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(2008)Weeds cause hard surfaces and pavements in cities to break down more quickly than they naturally would. Weed control on hard surfaces is mainly based on herbicides, of which glyphosate is the most effective and also most widely used. However, the use of glyphosate on paved areas has been restricted in some countries because of the risk of leaching in to groundwater and watercourse. Alternative methods for weed control on urban areas include mechanical, physical and biological methods and natural product herbicides. Many of the physical methods are based on thermal effect, and the most suitable on hard surfaces are flaming, hot water and hot steam. Vinegar is an alternative herbicide that is commonly in use. Oils have been used as adjuvants in herbicides, but many plant originated oils have phytotoxic effects of their own. Herbicides based on vegetable oils are available in several countries. Steaming and vinegar were tested on hard surface weed control during three growing seasons 2005-2007. The purpose of the study was to investigate whether steaming and vinegar have an effect on the number of weeds on hard surfaces, and how many applications are required to provide adequate control. The aim of the greenhouse experiment was to compare the effects of 12 % vinegar and different concentrations of pine oil and birch oil distillate on two weed species in two different developmental stages. The aim of the third experiment was to test pine oil, birch oil distillate and vinegar for weed control in practice on the bases of ornamental trees. The experiment was carried out during summer 2007. Vinegar and steaming controlled vegetation on hard surfaces, and the best result was obtained by three applications during one growing season. In this experiment vinegar provided better control than steaming. The greenhouse experiment proved the largest concentrations of pine oil and birch oil distillate to control weeds as well as or even better than vinegar. In the field experiment birch oil distillate and pine oil were slightly more effective than vinegar. Reducing the use of herbicides in cities is an important task, and successful weed control requires careful planning. Herbicides should be used only when other means are insufficient.
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(2018)The aim of this study was to determine the chemical hazards associated with the packaging materials of liquid packaging board with polyethylene coating on both sides, and if these chemical hazards would transfer to the liquid packaging board and to milk packaged in it. Consumers’ exposure to chemical hazards resulting from the packaging materials of the liquid packaging board used in the packaging of milk was assessed. Additionally, the process of safety assessment of new packaging materials of liquid packaging board was developed and described. A multinational manufacturer of food contact materials bears a great responsibility for the consumer safety and conformance of its products which is why conducting this study was important. A core made of recycled fibre and a tape used in the packaging of liquid packaging board were assessed for their chemical risk in this study. The core consists of adhesives and core board made of recycled fibre. Adhesive tapes consist of backing material and adhesive. Sometimes a primer is used between the backing material and adhesive. The chemical composition and potential sources of contamination were discussed in the literary review. Non-Intentionally Added Substances (NIAS) and substances known to cause alterations in the sensory properties of liquid packaging board and food in adhesive tapes and core board were analysed. Additionally, non-targeted screening methods were employed to detect unpredicted NIAS in the packaging materials, liquid packaging board and a food simulant for milk. The concentrations of NIAS were compared with specific migration limits in the European Commission Regulation (EU) 10/2011 on plastic materials and articles intended to come into contact with food. They were also compared with the values of acceptable and tolerable daily intakes if provided by the European Food Safety Authority (EFSA). The analytical methods that were used for qualitative and quantitative analyses were GC-MS and GC-FID. Predicted and unpredicted NIAS were detected from the packaging materials using the chosen methods. Some of the substances were found to transfer to liquid packaging board and to the food simulant. The migration to the food simulant was not be analysed for some of the NIAS. Additional information on the transfer of these substances to food is still needed. Substances for which adequate toxicological information was available did not pose a threat to consumer safety based on the exposure assessment. Furthermore, a process for the risk assessment of new packaging materials was successfully developed.
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(2020)The aim of this study was to examine if eating Finnish cereals and oil seeds cause more health benefits or harm. Cadmium was considered as the chemical hazard and dietary fiber as the useful nutrient. In this study food consumptions, the heavy metal contents and exposures, fiber intake and the biggest safe doses for cereals and seeds were evaluated. DALYs (disability adjusted life years) were used to compare benefits and harms. Exposure was estimated using the statistical BIKE model. To date, no risk benefit analysis concerning cereal and seed consumption is known to have been done. A common method for risk benefit analysis has not yet been developed, but generally a stepwise approach is recommended. Of the foods examined, poppy and sunflower seeds contained the most cadmium, pumpkin seed the least. In the long term, the most consumed seed was sesame and the most consumed cereal was wheat. The greatest cadmium exposure was due to wheat consumption, and for nickel oat consumption. Wheat was clearly the biggest source of fiber. Low fiber intake resulted in more DALYs than cereals’ cadmium resulted in osteoporotic DALYs in 2012. Compared to the situation in 2012, significantly less DALYs were resulted in scenario where 232 g of whole grains per day are consumed. It is because in the scenario, DALYs caused by low fiber intake, which amount is much higher than cadmium DALYs, are not formed. Based on the results obtained, with bigger cereal consumption than in 2012, the health benefits outweigh the disadvantages, as the impact of reducing the DALYs due to low fiber intake is much more significant than the impact of the increase of cadmium DALYs caused by higher intake. In the future, it would be beneficial to have a more comprehensive study of the health effects of the foods examined. However, this requires a lot of information that was not available in this study.
