Priority effects provide an advantage to early establishing species and are thought to significantly affect the course of succession. We conducted a 20-year long experiment sowing high- and low-diversity mixtures in an ex-arable field. We ask how long the effect of sowing persists and which sown species affect the course of succession. The experiment was established in the Czech Republic in five replicate blocks, each containing three random 10 × 10 m plots with three treatments: natural colonisation, sowing low- and high-diversity seed mixtures. The species cover was annually estimated in 12 permanent 1 m2 quadrates within each plot. To identify the effects of sowing, we used an innovative method analysing the data separately for each year using Redundancy analysis (RDA) with identity of sown species as explanatory variables. In the first year, the effect of sowing was small; the peak of explained variability occurred between third and fifth year. The legacy of sowing was detectable in the natural colonisers for 18 years and in the sown species for the whole 20-year period. For some species, the difference between the plots where they were and were not sown remained significant for the whole 20-year period (e.g. Lathyrus pratensis) although the plots were adjacent and the area was mown with the same machine. Other ones (e.g. Trisetum flavescens) colonised all the plots evenly. The long-lasting effect of the initial sowing confirms contingency of successional pathway on the propagule pressure in the time of start of succession due to the priority effects.
- MeSH
- Poaceae * MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Czech Republic MeSH
Melting glaciers are natural redistributors of legacy airborne pollutants, affecting exposure of pristine proglacial environments. Our data shows that melting Himalayan glaciers can be major contributors of polychlorinated biphenyls (PCBs) and high-molecular-weight polycyclic aromatic hydrocarbons (PAHs) for surface water in the Gangetic Plain during the dry season. Glacial emissions can exceed in some cases inputs from diffuse sources within the catchment. We analyzed air, deposition and river water in several sections along the Ganges River and its major headwaters. The predominant glacial origin of these contaminants in the Himalayan reach was demonstrated using air-water fugacity ratios and mass balance analysis. The proportion of meltwater emissions compared to pollutant discharge at downstream sections in the central part of the Gangetic Plain was between 2 and 200%. By remobilizing legacy pollutants from melting glaciers, climate change can enhance exposure levels over large and already heavily impacted regions of Northern India.
- MeSH
- Water Pollutants, Chemical analysis MeSH
- Climate Change MeSH
- Air Pollutants analysis MeSH
- Ice Cover chemistry MeSH
- Polychlorinated Biphenyls analysis MeSH
- Polycyclic Aromatic Hydrocarbons analysis MeSH
- Rivers chemistry MeSH
- Seasons MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- India MeSH
Knowledge regarding partitioning behavior and bioaccumulation potential of environmental contaminants is important for ecological and human health risk assessment. While a range of models are available to describe bioaccumulation potential of hydrophobic organic chemicals (HOCs) in temperate aquatic food webs, their applicability to tropical systems still needs to be validated. The present study involved field investigations to assess the occurrence, partitioning, and bioaccumulation behavior of several legacy and emerging HOCs in mangrove ecosystems in Singapore. Concentrations of synthetic musk fragrance compounds, methyl triclosan (MTCS), polychlorinated biphenyls, organochlorine pesticides, and polycyclic aromatic hydrocarbons were measured in mangrove sediments, clams, and caged mussels. Freely dissolved concentrations of the HOCs in water were determined using silicone rubber passive samplers. Results showed that polycyclic musks and MTCS are present in mangrove ecosystems and can accumulate in the tissues of mollusks. The generated HOC concentration data for mangrove water, sediments, and biota samples was further utilized to evaluate water-sediment partitioning (e.g., Koc values) and bioaccumulation behavior (e.g., BAF and BSAF values). Overall, the empirical models fit reasonably well with the data obtained for this ecosystem, supporting the concept that general models are applicable to predict the behavior of legacy and emerging HOCs in mangrove ecosystems.
