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  • Pusa, Taneli (2015)
    The objective of this work is to generalize the pseudolikelihood-based inference method from ordinary Markov networks to an extension of the model containing context-specific independencies: the labelled graphical model. Probabilistic graphical models like the Markov and Bayes networks are used to represent the dependence structure of multivariate probability distributions. Machine learning methodology can then be used to learn these dependence structures from sample data. The Markov network is a model, which assigns no directionality to interactions between variables: the probability distribution is represented by an undirected graph, where nodes correspond to variables and edges to direct interactions. A labelled graphical model extends this idea by assigning labels to edges to represent contexts, i.e outcomes of other variables in the distribution, in which the associated variables are independent. Bayesian inference can be used to learn the dependence structure of a set of variables using data. The standard procedure is to consider the posterior probability of a model given the data and aim to maximize this score. This involves explicitly calculating the marginal likelihood of the model. In the case of Markov networks and consequently labelled models, this can not be done analytically and approximation methods must be used. Pseudolikelihood is one such method, which allows for both the analytical calculation of the so-called marginal pseudolikehood replacing the actual marginal likelihood of a model and the computationally very advantageous property of a node-wise factorizable score-function. This thesis presents the general theory behind the labelled graphical models and the basics of Bayesian inference. The pseudolikelihood approximation is introduced and applied to labelled models and the consistency of the score is proved. Lastly a greedy hill climb -algorithm is used to demonstrate the inference in practice by a synthetic and a real data example.
  • Aarnio, P. (1934)
  • Niemi, Irmeli (1960)
  • Saarinen, Sirkka (1991)
  • Marin 
    Ojala, Enne-Liisa (1989)
  • Moisio, Arto (1989)
  • Särkilahti, Sirkka-Liisa (1969)
  • Oksanen, Katri Inkeri (1931)
  • Aalto, Hannele (Helsingin yliopisto, 2007)
    Sepsis is associated with a systemic inflammatory response. It is characterised by an early proinflammatory response and followed by a state of immunosuppression. In order to improve the outcome of patients with infection and sepsis, novel therapies that influence the systemic inflammatory response are being developed and utilised. Thus, an accurate and early diagnosis of infection and evaluation of immune state are crucial. In this thesis, various markers of systemic inflammation were studied with respect to enhancing the diagnostics of infection and of predicting outcome in patients with suspected community-acquired infection. A total of 1092 acutely ill patients admitted to a university hospital medical emergency department were evaluated, and 531 patients with a suspicion of community-acquired infection were included for the analysis. Markers of systemic inflammation were determined from a blood sample obtained simultaneously with a blood culture sample on admission to hospital. Levels of phagocyte CD11b/CD18 and CD14 expression were measured by whole blood flow cytometry. Concentrations of soluble CD14, interleukin (IL)-8, and soluble IL-2 receptor α (sIL-2Rα) were determined by ELISA, those of sIL-2R, IL-6, and IL-8 by a chemiluminescent immunoassay, that of procalcitonin by immunoluminometric assay, and that of C-reactive protein by immunoturbidimetric assay. Clinical data were collected retrospectively from the medical records. No marker of systemic inflammation, neither CRP, PCT, IL-6, IL-8, nor sIL-2R predicted bacteraemia better than did the clinical signs of infection, i.e., the presence of infectious focus or fever or both. IL-6 and PCT had the highest positive likelihood ratios to identify patients with hidden community-acquired infection. However, the use of a single marker failed to detect all patients with infection. A combination of markers including a fast-responding reactant (CD11b expression), a later-peaking reactant (CRP), and a reactant originating from inflamed tissues (IL-8) detected all patients with infection. The majority of patients (86.5%) with possible but not verified infection showed levels exceeding at least one cut-off limit of combination, supporting the view that infection was the cause of their acute illness. The 28-day mortality of patients with community-acquired infection was low (3.4%). On admission to hospital, the low expression of cell-associated lipopolysaccharide receptor CD14 (mCD14) was predictive for 28-day mortality. In the patients with severe forms of community-acquired infection, namely pneumonia and sepsis, high levels of soluble CD14 alone did not predict mortality, but a high sCD14 level measured simultaneously with a low mCD14 raised the possibility of poor prognosis. In conclusion, to further enhance the diagnostics of hidden community-acquired infection, a combination of inflammatory markers is useful; 28-day mortality is associated with low levels of mCD14 expression at an early phase of the disease.