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(2020)Euroopan unionin yhteinen lainsäädäntö edellyttää luomutarkastusten kohdentamista kohonneen riskin toimijoille. Riskiperusteisessa luomuvalvonnassa valvonnan resurssit pyritään kohdentamaan niille toimijoille, joilla laskennallinen riski luomutuotantoehtojen noudattamatta jättämiselle on suurin. Toimivan riskinarvioinnin edellytys on toimiva riskinarviointijärjestelmä, jonka avulla voidaan tunnistaa korkean riskin toimijat sekä arvioida mahdollisen toteutuneen riskin seuraukset. Tutkimuksessani arvioin Suomessa käytössä olevan riskinarviointilomakkeen toimivuutta ja sillä vuonna 2016 saatuja tuloksia. Mitä riskinarviointilomake kertoo suomalaisista luomutiloista ja kuinka hyvin sen antamat tulokset nostavat esille kohonneen riskin toimijat? Tutkimusaineistoni koostui yhden luomutarkastajan vuonna 2016 luomutarkastuksilla täyttämistä riskinarviointilomakkeista sekä koko vuoden 2016 kaikista kokonaisriskipisteistä ELY-keskuksittain. Tarkastelin tilastollisella ristiintaulukoinnilla, kuinka hyvin arvioidut riskipistekertymät ennakoivat sitä, että tarkastuskäynnillä todella havaitaan poikkeamia tuotantoehdoista. Lomakkeella saadut tulokset nostavat esille pääosin samoja seikkoja, jotka on aiemmissa tutkimuksissa havaittu riskiä kasvattaviksi tekijöiksi. Näitä ovat esimerkiksi suuri tilakoko ja tuotannon monipuolisuus. Hypoteesini oli, että korkea kokonaisriskipistemäärä ennustaisi havaittuja poikkeamia tarkastuksella, mikä pitikin paikkansa tiloilla, joilla pistekertymä oli hyvin suuri. Toisen hypoteesini mukaan tilan aiemmat poikkeamat ennustaisivat poikkeamia myös nykyisellä tarkastuksella. Poikkeaman todennäköisyys oli kuitenkin aiemmista poikkeamista riippumatta kaikissa tapauksissa sama. Tarkastelin myös riskinarviointilomakkeen eri osa-alueiden vaikutusta havaittuun poikkeamaan. Analyysin perusteella mikään osa-alue ei noussut esille poikkeamaa ennustavana. Euroopan maiden yhteinen riskinarviointijärjestelmä edellyttää määrätietoista sekä yhteisen tiedonkeruujärjestelmän, että kerätyn tiedon analysointi- ja arviointijärjestelmän kehittämistä. Lisäksi keskeisiä termejä olisi selvennettävä ja luotava selkeät, yhteiset kriteerit sääntöjenvastaisuuksien luokittelulle. Suomessa käytössä olevaa riskinarviointilomaketta tulisi selkiyttää ja luoda sähköiselle lomakkeelle soveltuva, yksinkertaisempi versio.
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(2018)Maatalousyritysten toimintaan vaikuttavilla riskeillä on kaksi merkittävää lähdettä: tuotannon epävarmuus sekä tuottajahintojen vaihtelu. Sään ja biologisten viiveiden kaltaisten hallitsemattomien elementtien takia maatalousyritysten tuotoksen määrä ja laatu vaihtelevat. Tuotantopanosten ja lopputuotteiden markkinahintojen muutokset sekä valuuttakurssien vaihtelut taas aiheuttavat yrityksille merkittäviä hinta- ja markkinariskejä. Tutkielman tavoitteena oli selvittää, millainen peltokasvien tuotantoyhdistelmä on lyhyellä aikavälillä riskitehokas. Lisäksi pyrkimyksenä oli selvittää, miten maatalousyritys voi vaikuttaa peltokasvien tuotannon odotettuihin katetuottoihin suhteessa näiden vaihtelusta aiheutuviin riskeihin muuttamalla tuotantoyhdistelmäänsä ja monipuolistamalla tuotantoaan. Tuotannon monipuolistamisen on yksi keino, jolla maatalousyritys voi sopeutua epävarmuuteen ja toimintaympäristön muutoksiin. Tuotannon monipuolistamisen avulla tulisi pyrkiä löytämään riskitehokkaat yhdistelmät, joiden odotetut tuotot ovat korkeimmat suhteessa niiden vaihtelusta aiheutuviin riskeihin. Maatalousyrityksen tavoitteena on lyhyellä aikavälillä pyrkiä maksimoimaan peltokasvien tuotannon epävarmojen katetuottojen odotettu hyöty. Yritys voi pyrkiä saavuttamaan tavoitteensa muuttamalla tuotannossaan olevaa peltokasviportfoliota. Tutkimustulosten perusteella tuotantoa monipuolistamalla maatalousyrityksen on mahdollista vähentää katetuottojen vaihtelua lyhyellä aikavälillä. Palkoviljojen ja öljykasvien tuotannon viljoja korkeampien maataloustukien sekä palkoviljojen typpijälkivaikutuksen huomioiminen lisäsivät kasvien katetuottoja ja paransivat niiden kilpailukykyä viljojen suhteen. Lisätuen maksaminen onkin tarpeen myös tulevaisuudessa, mikäli öljykasveja ja palkoviljoja halutaan lisätä maatalousyritysten viljelykiertoon. Kun öljykasveille ja palkoviljoille maksettavat lisätuet ja palkoviljojen typpijälkivaikutus otetaan huomioon, maatalousyritysten on kannattavaa pyrkiä alentamaan katetuottojen vaihtelua tuotantoaan monipuolistamalla lyhyellä aikavälillä. AB-tukialueella vaatimuksena on kuitenkin, että nykyisellä viherryttämistuen tasolla yrityksellä on tukioikeuksia yli 14 %:lle sen kokonaispinta-alasta, mikäli tuen ehtojen täyttämisestä ei aiheudu muita kustannuksia. Muussa tapauksessa AB-tukialueella sijaitsevan maatalousyrityksen kannattaisi lyhyellä aikavälillä erikoistua kaksitahoisen ohran tuotantoon. Tulosten perusteella maatalousyrityksen odotettua hyötyä maksimoiva tuotantoyhdistelmä on sama riippumatta maatalousyrittäjän riskin karttamisen tasosta. Tämä voi osaltaan johtua siitä, että maatalousyrityksillä on paljon varallisuutta verrattuna katetuottojen vaihteluun, jolloin yritysten tulisi kyetä kantamaan vaihtelusta aiheutuvat riskit. Maatalousyritysten heikon kannattavuuden takia katetuottojen alentuminen saattaa kuitenkin heikentää maksuvalmiutta, mikä osaltaan aiheuttaa haasteita yritystoiminnan jatkuvuudelle.
