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Background: There is a lack of population-based studies on acute mesenteric ischemia (AMI). We have therefore performed a nationwide epidemiological study in Estonia, addressing incidence, demographics, interventions and mortality of AMI. Methods: A retrospective population-based review was conducted of all adult cases of AMI accrued from the digital Estonian Health Insurance Fund and Causes of Death Registry for 2016–2020 based on international classification of diseases (ICD-10) diagnostic codes and procedure codes (NOMESCO). Results: Overall, 577 cases of AMI were identified—an annual incidence of 8.7 per 100,000. The median age was 79 (range 32–104) and 57% were female. Predominating comorbidities included hypertensive disease (81%), atherosclerosis (67%), and atrial fibrillation (52%). The majority of cases (60%) were caused by superior mesenteric artery occlusion (thrombosis 54%, embolism 12%, and unclear 34%). Inferior mesenteric artery occlusion occurred in 7%, non-occlusive mesenteric ischemia in 7%, venous thrombosis in 4%, whereas the type remained unclear in 21% of cases. 40% of patients received intervention (revascularization and/or intestinal resection) and 13% active non-operative treatment. In 21% an exploratory laparotomy or laparoscopy revealed unsalvageable bowel prompting end-of-life care, which was the only management in a further 25% of cases. Conclusions: The population-based annual incidence of AMI in Estonia was 8.7 per 100,000 during the study period. The overall hospital mortality and 1 year mortality were 64% and 74%, respectively. In the 53% of patients who received active treatment hospital mortality was 32% and 1 year all-cause mortality was 51%. Trial registration: ClinicalTrials.gov Identifier NCT04867499. [ABSTRACT FROM AUTHOR]

Soil quality indicates the soil's ability to provide ecosystem services. Reducing the tillage intensity has been suggested as an alternative to conventional tillage for sustaining soil quality. This study aimed to evaluate the effect of soil tillage systems on individual soil quality indicators in comparison to those on grassland with Stagnic Luvisol soil in Estonia. Four soil management systems were compared: no-tillage (NT), minimum tillage (MT), conventional tillage (CT) and grassland (G) as a reference. Soil quality indicators included physical (bulk density, water-stable aggregates, porosity, air-filled pores, moisture content, water-holding capacity, penetration resistance and water permeability), chemical (total N, total soil organic C, permanganate oxidisable C, pH, P, K, Ca and Mg) and biological (earthworm abundance) parameters. CT soils had a significantly lower aggregate stability compared to MT and G soils. The higher penetration resistance of CT under an arable layer suggested the presence of a plough pan. NT improved the soil's physical quality at 5–10 cm, which was indicated by higher moisture content, water-holding capacity and porosity and a lower bulk density, whereas penetration resistance exceeded 2 MPa in the lower part of the topsoil. NT also had significantly lower total soil organic C and total N compared to MT and G. The absence of tillage in the NT and G systems may have improved the soil's resistance to moisture loss under dry conditions, which, in turn, improved the soil habitability for earthworms a despite higher density. In general, NT or MT stabilised or increased the soil quality compared to CT. [ABSTRACT FROM AUTHOR]

