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(2016)Mitochondrion is an essential organelle capable to produce high amounts of energy from oxidative phosphorylation (OXPHOS). The organelle counts on its own set of mitoribosomes and quality control (QC) factors to efficiently translate the OXPHOS components encoded by the mitochondrial DNA. Organelle dysfunction leads to development of mitochondrial diseases, which show a wide variety of symptoms and poor prognosis. ybeY is a highly conserved gene amongst prokaryotes that acts as factor for maturation and QC of bacterial ribosome. The ybeY-homolog C21orf57 is found remarkably conserved in eukaryotes, but its role in mammalian cells is completely unknown. In this study we characterised the mouse gene C21orf57 (mYBEY) in mammalian cells. mYBEY is transcribed at low levels in mouse tissues, where nervous tissue, skeletal and cardiac muscle show relatively higher amounts of mYBEY transcript. Endogenous mYbey protein could not be detected immunoblot due to its low expression level and/or rapid protein turnover. In parallel, mYBEY was cloned and successfully expressed in mammalian cells using transient and stable expression methodologies. We discovered that mYbey is imported into mitochondria and not covalently associated with mitoribosomes. Interestingly, protein translation stress and mitoribosome decay promoted by actinonin treatment is accompanied by a decrease in mYbey protein. In addition, depletion of mYbey using iRNA promotes the accumulation of mitoribosome proteins. We hypothesise a model in which mYbey is part of a QC mechanism for mitoribosome, and possibly involved with mitoribosome turnover. Although we successfully deleted mYBEY gene in mouse embryonic fibroblasts using the CRISPR/Cas9 approach, the isolation of viable mYBEY knock-out cells was not possible due to the possible deleterious and/or suppressive effects. In conclusion, we verified for the first time that mYbey is located within mammalian mitochondria and may be involved in a possible QC mechanism as a factor recruited for mitoribosome turnover. Further studies are necessary to fully elucidate the role of mYbey in the mitochondrial context.
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(2021)Kirjallisuuskatsauksessa käydään läpi erilaisia menetelmiä C3-substituoitujen indolien synteeseihin 2-alkenyylianiliinityyppisistä lähtöaineista, joiden bentsyylinen asema oli substituoitu. Erityistä huomiota kiinnitetään menetelmiin, joiden reaktiomekanismeiksi ehdotettiin radikaalimekanismeja. Myös näitä ehdotettuja radikaalimekanismeja esitellään tutkielmassa. Kokeellisessa työssä tutkittiin C3-subsituoitujen indolien hapettavaa synteesiä hiilikatalyytin avulla. Lähtöaineina käytettiin bentsyylisesti aryylisubstituoituja 2-alkenyylianiliinijohdannaisia. Joidenkin lähtöaineiden typpeen oli kiinnitetty metoksipyridiini, jonka kiinnitystä varten kehitettiin Buchwald-katalyysi. Hiilikatalyysit tuottivat hyviä saantoja. Korkea elektronitiheys, etenkin aniliinin bentseenirenkaan ja/tai typen aromaattisen substituentin korkea elektronitiheys, oli eduksi. Reaktion mekanismin ehdotetaan alkavan hapettumisella radikaalikationiksi, ja näitä hapetuspotentiaaleja laskettiin aiemmin raportoidun menetelmän mukaisesti. Mikäli indolin 5-renkaan substituutiot (N1, C2, C3) olivat tarpeeksi samankaltaisia, korkea elektronitiheys, matala hapetuspotentiaali ja hyvä saanto korreloivat. Indolin 5-renkaan substituutio on kuitenkin merkittävämpi tekijä kuin hapetuspotentiaali ja/tai korkea elektronitiheys. Pyridiini typen suojaryhmänä toimi katalyysissä ja se onnistuttiin poistamaan helposti. Metoksipyridiini toimi katalyysissä hyvin, mutta sen kvantitatiivinen poistaminen ei onnistunut.
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(2013)Tutkielma on rakenteeltaan kaksiosainen. Kirjallisuustutkimus on tehty Helsingin yliopistossa ja kokeellinen tutkimus Espanjassa (Universidad Complutense de Madrid). Tästä johtuen ensimmäinen osa on kirjoitettu suomeksi ja toinen osa englanniksi. Kirjallisuuskatsauksessa perehdytään C6-substituoitujen pyrimidiininukleosidien valmistukseen. C6-substituoiduilla pyrimidiininukleosideilla on havaittu olevan monia erilaisia biologisia vaikutuksia. C6-substituoiduista pyrmidiininukleosideista ei ole kovin paljon julkaisuja johtuen synteettisten keinojen vähäisyydestä. C6-substituoituja pyrimidiininukleosideja voidaan valmistaa joko yhdistämällä C6-substituoitu silyloitu emäs ja suojattu sokeri tai muokkaamalla suoraan valmiin nukleosidin C6-asemaa. Happamissa olosuhteissa glykosylaatioreaktiolla valmistettujen C6-substituoitujen pyrimidiininukleosidien saantoa voidaan parantaa käyttämällä Friedel-Crafts-katalyyttejä ja suojaamalla emäksen N3-asema. Glykosylaatioreaktiolla valmistettujen pyrimidiininukleosidien C6-asemassa olevat substituentit ovat yleensä pieniä ryhmiä. Valmiin pyrimidiininukleosidin C6-aseman muokkaukseen on useita keinoja, joista palladiumkatalyytit tarjoavat yhden tehokkaimmista keinoista liittää esimerkiksi aryyliryhmiä C6-asemaan. Muokkaamalla valmista nukleosidia vältetään myös glykosylaatioreaktiossa syntyvien N3-isomeerien muodostuminen. Joidenkin substituenttien kohdalla havaittiin N-glykosidisidoksen hajoamista. Kokeellisen tutkimuksen tavoitteena oli valmistaa uusia asymmetrisessä katalyysissä käytettäviä kiraalisia kamferijohdannaisia ligandeja. Kahden kamferijohdannaisen ligandin valmistuksessa saatiin valmistettua lupaavia välituotteita. Kolme polyhydroksyloitunutta norbornaani- johdannaista eivät toimineet kiraalisina ligandeina vaan tuottivat raseemisen seoksen.
