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This paper delves into the integration of artificial intelligence within Estonia’s education system, showcasing the country’s global reputation for digital innovation. Utilising the method of the case study and the method of document analysis, we explore not only the practical outcomes, challenges, and strategies related to the adoption of artificial intelligence in the Estonian education system but also its economic implications. The research highlights artificial intelligence’s potential to lead to cost efficiencies and economic benefits for the education sector. Furthermore, we address the critical issue of fostering artificial intelligence literacy among students, schools, and universities, pinpointing data privacy and ethical considerations as key areas of concern. The strategies implemented by educational institutions to mitigate these challenges and promote a comprehensive understanding of artificial intelligence are also discussed. In conclusion, the paper underscores artificial intelligence’s transformative potential in reshaping education, offering guidance for other nations and academic entities aiming to successfully integrate artificial intelligence-based technologies. Emphasis is placed on the importance of a supportive policy framework and a solid ethical foundation to navigate the complexities of artificial intelligence adoption and ensure responsible use, while also considering the economic impact on the educational ecosystem and the labour market at large.

The Vaivara Deformation Zone (VDZ) in northeastern Estonia was studied with ground-penetrating radar (GPR). While the typical Paleozoic carbonate plateau in northern Estonia is characterized by a subhorizontal continuous reflection pattern in GPR images, the VDZ, located south of the erosional bedrock escarpment, known as the Baltic Klint, frequently contains deformed and tilted limestone blocks, thrusts, and folds. We categorize the structural features seen in the GPR images according to deformation intensity and show their areal distribution. In addition to the VDZ, bedrock segments are deformed in Tõrvajõe village, the Pähklimäed Hills, and Narva town, whereas the distribution and nature of deformations hint at a glaciotectonic origin. The study confirms that GPR is a suitable tool for discovering and interpreting bedrock structures. Auxiliary geological and geophysical techniques are required for outlining of bedrock blocks.

Details of the endolymphatic structures are described for the first time in the headshields of the osteostracan genus Tremataspis from the Silurian of Estonia. Tiny platelets, here termed covering platelets, are located within the openings of the endolymphatic duct. The details of their shapes and arrangements differ among the four studied species. In Tremataspis schmidti Rohon and Tremataspis milleri Patten, the covering platelets are usually arranged in an oval or circular shape around the opening of the endolymphatic duct. These species can have smooth, flat covering platelets at the mouth of an irregularly funnel-shaped aperture in the dorsal shield; the funnel often has a posterior extension. In Tremataspis rohoni Robertson and Tremataspis mammillata Patten, a distinct circular arrangement of platelets does not occur; instead, their funnel was capped with a few (2â3) smooth, flat covering platelets. The funnel of T. milleri sometimes has a long postero-lateral extension, while that of T. mammillata can have a short extension; no extensions of the funnel have been observed in T. schmidti or T. rohoni. The diameter of the pores in the covering platelets is larger than that of the pores in the superficial layer of the headshield and much larger than the diameter of the pores in the porous fields (these are thin perforated bony septa subdividing the sensory canals horizontally into lower and upper parts). In T. milleri, the larger pores are located on the side of the covering platelets that is closer to the body midline. The discovered system of covering platelets possibly functioned as a sieve for allowing in suitable grains of material and preventing material that is too fine or too coarse, or not sufficiently dense, from entering the inner ear.

The composition, diversity and distribution of various groups of organisms in the late Llandovery (Telychian) and early Wenlockian (Sheinwoodian) interval of the Pahapilli 675 and Kõrkküla 863 sections (western Estonia) were studied. Due to the small size, fragmentation and disarticulation of the specimens, the studied paleontological material could, in the major part, be tentatively considered as âbiodetritusâ or âbioclast materialâ occurring in the carbonate and siliciclastic lithologies. The recognized conodont biozonation provides a detailed stratigraphic framework for this study. The brachiopod fauna is represented by two different DicoelosiaâSkenidioides communities, comprising diverse associations of non-brachiopod fauna, whose composition changes over time. Successive associations of trilobites are based on dominating taxa among odontopleurids, encrinurids, calymenids and aulacopleurids. The distribution and taxonomic composition of Silurian echinoderms (cyclocystoids, bothriocidarid echinoids, pisocrinid crinoids) in the East Baltic area are documented for the first time. New data on bryozoans, corals, sponges and other fossils are provided, improving the knowledge of the whole biota of the open shelf and transition to basinal environments. The distribution of faunas is affected by different changes in the ecosystem. The highest diversity was recorded in the Upper Pterospathodus a. amorphognathoides Conodont Zone, before the main faunal turnover caused by the Ireviken Event, which was associated with rapid sea-level fall and climate changes. The faunal recovery started at the early Wenlockian in the second half of the Ireviken Event, above the base of the Lower Kockelella ranuliformisConodont Zone.

The Jõhvi magnetite quartzites (MagQ) occur as subvertical beds with a complicated structural outline in biotite-garnet-cordierite and pyroxene gneisses which in places also contain high concentrations of iron. Drill core study shows that the complex of MagQ and magnetite-rich gneisses may be up to 100 m thick. The MagQ provide a wide range of chemical composition: SiO2 ranges between 40.3 and 60.1 wt%, Al2O3 between 1.7 and 19.7 wt% and total iron between 15 and 45.2 wt%. This study also revealed unusually high manganese contents of 1â6 wt%. The rare earth element (REE) patterns of MagQ and the surrounding gneisses partly overlap. Cutting granitoids form two different REE patterns. Magnetite occurs as anhedral grains elongated along rock fabric, as rounded inclusions in other minerals or as tiny platelets along grain edges and along cleavage planes of amphibole and biotite. Sulphides are present as pyrite, pyrrhotite and other minor sulphide minerals (chalcopyrite, galena and sphalerite). Analysis of the magnetite grains from drill core J-1 shows that classifying Jõhvi magnetites into a certain deposit type is not unambiguous. The garnetâbiotite geothermometer revealed metamorphic temperatures between 650 and 750 ºC. The garnetâbiotiteâplagioclaseâquartz geobarometer yielded the pressure range of 2.9 to 4.9 kbar. However, having in mind that the entire Jõhvi ore complex may be a result of repeated metasomatic events, which have influenced the primary volcanic-sedimentary sequences, the estimate of primary pressureâtemperature conditions might not be a straightforward task. The current understanding of the geological-geochemical correlation hints at geological similarities between the Bergslagen area in Sweden and the Jõhvi Zone in Estonia.