Soil formation on the human time scale is immensely time consuming, although it can be significantly accelerated through the effects of vegetation. The content of water-stable aggregates (WSAs) is a useful indicator for determining both the soil development level and the soil quality. However, in severely degraded soils, especially in the Baltic pedoclimatic region, the effects of vegetation on the aggregate stability have been poorly studied. Therefore, to obtain more knowledge about the impact of vegetation on WSA, and thereby knowing how to improve it, this study was conducted on a long-term soil formation experiment in Estonia near Tartu. In 1964, the initial soil from an area of 20 × 8 m down to 100 cm depth was replaced with a sandy loam calcareous glacial till. The experiment started on April 26, 1965, when plants were sown on the plot. The topsoil (0–20 cm) samples were analyzed in 1966, 2000, 2007, and 2014. The study indicated that perennial grasses (meadow fescue and common meadow-grass) fertilized with P40K75, compared to N150P40K75, decreased the WSA content, as well at the accumulation rate of soil organic carbon (SOC) and the total nitrogen content (Ntot). The hybrid alfalfa treatment resulted in the significantly highest SOC and Ntot accumulation, but not in the overall highest WSA content. Under barley, manure positively affected the WSA and SOC, though many other physical properties were not improved. Compared to the initial till under bare fallow, the SOC and Ntot contents were significantly higher under grown crops, but the WSA content remained the same. In addition, regardless of the grown crops, the WSA of larger (0.25–2 mm) aggregates was substantially higher than that of smaller (0.25–1 mm) aggregates. Also, as the relationship between WSA and SOC in the study was linear, the soil was far from C saturation and still in development. Overall, it can be concluded that the cultivation of perennial grasses and hybrid alfalfa on the severely eroded soil is the most rational option to improve the water stability of aggregates and increase the SOC and Ntot contents. However, because of the complexity of the aggregation process, further research is still needed. [ABSTRACT FROM AUTHOR]

In agriculture as well for other purposes off-road vehicles have to move cross-country. Precompression stress is used to describe the load bearing capacity of different soils. The aim of the study is to investigate the relationship between precompression stress and rut depth for different Estonian soil types after 1 and 10 passes of a vehicle. Traffic experiments were conducted at eight experiment sites throughout Estonia using a 7 t truck and a 23 t wheeled vehicle. The experiment sites were selected based on the Estonian soil map. Rut depth was measured after the first pass and ten passes. Undisturbed soil samples were collected from topsoil and from subsoil right next to the track. Soil samples were compressed in an oedometer at stresses of 25, 50, 100, 200, 400 and 600 kPa. The Casagrande procedure was used to determine the precompression stresses. In topsoil, if the moisture content of a soil is high, then the differences in the precompression stress values of the various soil types disappears while in the subsoil layer the precompression stress is more dependent on the soil properties. The precompression stress cannot by itself be used as a threshold value to determine small and large sinkage. The choice of fitting methods for composing of stress compaction curve is critical and led to the preference of the logistic curve. The values of logistic functions at the points of their maximal curvature and calculation based on the area on stress-compaction graph can be used for prediction of rut depths. [ABSTRACT FROM AUTHOR]

About 60% (678,000 ha) of Estonian arable soils have a deficiency of plant-available magnesium (Mg). The soils formed from dolostone (or dolomite rock) till are considerably richer in Mg than those formed from limestone-rich and noncalcareous tills. Formerly, ground dolostone rock with a high content of mineral dolomite was used only as a soil liming material. Later, dolostone powder (DSP), received in the course of industrial manufacturing of dolostone rubble, was also applied for the mitigation of Mg deficiency in soil. The easily accessible resources of DSP as an industrial waste may also qualify as an Mg fertilizer. It soon became apparent, however, that with the application of DSP to the soil, an excessive quantity of Mg could be accumulated. This Mg surplus in soil destroys the equilibrium in plants' assimilation of nutrition elements and inhibits the normal development of agricultural crops. In our research, the influence of different DSP doses on the yield of red clover (Trifolium pratense L.), lucerne (Medicago sativa L.), barley (Hordeum vulgare L.), wheat (Triticum aestivum L.), and oil rape (Brassica napus L. var. Oleifera subvar. Annua) was studied on arable soils formed from different parent materials. We elucidated from the 2-year experiment the high efficiency of DSP application in increasing the yields of Mg-philic crops such as clover, lucerne, and oil rape. The negative influence of excessive Mg application on crop yields, especially in the first year of DSP application, is more clearly visible on soils that are calcium deficient for plant production. For the amendment of deficiency in Mg acid arable soils, 1-1.5 t ha-1 of DSP should be used every 2 to 3 years. The broad application of industrial-origin DSP is useful from at least three points of view: (1) industrially produced Mg fertilizers may be replaced by a readily available local industrial (mining) by-product, (2) managing costs and territories for the disposal of industrial wastes will be reduced, and (3) it will be possible to attain complex and environmentally friendly utilization of local mineral resources. [ABSTRACT FROM AUTHOR]

