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  • Kettunen, Joni (Helsingin yliopisto, 1999)
    The aim of the present study was to advance the methodology and use of time series analysis to quantify dynamic structures in psychophysiological processes and thereby to produce information on spontaneously coupled physiological responses and their behavioral and experiential correlates. Series of analyses using both simulated and empirical cardiac (IBI), electrodermal (EDA), and facial electromyographic (EMG) data indicated that, despite potential autocorrelated structures, smoothing increased the reliability of detecting response coupling from an interindividual distribution of intraindividual measures and that especially the measures of covariance produced accurate information on the extent of coupled responses. This methodology was applied to analyze spontaneously coupled IBI, EDA, and facial EMG responses and vagal activity in their relation to emotional experience and personality characteristics in a group of middle-aged men (n = 37) during the administration of the Rorschach testing protocol. The results revealed new characteristics in the relationship between phasic end-organ synchronization and vagal activity, on the one hand, and individual differences in emotional adjustment to novel situations on the other. Specifically, it appeared that the vagal system is intimately related to emotional and social responsivity. It was also found that the lack of spontaneously synchronized responses is related to decreased energetic arousal (e.g., depression, mood). These findings indicate that the present process analysis approach has many advantages for use in both experimental and applied research, and that it is a useful new paradigm in psychophysiological research. Keywords: Autonomic Nervous System; Emotion; Facial Electromyography; Individual Differences; Spontaneous Responses; Time Series Analysis; Vagal System
  • Sund, Reijo (Helsingin yliopisto, 2008)
    The resources of health systems are limited. There is a need for information concerning the performance of the health system for the purposes of decision-making. This study is about utilization of administrative registers in the context of health system performance evaluation. In order to address this issue, a multidisciplinary methodological framework for register-based data analysis is defined. Because the fixed structure of register-based data indirectly determines constraints on the theoretical constructs, it is essential to elaborate the whole analytic process with respect to the data. The fundamental methodological concepts and theories are synthesized into a data sensitive approach which helps to understand and overcome the problems that are likely to be encountered during a register-based data analyzing process. A pragmatically useful health system performance monitoring should produce valid information about the volume of the problems, about the use of services and about the effectiveness of provided services. A conceptual model for hip fracture performance assessment is constructed and the validity of Finnish registers as a data source for the purposes of performance assessment of hip fracture treatment is confirmed. Solutions to several pragmatic problems related to the development of a register-based hip fracture incidence surveillance system are proposed. The monitoring of effectiveness of treatment is shown to be possible in terms of care episodes. Finally, an example on the justification of a more detailed performance indicator to be used in the profiling of providers is given. In conclusion, it is possible to produce useful and valid information on health system performance by using Finnish register-based data. However, that seems to be far more complicated than is typically assumed. The perspectives given in this study introduce a necessary basis for further work and help in the routine implementation of a hip fracture monitoring system in Finland.
  • Siipilehto, Jouni (Metsäntutkimuslaitos, 2011)
    This thesis report attempts to improve the models for predicting forest stand structure for practical use, e.g. forest management planning (FMP) purposes in Finland. Comparisons were made between Weibull and Johnson s SB distribution and alternative regression estimation methods. Data used for preliminary studies was local but the final models were based on representative data. Models were validated mainly in terms of bias and RMSE in the main stand characteristics (e.g. volume) using independent data. The bivariate SBB distribution model was used to mimic realistic variations in tree dimensions by including within-diameter-class height variation. Using the traditional method, diameter distribution with the expected height resulted in reduced height variation, whereas the alternative bivariate method utilized the error-term of the height model. The lack of models for FMP was covered to some extent by the models for peatland and juvenile stands. The validation of these models showed that the more sophisticated regression estimation methods provided slightly improved accuracy. A flexible prediction and application for stand structure consisted of seemingly unrelated regression models for eight stand characteristics, the parameters of three optional distributions and Näslund s height curve. The cross-model covariance structure was used for linear prediction application, in which the expected values of the models were calibrated with the known stand characteristics. This provided a framework to validate the optional distributions and the optional set of stand characteristics. Height distribution is recommended for the earliest state of stands because of its continuous feature. From the mean height of about 4 m, Weibull dbh-frequency distribution is recommended in young stands if the input variables consist of arithmetic stand characteristics. In advanced stands, basal area-dbh distribution models are recommended. Näslund s height curve proved useful. Some efficient transformations of stand characteristics are introduced, e.g. the shape index, which combined the basal area, the stem number and the median diameter. Shape index enabled SB model for peatland stands to detect large variation in stand densities. This model also demonstrated reasonable behaviour for stands in mineral soils.
