Comparison and integration of MEG and fMRI

MEG directly measures the neuronal events and has greater temporal resolution than fMRI, which has limited temporal resolution mainly due to the larger timescale of the hemodynamic response. On the other hand fMRI has advantages in spatial resolution, while the localization results with MEG can be ambiguous due to the non-uniqueness of the electromagnetic inverse problem. Thus, these methods could provide complementary information and could be used to create both spatially and temporally accurate models of brain function. We investigated the degree of overlap, revealed by the two imaging methods, in areas involved in sensory or motor processing in healthy subjects and neurosurgical patients. Furthermore, we used the spatial information from fMRI to construct a spatiotemporal model of the MEG data in order to investigate the sensorimotor system and to create a spatiotemporal model of its function. We compared the localization results from the MEG and fMRI with invasive electrophysiological cortical mapping. We used a recently introduced method, contextual clustering, for hypothesis testing of fMRI data and assessed the the effect of neighbourhood information use on the reproducibility of fMRI results. Using MEG, we identified the ipsilateral primary sensorimotor cortex (SMI) as a novel source area contributing to the somatosensory evoked fields (SEF) to median nerve stimulation. Using combined MEG and fMRI measurements we found that two separate areas in the lateral fissure may be the generators for the SEF responses from the secondary somatosensory cortex region. The two imaging methods indicated activation in corresponding locations. By using complementary information from MEG and fMRI we established a spatiotemporal model of somatosensory cortical processing. This spatiotemporal model of cerebral activity was in good agreement with results from several studies using invasive electrophysiological measurements and with anatomical studies in monkey and man concerning the connections between somatosensory areas. In neurosurgical patients, the MEG dipole model turned out to be more reliable than fMRI in the identification of the central sulcus. This was due to prominent activation in non-primary areas in fMRI, which in some cases led to erroneous or ambiguous localization of the central sulcus.

Society by Numbers : Studies on Model-Based Explanations in the Social Sciences

The aim of this dissertation is to provide conceptual tools for the social scientist for clarifying, evaluating and comparing explanations of social phenomena based on formal mathematical models. The focus is on relatively simple theoretical models and simulations, not statistical models. These studies apply a theory of explanation according to which explanation is about tracing objective relations of dependence, knowledge of which enables answers to contrastive why and how-questions. This theory is developed further by delineating criteria for evaluating competing explanations and by applying the theory to social scientific modelling practices and to the key concepts of equilibrium and mechanism. The dissertation is comprised of an introductory essay and six published original research articles. The main theses about model-based explanations in the social sciences argued for in the articles are the following. 1) The concept of explanatory power, often used to argue for the superiority of one explanation over another, compasses five dimensions which are partially independent and involve some systematic trade-offs. 2) All equilibrium explanations do not causally explain the obtaining of the end equilibrium state with the multiple possible initial states. Instead, they often constitutively explain the macro property of the system with the micro properties of the parts (together with their organization). 3) There is an important ambivalence in the concept mechanism used in many model-based explanations and this difference corresponds to a difference between two alternative research heuristics. 4) Whether unrealistic assumptions in a model (such as a rational choice model) are detrimental to an explanation provided by the model depends on whether the representation of the explanatory dependency in the model is itself dependent on the particular unrealistic assumptions. Thus evaluating whether a literally false assumption in a model is problematic requires specifying exactly what is supposed to be explained and by what. 5) The question of whether an explanatory relationship depends on particular false assumptions can be explored with the process of derivational robustness analysis and the importance of robustness analysis accounts for some of the puzzling features of the tradition of model-building in economics. 6) The fact that economists have been relatively reluctant to use true agent-based simulations to formulate explanations can partially be explained by the specific ideal of scientific understanding implicit in the practise of orthodox economics.

