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  • Tuominen, Pirkko (Helsingin yliopisto, 2009)
    The drive for risk-based food safety management, systems and control has spread world-wide in recent decades. Since the term is still internationally undefined, its use and implementation vary, producing different realizations. In this Ph.D. thesis, microbiological risk assessment (MRA) was investigated as a basis for risk-based food safety management, which was defined as ‘food safety management based on risk assessment in order to achieve an appropriate level of protection (ALOP)’. Governments are responsible for commissioning MRAs and also for setting food safety targets up to a certain point, but the practical management measures that need to be in place in order to achieve the targets are to be addressed by the operators. On the plant level, food safety is usually managed through regulation, quality assurance systems and a hazard analysis and critical control point (HACCP) programme with its prerequisites. In Finland, food safety management on the food plant level is implemented through an HACCP-like regulated system termed an own-checking (OC) programme. A quantitative microbiological risk assessment (QMRA) was conducted on salmonella in the beef production chain according to the official standards of the Codex Alimentarius Commission (Codex Alimentarius), and utilized in determining the food safety metrics for beef production. The Finnish Salmonella Control Programme (FSCP) and the main official interventions due to it were examined in the light of risk-based food safety management. The targets set for beef processing plants by the government were converted into quantitative limits, and the results of salmonella monitoring included in the FSCP were examined by the QMRA. The goal of the FSCP was declared in 1994 to ‘maintain the present salmonella situation’, which was considered to refer to the salmonella incidence in humans at that time, and also the de facto ALOP. The requirement for a maximum salmonella prevalence of 1% at defined stages of the beef production chain was embodied in the FSCP. This statement was considered to convey performance objectives (PO) for the aforementioned stages. According to the QMRA, the de facto ALOP was achieved in the referred year 1999, and even the true prevalence levels in the FSCP were estimated to be clearly under the set PO limits with 95% credibility. However, the PO limits were set too high for the de facto ALOP to be maintained in practice. If the salmonella prevalence reached the PO limit of 1% or values near it, the public health risk would increase and overrun the de facto ALOP. The QMRA produced in this work has for the first time provided the possibility to quantitatively asses the relationships between targets set in the FSCP and their impact on public health. At present, imports of beef and beef-derived foods may impose on Finnish consumers a significantly greater exposure than domestic products. If their salmonella prevalence or their share of the foods consumed in Finland increase, the number of human cases could rapidly rise. The models for the QMRA were mainly Bayesian hierarchical models using Markov chain Monte Carlo (MCMC) techniques, which was found to be a flexible and appropriate method for this type of complex modelling. The resulting distributions were also regarded as an advantage compared to the results from models developed with the deterministic approach, because the presentation of results included the extent of the uncertainty, and also in this manner better illustrated the actual operational environment. Based on an inquiry, the personnel in food processing plants had a positive attitude towards food safety management systems, but the knowledge, training and involvement of those employees directly operating on the site with these systems were discovered to be deficient. Therefore, a generic semi-quantitative hygiene risk assessment model, Hygram®, was developed for small and medium-sized food enterprises to offer assistance in understanding, training, and, first of all, detecting the critical steps of the processes, and thereby to contribute to the development of their own-checking systems towards risk-based food safety management. Hygram® was not considered a risk-based tool as such, but whenever the critical limits of the process have been defined as equal to a risk assessment, Hygram® can be used as a risk-based management tool. It can also serve as a tool for systematic hazard analysis and CCP detection when establishing a food safety management system. To conclude, the development of risk-based food safety management is a process in which risk assessment is an essential tool. Scientific, technical, psychological and resource-bound barriers need to be overcome in order to put risk-based management systems into practice. This study showed that QMRA can be valuable in national risk management decision making, although few QMRAs are currently available. Appropriate tools for practical risk management decision making on the industrial level, such as Hygram®, need to be further developed.