  • Haimi, Perttu (Helsingin yliopisto, 2011)
    The analysis of lipid compositions from biological samples has become increasingly important. Lipids have a role in cardiovascular disease, metabolic syndrome and diabetes. They also participate in cellular processes such as signalling, inflammatory response, aging and apoptosis. Also, the mechanisms of regulation of cell membrane lipid compositions are poorly understood, partially because a lack of good analytical methods. Mass spectrometry has opened up new possibilities for lipid analysis due to its high resolving power, sensitivity and the possibility to do structural identification by fragment analysis. The introduction of Electrospray ionization (ESI) and the advances in instrumentation revolutionized the analysis of lipid compositions. ESI is a soft ionization method, i.e. it avoids unwanted fragmentation the lipids. Mass spectrometric analysis of lipid compositions is complicated by incomplete separation of the signals, the differences in the instrument response of different lipids and the large amount of data generated by the measurements. These factors necessitate the use of computer software for the analysis of the data. The topic of the thesis is the development of methods for mass spectrometric analysis of lipids. The work includes both computational and experimental aspects of lipid analysis. The first article explores the practical aspects of quantitative mass spectrometric analysis of complex lipid samples and describes how the properties of phospholipids and their concentration affect the response of the mass spectrometer. The second article describes a new algorithm for computing the theoretical mass spectrometric peak distribution, given the elemental isotope composition and the molecular formula of a compound. The third article introduces programs aimed specifically for the analysis of complex lipid samples and discusses different computational methods for separating the overlapping mass spectrometric peaks of closely related lipids. The fourth article applies the methods developed by simultaneously measuring the progress curve of enzymatic hydrolysis for a large number of phospholipids, which are used to determine the substrate specificity of various A-type phospholipases. The data provides evidence that the substrate efflux from bilayer is the key determining factor for the rate of hydrolysis.
  • Aunimo, Lili (Helsingin yliopisto, 2007)
    In this thesis we present and evaluate two pattern matching based methods for answer extraction in textual question answering systems. A textual question answering system is a system that seeks answers to natural language questions from unstructured text. Textual question answering systems are an important research problem because as the amount of natural language text in digital format grows all the time, the need for novel methods for pinpointing important knowledge from the vast textual databases becomes more and more urgent. We concentrate on developing methods for the automatic creation of answer extraction patterns. A new type of extraction pattern is developed also. The pattern matching based approach chosen is interesting because of its language and application independence. The answer extraction methods are developed in the framework of our own question answering system. Publicly available datasets in English are used as training and evaluation data for the methods. The techniques developed are based on the well known methods of sequence alignment and hierarchical clustering. The similarity metric used is based on edit distance. The main conclusions of the research are that answer extraction patterns consisting of the most important words of the question and of the following information extracted from the answer context: plain words, part-of-speech tags, punctuation marks and capitalization patterns, can be used in the answer extraction module of a question answering system. This type of patterns and the two new methods for generating answer extraction patterns provide average results when compared to those produced by other systems using the same dataset. However, most answer extraction methods in the question answering systems tested with the same dataset are both hand crafted and based on a system-specific and fine-grained question classification. The the new methods developed in this thesis require no manual creation of answer extraction patterns. As a source of knowledge, they require a dataset of sample questions and answers, as well as a set of text documents that contain answers to most of the questions. The question classification used in the training data is a standard one and provided already in the publicly available data.
  • Heikkilä, Anu (Helsingin yliopisto, 2014)
    UV radiation is one of the key factors ageing materials and thus limiting their service life time. Damages induced by UV radiation may be observed as changes in the properties of the material. Various types of weathering experiments are used to study the chemical and physical mechanisms behind the degradation process. Material samples are exposed to UV radiation and other environmental stress agents in natural outdoor and artificial conditions in laboratory. Quantification of the material s response to the exposure yields knowledge on the ageing behaviour of the material. This knowledge is essential when selecting materials to comply with the service requirements, as well as developing materials with extended durability. The focus of this study has been on certain methods used in investigation of the deleterious effects of UV radiation on materials. Various aspects of weathering and analysis of material property changes are considered. As regards weathering, three main topics unfold: sampling of data from outdoor weathering experiments; construction of continuous time series of UV radiation exposures over the weathering periods; and comparability of artificial UV radiation conditions to those encountered under the Sun. Within the scope of the property change analysis, the study has focused on the wavelength dependencies found in damage induction. A new method is proposed for planning the timetable of a natural outdoor weathering experiment in a way that the seasonal and geographical variations are accounted for. The method simplifies the post-exposure analysis of the material properties and improves the comparability of test results obtained at different weathering sites. A new approach is adopted to reconstruct the solar spectral UV irradiance at the Earth s surface through radiative transfer modelling. The method provides a means for deriving UV irradiance in cases where no direct measurements of the quantity are available. As a result, a continuous UV radiation time series is obtained, as required for the determination of the UV radiation exposure accumulated on the materials. To improve the comparability of accelerated ageing to that naturally occurring outdoors, a method for characterizing the UV radiation conditions used in a UV chamber is presented. Knowledge on the exposure is further used to establish a correlation between the artificial and natural ageing environments, facilitating predictions on how the materials would survive in their real service environments. The study aiming at improvements in the analysis of material property changes is two-fold. A novel facility designed and constructed for exposing materials with spectrally resolved UV radiation is reported. The instrument opens new pathways for the investigations on wavelength specific damages in materials. The facility has been exploited in a study on the wavelength sensitivity of newspaper to photoyellowing. A new approach in deriving the action spectrum of photoyellowing of a material is proposed. The resulting action spectrum may be used in optimizing the chemical and/or physical protection of the material against UV radiation.
