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  • Bredbacka, Patrik (2015)
    Bosniassa käytiin vuosina 1992–1995 sota, joka päättyi sen osapuolien Bosnian serbien, muslimien ja kroaattien väliseen rauhaan ja yhteisen Bosnia-Hertsegovinan valtion muodostamiseen. Aseellisten konfliktien uusiutumattomuus sodanjälkeisessä Bosnissa antaa viitteitä siitä, että sotaan osallistuneet osapuolet ovat onnistuneet käsittelemään sodan tapahtumia siten, että keskinäinen yhteiselo samassa valtiossa on mahdollista. Tässä tutkielmassa analysoidaan Bosnian sodanjälkeistä kehitystä sovinnon käsitteen kautta. Työn tarkoituksena on 1) muotoilla hahmotelma Bosnian kohdalla toimivasta yhteiskunnallisen sovinnon määritelmästä, 2) tutkia, millaisin keinoin sovintoa on Bosniassa tavoiteltu, sekä näiden sovintokeinojen valossa 3) tutkia, millainen arvo sovinnolle on Bosniassa annettu ja toisaalta perustella sovinnon merkitystä Bosnialle. Työ alkaa lyhyellä Bosnian sotaa ja maan sodanjälkeistä kehitystä esittelevällä luvulla. Luku 2.1 antaa viitteitä siitä, että Bosniassa vuonna 1995 käyttöönotettu poliittisiin kiintiöihin ja etnisiin jakoihin perustuva hallintojärjestelmä on aiheuttanut valtiolle mittavia kustannuksia ja toiminnallisia hidasteita. Luku 3 käsittelee työn keskeistä aihetta sovintoa ensin yleisesti ja sitten tarkemmin Bosnian kohdalla. Sovinto on moniulotteinen ja monipuolinen käsite, jolle ei ole onnistuttu luomaan yleispätevää määritelmää. Sovintoa koskevan keskeisen kirjallisuuden pohjalta luvussa 3.1 luodaan hahmotelma Bosnian kannalta realistisesta, hyödyllisestä ja syvällisestä sovinnon määritelmästä. Bosniassa sovinnon kannalta keskeisimmiksi keinoiksi määritellään oikeus, hallinnon politiikka ja anteeksiannon politiikka, joita tutkitaan luvuissa 4-6 niin yleisellä kuin Bosnian tasolla. Keskeisten aihepiiriensä sovinnon, anteeksiannon politiikan, oikeuden ja hallinnon politiikan välisen keskinäispoikkeavan mutta Bosnian tapauksessa vuorovaikutteisen olemuksen vuoksi työ ei sisällä tarkkarajaista metodologiaa, vaan pyrkii tutkimaan aiheiden välisiä ilmenemistapoja ja suhteita lavea-alaisten vaikutussuhteiden löytämiseksi. Tutkielmassa päädytään tulokseen, ettei Bosniassa ole aikaansaatu syvällistä sovintoa, vaan ennemmin kylmää rauhaa muistuttava tila, jossa etniset eroavaisuudet ovat edelleen keskeisiä yhteiskunnallisissa suhteissa. Oikeus ja hallinnon politiikka ovat muodostuneet Bosniassa keskeisiksi sovintokeinoiksi, mutta ne eivät ole kyenneet aikaansaamaan syvällistä sovintoa vaan ennemminkin vain ylläpitämään tai jopa kasvattamaan Bosnian etnisiä jännitteitä, jotka haittaavat valtion toimintaa ja ihmisryhmien välisiä suhteita. Sen sijaan anteeksiannon politiikka on jäänyt Bosniassa vähälle käytölle, mutta teoreettiset näkemykset ja empiiriset kokemukset anteeksiannon politiikasta muissa konfliktinjälkeisissä yhteiskunnissa antavat viitteitä sen mahdollisuudesta myös bosnialaisen sovinnon syventämiseen. Työn viimeisessä, seitsemännessä luvussa esitellään keinoja toteuttaa anteeksiannon politiikkaa Bosniassa, laventaa Bosniassa käytettyjä hallinnon politiikan ja oikeuden muotoja ja pohditaan sitä, miten syvällisemmän sovinnon tarpeen ymmärrys on keskeinen vaikutin siihen, millaisia painoarvoja sovinnolle päämääränä annetaan.
