E-thesis

Recent Submissions

  • Nikkari, Eeva (2017)
    The sentence segmentation task is the task of segmenting a text corpus into sentences. Segmenting well structured and fully punctuated data into sentences is not a very difficult problem. However, when the data is poorly structured or missing punctuation the task is more difficult. This thesis will look into this problem by using probabilistic language modeling, with special emphasis on the n-gram model. We will present theory related to language models and evaluating them, as well as empirical results achieved on documents provided by AlphaSense Oy and a freely available Reuters-21578 corpus. The experiments on n-gram models focused on the following questions. How does the smoothing and order of the n-gram affect the model? How well does a model trained on one type of data adapt to another type of text? How does retaining more or less symbols and punctuation affect the performance? And how much is enough training data for the model? The n-gram models performed rather well on the same type of data they were trained on. However, the performance was significantly worse when moving to another document type. In absence of punctuation the performance of the model was also rather poor. The conclusion is that the n-gram model seems inadequate in recovering the sentence boundaries in difficult settings such as separating the unpuncutated title from the body of the text.
  • Holstila, Ansku (Helsingin yliopisto, 2017)
    Physical inactivity is a significant risk factor for non-communicable diseases. It has also been associated with a decline in functioning and a higher risk of work disability. However, there is limited evidence concerning the causes and consequences of changes in physical activity. Most Finnish adults of working age do not meet the recommendations for health-enhancing physical activity, and people tend to become less physically active as they age. Increasing activity levels among older age groups could enhance functioning and work ability among the ageing population. The aim of this thesis was, first, to examine how changes in physical activity are associated with subsequent health functioning, sickness absence and disability retirement. The physical and mental health functioning and sickness absence attributable to musculoskeletal and mental causes were examined separately. Second, the intention was to investigate how physical activity changes after the transition to statutory retirement and during post-retirement years. The research was part of the Helsinki Health Study being carried out at the Department of Public Health, University of Helsinki. The baseline surveys were conducted in 2000-2002 (N=8,960, response rate 67%) among employees of the City of Helsinki aged 40-60. The employees who responded to the baseline survey were followed up in two later surveys, meanwhile the cohort aged and some of the employees retired. The phase-2 follow-up survey was conducted in 2007 (N=7,332, response rate 83%) and phase 3 in 2012 (N=6,814, response rate 79%). The survey data were linked with register data on sickness absence from the Social Insurance Institution of Finland, and on disability retirement from the Finnish Centre for Pensions among those who consented to the register linkage (N=6,606). The register data on sickness absence and disability retirement includes medically confirmed diagnoses. Sickness absence periods were followed up from phase 2 until 2009, and disability retirement from phase 2 until 2013. Increased physical activity was associated with better physical health functioning and decreased activity with worse physical health functioning. There were fewer associations between changes in physical activity and mental health functioning. Increases in physical activity were associated with a lower risk of sickness absence. Vigorous physical activity was especially beneficial for physical health functioning and contributed to a lower risk of sickness absence attributable to musculoskeletal diseases. In contrast, a higher intensity of physical activity had less of an effect on mental functioning and sickness absence attributable to mental causes. In some cases, moderate-intensity physical activity was more beneficial to mental health functioning than higher-intensity activity. In addition, adopting vigorous physical activity was associated with a lower risk of disability retirement, and decreasing the intensity from vigorous to moderate or low was associated with a higher risk. Physical activity increased after the transition to statutory retirement, but declined a few years after retirement. Given the results of this study, ageing employees and retirees engaging in a low level of physical activity should be encouraged to increase the level. Vigorous activity could also be promoted, at least among healthy individuals. The transition to statutory retirement is a good opportunity to promote physical activity and thereby facilitate a change for the better. It is also important to support the maintenance of physical activity in the years following the transition to retirement.  
