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Adaptive Sampling of Input Packets Implemented in FlowMon Probe
Kaštovský, Petr ; Martínek, Tomáš (referee) ; Kořenek, Jan (advisor)
There is a FlowMon probe being developed in a Libeouter project that is used for passive network measurements. The probe has better stability and accuracy than sofware based solutions even under a heavy load or network attack. To guarantee a precision of results there is a need to data reduction to prevent measuring system overload. There are few kinds of data reduction. Method used in the FlowMon probe is called sampling. Adaptive sampling unit sets the sampling rate (rate of processed and discarded packets) according to actual state of measured network.
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New insights on tau protein aggregation and the spreading of tau pathology in Alzheimer's disease
Pribiš, Matej ; Růžička, Jiří (advisor) ; Telenský, Petr (referee)
More than 100 years have passed since the original description of a "peculiar" disease of cerebral cortex by Dr. Alzheimer. Lots of discoveries on this disease and its cellular and molecular correlates has been done since then, the disease, however, up to this day resists most of the causal attempts of treatment. The major component of silver stained tangled bundles of fibrils that Alzheimer observed under his microscope has been identified as a microtubule associated protein tau and it has been shown to be a crucial part of many other neurodegenerative disorders, which were collectively named tauopathies. However, even after such a long time, the exact role of tau in neuronal physiology and pathology remains rather obscure. According to the latest research, it even seems that some of the widely accepted truths might require more closer observation and validation. The aim of this thesis is to sum up and clarify the important aspects of the mechanism of tau aggregation, the basic factors that influence it and its transcellular movement as a mechanism of pathology spreading. Keywords: aggregation, pathology spreading, tauopathy, Tau protein iii
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Coagulation of organic matter produced by phytoplankton
Načeradská, Jana
This dissertation thesis focuses on the removability of algal organic matter (AOM) by coagulation during water treatment and also on the influence of AOM on the coagulation of other substances present in source water. Special emphasis is put on the description of coagulation mechanisms. The effectiveness of AOM removal by coagulation was investigated by coagulation tests performed with optimized doses of coagulants (aluminium or ferric sulphate) under different pH values. Peptides and proteins contained in cellular organic matter of cyanobacterium Microcystis aeruginosa were used in the experiments since they have been previously reported to disturb the coagulation process. Moreover, peptides and proteins underwent coagulation experiments together with kaolin particles, representing clay particles in turbid waters, in both the presence and absence of coagulants to investigate the effect of AOM on the coagulation of turbid waters. To enable the description of coagulation mechanisms, AOM were characterised in terms of charge, functional groups, molecular weight and ability to form dissolved complexes with coagulant metals. The experimental results demonstrated that the removability of peptides and proteins is greatly dependent on pH value and on the properties of the involved particles or molecules....
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Magnetically assembled nanoparticle structures and their effect on mechanical response of polymer nanocomposites
Zbončák, Marek ; Khúnová,, Viera (referee) ; Crosby, Alfred (referee) ; Jančář, Josef (advisor)
Magneticky řízené samo-uspořádávání v polymerních nanokompozitech je studováno v této dizertační práci. Strukturování polymerních nanokompozitů pomocí relativně slabých magnetických polí (B=0-50 mT) bylo prokázáno jako praktická metoda pro kontrolu jejích nano a mikrostruktury. Vliv intenzity magnetického pole, množství nanočástic, viskozity a času uspořádávání na výslednou strukturu byl studován v různých systémech jako fotopolymer, polyuretan nebo koloidně dispergované nanočástice v acetonu s malým množstvím rozpuštěného polymeru. Samo-uspořádané struktury – bez aplikace vnějšího magnetického pole vykazují vícekrokovou agregaci nanočástic do uskupení s komplexním tvarem. Magnetické interakce byly označené jako odpovědné za agregaci nanočástic v samo-uspořádaných systémech pomocí výpočtů energii mezi-částicových interakcí. S rostoucím magnetickým polem, magnetické nanočástice jsou rychle uspořádané do jednorozměrných částicových řetězů s vysokým aspektním poměrem a homogenní orientaci v polymerní matrici. S prodluženým časem uspořádaní, tyto struktury postupně rostou z malých submikrometrových struktur do velkých mikroskopických super struktur. Táto metoda vykazuje velký potenciál pro kontrolovanou přípravu široké škály struktur v polymerních nanokompozitech vhodných pro technologické aplikace a také pro fundamentální studie. Magneticky uspořádané polymerní nanokompozity vykazují značnou směrovou anisotropii tuhosti kompozitu nad jeho skelným přechodem přičemž, pod skelným přechodem systému není pozorován žádný efekt. Podélně orientované struktury vykazují větší příspěvek k tuhosti kompozitů. Efektivnost vyztužení vykazuje teplotně závislý průběh a maximum je pozorováno přibližně 60 °C nad skelným přechodem. Struktura magneticky uspořádaného polymerního nanokompozitu byla popsána vícero-úrovňovým hierarchickým modelem materiálu. Mikromechanika byla využitá k popisu směrově závislého vyztužení polymerních nanokompozitů a k popisu teplotně závislé tuhosti hybridních struktur složených z nanočástic a polymeru. Schopnost nést napětí, deformovat se a nenulová tuhost hybridních struktur je odpovědná za vyztužení polymerních nanokompozitů. Přítomnost polymerních přemostění mezi nanočásticemi, které přenášejí napěti skrze magnetické struktury je označená jako nezbytná pro mechanickou odezvu polymerních nanokompozitů a pro tuhost hybridních struktur.