Two bisequal Gleysol profiles were studied in western Estonia to characterize pedogenetic features on aqueous sediments of the Litorina Sea and Ancylus Lake in similar topographical and geological situations. The development of Gleysols during the Late Holocene has been uniform and depends on the composition and sediment structure of both sandy and silty parent materials. Saturated R[sub2]O[sub3]-humic-fulvic organic matter of hydromorphic origin has increased the specific surface area and exchange properties during all stages of the Holocene while the textural-chemical properties of deposits in groundwater regimes have been preserved from Ancylus Lake time up to the present. [ABSTRACT FROM AUTHOR]

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A special experiment was established in 1963 and initiated in 1964 at Eerika, Tartu County, Estonia (58°22′ N, 26°36′ E) to study pedogenesis and its continuous development under grass-herbaceous vegetation on reddish-brown calcareous till which was practically free from organic carbon (0.6 g kg-1) and nitrogen (0.2 g kg-1). The results of the study of three earlier decades have been discussed earlier. This paper deals with the processes of synchronous production and soil formation as well as with pedogenetic activity during the fourth decade of the experiment and during the total period of 40 years. An intensive humusaccumulative process, wavy and cyclic in intensity, has continued, accompanied by the breakdown of skeletal carbonates, partial leaching of products, formation and accumulation of amorphous and crystalline nonsiliceous products of weathering, progress of argillization in situ, and slight lessivage of fine silt and clay within the thin top of enriched humus solum. Net accumulation of organic carbon and nitrogen was obtained by nearly equivalent amounts of humifiable issues of the production process. As these are temporally dynamic, the temporal periodicity of mineralization and humification relationships is also characteristic of synchronous pedogenesis. The low C : N ratio indicates an excellent quality of the humus formed since the beginning of primary soil formation. Against the background of the decadewise dynamic fulvicity of the humus and evident decrease in its total solubility, the transformation of Ca-humates into humins and the formation of R2O3-humic-fulvic complexes at the expense of RO-humic-fulvic complexes already during the third decade were ascertained. Intensification of the bonds of the humic-fulvic complexes with inactive sesquioxides and clay minerals and decrease in the amount of fulvic acids in the interlayeral structure of clay progressed during the fourth decade. Due to the weathering of sand fractions, an accumulation of silty-clayey particles, accompanied by an increase in the cation exchange capacity and in the specific surface area, progressed in the formed soils. The progress of Calcaric Cambisol (Rendollic Eutrochrept) can be diagnosed on the basis of data obtained during 40 years. [ABSTRACT FROM AUTHOR]

A profile of Eutric Cambisol, formed during 50-55 years on the cross-bedded whitish-grey Devonian sandstone of the Burtnieki Stage, was studied on the excavated outcrop on the bank of the Helme River at Helme, southern Estonia. The topsoil of 10 cm, being the A-Bw subsection, represents the result of humus accumulation, pedogenetic weathering of the sand fractions, and the accumulation in situ of silt and clay in the initial sand column of 6.18 cm. Considerable loosening, accompanied with the upward expansion of the solum, has taken place at an annual rate of 0.7-0.8 mm. As a consequence of interfraction changes, 260-290 g m[SUP-2] yr[SUP-1] of fine textural particles and 100-120 g m[SUP-2] yr[SUP-1] of chemical constituents have accumulated in the thin solum, while some air deposition and surface lateral inflow cannot be excluded. The annual input of organic carbon at a rate of 25-28 g m[SUP-2] has operated as the driving force for rapid and intensive soil formation of accumulative origin. Fulvic acids have played a great role in the progress of initial pedogenesis, while the formed fulvates bound with alkaline earths favour the development of accumulative phenomena. Increase in base exchange capacity of the solum several times is the direct result of accumulation of humus, silt, and clay. [ABSTRACT FROM AUTHOR]

