Varjutusmuutliku kaksiktähe BD+48 1098 füüsikaliste parameetrite määramine

http://tartu.ester.ee/record=b2693060~S1*es

Krediidiasutuste osaluse sundvõõrandamise põhiseaduspärasus

http://tartu.ester.ee/record=b2610489~S1*es

The potential of Estonian pilgrimage as a cultural heritage holder and as a proponent of cultural heritage tourism

Magistritöö Loodusturismi õppekavalPalverännak on pika ajalooga religioosne ja kultuuriline fenomen. Tänapäeval toimub palverännak ka ilmalikel eesmärkidel ning loodud on ilmalikud palverännuteed potentsiaaliga edendada päranditurismi. Investeeringud kultuuripärandile kasvavad, kuna järjest enam pööratakse tähelepanu mineviku väärtustele. Magistritöö teema on Eesti palverännutee potentsiaal kultuuripärandi hoidjana ja päranditurismi edendajana. Märkimisväärne roll päranditurismi edendamisel on kohalikel kogukondadel, kelle kaasamisel kasvab kultuuripärandi säilitamine ning tutvustamine. 2012. aastal loodud palverännutee Pirita kloostri ja Vastseliina piiskopilinnuse vahel annab läbilõike Eesti kultuurist ja ajaloost, pakkudes kohalikele kogukondadele võimaluse päranditurismi edendamisest saadava tuluga toetada kohaliku piirkonna majanduslikku arengut. Magistritöö eesmärk on hinnata Eesti palverännuteede hetkeolukord kultuuripärandi kontekstis ning võimalusi päranditurismi edendamiseks. Kuna Eesti palverännutee tuntus kasvab nii ilmalike kui ka religioossete palverändurite arvelt, on magistritöös tõstatatud probleemi lahendamiseks oluline määratleda kohalike kogukondade roll ja võimalused päranditurismi edendamiseks kultuuriajaloolistel palverännuteedel. Magistritöö uuringutes kasutab autor kombineeritud meetodit, milleks on intervjuud, küsitlused ning osalusvaatlus. Uuringute analüüs toimus temaatilise analüüsina, kuna tegemist on kvalitatiivsete uuringutega. Kuigi palverännakuid on uuritud traditsiooniliste palverännakute seisukohast, on ilmalikku palverännakut turismi seisukohast siiski vähe uuritud. Käesolevat magistritööd saab kasutada Eesti palverännutee arendamisel ning võtta eeskujuks teiste Euroopa palverännuteede arendamisele.The pilgrimage is a religious and cultural phenomenon with a long history. Today’s pilgrimage is also for secular purposes, and secular pilgrimage routes have been created with the potential to promote cultural heritage tourism. Investments in the cultural heritage are increasing as more and more attention is paid to the values of the past. The theme of the Master’s thesis is the potential of Estonia’s pilgrimage route as cultural heritage holder and as a proponent of cultural heritage tourism. A significant role in the promotion of cultural heritage tourism is in local communities, whose involvement is growing in the preservation and promotion of cultural heritage. In the context of Estonia, the cultural and historical journey is becoming more important. The pilgrimage route, created 2012 between Bridgettine convent and Vastseliina Episcopal Castle, gives an overview of Estonian culture and history, offering local communities the opportunity to benefit from the promotion of cultural heritage tourism to support the economic development of the local area. The aim of the Master’s thesis is to evaluate the current situation of Estonian pilgrimage route in the context of cultural heritage and the possibilities to promote cultural heritage tourism. The results showed that local communities have a will and enterprise in collecting and storing their cultural heritage. On this basis, to inform local people about how they can support pilgrims on their journey. Although pilgrimages as social movements have been investigated from the standpoints of traditional pilgrimages, the secular pilgrimage from a tourist point of view has been poorly studied. Usability for the development of the Estonian pilgrimage route and an example to other European pilgrimage routes

Air temperature and water level inferences from northeastern Lapland (69 degrees N) since the Little Ice Age

Independent Arctic records of temperature and precipitation from the same proxy archives are rare. Nevertheless, they are important for providing detailed information on long-term climate changes and temperature-precipitation relationships in the context of large-scale atmospheric dynamics. Here, we used chironomid and cladoceran fossil assemblages to reconstruct summer air-temperature and water-level changes, during the past 400 years, in a small lake located in Finnish Lapland. Temperatures remained persistently cold over the Little Ice Age (LIA), but increased in the 20th century. After a cooler phase in the 1970s, the climate rapidly warmed to the record-high temperatures of the most recent decades. The lake-level reconstruction suggested persistently wet conditions for the LIA, followed by a dry period between similar to 1910 and 1970 CE, when the lake apparently became almost dry. Since the 1980s, the lake level has returned to a similar position as during the IAA. The temperature development was consistent with earlier records, but a significant local feature was found in the lake-level reconstruction the LIA appears to have been continuously wet, without the generally depicted dry phase during the 18th and 19th centuries. Therefore, the results suggest local precipitation patterns and enforce the concept of spatially divergent LIA conditions.Peer reviewe