Gone with the Wind? : Immigrant Women and Transnational Everyday Life in Finland

Increased mass migration, as a result of economic hardship, natural disasters and wars, forces many people to arrive on the shores of cultures very different from those they left. How do they manage the legacy of the past and the challenges of their new everyday life? This is a study of immigrant women living in transnational families that act and communicate across national borders on a near-daily basis. The research was carried out amongst immigrant women who were currently living in Finland. The research asks how transnational everyday life is constructed. As everyday life, due to its mundane nature, is difficult to operationalise for research purposes, mixed data collection methods were needed to capture the passing moments that easily become invisible. Thus, the data were obtained from photographic diaries (459 photographs) taken by the research participants themselves. Additionally, stimulated recall discussions, structured questionnaires and participant observation notes were used to complement the photographic data. A tool for analysing the activities devealed in the data was created on the assumption that a family is an active unit that accommodates the current situation in which it is embedded. Everyday life activities were analysed emphasizing social, modal and spatial dimensions. Important daily moments were placed on a continuum: for me , for immediate others and with immediate others . They portrayed everyday routines and exceptions to it. The data matrix was developed as part of this study. The spatial dimensions formed seven units of activity settings: space for friendship, food, resting, childhood, caring, space to learn and an orderly space. Attention was also paid to the accommodative nature of activities; how women maintain traditions and adapt to Finnish life or re-create new activity patterns. Women s narrations revealed the importance of everyday life. The transnational chain of women across generations and countries, comprised of the daughters, mothers and grandmothers was important. The women showed the need for information technology in their transnational lives. They had an active relationship to religion; the denial or importance of it was obvious. Also arranging one s life in Finnish society was central to their narrations. The analysis exposed everyday activities, showed the importance of social networks and the uniqueness of each woman and family. It revealed everyday life in a structured way. The method of analysis that evolved in this study together with the research findings are of potential use to professionals, allowing the targeting of interventions to improve the everyday lives of immigrants.

Linnunkiikut ja kallen kaulukset : Kotitekoiset kuukautissiteet 1900-luvun alkupuolen Suomessa

The aim of this thesis was to study what kind of home-made menstrual pads were used in the early 20th century in Finland, how the home-made pads were made and which techniques and materials were used. The use and taking care of menstrual pads were also explored. The history of menstrual pads has been studied in Sweden, Germany and United States but none of those studies has concentrated on home-made pads. Instead, there are many studies about womanhood and menstruation. In many studies home-made menstrual pads are only briefly mentioned. Menstrual pads were not commonly used in Finland at the beginning of the 20th century, but already in the 1940s the use of menstrual pads had become common in every stratum of society. Home-made menstrual pads were used even until the 1960s. In Finland, factory-made disposable menstrual pads became common only in the 1930s and they were only slowly accepted. The study material consisted of nine interviews, three archival inquiries, health care guidebooks from 1893 to 1943 and authentic menstrual pads, menstrual belts and other objects related to them. The interviewed women were born between 1915 and 1939. The narrative approach was used in the study and it also guided the analysis. The interview and archival data were studied according to the basic rules of oral history studies. Literature consisted of publications from several disciplines. The extensive primary material played the most important role in this study. The reconstructions of the menstrual pads were made according to the interviewed women s advice. In Finland there were innumerable variations of home-made menstrual pads. The pads were most commonly crocheted and knitted either by hand or by knitting machine. Pads were also sewn of cloth, old bed linen or old underwear. The menstrual pads were self-made or made by a female relative. Word of mouth was important in spreading information on how to make pads, because there were hardly any instructions available. The biggest pads were 54 cm long and 13 cm wide. The most widely used pad model was a rectangle, which had triangle-shaped ends with a buttonhole or a loop. The pad was attached to the menstrual belt or to the buttons of the suspender belt. Knitted and crocheted pads had one, two or three layers. In sewn pads, there could be even more layers. Cellulose wadding or pieces of cloth could be placed inside the pad to increase the absorption ability. The experiences of the comfort of self-made pads varied. The crocheted and sewn pads were found chafing, knitted ones were found soft and comfortable. The menstrual pads were laborious to wash and boil in lye water. Therefore disposable pads made everyday life easier. The home-made menstrual pads were part of a unique tradition of handicrafts and folk culture. Hand-made pads were one of the most common handicraft products and were a part of every woman s life. Even so, the menstrual pads were unnoticeable. The large number of variations was probably caused by the silence around menstrual topics and by the lack of instructions for making pads. Variations are also explained by the uniqueness of every handicraft product. In Finland the home-made pads were used until relatively recent times. This was caused by the conditions of wartime and the following years and the rarity of commercial pads. Furthermore, until the late 20th century Finland was an agricultural society where all innovations spread slowly. Home-made menstrual pad was a secret handicraft of women and every woman needed to know how to make it by herself.

