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    <title>E-thesis / Viikki Campus</title>
    <description>E-thesis site contains doctoral dissertations and other publications from the University of Helsinki. All of these full-text publications are freely accessible via the Internet. This is RSS 2.0 feed for forthcoming dissertations from Viikki Campus</description>
    <link>http://ethesis.helsinki.fi</link>
    <language>en</language>
    <copyright>Copyright University of Helsinki</copyright>
    <webMaster>e-thesis@helsinki.fi</webMaster>
    <pubDate>Thu, 23 May 2013 03:00:01 +0300</pubDate>
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      <title>24.5. Markus Majaneva: Linking taxonomy and environmental 18S-rRNA-gene sequencing of Baltic Sea protists</title>
      <link>http://urn.fi/URN:ISBN:978-952-67851-4-1</link>
      <description><![CDATA[<p>Protists are unicellular eukaryotes. Some protistan species may be impossible to distinguish under the light or even electron microscope, and a complete balanced study of protistan taxonomy requires molecular analysis and light and electron microscopy. One of the main applications of taxonomic work is the assessment of diversity of organisms in an ecosystem. However, uncertainty in taxonomic precision undermines the diversity measures. DNA sequence data provide assistance since they are easily transformed to numbers that can be compared systematically and in a similar way throughout the eukaryotic domain, using sequence similarity to define operational taxonomic units (OTUs). DNA-based assessment of diversity is called environmental sequencing. The most commonly used gene in the environmental gene sequencing for eukaryotes and also in the protistan taxonomic studies has been the small subunit (18S) ribosomal RNA gene of the ribosomal operon. Also, internal transcribed spacers (ITS) are used.
</p><p>The studies in this thesis were conducted with Baltic Sea protists. The Baltic Sea is a subarctic brackish-water basin that partially freezes over every winter. If the salinity of parent water is higher than 0.6, the forming ice has a semi-solid structure with solid ice crystals and saline water (brine) channels. The brine channels offer habitats for small-sized organisms. Due to the low salinity of the Baltic Sea, the brine channels are small, and therefore, the Baltic Sea ice eukaryotic community is dominated by protists. Studies on Baltic sea-ice biology have been accumulating since the 1980s, but there are still gaps on knowledge; for example, what protistan species and how many there are associated with sea ice. In this
thesis, morphological, molecular and ecological information was combined to delineate species of a Baltic Sea cryptomonad, haptophyte and dinoflagellate. Protistan community composition in Baltic Sea ice was assessed with environmental sequencing, and diversity estimates were compared in different types of ice. The taxonomic and environmental-sequencing studies were linked using the gathered taxonomic information to evaluate the accuracy of the molecular diversity-measurement method.
</p><p>A new cryptomonad species, Rhinomonas nottbecki, was described based on morphological characters distinguished by light- and electron-microscopy together with molecular evidence from 18S rRNA gene and ITS region. The same approach was applied to the identification of the alternate stage Prymnesium polylepis (Haptophyta), which bloomed in the whole Baltic Proper during autumnspring 20072008. Also, a novel cold-water and sea-ice associated dinoflagellate subspecies, Heterocapsa arctica subsp. frigida, was described. Environmental 18S-rRNA-gene sequencing revealed that the richest eukaryotic lineages inhabiting the Baltic Sea ice were ciliates, cercozoa, dinoflagellates and diatoms. The different developmental stages and types of ice had different community composition. Protistan richness was higher in ice than water even though water included more divergent lineages. The Baltic fast ice had higher richness than pack and drift ice.
</p><p>The results of this thesis showed that there remains novelty to be described in the Baltic Sea, and what we know about the protistan community in Baltic Sea ice now is very incomplete. Although the environmental sequencing produced data that met the requirements of calculation of comparable diversity indices (all taxa defined at the same level), revealed cryptic taxa, and gave higher protistan richness than basic light microscopy of fixed samples, the lack of taxonomic detail was not restricted to the light-microscopic surveys but was also a result of the environmental-sequencing approach. This was shown when the environmental-sequencing approach was applied on the 18S-rRNA-gene data of the cryptomonad family Pyrenomonadaceae and the haptophyte genus Prymnesium. Only one Pyrenomonadaceae and two Prymnesium OTUs were found although both data sets included 15 distinct taxa. Errors in environmental sequencing and alignment make the use of high similarity levels in the OTU definition questionable, and the variability in the 18S rDNA is not equal within different eukaryotic lineages. Consequently, use of lower similarity level (97 %) is justifiable in the environmental-sequencing, but the approach used gave conservative estimates of the protistan richness in the Baltic Sea ice.
