Artikkelit: Recent submissions

Now showing items 1-20 of 43198
  • Mäkelä, Pirjo; Jokinen, Kari; Himanen, Kristiina (Springer, 2019)
  • Räsänen, Elina (Turun Historiallinen Yhdistys, 2016)
    Turun Historiallinen Arkisto
  • Alam, Syed Ariful (Helsingin yliopisto, 2020)
    Dissertationes Schola Doctoralis Scientiae Circumiectalis, Alimentariae, Biologicae. Universitatis Helsinkiensis
    This study focused on modification of rye bran to produce high fibre extruded cereal foods with a good texture and structure. Rye bran addition during extrusion is challenging due to high levels of insoluble dietary fibre, which leads to less expanded products and a hard texture. Bran modification by particle size reduction or fermentation significantly improved both the structural and textural properties of extrudates. Moreover, optimization of the processing parameters such as increasing the screw speed, lowering the water feed rate, as well as the use of in-barrel hydration regimens further improved the textural properties. The applicability of rye bran in extruded products could thus be improved by particle size reduction and fermentation. The extruded food structure and texture had a direct effect on the mastication and bolus formation process in the mouth. A hard and dense extrudate structure required more mastication effort than a crispy structure. Crispy and porous structures easily disintegrated in the mouth and produced smaller bolus particles than a hard and dense structure. A smaller particle size of the bolus was associated with increased starch hydrolysis. The bolus particle size was more effective than the matrix composition in altering the starch digestibility. Increased dietary fibre intake via appealing snack products could help reduce chronic diseases. Knowledge obtained in this thesis on cereal matrix formation and digestion and the effects of added dietary fibre on the structural and textural properties of extruded solid foams will help the food industry to develop healthy and appealing products. Understanding process-structure-digestibility relationships of high fibre extruded matrices is essential for designing health promoting foods.
  • Matkala, Laura (Faculty of Agriculture and Forestry of the University of Helsinki, 2020)
    Dissertationes Forestales
  • Koskela, Kaisu (University of Helsinki, 2020)
    Publications of the Faculty of Social Sciences
    This dissertation is about social identities, group boundaries and belonging among skilled migrants living in Finland. It is based on empirical data consisting of ethnographic fieldwork and interviews. The main research question I ask is: In their process of settling in in Finland, how do skilled migrants find and define a place for themselves within the structures of their new host society? In addition, I ask questions about the strategies of identity negotiations, the role of class and ethnicity for skilled migrants’ social identities, and how skilled migrants’ group identity is defined in relation to others around them. I approach these questions from the perspective of interactionist identity theories and intersectionality. The findings of the research are presented in four peer-reviewed articles. The main findings are firstly that despite their more privileged socio-economic situation, skilled migrants are experiencing similar issues with integrating, adapting and belonging in Finland as other migrants. They are subjected to racializing discourses, stereotypes and attitudes in much the same way as other migrants are. Secondly, while white skilled migrants are readily viewed as a ‘migrant elite’, racialized skilled migrants feel that they are perceived in the negative image of ‘the migrant’ as a non-western, non-skilled, nonprivileged subject. However, they themselves identify first and foremost as skilled migrants, a social group identity that is based largely on shared class status. Thirdly, there is a conflict between this internal group identification and how racialized skilled migrants perceive themselves to be categorized. This conflict leads to various boundary making strategies that aim at being seen in a more positive way and included in the ‘migrant elite’ category that is understood as a positive, valuable social identity in itself. Together, the findings of the articles point to the continued centrality of the intersection of class and ethnicity in the lives of skilled migrants in Finland. In answering the research question, I conclude that skilled migrants do not feel that they are accepted as full members of Finnish society or seen as equal to Finns. Belonging is therefore searched from a ‘parallel international society of Finland’ consisting of other skilled migrants and ‘internationally-minded Finns’, rather than Finnish society as a whole. As such, the research also demonstrates that ideas about what integration and belonging mean for skilled migrants are based on their own beliefs of their place within the societal whole. Rather than integrating unidirectionally into the host society in the host society’s terms, their integration is an ongoing process of negotiations between structure and agency: between the Finns’ attitudes towards immigrants and their own understandings of their value as members of an internationalizing society.
