Browsing Maatalous-metsätieteellinen tiedekunta by Publication Year

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  • Moilanen, Ville (Helsingin yliopisto, 2021)
    Maatalouden rakennemuutoksen seurauksena suomalaisten maatilojen määrä vähenee ja tilakoot kasvavat. Tilakokojen kasvaessa yhä useampi maatila tutkii mahdollisuuksia yhtiöittää yritystoimintaansa. Yhtiömuotoisten maatilojen määrän noustessa myös niiden yrityskaupat ovat määrältään yleistymässä. Maatilojen yrityskauppoja on tehty pääasiassa suku-polvenvaihdoskauppoina, jolloin niistä maksettavat kauppahinnat eivät ole aina linjassa niistä saatavien tuottojen kanssa. Tutkielman tavoitteena oli selvittää, miten yhtiömuotoisen maatilan arvo määräytyy, kun arvon määräytymisperusteina käytetään talousteoriaan perustuvia arvonmääritysmenetelmiä. Käytettävät arvonmääritysmenetelmät olivat substanssiar-vomenetelmä, vapaan kassavirran menetelmä ja taloudellisen lisäarvon menetelmä. Lisäksi tavoitteena oli luoda Excel-laskuri, jonka avulla nämä arvot pystyttiin laskemaan. Arvonmäärityksen näkökulmana käytettiin ainoastaan tilinpäätös-tiedoista saatavaa informaatiota. Tutkielman teoriaosuus koostui käytettyjen arvonmääritysmenetelmien teoriasta, pää-oman tuottovaatimuksen määräytymisperusteista sekä tilinpäätöksen teoriasta. Tutkielma suoritettiin tapaustutkimuksena, jolloin yritykseksi valikoitiin yksi suomalainen yhtiömuotoinen maatila. Aineis-tona käytettiin Suomen Asiakastiedosta saatavaa tilinpäätösinformaatiota. Arvonmääritystä varten työstettiin Excel-pohjainen laskuri, jonka avulla pystyttiin laskemaan case-yrityksen arvo kolmella eri menetelmällä ainoastaan tuloslas-kelma- ja tasetietoja hyödyntäen. Tutkielman tulokset olivat linjassa aikaisempien tutkimusten tulosten kanssa. Kaikki kolme menetelmää antoivat toisis-taan poikkeavat tulokset. Substanssiarvomenetelmä antoi case-yritykselle pienimmän arvon ja sitä voidaan pitää enin-tään yrityksen pohja-arvona. Taloudellisen lisäarvon malli antoi hieman korkeamman arvon kuin substanssiarvo, koska se otti oman pääoman lisäksi huomioon vuosittaiset lisävoitot diskontattuna nykyhetkeen. Korkeimman arvon antoi vapaan kassavirran menetelmä, sillä siinä yrityksen pääomarakenne ei vaikuttanut arvotukseen kovin vahvasti, vaan pääpaino oli case-yrityksen tuottokyvyssä. Kaikkien kolmen arvonmääritysmenetelmän todettiin olevan herkkiä erilaisille muutoksille. Substanssi- ja taloudellisen lisäarvon malli reagoivat vahvasti oman pääoman muutoksiin. Vapaan kassavirran malliin vaikutti puolestaan vahvasti kassavirtojen kasvuoletukset. Pääoman tuottovaatimuksella todettiin olevan myös suuri merkitys taloudellisen lisäarvon- ja vapaan kassavirran mallin antamille tuloksille. Tutkielmassa huomattiin, että vapaan kassavirran- ja taloudellisen lisäarvon mallissa tulisi ottaa jollain tavalla enemmän huomioon yrityksen kilpailukyvyn ylläpitäminen. Tutkielman ede-tessä myös huomattiin, että pääoman tuottovaatimuksen määräytymistä on olisi syytä tutkia enemmän.
  • Termonen, Maarit (Helsingin yliopisto, 2021)
    Kiinnostus monilajisiin nurmiseoksiin on kasvanut Suomessa. Nurmipalkokasvit tuovat seoksiin lisäarvoa biologisen typensidonnan ja syöntiä lisäävien ominaisuuksiensa vuoksi. Seosten lajikoostumuksen ja sen muutosten tarkempi selvittäminen auttaa ymmärtämään kasvuolosuhteiden vaikutusta eri lajien menestymiseen seoksissa ja tämän seurauksia. Tutkielman tavoitteena oli selvittää, kuinka nurmipalkokasvit ylläpitävät satoa ja pysyvät nurmiseoksissa sekä miten ne vaikuttavat ruokinnalliseen arvoon ja typen hyväksikäyttötehokkuuteen. Tutkimus toteutettiin kolmivuotisena ruutukokeena, jossa oli mukana viisi nurmipalkokasveja (puna-, valko- ja alsikeapila sekä rehumailanen) sisältävää nurmiseosta. Seoksille annettiin typpilannoitusta 50 + 50 kg/ha/v, ne niitettiin kahdesti kesän aikana, ja sadon lisäksi määritettiin kasvilajikoostumus ja rehuarvot. Seosten satotasot vaihtelivat välillä 5400–8200 kg ka/ha. Kokeen aikana esiintyi kuivia jaksoja, jotka suosivat puna-apilaa ja erityisesti rehumailasta. Puna-apila oli apiloista satoisin, ja pysyi kasvustossa koko koejakson ajan. Alsikeapilasta ja valkoapilasta ei ollut satoa alentavaa haittaa. Rehumailanen ylläpiti satoa tässä kokeessa hyvin ja runsastui nurmen vanhetessa, vaikka mailasten menestyminen on Suomen oloissa vaihtelevaa. Apiloiden vaikutus rehuarvoihin oli vähäinen. Runsas rehumailasen osuus kasvustossa laski D-arvoa ja nosti sulamattoman kuidun sekä raakavalkuaisen pitoisuuksia. Madalletun typpilannoituksen ja biologisen typensidonnan vuoksi seosten keskimääräinen typen hyväksikäyttötehokkuus oli 1,22–1,56. Kokeen tulokset osoittivat, että kohtuullista typpilannoitusta ja kahden korjuun taktiikkaa käytettäessä nurmipalkokasvien osuus kasvustossa säilyi rehumailasta lukuun ottamatta maltillisena. Kaikki seokset olivat rehuarvojen perusteella sopivia märehtijöiden rehuksi, eikä mikään seos osoittautunut myöskään sadon määrän perusteella muita huonommaksi. Rehumailanen osoitti hyvän kuivuuden sietokykynsä ja piti satotasoa yllä parhaiten kuivina kesinä.
