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  • Cantell, Mikko (2007)
    The weight of neoconservative ideology in world politics is generally identified and acknowledged. In spite of this more profound studies are found wanting. I attempt to make the ideology more understandable and approach it from a distinct point of view, examining neoconservatism's attitude to torture in the United States' "Global War on Terror". In so doing, my aim is also to clarify the thus far somewhat vague distinction between the current U.S. administration and neoconservatism in political and academic writing. I have utilized the theory of cognitive dissonance created by Leon Festinger to study the mechanisms in play concerning the different attitudes toward the use of torture. The theory has so far found very few applications in the study of international relations, but I believe there to be significant potential in its future use. On a more concrete level, I undertake to examine whether the core values of neoconservatism (human rights, liberal democracy, "American values" and "moral use of power") on the one hand, and condoning attitudes toward the use of torture on the other, give rise to an intolerable inner conflict that could be called cognitive dissonance. The use of torture is absolutely prohibited in international law, standards and norms. The most central internationally binding legal obligation prohibiting the use of torture is the Convention against Torture from 1984. The convention prohibits the use of torture in all cases and without exception. My study examines the question of torture in the context of the "War on Terror" and the relation of torture to the individual. The individual rises in fact to be one of the most salient levels of analysis in the paper: each of neoconservatism's core values can be said to be based on defending the rights of the individual while torture can simultaneously be defined as being the ultimate denial of the individual worth and dignity. I conclude my study by asserting that neoconservatism's attitude toward torture has led to severe conflicts with its own core values. Although accurate definitions of the mechanisms used in alleviating the dissonance are impossible to find, the study gives evidence indicating that denial of responsibility and a rearranging of the hierarchy of internal values can have been included in the reduction of dissonance. I consider the notion that attempts to reduce dissonance typically "spill over" to other seemingly unattached areas of decision-making very important. This means that in addition to core values or the fundamental level of ideology, past decisions also influence future decisions.
  • Iskanius, Anniina (2008)
    Euroopan unionin (EU) turvallisuus- ja puolustuspolitiikka on ollut yhteisen valuutan jälkeen nopeiten kehittynyt ja integroitunut politiikan lohko. Tällä osa-alueella EU on kyennyt luomaan lyhyessä ajassa itsenäisen kriisinhallintakyvyn ja ottamaan vastuun useiden kansainvälisten kriisinhallintaoperaatioiden johtamisesta. Institutionalisoituminen on edennyt myös puolustustarviketeollisuuteen ja yhteisten puolustusmarkkinoiden synnyttämiseen. Kehitys on huomattavaa, koska kylmän sodan aikana integraatiokehitys ei edennyt turvallisuus- ja puolustuspolitiikkaan. Tutkielmassa tutkitaan neofunktionalistisen ja funktionalistisen teorian mahdollisuuksia selittää Euroopan unionin kriisinhallintakyvyn kehittymistä. Valitut teoriat lisäävät tieteellistä relevanssia tarjoten tuoreen lähestymistavan. Tutkielmassa testataan valitun sotilaallisen kriisinhallintaoperaation avulla funktionalismin ja neofunktionalismin soveltuvuutta turvallisuuspolitiikan tutkimukseen. Lisäksi tutkielmassa käytetään realistista ja neorealistista teoriaa, konstruktivismia sekä institutionalismia ja selvitetään, millaisen vastauksen ne antavat tutkimuskysymykselle. Tutkimusmenetelmänä on laadullinen tutkimus. Tärkeimmät lähteet teorioiden osalta ovat David Mitranyn ja Ernest B. Haasin teokset. Kriisinhallinnan osalta tärkeimpiä lähteitä ovat Ranskan ja Ison-Britannian antama St. Malon julistus vuodelta 1998 sekä Eurooppa-neuvoston tekemät päätökset