  • Hagos, Elias Nahusenay (Helsingin yliopisto, 2015)
    Ethiopia is Africa’s biggest coffee exporter nation with deep history. Coffee discovered in Ethiopia and it continues to be pivotal for the country in many fronts till to date. The coffee linkage with Ethiopia is deep-rooted many historians believe back in 9th century coffee discovered by Kaldi, a goat herder. He discovered it after noticing coffee’s energizing effect on his goats. The word coffee itself also derived from place called ‘Kaffa’ where the trees blossomed. Coffee gradually became a world obsession by spreading from highlands of Ethiopia traveled along spice routes to Yemen, Turkey and Europe. Coffee exporting is a significant portion of Ethiopian economy. It accommodates more than twenty five million peasants which indicate its magnitude for the country. It is one of the leading sources of income for the government and other stakeholders. The establishment of Ethiopian Commodity Exchange (ECX) has seen the Ethiopian coffee trade system being transformed. It created a platform of primary, secondary and tertiary market divisions. In a way that the coffee can be traded based on value addition from one division to the other. Unlike the previous centralized warehousing system, it introduced decentralized warehousing and liquoring centers across the country where the coffee quality checked by use of laboratory tasting. It gives a temporary produce storage services until the coffee is sold and ownership of the produce transferred from seller to buyer. The introduction of modernized and transparent system enabled economic gain and helped farmers to enhance their life conditions. The objective of this study was to identify some of the contradictions that are solved in Ethiopian coffee trade activity by the establishment of ECX. In addition, the emerging contradictions and prevailing disturbances at present as well as the overall benefits it brought in relation to farmers’ day to day life conditions were analyzed.
  • Vuontela, Virve (Helsingin yliopisto, 2008)
    Intact function of working memory (WM) is essential for children and adults to cope with every day life. Children with deficits in WM mechanisms have learning difficulties that are often accompanied by behavioral problems. The neural processes subserving WM, and brain structures underlying this system, continue to develop during childhood till adolescence and young adulthood. With functional magnetic resonance imaging (fMRI) it is possible to investigate the organization and development of WM. The present thesis aimed to investigate, using behavioral and neuroimaging methods, whether mnemonic processing of spatial and nonspatial visual information is segregated in the developing and mature human brain. A further aim in this research was to investigate the organization and development of audiospatial and visuospatial information processing in WM. The behavioral results showed that spatial and nonspatial visual WM processing is segregated in the adult brain. The fMRI result in children suggested that memory load related processing of spatial and nonspatial visual information engages common cortical networks, whereas selective attention to either type of stimuli recruits partially segregated areas in the frontal, parietal and occipital cortices. Deactivation mechanisms that are important in the performance of WM tasks in adults are already operational in healthy school-aged children. Electrophysiological evidence suggested segregated mnemonic processing of visual and auditory location information. The results of the development of audiospatial and visuospatial WM demonstrate that WM performance improves with age, suggesting functional maturation of underlying cognitive processes and brain areas. The development of the performance of spatial WM tasks follows a different time course in boys and girls indicating a larger degree of immaturity in the male than female WM systems. Furthermore, the differences in mastering auditory and visual WM tasks may indicate that visual WM reaches functional maturity earlier than the corresponding auditory system. Spatial WM deficits may underlie some learning difficulties and behavioral problems related to impulsivity, difficulties in concentration, and hyperactivity. Alternatively, anxiety or depressive symptoms may affect WM function and the ability to concentrate, being thus the primary cause of poor academic achievement in children.