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(2023)Human induced pluripotent stem cells (hiPSCs) are derived from adult differentiated somatic cells and reprogrammed to an embryonic-like state. Pluripotent stem cells can be differentiated into almost any somatic cell type by using directed differentiation methods, but the differentiation efficiency often varies depending on the cell type. hiPSCs and cells differentiated from them can be used as a disease model carrying the patient’s phenotype and genotype. Amyotrophic lateral sclerosis (ALS) is a progressive motor neuron disease where both upper and lower motor neurons degenerate, leading to paralysis. There is no curative treatment for ALS, and it leads to the death of the patient in 3 to 5 years on average from the first symptoms. The most common genetic cause of familial ALS is a hexanucleotide repeat expansion in C9orf72-gene. ALS pathology is strongly linked to endoplasmic reticulum (ER) stress, which affects cell homeostasis and proteostasis, and leads to apoptosis when prolonged. The primary aim of this research is to characterize the differentiation of four hiPSCs lines towards lower motor neurons and to study the neuroprotective effects of cerebral dopamine neurotrophic factor (CDNF) and CDNF-derived peptide on ER stress and cell viability. This experiment used two control cell lines from two healthy donors and two patient cell lines from two different ALS patients carrying the C9orf72-mutation. To evaluate the efficiency of the differentiation towards motor neurons, molecular markers for pluripotent and neural progenitor cells as well as for maturated motor neurons were analyzed. Relative gene expression levels were measured from weekly time points with qPCR. Immunocytochemical (ICC) antibody staining was performed during differentiation. Endogenic CDNF levels were analyzed from differentiating cells at weekly time points and the effect of CDNF on Thapsigargin (TG) -induced ER stress in motor neurons was analyzed. In addition, cell viability was analyzed in TG-CDNF treatment. All pluripotent and progenitor markers were downregulated in differentiated cells, and the expression of the mature motor neuron markers was upregulated. Mature motor neuron markers were also expressed at the protein level. The endogenous CDNF levels were highest at the progenitor cell stage. The ER stress response was upregulated in TG-treated cells, and there were no differences between treatments against ER stress. Furthermore, TG and growth factor treatments differentially affected the viability of the control and patient cell lines. Treatment decreased viability in control cell lines and increased viability in patient cell lines. Pluripotent stem cells were successfully differentiated toward motor neurons. The differentiation was performed twice, and the results were similar on both individual biological repeats. Analysis of endogenous CDNF expression levels was performed for the first time on hiPSCs lines. In this study, CDNF or its derivate didn’t reduce ER stress but it influenced cell viability, especially in patient cell lines with growth factor treatment. In the future, TG-treatment could be optimized regarding timing and growth factor treatment, or the toxin could be changed to another ER-stress inducing toxin. In addition, the C9orf72 pathology should be identified in order to use differentiated motor neurons as a pre-clinical disease model.
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(2020)Wines are treated to ensure their quality and preservation in the winemaking process. Treatments also have their drawbacks. Premium winemakers have often avoided filtration because it is supposed to cause a loss of taste. Sulfurization of wine is important, for example, for microbiological quality, but it is assumed to reduce the fruity aroma of wines. The purpose of the literature section was to investigate in general the effects of the wine-making process on the volatile compounds of wines. The interest was to find out what happens in winemaking and what compounds are formed at different stages of the process. The literature section also looked at volatile compounds, their analytics and SPME technology. The aim of the experimental part of the work was to develop a research method using headspace-solidphasemicroextraction-gaschromatography-massspectrometry (HS-SPME-GC-MS) technology and to find out the aroma composition and possible differences of the receiving sample and the bag-in box (BIB) -packaged wine. Indicator compounds for volatile compounds were determined from Chardonnay and Cabernet Sauvignon wines using the HS-SPME-GC-MS method developed for the study of Cabernet Sauvignon wine. In the optimization of the method, the functionality of SPME fibers, the GC temperature program and the sample preparation were studied. Receipt, tank, and BIB packaging samples were collected for examination of the wines. The samples were analyzed by HS-SPME-GC-MS and the results were processed by principal component analysis (PCA) as well as other statistical methods. Receipt and BIB packaging samples from Cabernet Sauvignon wine were not divided into clear groups based on PCA. The model best describing the changes in the compounds was achieved with the profile of volatile compounds: ethyl acetate, 1-propanol, isoamyl alcohol, 2-methylbutanol, butanoic acid ethyl ester, isoamyl acetate, hexanol, hexanoic acid, octanoic acid ethyl ester and octanoic acid. In Cabernet Sauvignon wine, almost all the amounts of volatile compounds remained fairly constant as the process progressed. In 1-propanol, ethyl ester of butanoic acid and ethyl ester of octanoic acid, a decrease in the amount was observed between the receipt sample and the BIB packaging sample. In contrast, the amount of 2-methylbutanol and octanoic acid increased when receiving and BIB packaging samples were compared. Receipt and BIB packaging samples of Chardonnay wine were distinguished by PCA. The model best describing the changes in the compounds was achieved with the profile of volatile compounds: ethyl acetate, isoamyl alcohol, 3-methylbutanol, 2-methylbutanol, butanoic acid ethyl ester, isoamyl acetate, hexanol, hexanoic acid, benzene alcohol, octanoic acid ethyl ester, octanoic acid ethyl ester, octanoic acid ethyl ester. The amounts of volatile compounds studied in Chardonnay wine remained fairly constant. Octanoic acid ethyl ester, benzyl alcohol and decanoic acid decreased as the process. The results of the study show that the wine processing process affects the flavorings of Cabernet Sauvignon and Chardonnay wine. The HS-SPME-GC-MS method showed a reduction in several compounds, but previous studies have shown that this change has not been detected by sensory evaluation.
