Imaging of knee injuries with special focus on tibial plateau fractures

Acute knee injury is a common event throughout life, and it is usually the result of a traffic accident, simple fall, or twisting injury. Over 90% of patients with acute knee injury undergo radiography. An overlooked fracture or delayed diagnosis can lead to poor patient outcome. The major aim of this thesis was retrospectively to study imaging of knee injury with a special focus on tibial plateau fractures in patients referred to a level-one trauma center. Multi-detector computed tomography (MDCT) findings of acute knee trauma were studied and compared to radiography, as well as whether non-contrast MDCT can detect cruciate ligaments with reasonable accuracy. The prevalence, type, and location of meniscal injuries in magnetic resonance imaging (MRI) were evaluated, particularly in order to assess the prevalence of unstable meniscal tears in acute knee trauma with tibial plateau fractures. The possibility to analyze with conventional MRI the signal appearance of menisci repaired with bioabsorbable arrows was also studied. The postoperative use of MDCT was studied in surgically treated tibial plateau fractures: to establish the frequency and indications of MDCT and to assess the common findings and their clinical impact in a level-one trauma hospital. This thesis focused on MDCT and MRI of knee injuries, and radiographs were analyzed when applica-ble. Radiography constitutes the basis for imaging acute knee injury, but MDCT can yield information beyond the capabilities of radiography. Especially in severely injured patients , sufficient radiographs are often difficult to obtain, and in those patients, radiography is unreliable to rule out fractures. MDCT detected intact cruciate ligaments with good specificity, accuracy, and negative predictive value, but the assessment of torn ligaments was unreliable. A total of 36% (14/39) patients with tibial plateau fracture had an unstable meniscal tear in MRI. When a meniscal tear is properly detected preoperatively, treatment can be combined with primary fracture fixation, thus avoiding another operation. The number of meniscal contusions was high. Awareness of the imaging features of this meniscal abnormality can help radiologists increase specificity by avoiding false-positive findings in meniscal tears. Postoperative menisci treated with bioabsorbable arrows showed no difference, among different signal intensities in MRI, among menisci between patients with operated or intact ACL. The highest incidence of menisci with an increased signal intensity extending to the meniscal surface was in patients whose surgery was within the previous 18 months. The results may indicate that a rather long time is necessary for menisci to heal completely after arrow repair. Whether the menisci with an increased signal intensity extending to the meniscal surface represent improper healing or re-tear, or whether this is just the earlier healing feature in the natural process remains unclear, and further prospective studies are needed to clarify this. Postoperative use of MDCT in tibial plateau fractures was rather infrequent even in this large trauma center, but when performed, it revealed clinically significant information, thus benefitting patients in regard to treatment.

Acceleration of the Cosmological Expansion as an Effect of Inhomogeneities

The cosmological observations of light from type Ia supernovae, the cosmic microwave background and the galaxy distribution seem to indicate that the expansion of the universe has accelerated during the latter half of its age. Within standard cosmology, this is ascribed to dark energy, a uniform fluid with large negative pressure that gives rise to repulsive gravity but also entails serious theoretical problems. Understanding the physical origin of the perceived accelerated expansion has been described as one of the greatest challenges in theoretical physics today. In this thesis, we discuss the possibility that, instead of dark energy, the acceleration would be caused by an effect of the nonlinear structure formation on light, ignored in the standard cosmology. A physical interpretation of the effect goes as follows: due to the clustering of the initially smooth matter with time as filaments of opaque galaxies, the regions where the detectable light travels get emptier and emptier relative to the average. As the developing voids begin to expand the faster the lower their matter density becomes, the expansion can then accelerate along our line of sight without local acceleration, potentially obviating the need for the mysterious dark energy. In addition to offering a natural physical interpretation to the acceleration, we have further shown that an inhomogeneous model is able to match the main cosmological observations without dark energy, resulting in a concordant picture of the universe with 90% dark matter, 10% baryonic matter and 15 billion years as the age of the universe. The model also provides a smart solution to the coincidence problem: if induced by the voids, the onset of the perceived acceleration naturally coincides with the formation of the voids. Additional future tests include quantitative predictions for angular deviations and a theoretical derivation of the model to reduce the required phenomenology. A spin-off of the research is a physical classification of the cosmic inhomogeneities according to how they could induce accelerated expansion along our line of sight. We have identified three physically distinct mechanisms: global acceleration due to spatial variations in the expansion rate, faster local expansion rate due to a large local void and biased light propagation through voids that expand faster than the average. A general conclusion is that the physical properties crucial to account for the perceived acceleration are the growth of the inhomogeneities and the inhomogeneities in the expansion rate. The existence of these properties in the real universe is supported by both observational data and theoretical calculations. However, better data and more sophisticated theoretical models are required to vindicate or disprove the conjecture that the inhomogeneities are responsible for the acceleration.