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(2014)Aerogels are lightweight, porous and dry foams that are produced from gels by replacing the liquid phase by air. When produced from polysaccharide-based hydrogels, potential applications for aerogels could be found as bio-based packaging materials. The literature review focused on the production of polysaccharide-based hydrogels and their chemical crosslinking, as well as the production of aerogels and their properties. In the experimental study the possibilities for utilization of spruce galactoglucomannan (GGM), an abundant but largely unexploited raw material, as aerogel matrix was explored. Nanofibrillated cellulose (NFC) was used as reinforcement and the polysaccharides were crosslinked with ammonium zirconium carbonate (AZC). Hydrogels were prepared from GGM-NFC-suspensions and heat treatment was performed in order to induce crosslinking reaction. Prepared hydrogels were frozen in a bath of carbon dioxide ice and ethanol and subsequently freeze-dried into cubic aerogels. The aim was to investigate the effect of polysaccharide proportions and AZC content on the strength of hydrogels and on the mechanical properties and moisture sensitivity of aerogels. The formation of crosslinks was observed indirectly from the values of storage and loss moduli by dynamic rheological measurement. The strength of hydrogels was highly dependent on the AZC and NFC content. In contrast, the compressive modulus of aerogels instead was affected only by NFC content at relative humidity (RH) of 50% and 23 °C. Hydrogel strength could not be used for prediction of aerogel strength under these ambient conditions. AZC and NFC mainly decreased the sensitivity of aerogels towards moisture by decreasing the water absorption and its plasticizing effect on aerogels. The effect of crosslinking on mechanical and physical properties of aerogels appeared clearly at RH over 50%. GGM was shown to be a suitable aero-gel raw material when combined with NFC. The role of NFC in enhancing the aerogel’s me-chanical properties was significant. The mechanical properties of uncrosslinked aerogels, how-ever, weakened in a humid environment. In particular, AZC is needed to protect aerogels from the plastizicing effect of water. Properties of crosslinked aerogels in a humid environment would be an interesting subject of further studies.
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(2013)Increasing the use of biodegradable packaging materials could reduce the need of petroleumbased plastics. Hemicelluloses are a potential source of renewable raw material for packaging purposes. The literature review focused on polysaccharide-based packaging materials and properties of food packaging materials. In addition, crosslinking polysaccharides with citric acid and ammonium zirconium carbonate (AZC) were discussed. The objective of the experimental study was to prepare self-standing films from spruce galactoglucomannan (GGM), and to study their properties. The aim was to enhance the mechanical and permeability properties, and make the films less sensitive to moisture, via crosslinking. Crosslinking was carried out in solution and sorbitol was used as plasticiser. The films were prepared by a casting method and dried at room temperature. Tensile strength, elongation at break and Young’s modulus were measured by tensile testing. In addition, oxygen permeabi lity, water vapour permeability and water solubility of films were measured. The effect of moisture on films was investigated with sorption isotherm and humidity scanning dynamic mechanical analysis. Citric acid did not function as a crosslinking agent, but acted more as a plasticiser increasing elongation. The heating required for the crosslinking reaction should be performed in dry film instead of solution. Crosslinking with AZC resulted in strong films, with tensile strength up to 52 MPa. Sorbitol addition decreased the tensile strength and Young’s modulus, but increased the elongation, as expected. Crosslinking and sorbitol addition both decreased water vapour permeability, resulting in a better water vapour barrier. The deviations in oxygen permeability measurements were high, but it looks like crosslinking with AZC results in better oxygen barrier. In high relative humidity (RH) the film with AZC absorbed less water vapour and the storage modulus decreased slower than in the non-crosslinked film. Thus, crosslinking with AZC made the properties of GGM films less susceptible to changes in RH. AZC appears to be a promising crosslinking agent for hemicellulose films, therefore the suitability for food packaging applications should be further studied.