</p><p>The overall conclusion is that we need to apply all available techniques when assessing the diversity of protists, as each technique provides a biased perspective on nature. A labor intensive taxonomic approach that includes the study of live cells by light microscopy, detailed morphological description based on electron microscopy and phylogenetic analysis of suitable genetic markers gives us the best chance of finding out how many different species of protists live within the Baltic Sea ice or any other environment, and what they do.
</p>]]></description>
      <guid isPermaLink="true">http://urn.fi/URN:ISBN:978-952-67851-4-1</guid>
      <dc:creator>Majaneva, Markus</dc:creator>
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      <title>31.5. Salla Venäläinen: Abatement of phosphorus- and lead-induced environmental risks by means of apatite ore mine tailings</title>
      <link>http://urn.fi/URN:ISBN:978-952-10-8773-8</link>
      <description><![CDATA[<p>Mining of phosphorus (P) and lead (Pb) ores increases their amounts in biogeochemical cycles and, consequently, their environmental risks. Phosphorus is an important nutrient, but P loading from sewage waters and agricultural activities to watercourses may result in eutrophication, a process eventually detrimental to aquatic ecosystems. Lead, on the other hand, poses a direct risk of intoxication to all living organisms. In addition to technical applications, Pb is used in pellets and shots on shooting ranges, which accounts for a large source of Pb loading to the environment. Prevention and abatement of detrimental impacts of P and Pb require large-scale, cost-effective techniques that do not compromise the environment. 
</p><p>This thesis was undertaken to investigate the potential of tailings from apatite ore beneficiation at the Siilinjärvi phosphate mine, Finland, in the dephosphorization of sewage and in the remediation of metal-contaminated areas. The material is a mixture of minerals, mainly phlogopite [KMg3(Si3Al)O10(OH)2] and calcite (CaCO3), accompanied by apatite [Ca5(PO4)3F] residues. Based on the versatile chemical properties, this geomaterial was hypothesized to act as a sorbent for P and Pb, rendering the tailings a potential agent for environmental remediation. A part of the original tailings material was artificially weathered by treating with a strong acid to create reaction-active aluminium (Al) and iron (Fe) (hydr)oxide sites. Some of the acidified material was further subjected to partial neutralization by treating with a strong base to precipitate any metals dissolved from the mineral structure during the acidification. Furthermore, all of the tailings materials were sieved into two particle-size fractions somewhat differing in their mineralogical composition and investigated as separate amendments. 
</p><p>The ability of the tailings to retain P and Pb from aqueous solutions as well as the tailings-induced changes in the Pb retention capacity of a mineral soil were studied by means of an isotherm technique. A sequential fractionation procedure was undertaken to investigate (a) the distribution of inherent and added P between various chemical pools in the tailings and (b) the tailings-induced changes in the distribution of Pb between various chemical pools in a mineral soil artificially contaminated with Pb as well as in an organic shooting range soil contaminated with pellet-derived Pb. Because the toxicity of dissolved Pb depends on its chemical speciation, the tailings-induces changes in the chemical speciation of water-extractable Pb in contaminated shooting range soil was tested separately by means of a cation exchange resin.
The tailings retained both P and Pb efficiently. The removal of soluble P was primarily due to specific sorption by Al and Fe (hydr)oxides and possibly to retention to calcite. Lead sorption by the untreated tailings was a combination of various sorption mechanisms taking place simultaneously, primarily through precipitation and surface complexation. All tailings materials increased the Pb sorption capacity of a mineral soil and transferred Pb from the NH4NO3-extractable pool to the more strongly bound forms. In a contaminated shooting range soil, the pellets were found to undergo continuous weathering processes that released Pb into the soil. Amending the soil with the untreated tailings (a) reduced the solubility of the pellet-derived Pb through the formation of sparingly soluble fluorpyromorphite and cerussite, (b) reduced the bioavailability of Pb by transferring it from the water-soluble and NH4NO3-extractable pools into the NaOH-extractable one and (c) transferred the most toxic cationic Pb species to the less toxic non-cationic form.