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(Helsingin yliopistoUniversity of HelsinkiHelsingfors universitet, 2004)
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(2023)Ce mémoire de master étudie deux phénomènes de contact de langues, les emprunts linguistiques et l’alternance codique, dans les vidéos YouTube. L’objectif de cette étude est d’identifier les occurrences d’anglais dans le corpus, de les classifier et de les analyser. Nous examinons quelles sont les différences d’emprunts et d’alternance codique du point de vue quantitatif, quels types d’emprunts et d’alternance codique se trouvent dans le corpus étudié et comment la présence de l’anglais de manifeste dans les vidéos YouTube françaises et québécoises. Le corpus est constitué de vidéos YouTube de type vlog. Comme l’objectif de cette étude est de comparer l’utilisation de l’anglais dans les vidéos québécoises et françaises, des vidéos issues de ces deux pays ont été choisies. Le corpus inclut six créatrices de contenu, trois au Québec et trois en France. Par youtubeuse, nous avons sélectionné entre 34 et 48 minutes de vidéos, soit au total 4 heures, 9 minutes et 22 secondes de vidéo. L’étude combine l’analyse quantitative et l’analyse qualitative. Les emprunts sont rangés soit dans la catégorie d’emprunts établis, soit dans celle d’emprunts spontanés. Les alternances codiques sont classes en alternances extra-phrastiques, interphrastiques et intraphrastiques. L’étude se situe dans les domaines d’étude de la sociolinguistique et de la lexicologie. L’étude démontre qu’il y a plus d’énoncés en anglais dans les vidéos québécoises que dans les vidéos françaises. C’est le cas pour les emprunts et les alternances codiques. Sur un total de 1840 mots prononcés en anglais, 94,2 %, ou 1734 mots, viennent des vidéos québécoises. 5,8 %, ou 106 des mots prononcés en anglais, viennent des vidéos françaises. Nous avons trouvé 173 occurrences d’emprunts au total dans les vidéos québécoises, et 70 occurrences d’emprunts dans les vidéos françaises. L’analyse des alternances codiques montre qu’il y a plus d’alternance codique dans les vidéos québécoises du corpus étudié, comparé aux vidéos françaises. Nous avons pu identifier 1561 mots prononcés en alternance codique dans les vidéos québécoises, contre seulement 36 mots dans les vidéos françaises. L’étude montre que le contact de langues ne peut pas être évité. En examinant les vidéos issues de deux pays francophones, nous pouvons voir que les marques transcodiques sont observés dans le langage quotidien des youtubeuses québécoises et françaises, et que l’emprunt linguistique et l’alternance codique sont trouvés en abondance dans le corpus étudié. En tenant compte des dimensions sociolinguistiques du corpus examiné, l’étude montre que l’utilisation de l’anglais fonctionne comme une construction d’identité de youtubeur.euses et un signe d’appartenance au groupe social des jeunes.
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(2012)In analysis of structural information for transmembrane (TM) proteins it is ideal to work with a three-dimensional (3D) structure. This is not always possible as determining an accurate 3D structure can be challenging and expensive as pursuing one can take large amounts of time. Sequence analysis is often used as a surrogate to determine a subset of information regarding secondary and tertiary protein structure given the primary structure (an amino acid sequence). Using Equilibrative Nucleoside Transporter member 1 (ENT1) as a model, the objective of predicting secondary and tertiary structure given primary structure is attempted through computational (in silico) methods. The in silico methods include the use of a pipeline of programs spanning both custom made and ready built software. A set of 2034 homologous protein sequences are first obtained from the initial human ENT1 (hENT1) sequence through a BLASTp. This sequence information is then processed to acquire information on variation, conservation, and hydrophobicity through topology prediction, hydropathic moment plots and variation moment plots. Comparing these results with data acquired from Glycerol-3-Phosphate Transporter (GlpT), a protein with a known 3D structure of 3.3 Angstrom resolution is done to assess evidence of evolutionary origin. This in turn allows estimation on the reliability of predictions to be made on aspects of the secondary and tertiary structure for hENT1. The results show that within predicted TM alpha helical regions that there is some level of correlation between the variation of the amino acids within the alpha helical TM region and its orientation towards the membrane. This can be further refined by gathering statistics on other known proteins with a 3D structure for their relationships in TM regions to hydrophobicity and variability. This will aid in secondary and tertiary structure predictions of other TM proteins given further refinement and additional data. In addition, the sequence conservation information obtained should prove to be robust and allow for a large number of sequences to be analyzed to determine conservation of amino acids given a reference protein. Ideally this information will provide aid in determining interesting amino acids for experiments to be done on hENT1.
