192 research outputs found

    Allelopathic potential and cytostatic activity of Antarctic moss Sanionia georgicouncinata (Amblystegiaceae)

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    From the first half of the XX century, the maritime Antarctic was a region with high regional warming rates. At the beginning of the XXI century, regional warming strongly slowed down, but during the next twenty years the near-surface temperatures and mean annual precipitation at the Antarctic Peninsula will most probably increase. Higher temperatures and precipitation make the conditions in the maritime Antarctic more favourable for plants, including invasive species. Moreover, the increasing number of Antarctic tourists unintentionally transport thousands of seeds to the Antarctic on their clothes and equipment. In such circumstances, it is important to evaluate possible defensive mechanisms of native plant species, including their allelopathic potential. The objective of this study was to evaluate the allelopathic potential and cytostatic activity of Sanionia georgicouncinata. This species is widespread in the maritime Antarctic and is one of the most abundant moss species on the Argentine Islands (Wilhelm Archipelago). Seeds of cucumber Cucumis sativus, radish Raphanus raphanistrum subsp. sativus, wheat Triticum vulgare, and amaranth Amaranthus paniculatus were used as bioassay species. Fresh green biomass of S. georgicouncinata was used to prepare aqueous extracts with 1 : 10, 1 : 50, and 1 : 100 plant to water ratios. The average root length of wheat sprouts and cucumber sprouts in distilled water did not differ significantly from those in plant extracts. The root length of radish sprouts in 1 : 50 plant extract was significantly shorter than in distilled water. Meanwhile, in 1 : 50 and 1 : 100 water extracts, roots of amaranth plants were significantly longer than in water. The number of lateral roots of cucumber sprouts in water and studied aqueous extracts varied from 1 to 6 with medians from 3 to 4. The medians of control (distilled water) and sample groups (aqueous extracts) did not differ significantly, but only 38.1 ± 6.1% of cucumber sprouts developed lateral roots in the 1 : 10 aqueous extract of S. georgicouncinata, and even less – 28.3 ± 7.5% in the 1 : 50 aqueous extract. The results of this study show that the allelopathic potential of S. georgicouncinata is low. However, a significant cytostatic activity of the studied extracts shows that this species may still affect other plants and animals. Further research is needed to evaluate the impact of the studied extracts on root growth and germination of the invasive plants, particularly Poa annua

    Syntaxonomy and ecological differentiation of the pioneer vegetation of Ukraine. 2. Helichryso-Crucianelletea maritimae, Festucetea vaginatae, Koelerio-Corynephoretea canescentis classes

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    Pioneer psammophytic vegetation is usually developed on wind-drift sandy substrates such as arenas, spits, beaches, river terraces, and this vegetation occupies significant areas in all three natural zones of Ukraine. The Koelerio-Corynephoretea canescentis class was represented by 13 associations, 3 alliances and 1 order; Festucetea vaginatae class by 22 associations, 2 alliances and 1 order; Helichryso-Crucianelletea maritimae by 10 associations, 4 alliances and 1 order. The results of cluster analysis and synoptic tables of the classes are presented. 9 alliances are briefly described. Leading factors of territorial and ecological differentiation are identified. It was found that the territorial distribution of plant communities is influenced by the character of ecotope mesorelief, soil composition and humus horizon thickness, as well as the degree of eolian processes development. The main factors of their ecological differentiation are soil acidity, salt regime and ombroregime. Based on the results of DCA-ordination of syntaxa within certain vegetation classes, it was found that their distribution is influenced by factors that correlate with the environment-specific conditions. It has emerged that an ecological differentiation of syntaxa within Festucetea vaginatae is determined by the integrated effect of gradients, and soil salinity is leading among them. Temperature regime and climate continentality are leading factors in the distribution of syntaxa within the Koelerio-Corynephoretea canescentis class. The gradients of ombroregime and soil humidity have a significant impact. The distribution of communities of the Helichryso-Crucianelletea maritimae class in the ecological space is determined mainly by factors of variability of damping, ombroregime and climate continentality. The author’s syntaxonomic concept assumes the independence of the studied classes: Koelerio-Corynephoretea canescentis, Helichryso-Crucianelletea maritimae and Festucetea vaginatae, conside­ring that the leading factors of community differentiation of the Festucetea vaginatae and Koelerio-Corynephoretea canescentis classes are the origin (genesis) of sandy substrates, as well as soil acidity. Phytosociological analysis of a large number of relevés of coastal littoral vegetation also provides support for independence of the Helichryso-Crucianelletea maritimae and Ammophiletea classes diffe­rent floristically and ecologically. A review of the psammophytic vegetation of Ukraine will determine the place of the selected syntaxonomic units in the pan-European system

