Impact of precipitation on the water table level of different ombrotrophic raised bog complexes, central Estonia

Sadannan vaikutus vedenpinnan tasoon kohosuolla

Formation of polyelectrolyte multilayers and polyelectrolyte complexes in dual polymer treatment of papermaking pulp

The goal of this study was to find a new approach to modify chemically the properties of paper by improving fiber quality. This Master’s thesis includes the multiple polymer treatment in general and themeasurement methods with which the formation of multilayers and complexes can be noticed. The treatment by an oppositely charged dual polymer system is a good approach to increase paper strength. In this work, starch, a cationic polymer, and carboxymethyl cellulose (CMC), an anionic polymer, were used step-by-step to improve paper strength. The adsorption of cationic starch and CMC on cellulose fibers were analyzed via polyelectrolyte titration. The results showed that paper strength was enhanced slightly with a layer-by-layer assembly of the polymers. However, if the washing stage, which was required for layer-by-layer assembly, was eliminated, the starch/CMC complex was deposited on fibers more efficiently, and the paper strength was improved more significantly.

Probabilistic contact preferences in protein-ligand and protein-protein complexes

Modeller för intermolekulär växelvärkan utnyttjas brett inom biologin. Analys av kontakter mellan proteiner och läkemedelsforskning representerar typiska tillämpningsområden för dylika modeller. En modell som beskriver sådana molekylära växelverkningar kan utformas med hjälp av biofysisk teori, vilket tenderar att resultera i ytterst tung beräkningsbörda även för enkla tillämpningar. Ett alternativt sätt att formulera modeller är att utnyttja stora databaser som innehåller strukturmätningar gjorda med hjälp av till exempel röntgendiffraktion. Då man använder sig av empiriska mätdata direkt, möjliggör en statistisk modell att osäkerheten och inexaktheten i datat tas till hänsyn på ett adekvat sätt, samtidigt som beräkningsbördan håller sig på en rimligare nivå jämfört med kvantmekaniska metoder som i princip borde ge de optimala resultaten. I avhandlingen utvecklades en 3D modell för numerisk undersökning av intermolekulär växelverkan baserad på Bayesiansk statistik. Modellens syfte är att åstadkomma prognoser för det hurdana eller vilka molekylstrukturer prefereras i en given kontext, d.v.s. är mer sannolika inom ramen för interaktion. Modellen testades i essentiella molekyläromgivningar - en liten molekyl vid sin bindningsplats hos ett protein och en gränsyta mellan proteinerna i ett komplex. De erhållna numeriska resultaten motsvarar väl experimentella resultat som tidigare rapporterats i litteraturen, exempelvis kvalitativa bindningsaffiniteter och kemisk kännedom av vissa aminosyrors rumsliga förmågor att utgöra bindningar. I avhandlingen gjordes ytterligare preliminära tester av den statistiska ansatsen för modellering av den centrala molekylära strukturella anpassningsbarheten. I praktiken är den utvecklade modellen ämnad som ett led i en mer omfattande analysmetod, så som en s.k. farmakofor modell. Molekyylivuorovaikutusten mallintamista hyödynnetään laajasti biologisten kysymysten tarkastelussa. Tyypillisiä esimerkkejä sovelluskohteista ovat proteiinien väliset kontaktit ja lääkesuunnittelu. Vuorovaikutuksia kuvaavan mallin lähtökohta voi olla molekyyleihin liittyvä teoria, jolloin soveltamiseen liittyvä laskenta saattaa olla erityisen raskasta, tai suuri havaintojoukko joka on saatu aikaan esimerkiksi mittaamalla rakenteita röntgendiffraktio menetelmällä. Tilastollinen malli mahdollistaa havaintoaineistossa olevan epätarkkuuden ja epävarmuuden huomioimisen, samalla pitäen laskennallisen kuorman pienempänä verrattuna periaatteessa parhaan tuloksen antavaan kvanttimekaaniseen mallinnukseen. Väitöstyössä kehitettiin bayesiläiseen tilastotieteeseen perustuva 3D malli molekyylien välisten vuorovaikutusten laskennalliseen tarkasteluun. Mallin tehtävä on tuottaa ennusteita sen suhteen, minkä tai millaisten molekyylirakenteiden väliset kompleksit ovat etusijalla, toisin sanoen todennäköisempiä, vuorovaikutustilanteessa. Työssä kehitetyn menetelmän toimivuutta testattiin käyttötarkoituksen suhteen olennaisissa molekyyliympäristöissä - pieni molekyyli sitoutumiskohdassaan proteiinissa sekä rajapinta kahden proteiinin välilllä proteiinikompleksissa. Saadut laskennalliset tulokset vastasivat hyvin vertailuun käytettyjä kirjallisuudesta saatuja kokeellisia tuloksia, kuten laadullisia sitoutumisaffiniteetteja, sekä kemiallista tietoa esimerkiksi tiettyjen aminohappojen avaruudellisesta sidoksenmuodostuksesta. Väitöstyössä myös alustavasti testattiin tilastollista lähestymistapaa tärkeän molekyylien rakenteellisen mukautuvuuden mallintamiseen. Käytännössä malli on tarkoitettu osaksi jotakin laajempaa analyysimenetelmää, kuten farmakoforimallia.

