Recent Submissions

  • Keto, Antton (Helsingin yliopisto, 2017)
    Water-levels of lakes in Finland are artificially regulated for energy production, flood protection, navigation and recreational use. There is a need for changing water-level regulation practices, due to changing climate, increasing recreational use of lakes, and implementation of legally binding national targets for electrification of renewable sources. To obtain more knowledge-based assessments of new water management regulations, we need to develop water-level regulation assessment tools and to increase the sensitivity of ecological classification systems for hydromorphological pressures, as the European Union Water Framework Directive (WFD)requires. The main objectives of this study were to 1) develop criteria and threshold values for assessing the ecological status in regulated lakes, 2) identify both high-hydrological status and heavily modified lakes and 3) estimate the role of helophytes in the uppermost littoral zone. Impacts of water-level fluctuation on macrophytes, macrozoobenthos, and littoral fish fauna were clearly evident, and the threshold value between moderate and good ecological status was a 3.5 m winter water-level drawdown with the mean ecological quality ratio assessment method (1.8 m with the one-out-all-out principle). The vertical extension of Phragmites was most strongly associated with the water-level fluctuation of open water period (OWP), followed by Carex spp. and Equisetum. Overall, the RF models explained 4--41% of the variation observed in the helophytes zones. The models indicated that OWP fluctuation, slope, openness and cover of other macrophyte groups were key factors explaining the extent of the helophyte zones. The hydrological regime could be classified as having high hydrological status in 20% of the regulated lakes. Quite often, the ecological status was poorer, implying that high-hydrological status lakes often face other anthropogenic pressures, such as eutrophication that degrades high ecological status. Provisional designation with hydrological criteria seemed to work quite well, because 13 of the 15 lakes were estimated similarly with simple hydrological criteria, compared with the national HMWB designation only later produced by the environmental authorities.
  • Lehtisara, Leena (Helsingin yliopisto, 2017)
    The large area forest mapping is traditionally based on satellite images and laborious field plots. The newer lidar plot concept is the Airborne Laser Scanning (ALS) and a small amount of field plots based plot-level attribute estimation, which is treated similar to the field plots in satellite based mapping. The target of the study was to evaluate the satellite-based, the ALS-based and their combination based forest mapping in the large area by comparing the accuracy of the forest attribute estimations per different amounts of plots. The study area of 3 128 000 hectares in southern Finland included 3630 field plots from the Metsäkeskus of Finland. The attribute estimates were computed from the Landsat 8 image and from the low-density lidar dataset to the field plot locations. The plot-level attribute estimates were calculated for the volume, height, basal area and biomass using k-NN-method (k=5). The accuracy of the mapping methods was evaluated by relative RMSE (Root Mean Square Error), which measured the differences between the estimated and the measured attributes of the validation plots. From the results it can be seen that the relative RMSEs of the attribute estimates from the Landsat-image based mapping on plot-level were at their best 47.6 % for the volume, similarly 26.2 % for the height, 34.6 % for the basal area and 47.7 % for the biomass. For the ALS-based mapping, they were 23.2 %, 9.8 %, 21.0% and 23.7 % respectively. By using 400 field plots to estimate attributes for 2900 lidar plots, and these lidar plots were used further for Landsat-based attribute estimations, these results were quite close to the accuracy of field plots-based Landsat attribute estimations. In addition a small sample of the lidar cover of the area was needed, in this case having less than 1 % area coverage. The lidar plots in Landsat-based mapping could be used for the biomass and carbon mappings in large area even if there are no roads available in the area and only a small amount of plots can be measured. Also, it is suitable for the areas where forest mapping has not started. It can be used also to follow up the changes in large forest areas, due the frequent updates of the satellite image measurements.