  • Österberg-Englund, Lotta Marie (2006)
    Avsikten med denna avhandling är att undersöka bilden av bostadslösheten i finländsk press, närmare bestämt den bild som förmedlas av de två morgontidningarna Helsingin Sanomat och Hufvudstadsbladet. Undersökningen utgår från att tidningarnas rapportering är en av många faktorer som påverkar vår uppfattning och vår bild av det samhälle vi lever i. Avhandlingen kritiserar myterna om bostadslösheten som självvald eller enbart självförvållad och visar på hur strukturella faktorer ofta utgör den grundläggande orsaken till bostadslösheten. I avhandlingen diskuteras också hur vår bild av bostadslösheten påverkar arbetet för att minska densamma. Bilden kan antas påverka såväl politiska beslut som den enskilde myndighetspersonens, till exempel socialarbetarens, handlande. Miss­upp­fatt­ningar och felaktiga antaganden kan därför få ödesdigra följder. Den empiriska analysen bygger på de artiklar om bostadslöshet som publicerats i Helsingin Sanomat och Hufvudstadsbladet mellan åren 1990 och 2001. Undersökningen visar på en stor bredd i tidningarnas rapportering. Båda tidningarna ger också såväl strukturella som individcentrerade förklaringar till bostadslösheten. Fördelningen mellan strukturell respektive individcentrerad problembild är ganska jämn om man ser till antalet artiklar. Däremot syns en skillnad i den grafiska utformningen av de olika artiklarna. Artiklar med individcentrerad problembild får ofta mera utrymme, innehåller fler bilder och ser rent layoutmässigt mera "spännande" ut än artiklar som behandlar bostadslösheten ur ett mera samhällsinriktat perspektiv. Det är alltså möjligt att en läsare som inte är specifikt intresserad av ämnet i högre grad väljer att läsa artiklarna med individcentrerade problembilder. I förlängningen kan det betyda att medelläsarens bild av bostadslösheten snedvrids och att de individcentrerade faktorerna lyfts i förgrunden, medan de strukturella faktorerna hamnar i skymundan. Den empiriska delen omfattar också en genomgång av vem det är som får komma till tals i tidningarna och ge sin syn på bostadslösheten. Det visar sig att bostadslösa och statliga och kommunala tjänstemän är de som oftast kommer till tals. Däremot lyser politikerna med sin frånvaro, vilket är en tydlig skillnad mot resultaten av en liknande undersökning av pressens rapportering kring välfärdsservicen i allmänhet.
  • Virokannas, Elina (2004)
    The research considers stories of clients of a drug treatment unit for young people and children. The study focuses the construction of young peoples` identities in the speech in which they locate their lives and give significance to their use of drugs in their relationships with society, family, friends and authorities. In line with the constructionist view, identity is here understood in terms of self-constructions created in situations of interaction. The methods of discourse analysis are used to study excerpts of talk. The research material comprises 17 individual interviews of clients aged 14 to 18. Cannabis was the most common drug interviewed young people had used but everybody had also used medicines, opiates or amphetamine or both. Nine of the interviewed were girls and eight were boys. The stories of young clients are studied through different themes in five different articles. These considers the meanings of normal, information production and suprise turns of events in the interviews, drug screening tests and the treatment careers of young drug addicts, peer-relationships and experiences with the authorities. In the summary it is considered the kind of main meanings and identities which were common in all or at least several themes. The interviewed clients defined their life-experiences and drug using against the kind of lines between normal life and being outside. Drug using was situated in the outside world and not-using inside of the normal life. The interviewed clients identified themselves on the both sides of these lines. Their speaker positions varied partly according whether they spoke about their life in past, present or future terms. At the conclusion two kinds of different dimensions of diverse identities are described. There can be found a speaker who is conscious about his or hers deviance and on the contrast a speaker who has already started to live ”normal” life. On the other hand young clients defined their life actions as subordinated to other people or events and as opposite they emphasized their own autonomy. In addition loneliness and the lack of allies were also emphasized in the talk of interviewed clients. Constructionist research of identity, discourse analytical research of interaction and qualitative drug research have been used as the main sources of information.
  • Ronimus, Tomi (2013)
    Botnets have proven to be consistent nuisance on the Internet. They are the cause for many security concerns and issues that plague the Internet currently. Mitigating these issues is an important task and more research is needed in order to win the battle against constantly evolving botnets. In this thesis, botnets are reviewed thoroughly, starting from what botnets are and how do they manage to stay operational and then moving on to explore some of the more promising methods that can be used to detect botnet activity. A more detailed look is performed on DNS-based botnet detection methods as these methods show great promise and are very capable of detecting many different types of botnets. Finally, a review on the DNS-based botnet detection methods is compiled. Some of the best features of botnet detection are gathered to form an overall picture of what are the characteristics of a good detection method. As botnets evolve over time, botnet detection methods need to keep up with the progress. Gathering characteristics of a good detection method will help to suggest
  • Suominen, Kalle (2013)
    Business and operational environments are becoming more and more frenetic, forcing companies and organizations to respond to changes faster. This trend reflects to software development as well, IT units have to deliver needed features faster in order to bring business benefits quicker. During the last decade, agile methodologies have provided tools to answer to this ever-growing demand. Scrum is one of the agile methodologies and it is widely used. It is said that in large-scale organizations Scrum implementation should be done using both bottom-up and top-down approaches. In big organizations software systems are complicated and deeply integrated with each other meaning that no one team can handle whole software development processes alone. Individual teams want to start to use Scrum before whole organization is ready to support it. This leads to a situation where one team is applying agile principles while most of the other teams and organizations around are continuing with old established non-agile practices. In these cases bottom-up approach is the only option. When the top-down part is missing, are the benefits also lost? In this case study, the target is to find out, did it bring benefits when implementing Scrum using only bottom-up approach. In the target unit, which was part of the large organization, Scrum based practices were implemented to replace earlier waterfall based approach. Analyses for the study were made on data, which was collected by survey and from a requirement management tool. This tool was in use during the old and new ways of working. Expression Scrum based practices are used because all of the fine flavours of Scrum could not be able to be implemented because of surrounded non-agile teams and official non-agile procedures. This was also an obstacle when trying to implement Scrum as well as it could be possible. Most of the defined targets given to the implementation of Scrum based practices were achieved and other non-targeted benefit came out. In this context we can conclude that benefits were gained. The top-down approach absence clearly made the implementation more difficult and incomplete; however, it didn’t prevent to get benefits. The target unit also faced earlier mentioned difficulties in using Scrum based practices while other units around used non-agile processes. The lack of good established numerical estimations of requirements’ business values lowered the power of the Scrum on a company level, because these values were relative and subjective opinions of the business representatives, In the backlog prioritization, when most of the items are so called high priority ones there is no way to evaluate which one is more valuable and prioritization is more or less a lottery
