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  • Aalto, Joni (2014)
    Denna avhandling försöker med hjälp av konstruktivism och Howard Gardners multiintelligensteori som inlärningsstrategier redogöra och bestyrka vikten av ändamålsenlig användning av modern teknologi i undervisningen. De nya läroplanerna skall tas i bruk år 2014 och de kommer i en allt större grad att poängtera hur viktigt det är för eleverna att lära sig att använda webbmiljöer som grund för inlärning. Nätet ger eleverna en aktivare roll än de tidigare haft och möjliggör mer interaktivitet i undervisningen. En annan viktig sak som eleverna i framtiden måste behärska är medieläsfärdighet. Idag är informationsflödet som eleverna kommer i kontakt med mer visuellt än tidigare, eftersom elever gärna använder Web 2.0 -tjänster (t.ex. YouTube) som sina primära informationskällor. Att kunna söka, behandla, analysera och producera information har blivit allt viktigare i en teknologisk värld. Skolan och undervisningsmetoderna har inte förändrats i samma takt som teknologin och eleverna får idag inte tillräckliga färdigheter för fortsatta studier eller arbetslivet när de lämnar skolvärlden. För lärarna är situationen också knepig. Lärarstuderande får inte tillräcklig utbildning i tillämpningen av modern teknologi i undervisningen och avsaknaden av pedagogiska modeller gör det svårt för befintliga lärare att integrera modern teknologi i sina lektioner. Det har undersökts att elever har en negativ inställning till fysikundervisningen. De anser att de varken är intresserade, har nytta eller förstår ämnet. Dessutom har de svårt att tillämpa det de lär sig under lektionerna till vardagen. Inom naturvetenskaperna har man med framgång inkluderat simulationer i undervisningen. Dessa har t.o.m. i vissa fall gett bättre inlärningsresultat än traditionella laborationer och demonstrationer. Läraren har även tillgång till videon på nätet som kan illustrera ett fenomen på ett för eleverna underhållande sätt. Med modern teknologi kan man göra fysiken mer illustrativ och tack vare detta möjligen nå bättre inlärningsresultat.
  • Heikkilä, Sampsa (2005)
    Etnografiani tutkii kokemuksen "samankaltaisuutta" erilaisissa sosiaali-historiallisissa olosuhteissa. Editoidun audiovisuaalisen materiaalin käyttöön perustuva systemaattinen tutkimus kartoittaa variabiliteettia, eli "jotenkin" samankaltaisuutta geneerisessä ilmaisukulttuurissa. Performanssiteorian, musiikkikokemuksen ja puheen etnografian metodien ja teorioiden pohjalta tehty työ tulkitsee näistä lähtökohdista käsin musiikillista mediaatiota erilaisissa symbolisissa kommunikaatioprosesseissa. Työn kontribuutio on näiden tutkimusalojen piirissä niin, että sen pohjalta tehtyjä antropologisia väittämiä voidaan hyödyntää esteettisiin konfiguraatioihin perustuvien performanssikulttuurien tutkimuksessa. Havaintojen validiteettia ja relevanssia lisää monipuolinen audiovisuaalisen materiaalin käyttö. Työ pohjautuu n. 5 kuukauden pituiseen kenttätyöhön Sevillan provinssissa Espanjassa. Etnografinen materiaali on flamenco-puheyhteisöistä. Etnografinen metodi hyödyntää haastatteluaineistoja, etnografista video-elokuvaa, sosiaalihistoriallisia dokumentteja sekä antropologista kirjallisuutta. Tutkimusongelma on yleisluonteinen: kuinka tulkita kyseistä informaation paljoutta? Ongelman jäsentämiseksi asetettu hypoteesi olettaa draamallisten muotojen kehityksen mahdollisuuden kokemuksen samankaltaisuudessa. Tutkimuskysymykset ovat näistä kaikista lähtökohdista käsin: Mitkä ovat ilmaisukulttuurin symbolisten kommunikaatioprosessien varioidut muodot ja mitkä niiden funktiot? Mitkä ovat sosiaalihistorian dynamiikan ehdollistamat performanssistruktuuritilanneriippuvaiset "ehdot"? Ongelmat ja kysymykset on tutkittu etnografian metodologian alueella analysoimalla ja tulkitsemalla työn visuaali-antropologinen toteutus. Puheen merkityksellisten tyylien, tyylillisten struktuurien sekä tyylillisten muotojen funktio ja merkitys sosiaalisesti jaettuina prosesseina nousee päällimäiseksi tulkinnaksi kahdella osa alueella. Kulttuurinen subversio ja metaforinen identifikaatio. Kumpaankin osa-alueeseen liittyy symbolisesti tulkitseva yksilö sosiaali-historiallisena agenttina ja aktorina. Osa-alueiden laajempaa tutkimusta ja oman työni rajallisia mahdollisuuksia hahmottaen on työn päätteksi ehdotettu metodologista reduktiota, jolla työn narratiivisesta kokonaisuudesta erottuvia piirteitä voidaan ymmärtää kahdella tavalla 1) ehdollisina "partikulaareina muotoina"; 2) performanssin yleisinä ehtoina. Yleisesti työn merkitys on paikallisessa kulttuurin jatkuvuuden tutkimuksessa ja symbolisten arvojen "taidevälityksessä". Yksilöä painottavan sosiaalitieteen kentässä sen merkitys on genren ja muiden symbolisten muotojen tulkitsevan käytön hahmottamisessa ja ymmärtämisessa.
