Transcription termination of RNA polymerase II (Pol II) in mammals requires a functional poly(A) signal and either downstream pause sites or co-transcriptional cleavage (CoTC) sequences together with 3’transcript degradation by the nuclear 5’-3’ exonuclease Xrn2. However the molecular mechanism of pause-dependent transcriptional termination is not yet fully understood. This thesis investigates the molecular role of R-loop structures in pause-dependent transcriptional termination of mammalian genes. The results described in Chapters 3 and 4 indicate that nascent transcripts form RNA/DNA hybrid structures (R-loops) behind elongating Pol II and are especially prevalent over G-rich pause sites positioned downstream of gene poly(A) signals. Senataxin, a helicase protein and the human homologue of the yeast Sen1, acts to resolve these R-loop structures and by so doing allows access of Xrn2 at 3’ cleavage poly(A) sites. This ultimately leads to efficient Pol II termination. In effect R-loops formed over G-rich pause sites, followed by their resolution by senataxin, are required for efficient pause-dependent transcriptional termination. In addition to this, the 3’ end processing factor, Pcf11 is also involved in this process. Experiments presented in the final part of this study reveal a link between R-loops and RNAi-dependent H3K9me2 formation over G-rich termination regions. Overall my results suggest that R-loop structures and the H3K9me2 repressive mark over pause regions are important features of Pol II pause-dependent transcriptional termination of mammalian genes.

The final stages of replication fork termination requires the timely and orderly orchestration of catalytic and enzymatic activities. Given the complexity of this process, it is conceivable that the final stages of fork termination is susceptible to problems that could trigger recombination, which could lead to deleterious genomic rearrangements if ectopic homologous sequences are recombined. Using the site-specific RTS1 barrier in fission yeast, I demonstrated that fork termination is generally not a recombinogenic process, and that hyper-recombination-induced by fork blockage at RTS1 is largely a result of replication fork restart. To investigate the actual mechanisms and proteins, which drive and influence recombination at a replication barrier, I studied the MHF proteins, which assist Fml1 in limiting crossovers during double-strand break (DSB) repair and promoting Rad51-mediated recombination at impeded replication forks, and are also components of the constitutive centromere-associated network (CCAN). Intriguingly, structural studies revealed that the MHF can exist as an octamer in vitro. I examined the biological significance of octameric MHF by employing three mutations that disrupt the octamer configuration in vitro. In fission yeast, these mutations cause hypersensitivity to methyl methanesulfonate (MMS), suggesting that the MHF octamer may have a role in DNA repair. One of the “octamerisation” mutants, exhibits greater hypersensitivity to MMS than the other two, and biochemical experiments indicated that this is because it confers an additional defect in MHF’s interaction with Fml1. Further genetic experiments on this mutant suggest that the ability of Fml1 to unwind D-loops depends more critically on its interaction with MHF than fork reversal. Additionally, I showed a synergistic interaction between Dcr1 and MHF, and demonstrated that in the absence of Dcr1, there is a greater need for recombination to tolerate/repair DNA damage. Lastly, I uncovered a novel function for the MHF in controlling the initiation of septation.

The purpose of this study was to examine the characteristics that distinguish children with behavior disorders who drop out of psychotherapy treatment from those who remain in treatment. The sample included 379 children (268 male and 111 female) who were diagnosed with a behavior disorder at Dallas County Mental Health/Mental Retardation (MH/MR), a community mental health clinic in Dallas, Texas. The results indicated that certain characteristics increased the likelihood that a child would drop out of therapy, including reliance on aid, the presence of maternal psychopathology, and more severe externalizing and internalizing behaviors. This study also found that younger children with behavior disorders had a greater probability of dropping out of treatment. Minority status, gender, parent marital status, and referral source were not found to be associated with dropping out of treatment. Future studies should focus on specific interventions that clinicians could employ to deter premature termination from treatment.