  • Shulga, Anastasia (Helsingin yliopisto, 2011)
    Traumatic insults to the central nervous system are frequently followed by profound and irreversible neuronal loss as well as the inability of the damaged neurons to regenerate. One of the major therapeutic challenges is to increase the amount of surviving neurons after trauma. Thus it is crucial to understand how injury affects neuronal responses and which conditions are optimal for survival to prevent neuronal loss. During development neuronal survival is thought to be dependent on the competition for the availability of survival-promoting molecules called neurotrophic factors. Much less is known on the survival mechanisms of mature neurons under traumatic conditions. Increasing amount of evidence points towards the possibility that after injury neuronal responses might aquire some developmental characteristics. One of the important examples is the change in the responses to the neurotransmitter GABA: it is inhibitory in the intact mature neurons, but can induce excitation during development and after trauma. An important step in the maturation of GABAergic transmission in the CNS is the developmental shift in the action of GABAA receptor from depolarization in immature neurons to hyperpolarization in mature neurons. GABAA-mediated responses are tightly linked to the homeostasis of the chloride anion (Cl-), which in neurons is mainly regulated by Na+-K+-2Cl- cotransporter NKCC1 and K+-Cl- cotransporter KCC2. Trauma-induced functional downregulation of KCC2 promotes a shift from hyperpolarizing GABAA-mediated responses to depolarizing. Other important consequences of neuronal trauma are the emergence of dependency of central neurons on brain-derived neuro¬trophic factor (BDNF) for survival, as well as the upregulation of neurotrophin receptor p75NTR. Our aim was to answer the question whether these post-traumatic events are interrelated, and whether the regulation of BDNF and KCC2 expression is different under traumatic conditions and in intact neurons. To study responses of injured mature central neurons, we used an in vitro and in vivo axotomy models. For in vitro studies, we lesioned organotypic hippocampal slices between CA3 and CA1 regions, which resulted in selective axotomy of the CA3 neurons and denervation of the CA1 neurons. Some experiments were repeated in vivo by lesioning the neurons of the corticospinal tract at the internal capsule level, or by lesioning spinal motoneurons at the ventral root. We show that intact mature neurons do not require BDNF for survival, whereas in axotomized neurons apoptosis is induced upon BDNF deprivation. We further show that post-traumatic dependency on BDNF is mediated by injury-induced upregulation of p75NTR. Post-traumatic increase in p75NTR is induced by GABAA-mediated depolarization, consequent opening of voltage-gated Ca2+ channels, and the activation of Rho kinase ROCK. Thus, post-traumatic KCC2 downregulation leads to the dependency on BDNF through the induction of p75NTR upregulation. Neurons that survive after axotomy over longer period of time lose BDNF dependency and regain normal KCC2 levels. This phenomenon is promoted by BDNF itself, since after axotomy contrary to normal conditions KCC2 is upregulated by BDNF. The developmentally important thyroid hormone thyroxin regulates BDNF expression during development. We show that in mature intact neurons thyroxin downregulates BDNF, whereas after axotomy thyroxin upregulates BDNF. The elevation of BDNF expression by thyroxin promoted survival of injured neurons. In addition, thyroxin also enhanced axonal regeneration and promoted the regaining of normal levels of KCC2. Thus we show that this hormone acts at several levels on the axotomy-initiated chain of events described in the present work, and could be a potential therapeutic agent for the injured neurons. We have also characterized a previously unknown downregulatory interaction between thyroxin and KCC2 in intact neurons. In conclusion, we identified several important interactions at the neurotrophin-protein and hormone-neurotrophin level that acquire immature-like characteristics after axotomy and elucidated an important part of the mechanism by which axotomy leads to the requirement of BDNF trophic support. Based on these findings, we propose a new potential therapeutic strategy where developmentally crucial agents could be used to enhance survival and regeneration of axotomized mature central neurons.
  • Luchkina, Natalia V. (Helsingin yliopisto, 2015)
    Activity-dependent synaptic plasticity, and long-term potentiation in particular, represents the predominant model of memory and learning at the cellular level. In addition, synaptic plasticity plays a critical role in the activity-dependent refinement and fine-tuning of neuronal circuits during development by maintaining and stabilising certain synaptic connections and eliminating others. The main goal of this project was to increase our understanding of the molecular mechanisms underlying activity-dependent synaptic plasticity in the developing brain, with particular emphasis on the mechanisms that are specific to early postnatal development. First, we characterise in detail the properties of developmentally restricted neonatal presynaptic long-term potentiation (LTP) in CA1 area of the hippocampus and demonstrate its susceptibility to regulation via protein kinase C (PKC) signalling. Next, we explore the physiological functions of GluA4 subunit-containing AMPA type glutamate receptors, predominantly expressed at developing CA3 CA1 synapses. We show that GluA4 expression is necessary for protein kinase A (PKA)-dependent LTP at immature synapses. Further, the loss of GluA4 expression in parallel with circuit maturation explains the developmental switch in LTP signalling requirements from PKA- to Ca2+/calmodulin-dependent protein kinase II (CaMKII)-dependent. Further, we also explore the role of GluA4 C-terminal interaction partners in synaptic trafficking of GluA4-containing AMPA receptors and its importance for synapse maturation. We confirm a critical role for the membrane proximal region of GluA4 C-terminal domain in trafficking and identify a novel mechanism for activity-dependent synaptic delivery of GluA4 by the extreme C-terminal region. Finally, we show an important role of the GluA4 subunit in strengthening of AMPA receptor-mediated transmission, observed during early postnatal development. In summary, we provide novel information on the pre- and postsynaptic plasticity mechanisms operating at hippocampal CA3 CA1 synapses during the critical period of activity-dependent maturation of glutamatergic neuronal circuitry in rodents. This expands our knowledge on the cellular mechanisms guiding development of synaptic connectivity in the brain. Dysfunction of such mechanisms may play fundamental roles in the underlying pathophysiological causes of various neurodevelopmental disorders.