Studies of Earth Dynamics with the Superconducting Gravimeter

The superconducting (or cryogenic) gravimeter (SG) is based on the levitation of a super­conducting sphere in a stable magnetic field created by current in superconducting coils. Depending on frequency, it is capable of detecting gravity variations as small as 10-11ms-2. For a single event, the detection threshold is higher, conservatively about 10-9 ms-2. Due to its high sensitivity and low drift rate, the SG is eminently suitable for the study of geodynamical phenomena through their gravity signatures. I present investigations of Earth dynamics with the superconducting gravimeter GWR T020 at Metsähovi from 1994 to 2005. The history and key technical details of the installation are given. The data processing methods and the development of the local tidal model at Metsähovi are presented. The T020 is a part of the worldwide GGP (Global Geodynamics Project) network, which consist of 20 working station. The data of the T020 and of other participating SGs are available to the scientific community. The SG T020 have used as a long-period seismometer to study microseismicity and the Earth s free oscillation. The annual variation, spectral distribution, amplitude and the sources of microseism at Metsähovi were presented. Free oscillations excited by three large earthquakes were analyzed: the spectra, attenuation and rotational splitting of the modes. The lowest modes of all different oscillation types are studied, i.e. the radial mode 0S0, the "football mode" 0S2, and the toroidal mode 0T2. The very low level (0.01 nms-1) incessant excitation of the Earth s free oscillation was detected with the T020. The recovery of global and regional variations in gravity with the SG requires the modelling of local gravity effects. The most important of them is hydrology. The variation in the groundwater level at Metsähovi as measured in a borehole in the fractured bedrock correlates significantly (0.79) with gravity. The influence of local precipitation, soil moisture and snow cover are detectable in the gravity record. The gravity effect of the variation in atmospheric mass and that of the non-tidal loading by the Baltic Sea were investigated together, as sea level and air pressure are correlated. Using Green s functions it was calculated that a 1 metre uniform layer of water in the Baltic Sea increases the gravity at Metsähovi by 31 nms-2 and the vertical deformation is -11 mm. The regression coefficient for sea level is 27 nms-2m-1, which is 87% of the uniform model. These studies are associated with temporal height variations using the GPS data of Metsähovi permanent station. Results of long time series at Metsähovi demonstrated high quality of data and correctly carried out offsets and drift corrections. The superconducting gravimeter T020 has been proved to be an eminent and versatile tool in studies of the Earth dynamics.

On gravitational fields of stars in f(R) gravity theories

Einstein's general relativity is a classical theory of gravitation: it is a postulate on the coupling between the four-dimensional, continuos spacetime and the matter fields in the universe, and it yields their dynamical evolution. It is believed that general relativity must be replaced by a quantum theory of gravity at least at extremely high energies of the early universe and at regions of strong curvature of spacetime, cf. black holes. Various attempts to quantize gravity, including conceptually new models such as string theory, have suggested that modification to general relativity might show up even at lower energy scales. On the other hand, also the late time acceleration of the expansion of the universe, known as the dark energy problem, might originate from new gravitational physics. Thus, although there has been no direct experimental evidence contradicting general relativity so far - on the contrary, it has passed a variety of observational tests - it is a question worth asking, why should the effective theory of gravity be of the exact form of general relativity? If general relativity is modified, how do the predictions of the theory change? Furthermore, how far can we go with the changes before we are face with contradictions with the experiments? Along with the changes, could there be new phenomena, which we could measure to find hints of the form of the quantum theory of gravity? This thesis is on a class of modified gravity theories called f(R) models, and in particular on the effects of changing the theory of gravity on stellar solutions. It is discussed how experimental constraints from the measurements in the Solar System restrict the form of f(R) theories. Moreover, it is shown that models, which do not differ from general relativity at the weak field scale of the Solar System, can produce very different predictions for dense stars like neutron stars. Due to the nature of f(R) models, the role of independent connection of the spacetime is emphasized throughout the thesis.