  • Langohr, Laura (Helsingin yliopisto, 2014)
    With the increasing amount of graph-structured data available, finding interesting objects, i.e., nodes in graphs, becomes more and more important. In this thesis we focus on finding interesting nodes and sets of nodes in graphs or networks. We propose several definitions of node interestingness as well as different methods to find such nodes. Specifically, we propose to consider nodes as interesting based on their relevance and non-redundancy or representativeness w.r.t. the graph topology, as well as based on their characterisation for a class, such as a given node attribute value. Identifying nodes that are relevant, but non-redundant to each other is motivated by the need to get an overview of different pieces of information related to a set of given nodes. Finding representative nodes is of interest, e.g. when the user needs or wants to select a few nodes that abstract the large set of nodes. Discovering nodes characteristic for a class helps to understand the causes behind that class. Next, four methods are proposed to find a representative set of interesting nodes. The first one incrementally picks one interesting node after another. The second iteratively changes the set of nodes to improve its overall interestingness. The third method clusters nodes and picks a medoid node as a representative for each cluster. Finally, the fourth method contrasts diverse sets of nodes in order to select nodes characteristic for their class, even if the classes are not identical across the selected nodes. The first three methods are relatively simple and are based on the graph topology and a similarity or distance function for nodes. For the second and third, the user needs to specify one parameter, either an initial set of k nodes or k, the size of the set. The fourth method assumes attributes and class attributes for each node, a class-related interesting measure, and possible sets of nodes which the user wants to contrast, such as sets of nodes that represent different time points. All four methods are flexible and generic. They can, in principle, be applied on any weighted graph or network regardless of what nodes, edges, weights, or attributes represent. Application areas for the methods developed in this thesis include word co-occurrence networks, biological networks, social networks, data traffic networks, and the World Wide Web. As an illustrating example, consider a word co-occurrence network. There, finding terms (nodes in the graph) that are relevant to some given nodes, e.g. branch and root, may help to identify different, shared contexts such as botanics, mathematics, and linguistics. A real life application lies in biology where finding nodes (biological entities, e.g. biological processes or pathways) that are relevant to other, given nodes (e.g. some genes or proteins) may help in identifying biological mechanisms that are possibly shared by both the genes and proteins.
  • Zhou, Fang (Helsingin yliopisto, 2012)
    We propose network abstraction as a research area. It is motivated by the growth of networks in many areas of life. Consider, for instance, networks of thousands of genes, millions of people, or billions of web pages. They are too large to be directly analyzed by users. The aim of network abstraction is to summarize a large network as a smaller one. An abstracted network can then help users to see the overall topology of a large network, or to understand the connections of distant nodes. The general network abstraction task is: given a large network, transform it into a smaller one, which contains in some well-specified sense the most relevant information. In this thesis, we analyze this research area and propose methods to solve some instances of the problem. The methods also provide different trade-offs between the graph quality and simplicity, as well as between result quality and efficiency. More specifically, we propose two approaches to abstracting a network. The first one is to simplify a weighted network by removing edges under the constraint that distances between all pairs of nodes are preserved. We first empirically show that a number of edges can be removed from real biological networks without losing any graph connectivity. We next relax the constraint of fully preserving original graph connectivity, extend lossless network simplification to lossy network simplification, and demonstrate that many more edges can be removed with little loss of quality. The second approach we give for network abstraction is to compress a weighted network by grouping nodes and edges. We propose novel methods and experimentally show that real graphs can be compressed efficiently with relatively little error. We next consider graphs with weights also on the nodes, and utilize them as node importances to extend the definition of weighted graph compression. We present new compression operations and demonstrate that the compressed graph can preserve more information related to more important nodes. Furthermore, we propose the idea of using node weights and compression to summarize the metabolisms in a set of organisms, and apply the methodology to better understand the metabolic biodiversity between Archaea and Eubacteria, the two most fundamental branches of life.
