129 research outputs found
Identification of Cannabinoid Acids and Neutrals in Consumer Products via GC-EI-MS
The cannabis plant (Cannabis Sativa L., aka hemp) produces a variety of compounds covering numerous chemical classes such as cannabinoids, terpenes, and terpenoids. Cannabinoids (acidic and neutral) are responsible for producing psychoactive and other pharmacological effects. In the first stage of this project, cannabinoid acids were studied due to their ability to bind to the spike protein of the COVID-19 virus and thus inhibit cell entry, replication, and infection. In this second phase, we expanded the number and types of consumer products studied. We applied our methodology to analyze three new consumer products in several matrices containing various combinations of CBD, CBDA, and CBGA. Since the cannabinoid acids are prone to decarboxylate at elevated temperatures and revert to their neutral counterparts (ex. CBDA to CBD), they are found formulated mainly into non-smokable consumer products. The elevated temperatures used in GC-EI-MS analysis necessitated the addition of protective functionality to active –OH groups via derivatization. This methodology proved to be effective at preventing decarboxylation and allowed the acids to survive the analysis. We also investigated the use of a new derivatizing reagent (MSTFA vs. BSTFA)
Causes and consequences of soil bacterial rarity
In the highly diverse community of soil bacteria most species occur at extremely low numbers and are consequently called the “rare biosphere”. In this thesis I studied why these species are rare whereas others are common. I found that many rare bacterial species can grow rapidly and are doing well in competition, but that rare species could be more vulnerable to predation. This might account for their rarity in soil. Still growth, competitiveness and predation resistance differed greatly between rare species. In addition, I tested if rare soil bacterial species can protect plants from insect attack by stimulating resistance mechanisms in the plant. However, there was no effect of rare bacteria on plant resistance. Rather plant response varied with different bacterial communities regardless of whether rare species were present or not. Overall, my thesis demonstrates that there are likely no general causes of bacterial rarity or general consequences for plant health.</p
Where less may be more: how the rare biosphere pulls ecosystems strings
Rare species are increasingly recognized as crucial, yet vulnerable components of Earth’s ecosystems. This is also true for microbial communities, which are typically composed of a high number of relatively rare species. Recent studies have demonstrated that rare species can have an over-proportional role in biogeochemical cycles and may be a hidden driver of microbiome function. In this review, we provide an ecological overview of the rare microbial biosphere, including causes of rarity and the impacts of rare species on ecosystem functioning. We discuss how rare species can have a preponderant role for local biodiversity and species turnover with rarity potentially bound to phylogenetically conserved features. Rare microbes may therefore be overlooked keystone species regulating the functioning of host-associated, terrestrial and aquatic environments. We conclude this review with recommendations to guide scientists interested in investigating this rapidly emerging research area
An unfolding signifier: London's Baltic Exchange in Tallinn
In the summer of 2007 an unusual cargo arrived at Muuga and Paldiski harbors outside Tallinn. It consisted of nearly 50 containers holding over 1,000 tons of building material ranging from marble columns, staircases and fireplaces, to sculpted allegorical figures, wooden paneling and old-fashioned telephone booths. They were once part of the Baltic Exchange in the City of London. Soon they will become facets of the landscape of Tallinn. The following article charts this remarkable story and deploys this fragmented monument to analyze three issues relating to the Estonian capital: the relocation of the ‘Bronze Soldier’, the demolition of the Sakala Culture Center, and Tallinn’s future role as European Cultural Capital in 2011
Eesti üldhariduskoolide õpetajate valmidus meedia õpetamiseks läbiva teemana
In February 2002, The National Secondary Education Curriculum was adopted by the
Estonian Government, which declares media education as one of the disciplines
implemented in the cross-curricular principle, starting from this year. The aim of the
present Master Thesis is to find out the readiness of Estonian teachers to implement
media education across the curriculum.
The theoretical view-point, implemented in the Thesis, is the critical-constructivist
approach to media education. The aim of the mentioned approach is to teach media,
promoting methods of active learning in order to develop critical media literacy of the
students.
Critical media literacy contains raising motivated and competent members of citizen
society, besides developing criticism and awareness towards information presented by
media, as well as finding information in the media channels and using data to achieve
one‘s aims.
In order to find out the readiness of media teachers, the criteria of media teaching by
Sirkku Kotilainen were taken as the basis; the questions of the Master Thesis
developed from them.
The readiness of media teachers was researched in the Thesis by the formal
questionnaire, 252 teachers from different regions of Estonia took part of it. The other
method used was semistructured qualitative in-depth interviews with 20 teachers of
general education schools.
As the result, it is concluded in the Thesis that teachers in Estonian general education
schools are not ready to teach media. The preconditions for teaching media, media usage of the teachers and notion of media usage and media literacy of the pupils, are
fulfilled. Approximately half of the teachers are well enough aware of the need and
opportunities of teaching media in order to do so, they are ready to use active
constructivist teaching methods and assess their readiness to teach media adequatly.
The biggest obstacle is the insufficient media literacy of the teachers.
Taking into account poor preparation of the teachers, it is clear that the media
education cannot be implemented as an across-curriculum discipline without
developing co-operation of teachers, pupils, parents and media experts. Advanced
training courses must be developed for the teachers, support persons and educational
materials must be available.http://tartu.ester.ee/record=b1667355~S1*es
Lojaalsusprogrammi mõju klientide lojaalsusele OÜ Biomarket näitel
http://www.ester.ee/record=b4632505*es
Eesti kolmanda sektori organisatsioonide suhtekorraldus Säästva Renoveerimise Infokeskuse näitel
Non-profit organizations have a leading role in a democratic society: without their
contribution a strong civil society cannot be formed.
