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  • Palomäki, Anni-Mari (Helsingin yliopisto, 2008)
    Tämän tutkimuksen tarkoituksena on tutkia Venäjällä ilmestyvän ”Krest’janka”-lehden välittämää naiskuvaa. Tutkimukseen on valittu lehden vuosikerrat 1985, 1995 ja 2005, koska suuret muutokset Venäjällä ajoittuvat tälle aikavälille. Haluamme selvittää, miten naiskuva on muuttunut tänä aikana ja miten se välittyy lehden sivuilta. Tutkimukseemme olemme käyttäneet A.V. Kirilinan työssään käyttämiä metodeja. Keräsimme lehdistä kaikki verbilausekkeet, joiden subjektina on naista tarkoittava sana ja jaoimme ne luokkiin merkityksen mukaan. Jaottelun jälkeen analysoimme kerättyä aineistoa ja pyrimme löytämään kullekin vuosikerralle tyypillisiä verbilausekkeita. Tämän lisäksi keräsimme lehdistä kaikki naista kuvaavat adjektiivit ja vertailimme niiden käyttöä eri vuosina. Tulosten perusteella voidaan sanoa, että vuoden 1985 lehdissä vaikuttaa vielä voimakkaasti sosialismin ihanteet. Nainen kuvataan työnsä kautta aktiivisena ja tavoitteensa ylittävänä kansalaisena. Yksityiselämään ei juuri kiinnitetä huomiota. Vuoden 1995 ja 2005 lehtien naiset ovat keskenään hyvinkin samanlaisia. Naisen elämästä puhutaan nyt jo laajemmin. Työn lisäksi yksityiselämä ja tunteet ovat keskeisiä aiheita. Kun 1985 lehdissä ei puhuttu naisesta negatiiviseen sävyyn, niin 1995 ja 2005 vuosien lehdissä naista kuvataan myös negatiivisessa valossa. Myös yhteiskunnan epäkohtiin kiinnitetään huomiota naisen näkökulmasta.
  • Paasonen, Pauli (Helsingin yliopisto, 2012)
    Aerosol particles have various effects on our life. They affect the visibility and have diverse health effects, but are also applied in various applications, from drug inhalators to pesticides. Additionally, aerosol particles have manifold effects on the Earths radiation budget and thus on the climate. The strength of the aerosol climate effect is one of the factors causing major uncertainties in the global climate models predicting the future climate change. Aerosol particles are emitted to atmosphere from various anthropogenic and biogenic sources, but they are also formed from precursor vapours in many parts of the world in a process called atmospheric new particle formation (NPF). The uncertainties in aerosol climate effect are partly due to the current lack of knowledge of the mechanisms governing the atmospheric NPF. It is known that gas phase sulphuric acid most certainly plays an important role in atmospheric NPF. However, also other vapours are needed in NPF, but the exact roles or even identities of these vapours are currently not exactly known. In this thesis I present some of the recent advancements in understanding of the atmospheric NPF in terms of the roles of the participating vapours and the meteorological conditions. Since direct measurements of new particle formation rate in the initial size scale of the formed particles (below 2 nm) are so far infrequent in both spatial and temporal scales, indirect methods are needed. The work presented on the following pages approaches the NPF from two directions: by analysing the observed formation rates of particles after they have grown to sizes measurable with widely applied instruments (2 nm or larger), and by measuring and modelling the initial sulphuric acid cluster formation. The obtained results can be summarized as follows. i) The observed atmospheric new particle formation rates are typically connected with sulphuric acid concentration to the power close to two. ii) Also other compounds, most probably strong bases such as amines and oxidized organic vapours, influence the NPF. In some locations their impact even dictates the observed particle formation rate. iii) Air temperature has an explicit effect on the formation of stable sulphuric acid clusters, in which also the relative humidity seems to play a role. These impacts of meteorological quantities on the initial cluster formation seem to influence also the observed particle formation rate.