Biogeochemical cycling and ecological thresholds in a High Arctic lake (Svalbard)

Lakes are a dominant feature of the Arctic landscape and a focal point of regional and global biogeochemical cycling. We collected a sediment core from a High Arctic Lake in southwestern Svalbard for multiproxy paleolimnological analysis. The aim was to find linkages between the terrestrial and aquatic environments in the context of climate change to understand centennial-long Arctic biogeochemical cycling and environmental dynamics. Two significant thresholds in elemental cycling were found based on sediment physical and biogeochemical proxies that were associated with the end of the cold Little Ice Age and the recent warming. We found major shifts in diatom, chironomid and cladoceran communities and their functionality that coincided with increased summer temperatures since the 1950s. We also discovered paleoecological evidence that point toward expanded bird (Little Auk) colonies in the catchment alongside climate warming. Apparently, climate-driven increase in glacier melt water delivery as well as a prolonged snow- and ice-free period have increased the transport of mineral matter from the catchment, causing significant water turbidity and disappearance of several planktonic diatoms and clear-water chironomids. We also found sedimentary accumulation of microplastic particles following the increase in Little Auk populations suggesting that seabirds potentially act as biovectors for plastic contamination. Our study demonstrates the diverse nature of climate-driven changes in the Arctic lacustrine environment with increased inorganic input from the more exposed catchment, larger nutrient delivery from the increased bird colonies at the surrounding mountain summits and subsequent alterations in aquatic communities.Peer reviewe

Neoglacial lake-ecosystem changes above and below the subarctic Fennoscandian treeline inferred from changes in diatom functional groups

Algal communities act as sensitive indicators of past and present climate effects on northern lakes, but their responses can vary considerably between ecosystems. Functional trait-based approaches may help us better understand the nature of the diverse biotic responses and their underlying ecosystem changes. We explored patterns in diatom (Bacillariophyceae) growth forms and species composition during the Neoglacial in two shallow lakes typical of subarctic regions, including a dark-colored woodland lake and a clear tundra lake. Sediment carbon and nitrogen elemental and isotope biogeochemistry and spectral indices were used to track broadscale changes in lake productivity, the inflow of organic carbon from land, and benthic substratum over the past three millennia. The biogeochemical indices tracked declines in land-lake connectivity as well as lake-water and sediment organic enrichment above and below the subarctic treeline driven by Neoglacial cooling. This broadscale environmental transition was intercepted by periods of elevated primary production associated with transient Neoglacial warm anomalies and, in particular, the twentieth century warming. Although the Neoglacial development of the lakes showed conspicuous similarities, diatom functional and taxonomic responses were not uniform between the lakes pointing to intrinsic differences in the development of benthic habitats and underwater-light regimes. Many of the observed biotic shifts aligned with expectations based on earlier research linking diatom functional traits to changing light and organic levels but the results also point to further research needs, particularly to better differentiate the individual and interactive effects of substratum and light. Despite distinct anthropogenic imprints in the biogeochemical record, the scale of human impact on the lakes' biota has not, as yet, been profound, but the changes are nonetheless clear when compared to the previous three millennia of natural lake development.Peer reviewe

A hidden species becoming visible : biogeography and ecology of Rhynchotalona latens (Cladocera, Anomopoda, Chydoridae)

A long hidden chydorid (Chydoridae, Cladocera) taxon, first found as fossil specimens and recently redefined as Rhynchotalona latens (Sarmaja-Korjonen et al., Hydrobiologia 436: 165-169, 2000) is investigated for its biogeography and ecology. Late Holocene sediment sequence from Lake Sylvilampi, NE Finnish Lapland, and R. latens spatial distribution in relation to limno-climatic attributes in Finland were examined. Principal component analyses of fossil cladoceran communities showed that R. latens is mostly affiliated with Alonella excisa-Alonopsis elongata-Alonella nana species pool. Generalized linear modeling of R. latens responses to limno-climatic variation indicated that it prefers acidic, mesotrophic, humic and shallow lakes with organic sediments in NE Lapland and has a north boreal-subarctic climatic affiliation. At the northern end of its geographical distribution (NE Lapland), it reproduces with abundant gamogenesis under environmental stress. The specialized taxon is a benthic detritivore and scraper and has a Holarctic northern-alpine distribution. It is a glacial relict associated with modern analogs of periglacial aquatic environments, and it occurs in semi-aquatic wetlands, lush lake littorals and clear and cold waters. Examination of chydorids as bioindicators, especially those with restricted niches, allow us to understand biodiversity responses of lake littorals under changing limno-climatic regimes.Peer reviewe

