Aminopyridinato Complexes as Possible Alternatives for Metallocenes in Ethylene Polymerization

Polyethylene is the most widely used synthetic polymer in the world. Most polyethylene is made with Ziegler-Natta catalysts. Polyethylenes for special applications are made with metallocenes, which are nowadays heavily patented. It is laborious therefore, to develop new metallocenes. The aim of this work was to investigate the feasibility of replacing the cyclopentadienyl ligands of metallocenes by aminopyridinato ligands without losing the good properties of the metallocenes, such as high activity and formation of linear polymer. The subject was approached by studying what kind of catalysts the metallocenes are and how they catalyze polyethylene. The polymerization behavior of metallocenes was examined by synthesizing a piperazino substituted indenyl zirconocene catalyst and comparing its polymerization data with that of the indenyl zirconocene catalyst. On the basis of their isolobality, it was thought that aminopyridinato ligands might replace cyclopentadienyl ligands. It was presumed that the polymerization mechanism and the active center in ethylene polymerization would be similar for aminopyridinato and metallocene catalysts. Titanium aminopyridinato complexes were prepared and their structures determined to clarify the relationship between structure of the catalyst precursor and polymerization results. The ethylene polymerization results for titanium 2-phenylaminopyridinato catalysts and titanocene catalysts were compared.

Der Prediger vom weißen Berg : Zur Rezeption der besseren Gerechtigkeit aus Mt 5 in Martin Luthers Predigtüberlieferung 1522 1546.

The purpose of this study is to examine the reception of Matthew 5 in Martin Luther s sermons; in other words to investigate how Luther interprets and applies Jesus teaching of the better righteousness and the law in Mt 5. The study applies the reception-historical approach and contributes to the history of effects and the history of interpretation in New Testament exegesis. The study shows that Luther understands the better righteousness of Mt 5 as good works and fulfillment of the law. Luther s interpretation coheres with the intention of the Evangelist, even if Luther s overall concept of righteousness is foreign to Matthew. In Luther s view righteousness is twofold: The greater righteousness of Mt 5 is the second and the actual righteousness (iustitia activa), which follows the first and the foreign righteousness (iustitia passiva). The first righteousness (faith) is for Luther the work of God, while the second righteousness (good works) is co-operation between a Christian and God. In this co-operation the law, as it is taught by Jesus, is not the opposite of the gospel, but the gospel itself in the sense of Christ as an example . The task of the law is to show the dependence of a Christian on God and to help one to love and to serve one s neighbour (brothers as well as enemies) properly. The study underlines a feature in Luther s thinking that has received little attention in Lutheran theology: Luther insists on preaching the law to Christians. In his view Mt 5 is directed to all Christians and particularly to pastors, for whom Jesus here gives an example of how to preach the law. Luther believes similarly to Matthew that Jesus reveals the real meaning of Mosaic Law and confirms its validity for Christians in Mt 5. Like Matthew, Luther insists on the practicability of the commandments of Mt 5 in his view Christians fulfil the law also with joy yet his interpretation of Mt 5 attenuates the radical nature of its commandments. Luther s reception of the individual pericopes of Mt 5 is considerably generative and occasionally contradictory, which is explained by the following factors, among others: Luther receives many ideas from tradition and reads them and his own theological concepts into Matthew s Gospel. He interprets Mt 5 through his understanding of some Old Testament passages as well as Paul. Most of all, Luther s reception of Mt 5 is shaped by his own experience as a preacher, by his relation to his religious enemies, rulers and to the congregation of Wittenberg. Here Luther shares with Matthew the experience of being opposed and concern about the upright living of the believers, which in both cases also explains the polemical tone of the paraenesis.

Living Poetically in the Modern Age : The Situational Aspects of Kierkegaard's Thought

How did Søren Kierkegaard (1813 1855) situate the human subject into historical and social actuality? How did he take into consideration his own situatedness? As key for understanding these questions the research takes the ideal of living poetically that Kierkegaard outlined in his dissertation. In The Concept of Irony (1841) Kierkegaard took up this ideal of the Romantic ironists and made it into an ethical-religious ideal. For him the ideal of living poetically came to mean 1) becoming brought up by God, while 2) assuming ethical-religiously one s role and place in the historical actuality. Through an exegesis of Kierkegaard s texts from 1843 to 1851 it is shown how this ideal governed Kierkegaard s thought and action throughout his work. The analysis of Kierkegaard s ideal of living poetically not only a) shows how the Kierkegaardian subject is situated in its historical context. It also b) sheds light on Kierkegaard s social and political thought, c) helps to understand Kierkegaard s character as a religious thinker, and d) pits his ethical-religious orientation in life against its scientific and commonsense alternatives. The research evaluates the rationality of the way of life championed by Kierkegaard by comparing it with ways of life dominated by reflection and reasoning. It uses Kierkegaard s ideal of living poetically in trying to understand the tensions between religious and unreligious ways of life.