Helsingissä vuonna 1999 sekä Thessalonikissa vuonna 2003. Päätösten ja teosten lisäksi tutkielmassa on käytetty runsaasti myös muuta kirjallisuutta sekä tieteellisiä artikkeleja. Tapaukseksi on valittu Euroopan unionin ensimmäinen itsenäinen sotilaallinen kriisinhallintaoperaatio Artemis Kongon demokraattisessa tasavallassa. Hypoteesina esitetään, että taloudesta alkanut integraatio on yliläikkynyt turvallisuus- ja puolustuspolitiikkaan ja johtanut kriisinhallintakyvyn kehitykseen. Tutkimustulosten valossa hypoteesi osoittautui oikeaksi. Lisäksi todistetaan, että jäsenvaltioita motivoi kriisinhallintakyvyn kehittämiseen myös Euroopan unionin koheesion lisääminen sekä unionin vaikutusvallan kasvattaminen globaalina toimijana. Tutkimustulokset osoittavat neofunktionalismin selittävän hyvin kriisinhallintakyvyn kehittymisen. Se selittää hyvin myös Euroopan unionin päätöksen käynnistää operaatio Artemis. Tutkimustulokset myös osoittavat, ettei EU halua erottaa puolustuspolitiikkaa taloudesta, johon se on läheisesti yhteydessä. Funktionalismin osalta tutkimustulokset osoittavat, ettei se sovellu erityisen hyvin selittämään Euroopan unionin kriisinhallintakyvyn kehittymistä. Myös realismin ja neorealismin, konstruktivismin sekä institutionalismin tarjoamat selitykset ovat puutteellisia eivätkä tarjoa yhtä uskottavaa vastausta tutkimuskysymykseen kuin neofunktionalismi.
  • Kaila, Eero (2007)
    Tutkimus luotaa käsitteen “uusliberalismi” merkityssisältöä ja sen mahdollisia käyttötapoja poliittisen filosofian kontekstissa. Uusliberalismi on ensisijaisesti taloustieteellinen ja poliittinen suuntaus, jonka oletetaan tässä ilmentävän klassisen liberalismin ajatussisällön paluuta. Liittyen 1970-luvun jälkeiseen poliittisen filosofian elpymiseen suuntaukselle on alkanut kehittyä myös filosofista rakennetta. Mitään yhtä selkeää kokonaisuutta tai koulukuntaa ei kuitenkaan ole muodostunut, vaan useimpien edeltävien kommentaarien, kuten Eerik Lagerspetzin ja Anna-Maria Blomgrenin, mielestä kenttä on liian hajanainen käsitteen käyttöönoton puoltamiseksi. Menetelmältään tutkimus etenee systemaattisen analyysin rakennetta mukaillen, jonka lisäksi apuna on vaikutteita hermeneutiikasta. Hermeneuttinen kehä tarjoaa mahdollisuuden tarkastella laajaa kokonaisuutta suhteellisen vähäisellä määrällä alustavaa tutkimusta, kun taas kappale kappaleelta tutkimus keskittyy suuntauksen tarkkaan käsitteelliseen analyysin. Alustavan käsitteen hahmotelman muodostamisen jälkeen tarkasteluun otetaan yleisesti uusliberalisteina pidettyjä filosofis-painotteisia kirjoittajia, joista tässä tapauksessa esiin nostetaan Friedrich August von Hayek, Robert Nozick sekä James M. Buchanan. Kyseisten henkilöiden tärkeimmistä teksteistä poimitaan tämän jälkeen suuntaukselle olennaisimpia käsitteitä, joita systemaattisessa osuudessa pystytään näin vertailemaan. Tärkeiksi käsitteiksi valikoituu yksilö, vapaus, oikeudet, oikeudenmukaisuus sekä valtio. Tutkimuksen päättävä analyysi kokoaa kaksi vallitsevaa uusliberalismin variaatiota (deontologinen ja konsekventialistinen) käsitteiden ja niiden välisten vaikutussuhteiden mukaisesti järjestettynä. Näiden variaatioiden sisäiset ongelmat sekä poliittisen filosofian diskurssissa vakiintuneen, läheisen ”libertarismi” –termin päällekkäisyys johtavat edeltävien kommentaarien kanssa vastaavaan loppusuositukseen: ”uusliberalismi” –käsitteen käyttöönottoa ei nykyisen, määritellyn tutkimuskentän sisältävien teorioiden määrän ja laadun matalan tason vuoksi voi suositella. Mahdollisuus käyttää ”uusliberalismia” kokoluokaltaan liberalismin ja libertarismin väliin jäävänä kategoriana jätetään kuitenkin auki. Tällöin edellytyksenä on, että tutkimuksessa käsiteltyjen liberalismin äärimmäisten nykymuotojen rinnalle syntyy lisää vastaavia tai vaihtoehtoisia teorioita, joiden argumentatiivinen painoarvo olisi nykyisiä teorioita merkittävämpää. Lopuksi uusliberalismin filosofinen tutkimus todetaan myös siinä mielessä hedelmälliseksi, että käsite sijoittuu kansantaloustieteen ja poliittisen filosofian koulukuntien rajapintaan tarjoten mahdollisesti esimerkiksi uusia keinoja taloustieteen filosofisen perustan arviointiin.