  • Tarmi, Siina (Helsingin yliopisto, 2017)
    The scope of the literature review was to define the process for oil-in-water emulsion formation and the important properties of the emulsions which are suitable for microencapsulation. The aim of this study was to determine how whey protein isolate together with maltodextrin affects the properties of the emulsion. Camelina oil and black currant seed oil were used as core materials. The wall materials used were: maltodextrin (MD) and whey protein isolate (WPI). Six different wall systems consisting WPI in combination with MD at various ratios (1:1, 1:3 and 1:9) were used. In premilinary tests the emulsions were characterized for temperature, creaming index, apparent viscosity, flow behavior index, flow consistency index, droplet size (D4,3 zetasize,), droplet size distribution (PDI, span) and zetapotential. Droplet size and droplet size distributions were measured by a laser light scattering using a Zetasizer and by laser light diffraction instrument, Mastersizer 2000/3000. Oil droplet size was also measured with light blockade using a PAMAS. Rheological properties were characterized with rheometer. In actual test the emulsions were characterized for time (foam removal), temperature, droplet size (D10, D50, D90 ja D4,3), apparent viscosity, flow behavior index and flow consistency index. First degree polynomial was fitted with PLSR to the results. Statistical significances of regression coefficients were analyzed with t-test. In premilinary tests all the emulsions were stable during storage at 25 °C after 24 h. pH and zetapotentials which were all lower than -35 mV refer to good stability of emulsions. Change in droplet size and droplet size distribution was observed. Increasing maltodextrin concentration decreased droplet size (D4,3) and droplet size distribution width (PDI) when measuring by Mastersizer and Zetasizer. Apparent viscosity of the emulsions decreased by increasing maltodextrin concentration. PLS-regression showed that there were statistically differences between wall materials and temperatures, droplet size, size distribution and apparent viscosity. There were also statistically differences between oil and droplet size measured by PAMAS. In actual tests apparent viscosity of the emulsions decreased by increasing maltodextrin concentration. Increasing maltodextrin concentration also decreased the time of foam removal. PLS-regression showed that there were statistically differences between wall materials and temperatures after homogenization, time (foam removal), flow consistency index and apparent viscosity. There were also statistically differences between oil and temperatures, flow behavior index and droplet size distribution width. Whey protein isolate together with maltodextrin affect mostly to apparent viscosity of emulsions.
  • Finne, Maria (Helsingin yliopisto, 2017)
    The proportion of older adults has dramatically increased in developed countries due to longer life expectancy. The wellbeing of this group has large economic implications. Self-rated health (SRH) is a globally used method to measure both physical and psychosocial health and in some conditions considered as a better indicator than medical records. The main aim of this thesis was to study whether socioeconomic (SES) factors as well as nutritional intake are associated with physical and psychosocial SF-36 score change during a ten year period. Helsinki Birth Cohort Study (HBCS) consists of 8760 participants who were born at Helsinki University Central Hospital between 1934 and 1944. HBCS is a longitudinal study where data has been collected along the life span. In this thesis material was used from the baseline clinical visit (years 2001-2004) and the follow-up clinical visit (years 2011-2013). During the follow-up, 1094 participants (men n=478, women n=616) were traceable and took part in the follow-up visit which makes the participants 67 to 77 years old at that point. At the baseline clinical examination (n=2003), diet was assessed with a validated food-frequency questionnaire from which the Baltic Sea diet score (BSDS) was calculated. Higher scores indicated better adherence to the Baltic Sea diet. Self-rated psychosocial and physical wellbeing was assessed with the Short Form 36 scale (SF-36) in 2001-2004 and 2011-2013. The difference between baseline and follow-up SF-36 psychosocial and physical measurement was calculated. Socioeconomic indicators included degree of education, length of education and the average monthly taxable income. Men and women were studied separately. Also the group of those still in work life at baseline were evaluated separately from those who were already retired. Associations between BSDS and the SES factors were also tested. The statistical analysis program SPSS version 22 was used to calculate associations between the SES factors and BSDS with psychosocial and physical change. Linear regression method was used for the analyses. In addition, a comparison of the follow-up SF-36 scores according to socioeconomic factors were examined with ANOVA post hoc Tukey HSD test. Degree of education was positively associated with changes in psychosocial functioning at old age among men (p=0.009), whereas length of education associates positively among women (p=0.027). Both degree and length of education were positively associated with psychosocial functioning within the group that was still in work life at baseline. Change in physical functioning was not associated with SES or BSDS. Adherence to the BSD was not significantly associated with either of the SF-36 measurement factors but was related to higher income. Degree of education and length of education seem to indicate the direction of psychosocial functioning in early old age. Physical degeneration during late adulthood is normal and is less predictable by SES factors. BSDS did not predict physical or psychosocial wellbeing among this population but was positively associated with income among the participant.