    Syntaxonomy and ecological differentiation of the pioneer vegetation of Ukraine. 1. Classes: Cakiletea maritimae, Ammophiletea, Crithmo-Staticetea, Crypsietea aculeatae, Therosalicornietea

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    Pioneer plant communities grow on newly-formed ecotopes of coastal and partially continental areas, on patches that have dried after the surface water flooding. They are affected by sea tides, wind-induced effect, salinity, denudation, accumulation and sharp changes in soil humidity. To these factors are added chemical and biological pollution, as well as anthropogenic pressure. Due to these reasons, such plant communities have a specific floristic composition, structure, functional regime and resilience mechanisms, which are different from coenoses of more stable habitats. On the basis of the analysis of more than 600 phytosociological relevés using TWINSPAN modified algorithm the current state of littoral and halophytic classes of pioneer vegetation in Ukraine has been established and their syntaxonomic structure identified. It has been determined that the level of pioneer phytocoenoses diversity in Ukraine is similar to that of Central Europe. The Cakiletea maritimae class is presented by 1 order, 1 alliance, and 4 associations; Ammophiletea – by 1 order, 1 alliance, and 8 associations; Crithmo-Staticetea – by 1 order, 2 alliances, and 3 associations; Crypsietea aculeatae – by 1 order, 3 alliances, and 4 associations, Therosalicornietea – by 1 order, 2 alliances, and 10 associations. Synoptic tables of vegetation classes are given and nine alliances are briefly characterized. Using DCA-ordination analysis of syntaxa in the association-rank level we identified that the main factors of ecological differentiation are soil humidity and aeration as well as the nitrogen content. For the pioneer plant communities, other significant impact factors are the extremality of environmental conditions, their unevenness and non-equilibrium, in particular, the mechanical action of the sea waves, the dynamic processes of denudation and accumulation, salinity, as well as the variability of damping during the year. This research contributes to the identification of the place of the distinguished syntaxa of Ukrainian pioneer vegetation in the European system

    Modulation of physico-chemical properties of bovine β-casein by nonenzymatic glycation associated with enzymatic dephosphorylation

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    A major bovine casein fraction, β-casein was chemically glycated and/or enzymatically dephosphorylated. Ten glucose and nine lactose moieties were attached while all phosphate groups were removed. Glycation shifted the pI to acidic pH range and decreased the solubility at acidic pHs while dephosphorylation shifted the pI to neutral pH range and increased the solubility at acidic pHs. Dephosphorylation led to longer retention time measured using the reversed-phase high-performance liquid chromatography and affected UV-spectra of β-casein which suggested structural changes. Glycation did not affect these properties. Both modifications decreased the calcium sensitivity of β-casein, making it to keep αS1-casein in solution in the presence of Ca2+

    Comparison of ratioing and RCNA methods in the detection of flooded areas using Sentinel 2 Imagery (case study: Tulun, Russia)

