Pro gradut ja vastaavat opinnäytteet: Recent submissions

Now showing items 1-20 of 22836
  • Atti, Sanna (Helsingin yliopisto, 2021)
    Underwater light climate in mountain lakes is controlled by dissolved organic carbon concentrations and by lake ice regimes. Both are affected by local, regional and global variables linked to anthropogenic disturbances such as climate change and atmospheric pollution. Aim of this work was to investigate changes in underwater light climate over the past ~200 years in two oligotrophic mountain lakes and how it reflects on diatom (Bacillariophyceae) guild distribution. For these aims, diatom communities and ecological guilds were analyzed from sediment core and contemporary habitat samples along a depth gradient. In addition, sediment inferred chlorophyll a (CHLa) and lake water total organic carbon (TOC) were analyzed to detect development of primary production and lake water carbon content. Results showed that acidification of the lakes together with climate induced changes have been important drivers of the ecology of the lakes. Lake water TOC showed a decline and subsequent increase in line with the acidification and subsequent recovery of the lakes, likely affecting underwater light climate in the lakes. However, this did not reflect unambiguously into changes in diatom functionality. Warming has likely contributed to diversification of the diatom community over the study period while no distinct increases were observed in whole lake primary production. Overall, if the present study could not distinguish the exact role of underwater light in driving changes in diatom communities and functional traits, the result show that human pressures have left distinct imprints in the development of biotic communities in these remote mountain lakes.
  • Zhou, Quan (Helsingin yliopisto, 2020)
    Leaf senescence is a developmental and physiological phase in plants to end leaf development. Environment factors such as drought stress, extreme temperature, and pathogen threat and internal factors including age and reactive oxygen species induce leaf senescence. Some phytohormones such as jasmonic acid and salicylic acid play a key function in cell death in plants. WRKY transcription factors is known as one of the largest transcription factor family in plants which regulates a variety of plants processes. WRKY75 which belong to WRKY transcription factors has shown multiple functions in plant development like regulation of Pi starvation responses and root development and flowering. In my thesis, I focused on the role of WRKY75 in senescence and stress responses. WRKY75 was identified as a positive regulator of cell death in Arabidopsis. WRKY75 can promote salicylic acid biosynthesis by promote transcript levels of SID2 and also cause hydrogen peroxide accumulation by suppressing the transcription of CAT2. Hydrogen peroxide and salicylic acid can promote WRKY75 transcription at the same time. To evaluate the function of WRKY75 transcription factor in SA signalling and cell death, three lesion mimic mutants acd5, cat2, dnd1 and their corresponding wrky75 double mutant were used. Interestingly, no different phenotypes were found between acd5, cat2, dnd1 and their corresponding wrky75 double mutants in cell death and hydrogen peroxide accumulation detection in Arabidopsis leaves. Meanwhile, marker genes transcription levels were not different in both short day and long day growth condition. However, different phenotypes were observed in botrytis infection. Based on these results, we formed a hypothesis that gene redundancy could influence genetic characterization of WRKY75. To overcome this problem, SRDX-WRKY75 chimeric repressor transgenic lines were generated. The SRDX domain act as a dominant negative regulator to suppress WRKY75 target genes. In future research, these new lines can be used to test transcript levels for putative WRKY75 target genes.
  • Martikainen, Sanni (Helsingin yliopisto, 2020)
    The production and consumption of foodstuffs has a strong impact on climate change, and vice versa. Agriculture and the food industry are responsible for over 25% of man-made greenhouse gas emissions. Thus, food choices are a significant way in which individuals can influence greenhouse gas emissions. By comprehensively changing one’s food consuming habits to align with the principles of sustainability, an individual can decrease the climate impact of their total consumption by approximately ten percent. Sustainable habits, such as food consumption, are part of wider social and cultural processes. Therefore, in research relating to food consumption, it is important to consider both the background of the research participants and the community and society in which they live. Through food choices, an individual expresses their identity, status, and belonging in the community. Eating is a social event that is affected by the values and attitudes of the surrounding community and society. These things strongly influence an individual’s food choices, but on the other hand, individuals can also reshape the attitudes and values of their community through their choices. In order to advance sustainable food decisions on a societal level, it is important to examine what factors influence people’s consuming and eating habits. There has been a considerable amount of research done on sustainable foods, but the research focus has not often been on aware consumers. Studying aware consumers provides information about which factors hinder the making of sustainable decisions when the obstacle is not a lack of awareness. As more is known about the reasons behind people’s food choices, it becomes possible to consider new methods for getting people to make more sustainable choices. The students of the Environmental Change and Global Sustainability program at the University of Helsinki are interesting subjects of research, because they presumably are aware of and interested in the impacts of their food choices. Therefore, in studying them it is possible to focus on other factors determining their food choices, rather than obstacles related to a lack of awareness. In addition, Helsinki as a study location offers good possibilities for making sustainable choices, because there is a diverse supply of sustainable foods in the urban centre. In this master’s thesis, I aim to answer the question: What kinds of perceptions of a sustainable diet do the students of the University of Helsinki program of Environmental Change and Global Sustainability have and what kinds of obstacles do they face when making sustainable food choices? My study is a qualitative case study. I gathered the research material by conducting semi-structured theme interviews with eight students. I analyzed the material by employing thematic analysis methods. My study indicates that the students found it most difficult to follow a totally plant-based diet, even though they consider it to be a sustainable choice. Choosing plant-based food was challenging for them especially in certain social situations. These included situations in which the students felt pressured into eating animal-based food, or situations in which they wanted to please another person by eating the animal-based food they were offering. In such situations, the students were inclined to make choices that differ from those they make in their everyday lives. In social situations that involve food and eating, people have a human need to indicate a sense of community and respect towards people important to them. The students I studied have a lot of knowledge and awareness of the sustainability impacts of their food choices. However, my study indicates that in some situations the need for social cohesion is more important than the need to make a sustainable food choice. The social meaning of eating is important to take into account when considering how to get people to make more sustainable food choices.