Formation of soil organic matter in three quarry detritus areas was investigated at Sirgala, north-east Estonia (27°47′E, 59°19′N). The sites were afforested in 1965–1970 with 2-years-old seedlings of Scots pine. During the first decade after planting, forest floor (ground litter) had not formed. In 1988, ground litter occurred as a single layer. After 29–34 years, a brownish black (10YR2/2) A-horizon and a very dark greyish-brown (10YR3/2) AC-horizon had developed to a depth of 20–25 cm. Falling litter (litterfall) and ground litter of a Moder-type had also formed. Organic matter of the ground litter was rich in carbon but poor in nitrogen. A large accumulation of organic carbon and nitrogen in the mineral topsoil, a high C:N ratio, and significant amount of humus accumulation were characteristics of these young soils. As a result of pedogenesis, part of the residual oil-shale (kukersite) in detritus was humified as insoluble fraction. Organic carbon (14.4–19.7 g kg−1) of kukersite, contained in the quarry detritus were subtracted from the measured values to calculate the amount of organic matter of plant origin. Sesquioxides–humic–fulvic humus was rich in substances bound with mineral content of the detritus, but poor in free fulvic acids and Ca–humates. Highly productive forest ecosystems with the formation of Calcaric Regosols have developed on pure skeletal quarry detritus within about three decades. [Copyright &y& Elsevier]

An outcrop of Carbic Podzol on aeolian sand, underlain by Molli-Histic Gleysol on calcareous till of the last glaciation, was studied on the bank of the Lemmejgi River, SW Estonia. Molli-Histic Gleysol at depths of 342--380 cm formed as a result of pedogenesis within the Younger Dryas--Pre-Boreal during about 1500--3200 years at an average accumulation rate of organic carbon of 5.3--2.5 g m --2 yr --1 . The histic horizon formed during about 1000 years at a rate of 12--13 g m --2 yr --1 of organic carbon. Gleying of underlying till has led to slight textural changes but to some essential changes in mineral and chemical status. Gleysol was buried under the sediments of the Ancylus transgression about 9200--9000 years ago. Within the uppermost stratum, stratified sands have been reshaped by coastal winds after the retreat of the shoreline. Simultaneously with the development of the forest vegetation, pedogenesis started a little later than 9000 BP, and a unitary Carbic Podzol with the A--E--Bhs--Bs--BC--C sequence was formed. Organic C has accumulated at an average rate of 8.1 mg m --2 yr --1 cm --1 in the A--E--Bhs sequence, while the A- and Bhs-horizons were humus-accumulative and humus-illuvial in origin, respectively. Under the influence of R2 O3 - and/or Ca-fulvic humus, total cheluviation and formation of the albic horizon has proceeded at a rate of 55 um yr-1 . [ABSTRACT FROM AUTHOR]