  • Grönfors, Markus (2014)
    In this thesis the main idea is analyse bacterial data obtained with specific technology called phenotype microarrays. The goal is to implement statistical methods and model cell respiration over period of 48 hours. The data are a bacterium called yersinia enterocolitica, which is a pathogen mainly carried by animals. Data was originally published in a scientific journal called Proceedings of the National Acedemy of Sciences of the United States of America and a small part of strain was chosen for thesis. Data consists about 110 000 rows of observations and it is divided to two experimental setups that are tested in two different temperatures. Data analysis consists three steps: cluster analysis, data normalization and comparing experimental setups. Statistical methods used are k-means clustering, Michaelis-Menten kinetics for growth curves, linear mixed effects models, restricted maximum likelihood estimation, random walk Metropolis-Hastings algorithm and highest posterior density intervals. Main results are there is a recognizable cluster for substrates implying grow and there are no differences between experimental setups. In conclusion statistical methods used in thesis are satisfactory for modelling data and while there are noticeable clusters, there lies no differences between experimental setups. In further analyses it should be better to include more experimental setups in one analysis.
  • Salonen, Maria (Helsingin yliopisto, 2014)
    Accessibility plays a key role in shaping the patterns of human activity on all spatial scales. Accessibility questions are particularly topical now that cities around the word strive for more sustainable urban mobility and information on human influence on natural systems is needed in order to better understand processes of global environmental change. Following these lines of development, supporting different spatial planning processes with quantitative accessibility information has become increasingly important, and different accessibility analysis methods are actively being developed for this purpose. Furthermore, availability of new types of data and increasing computational power enable novel approaches and a level of detail in analysis that were unfeasible in the past. This thesis addresses accessibility questions through five case studies in two different contexts. Two case studies take place in the rural Peruvian Amazonia (Loreto region) where the extensive river network forms the backbone of regional transportation and people s daily mobility. The other three case studies are conducted in the capital region in Finland (Greater Helsinki), and the focus of these studies is on urban environments. The contribution of my work is both methodological and contextual; I aim at finding novel data sources for spatial accessibility analyses and further developing methods for quantifying accessibility as distances and travel times. On the other hand, I aim at (visually) describing and understanding the spatial patterns of accessibility in my study areas and at analysing and discussing the implications of accessibility for the spatial organisation of land-use and people s daily mobility. My results show that realistic accessibility analyses require a consideration of different travel modes and regionally specific transport network properties. In fluvial transport networks, travel time analysis is particularly sensitive to river channel types, direction of movement and seasonality. In urban settings the door-to-door approach for multimodal travel time calculations gives more realistic results than in-vehicle travel time only, and it also makes the different travel modes mutually comparable. The value of the more advanced quantification methods becomes particularly visible when the results obtained from the accessibility calculations are further applied in new analyses. The use of simple Euclidean distances may, however, be justified in situations where appropriate data for more advanced analysis is lacking, but knowing the limitations and simplifying assumptions of these measures is important when applying them. The key contextual findings of this thesis are based on quantitative descriptions and visualisations of the spatial patterns of accessibility in the case study areas. Quantitative data on accessibility also serve as an input for analyses of human livelihoods (such as modelling of potential production zones for different agricultural produce in Loreto) and land-use pressure (such as Amazonian deforestation modelling). My results furthermore show how accessibility to services and other daily activities is an important factor influencing urban residents travel behaviour and its environmental sustainability in Greater Helsinki. Finally, this thesis provides examples of how different types of data sources and their innovative combinations can be used in accessibility analyses. In the case studies I utilize and thus also introduce freely available computational tools for detailed multimodal travel time analysis.