- MeSH
- Water Pollutants, Chemical * MeSH
- Ecosystem MeSH
- Geologic Sediments MeSH
- Environmental Monitoring MeSH
- Organic Chemicals MeSH
- Polychlorinated Biphenyls * MeSH
- Polycyclic Aromatic Hydrocarbons * MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Gregor Mendel is generally acknowledged not only as the founder of genetics but also as the author of the first mathematical result in biology. Although his education had been questioned for a long time, he was profoundly educated in botany as well as physics and in those parts of mathematics (combinatorics, probability theory) applied in his later pea plants experiments. Nevertheless, there remain debates in statistical literature about the reasons why are Mendel’s results in such a too good accordance with expected values [22, 28]. The main aim of this paper is to propose new two-stage statistical models, which are in a better accordance with Mendel’s data than a classical model, where the latter considers a fixed sample size. If Mendel realized his experiments following such two-stage algorithm, which cannot be however proven, the results would purify Mendel’s legacy and remove the suspicions that he modified the results. Mendel’s experiments are described from a statistical point of view and his data are shown to be close to randomly generated data from the novel models. Such model is found as the most suitable, which is remarkably simpler according to the model of [28], while the new model yields only slightly weaker results. The paper also discusses Mendel’s legacy from the point of view of biostatistics.
- MeSH
- Clinical Studies as Topic MeSH
- Clinical Decision-Making * MeSH
- Humans MeSH
- Statistics as Topic * MeSH
- Check Tag
- Humans MeSH
- Publication type
- Editorial MeSH
To address the lack of high-resolution electron ionisation mass spectral libraries (HR-[EI+]-MS) for environmental chemicals, a retention-indexed HR-[EI+]-MS library has been constructed following analysis of authentic compounds via GC-Orbitrap MS. The library is freely provided alongside a compound database of predicted physicochemical properties. Currently, the library contains over 350 compounds from 56 compound classes and includes a range of legacy and emerging contaminants. The RECETOX Exposome HR-[EI+]-MS library expands the number of freely available resources for use in full-scan chemical exposure studies and is available at: https://doi.org/10.5281/zenodo.4471217.
BACKGROUND: Severe canopy-removing disturbances are native to many temperate forests and radically alter stand structure, but biotic legacies (surviving elements or patterns) can lend continuity to ecosystem function after such events. Poorly understood is the degree to which the structural complexity of an old-growth forest carries over to the next stand. We asked how pre-disturbance spatial pattern acts as a legacy to influence post-disturbance stand structure, and how this legacy influences the structural diversity within the early-seral stand. METHODS: Two stem-mapped one-hectare forest plots in the Czech Republic experienced a severe bark beetle outbreak, thus providing before-and-after data on spatial patterns in live and dead trees, crown projections, down logs, and herb cover. RESULTS: Post-disturbance stands were dominated by an advanced regeneration layer present before the disturbance. Both major species, Norway spruce (Picea abies) and rowan (Sorbus aucuparia), were strongly self-aggregated and also clustered to former canopy trees, pre-disturbance snags, stumps and logs, suggesting positive overstory to understory neighbourhood effects. Thus, although the disturbance dramatically reduced the stand's height profile with ~100% mortality of the canopy layer, the spatial structure of post-disturbance stands still closely reflected the pre-disturbance structure. The former upper tree layer influenced advanced regeneration through microsite and light limitation. Under formerly dense canopies, regeneration density was high but relatively homogeneous in height; while in former small gaps with greater herb cover, regeneration density was lower but with greater heterogeneity in heights. CONCLUSION: These findings suggest that pre-disturbance spatial patterns of forests can persist through severe canopy-removing disturbance, and determine the spatial structure of the succeeding stand. Such patterns constitute a subtle but key legacy effect, promoting structural complexity in early-seral forests as well as variable successional pathways and rates. This influence suggests a continuity in spatial ecosystem structure that may well persist through multiple forest generations.
Human health is the main role of medical research. Scientists were always intrigued by disease prevention, their diagnostics and proper treatment. In fact, research in medicine is always directed towards the improvement of the health care and improvement of the quality of life of the target population. Nowadays, physiological research, which is the base stone for clinical research, progresses fast forward, providing new information about body functions in health and diseases. This obvious progress is associated with modern methods, such as neuronal tracing, patch-clamp methods, electrophysiology, molecular biology and many more, which supported by comprehensive information technology guarantees high quality and complex data. Our younger colleagues, young scientists, post-docs or PhD students are well-trained and qualified in utilizing these new methods.