Structural studies and in vivo characterisation of Oct4:PORE and Oct4/Sox2:UTF1 complexes

Monikykyiset kantasolut pystyvät erilaistumaan alkion kehityksen aikana miksi tahansa kehittyvän eläimen kudokseksi. Alkion kehitystä on tutkittu vuosikymmeniä ja ensimmäisen kerran kantasoluja viljeltiin 1980-luvulla. Noin vuosikymmen myöhemmin kloonattiin ensimmäinen nisäkäs, Dolly-lammas, mikä oli läpimurto perimän kloonauksessa. Vajaa kymmenen vuotta sitten japanilaiset tutkijat pystyivät ensimmäisen kerran tuottamaan indusoituja monikykyisiä kantasoluja. Nämä kantasolut tuotettiin ilmentämällä neljää geeniä, jotka uudelleenohjelmoivat erilaistuneet solut takaisin kantasoluiksi. Geenien ilmentymistä säätelevä ja DNA:han sitoutuvan proteiinin Oct4:n on todettu olevan tärkeä tekijä uudelleenohjelmissa. Oct4 kuuluu transkriptiotekijäperheeseen, joka säätelee geenien ilmentymistä kantasoluissa. Tässä työssä kiteytin Oct4-proteiinin sen kohde-DNA:n kanssa sekä tutkin sen sitoutumista ja atomitason rakennetta röntgensädekristallografian avulla. Tutkimuksessamme paljastui useita Oct4:n atomitason rakenteellisia ominaisuuksia, jotka selittävät sen säätelymekanismeja kantasoluissa.