  • Zhou, Fang (Helsingin yliopisto, 2012)
    We propose network abstraction as a research area. It is motivated by the growth of networks in many areas of life. Consider, for instance, networks of thousands of genes, millions of people, or billions of web pages. They are too large to be directly analyzed by users. The aim of network abstraction is to summarize a large network as a smaller one. An abstracted network can then help users to see the overall topology of a large network, or to understand the connections of distant nodes. The general network abstraction task is: given a large network, transform it into a smaller one, which contains in some well-specified sense the most relevant information. In this thesis, we analyze this research area and propose methods to solve some instances of the problem. The methods also provide different trade-offs between the graph quality and simplicity, as well as between result quality and efficiency. More specifically, we propose two approaches to abstracting a network. The first one is to simplify a weighted network by removing edges under the constraint that distances between all pairs of nodes are preserved. We first empirically show that a number of edges can be removed from real biological networks without losing any graph connectivity. We next relax the constraint of fully preserving original graph connectivity, extend lossless network simplification to lossy network simplification, and demonstrate that many more edges can be removed with little loss of quality. The second approach we give for network abstraction is to compress a weighted network by grouping nodes and edges. We propose novel methods and experimentally show that real graphs can be compressed efficiently with relatively little error. We next consider graphs with weights also on the nodes, and utilize them as node importances to extend the definition of weighted graph compression. We present new compression operations and demonstrate that the compressed graph can preserve more information related to more important nodes. Furthermore, we propose the idea of using node weights and compression to summarize the metabolisms in a set of organisms, and apply the methodology to better understand the metabolic biodiversity between Archaea and Eubacteria, the two most fundamental branches of life.
  • Galbrun, Esther (Helsingin yliopisto, 2013)
    In scientific investigations data oftentimes have different nature. For instance, they might originate from distinct sources or be cast over separate terminologies. In order to gain insight into the phenomenon of interest, a natural task is to identify the correspondences that exist between these different aspects. This is the motivating idea of redescription mining, the data analysis task studied in this thesis. Redescription mining aims to find distinct common characterizations of the same objects and, vice versa, to identify sets of objects that admit multiple shared descriptions. A practical example in biology consists in finding geographical areas that admit two characterizations, one in terms of their climatic profile and one in terms of the occupying species. Discovering such redescriptions can contribute to better our understanding of the influence of climate over species distribution. Besides biology, applications of redescription mining can be envisaged in medicine or sociology, among other fields. Previously, redescription mining was restricted to propositional queries over Boolean attributes. However, many conditions, like aforementioned climate, cannot be expressed naturally in this limited formalism. In this thesis, we consider more general query languages and propose algorithms to find the corresponding redescriptions, making the task relevant to a broader range of domains and problems. Specifically, we start by extending redescription mining to non-Boolean attributes. In other words, we propose an algorithm to handle nominal and real-valued attributes natively. We then extend redescription mining to the relational setting, where the aim is to find corresponding connection patterns that relate almost the same object tuples in a network. We also study approaches for selecting high quality redescriptions to be output by the mining process. The first approach relies on an interface for mining and visualizing redescriptions interactively and allows the analyst to tailor the selection of results to meet his needs. The second approach, rooted in information theory, is a compression-based method for mining small sets of associations from two-view datasets. In summary, we take redescription mining outside the Boolean world and show its potential as a powerful exploratory method relevant in a broad range of domains.
  • Räty, Minna (Helsingin yliopisto, 2011)
    The aim of this study was to evaluate and test methods which could improve local estimates of a general model fitted to a large area. In the first three studies, the intention was to divide the study area into sub-areas that were as homogeneous as possible according to the residuals of the general model, and in the fourth study, the localization was based on the local neighbourhood. According to spatial autocorrelation (SA), points closer together in space are more likely to be similar than those that are farther apart. Local indicators of SA (LISAs) test the similarity of data clusters. A LISA was calculated for every observation in the dataset, and together with the spatial position and residual of the global model, the data were segmented using two different methods: classification and regression trees (CART) and the multiresolution segmentation algorithm (MS) of the eCognition software. The general model was then re-fitted (localized) to the formed sub-areas. In kriging, the SA is modelled with a variogram, and the spatial correlation is a function of the distance (and direction) between the observation and the point of calculation. A general trend is corrected with the residual information of the neighbourhood, whose size is controlled by the number of the nearest neighbours. Nearness is measured as Euclidian distance. With all methods, the root mean square errors (RMSEs) were lower, but with the methods that segmented the study area, the deviance in single localized RMSEs was wide. Therefore, an element capable of controlling the division or localization should be included in the segmentation-localization process. Kriging, on the other hand, provided stable estimates when the number of neighbours was sufficient (over 30), thus offering the best potential for further studies. Even CART could be combined with kriging or non-parametric methods, such as most similar neighbours (MSN).