Diagnostic Tests Based on Quantile Residuals for Nonlinear Time Series Models

This thesis studies quantile residuals and uses different methodologies to develop test statistics that are applicable in evaluating linear and nonlinear time series models based on continuous distributions. Models based on mixtures of distributions are of special interest because it turns out that for those models traditional residuals, often referred to as Pearson's residuals, are not appropriate. As such models have become more and more popular in practice, especially with financial time series data there is a need for reliable diagnostic tools that can be used to evaluate them. The aim of the thesis is to show how such diagnostic tools can be obtained and used in model evaluation. The quantile residuals considered here are defined in such a way that, when the model is correctly specified and its parameters are consistently estimated, they are approximately independent with standard normal distribution. All the tests derived in the thesis are pure significance type tests and are theoretically sound in that they properly take the uncertainty caused by parameter estimation into account. -- In Chapter 2 a general framework based on the likelihood function and smooth functions of univariate quantile residuals is derived that can be used to obtain misspecification tests for various purposes. Three easy-to-use tests aimed at detecting non-normality, autocorrelation, and conditional heteroscedasticity in quantile residuals are formulated. It also turns out that these tests can be interpreted as Lagrange Multiplier or score tests so that they are asymptotically optimal against local alternatives. Chapter 3 extends the concept of quantile residuals to multivariate models. The framework of Chapter 2 is generalized and tests aimed at detecting non-normality, serial correlation, and conditional heteroscedasticity in multivariate quantile residuals are derived based on it. Score test interpretations are obtained for the serial correlation and conditional heteroscedasticity tests and in a rather restricted special case for the normality test. In Chapter 4 the tests are constructed using the empirical distribution function of quantile residuals. So-called Khmaladze s martingale transformation is applied in order to eliminate the uncertainty caused by parameter estimation. Various test statistics are considered so that critical bounds for histogram type plots as well as Quantile-Quantile and Probability-Probability type plots of quantile residuals are obtained. Chapters 2, 3, and 4 contain simulations and empirical examples which illustrate the finite sample size and power properties of the derived tests and also how the tests and related graphical tools based on residuals are applied in practice.

Hyvinvointivaltion optimaalisen köyhyyspolitiikan määrittelyä

The purpose of this research is to identify the optimal poverty policy for a welfare state. Poverty is defined by income. Policies for reducing poverty are considered primary, and those for reducing inequality secondary. Poverty is seen as a function of the income transfer system within a welfare state. This research presents a method for optimising this function for the purposes of reducing poverty. It is also implemented in the representative population sample within the Income Distribution Data. SOMA simulation model is used. The iterative simulation process is continued until a level of poverty is reached at which improvements can no longer be made. Expenditures and taxes are kept in balance during the process. The result consists of two programmes. The first programme (social assistance programme) was formulated using five social assistance parameters, all of which dealt with the norms of social assistance for adults (€/month). In the second programme (basic benefits programme), in which social assistance was frozen at the legislative level of 2003, the parameter with the strongest poverty reduction effect turned out to be one of the basic unemployment allowances. This was followed by the norm of the national pension for a single person, two parameters related to housing allowance, and the norm for financial aid for students of higher education institutions. The most effective financing parameter measured by gini-coefficient in all programmes was the percent of capital taxation. Furthermore, these programmes can also be examined in relation to their costs. The social assistance programme is significantly cheaper than the basic benefits programme, and therefore with regard to poverty, the social assistance programme is more cost effective than the basic benefits programme. Therefore, public demand for raising the level of basic benefits does not seem to correspond to the most cost effective poverty policy. Raising basic benefits has most effect on reducing poverty within the group of people whose basic benefits are raised. Raising social assistance, on the other hand, seems to have a strong influence on the poverty of all population groups. The most significant outcome of this research is the development of a method through which a welfare state’s income transfer-based safety net, which has severely deteriorated in recent decades, might be mended. The only way of doing so involves either social assistance or some forms of basic benefits and supplementing these by modifying social assistance.

Yhteinen verkosto? : Tutkimus nuorten syrjäytymistä ehkäisevistä poikkihallinnollisista ryhmistä