</p><p>The results suggest that the tailings may serve as an agent for dephosphorization of sewage and for Pb immobilization in polluted soil. The sorption properties of the material may be further optimized by chemical and physical pre-treatments. At present, the tailings material represents an uneconomic fraction of the ore deposit, but its components may render it a natural, environmentally sound and cost-effective remediation agent. 
</p>]]></description>
      <guid isPermaLink="true">http://urn.fi/URN:ISBN:978-952-10-8773-8</guid>
      <dc:creator>Venäläinen, Salla</dc:creator>
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      <title>7.6. Joonas Jernberg: Novel analytical methods for the identification of emerging contaminants in aquatic environments</title>
      <link>http://urn.fi/URN:ISBN:978-952-10-8811-7</link>
      <description><![CDATA[<p>Growth in economics and prosperity has been a global trend during recent decades and the use of chemicals has increased tremendously as a part of industrial production, agriculture and everyday life. The use of hazardous chemicals has been restricted by many intergovernmental treaties and legislation but new replacement chemicals are synthesized constantly and no decrease in the future production volumes of chemicals is soon expected. The term chemicalization is used to describe the increased use of chemicals and resultant environmental contamination. In the analysis of environmental samples, usually only some selected regulated compounds are measured. The problem with these target analyses is that other compounds remain undetected. Complementary techniques without any preselection of the analytes are thus required to identify new compounds.
</p><p>The aim of this study was to develop novel instrumental techniques for the determina-tion of organic compounds without any analyte preselection and to identify unknown anthropogenic contaminants in different water matrices. The methods developed were based on analytical separation, using gas and liquid chromatography combined with accurate mass measurement using time-of-flight mass spectrometry. The data produced were then processed with a deconvolution program to locate the chromatographic peaks and to extract their mass spectra. The measured accurate masses were then used to confirm the elemental compositions of the detected ions. The identification processes were validated, using spiked water samples, and finally the methods were applied to the identification of organic xenobiotics from wastewater effluent, stormwater, surface water and landfill leachate samples.
</p><p>The results showed that analysis using time-of-flight mass spectrometry enables screening of large analyte groups without previous information on sample composition. The most comprehensive knowledge is yielded by analysing the sample with both gas and liquid chromatography. In many cases, tentative compound identification can be obtained if the deconvoluted spectra and accurate mass data are complemented with information, e.g. from spectral libraries and peak isotope patterns. This tentative identifications must, however, always be confirmed with a pure standard compound. The main limitations of the methods were related to insufficient features of the deconvolution program used. Most of the data-processing stages had to be performed manually or visually, which slows down the data processing and hinders their applicability, especially with large sample sets. Dozens of compounds were tentatively identified from water samples and several of them were also confirmed with a standard compound. The highest numbers of compounds were identified from wastewater effluent, stormwater and landfill leachate samples. The results confirmed the fact that anthropogenic waste streams are an important route for organic xenobiotics into the environment. Since the future volumes of chemicals will increase, the control and efficient treatment of these fluxes becomes evermore essential.
</p>]]></description>
      <guid isPermaLink="true">http://urn.fi/URN:ISBN:978-952-10-8811-7</guid>
      <dc:creator>Jernberg, Joonas</dc:creator>
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      <title>7.6. Unni Tengvall: Modifications and carriers for improved oligonucleotide delivery</title>
      <link>http://urn.fi/URN:ISBN:978-952-10-8916-9</link>
      <description><![CDATA[<p>Several serious diseases remain without non-toxic curative treatments. To fill this void, one of the promising groups of medicines is that of oligonucleotides, encompassing aptamers, transcription factor decoys, and antisense therapeutics such as short interfering RNA and splice-correcting oligonucleotides. These short strands of DNA or RNA can bind to specific cellular nucleic acids or proteins and thereby inhibit or correct the function of disease-causing molecules. Extensive enzymatic degradation and poor cellular uptake are the most important obstacles for systemic oligonucleotide therapy. Numerous chemical modifications have been introduced to improve enzymatic stability, but they must be carefully optimized to avoid toxicity and to maintain target affinity. One solution is to design topological modifications, such as looped or circular oligonucleotides, which conserve the natural phosphodiester backbone but cannot be attacked by exonucleases. 
