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EMU DSpace – Eesti Maaülikooli digitaalarhiiv

Digitaalarhiiv EMU DSpace kogub, säilitab ja loob ligipääsu Eesti Maaülikooli liikmeskonna poolt loodud või Eesti Maaülikooli vastutusvaldkondadega seotud teadustöödele toetamaks maaülikooli konkurentsivõimet ja teadmistepõhist ühiskonna arengut. Digitaalarhiivi haldab Eesti Maaülikooli raamatukogu.
 

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Kirje
Proteome profile of bovine uterine extracellular vesicles during the oestrous cycle and in endometritis
(Estonian University of Life Sciences, 2024) Piibor, Johanna; Valdmann, Andres (advisor); Institute of Veterinary Medicine and Animal Sciences; Forde, Niamh (opponent)
Uterine fluid (UF) provides a microenvironment for the growth and survival of pre-implantation embryos and facilitates embryo-maternal communication. While effective communication and nurturing of pre-implantation embryos via UF contribute to improved embryonic implantation and development, the disrupted or suboptimal conditions can lead to implantation failure and pregnancy loss. Recent studies have revealed the role of extracellular vesicles (EVs) in cell-to-cell communication. EVs are lipid membrane-bound nanoparticles containing a range of biomolecules, which when transferred from one cell to another can influence the state of another cell. Several postpartum reproductive inflammatory diseases have been documented, with endometritis emerging as the primary long-lasting fertility-affecting ailment. Postpartum endometritis in dairy cattle refers to inflammation of the endometrium that occurs three weeks or more after parturition, exhibiting no systemic signs of illness. We studied the bovine UF-EV profiles in healthy cows and those with endometritis. We found that UF-EV concentration, size and proteomic profile show clear differences between follicular and luteal phases in naturally cyclic, the days of the oestrous cycle in synchronized cows and cows with clinical (CLE) and subclinical endometritis (SE). Moreover, supplementing UF-EVs from cows with CLE or SE to embryo cultures in vitro had determinantal impact on blastocyst rates and/or quality compared to UF-EVs from healthy cows. Our study identified HTRA1 as potential biomarker for SE. Future investigations building upon the insights gained from this thesis could potentially address challenges with diagnosing SE and improve in vitro fertilization technologies (e.g., increase blastocyst rates, improve embryo quality) making it more feasible to use in farms.
Kirje
Delayed storm and salvage logging effects on forest vegetation recovery and development
(Estonian University of Life Sciences, 2024) Palm-Hellenurm, Kristiina; Vodde, Floortje (advisor); Jõgiste, Kalev (advisor); Tullus, Tea (advisor); Institute of Forestry and Engineering; Hedwall, Per-Ola (opponent)
The doctoral thesis examined the diversity and composition of understory communities in permanent sample plots established in hemiboreal spruce-hardwood forests, where storm disturbance occurred approximately 20 years ago. Data were also collected from control areas in forests of a similar type that were unaffected by wind disturbance, as well as from post-storm salvage-logged sample plots. In addition, the main agents and processes influencing the fate of remnant trees (i.e., trees that survived a wind disturbance) were analyzed to provide insights into the temporal stability of these important biological legacies. Light conditions, microsite richness and substrate diversity differed significantly among treatments, whereas salvaged areas exhibited the greatest canopy openness and the lowest levels of microsite richness and substrate diversity. Altogether, 100 herb and dwarf shrub taxa and 108 bryophyte taxa (81 mosses and 27 liverworts) were found in the study plots. Vascular plant and bryophyte communities exhibited contrasting responses due to their differing habitat requirements, life-history strategies, and the resource competition between these two groups. Salvaged stands displayed higher coverage and species richness of herbaceous species compared to uncleared wind-disturbed areas and control plots. Salvaging did not have a detrimental effect on bryophyte species richness compared to reference sites (control plots), but wind-damaged, unharvested areas hosted significantly more diverse bryophyte communities than both control and salvaged plots. The understory assemblages in salvaged plots differed most from those in reference plots, indicating significant changes in species composition and community structure following salvage logging. Moderately damaged study plots displayed the highest variability in terms of species composition compared to other treatments, highlighting the importance of these areas in maintaining beta-diversity at the landscape scale. Temporal stability of wind-disturbed ecosystems can, however, be compromised due to the high susceptibility of the remnant trees to further disturbances. Many species, including several of high conservation value, were found only in unsalvaged storm-affected areas, confirming the positive impact of wind disturbance on biodiversity. At the same time, salvage logging may help prevent future disturbances that could exceed the ecosystem’s resilience threshold, while also reducing timber loss and carbon emissions. Therefore, the selection and implementation of post-disturbance management methods and practices require a comprehensive analysis. The results demonstrated that plant species groups with distinctive life-history traits exhibit different mid-succession responses to wind disturbances and post-windthrow salvaging. Disturbance legacies such as surviving remnant trees, snags, coarse woody debris, and pit-and-mound complexes can promote habitat heterogeneity, enhance biodiversity, and support ecological resilience in post-disturbance forest ecosystems. Thus, it is advisable to retain some biological legacies of wind disturbances – such as pit-and-mound complexes, snags, woody debris, and remnant trees – during salvage operations, as these elements are crucial for maintaining structural diversity and providing essential habitats for various plant species.