Inclusion or Exclusion? Trade union strategies and Labor migration

Inclusion or Exclusion? Trade Union Strategies and Labor Migration This research identified and analyzed immigration-related strategies of the Finnish Construction Trade Union (FCTU) and the Service Union United (SUU); e.g. how the unions react to labor immigration, whether unions seek to include migrants in the unions, and what is migrants’ position in the unions. The two unions were chosen as the focus of the research because the workforce in the sectors they represent is migrant-dense. The study also analyzed the experiences that migrants who work in these sectors have with trade unions. The Estonian labor market situation –including the role of Estonian trade unions– was also examined as it has a considerable impact on the operating environment of the FCTU. The results of the study indicate that immigration is a contradictory issue for both unions. On the one hand, they strive to include migrants as trade union members and to defend migrants’ labor rights. On the other hand, they, together with their umbrella organization the Central Organisation of Finnish Trade Unions (SAK), seek to prevent labor immigration from outside the EU and EEA countries. They actively defend current labor immigration restrictions by drawing atten- tion to high unemployment figures and to the breaches of working conditions migrants encounter. In contrast, the employer organizations promote a more liberal state policy on labor immigration because they see it as a boost for business. Both the unions and the employer organizations ground their arguments on national interest. However, the position of the trade union movement is not uniform: unions belonging to the Confederation of Unions for Professionals and Managerial Staff in Finland (Akava) embrace more liberal labor immigration stances than the SAK. A key trade union strategy is to try to guarantee that migrants’ working condi- tions do not differ from those of the natives. The FCTU and the SUU inform migrants about Finnish collective agreements and trade union membership in the most common migrant languages. This is important for the unions because it is not in their interest that migrants’ working conditions are undercut. The interviewed migrants said that natives had more negotiating power with employers, which is often negatively portrayed in migrants’ working conditions. Migrants perceive that trade unions have an important role in protecting their working conditions. However, they stressed that migrants’ knowledge of unions is often very limited. The number of migrants in both two unions studied here is increasing. Espe- cially in the SUU, a considerable proportion of the new members are migrants. The FCTU is in a more challenging situation than the SUU because migrant construc- tion workers often work only for short periods in Finland and are consequently not interested in becoming union members. The unions’ strategies partly differ: the FCTU was the first Finnish trade union to establish a trade union branch/lo- cal for migrant members. The goal is to facilitate migrants’ inclusion in the union and to highlight the specific problems they face. The SUU, for its part, insists that such a special strategy would exclude migrants within the union organization. Despite the unions’ strategies, migrants are still underrepresented as union members and officials, which some of the interviewed migrants saw as a problem. Immigrants’ perception of trade unions was pragmatic: they had joined unions when membership yielded concrete benefits. In spite of the unions’ strategies, migrants –and temporary migrants– encoun- ter specific problems in terms of working conditions. Both unions demand more state intervention to protect migrants’ labor rights because overseeing working conditions consumes union resources. However, without the unions’ intervention, these problems would be more common than is currently the case. For instance, some of the interviewed migrants had received trade union assistance in claim- ing unpaid wages. The study demonstrated with the help of building on Walter Korpi’s power resources theory, that immigration is a power resource issue for the unions: suc- cessful immigration-related strategies strengthen unions –and vice versa. The research also showed how the unions’ operating environments constrain and enable their immigration-related strategies. This study has illuminated a previously ignored dimension: the immigrant- inclusive strategies of the Finnish trade unions. The research material consists of 78 qualitative interviews, observation in trade union events, and trade unions’ and employer organizations’ public state- ments.

Practices of Inclusion and Exclusion in Premodern Culture

In Practices of Inclusion and Exclusion in Premodern Culture a group of Finnish cultural historians discuss the meanings of cultural belonging, experiences and practices of construing boundaries between cultures and their others. What were the motives behind these constructions of differences in Premodern cultures? Why and through what kind of practices were differences created in specific cultural contexts? This book deals with Premodern people having multiple ways of construing their relationship to others, simultaneously being active agents in their own lives. Practices of Inclusion and Exclusion in Premodern Culture is suitable for course book for Master's Degree studies of history.

Recognition of nucleic acids by metal ion complexes

Metal-ion-mediated base-pairing of nucleic acids has attracted considerable attention during the past decade, since it offers means to expand the genetic code by artificial base-pairs, to create predesigned molecular architecture by metal-ion-mediated inter- or intra-strand cross-links, or to convert double stranded DNA to a nano-scale wire. Such applications largely depend on the presence of a modified nucleobase in both strands engaged in the duplex formation. Hybridization of metal-ion-binding oligonucleotide analogs with natural nucleic acid sequences has received much less attention in spite of obvious applications. While the natural oligonucleotides hybridize with high selectivity, their affinity for complementary sequences is inadequate for a number of applications. In the case of DNA, for example, more than 10 consecutive Watson-Crick base pairs are required for a stable duplex at room temperature, making targeting of sequences shorter than this challenging. For example, many types of cancer exhibit distinctive profiles of oncogenic miRNA, the diagnostics of which is, however, difficult owing to the presence of only short single stranded loop structures. Metallo-oligonucleotides, with their superior affinity towards their natural complements, would offer a way to overcome the low stability of short duplexes. In this study a number of metal-ion-binding surrogate nucleosides were prepared and their interaction with nucleoside 5´-monophosphates (NMPs) has been investigated by 1H NMR spectroscopy. To find metal ion complexes that could discriminate between natural nucleobases upon double helix formation, glycol nucleic acid (GNA) sequences carrying a PdII ion with vacant coordination sites at a predetermined position were synthesized and their affinity to complementary as well as mismatched counterparts quantified by UV-melting measurements.