  • Norrback, Josefin (Helsingin yliopisto, 2021)
    Gastrointestinal parasites (GIP) and resistance against anthelmintics are and will be one of the biggest challenges for the sheep husbandry. Research within this area is very important today and it is important to figure out new methods to identify individuals with high burden of parasites and to treat just these individuals. The aim of the study was to investigate the effects of GIP on activity patterns and weight gain in first season grazing lambs. A sub-study accompanied with the aim was to see if the manually made behavioural observations supported data from the sensors. The study took place at the Swedish University of Agricultural Sciences (SLU) during the summer of 2019. The study was divided into two experimental periods. In the first experimental period 30 ewes and their 60 twins were used. Of those, 58 lambs continued to the second experimental period. Two groups were dewormed with ivermectin (high group) and two groups were untreated (low group). All lambs were fitted with sensors, and the data was downloaded once a week, at the same time with the weighting of animals. Individual faecal samples were collected four times. The pasture where the lambs grazed was a first-year pasture. Sward height was measured, and herbage samples were collected three times during the experiment. Herbage samples were analysed for nutritional and mineral content. The manual behavioural observations were made two days a week during five weeks. The high group had higher weight (28.9 kg) in the beginning of the experiment, compared with the low group (28.1 kg). On the contrary, the high group had lower weight (42.7 kg), compared with the low group (44.8 kg) at the end of the experiment. According to data from the sensors there were differences in lying time and motion index (MI) during the 7-10 first days after weaning. The low group laid down more, compared with the high group. The low group had higher MI compared with the high group. During the whole experiment there were no differences in lying time, lying bouts or MI. The manual behavioural observations showed that “standing still” had significantly more registrations for the high group compared to the low group. It is possible to see differences in behaviour with sensors at an early stage of parasitic infection, even with low levels of parasites. This means, that there is a potential to use automatic behaviour observations as a diagnostics tool during infection of GIP.
  • Linnainmaa, Eeva (Helsingin yliopisto, 2021)
    Dairy cattle breeding has been driven by economics since the 1930s. For a longer period, the costeffectiveness of dairy farming has been poor, and the farmers have been forced to look for all possible ways to improve economics, through either reducing costs or increasing profit. Finland had in 2018 6250 dairy farms, which all differ from each other by size, economics and production environment. Finland participates to Nordic Cattle Genetic Evaluation (NAV) and uses Nordic Total Merit (NTM) as a joint total merit index for Finland, Denmark and Sweden. It has not been published, whether Finnish dairy farms would need more farm specific total merit indices. Breeding goal preferences do differ not only between farms but also between production types, since organic farmers tend to put more emphasis on production, compared to conventional. The aim of this study was to study whether economic values on breeding goal traits differ between farms and production types. Herd specific economic values were counted for ten breeding goal traits. The study was fulfilled with seven dairy herds, who differed from each other by herd size and production environment. Two of the herds were organic. The calculation of economic values was based on a bioeconomic model SimHerd. It is a stochastic simulation model, which simulates the herd in weekly steps, taking all events in a cow’s life into account. Traits analyzed in this study were chosen according to hypotheses of their economic values. Traits analyzed were ECM yield, mastitis, conception rate of cows, conception rate of heifers, cow mortality, calf mortality, claw and leg diseases, feed efficiency, body weight and other culling. Prices and variable costs as well as the phenotypic data of the farms was collected from the year 2018. Finnish milk production is highly dependent of subsidies, but due to their complexity, only direct subsidies for milk were considered in this study. Relations between traits were cut off from the model before simulation. The maximum number of cows for each farm was set to 1000 to improve the reliability of the simulations. Each trait was simulated three times: with the phenotypic data and then twice with changing the parameter. According to the results, the relative economic value of ECM yield was the highest for all farms. The highest economic values differ between farms, but on average the next highest economic values were for body weight, conception rate of cows and cow mortality. These economic values were in the same range for both conventional and organic farms. When relative economic values are presented as percentages of the sum of standardized economic values, traits affecting longevity cover together the greatest percentage. With improved longevity the cows have more productive years, which means greater lifetime milk yield, less replacement cots and smaller environmental impact. When results were compared between farms, they showed no need for farm specific TMI. A different TMI for organic production would need a further research.
  • Tiira, Matilda Anniina (Helsingin yliopisto, 2021)
    High moisture extrusion (HME) can be used to create meat-like structures in plant-protein-based products. This study aimed to describe sensory and textural properties of minced-meat-like products made from a legume ingredient and a plant fibre concentrate using HME. Extrudates with two different ratios of the ingredients, both with and without added hydrocolloid, were produced for the study. Sensory profiling (n = 9) was conducted as generic descriptive analysis (GDA). Instrumental texture profile analysis (TPA) as well as a consumer study (n = 55) were done to complement the data. GDA attributes, TPA parameters and consumers’ hedonic responses were compared, and connections were studied. Also, TPA results were compared to those from sensory analysis, aiming to find connections between instrumentally and sensorially measured parameters. The dry ingredient ratio clearly affected hedonic responses, while the effect of added hydrocolloid was smaller. Several descriptive sensory attributes, such as bitterness, gumminess, cohesiveness and stickiness, were related to the hedonic responses to smell, texture and taste. Plant fibre concentrate content was also clearly linked to these descriptive attributes. Samples perceived as gummy, cohesive, less bitter and less sticky got higher hedonic responses, but TPA parameters could predict neither GDA attributes nor hedonic responses. The results of this study showed that certain ingredients have a clear impact on sensory attributes and therefore hedonic responses of the final products. To further improve the consumer acceptance, pre-processing of the ingredients could be studied. To explain the differences in textural properties, more research on the molecular level assembly of specifically fibres and carbohydrates in the matrix is needed.