  • Gupta, Rashi (Helsingin yliopisto, 2009)
    Microarrays are high throughput biological assays that allow the screening of thousands of genes for their expression. The main idea behind microarrays is to compute for each gene a unique signal that is directly proportional to the quantity of mRNA that was hybridized on the chip. A large number of steps and errors associated with each step make the generated expression signal noisy. As a result, microarray data need to be carefully pre-processed before their analysis can be assumed to lead to reliable and biologically relevant conclusions. This thesis focuses on developing methods for improving gene signal and further utilizing this improved signal for higher level analysis. To achieve this, first, approaches for designing microarray experiments using various optimality criteria, considering both biological and technical replicates, are described. A carefully designed experiment leads to signal with low noise, as the effect of unwanted variations is minimized and the precision of the estimates of the parameters of interest are maximized. Second, a system for improving the gene signal by using three scans at varying scanner sensitivities is developed. A novel Bayesian latent intensity model is then applied on these three sets of expression values, corresponding to the three scans, to estimate the suitably calibrated true signal of genes. Third, a novel image segmentation approach that segregates the fluorescent signal from the undesired noise is developed using an additional dye, SYBR green RNA II. This technique helped in identifying signal only with respect to the hybridized DNA, and signal corresponding to dust, scratch, spilling of dye, and other noises, are avoided. Fourth, an integrated statistical model is developed, where signal correction, systematic array effects, dye effects, and differential expression, are modelled jointly as opposed to a sequential application of several methods of analysis. The methods described in here have been tested only for cDNA microarrays, but can also, with some modifications, be applied to other high-throughput technologies. Keywords: High-throughput technology, microarray, cDNA, multiple scans, Bayesian hierarchical models, image analysis, experimental design, MCMC, WinBUGS.
  • Ollilainen, Matti (2015)
    Metisilliiniresistentti Staphylococcus pseudintermedius (MRSP) on viime vuosina muodostunut merkittäväksi ongelmaksi eläinlääketieteessä. MRSP-kannat ovat usein vastustuskykyisiä useille mikrobilääkeryhmille, mikä hankaloittaa merkittävästi näiden aiheuttamien infektioiden hoitoa. Metisilliiniresistentti Staphylococcus aureus (MRSA) on merkittävä humaanipatogeeni ja yleinen terveydenhoitoperäisten infektioiden aiheuttaja. Viime vuosina bakteerin merkitys ihmisten yhteisöissä hankittujen infektioiden aiheuttajana on myös kasvanut. Koirista eristettyjen MRSP- ja MRSA-löydösten määrä on lisääntynyt viime vuosina ympäri maailmaa, ja myös Suomessa on havaittu metisilliiniresistenttien stafylokokkien yleistyminen koirilla. Esimerkiksi vuosien 2012−2013 aikana kolmella Opaskoirakoulun koiralla todettiin MRSP−tartunta, mikä johti tarpeeseen selvittää laajemmin bakteerin esiintyvyyttä ja sen merkitystä Opaskoirakoulun koirapopulaatiossa. Opaskoirakoulun tehtävänä on kasvattaa, kouluttaa ja luovuttaa käyttöön opaskoiria sokeille ja vaikeasti