  • Larkiala, Taru (Helsingin yliopisto, 2020)
    Calsyntenin-3 is a type I transmembrane protein, that is mainly expressed on the post-synaptic cell membranes. It belongs to the calsyntenin family that is part of the cadherin superfamily. Calsyntenin-3 consists of a cytosolic C-terminal region, a transmembrane domain and an extracellular N-terminal part, that consists of a laminin G-like domain (LNS) and two cadherin domains (CAD). Calsyntenin-3 is mainly expressed in the brain, but it can also be found in the heart, liver, pancreas, lung, skeletal muscle and placenta. Calsyntenin-3 has an effect on neurogenesis by affecting the development of excitatory and inhibitory synapses. It might also play a role in Alzheimer’s disease, as it has been found to be able to bind β-amyloid peptide, that is known to play a key role in the development of Alzheimer’s disease. Calsyntenin-3 acts as a synaptic adhesion protein, that binds to the post-synaptic neurexins with its extracellular region. However, the previous studies have contradicting results regarding the calsyntenin-3 domains that mediate the interaction between the calsyntenin-3 and neurexins. There is also disagreement whether calsyntenin-3 binds neurexin-α, neurexin-β or both. Because of these discrepancies, the aim of this master’s thesis study was to produce the calsyntenin-3 ectodomain constructs that contained either the two CAD domains, the LNS domain or all three domains, using baculovirus mediated protein production in insect cell cultures. These purified protein constructs were meant to be used for the determination of the binding domains. Unfortunately, only the purification of the calsyntenin-3 LNS domain was successful and the purification of the constructs, containing the CAD domains, was unsuccessful. A SEC-MALLS experiment, that was performed for the calsyntenin-3 LNS domain, revealed that it forms dimers in a solution, which is consistent with experiments performed with the LNS domain of human sex hormone‐binding globulin. The second aim of this master’s thesis study was to express the calsyntenin-3 ectodomain constructs on the surface of HEK293T cells and to test the binding between calsyntenin-3 and neurexins in a cell surface binding assay. The results of the cell surface binding assay indicated that the binding is mediated by the calsyntenin-3 CAD domains and that calsyntenin-3 binds to neurexin-α, but the binding to neurexin-β was not detected. However, the results from the cell surface binding assay were conflicting: the binding between the calsyntenin-3 full ectodomain construct and neurexin-α was not detected, but the binding was detected between calsyntenin-3 CAD ectodomain construct and neurexin-α. Therefore, the cell surface binding assay cannot be considered entirely reliable and should be repeated before making further conclusions.
  • Törrönen, Essi (Helsingin yliopisto, 2020)
    4-Methylmethcathinone (Mephedrone) is one of the the most prevalent synthetic cathinones that bears close structural similarity to amphetamines. Like other stimulants, mephedrone is often used with alcohol (ethanol). In animal studies ethanol has been observed to potentiate the neurotoxicity of amphetamine-type stimulants, and same has been observed when mephedrone and alcohol is combined. The long-term effects of mephedrone have still remained largely elusive. The aim of this thesis is to study the effects of mephedrone, methamphetamine, and ethanol on dendritic spine density and morphology in the hippocampus, nucleus accumbens and caudate putamen, and compare the spine densities with changes in brain activation observed in manganese-enhanced magnetic resonance imaging (MEMRI). Dendritic spines are small membranous protrusions on dendrites that act as the post-synaptic sites for most of the excitatory synapses. Amphetamine and methamphetamine have been shown to affect the density and morphology of the spines. The goal of this thesis was to investigate the long-term effect of binge-like (two times a day, four consecutive days) stimulant treatment on dendritic spines using Golgi-stained rat brain sections. The brains of 48 male Wistar rats were imaged using AxioImager Z2 microscope and the number and the size of the spines was analyzed using Reconstruct software. In this thesis no effect on dendritic spines was observed in the hippocampus and nucleus accumbens in animals treated with mephedrone, methamphetamine, ethanol or combination of them. In the caudate putamen significant increase in the total density of dendritic spines and in the density of filopodia-like spines was observed in mephedrone-treated animals. Other treatments showed no observable effect. These results were conflicting with previous studies where amphetamine-type stimulants have been shown to increase the spine density in the nucleus accumbens and the hippocampus and increase the density of branched spines. In the caudate putamen methamphetamine has been observed to decrease the spine density. There was no correlation between spine densities and brain activation observed in MEMRI. To my best knowledge this is the first time when the effect of mephedrone on dendritic spines has been studied. It is possible that the treatment regimen used here was not strong enough to produce marked long-term changes on dendritic spines. It is also possible, that mephedrone is not as neurotoxic as other amphetamine-type stimulants, which may explain why the effects remained limited and conflicting. More research is still required to establish the long-term structural effects of mephedrone.