ExoClock Project III: 450 new exoplanet ephemerides from ground and space observations

The ExoClock project has been created with the aim of increasing the efficiency of the Ariel mission. It will achieve this by continuously monitoring and updating the ephemerides of Ariel candidates over an extended period, in order to produce a consistent catalogue of reliable and precise ephemerides. This work presents a homogenous catalogue of updated ephemerides for 450 planets, generated by the integration of $\sim$18000 data points from multiple sources. These sources include observations from ground-based telescopes (ExoClock network and ETD), mid-time values from the literature and light-curves from space telescopes (Kepler/K2 and TESS). With all the above, we manage to collect observations for half of the post-discovery years (median), with data that have a median uncertainty less than one minute. In comparison with literature, the ephemerides generated by the project are more precise and less biased. More than 40\% of the initial literature ephemerides had to be updated to reach the goals of the project, as they were either of low precision or drifting. Moreover, the integrated approach of the project enables both the monitoring of the majority of the Ariel candidates (95\%), and also the identification of missing data. The dedicated ExoClock network effectively supports this task by contributing additional observations when a gap in the data is identified. These results highlight the need for continuous monitoring to increase the observing coverage of the candidate planets. Finally, the extended observing coverage of planets allows us to detect trends (TTVs - Transit Timing Variations) for a sample of 19 planets. All products, data, and codes used in this work are open and accessible to the wider scientific community.Comment: Recommended for publication to ApJS (reviewer's comments implemented). Main body: 13 pages, total: 77 pages, 7 figures, 7 tables. Data available at http://doi.org/10.17605/OSF.IO/P298

ExoClock Project. III. 450 New Exoplanet Ephemerides from Ground and Space Observations

The ExoClock project has been created to increase the efficiency of the Ariel mission. It will achieve this by continuously monitoring and updating the ephemerides of Ariel candidates, in order to produce a consistent catalog of reliable and precise ephemerides. This work presents a homogenous catalog of updated ephemerides for 450 planets, generated by the integration of ∼18,000 data points from multiple sources. These sources include observations from ground-based telescopes (the ExoClock network and the Exoplanet Transit Database), midtime values from the literature, and light curves from space telescopes (Kepler, K2, and TESS). With all the above, we manage to collect observations for half of the postdiscovery years (median), with data that have a median uncertainty less than 1 minute. In comparison with the literature, the ephemerides generated by the project are more precise and less biased. More than 40% of the initial literature ephemerides had to be updated to reach the goals of the project, as they were either of low precision or drifting. Moreover, the integrated approach of the project enables both the monitoring of the majority of the Ariel candidates (95%), and also the identification of missing data. These results highlight the need for continuous monitoring to increase the observing coverage of the candidate planets. Finally, the extended observing coverage of planets allows us to detect trends (transit-timing variations) for a sample of 19 planets. All the products, data, and codes used in this work are open and accessible to the wider scientific community

Touchscreen interfaces for machine control and education

The touchscreen user interface is an inherently dynamic device that is becoming ubiquitous. The touchscreen’s ability to adapt to the user’s needs makes it superior to more traditional haptic devices in many ways. Most touchscreen devices come with a very large array of sensors already included in the package. This gives engineers the means to develop human-machine interfaces that are very intuitive to use. This thesis presents research that was done to develop a best touchscreen interface for driving an industrial crane for novice users. To generalize the research, testing also determined how touchscreen interfaces compare to the traditional joystick in highly dynamic tracking situations using a manual tracking experiment. Three separate operator studies were conducted to investigate touchscreen control of cranes. The data indicates that the touchscreen interfaces are superior to the traditional push-button control pendent and that the layout and function of the graphical user interface on the touchscreen plays a roll in the performance of the human operators. The touchscreen interface also adds great promise for allowing users to navigate through interactive textbooks. Therefore, this thesis also presents developments directed at creating the next generation of engineering textbooks. Nine widgets were developed for an interactive mechanical design textbook that is meant to be delivered via tablet computers. Those widgets help students improve their technical writing abilities, introduce them to tools they can use in product development, as well as give them knowledge in how some dynamical systems behave. In addition two touchscreen applications were developed to aid the judging of a mechanical design competition.M.S