heikkonäköisille. MRSP- ja MRSA-bakteerien esiintyvyyden pitäminen alhaisena Opaskoirakoulun koirapopulaatiossa on tärkeää, sillä koirat ovat koululla ollessaan läheisessä kontaktissa toisiinsa ja koirien parissa työskenteleviin ihmisiin, mikä edistää tartuntojen leviämistä. Tutkielma koostuu kirjallisuuskatsauksesta ja alkuperäistutkimuksesta. Kirjallisuuskatsauksen tarkoituksen on esitellä Staphylococcus pseudintermedius ja Staphylococcus aureus -bakteerit sekä näiden metisilliiniresistentit kannat. Pääpaino on bakteerien ekologian ja epidemiologian kuvauksessa koirilla. Katsauksessa käsitellään myös MRSP- ja MRSA-tartuntojen torjuntaa sekä esitellään bakteerien diagnostiikkaa. Tutkielmaan sisältyvän tutkimuksen tarkoituksena oli kartoittaa MRSP- ja MRSA-bakteerien esiintyvyyttä Opaskoirakoulun koirilla sekä selvittää MRSP-tartunnan riskitekijöitä positiivisiksi todetuilla koirilla. Tutkittava populaatio koostui Opaskoirakoulun opas- ja siitoskoirista sekä koulutettavista koirista. Tutkimuksessa näytteitä kerättiin 124 Opaskoirakoulun koirasta, joista 48 oli oppaita, 8 siitoskoiria ja 68 koulutettavia koiria. Kahdella opas- ja kahdella siitoskoiralla todettiin MRSP-tartunta. Bakteerin esiintyvyydeksi Opaskoirakoulun koirapopulaatiossa arvioitiin 3 % (95 % luottamusväli: 1-5 %). MRSA-bakteeria ei todettu yhdelläkään koiralla (ylempi 95 % luottamusväli: 3 %). Todetut esiintyvyydet olivat odotettuja ja vastasivat aiemmissa tutkimuksessa todettuja esiintyvyyksiä koirilla. MRSP-riskitekijäanalyysissä eläinlääkärikäyntien lukumäärän ja antibioottikuurien lukumäärän edellisen 12 kk:n aikana todettiin olevan yhteydessä MRSP-tartuntaan. Tässä tutkimuksessa eristetyt neljä ja kolme aiemmin eristettyä MRSP-kantaa tyypitettiin käyttäen PFGE-, MLST- ja SCCmec-menetelmiä. Tässä tutkimuksessa eristetyistä kannoista kolme todettiin keskenään identtisiksi. Identtiset kannat olivat sekvenssityyppiä ST45, mutta kantojen SCCmec-tyyppiä ei kyetty määrittämään. Tämän tyyppistä kantaa on aiemmin eristetty Israelissa, Thaimaassa ja Hollannissa, joista Israelissa ja Thaimaassa tämä kanta on vallitseva kanta. Myös Suomessa on aiemmin eristetty tätä sekvenssityyppiä olevia kantoja. Neljäs muista eroava kanta kuului sekvenssityyppiin ST71 ja SCCmec-tyyppiin II-III. Tämä kanta on maailman ja Euroopan laajuisesti yleisin MRSP-kanta. Suomessa kannan on aiemmin todettu aiheuttaneen Yliopistollisessa pieneläinsairaalassa vuosien 2010-2012 aikana ilmenneen epidemian. Kolme Opaskoirakoulun koirilta aiemmin eristettyä MRSP-kantaa erosivat toisistaan ja tässä tutkimuksessa eristetyistä kannoista. Opaskoirakoulun koirilta eristettyjen MRSP-kantojen erilaisuus lukuun ottamatta kolmea identtistä kantaa viittaa siihen, että Opaskoirakoululla ei ole laajamittaista MRSP-epidemiaa ja että tartuntalähteitä on useita. Tässä tutkimuksessa edellä mainittuja tartuntalähteitä ei kyetty tunnistamaan. Tässä tutkimuksessa saatujen tulosten perusteella MRSP-tartuntariskiä Opaskoirakoulun koirilla voidaan pitää melko vähäisenä. Tällä hetkellä tartuntojen torjumiseksi riittävät normaalit varotoimet, joita ovat mm. hyvä käsihygienia ja tilojen sekä välineiden puhdistaminen ja desinfiointi käytön jälkeen. Opaskoirakoululla on jo nyt olemassa toimintamalleja, joilla tartuntoja pyritään ehkäisemään. Jatkossa tulee kuitenkin miettiä entistä tarkemmin tapoja erityisesti MRSP-tartuntojen torjumiseksi.