  • Benjamin, Saija (Helsingin yliopisto, 2017)
    This qualitative PhD study examines the lived experiences of eight young individuals who moved from one country to another several times during their childhood because of their parents’ profession, hence the term hypermobility in the title. As international, work-based mobility is increasing, it is of critical importance to observe how it affects childhood in general and how the children experience it in particular. The various socio-emotional aspects related to children’s hypermobility – often overlooked in discourses surrounding internationalization – are examined. This interdisciplinary study is situated in the field of intercultural education and guided by the following research question: How do children relocating with their families experience hypermobility? The data were gathered in Prague in 2013 with one-to-one semi-structured interviews that were conducted in English with eight youths (13 to 17 years old) who had moved internationally several times during their childhood and who had a “mixed” parental heritage. The interviews were complemented with self-chosen photographs and a life-grid. Interpretative Phenomenological Analysis (IPA, Smith, Flowers & Larkin 2009) was used as the methodological and analytical framework for the study. Four master themes emerged from the analysis as the predominant topics regarding the informants’ experiences of hypermobility. The themes disclose 1) the pervasive feelings of ephemerality and uncertainty outlining the youths’ everyday lives and relationships, 2) the different strategies the youths’ deploy to cope with the psychological strain related to the major life changes, 3) the ways the youths resort to multivoiced biographical narratives as a way to understand and describe the self, and 4) the feelings of connectedness that are grounded in self-created imageries, personal memories and (trans-generational) family narratives. In addition to the master themes, the role of international schools is discussed as significant in the youths’ identity and worldview development and as an environment where the youths’ complex life trajectories are normalized and validated. The rising calls for closed borders and nationalism necessitate increasing awareness of the diverse ways of being and belonging in societies and communities. Although based on a small sample of informants, this study opens a window for examining one way of inhabiting this world through the experiences of young mobile individuals. The findings enhance the current understanding of what it is like to grow up in the midst of international relocations in a world predominantly defined by sedentary norms and majority. The study’s conclusions should also prove to be particularly valuable to parents who consider or pursue an international career and for educators who work in schools with a high student turnover. Keywords: youth, third culture kids, international mobility, expatriates, international education
  • Bennett, Rachel (Helsingin yliopisto, 2017)
    Background and rationale Alpha2-adrenoceptor agonists, such as medetomidine, are commonly used in veterinary medicine for the sedation and premedication of animals. Their use is associated with a range of undesirable pharmacodynamic effects most notably vasoconstriction, bradycardia (Pypendop and Verstegen 1998), hyperglycaemia (Hsu and Hummel 1981) and diuresis (Thurmon et al. 1978). MK-467 is a peripheral α2-adrenoceptor antagonist (Clineschmidt et al. 1988), which ameliorates the aforementioned side effects of (dex-)medetomidine whilst maintaining the sedative effects (Enouri et al. 2006; Honkavaara et al. 2008; Restitutti et al. 2012; Rolfe et al. 2012). Therefore MK-467 may offer some important clinical benefits, although some questions remain concerning its pharmacodynamic and pharmacokinetic interaction with other anaesthetic drugs. The main objectives of the following studies were to: determine the protein-binding fraction of MK-467, to assess the possible role of MK-467 as a P-glycoprotein substrate in vitro; and to evaluate the impact of MK-467 on the disposition of medetomidine in vivo. During in vivo studies, the impact of MK-467 on the centrally mediated effects: sedation and antinociception and peripherally mediated cardiovascular effects of medetomidine were assessed simultaneously. The protein-binding characteristics of MK-467 were investigated using the technique of equilibrium dialysis. Drug concentrations were measured using the technique of liquid chromatography and tandem mass spectrometry. Protein-binding fraction of MK-467 was approximately 70% and it was unaltered by the presence of medetomidine. Transcellular drug movement was determined using Madin-Darby Canine Kidney cells - wild type (WT-MDCKII) and cells transfected with the human gene encoding P-glycoprotein (MDR1-MDCKII). In addition to MK-467, acepromazine, a putative P-glycoprotein substrate, and dexmedetomidine were also investigated. Based on measured drug concentrations, apparent permeability of the cells was calculated and used to determine the role of active transport in the transcellular movement of the selected