  • Syväjärvi, Elena (Helsingin yliopisto, 2017)
    Perunatärkkelyksen valmistusprosessin sivuvirtana saadaan perunan solunestettä, joka on aikaisemmin hyödynnetty lannoitteena. Perunan soluneste sisältää arvokasta proteiinia, jota voidaan hyödyntää rehu- ja elintarviketeollisuudessa. Finnamyl Oy Kokemäellä on rakentanut prosessin, jolla perunaproteiini saadaan otettua talteen. Tässä työssä tavoitteena oli tutkia perunaproteiinin erotusprosessia ja perunaproteiinikon-sentraatin ominaisuuksia. Kirjallisuuskatsauksessa perehdyttiin perunaproteiinikonsentraatin kemiallisiin ja fysikaalisiin ominaisuuksiin elintarviketeollisuuden näkökulmasta. Lisäksi työssä selvitettiin perunaproteiinikonsentraatille soveltuvia käyttösovelluksia ja perehdyttiin erilaisiin proteiinin erotusmenetelmiin. Kokeellisessa tutkimuksessa tutkittiin monipuolisesti perunaproteiinikonsentraatin funktionaalisia ominaisuuksia. Työssä tutkittiin koeajoista saa-tuja näytemateriaaleja. Lisäksi tutkimuksissa oli vertailunäytteinä mukana soijaproteiinikon-sentraatti ja rehulaatuinen perunaproteiinikonsentraatti. Työssä testattiin menetelmiä, joita voidaan jatkossakin käyttää perunaproteiinikonsentraatin tutkimiseen. Koeajoista saatujen näytemateriaalien tuloksia verrattiin kaupallisiin tuotteisiin. Prosessi vaatii vielä kehittämistä, jotta elintarvikelaatuista proteiinia saadaan valmistettua. Tutkimuksissa havaittiin eroja eri saostuslämpötiloissa valmistetuissa näytemateriaaleissa. Perunaproteiinikonsentraatin funktionaaliset ominaisuudet olivat hieman huonompia kuin soijaproteiinikonsentraatilla.
  • Hannele, Rissanen (Helsingin yliopisto, 2017)
    Tiivistelmä * Referat * Abstract This thesis presents the results of the pedigree based genetic diversity study of the Kainuu Grey sheep. Data, including 22 467 animals born between 1981 and 2014, was received from ProAgria - Rural Advisory Services. Inbreeding coefficients were calculated for all animals. For birth-year averages only animals with sufficient pedigree depth (pedigree completeness value, PEC>0.8 using five generations) were considered. Averages were calculated separately for all breeding animals, breeding rams, and ewes. Average relationships were calculated within breeding rams, within breeding ewes, and between breeding rams and ewes. The thesis presents also estimates of the effective population size for birth-years 2000–2014, the contributions of the most influential ancestors, and average generation intervals. The average inbreeding and relationship coefficients have decreased during the last 20 years. The average inbreeding coefficient of the lambs born in 2014 was around 7 % when it was at its highest in 1990’s over 13 %. Average relationship between breeding animals born in 2013 was 17 % when it was at its highest over 20 % in 2000’s. Also effective population size has increased from 40 to the current figure of 70 animals. 32 % of the genetic variation of the current Kainuu Grey population can be traced back to seven founder rams that lived in 1980’s: Pertti, Risto, Immo, Lassi, Antti, Matti, and Topi. Out of those, Pertti has the most remarkable influence on the breed: around 11 % of the germ plasm of the lambs born in 2014 can be traced back to Pertti. The mean generation interval during last 20 years was 3.3 years. Genetic diversity of the Kainuu Grey has improved during the last years as the number of Kainuu Grey has increased. Inbreeding and relationship coefficients have declined slightly during last few years. Correspondingly, the effective population size has increased. To ensure genetic diversity of the Kainuu Grey in the future, artificial insemination, optimal contribution and genomic information could be utilized in breeding and in conservation work.