The COVID-19 pandemic has changed the world and imposed restrictions and rules that democratic countries could not have foreseen. The global health and social care system was put under enormous pressure, and preventing it from a total collapse became the primary objective. This paper looks at how the pandemic affected the illicit drug market, people who use drugs and services designed to support and help them. Based on the available studies and administrative statistics from 2019 and 2020, illicit drug use and need for services remained the same despite the pandemic. Services quickly adopted new operating rules and became available for the target group. There is ample evidence that in some cases illicit drug use (e.g. cannabis) even gained in popularity as a coping method for anxiety and stress. The drug supply fell only temporarily due to the COVID-19, to which it quickly adapted through new IT and crypto possibilities (dark web). [ABSTRACT FROM AUTHOR]

Groundwater pumped from the terrigenous Middle Devonian (D2) aquifer system is naturally rich in iron (Fe), making it a challenge to fulfil the requirements for drinking water quality. The total iron (Fetot) concentrations are above the limit value set for drinking water (0.2 mg/L) in 81% of the analysed water samples. The highest Fetot values reach up to 26 mg/L in some locations of southern Estonia. Due to the reducing conditions in the aquifer system, most of the Fetotconcentrations are caused by a high Fe2+ content. Infiltrated aerobic water becomes anaerobic and Fe3+ reducing along a deep flow path, leading to the downgradient increase in dissolved Fe concentrations. In order to study the natural sources of Fe in the Middle Devonian aquifer system, rock samples from the Narva, Aruküla, Burtnieki and Gauja stages were used for chemical analyses and leaching experiments. The whole-rock chemical analyses showed large variation in the Fe2O3 content (1.20â9.91%), whereas the values were higher in aquifer-forming siltstones than in sandstones. The amount of the leached Fe in groundwater is partly controlled by the granulometric composition of terrigenous rocks. The highest leached Fetot (up to 1.7 mg/L) concentrations were detected in the rocks where the share of the sand fraction is over 70%. As a rule, water is abstracted from sandstones having large pores and good groundwater yield, therefore water quality problems could only be solved by installing Fe removal facilities in southern Estonia.

On the basis of detailed SEM-EDS study and computer tomography scanning, the single specimen of the enigmatic Martsaphyton moxi from the Aseri Stage (Darriwilian; Middle Ordovician) of Estonia, was identified as a member of the phylum Cnidaria and subphylum Medusozoa, with unspecified (incertae sedis) class placement. Our results confirm a number of similarities in the morphology and chemical composition with previously described Sphenothallus Hall 1847 and Torellella Holm 1893, also interpreted as cnidarians. All three show tubiculous morphology, lamellar skeleton structure and calcium phosphatic composition. The new species differs from the previously described members in its unique root-like appendages, widened apertural chamber and lack of a laterally thickened skeleton wall. The element analysis revealed an unexpected chemical composition â high content of silica, iron, aluminium, potassium and sodium â of the rock matrix surrounding the specimen, which suggests possible involvement of material of volcanic origin in the sediment.

The Jõhvi magnetic anomaly is situated within the Jõhvi structural zone that is part of the BergslagenâLivonia microcontinent. Drilling in the 1930s and 1960s has revealed a complex of magnetite ore alternating with granites, pegmatites and gneisses. The study presents the results of ground magnetic mapping, measurements of drill core (Jõhvi I and II) petrophysical properties (density, magnetic susceptibility, intensity and inclination of the natural remanent magnetization), modelling of the anomalous magnetic field in the Jõhvi area and frequency domain electromagnetic (FrEM) measurements. The magnetic anomaly is composed of three major peaks named western, eastern and northern anomalies. The maximum amplitude of the western total field anomaly is 19 290 nT, of the eastern anomaly 15 880 nT and of the northern anomaly 8080 nT. The 3-dimensional model along five profiles extends from the basement surface to a depth of 1000 m. The direction of strong remanent magnetization coincides with the dip of the iron ore formation. The strong remanence hints at the significant presence of small (

Coprolites (fossil faeces) constitute a group of soft sediment trace fossils that provide useful palaeoecological and sedimentological information, but have generally low preservational potential. In this paper we report abundant occurrence and high diversity of small faecal pellets preserved inside different shelly fossils from Middle and Upper Ordovician carbonates of the Baltoscandian palaeobasin. The material contains ca 180 body fossils with faecal pellets from 40 localities, corresponding to a range of shallow-marine environments from cool-water carbonate ramp to tropical open shelf settings. Stratigraphically the finds range from the Volkhov to Pirgu regional stages (Dapingian to uppermost Katian). The pellets are elliptical or rod-shaped, 0.1–1.8 mm long and 0.08–0.75 mm in diameter, with the length/diameter ratio ranging from less than 2 to ca 6. They occur in shells of gastropods, bivalves, cephalopods, brachiopods, echinoderms and trilobites and represent two ichnospecies, Coprulus oblongus and Coprulus bacilliformis, and some intermediate forms belonging to the same ichnogenus. Additionally, two compound traces were identified: Tubularina (pellets inside small burrows with circular cross section) and Alcyonidiopsis (pellets inside ribbon-shaped burrows). The pellets were produced when the empty shells were located on the seafloor, or possibly during shallow burial in the oxic zone. The preservation of faecal pellets is due to an interaction of several factors, notably protection by the shells and rapid mineralization. The origin of trace makers remains speculative, but polychaete worms having compatible size and body plan and living representatives who produce similar faecal pellets are among the most likely groups. Possibly organisms with different feeding strategies were involved in producing the faecal pellets. Systematic examination of shelly fossils from selected localities showed that up to about half of the shells may contain pellets, which indicates great abundance and diversity of pellet-producing organisms in the Ordovician Baltoscandian basin. Our material also shows that the trace maker of Arachnostega was not related to the faecal pellets inside the shells.