  • Kerosuo, Hannele (Helsingin yliopisto, 2006)
    This study examines boundaries in health care organizations. Boundaries are sometimes considered things to be avoided in everyday living. This study suggests that boundaries can be important temporally and spatially emerging locations of development, learning, and change in inter-organizational activity. Boundaries can act as mediators of cultural and social formations and practices. The data of the study was gathered in an intervention project during the years 2000-2002 in Helsinki in which the care of 26 patients with multiple and chronic illnesses was improved. The project used the Change Laboratory method that represents a research assisted method for developing work. The research questions of the study are: (1) What are the boundary dynamics of development, learning, and change in health care for patients with multiple and chronic illnesses? (2) How do individual patients experience boundaries in their health care? (3) How are the boundaries of health care constructed and reconstructed in social interaction? (4) What are the dynamics of boundary crossing in the experimentation with the new tools and new practice? The methodology of the study, the ethnography of the multi-organizational field of activity, draws on cultural-historical activity theory and anthropological methods. The ethnographic fieldwork involves multiple research techniques and a collaborative strategy for raising research data. The data of this study consists of observations, interviews, transcribed intervention sessions, and patients' health documents. According to the findings, the care of patients with multiple and chronic illnesses emerges as fragmented by divisions of a patient and professionals, specialties of medicine and levels of health care organization. These boundaries have a historical origin in the Finnish health care system. As an implication of these boundaries, patients frequently experience uncertainty and neglect in their care. However, the boundaries of a single patient were transformed in the Change Laboratory discussions among patients, professionals and researchers. In these discussions, the questioning of the prevailing boundaries was triggered by the observation of gaps in inter-organizational care. Transformation of the prevailing boundaries was achieved in implementation of the collaborative care agreement tool and the practice of negotiated care. However, the new tool and practice did not expand into general use during the project. The study identifies two complementary models for the development of health care organization in Finland. The 'care package model', which is based on productivity and process models adopted from engineering and the 'model of negotiated care', which is based on co-configuration and the public good.
  • Ekholm, Laura Katarina (Helsingin yliopisto, 2013)
    The aim of this study is to analyze how ethnic-boundary drawing has been influenced in the urban context by the turbulent events of twentieth-century Europe. The analysis is specifically applied to the social boundaries of the small Helsinki Jewish community from the early twentieth century until the 1970s. In the period covered by this research, Helsinki evolved from a multilingual and heterogeneous military town of the Russian empire into the capital of an independent nation. As one of the few Eastern European Orthodox Jewish communities not destroyed in the Holocaust, the history of the Helsinki Jewish community offers a different set of spatial contexts that make this history an empirical case study of changing ethnic relations from one generation to another. My study suggests that empirical materials can be used as clues for teasing into existence the long-vanished practices of boundary-drawing done at various times in the past. Collecting and organizing information in archives is always guided by decisions that reflect the contemporary ideas of relevant and meaningful social categories. Consequently, as Jews in Finland became Finnish Jews, the ethnic background subsequently lost its distinction in the archival material; in short, the sources gradually became mute in this respect. My research strategy is to focus on questions concerning the economic aspects of social boundaries, for example, whether the members of the Helsinki Jewish congregation were entrepreneurs or were self-employed. I have operationalized occupational status to analyze changes in the social position of the community. The occupational titles were collected from three different cross-section years and organized by using a Historical International Classification of Occupations (HISCO) Scheme. By combining the occupational titles with the data on the Jewish-owned companies, I have established a set of descriptive statistics. Supported by the findings of this empirical material, my study analyzes how the concept of Finnish Jews has taken shape over the entire period of this study. Contemporaries writing about the Jews of Finland did not use concepts of ethnic boundaries, but nevertheless considered questions related to economic aspects as the key elements in modern societies. Such questions were a constant theme in modern economic antisemitism with a major influence on Jewish policies, such as the restriction of Jewish occupations in Finland until 1918, which in turn influenced the (counter-)narratives of Jewish business. This is what makes the Jewish occupations so interesting and also makes discussing them such a sensitive issue. The community is an important part of the history of Helsinki, but it has only been accepted as a part of the larger Finnish society since the Second World War. During this process, Jews were clearly less frequently categorized as Jews and more frequently categorized by the professions they represented. In this study I have contextualized different aspects of what has been selected and written down as Finnish-Jewish history. This involves discovering the political positions of its various authors. All histories on the Finnish Jews have been written during the post-Second World War period and, in consequence, are unavoidably viewed through post-Shoah/Cold War lenses. In these writings, the national and transnational aspects are totally severed and become, indeed, mutually exclusive. The Jewish history of Helsinki is often told as a collective story, where each generation faces similar challenges and options. In this way, the past has been described as a joint striving for all Finnish Jews. In reality, wide economic differences have played an important role in what is ultimately a business-oriented community. In this narrative, the Jewish history has been reduced to a bare minimum in order to serve as a collective story. Consequently, in the histories of the city of Helsinki, Jews have either been described as poor, or they have not been remembered at all.