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(2023)The outsourced emissions, particularly from transport and construction, pose a challenge for cities like Helsinki in achieving carbon neutrality. Helsinki, epitomizing this struggle, unveiled the 'Carbon-neutral Helsinki 2035 Action Plan' in 2018, aiming to achieve carbon neutrality by 2030. However, this plan, primarily employing a production-based emissions accounting method, neglects the crucial aspect of outsourced emissions. This thesis undertakes a focused examination of the outsourced emissions in Helsinki's transport sector, utilizing a consumption-based emissions accounting method, with a particular focus on emissions originating from car traffic. To ensure a comprehensive evaluation of emissions, this study employs a fleet-based life-cycle assessment (LCA) methodology, providing a holistic perspective encompassing the entire life cycle of vehicles. This approach diverges from conventional product-centric LCAs, incorporating the dynamic interplay between production, usage, and disposal. The study's outcomes are contrasting against the City of Helsinki's Business-As-Usual scenario, emphasizing electrification and technological advancements to reduce emission intensity. Key research questions include uncovering disparities between consumption-based and production-based methodologies, assessing the feasibility of Helsinki's emission reduction goals, and exploring differences between fleet-based and traditional LCA approaches. The thesis is organized into eight chapters, delineating the analytical framework, City of Helsinki's emission mitigation efforts, methodology, data, results, and concluding insights. The consumption-based methodology illuminates substantial disparities in emissions compared to the production-based approach, posing formidable challenges for Helsinki's emission reduction aspirations. The study emphasizes the imperative of actively curtailing the number of vehicles and promoting alternative modes of transportation to achieve meaningful reductions. The fleet-based LCA methodology not only provides a nuanced understanding of emissions but also highlights the necessity of considering evolving technologies and lifecycles. To make significant strides in emissions reduction, Helsinki must adopt a comprehensive and transparent approach, surpassing mere reporting standards and actively contributing to global climate efforts. The study underscores the urgency for cities to transcend greenwashing tactics, aligning policies with public sentiment, and committing to tangible actions for a sustainable future.
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(2023)Polygenic risk scores (PRSs) estimate the genetic risk of an individual for a certain polygenic disease trait by summing up the effects of multiple variants across the genome affecting the disease risk. Currently, polygenic risk scores (PRSs) are calculated from imputed array genotyping data which is inexpensive to produce use and has standard procedures and pipelines available. However, genotyping arrays are prone to ascertainment bias, which can also lead to biased PRS results in some populations. If PRSs are utilized in healthcare for screening rare diseases, usage of whole-genome sequencing (WGS) instead of array genotyping is desirable, because also individual samples can be analyzed easily. While high-coverage WGS is still significantly more expensive than array genotyping, low-coverage whole genome sequencing (lcWGS) with imputation has been proposed as an alternative for genotyping arrays. In this project, the utility of imputed low-coverage whole-genome sequencing (lcWGS) data in PRS estimation compared to genotyping array data and the impact of the choice of imputation tool for lcWGS data was studied. Down-sampled WGS data with six different low coverages (0.1x-2x) was used to represent lcWGS data. Two different pipelines were used in genotype imputation and haplotype phasing: in the first one, pre-phasing and imputation were performed directly for the genotype likelihoods (GLs) calculated from the down-sampled data, whereas in the second one, the GLs were converted to genotype calls before imputation and phasing. In both pipelines, PRS for 27 disease phenotypes were calculated from the imputed and phased lcWGS data. Imputation and PRS calculation accuracy of the two pipelines were calculated in relation to both genotyping array and high-coverage whole-genome sequencing (hcWGS) data. In both pipelines, imputation and PRS calculation accuracy increased when the down-sampled coverage increased. The second imputation and phasing pipeline lead to better results in both imputation and PRS calculation accuracy. Some differences in PRS accuracy between different phenotypes were also detected. The results show similar patterns to what is seen in other similar publications. However, not quite as high imputation and PRS accuracy as seen in earlier studies could be attained, but possible limitations leading to lower accuracy could be identified. The results also emphasize the importance of choosing suitable imputation and phasing methods for lcWGS data and suggest that methods and pipelines designed particularly for lcWGS should be developed and published.
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(2018)Parisian cycling increased importantly in the past twenty years. Reviewing fifty years of Parisian transport planning and details of the bike-sharing programme Vélib’, I argue in the background research that municipal biking planning and the public bicycles Vélib’ can explain this development of urban biking (1997-2015). The city also has high ambitions for the biking modal share, aiming for fifteen per cent of all Parisian transport by 2020. I want to discover what the determinants of Parisian biking are, and if the latter can be modelled and predicted; thereby, I can verify if predictions match municipal objectives for 2020. I calculate correlations between the Parisian cycling index and its possible determinants with annual values on biking and other variables from 1997 to 2015 in the first part of the analysis (chapter V). This analysis shows that cycling infrastructure, Vélib’ memberships and gasoline price are the strongest positive biking determinants, while car traffic is the strongest negative determinant. In the second part of the analysis, knowing these determinants, I can find multiple linear regression models with high R-squared values (around 0,97 and 0,98) and low standard errors. The best regression model combines linear infrastructure, car traffic volume and Vélib’ memberships. The predictions in the last part of the analysis chapter reveal that in the current tendencies, the Parisian biking modal share will reach about 7 per cent by 2020, instead of the 15 per cent aimed. But I illustrate how the objective can be accomplished, by either improving drastically one of the determinants or the three of them simultaneously to reach a modal share of 15 per cent. The results and the models found appear to be more satisfactory and accurate than the ones of previous researches, presented in the literature review. The findings may be useful for public authorities and decision-makers during processes of biking planning, and it might contribute to future research in this topic.