The present bachelor thesis “Estonian third-sector organizations´ public relations:
Sustainable Renovation Information Center example” gives overview about the public
relations in Estonian non-profit organizations and foundations.
The mutual relations of organization and its stakeholders are described in depth on the
sample organization (Sustainable Renovation Information Centre).
The theoretical part of the thesis is based on the stakeholders approach. The third-sector
approaches are also being introduced. According to the stakeholders approach
organization has to understand the world of stakeholders and plan its actions accordingly,
otherwise the organization cannot be successful.
In order to get the answers to the research questions the questionnaire was implemented
among the Estonian third-sector organizations. Additionally, qualitative semi-structured
interviews were carried through with the members of Sustainable Renovation Information
Centre and with the representatives from the stakeholders.
The main finding of the thesis is that public relations in Estonian third-sector
organizations is generally insufficient.
On the basis of research findings the model was formulated for describing the relations
between Estonian third-sector organizations and their stakeholders.
Public relations are usually managed by CEO. Different means of communications are
used as a channel for public relations. Organizations have lots of cooperative relations, however, considering the opinion of stakeholders is irregular. Public relations are planned
randomly, partly because of the lack of time, money and knowledge.
Stakeholders have great expectations towards the organizations, they estimate the growth
potential of the non-profit organizations to be comparatively high.http://tartu.ester.ee/record=b1737533~S1*es
Kohverteater -mitmekülgne metoodiline õppevahend I kooliastme õpilastele ja õpetajatele erinevate õppemeetodite, lõimingu ja draamaõppe läbiviimiseks
https://www.ester.ee/record=b5359412*es
Andres Ehini sürrealistliku luule kujunemine ja lähtekohad
Selle töö eesmärk on anda ülevaade ja analüüsida Ehini varasema perioodi loomingut,
käsitledes teda kui üht vähestest eesti sürrealistlikest luuletajatest ning vaadeldes just selle
perioodi loomingut kui algtuuma, kust kogu edasine looming välja arenes, kuid samas ka
perioodi, kus autori isiklik stiil kujunes selgelt välja. Ehini luule põhineb algusest peale
fragmentaarsel ja kujundikesksel lähenemisel, mis ühendab loomulikku ja ebaloomulikku.
See vastandite ühendamine seob Ehini sürrealistidega, sõnulseletamatu edasiandmine
annab aga tema luulele igavikulise ja avara tasandi.
Töö koosneb neljast peatükist: esimene peatükk annab ülevaate sürrealismi kujunemisloost
ja selle põhiprintsiipidest, teine peatükk räägib lühidalt Ehini luuleloomingust käsitletaval
perioodil. Kolmandas peatükis seostan Ehinit sürrealismiteooriaga, annan ülevaate tema
enda esseest ''Kujund ja meeled'' (1966) ning tema luulekeele peamistest eripäradest.
Neljas peatükk hõlmab sisulist analüüsi, kus käsitlen kolme luulekogu: esikkogu
''Hunditamm'' (1968), ''Uks lagendikul'' (1971) ning samal perioodil kirjutatud luuletused
kogust ''Tumedusi rüübatan'' (1988). Toon neist välja mõned kõnekamad tekstid, mis
illustreerivad kolmandas peatükis viidatud lähtekohti
Recommended from our members
Ectomycorrhizal fungal communities and their functional traits mediate plant–soil interactions in trace element contaminated soils
There is an increasing consensus that microbial communities have an important role in mediating ecosystem processes. Trait-based ecology predicts that the impact of the microbial communities on ecosystem functions will be mediated by the expression of their traits at community level. The link between the response of microbial community traits to environmental conditions and its effect on plant functioning is a gap in most current microbial ecology studies. In this study, we analyzed functional traits of ectomycorrhizal fungal species in order to understand the importance of their community assembly for the soil–plant relationships in holm oak trees (Quercus ilex subsp. ballota) growing in a gradient of exposure to anthropogenic trace element (TE) contamination after a metalliferous tailings spill. Particularly, we addressed how the ectomycorrhizal composition and morphological traits at community level mediate plant response to TE contamination and its capacity for phytoremediation. Ectomycorrhizal fungal taxonomy and functional diversity explained a high proportion of variance of tree functional traits, both in roots and leaves. Trees where ectomycorrhizal fungal communities were dominated by the abundant taxa Hebeloma cavipes and Thelephora terrestris showed a conservative root economics spectrum, while trees colonized by rare taxa presented a resource acquisition strategy. Conservative roots presented ectomycorrhizal functional traits characterized by high rhizomorphs formation and low melanization which may be driven by resource limitation. Soil-to-root transfer of TEs was explained substantially by the ectomycorrhizal fungal species composition, with the highest transfer found in trees whose roots were colonized by Hebeloma cavipes. Leaf phosphorus was related to ectomycorrhizal species composition, specifically higher leaf phosphorus was related to the root colonization by Thelephora terrestris. These findings support that ectomycorrhizal fungal community composition and their functional traits mediate plant performance in metal-contaminated soils, and have a high influence on plant capacity for phytoremediation of contaminants. The study also corroborates the overall effects of ectomycorrhizal fungi on ecosystem functioning through their mediation over the plant economics spectrum
- …