  • Toropainen, Siiri (Helsingin yliopisto, 2020)
    Human induced pluripotent stem cells (hiPSC) can be propagated in a long-term culture and further differentiated into many cell types, including cardiomyocytes (CM) and endothelial cells (EC). Human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CM) are promising tools in cardiac research, since they retain the original genotype of the individual donor and thus enable the use of patient- and disease specific cells. Crucial for the optimal use of hiPSC-CMs in experiments are methods for assessing cardiomyocyte phenotype. Contraction is a prominent feature for CMs, and it is essential that contraction can be quantified accurately. Reliable quantification is relevant when hiPSC-CMs are used for studying disease phenotypes, cardiac safety pharmacology, genotype-phenotype correlations, cardiac disease mechanisms and cardiac function over time. In this thesis project, contractile behavior of hiPSC-CMs was analyzed using video microscopy and online tool MUSCLEMOTION. Contraction parameters were obtained from hiPSC-CMs derived from patients with hypoplastic left heart syndrome (HLHS) and healthy controls on multiple timepoints during differentiation. In addition, contraction was analyzed in iPSC-CMs cocultured with induced pluripotent stem cell derived endothelial cells (iPSC-ECs), since it has been suggested that ECs can promote morphological and functional maturation of CMs in culture. Contraction duration (CD), time to peak (TTP), relaxation time (RT) and contraction amplitude (CA) was compared between different timepoints as well as between CMs cocultured with ECs and CMs cultured alone. Compared to control cell lines, HLHS patient hiPSC-CMs exhibited longer CD, TTP and RT as well as higher CA values. This difference was present in most of the timepoints, suggesting slower contractile kinetics in HLHS patient iPSC-CMs compared to control iPSC-CMs. Significant changes were also observed in contraction parameters when comparing hiPSC-CMs in coculture and monoculture. Contraction parameters of coculture iPSC-CMs changed in a relatively consistent manner over time, increasing or decreasing throughout the monitoring period whereas in hiPSC-CM monoculture there was more variation between timepoints. This project and results support the use of modern methods in detailed functional characterization of hiPSC-derived cells. In addition, it highlights the potential of coculture in disease modeling and the fact that hiPSC-CMs express variation in phenotypes. However, experiments should be repeated, and additional methods should be used in order to further validate the results and conclusions.
  • Ahonen, Nenna (Helsingin yliopisto, 2020)
    Abandoning carbon intensive lifestyles plays an integral role in mitigating the current climate crisis, especially in wealthy countries such as Finland where citizens’ carbon footprints are large. Mitigative lifestyle change can however be hard as many factors hinder the adoption of low-carbon practices. It can also be hard to recognize factors that could push lifestyle change forward. The significance and range of these factors, often called barriers and enablers, can vary between different places as each place constitutes its unique context. Studying barriers and enablers in different places can help us decide how to best advance the adoption of low-carbon practices in these contexts. In this thesis barriers and enablers are examined in the context of rural Finland. Characteristics that are often connected to rural Finland include long distances, scarcer services, conservativeness, and communality. The aim of this study was to examine what kinds of barriers to and enablers of low-carbon lifestyle change people dwelling in rural Finland experience, and which of these barriers and enablers have special links to the rural context. Eight citizens of Kauhajoki municipality were interviewed. The transcribed interview data was analysed with qualitative content analysis. Barriers and enablers were coded from the data, and 14 barrier and 13 enabler categories were formed. The themes of the barrier and enabler categories coincided well in terms of their content. Barriers were mentioned more often. Both barriers and enablers included factors related to infrastructure, availability of services and products, time, money, knowledge, health, social environment, habit formation, life situation, feelings, and perceptions of difficulty or easiness. They stemmed from the participants’ psychological processes and personal lives, the resources they had, and the physical and social aspects of their environment. Barriers and enablers with links to the rural context were most abundantly connected to infrastructure and availability. Based on the results, rural citizens live in a complicated push-pull environment of different barriers and enablers. Given that barriers appear to be more easily identified, it is important to start highlighting enablers. Even though in rural areas barriers and enablers related to the physical environment are most visible, attention should be paid to all factors to ensure that no potential for change is wasted. The results of this thesis help recognize both hurdles and helpers of low-carbon lifestyle change in rural Finland.
  • Lehtiniemi, Heidi (Helsingin yliopisto, 2020)
    Mallintaminen on erittäin ajankohtainen tapa tuottaa tietoa kompleksisista ilmiöistä ja niihin liittyvistä kausaalisuhteista. Mallinnus nähdään parhaana saatavilla olevana työkaluna tarjota päättäjille tietoa lähitulevaisuuden skenaarioista ja tarvittavista toimista (Meah, 2019; Schirpke et al., 2020). Tässä tutkielmassa luodaan kokonaiskuva modernista ympäristömallinnuksesta vertaamalla globaaleja, objektiiviseen dataan pohjaavia ilmastomalleja paikallisiin, ekologista ja sosiaalista tietoa yhdistäviin ekosysteemipalvelumalleihin. Mallinnuksen lisäksi tarkastellaan tieteen ja päätöksenteon rajapintaa, joka on etenkin mallien yhteiskunnallisen käyttökelpoisuuden keskiössä. Käyttökelpoista ja yhteiskunnallisesti relevanttia mallinnusta analysoidaan integroivan kirjallisuuskatsauksen (Whittemore & Knafl, 2005) kautta. Kirjallisuuden aiheina ovat ilmastonmuutos, ekosysteemipalvelut, mallinnus ja tieteen ja politiikan rajapinta, n=58. Eri tieteenalat ja näkökulmat ovat edustettuna aineistossa. Koska päämääränä on luoda kattava ymmärrys mallinnuksesta poikkitieteellisenä ilmiönä, tutkielma ei keskity mallinnuksen teknisiin näkökulmiin. Kirjallisuudesta tyypitellään epävarmuuden lajeja sekä niiden hallintaan pyrkiviä strategioita (mm. van der Sluijs, 2005). Lisäksi tunnistetaan käyttökelpoisten mallien ja muiden tieteen muotojen tunnuspiirteitä (mm. Saltelli et al., 2020). Käyttökelpoisimpia ovat tilanteeseen sopivat, ratkaisukeskeiset ja saatavilla olevat mallit yhdistettynä riittävään vuorovaikutukseen ja luottamukseen mallien käyttäjien ja luojien välillä. Ilmastonmuutos ja ekosysteemipalvelut toimivat tapausesimerkkeinä, joita analysoidaan läpileikkaavasti kaikissa kappaleissa. Keskustelu tieteen ja päätöksenteon suhteesta on erityisen tärkeää kestävyyskriisiä ratkaistaessa. Koska mallinnus sijoittuu tieteen ja päätöksenteon rajapinnalle (Duncan, Robson-Williams, & Edwards, 2020), rajapintatyön rooli epävarmuuden hallitsijana ja viestijänä sekä mallin käyttökelpoisuuden varmistajana on analyysin keskiössä.