The taxonomic composition of the acanthodian assemblage of the Karksi outcrop, Estonia, is discussed. Two new species, Rhadinacanthus deltosquamosus n. sp. (Diplacanthiformes, Diplacanthidae) and Ginkgolepis tenericostatus n. sp. (Acanthodiformes, Cheiracanthidae), are described based on isolated scales. A re-description of Nostolepis gaujensis Valiukevičius (Climatiiformes, Climatiidae) scales from this locality is also given. Three diplacanthiform taxa, Diplacanthus sp. cf. D. crassisimus (Duff), Diplacanthus sp. cf. D. tenuistriatus Traquair and Diplacanthiformes indet., are described in open nomenclature.

Conodonts from the type region of the Oandu Regional Stage (Katian, Upper Ordovician) in NE Estonia were studied. Here, the lower boundary of the stage corresponds to a discontinuity surface at the base of the Hirmuse Formation and, in conodont succession, is marked by the disappearance of Semiacontiodus sp. and Besselodus? sp. The most characteristic taxa of the Oandu Stage are Phragmodus undatus, Icriodella cf. superba and Plectodina sp., which are rare or missing below and above this stratigraphic interval in Estonia. The comparison of conodont faunas from North and South Estonia suggests that the strata in North Estonia correspond to the upper part of the Oandu Stage only as identified in sections in South Estonia. However, the position of the lower boundary of the stage in South Estonia is highly problematic. The boundary between the Amorphognathus tvaerensis and A. superbus conodont zones in Estonia lies within the (upper) Oandu Stage.

Magnetic susceptibility (MS), its frequency-dependence and anisotropy of the Middle Ordovician Dapingian and Darriwilian sedimentary sequence from three sites (Uuga, Testepere and Leetse) in the Pakri Peninsula, NW Estonia are analysed in combination with the mineralogical composition. The study is based on 463 cores drilled at intervals of a few centimetres to a maximum of about 1 m. All the samples show low and positive MS, which suggests the presence of small quantities of para- and/or ferromagnetic minerals. The stratigraphic units of the three studied sites have a similar along-section appearance, which provides a base for a composite curve. The relatively higher susceptibilities are carried by secondary Fe–Ti oxides (Toila Formation), goethite ooids (Kandle Formation) and ferrous dolomite (Pae Member), whereas paramagnetic minerals are mostly responsible for the rest of the sequence. Considering the dependence of MS on regressive–transgressive cycles (high/low MS within deposits of regressive/transgressive parts of the cycles, respectively), the MS data do not agree with sedimentologically derived sea-level compilations. The measured changes in MS in the Pakri Peninsula outcrops correlate at certain characteristic levels with those deposited in the deeper part of the palaeobasin (Viki core), indicating that the post-depositional iron mobilization within the sediments took place at least at a regional level. Because of post-depositional reorganization of ferromagnetic carrier minerals, the MS values may, however, not be used as a detrital proxy.

The Kalana quarry in central Estonia is known for its exceptionally well-preserved non-calcified algal and other fossils. The interval with the fossil Konservat Lagerstätte in the Kalana section has previously been tentatively dated as early Aeronian. Recent findings of graptolites now enable more precise dating of these beds. The strata yielding the Lagerstätte are not older than the mid-Aeronian and correspond to the Pribylograptus leptotheca graptolite Biozone. In terms of conodont biostratigraphy they correlate with the middle of the Pranognathus tenuis conodont Biozone. It has also become evident that the uppermost Jõgeva Beds of the Nurmekund Formation, and probably also the uppermost Ikla Member of the Saarde Formation, are younger than previously thought and correlate with the Pribylograptus leptotheca graptolite Biozone. Our data additionally indicate that the conodont genus Aulacognathus had appeared by the mid-Aeronian.

Mobilising fl at owners into renovating residential blocks in post-socialist countries has been a complicated process. Evidence from Estonia shows that the success of collective renewal strategies depends not only on economic issues but also on ways investments are organised and, signifi cantly, the relationship of trust between diff erent actors. The paper aims at conceptualising the issue of institutional trust upon the experience of urban housing renewal in Estonia. It is contended that trust is crucial for the joint decision-making in a block as well as for facilitating negotiations between fl at owners’ associations, local municipalities and market actors. The paper draws on three qualitative studies conducted in Estonia during the 2000s, which allow asserting that trust towards new strategies of housing renewal can be achieved and maintained by ‘best practices’, which by concentrating expert knowledge also denote direct communication between experts and fl at owners. While it is important to raise the residents’ technical knowledgeability, it is indispensable to develop abilities to manage and communicate the renovation process between diff erent parties. The public sector is conceived to be a central actor in sustaining trust between actors who have no previous positive experience from collective residential strategies

The diurnal cycle of precipitation in Estonia during the warm period (from April to October) is analysed separately at continental and coastal stations. The results were obtained using hourly data from the automated gauges at 13 stations in 2003–2013 as well as from the pluviographic records at 10 stations in 1991–2003. The diurnal cycle is approximated using the second-order trigonometric polynomial. A clear diurnal cycle of precipitation with the maximum in the afternoon and evening (13–19 EET – East European Time), and the minimum at night and in the morning (22–11 EET) was revealed at the continental stations of Estonia. The daily amplitude was the highest in summer and much lower in spring and autumn. The highest monthly mean daily amplitudes up to 7 mm were observed in June and July. The diurnal cycle of precipitation was much weaker at the coastal stations without clear maxima and minima and with lower amplitudes. In autumn, the coastal stations showed clearer and bimodal maxima in the early morning and in the evening. The diurnal distribution of precipitation is quite stable, which is confirmed by the high similarity of the curves characterizing these two periods.