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(2019)Tutkin tässä työssä mahdollisuutta laskea paineistetussa vesiputkistossa virranneen veden määrää muinaisessa Pompejissa säilyneiden arkeologisten jäännösten perusteella ja teen huomioita Pompejin vesijärjestelmän eri osien toiminnasta. Kuvailen soveltuvin osin antiikin kirjallisia alkuperäislähteitä sekä modernia tutkimushistoriaa. Teen yleiskatsauksen vesijärjestelmään Pompejissa ja esitän omia tulkintojani järjestelmän joidenkin osien toiminnasta. Näitä osia ovat päävesitorni, toissijaiset vesitornit ja lyijystä tehdyt vesiputkistot. Esitän perustelut virtauslaskujen tekemiseen sopivien testikohteiden valinnalle. Testikohteita ovat korttelit V1, IX 3 ja kaksi taloa korttelissa VII 4. Esitän yleisen kuvauksen kustakin korttelista ja yksityiskohtaisen kuvauksen taloista ja huoneista, joissa on vesiputkia. Kuvailen myös lyhyesti testikohteisiin liittyvät toissijaiset vesitornit, joita ovat vesitornit numero yksi, kaksi, kolme ja seitsemän. Kuvaan yksityiskohtaisesti mahdollisia putkilinjoja toissijaisista vesitorneista testikohteisiin ja esitän perustelut putkilinjojen valinnalle. Kuvailen lyhyesti fysikaalisia virtausopin kaavoja ja ainoastaan putkivirtauslaskelmien kannalta katsottuna. Esitän myös kaavan neljännen asteen yhtälölle, jonka kuvaaja, kun se on piirretty koordinaatistoon muistuttaa roomalaisten vesiputkien muotoa ja esitän syyt miksi tätä yhtälöä voi käyttää roomalaisten vesiputkien yhteydessä. Esitän kuvauksen putkivirtauslaskelmien kulusta ja esitän tuloksia edustavin osin. Lopuksi puhun laskelmiin liittyvistä ongelmista ja esitä suosituksia mahdollisia jatkotutkimuksia varten.
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(2012)Tässä tutkielmassa esitellään algebrallisen ryhmän käsite sekä hieman tavallisesta poikkeava tapa ymmärtää permutaatioita. Työn tärkeimpinä kohtina voi pitää Caleyn lausetta, joka yhdistää permutaation ja ryhmän käsitteet, sekä p-ryhmän käsitettä. Työssä käsitellään myös pintapuolisesti suoraan tuloon liittyviä ryhmiä. Varsinaisia esitietovaatimuksia työn ymmärtämiseksi ei ole, mutta tietynlainen matemaattinen yleissivistys on toivottavaa. Kenen tahansa kandidaattitasoisen matematiikan opiskelijan kuitenkin pitäisi pystyä ymmärtämään tämän tutkielman oleellinen sisältö. Esitelmäni perustuu Joseph J. Rotmanin kirjaan An Introduction to the Theory of Groups [2]. Tukena olen käyttänyt Tauno Metsänkylän ja Marjatta Näätäsen teosta Algebra I [1]. Permutaatioita käsittelevässä luvussa olen tukeutunut Pekka Tuomisen Todennäköisyyslaskenta I- kirjaan [3]. Permutaatioita oli tutkittu jo aikaisemminkin, mutta ryhmien teorian tutkimuksen aloitti varsinaisesti Galois (1811-1832). 1800-luvun lopussa ryhmäteoriaa tutkittiin lähinnä kahdessa päähaarassa. Nämä päähaarat olivat algebralliset ryhmät, erityisesti Lien ryhmät, sekä äärelliset ryhmät. 1900-luvulla ilmaantui kuitenkin kolmas päähaara, äärettömät ryhmät. Nykyään ryhmät esiintyvät monilla matematiikan aloilla, esimerkiksi geometriassa, topologiassa ja logiikassa.
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(2020)The feasibility of quantitatively measuring ultrasound in air with a Schlieren arrangement has been demonstrated before, but previous work demonstrating calibration of the system combined with computation to yield the 3D pressure field does not exist. The present work demonstrates the feasibility of this both in theory and practice, and characterizes the setup used to gain the results. Elementary ray optical and Schlieren theory is exhibited to support the claims. Derivation of ray optical equations related to quantitative Schlieren measurements are shown step by step to help understand the basics. A numerical example based on the theoretical results is then displayed: Synthetic Schlieren images are computed for a theoretical ultrasonic field using direct numerical integration, then the ultrasonic field is recovered from the Synthetic Schlieren images using the inverse Abel transform. Accuracy of the inverse transform is evaluated in presence of synthetic noise. The Schlieren arrangement, including the optics, optomechanics, and electronics, to produce the results is explained along with the stroboscopic use of the light source to freeze ultrasound in the photographs. Postprocessing methods such as background subtraction and median and Gaussian filtering are used. The repeatability and uncertainty of the calibration is examined by performing repeated calibration while translating or rotating the calibration targets. The ultrasound fields emitted by three transducers (100 kHz, 175 kHz, and 300 kHz) when driven by 5 cycle sine bursts at 400 Vpp are measured at two different points in time. The measured 3D pressure fields measured for each transducer are shown along with a line profile near the acoustic axis. Pressure amplitudes range near 1 kPa, which is near the acoustic pressure, are seen. Nonlinearity is seen in the waveforms as expected for such high pressures. Noise estimates from the numerical example suggest that the pressure amplitudes have an uncertainty of 10% due to noise in the photographs. Calibration experiments suggest that additional uncertainty of about 2% per degree of freedom (Z, X, rotation) is to be expected unless especial care is taken. The worst-case uncertainty is estimated to be 18%. Limitations and advantages of the method are discussed. As Schlieren is a non-contacting method it is advantageous over microphone measurements, which may affect the field they are measuring. As every photograph measures the whole field, no scanning of the measurement device is required, such as with a microphone or with an LDV. Suggestions to improve the measurement setup are provided.