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    Climate change and natural disasters caused by hydrological, meteorological, and climatic phenomena have a significant impact on cities. Russia, a continental country with a vast territory of complex geographic–ecological environments and highly variable climatic conditions, is subject to substantial and frequent natural disasters. On 29 June 2019, an extreme precipitation event occurred in the city of Tulun in the Irkutsk oblast, Russian Federation, which caused flooding due to the increase in the water level of the Iya River that passes through the city, leaving many infrastructures destroyed and thousands of people affected. This study aims to determine the flooded areas in the city of Tulun based on two change detection methods: Radiometric Rotation Controlled by No-change Axis (RCNA) and Ratioing, using Sentinel 2 images obtained before the event (19 June 2019) and during the flood peak (29 June 2019). The results obtained by the two methodologies were compared through cross-classification, and a 98% similarity was found in the classification of the areas. The study was validated based on photointerpretation of Google Earth images. The methodology presented proved to be useful for the automatic precession of flooded areas in a straightforward, but rigorous, manner. This allows stakeholders to efficiently manage areas that are buffeted by flooding episodes.LA/P/0069/2020info:eu-repo/semantics/publishedVersio

    Rare steppe plant communities in Ukraine: Status, threats and their minimization

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    Nowadays, the impact of anthropogenic activities on natural vegetation is constantly increasing, the level of threats is raised, and newer risk factors are emerging. Recent trends in the anthropogenic impact on plant communities are extremely pronounced, especially on those listed in the Green Book of Ukraine (GBU). Identifying such trends is required for the further development of strategic and tactical planning for the preservation and restoration of rare grass, shrub, and subshrub steppe, petrophyte and psammophyte plant communities of the steppe and forest-steppe zones of Ukraine. In addition to well-established threat factors that cause changes in the habitat of plant communities or mechanically affect plants, new specific threats occur. Today, the most important among them in Ukraine are as follows: climate change, military activity, growing population in the industrial cities, population poverty and government corruption, changes in forms of land ownership and the creation of a land market, lack of knowledge and effective policy, including lack of popular scientific information about the status of specific species and plant groupings, inadequate management of protected areas, uncoordinated environmental protection measures, ineffective sanctions, insufficient monitoring of the consumption of natural biological resources. The preservation of rare grass, shrubby and subshrubby communities in the steppe zone of Ukraine should be provided with proper support at the state level. There is a pressing need for a law of Ukraine “On the preservation of the steppes in Ukraine” and this will require mechanisms for its implementation. The issue of developing a strategy for the conservation and balanced use of steppe ecosystems in Ukraine, whose area is one of the largest in Europe, has long been raised. The main goal of the strategy is the actual preservation of steppe communities (most of which are currently rare) ensuring their restoration, minimizing degradation, and stopping biodiversity loss. In order to develop specific actions to eliminate threats or reduce their impact on rare plant groupings, it is required to investigate the causes of threats and assess their level and duration. This is required to preserve the landscape and biotic diversity in the steppe zone of Ukraine

    Features of ecological differentiation of halophytic, steppe and petrophytic vegetation in the valley of the Liman Kuyalnik (Odesa Oblast)