Kirje
Guidelines for writing and formatting final theses
(Estonian University of Life Sciences, 2024) Järve, Ina; Külvik, Mart; Laarmann, Diana; Naruskov, Karin; Reinvee, Märt; Roosmaa, Ülle; Talgre, Liina
The present guide has been prepared with the aim of updating and simplifying the requirements for formatting theses at Estonian University of Life Sciences (hereinafter: the university), which were approved by the regulation No. 1-8/45 of the Rector of the Estonian University of Life Sciences on 14.12.2017. The guide regulates the formatting of bachelor's, professional higher education, and master's theses, as well as master's and integrated study program theses at the university. The updated guide is based on the university's practices for formatting written student work; therefore, it does not contain significant changes. Compared to the previous version, the guide's structure has primarily been revised, and more examples have been added, which are now enclosed within a border to distinguish them from the rest of the text. The general requirements for formatting theses are now presented in Appendix 1. The guide continues to be based on the capabilities of the MS Word word processing program. A new topic discussed in the guide is the use of artificial intelligence for generating ideas and examples, but it is emphasised that this does not replace the author's analysis or synthesis in the thesis. The guide has been prepared using the thesis template and also serves as an example of correct formatting. Unless otherwise stated, these requirements should also be followed for other types of written student work, such as course papers, reports, essays, projects, research papers, reports, and business plans. The requirements for selecting a thesis topic, supervision, reviewing, defence, and publication are outlined in the university council's regulation "Requirements and Procedure for the Awarding of Bachelor’s and Master’s Degree". A thesis is an independent academic research work that includes both theoretical and empirical components. Its purpose is to apply, reinforce, and generalise the specialised knowledge and skills acquired during higher education studies, as well as to gain experience in conducting a scientific investigation in the field. Authors: Ina Järve, Mart Külvik, Diana Laarmann, Karin Naruskov, Märt Reinvee, Ülle Roosmaa, Liina Talgre. Design and layout: Märt Reinvee. Content and language editing (Estonian): Helika Mäekivi. Translation: Laura Erik.
Kirje
Impacts of nitrogen fertilization and planting date on the physiology and yield of purple sweet potato at the extreme Northern edge of cultivation
(Estonian University of Life Sciences, 2019) Zekker, Ivar; Kännaste, Astrid; Eremeev, Viacheslav; Kask, Kaia; Meinson, Pille; Nassar, Helina; Mäeorg, Erkki; Runno-Paurson, Eve; Niinemets, Ülo
Global warming causes plant stress and reduces crop productivity. Cultivation of the warmer region crop sweet potato (Ipomoea batatas (L.) Lam) in Northern regions can be an opportunity to benefit from climate warming, but there is little information of how growing season length interacts with agricultural practices such as nitrogen (N) fertilization. We studied the photosynthetic characteristics, biomass accumulation, carbon (C) and N contents of plant organs of the cultivar ´Purple Bud´ in relation to the planting date (the 2nd of May, 10th of May, 20th of May, 30th of May and 10th of June) and N fertilization (kg ha-1; N0, N50, N100 and N150). Nitrogen content of leaves (NL) and tubers (NT) increased with N application dose and was moderately affected by planting time. Despite the fertilization-dependent increase of leaf N content, photosynthesis rate (A) was unaffected or somewhat reduced by N fertilization. This reflected reductions in stomatal conductance (gs) and ratio of intercellular CO2 to ambient CO2 (Ci/Ca), suggesting that enhanced N availability and concomitant increase in whole plant area resulted in reduced plant water availability. The highest tuber C/N ratio, tuber biomass and dry matter content of roots were found in N0 and N50 plants from the longest growing period. Our results collectively demonstrate that the growth and productivity of sweet potato is strongly dependent on the length of the growing season, and can be further constrained by utilization efficiency of N. We conclude that future research should focus on optimum sweet potato cultivation technologies at Northern latitudes.
Kirje
Eesti aasta 2024 mullaks valitud leostunud gleimulla tutvustus
(Eesti Maaülikool, 2024) Kõlli, Raimo; Tõnutare, Tõnu
The name of Estonian year 2024 soil by Estonian soil classification is the Leached gley soil, but by the WRB system Mollic Gleysol. By its properties the Leached gley soil belongs to the permanently wet with calcareous subsoil mineral soils group. The typical its profile fabric’s formula is (O)–AT–BwG–CG. On natural areas these soils’ humus covers (or humipedons) belong by the local classification to the wet forest-mull type, on the base of which on drained arable areas mostly the humus covers with eutrophic raw humuous type were formed. In diminishing order of these soils textures is - loams 44% > sands 22% > loamy sands 17% > clays 17%. The position of Leached gley soils among other soil species is analysed by mean of Estonian normally developed soil matrix. The Leached gley soils form approximately 13% from the total Estonian soil cover and 40% from the total area of wet soils. Most of Leached gley soils with loamy texture were drained and are used in quality of arable lands. Besides the analysis of Leached gley soil profiles’ fabric, humus status and texture, the different chemical-physical properties separately for forest and arable soils are presented. By the comparative analysis of arable and forest soils’ properties and pedo-ecological functioning regularities, the changes happened with land use changes in Leached gley soils are elucidated. It reveals that formed on Leached gley soils’ forests and grasslands plant cover composition depends in great extent from the properties of soils. Consequently in the management of arable Leached gley soils their suitability for agricultural crops should be taken also into account.