  • Chousionis, Vasileios (Helsingin yliopisto, 2008)
    The topic of this dissertation lies in the intersection of harmonic analysis and fractal geometry. We particulary consider singular integrals in Euclidean spaces with respect to general measures, and we study how the geometric structure of the measures affects certain analytic properties of the operators. The thesis consists of three research articles and an overview. In the first article we construct singular integral operators on lower dimensional Sierpinski gaskets associated with homogeneous Calderón-Zygmund kernels. While these operators are bounded their principal values fail to exist almost everywhere. Conformal iterated function systems generate a broad range of fractal sets. In the second article we prove that many of these limit sets are porous in a very strong sense, by showing that they contain holes spread in every direction. In the following we connect these results with singular integrals. We exploit the fractal structure of these limit sets, in order to establish that singular integrals associated with very general kernels converge weakly. Boundedness questions consist a central topic of investigation in the theory of singular integrals. In the third article we study singular integrals of different measures. We prove a very general boundedness result in the case where the two underlying measures are separated by a Lipshitz graph. As a consequence we show that a certain weak convergence holds for a large class of singular integrals.
  • Vähäkangas, Antti (Helsingin yliopisto, 2009)
    The monograph dissertation deals with kernel integral operators and their mapping properties on Euclidean domains. The associated kernels are weakly singular and examples of such are given by Green functions of certain elliptic partial differential equations. It is well known that mapping properties of the corresponding Green operators can be used to deduce a priori estimates for the solutions of these equations. In the dissertation, natural size- and cancellation conditions are quantified for kernels defined in domains. These kernels induce integral operators which are then composed with any partial differential operator of prescribed order, depending on the size of the kernel. The main object of study in this dissertation being the boundedness properties of such compositions, the main result is the characterization of their Lp-boundedness on suitably regular domains. In case the aforementioned kernels are defined in the whole Euclidean space, their partial derivatives of prescribed order turn out to be so called standard kernels that arise in connection with singular integral operators. The Lp-boundedness of singular integrals is characterized by the T1 theorem, which is originally due to David and Journé and was published in 1984 (Ann. of Math. 120). The main result in the dissertation can be interpreted as a T1 theorem for weakly singular integral operators. The dissertation deals also with special convolution type weakly singular integral operators that are defined on Euclidean spaces.
  • Liljavirta, Jenni (Helsingin yliopisto, 2014)
    The majority of research studies on immunological mechanisms have been conducted in human or rodent models and the results are generalized in respect of other vertebrates. However, the generation of B cells varies considerably between species. B cells are produced in the bone marrow of rodents and humans throughout life. The initial antibody diversity is produced by the random assembly of a great variety of antibody encoding gene segments. The repertoire of these gene segments is limited in many domestic species such as cattle, sheep, chicken, rabbit and pig and de novo B lymphopoiesis takes place only during fetal and/ or neonatal life. This results in a basal B cell population but one that is capable of being further expanded by other mechanisms. In this thesis, the specific diversification mechanisms in the bovine are explored. Knowledge of immunoglobulin genes is essential in order to distinguish various biological mechanisms, which are involved in antibody repertoire diversification. After the bovine genome was sequenced in 2009, the characterization of the immunoglobulin loci became possible. Previously, the bovine immunoglobulin light chain loci were characterized by only a small number of functional gene segments that had been found. Subsequently, we were able to analyse the heavy chain locus and found a total number of 62 heavy chain variable gene segments, of which 10-20 were verified as functional genes. Many livestock species and chicken rely on gut-associated lymphoid tissue for further expanding their fetal/neonatal antibody repertoire to compensate for the limited effective recombinatorial diversity. In cattle, the ileal Peyer s patch (IPP) is considered to be the major organ for B cell proliferation. In this research, the fingerprints of somatic hypermutation (SHM) in the IPP were analysed. SHM is dependent on activation-induced cytidine deaminase (AID), which contributes to modifying the immunoglobulin variable regions. SHM is conventionally considered to be a secondary diversification mechanism, which is activated with external antigens. AID-mediated SHM was shown to diversify the antibody repertoire in the fetal IPP, before the exposure of exogenous antigen encounters. Junctional diversity is produced by the random additions and excisions of nucleotides between immunoglobulin gene segments that occur during the somatic recombination. Non-templated nucleotides are added by terminal deoxynucleotidyl transferase (TdT). Sequence investigation in this study indicated that TdT-mediated junctional diversity contributes to the diversification of the antibody repertoire in bovine fetuses. Extensive junctional diversity mainly in the heavy chain sequences in bone marrow, ileum and spleen but also to a lesser extent in the light chains was detected in this study. The following model for bovine preimmune repertoire diversification was suggested in this study. First, the restricted immunoglobulin germline repertoire is diversified by junctional diversity in fetal bone marrow. Second, a small population of the B cell clones migrates to the fetal/neonatal IPP. In the IPP, further diversification by AID-mediated SHM takes place, which is associated with extensive proliferation. Third, these clones migrate to other peripheral organs where they are subjected to secondary, antigen-induced modifications. The IPP starts to involute in young animals and the animal survives for the rest of its life by proliferating and differentiating its B cell clones from the peripheral repertoire.
