optimazations in different parts of the HFT system can make system faster. Using FPGAs signifacantly decreases l…
Extracellular vesicle DNA from human melanoma tissues contains cancer-specific mutations
2022
Liquid biopsies are promising tools for early diagnosis and residual disease monitoring in patients with cancer, and circulating tumor DNA isolated from plasma has been extensively studied as it has been shown to contain tumor-specific mutations. Extracellular vesicles (EVs) present in tumor tissues carry tumor-derived molecules such as proteins and nucleic acids, and thus EVs can potentially represent a source of cancer-specific DNA. Here we identified the presence of tumor-specific DNA mutations in EVs isolated from six human melanoma metastatic tissues and compared the results with tumor tissue DNA and plasma DNA. Tumor tissue EVs were isolated using enzymatic treatment followed by ultra…
Pārejas metālu halkogenīdu mikrokristālu ultraskaņas eksfoliācija un fotoelektrisko īpašību pētījumi
2018
Darbā tika pētīta un attīstīta metālu halkogenīdu divdimensiju mikrokristālu iegūšanas metode, izmantojot ultraskaņas eksfoliāciju šķidrumā, un no iegūtajiem mikrokristāliem tika izgatavoti un raksturoti fotodetektoru prototipi. Ierīču izveidošanai un raksturošanai tika izmantotas LU CFI pieejamās zinātniskās iekārtas. Darbs sastāv no literatūras apskata un eksperimentālās daļas, kurā aprakstītas izmantotās eksperimentālās metodes un ietverti iegūtie rezultāti. Pētot izveidoto ierīču fotoelektriskās īpašības, tika izdarīti secinājumi par piemērotākajiem materiāliem modernu fotodetektoru izgatavošanai. Izmantojot suspensijas, kas veidotas no divdimensiju mikrokristāliem ar labām fotoelektris…
Movement pattern of spawners of white seabream, Diplodus sargus sargus (Linnaeus, 1758), in the gulf of Castellammare (NW Sicily)
2011
ULTRASONIC WAVES IN HETEROGENEOUS MATERIALS - MECHANICAL CHARACTERIZATION OF HETEROGENEOUS MATERIALS BY MEANS OF ULTRASONIC TESTS AND NUMERICAL MODEL…
2014
This Ph.D thesis treats the propagation of ultrasonic waves in heterogeneous materials. It is widely known how waves propagate in homogeneous materials like metallic ones. But very few aspects are known about the propagation in the heterogeneous materials because of the complex behavior regarding these materials. The heterogeneity can be related with the intrinsic properties, elastic and chemical, of each phase of the material, or with the periodic or random arrangement of inclusions of constant or different shapes. Concrete is a common case. In this work the first chapter gives a description of the main characteristics of heterogeneous materials.. In the second one, the methods of inspecti…