  • Kaila, Eero (2007)
    This study examines the content of the term "neoliberalism" and the possible ways to utilize it as a concept in the context of political philosophy. Neoliberalism is primarily an economic and a political doctrine, which is here presumed to represent the return of the ideas from the classical liberal period. Since the revival of political philosophy in the 1970's, neoliberalism can be seen to have developed philosophical content. However, any specific structure or a discipline, to which any writer would declare to belong to, has not formed yet. This has lead several commentators, such as Eerik Lagerspetz and Anna-Maria Blomgren, to recommend against using the concept as the field of study is still too fragmented. The process of study will advance following the structure of systematic analysis. Additionally some influences are taken from the hermeneutic tradition. The hermeneutic circle will provide an opportunity to examine a large subject matter with a relatively small amount of preliminary research. On a chapter-to-chapter basis the study will concentrate on an accurate systematic analysis of the concept. After an initial sketch of the concept is made, some philosophically inclined writers who are considered neoliberal are examined. In this case Friedrich August von Hayek, Robert Nozick and James M. Buchanan are presented. Essential concepts are selected from the most important political-philosophical texts of these writers.These concepts are then compared with each other in the systematic section. The following concepts are discussed here: the individual, liberty, rights, social justice and the state. The analysis at the end of this study will compile, on the grounds of the examined concepts and their relations with each other, two dominant varieties (deontological and consequentialist) of neoliberalism. The internal problems of these varieties and the similarity with the term "libertarianism", which is already recognized in the discourse of political philosophy, lead to a concurring recommendation with the previous commentaries: the application of the concept "neoliberalism" is not recommended due to poor quality of the theories within the field of study. The possibility to use "neoliberalism" as an intermediatory category between liberalism and libertarianism is, however, not overruled. The prerequisite for this is that new forms of contemporary, extreme liberalism would be created, with preferably more argumentative force than the ones examined here. In the end, the philosophical examination of neoliberalism is deemed fruitful in the sense that the concept is located between the disciplines of economics and political philosophy. This implies the possible result of discovering new tools for the analysis of philosophical foundations of economic theory.
  • Rahkonen, Petri (Helsingin yliopisto, 2014)
    Despite advancements in neonatal intensive care and increased survival of infants born extremely preterm, many of them still develop with motor, sensory, cognitive, and behavioral impairments. Predicting adverse neurodevelopmental outcome as early as possible is a challenge in neonatology. Structural neuroimaging methods partly fail to detect milder brain abnormalities that may interfere with later developmental outcome, and neurological assessment is more unreliable in the neonatal period than in childhood. Thus, additional methods are needed for earlier and more accurate recognition of extremely preterm infants with adverse neurodevelopmental outcome. The first purpose of this study was to assess the value of measuring higher cortical function by neurophysiological methods in predicting outcome of infants born extremely preterm. Second, we aimed to examine possible difficulties in behavioral somatosensory processing and in mother-child interaction and their associations with developmental outcome. The lack of somatosensory evoked magnetic fields from the secondary somatosensory cortex in magnetoencephalography at term equivalent age, reflecting abnormal higher cortical functioning during somatosensory processing, was associated with worse neuromotor outcome of extremely preterm infants at two years of corrected age, not foreseen with structural neuroimaging methods. Further, we showed that responses from the secondary somatosensory cortex can also be detected by measuring somatosensory evoked potentials during electroencephalography. The quality of mother-infant interaction in mother- extremely preterm child dyads did not differ from that in mother-term child dyads. However, among children born extremely preterm worse child adjustment and lower quality of maternal and dyadic behavior were associated with lower neurocognitive outcomes. Half of the children born extremely preterm presented atypical behavioral sensory processing at two years of corrected age. Sensation seeking was common in extremely preterm children with neonatal neuroanatomical lesions. In conclusion, the functional neurophysiological methods magnetoencephalography and measurement of somatosensory evoked potentials during electroencephalography hold promise as valuable additional tools in predicting outcome of children born extremely preterm. The quality of mother-infant interaction may play a significant role in optimizing cognitive outcome after extremely preterm birth. Atypical behavioral sensory processing in children born extremely preterm is common, but the pathogenesis and developmental significance of this phenomenon call for more research in the future.