Twenty-six samples from two major altered volcanic ash beds, Kinnekulle and BII Bentonite of the Kuressaare core section (K-3), Saaremaa Island, were explored to record the geochemical and mineralogical heterogeneity of beds. Signs of ash transport fractionation, redeposition of volcanic ash and diagenetic redistribution of material are described and interpreted. In authigenic mineralogy of the Kinnekulle Bentonite illite–smectite dominates with addition of K-feldspar at the margins. The BII Bentonite is composed of chlorite–smectite and illite–smectite. The stability of phenocryst compositions, including that of sanidine and biotite, indicates that both bentonites originate from a single eruption. The observed rather stable pyroclastic sanidine compositions in the cross section of bentonites confirm the reliability of sanidine-based fingerprinting of altered volcanic ash beds. Trace element distribution in bentonites and host rocks indicates that Zr, Ga, Rb, Nb, Ti and Th stayed largely immobile during volcanic ash alteration and reflect primary ash composition. However, some redistribution of Nb and Ti as well as Y has probably occurred near the contacts of bentonite with the host rock. More scattered grain size distribution and immobile element patterns of the Kinnekulle Bentonite support the idea that the primary ash bed had a heterogeneous composition and it was one of the biggest bentonites of the Phanerozoic and most likely records an extended volcanic event. Significant geochemical variations, including a high S content, near the upper and lower contacts of the Kinnekulle Bentonite and elevated Ca and P in host rocks of both bentonites suggest that the studied large ash-falls caused notable perturbations in shallow marine and early post-sedimentary environment.

Reefs developed simultaneously during the latest Sandbian/earliest Katian global Guttenberg Isotopic Carbon Excursion (GICE) in several places across Baltoscandia. Latest Sandbian/earliest Katian patch reefs are also described from the Vasalemma Formation of northern Estonia. The Saku Member of the Vasalemma Formation was previously considered as a proximal facies related to the reefs. However, the Saku Member clearly post-dates the GICE interval and ranges from the latest Keila to Rakvere in terms of regional stages. Some small reefs occur in direct proximity to the stratotype of the Saku Member. New δ13C data from the stratotype section and the adjacent reefs indicate that these reefs developed before the deposition of the Saku Member during the GICE interval. The chemostratigraphic data support the hypothesis of a short-time Baltoscandian reef growth event that terminated during the GICE interval.

Climate change scenarios were created for Estonia by employing the SRES (= Special Report on Emission Scenarios) emission scenarios and general circulation model (GCM) outputs used in the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR4) and presented at the IPCC Data Distribution Centre. Control simulations were explored for the estimation of the suitability of different GCMs to describe climatic conditions in Estonia. Comparing the modelled and observed monthly mean temperatures and precipitation during 1961–1990, better-quality GCM outputs were selected for further analysis. Climate change scenarios based on GCMs were created for Estonia for the period 2070–2099. The mean projected increase in air temperature was 3–4 K; it was slightly higher in winter than in summer. All models revealed some warming in all months. The projections of precipitation were more variable. The mean increase in annual precipitation was estimated to be mostly between 10% and 20%. An increase in precipitation was uniformly predicted for the cold season, while a variety of possible changes existed in summer. Some models projected even a decrease in precipitation in July, August and September.

New teeth belonging to Karksiodus mirus Ivanov & Märss (Chondrichthyes) were found together with putative chondrichthyan scales in five new localities of the Leningrad Region, northwestern Russia, within the Aruküla and Burtnieki regional stages, Givetian, Middle Devonian. The teeth exhibit variability in the number of cusps, angles between the lateral cusps, base curvature, length of lateral parts and the prominence of the wall of the transversal basal canal. Karksiodus tooth material collected from these sites suggests that this taxon possesses an heterodont dentition and a specific, complex vascularization system affecting the dental base and the crown. Enameloid tissue seems to be absent, thus the surface striations on the cusps are presumably made up by orthodentine. The fish fauna from these localities is listed.

The ichnogenus Oikobesalon is here described from the Ordovician of Baltica for the first time. All the specimens in this study were found on Osmussaar Island, Estonia. They belong to the ichnospecies Oikobesalon coricaceum. In the Cambrian and Ordovician, Oikobesalon seems to have occurred only in cold to temperate seas. The Oikobesalon trace-maker presumably used its burrow permanently for dwelling and searched for its food through the burrow aperture that likely opened to the sediment–water interface.

The relationships between the frequency and duration of thunderstorms, lightning and southern cyclones over Estonia are presented for the period 1950–2010. A total of 545 southern cyclones and 2106 thunderstorm days were detected, whereas 11.3% of the observed thunder days were associated with southern cyclones. At the same time, 29.2% of all southern cyclones were accompanied by thunderstorms. In the thunder season, however, this percentage was much higher, reaching up to 80% in summer months. The number of thunder days was largest when the centres of southern cyclones passed a measuring station at a distance less than 500 km. The number of cloud-to-ground lightning strikes related to southern cyclones was larger than that of any other thunder events. The results of our study demonstrate that the intensity of thunderstorms related to southern cyclones is higher than that of other thunderstorms. Correlation analysis revealed statistically significant relationships between the frequency of thunder days related to southern cyclones and the frequency of southern cyclones, also between the frequency of thunder days related to southern cyclones and days of other thunder events.

The sedimentary environments, morphology and formation of carbonate cement in the late glacial glaciofluvial outwash and beach deposits in northern Estonia are discussed. Cementation is observed in well-drained, highly porous carbonaceous debris-rich gravel and sand-forming, resistant ledges in otherwise unconsolidated sediments. The cemented units occur as laterally continuous layers or as isolated lenticular patches with thicknesses from a few centimetres to 3 m. The cement is found in two main morphologies: (1) cement crusts or coatings around detrital grains and (2) massive cement almost entirely filling interparticle pores and intraparticle voids. It is exclusively composed of low-Mg calcite with angular equant to slightly elongated rhombohedral and scalenohedral or prismatic crystals, which indicate precipitation from meteoric or connate fresh surface (glacial lake) water and/or near-surface groundwater under low to moderate supersaturation and flow conditions. The absence of organic structures within the cement suggests that cementation is essentially inorganic. The cement exhibits both meteoric vadose and phreatic features and most probably occurred close to the vadose–phreatic interface, where the conditions were transitional and/or fluctuating. Cementation has mainly taken place by CO2-degassing in response to fluctuations in groundwater level and flow conditions, controlled by the Baltic Ice Lake water level, and seasonal cold and/or dry climate conditions.