  • Rauhala, Jussi (Helsingin yliopisto, 2017)
    High quality milk is an important thing for dairy industry and the most important determinator for milk price paid to the producer. The quality of milk is measured with somatic cell and bacteria count. Milks somatic cell count doesn’t change after milking that emphasizes the importance of udder health and successful milking. The total annual cost of the mastitis in an 100 head of cattle was estimated to be 21 000 – 25 000 euros in Finland (calculated with price level in 2010). Liner is the only part of the milking machine that contacts cow’s teat and the only way of bacteria into udder is through teat canal. Many bacterial infections occur in teat injuries and due to the teat-end roughness that makes teat canal closure slower, which makes bacteria access easier into udder. The aim of this thesis was to study the effects of CloverTM -liner on milking. Results were compared to the traditional HarmonyTM -liner. Cross section of a CloverTM -liner looks like clover whereas the shape of traditional liner cross section is round. Udder health and milking characteristics were measured attributes for comparison of the two liner models in this thesis. Udder health was evaluated by measuring somatic cell count, teat-end health and short-term changes in teat condition after milking. Milking characteristics were evaluated by measuring milk yield, milking duration and milk flow. The measurements were taken in two farms in summer 2015. The results of this study were estimated with line and bar charts as well as statistical significances were estimated with appropriate models. The differences between groups were small in teat-end health and there was a lot of deviation in the results so there were no statistically significant differences between groups. Total number of teats with short-term changes in teat condition after milking was so small that statistical testing was not appropriate. There were no differences in milk yield, milk flow, milking duration or somatic cell count between groups. The only statistically significant difference was peak flow that was lower for ClowerTM -liner.
  • Juselius, Teemu (Helsingin yliopisto, 2017)
    Nowadays a greater number of people live in cities than in earlier times. In Finland, the portion of urban dwellers has nearly doubled in last 50 years. The urbanization has had undisputable benefits for mankind but it has also had widespread negative effects on nature. As cities grow natural habitats are replaced by spreading infrastructure. Remaining mires, forests and other natural habitats are smaller and more isolated than their rural counterparts. These urban habitats are affected by increased pollution and nutrient loads, trampling and other detrimental effects caused by human activity. Alien invasive species may also spread into indigenous vegetation and more of these areas are affected by edge-effects. Ombrotrophic bogs are one of the most nutrient-poor habitats in the North and receive nutrients only by dry and wet deposition. They have been reported to suffer from increased nutrient deposition. Hydrology also has a vital part in function and form of ombrotrophic bogs. Spread of urban infrastructure may alter the way bogs receive water due to increased sealed surface in the catchment areas of these bogs. The effects of urbanization on ombrotrophic bogs in Finland has not been studied previously and the aim of this Master’s thesis is to examine the differences between vegetation in urban and rural bogs and the effects of the size of bog area, nearby population and total N content of surface peat on bog vegetation in different bog types: dwarf shrub pine bogs, low sedge bogs, Sphagnum fuscum pine bog and Sphagnum fuscum bog. Last two were studied together due to their similarities. According to this study the differences between urban and rural bogs in Southern Finland are small. The greatest differences were observed among dwarf shrubs typical for bogs but the effects varied between bog types. In dwarf shrub pine bogs, the amount of dwarf shrubs decreased while in low sedge bogs, the cover of Vaccinium oxyccocos, and in Sphagnum bogs, the occurrence of Empetrum nigrum increased. The bogs studied in urban sites were generally smaller and more isolated than rural bogs. Around urban bogs, there were also significantly higher number of residents than in rural areas, and one of the most distinct effects of urbanization on bog vegetation discovered was reduction of cover and appearance of species vulnerable to trampling. The increased nutrient loads usually reported in urban habitats was not visible in nitrogen content of surface peat. On the contrary, low sedge bogs seemed to have higher nitrogen content on rural bogs, which may be caused by intense agriculture in rural areas. The reason for not detecting increased urban nitrogen deposition based on peat samples may be caused by increased nitrogen uptake of Sphagnum mosses. Sphagnum mosses have been reported to benefit from increased nitrogen deposition until they reach nitrogen saturation point. After this the excess nitrogen enters peat soil. Low nitrogen deposits in Southern Finland can probably be used fully by Spaghnum mosses and thus no increase in nitrogen content was observed. The results of this study indicate that ombrotrophic peat bogs are at least partly resistant to the effects of urbanization. The level of urbanization in Finland is lower than in Central Europe, which may lead to lowered levels of detrimental effects caused by urbanization. Alien species are probably also unable to invade the acidic and nutrient poor urban bogs. The mire types studied here are also usually situated in the centre of ombrotrophic bogs and may have avoided most of the edge effects. However, if studied, the edges of the urban bogs might have shown large number of harmful effects caused by urbanization.
