Vrsna specifičnost i evolucija satelitnih DNA s naglaskom na satelitne DNA kornjaša iz roda Tenebrio

Satellite DNAs are highly reiterated non-coding sequences, organized in long arrays of tandem repeats that represent major DNA constituents of heterochromatic genome compartments. Satellite monomers build domains that stretch over functionally important regions such as that of the functional centromere. In short evolutionary periods satellite DNA components often change rapidly in copy number, nucleotide sequence, or both. Species specific profiles of satellite repeats can be formed by differential amplification of sequences coexisting in the genomes of a group of related organisms as a common library of satellite DNAs. This hypothesis has been experimentally approved for the first time in an analysis of satellite sequences in species of the genus Palorus (Insecta, Coleoptera). Due to the complexity of their evolution, the application of satellite DNAs in phylogenetic studies has limitations and results should be interpreted cautiously. Nevertheless, satellites can help to resolve phylogenetic relationships in some cases and in addition they can represent excellent and reliable molecular markers in the identification of some organisms.Satelitne DNA su visokoponovljene nekodirajuće sekvence organizirane kao dugi nizovi uzastopnih ponavljanja koji predstavljaju glavne elemente DNA u heterokromatinskim genomskim odjeljcima. Domene satelitnih monomera protežu se i u funkcionalno značajnim područjima kao što su centromere. Satelitne se DNA najčešće već tijekom kratkih evolucijskih razdoblja brzo mijenjaju u broju kopija, nukleotidnoj sekvenci ili i u jednom i u drugom. Vrsno specifični profili satelitnih jedinica ponavljanja mogu nastati diferencijalnom amplifikacijom sekvenci koje istovremeno postoje u genomima skupine srodnih organizama kao zajednička biblioteka satelitnih DNA. Ova pretpostavka je prvi puta bila eksperimentalno dokazana tijekom analize satelitnih sekvenci u vrstama roda Palorus (Insecta, Coleoptera). Zbog složenosti njihove evolucije, primjena satelitnih DNA u filogenetskim studijama ima ograničenja i rezultati se moraju interpretirati oprezno. Usprkos tomu satelitne DNA mogu u nekim slučajevima pomoći u razrješavanju filogenetskih odnosa te također predstavljati izvrsne i pouzdane molekularne biljege u identifikaciji pojedinih organizama

Measurement of polymeric time scales from linear drop oscillations

[EN] The oscillating drop method allows material properties of liquids to be measured from damped drop oscillations. The literature discusses, e.g., the measurement of the liquid dynamic viscosity and the surface tension against the ambient medium, predominantly for Newtonian liquids. We use this method for measuring pairs of material properties of polymeric liquids. Pairs of properties may be measured, since the quantity measured is a complex frequency with a real and an imaginary part. For the measurements, individual drops are levitated in air by an ultrasonic levitator and imaged with a high-speed camera. Amplitude modulation of the ultrasound drives shape oscillations of the levitated drop. When the modulation is switched off, with the levitating force maintained, the drop performs free oscillations which are damped due to the liquid viscosity. The data acquired from the images recorded are the angular frequency and the damping rate which are used as an input into the characteristic equation of the oscillating drop. Our measurements intend to yield either two viscoelastic time scales with the zero-shear viscosity known, or one time scale and the zero-shear viscosity, with the other time scale known. The two time scales are the stress relaxation and the deformation retardation times. The latter is difficult to get for polymer solutions. The present contribution presents results from a large set of measurements of the deformation retardation time. Liquids studied are aqueous solutions of poly(acryl-amides) at varying concentration. The corresponding values of the zero-shear viscosity agree well with the values from shear rheometry. Values of the deformation retardation time differ substantially from the values commonly used in viscoelastic flow simulations. Furthermore, the measured values disagree with the predictions from the viscous-elastic stress splitting approach in linear viscoelasticity. With our study we will provide a consistent set of material properties for the Oldroyd-B model in linear viscoelasticity. This will be important for material modelling in viscoelastic spray simulations.Plohl, G.; Brenn, G. (2017). Measurement of polymeric time scales from linear drop oscillations. En Ilass Europe. 28th european conference on Liquid Atomization and Spray Systems. Editorial Universitat Politècnica de València. 968-975. https://doi.org/10.4995/ILASS2017.2017.4686OCS96897

Unjamming strongly compressed particle rafts

We experimentally study the unjamming dynamics of strongly compressed particle rafts confined between two fixed walls and two movable barriers. The back barrier is made of an elastic band, whose deflection indicates the local stress. The front barrier is pierced by a gate, whose opening triggers local unjamming. The rafts are compressed by moving only one of the two barriers in the vicinity of which folds form. Using high speed imaging, we follow the folded, jammed, and unjammed raft areas and measure the velocity fields inside and outside of the initially confined domain. Two very different behaviors develop. For rafts compressed by the back barrier, only partial unjamming occurs. At the end of the process, many folds remain and the back stress does not relax. The flow develops only along the compression axis and the particles passing the gate form a dense raft whose width is the gate width. For rafts compressed at the front, quasi-total unjamming is observed. No folds persist and only minimal stress remains, if any. The particles flow along the compression axis but also normally to it and form, after the gate, a rather circular and not dense assembly. We attribute this difference to the opposite orientation of the force chain network that builds up from the compressed side and branchs. For rafts compressed at the gate side, keystone particles are immediately removed which enhances local disentanglement and leads to large scale unjamming. In contrast, for back compressed rafts, the force chain network redirects the stress laterally forming arches around the gate and resulting in a limited unjamming process