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(2019)Suorakylvö ja peltojen kevennetty perusmuokkaus ovat lisääntyneet 2000-luvulla vauhdilla. Kevyemmän perusmuokkauksen johdosta kylvölannoittimen rakenteita on pitänyt muuttaa, jottei se tukkiutuisi olkisissakaan oloissa. Esimerkiksi vantaiden lukumäärää on vähennetty, suurentamalla riviväliä tai sijoittamalla lannoite ja siemen saman vantaan kautta maahan. Tutkimuksen tavoitteena oli selvittää, miten rivivälin suurentaminen tai lannoitteen sijoittaminen samaan riviin siemenen kanssa vaikuttavat kevätvehnän (Triticum aestivum L.) kasvuun ja sadonmuodostukseen. Tätä varten savimaalle Jokioisiin perustettiin kaksi kenttäkoetta, joissa tutkittiin viittä eri riviväliä sekä kahta eri lannoitteen sijaintia siemeneen nähden. Rivivälin osalta toisessa kokeessa koejäseninä olivat: 125, 154, 167 sekä 190 mm. Toisessa koekentässä koejäseninä olivat: 125, 167 sekä 250 mm. Ensimmäisellä koekentällä lannoite oli sijoitettu joko siemenriveihin tai siemenrivien väliin. Toisella koekentällä lannoite oli levitetty pellon pintaan. Kasvien kasvua mitattiin orastumisesta sadonkorjuuseen. Sadonkorjuun jälkeen korjattu sato analysoitiin. Lisäksi kasvukauden sääoloja seurattiin jatkuvatoimisesti. Kasvukauden 2018 sääolot olivat erittäin kuivat. Ne vaikuttivat oleellisesti kokeen tuloksiin. Kylvöjen jälkeinen pitkä kuivuus jätti koeruutujen kasvustot epätasaisiksi ja harvoiksi. Kuivuuden vuoksi päätettiin kylvää toinen koe, jotta tuloksia saataisiin enemmän. Toisella koekentällä oli myös kastelumahdollisuus. Luotettavien tulosten saamiseksi tarvitaan kuitenkin vielä lisätutkimusta. Näiden tulosten mukaan rivivälin suurentaminen ei vaikuttanut kevätvehnän sadon suuruuteen tai sen laatuun. Lannoitteen sijainti sen sijaan vaikutti kasvuston rakenteeseen sekä kasvuun. Kun lannoite sijoitettiin lähelle siementä, kasvusto oli tummemman vihreä sekä vankempi. Lisäksi se kasvatti tuuhean juuriston siemenen ympärille. Lannoitteen läheisyys viivästytti hieman itämistä ja todennäköisesti vähensi myös itävyyttä, kun lannoite ja siemen olivat kosketuksissa toisiinsa ja lannoitemäärä oli suuri.
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(2024)Faba bean (Vicia faba L.) is a grain legume crop, its seeds are a generous source of plant protein for both food and feed. In addition to having a high nutritional value, faba beans are an essential part of a sustainable cropping system. Faba bean increases the biodiversity of crop rotation, and due to its' superior symbiotic nitrogen fixation, it reduces the need for chemical nitrogen fertilizers. Due to climate change, drought is predicted to increase during the growing season, especially in middle and high latitudes. Drought limits the growth of crops and reduces both grain and straw yields. Faba bean is a cool-season crop, and it has adapted to cool and moist conditions and has a low tolerance to water deficit. The main aim of this study is to determine whether Rhizobium leguminosarum inoculation improves adaptation of faba bean to water deficit. In addition, the study analyzes the effect of chemical nitrogen fertilizer on adaptation to water deficit and compares these results. The research was conducted under controlled greenhouse conditions and field experiment. In the greenhouse experiment, the effect of three different moisture treatments with field capacities of 100%, 45%, and 20% was compared on the growth between three different faba bean varieties. The genotypes used in the greenhouse experiment were Aurora, which is sensitive to water deficit; Mélodie, which has an efficient water absorption capacity; and Vire. Plants received three different nitrogen treatments: rhizobial inoculation, synthetic nitrogen fertilizer, and control that was not given nitrogen treatment. In the field experiment, a Finnish genotype, Sampo, was used, and the effects of four different nitrogen treatments on its growth were compared. The nitrogen treatments were inoculation, synthetic nitrogen fertilizer, a combination of these, and an untreated control. In the greenhouse experiment, water deficit and synthetic nitrogen fertilizer significantly reduced the number of active root nodules of the faba bean, while rhizobial inoculation increased the number of root nodules even under dry conditions. At 20% field capacity, inoculation increased shoot dry weight by 38%, while synthetic nitrogen fertilizer increased shoot dry weight by 26%. Synthetic nitrogen fertilizer, on the other hand, increased leaf area and SPAD results more than rhizobial inoculation. Leaf temperature raised as the stomatal conductance decreased under water deficit. Increasing the amount of nitrogen either by inoculating with rhizobia or synthetic nitrogen fertilizer promotes the growth of faba bean under water deficit conditions. Synthetic nitrogen fertilizer increases the adaptation of faba bean to water deficit slightly more than inoculation. Inoculation can ensure the formation of root nodules and efficient nitrogen fixation under water deficit.
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(2021)Soil acidity limits the growth and development of crops. Yield of plants decreases due to not only low pH conditions in acid soils but also dissolution of detrimental elements affecting the availability of essential nutrients. Aluminum toxicity have been one major cause of decline in yield due to the stunting of the primary root and inhibition of lateral root formation. Plants have ways to mitigate aluminum toxicity which includes Al exclusion mechanisms as a first defense to external Al ions and Al detoxifying mechanisms where Al ions are transported and sequestered inside the plant cells. Vicia faba, commonly known as faba or broad bean is one of the oldest crops grown for being a cheap but excellent foundation of protein in human diets, a good fodder and a forage crop for animals, and one of the most powerful nitrogen fixers. The crop is well adapted to low temperatures but moderately susceptible to hostile subsoils and has very low exchangeable Aluminum tolerance. Responsive varieties were previously identified but mechanisms to counteract with the conditions are still to be realized hence the study aimed to understanding the molecular mechanisms of rootzone aluminum toxicity tolerance in faba bean which was realized by using RNA-Seq technique to analyze the transcriptome of roots of faba bean exposed to acidic and aluminum stressed environment and by then, Al responsive genes were identified. The administration of stress was done in a aquaponics set-up. Results revealed that although gene directly interacting with Al was not identified, faba bean have a variety of well-adapted mechanisms to encounter with the Al stressed condition and mitigate the adverse effects to the plant growth and development which includes (1)transporter activity, (2)signaling(ROS), and (3)ubiquitination. The findings will provide valuable information for designing future crop breeding programs.