A gap corresponding to several conodont and chitinozoan zones occurs in the Llandovery–Wenlock boundary interval in some sections in the western coastal region of Estonia and on islands in the Muhu Strait. New data from the Suigu (S-3) core section demonstrate that the gap has geographically wider distribution in western continental Estonia. Detailed study of faunas from that section revealed that here the gap corresponds to at least four conodont zones (from below): the Lower and Upper Pseudooneotodus bicornis and Lower and Upper Pterospathodus pennatus procerus zones, but probably also the upper(most) Upper Pt. amorphognathoides amorphognathoides Subzone and the Lower Kockelella ranuliformis Zone (or part of it) are missing. In sense of chitinozoan biostratigraphy, the gap correlates with most of the Margachitina margaritana Zone. Only the uppermost part of this zone is represented in the section. However, although the gap in the Suigu (S-3) core section is distinct and well dated biostratigraphically, the d13C curve demonstrates no evidence of it. Causes of this controversy are still waiting to be revealed. Our data indicate that changes in sedimentation in the Llandovery–Wenlock boundary interval occurred earlier in the distal graptolite-bearing and later in the proximal environments. Most probably, sedimentation in the Baltic Palaeobasin in the late Telychian and early Sheinwoodian was strongly affected by tectonic evolution of the Baltoscandian foreland basin.

Scanning electron microscopy of untreated and uncoated fracture sections of a secondary shell of a Cambrian (Furongian) linguloid brachiopod Ungula inornata (Mickwitz) in concurrent backscattered electron and secondary electron imaging regimes revealed phosphatized organic fibril-like nanostructures, less than 200 nm in diameter. By analogy with published data on a living lingulate genus Discinisca, the nanofibrils are interpreted as parts of the organic biopolymer matrix, which are composed of axial protein strands of bacula connected by chitin and participate in the formation of baculate sets. The nanofibrils are relevant structural units in the hierarchical structure of lingulate brachiopods with baculate shell structure. It is concluded that these structures are preserved by instant post-mortem precipitation of apatite. The shell structure of U. inornata is most similar to the other species of the genus Ungula Pander and the species of the genus Obolus Eichwald.

The Water Framework Directive (WFD) of the European Union requires the quality of all European water bodies to be examined, and aims to achieve good status by 2015. This study was initiated to assess whether a potential reference lake for identifying lake-type specific reference conditions meets the WFD requirements, of being minimally impacted by human activity during the last centuries. The sediments of Lake Kooraste Kõverjärv were analysed for diatom assemblages and sediment composition; past changes in the lake-water pH and total phosphorus were reconstructed, using quantitative models on sedimentary diatoms. The chronology of sediments was established, using spheroidal fly-ash particles stratigraphy. Palaeolimnological investigations, supported by information from historical maps, revealed that man-made changes around the lake have severely influenced its ecological conditions. The lake, which had been oligotrophic with soft and clear water before the mid-17th century, has been trans­formed into a hard-water lake by modifications to the inflow and outflow. The lake water quality has also been altered by the infiltration of nutrients from a nearby hypertrophic lake that was used for flax retting since the 19th century. Although the ecological status of the lake has remained good despite all these changes, it is still questionable whether to nominate it as a reference lake for stratified hard-water lake types.

A fundamental knowledge of processes that control groundwater composition is required for informed management of water quality. The Voronka groundwater body in northeastern Estonia represents a good example of a complicated, overexploited groundwater system where conceptual understanding of baseline quality and governing hydrogeochemical processes can support sustainable aquifer management. A conceptual understanding or conceptual model is a simplified representation or a working understanding of the real hydrogeological system and its processes. The baseline chemical composition of the Voronka ground­water body was formed during the last glaciations, when glacial meltwater intruded into water-bearing rocks. Two main processes that can change Voronka groundwater body quality at the present day are: (1) seawater intrusion and (2) water exchange between buried valleys and formation’s groundwater. Future monitoring and management should focus on changes in the natural composition of groundwater caused by abstraction. The HCO3–/Cl– value is the best parameter to describe the fluctuations in natural back­ground chemistry in the Voronka groundwater body and to assess significant trends induced by abstraction. In case of the discovered trends, a suite of isotope methods, especially 14C, 3H, δ2H, δ18O and δ13C, can be used to detect whether the intrusion of seawater or exchange of water with buried valleys is taking place.

Research on drinking in Estonia, mainly surveys, indicates that alcohol consumption has increased steadily over the last fifteen years. However, these quantitative studies provide little information about drinking habits and the meanings that are attributed to different consumption patterns. In addition, there is no research that explores how alcohol-related harm is controlled or managed, especially among young people. Current research on alcohol-related harm, primarily from the UK, emphasises calculated hedonism and shows clearly that drinking ‘depends on the context’. Relying on Goffman’s concept of ‘framework’, the aim of the current paper is to analyse or give structure to the ‘context’ by distinguishing the frameworks of drinking time, space and networks that guide young Estonians in their interpretations and perceptions of alcohol related harm, and that also act as a basis for legitimising drinking practices. Differentiating the frames helps to show the dynamics of drinking practices and the interactions in ‘context’. The research is based on open-ended and focus group interviews with young people from rural and urban areas in Estonia and is supported by participant observation in different situations where alcohol is consumed in order to provide a broader view and interpretation on young people’s drinking.

The marine-freshwater environmental transition, i.e. basin isolation from the Limnea Sea, has been identified in two short sediment cores with respect to their diatom composition, loss-on-ignition and magnetic susceptibility content. The isolation level of the basins was dated by accelerator mass spectrometry radiocarbon measurements. The basins are situated on the southern coast of the Gulf of Finland between altitudes 5.5 and 3.9 m above sea level. The Lohja basin became isolated from the sea around 2300 cal yr BP and Käsmu basin around 1800 cal yr BP as a result of glacio-isostatic uplift. The total land upheaval rate that has been 2.6 mm yr –1 since 2500 cal yr BP has currently decreased to 2.0 mm yr –1. We present a GIS-based 3D palaeogeographic reconstruction of the palaeocoastline changes in northern Estonia for two peninsulas, Pärispea and Käsmu, as well as compose a shoreline displacement curve for the study area, which is a compilation of previous and ongoing investigations.

In this short essay, we try to assess the utility of class analyses for understanding the contemporary Estonian society. Erik Wright (2009) identifies three strands of class analysis: a stratification approach, a Weberian approach and a Marxist approach. We address the following questions: Which kind of class analysis is most present in Estonia today? Which is most needed? The main conclusion is that due to this marginalisation of class discourse, as well as the power of national/ethnic discourse and transitional culture, those most economically vulnerable were deprived of the cultural and discursive resources to resist the most the extreme market-oriented policies. The conditions for structuration of class relations were created, while the class and inequality discourse was marginalised.