  • Karhumäki, Aune (2013)
    Tämän tutkimuksen tarkoituksena oli tutkia kerronnallisen analyysin keinoin monikkolapset saaneiden naisten kertomuksia äitiydestään. Varsinaisena tutkimusaineistona oli pääkaupunkiseudulla asuvien, 0-3-vuotiaiden monikkolasten äitien haastattelut, joita toteutui yhteensä 25. Tarkemmin analysoitavaksi päätyi 14 haastattelua. Tausta-aineistona toimi Helsingin Ensikoti Ry:n Baby Blues yksikön monikkoperheiden asiakkuusprofiilit (N=7) ja monikkolapset saaneen äidin kirjoitus. Tutkimukselle asetetut tutkimuskysymykset olivat: kuinka naiset kertovat kokemuksistaan monikkoarjessa? Miten äitien lausumat toimivat argumentointeina? Millä tavoin äitiys toimii monikkolapset saaneen naisen kertomuksissa? Lähestyin haastatteluaineistoa ensin temaattisen luennan keinoin ja sitten kerronnan tutkimuksen analyysikäsitteiden avulla, pohtien myös sitä, kuinka kerronta ilmentää sosiaalisia rakenteita (sukupuoli ja perhe) ja representaatioita. Kerronta tarkoitti tässä tutkimuksessa haastatteluaineiston tarkastelua sosiaalisena toimintana. Esioletuksena oli, että kerronta mahdollistaa etäisyyden säätelemisen (fokalisaatiot ja deiktiset siirtymät) ja intensiteetin vaihtelut (kerronnalliset tihentymät) suhteessa koettuun. Kerronnalla jäsennetään merkityksellisiä kokemuksia, ja sijoitetaan niitä sekä elämänkaarelle (käännekohdat) että minuuden (epifaniat) näyttäytymiseen. Tutkimus osoitti, että tieto monikkoraskaudesta kääntyi alkuyllätyksen jälkeen useinmiten myönteiseksi asiaksi, jota jopa selitettiin kohtalon sanelemaksi ihmeeksi. Lasten synnytys saattoi tuottaa naiselle merkittäviä itseymmärrystä lisääviä kokemuksia. Monikkoarjessa koettiin kuitenkin myös riittämättömyyttä, masennustakin. Naiset kertoivat joutuneensa salaamaan yhtäältä monikkoarjen raskautta ja toisaalta sen tuottamaa iloa ja mielihyvää. Arjen raskaaksi kokemisesta ja masentuneisuudesta kertominen oli vähäistä lastentahtista hoivaorientaatiota toteuttavilla äideillä. Tälle vastakkainen orientaatio oli lasten samantahtinen hoiva. Aineiston avulla voi todeta, että naiset tuottivat monipuolista kuvastoa esiintyvistä äideistä. Tämä kutsui näkyviin sukupuoliin ja perheeseen liittyviä kulttuurisia ja sosiaalisia rakenteita sekä jaettuja tulkintoja. Näitä muotoiltiin naisten toimesta aktiivisesti uudelleen, sillä eroavaisuuden ja yhtenevyyden vuorottelu lävisti monikkoarkea. Naisten kerronta kuvasti vaikeuksien voittamista ja itsetuntemuksen lisääntymistä. Tämän aineiston kertomukset monikkolasten äitiydestä näyttäytyivät henkilökohtaisina projekteina, hyvää ja oikeaa tavoittelevina hankkeina.