  • Särkiniemi, Eeva (Helsingin yliopisto, 2017)
    Perinnebiotoopit ovat perinteisen laidunnuksen ja niiton muovaamia luonnontyyppejä, joiden lajisto on rikas. Karjan laidunnuksen muututtua ja keskityttyä, perinnebiotoopit ovat muuttuneet yhä harvinaisemmiksi. Laiduntaminen on yksi keinoista ylläpitämään perinnebiotooppien monimuotoisuutta ja tuottavuutta. Hevosten määrä etenkin Etelä-Suomessa on noussut huomattavasti. Hevosen laidunnuskäyttäytyminen on kuitenkin valikoivampaa, kun karjalla. Laiduntamisen tärkein tavoite on saavuttaa tyydyttävä eläintuotos, jotta saadaan hevosten omistajat kiinnostumaan riittävän laajasti luonnonlaitumien laiduntamisesta. Tässä tutkimuksessa selvitetään luonnonlaitumella laiduntavien hevosten ravintotarpeiden täyttymistä (kuten energian, sulavan raakavalkuaisen, kivennäis- ja hivenaineiden perustarpeet), luonnonlaitumen sadontuottokykyä sekä laitumien botaanista koostumusta. Luonnonlaitumen eri lohkoilta määritettiin laidunnuskauden aikana kuiva-aineen kertymistä, sadon määrää ja laatua sekä kasvuston botaanista koostumusta. Botaanisen koostumuksen avulla haluttiin selvittää kuinka suuren osan sadosta hevoset syövät. Laitumen kasvustoa suojattiin häkeillä, joita oli 4:llä eri lohkolla. Kaikilla lohkoilla otettiin rehuanalyysinäytteitä sekä laidunnukselta suojatusta, että suojaamattomasta sadosta. Otetut näytteet jaettiin silmämääräisesti syötäviin ja ei syötäviin lajeihin aiempien tutkimusten pohjalta ja punnittiin satomäärien määritystä varten. Näytteet kerättiin yhteensä 9 kertaa kasvukauden aikana. Lisäksi alkukesästä tehtiin botaaninen kasvilajimääritys. Näytteet analysoitiin Valion laboratoriossa NIRS-analyysin avulla. Hevoset saivat energiaa ja valkuaista riittävästi koko laidun kauden ajan. Kivennäisaineiden osalta fosforin päivä saanti jäi suositusarvoja pienemmiksi ja vääristi hevosten Ca:P suhteen liian suureksi. Hivenaineista kuparin ja sinkin saanti ei ollut riittävää. Luonnonlaidun on kivennäislisän kanssa hyvää rehua tyydyttämään hevosen perustarpeet. Luonnonlaitumen ravitsemuksellinen koostumus on viljeltyjä laitumia köyhempi energian ja valkuaisen osalta mikä, vähentää herkästi lihomaan taipuvaisilla hevosilla ylipainosta johtuvia terveysongelmia ja mahdollistaa niiden laiduntamisen.
  • Basaran, Zeren (Helsingin yliopisto, 2017)
    Fear of falling (FOF) and falling are urgent public health and economical challenges. Approxi-mately half of the elderly people experience FOF regardless of whether they had experienced fall or not. Increasing level of FOF can lead to self-induced restriction in mobility, physical func-tioning and activities of daily living (ADLs). Avoidance of activities weakens elderly's perfor-mance, well-being and increases the risk of falling. One-third of people over 65 years fall. For elderly 80 % of injuries are falls. Falls results in fractures, hospitalization, FOF, depression, loss of independence, premature residential care admission and even death in older persons. Number of falls has quadrupled over the past 25 years. Incidence of falling will increase in the future, as world population of people aged 65 and older is projected to increase to 997 million. Exercise is an essential method to maintain mobility, reduce FOF and prevent incidence of falling among community-dwelling elderly. “Strength in Old Age Programme” is a health enhancing exercise program (2005-2015) coordinated by the Age Institute. The project promotes independent living and quality of life (QOL) for elderly with weakened functional ability. A questionnaire was mailed to programmes’ participants consisting of questions about demographic and socio-economic status, health and well-being, physical activity habits and self-reported health improvements after participating the exercise group in April 2015. The aims of this study were 3-fold: first to identify biological, socio-economic, health and well-being, and behavioral factors affecting FOF and falling; second, to study perceived health improvements effect on FOF and falling; and last to investigate the complex association between FOF and falling. The key achievement was that “Strength in Old Age Programme” improved physical activity of elderly people involved in the study and affected biological, socio-economic and behavioral risk factors. This resulted in improvement in physical, functional, psychological and social domains reducing perceived FOF. Particularly good results in FOF reduction were seen in the participants who had higher age, were living alone and had lower socio-economic status. The incidence of falling was reduced through balance improvement in the exercise group. Similar yet smaller changes were observed in more vulnerable participants having poorer health and well-being related status. It would be important to influence the attitudes of elderly and motivate them proactively increase their physical activity to maintain balance, mobility, muscle strength, ADLs, health and well-being.