The stability of the soil aggregates is an important soil quality indicator, as it affects the soil's overall functionality. As the soil aggregates are highly affected by agricultural practices, it is essential to know how crops interact with the aggregation process. Therefore, for obtaining more knowledge, this research was conducted in Estonia in an organic crop rotation field experiment from 2012/2013 through 2015/2016 to study the effects of crops (potato → spring barley undersown with red clover → red clover → winter wheat → pea) under different treatments (TC—control; TW—winter cover crops; TW+M—TW with farmyard manure 40 Mg ha−1 per crop rotation). The results showed that in the topsoil (5–10 cm), the soil water-stable aggregate (WSA) content (determined by the wet sieving method) from highest to lowest was following: pea (61.7%), winter wheat (61.6%), spring barley (61.5%), red clover (59.3%), potato (57.1%); whereas in the subsoil (30–35 cm): potato (50.6%), pea (48.5%), red clover (47.9%), spring barley (47.7%), winter wheat (46.4%). Therefore, potato was a noticeable crop, as among the crops, it had the lowest WSA content in the topsoil, while highest in the subsoil. The results shown gave an assumption that the after-effects of some crops (foremost with pea) were noticeable in the soil properties during the following crop. In the topsoil, the differences between crops were significant among crops just for TW and TW+M treatments. In TW, potato was lower than spring barley and winter wheat, but not significantly lower than pea or red clover. In the subsoil, significant differences between crops were observed for TC and TW treatments: in TC, potato was just significantly greater than red clover (but similar to other crops), and in TW, significantly greater than winter wheat. Furthermore, in the topsoil the soil organic carbon (SOC) content was not significantly affected by crops, and the use of winter cover crops generally increased the SOC content while concurrently decreased the WSA content and the soil maximum water holding capacity. This was probably caused by the additional tillage operations which cancelled out the possible benefits for the soil aggregates. As a consequence of the constantly declining SOC content, caused by the weakened soil aggregates, the plant-available P and K contents, especially in the absence of manure applications, decreased as well, probably due to the combination of fixation and removal of plant biomass. Therefore, it is expected that by continuing this trend, the plant growing conditions decline, which in turn will have a negative effect for the aggregate formation and carbon sequestration, which are essential for plant growth. [ABSTRACT FROM AUTHOR]

Deep ruts in soil hinder the movement of off-road vehicles and harm drastically the soil environment. The aim of this study was to determine the most suitable cone and remoulding index based methods for rut depth estimation for single and repeated military vehicle passage in typical Estonian soils. Cone index based sinkage models – US Army ERDC, Maclaurin (1990) and Willoughby and Turnage sinkage models applicable for military vehicles were tested, using different critical layers (0–15 cm, 7.5–23 cm or 15–30 cm). The test vehicles were a 7 Mg truck and a 23 Mg armoured personnel carrier. At eight experimental sites covering mechanically very variable soil conditions (from peat to clay soil), rut depth was measured after one and ten vehicle passes, cone penetration tests were conducted in situ, and samples were collected for determination of bulk density, organic carbon content, texture, gravimetric water content, plastic and liquid limits of the topsoil and subsoil. According to average RMSD values for military truck the Willoughby and Turnage model was the most accurate prediction method. For one pass and 10 passes the rating cone index values from the 7.5–23 cm and 15–30 cm soil layer, respectively, produced the lowest RMSD values. [ABSTRACT FROM AUTHOR]

Background: While gastrointestinal problems are common in ICU patients with multiple organ failure, gastrointestinal failure has not been given the consideration other organ systems receive. The aim of this study was to evaluate the incidence of gastrointestinal failure (GIF), to identify its risk factors, and to determine its association with ICU mortality., Methods: A retrospective analysis of adult patients (n = 2588) admitted to three different ICUs (two ICUs at the university hospital Charité-Universitätsmedizin Berlin, Germany and one at Tartu University Clinics, Estonia) during the year 2002 was performed. Data recorded in a computerized database were used in Berlin. In Tartu, the data documented in the patients' charts was retrospectively transferred into a similar database. GIF was defined as documented gastrointestinal problems (food intolerance, gastrointestinal haemorrhage, and/or ileus) in the patient data at any period of their ICU stay. ICU mortality, length of stay, and duration of mechanical ventilation were assessed as outcome parameters., Results: GIF was identified in 252 patients (9.7% of all patients). Only 20% of GIF patients were identifiable at admission. GIF was related to significantly higher mortality (43.7% vs. 5.3% in patients without GIF), as well as prolonged length of ICU stay (10 vs. 2 days) and mechanical ventilation (8 vs. 1 day), p < 0.001, respectively. Patients' profile (emergency surgical or medical), APACHE II and SOFA scores and the use of catecholamines at admission were identified as independent risk factors for the development of GIF. Development of GIF during ICU stay was an independent predictor for death., Conclusion: Gastrointestinal failure represents a relevant clinical problem accompanied by an increased mortality, longer ICU stay and mechanical ventilation.