  • Kärkkäinen, Anna Katarina (2008)
    Denna avhandling behandlar modeindustrin i Finland. Avhandlingens syfte är att undersöka kulturella mellanhänders (cultural intermediaries) roll i smakformningsprocessen inom modeindustrin i Finland samt att utreda vilka metoder och kanaler de använder för att förmedla kunskap om smak och mode. Samtidigt utreds hur de kulturella mellanhänderna själva uppfattar sin roll inom modeindustrin. Materialet i undersökningen består av sju intervjuer med moderedaktörer, designers, butiksägare och stilister. Som utgångspunkt i denna avhandling används Mike Featherstones beskrivning av kulturella mellanhänder som ambassadörer för den postmoderna konsumtionskulturen. De kulturella mellanhänderna arbetar med symbolisk produktion av kulturella produkter och deras roll i smakförmedlingsprocessen och smakbildandet är central i fråga om mode. Speciellt moderedaktörer och butikers inköpare har en stor inflytelse gällande konsumenternas val och smak. De kulturella mellanhänderna har vad Pierre Bourdieu kallar legitim smak som de förmedlar vidare till konsumenterna via bland annat modetidningar. Förutom sin roll som smakförmedlare fungerar de kulturella mellanhänderna som apostlar i en nästan religiös process att skapa ett kollektivt koncept om och en kollektiv tro på mode. Kulturella mellanhänder arbetar inom modefältet som är beläget mellan det konstnärliga fältet och det ekonomiska fältet. Modeindustrin är ytterst hierarkisk och statusskillnaden mellan å ena sidan det konstnärliga designmodet och å andra sidan det ekonomiska massmodet är tydlig. Den empiriska studien visar att de kulturella mellanhänderna legitimerar sin smak genom åtskilliga motiveringar och samtidigt legitimerar de sin position som smakbildare inom modeindustrin. De tar avstånd från konsumenterna som befinner sig på utkanterna av det hierarkiska modefältet och förmedlar den goda smaken vidare i form av ett glädjebudskap av mode.
  • Hekkala, Anna-Mari (Helsingin yliopisto, 2011)
    Congenital long QT syndrome (LQTS) is a familial disorder characterized by ventricular repolarization that makes carriers vulnerable to malignant ventricular tachycardia and sudden cardiac death. The three main subtypes (LQT1, LQT2 and LQT3) constitute 95% of cases. The disorder is characterized by a prolonged QT interval in electrocardiograms (ECG), but a considerable portion are silent carriers presenting normal (QTc < 440 ms) or borderline (QTc < 470 ms) QT interval. Genetic testing is available only for 60-70% of patients. A number of pharmaceutical compounds also affect ventricular repolarization, causing a clinically similar disorder called acquired long QT syndrome. LQTS carriers - who already have impaired ventricular repolarization - are especially vulnerable. In this thesis, asymptomatic genotyped LQTS mutation carriers with non-diagnostic resting ECG were studied. The body surface potential mapping (BSPM) system was utilized for ECG recording, and signals were analyzed with an automated analysis program. QT interval length, and the end part of the T wave, the Tpe interval, was studied during exercise stress testing and an epinephrine bolus test. In the latter, T wave morphology was also analyzed. The effect of cetirizine was studied in LQTS carriers and also with supra- therapeutic dose in healthy volunteers. At rest, LQTS mutation carriers had a slightly longer heart rate adjusted QTc interval than healthy subjects (427 ± 31 ms and 379 ± 26 ms; p<0.001), but significant overlapping existed. LQT2 mutation carriers had a conspicuously long Tpe-interval (113 ± 24 ms; compared to 79 ± 11 ms in LQT1, 81 ± 17 ms in LQT3 and 78 ± 10 ms in controls; p<0.001). In exercise stress tests, LQT1 mutation carriers exhibit a long QT interval at high heart rates and during recovery, whereas LQT2 mutation carriers have a long Tpe interval at the beginning of exercise and at the end of recovery at low heart rates. LQT3 mutation carriers exhibit prominent shortening of both QT and Tpe intervals during exercise. A small epinephrine bolus revealed disturbed repolarization, especially in LQT2 mutation carriers, who developed prolonged Tpe intervals. A higher epinephrine bolus caused abnormal T waves with a different T wave profile in LQTS mutation carriers compared to healthy controls. These effects were seen in LQT3 as well, a group that may easily escape other provocative tests. In the cetirizine test, the QT and Tpe intervals were not prolonged in LQTS mutation carriers or in healthy controls. Subtype-specific findings in exercise test and epinephrine bolus test help to diagnose silent LQTS mutation carriers and to guide subtype-specific treatments. The Tpe interval, which signifies the repolarization process, seems to be a sensitive marker of disturbed repolarization along with the QT interval, which signifies the end of repolarization. This method may be used in studying compounds that are suspected to affect repolarization. Cetirizine did not adversely alter ventricular repolarization and would not be pro-arrhythmic in common LQT1 and LQT2 subtypes when used at its recommended doses.