  • Feldt, Kimmo (Helsingin yliopisto, 2010)
    The model of developmental origins of health and disease proposes that organisms during fetal period utilize cues that enable their adaptation in the postnatal environment they are likely to live, having short-term advantages when trying to survive in environment but simultaneously in the long run have costs for health. A large body of epidemiological research has found that low birth weight, a marker of intrauterine conditions, is associated with cardiovascular (CV) disease. Since the reported associations of birth weight with normal variation in the resting blood pressure (BP), a major predictor of CV disease risk, have been modest, a key candidate mediating the link has been CV and hypothalamus-pituitary-adrenal axes (HPAA) reactivity to stress. In addition, not only weight at birth but also gestational age and early postnatal growth may have independent associations to stress reactivity. The aim of this thesis was to investigate whether pre- and postnatal growth and gestational age are associated with CV and HPAA activity before, during and after stress in childhood and in late adulthood. Altogether 287 men and women aged 60-70 and 299 boys and girls aged 7-9 underwent Trier Social Stress Test. Several indices of HPAA and CV were measured and birth size and gestational age were obtained from birth records. Results showed that low birth weight was associated with low HPAA activity during psychosocial stress, and rapid gain in BMI during years 7-11 was related to heightened stress reactivity to psychosocial stress. Size at birth in children and gestational age and early postnatal (0-2 years) gain in height in adults were associated with CV stress responses; however, in a sex-specific manner. Given that CV stress responses and HPAA activity are markers of CV disease vulnerability, our results may partly explain the associations between early environment and later CV disease.
  • Lahti, Jari (Helsingin yliopisto, 2009)
    Premature birth and associated small body size are known to affect health over the life course. Moreover, compelling evidence suggests that birth size throughout its whole range of variation is inversely associated with risk for cardiovascular disease and type 2 diabetes in subsequent life. To explain these findings, the Developmental Origins of Health and Disease (DOHaD) model has been introduced. Within this framework, restricted physical growth is, to a large extent, considered either a product of harmful environmental influences, such as suboptimal nutrition and alterations in the foetal hormonal milieu, or an adaptive reaction to the environment. Whether inverse associations exist between body size at birth and psychological vulnerability factors for mental disorders is poorly known. Thus, the aim of this thesis was to study in three large prospective cohorts whether prenatal and postnatal physical growth, across the whole range of variation, is associated with subsequent temperament/personality traits and psychological symptoms that are considered vulnerability factors for mental disorders. Weight and length at birth in full term infants showed quadratic associations with the temperamental trait of harm avoidance (Study I). The highest scores were characteristic of the smallest individuals, followed by the heaviest/longest. Linear associations between birth size and psychological outcomes were found such that lower weight and thinness at birth predicted more pronounced trait anxiety in late adulthood (Study II); lower birth weight, placental size, and head circumference at 12 months predicted a more pronounced positive schitzotypal trait in women (Study III); and thinness and smaller head circumference at birth associated with symptoms of attention-deficit hyperactivity disorder (ADHD) in children who were born at term (Study IV). These associations occured across the whole variation in birth size and after adjusting for several confounders. With respect to growth after birth, individuals with high trait anxiety scores in late adulthood were lighter in weight and thinner in infancy, and gained weight more rapidly between 7 and 11 years of age, but weighed less and were shorter in late adulthood in relation to weight and height measured at 11 years of age (Study II). These results suggest that a suboptimal prenatal environment reflected in smaller birth size may affect a variety of psychological vulnerability factors for mental disorders, such as the temperamental trait of harm avoidance, trait anxiety, schizotypal traits, and symptoms of ADHD. The smaller the birth size across the whole range of variation, the more pronounced were these psychological vulnerability factors. Moreover, some of these outcomes, such as trait anxiety, were also predicted by patterns of growth after birth. The findings are concordant with the DOHaD model, and emphasise the importance of prenatal factors in the aetiology of not only mental disorders but also their psychological vulnerability factors.