  • Kosunen, Maiju (Faculty of Agriculture and Forestry of the University of Helsinki, 2020)
    Dissertationes Forestales
  • Kaaronen, Roope Oskari (University of Helsinki, 2020)
    Publications of the Faculty of Social Sciences
  • Lehtiniemi, Tuukka (University of Turku, 2020)
    Turun yliopiston julkaisuja. Sarja B: Humaniora
    The digital environment is increasingly organised to transform aspects of people’s lives into data in order to make use of those data in the production of economic value. Data activism has emerged as one response to the resulting asymmetries in data usage and distribution. Adopting the concept of collective imagination, this thesis investigates imaginaries about an alternative data economy developed in data activism. Based on the data studies literature, a view of the dominant data economy imaginary is first constructed. It consists of collectively shared notions about how the data economy currently functions and ought to function. Based on four original publications, alternative imaginaries are compared with the dominant imaginary. The aim is to examine the alternative imaginaries and their underpinnings and to scrutinize the desirability of the data futures they promote. Empirical research in this thesis has focused on MyData, a data governance initiative striving for a more central role for people in the data economy. The thesis identifies two alternative imaginaries developed in the context of the initiative: the market imaginary and the citizen imaginary. Both build on the notion of data agency, that is, providing people with new capabilities to act in relation to personal data. The market imaginary is based on viewing data agency as market choice, and relies on the market for data governance. Individuals are imagined to act in data markets to improve their lives, making data serve their personal ends. The citizen imaginary foregrounds collective data governance and the common good. Here, data agency is imagined as citizens’ collective capability to participate in the processes that determine how and for what purposes their data are used. This thesis discusses how the market imaginary is the better positioned of the two to expand beyond data activism; it resonates with notions about technology as the enabler of individual choice, leverages existing regulatory instruments, and is aligned with commercial views of the value of data. Based on this research, however, the reliance on market agency appears as a precarious starting point for a desirable data future. The practical implication is to encourage data activists to experiment on collective data governance and on new ways to make data valuable alongside the market-oriented ones. The implication for data activism research is that identifying imaginaries underpinning activist initiatives can aid with shaping pathways toward a desirable digital environment.
  • Miettinen, Jenni (2020)
    Dissertationes Forestales
  • Kulha, Niko (Finnish Society of Forest Science, 2020)
    Dissertationes Forestales
  • Hellemann, Dana (University of Helsinki, 2019)
    Dissertationes schola doctoralis scientiae circumiectalis, alimentariae, biologicae Universitatis Helsinkiensis
    Benthic nitrogen (N) cycling in sandy sediments in the stratified aphotic coastal zone (> 15 m) of the Baltic Sea was investigated along a north–south environmental gradient of N loading, trophic status, coastal geomorphology and sediment permeability. The aim was to establish a more comprehensive view of the Baltic Sea coastal N filter, where N transformation processes remove (via denitrification and anaerobic ammonium oxidation) and retain (via dissimilatory nitrate reduction to ammonium) land-derived N and thereby reduce its availability to the open sea; so far these processes have not been quantified in the deeper, aphotic sandy sediments. The main results are that a) not all sandy sediments were permeable enough to experience advective pore-water flow – mass transport in non-permeable sands functions via diffusion and fauna-mediated fluxes only, which simplifies biogeochemical measurement design; b) N removal rates were affected by the availability of labile particulate organic matter as a source of labile organic carbon and N, resulting in higher removal rates in eutrophic than in oligotrophic conditions, as well as similar removal rates in non-permeable sands and muds when also the substrate availability was similar; c) seasonal N removal in the stratified aphotic coastal zone is largely driven by the hydrography-controlled development of bottom water temperature, and differs from the seasonal pattern observed in the mixed photic coastal zone; and d) the role of dissimilatory nitrate reduction to ammonium in the aphotic coastal sandy sediments of the Baltic Sea is presumably more important than previously anticipated. These results indicate that the sandy sediments in the aphotic coastal zone of the Baltic Sea have an important role in N removal and retention, and are thus an integral component of the Baltic coastal N filter. The results further show the strong influence of the local environment on N cycling rates, emphasizing the need for context dependent data analysis, particularly in a diverse coastal setting such as in the Baltic Sea.
  • Hou, Jue (University of Helsinki, 2020)
    Named entity recognition is a challenging task in the field of NLP. As other machine learning problems, it requires a large amount of data for training a workable model. It is still a problem for languages such as Finnish due to the lack of data in linguistic resources. In this thesis, I propose an approach to automatic annotation in Finnish with limited linguistic rules and data of resource-rich language, English, as reference. Training with BiLSTM-CRF model, the preliminary result shows that automatic annotation can produce annotated instances with high accuracy and the model can achieve good performance for Finnish. In addition to automatic annotation and NER model training, to show the actual application of my Finnish NER model, two related experiments are conducted and discussed at the end of my thesis.