  • Nyroos, Erik (Helsingin yliopisto, 2020)
    Participatory budgeting is one of the major democratic innovations of the recent decades. This participatory method from Brazil has been started to actively utilize in Finnish municipalities during 2010s. The basic idea of this methodology is that citizens can together decide how to use public assets. The goal of this thesis is to understand how participatory budgeting can have an impact on ecological sustainability in Finland. I’m focusing on the proposals of participatory budgeting which the citizens have voted for to be implemented. Research material has been collected from public online sources on all the Finnish participatory budgeting projects. Some of these projects have been excluded as they do not fulfill the characteristics of participatory budgeting. The material is analyzed using content analysis, building categories, themes and types. There are three key findings in this thesis. First, participatory budgeting has created ecologically sustainable solutions, but sustainability has been an unintended by-product. Proposals concerning environment focus primarily on people’s living environment. Second, the changes are minor, and individuals are the ones carrying the responsibility for the sustainability. Third, the means how proposals are carried out influences ecological sustainability. Here, municipal authorities have a significant role. Finnish participatory budgeting projects therefore have the chance to create ecologically sustainable proposals. However, the capability is limited by both small, project specific budgets and processes that do not acknowledge ecological sustainability. In the long run, the changes might be more significant as participatory budgeting still is relatively new method in Finnish society.
  • Rissanen, Jason (Helsingin yliopisto, 2020)
    Ants are among the most successful organisms in the world. They can be found almost anywhere on the planet and due to their high degree of sociality and complex societies they have become some of the most abundant creatures in most terrestrial ecosystems. Although sociality has benefits in the form of more efficient foraging, brood care, reproduction and protection from predators, it has costs too. Ants live in high densities in their nests and have frequent contact between them which can facilitate an efficient transmission of pathogens within the nest. Ants have become highly successful in spite of their potentially high susceptibility to pathogens. They share the same innate immune responses of other arthropods and have unique adaptations for coping with pathogens. In extension to physiological strategies for coping with pathogens, ants engage in behavioural strategies as well. Ants and other eusocial insects can also harness the structure and behaviour of the colony to prevent and cope with pathogen infections through social immunity. Ants can also engage in self-medication behaviour to combat disease. Self-medication is a behavioural strategy where individuals respond to pathogen infections by seeking out and using biologically active compounds to alleviate the effects of pathogens in a way that would be detrimental for uninfected individuals. The behaviour can be either therapeutic of prophylactic depending on when the compounds are used in relation to encountering the pathogen, and it can be extended beyond the self to other kin. While ants have been proven to medicate themselves with reactive oxygen species (ROS) in laboratory conditions, it remains unknown how they do it in the wild. In my thesis, I studied how the ant Lasius platythorax self-medicate in a natural setting by developing a multi-trophic system of ant – pathogen – aphid – plant interactions. In this system, the ants infected with a fungal pathogen (Beauveria bassiana) had the opportunity to forage on the nectar produced by the extrafloral nectaries (EFNs) of a broad bean plant (Vicia faba) infested by vetch aphids (Megoura viciae). Plants that are stressed by aphids react with a systemic production of ROS, which ants are known to use for self-medication, and ROS could therefore be present in the EFN nectar as well, along with other potentially medicinal compounds. The aphids themselves could present the ants with both ROS, if it accumulates in the aphids due to the immune responses of the plant, and protein if eaten. In my thesis I found out that infected ants increase their foraging on EFN nectar during the first three days after infection compared to healthy ants. This immediate response to a pathogen infection shown by the infected ants fits in a self-medication context as well as the infection cycle of the pathogen, making this a strong case for self-medication. The change in foraging by the infected ants did not reflect on the changes in ROS content in the ants, possibly due to a lack of ROS in the nectar, but instead were likely to be caused by self-generation of ROS in the infected ants. The aphids feeding on the plant contained a higher ROS content compared to the ants, but I found no evidence of ants preying on the aphids, possibly due to the M. viciae being unpalatable for the ants or the ants finding medicinal compounds in the EFN nectar. The result of my thesis is a first step in to identifying natural ways for ants to obtain and use medicinal compounds from their environments and opens up new avenues of research in the topic of self-medication. The result also highlights the importance of biodiversity for the conservation efforts for ants and other insects. Insects are facing a drastic decline in both abundance and diversity due to human impact on their environments, including the prevalence in pathogens. By understanding the full extent of the immune strategies that insects use, including self-medication, we can develop more efficient methods of conservation to help them.