drugs. Passive movement of MK-467 was undetectable. Therefore, efflux ratios for MK-467 were not determined. However, movement in the basolateral to apical direction occurred in both cell lines. The identity of the possible transporter remains unclear. Transport ratios for acepromazine were 1.17:1:1.0 and 1.51:1.0 for WT-MDCKII and MDR1-MDCKII transfected cells, respectively. Currently acepromazine cannot be defined as a P-glycoprotein substrate based on these results. Whilst, dexmedetomidine transport ratios were 0.98:1.0 and 1.15:1.0 for WT-MDCKII and MDR1-MDCKII respectively. It does not appear to be a substrate for an active transport mechanism. In vivo drug concentration data underwent non-compartmental analysis. MK-467 increased the volume of distribution and clearance of dexmedetomidine and levomedetomidine, whilst area under the curve and elimination half-life were significantly decreased when compared with medetomidine alone. Medetomidine significantly decreased the clearance of alfaxalone during co-administration, whilst the additional administration of MK-467 counteracted the effect of medetomidine on alfaxalone clearance. The quality and duration of sedation were assessed using a composite sedation score, whilst hypnosis was evaluated by measurement of bispectral index or analysis of the electroencephalogram. Antinociception was determined by the measurement of limb withdrawal times and head lift times following the application of a nociceptive stimulus applied to the nailbed of a hind limb digit. Measured haemodynamic variables included arterial blood pressure, heart rate, cardiac output and systemic vascular resistance. Ventilatory effects of medetomidine and co-administered MK-467 were also assessed by the analysis of arterial and venous blood gas samples taken during these studies. The co-administration of MK-467 did not alter the initial quality of sedation but reduced the duration of sedation produced by medetomidine. MK-467 significantly diminished the antinociceptive action of medetomidine. MK-467 ameliorated the cardiovascular, haemodynamic and ventilatory effects of medetomidine prior to and during general anaesthesia. In conclusion, MK-467 is moderately protein bound and it is unlikely to be subject to drug-drug interactions in vivo. MK-467 shows little passive movement in MDCKII cells but may undergo active cellular efflux. It is unclear whether MK-467 is suitable for use in animals carrying the P-glycoprotein mutation. The addition of MK-467 alters the disposition of co-administered drugs resulting in lower plasma drug concentrations. The reduction in some pharmacodynamic effects may be attributed to the alteration in pharmacokinetics caused by the peripheral α2-adrenoceptor antagonist.
  • Kerminen, Kaisa (Helsingin yliopisto, 2017)
    The wide use of pesticides has led to the contamination of soils, subsoils, surface and ground waters. This motivated research on pesticide dissipation and remediation of pesticide contaminated soils and groundwater. The herbicide dissipation was studied in boreal surface soils, subsurface sediment slurries and pilot-scale sediment columns. The sediments were from a groundwater area that was contaminated with atrazine, desethylatrazine (DEA), simazine and 2,6-dichlorobenzamide (BAM). The aim was to enhance dissipation by microbes (indigenous / Pseudomonas ADP), sonication (0, 5, 10, 20 or 30 min, 43 kHz, 320 W) or the following additives: surfactant methyl-β-cyclodextrin, a mixture of zero-valent iron and organic matter (EHC®), peat or a compost-peat-sand (CPS) mixture. Microbes enhanced atrazine (half-lives 57–181 d) and terbutryn (70–291 d) degradation in surface soils. Atrazine was also degraded chemically in four soils (half-lives 120–183 d). Oxygen did not affect atrazine half-lives significantly, while terbutryn was only degraded in aerobic soils. Herbicide dissipation was poorest in the soil that had the lowest amounts of organic matter and nitrogen. Sonication did not decrease the atrazine concentrations, compared with the non-sonicated controls, despite of indications of microbial and chemical degradation. Surfactant did not stimulate atrazine degradation by indigenous sediment microbes, and Pseudomonas ADP degraded atrazine even without surfactant. EHC® enhanced chemical atrazine dissipation under aerobic conditions and, in columns, cleaned atrazine-, DEA- and BAM-contaminated groundwater for about a month. Peat and CPS enhanced the chemical dissipation of atrazine and simazine. Peat also enhanced hexazinone dissipation. Only trace amounts of atrazine, simazine and hexazinone could be extracted from peat and sediment, which indicates that the dissipation was caused by chemical degradation and/or unextractable bound residue formation. In conclusion, the addition of peat, CPS and Pseudomonas ADP were the best approaches for reducing pesticide concentrations. EHC® could also be useful in remediation of small quantities of pesticides, preferably in the presence of oxygen. However, the usability of peat, CPS and EHC® in remediation should be further studied to avoid the possible adverse effects of organic matter additions to drinking water quality.