  • Leinonen, Juho (Helsingin yliopisto, 2019)
    Department of Computer Science, Series of Publications A
  • Häyrinen, Liina (Finnish Society of Forest Sciences, University of Helsinki - Department of Forest Sciences, 2019)
    Dissertationes Forestales
    Non-industrial private forest (NIPF) owners are important forest ecosystem service providers and users. Along with the structural and general lifestyle changes of owners, their forest ownership objectives have become more diverse, strongly emphasizing intangible forest values alongside timber production. Therefore, NIPF owners and their versatile forest ownership objectives are a potential source of information for exploring the untapped future potential that could help the forest sector to retain its future viability on the road towards a bioeconomy. This doctoral thesis aims to understand the drivers of demand for new forestry services and forest-based business opportunities from the perspective of NIPF owner objectives and forest meanings. Objectives and forest meanings are examined from methodological, sociodemographic and NIPF owner sustainable lifestyle perspectives, leading to more general examination of NIPF owner perceptions of future utilization prospects of forests and the forest sector. Thus, the objective of the thesis is to build a more in-depth understanding of NIPF owner objectives and to examine how this information could be used in the development and marketing of forestry services and other forest-related products and services. The findings present a way to systematically analyse the objectives of forest ownership and also illustrate how certain segments of forest owners value aesthetics and biodiversity conservation over a traditional monetary value orientation. The results also indicate that the owners with the highest sustainable consumption orientation place a greater emphasis on multiple benefits of forests than owners who have a lower such orientation. The findings show that the future value creation of forests will be based on multiple aspects, and the widening of perspective beyond raw material dominance in the utilization of forests is important. Thus, recognizing customer pressure towards more diversified forestry services would be essential in meeting the versatile needs of forest owners but also from the perspective of developing new forest-based businesses.
  • Junttila, Samuli (Finnish Society of Forest Sciences, University of Helsinki - Department of Forest Sciences, 2019)
    Dissertation Forestales
  • Kantola, Tuula (Finnish Society of Forest Science, 2019)
    Dissertationes Forestales
    Climate change is amplifying forest disturbances, especially those by insect pests. In addition to native species, alien insects are threatening forest health, ecosystem sustainability, and economic return. Uncertainties related to insect pest infestations are increasing along the risk of high impacts. There is a high demand of accurate and cost-effective methods for forest health monitoring to prevent, control, and mitigate the various negative impacts, as well as to support decision-making. Current needs for information for efficient forest management are complex and extensive. The required quality cannot be met with traditional forest inventory methods. Forest information should be up-to date and available across spatial and temporal scales. The developing field of remote sensing and geographical information systems provide new means for various forest monitoring. However, disturbance monitoring, especially by insect pests, gives an extra challenge and increased uncertainties compared to other forest monitoring tasks. With new approaches, valuable information on disturbances can be derived for evaluation of insect-induced forest disturbance at reasonable high accuracy and reduced amount of fieldwork. This dissertation aims towards improved forest health monitoring. Insect-induced disturbances from tree level to larger areas were evaluated in six sub-studies. Different remote sensing sensors and approaches, and ecological niche modeling were employed in disturbance evaluation. Study species include native and invasive insect pests. In context of recent research, issues specific to insect disturbance monitoring are discussed. Pattern, frequency, scale, and intensity of insect infestations vary depending on the pest and landscapes in question affecting disturbance detection and impact evaluation. Sensors, platform, and/or modeling methods have to be chosen accordingly. Environmental features, such as topography, and level of landscape fragmentation give restrictions to the method selection, as well as to the appropriate spatial resolution. Importance of varying information is also affected by the scale and resolution of investigation. Timing of data acquisition is crucial. Early detection and timely management operations are often the only way to mitigate insect outbreaks. Moreover, amount and accuracy of auxiliary information, including forest inventory data, and disturbance history, differ between countries and continents. Forest policies and practices differ between regions affecting selection of usable data sets and methods. Forest health monitoring should be included into forest monitoring systems for timely disturbance detection, accurate monitoring, and impact evaluation. Higher and lower spatial resolution remote sensing should be combined over varying spatial ranges and modeling techniques incorporated for flexible and cost-efficient monitoring over a gradient of different forest ecosystems, climatic conditions, and forest inventory and management practices. Open access remote sensing archives with high temporal resolution could facilitate continuous monitoring of wide forest areas. Developing satellite technology may respond to these needs. Plenty of valuable research on forest health monitoring exist. However, considerably more research is still needed before comprehensive monitoring systems can be adopted at the operational level. Development of remote sensing and modeling techniques, as well as improving computational power and databases facilitate continuous improvement of forest health management practices.