</p><p>Cellular uptake has proven to be even more challenging. Oligonucleotides are internalized into cells by endocytosis, after which they often remain trapped in endosomes. Therefore, it would be advantageous to develop delivery vectors capable of bypassing endocytic routes of uptake or enhancing endosomal escape. Cell-penetrating peptides, for example, exploit several mechanisms of uptake, some of which lead to rapid entry without endosomal localization. In addition, encouraging results have been achieved using liposomes, gold nanoparticles, and other nanocarriers, which also shield the oligonucleotide from degrading enzymes.
</p><p>The aim of this work was to improve the in vitro delivery of oligonucleotides by employing chemical modifications and nanoparticle carriers. The synthesis of the compounds, their characterization by various analytical methods, and the evaluation of biological effects are described. Antisense oligonucleotides covalently linked to cell-penetrating peptides via convergent conjugation displayed improved cellular uptake but failed to inhibit reporter genes due to endosomal entrapment in cells. Circular oligonucleotides  exhibited enhanced selectivity of mismatch detection and increased stability in biological fluids compared to linear oligonucleotides. Altogether 44 compounds were analyzed by electrospray ionization mass spectrometry and liquid chromatographymass spectrometry, which were found to be excellent methods for the characterization of modified oligonucleotides. Finally, we synthesized cationic gold nanoparticles modified with a Tat-related peptide, which did not adversely affect cell viability and effectively delivered short interfering RNA into cells as non-covalent complex.
</p>]]></description>
      <guid isPermaLink="true">http://urn.fi/URN:ISBN:978-952-10-8916-9</guid>
      <dc:creator>Tengvall, Unni</dc:creator>
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      <title>14.6. Hanna Tuovila: Sticky business</title>
      <link>http://urn.fi/URN:ISBN:978-952-10-8866-7</link>
      <description><![CDATA[<p>Species of Mycocaliciales are a group of small ascomycetes with pin-like ascocarps. Among Fungi, many mycocalicioid species are rather unique in having specialized to live on the resinous exudates of vascular plants. Terpenoid and phenolic resins essentially are repellents for fungi, but some of these species even appear to use resins for their nutrition. This peculiar ecology has a long evolutionary history, judging from 20 to 40 Ma old amber fossils, in which the ascocarps growing on ancient resin bear remarkable resemblance to those of extant resinicolous species. In addition to resinicolous species, mycocalicioid fungi also include species that are saprotrophic on lignum or associated with lichens or non-symbiotic algal colonies.
</p><p>The aim of this theses was to study the diversity, ecology and evolutionary relationships of mycocalicioid fungi, especially the resinicolous species. The study is based on specimens collected from different parts of the world, and analyzed using both molecular and morphological methods.
</p><p>In this study seven new resinicolous Chaenothecopsis species are described from boreal North America and Europe, tropical Africa, and temperate China, four from angiosperm exudates and three from conifer resins. Two newly found fossils of Chaenothecopsis from Eocene and Oligocene ambers are described and their relations to extant species are elucidated. The phylogenetic relationships of several species and lineages, and the evolution of the resinicolous ecology are discussed in considerable detail. In addition, new morphological and chemical characters that can be used in future taxonomic studies are described.</p>]]></description>
      <guid isPermaLink="true">http://urn.fi/URN:ISBN:978-952-10-8866-7</guid>
      <dc:creator>Tuovila, Hanna</dc:creator>
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      <title>14.6. Anu Lappalainen: Radiographic Screening for Hereditary Skeletal Disorders in Dogs</title>
      <link>http://urn.fi/URN:ISBN:978-952-10-8854-4</link>
      <description><![CDATA[<p>Screening in dog breeding refers to testing or examining individuals for hereditary diseases or faults.  Results can help dog breeders in decision-making when selecting breeding material. Radiographic screening for canine elbow dysplasia (ED) began several decades ago, but genetic improvements have been modest. Several reasons for slow progress exist; perhaps one of the most important is that affected individuals continue to be used for breeding. On the other hand, disorders like lumbosacral transitional vertebrae (LTV) in several dog breeds and intervertebral disc calcifications in Dachshunds are not widely screened even though this would reduce the incidence of debilitating orthopaedic and neurological diseases caused by these disorders. The aim of this study was to initiate radiographic screening protocols for intervertebral disc calcifications and LTV in Finland and to revise the existing Finnish screening protocol for ED. Breeds used were the miniature long-haired and wire-haired Dachshund, Belgian shepherd dog, Labrador retriever and German shepherd dog. The imaging methods applied were radiography and computed tomography (CT). 