  • Helin, Tuukka (Helsingin yliopisto, 2017)
    Direct oral anticoagulants (DOACs), the thrombin inhibitor dabigatran and the anti-Xa inhibitors rivaroxaban and apixaban are are simple to use as standard dosing is recommended and no routine monitoring of coagulation is advocated. However, in certain clinical situations, e.g. acute thrombosis or bleeding, emergency surgery and renal or hepatic failure, assessing anticoagulant bioactivity is essential. The aims of this study were to firstly assess the effects of these DOACs in commonly used coagulation screening tests (PT, INR and APTT) using both spiked samples and samples collected from patients on treatment. Secondly, the availability of specific methods for drug effect assessment, namely drug-calibrated thrombin time (dabigatran) and anti-Xa (rivaroxaban, apixaban) assays were assessed in laboratory surveys. Thirdly, the effects of DOACs on these specific assays were explored using patient samples. Finally, the effect of DOACs on the global coagulation assay thrombin generation (TG) was assessed in patients using dabigatran, rivaroxaban or apixaban. The spiked sample laboratory surveys included a total of 86 European laboratories. The effects of all DOACs on INR were modest, but large reagent variability was noted in the responses (p<0.001). In APTT, rivaroxaban and apixaban prolonged the APTT only modestly, but with dabigatran there was a clear prolongation. Only about a fourth of the laboratories were able to provide more specific methods, TT or anti-Xa assays for drug quantification. Dabigatran effects in patient samples were studied 241 unselected patient samples. The PT was rarely prolonged and the APTT was in curvilinear relationship (R2 = 0.71) with dabigatran. However, the sensitivity effects among patients varied, with some patients having a normal APTT at dabigatran levels up to 160 ng/mL. Several specific assays, (diluted thrombin time, ecarin clotting assay and anti-IIa assay) accurately quantified dabigatran concentrations. In TG, a paradoxical increase was observed in the endogenous thrombin potential (ETP) and Peak TG, while lag time also prolonged with increasing concentrations of dabigatran. Rivaroxaban and apixaban effects on coagulation in patient samples were further assessed in a well-characterised group of patients using these drugs for thromboprophylaxis after orthopaedic surgery. Rivaroxaban peak drug levels were higher and trough levels lower than with apixaban, reflecting the once daily vs twice daily dosing of the drugs. In TG, the ETP response at peak drug levels was strong with rivaroxaban, whereas with the trough drug levels, the TG parameters were close to the baseline levels. With apixaban the responses were more stable. The RVVT, used as a qualitative test, detected prolongation only at rivaroxaban peak levels. In conclusion, DOACs present significant challenges in the clinical laboratory, as a wide variety of reagents are used in coagulation assays, and the drug responses also vary widely between individual patients. Many factors other than drug concentration influence the responses in coagulation assays and TG. In clinical practice, care and diligence is required when assessing the effects of DOACs on patients.
  • Karimi, Farid (Helsingin yliopisto, 2017)
    A consensus exists that the current trend of energy consumption growth and CO2 emissions cannot continue if global warming is to be tackled. Carbon Capture and Storage (CCS) has been considered in many countries for addressing climate change. CCS is a technology that curbs CO2 emission by removing CO2 from the atmosphere and storing it in carbon sinks, such as depleted oil and gas fields. CCS is a controversial technology. Notable opposition to and different perceptions of the technology exist among stakeholders, including experts, politicians and laypeople. Therefore, it is important to understand these diverse perceptions and their roots. I have developed a means towards such an understanding. I show that national culture influences both laypeople and expert perceptions. Moreover, it seems likely that cultural orientation affects some of the other factors, such as trust. In addition, I show that although mainstream research and literature consider experts as unbiased and rational stakeholders, both laypeople and experts have similar underlying cultural features and thus their models of perception follow a similar trend in a society. I specify how cultural orientations and their characteristics shape the perception of CCS technology and influence the reactions of people. For instance, hierarchical nations with high uncertainty avoidance have a tendency towards a higher level of risk perception. In contrast, nations that are characterised by social harmony might have a lower level of risk perception of a technology that could increase the long-term quality of life. This research is a comparative study; comparisons were performed between countries and between laypeople and experts. I used mixed methods to address the research questions. The quantitative part of the study is based on survey data analysis and the qualitative part involves both discourse analysis of interviews and Function of Innovations Systems (FIS) analysis. This research contributes to risk governance of CCS by developing a new framework that policymakers and authorities can use as a tool to consider the unheeded issue of culture in their planning. I demonstrate who is concerned with what and why with respect to the technology. Finally, I discuss the implications of this study, including policy recommendations. For instance, the European Commission might plausibly benefit from the framework when considering its budget allocation and communication with member states to study CCS projects and to estimate the failure or success of a project.