  • Ekman, Anna (Helsingin yliopisto, 2012)
    Immunological research is dominated by studies on man and mouse, however, only some aspects of this field are universal among vertebrates. Whilst the production of T cells is universal, B cell production cannot be extrapolated from one species to another. As such, ruminant B cell biology has distinctive features not similar to the conventional man or mouse based models. Cattle are large long-lived ruminants, of major significance globally. The bovine ileal Peyer s patch, an organ of B cell follicles along the gut, is where V(D)J immunoglobulin gene rearranged B cells proliferate, however it is not known where and how the DNA rearrangements take place before the B cells enter these follicles. Furthermore, it is unclear whether post-recombinatorial modifications, such as somatic hypermutation or gene conversion, facilitate the generation of more antibody specificities of the immunoglobulin genes in these follicles. Herein, the bovine immunoglobulin light chain genomic locus was characterized and only a moderate number of functional gene segments that cause low combinatorial antibody diversity were found. The lambda locus is the larger of the two light chain loci, containing 25 functional variable gene segments, compared to the kappa locus, which contains only eight. Functional genes comprise less than half of all the variable genes in both loci, the remainder representing unfunctional pseudogenes. The immunoglobulin genes of the fetal ruminant ileal Peyer s patch can possibly be further modified. Accordingly, the expression of activation-induced cytidine deaminase (AID), a mutator protein, was demonstrated here in fetal cattle ileal Peyer s patch. Sequencing of expressed heavy chain variable genes in these follicles showed ongoing hypermutation. The mutations were concentrated on the complementarity determining regions (CDR) of the variable genes, and on the hotspot target sequences of AID. AID-dependent mutations have usually been ascribed to antigen dependent affinity maturation, but this work demonstrates mutations in fetal immunoglobulin genes before exposure to external antigen. Bovine B lymphopoiesis is studied here, its localization in the fetal cattle in particular. By analyzing the expression of RAG1 and RAG2, which take part in the rearrangement of immunoglobulin genes, active B lymphopoiesis was demonstrated in fetal bone marrow and lymph node. The expression of surrogate light chain genes VPREB1 and IGLL1 was also shown in these same tissues. The expression of these genes implicated that a pre-B cell stage exists in cattle. This was further confirmed by the presence of a phenotypic pre-B cell population in fetal bone marrow and lymph node. VPREB2 and VPREB3 were expressed differently from the other surrogate light chain genes, which indicate that their function in cattle might not be related to pre-B cells. Overall, B lymphopoiesis was shown to take place in fetal, but not in adult, bovine tissues. Pre-B cell related genes RAGs, VPREB1 and IGLL1 were not expressed in adult tissues. Further, adult bone marrow cells were not able to differentiate into B lineage cells in cell culture. These results suggest that no new immunoglobulin rearrangements are generated during bovine adult life. Thus it is likely that the animal manages its whole life with the peripheral B cell pool produced during the fetal and neonatal period.
  • Taponen, Suvi (Helsingin yliopisto, 2008)
    Bovine mastitis caused by coagulase-negative staphylococci Mastitis is the most common disease affecting dairy cows, and staphylococci are the most common cause of mastitis. According to Finnish studies, staphylococci are isolated from 36% of clinical and 60% of subclinical mastitis cases. In mastitis diagnostics, staphylococci are divided into coagulase-positive and coagulase-negative based on their ability to coagulate plasma. Majority of staphylococcal mastitis is caused by coagulase-negative staphylococci (CNS). In mastitis diagnostics they are not identified at species level but are treated as a uniform group. Usually they cause subclinical or mildly clinical mastitis, and are considered as harmless bacteria of the normal skin flora. CNS mastitis is most common on the first lactation. It is assumed to cure spontaneously and antimicrobial treatment is not recommended. Although usually subclinical or mildly clinical, CNS mastitis causes increase of milk leucocytes and may decrease the milk quality. CNS mastitis seems to be especially a problem in well managed dairy herds with good udder health. In contrast to the usual assumption that CNS mastitis cures spontaneously, it may persist in the udder throughout the entire lactation. In addition, the CNS species are not necessarily a uniform group but differences between the species in virulence and clinical characteristics may exist. In this dissertation, different aspects of bovine mastitis caused by CNS were studied. The response of CNS mastitis to antimicrobial treatment was investigated, as well as the persistence of CNS intramammary infection when left without antimicrobial treatment. The prevalence of different CNS species in mastitis and on cows skin, and possible differences in clinical characteristics and persistence between CNS species were studied. Species identification was performed based on bacterial phenotype and genotype. Identification using different methods was compared. Majority of CNS mastitis was caused by S. chromogenes or S. simulans. Many other CNS species were isolated from mastitis sporadically. Molecular genetic identification methods based on bacterial genotype proved more reliable than biochemical methods based on bacterial phenotype. In some cases the identification results of genotypic and phenotypic methods disagreed. About half of CNS mastitis detected during lactation persisted without antimicrobial treatment, commonly until the end of lactation. Mastitis caused by penicillin-susceptible CNS cured well, about 90% cured. Of mastitis caused by penicillin-resistant CNS, 60 to 70% cured, although the causing bacteria were susceptible to the antimicrobial used. Most often CNS mastitis was subclinical or mildly clinical. Statistically significant differences in clinical characteristics or persistence between the two most common CNS species were not detected.