  • Vuorela, Satu (Helsingin yliopisto, 2005)
  • Dal Maso, Miikka (Helsingin yliopisto, 2006)
    Atmospheric aerosol particle formation events can be a significant source for tropospheric aerosols and thus influence the radiative properties and cloud cover of the atmosphere. This thesis investigates the analysis of aerosol size distribution data containing particle formation events, describes the methodology of the analysis and presents time series data measured inside the Boreal forest. This thesis presents a methodology to identify regional-scale particle formation, and to derive the basic characteristics such as growth and formation rates. The methodology can also be used to estimate concentration and source rates of the vapour causing particle growth. Particle formation was found to occur frequently in the boreal forest area over areas covering up to hundreds of kilometers. Particle formation rates of boreal events were found to be of the order of 0.01-5 cm^-3 s^-1, while the nucleation rates of 1 nm particles can be a few orders of magnitude higher. The growth rates of over 3 nm sized particles were of the order of a few nanometers per hour. The vapor concentration needed to sustain such growth is of the order of 10^7--10^8 cm^-3, approximately one order of magnitude higher than sulphuric acid concentrations found in the atmosphere. Therefore, one has to assume that other vapours, such as organics, have a key role in growing newborn particles to sizes where they can become climatically active. Formation event occurrence shows a clear annual variation with peaks in summer and autumns. This variation is similar to the variation exhibited the obtained formation rates of particles. The growth rate, on the other hand, reaches its highest values during summer. This difference in the annual behavior, and the fact that no coupling between the growth and formation process could be identified, suggest that these processes might be different ones, and that both are needed for a particle formation burst to be observed.
  • Wan, Minli (2009)
    China's primary wood processing industry and wood consuming sectors have experienced rapid growth in recent years. Industries like sawnwood and plywood have developed very quickly. The purpose of this study is to: 1) provide an overview of the demand, supply, imports and exports of raw wood and primary wood products in the China market between 1993 and 2007, 2) present quantitative estimates of the relative importance of factors influencing the demand, supply and exports of Chinese plywood, 3) draw conclusions about China's potentials and challenges for foreign enterprises, including Finnish companies. The information, analyses and findings presented in this study can give a reference for wood processing companies, especially for sawnwood and plywood firms, and governmental agencies in China. In addition, the study provides a basis for further study and research. Even though much information has been published in China, academic research in the Chinese woodworking market is scarce, and especially, time-series data is missing and unreliable. This study tries to fill this gap. It is based on secondary data collected from various sources, including literatures, journals, magazines, consulting reports, industry analysis, news, and so on. The annual time-series data obtained for variables in models are mainly gathered from original official Chinese sources. The study increases the information and understanding on the Chinese wood products markets by using descriptive and explanatory methods to analyze the data for background information, markets and empirical modeling. By employing econometric models, based on the elasticity estimates, Chinese plywood demand seems to be income elastic but price inelastic, Chinese plywood supply would be highly elastic with raw material price but scale inelastic, and Chinese plywood exports appear to be highly income elastic.
  • Dinku, Zerihun Megersa (2014)
    Coronal magnetic field governs most of the coronal activities. Despite of its importance in solar atmosphere, there is no accurate method of measuring the coronal magnetic field. The current measurement methods of coronal magnetic fields depend on extrapolation of photospheric magnetic fields. There are different models to study the global structure of coronal magnetic field. The most commonly used models are PFSS model and magnetohydrodynamic (MHD) model. In this thesis, we study the coronal magnetic field condition during major solar energetic particle (SEP) event of 23rd solar cycle by using the PFSS model. We use 114 SEP events observed by the SOHO/ERNE experiment in 1996-2010. In the beginning we identified 43 events that are relatively free from the disturbance caused by interplanetary coronal mass ejections (ICMEs). We examined these SEP events using IDL software developed by Lockheed Martin Solar and Astrophysics Lab (LMSAL). We produced plots of open coronal magnetic field of each events using SolarSoft. We also classified SEP events according to their number of connection points as events with; single connection point, double connection points and multiple connection points. Events with multiple connection points make up almost one third of the total events. These events show that the coronal magnetic connection are typically complicated and neighboring magnetic field lines in the solar wind can be magnetically connected to regions that are well separated in the low corona. We also found that the actual connection longitude (a longitude that takes in to account the coronal magnetic field) is most of the time is closer to the flare site associated with the event than the Parker spiral connection longitude. The Parker spiral longitudes, connection longitudes and flare longitudes are analyzed in detail by histograms. Finally, we chose two example events and analyzed them by using intensity-time profile of particles, plots of from LASCO CME catalog and plots produce by the SolarSoft. Based on our analysis we classified the example events into gradual and hybrid SEP events.