  • Vikfors, Sofia (Helsingin yliopisto, 2020)
    Microplastics (MPs) are widespread environmental pollutants that have been detected in virtually all environmental compartments. Despite this, research has mainly focused on the impacts of microplastic on shorelines and at sea. The effects of MPs on terrestrial ecosystems has been sparsely investigated, and there are only a few studies on direct effects on terrestrial plants. Although plastic polymers are considered inert and non-hazardous, toxic additives are often added to the polymers during manufacture which may leach out into the environment, displaying ecotoxic effects. In this work, the effects of microplastic particles and microplastic leachate on the germination and growth of Lolium multiflorum (Italian ryegrass) was investigated. High density polyethylene (HDPE), which is one of the plastic polymers with the largest annual production, was chosen as the plastic material for investigation. New MPs, artificially aged MPs, MPs from the Lahti region, and MPs from Port Elizabet, South Africa was used in parallel to compare the effects of ageing and regional environmental factors on the ecotoxicity of MPs. The total germination percentage, mean germination rate, synchronization index, germination index, and time to 50% germination was investigated, as well as the root lengths, shoot lengths, root/shoot ratio, and fresh weights of the seedlings. The results showed that exposure to new and Lahti MPs and leachates severely inhibited the extent and speed of the germination of L. multiflorum, whereas all categories of MPs and leachates inhibited the growth to some extent. Most severe inhibition in germination and growth was seen for the new MP and new leachate, followed by Lahti MP and Lahti leachate. The root growth, shoot growth, and plant biomass were also severely reduced for these exposure media. For the aged and Port Elizabeth material, there were slight but significant (p < 0.05) inhibition in root lengths and fresh weights, but no significant inhibition in the germination parameters. These findings indicate that ageing severely reduces the ecotoxic effects of MPs, and that regional environmental factors affect the ecotoxicity of MPs. Microplastics from Port Elizabeth were significantly less toxic to L. multiflorum than MPs from the Lahti region, possibly due to the warmer climate in South Africa. Another explanation could be that the plastic material collected in Port Elizabeth wast older than the one from Lahti. There was little to no difference in germination and growth between seeds exposed to MPs or leachates of the same origin, indicating that it is the substances leaching out of the MPs that are responsible for their ecotoxicity.
  • Kovakoski, Elina (Helsingin yliopisto, 2020)
    Microplastics are widely studied subject and have raised concern towards water security worldwide but the vector effect of microplastic has not yet fully understood. In this study the ability of microplastic to attach hydrophobic organic compounds is tested with a nonsteroidal anti-inflammatory drug diclofenac. The ability to attach hydrophobic organic compounds has been proved by microplastics but not with diclofenac. Diclofenac is also causing water security threats nearby wastewater treatment plants because it is biologically active and can cause stress to the aquatic organisms even in small quantities. The aim of this study is to see if microplastic has vector effect for the diclofenac. If microplastic retains diclofenac on its surface area it would decrease the stress factor effect of diclofenac towards the investigated macroalgae Aegagropila linnaei. The possible change of oxidative stress levels in A. linnaei is measured by peroxidase enzyme activity. The aim is to see if the enzyme activity raises or decreases when A. linnaei is exposed to microplastic with and without diclofenac. If the peroxidase enzyme activity decreases in macroalgae while exposing A. linnaei to both microplastic and diclofenac it would strengthen the vector effect hypothesis. As a result, the peroxidase enzyme activity seems to have a decreasing trend when the diclofenac concentrations increase. Diclofenac affected to peroxidase enzyme activity but microplastic does not show any signs of binding of diclofenac in this study, and therefore microplastic cannot act as a vector for diclofenac.
  • Kokko, Miia (Helsingin yliopisto, 2020)