  • Pasupulate, Avinash (Helsingin yliopisto, 2015)
    The aim of this study was to develop and apply a high throughput and cost effective method for screening food samples for antibiotic contamination. This method can be used to reduce the number of samples that have to be analysed using expensive chemical methods that are at currently being used for determining antibiotic concentrations. The primary objective of this study involved the construction of a macrolide sensitive bacterial bioreporter, which can be used to detect the levels of macrolide antibiotics in meat samples. The bioreporter was constructed by merging a macrolide promoter region to a bioluminescent signalling gene like the lux operon, this fused segment was then cloned into a suitable vector and transformed to a host E. coli along with the repressor (producing) plasmid. The bioreporter works in the presence of macrolides, when the repressor protein is released from the promoter region, resulting in the expression of the lux operon, which produces light. This light signal can be used for the detection and estimation of macrolide antibiotics using a luminometer. The secondary objective was to use the macrolide bioreporter along with a previously constructed tetracycline bioreporter to measure antibiotic concentrations in bovine meat samples acquired from EVIRA (Finnish Food Safety Authority). On analysis of the resulting luminescence data, calculated concentrations of oxytetracycline were found to be in correlation to the data acquired from EVIRA and also using solid meat samples in assays, instead of extracted muscle fluid produced more accurate results. This shows the usability of bioreporters in the detection of antibiotics in animal-based foods from different sources. The resulting data can also be used to monitor and control the spread of antibiotic resistance through animal farms.
  • Leikola, Saija (Helsingin yliopisto, 2012)
    Populations in Western countries are ageing. At the same time, use of medications is increasing among older people. Age-related changes in the body make the elderly vulnerable to adverse drug events. Thus, ensuring medication safety among this patient group is a growing health care concern. The aim of this study was to examine the Finnish collaborative Comprehensive Medication Review (CMR) model as a means to improve the appropriateness of pharmacotherapy among community-dwelling elderly. The specific aims were 1) to determine the prevalence of potentially inappropriate medication use according to the Beers 2003 criteria among Finnish non-institutionalized population aged ≥65 years; 2) to describe the development and assess participant satisfaction on the CMR accreditation training; 3) to describe the development of the CMR procedure and related documentation; and 4) to assess the drug-related problems (DRPs) pharmacists report to collaborating physicians during CMR and the resulting interventions among outpatients aged ≥65 years. The prevalence of potentially inappropriate drug use was studied by using the drug reimbursement register of the Social Insurance Institution covering the entire non-institutionalized population aged ≥65 years in 2007 (n=841 509, Study I). The development of the CMR procedure and accreditation training involved a review of literature and international medication review procedures, and pilot testing by 26 experienced pharmacists undergoing the CMR training in 2005 - 2006 (Studies II, III). Pharmacists satisfaction on the CMR training (n=38) and documentation (n=27) were assessed by surveys completed by CMR training participants in 2006 - 2007 (Studies II, III). The DRPs reported to the collaborating physicians were studied by a retrospective review of CMR case reports (n=121) by 26 community pharmacists attending the CMR training in 2006 - 2007 (Study IV). Approximately 15% of the non-institutionalized population aged ≥65 years used potentially inappropriate medications in 2007. The most worrying finding was the common use of benzodiazepines, particularly high-dose temazepam. The 1.5-year CMR accreditation training for practicing pharmacists combines distance learning and face-to-face learning. The participating pharmacists satisfaction with the training was high but several factors prevent them from conducting CMRs after the training. The collaborative CMR procedure involves access to clinical patient information, in-home patient interview, a case conference with the collaborating physician and standard documentation to support the process. The procedure covers four dimensions critical for safe and appropriate geriatric pharmacotherapy: Aging and Safety; Co-Morbidities; Polypharmacy; and Adherence. During CMR pharmacists reported to collaborating physicians an average of 6.5 DRPs/patient. Most common DRPs were inappropriate drug selection, especially involving psychotropics, and undertreatment. Also treatment of pain was often found to need improvement. Approximately half of the pharmacists recommendations led to medication changes, i.e., to an average of 3 changes/patient. The most common agreed change was to stop hypnotics or sedatives. The CMR procedure could be beneficial for improving pharmacotherapy among older outpatients as a large portion of DRPs identified by pharmacists led to medication changes. Actions to facilitate implementation of the model to Finnish health care system are needed. Also, further studies are needed to evaluate the effects of CMR on clinical, humanistic and economic outcomes.