Enzymes with radical tendencies: the PFL family

The first glycyl radical in an enzyme was described 20 years ago and since then the family of glycyl radical enzymes (GREs) has expanded to include enzymes catalysing five chemically distinct reactions. The type enzymes of the family, anaerobic ribonucleotide reductase (RNRIII) and pyruvate formate lyase (PFL) had been studied long before it was known that they are GREs. Spectroscopic measurements on the radical and an observation that exposure to oxygen irreversibly inactivates the enzymes by cleavage of the protein proved that the radical is located on a particular glycine residue, close to the C-terminus of the protein. Both anaerobic RNRIII and PFL, are important for many anaerobic and facultative anaerobic bacteria as RNRIII is responsible for the synthesis of DNA precursors and PFL catalyses a key metabolic reaction in glycolysis. The crystal structures of both were solved in 1999 and they revealed that, although the enzymes do not share significant sequence identity, they share a similar structure - the radical site and residues necessary for catalysis are buried inside a ten stranded $\ualpha $/$\ubeta $-barrel. GREs are synthesised in an inactive form and are post-translationally activated by an activating enzyme which uses S-adenosyl methionine and an iron-sulphur cluster to generate the radical. One of the goals of this thesis work was to crystallise the activating enzyme of PFL. This task is challenging as, like GREs, the activating component is inactivated by oxygen. The experiments were therefore carried out in an oxygen free atmosphere. This is the first report of a crystalline GRE activating enzyme. Recently several new GREs have been characterised, all sharing sequence similarity to PFL but not to RNRIII. Also, the genome sequencing projects have identified many PFL-like GREs of unknown function, usually annotated as PFLs. In the present thesis I describe the grouping of these PFL family enzymes based on the sequence similarity and analyse the conservation patterns when compared to the structure of E. coli PFL. Based on this information an activation route is proposed. I also report a crystal structure of one of the PFL-like enzymes with unknown function, PFL2 from Archaeoglobus fulgidus. As A. fulgidus is a hyperthermophilic organism, possible mechanisms stabilising the structure are discussed. The organisation of an active site of PFL2 suggests that the enzyme may be a dehydratase. Keywords: glycyl radical, enzyme, pyruvate formate lyase, x-ray crystallography, bioinformatics

Living on voles - plastic life of the Ural owl

Individuals face variable environmental conditions during their life. This may be due to migration, dispersion, environmental changes or, for example, annual variation in weather conditions. Genetic adaptation to a novel environment happens through natural selection. Phenotypic plasticity allows, however, a quick individual response to a new environment. Phenotypic plasticity may also be beneficial for individual if the environment is highly variable. For example, eggs are costly to produce. If the food conditions vary significantly between breeding seasons it is useful to be able to adjust the clutch and egg size according to the food abundance. In this thesis I use Ural owl vole system to study phenotypic plasticity and natural selection using a number of reproduction related traits. The Ural owl (Strix uralensis) is a long-lived and sedentary species. The reproduction and survival of the Ural owl, in fact their whole life, is tied to the dramatically fluctuating vole densities. Ural owls do not cause vole cycles but they have to adjust their behaviour to the rather predictable population fluctuations of these small mammals. Earlier work with this system has shown that Ural owl laying date and clutch size are plastic in relation to vole abundance. Further, individual laying date clutch size reaction norms have been shown to vary in the amount of plasticity. My work extends the knowledge of natural selection and phenotypic plasticity in traits related to reproduction. I show that egg size, timing of the onset of incubation and nest defense aggressiveness are plastic traits with fitness consequences for the Ural owl. Although egg size is in general thought to be a fixed characteristic of an individual, this highly heritable trait in the Ural owl is also remarkably plastic in relation to the changes in vole numbers, Ural owls are laying the largest eggs when their prey is most abundant. Timing of the onset of incubation is an individual-specific property and plastic in relation to clutch size. Timing of incubation is an important underlying cause for asynchronous hatching in birds. Asynchronous hatching is beneficial to offspring survival in Ural owl. Hence, timing of the onset of incubation may also be under natural selection. Ural owl females also adjust their nest defense aggressiveness according to the vole dynamics, being most aggressive in years when they produce the largest broods. Individual females show different levels of nest defense aggressiveness. Aggressiveness is positively correlated with the phenotypic plasticity of aggressiveness. As elevated nest defense aggressiveness is selected for, it may promote the plasticity of aggressive nest defense behaviour. All the studied traits are repeatable or heritable on individual level, and their expression is either directly or indirectly sensitive to changes in vole numbers. My work considers a number of important fitness-related traits showing phenotypic plasticity in all of them. Further, in two chapters I show that there is individual variation in the amount of plasticity exhibited. These findings on plasticity in reproduction related traits suggest that variable environments indeed promote plasticity.

