Kvantitatiivse polümeraasi ahelreaktsiooni modifikatsioonide mõju märklaudgeeni kvantifitseerimisele keskkonnaproovidest bioremediatsiooni hindamisel

Väitekirja elektrooniline versioon ei sisalda publikatsioone.Keskkonna reostumine erinevate saasteainetega (nt. naftasaadused, kloororgaanilised ühendid) on muutunud kriitiliseks probleemiks üle maailma kahjustades inimtervist, kahandades puhta joogivee varusid ning mõjutades terveid ökosüsteeme. Et klassikalised „pumpa-ja-töötle“ saastuse eemaldamise meetodid on töömahukad ja kallid, on viimastel kümnenditel hakatud aina enam otse reostuspaigas rakendama erinevaid bioloogilise tervenduse ehk bioremediatsiooni tehnoloogiaid, mis tuginevad suuresti saasteainete mikroobsele lagundamisele. Toimuvate protsesside käiku ja jätkusuutlikkust vastusena muutuvatele keskkonnatingimustele hinnatakse seejuures enamasti keemiliste ja mikrobioloogiliste parameetrite pikaajalise seire abil. Kvantitatiivne polümeraasi ahelreaktsioon (qPCR) on aina sagedamini kasutust leidev metoodika saasteaineid lagundava mikroobikoosluse esinemise ja arvukuse hindamiseks bioremediatsiooni seirel. QPCR on kiire ja tundlik meetod, mis võimaldab nii taksonoomiliste kui funktsionaalsete märklaudgeenide arvukuse määramist hõimkonna tasemest liigi tasandini. Määratud arvukusi muude seireparameetritega (nt. saasteaine kontsentratsioon) kõrvutades on võimalik hinnata bioremediatsiooniprotsesside efektiivsust ja kulgemist uuritavas kohas. Et märklaudgeenide arvukuse määramise edukus keskkonnaproovidest sõltub mitmetest faktoritest, näiteks mikroobikoosluse DNA eraldamise meetodist ja kvaliteedist, inhibiitorite esinemisest eraldatud DNA-s, qPCR reaktsioonikeemia tüübist, märklaudjärjestuse amplifikatsiooni efektiivsusest ja tulemuste analüüsi kvaliteedist, hindasimegi erinevate qPCR reaktsiooni- ja analüüsiprotsessi modifikatsioonide mõju keskkonnaproovidest märklaudgeeni absoluutse ja suhtelise arvukuse määramisele. Leidsime, et varieeruvused qPCRi töövoos ja analüüsiprotsessis mõjutavad oluliselt märklaudgeeni absoluutse ja suhtelise arvukuse määramist keskkonnaproovidest ning seeläbi ka bioremediatsiooniga rakendamisega seotud otsuseid.The increasingly industrialized global economy that has emerged over the last century has led to dramatically elevated releases of anthropogenic chemicals into the environment impacting whole ecosystems (i.e. the Gulf of Mexico oil spill), drinking water supplies or directly human health. Concurrently with increasing pollution levels, avid interest in developing strategies for remediation of environmental contaminants has emerged. As classic “suck and truck” strategies followed by off-site treatments are expensive, the in situ bioremediation processes like monitored natural attenuation (MNA), biostimulation, bioaugmentation and rhizoremediation have become an attractive way to rehabilitate contaminated sites. These bioremediation techniques rely extensively on the presence of an active microbial degrader population able to transform the bioavailable contaminants into harmless or less dangerous compounds. Bioremediation processes need to be continuously monitored to ensure their efficiency and sustainability. One of the increasingly used methods in bioremediation monitoring is quantitative polymerase chain reaction (qPCR) which enables quantification of the abundance of gene markers within the environment. The quantitative data generated can be used to relate variation in gene abundances with variation in abiotic and biotic factors and process rates. However, target gene quantification results from environmental samples depend on a number of factors such as the method and quality of DNA extraction, the subsequent presence of inhibitory substances in the extracted microbial community DNA, the qPCR chemistry used, the amplification efficiency achieved and the overall quality of the resultant datasets. We evaluated the scope of these aspects affecting gene enumerations by qPCR and found that modifications in qPCR workflow and analysis procedure steps can significantly influence the target gene quantification and normalization results from environmental samples and consequently also bioremediation related decision-making. For environmental monitoring purposes the most suitable method workflow relating to the characteristics of individual experiment conducted should be chosen to ensure the quality and truthfulness of obtained results

Andekate õpilaste diferentseeritud õppe ja õpimotivatsiooni toetamine esimese klassis: projektipõhisele õppele suunatud tegevuskonspektide väljatöötamine ja katsetamine

https://www.ester.ee/record=b5510208*es

A modern assessment of Ordovician chitinozoans from the Shelve and Caradoc areas, Shropshire, and their significance for correlation