  • Loponen, Mika (Unigrafia, 2019)
    This study discusses the evolution of racialized concepts in the genres of the fantastic, especially fantasy, science fiction, and supernatural horror. It provides the first detailed interpretation of how such concepts are constructed and how they develop based on their interaction with the evolving cultural landscapes, thus showing how characteristics are borrowed from real world cultural stereotypes. The analysis concentrates on fantastic renderings of racialized stereotypes based on real world cultural fears. The concepts are examined both in their source cultures and through the lenses of transmediality and translation. As the fantastic arts have always been heavily transmedial in nature, the study is not limited to a certain art form, but views all media as complementary in producing concepts of the fantastic, either by adding new facets to the concepts, or by changing them on a temporal basis. Contextualizing concepts in the fantastic arts through their linkage to the real world cultural development provides a method through which we can perceive how the concepts are built on – and preserve – racialized stereotypes of their cultures of origin. In order to do so, this study provides a framework that utilizes several approaches from cultural semiotics as well as translation studies. Furthermore, it presents a view of the evolution of the genres in specific media through case studies. The framework is applied to some well-known fantastic concepts (orcs, dwarves, goblins, and gnomes), by mapping their entry into the fantastic arts and examining how the changes in their signifying imagery have affected their allusive links to the real world stereotypes that are (intentionally or non-intentionally) portrayed through them. In addition, translational tools are applied in a case study to examine how racialized features are transported to a new cultural setting in translation. The study argues that the inclusion of properties of racialized stereotypes from real world cultures to fantastic concepts is widespread and that especially negative racialized allusions often survive in texts of the fantastic, even after they have been perceived as offensive in the real world cultures from which they stem. It displays how racialized narratives can change when fantastic concepts inherit properties from new real world racialized stereotypes, and how inheriting signifiers from a “positive” real world racialization can affect the negative properties of fantastic concepts.
  • Tammisto, Tuomas (University of Helsinki, 2018)
    Research Series in Anthropology
    The thesis examines how the Mengen living in the rural Pomio District in Papua New Guinea reproduce their society and their lived environment by engaging in swidden horticulture, logging, wage labor on plantations and community conservation. These four practices have created and continue to create different kinds of places and social relations that involve the Mengen, like other inhabitants of Pomio, within larger political and economic structures. These have also produced, reproduced and at times significantly changed the environment of the Mengen. By examining the four complex modes of engaging with the environment, the thesis seeks to answer two questions. First, how the Mengen produce their livelihood, a socially meaningful environment and valued social relations in the process. Second, how the Mengen take part in natural resource extraction, the expansion of industrial agriculture and state territorialization on a resource frontier---a spatialized process in which resources, practices and their values are defined. This often involves struggle, which reflects the notion that the greatest political struggles are not only over who gets to appropriate value, but who gets to define it. The study is aimed as a contribution to the understandings of human-environmental relations and natural resource extraction. It suggests that political ecology combined with anthropological theories of value help us understand how people who have intimate relations with their lived environment engage in a globalized resource economy. The thesis argues that there is no uniform way in which "the Mengen" take part in logging or the making of the state. The very different approaches deployed and the ensuing disagreements are, however, often disagreements over how best to pursue Mengen values of establishing productive relations with each other, the land and people from elsewhere. The Mengen have been successful in retaining their system of values over long and extensive contact with commodity relations, foreign companies and state administrations, while adapting to and incorporating these changes into their lives without losing hold of what they value. A key reason for this is that they have not been dispossessed of their lands, but continue to hold them communally.
  • Lintulaakso, Kari-Erik Johannes (University of Helsinki, Faculty of Science, Department of Geosciences and Geography, 2018)
    Department of Geosciences and Geography
  • Canarecci, Giovanni (University of Helsinki, 2018)
    The purpose of this study is to analyse two related topics: the Rumin cohomology and the H-orientability in the Heisenberg group H^n. In the first three chapters we carefully describe the Rumin cohomology with particular emphasis at the second order differential operator D, giving examples in the cases n+1 and n+2. We also show the commutation between all Rumin differential operators and the pullback by a contact map and, more generally, describe pushforward and pullback explicitly in different situations. Differential forms can be used to define the notion of orientability; indeed in the fourth chapter we define the H-orientability for H-regular surfaces and we prove that H-orientability implies standard orientability, while the opposite is not always true. Finally we show that, up to one point, a Mobius strip in H^1 is a H-regular surface and we use this fact to prove that there exist H-regular non-H-orientable surfaces, at least in the case n+1. This opens the possibility for an analysis of Heisenberg currents mod 2.