This article analyses the risk of receiving online sexual messages and experiencing harm among Estonian children. In particular, the paper examines the association between receiving sexual messages and behavioural, psychological and demographic characteristics, and the social mediation of children’s Internet use. Estonian data from EU Kids Online survey are used, involving 780 children aged 11-16. Results demonstrate that 19% of children who use the Internet have received online sexual messages, and 6% have felt disturbed. The probability of receiving sexual messages online is higher for children with risky online and offline behaviour and psychological difficulties. Perceiving online messages as sexually harassing is higher among children with excessive Internet use, lower levels of parental monitoring and higher levels of peer mediation of Internet use. The risk of exposure to harassing sexual messages also differs by age and, more notably, by the minority status. Mediation by parents and teachers plays an insignificant role in reducing teenagers’ risks of receiving sexual messages.

Various mechanisms have hitherto been suggested to explain the formation of the Kundan (Middle Ordovician) Osmussaar Breccia in northwestern Estonia. Following the recent discovery of L-chondritic chromite in these peculiar, sand-penetrated strata, it seems plausible that the breccia is impact-related. Herein, the conodont faunas of three thin limestone intervals overlying the breccia at Osmussaar Island have been investigated, with the aim of establishing the age of the event in terms of the Baltoscandian conodont-based biostratigraphical scheme. Based on the presence of Microzarkodina ozarkodella, the limestone directly overlying the breccia is assigned to the M. ozarkodella Subzone of the Lenodus (Eoplacognathus?) pseudoplanus Zone. This is reinforced by means of a faunal shift between this sample interval and the subsequent one, which is directly comparable with a faunal shift in the Mäekalda section, mainland Estonia. The middle, orthoceratite-yielding interval is assigned to the uppermost L. (E.?) pseudoplanus Zone (or, alternatively, the lowermost Eoplacognathus suecicus Zone), whereas the uppermost interval, an oolitic limestone, is referable to the E. foliaceus Subzone, corresponding to the lower part of the Lasnamägi Stage. These results support a connection between the Osmussaar event and the stratigraphic interval yielding abundant meteorites and/or high levels of L-type chromite in Sweden, as they both can be referred to the lower and/or middle part of the Kunda Stage. The minor difference in age between the first limestones deposited after the brecciation and the meteorite and L-chromite-yielding interval in Baltoscandia can be explained as caused by a period of non-deposition, seen as numerous hiatuses of various extent in the Kunda Stage in northwestern Estonia.

An updated version of the Devonian stratigraphical chart of Estonia with comments is presented. Estonian regional stratigraphical units are correlated with the standard conodont zonation and miospore zonation, used in the western part of the East European Platform. The fossil fish zonations, largely accepted in the Main Devonian Field, are discussed. Differences in the position of series and stage boundaries and age determination of regional units in the Baltic area, Belarus and NW Russia are dealt with. Two key markers for the correlation of the Middle Devonian of the Baltic area and Scotland, based mainly on placoderms, are described. Special attention is paid to occurrences of inarticulate brachiopods and finds of rare articulate brachiopods in siliciclastic rocks of the Baltic area, indicating their marine origin.

Changes in the percentages of eight main surface wind directions at 14 meteorological stations in Estonia, Northeast Europe, were studied during 1966–2008. Long-term changes in wind directions are related to variations in the large-scale atmospheric circulation but partly also to changes in the surroundings of the stations and in wind obstacles. Significant alterations in wind directions were determined, and found to be the strongest in the winter season. The percentages of W and SW winds have clear positive trends, while SE, E and NE winds are characterized by negative tendencies in winter. In conclusion, wind directions have probably been shifted from east to west. Differences in trends between the stations are explained by changes in wind obstacles around the stations. The trends in wind roses in Estonia were caused by the intensification of the westerly circulation over the Atlantic/European sector during the winter season.

A partly preserved squamation of Thelodus laevis (Pander) from the Himmiste outcrop (Saaremaa Island, Estonia) is described. Most of the trunk with a pectoral fin fragment and three fragments of posterior fins are present, while part of the head and the caudal fin are absent. Ontogenetic development of the scale cover of T. laevis is explained by comparing it with the squamation of Lanarkia horrida Traquair, Loganellia scotica (Traquair) and a modern fish. It is supposed that newly forming trunk scales of early juvenile Thelodus were smooth and rhomboidal. When the individual grew, ridged scales were added between smooth ones in irregular rows in the posterior part of the trunk. Adult individuals were covered with species-specific scales with particular morphology and sculpture of the crown. Co-occurrence of smooth and ridged scales on the trunk in the specimen studied corresponds to a young stage of ontogeny.

The distribution of conodonts in the Lower–Middle Ordovician beds was studied in five drill core sections of south­eastern Estonia. Ten conodont zones and six subzones, from the Paroistodus proteus Zone to the Eoplacognathus lindstroemi Subzone, were established. The peculiarity of the studied sequence is that the Volkhov Stage is notably poor in conodonts, in particular Baltoniodus species. Large specimens of Drepanodus arcuatus and Protopanderodus rectus, however, are found in great numbers in the uppermost Volkhov and lower Kunda stages. The deeper shelf conodont faunas recognized in SE Estonia (Central Baltoscandian confacies belt) are compared with shallow shelf faunas of northern Estonia (North Estonian confacies belt).

The current case study presents results of the ground-penetrating radar (GPR) profiling at one of the Saadjärve drumlin field interstitial troughs, the Rahivere bog, eastern Estonia. The study was conducted in order to identify the bog morphology, and the thickness and geometry of the peat body. The method was also used to describe the applicability of GPR in the evaluation of the peat deposit reserve as the Rahivere bog belongs among the officially registered peat reserves. Fourteen GPR profiles, ~ 100 m apart and oriented perpendicular to the long axis of the depression, covering the bog and its surrounding areas, were acquired. In order to verify the radar image interpretation as well as to evaluate the velocity of electromagnetic waves in peat, a common source configuration was utilized and thirteen boreholes were drilled on the GPR profiles. A mean value of 0.036 m ns–1 corresponding to relative dielectric permittivity of 69.7 was used for the time–depth conversion. Radar images reveal major reflection from the peat–soil interface up to a depth of about 4 m, whereas drillings showed a maximum thickness of 4.5 m of peat. Minor reflections appear from the upper peat and mineral soil. According to the borehole data, undecomposed peat is underlain by decomposed one, but identifying them by GPR is complicated. Mineral soil consists of glaciolimnic silty sand in the peripheral areas of the trough, overlain by limnic clay in the central part. The calculated peat volumes (1 200 000 m3) were found to exceed the earlier estimation (979 000 m3) that was based solely on drilling data. Ground-penetrating radar, as a method that allows mapping horizontal continuity of the sub-peat interface in a non-destructive way, was found to provide detailed information for evaluating peat depth and extent.