Hydrogen terminated silicon surfaces have been utilized to develop sensors for semiconductor and environmental applications. The interaction of these surfaces with different environments has also been studied in detail. The sensor assembly relevant to the semiconductor industry utilizes a silicon-based sensor to detect trace levels of metallic contaminants in hydrofluoric acid. The sensor performance with respect to two non-contaminating reference electrode systems was evaluated. In the first case, conductive diamond was used as a reference electrode. In the second case, a dual silicon electrode system was used with one of the silicon-based electrodes protected with an anion permeable membrane behaving as the quasi reference electrode. Though both systems could function well as a suitable reference system, the dual silicon electrode design showed greater compatibility for the on-line detection of metallic impurities in HF etching baths. The silicon-based sensor assembly was able to detect parts- per-trillion to parts-per-billion levels of metal ion impurities in HF. The sensor assembly developed for the environmental application makes use of a novel method for the detection of Ni2+using attenuated total reflection (ATR) technique. The nickel infrared sensor was prepared on a silicon ATR crystal uniformly coated by a 1.5 micron Nafion film embedded with dimethylglyoxime (DMG) probe molecules. The detection of Ni2+ was based on the appearance of a unique infrared absorption peak at 1572 cm-1 that corresponds to the C=N stretching mode in the nickel dimethylglyoximate, Ni(DMG)2, complex. The suitable operational pH range for the nickel infrared sensor is between 6-8. The detection limit of the nickel infrared sensor is 1 ppm in the sample solution of pH=8. ATR - FTIR spectroscopy was used to study the changes that the hydride mode underwent when subjected to different environments. The presence of trace amounts of Cu2+ in HF solutions was found to roughen the silicon surface as observed ATR-IR spectroscopy. The initial stages of oxidation in UPW and Cu2+ / UPW was studied. Trace amounts of Cu2+ were found to drastically increase the rate of oxidation, while the rate of oxidation was found to be retarded on removing dissolved oxygen that was present in UPW.

Members of the 2-oxoglutarate (2OG)- and Fe(II)-dependent oxygenase (2OG oxygenase) superfamily catalyse a wide range of oxidative reactions in biology. 2OG oxygenases require Fe(II) and atmospheric oxygen for their activity, and couple substrate oxidation with the decarboxylation of 2OG into succinate and carbon dioxide. There are more than sixty known 2OG oxygenases in the human genome; they modify small molecules, nucleic acids and proteins implicated in diverse biological processes. Importantly, the seemingly disparate functions of 2OG oxygenases often converge to regulate gene expression. 2OG oxygenases have been shown to affect epigenetic reprogramming, chromatin remodelling, transcription factor activity and mRNA splicing. Emerging evidence indicates that 2OG oxygenases are also involved in the translational control of gene expression. Oxygenases TYW5, ALKBH8, ALKBH5 and FTO were found to catalyse modifications of tRNA and mRNA. The work in this thesis extends these observations by demonstrating that 2OG oxygenase-catalysed protein hydroxylations also play an important role in protein synthesis. The catalytic activities of two oxygenases belonging to the JmjC-only family, NO66 and JMJD4, are described. NO66 catalyses the histidinyl hydroxylation of 60S ribosomal subunit protein L8. NO66 is part of a conserved group of ribosomal protein hydroxylases that can be traced back to prokaryotes. JMJD4 is a lysyl hydroxylase of eRF1, the eukaryotic release factor responsible for translation termination. The hydroxylation of eRF1 takes place on a conserved NIKS motif important for release factor activity, and promotes effcient translational termination. JMJD4 is further implicated in cell growth and cancer, though the link between its activity and tumourigenesis remains to be determined. These results highlight the potential of 2OG oxygenases as regulators of protein synthesis, and further extend the scope of 2OG oxygenase function. The small molecule inhibition of 2OG oxygenases presents a novel therapeutic possibility targeting translational control in cancer and other diseases.

Termination of employment in an international comparison - a comparison of the Czech republic and the Slovakia Resumé: The aim of this thesis is to discuss the termination of employment contract from the multinational perspective, ČR a SR. Thesis is thematically divided into 4 large groups containing the termination of employment contract on international, Czech and Slovak legal grounds respectively alongside with the comparison of individual dissolution acts. Labor law is a legal discipline which is dynamically evolving and modernized whilst there are apparent differences in the comparison of labor law regulation within the EU member states. ČR and SR both approach the modernization of labor law in a different manner and the necessary flexibility of the labor market, employee protection and social security are incorporated in their systems of law with certain differences. The beginning of the thesis provides a brief excursus to the history of labor law. The following part aims to describe the institute of termination of employment contract in the context of international law regulation and its impact on Czech and Slovak labor law. Prior to the description of the individual means of termination of employment contract according to national regulations, there is a brief introduction into the issues of...