  • Simojoki, Heli (Helsingin yliopisto, 2011)
    Coagulase-negative staphylococci (CNS) are the most common bacteria isolated in bovine subclinical mastitis in many countries, and also a frequent cause of clinical mastitis. The most common species isolated are Staphylococcus (S) chromogenes, S. simulans, S. epidermidis, and S. xylosus. One half of the intramammary infections (IMI) caused by CNS persist in the udder. The pathogenesis of IMI caused by CNS is poorly understood. This dissertation focuses on host response in experimental intramammary infection induced by S. chromogenes, S. epidermidis and S. simulans. Model for a mild experimental CNS infection was developed with S. chromogenes (study I). All cows were infected and most developed subclinical mastitis. In study II the innate immune response to S. epidermidis and S. simulans IMI was compared in eight cows using a crossover design. A larger dose of bacteria was used to induce clinical mastitis. All cows became infected and showed mild to moderate clinical signs of mastitis. S. simulans caused a slightly stronger innate immune response than S. epidermidis, with significantly higher concentrations of the interleukins IL-1beta and IL-8 in the milk. The spontaneous elimination rate of the 16 IMIs was 31%, with no difference between species. No significant differences were recorded between infections eliminated spontaneously or remaining persistent, although the response was stronger in IMIs eliminated spontaneously, except the concentration of TNF-α, which remained elevated in persistent infections. Lactoferrin (Lf) is a component of the humoral defence of the host and is present at low concentrations in the milk. The concentration of Lf in milk is high during the dry period, in colostrum, and in mastitic milk. The effect of an inherent, high concentration of Lf in the milk on experimental IMI induced with S. chromogenes was studied in transgenic cows that expressed recombinant human Lf in their milk. Human Lf did not prevent S. chromogenes IMI, but the host response was milder in transgenic cows than in normal cows, and the former eliminated infection faster. Biofilm production has been suggested to promote persistence of IMI. Phenotypic biofilm formation and slime producing ability of CNS isolates from bovine mastitis was investigated in vitro. One-third of mastitis isolates produced biofilm. Slime production was less frequent for isolates of the most common mastitis causing species S. chromogenes and S. simulans compared with S. epidermidis. No association was found between the phenotypic ability to form biofilm and the persistence of IMI or severity of mastitis. Slime production was associated with persistent infections, but only 8% of isolates produced slime.
  • Suojala, Leena (Helsingin yliopisto, 2010)
    Bovine mastitis caused by Escherichia coli remains a problem in many countries despite of improvements in managing and housing of dairy cattle. Cows with compromised immune systems, especially those in early lactation, are particularly susceptible to E. coli intramammary infection. Mastitis caused by E. coli varies from mild, with local signs only, to severe systemic. The severe form of E. coli mastitis is associated with loss of milk production and can result in death of the cow. Intramammary infection caused by E. coli is often eliminated spontaneously as the defense mechanisms of the cow are able to clear the bacteria from the udder. The aims of this thesis were to investigate host response to E. coli mastitis in terms of characteristics of bacteria, effect of antimicrobial and non-antimicrobial treatment, and prophylactic effect of recombinant human lactoferrin expressed in milk. Host response was studied using two consecutive intramammary challenges with E. coli in the same cows at a short interval. All cows became infected, but local signs were significantly milder and disappeared faster after the second challenge. The same pattern was recorded for the indicators of inflammation; the differences being statistically significant for serum and milk haptoglobin, milk serum amyloid A, and white blood cell count. Milk production returned to the pre-challenge level significantly faster after the second challenge. This study revealed a possible carry-over or immunizing effect of the previous intramammary infection by the same pathogen. Broad-spectrum antimicrobials have been widely used for treating E. coli mastitis, although the results of treatment studies have been controversial. In our field study, systemic enrofloxacin treatment did not result in better bacteriological or clinical cure of acute clinical mastitis caused by E. coli than supportive treatment alone. Enrofloxacin treatment did not affect survival of the cows, return of quarter milk production or tissue damage of the affected quarter within three weeks post-treatment; nor did it affect the length of time the cow remained in the herd during the six-month follow-up period. The only positive effect of the enrofloxacin treatment was a higher bacteriological cure 2 days post-treatment. On the contrary, clinical cure on day 2 was lower in the enrofloxacin treated cows. Clinical cure assessed 21 days post-treatment was relatively low in both groups, which probably reflects the severe nature of acute E. coli mastitis. Our study did not support the use of parenteral antimicrobial treatment of clinical E. coli mastitis. In severe cases of coliform mastitis, antimicrobial treatment could, however, still be recommended for safety reasons, as it can increase the elimination of bacteria and prevent possible bacteraemia. Our results indicated also that