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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.

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.

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.

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.

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.

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.

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.

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.

Acrylamide is a small molecular compound, which has been labeled as a probable carcinogen in humans. Acrylamide cannot be found natively in food raw material. It is formed when a carbohydrate and protein rich matrix is heated in temperatures above 120 °C. Foodstuff with high risk of containing higher levels of acrylamide are bread and bakery products, potato based foods and coffee. The most critical parameters for the formation of acrylamide are process temperature, the duration of the heating and moisture of the food matrix. A dry matrix, heated in high temperatures for longer periods gives high concentrations of acrylamide. The European Commission has given an opinion on the indicative values of acrylamide content in various foodstuffs. The indicative values are not safety limits for intake, but meant to indicate the need for action. The literature review of this thesis focused on the chemical properties of acrylamide and factors impacting the formation. The occurrence of acrylamide in food and means of mitigation were also reviewed. In the experimental part of this thesis the acrylamide content of rye bread and mämmi were studied. The effect of toasting on the acrylamide content of the rye bread was also studied. The formation of acrylamide during toasting was explained by measurement of moisture and amino acid content of the bread. The samples used in the experimental toasting study were four commercially available sliced rye breads with a wheat toast as reference material. All breads were toasted 0 – 210 seconds in a regular toaster. Method of acrylamide analysis was high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). The acrylamide content varied between the untoasted rye breads, 50 – 350 µg/kg. With the longest toasting time the content rose to 50 – 830 µg/kg. In the European Commission indicative values there is no equivalent to the rye bread. The closest product group is rye crisps, with and indicative value of 450 µg/kg. All the studied untoasted rye bread acrylamide contents fall below this value. When toasted, only one of the rye breads exceeded the indicative values with the longer frying times. The regular toast had levels between 0 and 210 µg/kg respectively. The commission indicative value for wheat based bread is 80 µg/kg was exceeded only with longer toasting times. The mämmi contained 100 µg/kg of acrylamide. For mämmi there are no indicative values.