</p><p>Occurrence of intervertebral disc calcifications was higher in Finnish miniature Dachshunds than previously reported; 76% of longhaired and 87% of wirehaired variety had at least one calcification. Therefore screening protocol excluding every dog with calcifications from breeding would not be possible. The number of calcifications varied between none and 13, and therefore radiographic screening, together with favouring dogs with fewer calcified discs in breeding, is suggested. 
</p><p>Accuracy of the Finnish screening protocol for mild (grade 1) ED differed between the two breeds studied. In Belgian shepherd dogs, the Finnish protocol based mainly on evaluation of osteophytes was inaccurate, as 47% of the joints free of ED were incorrectly graded as dysplastic and 40% of dysplastic joints were graded as normal.  On the other hand, assessment of the radiographic signs indicative of medial coronoid process disease proved to be accurate in this breed; sensitivity and specificity of blurring of the cranial border of the medial coronoid process were 80% and 90%, respectively. In Labrador retrievers, the Finnish protocol proved to be accurate, as sensitivity of grading was 79% and specificity 92%. Osteophytes seen in the supplemental craniocaudal oblique radiographic projection was the most reliable sign of ED in Labrador retrievers with sensitivity of 93% and specificity of 92%. Adding this view might be a valuable addition to the screening protocol. Labrador retrievers with grade 1 ED should not be used for breeding since most of them have ED, as was clearly demonstrated in the study. 
</p><p>LTV was common in Finnish German shepherd dogs studied with occurrence of 40%. A laterolateral (LL) radiograph appeared to be a useful supplement to the currently used ventrodorsal (VD) radiograph in diagnosis of LTV. Sensitivity of the diagnosis based on the VD projection alone was 90% increasing to 100% when LL projection was used together with the VD projection. Additionally, diagnosis of the eighth lumbar vertebra (L8) was only possible based on the LL projection. It is therefore suggested for inclusion in the radiographic screening protocol. The L8 resembled an LTV, and is therefore proposed as a part of the LTV-complex and for consideration when screening for LTV.
</p>]]></description>
      <guid isPermaLink="true">http://urn.fi/URN:ISBN:978-952-10-8854-4</guid>
      <dc:creator>Lappalainen, Anu</dc:creator>
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      <title>14.6. Meeri Pearson: Maximizing peatland forest regeneration success at lowest cost to the atmosphere: Effects of soil preparation on Scots pine seedling vitality and GHG emissions </title>
      <link>http://urn.fi/URN:ISBN:978-951-651-406-5</link>
      <description><![CDATA[<p>This dissertation investigated the impacts of soil preparation after clearcutting Scots pine (Pinus sylvestris L.) forest on thick-peated soil from silvicultural and climatic standpoints. Three growing seasons after outplanting, mounding most effectively secured seedling survival, growth, and vitality through improved soil aeration of the planting spot. However, other presumed benefits of mounding to seedlings such as warmer soil temperatures and faster organic matter decomposition were not confirmed here. Regeneration in scalps was unsuccessful due to waterlogged soil. Importantly when scalping, only the humus layer should be scraped off without creating depressions in the peat. 
Seedling tolerance to desiccated as well as waterlogged peat soil over one growing season was remarkable in controlled conditions. The impact of drought, however, was more immediate and severe as root and shoot growth, fractional colonization of ectomycorrhizal fungi, and root hydraulic conductance were reduced. Nevertheless, maintenance of rather high photochemical efficiency (expressed as variable to maximal chlorophyll fluorescence, Fv/Fm) especially in current-year needles despite harsh drought seemed to indicate a potential for seedling recovery. Polyamine analysis also revealed that new needles are preferred in protecting the different parts of the seedlings against drought stress. Wet-stressed seedlings, on the other hand, exhibited few signs of suffering. It was also demonstrated how the experimental environmenta controlled versus field settinginfluences seedling tolerance to stress. The differing moisture levels within comparable micrositesdry vs. wet scalps and ditch vs. inverted moundshad little influence on seedling growth and condition although physiological upset (i.e., Fv/Fm) was evident within scalps. Namely, the wetter the soil was, the lower Fv/Fm was. 
