Skip to main content
Login | Suomeksi | På svenska | In English

Master's theses

Collections

Recent Submissions

  • Anopheles maculipennis-kompleksi (Diptera Culicidae) Suomessa : Lajien levinneisyys sekä lajien munamorfologian SEM kuvaus 
    Korvenkontio, Pekka (2024)
    Työssä kuvataan eri puolilta Suomea toukokuussa 1976 eläinsuojista kerättyjen talvehtineiden hibernaatiossa olleiden naaraiden insektaariossa munimien munien morfologiaa. Valomikroskoopilla munista määritettiin yläpinnan kirjailu, mitattiin munan kokonaispituus, yläpinnan leveys,kellukkeiden pituus sekä laskettiin kellukkeiden kaarien määrä. Munan yläpinnan kirjailuun ja yläpinnan leveyden - munan kokonaispituuden väliseen suhteeseen perustuvien määritysten avulla aineistosta oli todettavissa kaksi lajia: Anopheles messeae messeae Falleroni sekä Anopheles beklemishevi beklemishevi Stegnii & Kabanova. A. b. beklemishevi määritetään Suomesta ensimmäistä kertaa. SEM- ja TEM-kuvauksissa tutkitaan Hintonin (1968) mainitsemia piirteitä, joiden hän katsoo eroavan eri Anopheles lajeilla. Lajinmäärityksen kannalta SEM-tarkastelu ei ole tarpeellinen, sillä mainittavia eroja ei löytynyt kuin yläpintaa ympäröivän reunuksen ja kellukkeiden liittymäkohdasta. Lisäksi työssä esitetään em. lajien levinneisyys ja vertaillaan saatuja levinneisyyskarttoja vanhoihin malarian levinneisyyttä Suomessa ja muualla Pohjoismaissa käsitteleviin tietoihin.
  • Hyttyslajien (Dipt.Culinae) runsaussuhteista ja aikuistumisesta eräissä Pohjois-Savon lammikoissa 
    Hämeen-Anttila, Riitta (1967)
    -
  • Synthesis of new etrasimod derivatives and evaluation of their antibacterial activity using Caenorhabditis elegans as an infection model 
    Venäläinen Birgitta (2024)
    Antimicrobial resistance (AMR) is a growing global health concern, and the development of new antibacterial agents is crucial to addressing this issue. Commercial antibiotics are not as effective as they used to be to combat infections. Previous studies have demonstrated the promising antimicrobial activity of etrasimod and one of its derivatives, compound 24f, against Gram-positive species. Therefore, as part of this study, we modified the carboxylic acid functional group to produce new derivatives. We synthesized derivatives of etrasimod and 24f, in order to generate a variety of compounds for evaluation of their antimicrobial effectiveness. Furthermore, the study evaluates the compounds' in vitro antibacterial activity and in vivo efficacy using Caenorhabditis elegans worms as an infection model. C. elegans is a widely used model organism in biological research, and it is particularly useful for studying host-pathogen interactions and drug efficacy. In addition, the cytotoxicity on mammalian cells (HeLa) was determined. Compound 18 showed the lowest cytotoxicity level (CC50 = 75.71±14.4 µM) of tested compounds. The antibacterial activity of new etrasimod derivatives was tested against Gram-positive (Staphylococcus aureus, including methicillin-resistant strains (MRSA)) and Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli). The tested compounds showed activity against Gram-positive bacteria but not against any of the Gram-negative strains. Compounds 9 and 18 showed to be the most active compounds, having a minimum inhibitory concentration of 5–6 and 8–10 μM, respectively. Moreover, both compounds showed promising activity in vivo, being able to significantly reduce the bacterial load in infected worms and improve their survival rates in survival experiments. The study provides insights into the development and assessment of potential antibacterial agents, addressing the contemporary challenge of AMR. The study's findings suggest that compounds 9 and 18 could be potential candidates for further development as novel antimicrobial agents.
  • Transducing earthworms with GFP-expressing baculoviruses 
    Pagès Guitart, Mireia (2024)
    In recent years, animals have been recognized as promising next-generation protein production systems. Animal transgenesis has been achieved primarily in insect cells infected by recombinant baculoviruses. Baculovirus Expression Vector Systems (BEVS) transform the DH10Bac strain of Escherichia coli with the shuttle vector to produce recombinant baculovirus carrying the cargo of interest. The cargo includes at least one promoter driving the expression of at least one protein. PGK is a strong promoter that is naturally active in almost all species where it has been tested, including invertebrates like Drosophila. The PiggyBac transposon-based system is a known strategy for genome integration of foreign genes to create transgenic animals. Nevertheless, nobody has used baculoviruses to deliver genes and produce proteins in earthworms nor to create transgenic earthworms. There is also no information on the sequence of any endogenous E. fetida (earthworm) promoter yet. This project aimed to pilot a novel gene delivery method by creating baculoviruses through the BEVS, carrying the PGK promoter and the GFP reporter gene, and to assess the promoter activity in both Sf9 insect cells and E. fetida through evaluation of GFP fluorescence. Another target was to test the fluorescence after the addition to the baculovirus of the PiggyBac-based inverted terminal repeats (ITRs), flanking the PGK-GFP transcriptional unit. The secondary objective was to develop a non-lethal method for live worm imaging. Conventional restriction enzyme cloning was used to create the shuttle vectors, and restriction digest and Sanger Sequencing were used to identify the positive clones. The Bac-to-Bac BEVS was followed to create baculovirus particles carrying the cargo (PGK-GFP and PGK-GFP-ITR), infect Sf9 insect cells and monitor the PGK activity. Prior to in vitro transfection, the bacmid DNA was confirmed by PCR. These baculoviruses were also used to infect E. fetida and monitor the PGK activity in vivo. E. fetida autofluorescence was assessed before infection. PGK resulted in being much weaker in Sf9 than expected. The flanking of the transcriptional unit of GFP with the ITRs improved the GFP expression. 16% ethanol was shown to anaesthetize E. fetida for 10 to 15 minutes safely. Wild-type and starved E. fetida were shown to have very mild autofluorescence in their digestive system and setae. The coelomic fluid was shown to have strong autofluorescence. Thus, its excretion is crucial before imaging GFP. Likely, all the in vivo fluorescence after infection was due to the worm’s autofluorescence. Therefore, PGK and GFP were unlucky choices for E. fetida.
  • The effects of location and year of construction on the floor plan of an apartment 
    Ovaskainen, Osma (2024)
    Abstract Objective The objective of this thesis is to create methods to transform the most accessible digitalized version of an apartment, the floor plan, into a format that can be analyzed by statistical modeling and use the created data to find if there are any spatial or temporal effects in the geometry of apartments floor plans. Methods The first part of the thesis was created using a mix of computer vision image manipulation methods combined with text recognition. The second portion was performed using a oneway ANOVA model. Results With the computer vision portion, we were able to successfully classify a portion of the data, however, there is a lot of room for improvement due to the recognition had a lot of room for improvement. From the created data, we were able to identify some key differences concerning our parameters, location, and year of construction. The analysis however sufferers from a quite limited dataset, where few housing corporations play a large role in the final results, so it would be wise to repeat this experiment with a more comprehensive dataset for more accurate results

Yhteystiedot

HELSINGIN YLIOPISTO