2,272 research outputs found

    The small-scale variation of herb-layer community structure in a riparian mixed forest

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    The ground vegetation layer is the most diverse plant community in forest ecosystems. We have shown the role of spatial variables, soil properties and overstorey structure in spatial variation of the herb-layer community in a riparian mixed forest . The research was conducted in the "Dnipro-Orils’kiy" Nature Reserve (Ukraine). The research polygon was located in the forest in the floodplain of the River Protich, which is a left tributary of the River Dnipro. Plant abundance was quantified by measuring cover within an experimental polygon. The experimental polygon consisted of 7 transects, each comprising 15 test points. The distance between the rows in the site was 3 m. At the site we established a plot of 45 × 21 m, with 105 subplots of 3 × 3 m organized in a regular grid. A list of vascular plant species was composed for each 3 × 3 m subplot along with visual estimates of species cover projection. The plant community was represented by 43 species, of which 18.6% were phanerophytes, 39.5% were hemicryptophytes, 9.3% were therophytes, 7.0% were geophytes. An overall test of random labelling revealed the total nonrandom distribution of the tree stems within the site. The species-specific test of random labelling showed the nonrandom segregated distribution of Acer tataricum, Pyrus communis, Quercus robur, and Ulmus laevis. Crataegus monogyna and Euonymus europaeus were distributed randomly. The nearest neighbour of Acer tataricum was less likely to be Ulmus laevis. There was no direct spatial connection between Acer tataricum and other trees. Crataegus monogyna, Pyrus communis, Quercus robur and Euonymus europaeus were not segregated from all other species. The nearest neighbour of Ulmus laevis was less likely to be Acer tataricum. Constrained correspondence analysis (CCA) was applied as ordination approach. The forward selection procedure allowed us to select 6 soil variables which explain 28.3% of the herb-layer community variability. The list of the important soil variables includes soil mechanical impedance (at the depth 0–5, 30–35, 75–80, and 95–10 cm), soil moisture, and soil bulk density. The variation explained by pure spatial variables accounted for 11.0 %. The majority of the tree-distance structured variation in plant community composition was broad-scaled. The spatial scalograms were left-skewed asymmetric. Significant relationship was found between the pure spatial component of the community variation and a number of phytoindicator estimations, most important of which were the variability of damping and humidity. Tree stand was obseerved to be a considerable factor structuring both the herb-layer community and spatial variation of the physical properties of soil

    Phytoindication assessment of the effect of reconstruction on the light regime of an urban park

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    The ecological restoration of urban parks is used to increase their recreational attractiveness, improve air quality, mitigate urban heat island effects, improve stormwater infiltration, and provide other social and environmental benefits. The dynamics of plant communities after urban forest restoration requires investigation. The study assessed the impact of urban park reconstruction on the state of grass cover, phytoindication of changes in light regime caused by park reconstruction and found out the dependence of reliability of phytoindication assessment on the number of species in the relevant area. The study was conducted in the recreational area of the Botanical Garden of the Oles Honchar Dnipro National University (Ukraine). A tree plantation was created after the Second World War in the location of a natural oak forest. In 2019, a 2.8 ha area of the park was reconstructed. The samples were taken within polygons, two of which were placed in the reconstruction area and two of which were placed in a similar section of the park where no reconstruction was performed. During the reconstruction process, walkways were rebuilt, shrubs were removed, old, damaged trees were removed, and tree crowns were trimmed. Juvenile trees were planted in place of the removed old trees. Old outbuildings, which greatly impaired the aesthetic perception of the park, were also removed. Transport and construction machinery was involved in the reconstruction. A total of 65 plant species were found within the studied polygons. The number of herbaceous species in the park area after reconstruction was higher than without reconstruction. The crown closure in the reconstructed area was significantly lower than that in the untreated conditions. The phytoindication assessment showed that the light regime varies from the conditions suitable for the scyophytes (plants of typical foliage forests) to the conditions suitable for the sub-heliophytes (plants of light forests and shrubberies, or high herbaceous communities; lower layers are in the shade). The light regime in the park area after reconstruction was statistically significantly different from the regime in the untreated park area. The lighting regime after the reconstruction was favourable to sub-heliophytes, and without reconstruction the regime favoured hemi-scyophytes. Tree canopy crown closure negatively correlated with grass height and herbaceous layer projective cover. The tree canopy crown closure, grass height, and herbaceous layer projective cover were able to explain 86% of the phytoindication assessment of the lighting regime variation. These parameters negatively affected the light regime. The prospect of further research is to investigate the dependence of indicative reliability of the assessment of other environmental factors with the help of phytoindication depending on the number of species. In addition to the indication of traditional ecological factors it is of particular interest to clarify the aspect of the dynamics of hemeroby indicators as a result of park reconstruction