  • Keto, Antton (Helsingin yliopisto, 2017)
    Water-levels of lakes in Finland are artificially regulated for energy production, flood protection, navigation and recreational use. There is a need for changing water-level regulation practices, due to changing climate, increasing recreational use of lakes, and implementation of legally binding national targets for electrification of renewable sources. To obtain more knowledge-based assessments of new water management regulations, we need to develop water-level regulation assessment tools and to increase the sensitivity of ecological classification systems for hydromorphological pressures, as the European Union Water Framework Directive (WFD)requires. The main objectives of this study were to 1) develop criteria and threshold values for assessing the ecological status in regulated lakes, 2) identify both high-hydrological status and heavily modified lakes and 3) estimate the role of helophytes in the uppermost littoral zone. Impacts of water-level fluctuation on macrophytes, macrozoobenthos, and littoral fish fauna were clearly evident, and the threshold value between moderate and good ecological status was a 3.5 m winter water-level drawdown with the mean ecological quality ratio assessment method (1.8 m with the one-out-all-out principle). The vertical extension of Phragmites was most strongly associated with the water-level fluctuation of open water period (OWP), followed by Carex spp. and Equisetum. Overall, the RF models explained 4--41% of the variation observed in the helophytes zones. The models indicated that OWP fluctuation, slope, openness and cover of other macrophyte groups were key factors explaining the extent of the helophyte zones. The hydrological regime could be classified as having high hydrological status in 20% of the regulated lakes. Quite often, the ecological status was poorer, implying that high-hydrological status lakes often face other anthropogenic pressures, such as eutrophication that degrades high ecological status. Provisional designation with hydrological criteria seemed to work quite well, because 13 of the 15 lakes were estimated similarly with simple hydrological criteria, compared with the national HMWB designation only later produced by the environmental authorities.
  • Finne, Maria (Helsingin yliopisto, 2017)
    The proportion of older adults has dramatically increased in developed countries due to longer life expectancy. The wellbeing of this group has large economic implications. Self-rated health (SRH) is a globally used method to measure both physical and psychosocial health and in some conditions considered as a better indicator than medical records. The main aim of this thesis was to study whether socioeconomic (SES) factors as well as nutritional intake are associated with physical and psychosocial SF-36 score change during a ten year period. Helsinki Birth Cohort Study (HBCS) consists of 8760 participants who were born at Helsinki University Central Hospital between 1934 and 1944. HBCS is a longitudinal study where data has been collected along the life span. In this thesis material was used from the baseline clinical visit (years 2001-2004) and the follow-up clinical visit (years 2011-2013). During the follow-up, 1094 participants (men n=478, women n=616) were traceable and took part in the follow-up visit which makes the participants 67 to 77 years old at that point. At the baseline clinical examination (n=2003), diet was assessed with a validated food-frequency questionnaire from which the Baltic Sea diet score (BSDS) was calculated. Higher scores indicated better adherence to the Baltic Sea diet. Self-rated psychosocial and physical wellbeing was assessed with the Short Form 36 scale (SF-36) in 2001-2004 and 2011-2013. The difference between baseline and follow-up SF-36 psychosocial and physical measurement was calculated. Socioeconomic indicators included degree of education, length of education and the average monthly taxable income. Men and women were studied separately. Also the group of those still in work life at baseline were evaluated separately from those who were already retired. Associations between BSDS and the SES factors were also tested. The statistical analysis program SPSS version 22 was used to calculate associations between the SES factors and BSDS with psychosocial and physical change. Linear regression method was used for the analyses. In addition, a comparison of the follow-up SF-36 scores according to socioeconomic factors were examined with ANOVA post hoc Tukey HSD test. Degree of education was positively associated with changes in psychosocial functioning at old age among men (p=0.009), whereas length of education associates positively among women (p=0.027). Both degree and length of education were positively associated with psychosocial functioning within the group that was still in work life at baseline. Change in physical functioning was not associated with SES or BSDS. Adherence to the BSD was not significantly associated with either of the SF-36 measurement factors but was related to higher income. Degree of education and length of education seem to indicate the direction of psychosocial functioning in early old age. Physical degeneration during late adulthood is normal and is less predictable by SES factors. BSDS did not predict physical or psychosocial wellbeing among this population but was positively associated with income among the participant.