frequent milking at the acute stage of mastitis might improve the initial clinical cure of E. coli mastitis and decrease inflammation and tissue damage in the infected quarter. Most E. coli isolates belonged to the phylogenetic group A, indicating their commensal nature. Close to 40% of the isolates had at least one virulence gene, but combinations of virulence genes varied greatly, each combination being present mainly in a single isolate. Approximately 30% of the isolates showed resistance to one or more antimicrobials tested, most commonly against ampicillin, streptomycin, tetracycline and sulphonamides. No specific virulence factor, phylogenetic group or resistance to antimicrobials was associated with persistence or severity of disease among mastitis E. coli isolates in our field study. These results indicate that characteristics of bacteria are not likely to affect the clinical course and outcome of E. coli mastitis. In 11% of mastitis cases, the same genotype of E. coli was isolated from the affected quarter three weeks post-treatment as originally, indicating persistence of the same genotype of E. coli in the quarter. Non-antimicrobial treatments, such as lactoferrin, which has antibacterial and lipopolysaccharide neutralizing properties, could be beneficial in the treatment of E. coli mastitis. The efficacy of intramammary lactoferrin was compared with that of systemic enrofloxacin in an experimentally induced E. coli model. No significant differences were found in the clinical signs between cows treated with lactoferrin and those treated with enrofloxacin. The results from this study remained inconclusive. The prophylactic effect of lactoferrin against E. coli mastitis was studied in a new model of using hLf-transgenic cows, which expressed recombinant human lactoferrin in their milk. This was the first study to describe an experimentally induced E. coli mastitis model using transgenic cows. The high concentration of lactoferrin in the milk of the transgenic cows did not protect the cows from E. coli intramammary infection, and all of them became infected. No differences were noted in the bacterial growth, times to bacterial elimination, local signs or in any of the milk or blood inflammatory parameters, except in concentrations of haptoglobin and cortisol in the serum. However, systemic signs were significantly milder in transgenic cows. Prevention of E. coli mastitis relies on decreasing the infection pressure in the environment of the cows and improving the cow comfort and herd management. In E. coli mastitis, the treatment should be as efficient as possible, but novel therapeutic approaches are needed, as the efficacy of the current commonly used antimicrobial treatments is not satisfactory.
  • Ollikainen, Pia (Helsingin yliopisto, 2013)
    Bovine milk is a rich source of nutrients, such as protein, fat, carbohydrate, minerals and vitamins. In addition to the major protein components of casein and whey proteins, milk has low concentrations of compounds with bioactivity, growth factors and insulin. Insulin-like growth factor I (IGF-I) and transforming growth factor-β2 (TGF-β2) are the most studied because of their various growth-promoting activities and the possibility to use them as bioactive supplements in foodstuffs. In the present work heat-stability and separation of IGF-I, TGF-β2 and insulin were studied using ELISA immunoassay. Milk from a dairy farm was heat-treated at 65, 72, 90 or 135⁰C for 15 s using an indirect pilot heating processor. Both IGF-I and TGF-β2 showed good heat stability up to 90⁰C, but at 135⁰C both growth factors had lost most of their immunochemical activity. Heating also activated the latent forms of IGF-I and TGF-β2 to immunoreactive form, which was possible to analyse without any separate pre-treatment. Heat-activation of TGF-β2 was temperature-dependent and at 90⁰C all the TGF-β2 concentration was activated by heat. IGF-I was less sensitive, but at 90⁰C it showed a sharp increase in immunoreactivity. Heating as a pre-treatment method was introduced as a new method to analyse and compare IGF-I concentrations in samples with no or low whey protein concentrations. When heat-treated milks were separated to casein and whey fractions by acid, ultracentrifugation or membrane filtration, the heat-activated immunoreactive form of the growth factor followed the casein fraction and the latent form remained in whey. Bovine insulin was heat stable during pasteurization at 65 and 72⁰C, but lost some of its immunochemical activity at higher temperatures. During membrane filtration a higher share of insulin was concentrated in MF retentate than in UF retentate when compared to IGF-I. An in vitro digestion experiment was performed in order to compare the digestibility of the latent and active forms of TGF-β2. In the adult model TGF-β2 was hydrolysed in gastric phase, but in the infant model a small share of TGF-β2 survived the gastric and duodenal phases. There was no difference in survival or digestibility between the latent or active forms of the growth factor. The digestibility of IGF-I was tested in the infant model and this growth factor was hydrolysed during duodenal phase. The results obtained in this study have great importance when separating and concentrating the growth factors from milk or colostrum. If the separation and concentration is performed from whey, these results show that the heating history of milk has a great effect on the yields. The results also demonstrate that heating as a pre-treatment method and membrane filtration can be used to lead growth factors to different fractions, depending on the intended usage.