  • Metsämuuronen, Tuua Maria (Helsingin yliopisto, 2014)
    The study focuses on the Nepalese 8 grade Mathematics, Nepali language and Social study teachers confidence to teach their own subject. Every skill, such as teaching skills, brings with uncertainty and insecurity creates a need for security. The aim of the master's thesis is to research how substance knowledge, the teacher's personality, pedagogical knowledge and classroom management, and their components are connected to each other. In addition, has been researched how much personality, pedagogical knowledge and classroom management, explain the teacher's self-perceived competence assurance to teach. Altogether, 1224 of Nepalese teachers responded to the survey. The survey sample was stratified. The questionnaire, teachers were asked to assess their teaching confidence in their teaching subject and its sections, on a scale of 1 to 4. Many studies have been done about teaching and the teacher's impact on learning outcomes. That has been considered as a possible cause of Finnish students' good learning achievements. Since the schools have small differences between them, it is easier to study the teachers and the teaching effect of the student's achievements in a country, where the school differences are considerable bigger. According to Hattie (2003, 2), the teacher effect is 30% of the student learning achievements, in Nepal the corresponding figure is 68% (Acharya, Metsämuuronen and Metsämuuronen 2013, 281 316). The study examined by tree-analysis how personality, pedagogical knowledge and classroom management elements are linked to educational confidence and by regression analysis how much these independent variables explain together the effect of the phenomenon. According to regression analysis, there are age, teaching years, assessment, professional development over the last two years, and the curriculum understanding and using, as well as the school equipment shortages. The study found that the most confident were those teachers who were under the age of 30 teachers; who had teaching experience five years or less; who used the project work as assessment; who experienced that they understood the objectives of the school curriculum, and in addition they experienced to implement it successfully. This study was empirical and explorative work and the results obtained on the regression model shows that the model explains 9.5% of teacher's confidence to teach their own subjects. As regression model explains less than 10% certainty, is the teacher's teaching confidence and competence a good follow-up research object. Another good object would be to compare the self-perceived reliability and the validity of the comparison of the measured whether teachers' own experience of the same qualifications as a measurable skill.
  • Palmén, Tuula (Helsingin yliopisto, 2003)
  • Aaltonen, Petri (Helsingin yliopisto, 2006)
    End-stage renal disease is an increasingly common pathologic condition, with a current incidence of 87 per million inhabitants in Finland. It is the end point of various nephropathies, most common of which is the diabetic nephropathy. This thesis focuses on exploring the role of nephrin in the pathogenesis of diabetic nephropathy. Nephrin is a protein of the glomerular epithelial cell, or podocyte, and it appears to have a crucial function as a component of the filtration slit diaphragm in the kidney glomeruli. Mutations in the nephrin gene NPHS1 lead to massive proteinuria. Along with the originally described location in the podocyte, nephrin has now been found to be expressed in the brain, testis, placenta and pancreatic beta cells. In type 1 diabetes, the fundamental pathologic event is the autoimmune destruction of the beta cells. Autoantibodies against various beta cell antigens are generated during this process. Due to the location of nephrin in the beta cell, we hypothesized that patients with type 1 diabetes may present with nephrin autoantibodies. We also wanted to test whether such autoantibodies could be involved in the pathogenesis of diabetic nephropathy. The puromycin aminonucleoside nephrosis model in the rat, the streptozotocin model in the rat, and the non-obese diabetic mice were studied by immunochemical techniques, in situ -hybridization and the polymerase chain reaction -based methods to resolve the expression of nephrin mRNA and protein in experimental nephropathies. To test the effect of antiproteinuric therapies, streptozotocin-treated rats were also treated with aminoguanidine or perindopril. To detect nephrin antibodies we developed a radioimmunoprecipitation assay and analyzed follow-up material of 66 patients with type 1 diabetes. In the puromycin aminonucleoside nephrosis model, the nephrin expression level was uniformly decreased together with the appearance of proteinuria. In the streptozotocin-treated rats and in non-obese diabetic mice, the nephrin mRNA and protein expression levels were seen to increase in the early stages of nephropathy. However, as observed in the streptozotocin rats, in prolonged diabetic nephropathy the expression level decreased. We also found out that treatment with perindopril could not only prevent proteinuria but also a decrease in nephrin expression in streptozotocin-treated rats. Aminoguanidine did not have an effect on nephrin expression, although it could attenuate the proteinuria. Circulating antibodies to nephrin in patients with type 1 diabetes were found, although there was no correlation with the development of diabetic nephropathy. At diagnosis, 24% of the patients had these antibodies, while at 2, 5 and 10 years of disease duration the respective proportions were 23%, 14% and 18%. During the total follow-up of 16 to 19 years after diagnosis of diabetes, 14 patients had signs of nephropathy and 29% of them tested positive for nephrin autoantibodies in at least one sample. In conclusion, this thesis work could show changes of nephrin expression along with the development of proteinuria. The autoantibodies against nephrin are likely generated in the autoimmune process leading to type 1 diabetes. However, according to the present work it is unlikely that these autoantibodies are contributing significantly to the development of diabetic nephropathy.