  • Hofmeister, Marika (1999)
    This thesis studies the urban experience of Malian market women. The aim is to show how these women, despite their poverty, are able to negotiate a social position for themselves in the urban structure. The practices used by marketers is examined, as well as the time and energy spent in order to assure the mastery of their urban situation. Social relations are extremely important in Mali and especially in Bamako where the living conditions are hard. Having relations helps a person in all situations of daily life. A wide social network will make it easier to obtain for example an employment, an important paper, child minding, a train ticket free of charge, a place on the market, goods on credit, water from the pump, a clientele, or simply food for the day. It is therefore very important to hold a large capital of family-, friendship-, neighbourly-, and/or professional relations and market women are constantly struggling to establish and maintain social relations. This study, based on fieldwork, shows that market women invest a large part of the money they earn from the marketplace in their social relations. The theoretical framework in this study is based on Pierre Bourdieu's analyse in terms of capitals and is used in order to show how women, by generously converting economic capital into social capital, accumulate symbolic capital in the form of bonya; prestige, social recognition, respectability, reputation and honour. This is done mainly through ceremonial events like marriages and baptisms, where the important gifts-givings take place. The fundamental Bamana notion of bonya runs throughout the entire work. In order to understand how this concept is linked to hierarchy and in what way it is structuring the entire society, the initial part of this study provides a thorough description of the caste system in Mali which still divides society into categories of unequal status. Apart from their trading activities, the family position of market women is discussed as well. Attention is given to how market women constantly negotiate their position on the one hand as traders and on the other as "proper" wives and "good" mothers. The primary source of data for this study is fieldwork carried out during four months in Bamako, the capital of Mali. The methods used include participant observation and interviews with 22 women, of which 19 were vendors, and with 5 men. Main references are: Bourdieu, P.; Clark, G.; Camara, S.; Godelier, M.; Weiner, A.
  • Herler, Casper (Talentum Media Oy, 2008)
    Väitöskirja käsittelee maaperän ja pohjaveden pilaantumisen ympäristöoikeudellista ennallistamisvastuuta. Nykyinen ympäristöoikeudellinen lainsäädäntö sisältää erilliset pilaamiskiellot maaperän ja pohjaveden osalta. Mikäli näitä kieltoja on rikottu, voi ympäristöviranomainen kohdistaa pilaajaan tai nykyiseen alueen haltijaan vaatimuksia alueen pilaantuneisuuden selvittämiseksi ja kunnostamiseksi. Aikaisemmin kyseisen kaltaisia nimenomaisia pilaamiskieltoja ja vastuusäännöksiä ei ole sisältynyt lainsäädäntöön. Maaperän ja pohjaveden pilaantumisen ilmetessä tavanomaisesti viiveellä, on pilaava toiminta usein ehtinyt joko päättyä tai sitä on ehditty harjoittaa jo pidemmän aikaa ennen kuin kunnostustarve ajankohtaistuu. Kunnostuskustannusten ollessa määriltään yleensä huomattavat, on huomio kohdistunut siihen millä edellytyksin vastuulainsäädäntöä vanhemmissa pilaantumistapauksissa voidaan asettaa taannehtivasti, eli toisin sanoen pilaantumisen jälkeen. Tämä on yksi väitöskirjan keskeisistä tutkimuskysymyksistä. Väitöskirjassa on tutkittu historiallisesti sitä, mitä aikaisemmin tiedettiin maaperän ja pohjaveden pilaantumisesta sekä minkälaista varhaista lainsäädäntöä tätä pilaantumista koskien aikaisemmin on ollut olemassa. Lisäksi kirjassa arvioidaan millaista painoarvoa voidaan tälle aikaisemmalle tiedolle ja lainsäädännölle antaa, kun nykyisin arvioidaan pilaajan vastuuta pilaantumisesta. Yhtenä osana tätä tutkimustehtävää kirjassa analysoidaan taannehtivuuskiellon ulottuvuutta rikosoikeudessa, siviilioikeudessa, vero-oikeudessa ja ympäristöoikeudessa. Tältä osin väitöskirjassa todetaan, että taannehtivalle lainsäädännölle ei rikosoikeuden ulkopuolella ole ehdotonta kieltoa. Sen sijaan muilla oikeudenaloilla kyse