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Rodun ja kasvatusajan vaikutus liharotuisten nautojen teurasominaisuuksiin sekä lihan syöntilaatuun (2020)Tässä tutkimuksessa selvitettiin liharotuisten nautojen rodun ja kasvatusajan yhteyttä ruhon teurasominaisuuksiin sekä lihan syöntilaatuun. Lisäksi tässä tutkimuksessa selvitettiin ultraäänellä mitattujen ominaisuuksien fenotyyppistä korrelaatiota eläimen teurasominaisuuksiin sekä lihan syöntilaatuun. Tutkimuksen aineistona oli Rotukarjan hyvinvoinnin ja taloudellisten toimintaedellytysten parantaminen -hankkeen (2010–2013) ruokintakokeen tulokset. Lopullinen aineisto sisälsi 158 sonnin tiedot, jotka edustivat viittä yleistä Suomessa kasvatettavaa liharotua. Rodut olivat aberdeen angus, charolais, hereford, limousin ja simmental. Teurasominaisuuksista mitattiin teuraspainoa, teurasprosenttia, lihakkuutta ja rasvaisuutta. Lihan syöntilaadun tutkimus sisälsi tiedon lihan marmoroitumisasteesta, pH-arvosta, leikkuuvasteesta, valumasta ja väriominaisuuksista, vaaleudesta (L), punaisuudesta (a) ja keltaisuudesta (b) sekä arvion aistinvaraisesta syöntilaadusta. Aistinvarainen syöntilaatu sisälsi mureuden, mehukkuuden, maun sekä näiden yhteispisteet. Tilastollisina menetelminä käytettiin type 2-testauksen sisältävää ANOVA-mallia sekä ls-keskiarvoja, Tukeyn parittaisvertailua ja regressioanalyysiä. Tutkimuksen tulosten perusteella voidaan todeta, että rodulla on merkitsevä vaikutus useaan tutkittuun ominaisuuteen. Taloudellisesti näistä merkittävämpiä ovat teurasprosentti, lihakkuus ja rasvaisuus. Lyhyt kasvatusaika on taloudellisesti kannattavampi kuin pitkä kasvatusaika, kun huomioidaan ominaisuuksiin vaikuttavat panostetut resurssit. Lyhyellä kasvatusajalla kasvatettujen sonnien teuraspaino, teurasprosentti ja lihakkuus olivat suhteessa korkeammat kuin pitkän kasvatusajan ryhmän eläimillä. Ultraäänellä mitatulla ulkofileen paksuudella on suotuisa yhteys teurasprosenttiin. Ultraäänellä mitatulla marmoroitumisasteella on suotuisa yhteys lihan marmoroitumisasteeseen, punaisuuteen, mureuteen (aistinvarainen ja leikkuuvaste), mehukkuuteen ja aistinvaraisen arvioinnin yhteispisteisiin.
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(2010)Actin stress fibers are dynamic structures in the cytoskeleton, which respond to mechanical stimuli and affect cell motility, adhesion and invasion of cancer cells. In nonmuscle cells, stress fibers have been subcategorized to three distinct stress fiber types: dorsal and ventral stress fibers and transverse arcs. These stress fibers are dissimilar in their subcellular localization, connection to substratum as well as in their dynamics and assembly mechanisms. Still uncharacterized is how they differ in their function and molecular composition. Here, I have studied involvement of nonmuscle alpha-actinin-1 and -4 in regulating distinct stress fibers as well as their localization and function in human U2OS osteosarcoma cells. Except for the correlation of upregulation of alpha-actinin-4 in invasive cancer types very little is known about whether these two actinins are redundant or have specific roles. The availability of highly specific alpha-actinin-1 antibody generated in the lab, revealed localization of alpha-actinin-1 along all three categories of stress fibers while alphaactinin-4 was detected at cell edge, distal ends of stress fibers as well as perinuclear regions. Strikingly, by utilizing RNAi-mediated gene silencing of alpha-actinin-1 resulted in specific loss of dorsal stress fibers and relocalization of alpha-actinin-4 to remaining transverse arcs and ventral stress fibers. Unexpectedly, aberrant migration was not detected in cells lacking alpha-actinin-1 even though focal adhesions were significantly smaller and fewer. Whereas, silencing of alpha-actinin-4 noticeably affected overall cell migration. In summary, as part of my master thesis study I have been able to demonstrate distinct localization and functional patterns for both alpha-actinin-1 and -4. I have identified alpha-actinin-1 to be a selective dorsal stress fiber crosslinking protein as well as to be required for focal adhesion maturation, while alpha-actinin-4 was demonstrated to be fundamental for cell migration.
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(2018)Oat β-glucans are water soluble non-starch polysaccharides. The health benefits of β-glucan including reduction of post-prandial glycemic response are correlated to its ability of forming viscous solutions. Phytate has also been reported to reduce starch digestion due to its potential of binding starch-digestion-related enzymes such as α-amylase or enzyme co-factors. The previous study showed that a significant amount of phytate was found in both oat β-glucan extract and highly purified β-glucan. The aim of this research was to study the role of residual phytate in the oat β-glucan extracts in starch hydrolysis. Oat β-glucan (OBG) was extracted from oat bran concentrate. OBG with phytate-removal treatment (OBG-PR) was prepared with ion-exchange resin and dialysis. The content of β-glucan, phytate and starch in OBG and OBG-PR were determined with Megazyme kits. The protein and calcium content was also measured. Before adding into the gelatinized wheat starch solution, the β-glucan solutions or phytic acid solution were pre-incubated with porcine pancreatic α-amylase. The starch hydrolysis was induced at physiological pH 6.9 and 37°C. Aliquots were collected at 20 min and 120 min digestion time. Digested starch was calculated based on the released glucoses. Both OBG and OBG-PR inhibited the starch hydrolysis. OBG contained a higher amount of phytate. And it had a stronger inhibitory effect (46%) than that of OBG-PR (34%). Pure phytic acid showed a comparable inhibitory effect on the starch hydrolysis as the OBG intrinsic phytic acid did, when the pure phytic acid was used at the same level as the concentration of intrinsic phytic acid in OBG. The decrease of intrinsic calcium in OBG-PR was found due to the ion-exchange and dialysis process. Consequently, the same amount of calcium was added to OBG-PR. The inhibitory effect of phytic acid on starch hydrolysis was completely reversed by the addition of calcium. Moreover, degradation of β-glucan by lichenase increased starch hydrolysis rate, which confirmed the role of β-glucan viscosity in the reduction of starch hydrolysis. In summary, the residual phytic acid of oat β-glucan, in addition to viscosity, reduced starch hydrolysis, while calcium contributed to promote starch hydrolysis.