- MeSH
- Faculty, Medical history MeSH
- Biomedical Research history MeSH
- History, 20th Century MeSH
- History, 21st Century MeSH
- Internationality MeSH
- Physicians history MeSH
- Humans MeSH
- Respiratory Mechanics physiology MeSH
- Respiration Disorders history physiopathology MeSH
- Check Tag
- History, 20th Century MeSH
- History, 21st Century MeSH
- Humans MeSH
- Male MeSH
- Publication type
- Biography MeSH
- Historical Article MeSH
- Editorial MeSH
- Geographicals
- Slovakia MeSH
Background Many patients with severe aortic stenosis are referred late with advanced symptoms or inappropriately denied intervention. The objective was to investigate whether a structured communication to referring physicians (facilitated data relay) might improve the rate and timeliness of intervention. Methods and Results A prospective registry of consecutive patients with severe aortic stenosis at 23 centers in 9 European countries with transcatheter as well as surgical aortic valve replacement being available was performed. The study included a 3-month documentation of the status quo (phase A), a 6-month intervention phase (implementing facilitated data relay), and a 3-month documentation of a legacy effect (phase-B). Two thousand one hundred seventy-one patients with severe aortic stenoses were enrolled (phase A: 759; intervention: 905; phase-B: 507). Mean age was 77.9±10.0 years, and 80% were symptomatic, including 52% with severe symptoms. During phase A, intervention was planned in 464/696 (67%), 138 (20%) were assigned to watchful waiting, 8 (1%) to balloon aortic valvuloplasty, 60 (9%) were listed as not for active treatment, and in 26 (4%), no decision was made. Three hundred sixty-three of 464 (78%) patients received the planned intervention within 3 months. Timeliness of the intervention improved as shown by the higher number of aortic valve replacements performed within 3 months (59% versus 51%, P=0.002) and a significant decrease in the time to intervention (36±38 versus 30±33 days, P=0.002). Conclusions A simple, low-cost, facilitated data relay improves timeliness of treatment for patients diagnosed with severe aortic stenosis, resulting in a shorter time to transcatheter aortic valve replacement. This effect was mainly driven by a significant improvement in timeliness of intervention in transcatheter aortic valve replacement but not surgical aortic valve replacement. Clinical Trial Registration URL: https://www.clinicaltrials.gov/. Unique identifier: NCT02241447.
- MeSH
- Aortic Valve Stenosis diagnostic imaging nursing therapy MeSH
- Balloon Valvuloplasty * adverse effects MeSH
- Time-to-Treatment * MeSH
- Time Factors MeSH
- Heart Valve Prosthesis Implantation * adverse effects MeSH
- Echocardiography MeSH
- Clinical Decision-Making MeSH
- Referral and Consultation * MeSH
- Humans MeSH
- Watchful Waiting * MeSH
- Prospective Studies MeSH
- Cross-Sectional Studies MeSH
- Registries MeSH
- Nurse's Role * MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Severity of Illness Index MeSH
- Transcatheter Aortic Valve Replacement * adverse effects MeSH
- Eligibility Determination MeSH
- Patient Selection MeSH
- Treatment Outcome MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Multicenter Study MeSH
- Observational Study MeSH
- Research Support, Non-U.S. Gov't MeSH
- Comparative Study MeSH
- Geographicals
- Europe MeSH
The development of a soil cover is a dynamic process. Soil cover can be altered within a few decades, which requires updating of the legacy soil maps. Soil erosion is one of the most important processes quickly altering soil cover on agriculture land. Colluvial soils develop in concave parts of the landscape as a consequence of sedimentation of eroded material. Colluvial soils are recognised as important soil units because they are a vast sink of soil organic carbon. Terrain derivatives became an important tool in digital soil mapping and are among the most popular auxiliary data used for quantitative spatial prediction. Prediction success rates are often directly dependent on raster resolution. In our study, we tested how raster resolution (1, 2, 3, 5, 10, 20 and 30 meters) influences spatial prediction of colluvial soils. Terrain derivatives (altitude, slope, plane curvature, topographic position index, LS factor and convergence index) were calculated for the given raster resolutions. Four models were applied (boosted tree, neural network, random forest and Classification/Regression Tree) to spatially predict the soil cover over a 77 ha large study plot. Models training and validation was based on 111 soil profiles surveyed on a regular sampling grid. Moreover, the predicted real extent and shape of the colluvial soil area was examined. In general, no clear trend in the accuracy prediction was found without the given raster resolution range. Higher maximum prediction accuracy for colluvial soil, compared to prediction accuracy of total soil cover of the study plot, can be explained by the choice of terrain derivatives that were best for Colluvial soils differentiation from other soil units. Regarding the character of the predicted Colluvial soils area, maps of 2 to 10 m resolution provided reasonable delineation of the colluvial soil as part of the cover over the study area.
- MeSH
- Surveys and Questionnaires MeSH
- Soil chemistry MeSH
- Models, Theoretical * MeSH
- Geography MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Czech Republic MeSH