  • Lehtisara, Leena (Helsingin yliopisto, 2017)
    The large area forest mapping is traditionally based on satellite images and laborious field plots. The newer lidar plot concept is the Airborne Laser Scanning (ALS) and a small amount of field plots based plot-level attribute estimation, which is treated similar to the field plots in satellite based mapping. The target of the study was to evaluate the satellite-based, the ALS-based and their combination based forest mapping in the large area by comparing the accuracy of the forest attribute estimations per different amounts of plots. The study area of 3 128 000 hectares in southern Finland included 3630 field plots from the Metsäkeskus of Finland. The attribute estimates were computed from the Landsat 8 image and from the low-density lidar dataset to the field plot locations. The plot-level attribute estimates were calculated for the volume, height, basal area and biomass using k-NN-method (k=5). The accuracy of the mapping methods was evaluated by relative RMSE (Root Mean Square Error), which measured the differences between the estimated and the measured attributes of the validation plots. From the results it can be seen that the relative RMSEs of the attribute estimates from the Landsat-image based mapping on plot-level were at their best 47.6 % for the volume, similarly 26.2 % for the height, 34.6 % for the basal area and 47.7 % for the biomass. For the ALS-based mapping, they were 23.2 %, 9.8 %, 21.0% and 23.7 % respectively. By using 400 field plots to estimate attributes for 2900 lidar plots, and these lidar plots were used further for Landsat-based attribute estimations, these results were quite close to the accuracy of field plots-based Landsat attribute estimations. In addition a small sample of the lidar cover of the area was needed, in this case having less than 1 % area coverage. The lidar plots in Landsat-based mapping could be used for the biomass and carbon mappings in large area even if there are no roads available in the area and only a small amount of plots can be measured. Also, it is suitable for the areas where forest mapping has not started. It can be used also to follow up the changes in large forest areas, due the frequent updates of the satellite image measurements.
  • Tarmi, Siina (Helsingin yliopisto, 2017)
    The scope of the literature review was to define the process for oil-in-water emulsion formation and the important properties of the emulsions which are suitable for microencapsulation. The aim of this study was to determine how whey protein isolate together with maltodextrin affects the properties of the emulsion. Camelina oil and black currant seed oil were used as core materials. The wall materials used were: maltodextrin (MD) and whey protein isolate (WPI). Six different wall systems consisting WPI in combination with MD at various ratios (1:1, 1:3 and 1:9) were used. In premilinary tests the emulsions were characterized for temperature, creaming index, apparent viscosity, flow behavior index, flow consistency index, droplet size (D4,3 zetasize,), droplet size distribution (PDI, span) and zetapotential. Droplet size and droplet size distributions were measured by a laser light scattering using a Zetasizer and by laser light diffraction instrument, Mastersizer 2000/3000. Oil droplet size was also measured with light blockade using a PAMAS. Rheological properties were characterized with rheometer. In actual test the emulsions were characterized for time (foam removal), temperature, droplet size (D10, D50, D90 ja D4,3), apparent viscosity, flow behavior index and flow consistency index. First degree polynomial was fitted with PLSR to the results. Statistical significances of regression coefficients were analyzed with t-test. In premilinary tests all the emulsions were stable during storage at 25 °C after 24 h. pH and zetapotentials which were all lower than -35 mV refer to good stability of emulsions. Change in droplet size and droplet size distribution was observed. Increasing maltodextrin concentration decreased droplet size (D4,3) and droplet size distribution width (PDI) when measuring by Mastersizer and Zetasizer. Apparent viscosity of the emulsions decreased by increasing maltodextrin concentration. PLS-regression showed that there were statistically differences between wall materials and temperatures, droplet size, size distribution and apparent viscosity. There were also statistically differences between oil and droplet size measured by PAMAS. In actual tests apparent viscosity of the emulsions decreased by increasing maltodextrin concentration. Increasing maltodextrin concentration also decreased the time of foam removal. PLS-regression showed that there were statistically differences between wall materials and temperatures after homogenization, time (foam removal), flow consistency index and apparent viscosity. There were also statistically differences between oil and temperatures, flow behavior index and droplet size distribution width. Whey protein isolate together with maltodextrin affect mostly to apparent viscosity of emulsions.