  • Grönthal, Thomas (2012)
    Metisilliiniresistentin Staphylococcus pseudintermedius -bakteerin (MRSP) leviäminen on 2000-luvulla yleistynyt ongelma pieneläinlääketieteessä. Se aiheuttaa ongelmia hankalahoitoisten infektioiden ja lisääntyneiden hoitokustannusten kautta. Bakteeri kykenee lisäksi aiheuttamaan sairaalaepidemioita. Sellainen koettiin Yliopistollisen eläinsairaalan Pieneläinsairaalassa vuosina 2010 – 2011. Tämän lisensiaatin tutkielma on kaksiosainen. Kirjallisuusosiossa annetaan tietoa MRSP:stä, sen kyvystä tulla resistentiksi tavallisimmille mikrobilääkkeille, sekä MRSP-infektion hoidosta. Tutkimusosiossa kuvaillaan Pieneläinsairaalan MRSP-epidemian vaiheet ja vastustustoimenpiteet, sekä selvitetään tartunnalle altistaneita tekijöitä tapaus-verrokkitutkimuksella. Marraskuussa 2010 Pieneläinsairaalassa tehtiin ensimmäinen moniresistentti MRSP-löydös. Tavattu kanta oli vastustuskykyinen erytromysiinille, klindamysiinille, sulfa-trimetopriimille, enrofloksasiinille, gentamisiinille, sekä kloramfenikolille. Kanta oli herkkä vain fusidiinihapolle ja amikasiinille. Seurantajakson (1.11.2010 – 31.10.2011) aikana epidemiakanta eristettiin kaikkiaan 55 potilaalta, joilta 24:llä MRSP löydettiin infektiopesäkkeestä. 15 tapauksessa kyseessä oli leikkaushaavainfektio. Loput löydökset (n=31) tehtiin seulontanäytteistä. Pieneläinsairaalan tapauskertymä osastopotilailla oli 2,2 % (55/2483). Riskitekijöiden selvittämistä varten kerättiin tiedot MRSP-tapauspotilaista, sekä 213 kontrollipotilaasta, joilta oli otettu MRSP-negatiivinen seulontanäyte seurantajakson aikana. Tutkitut muuttujat liittyivät potilaan seurantajakson aikana saamaan lääkehoitoon, potilaalle tehtyihin toimenpiteisiin, sekä potilaan käynteihin eri osastoilla. Tilastollisesti merkittäviä, MRSP-kantajuudelle tai infektiolle altistavia tekijöitä, olivat ihorikko (OR 12,9; p: <0,0001), kirurginen toimenpide (OR 9,8, p: <0,0001), mikrobilääketerapia (OR 11,1; p: <0,0001), sekä teho-osastohoito (OR 2,0; p: 0,036). Se oliko kirurginen toimenpide ortopedinen vai ei (OR 1,8; p: 0,13), tai oliko se tehty päivystyskirurgiana (OR 1,0; p: 1,0) ei ollut tilastollisesti merkittävä tekijä. Mahahapposalpaajahoito ei altistanut tartunnalle (OR 1,6; p: 0,15). Tulokset ovat alustavia ja niistä suoritetaan vielä lisätutkimuksia sekoittavien tekijöiden hallitsemiseksi. Pieneläinsairaalassa tehtiin epidemia-aikana mittavia vastustustoimenpiteitä. Riskipotilaita seulottiin aktiivisella näytteenotolla ja Pieneläinsairaalaan perustettiin kohorttiosasto tunnettujen kantajapotilaiden hoitoa varten. Sairaala jaettiin lisäksi eri alueisiin joihin eri riskiluokan potilaat ohjattiin. Sairaalassa otettiin myös lukuisia ympäristönäytteitä. Vastustustoimilla uusien tautitapausten esiintyminen väheni. Helmikuussa 2012 tilanne näyttää rauhoittuneen. Saadut tulokset tukevat ja täydentävät aiempia tutkimuksia, ja antavat lisätietoa riskipotilaiden tunnistamisen helpottamiseksi. Vaikka lisää tutkimuksia riskitekijöistä vielä tarvitaan, niiden tunteminen mahdollistaa torjuntakeinojen oikean kohdentamisen ja epidemiapurkausten ehkäisemisen.
  • Haara, Heikki (2008)
    Syyskuun yhdennentoista terrori-iskujen jälkeinen poikkeusaika mahdollisti presidentti Bushin toimille suuren poliittisen tilan ja tilaisuuden edistää paitsi ulkomaisia myös kotimaisia poliittisia tavoitteitaan. Iskujen jälkeen presidentti Bush määritteli, mistä konfliktissa on kyse, kuka on vihollinen ja keitä ”me” olemme. Kansallisen kriisin aikana ehdottoman poliittisen auktoriteetin, presidentin, verbaaliset teot antoivat suunnan ja merkityksen konkreettisimmille toimille. Bushin puheissa nykyisyys kytkettiin paitsi menneisyyteen myös tulevaisuuteen. Tutkielmassa analysoidaan, miten Bush antoi menneisyydelle merkityksiä poliittisessa retoriikassaan ajanjaksolla syyskuun yhdennentoista terrori-iskuista Irakin sotaan. Tutkielmassa analysoidaan Bushin retoriikkaan niin eksplisiittisesti kuin implisiittisesti sisältyvää historiallista tietoa ja pohditaan, mitä Bushin käyttämät erilaiset historialliset konstruktiot olivat ”tekemässä”. Presidentti