New chitinozoan data are presented from the classical section along the Onny River in the type Caradoc area, and from the deeper-water sections in the Shelve area, including the former British candidate GSSP for the base of the Upper Ordovician Series. The rich and well-preserved chitinozoan fauna of the Onny River has been a standard for 40 years, but new data revise some of the identifications. The assemblages are now attributed to biozones that are more readily applicable for international cor relation. The main part of the section can be inter preted as belonging to the originally Baltoscandian Spinachitina cervicornis Biozone, although this is uncertain in the lower part. Within this biozone, the Fungochitina actonica Subzone has been defined. The Onny Formation at the top of the section is equated with the Acanthochitina latebrosa–Ancyrochitina onniensis Biozone; contrary to earlier reports, Acanthochitina barbata is absent. The Lower Wood Brook and Spy Wood Brook section from the Shelve Inlier yielded a great number of moderately to well-preserved chitinozoans, but a low-diversity assemblage. Their ranges have been neatly positioned against the well-known graptolite stratigraphy in the area. A local Eisenackitina rhenana Biozone? has been recognized, allowing us to suggest some international cor relations

Episteemilised partiklid komi keele ižma murdes

https://www.ester.ee/record=b5240821*es

Ütrium- ja skandiumoksiidiga stabiliseeritud tsirkooniumoksiidmikrotorude ioonjuhtivuste mõõtmine

http://www.ester.ee/record=b4610653*es

Mis on filosoofia ja miks seda vaja on? Deleuze'i ja Guattari "Mis on filosoofia?" põhjal

Antud tagasihoidliku uurimuse eesmärgiks ongi esitada Deleuze’i ja Guattari filosoofia mõiste, vaadelda, mis moodi see erineb teadusest, kunstist ning eelkõige loogikast. Ja seejärel näidata, miks filosoofia vajalik on ja kahtlemata selleks ka jääb.http://www.ester.ee/record=b4495782*es

The succession of Hirnantian events based on data from Baltica: brachiopods, chitinozoans, conodonts, and carbon isotopes

The Hirnantian (late Ordovician) environment was complex and dynamic. Understanding the correct order of events and their precise correlation with a time scale are extremely important for the development of different kinds of environmental interpretations. The lower boundary of the Hirnantian Stage is officially defined by “the lowest occurrence of Normalograptus extraordinarius, the base of major positive carbon-13 isotope excursion, and the beginning of a pronounced sea-level fall associated with onset of a major glaciation” (ICS website). Our aim is to check if these events are synchronous, particularly how the situation is with respect to the Baltic. Thus several sections were analysed using mainly East Baltic data (drill cores), but also data from elsewhere, including brachiopod, chitinozoan, and conodont biostratigraphy combined with graptolite and carbon isotope data. Brachiopod faunas of the Pirgu and Porkuni stages are rather similar to those of the Ellis Bay Formation of Anticosti Island, Quebec, but the Pirgu assemblage, as well as that of the lower Ellis Bay Fm. lack key elements of the Hirnantian faunas. The primary criterion quoted above is stable, but auxiliary data like the isotope curve are less convincing. When the latter is used, it should be specified, e.g. that the carbon isotope excursion begins usually slightly earlier (in the Diceratograptus mirus Biozone), but it might be conventionally placed into the N. extraordinarius Biozone when a biostratigraphical proxy is available. The peak of the excursion is in the lower N. persculptus Biozone, but the main increase in values takes place in the N. extraordinarius Biozone. The Spinachitina taugourdeaui Biozone marks at many localities the bottom of the Hirnantian, and only the recent chitinozoan–graptolite data from the topmost Lousy Cove Member (on Anticosti Island) suggest a mid-Hirnantian age, which is at variance with common correlation schemes

Latest Sandbian brachiopods and chitinozoan biostratigraphy in North Estonia

The latest Sandbian brachiopods and chitinozoans were studied in the Kõrgessaare and Haapsalu drill cores of Estonia. The brachiopod fauna shows a gradual renewal through the Keila Regional Stage (RS), differently from the rather persistent association of chitinozoans. An exception is the uppermost part of the stage, which differs in two sections in the taxonomic composition of chitinozoans and the occurrence of two species-level taxa of the Dalmanella kegelensis brachiopod group. D. kegelensis sensu lato has been considered an index taxon of the biozone in the Keila RS. It links the brachiopod faunas of North Estonia to those in NW Russia. In the latter region, the dolomitic and siliciclastic lagoonal and peritidal deposits overlying the strata with brachiopods of the D. kegelensis group are considered the youngest part of the Keila RS