  • Syväjärvi, Elena (Helsingin yliopisto, 2017)
    Perunatärkkelyksen valmistusprosessin sivuvirtana saadaan perunan solunestettä, joka on aikaisemmin hyödynnetty lannoitteena. Perunan soluneste sisältää arvokasta proteiinia, jota voidaan hyödyntää rehu- ja elintarviketeollisuudessa. Finnamyl Oy Kokemäellä on rakentanut prosessin, jolla perunaproteiini saadaan otettua talteen. Tässä työssä tavoitteena oli tutkia perunaproteiinin erotusprosessia ja perunaproteiinikon-sentraatin ominaisuuksia. Kirjallisuuskatsauksessa perehdyttiin perunaproteiinikonsentraatin kemiallisiin ja fysikaalisiin ominaisuuksiin elintarviketeollisuuden näkökulmasta. Lisäksi työssä selvitettiin perunaproteiinikonsentraatille soveltuvia käyttösovelluksia ja perehdyttiin erilaisiin proteiinin erotusmenetelmiin. Kokeellisessa tutkimuksessa tutkittiin monipuolisesti perunaproteiinikonsentraatin funktionaalisia ominaisuuksia. Työssä tutkittiin koeajoista saa-tuja näytemateriaaleja. Lisäksi tutkimuksissa oli vertailunäytteinä mukana soijaproteiinikon-sentraatti ja rehulaatuinen perunaproteiinikonsentraatti. Työssä testattiin menetelmiä, joita voidaan jatkossakin käyttää perunaproteiinikonsentraatin tutkimiseen. Koeajoista saatujen näytemateriaalien tuloksia verrattiin kaupallisiin tuotteisiin. Prosessi vaatii vielä kehittämistä, jotta elintarvikelaatuista proteiinia saadaan valmistettua. Tutkimuksissa havaittiin eroja eri saostuslämpötiloissa valmistetuissa näytemateriaaleissa. Perunaproteiinikonsentraatin funktionaaliset ominaisuudet olivat hieman huonompia kuin soijaproteiinikonsentraatilla.
  • Hannele, Rissanen (Helsingin yliopisto, 2017)
    Tiivistelmä * Referat * Abstract This thesis presents the results of the pedigree based genetic diversity study of the Kainuu Grey sheep. Data, including 22 467 animals born between 1981 and 2014, was received from ProAgria - Rural Advisory Services. Inbreeding coefficients were calculated for all animals. For birth-year averages only animals with sufficient pedigree depth (pedigree completeness value, PEC>0.8 using five generations) were considered. Averages were calculated separately for all breeding animals, breeding rams, and ewes. Average relationships were calculated within breeding rams, within breeding ewes, and between breeding rams and ewes. The thesis presents also estimates of the effective population size for birth-years 2000–2014, the contributions of the most influential ancestors, and average generation intervals. The average inbreeding and relationship coefficients have decreased during the last 20 years. The average inbreeding coefficient of the lambs born in 2014 was around 7 % when it was at its highest in 1990’s over 13 %. Average relationship between breeding animals born in 2013 was 17 % when it was at its highest over 20 % in 2000’s. Also effective population size has increased from 40 to the current figure of 70 animals. 32 % of the genetic variation of the current Kainuu Grey population can be traced back to seven founder rams that lived in 1980’s: Pertti, Risto, Immo, Lassi, Antti, Matti, and Topi. Out of those, Pertti has the most remarkable influence on the breed: around 11 % of the germ plasm of the lambs born in 2014 can be traced back to Pertti. The mean generation interval during last 20 years was 3.3 years. Genetic diversity of the Kainuu Grey has improved during the last years as the number of Kainuu Grey has increased. Inbreeding and relationship coefficients have declined slightly during last few years. Correspondingly, the effective population size has increased. To ensure genetic diversity of the Kainuu Grey in the future, artificial insemination, optimal contribution and genomic information could be utilized in breeding and in conservation work.