Peroxidases in lignifying xylem of Norway spruce, Scots pine and silver birch

Lignin is a complex plant polymer synthesized through co-operation of multiple intracellular and extracellular enzymes. It is deposited to plant cell walls in cells where additional strength or stiffness are needed, such as in tracheary elements (TEs) in xylem, supporting sclerenchymal tissues and at the sites of wounding. Class III peroxidases (POXs) are secreted plant oxidoreductases with implications in many physiological processes such as the polymerization of lignin and suberin and auxin catabolism. POXs are able to oxidize various substrates in the presence of hydrogen peroxide, including lignin monomers, monolignols, thus enabling the monolignol polymerization to lignin by radical coupling. Trees produce large amounts of lignin in secondary xylem of stems, branches and roots. In this study, POXs of gymnosperm and angiosperm trees were studied in order to find POXs which are able to participate in lignin polymerization in developing secondary xylem i.e. are located at the site of lignin synthesis in tree stems and have the ability to oxidize monolignol substrates. Both in the gymnosperm species, Norway spruce and Scots pine, and in the angiosperm species silver birch the monolignol oxidizing POX activities originating from multiple POX isoforms were present in lignifying secondary xylem in stems during the period of annual growth. Most of the partially purified POXs from Norway spruce and silver birch xylem had highest oxidation rate with coniferyl alcohol, the main monomer in guaiacyl-lignin in conifers. The only exception was the most anionic POX fraction from silver birch, which clearly preferred sinapyl alcohol, the lignin monomer needed in the synthesis of syringyl-guaiacyl lignin in angiosperm trees. Three full-length pox cDNAs px1, px2 and px3 were cloned from the developing xylem of Norway spruce. It was shown that px1 and px2 are expressed in developing tracheids in spruce seedlings, whereas px3 transcripts were not detected suggesting low transcription level in young trees. The amino acid sequences of PX1, PX2 and PX3 were less than 60% identical to each other but showed up to 84% identity to other known POXs. They all begin with predicted N-terminal secretion signal (SS) peptides. PX2 and PX3 contained additional putative vacuolar localization determinants (VSDs) at C-terminus. Transient expression of EGFP-fusions of the SS- and VSD-peptides in tobacco protoplasts showed SS-peptides directed EGFP to secretion in tobacco cells, whereas only the PX2 C-terminal peptide seems to be a functional VSD. According to heterologous expression of px1 in Catharanthus roseus hairy roots, PX1 is a guaicol-oxidizing POX with isoelectric point (pI) approximately 10, similar to monolignol oxidizing POXs in protein extracts from Norway spruce lignifying xylem. Hence, PX1 has characteristics for participation to monolignol dehydrogenation in lignin synthesis, whereas the other two spruce POXs seem to have some other functions. Interesting topics in future include functional characterization of syringyl compound oxidizing POXs and components of POX activity regulation in trees.

Vanhustenhuolto + living lab = mahdollinen yhtälö?