  • Markkanen, Jani (2012)
    B-puut ovat yleisesti käytettyjä hakemistopuita. Tutkielmassa tutustutaan B-puiden samanaikaisuudenhallintaan ja elvytykseen erityisesti tietokannanhallintajärjestelmän kannalta. Tehokkaan samanaikaisuudenhallinnan tarjoavan Blink-puun algoritmeista esitellään solmujen poistojen seurantaan ja läpikäydessä rakennemuutoksien viimeistelyyn perustuvat algoritmit. Näistä jälkimmäinen toteutetaan ja sen tehokkuutta arvioidaan kokeellisesti. Kokeellisessa arvioinnissa huomataan, että lisäys- ja poisto-operaatioissa samanaikaisuudenhallinnan kustannus nousee jopa 94 %:iin arvioinnin maksimioperaatiotiheydellä. Samalla maksimioperaatiotiheydellä hakuoperaation samanaikaisuudenhallinta vie alle prosentin kokonaisajasta. Korkea samanaikaisuudenhallinnan kustannus lisäys- ja poisto-operaatioissa johtuu päivitysoperaatioiden U-salpaamasta juurisolmusta. Juurisolmun U-salpaus on usein turhan vahva toimenpide, sillä sitä tarvitaan vain 0,06 % päivitysoperaatioita, kun salpa halutaan korottaa kirjoittamista varten X-salvaksi. Puun juuren ruuhkan helpottamiseksi esitellään algoritmille jatkokehitysideoita, jotka perustuvat juuren U-salpauksen tarpeen harvinaisuuteen ja mahdollisuuteen aloittaa puun läpikäynti aina uudelleen puun juuresta.
  • Nojonen, Kati (2013)
    Denna avhandling behandlar frivilliga substitutionsvårsklienters upplevelser på HAL-(Huume Alkoholi Lääkkeet) polikliniken, som är en enhet vid HNS/ HUCS Kvinnoklinik där vård finns tillgänglig för gravida som har missbruksproblem. Kvinnokliniken är främst ett förlossningssjukhus. HAL-polikliniken erbjuder stöd för de gravida som har missbruksproblem. Läkare, sjuksköterskor/barnmorskor samt socialarbetare jobbar på HAL-polikliniken. Klienterna kan söka sig till HAL-polikliniken antingen själva eller komma med remiss från mödrarådgivningen eller en missbrukarvårdsanstalt. På HAL-polikliniken vårdar man de som har drog, alkohol, medicin – eller blandmissbruk och är gravida. Denna undersökning koncentrerade sig på de kvinnor som är i substitutionsvård, det vill säga de kvinnor, som har haft ett opioidberoende och behandlas med buprenorfin. Genom ett livsloppsperspektiv beskriver avhandlingen informanternas upplevelser om livet före graviditeten, under graviditeten, och vad de gravida kvinnorna önskar och vill i framtiden. I denna pro-gradu intervjuas gravida kvinnor (n=7) i substitutionsvård. Avhandlingen har ett fenomenologiskt forskningsangrepp och syftet med avhandlingen är att lyfta fram kvinnornas upplevelser. Ett annat syfte med avhandlingen är att berättelserna ska vara till hjälp för andra i liknande situation och även i utvecklandet av missbrukarvården. Det transkriberade materialet har jag analyserat med innehållsanalys då olika teman lyfts fram. De centrala slutsatserna var att kvinnorna är nöjda med vården de får på HAL-polikliniken och även övrigt samhälleligt stöd. Kvinnorna upplever att det varit deras egna val att söka vård, vilket de ser som det viktigaste stödet för ett drogfritt liv i fortsättningen. Kvinnorna har även upplevt mycket fördomar vilket leder till att de ser substitutionsvården som sin egna hemlighet som de ogärna talar om. Informanterna i avhandlingen påvisade en rädsla för barnets hälsa och attityden till buprenorfinet var paradoxalt. En upplevelse var att substitutionsvården gav stöd till kvinnorna i ett drogfritt liv men samtidigt upplevde de blivande mödrarna en rädsla för barnets eventuella kommande abstinensbesvär. Det som informanterna i avhandlingen upplevde som bristfälligt var stödet till den blivande fadern i familjen. Mödrarna upplevde att enbart mödrarna togs i beaktande, trots att fädrarna också skulle behövt stöd med att få missbrukarvård innan barnet föds. Avhandlingen påvisar att de kvinnor som deltagit i studien varit nöjda med den vård de fått på HAL-polikliniken men att de känner ett personligt ansvar för det, att de börjat ta droger och även att de slutar ta droger. Det går inte att göra större slutsatser utifrån dessa resultat då det grundar sig på sju informanter men det ger en inblick i hur det kan upplevas att vara gravid i substitutionsvård.