  • Rauhala, Jussi (Helsingin yliopisto, 2017)
    High quality milk is an important thing for dairy industry and the most important determinator for milk price paid to the producer. The quality of milk is measured with somatic cell and bacteria count. Milks somatic cell count doesn’t change after milking that emphasizes the importance of udder health and successful milking. The total annual cost of the mastitis in an 100 head of cattle was estimated to be 21 000 – 25 000 euros in Finland (calculated with price level in 2010). Liner is the only part of the milking machine that contacts cow’s teat and the only way of bacteria into udder is through teat canal. Many bacterial infections occur in teat injuries and due to the teat-end roughness that makes teat canal closure slower, which makes bacteria access easier into udder. The aim of this thesis was to study the effects of CloverTM -liner on milking. Results were compared to the traditional HarmonyTM -liner. Cross section of a CloverTM -liner looks like clover whereas the shape of traditional liner cross section is round. Udder health and milking characteristics were measured attributes for comparison of the two liner models in this thesis. Udder health was evaluated by measuring somatic cell count, teat-end health and short-term changes in teat condition after milking. Milking characteristics were evaluated by measuring milk yield, milking duration and milk flow. The measurements were taken in two farms in summer 2015. The results of this study were estimated with line and bar charts as well as statistical significances were estimated with appropriate models. The differences between groups were small in teat-end health and there was a lot of deviation in the results so there were no statistically significant differences between groups. Total number of teats with short-term changes in teat condition after milking was so small that statistical testing was not appropriate. There were no differences in milk yield, milk flow, milking duration or somatic cell count between groups. The only statistically significant difference was peak flow that was lower for ClowerTM -liner.
  • Juselius, Teemu (Helsingin yliopisto, 2017)
    Nowadays a greater number of people live in cities than in earlier times. In Finland, the portion of urban dwellers has nearly doubled in last 50 years. The urbanization has had undisputable benefits for mankind but it has also had widespread negative effects on nature. As cities grow natural habitats are replaced by spreading infrastructure. Remaining mires, forests and other natural habitats are smaller and more isolated than their rural counterparts. These urban habitats are affected by increased pollution and nutrient loads, trampling and other detrimental effects caused by human activity. Alien invasive species may also spread into indigenous vegetation and more of these areas are affected by edge-effects. Ombrotrophic bogs are one of the most nutrient-poor habitats in the North and receive nutrients only by dry and wet deposition. They have been reported to suffer from increased nutrient deposition. Hydrology also has a vital part in function and form of ombrotrophic bogs. Spread of urban infrastructure may alter the way bogs receive water due to increased sealed surface in the catchment areas of these bogs. The effects of urbanization on ombrotrophic bogs in Finland has not been studied previously and the aim of this Master’s thesis is to examine the differences between vegetation in urban and rural bogs and the effects of the size of bog area, nearby population and total N content of surface peat on bog vegetation in different bog types: dwarf shrub pine bogs, low sedge bogs, Sphagnum fuscum pine bog and Sphagnum fuscum bog. Last two were studied together due to their similarities. According to this study the differences between urban and rural bogs in Southern Finland are small. The greatest differences were observed among dwarf shrubs typical for bogs but the effects varied between bog types. In dwarf shrub pine bogs, the amount of dwarf shrubs decreased while in low sedge bogs, the cover of Vaccinium oxyccocos, and in Sphagnum bogs, the occurrence of Empetrum nigrum increased. The bogs studied in urban sites were generally smaller and more isolated than rural bogs. Around urban bogs, there were also significantly higher number of residents than in rural areas, and one of the most distinct effects of urbanization on bog vegetation discovered was reduction of cover and appearance of species vulnerable to trampling. The increased nutrient loads usually reported in urban habitats was not visible in nitrogen content of surface peat. On the contrary, low sedge bogs seemed to have higher nitrogen content on rural bogs, which may be caused by intense agriculture in rural areas. The reason for not detecting increased urban nitrogen deposition based on peat samples may be caused by increased nitrogen uptake of Sphagnum mosses. Sphagnum mosses have been reported to benefit from increased nitrogen deposition until they reach nitrogen saturation point. After this the excess nitrogen enters peat soil. Low nitrogen deposits in Southern Finland can probably be used fully by Spaghnum mosses and thus no increase in nitrogen content was observed. The results of this study indicate that ombrotrophic peat bogs are at least partly resistant to the effects of urbanization. The level of urbanization in Finland is lower than in Central Europe, which may lead to lowered levels of detrimental effects caused by urbanization. Alien species are probably also unable to invade the acidic and nutrient poor urban bogs. The mire types studied here are also usually situated in the centre of ombrotrophic bogs and may have avoided most of the edge effects. However, if studied, the edges of the urban bogs might have shown large number of harmful effects caused by urbanization.