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(2022)Plant vascular cambium development involves dynamic changes in transcriptional profiles, which are mediated by key transcription factors. Understanding secondary growth through complex molecular processes of vascular cambium development has remarkable significance in maximizing carbon storage in trees and is crucial for the genetic improvement of trees for wood production. Here, we studied the functions of NO TRANSMITTING TRACT (NTT)/WIP DOMAIN PROTEIN2 (WIP2) zinc-finger transcription factor in regulating vascular cambium activity and xylem formation using Arabidopsis roots and tree stems as model organisms. Reporter lines carrying red fluorescent protein driven by the promoter of NTT/WIP2 showed cambium specific expression in Arabidopsis roots under confocal microscope. Inducible overexpression of NTT/WIP2 after cambium activation reduced vascular diameter, primary phloem pole distance and secondary vessel number in Arabidopsis roots. In loss of function ntt mutants, significant reductions of vascular diameter, phloem pole distance and number of secondary vessels were also evident. Our data suggests that, both increased expression and loss of function of NTT/WIP2 gene significantly reduce secondary growth in Arabidopsis roots. Simultaneous to our Arabidopsis experiments we also tested the possibility of increasing wood formation amounts through manipulation of PttNTT (putative Populus ortholog of Arabidopsis NTT/WIP2 gene) expression in hybrid aspen trees. But increased expression of NTT/WIP2 in Poplar significantly reduced plant height, stem girth and internode numbers. Altogether, we hypothesize that, appropriate spatiotemporal expression pattern and levels of NTT/WIP2 is required for cambial activity to proceed properly in plants. These findings represent a new foundation toward a more comprehensive understanding of the molecular mechanisms of NTT/WIP2 gene in regulation of cambium development and secondary growth in plants.
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(2021)Tiivistelmä Referat Abstract Lettuce (Lactuca sativa L.) may accumulate high amounts of nitrate in the hydroponic NFT-cultivation system. Accumulation is known to increase under low light conditions, and thus high nitrate content causes problems in year-round lettuce production in Finland. Nitrate is classified as a harmful food additive, and the regulation (194/97) of the European Commission requires the Member States to monitor the nitrate content of commercial lettuce. Hence, to control the nitrate content, farmers have requested an efficient method that does not shorten the shelf-life or negatively affect the quality of lettuce. In the earlier studies, root-applied glycinebetaine (GB) was shown to reduce lettuce nitrate content and increase the contents of amino acids and minerals. The present study aimed to investigate, whether glycinebetaine can serve as a precise method to control lettuce nitrate content in commercial-scale greenhouse production. Glycinebetaine 10 mM was applied into the nutrient solution twice at three days intervals, and lettuce was exposed to treatment during the last six growing days before the harvest. Plant samples were collected every second day for 14 days after the first GB application, and samples from nutrient solution were collected simultaneously. The reduction of GB from the nutrient solution was monitored. The fresh weight of the plants was weighed during the harvest, and contents of nitrate, dry matter, minerals, amino acids, and GB in the plant samples were analyzed. Root-applied GB reduced lettuce nitrate content by over 29 % in comparison to control plants. The total contents of hydrolyzed- and free amino acids were increased. The total content of essential amino acids was increased up to 14 % following the GB treatment. Also, the contents of minerals in the lettuce leaves were altered. The potassium (K+) content in lettuce was reduced by over 40 % after GB application. Lettuce accumulated the applied GB and leaf GB content was 7 mg kg-1 fresh lettuce at the highest. Root-applied GB reduced the fresh weight of the harvested lettuce, but all plants reached the commercial size (>100 g) during the typical commercial growing period of 41–43 days. The result of the present study proved that GB is a practical method to control nitrate content and the quality of lettuce on commercial-scale lettuce production. Glycinebetaine was detectable in the nutrient solution for three days after application and thus, continuously maintained lower nitrate content in plants requires continuous GB application in the commercial lettuce production. The reduction of the nitrate content was significant six days after the first GB application, which indicates that a six-day treatment period is required.