  • Kotka, Juhani (Helsingin yliopisto, 2017)
    Kiinnostus syysrapsin (Brassica napus L.) viljelyä kohtaan on kasvanut Suomessa tasaisesti viime vuosina. Syysrapsin satopotentiaali on korkea verrattuna kevätkylvöisiin öljykasvilajikkeisiin, mutta vaatimus aikaisesta kylvöajankohdasta sekä haastavat talvehtimisolosuhteet hidastavat viljelyalan lisäämistä. Tämän tutkimuksen tavoitteena oli kerätä kokemuksia syysrapsin viljelytekniikoista suomalaisissa olosuhteissa, joista tutkittua tietoa on toistaiseksi melko vähän saatavilla. Tiedon hankkimista varten perustettiin elokuussa 2014 yksivuotinen kenttäkoe Inkooseen, Västankvarnin koetilalle, jossa tutkittiin kuuden eri perustamismenetelmän eli muokkaus- ja kylvömenetelmien yhdistelmän soveltuvuutta syysrapsin viljelyyn hiesusavimaalla. Vertailtavia koejäseniä olivat: kyntö, kultivointi, lautasmuokkaus, suorakylvö, jankkurikylvö ja harjukylvö. Kokeen aikana mitattiin jatkuvatoimisesti maan kosteutta ja lämpötilaa 10 cm syvyydessä sekä sademäärää, ilman lämpötilaa ja maan pinnan lämpötiloja. Lisäksi koeruuduilla mitattiin maan tiiviyttä penetrometrin avulla ja tehtiin taimitiheys- sekä juuristomittauksia. Elokuun 2014 runsaat sateet Västankvarnissa (yht. 247 mm) vaikeuttivat kenttäkokeen perustamista ja edistivät etanoiden aiheuttamia taimituhoja. Etanoiden aikaansaamat kasvustotappiot olivat niin suuria, että joidenkin koeruutujen kasvustot tuhoutuivat lähes täydellisesti. Muilla koeruuduilla kasvustot jäivät epätasaisiksi ja harvoiksi. Kunnollisia kasvustomittauksia ei ollut mahdollista tehdä, eikä koeruuduilta kannattanut korjata satoa vertailua varten. Lisätutkimusta, jossa kasvustoja ja satomääriä pystyttäisiin mittaamaan, tarvittaisiin ainakin jankkurikylvön soveltuvuuden varmistamiseksi syysrapsin perustamiseen. Maan ominaisuuksiin kohdistuneiden mittausten perusteella jankkuroinnin ja syysrapsin kylvön yhdistäminen samalla ajokerralla vaikuttaisi olevan hyvä vaihtoehto syysrapsin perustamiseen. Jankkuroitu maa kuivui nopeammin kuin muilla vertailukohteilla varsinkin syyskauden mittausten perusteella ja jankkurointi myös vähensi maan penetrometrivastusta kylvörivin kohdalta jankkurointisyvyyteen (30 cm) asti kyntöanturan murtumisen seurauksena. Suorakylvetty maa pidätti kosteutta muita koetekijöitä paremmin, mutta oli sateisina jaksoina kaikkein märintä 10 cm syvyydessä. Kynnetyn ja kevyesti muokatun maan välillä ei havaittu sellaisia eroja jatkuvatoimisten eikä maan tiiviysmittausten perusteella, jotka puoltaisivat esimerkiksi kyntöä kultivointia parempana vaihtoehtona tai toisinpäin.