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(2012)The most important parameters describing the aerosol particle population are the size, concentration and composition of the aerosol particles. The size and water content of the aerosol particles are dependent of the relative humidity of the ambient air. Hygroscopicity is a measure to describe the water absorption ability of an aerosol particle. Volatility of an aerosol defines how the aerosol particles behave as a function of temperature. A Volatility-Hygroscopicity Tandem Differential Mobility Analyzer (VH-TDMA) is an instrument for size-selected investigation of particle number concentration, volatility, hygroscopicity and the hygroscopicity of the particle core, i.e. what is left of the particle after the volatilization. While knowing these qualities of aerosol particles, one can predict their behavior in different atmospheric conditions. Volatility and hygroscopicity can also be used for indirect analysis of chemical composition. The aim of this study was to build and characterize a VH-TDMA, and report the results of its field deployment at the California Nexus (CalNex) 2010 measurement campaign. The calibration measurements validated that with the VH-TDMA one can obtain accurate volatility and hygroscopicity measurements for particles between 20 nm and 145 nm. The CalNex 2010 results showed that the instrument is capable in field measurements at varying measurement conditions; and valuable data about hygroscopicty, volatility and the mixing state of several types of aerosols were measured. The data obtained was in line with the observations based on the data measured with other instruments.
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(2024)In the Anglophone world, California remains a glamorized place, reserved for movie stars, surfers, and cowboys. While there are many famous Californian writers, Joan Didion and Eve Babitz remain incredibly popular for their depictions of California. Though Didion and Babitz hailed from slightly different social strata, both have an obsessive focus on California. Both write in a New Journalistic style and focus on similar happenings in their state. This makes a comparison of their works effective for analyzing cultural attitudes in their age group and social position. This thesis analyzes the works of Joan Didion and Eve Babitz. With Didion, I examine The White Album, Slouching Towards Bethlehem, Where I was From, and South and West. With Babitz I focus on Eve’s Hollywood, Slow Days, Fast Company, and Black Swans. In this thesis, I will closely examine Didion and Babitz’s portrayal of Californian history, the environment, and identity, and the consequences of these portrayals. In this thesis I primarily use postcolonial theory, econarratology, and historical contextualization to analyze how California is depicted. After analyzing these works in these contexts, I find that although Didion and Babitz share a similar focus, they end up having very different treatments of those subjects. Didion’s past filled mythology end up erasing the horrors of colonization and cements a present where there is no space for those outside her circle. Babitz’s focus on the present makes her ignorant of the past that her present is dependent on. I additionally find that Didion relies on metaphor where Babitz uses the literal to create mythology. Finally, I find that California has been mythologized to such an extent that those born there at times see it as foreign and exotic.
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(2020)Calsyntenin-3 is a type I transmembrane protein, that is mainly expressed on the post-synaptic cell membranes. It belongs to the calsyntenin family that is part of the cadherin superfamily. Calsyntenin-3 consists of a cytosolic C-terminal region, a transmembrane domain and an extracellular N-terminal part, that consists of a laminin G-like domain (LNS) and two cadherin domains (CAD). Calsyntenin-3 is mainly expressed in the brain, but it can also be found in the heart, liver, pancreas, lung, skeletal muscle and placenta. Calsyntenin-3 has an effect on neurogenesis by affecting the development of excitatory and inhibitory synapses. It might also play a role in Alzheimer’s disease, as it has been found to be able to bind β-amyloid peptide, that is known to play a key role in the development of Alzheimer’s disease. Calsyntenin-3 acts as a synaptic adhesion protein, that binds to the post-synaptic neurexins with its extracellular region. However, the previous studies have contradicting results regarding the calsyntenin-3 domains that mediate the interaction between the calsyntenin-3 and neurexins. There is also disagreement whether calsyntenin-3 binds neurexin-α, neurexin-β or both. Because of these discrepancies, the aim of this master’s thesis study was to produce the calsyntenin-3 ectodomain constructs that contained either the two CAD domains, the LNS domain or all three domains, using baculovirus mediated protein production in insect cell cultures. These purified protein constructs were meant to be used for the determination of the binding domains. Unfortunately, only the purification of the calsyntenin-3 LNS domain was successful and the purification of the constructs, containing the CAD domains, was unsuccessful. A SEC-MALLS experiment, that was performed for the calsyntenin-3 LNS domain, revealed that it forms dimers in a solution, which is consistent with experiments performed with the LNS domain of human sex hormone‐binding globulin. The second aim of this master’s thesis study was to express the calsyntenin-3 ectodomain constructs on the surface of HEK293T cells and to test the binding between calsyntenin-3 and neurexins in a cell surface binding assay. The results of the cell surface binding assay indicated that the binding is mediated by the calsyntenin-3 CAD domains and that calsyntenin-3 binds to neurexin-α, but the binding to neurexin-β was not detected. However, the results from the cell surface binding assay were conflicting: the binding between the calsyntenin-3 full ectodomain construct and neurexin-α was not detected, but the binding was detected between calsyntenin-3 CAD ectodomain construct and neurexin-α. Therefore, the cell surface binding assay cannot be considered entirely reliable and should be repeated before making further conclusions.