  • Knappe, Aaro (Helsingin yliopisto, 2021)
    Tutkin maisterintutkielmassani suomalaisten kelloharrastajien näkemyksiä luksuksesta ja kuluttajien aktiivista roolia luksuksen merkityksien tuottajina. Kelloharrastajat osoittautuivat mielenkiintoiseksi aiheeksi. Aktiiviset harrastajat ovat joutuneet pohtimaan luksuksen merkityksiä osallistuessaan yhteisön toimintaan. Luksuksen vaikean määrittelyn ja tulkinnanvaraisuuden vuoksi tavoitteena oli tutkia, millaisena kelloharrastajat itse näkevät luksuksen. Aiheen tekee tärkeäksi luksuksen suuri yhteiskunnallinen merkitys ja jatkuva esillä olo mediassa sekä katukuvassa. Taustateoriana tutkimukselle toimii Veblenin huomiota herättävän kulutuksen teoria ja sen kritiikkinä toimiva keskustelu huomiota herättämättömästä kulutuksesta. Luksusta ja huomiota herättävää kulutusta on pitkään pidetty lähes synonyymeinä, ja vasta viime aikoina niiden yhtäläisyyttä on kyseenalaistettu. Tutkimus toteutettiin teemahaastatteluin syksyn 2020 aikana. Haastattelujen kohteena olivat Facebookin kelloharrastajat ryhmän jäsenet. Aineistoa lähestytään sisällönanalyysin avulla, jakaen materiaali kolmeen teemaan. Luksuksen määritelmiä lähestytään toiminnallisen, kokemuksellisen ja symbolisen maailman kautta. Näiden avulla on tarkoitus selvittää, millaisia merkityksiä kuluttajat itse antavat luksustuotteille. Tutkimuksen aikana selvisi, että kelloharrastajat tekevät selkeän jaon arvokkuuden ja luksuksen välille. Luksus nähtiin pääosin negatiivisessa valossa ja yhdistettiin juuri huomionhakuisuuteen sekä näyttämisen haluun. Erottamalla arvokkuus ja luksus toisistaan kuluttajat saavat neuvoteltua merkitykset sopimaan paremmin omaan maailmaan. Symbolinen maailma osoittautui haastavaksi tutkimuksen kohteeksi. Selkeä jako arvokkuuden ja luksuksen välillä aiheutti sen, että puhe luksuksesta erotettiin kokonaan omasta toiminnasta. Näin puhe luksuksesta esittäytyy pelkästään mielikuvina ja yleistyksinä luksuksen merkityksistä. Unelmien ja unelmoinnin tärkeys nousi kuitenkin vahvasti esille osana arvokkaiden tuotteiden kulutusta. Unelmoinnin kautta saavutetaan juuri suuri osa kulutuksen nautinnosta. Selkeä havainto oli myös kuluttajien halu tuottaa aktiivisesti merkityksiä. Luksuksella ja arvokelloilla ei itsellään ole sisäänrakennettuja merkityksiä, vaan ne syntyvät kuluttajien tekemän aktiivisen neuvottelun tuloksena.
  • Mäkelä, Heini (Helsingin yliopisto, 2021)
    Including feed efficiency in a selection index and its estimation on farms cannot be done by dry matter intake, because it’s not possible to measure dry matter intake on farms. It could be possible to evaluate dry matter intake by using rumination time as an indicator trait. Many farms already have devices to observe rumination. To be a useful candidate trait in selective breeding, rumination time needs to be heritable. The aim of this study was to evaluate genetic parameters of daily rumination time in first three lactations in Finnish Ayrshire. The data was received from FABA co-op and it contained production-, insemination-, calving- and herd data as well as pedigree data of Finnish Ayrshire cows. In addition, rumination data collected by Heatime and SenseHub equipments, were included in the study with the permission of SCR Engineers Ltd. The data was edited into the form to be processed and examined with RStudio, pedigree data was processed with RelaX2 and variance components for daily rumination time and daily milk production were computed by REML method with DMU. Tables and graphs were made in their final form with Excel spreadsheet software. Two separate materials were made from the data: the data of first-time calved cows and the data of 1 to 3 times calved cows. The data was studied as two-trait repeatability model in which observations of rumination time were from all lactation stages. The heritability of rumination time was 0,14 (SE 0,05) for primiparous cows and 0,19 (SE 0,02) for cows having 1 to 3 lactations. The genetic correlation between rumination time and milk production was 0,05 (SE 0,21) for primiparous cows and 0,31 (SE 0,06) for cows having 1 to 3 lactations. Daily rumination time is a heritable trait and hence it can be used as a direct or indicator trait in selective breeding. Further studies of the genetic correlations between rumination time and dry matter intake should be done to evaluate the usability of rumination time as an indicator of dry matter intake.