  • Brilhante, Virginia (2013)
    This thesis presents a workflow for analysis of exome sequencing data aiming at identification of single nucleotide variants (SNVs) causing recessively inherited mitochondrial disease in children. Several variant selection criteria that are consistent with such group of genetic disorders are applied along the workflow in relation to mode of inheritance, allele frequency and the Finnish ancestry of the patients. These are combined with knowledge of nuclear-encoded mitochondrial proteins and prediction of pathogenic variants, narrowing down the total set of SNVs found in a patient to those most likely to be causative. Patient exomes are analysed individually (n=1 studies). The bioinformatic resources used for implementation include public and in-house databases of mitochondrial nuclear genes, human genetic variation and exome controls, as well as software tools for prediction of pathogenic SNVs and mitochondria-targeting proteins. Exome variant data from a cohort of 49 molecularly undiagnosed children were analysed through the workflow, leading to the identification of mitochondrial disease-causing SNVs located in nuclear genes for 10 of the patients. Therefore, a success rate of 20% was achieved. The workflow has been an important element in the use of exome sequencing as a new research tool at the Wartiovaara group of the Research Program for Molecular Neurology, Faculty of Medicine, University of Helsinki.
  • Brilhante, Virginia (2013)
    This thesis presents a workflow for analysis of exome sequencing data aiming at identification of single nucleotide variants (SNVs) causing recessively inherited mitochondrial disease in children. Several variant selection criteria that are consistent with such group of genetic disorders are applied along the workflow in relation to mode of inheritance, allele frequency and the Finnish ancestry of the patients. These are combined with knowledge of nuclear-encoded mitochondrial proteins and prediction of pathogenic variants, narrowing down the total set of SNVs found in a patient to those most likely to be causative. Patient exomes are analysed individually (n=1 studies). The bioinformatic resources used for implementation include public and in-house databases of mitochondrial nuclear genes, human genetic variation and exome controls, as well as software tools for prediction of pathogenic SNVs and mitochondria-targeting proteins. Exome variant data from a cohort of 49 molecularly undiagnosed children were analysed through the workflow, leading to the identification of mitochondrial disease-causing SNVs located in nuclear genes for 10 of the patients. Therefore, a success rate of 20% was achieved. The workflow has been an important element in the use of exome sequencing as a new research tool at the Wartiovaara group of the Research Program for Molecular Neurology, Faculty of Medicine, University of Helsinki.
  • Brilhante, Virginia (2013)
    This thesis presents a workflow for analysis of exome sequencing data aiming at identification of single nucleotide variants (SNVs) causing recessively inherited mitochondrial disease in children. Several variant selection criteria that are consistent with such group of genetic disorders are applied along the workflow in relation to mode of inheritance, allele frequency and the Finnish ancestry of the patients. These are combined with knowledge of nuclear-encoded mitochondrial proteins and prediction of pathogenic variants, narrowing down the total set of SNVs found in a patient to those most likely to be causative. Patient exomes are analysed individually (n=1 studies). The bioinformatic resources used for implementation include public and in-house databases of mitochondrial nuclear genes, human genetic variation and exome controls, as well as software tools for prediction of pathogenic SNVs and mitochondria-targeting proteins. Exome variant data from a cohort of 49 molecularly undiagnosed children were analysed through the workflow, leading to the identification of mitochondrial disease-causing SNVs located in nuclear genes for 10 of the patients. Therefore, a success rate of 20% was achieved. The workflow has been an important element in the use of exome sequencing as a new research tool at the Wartiovaara group of the Research Program for Molecular Neurology, Faculty of Medicine, University of Helsinki.