    Interaction of Drugs Used for the Treatment of Cardiovascular Diseases

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    Combined therapy in cardiology is currently the most recognized method of treatment, especially in patients with hypertension. Approximately in 50 % of patients with hypertension, monotherapy is effective. However to achieve the desired effect in the remaining half of patients, simultaneous administration of two and sometimes three drugs is required. Numerous drugs with a fixed combination of two (and even three) antihypertensive drugs, often used in clinical practice, greatly simplify the dosage regimen of drugs and improve patients’ adherence to treatment. Unfortunately, simultaneous prescription of several drugs increases sharply the probability of inter-drug interaction with the increase in the number of prescribed drugs. The result of drug-drug intereaction may be unpredictable. Therefore, the ability to predict the possible adverse reactions in patients with cardiovascular diseases and to prescribe rationally combined pharmacotherapy is a guarantee of highly efficient and safe treatment.Currently, rational combinations of antihypertensive drugs of different groups make hypertension therapy more comfortable and increases patients’ adherence to treatment. The authors present topical combinations of antihypertensive drugs in one drug: angiotensin converting enzyme inhibitor + diuretic, β-adrenoblocker + diuretic; diuretic + angiotensin receptor antagonist; calcium antagonist + angiotensin receptor antagonist; calcium antagonist + β-adrenoblocker, and others.The article presents an overview of both rational (calcium antagonist + diuretic, β-adrenoblocker + diuretic,) and irrational (angiotensin converting enzyme Inhibitor + potassium-sparing diuretic, angiotensin receptor blocker + potassium-sparing diuretic) combinations of antihypertensive drugs. Combinations of some hypotensive and antianginal drugs with drugs of other groups with a high risk of adverse reactions are presented

    Spin excitations of the correlated semiconductor FeSi probed by THz radiation

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    By direct measurements of the complex optical conductivity σ(ν)\sigma(\nu) of FeSi we have discovered a broad absorption peak centered at frequency ν0(4.2K)32cm1\nu_{0}(4.2 K) \approx 32 cm^{-1} that develops at temperatures below 20 K. This feature is caused by spin-polaronic states formed in the middle of the gap in the electronic density of states. We observe the spin excitations between the electronic levels split by the exchange field of He=34±6TH_{e}=34\pm 6 T. Spin fluctuations are identified as the main factor determining the formation of the spin polarons and the rich magnetic phase diagram of FeSi.Comment: 5 pages, 4 figure

    Conspiracy in the activities of law enforcement agencies of the Russian Federation and foreign states: issues of terminology

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    Based on the analysis of regulatory legal acts relating to the activities of law enforcement agencies of different states, this paper presents an ambiguous interpretation of thelegal concept of "conspiracy" and the expediency of using this term in regulatory legal acts that determine the content and regulate the organization of international cooperation with law enforcement agencies of the Russian Federation and foreign countrie

    SOME ASPECTS OF EFFECTIVENESS AND SAFETY OF ANTIBACTERIAL DRUGS IN PREGNANCY

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    Analysis of published data on clinical effectiveness and safety of antimicrobial drugs indicates that original and generic antibacterial medicines sometimes significantly differ in the therapeutic equivalence and in the frequency and severity of side effects

    Evidence of a subenergy gap in the overdoped regime of Y_{1-x}Ca_{x}Ba_{2}Cu_{3}O_{7-\delta} thin films from THz Spectroscopy