  • Venkat, Vinaya (Helsingin yliopisto, 2021)
    The COVID-19 pandemic has brought into discussion the role of airborne transmission in infectious diseases. Many studies on enveloped viruses such as influenza suggest that respiratory viruses can be transmitted with large or small droplets formed when the patients talk, breathe, sneeze or cough. This comes under the category of direct contact. These droplets may also be transmitted indirectly as fomites through contact with contaminated surfaces. It has been difficult to prove that aerosols' transmission as the methods to capture virus in the air are not very sensitive. SARS-CoV-2 is a novel coronavirus affecting millions of people since 2019, and it has been challenging to contain the spread of this virus. Hence it is of vital importance to understand the transmission of the virus through aerosol and droplets. In this study, aerosol samples were collected from patients in the Surgical Hospital in Helsinki and patients at home in quarantine using various bioaerosols sampling devices like Biospot, Dekati, Button, and Andersen samplers, and passive sampling techniques to capture aerosols and droplets in the air. Such samples were subjected to cell culture on TMPRSS2 expressing Vero E6 cells to check for infectious viruses and RT-PCR using the N-gene targeting method to detect the presence of SARS-CoV-2 RNA in the samples. Out of the 32 saliva samples collected, 19 samples were tested positive by RT-PCR, but cell culture was not always positive. Bioaerosol samples collected using Dekati, Button, and Biospot samplers were negative by PCR. However, Andersen samplers showed positive results along with various passive aerosol samples collected on MEM, indicating aerosols' production of small sizes that can be transmitted air in the air to far distances and settling due to gravity. A relation between saliva samples and symptom days indicates the decrease in saliva viruses' infectivity with the prolonged infection as seen from the RT-PCR. From these findings, it can be concluded that SARS-CoV-2 can be spread by airborne and fomite transmission, and more so by patients with symptoms day 2-7 who are proven to be more infectious. Additionally, it was inferred that the Six Stage Andersen impactor would be the most efficient for aerosol sampling. Further studies are still needed to understand the characteristics of the spread and extent of infection caused by the variants of SARS-CoV-2.
  • Laajalahti, Janne (Helsingin yliopisto, 2021)
    Traktorien nostolaitteen sivurajoittimia on yritetty hydraulisoida 1970-luvulta lähtien. Kiuruvetinen yritys Piippo Hydraulic on kehittänyt Farmiventtiili -nimisen erikoisventtiilin, joka kykenee ohjaamaan sivurajoittimia yhdessä ja erikseen. Lisäksi traktorin ohjausjärjestelmiä varten on kehitetty ISO 11783-standardi, jossa määritellään traktorin, työkoneiden ja niiden ohjainlaitteiden välinen väyläliikenne. Tämä mahdollistaa eri valmistajien laitteiden kytkemisen yhteen ja samaan ohjaus- sekä tietoväylään. Tässä maisterintutkielmassa tehtiin prototyyppi Farmiventtiilin ISOBUS-pohjaisesta ohjauksesta. Farmiventtiilin ohjaus toteutettiin Epec Oy:n toimittamalla ohjauslaitteella, Multitool-konfigurointiohjelmalla, CodeSys PLC-ohjelmointiympäristöllä sekä IsoDesigner-käyttöliittymän suunnitteluohjelmalla. Näillä työkaluilla suunniteltiin virtuaaliterminaalille käyttönäkymä, laitteen ECU:lle toimintalogiikka sekä 3D-tulostamisen avulla prototyyppiasteen monitoimiohjain. Laitteelle tehtiin myös valmius väyläpohjaiselle ohjaukselle traktorin oman tai muun valmistajan hallintalaitteiden kautta AUX-N -standardiosan mukaisesti. Prototyypissä testattiin myös nostolaitteen työntövarren, kallistajan ja sivurajoittimien anturointia ja siihen pohjautuvaa automatiikkaa. Lopputuloksena saatiin prototyyppiasteen ohjausjärjestelmä, jossa on toteutettu nämä toiminnallisuudet. Työn edetessä havaittiin, että sinällään yksinkertaiseen venttiiliin voidaan mahduttaa ohjelmoitavuuden ansiosta runsaasti sellaisia toiminnallisuuksia, joita yksinkertaisella analogiohjauksella ei voida saavuttaa. ISOBUS:ssa toimiva ohjausyksikkö kykenee toimimaan myös muiden venttiilijärjestelmien siltalaitteena, jos järjestelmää on laajennettava. ISOBUS:n avulla toteutettu ohjaus alentaa kustannuksia, kun omia ohjainlaitteita ja kaikkia antureita ei tarvita väylällä valmiiksi olevien laitteiden ansiosta.
  • Huhdanmäki, Tuukka (Helsingin yliopisto, 2021)
    CRISPR-Cas9 is one variant of newly emerging technologies utilizing targeted mutagenesis based on Cas family proteins and guide RNA that enable binding and modifying selected target sequence. The aim of the master’s thesis was to compare different methods of CRISPR-Cas9 induced gene editing in the genus Nicotiana and other secondary protocols necessary to identify successful mutations. PDS1 and PDS2 genes coding phytoene desaturase in plants were selected as target genes as mutant genotype produce visually identifiable photobleaching phenotype. CRISPR-Cas9 ribonucleoprotein complex mediated transformation uses separately produced Cas9 protein and guide RNA that when combined perform transient gene editing in cell. This method was planned to be used but Cas9 protein was challenging to produce in soluble form and final transformation was not achieved. This study suggests that acquiring ready-to-use Cas9 protein might be preferable choice when targeting only few transformations with CRISPR-Cas9 RNP-complex. Agrotransformation is well established method for genus Nicotiana and using Single Transcriptional Unit CRISPR-Cas9 system it is straightforward procedure from plasmid design to transformation. Successfully transformed plants were redeemed from transient agroinfiltration and stable agrotransformation experiments. Off-target mutations are possible and selective outbreeding may be needed. This method lacks the several advantages of CRISPR-Cas9 RNP-complex such as instant gene editing in cell, avoiding RNA interference and transformation over species boundaries, but is simple and functional in genus Nicotiana. Successful mutations were detected using commercial T7E1 and with natural CEL I endonuclease from celery extract. Celery extract can be used as cost-effective alternative to T7E1 for verifying or replicating previously confirmed results.