  • Judström, Aili (2013)
    A class action is a procedural instrument where the traditional constellation of two party litigation is set aside. In a class action, a group is summoned and the group together pursues a lawsuit, normally aiming to receive a compensatory relief. Like any other civil law judgement, class actions decisions are injunctive, declaratory or compensatory. The Finnish Act on Class Actions entered into force in October 2007. The first memorandum of the Act was wide in scope and even allowed the opt-out system. The only restriction in applicability was that the case had to be a civil claim. Over the several years of law-drafting the Act went from liberal to restrict. Today the Act allows only the Consumer Ombudsman to have exclusive standing to bring forth a case on the behalf of numerous consumers. The ratio of the act was to ease the consumers’ access to court and through that, help consumers to gain compensation when hurt by a unlawful company practise. Six years in force, the Act remains unused. This thesis sets out to study why such an act exists in the Finnish legal system. When the Act on Class Action was drafted it met heavy resistance from the industry and commerce. Stakeholders not in favour of the proposals used the US class action as a deterrent when arguing against the introduction of class action in Finland. The stakeholders boldly mixed challenges in US litigation, such as punitive damages, contingency fees and frivolous lawsuits with the class action instrument and blamed it all on Rule 23 in FedRCP allowing the federal class action. Analysing class action from a law & economic point of view, it becomes evident that it is a procedural instrument with two major positive functions, deterrence and the reparative effect. The Act does however not reach these functions and should thus be amended. The Swedish model allows three different forms of class action - the private, the organisation and the public group action. The act allows all civil claims in general courts as well as environmental claims in special courts. The Swedish act is actively used and there are no signs of abusive litigation in Sweden. The Swedish Act resembles its US paragon, the big difference being that the US enforces the opt-out model. Finland should follow Sweden and dramatically widen the applicability of the Class Action Act.
  • Finne, Patrik (Helsingin yliopisto, 2000)
  • Minetti, Mika (2000)
    Tämän tutkielman tarkoituksena on analysoida Laosin demokraattisessa tasavallassa hiljattain toteutettuja taludellisia uudistuksia. Kiinan, Vietnamin, Kamputsean, Thaimaan ja Myanmarin ympäröimä Laos on eräs maailman köyhimmistä kehitysmaista, jonka avautumisen jälkeen syntynyttä uutta tilannetta on määrittänyt politiikan ja talouden välisen tasapainon etsiminen. Maan hallitus on vapauttanut talouden sääntelystä ja toivottanut kansainväliset investoinnit tervetulleiksi, mutta samanaikaisesti se on pitänyt voimakkaasti kiinni yksipuoluejärjestelmästä. Kommunistisella puolueella on edelleen keskeinen asema maan kaikissa poliittisissa instituutioissa. Laosin sisäisen kehityksen ohjaaminen sekä globalisaation mukanaan tuomiin haasteisiin vastaamiin on osoittautunut vaikeaksi. Tästä huolimatta Laosissa, ja myös kansainvälisen yhteisön parissa, esiintyy toiveikkuutta ja pyrkimyksiä vaikuttaa myönteisesti maassa tapahtuvaan taloudelliseen ja inhimilliseen kehitykseen globalisaation aikakaudella. Tutkielmassa käsitelläänkin poliittisen vaikuttamisen mahdollisuuksia aikana, jolloin valtio ja markkinat on erotettu toisistaan. Laosissa tapahtuvaa transformaatiota määrittää parhaiten the New Economic Mechanism, joka otettiin käyttöön 1980-luvun puolivälissä. Kuluneina vuosina laajamittaisia maan sisäisiä uudistuksia on käynnistetty ulkomaankaupan samanaikaisesti kansainvälistyessä. Kaiken aikaa