  • Rinne, Iiro (Helsingin yliopisto, 2017)
    Tutkimuksen tarkoituksena oli selvittää, miten sekä myymälämuotoista- että verkkokauppaa harjoittava monikanavainen vähittäiskauppayritys voi kehittää tuottamaansa asiakasarvoa. Tarve asiakasarvon kehittämiselle vähittäiskaupassa erityisesti monikanavaista toimintamallia hyödyntäen kumpuaa kaupan murroksesta: muun muassa viestintäteknologian kehityksen myötä perinteiset, vahvasti myymälöihin nojaavat kauppaketjut ovat saaneet uudenlaisia kilpailijoita niin kotimaisista kuin ulkomaisistakin verkkokaupoista. Asiakasarvon muodostumista mallinnetaan aiemmassa tutkimuksessa esitetyn neljän arvoulottuvuuden, funktionaalisen, taloudellisen, emotionaalisen sekä symbolisen ulottuvuuden, avulla. Asiakasarvon muodostumiseen vaikuttavat lisäksi kaikkeen vaihdantaan liittyvät transaktiokustannukset. Tutkimuksessa pyrittiin selvittämään erityisesti, miten verkko-ostamista suosivien kuluttajien kokemukset eroavat perinteisiä myymälöitä suosivien kokemuksista koskien sekä myymälämuotoisen- että verkkokaupan arvoulottuvuuksia ja ostamisen transaktiokustannuksia. Tutkimuksen aineisto kerättiin kvantitatiivisella kyselytutkimuksella. Kyselylomakkeen kysymykset muodostettiin asiakasarvon neljän ulottuvuuden mallin sekä transaktiokustannusteorian pohjalta. Internet-pohjaisella lomakkeella saatiin 210 vastaajan otos. Aineiston analysointiin käytettiin IBM SPSS -ohjelmaa, analyysimenetelminä olivat muun muassa ristiintaulukointi, varianssianalyysi sekä Spearmanin järjestyskorrelaatioanalyysi. Verkkokauppaa suosivat kuluttajat pitivät verkkokauppaa ensisijaisesti käytännöllisenä ostokanavana, myymälöitä puolestaan epäkäytännöllisinä ja kalliina. Suurimmilta osin epävarmuudesta kumpuaviin ostamisen transaktiokustannuksiin aktiiviset verkko-ostajat suhtautuivat huolettomasti. Perinteisiä myymälöitä suosivat kuluttajat kokivat myymäläostamisen itsessään miellyttävänä toimintana ja varteenotettavana tapana toteuttaa itseään. Myymäläostajien suhtautumisesta ostamisen transaktiokustannuksiin ei kyetty tekemään johtopäätöksiä. Näiden tulosten perusteella esitetään, että verkkokaupan tulee uskollisimpia asiakkaitaan miellyttääkseen panostaa arvolupauksessaan funktionaaliseen ja emotionaaliseen tai symboliseen ulottuvuuteen. Myymäläostajia houkutellakseen verkkokaupan tulisi puolestaan panostaa funktionaaliseen ja taloudelliseen ulottuvuuteen. Myymälävetoisen yrityksen tulisi palvella uskollisimpia asiakkaitaan emotionaalisen ja symbolisen ulottuvuuden yhdistävällä arvolupauksella, kun taas verkko-ostamista suosivien kuluttajien houkuttelemiseksi sen tulisi panostaa heikkouksiinsa, funktionaaliseen ja taloudelliseen ulottuvuuteen.
  • Saksi, Ville (Helsingin yliopisto, 2017)
    Pro Gradu -tutkielman tavoitteena oli tutkia High Capacity Transport-yhdistelmien polttoaineen kulutusta ja päästöjä. Tutkimus on osa Metsäteho Oy:n HCT-tutkimushankkeita. Tutkimus toteutettiin Metsätehon yhteistyöyritysten avulla ja tuella. Tutkimuksessa tarkastelin kolmea 84¬104 tonnin painoista HCT-yhdistelmää ja niiden verrokkiajoneuvoja. Verrokkien kokonaispaino oli 76 tonnia. Pro Gradu -työssä käydään lävitse yhdistelmien rakenne ja tiedonkeruussa käytetyt järjestelmät. Tiedonkeruujärjestelminä on käytetty Scanian Fleet Managementia, Volvon Dynafleetia ja Paetronicsin valmistama Econenia. Tulosten mukaan HCT-yhdistelmät voivat merkittävästi parantaa puutavaran hankinnan polttoainetehokkuutta. Tämä helpottaisi Suomen pääsyä kansallisiin ja EU:n asettamiin päästötavoitteisiin.