  • Xu, Yuan (2013)
    The increasing recognition of eco-friendly packaging in the packaging industry makes paperboard one of the most promising green packaging materials. The global demand for paperboard has increased rapidly in the past two decades. The purposes of the study are: firstly, to provide an overview of the consumption, production, imports and exports of paperboard products in different regions worldwide between 1992 and 2010. Secondly, as the Finnish paperboard industry has been highly export-oriented, the study also aims to provide quantitative analysis of the main determinants influencing the demand for Finnish paperboard exports in its main destinations-Germany and Russia by applying economic models from the first quarter of 1995 to the third quarter of 2011. Finally, trends projection for the future development of Finnish paperboard is presented based on results of analysis. The research is both descriptive and explanatory based on secondary data collected from various databases. The regional analysis of paperboard market from 1992 to 2010 revealed that North America and Western Europe’s paperboard production exceeded the consumption, where Asia, Eastern Europe and Latin America’s consumption exceeded the production. The consumption and production growth was extremely fast in Asia and it has been the largest consumer and producer of paperboard products since 2000s. Western Europe has been the largest exporter and importer throughout the years. The empirical modeling of Finnish paperboard export demand showed that the export demand for Finnish paperboard in Germany was highly affected by the total paperboard imports of Germany and its GDP. It also has high sensitivity to the income changes of Germany in long term, but the price effect was not significant. The export demand for Finnish paperboard in Russia has low income elasticity and the price effect was statistically significant. Oil price has also significant influence on Finnish paperboard export demand to Russia. According to the linear trends projection for Finnish paperboard market to 2020, the consumption and imports will grow very slowly or even stagnate, but the production and exports will continuously increase at a faster pace.
  • Järvinen, Ilpo (Helsingin yliopisto, 2006)
    Wireless access is expected to play a crucial role in the future of the Internet. The demands of the wireless environment are not always compatible with the assumptions that were made on the era of the wired links. At the same time, new services that take advantage of the advances in many areas of technology are invented. These services include delivery of mass media like television and radio, Internet phone calls, and video conferencing. The network must be able to deliver these services with acceptable performance and quality to the end user. This thesis presents an experimental study to measure the performance of bulk data TCP transfers, streaming audio flows, and HTTP transfers which compete the limited bandwidth of the GPRS/UMTS-like wireless link. The wireless link characteristics are modeled with a wireless network emulator. We analyze how different competing workload types behave with regular TPC and how the active queue management, the Differentiated services (DiffServ), and a combination of TCP enhancements affect the performance and the quality of service. We test on four link types including an error-free link and the links with different Automatic Repeat reQuest (ARQ) persistency. The analysis consists of comparing the resulting performance in different configurations based on defined metrics. We observed that DiffServ and Random Early Detection (RED) with Explicit Congestion Notification (ECN) are useful, and in some conditions necessary, for quality of service and fairness because a long queuing delay and congestion related packet losses cause problems without DiffServ and RED. However, we observed situations, where there is still room for significant improvements if the link-level is aware of the quality of service. Only very error-prone link diminishes the benefits to nil. The combination of TCP enhancements improves performance. These include initial window of four, Control Block Interdependence (CBI) and Forward RTO recovery (F-RTO). The initial window of four helps a later starting TCP flow to start faster but generates congestion under some conditions. CBI prevents slow-start overshoot and balances slow start in the presence of error drops, and F-RTO reduces unnecessary retransmissions successfully.