  • Suuronen, Juulia (Helsingin yliopisto, 2021)
    Forests play a central role in climate change mitigation actions, and substitution, that is the use of wood products in place of fossil intensive materials, has been recognized as a potential way to avoid emissions. While there are studies estimating the substitution impact of products, i.e., the avoided emissions, there is a lack of studies integrating market perspectives into substitution estimation. To contribute to this research gap, this study explores the market assumptions of substitution through the theoretical lenses of value chains and microeconomic theory on demand. The objectives are to recognize powerful decision-makers in the value chains, to establish a better understanding for the current state of substitution in the markets, and to explore the determinants of demand of the wood-based products. To limit the scope of this study, the use of pulp-based products was examined in the cases of packaging and textile sectors. Semi-structured interviews with 14 experts were arranged to discuss their views on substitution and demand of the pulp-based products in the chosen sectors. Additionally, a Likert scale was filled at the end of each interview to supplement the interview answers and enable elasticity and cross-price elasticity analyses to examine substitution. The sample of respondents was chosen through the use of snowball sampling and a matrix to recognize potential interviewees. First, the findings of this study suggest that in both sectors, the decision-making power on materials is held by the operators at the end of the value chain whereas the forest sector is located at the beginning of the chain. Second, in both sectors, there is willingness to find more sustainable material solutions, but the tools for this are lacking. In the case of packaging sector, the barrier capacities of plastic are unattainable with fiber-based materials, meaning that reducing plastic use does not always imply switching the feedstock itself. In the textile sector, the production of wood-based textile fibers is not yet scaled enough for it to compete with similar materials. However, the analysis of elasticities indicates that some substitution can be expected in both sectors. Third, a number of important determinants of demand were identified, yet no single factor could be identified as the most important one. This study concluded that there is room to improve the market assumptions for substitution impact estimation. In packages, the market preferences of fiber-based packaging in some uses give a rise for interpretational issues, while plastic reduction goals do not always imply switching to wood feedstock. In textiles, the new man-made cellulosic fibers (MMCFs) are expected to mostly substitute for viscose and fill the cellulosic gap from stagnating production of cotton instead of substituting for synthetic fibers. To conclude, it is central to integrate market data and concepts better into future substitution impact analyses to facilitate more realistic estimates.
  • Sainio, Mette (Helsingin yliopisto, 2021)
    Cattle breeding has become much more effective in recent decades thanks to the development of reproductive biotechnologies and genetic testing. In 1970s it was discovered that embryo transfer techniques make it possible to produce plenty of offspring from top quality females which intensified dairy cattle breeding. Nowadays, there is two embryo transfer techniques in use, MOET and OPU-IVP. A genomic selection has also made genetic improvement of cattle populations more intense than before. Genomic selection is a method that utilizes single nucleotide polymorphisms that appear in individual genome. Today both the embryo transfer techniques and genomic selection are essential elements of cattle breeding all over the world. Genomic selection has typically been carried out on newborn calves. During the recent years, selection has been increasingly carried out and studied on embryo level. Embryo genomic selection always starts with a biopsy taking. After this, sample needs to be genotyped and the results needs to be analysed. Biopsy size has effect on quality of the genotyping outcomes. When the biopsy size grows, quality and reliability of the results will get higher. The aim of this study was to determine if there was any difference in genotyping success between embryos and newborn calves and is it possible to predict embryo-calf genotype similarities via embryo call rate. Material included SNP-genotyping results from a total of 214 embryo and 13 corresponding calves. R programming language was used to statistically analyse the results. Embryo call rates, SNP call rates and embryo-calf genotype similarities were determined from the data. Embryos and their corresponding calves had high similarity with their genotypes, 91,7 % on average. This supports the hypothesis that embryo and their corresponding calves will not have major differences in their genotyping results. Embryo call rates were also in high levels (on average 90,3 %) as was found also in the previous studies. Hence, results from this study confirmed the hypothesis that genotyping of the embryos is a reliable and successful method. There was no clear relationship between embryo call rates and embryo-calf genotype similarities; embryo-calf pair with weakest genotype similarity results, had good embryo and calf call rates. On the other hand, embryo call rates of the two following pairs that got the second and third worst results were clearly below average. In the cases with overall weakest embryo-calf genotype similarities, it was not possible to improve it by eliminating the worst embryo genotypes. Reliable genotyping of embryos enables prediction of genomic breeding values for embryos. Instead of making decision on embryo purchase according to breeding values of the parents of the embryo, purchaser can select embryos according to their own breeding value. Thereby, in the future, embryo genomic selection is likely to become more common than today.
  • Kinnunen, Aleksi (Helsingin yliopisto, 2021)
    Trees face an increasing variety of health threats. The overall effects of climate change on trees and forests are difficult to predict. As a result of the warming climate, the growing season is lengthening, improving the growth of the trees, but at the same time drought and insect damages may become more common and the risk of storm damage increases. There are many benefits to monitoring tree mortality. It can be used to assess the health status of forests, productivity, carbon sequestration and the ecological impacts of dead trees on forest ecosystems. Causes leading to tree death can include biological, climatic or human related factors. Monitoring can increase understanding of the causes of death and potentially help to protect forests better. Tree-related mortality is a spatially and temporally irregular process that is difficult to monitor using traditional inventory methods. Remote sensing makes it possible to map and monitor tree mortality more effectively. The purpose of this thesis was to find out how remote sensing data can be utilized in monitoring tree mortality. The aim was to find out how tree mortality has varied regionally and quantitatively in the Central Park of Helsinki and how accurately dead trees can be identified from aerial imagery. The study period was 2005–2019, during which orthophotos of seven different years were examined. Reference data of 14 212 trees were collected from the aerial time series covering a 15-year period by visual image interpretation. The data included healthy, weakened and dead trees. Heatmap time series were created from the locations of weakened and dead trees to examine quantitative and regional variability in mortality. The average temperatures over the years as well as the rainfall were compared with the dead tree numbers and the correlations between the observations were examined. The collected reference data was also utilized in health status classifications, which were implemented using semi-automatic machine learning methods. The object of the classifications was to identify healthy, weakened and dead trees as well as possible from each other. The canopies of individual trees were delimited by canopy segments obtained from laser scanning data. From the pixels contained in the delimited canopies, image features describing individual trees were calculated. Considerable changes in tree mortality were observed. The number of dead trees at the beginning of the study period increased significantly from year 2005 to year 2009. An exceptionally dry summer in 2006 was identified as a possible reason. In the following years, the situation remained moderate, but in quantitative and regional terms, mortality was at its highest in 2017. Overall, there was an upward trend in mortality during the study period, and average annual temperatures were found correlating strongly with the number of dead trees (r=0.73). The classification accuracies of tree health status varied annually between 89–96%. The seven-year average accuracy was 93.6% with a kappa value of 0.88. The most important features in the classification were the features calculated from the blue channel, such as the maximum value of the channel (B_max), the difference between the maximum and minimum of the channel (B_range) and the skewness of the distribution (B_skew). The results of the thesis showed that tree mortality can be monitored using remote sensing data. Clear changes in the number of dead trees were observed using the time series and possible causes were identified. By identifying the causes behind rising mortality, the effects of climate change can also be better understood. Tree health status classification accuracies were at a good level and dead trees can be mapped from aerial imagery by semi-automatic methods. Based on the thesis, it can be rightly stated that changes in tree mortality can be observed with aerial imagery time series. In addition, the semi-automatic identification of dead trees from aerial imagery can be said to be accurate enough for large-scale use.