Inverse Problem for Fractional Brownian Motion with Discrete Data

The problem of recovering information from measurement data has already been studied for a long time. In the beginning, the methods were mostly empirical, but already towards the end of the sixties Backus and Gilbert started the development of mathematical methods for the interpretation of geophysical data. The problem of recovering information about a physical phenomenon from measurement data is an inverse problem. Throughout this work, the statistical inversion method is used to obtain a solution. Assuming that the measurement vector is a realization of fractional Brownian motion, the goal is to retrieve the amplitude and the Hurst parameter. We prove that under some conditions, the solution of the discretized problem coincides with the solution of the corresponding continuous problem as the number of observations tends to infinity. The measurement data is usually noisy, and we assume the data to be the sum of two vectors: the trend and the noise. Both vectors are supposed to be realizations of fractional Brownian motions, and the goal is to retrieve their parameters using the statistical inversion method. We prove a partial uniqueness of the solution. Moreover, with the support of numerical simulations, we show that in certain cases the solution is reliable and the reconstruction of the trend vector is quite accurate.

Stochastic Filtering

The stochastic filtering has been in general an estimation of indirectly observed states given observed data. This means that one is discussing conditional expected values as being one of the most accurate estimation, given the observations in the context of probability space. In my thesis, I have presented the theory of filtering using two different kind of observation process: the first one is a diffusion process which is discussed in the first chapter, while the third chapter introduces the latter which is a counting process. The majority of the fundamental results of the stochastic filtering is stated in form of interesting equations, such the unnormalized Zakai equation that leads to the Kushner-Stratonovich equation. The latter one which is known also by the normalized Zakai equation or equally by Fujisaki-Kallianpur-Kunita (FKK) equation, shows the divergence between the estimate using a diffusion process and a counting process. I have also introduced an example for the linear gaussian case, which is mainly the concept to build the so-called Kalman-Bucy filter. As the unnormalized and the normalized Zakai equations are in terms of the conditional distribution, a density of these distributions will be developed through these equations and stated by Kushner Theorem. However, Kushner Theorem has a form of a stochastic partial differential equation that needs to be verify in the sense of the existence and uniqueness of its solution, which is covered in the second chapter.

DNA Packaging and Host Cell Lysis: Late Events in Bacteriophage PRD1 Infection

The object of this study is a tailless internal membrane-containing bacteriophage PRD1. It has a dsDNA genome with covalently bound terminal proteins required for replication. The uniqueness of the structure makes this phage a desirable object of research. PRD1 has been studied for some 30 years during which time a lot of information has accumulated on its structure and life-cycle. The two least characterised steps of the PRD1 life-cycle, the genome packaging and virus release are investigated here. PRD1 shares the main principles of virion assembly (DNA packaging in particular) and host cell lysis with other dsDNA bacteriophages. However, this phage has some fascinating individual peculiarities, such as DNA packaging into a membrane vesicle inside the capsid, absence of apparent portal protein, holin inhibitor and procapsid expansion. In the course of this study we have identified the components of the DNA packaging vertex of the capsid, and determined the function of protein P6 in packaging. We managed to purify the procapsids for an in vitro packaging system, optimise the reaction and significantly increase its efficiency. We developed a new method to determine DNA translocation and were able to quantify the efficiency and the rate of packaging. A model for PRD1 DNA packaging was also proposed. Another part of this study covers the lysis of the host cell. As other dsDNA bacteriophages PRD1 has been proposed to utilise a two-component lysis system. The existence of this lysis system in PRD1 has been proven by experiments using recombinant proteins and the multi-step nature of the lysis process has been established.

Kulutus, tieto, hallinta : Kulutuksen tilastoinnin muutokset 1900-luvun Suomessa

The aim of the study was to find out how the consumption of the population in Finland became a target of social interest and production of statistical data in the early 20th century, and what efforts have been made to influence consumption with social policy measures at different times. Questions concerning consumption are examined through the practices employed in the compilation of statistics on it. The interpretation framework in the study is Michael Foucault s perspective of modern liberal government. This mode of government is typified by pursuit of efficiency and search of equilibrium between economic government and a government of the processes of life. It shows aspirations towards both integration and individualisation. The government is based on freedom practices. It also implies knowledge-based ways of conceptualising reality. Statistical data are of specific significance in this context. The connection between the government of consumption and the compilation of statistics on it is studied through the theoretical, socio-political and statistical conceptualisation of consumption. The research material consisted of Finnish and international documentation on the compilation of statistics on consumption, publications of social programmes, and reports of studies on consumption. The analysis of the material focused especially on the problematisations related to consumption found in these documents and on changes in them over history. There have been both clearly observable changes and as well as historical stratification and diversity in the rationalities and practices of consumption government during the 20th century. Consumption has been influenced by pluralistic government, based at different times and in varying ways on the logics of solidarity and markets. The difference between these is that in the former risks are prepared for collectively while in the latter risks are individualised. Despite the differences, the characteristic that is common to these logics is certain kind of contractuality. They are both permeated by the household logic which differs from them in that it is based on the normative and ethical demands imposed on an individual. There has been a clear interactive connection between statistical data and consumption government. Statistical practices have followed changes in the way consumption has been conceptualised in society. This has been reflected in the statistical phenomena of interest, concepts, classifications and indicators. New ways of compiling statistics have in their turn shaped perceptions of reality. Statistical data have also facilitated a variety of rational calculations with which the consequences of the population s consumption habits have been evaluated at the levels of economy at large and individuals.