    Tarkastelen tutkielmassani lukion kirjoitustaidon koetta ja sen vastaustekstiä moniäänisyyden näkökulmasta. Kirjoitustaidon koe on ensimmäistä kertaa syksyllä 2018 käyttöön otettu äidinkielen ja kirjallisuuden ylioppilaskoe, jossa kokelaan on tarkoitus kirjoittaa pohtiva tai kantaa ottava, noin 6000 merkin esseemäinen teksti. Vastaustekstissä on hyödynnettävä oman ajattelun tukena kokeessa annetuista aineistoista vähintään kahta. Aineistot voivat olla esimerkiksi asia- tai mediatekstejä tai fiktiivisiä tekstejä eri muodoissaan. Tutkimuksessani tarkastelen, minkälaisia referoinnin keinoja vastausteksteissä esiintyy. Tarkastelun kohteina ovat suora ja epäsuora esitys, vapaa suora ja vapaa epäsuora esitys, upotettu referaatti ja sellaiset referaatit, jotka sisältävät lähdeviitteen. Referoinnin keinojen lisäksi tutkimukseni valottaa sitä, minkälaisia merkityksiä eri referoinnin keinot saavat vastaustekstissä. Tarkastelun kohteena on siis se, millä tavoin kokelaat rakentavat teksteihinsä itse rajaamaansa näkökulmaa ja dialogisuutta eli keskustelua aineistojen välille. Tutkimukseni aineisto koostuu yhteensä 15 kirjoitustaidon vastaustekstistä, jotka ovat kahtalaiset. Toisen osan aineistostani muodostaa yhdeksän preliminäärikokeessa kirjoitettua vastausta, jotka olen kerännyt eräästä lukiosta. Loput aineistostani koostuu kuudesta aidosta ylioppilaskokeesta, jotka on julkaistu Ylioppilastutkintolautakunnan ja kokelaiden luvalla julkisesti. Hyödynnän tutkimuksessani aiempaa suomen kielen tutkimusta siitä, millä tavoin referointi on niissä määritelty. Aineiston referointia tarkastellessani hyödynnän ajatuksia genrejen funktionaalisista jaksoista ja Martinin ja Whiten suhtautumisen teoriasta ja sitoutumisen keinoista. Tutkimukseni osoittaa, että kirjoitustaidon vastaus on varsin moniääninen tekstilaji. Aineiston referointi ei esiinny vastaustekstissä vailla päämäärää, vaan sillä on tekstiyhteydessään aina jokin funktionaalinen tarkoitus. Aineiston referointi ja kokelaan oma pohdinta tai ääni muodostavat eräänlaisen parin, joka voi saada näkökulman rajauksessa muun muassa argumentoivan, esimerkinomaisen tai kommentoivan funktion. Referointi näyttää rakentavan tekstiin abstraktin ja konkretian tason vaihtelun, jolla kokelas luo tekstiinsä pohdintaa. Vastaustekstin aloitus- ja lopetuskappaleissa esiintyy tarinallisuutta sekä kertovaa ja kuvailevaa tekstityyppiä, joilla tekstiin rakennetaan esimerkkejä. Esimerkillä sen sijaan rakennetaan kokelaan näkökulmaa abstraktin ja konkretian tason vaihtelulla. Erilaiset tekstityypit ja referoinnin keinot näyttävät kaikki liittyvän merkittävästi siihen, millä tavalla vastaustekstiin rakentuu näkökulmaa ja pohtivuutta. Tutkimustulokseni osoittavat, että erityisesti erinomaisissa vastausteksteissä näkökulma ja pohtivuus rakentuu siten, että pääpaino on kokelaan omassa pohdinnassa. Tutkimukseni paljastaa kirjoitustaidon kokeen vastauksen tekstilajista suuntaa antavia tuloksia, joita voi tietyin varauksin liittää äidinkielen ja kirjallisuuden didaktiikkaan ja esimerkiksi genrepedagogiikkaan.
  • Heinämäki, Noora (Helsingin yliopisto, 2020)
    Tämän tutkielman tarkoituksena on selvittää, millaista slangia henkilöhahmot käyttävät Jens Lapiduksen kirjoittamassa rikosromaanissa Snabba Cash. Henkilöhahmot, joiden repliikkeihin ja käyttämään kieleen aineisto pohjautuu, ovat ulkomaalaistaustaisia tukholmalaisia. Analyysiisa keskitytään erityisesti siihen, miten henkilöhahmojen käyttämä kieli eroaa ruotsin yleiskielestä sekä kieliopin että sanaston osalta. Tutkielman materiaalin analysoinnin pohjana käytän aikaisempia tutkimuksia, jotka perustuvat maahanmuuttajien käyttämään erityiseen kieleen Tukholman esikaupunkialueella. Teoriaosuudessa käytän lähteenä mm. kielitieteilijä ja professori Ulla-Britt Kotsinasin tutkimuksia ja teoksia aiheesta. Aineistossa esiintyy useita esimerkkejä, jotka aikaisempien tutkimusten perusteella voidaan kategorisoida ns. rinkebysvenskaksi tai maahanmuuttajaruotsiksi. Tämä slangimuoto on syntynyt ruotsissa Tukholman esikaupunkialueella 1960- luvulla, kun Ruotsiin värvättiin teollisuustyövoimaa ulkomailta. Asuinalueella asuvat maahanmuuttajat puhuivat ruotsia enimmäkseen keskenään ja pikkuhiljaa kieli muotoutui sellaiseksi kuin se nykyään on. Kirjan henkilöhahmojen juuret ovat Chilessä, entisessä Jugoslaviassa ja _Lähi-idässä. Henkilöhahmojen äidinkieli vaikuttaa heidän käyttämäänsä sanastoon siten, että slangisanat otetaan usein omasta äidinkielestä. Yksi henkilöhahmoista on sen sijaan kantaruotsalainen ja hänen käyttämänsä slangi on kategorisoitavissa Tukholmassa käytettävään slangiin, jossa on piirteitä myös nuorisokielestä. Tutkielman analyysi-osuudessa esitellään poikkeavan sanaston lisäksi poikkeavuutta ruotsin kielioppisääntöihin. Keskeisimpiä kielioppipoikkeavuuksia ilmenee ruotsin V2- säännössä, verbimuodoissa ja verbien käytössä ylipäätään. Tutkielman lopussa pohditaan rinkebysvenska-slangin tulevaisuutta perustuen siihen, miten kieltä puhuvat muuttavat kielenkäyttöään aikuistuessaan. Kirjan henkilöhahmot ovat aikuisia, minkä voi päätellä vaikuttaneen heidän puheessa käyttämäänsä slangisanojen määrään. Kuitenkin slangin asema säilyy heidän puheessaan, joskin hieman muuttuneena.