  • Luukkainen, Pekka (2003)
    Sydän- ja verisuonitaudit nousivat teollisuusmaissa suurimmaksi julkisen terveydenhuollon ongelmaksi 1940-luvulla, tartuntatautien hävittyä lääketieteen kehityksen seurauksena. Suomi saavutti jopa kyseenalaista kunniaa 1950- ja 1960-luvuilla korkeimmilla mitatuilla sydän- ja verisuonitautikuolleisuusluvuilla maailmassa. Kuolleisuudessa on kuitenkin havaittu selviä alueellisia eroja, ja varsinkin Itä-Suomi on kärsinyt erittäin korkeasta sydän- ja verisuonitautikuolleisuudesta. Useissa tutkimuksissa on todettu kohonneen verenpaineen, korkean kolesterolin, ylipainon ja tupakoinnin olevan tärkeimpiä sydän- ja verisuonitautien riskitekijöitä. Näihin tekijöihin yksilö voi kuitenkin helposti vaikuttaa muokkaamalla elintapojaan ja ruokavaliotaan. Tässä tutkielmassa on seurattu vuodesta 1959 lähtien kahta vuosina 1900-1919 syntyneiden miesten kohorttia Itä- ja Länsi-Suomesta. Tarkoituksena oli selvittää eroja alueiden kuolleisuudessa ja riskitekijöiden kehityksessä kilpailevien kuolinsyiden näkökulmasta käyttäen Coxin verrannollisten hasardien mallia. Tutkimuksen kuluessa huomattiin sydän- ja verisuonitautikuolleisuuden alueellisten erojen vähentyneen, sekä kolesterolin ja tupakoinnin olevan merkittävimpiä riskitekijöitä ikääntyneiden ihmisten joukossa.
  • Luukkainen, Pekka (2003)
    Cardiovascular diseases became the leading public health problem in the developed countries in the late 1940s. Finland has obtained questionable fame for having even the highest coronary heart disease mortality in the world. Previous studies have shown that there are clear regional differencies in mortality due to cardiovascular diseases, especially eastern Finland has suffered from exeptionally high cardiovascular disease mortality. Elevated blood pressure, high total cholesterol, obesity and smoking are suggested to be the main risk factors for the cardiovascular diseases. These factors could be easily affected by making changes in the way of life and dietary habits. In this thesis, we studied two cohorts consisting men born between 1900-1919 from east and west Finland. Cohorts have been examined since year 195$ The aim was to clarify the differensies in the mortality between the cohorts and in the risk factor levels by using competing risks. Data was analysed with Cox's proportional hazards model. During the follow-up study, differensies between the cohorts in mortality due to cardiovascular diseases diminished. According to this study the main risk factors for aging population are high total cholesterol and smoking.
  • Döhla, Julia Maria (2013)
    Peroxisome proliferator activated receptor γ coactivator 1α (PGC-1α) is a transcriptional coactivator involved in mitochondrial biogenesis, oxidative stress response, and energy metabolism. PGC-1α is part of an energy sensing network that translates environmental influences into alterations in gene expression of mainly mitochondrial molecular pathways. A role in neuroprotection has been implicated for PGC-1α in the context of mitochondrial expression networks. Our research group has previously established a transgenic mouse line with stable overexpression of PGC-1α in brain neurons. Transgenic overexpression of PGC-1α is associated with an enhanced functional state of mitochondrial energy production. In the context of neurodegenerative processes, brain neurons of PGC-1α transgenic mice are protected against oxidative stressors in the MPTP mouse model of Parkinson’s Disease. To further characterize the transcriptional activity of PGC-1α regulated gene networks in brains of transgenic mice, a quantitative real-time PCR based system was established. Gene expression was measured for a subset of genes found to be differentially regulated in a microarray based screening of RNA obtained from hippocampus and cortex of PGC-1α transgenic mice. Increased PGC-1α gene expression was found in hippocampus and cortex of PGC-1α transgenic mice, and their translation into protein was confirmed immunohistochemically. Expression analysis revealed significant changes in mRNA levels of PGC-1α controlled molecular pathways involved in mitochondrial energy production and antioxidant responses. Furthermore, alterations in the expression of some non-mitochondrial genes with established links to neurodegeneration were observed. Furthermore, a change in GABAA receptor subunit expression was detected. In accordance with previous studies on the PGC-1α transgenic mouse line, these findings suggest that differential gene expression associated with PGC-1α overexpression contributes to an enhanced functional state of neurons in hippocampus and cortex of PGC-1α transgenic mice. Increased knowledge about the transcriptional modulation of neuronal genes regulated by PGC-1α can lead to better insights into mechanisms governing neurodegeneration and neuroprotective pathways. Pharmacological modulation of PGC-1α activity may be a feasible approach for neuroprotective treatments in neurodegenerative diseases, such as Parkinson’s Disease.