Bushin pitämien poliittisten puheiden tarkoitus oli saada kuulijat tukemaan hänen esittämiään argumentteja. Bushin tuli legitimoida toimensa paitsi Yhdysvaltojen kansalaisille ja kongressille myös kansainväliselle yleisölle. Argumentaation tutkiminen on tutkielmassa keskeistä, mutta siinä ei rajata poliittisen toiminnan kielellistä aspektia pelkästään argumentaatioon, vaan Bushin esittämistä ”teksteistä” luetaan esiin myös puhujan välittömistä tarkoituksista riippumattomia poliittisia aspekteja. Bush esitti retoriikassa historian omalakisena prosessina. Hänen oli mahdollista määritellä nykyisyyden ja tulevaisuuden toimintaa, koska historian suunta ja sitä ohjaavat lainalaisuudet esitettiin annettuina. Samalla historia tarjosi Bushille loputtoman varaston muuntautumiskykyisiä menneisyysresursseja, joiden avulla omaa toimintaa voitiin legitimoida. Erityisesti monet historialliset metaforat olivat Bushin retoriikassa voimakkaasti todellisuutta muokkaavia retorisia välineitä. Tutkielmasta käy ilmi, että menneisyyden merkitykset olivat presidentti Bushille poliittisen toiminnan resurssi, jonka avulla omaa toimintaa voitiin oikeuttaa. Samaan aikaan menneisyyden merkitykset myös muovasit toimijuutta itseään, kun Bush esitti tietyt toimenpiteet välttämättömyyksinä, vahvimmillaan historiallisena velvollisuutena. Presidentti Bushin tavassa esittää tiettyjä toimenpiteitä välttämättömyyksinä, jopa historiallisina velvollisuuksina, oli kyse vallasta suunnata poliittista ja sosiaalista toimintaa sekä asettaa sen rajoja. Bushin tapa määrittää menneisyyden, nykyisyyden ja tulevaisuuden välistä yhteyttä voidaan ymmärtää vallan hegemonisena muotona, joka toimii merkitysten, kulttuurin ja tiedon tuottamisen kautta. Tutkielman lopuksi pohditaan, kuinka politisoimalla poliittisten auktoriteettien esittämiä menneisyyden merkityksiä on mahdollista pyrkiä avaamaan vaihtoehtoisen toimijuuden mahdollisuuksia. Tutkielman alkuperäislähteinä ovat presidentti Bushin julkiset esiintymiset ja puheet syyskuun yhdennentoista terrori-iskuista Irakin sodan alkuun sekä lokakuussa 2002 ilmestynyt Yhdysvaltojen kansallinen turvallisuusstrategia.
  • Ahlsten, Katja; Järvimaa, Taru (1995)
    Syventävät opinnot sisältävät kirjallisuuskatsauksen ja tutkimusosan. Kirjallisuuskatsauksessa käsitellään pahoinvoinnin ja oksentamisen patofysiologiaa koiralla ja antiemeettisiä lääkeaineita. Lääkeaineissa on keskitytty Suomessa saatavilla oleviin valmisteisiin. Tutkimusosa koostuu röntgentutkimuksesta ja imeytymiskokeesta. Röntgentutkimuksella selvitettiin hydroksipropyylimetyyliselluloosatabletin (HPMC) käyttäytymistä koiran mahalaukussa seuraamalla varjoaineella merkityn tabletin kulkeutumista beaglekoirien ruoansulatuskanavassa. Tutkimuksessa oli mukana kaksi tablettivalmistetta, jotka poikkesivat toisistaan kaliumkarbonaatin osalta. Tutkimuksessa ei saatu tilastollisesti merkitseviä eroja tabletin mahalaukussa viipymisen suhteen eri tablettivalmisteita vertailtaessa ruoan kanssa tai ilman ruokaa annosteltuna. Imeytymiskokeessa etsittiin vastausta siihen, onko HPMC-tabletti käyttökelpoinen hitaasti metoklopramidia vapauttavana valmisteena koiralla ja onko kaliumkarbonaattilisällä vaikutusta metoklopramidin imeytymiseen. Tilastollisesti merkitseviä eroja koevalmisteiden ja vertailuvalmisteena olleen kaupallisen valmisteen välille imeytymistä kuvaavien parametrien suhteen ei saatu mm. tulosten suuren hajonnan vuoksi, mutta HPMC:n todettiin hidastavan metoklopramidin imeytymistä. Kaliumkarbonaattilisän ei voitu osoittaa hidastavan lääkeaineen imeytymistä, koska sen havaittiin pikemminkin estävän lääkeaineen vapautumista valmisteesta.
  • Tiilikainen, Toni-Petri (2012)
    Gradussa käsitellään jatkuvia logiikoita, joissa pääasiallisesti paneudutaan kompaktisuuslauseeseen, konnektiiveihin ja kvanttorien eliminointiin. Kompaktisuutta varten käydään läpi ultrafilttereitä käsitteleviä tuloksia. Vuorostaan kvanttorien eliminointia varten todistetaan tuloksia monsterimallien olemassa olosta. Lopussa annetaan vielä lyhyesti esimerkki kvanttorien eliminoinnista Hilbertin avaruuksissa.