on periaatteesta, jonka punninnassa tulee huomioida yhtäältä vastuullisen luottamuksensuoja aikaisempaan tilanteeseen ja toisaalta vastuuta puoltavat seikat. Tutkimuksessa selvitetään myös seikkaperäisesti maaperän, pohjaveden ja rakennusten pilaantumista koskevaa lainsäädäntöä ja oikeuskäytäntöä. Yksi johtopäätöksistä on, että vuonna 1993 kumotun jätehuoltolain merkitystä vastuuperusteena vanhoissa pilaantumistapauksissa on ylikorostettu. Väitöskirjan jälkimmäisessä osassa arvioidaan mahdollisuutta kohtuullistaa kohtuutonta kunnostusvastuuta. Suomalaisessa julkisoikeudessa ei ole yleistä periaatetta julkisoikeudellisten velvollisuuksien kohtuullistamisesta subjektiivisesti, eli yksilön näkökulmasta katsottuna kohtuuttomien olosuhteiden vallitessa. Väitöskirjassa väitetään, että niin nykyisen alueen haltijan kuin pilaajankin vastuuta voidaan kohtuullistaa tiettyjen edellytysten vallitessa. Kohtuullistamismahdollisuuden arvioinnille on väitöskirjassa esitetty viisi arviointikriteeriä. Kriteerien soveltaminen on olennaisesti sidoksissa tilanteen kokonaisharkintaan. Kohtuullistamisen luonne on näkökohta, joka ei ole saanut suurempaa huomiota maaperän pilaantumisen vastuukysymyksiä koskevassa keskustelussa. Kohtuullistaminen merkitsee myös julkisoikeudellisessa asiayhteydessä sitä, ettei vastuuta tarvitse määrittää – joko tai – vaan se voidaan kohtuullistaa tietyksi – kohtuulliseksi – osaksi alkuperäisestä.
  • Leskelä, Ari (Helsingin yliopisto, 2006)
    Anadromous whitefish is one of the most important fish species in the Finnish coastal fisheries in the Gulf fo Bothnia. To compensate the lost reproduction due to river damming and to support the fisheries, several million one-summer old whitefish are released yearly into the Gulf of Bothnia. Since there are naturally reproducing whitefish in the Gulf as well, and the wild and stocked fish can not be separated in the catch, stocking impact can only be estimated by marking the stocked fish. Due to the small size and large number of released whitefish, the scattered fishery and large area where the whitefish migrate, most of the traditionally used fish marking methods were either unsuitable (e.g. Carlin-tags) or proved to be too expensive (e.g. coded wire tags). Fluorescent pigment spraying method offers a fast and cost-effective method to mass-mark young fish. However, the results are not always satisfactory due to low long-time retention of the marks in some species. The method has to be tested and proper marking conditions and methods determined for each species. This thesis is based on work that was accomplished while developing the fluorescent pigment spraying method for marking one-summer old whitefish fingerlings, and it draws together the results of mass-marking whitefish fingerlings that were released in the Gulf of Bothnia. Fluorescent pigment spraying method is suitable for one-summer old whitefish larger than 8 cm total length. The water temperature during the marking should not exceed 10o C. Suitable spraying pressure is 6 bars measured in the compressor outlet, and the distance of the spraying gun nozzle should be ca 20 cm from the fish. Under such conditions, the marking results in long-term retention of the mark with low or no mortality. The stress level of the fish (measured as muscle water content) rises during the marking procedure, but if the fish are allowed to recover after marking, the overall stress level remains within the limits observed in normal fish handling during the capture-loading-transport-stocking procedure. The marked whitefish fingerlings are released into the sea at larger size and later in the season than the wild whitefish. However, the stocked individuals migrate to the southern feeding grounds in a similar pattern to the wild ones. The catch produced by whitefish stocking in the Gulf of Bothnia varied between released fingerling groups, but was within the limits reported elsewhere in Finland. The releases in the southern Bothnian Bay resulted in a larger catch than those made in the northern Bothnian Bay. The size of the released fingerlings seemed to have some effect on survival of the fish during the first winter in the sea. However, when the different marking groups were compared, the mean fingerling size was not related to stocking success.