  • Ihalmo, Pekka (Helsingin yliopisto, 2007)
    The glomerular epithelial cells and their intercellular junctions, termed slit diaphragms, are essential components of the filtration barrier in the kidney glomerulus. Nephrin is a transmembrane adhesion protein of the slit diaphragm and a signalling molecule regulating podocyte physiology. In congenital nephrotic syndrome of the Finnish type, mutation of nephrin leads to disruption of the permeability barrier and leakage of plasma proteins into the urine. This doctoral thesis hypothesises that novel nephrin-associated molecules are involved in the function of the filtration barrier in health and disease. Bioinformatics tools were utilized to identify novel nephrin-like molecules in genomic databases, and their distribution in the kidney and other tissues was investigated. Filtrin, a novel nephrin homologue, is expressed in the glomerular podocytes and, according to immunoelectron microscopy, localizes at the slit diaphragm. Interestingly, the nephrin and filtrin genes, NPHS1 and KIRREL2, locate in a head-to-head orientation on chromosome 19q13.12. Another nephrin-like molecule, Nphs1as was cloned in mouse, however, no expression was detected in the kidney but instead in the brain and lymphoid tissue. Notably, Nphs1as is transcribed from the nephrin locus in an antisense orientation. The glomerular mRNA and protein levels of filtrin were measured in kidney biopsies of patients with proteinuric diseases, and marked reduction of filtrin mRNA levels was detected in the proteinuric samples as compared to controls. In addition, altered distribution of filtrin in injured glomeruli was observed, with the most prominent decrease of the expression in focal segmental glomerulosclerosis. The role of the slit diaphragm-associated genes for the development of diabetic nephropathy was investigated by analysing single nucleotide polymorphisms. The genes encoding filtrin, densin-180, NEPH1, podocin, and alpha-actinin-4 were analysed, and polymorphisms at the alpha-actinin-4 gene were associated with diabetic nephropathy in a gender-dependent manner. Filtrin is a novel podocyte-expressed protein with localization at the slit diaphragm, and the downregulation of filtrin seems to be characteristic for human proteinuric diseases. In the context of the crucial role of nephrin for the glomerular filter, filtrin appears to be a potential candidate molecule for proteinuria. Although not expressed in the kidney, the nephrin antisense Nphs1as may regulate the expression of nephrin in extrarenal tissues. The genetic association analysis suggested that the alpha-actinin-4 gene, encoding an actin-filament cross-linking protein of the podocytes, may contribute to susceptibility for diabetic nephropathy.