Since the 1990s, European policy strategies have stressed the mutual responsibility and joint action of all societal branches in preventing social problems. Network policy is an integral part of the new governance that generates a new kind of dependency between the state and civil society in formulating and adhering to policy goals. Using empirical group interview data collected in Helsinki, the capital of Finland, this case study explores local multi-agency groups and their efforts to prevent the exclusion of children and young people. These groups consist mainly of professionals from the social office, youth clubs and schools. The study shows that these multi-agency groups serve as forums for professional negotiation where the intervention dilemma of liberal society can be addressed: the question of when it is justified and necessary for an authority or network to intervene in the life of children and their families, and how this is to be done. An element of tension in multi-agency prevention is introduced by the fact that its objectives and means are anchored both in the old tradition of the welfare state and in communitarian rhetoric. Thus multi-agency groups mend deficiencies in wellbeing and normalcy while at the same time try to co-ordinate the creation of the new community, which will hopefully reduce the burden on the public sector. Some of the professionals interviewed were keen to see new and even forceful interventions to guide the youth or to compel parents to assume their responsibilities. In group discussions, this approach often met resistance. The deeper the social problems that the professionals worked with, the more solidarity they showed for the families or the young people in need. Nothing seems to assure professionals and to legitimise their professional position better than advocating the under-privileged against the uncertainties of life and the structural inequalities of society. The groups that grappled with the clear, specific needs of certain children and families were the most capable of co-operation. This requires the approval of different powers and the expertise of distinct professions as well as a forum to negotiate case-specific actions in professional confidentiality. The ideals of primary prevention for everyone and value discussions alone fail to inspire sufficient multiagency co-operation. The ideal of a network seems to give word and shape to those societal goals that are difficult or even impossible to reach, but are nevertheless yearned for: mutual understanding of the good life, close social relationships, mutual trust and active agency for all citizens. Individualisation, the multiplicity of life styles and the possibility to choose have come true in such a way that the very idea of a mutual and binding network can be attained only momentarily and between restricted participants. In conclusion, uniting professional networks that negotiate intervention dilemmas with citizen networks based on changing compassions and feelings of moral superiority seems impossible. Rather, one should encourage openness to scrutiny among tangential or contradicting groups, networks and communities. Key words: network policy, prevention of exclusion, multi-agency groups, young people

Kansallinen identiteetti ja suomalaiseksi samastuminen

National identity is a general, more or less shared meaning structure. Those who share it, identify with a nation according to their beliefs of what national identity consists of. The present study examined the Finnish national identity in relation to other spatial identities, such as local or European identity. Data were drawn from a sample of 179 respondents who represented the adult population in the year 1993. The focus was on the representation of the Finnish national identity, the limits and components of this identity, and on the position of national identification among all human identifications. Categorization, the basic process in the construction of national identity, consists of inclusion and exclusion. Different forms of identification could be distinguished along with different contents. Discrimination and derogation of outgroups were associated with identification that emphasized inter-nation comparison and framed identity in an essentialistic and thus exclusionary way. The contents of national identity were examined using a quantitative word-assessment method, and related to different forms of identification. With regard to Finnish identification, few differences between age, educational or SES groups were found. Despite the lack of differences in the strength of Finnish identification, those with more education to a greater extent relativized their Finnishness. Those who held positive attitudes to immigrants associated Finnishness with both positive and negative traits. Pro-immigrant attitude was related to an emphasis on cultural Finnishness and a de-emphasis on comparative and status-oriented Finnishness. Among the respondents with lower level of education, the emphasis on cultural Finnishness clearly predicted pro-immigrant attitudes. Those who did not produce any spontaneous response to a request to define Finnishness were more likely to be anti-immigrant. Thus, reflexive self-understanding implies openness towards other nationalities. Changes in the representation of Finnishness are suggested by differential weights given by respondents to different aspects of the national identity. Older respondents regarded the moral-anthropomorphic aspects of identity as more important. The younger respondents felt relatively more Finnish in the company of foreigners than did the older generations, to whom being with friends and in other close relationships stood out as contexts of national identification. The aspect of identity which is based on categorization and comparison could be called identity for others. The other aspect of the national identity is identity for ourselves, which emphasizes self and cultural self-understanding. A modern marketing oriented “image-of-Finland” identity represents identity for others.

'Someone to welcome you home' : Infertility, medicines and the Sukuma-Nyamwezi

This study Someone to Welcome you home: Infertility, medicines and the Sukuma-Nyamwezi , looks into the change in the cosmological ideology of the Sukuma-Nyamwezi of Tanzania and into the consequences of this change as expressed through cultural practices connected to female infertility. This analysis is based on 15 months of fieldwork in Isaka, in the Shinyanga area. In this area the birth rate is high and at the same time infertility is a problem for individual women. The attitudes connected to fertility and the attempts to control fertility provide a window onto social and cultural changes in the area. Even though the practices connected to fertility seem to be individualized the problem of individual women - the discourse surrounding fertility is concerned with higher cosmological levels. The traditional cosmology emphasized the centrality of the chief as the source of well-being. He was responsible for rain and the fertility of the land and, thus, for the well-being of the whole society. The holistic cosmology was hierarchical and the ritual practices connected to chiefship which dealt with the whole of the society were recursively applied at the lower levels of hierarchy, in the relationships between individuals. As on consequence of changes in the political system, the chiefship was legally abolished in the early years of Independence. However, the holistic ideology, which was the basis of the chiefship, did not disappear and instead acquired new forms. It is argued that in African societies the common efflorence of diviner-healers and witchcraft can be a consequence of the change in the relationship between the social reality and the cosmological ideology. In the Africanist research the increase in the numbers of diviner-healers and witchcraft is usually seen as a consequence of individualism and modernization. In this research, however, it is seen as an altered form of holism, as a consequence of which the hierarchical relations between women and men have changed. Because of this, the present-day practices connected to reproduction pay special attention to the control of women s sexuality.