Vain hätapua? : Taloudellinen avustaminen diakoniatyön professionaalisen itseymmärryksen ilmentäjänä

Financial Help Alone? Financial help as an exponent of professional diaconal work One essential form of helping people in the Evangelical Lutheran Church s diaconal work is providing economic aid. It can be seen as work which is in accordance with the spirit of the Church Order (4:3). One of the tasks of diaconal work, determined by the Church Order, is to help those whose distress is the greatest and who have no other source of help. This financial support has become a permanent and essential working method, which has also created tension of various kinds. Financial support has been criticized, especially when the support has been used to fill a gap in the social services provided by the government. It has been argued that diaconal work has been forced to take on responsibility for tasks that belong to the welfare state. The tensions involved in the financial support of diaconal work do not only concern the patching up and supplementing of the deficiencies in the welfare state s services but also the question of diaconal workers self-understanding of financial support and how it relates to their professionalism. In this thesis, I examine the experiences and visions diaconal workers have concerning financial support in their work with clients. The viewpoint of my work is the diaconal workers own experiences and interpretations of the meaning of financial support in customer service. In the articles of my thesis, I examined the meanings that diaconal workers gave to financial support in the aspects of work motivation, empowerment, expertise and tensions. The research material of my articles consists of three different data, which are theme interviews from diaconal workers, a survey from diaconal workers of Espoo and a diaconal barometer of 2009. I have analysed the theme interviews and the survey using qualitative content analysis. The results of my articles showed that diaconal workers motivation in tasks concerning economic aid was sustained by the nature and spiritual aspects of support activities. Work that supported empowerment through financial assistance meant influencing the client s personal life, community and local ties and structural circumstances of the surrounding society. Diaconal workers expertise in financial support work can be characterised as horizontal, which means that the expertise was built on acknowledging the client s dignity, the uniqueness of the client s life situation and listening to the client s own voice. Diaconal workers were also experts in community and area-based work. The tensions in financial support work are linked to its unofficial and undefined role in the field of social welfare and the inability of other aiding parties to respond to their duties. The results of my thesis on the experiences and visions of financial support reveal that it is multilateral and multidimensional. Diaconal workers used financial support to help the clients, taking into account their individual, communal, social and spiritual context. The professionalism of this financial support is reflectively related to the client s need of help and the spontaneity and unexpectedness of the situation. Support work was deeply bound to diaconal workers experiences of spirituality as the basic value in their work, the foundation of their idea of humanity and their method of helping others. In different tasks of financial support diaconal workers balanced between traditional, individual client work based on caritas and working methods which are based on supporting the individual s empowerment and active citizenship, as in postmodern social work. Diaconal workers experiences of financial support illustrated the transition or turning point in the professionalism of diaconal work, which involves finding one s own, stronger and clearer professional identity than earlier with respect to other helpers in society. Creating a unique identity is part of the empowerment process of diaconal work, in which it must define its professional role by itself. In postmodern pluralism and the fragmented context of diaconal activities, the question arose as to whether the spiritual traditions and traditional values of diaconal work support the modifications and adaptations needed in new, unpredictable situations. Diaconal work is said to be fast to react, able to predict changes and adapt to those changes. To preserve its sensitive reactive ability, also in the complex postmodern world, it must retain its own views and orientations. Otherwise, the distinctive values and traditions of diaconal work might sustain static diaconal work, employee-centeredness and a smug attitude when defining beneficiaries and needs, which highlights the paternalism of diaconal work. Such paternalism may complicate the progress of working methods which are based on empowerment and citizenship.