  • Patrakka, Jaakko (Helsingin yliopisto, 2001)
  • Knuutinen, Jenna (2014)
    Neptunium on yksi käytetyssä ydinpolttoaineessa olevista transuraaneista plutoniumin, amerikiumin ja curiumin lisäksi. Sen lähteitä luonnossa ovat lähinnä ydinvoimateollisuus ja ilmakehän ydinasekokeet. Käytetyn ydinpolttoaineen loppusijoituksen turvallisuusanalyysien ja ydinvoimateollisuudesta sekä ydinasekokeista vapautuneiden nuklidien kulkeutumisen kannalta on tärkeää tuntea radioaktiivisten aineiden hydrogeokemiallinen käyttäytyminen ympäristössä. Pro gradu –työssä tutkittiin neptuniumin sorptiokäyttäytymistä ja spesiaatiota karbonaattivapaissa olosuhteissa magnetiittiin, hematiittiin ja korundiin. Pro gradu -tutkimukseen valituista mineraaleista korundi ja hematiitti ovat rakenteeltaan hyvin samankaltaisia mineraaleja ja siksi niiden pintaominaisuudet ovat vertailtavissa keskenään. Neptuniumin sorptiokäyttäytymisen odotettiin olevan melko samankaltainen näihin kahteen mineraaliin. Pro gradu -tutkimuksessa oltiin kiinnostuneita myös magnetiitin ja hematiitin sisältämän kahdenarvoisen raudan vaikutuksista neptuniumin spesiaatioon ja sorptioon mahdollisten hapetus-pelkistys-reaktioiden kautta. Pro gradu -tutkimuksessa neptuniumin sorptiota valittuihin oksidimineraaleihin tutkittiin sorptiokokeilla pH:n funktiona ja lisäksi sorptioisotermien avulla eri pH-arvoissa. Sorptiokokeiden tasapainottumisajan ja kiinteä/neste-suhteen vaikutusta tutkittiin koesarjoilla kaikkissa kolmessa mineraalissa. Neptuniumin hapetustilaa ja spesiaatiota selvitettiin liuoksesta lantanidifluoridi-kerasaostuksella ja mineraalipinnalta XAFS-analyysillä. Pro gradu -tutkimuksen perusteella voidaan todeta neptuniumin sorptioon tutkittuihin oksideihin vaikuttavan neptuniumpitoisuus, pH ja mineraalin pitoisuus sekä pintaominaisuudet. Mineraalipitoisuuden ja liuoksen pH-arvon noustessa sekä neptuniumpitoisuuden laskiessa kasvaa neptuniumin suhteellinen sorptio mineraalipintaan. Rautaoksidien pinnoilla havaittiin neptuniumilla esiintyvän mahdollisesti kahdenlaisia sorptiopaikkoja. Lisäksi magnetiitilla arvioitiin olevan neptuniumia pelkistäviä ominaisuuksia. Hematiitilla ja korundilla puolestaan havaittiin olevan samanlaisia sorptio-ominaisuuksia. Neptuniumin hapetustilanmäärityksissä kerasaostuksella ja XAFS-analyysillä ei saatu luotettavaa tietoa liuoksessa ja mineraalipinnalla esiintyvän neptuniumin hapetustilasta.
  • Elo, Outi (2014)
    The largest amount of actinides possibly to be released into the environment, however, can be attributed to the geological disposal of spent nuclear fuel. Neptunium is more environmentally mobile than other transuranic elements and thus could escape into the environment. The long-lived neptunium isotope Np-237 (2.14 x 10^6 y) is an actinide of concern in safety assessments of a spent nuclear fuel repositories. It is created by irradiating uranium (U-235 or U-238) in a nuclear reactor and also formed from the decay of americium (Am-241). Radiotoxic Np-237 has been identified as a dominant long-term dose contributor of nuclear waste after one million years. The Np oxidation states under environmental conditions are Np(IV) and Np(V). Under mildly oxic conditions, Np(V) is likely to be the dominant oxidation state. Neptunium is quite soluble, poorly sorbed, and readily mobile under environmental conditions making it highly relevant for research within nuclear safety aspects. Aluminosilicate clay minerals are known to sorb actinides and contribute to actinide immobilization. However, their sorption to these same minerals may also result in colloid-facilitated transport. The bentonite buffer used in the Engineered Barrier System (EBS) consists mainly of montmorillonite and is assumed to be a potential source of colloids. The potential relevance of colloids for radionuclide transport is highly dependent on the stability of colloids in different chemical environments and their interaction with radionuclides. The dimensions of colloids are 1 – 1000 nm and they have strong sorbing properties due to large specific surface area and surface charge. In low salinity groundwater conditions, colloids are mobile unlike rock surfaces. Np(V) sorption behavior on clay minerals has been previously investigated in relatively few studies. In this study, the interaction of neptunium with the clay mineral montmorillonite and bentonite colloid suspension was investigated under simplified but environmentally relevant conditions. Sorption of Np(V) on corundum, Na-montmorillonite and bentonite colloids was studied by conducting batch experiments. Zeta potential measurements were