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(2022)Breeding-dispersal and philopatry are important life-history traits when it comes to the ecology of animals. A number of factors such as sex, age, habitat stability, population density, predation and various environmental factors influence the movement patterns of species. Philopatry, in general, can be used by organisms as a predator avoidance strategy and to improve feeding efficiency. Dispersal on the other hand has been shown to help avoid inbreeding and competition within groups or between kin. Among the different types of dispersal and philopatry, breeding dispersal and site fidelity to breeding sites have been studied in many vertebrates. Many birds and some ungulate species have been the focus of these studies and have shown that breeding success influences site fidelity. Among ungulates, the reindeer genus (Rangifer tarandus spp.) however, has received little attention for this topic. A species of special conservational value is the wild forest reindeer (Rangifer tarandus fennicus), which is a rare, and near-threatened subspecies of reindeer living in Finland. Knowledge of factors influencing the dispersal and site fidelity for this species is lacking but has important implications for the conservation and management of this and other vulnerable species. In my thesis I investigated the philopatry of wild forest reindeer females from eastern Finland and tested if the calving site fidelity was influenced by breeding success, predator pressure and the female’s age. Given the high densities of predators in the study area (Kainuu) and thus high predator pressure on reindeer, I expected (i) the philopatry of the wild forest reindeer female’s to be stronger in areas with higher predator pressure but (ii) higher dispersal movement when wild forest reindeer females had no breeding success the previous year. Additionally, I expected (iii) the dispersal distances of wild forest reindeer females to be negatively correlated with their age. For this study I used long-term GPS monitoring data of 53 collared wild forest reindeer females, which were followed for varying periods (2-6 years) between 2010-2021 from Eastern Finland. I found that the inter-year distances between calving sites per female had a median distance of 2.84 km, confirming that female wild forest reindeer show philopatry to calving sites, as do other reindeer subspecies. Even though the movement ranged from 4.8 m to 36.99 km, showing substantially longer dispersal for some individuals. The model outcomes indicate some association between predation pressure and site fidelity, and reduced philopatry following calf mortality, although none of these associations were significant. The age of the mother did also not show any significant influence on a female’s site fidelity. Nonetheless, these results would suggest that a mother's choice to leave or return to the same calving site might be influenced by the previous year's calf mortality but more complex variables like anthropogenic disturbances, environmental factors, as well as intrinsic factors and the physical condition of the mother most likely also play a role in this.
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(2023)Väestönkasvu lisää tarvetta öljykasvien tuotannolle ihmisravinnoksi ja biopolttoaineeksi. Öljynpuristamisesta saatavat sivutuotteet, kuten rouheet ja puristeet sisältävät hyvälaatuista valkuaista eläinten ruokintaan. Camelina (Camelina sativa) ja hamppu (Cannabis sativa) ovat potentiaalisia vaihtoehtoja nautojen valkuaisruokinnassa. Tutkimuksen tavoitteena oli selvittää camelina- ja hamppupuristeen vaikutusta in vitro pötsikäymiseen eri karkearehukäsittelyillä. Karkearehuina käytettiin lämpökuivattua nurmi-, puna-apila- ja maissisäilörehua ja väkirehuna ohraa. Kontrollina toimivat rypsipuriste ja käsittelyt, jotka eivät sisältäneet täydennysvalkuaisrehua eli koostuivat ainoastaan karkearehusta ja ohrasta. Kaikkien käsittelyiden karkearehu:väkirehusuhde oli 1:1 kuiva-aineessa. Valkuaislisättömien käsittelyiden raakavalkuaispitoisuudet vaihtelivat 95–140 g/kg ka välillä riippuen käytetyn karkearehun raakavalkuaispitoisuudesta. Valkuaiskäsittelyissä raakavalkuaispitoisuudeksi tuli 170 g/kg ka. Inkubaatiopulloihin punnittiin rehuja yhteensä 3,5 g ka. Käsittelyitä oli 12 kpl ja lisäksi jokaisessa ajossa oli 2 kpl blancoja, joihin ei punnittu rehuja. Ajoja tehtiin neljä. Jokainen ajo kesti 30 h ja näytteitä otettiin 1, 4, 8, 12, 24 ja 30 h kuluttua inkubaation aloituksesta. Näytteistä