  • Tengvall, Unni (Helsingin yliopisto, 2013)
    Several serious diseases remain without non-toxic curative treatments. To fill this void, one of the promising groups of medicines is that of oligonucleotides, encompassing aptamers, transcription factor decoys, and antisense therapeutics such as short interfering RNA and splice-correcting oligonucleotides. These short strands of DNA or RNA can bind to specific cellular nucleic acids or proteins and thereby inhibit or correct the function of disease-causing molecules. Extensive enzymatic degradation and poor cellular uptake are the most important obstacles for systemic oligonucleotide therapy. Numerous chemical modifications have been introduced to improve enzymatic stability, but they must be carefully optimized to avoid toxicity and to maintain target affinity. One solution is to design topological modifications, such as looped or circular oligonucleotides, which conserve the natural phosphodiester backbone but cannot be attacked by exonucleases. Cellular uptake has proven to be even more challenging. Oligonucleotides are internalized into cells by endocytosis, after which they often remain trapped in endosomes. Therefore, it would be advantageous to develop delivery vectors capable of bypassing endocytic routes of uptake or enhancing endosomal escape. Cell-penetrating peptides, for example, exploit several mechanisms of uptake, some of which lead to rapid entry without endosomal localization. In addition, encouraging results have been achieved using liposomes, gold nanoparticles, and other nanocarriers, which also shield the oligonucleotide from degrading enzymes. The aim of this work was to improve the in vitro delivery of oligonucleotides by employing chemical modifications and nanoparticle carriers. The synthesis of the compounds, their characterization by various analytical methods, and the evaluation of biological effects are described. Antisense oligonucleotides covalently linked to cell-penetrating peptides via convergent conjugation displayed improved cellular uptake but failed to inhibit reporter genes due to endosomal entrapment in cells. Circular oligonucleotides exhibited enhanced selectivity of mismatch detection and increased stability in biological fluids compared to linear oligonucleotides. Altogether 44 compounds were analyzed by electrospray ionization mass spectrometry and liquid chromatography mass spectrometry, which were found to be excellent methods for the characterization of modified oligonucleotides. Finally, we synthesized cationic gold nanoparticles modified with a Tat-related peptide, which did not adversely affect cell viability and effectively delivered short interfering RNA into cells as non-covalent complex.
  • Määttä, Jenni (Helsingin yliopisto, 2007)
    Modifications of surface materials and their effects on cleanability have important impacts in many fields of activity. In this study the primary aim was to develop radiochemical methods suitable for evaluating cleanability in material research for different environments. Another aim was to investigate the effects of surface modifications on cleanabilitity and surface properties of plastics, ceramics, concrete materials and also their coatings in conditions simulating their typical environments. Several new 51Cr and 14C labelled soils were developed for testing situations. The new radiochemical methods developed were suitable for examining different surface materials and different soil types, providing quantitative information about the amount of soil on surfaces. They also take into account soil soaked into surfaces. The supporting methods colorimetric determination and ATP bioluminescence provided semi-quantitative results. The results from the radiochemical and supporting methods partly correlated with each other. From a material research point of view numerous new materials were evaluated. These included both laboratory-made model materials and commercial products. Increasing the amount of plasticizer decreased the cleanability of poly(vinyl chloride) (PVC) materials. Microstructured surfaces of plastics improved the cleanability of PVC from particle soils, whereas for oil soil microstructuring reduced the cleanability. In the case of glazed ceramic materials, coatings affected the cleanability. The roughness of surfaces correlated with cleanability from particle soils and the cleanability from oil soil correlated with the contact angles. Organic particle soil was removed more efficiently from TiO2-coated ceramic surfaces after UV-radiation than without UV treatment, whereas no effect was observed on the cleanability of oil soil. Coatings improved the cleanability of concrete flooring materials intended for use in animal houses.
