64 research outputs found
Adaptation mechanisms to wide salinity gradient in algae; transitions between marine and freshwater environments in chrysophytes
The transition from the marine to the freshwater environment and vice versa is a key event in the evolution of organisms. Although these transitions are relatively rare from an evolutionary point of view, most large groups of organisms have undergone this event at least once. The marine and freshwater environment differs in many aspects, especially salinity. During the transition between these two environments, the organisms are forced to overcome a significant salinity gradient and adapt to changes in the osmotic potential. However, biotic factors also play an important role, especially competition and predation in the new environment. The aim of the bachelor 's thesis is to provide comprehensive information on the mechanisms of adaptation to a wide gradient of salinity in algae in general and to focus on freshwater-marine transitions in chrysophytes, that occurred repeatedly and relatively frequently in the course of evolution. Key words: chrysophytes, Chrysophyceae, salinity gradient, osmoregulation, marine- freshwater transitionPřechod z mořského do sladkovodního prostředí a naopak, představuje klíčovou událost v evoluci organismů. Přestože jsou tyto přechody z evolučního hlediska relativně vzácné, většina velkých skupin organismů podstoupila tuto událost minimálně jednou. Mořské a sladkovodní prostředí se liší v mnoha aspektech, především salinitou. Při přechodu mezi oběma prostředími musí organismy překonat výrazný gradient salinity a přizpůsobit se změnám osmotického potenciálu. Nemalou roli však hrají i biotické faktory, a to zejména kompetice a predace v novém prostředí. Cílem bakalářské páce je poskytnout ucelenou informaci o mechanismech adaptace na široký gradient salinity u řas obecně a zaměřit se na přechody mezi mořským a sladkovodním prostředím u chrysofyt, ke kterým došlo v evoluci opakovaně a relativně často. Klíčová slova: chrysofyta, Chrysophyceae, gradient salinity, osmoregulace, přechod mořské- sladkovodní prostředíDepartment of BotanyKatedra botanikyPřírodovědecká fakultaFaculty of Scienc
Aligned nanofibres made of poly(3-hydroxybutyrate) grafted to hyaluronan for potential healthcare applications
In this work, a hybrid copolymer consisting of poly(3-hydroxybutyrate) grafted to hyaluronic acid (HA) was synthesised and characterised. Once formed, the P(3HB)-g-HA copolymer was soluble in water allowing a green electrospinning process. The diameters of nanofibres can be tailored by simply varying the Mw of polymer. The optimization of the process allowed to produce fibres of average diameter in the range of 100-150 nm and low polydispersity. The hydrophobic modification has not only increased the fibre diameter, but also the obtained layers were homogenous. At the nanoscale, the hybrid copolymer exhibited an unusual hairy topography. Moreover, the hardness and tensile properties of the hybrid were found to be superior compared to fibres made of unmodified HA. Particularly, this reinforcement was achieved at the longitudinal direction. Additionally, this work reports the use in the composition of a water-soluble copolymer containing photo cross-linkable moieties to produce insoluble materials post-electrospinning. The derivatives as well as their nanofibrous mats retain the biocompatibility of the natural polymers used for the fabrication
Pattern as a functional trait, case study on Mallomonas chrysophytes
The patterns that can be admired on the surface of many living creatures are also found in many microscopic organisms outside of the macroscopic world we are familiar with. However, their significance and function are yet little understood compared to those of the macroscopic world. In diatoms (Bacillariophyceae) and coccoliths (Haptophyceae), several hypotheses have already been developed concerning the function of their patterned shells. One hypothesis considers the shell as a photonic entity that could reflect UV radiation away from the cell. Others focus more on its mechanical properties, which are among the most impressive within biological structures. Silica-scaled chrysophytes (Synurales, Stramenopiles) also possess a complex shell (or scale-case). Cells are covered with scales (about 4 µm in size) that are very regularly arranged and form a siliceous scale-case on the surface. The pattern on the scales is species-specific and has undergone gradual modification during evolution. This work aims to assess whether the patterning of siliceous scales in the order Synurales can be considered a functional trait or it is a result of neutral evolution. To test the possible photonic properties of the patterned structures, a pair of growth experiments were performed. The experimental cultures were..
Application of blockchain technology and smart contacts in IoT
This thesis focuses on the use of blockchain and smart contract technology in the context of the Internet of Things (IoT). The thesis aimed to map different blockchain and smart contract technologies, select the most suitable ones and create an application that works with IoT devices. The theoretical part of the thesis provides a comprehensive overview of blockchain technology, smart contracts and the Internet of Things. The thesis explores individual technologies such as blockchain platforms supporting smart contracts or smart contract applications for data transfer through IoT networks. The analysis of different blockchain platforms allowed us to choose the most suitable one for the development of our application, which was Ethereum. Solidity became our programming language for smart contracts because of its compatibility with Ethereum. The practical part of the thesis starts with a brief description of the decision on the purpose, what the application will focus on and what technology will be chosen to develop our application. Within this description, we will focus on what tools will be needed for our development and the functioning of the application itself, and finally the solution of the application's architecture itself. In the second half of the practical part, we focus on the actual programming of the different parts of our application such as the smart contract or its test suite through frameworks. And lastly, the web application itself is written in HTML, CSS, and JS, which ties all these parts together. The proposed application should replace the centralized voting system, which has faced a lot of fraud in the past and is not met with the best criticism. Our app enables decentralized elections that are secured by blockchain and smart contract technologies specifically, which gives us confidence in its immutability and the IoT network gives it the ability to maximize its reach in terms of usage. Testing of the app has demonstrated its functionality and security and connectivity with IoT devices. The app has met all its expectations, although there is room for improvement
Utilization of temperature programmed techniques for characterization of Cu-zeolites
Práce se zabývá využitím teplotně programovaných technik (teplotně programovaná redukce vodíkem vzorků vykalcinovaných v O2 a CO; teplotně programovaná redukce a desorpce CO) na charakterizaci Cu-MFI zeolitů.Dokončená práce s úspěšnou obhajobo
Development of departmental websites using a content management system
The bachelor's thesis deals with the development of a website for the Department of Applied Mathematics and Informatics. The thesis is divided into a theoretical part and a practical part. The first part is designed to explore current trends connected to web design. It shows a general overview of the development of programming languages through time. The practical part of the thesis shows the development of a modern website for the Department of Applied Mathematics and Informatics with use of content management system. It shows a concrete design and whole process of developing with using PHP, CSS, JS. It also show finding a suitable content management system and the actual implementation of the selected content management system. At the end, it includes evaluation of usage the website in real environment
Personal Income Tax Optimization
Bakalářská práce je zaměřena na optimalizaci daňové povinnosti vybrané fyzické osoby. V teoretické části jsou vysvětleny základní pojmy z oblasti daní z příjmů fyzických osob, které jsou potřebné pro výpočet daňové povinnosti, a dále je zde vysvětlena problematika sociálního a zdravotního pojištění. V analytické části bude představen subjekt, jehož daňová povinnost se bude optimalizovat. V praktické části jsou uvedeny návrhy daňové optimalizace.The bachelor thesis is focused on optimizing the tax liability of a selected natural person. In the theoretical part are explained the basic concepts in the field of personal income taxes, which are needed for calculation of personal income tax as well as the issue of social and health insurance. The analytical part will introduce the entity whose tax liability will be optimized. The practical part contains recommendations for tax optimization.
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