Suomessa mallintaminen on ollut keskeinen osa metsänarviointia, koska kaikkea ei ole ollut kustannustehokasta mitata. Malleilla on kuvattu tunnuksia, jotka kiinnostavat esimerkiksi metsän rahallisen arvottamisen, käyttöarvon, kasvun tai tuotoksen näkökulmasta. Runkokäyrä- ja tilavuusmallit ovat historiallisessa mielessä olleet metsätaloudellisesti hyvin tärkeät, koska puun arvottaminen edellyttää puun mittaamista kuutioissa ja toisaalta käyttöarvon näkökulmasta puun jakamista tukki- ja kuituositteeseen. Laasasenahon (1982) laatimia runkokäyrä- ja tilavuusmalleja voidaan pitää näistä malleista hyvästä syystä merkittävimpinä. Vaikka kyseisten mallien laadintahetkestä on kulunut jo lähes 40 vuotta, ovat ne edelleen käytössä metsäalalla niin tutkimuksessa, käytännön metsäsuunnittelussa, Valtakunnan metsien inventoinneissa, metsäsuunnitteluohjelmistoissa ja hakkuukoneen apteerausalgoritmeissa. Mallien pohjalla on tuhansien koepuiden runkoanalyysiaineisto, jota on käytetty mallien sovittamiseen kolmelle metsätaloudellisesti tärkeimmälle puulajille: männylle, kuuselle ja koivulle. Runkoanalyysissä puut kaadetaan ja rungot mitataan pituuden ja runkokäyrän osalta. 2010-luvulla on tehty suuria edistysaskelia laserkeilaustutkimuksessa ja tuoreimpien tutkimusten perusteella on havaittu maastolaserkeilauksen tarjoavan varteenotettavan vaihtoehdon runkoanalyysin tekemiseen koepuista. Maastolaserkeilauksen etuna on, että mitattavia puita ei tarvitse mittausten suorittamiseksi kaataa. Tämän vuoksi maastolaserkeilauksella voidaan mitata sellaisia puita, joita ei ole ollut mahdollista aikaisemmin mitata, koska puiden kaataminen ei ole ollut mahdollista. Tuoreimpien maastolaserkeilaustutkimusten perusteella runkokäyrän mittaaminen ja sitä kautta runkotilavuuden laskeminen voidaan tehdä suurella tarkkuudella laserkeilauksessa syntyvästä kolmiulotteisesta pistepilvestä. Katupuiden saanti tutkimuskäyttöön on ollut lähes mahdotonta, mikäli se edellyttää puiden kaatamista. Lukumääräisesti Helsingin kaupungin alueella kasvaa noin 30 000 kpl katupuita, joista lähes 50 % on puistolehmuksia (Tilia x europaea), metsälehmuksia (Tilia cordata) ja isolehtilehmuksia (Tilia platyphyllos). Vastikään Helsingin kaupunki julkaisi toimenpidesuunnitelman, jossa pyritään saamaan Helsinki hiilineutraaliksi vuoteen 2030 mennessä. Tässä ohjelmassa puut ja kasvillisuus olivat listattu yhdeksi päästökompensaation lähteeksi hiilineutraalisuuslaskennassa. Puun runko sisältää tyypillisesti ison osan puun maanpäällisestä biomassasta, mutta lehmuksille sen arviointiin ei vielä ole ollut olemassa malleja. Tässä tutkimuksessa tutkittiin maastolaserkeilauksella kerättävän pistepilven hyödyntämistä Laasasenahon (1982) kehittämien runkokäyrä- ja tilavuusmallien uudelleen sovittamisessa Helsingin katulehmuksille. Aineistoon kerättiin 75 kpl katupuita, joista 36 kpl keilattiin lehdelliseen aikaan kesällä ja 39 kpl lehdettömään aikaan talvella. Jokaisesta koepuusta tehtiin 2 kpl keilauksia vastakkaisilta puolilta puuta ja keskimäärin 50 % etäisyydeltä suhteessa puun pituuteen. Rungot erotettiin pistepilvistä ja niille estimoitiin läpimittoja automaattista runkokäyräalgoritmia käyttäen. Lopulliset runkokäyrät saatiin splini-interpoloinnin avulla. Pistepilvestä mitattuja tunnuksia vertailtiin maastomittausten yhteydessä mitattuihin tunnuksiin. Rinnankorkeusläpimitat onnistuttiin pistepilvestä mittaamaan 2,4 cm (9 %) tarkkuudella (RMSE) harhan ollessa -1,1 cm (-4 %). Koepuiden pituudet onnistuttiin mittaamaan 0,9 (8 %) metrin tarkkuudella (RMSE) harhan ollessa -0,2 metriä (-2 %). Mitattujen läpimittojen lukumäärät olivat lehdettömään aikaan keskimäärin 89 % ja lehdelliseen aikaan 60 % läpimittojen laskennallisesta enimmäismäärästä. Runkokäyrä- ja tilavuusmallit linearisoitiin ja muunnettiin muotoon, jossa mallien sovitus voitiin tehdä pienimmän neliösumman menetelmällä. Mallit sovitettiin erikseen osa-aineistoihin ja koko aineistoon. Tällä haluttiin tutkia ajankohdan, ja toisaalta aineiston koon vaikutusta mallien sovittamisen onnistumiseen. Lehmukselle sovitetun runkokäyrämallin tarkkuudeksi (RMSE) saatiin ristiinvalidoinnilla 71,7 dm3 (17,0 %) ja harhaksi -8,2 dm3 (-1,9 %). Tilavuusmallit validoitiin myös ristiinvalidointia käyttämällä. Rinnankorkeusläpimittaan perustuvan tilavuusmallin tarkkuudeksi saatiin 102,6 dm3 (23,2 %) (RMSE) harhaksi 2,6 dm3 (0,6 %). Rinnankorkeusläpimittaan ja pituuteen perustuvan mallin tarkkuus oli 70,1 dm3 (16,7 %) harha -0,4 dm3 (-0,1%). Rinnankorkeusläpimittaan, pituuteen ja yläläpimittaan perustuvan malli oli tarkkuudeltaan 31,5 dm3 (7,5 %) harha -0,1 dm3 (0,0 %). Tilavuusmallien keskivirheet olivat: 23,4 %, 16,8 %, 7,5 %. Tutkimuksen tulosten perusteella ei havaittu keilausajankohdalla tai aineiston koolla olevan merkittävää vaikutusta mallien hyvyyteen. Rungolta mitattujen läpimittojen osalta keilausajankohdalla havaittiin olevan olennainen vaikutus läpimittaestimaattien määrään, joka oli selvästi suurempi lehdettömään aikaan.