The aim of the thesis is to analyse different kinds of apartment lease termination. The reason for choosing this subject was common occurrence of this institute in a real life. In my opinion this thesis could be interesting not only for lawyers, but for the common people as well. The thesis is composed of five chapters. Chapter One is introductory and defines basic terminology used in the thesis: apartment, accessories of the apartment, apartment lease and lease contract. Chapter Two focuses on the apartment lease termination. It divides the termination in two different types - absolute and relative apartment lease termination. Chapter Three concentrates on absolute apartment lease termination. The most important kinds of absolute apartment lease termination are described there. The notice made by the lessor dominates among these kinds. The chapter Four analyzes different types of relative apartment lease termination. It deals with various changes either on the side of the leasee or the side of the lessor. The exchange of the apartment is mentioned in this chapter as well. The chapter Five looks at special kinds of apartment and consists of two parts according to these kinds - cooperative apartments and apartments for handicapped people. Different ways of apartment lease termination, which come on...

The thesis deals with notice of termination of employment relationship. It aims not only to analyse current Czech legislation including existing case law, but also to outline possible proposals of amendments (de lege ferenda considerations). It consists of eight chapters. The first chapter is concerned with general issues of labour law - its concept and function, its role in legal system, its relation to civil law and directory or mandatory nature of labour law rules. The second chapter provides a basic analysis of further ways of termination of employment relationship, which are further legal acts leading to termination of employment (i.e. agreement on termination of employment, instant termination of employment, termination of employment during the probationary period), termination of employment on the basis of an official decision and termination of employment by legal events. The third chapter to the sixth chapter deals with current Czech legislation regulating notice of termination of employment and with further related issues - prohibition of notice of termination during protective period and exemptions from this prohibition (chapter 4), invalidity of notice of termination (chapter 5) and employer's obligations consequent upon termination of employment (chapter 6). The third chapter mainly...

The thesis deals with the concept of flexicurity and its effects in the termination of the employment contract in the Czech Republic and the Kingdom of Sweden. The main aim of the thesis is to describe and compare both legislations from flexicurity perspective and suggest changes in the czech legislation. Strategy of flexicurity is one of the most discussed topics not only in the field of labour law but also in the field of social security systems and active labour market policies during the past few years. The concept of flexicurity can in a simplified way be characterized as a policy approach that tries to combine the flexibility of labor markets and job security for employees. According to the experts, flexicurity could help solve issues such as globalization or effects of economic crisis and higher unemployment occured due to the crisis. The thesis is composed of five chapters, each of them dealing with different aspect of the concept of flexicurity and its application in the Czech Reoublic and the Kingdom of Sweden. Chapter One defines and explaines the concept of flexicurity as such, followed by examples of succesful European flexicurity models. The chapter concludes with a brief outline of current development of flexicurity at European level. Chapter Two describes the individual components...

Zusammenfassung Das Thema dieser Diplomarbeit ist die Beendigung des Arbeitsverhältnisses - Vergleich der Rechtsregelung der Tschechischen Republik und die Bundesrepublik Deutschland. Die Arbeit gliedert sich in fünf Teile, die verschiedene Möglichkeiten der Beendigung des Arbeitsverhältnisses durch den tschechischen und deutschen Gesetzgebung behandelt, und befasst sich detailliert um einzelnen Kündigungsgründe in beiden Rechtsregelungen. Zwischen arbeitsrechtliche Rechtsregelungen beiden Nachbarländern, der Tschechischen Republik und der Bundesrepublik Deutschland gibt es auf einer Seite erhebliche Unterschiede, die sich aus wesentlichen Teil aus der unterschiedlichen rechtlichen und historischen Entwicklung ergeben. Auf der anderen Seite kommt es in der Einigung Europas zur Angleichung der Rechtsvorschriften der einzelnen Staaten, die sich im Bereich des Arbeitsrechts zum Ausdruck kommt. Obwohl sich das Arbeitsrecht ständig weiterentwickelt, behalt sich in jedem Staat seine Individualität, angesichts der Situation des Landes. Derzeit ist die Bundesrepublik Deutschland ein wichtiger Wirtschaftspartner der Tschechischen Republik. Angesichts der Existenz von internationalen Wirtschaftsunternehmen, Arbeitsmigration und grenzüberschreitende Beschäftigung, es ist praktisch, einen Überblick über die...