taloudellinen globalisaatio on kiihtynyt. Tutkielmani pyrkii vastaamaan kysymyksiin siitä, mitkä voimat ja toimijat ovat vieneet muutoksia eteenpäin Laosissa, kuinka uudistukset on toteutettu sekä koska ja missä olosuhteissa siirtyminen sosialistisesta suunnitelmataloudesta markkinatalouteen tapahtui. Tutkielman teoreettisen viitekehyksen tarjoavat tunnetut kehitysteoriat (Frank, Wallerstein jne.), globalisaatioteoriat sekä kansainvälisen politiikan teoriat (realismi ja institutionalismi). Tutkielmassa käsitellään sekä sisäisten että ulkoisten toimijoiden osuutta muutoksiin. Vuodesta 1975 vuoteen 1985 kestäneen eristyneisyyden ajan poliittinen ja taloudellinen todellisuus johdatti niihin sisäisiin paineisiin, jotka sysäsivät talousuudistukset liikkeelle. Ulkoisia vaikuttimia olivat niin kylmän sodan päättyminen, Kaakkois-Aasian integraatio (ASEAN) kuin globaalien markkinoiden mukanaan tuomat mahdollisuudet. Laosin oli avattava rajansa ja ryhdyttävä etsimään yhteistyökumppaneita sosialistisen leirin ulkopuolelta. Valtion mahdollisuudet onnistua tulevaisuudessa luomaan itselleen uusi rooli alueellisena kohtauspaikkana toimittuaan läpi historiansa puskurina suurvaltaintressien välillä riippuu pitkälti maan poliittisen järjestelmän uusiutumiskyvystä ja taidosta allokoida uudistusten mahdollisesti mukanaan tuomaa hyvinvointia tasaisesti.
  • Minetti, Mika (2000)
    The purpose of this thesis is to analyze different dimensions of the recent economic transformation of the Lao People's Democratic Republic (also known as Laos); one of the world's poorest developing countries sandwiched between China, Vietnam, Cambodia, Thailand and Myanmar. A balancing act between politics and markets has been exercised ever since the country opened up. While the country's leadership opted for free market economy and invited foreign investments, the political institutions remained in the hands of the communist party. However, means to control the development including unwelcome side effects unfolding as a consequence of the globalization are few, but a certain conviction and intention to improve the economic and human development of Laos prevails among local politicians and foreign donors as well. From this perspective, prospects for political direction in the globalized world are being discussed. The New Economic Mechanism, a nucleus of the transformation process, was introduced in Laos in the mid-1980s. During following years, comprehensive domestic reforms have been implemented, and Laotian foreign trade has internationalized along with the acceleration of the globalization. This thesis work aims to answer questions concerning the role of relevant actors presiding over the change, how the reforms have been conducted and when and under which circumstances the 'turn' took place. Writings on the subjects of development theories (Frank, Wallerstein etc.), globalization and international relations (realism and institutionalism) offer a theoretical framework for the thesis work. Internal and external actors contributing to the change are being discussed: political structures and economic performance during the isolationist period of the country stretching from 1975 to 1985 help us to understand the internal motivation for the reform policy. In addition to the domestic pressure, the end of the cold war, the Southeast Asian integration (ASEAN, for instance) and the boosting globalization of world markets forced Laos - and simultaneously gave the country an opportunity - to break its isolation and seek new partners after the Soviet support had vanished. Whether Laos manages to turn its traditional role of a buffer-state between greater powers into a regional crossroads depends largely on the flexibility of its political system and on its capability to distribute the fruits of reforms for the benefit of the whole populace.