Medicalising Prohibition : Harm reduction in Finnish and International Drug Policy

The increase in drug use and related harms in the late 1990s in Finland has come to be referred to as the second drug wave. In addition to using criminal justice as a basis of drug policy, new kinds of drug regulation were introduced. Some of the new regulation strategies were referred to as "harm reduction". The most widely known practices of harm reduction include needle and syringe exchange programmes for intravenous drug users and medicinal substitution and maintenance treatment programmes for opiate users. The purpose of the study is to examine the change of drug policy in Finland and particularly the political struggle surrounding harm reduction in the context of this change. The aim is, first, to analyse the content of harm reduction policy and the dynamics of its emergence and, second, to assess to what extent harm reduction undermines or threatens traditional drug policy. The concept of harm reduction is typically associated with a drug policy strategy that employs the public health approach and where the principal focus of regulation is on drug-related health harms and risks. On the other hand, harm reduction policy has also been given other interpretations, relating, in particular, to human rights and social equality. In Finland, harm reduction can also be seen to have its roots in criminal policy. The general conclusion of the study is that rather than posing a threat to a prohibitionist drug policy, harm reduction has come to form part of it. The implementation of harm reduction by setting up health counselling centres for drug users with the main focus on needle exchange and by extending substitution treatment has implied the creation of specialised services based on medical expertise and an increasing involvement of the medical profession in addressing drug problems. At the same time the criminal justice control of drug use has been intensified. Accordingly, harm reduction has not entailed a shift to a more liberal drug policy nor has it undermined the traditional policy with its emphasis on total drug prohibition. Instead, harm reduction in combination with a prohibitionist penal policy constitutes a new dual-track drug policy paradigm. The study draws on the constructionist tradition of research on social problems and movements, where the analysis centres on claims made about social problems, claim-makers, ways of making claims and related social mobilisation. The research material mainly consists of administrative documents and interviews with key stakeholders. The doctoral study consists of five original articles and a summary article. The first article gives an overview of the strained process of change of drug policy and policy trends around the turn of the millennium. The second article focuses on the concept of harm reduction and the international organisations and groupings involved in defining it. The third article describes the process that in 1996 97 led to the creation of the first Finnish national drug policy strategy by reconciling mutually contradictory views of addressing the drug problem, at the same as the way was paved for harm reduction measures. The fourth article seeks to explain the relatively rapid diffusion of needle exchange programmes after 1996. The fifth article assesses substitution treatment as a harm reduction measure from the viewpoint of the associations of opioid users and their family members.

Sikiöaikana päihteille altistuneiden lasten kasvuympäristö ja kehitys

Life of children exposed to alcohol or drugs in utero This study focused on the growth environment, physical development and socio-emotional development of children, aged 16 and under, who had been exposed to alcohol (n=78) or drugs (n=15) in utero. The aim of the study was to obtain a comprehensive picture of the living conditions of these children and to examine the role of the growth environment in their development. The study was carried out using questionnaires, written life stories and interviews. Attachment theory was used as a background theory in the study. Over half of the children exposed to alcohol were diagnosed with foetal alcohol syndrome (FAS), one quarter was diagnosed with foetal alcohol effects (FAE), and one fifth had no diagnosis. Most of the children exposed to drugs had been exposed to either amphetamines or cannabis, and a smaller number to heroin. Some of the children exposed to alcohol were mentally handicapped or intellectually impaired. The children exposed to drugs did not exhibit any serious learning difficulties but a considerable number of them had socio-emotional development problems. Language and speech problems and attention, concentration and social interaction problems were typical among both the children exposed to alcohol and those exposed to drugs. Only one child had been placed into long-term foster care in a family immediately after leaving the maternity hospital. In biological families there had been neglect, violence, mental health problems, crime and unemployment, and many parents were already dead. Two of the children had been sexually abused and four were suspected of having been abused. From the point of view of the children's development, the three most critical issues were 1) the range of illnesses and handicaps that had impaired their functional capacity as a result of their prenatal exposure to alcohol, 2) child's age at the time of placement on a long-term basis, and 3) the number of their traumatic experiences. The relationship with their biological parents after placement also played a role. Children with symptoms were found in all diagnosis categories and types of exposure. Children with the smallest number of symptoms were found among those who had never lived with their biological parents. Almost all children were exhibiting strong symptoms at the time of placement in foster care. In most cases, they were behaving in a disorderly manner towards others, but some children were withdrawn. The most conspicuous feature among those with the most severe symptoms was their disorganized behaviour. Placement in a foster family enhanced the children's development, but did not solve the problems. The foster parents who brought these children up did not receive as much therapy for the children and support for the upbringing as they appear to have needed. In Finland, transfer to long-term custody is based on strict criteria. The rights of children prescribed in the child protection law are not fulfilled in practice. Key words: FASD, FAS, FAE, alcohol exposure, drugs exposure, illegal drugs, early interaction, child development, attachment