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    Assessment of key environmental factors that influence vegetation distribution and formation of plant communities is one of the most important challenges in modern phytocenology. Nowadays, several bioindication systems are applied to determine ecological specificity of plant communities and to establish the leading factors for their environmental differentiation. The system most widely used in Europe, that of H. Ellenberg, contains a numerical score on 6 ecological factors. On the example of vegetation of the valley of the Liman Kuyalnik, Y. Didukh developed the synphytoindication method based on evaluation of phytocenoses with respect to 12 ecological factors: 7 edaphic factors and 5 climatic factors; the method determines a more accurate and complete presentation of the analysis. In the valley of the Liman Kuyalnik (Odesa Oblast) the largest area is covered with halophytic and steppe vegetation. Halophytic vegetation (Therosalicornietea, Festuco-Puccinellietea classes, Juncetea maritimi, Bolboschoenetea maritimi) predominated in the shoreline areas of the valley, whereas steppe (Festuco-Brometea) and petrophytic (Sedo-Scleranthetea) vegetation dominated on the slope sites. With the application of DCA-ordination and synphytoindication methods it was established that distribution of plant communities in the hyper-space of the environmental conditions was most strongly correlated with edaphic factors, whereas microclimatic (light intensity) and climatic (thermo-regime) conditions had somewhat less influence on their differentiation. Water regime and level of soil salinity served as key factors for syntaxa of halophytic vegetation; moisture variability and salt regime, as well as soil moisture and carbonate content were key factors for the steppe vegetation, and thermo-regime was the main factor for petrophytic-steppe and petrophytic vegetation. The "eco-spaces" of these groups largely overlap. Halophytic cenoses are characterized by quite wide ecological ranges by most ecological factors. Steppe communities show much less ecological diversity. In the valley of the liman, all the steppe communities were characterized by stenotopicity in relation to most ecological factors; these factors complexly determine the specificity and diversity of biotopes within the valley, which are unique and require protection and the taking of appropriate measures, depending on the changes in activity of one or another limiting factor. Nowadays, the valley of the Liman Kuyalnik is in a state of environmental disaster. The established relationships in ecological differentiation of plant communities will be applied to further monitoring of biodiversity state, preservation and possible restoration of vegetation types that were native for this unique territory

    Large-scale mapping of bioactive peptides in structural and sequence space

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    Health-enhancing potential bioactive peptide (BP) has driven an interest in food proteins as well as in the development of predictive methods. Research in this area has been especially active to use them as components in functional foods. Apparently, BPs do not have a given biological function in the containing proteins and they do not evolve under independent evolutionary constraints. In this work we performed a large-scale mapping of BPs in sequence and structural space. Using well curated BP deposited in BIOPEP database, we searched for exact matches in non-redundant sequences databases. Proteins containing BPs, were used in fold-recognition methods to predict the corresponding folds and BPs occurrences were mapped. We found that fold distribution of BP occurrences possibly reflects sequence relative abundance in databases. However, we also found that proteins with 5 or more than 5 BP in their sequences correspond to well populated protein folds, called superfolds. Also, we found that in well populated superfamilies, BPs tend to adopt similar locations in the protein fold, suggesting the existence of hotspots. We think that our results could contribute to the development of new bioinformatics pipeline to improve BP detection.Fil: Nardo, Agustina Estefania. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Añon, Maria Cristina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Parisi, Gustavo Daniel. Universidad Nacional de Quilmes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Ellenberg-type indicator values for European vascular plant species

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    Aims: Ellenberg-type indicator values are expert-based rankings of plant species according to their ecological optima on main environmental gradients. Here we extend the indicator-value system proposed by Heinz Ellenberg and co-authors for Central Europe by incorporating other systems of Ellenberg-type indicator values (i.e., those using scales compatible with Ellenberg values) developed for other European regions. Our aim is to create a harmonized data set of Ellenberg-type indicator values applicable at the European scale. Methods: We collected European data sets of indicator values for vascular plants and selected 13 data sets that used the nine-, ten- or twelve-degree scales defined by Ellenberg for light, temperature, moisture, reaction, nutrients and salinity. We compared these values with the original Ellenberg values and used those that showed consistent trends in regression slope and coefficient of determination. We calculated the average value for each combination of species and indicator values from these data sets. Based on species’ co-occurrences in European vegetation plots, we also calculated new values for species that were not assigned an indicator value. Results: We provide a new data set of Ellenberg-type indicator values for 8908 European vascular plant species (8168 for light, 7400 for temperature, 8030 for moisture, 7282 for reaction, 7193 for nutrients, and 7507 for salinity), of which 398 species have been newly assigned to at least one indicator value. Conclusions: The newly introduced indicator values are compatible with the original Ellenberg values. They can be used for large-scale studies of the European flora and vegetation or for gap-filling in regional data sets. The European indicator values and the original and taxonomically harmonized regional data sets of Ellenberg-type indicator values are available in the Supporting Information and the Zenodo repository

    Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

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    Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)
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