Teeth of a new elasmobranch Karksiodus mirus gen. et sp. nov. were discovered on two levels in the sandstones of the Karksi outcrop (South Estonia), corresponding to the Härma Beds, lower part of the Burtnieki Regional Stage (Givetian, Middle Devonian). These teeth differ from all known Palaeozoic elasmobranch teeth in the presence of a unique wide transversal tube-shaped basal canal, in very fine and dense striation of cusps and in an arched base without well-developed extensions. The order and family of this taxon are notspecified.

Ratas, U., Rivis, R., Kont, A., Tõnisson, H., Vilumaa, K., Anderson, A., Szava-Kovats, R.,2014. Regional variation in the dynamics of Estonia's coastal landscapes. In: Green, A.N. and Cooper, J.A.G. (eds.), Proceedings 13th International Coastal Symposium (Durban, South Africa), Journal of Coastal Research, Special Issue No. 70, pp. 139-144, ISSN 0749-0208. The coastal landscapes of Estonia are young (less than 10,000 years old). Their development is affected by the Baltic Sea, by pre-existing geomorphology and by regional tectonic uplift. Since emerging from the sea ~5,000 years ago, the coastal landscapes have been evolving under regressive sea conditions. The landscape diversity is greatest on coasts with variable topographies and those exposed to wind and waves. Low and flat parts of the coast, which are seasonally inundated, exhibit less variable landscapes. Landscape changes in coastal areas no longer affected directly by the sea have been caused largely by human activity. Abrupt socio-political and economic changes over the last century led to a cessation of traditional land use during the Soviet era with urban sprawl and expansion of recreation areas after re-independence in the beginning of the 1990s. The aim of this paper is to analyze the structure, formation conditions, and the velocity and extent of change in coastal landscapes (for both natural and human-induced impacts) along different coastal regions of Estonia. The Estonian coast can be divided into four distinct regions: 1) Gulf of Finland; 2) Baltic Proper; 3) Gulf of Livonia and 4) Coast of Väinameri, making it possible to compare the influence of sea exposure, geological structure, vegetation, soil productivity, age of human settlements and character of land use on the development of coastal landscapes. The results of the current study are applicable to coastal conservation, to the development of sustainable coastal land use and to the facilitation of transnational tourism. [ABSTRACT FROM AUTHOR]

Objectives: Although widely used in epidemiological studies, self-report has been shown to underestimate the prevalence of smoking among pregnant women. Objectives of this study were to examine the discrepancy between self-reported and cotinine-validated smoking status, and the sociodemographic characteristics associated with the misclassification of real smoking status among pregnant women in Tallinn, the capital of Estonia. Methods: Serum cotinine assays were performed on a subsample ( n= 1360) of the pregnant women, who had participated in a recent study of human papillomavirus type 16 (HPV-16) seroprevalence in Estonia. In the present study, serum concentrations ≥15 ng/ml were used to distinguish current smokers from nonsmokers. The serum-validated smoking level was compared with the self-reported level in the records of the Estonian Medical Birth Registry. For the group of self-reported non-smokers, the differences between the cotinine-validated smokers and the cotinine-validated nonsmokers, with respect to their sociodemographic characteristics (age, ethnicity, educational level, employment status, marital status, parity), were estimated by logistic regression. Results: Of 1239 women who reported being nonsmokers, 259 (20.9%) had serum cotinine levels ≥15 ng/ml, and can be regarded as current smokers. Among self-reported nonsmokers, nondisclosure of current smoking was significantly more frequent in non-Estonian, less educated, socially inactive, cohabiting and multiparous women. Conclusions: Self-reported data on smoking in pregnant women underestimates the real smoking prevalence in Estonia. Maternal unwillingness to declare smoking during pregnancy needs to be taken into account in the practice of maternal and child health to better target prenatal smoking cessation interventions. [ABSTRACT FROM AUTHOR]

Surface sediments and sediment cores from Lake Väike Juusa were studied in order to examine the dependence of the sedimentation regime on the topography and development of the lake. Close relationship was established between the grain size of the surface samples and depth of water at the sampling site. The data obtained show that in the lake the accumulation area is situated deeper than 4.0 m. The grain size data for three sediment cores allowed reconstruction of lake-level fluctuations and their amplitude. [ABSTRACT FROM AUTHOR]

The morphology of Reraspis Öpik, 1937 is reviewed and compared with other cyrto-metopinines. Species previously referred to Reraspis are discussed and the generic composition is revised. Reraspis ranges from the Kunda (lower Middle Ordovician) to the Oandu (middle Upper Ordovician) Stage. It occurs in northern Estonia, Russia, and central Sweden (Dalarna). The earliest representative of the genus is the new species Reraspis orvikui from the Pakri Sandstone of Väike-Pakri Island, NW Estonia. The genus also includes the type species R. plautini (Schmidt, 1881), R. latifrons (Warburg, 1925), and possibly R. kaljoi Männil, 1958. Specimens from the Keila Stage of Estonia, originally referred to as Ceraurinella? cf. latifrons, are rather similar to R. latifrons and may either prove conspecific or closely related. Hemisphaerocoryphe? rosenthali (Schmidt, 1881) and Reraspis? kaljoi Männil, 1958 share several characters with Reraspis and Cyrtometopella Nikolaisen, 1961, but a safe generic assignment requires better knowledge of the latter genus, especially concerning the pygidia. Reraspis? sexermis Öpik, 1937 is better assigned to Xylabion Lane, 1971. The closely similar X. helgoeyense (Nikolaisen, 1961) may constitute a junior synonym. Remipyga? sp. sensu Männil, 1958, [=Xylabion sp. (Männil)] is also very closely related to Xylabion glaber. All three may in turn prove junior synonyms of Xylabion glaber (Angelin, 1854). [ABSTRACT FROM AUTHOR]