  • Ho Huu, Tho (Helsingin yliopisto, 2015)
    The aim of this study was to utilize molecular biology knowledge to develop novel amplification-based technologies, which enable enrichment of challenging nucleic acid targets to a level sufficient for detection, including those with extremely long, GC-rich and/or repetitive sequences and low-abundance single nucleotide RNA variants in the excess of alternative variants. We have introduced multiple heat pulses in the extension step of a PCR cycling protocol to generate a novel amplification technology (HPE-PCR), which temporarily destabilize secondary structures, in order to enhance DNA polymerase extension over GC-rich sequences. Different GC rich target sequences in the human genome, extremely long Fragile X GGC repeats and Myotonic Dystrophy type 1 CTG repeats have been used as models to develop and validate this novel technology. In order to detect a low-abundance RNA variant, we devised a novel technology using a competitive Extendable Blocking Probe (ExBP) in the reverse transcription reaction for allele-specific priming with superior selectivity. In ExBP-reverse transcription, the mismatch priming site on the alternative variant is blocked by a perfectly matched ExBP. This initiates formation of a stable cDNA-RNA hybrid that completely blocks false cross-priming by the target specific primer. In experimental models, the ExBP-based reverse transcription assay allowed for detection of multiple mutation types on different genes in at least 1000-fold excess of wildtype RNA and detection was linear over a 4 log dynamic range. This technique not only reveals the presence or absence of rare mutations with an exceptionally high selectivity, but also provides a convenient tool for accurate determination of RNA variants in different settings, such as quantification of allele-specific expression. In conclusion, we have established HPE-PCR and ExBP-RT techniques to enable enrichment of different nucleic acid templates that are currently challenging to detect by PCR, such as long, GC rich and/or repetitive sequences as well as low-abundance point mutations in a vast excess of wildtype alleles. These techniques expand the capacities of current PCR technology; provide versatile and convenient research tools and open many new possibilities for its applications in molecular diagnostics.
  • Salminen, Susanna (Helsingin yliopisto, 2009)
    In this work, separation methods have been developed for the analysis of anthropogenic transuranium elements plutonium, americium, curium and neptunium from environmental samples contaminated by global nuclear weapons testing and the Chernobyl accident. The analytical methods utilized in this study are based on extraction chromatography. Highly varying atmospheric plutonium isotope concentrations and activity ratios were found at both Kurchatov (Kazakhstan), near the former Semipalatinsk test site, and Sodankylä (Finland). The origin of plutonium is almost impossible to identify at Kurchatov, since hundreds of nuclear tests were performed at the Semipalatinsk test site. In Sodankylä, plutonium in the surface air originated from nuclear weapons testing, conducted mostly by USSR and USA before the sampling year 1963. The variation in americium, curium and neptunium concentrations was great as well in peat samples collected in southern and central Finland in 1986 immediately after the Chernobyl accident. The main source of transuranium contamination in peats was from global nuclear test fallout, although there are wide regional differences in the fraction of Chernobyl-originated activity (of the total activity) for americium, curium and neptunium.
  • Jernström, Jussi (Helsingin yliopisto, 2006)
    Radioactive particles from three locations were investigated for elemental composition, oxidation states of matrix elements, and origin. Instrumental techniques applied to the task were scanning electron microscopy, X-ray and gamma-ray spectrometry, secondary ion mass spectrometry, and synchrotron radiation based microanalytical techniques comprising X-ray fluorescence spectrometry, X-ray fluorescence tomography, and X-ray absorption near-edge structure spectroscopy. Uranium-containing low activity particles collected from Irish Sea sediments were characterized in terms of composition and distribution of matrix elements and the oxidation states of uranium. Indications of the origin were obtained from the intensity ratios and the presence of thorium, uranium, and plutonium. Uranium in the particles was found to exist mostly as U(IV). Studies on plutonium particles from Runit Island (Marshall Islands) soil indicated that the samples were weapon fuel fragments originating from two separate detonations: a safety test and a low-yield test. The plutonium in the particles was found to be of similar age. The distribution and oxidation states of uranium and plutonium in the matrix of weapon fuel particles from Thule (Greenland) sediments were investigated. The variations in intensity ratios observed with different techniques indicated more than one origin. Uranium in particle matrixes was mostly U(IV), but plutonium existed in some particles mainly as Pu(IV), and in others mainly as oxidized Pu(VI). The results demonstrated that the various techniques were effectively applied in the characterization of environmental radioactive particles. An on-line method was developed for separating americium from environmental samples. The procedure utilizes extraction chromatography to separate americium from light lanthanides, and cation exchange to concentrate americium before the final separation in an ion chromatography column. The separated radiochemically pure americium fraction is measured by alpha spectrometry. The method was tested with certified sediment and soil samples and found to be applicable for the analysis of environmental samples containing a wide range of Am-241 activity. Proceeding from the on-line method developed for americium, a method was also developed for separating plutonium and americium. Plutonium is reduced to Pu(III), and separated together with Am(III) throughout the procedure. Pu(III) and Am(III) are eluted from the ion chromatography column as anionic dipicolinate and oxalate complexes, respectively, and measured by alpha spectrometry.