  • Vehola, Anni (Helsingin yliopisto, 2021)
    Forests play a key role in climate change mitigation. There are different ways in which forests can contribute to both increasing carbon sequestration and reducing emissions. In Finland, forests are largely owned by private forest owners and thus the actions of these forest owners have a great impact on the climate change mitigation potential of forests. Thereby, this study examined the perceptions of Finnish forest owners on the following climate change mitigation strategies in the forest sector: Forest management, More harvest, Less harvest, Wood products, Conservation, Adaptation, and Land use change. Especially, the study focused on “Less intervention” (a combination of three individual strategies), and “Forest management” as strategies and tested how the following hypothesized aspects are associated with the support for these strategies: the prioritized values affecting the choice between climate change mitigation strategies in the forest sector, risk perception of climate change, political orientation, education level, and the size of forest land. The tested hypotheses were derived from the existing literature on theories and empirical findings on the perceptions of citizens and forest owners. The effect of the independent variables on the chosen climate change mitigation strategies was studied through linear regression analysis based on a quantitative survey with 892 responses. Regression models were established separately for both chosen strategies. On average, forest owners supported all climate change mitigation strategies in the forest sector, except Less harvest. Further the results of the linear regression analysis supported all hypotheses to some degree. Perceived risk of climate change emerged as an important measure affecting the support for climate change mitigation strategies in general. Left-right political orientation was found important, where individuals positioned more on the right side of the political spectrum generally supported strategies that have more human intervention in forests. Forest owners’ prioritized values were discovered to significantly affect the support for climate change mitigation strategies in the forest sector, and forest owners who valued biodiversity gave more support towards Less intervention and less support towards Forest management. Forest owners with a smaller property tended to be slightly more supportive towards Less intervention, but in the Forest management model, the effect was not significant. Similarly, the simultaneous effect of education and political orientation was significant in the Less intervention model, indicating that forest owners with a university degree and right-winged political orientation tended to be more supportive towards strategies with more human intervention in forests, compared to forest owners with a university degree and left-winged political orientation. Apart from hypothesized variables, gender was found a significant predictor of support towards strategies, where, on average, women were more likely to support Less intervention, and similarly be more opposing towards Forest management, compared to men. In light of the results, Finnish forest owners tend to be rather conscious about climate change and support on average different climate change mitigation strategies in the forest sector. Nevertheless, private forest owners are a heterogeneous group of people whose preferences vary greatly, and thus policies need to be implemented accordingly.
  • Thiruvaiyaru, Aditya (Helsingin yliopisto, 2021)
    Semliki Forest virus (SFV) is an enveloped virus with positive-sense single-stranded RNA genome that encodes nine proteins, of which four non-structural proteins, nsP1-4, form the replication/transcription complex (RTC) along with several host proteins, which play an important role in the replication of the virus. To establish the interactome of SFV RTC, a promiscuous biotin ligase capable of biotinylating proximal endogenous proteins in the presence of exogenous biotin was genetically fused to nsP3. After establishing the stability, kinetics and functionality of this virus, BHK-21 cells were infected with this mutant SFV at multiplicity of infection of 50 plaque forming units per cell. At an early time point of 2.5 hours post infection, 50 μM biotin was added to medium for 15 minutes. Cells were lysed, and biotinylated proteins were enriched with streptavidin beads, and analyzed through tandem mass-spectrometry. We were able to identify several key host protein interactions, some of which were already established before, but also a several new ones. Many of the host proteins detected were involved with the formation of stress granules, including G3BP’s, or contained a SH3-binding domain (SRC homology 3) like CD2AP, SH3KBP1 and BIN1, and some of them also had RNA binding motifs. In future, we wish to study the role of these identified host proteins in the replication of SFV through gene silencing as well as their co-localization with the RTC and nsP3 with the help of Immunofluorescence.