The EU and Institutional Twinning in Morocco - An inquiry into the motives of cooperation through discourse ethics

This study examines Institutional Twinning in Morocco as a case of EU cooperation through the pragmatic, ethical and moral logics of reason in Jürgen Habermas’s discourse ethics. As a former accession tool, Twinning was introduced in 2004 for legal approximation in the context of the European Neighborhood Policy. Twinning is a unique instrument in development cooperation from a legal perspective. With its long historical and cultural ties to Europe, Morocco presents an interesting case study of this new form of cooperation. We will analyse motives behind the Twinning projects on illegal immigration, environment legislation and customs reform. As Twinning is a new policy instrument within the ENP context, there is relatively little preceding research, which, in itself, constitutes a reason to inquire into the subject. While introducing useful categories, the approaches discussing “normative power Europe” do not offer methodological tools precise enough to analyse the motives of the Twinning cooperation from a broad ethical standpoint. Helene Sjursen as well as Esther Barbé and Elisabeth Johansson-Nogués have elaborated on Jürgen Habermas’ discourse ethics in determining the extent of altruism in the ENP in general. Situating the analysis in the process-oriented framework of Critical Theory, discourse ethics provides the methodological framework for our research. The case studies reveal that the context in which they operate affects the pragmatic, ethical and moral aspirations of the actors. The utilitarian notion of profit maximization is quite pronounced both in terms of the number of Twinning projects in the economic sphere and the pragmatic logics of reason instrumental to security and trade-related issues. The historical background as well internal processes, however, contribute to defining areas of mutual interest to the actors as well as the motives Morocco and the EU sometimes described as the external projection of internal values. Through its different aspects, Twinning cooperation portrays the functioning of the pragmatic, ethical and moral logics of reason in international relations.

The Structure and Functions of Hantavirus Nucleocapsid Protein

Hantaviruses, members of the genus Hantavirus in the Bunyaviridae family, are enveloped single-stranded RNA viruses with tri-segmented genome of negative polarity. In humans, hantaviruses cause two diseases, hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS), which vary in severity depending on the causative agent. Each hantavirus is carried by a specific rodent host and is transmitted to humans through excreta of infected rodents. The genome of hantaviruses encodes four structural proteins: the nucleocapsid protein (N), the glycoproteins (Gn and Gc), and the polymerase (L) and also the nonstructural protein (NSs). This thesis deals with the functional characterization of hantavirus N protein with regard to its structure. Structural studies of the N protein have progressed slowly and the crystal structure of the whole protein is still not available, therefore biochemical assays coupled with bioinformatical modeling proved essential for studying N protein structure and functions. Presumably, during RNA encapsidation, the N protein first forms intermediate trimers and then oligomers. First, we investigated the role of N-terminal domain in the N protein oligomerization. The results suggested that the N-terminal region of the N protein forms a coiled-coil, in which two antiparallel alpha helices interact via their hydrophobic seams. Hydrophobic residues L4, I11, L18, L25 and V32 in the first helix and L44, V51, L58 and L65 in the second helix were crucial for stabilizing the structure. The results were consistent with the head-to-head, tail-to-tail model for hantavirus N protein trimerization. We demonstrated that an intact coiled-coil structure of the N terminus is crucial for the oligomerization capacity of the N protein. We also added new details to the head-to-head, tail-to-tail model of trimerization by suggesting that the initial step is based on interaction(s) between intact intra-molecular coiled-coils of the monomers. We further analyzed the importance of charged aa residues located within the coiled-coil for the N protein oligomerization. To predict the interacting surfaces of the monomers we used an upgraded in silico model of the coiled-coil domain that was docked into a trimer. Next the predicted target residues were mutated. The results obtained using the mammalian two-hybrid assay suggested that conserved charged aa residues within the coiled-coil make a substantial contribution to the N protein oligomerization. This contribution probably involves the formation of interacting surfaces of the N monomers and also stabilization of the coiled-coil via intramolecular ionic bridging. We proposed that the tips of the coiled-coils are the first to come into direct contact and thus initiate tight packing of the three monomers into a compact structure. This was in agreement with the previous results showing that an increase in ionic strength abolished the interaction between N protein molecules. We also showed that residues having the strongest effect on the N protein oligomerization are not scattered randomly throughout the coiled-coil 3D model structure, but form clusters. Next we found evidence for the hantaviral N protein interaction with the cytoplasmic tail of the glycoprotein Gn. In order to study this interaction we used the GST pull-down assay in combination with mutagenesis technique. The results demonstrated that intact, properly folded zinc fingers of the Gn protein cytoplasmic tail as well as the middle domain of the N protein (that includes aa residues 80 248 and supposedly carries the RNA-binding domain) are essential for the interaction. Since hantaviruses do not have a matrix protein that mediates the packaging of the viral RNA in other negatve stranded viruses (NSRV), hantaviral RNPs should be involved in a direct interaction with the intraviral domains of the envelope-embedded glycoproteins. By showing the N-Gn interaction we provided the evidence for one of the crucial steps in the virus replication at which RNPs are directed to the site of the virus assembly. Finally we started analysis of the N protein RNA-binding region, which is supposedly located in the middle domain of the N protein molecule. We developed a model for the initial step of RNA-binding by the hantaviral N protein. We hypothesized that the hantaviral N protein possesses two secondary structure elements that initiate the RNA encapsidation. The results suggest that amino acid residues (172-176) presumably act as a hook to catch vRNA and that the positively charged interaction surface (aa residues 144-160) enhances the initial N-RNA interacation. In conclusion, we elucidated new functions of hantavirus N protein. Using in silico modeling we predicted the domain structure of the protein and using experimental techniques showed that each domain is responsible for executing certain function(s). We showed that intact N terminal coiled-coil domain is crucial for oligomerization and charged residues located on its surface form a interaction surface for the N monomers. The middle domain is essential for interaction with the cytoplasmic tail of the Gn protein and RNA binding.