It is customary to utilize the Earth's artificial satellites for detecting long-wavelength components of the Earth's gravity field. The tracking data of the GRACE twin-satellites are the basis of the new geopotential model GGM01, released by the Centre for Space Research at the University of Texas in July 2003. The present paper assesses the quality of the GGM01 model through comparisons with an earlier geopotential model (EGM96). The method of spherical harmonic expansions is used in numerical investigations. The results of evaluation in Fennoscandia and the Baltic Sea region illuminate the discrepancies between the long-wavelength contributions of the models, which may reach several decimetres in the geoidal heights. Thus, even in the gravimetrically well studied area like the Baltic Sea region, the new satellite gravity missions may improve the gravity data significantly. Tests with high-precision GPS-levelling data indicate the offsets between global geoid models and national vertical datums in the Baltic Sea region. The gravity anomaly grid and the GGM01 model are utilized in the computation of the Estonian gravimetric geoid model by the least squares modification of Stokes' formula. The new model EST-03 is fitted to a set of 26 high-precision GPS-levelling points, yielding a root mean square error of 3 cm for the post-fitting residuals. This order of discrepancies is sufficient for many practical and scientific applications. [ABSTRACT FROM AUTHOR]

The aim of our study was to evaluate the clinical features, predisposing factors and pathogens of toenail onychomycosis in Estonia. During study period we interviewed and examined 436 dermatological patients with clinical signs of toenail onychomycosis in all counties of Estonia. In 69% of cases, the clinical diagnosis of onychomycosis was confirmed by the mycological analysis. The most common clinical symptoms of onychomycosis both in mycologically proven and non-proven cases were discolorization of nail plate, hyperkeratosis and brittle nails. The number of infected toenails positively correlated with patients’ age. On average, patient had 5.4 infected nails. In 78% of culture-positive cases, a dermatophyte was isolated as the causative agent, in 10% yeasts and in 7% moulds. In 6% of culture-positive cases we reported mixed infections. Trichophyton rubrum was the most common pathogen. The high occurrence of mixed infections, clinical symptoms characteristic to long lasting or chronic infection and high number of infected toenails indicate that Estonian patients have more advanced stage of toenail onychomycosis compared with other western and central European countries. [ABSTRACT FROM AUTHOR]

Conodonts of the genus Ctenognathodus form an important part of the fossil fauna through the Wenlock--Ludlow boundary beds on Saaremaa Island. In the collections from the Anikaitse, Hülge, and Soeginina cliffs of the uppermost Rootsiküla and lowermost Paadla stages three new species of Ctenognathodus are identified, together with two new species of Ozarkodina. One more new species, Ctenognathodus jeppssoni sp. nov., is described from the Sauvere Beds of the Paadla Stage. Conodont evidence suggests that the Soeginina Beds in the stratotype section are the lowest stratigraphic unit of the Paadla Stage and the Ludlow Series, as presumed earlier by cyclostratigraphic investigations. The layers of the Anikaitse cliff with unique conodont fauna are considered as an independent rock-unit --the Anikaitse Beds. [ABSTRACT FROM AUTHOR]

Clastic dikes of sedimentary origin are exotic, but still remarkable minor geological structures in the Lower Palaeozoic sequence of northern Baltoscandia. They often carry essential information about the processes and environments that governed during sedimentary breaks. The first up to 10 cm wide clastic dikes in the Devonian sequence of Estonia were found in sandstones of the Gauja Formation in Piusa and Tabina glass sand quarries. Field observations, lithological, mineralogical, and geochemical studies of dikes revealed that these dikes were formed during a short sedimentary break at the end of the Middle Devonian. Eluvial sediments that were partly cemented in tropical arid conditions were the probable source of sandy matrix of dikes and abundant clasts embedded in it. Gravitational failure and temporary water stream processes were the ways of mass transport into the fractures. However, the amount of water was not large enough to fill the fractures and to cause any kind of stratification during the within- fracture sedimentation. Local uplift of the area and extensional deformation of rocks with the formation of open fractures in Middle Devonian layers suggest a tectonic phase in the vicinity of the regional Liepaja-Riga-Pskov zone of tectonic dislocations. This regional zone was formed due to the Late Caledonian compression and was afterwards recurrently activated. Opening of the fractures was immediately followed by filling. At that moment the levels observable in the present sandstone quarries must have been located more than 20-30 m above the groundwater level. Subsequent subsidence of the area caused preferable vertical circulation of groundwater along the clastic dikes. In comparison with the surrounding rocks goethite-rich fluids have caused stronger cementation of clastic dikes during the post-dike history. Also some other minor diagenetic alternation processes took place in dikes. [ABSTRACT FROM AUTHOR]

Background: To investigate social variation in birthweight and length of gestation in Estonia in the period of transition to a democracy and market economy.Methods: All live births resulting from singleton pregnancies reported to the Estonian Medical Birth Registry in 1992-1997 (n = 84, 629) were studied with respect to social variation in birthweight and preterm delivery (<37 weeks gestation). The results were adjusted for maternal age, parity, education, nationality, marital status, smoking in pregnancy, sex of the infant (and gestational age).Results: Between 1992 and 1997, mean birthweight increased from 3,465g to 3,497g (P < 0.001) and the preterm rate fell from 5.8% to 5.1% (P = 0.001). Maternal education, marital status and nationality were all independently related to the mean birthweight and the risk of preterm birth. The mean difference in birthweight between children of mothers with basic and university education was 87 g (95% CI : 74-100). Children born to mothers of non-Estonian compared to Estonian nationality were on average 77 g lighter (95% CI: 70-84). While the effect of nationality and marital status on birthweight was relatively stable during the study period, differences in birth outcome by maternal education became stronger.Conclusions: The mean birthweight increased and the preterm rate decreased in Estonia as a whole during the transition. However, the improvements were not shared equally by all social groups. An increase in variation in birthweight by maternal education was particularly notable. [ABSTRACT FROM AUTHOR]