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Antipredatory function of aggregations in aposematic prey
Mitlenerová, Barbora ; Exnerová, Alice (advisor) ; Pipek, Pavel (referee)
Aggregation is a very important strategy of many organisms. It occurs in both vertebrates and invertebrates. Besides other functions (foraging, thermoregulation, maintenance of humidity protection against dessication, epigamic, hibernation or aestivation), aggregation also carries out antipredatory function. Aggregation of animals may reduce the risk of attacks by predators and prey mortality. Reduction of the attack probability might be caused by the predator confusion effect, lower risk of prey detectability, dilution effect, more effective vigilance of aggregation members and increase of strength of the warning signal produced by aposematic prey. Experimental studies, focused on the role of aposematic coloration in antipredatory functions use usually birds as predators. There are many kinds of insects, such as true bugs or mealworms, or artificial prey used as a prey in the experiments. The combination of aposematic signals and gregariousness of prey might have a significant influence on both probability and frequency of predator attacks. The length of predator's hesitation before the attack and the attack intensity used on attack may differ according to the coloration and presentation (gregariousness) of the prey and therefore the chance of survival varies. Aggregation may also improve...
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Deep Learning for Facial Recognition in Video
Jeřábek, Vladimír ; Sochor, Jakub (referee) ; Hradiš, Michal (advisor)
This work deals with face recognition in video using neural networks. In the beginning, there is described the process of selection and verification of convolution neural network to generate feature vectors from images of different identities. In the next part, this work deals with the aggregation of feature vectors from video frames. Aggregation takes place through aggregation neural networks. At the end of this work, the results obtained by the aggregation methods are discussed.
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Antiplatelet effects of flavonoids
Kopková, Nikola ; Mladěnka, Přemysl (advisor) ; Jirkovský, Eduard (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Nikola Kopková Supervisor: Assoc. Prof. Přemysl Mladěnka, Pharm.D., Ph.D. Title of diploma thesis: Antiplatelet effects of flavonoids The most common antioxidants in ordinary food are flavonoids. They show antioxidant and anti-aggregation effects and other positive effects on cardiovascular diseases. Flavonoids are promising candidates to be antiplatelet drugs. Although several mechanisms responsible for antiplatelet activity have been suggesteed, only a few have been documented by published studies. The inhibition of blood platelet aggregation by flavonoids is reversible, which is another important factor. Data on thrombin-induced aggregation are controversial, some claim that flavonoids have no effect, the others says they have positive effects. (In the case of quercetin and genistein, inhibition of aggregation induced by thrombin was documented). The effect on arachidonic acid in the aggregation cascade is well documented, but there are several inconsistencies resulting from the use of different materials. Other mediators of aggregation are phospholipase A2, which plays a key role in the formation of inflammatory mediators. In this case, it has been shown that mainly genistein is capable of...
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The influence of algal organic matter on the character of aggregates formed during the coagulation/flocculation process in drinking water treatment
Filipenská, Monika ; Pivokonský, Martin (advisor) ; Janda, Václav (referee)
Tato práce se zabývá studiem vlivu kaolinitových ástic (reprezentujících látky tvo ící zákal vody) a peptidové/proteinové složky COM (Cellular Organic Matter) produkovaných sinicí Microcystis aeruginosa na velikost, strukturu a tvar tvo ených agregát v prom nných hydrodynamických podmínkách (gradientu rychlosti) p i úprav vody. Agregace probíhala v Taylor-Couettov reaktoru. Koagulace vybraných typ zne iš ujících p ím sí (kaolinitové ástice, COM peptidy/proteiny a jejich sm s) probíhala pomocí síranu hlinitého a síranu železitého. Vzniklé agregáty byly hodnoceny ve fázi homogenní velikosti (steady state) po 60 min míchání pomocí ukazatel : velikost (polom r) agregát , fraktální dimenze D2 a Dpf a velikostní distribuce. Bylo zjišt no, že velikost agregát je závislá na typu koagula ního inidla, typu koagulované p ím si a aplikovaném gradientu rychlosti. S rostoucím gradientem rychlosti se velikost agregát zmenšuje. Železité koagula ní inidlo produkuje v tší agregáty než hlinité koagula ní inidlo. Podle p ím si roste velikost agregát v po adí kaolinit < COM < kaolinit + COM. Struktura agregát se stává kompaktn jší s gradientem rychlosti. P i použití hlinitého koagula ního inidla vznikají ve srovnání s inidlem železitým kompaktn jší agregáty (mají vyšší hodnotu D2). Kompaktnost agregát klesá v po adí...
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Deep Learning for Facial Recognition in Video
Stratil, Jan ; Sochor, Jakub (referee) ; Hradiš, Michal (advisor)
This bachelor's thesis deals with facial recognition in video using deep neural networks. This task is split into 2 parts. The first part deals with training network that produces compact feature vector which represents the face identity from a video frame. The second part deals with training aggregation network that aggregates those feature vectors into one. This aggregation is fast and it has shown that its results are better than naive pooling methods. Results are tested on the LFW dataset, where it achieves 92.8% accuracy and on the YTF dataset, where the accuracy is 84.06%.
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Nanoparticles formed by complexes of copolymers with low-molar-mass compounds
Vojtová, Jana ; Štěpánek, Miroslav (advisor) ; Filippov, Sergej (referee) ; Hoffmann, Ingo (referee)
This thesis is focused on mixed systems of various copolymers (double hydrophilic block and gradient polyelectrolytes, hydrophobic graft copolymers) and low-molar-mass compounds (sodium dodecyl sulfate as a representative of a ionic surfactant or superparamagnetic iron oxides in the form of nanocrystals). The electrostatic and hydrophobic interactions in the studied systems in aqueous solutions leading to aggregation behavior and to the formation of co-assembled nanoparticles were investigated by combination of scattering and microscopy techniques, including light, X-ray and neutron scattering, electron microscopy and atomic force microscopy. Powered by TCPDF (www.tcpdf.org)
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