Kulinaarinen kolmio analyysivälineenä

Tutkielman aiheena on ranskalaisen antropologin Claude Lévi-Straussin laajalti tunnettu malli, kulinaarinen kolmio, jonka Lévi-Strauss esitti alun perin primitiivistä mytologiaa käsittelevän tutkimusprojektinsa yhteydessä. Hänen mukaansa mallin avulla oli mahdollista esittää eräs tutkimuksen kohteena olevaa myyttiaineistoa jäsentävä syvärakenne. Myyttitutkimuksessaan Lévi-Strauss osoitti, että mallin avulla on mahdollista jäsentää ennen kaikkea erilaisia luonnon ja kulttuurin väliseen vastakkaisuuteen liittyviä ilmiöitä. Mallia on mahdollista käyttää myyttien ja niissä ilmenevän symbolisen ajattelun ohella myös konkreettisten ruokajärjestelmien analyysivälineenä. Mallia onkin sovellettu erilaisissa empiirisissä tutkimuksissa sekä määrättyihin empiirisiin ruokajärjestelmiin, että mitä erilaisimpiin kulttuurisiin ilmiöihin. Vaikka malli on ollut laajalti tunnettu ja synnyttänyt runsaasti keskustelua, ei siitä ole esitetty minkäänlaista systemaattista tulkintaa. Mallia koskeva keskustelu on ollut suurimmaksi osaksi kuvailevaa ja siihen kohdistetut kriittiset arviot ovat usein keskittyneet johonkin määrättyyn mallin aspektiin. Tutkielmani tehtävänä on täsmentää sitä, mistä mallissa on itse asiassa kyse ja millä tavalla Lévi-Strauss itse mallinsa mielsi. Tehtävä edellyttää mallin suhteuttamista sen taustalla olevaan teoreettiseen ja metodologiseen viitekehykseen. Tutkielmani ensimmäinen aineisto muodostuu Lévi-Straussin kulinaariseen kolmioon ja mallin taustalla olevaan viitekehykseen liittyvistä teksteistä. Erityisen keskeisiä lähteitä ovat artikkeli The Culinary Triangle ja myyttitutkimussarjan (Mythologiques) teokset. Tutkielman toisena tehtävänä on kartoittaa sitä, miten mallia on sovellettu erilaisissa empiirisissä tutkimuksissa ja millä tavalla nämä suhteutuvat Lévi-Straussin tapaan käyttää mallia ja hänen noudattamaansa tutkimusmetodologiaan. Keskityn kolmen mallia käyttävän tutkimuksen tarkastelemiseen ja erittelen sitä, millä tavalla ne suhteutuvat Lévi-Straussin tapaan käyttää mallia. Mallia soveltavat tutkimukset muodostavat opinnäytteeni toisen aineiston. Tutkielmani osoittaa, että malli on yleisestä luonteestaan johtuen altis erilaisille tulkinnoilla ja sovellusmahdollisuuksille. Tuon myös esille sen, millaisia reunaehtoja mallin soveltamiseen yleisesti liittyy ja millaisia seikkoja on otettava huomioon, kun mallia sovelletaan nyky-yhteiskuntiin. Vaikka mallia on mahdollista soveltaa hyvin erilaisiin ilmiöihin, ei sen avulla ole mahdollista käsitellä monia yhteiskuntatieteiden kannalta keskeisiä kysymyksiä.