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    We measured the terahertz (THz) complex conductivity of Ca doped YBa_{2}Cu_{3}O_{7-\delta} thin films in the frequency range of 0.1 to 3 THz (3 to 100 cm^{-1}) and at a temperature range of 20 to 300 K. The films were measured using both time domain and frequency domain THz methods. We showed evidence for the existence of a sub-gap in overdoped Y_{1-x}Ca_{x}Ba_{2}Cu_{3}O_{7-\delta} samples doped with 5% and 10% Ca. Evidence for the opening of this sub-gap appears as a sharp decrease in the spectrum of the real part of conductivity at frequencies equivalent to a gap energy of 1 meV and is more prominent with increased doping. This decrease in conductivity can be explained by using d-wave pairing symmetry with an imaginary part of is or id_{xy} which suggests node removal.Comment: 7 pages, 7 figure

    Techno legal problems of ensuring international and national security

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    This paper deals with the problem of socio-economic security of the state. The paper examines possible ways of ensuring the social security of society by training personnel in public services and social workers having modern competencies that can ensure social security and create conditions for social stability and consistently solve the tasks of social and economic development in the interests of

    PROJECTIVE METHODS OF STUDYING ATTITUDES TO THE DEATH OF ADOLESCENTS

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    The article presents the experience of using projective methods to study the attitude to the death of adolescents. There were 120 adolescents aged 14–16 participated in the research. The analysis of the stories (TAT) revealed the peculiarities of adolescents’ attitude to death: focus on the present and feelings, difficulties in understanding oneself and one’s experience, the significance of the topic of death, death is understood as loss.В статье представлен опыт применения проективных методов для исследования отношения к смерти подростков. В исследованиях приняли участие 120 подростков 14–16 лет. Анализ рассказов выявил особенности отношения подростков к смерти: сосредоточенность на настоящем и переживаниях, трудности в осмыслении себя и своего опыта, значимость темы смерти, смерть понимается как утрата

    Phytoindication assessment of the effect of reconstruction on the light regime of an urban park

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    The ecological restoration of urban parks is used to increase their recreational attractiveness, improve air quality, mitigate urban heat island effects, improve stormwater infiltration, and provide other social and environmental benefits. The dynamics of plant communities after urban forest restoration requires investigation. The study assessed the impact of urban park reconstruction on the state of grass cover, phytoindication of changes in light regime caused by park reconstruction and found out the dependence of reliability of phytoindication assessment on the number of species in the relevant area. The study was conducted in the recreational area of the Botanical Garden of the Oles Honchar Dnipro National University (Ukraine). A tree plantation was created after the Second World War in the location of a natural oak forest. In 2019, a 2.8 ha area of the park was reconstructed. The samples were taken within polygons, two of which were placed in the reconstruction area and two of which were placed in a similar section of the park where no reconstruction was performed. During the reconstruction process, walkways were rebuilt, shrubs were removed, old, damaged trees were removed, and tree crowns were trimmed. Juvenile trees were planted in place of the removed old trees. Old outbuildings, which greatly impaired the aesthetic perception of the park, were also removed. Transport and construction machinery was involved in the reconstruction. A total of 65 plant species were found within the studied polygons. The number of herbaceous species in the park area after reconstruction was higher than without reconstruction. The crown closure in the reconstructed area was significantly lower than that in the untreated conditions. The phytoindication assessment showed that the light regime varies from the conditions suitable for the scyophytes (plants of typical foliage forests) to the conditions suitable for the sub-heliophytes (plants of light forests and shrubberies, or high herbaceous communities; lower layers are in the shade). The light regime in the park area after reconstruction was statistically significantly different from the regime in the untreated park area. The lighting regime after the reconstruction was favourable to sub-heliophytes, and without reconstruction the regime favoured hemi-scyophytes. Tree canopy crown closure negatively correlated with grass height and herbaceous layer projective cover. The tree canopy crown closure, grass height, and herbaceous layer projective cover were able to explain 86% of the phytoindication assessment of the lighting regime variation. These parameters negatively affected the light regime. The prospect of further research is to investigate the dependence of indicative reliability of the assessment of other environmental factors with the help of phytoindication depending on the number of species. In addition to the indication of traditional ecological factors it is of particular interest to clarify the aspect of the dynamics of hemeroby indicators as a result of park reconstruction. Keywords: recreation; diversity; indicator reliability; hemeroby; ecosystem transformation; plant community
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