  • Lehto, Iina (Helsingin yliopisto, 2021)
    Tämän tutkielman tavoitteena oli tarkastella työnantajakuvan muodostumista sosiaalisessa mediassa milleniaalien silmin. Tutkimus toteutettiin laadullisesti teemahaastatteluja hyödyntäen. Haastateltaviksi valittiin kymmenen milleniaalia. Haastatteluihin valitut milleniaalit erosivat toisistaan sekä iältään että uransa vaiheilta. Tarkoituksena oli saada mahdollisimman monipuolinen haastattelutulos. Tutkimuksen tavoitteena on kuvailla ja analysoida, miten potentiaalisen milleniaali työntekijän kokema työnantajakuva muodostuu sosiaalisessa mediassa ja mitkä asiat vaikuttavat työnantajakuvan muodostumiseen. Milleniaalit valikoituivat kohderyhmäksi, sillä heitä ei oltu aikaisemmin käytetty kohderyhmänä sosiaalisessa mediassa muodostuvaa työnantajakuvaa tutkiessa. Milleniaalit käyttävät sosiaalista mediaa päivittäin, joten he sopivat kohderyhmäksi myös sosiaalisen median aktiivisuutensa vuoksi. Tutkimukseen kuuluu teoreettinen osuus, jossa avataan aiemman tutkimuksen kannalta keskeiset käsitteet ja esitellään työnantajakuvan muodostuminen. Lisäksi teoriaosuudessa kuvataan milleniaaleja työelämässä ja heitä ohjaavia arvoja. Tutkimuksen tuloksena havaittiin, että milleniaalit etsivät sosiaalisen median kanavista signaaleja yrityksestä, joiden avulla he muodostavat päässään työnantajakuvan organisaatiosta. Tämän tutkimuksen mukaan milleniaalit arvostivat erityisesti psykologisia ja toiminnallisia ominaisuuksia työnantajakuvan muodostamisessa. Lisäksi sosiaalisen median kanavista Instagram ja Linkedin osoittautuivat tärkeimmiksi alustoiksi työnantajakuvan muodostamiselle. Teemahaastattelujen tavoitteena on päästä tiettyyn ilmiöön sisään. Tässä tutkimuksessa onnistuttiin pääsemään perille siitä, miten työantajakuva muodostuu sosiaalisessa mediassa haastateltujen milleniaalien mielestä. Kuten laadullisissa tutkimuksissa yleensäkin, myös tässä tutkimuksessa on omat rajoitteensa. Haastattelut keskittyvät yksilökohtaisiin kokemuksiin, ja nämä kokemukset voivat muuttua ajan saatossa. Tulevaisuudessa samat haastateltavat saattaisivat kertoa eri huomioita työnantajakuvan muodostumisesta sosiaalisessa mediassa.
  • Kohli, Juliana (Helsingin yliopisto, 2021)
    Boreal forests are an important storage of carbon (C), representing over one-third of terrestrial C stocks. The continuity of C storage in boreal forests and forest soils is critical to mitigate climate change. Climate change will likely increase the fire season length and the frequency of forest fires in Finland, of which surface fires are the dominant type. Fire affects C dynamics by modifying biotic (SOM, vegetation, microbial activity) and abiotic (soil temperature, moisture, chemistry) components of the forest ecosystem. These fire-induced effects will depend on the intensity of the fire (duration, flame temperature) and the site characteristics, ultimately resulting in either the persistence of, or in a net C loss, which has implications on both a local and global scale. There is a lack of existing research regarding the short-term impacts of surface forest fires and comparisons between different fire intensities. Subsequently, this thesis describes an experimental burn conducted in an even-aged Pinus sylvestris forest in southern Finland and the short- term post-fire impacts on soil biogeochemical processes (June-October 2020). The aims of this study were: (1) to study the effects of low- (200-300 oC) and high- (500-600 oC) intensity surface fires on soil temperature, moisture and soil surface CO2 fluxes straight after fire and through four months after experimental fire; (2) to study the effects of low- and high-intensity surface fires on plant (above and below ground) biomass immediately and four months after fire; (3) to identify the most important factors driving soil CO2 effluxes shortly after the fire. Eight sample plots (225 m2 each) were used, divided between high and low biomass loads to achieve high- and low-intensity fires. Continuous soil temperature and moisture measurements, vegetation inventories, soil sampling (0-30 cm), and soil CO2 efflux measurements were obtained using portable chambers. The results of this study showed that some soil physical and chemical properties were significantly altered due to the experimental surface fire (vegetation, temperature, moisture, root biomass, C, N (nitrogen), C/N), whereas some remained unchanged (pH, humus thickness). Soil moisture was the only variable, which increased as a result of higher fire intensity. Fires at both intensities resulted in the mortality of ground vegetation whilst trees did not experience mortality by the end of the monitoring period. Soil CO2 fluxes decreased in burned areas compared to unburned plots over time, but this change was not significantly different between burning intensities. Future research should investigate the mechanisms of C and N translocation through the soil profile following the addition of water, the relationship between post-fire soil temperature and soil CO2 efflux, how burning different biomass components changes the composition of ash, and how larger differences in burning intensities affect soil properties and soil CO2 effluxes. If trees experience mortality after the time period encompassed by this study, the site could become a potential C source; further monitoring of the study site could account for delayed indirect impacts such as these.
  • Liu, Yu (Helsingin yliopisto, 2021)
    A growing population is suffering from protein insufficiency and seas of over-fishing. On the other hand, an abundant amount of low-value or underutilized fish species remains unexploited for human consumption mainly due to low consumer preferences. For this reason, new solutions are needed to utilize these fish better. This study was carried out in two phases. In phase I, extrudates from five underutilized fish species and pea protein isolate (PPI) were produced by using a high-moisture extrusion process (HMEP). The aim was to successfully produce extrudates and study their sensory and texture properties by generic descriptive analysis (GDA), instrumental color measurements, and instrumental tensile strength measurements. In phase II, PPI was partially replaced in the recipe by two cereal fractions. The experiment was generated by simplex-centroid mixture design to study the effects of PPI and two cereal fractions on the texture of extrudates. The results of phase I showed that the extrudates were successfully produced. Extrudates from Baltic herring were one extreme with intense flavor and odor, such as seaweed, and the highest fracturability. Smelt extrudates were another extreme with intense flavor, odor, and greyness. For further studies, a combination of the present analytical sensory profiling data and the hedonic response of consumers will be needed for the product development. In phase II, the extrudates produced from a low amount of PPI with a high amount of cereal fractions were doughy and too soft. Other ingredients should be considered in further studies to replace PPI.