  • Matihaldi, Hilkka-Liisa (1971)
  • Meri-Kinisjärvi, Sinikka (1973)
  • Matihaldi, Hilkka-Liisa (1973)
  • Gustafsson, Anna Maria (1990)
  • Hero, Matti (Helsingin yliopisto, 2007)
    Without estrogen action, the fusion of the growth plates is postponed and statural growth continues for an exceptionally long time. Aromatase inhibitors, blockers of estrogen biosynthesis, have therefore emerged as a new potential option for the treatment of children with short stature. We investigated the efficacy of the aromatase inhibitor letrozole in the treatment of boys with idiopathic short stature (ISS) using a randomised, placebo-controlled, double-blind research setting. A total of 30 boys completed the two-year treatment. By decreasing estrogen-mediated central negative feedback, letrozole increased gonadotrophin and testosterone secretion in pubertal boys, whereas the pubertal increase in IGF-I was inhibited. Treatment with letrozole effectively delayed bone maturation and increased predicted adult height by 5.9 cm (P0.001), while placebo had no effect on either parameter. The effect of letrozole treatment on near-final height was studied in another population, in boys with constitutional delay of puberty, who received letrozole (n=9) or placebo (n=8) for one year, in combination with low-dose testosterone for six months during adolescence. The mean near-final height of boys randomised to receive testosterone and letrozole was significantly greater than that of boys who received testosterone and placebo (175.8 vs. 169.1 cm, P=0.04). As regards safety, treatment effects on bone health, lipid metabolism, insulin sensitivity, and body composition were monitored in boys with ISS. During treatment, no differences in bone mass accrual were evident between the treatment groups, as evaluated by dual-energy x-ray absorptiometry measurements of the lumbar spine and femoral neck. Bone turnover and cortical bone growth, however, were affected by letrozole treatment. As indicated by differences in markers of bone resorption (U-INTP) and formation (S-PINP and S-ALP), the long-term rate of bone turnover was lower in letrozole-treated boys, despite their more rapid advancement in puberty. Letrozole stimulated cortical bone growth in those who progressed in puberty: the metacarpal index (MCI), a measure of cortical bone thickness, increased more in letrozole-treated pubertal boys than in placebo-treated pubertal boys (25% vs. 9%, P=0.007). The change in MCI correlated positively with the mean testosterone-to-estradiol ratio. In post-treatment radiographic evaluation of the spine, a high rate of vertebral deformities - mild anterior wedging and mild compression deformities - were found in both placebo and letrozole groups. In pubertal boys with ISS treated with letrozole, stimulated testosterone secretion was associated with a decrease in the percentage of fat mass and in HDL-cholesterol, while LDL-cholesterol and triglycerides remained unchanged. Insulin sensitivity, as evaluated by HOMA-IR, was not significantly affected by the treatment. In summary, treatment with the aromatase inhibitor letrozole effectively delayed bone maturation and increased predicted adult height in boys with ISS. Long-term follow-up data of boys with constitutional delay of puberty, treated with letrozole for one year during adolescence, suggest that the achieved gain in predicted adult height also results in increased adult height. However, until the safety of aromatase inhibitor treatment in children and adolescents is confirmed, such treatment should be considered experimental.
  • Pyöli, Jouko (1975)
  • Vuorela, Marja-Liisa (1980)
  • Sarvamaa, Pirkko (1973)
  • Laurila, Jussi (2013)
    The aim of this thesis was to improve the quality of energy wood and therefore increase the potential of forest energy. About half of the mass of a freshly-felled tree consists of water. From the point of view of energy generation this water is unwelcome. There are two main ways to dry energy wood; these are artificial drying and drying naturally. The Norway spruce (Picea abies L. Karst.) stump wood dries fairly quickly in favourable natural conditions. The average moisture content (wet basis) of a stump was about 31 % one month after stump harvesting. Small-sized whole trees did not dry well at roadside storage sites under natural conditions. About one year after harvesting the moisture content of a small-sized whole tree was still about 43 %. However, during storing a remarkable weight loss of 37 % was detected between the forest and the heating plant. The most effective and the fastest drying method found in this study was the continuous compression drying method. The lowest moisture content of 30 % was achieved for Downy birch (Betula pubescens Ehrh.) by continuous pressing using 38 MPa and with a pressing time of 30 seconds. The energy consumption for compression drying is very low compared to the energy required to vaporise water in thermal drying. The techno-economic forest energy potential of the study area was 1.6 TWh/y. The forest energy potential calculations were made using the heating value of fresh wood and therefore the real potential will be greater when using dried energy wood. For absolutely dry wood the potential was about 1.9 TWh/y. The properties of energy wood vary widely depending on its assortment, storage conditions, as well as the weather conditions and the origin of the energy wood. However, a better understanding of energy wood properties will increase forest energy s potential and the use of renewable energy and thus help mitigate climate change globally.