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(2014)Quantitative reverse transcription PCR (RT-qPCR) assay is widely used for the detection of RNA viruses in environmental water samples. However, a major limitation of using RT-qPCR assay to quantify virus titers is its inability to discriminate between infectious and non-infectious viruses, resulting in overestimation of viral infectivity. Thus, the aim of this study was to develop a reliable molecular method for rotavirus detection with information on viral infectivity, and which may contribute to the development of molecular detection methods for correct estimation of infectivity of non-cultivable viruses. In experimental work, the potential of using propidium monoazide (PMA) or RNase treatment prior to RT-qPCR assay was evaluated to measure the infectivity of human rotavirus. In brief, original human rotavirus (HRV) stock was produced by propagating viruses in MA-104 cells. The virus stocks (including HRV stock A and B) were thermally treated at 80 °C at different time points. The virus titer was measured by (1) cell culture-based infectivity assay, (2) RT-qPCR assay, and (3) RT-qPCR assay with PMA or RNase pretreatment. The result of cell culture-based infectivity assay showed that heat exposure for 5 min at 80 °C was sufficient to inactivate the HRV, while RT-qPCR assay alone overestimated the viral infectivity. The results of RT-qPCR assay with pre-treatments showed that, for thermally-inactivated HRV stock A, similar level of false-positive results was reduced with PMA treatment regardless of inactivation time (ranges from 1.04 to 1.18 log10 PCR-units), while higher reduction level was observed with RNase treatment (ranges from 2.64 to 2.89 log10 PCR-units). On the other hand, the effects of both pre-treatments on thermally-inactivated HRV stock B were negligible. In conclusion, both PMA and RNase pre-treatments eliminated the false-positive results of RT-qPCR assay to some extent in defined conditions, while the discrepancy between the infectivity assay and RT-qPCR assay even with PMA or RNase treatment was observed. In order to confirm the potential of using RT-qPCR assay combined with pre-treatments to measure the infectivity of rotavirus, further studies on optimization of PMA and RNase treatments and production of optimal virus stock would be necessary.
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(2012)The main objective of this study was to estimate genetic parameters to aggression- and fear-related traits in Rottweiler-breed. We also determined which kind of variables could be useful in genetic studies. We used a questionnaire which was sent to Rottweiler owners. Genetic parameters were estimated from a data including responses from owners of 510 dogs. Analysis were carried out with Restricted Maximum Likelihood method for three different variables: owner impression, behaviour components and single behaviour guestions. Heritability estimates for different types of aggression and fear were low or moderate. Most common aggression was dog-directed aggression while owner-directer aggression was most rare. Aggressive behaviour was divided into three genetic complex: social unsureness, aggression in encounter situations and sharpness. The widest complex, social unsureness, had highest heritability estimate. Dog’s aggression in social situations was related to fear and unsureness. Owner impression –guestions and behaviour components could be useful when studying personality traits because they measure a wider complex than just a single behaviour. In this study social dogs had less aggressive and fearful behaviour. It could be possible to reduce aggression- and fear-related behaviour problems by raising dog’s sociality by breeding. This study showed that owner impressions could be used to measure dog’s sociality.
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(2007)The literature review deals with the composition of rye flour and the significance of en-zymes and sourdough in rye flour processing. The operational principles of twin screw extruders, the extrusion of grain based materials and the formation of aroma during grain based extrusion are also reviewed. The aim of this study was to determine the influence of the amount of powered rye sourdough and extrusion cooking parameters on the structure and properties of rye extrudate. Three process parameters were varied: content of rye sourdough powder, process temperature during the final stages of extrusion and revolution speed of the extruder's screws. A Box-Behnken's experimental design was used with 3 levels of dried sourdough powder content (0, 20 and 40%), 3 screws revolution speeds (200, 350 and 500 rpm) and 3 exit temperatures (120, 150 and 180°C). Feed rate was set at 4.0 kg/h and the moisture of the feed was 17.4%. A total of 15 experiments were perfomed. Pasting properties, acidity, acid value and D- and L-lactic acid concentration of full grain rye flour, dried rye sourdough flour and ground extrudate powder were determined. Acetic acid concentration of dried rye sourdough powder was also determined. Moisture content, expansion, texture, bubble sizes and colour of extrudate were determined. Extrusion cooking produce very different types of rye extrudates and the effect of process parameters on structure of extrudate was significant. When the pressure at the die was 30–40 bar, structure of extrudates were porous. Freeze dried extrudates were harder than extru-dates stored for one day at room temperature. Young's modulus decreased with increasing screws speed and processing temperature. Extrudate’s expansion increased as a function of increased revolution speed of screws and decreased processing temperature. As the content of dried sourdough increased, the bubble sizes of extrudate increased and also yellow (a) and red (b) colour and acidity of extrudates became stronger. Lightness (L) was statistical significantly higher when temperature was higher. As expected, the concentration of D- and L-lactic acid increased with increasing dried sourdough content. Decreased content of dried rye sourdough and slower revolution speed of screws increased cold peak viscosity signifi-cant. Peak and hold viscosities increased with slower revolution speed of the screws and decreased content of dried sourdough. Final viscosity and setback value increased signifi-cantly with slower revolution speed of the screws. The optimal extrudate, which was crispy and had a good flavour, was obtained when the content of dried sourdough powder was 20%, revolution speed of the screws was 500 rpm and processing temperature was 120°C.