määritettiin haihtuvat rasvahapot (VFA), ammoniumtyppi ja pH. Analyysituloksista laskettiin haihtuvien rasvahappojen moolisuhteet. Tutkittavista rehuista analysoitiin lisäksi sekundäärinen kuiva-aine, tuhka, tuhkaton neutraalidetergenttikuitu (NDF), raakavalkuainen ja kokonaisrasva. Valkuaisrehuista analysoitiin typpifraktiot (A, B1, B2, B3 ja C). Rypsi-, camelina- ja hamppupuristeen raakavalkuaispitoisuudet olivat 332, 367 ja 286 g/kg ka vastaavasti. Hypoteesin vastaisesti valkuaisrehun lisääminen ei lisännyt VFA:n kokonaismäärää ja ammoniumtypen muodostusta. Hypoteesin mukaisesti valkuaisrehun lähde vaikutti pötsikäymisen voimakkuuteen. Camelina- ja rypsipuristetta sisältävät käsittelyt vastasivat toisiaan VFA:n kokonaismäärässä (P>0,05) hypoteesin mukaisesti. Camelina lisäsi kuitenkin propionihapon kokonaismäärää (P<0,05) ja mooliosuutta (P<0,01) verrattuna rypsiin sekä pienensi voihapon mooliosuutta verrattuna rypsiin (P<0,01). Hamppupuristeella VFA:n kokonaismäärä oli pienempi kuin camelinapuristeella (P<0,05) ja suuntaa antavasti pienempi kuin rypsipuristeella (P=0,063). Hamppupuriste vähensi propionihapon kokonaismäärää ja lisäsi etikkahapon mooliosuutta verrattuna rypsiin (P<0,001 ja P<0,01, vastaavasti) ja camelinaan (P<0,001 ja P<0,01, vastaavasti). Karkearehun lähde vaikutti VFA:n kokonaismääriin ja moolisuhteisiin. Puna-apilasäilörehua sisältävissä käsittelyissä VFA:n kokonaismäärät olivat suuremmat kuin maissisäilörehua sisältävissä käsittelyissä (P<0,05). Puna-apilasäilörehukäsittely lisäsi etikkahapon ja propionihapon kokonaismääriä verrattuna nurmisäilörehukäsittelyihin (P<0,05 ja P<0,01 vastaavasti) ja maissisäilörehukäsittelyihin (P<0,01 ja P<0,05, vastaavasti). Tulosten perusteella camelinapuristeen raakavalkuaispitoisuus oli rypsiä suurempi ja näiden VFA:n kokonaismäärät ja typpifraktiot vastasivat toisiaan. Camelina voisi siis vastata rypsiä nautojen valkuaisruokinnassa, mutta hampun valkuaisarvo on mahdollisesti näitä alhaisempi VFA:n kokonaismäärän ja moolisuhteiden perusteella. Hamppupuristeen suurempi NDF-kuidun määrä voisi selittää camelina- ja rypsipuristekäsittelyitä suuremman etikkahapon mooliosuuden. Karkearehun lähde vaikutti pötsikäymiseen ja puna-apila lisäsi VFA:n kokonaismäärää verrattuna nurmi- ja maissisäilörehuun, jolla voi olla positiivisia vaikutuksia energiansaantiin ja maitotuotokseen.
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(2022)Suomessa on tarvetta uusille kotimaisille valkuaislähteille. Öljyntuotannosta ylijäävä camelinapuriste vastaa aminohappokoostumukseltaan melko hyvin lypsykarjan ruokinnassa yleisesti käytettyä ryp-siä, joten se voisi sopia hyvin valkuaisrehuksi. Camelina ei tarvitse paljon ravinteita ja sitä pystytään kasvattamaan monenlaisissa ilmasto-oloissa, koska se kestää hyvin vaikeita ympäristöoloja, kuten kuivuutta, sekä tauteja ja tuholaisia. Tutkimuksen tavoitteena oli tutkia camelinan soveltuvuutta valkuaisrehuksi lypsylehmillä. Tutkimus koostui kahdesta osakokeesta, joissa mitattiin ohutsuoleen virtaavan käyttökelpoisen valkuaisen määrää in vitro. Osakokeessa 1 verrattiin kahta eri camelinalajiketta rypsiin ja osakokeen 2 koe-dieetti sisälsi camelinaa nousevina tasoina siten, että camelinavalkuainen korvasi rypsivalkuaista 0, 1/3, 2/3 ja 3/3. Hypoteesi oli, että camelina voi korvata rypsin täysin ilman ohutsuoleen virtaavan käyttökelpoisen valkuaisen määrän vähenemistä. Tutkimuksessa koerehuista analysoitiin perusanalyysien lisäksi aminohappokoostumus ja Cornellin typpifraktiot. Typpifraktioiden perusteella camelinalla ja rypsillä on samankaltainen hajoavuuspoten-tiaali pötsissä. Ohutsuoleen virtaavan käyttökelpoisen valkuaisen määrää mitattiin laboratoriossa Bioprocess control’in Gas Endeavor in vitro –laitteella inkuboimalla rehuja naudan pötsinesteessä. Osakokeiden tulokset olivat keskenään ristiriitaisia. Osakoe 1:n mukaan ohutsuoleen virtaavan käyt-tökelpoisen valkuaisen määrässä ei ollut merkittäviä eroja valkuaisrehujen välillä. Osakoe 2:ssa ohutsuoleen virtaavan käyttökelpoisen valkuaisen määrä yllättäen väheni camelinan annostasoa nostettaessa. Tässä tutkimuksessa hypoteesi ei toteutunut kaikkien tulosten osalta, mutta sekä osakoe 1:n että typpifraktioiden mukaan camelinan pitäisi soveltua rypsin korvaajaksi valkuaisrehu-na. On epäselvää, miksi osakoe 2:ssa tämä ei toteutunut. Tulevaisuudessa tarvitaan lisää tutkimuk-sia camelinan soveltuvuudesta valkuaisrehuksi, ja in vitro -menetelmä on hyvä tutkimuskeino ennen in vivo -kokeita.
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