  • Xu, Yi (Helsingin yliopisto, 2020)
    Tiivistelmä/Referat – Abstract Global warming and its coinstantaneous disturbance are intensively influencing the northern area. As a major natural disturbance in northern forest, winter moth (Operophtera brumata) and autumn moth (Epirrita autumnata) has caused wide defoliation in the mountain birch forest (Betula pubescens ssp. czerepanovii) at the subarctic area, exerting great impact on soil C stocks. Increasing temperature has promoted the vegetation expansion in the northern area and elevated the plant productivity, leading to higher C input to soil C stock. Litter decomposition may be accelerated by higher temperature, which decreases soil C storage. Moth herbivory usually increases the soil C stock in the short-term through litter and frass deposition, despite its aboveground suppression on photosynthesis. Belowground microbial community and composition shift would happen after moth outbreak, mediating the soil C turnover. However, the long-term effect of moth outbreak on soil C stock is still uncertain. This study investigated the influence of different tree status on soil C stock at subarctic mountain birch treeline forest, which went through severe moth outbreaks at 10 and 60 years ago. Living trees have observed with higher soil C stock than dead trees and treeless tundra, indicating the living tree may have a positive impact on soil C stock probably due to great aboveground photosynthesis. Living tree and its understory vegetation enhanced the soil respiration and ecosystem respiration, which would speed the C turnover, especially in the peak growing season. Dead trees were observed with slightly higher soil C stock than treeless tundra, both at 10 and 60 years’ perspectives. In contrast to direct C input provided by the living tree, the positive effect of dead tree on soil C stock is mainly due to the recalcitrant accumulation in the soil organic layer. Thus, soil C stock at the subarctic treeline after moth outbreak showed variations depending on the tree status, but overall remained as a C sink, which is good for mitigating the climate change. The mechanism behind the changes of soil C stock needs to be further investigated in future.
  • McPartlin, Maria (Helsingin yliopisto, 2020)
    Cellular agriculture is a novel food production technology that utilizes tissue engineering techniques to culture muscle cells to make cultured meat, or microbes and fermenting to create proteins such as casein, albumin and collagen which can be processed to products similar to milk and egg white for example. This thesis aims to explore the challenges that cellular agriculture faces in terms of policy, politics and the society mainly in a Finnish context, but also observing EU regulations. These challenges were investigated by interviewing altogether 15 representatives of stakeholder groups, which are political parties, government administration, organizations of policy executioners, NGO’s, food-tech companies, -funds and research centres. The data from the interviews was transcribed and processed in Atlas.ti-software using the analysis of qualitative content -method. The processed data was then analysed using the analysis of a specialist interview -method. The study revealed that specialists agree that cellular agriculture products will follow EU Novel Food regulations, but that cellular agriculture might have to overcome some regulation-related challenges. Challenges might also arise from markets, consumers and competing with conventionally produced food. Some believed cellular agriculture to have a negative impact on the Finnish society in the form of eroding rural livelihoods, and that the production will be in the hands of large corporations. Many stated that they do not believe cellular agriculture will surpass conventional agriculture, but that it will become just another food innovation. Some believed cellular agriculture offers great possibilities in the form of more sustainable food production. Many of the statements of the interviewees reflected current events already underway in the cellular agriculture and alternative protein field. The challenges cellular agriculture will face are multifaceted, and more information is still needed, especially on the societal effects of cellular agriculture.
  • Sarasto, Johan (Helsingin yliopisto, 2020)
    Pro gradu-avhandlingens tema var preliminärt organisatorisk miljöansvarig kommunicering inom sociala medier. Hur man eventuellt kunde mäta/kvantifiera miljöansvariga kommuniceringens olika identifierbara kriterier och mängden av dessa kriterier fungerade som huvudmålsättningen till avhandlingen. Avhandlingen baserar sig på en utveckling av en kriteriebaserad kvantifierbar metod. Kriterierna som metoden strävar efter att kvantifiera är identifierbara inom miljöansvarighetsrelaterade publikationer i sociala medier. Med kriterierna som metoden strävar efter att kunna identifiera och kvantifiera är ändamålet att kunna skapa en tydligare helhetsbild av organisatoriska prioriteringar inom miljöansvarig kommunicering i sociala medier. De slutliga kvantifierade mängderna av de olika kriterierna är också jämförbara mellan olika företag, man kan med andra ord sammanställa olika företags mängder av olika identifierbara kriterier och jämföra dem sinsemellan. Kriterierna som identifieras och kvantifieras i metodutvecklingen var resultat av en fokusgruppdiskussion där målsättningen var att diskutera om miljöansvarighet och dess kommunicering i sociala medier och hur man eventuellt kunde tolka nivån av pålitligheten i olika miljöansvarighetsrelaterade publikationer i sociala medier. Från diskussionens valdes ut fem kriterier som kan identifieras och kvantifieras i olika publikationer. Data där de olika kriterierna identifierades var tre olika skogsföretags miljörelaterade publikationer i olika sociala media kanaler under år 2019. När publikationerna granskades igenom var målsättningen att identifiera olika kriterier och sammanställa dem och jämföra dem sinsemellan företagen. Resultaten presenteras kriteriespecifikt 1-5 från året 2019. Kriterierna innehöll också olika specifika dimensioner som strävade efter att ge ytterligare information av kriterierna och deras detaljer. Kriterierna identifierades och kvantifierades relativt ofta i de olika publikationerna. Resultaten av de olika kriterierna och dess dimensioner hade relativt mycket avvikelse och skillnad sinsemellan. Resultaten varierade också mellan de olika företagen. Slutsatsen av metoden var att man med hjälp av de kvantifierade kriterierna fick en jämförbar helhetsbild av prioriteringar inom miljöansvarig kommunicering i sociala medier. För att kunna tydligare identifiera pålitligheten av miljöansvarighet konstaterades det slutligen att man i fortsatta studier kunde koncentrera mer på vad som inte publiceras i sociala medier, s.k. selektivt avslöjande.