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(2016)Johdanto: Ärtyvän suolen oireyhtymä on toiminnallinen vatsavaiva, johon liittyy kipu tai epämiellyttävä tunne vatsassa ja muuttunut ulostustiheys tai ulosteen koostumus. Viime aikoina on saatu tutkimusnäyttöä paksusuolessa herkästi fermentoituvia FODMAP-hiilihydraatteja (fermentable oligo , di- and monosaccharides and polyols) rajoittavan ruokavalion tehosta ärtyvän suolen oireyhtymän hoidossa. Ruisleipä on keskeinen kuidun ja folaatin lähde suomalaisille, mutta se sisältää runsaasti FODMAP-hiilihydraatteja ja voi sen vuoksi aiheuttaa oireita herkkävatsaisille. Ruisleivän valmistusprosessia muuttamalla voidaan tehdä vähemmän FODMAP-hiilihydraatteja sisältävää ruisleipää. Tavoitteet: Tutkimuksen päätavoitteena oli verrata kahden, FODMAP-hiilihydraattien määrän suhteen toisistaan eroavan ruisleivän vaikutuksia IBS-potilaiden aterianjälkeisiin vatsaoireisiin, uloshengitysilman vetypitoisuuteen ja mahasuolikanavan läpikulkuaikoihin, happamuuteen ja paineeseen. Muina tavoitteina oli saada tietoa SmartPill®-laitteen toimivuudesta vatsaoireiden mittausmenetelmänä ja tutkia vatsaoireiden voimakkuuden ja uloshengitysilman vetypitoisuuden välistä yhteyttä. Aineisto ja menetelmät: Tutkittavana olivat normaalipainoiset ja ylipainoiset naiset, joilla oli IBS (n=7). Tutkimus oli kaksoissokkoutettu, satunnaistettu, vaihtovuoroinen ateriakoe kahdella eri ruisleivällä. Tutkittavat söivät satunnaisessa järjestyksessä kumpaakin leipää erillisillä koejaksoilla, minkä jälkeen heiltä mitattiin vatsaoireita, uloshengitysilman vetypitoisuutta ja suoliston sisäisiä olosuhteita. Suoliston lämpötilaa, painetta ja pH:ta mitattiin SmartPill®-laitteella, joka on pienikokoinen nieltävä kapseli. Kapselin mittaamista tiedoista saadaan läpikulkuajat, pH:n mediaanit, keskipaine ja supistuksien määrät mahasuolikanavan eri osille. Tutkimuksen tulokset esitettiin mm. käyrän alaisina pinta-aloina ja maksimiarvoina. Mittausjaksojen välisiä eroja analysoitiin tilastollisesti Wilcoxonin merkittyjen sijalukujen testillä. Vatsaoireiden voimakkuuden yhteyttä suoliston paineeseen ja uloshengitysilman vetypitoisuuteen analysoitiin Spearmanin järjestyskorrelaatiokertoimen avulla. Tulokset: Uloshengitysilman vetypitoisuuden käyrän alainen pinta-ala (AUC0-630min) erosi koejaksojen välillä (p=0,028). Uloshengitysilman vetypitoisuus oli matalampi tutkittavien syödessä vähemmän FODMAP-hiilihydraatteja sisältävää ruisleipää verrattuna tavalliseen ruisleipään. Ilmavaivojen voimakkuuden maksimiarvo oli suurempi tavallisella ruisleivällä (p=0,034). SmartPill®-kapselilla mitatut läpikulkuajat, pH, paine ja supistuksien määrä eivät eronneet koejaksojen välillä. Vatsaoireiden yhteenlaskettu voimakkuus oli positiivisesti yhteydessä paksusuolen keskipaineeseen toisella koejaksolla (ρ=0,786, p=0,036). Vatsaoireiden voimakkuuden ja uloshengitysilman vetypitoisuuden välillä ei havaittu yhteyttä. Johtopäätökset: Ruisleivän FODMAP-hiilihydraattien määrä saattaa vaikuttaa paksusuolessa tapahtuvaan mikrobifermentaatioon, joka lisää vetykaasun muodostumista suolistossa. Lisääntynyt kaasun määrä suolessa voi aiheuttaa ilmavaivoja ja nostaa paksusuolen painetta, mikä saattaa aiheuttaa myös muita vatsaoireita. Vähemmän fermentoituvia hiilihydraatteja sisältävä ruisleipä voi auttaa hillitsemään kaasun tuotantoa ja siihen liittyviä oireita IBS-potilailla, jotka saavat vatsaoireita tavallisesta ruisleivästä. SmartPill®-kapselin soveltuvuudesta vatsaoireiden mittausmenetelmäksi tarvitaan huomattavasti enemmän tutkimustietoa.
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(2011)The literature review focused on the composition of oats along with wheat-free oat baking technology. Enzyme active baking and rye malt utilization in low gluten baking was also reviewed. In the experimental part the effect of an extract prepared from rye malt sourdough on dough viscosity and oat bread quality was studied in order to develop technology to good quality rye flavored oat bread. Rye malt flour of high enzyme activity was used to prepare a sourdough enabling degradation of rye prolamins, harmful to celiac patients. Rye malt extract was prepared from the sourdough by centrifugation. Part of the extract was heated for enzyme inactivation to compare the effects of the enzyme active and inactive extracts on oat dough and bread. The extract was used for baking 15, 25 and 30 % (dough weight) by reducing water. Miniature size breads (20 g) were baked in small pans. Dough viscosity was measured to show partial hydrolyzation of beta-glucan due to enzyme activity. Rye flavor was measured with the help of trained jury. Rye malt extract decreased dough pH approximately from 5.8 to 4.4 and increased the titratable acidity. The dough was less viscous when using enzyme active extract and more viscous when using the inactivated extract. The rye malt extract increased bread firmness and flavor and aroma were improved. Also the pores in the crumb were smaller and more evenly distributed. The inactivated extract increased bread crumbliness. The results suggest that the production of good quality rye flavored oat bread is technologically possible when using an enzyme active extract. This can possibly be explained by the low pH inhibiting the amylases together with high gelatinization temperature of oat starch. During fermentation, the pH of the rye malt sourdough drops so low that it inhibits the excessive ?-amylase activity in the dough so that excessive starch hydrolysation cannot occur. Therefore the use of the rye malt extract in baking process is possible without inactivation. Sourdough fermentation as part of gluten-free baking can improve bread color, aroma, flavor and texture. Also, the addition of rye malt extract improved mold-free time by lowering the pH. It seems that with the help of this technology it is possible to add long yearned rye flavor to low gluten oat bread. Based on earlier results it was concluded that it is possible to achieve bread prolamin content of 63.5 mg/kg. However, it should be possible to obtain even better results with the help of further development.
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