Sairaanhoitajat työn imussa? Palkkatyön sisällön ja kulttuuristen lähtökohtien tasapainossa

Tutkimuksen tavoitteena on selvittää, mikä saa pitkän työuran tehneet sairaanhoitajat innostumaan työstään. Taustalla on yhteiskunnallinen tilanne, jossa työelämän vetovoimaisuuden lisääminen ja ikääntyvien työntekijöiden työssä jaksaminen ovat keskeisiä poliittisia tavoitteita. Aihetta lähestytään positiivisesta psykologiasta lähtöisin olevan työn imun käsitteen avulla. Se on määritelty pysyväksi, ”myönteiseksi, tunne- ja motivaatiotäyttymyksen tilaksi, jota luonnehtivat tarmokkuus, omistautuminen ja uppoutuminen työhön” (Hakanen 2009a, 9). Tutkimuksessa kysytään, voidaanko työn imua ymmärtää myös sosiologisesta näkökulmasta. Oletuksena on, että käsitteen taustalla on muutakin kuin psykologisesta perinteestä käsin jäsentyvää vaihtelua. Empiirisen aineiston muodostavan 11 sairaanhoitajan koko työuraa ja nykyistä työtä koskevat tiettyihin teemoihin ankkuroidut syvähaastattelut. Otosta poimittaessa on etsitty sellaisia haastateltavia, jotka kokevat kantavansa työn imua. Aineiston analyysitapana on käytetty matriisin avulla sovellettua kvalitatiivista sisällönanalyysiä. Työn imua hahmotetaan analyysissä henkilöhistoriallisten haastatteluiden – menneen, nykyisen ja tulevan – kautta. Pyrkimyksenä on etsiä tarinoita mahdollisesti yhdistävää kulttuurista muotoa ja ymmärtää, mihin se perustuu. Analyysin nojalla vastuurationaalisuuden käsite (esim. Korvajärvi 1986) näyttäisi jäsentävän osan haastateltavien suhteesta työhönsä. Avain työn imun löytymiseen näissä tarinoissa on kuitenkin se, kuinka haastateltavilla on ollut henkilökohtainen halu mennä eteenpäin ja kykyä ratkaista ongelmia työuransa aikana ja nykyisessä työssään. Tämä havainto tulkitaan Max Weberin (1922, 1980) käsitteiden – arvorationaalisen ja päämäärärationaalisen toiminnan väliseen suhteen – avulla. Tulokseksi syntyy oletus siitä, että analyysin kohteena olevissa tarinoissa on kyse yhteisestä kulttuurisesta tarinasta siitä, millainen on hyvä ihminen, miten hyvä ihminen toteuttaa itseään työssä ja miten hän tekee työtään: tarmokkaasti, omistautuen ja uppoutuen. Henkilökohtainen halu mennä eteenpäin ja kyky ratkaista ongelmia nojaa sairaanhoitajien erityiseen eetokseen, kutsumustyöhön ja hoivan moraaliin tavalla, joka on rakenteellisesti yhtäläinen protestanttisuutta leimaavan yksilöllisen jumalasuhteen kanssa. Lisäksi analyysin perusteella esitetään, että työn imun edellytys on arvorationaalisen eetoksen lisäksi oikeanlainen, riittävät työn voimavarat sisältävä ympäristö, jossa hoitotyön keskeiset palkinnot on mahdollista saavuttaa. Tällöin palkkatyön sisältö kohtaa kulttuuriset lähtökohdat, ja tulos näkyy työn imuna. Keskeisimmät taustoittavat lähteet ovat Henriksson, Lea & Wrede, Sirpa (toim.) (2004a). Hyvinvointityön ammatit ja Hakanen, Jari (2009a). Työn imun arviointimenetelmä (Utrecht Work Engagement Scale). Sosiologisen tulkinnan kannalta tärkein teoreettinen lähde on Weber, Max (1980): Protestanttinen etiikka ja kapitalismin henki.