Työ on laajaan dokumenttiaineistoon, haastatteluihin ja havaintoihin perustuva living lab - tyyppisen tuotekehitysprosessin yksityiskohtainen kuvaus. Hankehistoriallisessa tapaustutkimuksessa on käytetty historiantutkimuksen menetelmiä. Vanhustenkeskuksessa toteutetun living lab -hankkeen lopputuloksena syntyi vanhusten liikkeitä monitoroiva hoitotyön apuväline: turvalattia. Living lab -tyyppisessä tuotekehittämisessä on keskeistä teknologian kehittäminen tuotteen todellisessa käyttöympäristössä siten, että käyttäjät osallistuvat aktiivisesti kehitystyön kaikkiin vaiheisiin. Tutkimuksessa hankkeen etenemistä ja turvalattiateknologian rakentumista tarkastellaan toimijaverkostoteorian ja yhteisöllisen oppimisen käsitteen tarjoamista näkökulmista. Tutkimuksessa kiinnitetään erityisesti huomiota siihen, minkälaisia intressejä teknologian kehittämiseen osallistuvilla ryhmillä on ja minkälaisia konflikteja näiden intressien pohjalta syntyy. Lisäksi tarkastelun keskiössä on käyttäjien ja tuotekehittäjien välinen oppiminen, jonka mahdollistaminen ja edistäminen on living lab -kehittämisen päämäärä. Tutkimuksen keskeinen johtopäätös on, että käyttäjiltä saatu palaute on välttämätöntä käyttökelpoisen sosiaali- ja terveydenhuollon alan teknologian aikaansaamiseksi, ja turvalattian tapauksessa käyttäjäpalaute myös uudelleensuuntasi teknologisen järjestelmän innovaatioprosessia. Käyttäjien ja tuotekehittäjien yhteistyön myötä turvalattiaan kehitettiin joukko uusia toiminnallisuuksia ja käsitys tuotteen ydinominaisuuksista sekä hyötylupauksesta muuttuivat. Turvalattian tapaus osoittaa lisäksi yhteisöllisen oppimisen merkityksen innovaatioprosessissa sekä living lab -tyyppisen tuotekehittämisen potentiaalin näiden oppimisprosessien mahdollistajana ja kiihdyttäjänä. Tapaus myös valottaa sitä, kuinka monimutkainen toimintakenttä vanhustenhuolto on teknologian kehittämisen ja sen käyttöönoton näkökulmasta. Näyttäisi kuitenkin siltä, että living lab -metodologian avulla voidaan ylittää joitakin geronteknologian kehittämiseen ja myös käyttöönottoon liittyviä haasteita.

Vanhustenhuolto + living lab = mahdollinen yhtälö? Tutkimus geronteknologisen järjestelmän tuotekehitysprosessista

Työ on laajaan dokumenttiaineistoon, haastatteluihin ja havaintoihin perustuva living lab - tyyppisen tuotekehitysprosessin yksityiskohtainen kuvaus. Hankehistoriallisessa tapaustutkimuksessa on käytetty historiantutkimuksen menetelmiä. Vanhustenkeskuksessa toteutetun living lab -hankkeen lopputuloksena syntyi vanhusten liikkeitä monitoroiva hoitotyön apuväline: turvalattia. Living lab -tyyppisessä tuotekehittämisessä on keskeistä teknologian kehittäminen tuotteen todellisessa käyttöympäristössä siten, että käyttäjät osallistuvat aktiivisesti kehitystyön kaikkiin vaiheisiin. Tutkimuksessa hankkeen etenemistä ja turvalattiateknologian rakentumista tarkastellaan toimijaverkostoteorian ja yhteisöllisen oppimisen käsitteen tarjoamista näkökulmista. Tutkimuksessa kiinnitetään erityisesti huomiota siihen, minkälaisia intressejä teknologian kehittämiseen osallistuvilla ryhmillä on ja minkälaisia konflikteja näiden intressien pohjalta syntyy. Lisäksi tarkastelun keskiössä on käyttäjien ja tuotekehittäjien välinen oppiminen, jonka mahdollistaminen ja edistäminen on living lab -kehittämisen päämäärä. Tutkimuksen keskeinen johtopäätös on, että käyttäjiltä saatu palaute on välttämätöntä käyttökelpoisen sosiaali- ja terveydenhuollon alan teknologian aikaansaamiseksi, ja turvalattian tapauksessa käyttäjäpalaute myös uudelleensuuntasi teknologisen järjestelmän innovaatioprosessia. Käyttäjien ja tuotekehittäjien yhteistyön myötä turvalattiaan kehitettiin joukko uusia toiminnallisuuksia ja käsitys tuotteen ydinominaisuuksista sekä hyötylupauksesta muuttuivat. Turvalattian tapaus osoittaa lisäksi yhteisöllisen oppimisen merkityksen innovaatioprosessissa sekä living lab -tyyppisen tuotekehittämisen potentiaalin näiden oppimisprosessien mahdollistajana ja kiihdyttäjänä. Tapaus myös valottaa sitä, kuinka monimutkainen toimintakenttä vanhustenhuolto on teknologian kehittämisen ja sen käyttöönoton näkökulmasta. Näyttäisi kuitenkin siltä, että living lab -metodologian avulla voidaan ylittää joitakin geronteknologian kehittämiseen ja myös käyttöönottoon liittyviä haasteita.