  • Kolehmainen, Katri (Helsingin yliopisto, 2021)
    Eläimille on ihmisen rakentamassa sosiaalisessa todellisuudessa muodostunut rooleja, jotka vaikuttavat eläinten moraaliseen arvottamiseen ja kohteluun. Eläimet ovat osa ihmisten elämää niin lemmikkeinä, elintarvikkeina, raaka-aineina, harrastuksina, viihteenä kuin tieteenteon välineinäkin. Siinä missä koirat ja kissat ovat länsimaissa rakastettuja kumppanieläimiä, siat ja naudat ovat ruokaa ja raaka-aineita. Tämän tutkielman tarkoitus on spesismin käsitteen avulla selvittää, miten luokittelemme ja moraalisesti arvotamme eri eläinlajeja sekä miten nämä luokitukset syntyvät ja pysyvät ihmisten keskuudessa yllä, yksilön ja ryhmän tasolla tarkasteltuna. Spesismi (myös lajisorto tai lajisyrjintä) tarkoittaa eläinten epätasa-arvoista kohtelua lajijäsenyyden perusteella. Tässä tutkielmassa spesismiä käsitellään rasismiin ja seksismiin verrattavissa olevana ennakkoluulona. Tutkielma on luonteeltaan kuvaileva kirjallisuuskatsaus. Tutkimusaineisto koostuu kirjallisuudesta eli tutkimusmetodi on sekundäärianalyysi. Käytetyssä kirjallisuudessa painottuvat eläintutkimuksen sekä sosiaalipsykologian alan kirjallisuus. Tutkielma jakautuu kolmeen päälukuun, joista ensimmäisessä selvitetään tarkemmin, mitä on spesismi, onko spesismi oikeutettua sekä millaiset eläinasenteet ja luokittelut määrittävät ihmisten ja eläinten välistä suhdetta. Toisessa luvussa käydään läpi spesismin mekanismeja ja taustatekijöitä ennakkoluulojen sosiaalipsykologian kautta. Yksilötasolla tarkastellaan, mitkä luontaiset psyykkiset prosessit ovat ennakkoluuloisuuden taustalla sekä mitkä yksilön ominaisuudet mahdollisesti vaikuttavat yksilön ennakkoluuloisuuteen. Ryhmätasolla tarkastellaan, kuinka ryhmäjaot vaikuttavat ennakkoluulojen syntyyn ja kuinka olemassa olevat ennakkoluulot välittyvät ja pysyvät yllä ryhmässä. Kolmannessa luvussa käydään tarkemmin läpi kahta ihmisen eläimille antamaa roolia – eläimiä ruokana ja eläimiä lemmikkeinä. Kirjallisuuden perusteella voidaan esittää, että eläinten saamat luokitukset ja roolit ovat yhdistelmä eläinten biologisia piirteitä, eläimelle oletettuja piirteitä sekä ihmisen sosialisaatioprosessissa oppimia ennakkoluuloja. Kaiken kaikkiaan sosiaaliset tekijät kuten sosiaaliset normit, jaettu käsitys normaalista vallitsevassa kulttuurissa, ryhmäjaot sekä niiden synnyttämät todelliset ja kuvitellut eturistiriidat sekä mukautumisen paine keskimäärin määrittävät ennakkoluuloisuuden tason tietyssä sosiaalisessa systeemissä ja henkilöiden alttius ennakkoluuloisuudelle muodostaa variaatioita ennakkoluuloisuudessa yhteisön sisällä.
  • Lahtinen, Tuulia (Helsingin yliopisto, 2021)
    Finland has a relatively small amount of mixed forests in comparison to monoculture forests. Mixed forests can provide opportunities to improve and increase different ecosystem services. Regardless of the several studies conducted in Nordic countries around the mixed species forests, on-going and up-to-date research is still greatly needed. The most common mixed species forests in Finland have a mixture of spruce and birch or pine and spruce. The main objective of this study was to examine the growth dynamics and the present state of single storied, young commercial spruce-birch (Picea abies, Betula pendula, Betula pubescens) mixture stands, where juvenile stand management practices have been done. The data gathering was conducted in southern Finland from 10 different stands which all had two 500 square meter area plots. This project is part of SEKAVA-programme led by Luonnonvarakeskus (Natural Resources Institute Finland). The stand level data was first analyzed and described with Excel program. The first hypothesis assumed that in these forests silver birch was naturally regenerated to site after planted spruce. The second hypothesis was that spruce and silver birch have been growing height in phase for the last 4 years. It was established that the silver birch was approximately only one year younger on stump height than spruce. The height difference of dominant sample trees between spruce and silver birch was only 1,4 meters. The data also showed how within the last four years the height growth of spruce and birch has been very different. The spruce could have up to 10 cm bigger annual height growth in comparison to the height growth of the silver birch. These measurements were taken as the average annual growth from the past 4 years. The tree level data was modelled with R studio -program to observe the factors affecting the tree growth. During the data analysis, it was established that Chapman-Richards model was more suitable for the needs of the research than the generalized mixed model. The Root Mean Square Error (RMSE) for Chapman-Richards model for spruce model was 26,3 % and 9,1 % for birch model. The annual height increment of the tree level was modelled by a linear mixed model. The RMSE for linear mixed spruce model was 14,4 % and 19,3 % for the birch model. These models showed how the nutrition levels of the ground work as a contributing factor of the diameter growth for both spruce and birch. Additionally, spruce trees had the better annual height growth the longer the tree was, and the lower the crownline was. Birch trees had also the better annual height growth the longer the tree was. The research was able to conclude that spruce trees had the strongest annual height increment when aged 20 years while the growth of birch trees started to slow down when reaching the age of 20 years. Based on the research data, silver birch grows notably better than downy birch in a mixed forest of birch and spruce trees. The models used in this research were specifically built to support this thesis and therefore are not exactly transferable for other studies.