  • Viloma, Veera (Helsingin yliopisto, 2020)
    Sustainable supply chain management in the food industry has become not only an emerging trend but also a necessity in the light of social and environmental demands. Measuring the development of the degrees of sustainability in supply chains is important to depict the impacts of procurement activities, but organizations have faced difficulties in selecting metrics and objectives. The research objective is to provide an overview of sustainable supply chain measurement practices and implications in the food sector and propose applicable metrics for a case company. Principles of sustainable food supply chain management and assumptions of agency theory and institutional theory explain why specific metrics are used in the food industry. They also highlight challenges in measurement. Aligning trends, possibilities, and challenges in sustainable supply chain measurement are then shown to guide the selection of sustainability metrics. The study highlights trends in sustainability measurement in the food industry and provides an overview of the role of triple bottom line sustainability before highlighting practical challenges in supply chain measurement with regard to sustainability. The data collection and content analysis of corporate sustainability reports and industry-specific case studies provide an overview of sustainable supply chain metrics and emerging trends in measurement. Furthermore, a survey was conducted in cooperation with the focal company to evaluate the applicability of selected metrics to the case company. This joint approach, the content analysis and application to the case company were used to guide the development of a new group of sustainability metrics for the case company. The overall analysis results suggest eight sustainability metrics for the case company. The results show that organizational strategy, current practices, and assumptions of sustainability affect what metrics are considered applicable. Therefore, results must be evaluated critically to ensure long-term sustainability in supply chains. From a broader industry perspective, the results sug-gest that high-quality data and keeping track of relevant sustainability-measurement trends are useful for future strategy purposes. All in all, the analysis indicates that sustainable supply chain measurement in the food industry has taken a leap toward more sustainable practices during the past decade.
  • Laakkonen, Anna-Katri (Helsingin yliopisto, 2020)
    In beef production, the successful reproduction of animals plays a significant role. The gestation length in cattle is about 9 months, but there is variability between breeds. Gestation length in beef breeds is longer than in dairy breeds. Gestation length is correlated with calving difficulties. The objective of this study was to investigate factors affecting gestation length in beef cattle. Data was received from Faba co-op. The aim was to calculate the phenotypic gestation lengths for Charolais and Hereford, as well as for their crossbreeds with the most common beef breeds used in Finland. One of the objectives of this study was to calculate heritability estimates for gestation length for pure Charolais and Hereford breeds. Data from Charolais and Hereford calves born in 2009-2018 were used in the analysis. There were 2883 Hereford calves and 3370 Charolais calves in the data. Finally, only pregnancies that had resulted from artificial insemination with the minimum length of 165 and maximum length of 305 days long were included in the analysis. Two different models were used to estimate the variance components, one involving only the direct genetic effect of the calf and the other also considering the maternal effect. Fixed factors in both models included sex of calf, number of calves born, calving season, herd-year, and parity-age. All fixed factors were statistically significant. Based on the results, there were phenotypic differences in gestational lengths between breeds, heavier beef breeds having longer gestations. In the model including only the direct genetic effect of the calf, relatively high heritability estimates were obtained, but in the maternal model the direct heritability was lower, and the maternal heritability was very high. The current data was not well suited for the evaluation of the key figures of the maternal model, so the results should be treated as preliminary.
  • Kilpeläinen, Henna (Helsingin yliopisto, 2020)
    Suomesta viedään elintarvikkeita eniten naapurimaahan Ruotsiin. Ruotsin markkinoiden etuna voidaan katsoa olevan sen maantieteellinen läheisyys, markkinoiden suurempi koko sekä vapaakaupan mahdollisuus. Eduista huolimatta Ruotsin markkinat vaativat yrityksiltä resursseja ja taitoja sekä pitkäjänteistä työtä. Tutkielma tarkastelee elintarvikevientiä ja niitä taitoja, joita tarvitaan vientitoiminnan onnistumiseksi, kun viennin kohdemaana on Ruotsi. Lisäksi on selvitetty, mitkä tekijät voivat edistää elintarvikevientiä Ruotsiin. Tutkielman lähestymistapa on laadullinen ja aineisto on kerätty teemahaastattelun menetelmällä. Tähän tutkielmaan on valittu pieniä ja keskisuuria elintarvikeyrityksiä, jotka jo harjoittavat vientiä Ruotsiin. Tutkielmaan haastateltiin yhteensä neljän eri yrityksen edustajaa. Tutkielman tulosten mukaan Ruotsiin suuntautuvassa elintarvikeviennissä tarvitaan eniten taitoa löytää ja solmia oikeat kumppanuudet sekä markkinoida omaa tuotetta. Tulos on yhtenevä aiempien tutkimusten kanssa. Tutkielman tulokset osoittavat myös, että ulkopuolinen apu edistää vientiä. Siitä on hyötyä etenkin vientitoiminnan aloitusvaiheessa yleisesti sekä kontaktien hankkimisessa. Tulevaisuudessa vientitoiminta tulee todennäköisesti kasvamaan ja yhä useampi yritys aloittaa ja pyrkii myös laajentamaan kansainvälistä liiketoimintaa. Tämä tulee vaatimaan yrityksiltä enemmän resursseja ja taitoja. Erityisesti pienempien yritysten kohdalla oikeat kumppanit ja ulkopuolinen apu voivat vaikuttaa merkittävästi vientitoiminnan käynnistämiseen ja sen laajentamiseen.