  • Koljonen, Paula (Helsingin yliopisto, 2017)
    Aflatoxins are harmful compounds found in food and feed. The literature review of this thesis looked at aflatoxin M1 (AFM1) found in milk and its occurrence, significance and prevention methods using lactic acid bacteria (LAB). Furthermore, the assay methods of aflatoxins and the factors affecting the analysis were discussed. The aim of the experimental work was 1) to investigate the ability of five LAB strains to bind AFM1 in vitro and 2) to investigate how different matrixes affect the assay of AFM1 and to evaluate the feasibility of the selected ELISA kit for the study. In the first phase of the study the AFM1 concentrations of three different matrixes were analyzed using ELISA when known concentrations of the AFM1-standardsolution were added (0, 20 ja 40 ppt). In the second phase of the study the abilities of five LAB strains to bind AFM1 in UHT skimmed milk and MRS-broth were investigated. The bacterial suspensions were incubated at +32 °C for one hour, and the AFM1 concentration in the matrixes were 50, 15 and 10 ppt. The unbound AFM1 concentrations of the supernatants were analyzed from the samples using ELISA. The unbound AFM1 concentrations were converted to the proportional portion of the bound AFM1. In this study, statistically significant differences were observed in the abilities of the LAB to bind AFM1. The viable cells of strain B2 27 (Lb. plantarum-, pentosus- or paraplantarum) were the best binders of AFM1. They removed 43.7 % AFM1 in UHT skimmed milk, where the AFM1 concentration was 15 ppt. Unlike in previous studies viable cells bound AFM1 better than the heat-killed cells. The used ELISA kit was a sensitive method for analyzing low concentrations of AFM1, but at higher concentrations the assay results were inaccurate. The nonspecific interaction due to the components of the matrixes had to be taken into account when the results were reviewed. In the future, it may be possible to utilize the LAB strains, such as B2 27 for reducing AFM1 the concentration in milk and probably in other foodstuffs. There is a need to develop a practical application which can be used in the binding of AFM1 using lactic acid bacteria and thus reduce the bioavailability of AFM1.
  • Daoud, Sylvie (Helsingin yliopisto, 2017)
    Tutkimus tarkastelee ruokavalintojen merkityksiä kuluttajalle ja etenkin kuluttajien näkemyksiä kaurasta. Tarkastelun kohteena on se, miten kuluttajat perustelevat arjen ruokavalintojaan. Tutkimuksen empiirinen osa koostuu kolmesta ryhmähaastattelusta, joihin osallistui 21 henkilöä. Haastattelut tehtiin syksyn 2016 ja kevään 2017 aikana. Tutkimuskohteena ovat pääkaupunkiseudulla asuvat 24–64-vuotiaat kuluttajat. Haastatteluaineisto analysoitiin käyttämällä teemoittelua. Teoreettinen viitekehys pohjaa sosiologisen ruokatutkimuksen perinteeseen. Tutkimuksen mukaan ruokavalinnoilla on merkitystä kuluttajalle niin oman itsensä, kuin myös ympäröivän maailman jäsentämisessä. Ruoan ominaisuudet ikään kuin siirtyvät syöjään. Ruokavaliolla perustellaan kulutuskäyttäytymistä ja rakennetaan kuvaa itsestä sosiaalisessa ympäristössä. Kasvipainotteinen ruokailu on ideaali tavoite, joka koetaan kestävän ruokavalion tärkeänä osana. Tutkimus esittää, että kaura muodostaa sellaisen ruokatrendin, joka houkuttelee siihen yhdistettyjen merkitysten ja mielikuvien takia. Kauraa ei itsessään koettu mielenkiintoisena tai erityisenä raaka-aineena. Kauratuotteiden kautta on kuitenkin mahdollista saavuttaa tavoiteltu kasvipainotteinen ruokavalio. Positiivisista mielikuvista huolimatta, kuluttajan suhde kauraan on neutraali. Haastatteluista selvisi, että ruokavalinnat eivät muodostu huolellisesti perusteltujen päätösten kautta. Syöminen perustuu ruokamielikuviin ja arjen olosuhteisiin, jotka pakottavat toiminaan tietyllä tavalla. Kuluttajat kuitenkin kokevat tietävänsä, kuinka heidän pitäisi kuluttaa. Arjen asettamat haasteet vaikuttavat ekologisten valintojen toteutumiseen. On epäselvää, onko vastuu oikeiden valintojen toteutumisesta yksilöllä vai yhteiskunnalla. Nykytilanteessa tiedon määrän kasvu ei siis välttämättä auta päätöksenteossa. Tiedon lisääntyminen ruokateollisuuden toimintatavoista johtaa epävarmuuteen ja ahdistukseen, sillä täydellistä tietoa kokonaisuudesta on mahdotonta saavuttaa.