Model independent study of the Dirac structure of the nucleon-nucleon interaction

Relativistic and non-relativistic modern nucleon-nucleon potentials are mapped on a relativistic operator basis using projection techniques. This allows to compare the various potentials at the level of covariant amplitudes were a remarkable agreement is found. In nuclear matter large scalar and vector mean fields of several hundred MeV magnitude are generated at tree level. This is found to be a model independent feature of the nucleon-nucleon interaction.Comment: 5 pages, 2 figures, results for V_lowk added, to appear in PR

Vrsna specifičnost i evolucija satelitnih DNA s naglaskom na satelitne DNA kornjaša iz roda Tenebrio

Satellite DNAs are highly reiterated non-coding sequences, organized in long arrays of tandem repeats that represent major DNA constituents of heterochromatic genome compartments. Satellite monomers build domains that stretch over functionally important regions such as that of the functional centromere. In short evolutionary periods satellite DNA components often change rapidly in copy number, nucleotide sequence, or both. Species specific profiles of satellite repeats can be formed by differential amplification of sequences coexisting in the genomes of a group of related organisms as a common library of satellite DNAs. This hypothesis has been experimentally approved for the first time in an analysis of satellite sequences in species of the genus Palorus (Insecta, Coleoptera). Due to the complexity of their evolution, the application of satellite DNAs in phylogenetic studies has limitations and results should be interpreted cautiously. Nevertheless, satellites can help to resolve phylogenetic relationships in some cases and in addition they can represent excellent and reliable molecular markers in the identification of some organisms.Satelitne DNA su visokoponovljene nekodirajuće sekvence organizirane kao dugi nizovi uzastopnih ponavljanja koji predstavljaju glavne elemente DNA u heterokromatinskim genomskim odjeljcima. Domene satelitnih monomera protežu se i u funkcionalno značajnim područjima kao što su centromere. Satelitne se DNA najčešće već tijekom kratkih evolucijskih razdoblja brzo mijenjaju u broju kopija, nukleotidnoj sekvenci ili i u jednom i u drugom. Vrsno specifični profili satelitnih jedinica ponavljanja mogu nastati diferencijalnom amplifikacijom sekvenci koje istovremeno postoje u genomima skupine srodnih organizama kao zajednička biblioteka satelitnih DNA. Ova pretpostavka je prvi puta bila eksperimentalno dokazana tijekom analize satelitnih sekvenci u vrstama roda Palorus (Insecta, Coleoptera). Zbog složenosti njihove evolucije, primjena satelitnih DNA u filogenetskim studijama ima ograničenja i rezultati se moraju interpretirati oprezno. Usprkos tomu satelitne DNA mogu u nekim slučajevima pomoći u razrješavanju filogenetskih odnosa te također predstavljati izvrsne i pouzdane molekularne biljege u identifikaciji pojedinih organizama

Tools and databases for solving problems in detection and identification of repetitive DNA sequences

Genome compartments known to carry out very important biological functions (e.g. centromeres and telomeres) are mostly constituted of repetitive sequences. At the same time, regions of the genomes enriched in repetitive sequences have always presented great technical challenges for sequence alignments and genome assemblies. Fast evolving sequencing technologies and the increasing accessibility of genomic datasets have opened the opportunity to gain new insights into poorly explored genome fractions, built of repetitive DNA. Comprehensive and accurate annotation and characterization of these sequences is therefore an important contribution to the understanding of genomic architecture and function as a whole. In order to attend the emerging needs in repeat analysis and characterization, many bioinformatics tools, databases and pipelines have been generated. This review is intended to draw attention to the problems encountered in the genomic studies of repetitive sequences and to provide an overview of a spectrum of most prominent bioinformatics tools used for gaining better insight into these important genomic components. Some of the described assets are focused on detection of a wide range of repeats while the others are focused on a specific type of repetitive DNA sequences, generated as an answer to specific research interests and needs of the scientific community.</p

Comparison of Unity3D and Construct 2 tools for development of games on mobile platforms

With smart phones the popularity of mobile games has increased significantly. Accordingly, the number of game drives, which are designed to produce games for the mobile platform has also increased. The aim of this thesis is comparison of gaming drives Unity 3D and Construct 2 regarding production of games for mobile platforms. The first part presents theoretical background needed for production of a game. The second part compares the gaming drives. Comparison was made by implementing the same game on both drives (platforms). The task of manufacturing a game is divided into several subtasks. Each subtask is presented and how it is implemented on both drives. At the end of the thesis we describe how this two versions of the same game (made in two different environments) are working on mobile phone with Android operating system