</p><p>The fear of soil preparation accelerating GHG emissions, particularly CO2, from peat into the atmosphere appears unwarranted at least on nutrient-poor, boreal forestry-drained peatland sites. The overall climatic impact of soil preparation, in the forms of mounding and scalping, three years after application expressed in terms of CO2 equivalents (100-year GWP), was neutral compared to leaving soil unprepared. 
</p><p>The core findings of this research support mounding as the best alternative on nutrient-poor, drained peatland sites when the goal is to maximize the regeneration success of Scots pine after clearcutting with minimal impact on soil GHG emissions. In the future, development of soil preparation methodology is particularly deserving of further attention. While it may not be the sexiest research topic in the worldwide rat race of the modern day, it is nonetheless of substantial importance in a country highly specialized not only in the utilization but also the rejuvenation of wood resources on drained peatlands.
</p><p>Keywords: forestry-drained peat soil, clearcutting, mounding, scalping, CO2, CH4, and N2O fluxes, drought and waterlogging stress
</p>]]></description>
      <guid isPermaLink="true">http://urn.fi/URN:ISBN:978-951-651-406-5</guid>
      <dc:creator>Pearson, Meeri</dc:creator>
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      <title>14.6. Johanna Rajasärkkä: Development of high-throughput yeast-cell-based bioreporter assays for specific monitoring of bisphenol A and chemical testing of endocrine disrupting compounds</title>
      <link>http://urn.fi/URN:ISBN:978-952-10-8918-3</link>
      <description><![CDATA[<p>Chemicalization of the modern society has become a topic of debate in the past few decades. Especially chemicals that affect the human reproduction and hormonal system, the so-called endocrine disrupting compounds, have raised concern in public and regulatory agencies. There is a growing need for suitable testing methods to screen endocrine disrupting potential of new and old chemicals. While the European Union chemical legislation REACH has increased the need of chemical testing methods, one of its targets is also to decrease the use of animals in these tests. It has been proposed that inexpensive high throughput in vitro assays could be used for initial screening of chemicals for further testing with other methods.
</p><p>In addition to chemical testing, environmental monitoring of endocrine disrupting compounds is important to assess the level of exposure and possible adverse effects of chemicals on humans and wildlife. Chemical analysis methods used in environmental monitoring are sensitive, but they are also laborious, expensive, and require specialized instruments. Consequently, robust biological methods have become valuable tools to measure endocrine disrupting potency of chemicals and environmental samples. For this purpose, several Saccharomyces cerevisiae yeast cell-based bioreporters utilizing different nuclear receptors have been developed.
Yeast-cell-based bioreporter assays have several advantages in environmental analytics. In addition to being inexpensive, they are particularly useful in determining the bioavailability of contaminants. Yeast is also very tolerant towards toxicity of different sample matrices. Yeast nuclear receptor bioreporter assays have been used to determine the total hormonal activity of samples containing unknown mixture of chemicals. However, these assays cannot identify the chemicals in the sample, and thus, monitoring of a single chemical has not been possible.
</p><p>Many cell-based assays have already been adapted to high throughput screening plate formats of 384 and 1536 wells and even higher. However, nearly all yeast nuclear receptor bioreporter assays are still performed in 96-well plates. Consequently, yeast bioreporter assays should be adapted to automated liquid handling and high density well plates to enable screening of large chemical libraries and high number of samples.
</p><p>In this thesis study, a yeast nuclear receptor bioreporter assay for specific detection of a single chemical, bisphenol A (BPA) was developed. The creation of the BPA-targeted receptor included application of a oligonucleotide-based mutation method and a positive-negative genetic selection method for human estrogen receptor &#945; (publication I). Chemical specificity of the BPA-targeted receptor (BPA-R) bioreporter assay was characterized, and its use demonstrated with chemical mixture and waste water samples (publication II). In addition, the existing battery of yeast bioreporters was adapted to automated liquid handling and high density 384 and 1536 well plates to meet the requirements of high throughput screening (publication III). Finally, a new yeast-based bioreporter utilizing a chimeric human retinoid X receptor was constructed and characterized (publication IV). This bioreporter can be used to measure organotin compounds such as tributyl tin in environmental samples.</p>]]></description>
      <guid isPermaLink="true">http://urn.fi/URN:ISBN:978-952-10-8918-3</guid>
      <dc:creator>Rajasärkkä, Johanna</dc:creator>
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