made to obtain data from the surface potential of montmorillonite. Specific surface area, BET, measurements were conducted for montmorillonite and bentonite to get information of the possible sorption capacities. In situ Attenuated Total Reflection (ATR) FT-IR spectroscopy determinations were made to identify neptunium’s surface speciation. Aim of the ATR FT-IR measurements is to identify the dominating surface reactions during the sorption of neptunium on mineral and colloid surfaces and to describe them with suitable surface complex formation models. Due to the results the neptunium adsorption onto corundum, montmorillonite and bentonite colloids is detectable. The neptunium adsorption increases as the pH of the solution increases. The sorption is relevant in pH 9 - 11. More isotherm studies are needed to examine the possible saturation of the sorption places for neptunium on the montmorillonite. In addition the reversibility, observed in the ATR FT-IR measurements, of the neptunium sorption should be studied also in batch experiments. The bond between neptunium and corundum or montmorillonite, based on zeta potential and ATR FT-IR measurements, seems to be an inner-sphere complex. For bentonite colloids it was not possible to measure ATR FT-IR because the colloids did not sorb enough neptunium to obtain any spectra. Although the ATR FT-IR measurements showed high reversibility for the bond, indicating it is rather weak inner-sphere complex.
  • Englund, Bengt (1931)
  • Nordström, Sabina (2010)
    Parkinson´s disease is a chronic progressive neurodegenerative disorder, characterized by muscle rigidity, hypokinesia, tremors and bradykinesia. The cause of symptoms in Parkinson´s disease is loss of dopaminergic nerve cells in the substantia nigra, which attenuates the nigrostriatal dopaminergic signaltransmission. Oxidative stress, mitochondrial dysfunction, protein misfolding and aggregation, inflammation, excitotoxicity, apoptosis and other routes for cell death, and loss of neurotrophic factors have shown to be mechanisms in the pathogenesis of Parkinson´s disease. Microglia might have a double role in the pathogenesis of Parkinson´s disease. Microglia stimulated by Į- synuclein does not only produce toxic factors such as certain cytokines and reactive oxygen and nitrogen species, which contribute to the neuronal cell death but also produce anti-inflammatory cytokines and neurotrophic factors, which can be neuroprotective. Deeper knowledge of the mechanisms underlying Parkinson´s disease is needed for developing restorative medicines. Three different neurotrophic factor families are known to be important in the research of Parkinson’s disease. The GDNF-family consists of glial cell line-derived neurotrophic factor (GDNF), neurturin (NRTN), artemin (ARTN) and persephin (PSPN). The neurotrophin-family consists of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and neurotrophins NT3 and NT4/5. The most recently discovered family is the MANF-family, which consists of mesencephalic astrocyte-derived neurotrophic factor (MANF) and conserved dopamine neurotrophic factor (CDNF). In Parkinson´s disease the neurotrophic factors could stop, slow or ideally even reverse the neurodegeneration in the dopaminergic system and decrease the functional decline of the neurons. Research has already shown that GDNF has both a neurorestorative and neuroprotective effect in animal models of Parkinson´s disease. Clinical trials have however shown controversial results. The challenge with neurotrophic factors can be the administration to the brain through the blood-brain-barrier, sideeffects because of receptor binding in other organs or sites of the body and low diffusionrate. Research of both MANF and CDNF has shown promising neurorestorative and –protective results in vivo. Local diffusion of MANF has been shown to be better than of GDNF. In this Master´s thesis research was done on whether MANF and CDNF have a neurorestorative effect on the dopaminergic nerve cells in mixed primary culture in vitro after 6-OHDA exposure. The aim of the study was to receive information about whether MANF and CDNF are as effective as GDNF at repairing celldamages caused by 6-OHDA in vitro in this experimental model. GDNF was used as a posivite control in this study. The results from this study suggest that MANF might have a neurorestorative effect, but this effect is much smaller than with the neurotrophic factor GDNF. The results show no neurorestorative effect with CDNF. Neither the dopamine uptake nor the tyrosine hydroxylase staining showed statistical significance.