59 research outputs found
THE EFFECT OF CLAY AMENDMENT ON SUBSTRATE PROPERTIES AND GROWTH OF WOODY PLANTS
Abstract MEISL, T., DUBSKÝ, M., ŠRÁMEK, F., NEČAS, T.: The eff ect of clay amendment on substrate properties and growth of woody plants. Acta univ. agric. et silvic. Mendel. Brun., 2012, LX, No. 8, pp. 163-170 This work deals with the eff ect of two clay products diff ering in particle size distribution on properties of growing substrate and on growth of containerized woody plants in substrates amended with these clay products. Fine and coarse clay were added to a peat substrate, each at two rates. The peat substrate without clay was used as a control. The substrates were tested in experiments with two woody ornamentals (Thuja occidentalis 'Smaragd' and Prunus cistena). Chemical and physical properties of the substrates were measured according to European Standards before planting. Proportion of water categories diff ering in availability to the plants were calculated from retention curves measured on the sand box. Properties of substrates in containers with and without plants were evaluated in the same way at the end of the culture. Clay addition changed chemical and physical properties of the tested substrates in terms: available nutrients content, particle density, bulk density, total pore volume, easy available water, water buff ering capacity, air capacity, and shrinkage. The eff ect of fi ne clay was much stronger. In comparison with the clear eff ect of clay addition on the substrate chemical and physical properties, the eff ect on the growth and quality of model woody plants was not so explicit
Geoneutrinos
Neutrino geophysics is an emerging interdisciplinary field with the potential to map the abundances and distribution of radiogenic heat sources in the continental crust and deep Earth. To date, data from two different experiments quantify the amount of Th and U in the Earth and begin to put constraints on radiogenic power in the Earth available for driving mantle convection and plate tectonics. New improved detectors are under construction or in planning stages. Critical testing of compositional models of the Earth requires integrating geoneutrino and geological observations. Such tests will lead to significant constraints on the absolute and relative abundances of U and Th in the continents. High radioactivity in continental crust puts limits on land-based observatories' capacity to resolve mantle models with current detection methods. Multiple-site measurement in oceanic areas away from continental crust and nuclear reactors offers the best potential to extract mantle information. Geophysics would benefit from directional detection and the detectability of electron antineutrinos from potassium decay
Geophysical and geochemical constraints on geoneutrino fluxes from Earth's mantle
Knowledge of the amount and distribution of radiogenic heating in the mantle
is crucial for understanding the dynamics of the Earth, including its thermal
evolution, the style and planform of mantle convection, and the energetics of
the core. Although the flux of heat from the surface of the planet is robustly
estimated, the contributions of radiogenic heating and secular cooling remain
poorly defined. Constraining the amount of heat-producing elements in the Earth
will provide clues to understanding nebula condensation and planetary formation
processes in early Solar System. Mantle radioactivity supplies power for mantle
convection and plate tectonics, but estimates of mantle radiogenic heat
production vary by a factor of more than 20. Recent experimental results
demonstrate the potential for direct assessment of mantle radioactivity through
observations of geoneutrinos, which are emitted by naturally occurring
radionuclides. Predictions of the geoneutrino signal from the mantle exist for
several established estimates of mantle composition. Here we present novel
analyses, illustrating surface variations of the mantle geoneutrino signal for
models of the deep mantle structure, including those based on seismic
tomography. These variations have measurable differences for some models,
allowing new and meaningful constraints on the dynamics of the planet. An ocean
based geoneutrino detector deployed at several strategic locations will be able
to discriminate between competing compositional models of the bulk silicate
Earth.Comment: 34 pages, 6 tables, 5 figures, 2 supplementary figures; revised
version submitted to Earth Planet. Sci. Let
Letter of Intent: Jinping Neutrino Experiment
Jinping Neutrino Experiment (Jinping) is proposed to significantly improve
measurements on solar neutrinos and geoneutrinos in China Jinping Laboratory -
a lab with a number of unparalleled features, thickest overburden, lowest
reactor neutrino background, etc., which identify it as the world-best
low-energy neutrino laboratory. The proposed experiment will have target mass
of 4 kilotons of liquid scintillator or water-based liquid scintillator, with a
fiducial mass of 2 kilotons for neutrino-electron scattering events and 3
kilotons for inverse-beta interaction events. A number of initial sensitivities
studies have been carried out, including on the transition phase for the solar
neutrinos oscillation from the vacuum to the matter effect, the discovery of
solar neutrinos from the carbon-nitrogen-oxygen (CNO) cycle, the resolution of
the high and low metallicity hypotheses, and the unambiguous separation on U
and Th cascade decays from the dominant crustal anti-electron neutrinos in
China.Comment: Proposal for the Jinping Neutrino Experimen
Global Impact of the COVID-19 Pandemic on Cerebral Venous Thrombosis and Mortality
Background and purpose: Recent studies suggested an increased incidence of cerebral venous thrombosis (CVT) during the coronavirus disease 2019 (COVID-19) pandemic. We evaluated the volume of CVT hospitalization and in-hospital mortality during the 1st year of the COVID-19 pandemic compared to the preceding year.
Methods: We conducted a cross-sectional retrospective study of 171 stroke centers from 49 countries. We recorded COVID-19 admission volumes, CVT hospitalization, and CVT in-hospital mortality from January 1, 2019, to May 31, 2021. CVT diagnoses were identified by International Classification of Disease-10 (ICD-10) codes or stroke databases. We additionally sought to compare the same metrics in the first 5 months of 2021 compared to the corresponding months in 2019 and 2020 (ClinicalTrials.gov Identifier: NCT04934020).
Results: There were 2,313 CVT admissions across the 1-year pre-pandemic (2019) and pandemic year (2020); no differences in CVT volume or CVT mortality were observed. During the first 5 months of 2021, there was an increase in CVT volumes compared to 2019 (27.5%; 95% confidence interval [CI], 24.2 to 32.0; P<0.0001) and 2020 (41.4%; 95% CI, 37.0 to 46.0; P<0.0001). A COVID-19 diagnosis was present in 7.6% (132/1,738) of CVT hospitalizations. CVT was present in 0.04% (103/292,080) of COVID-19 hospitalizations. During the first pandemic year, CVT mortality was higher in patients who were COVID positive compared to COVID negative patients (8/53 [15.0%] vs. 41/910 [4.5%], P=0.004). There was an increase in CVT mortality during the first 5 months of pandemic years 2020 and 2021 compared to the first 5 months of the pre-pandemic year 2019 (2019 vs. 2020: 2.26% vs. 4.74%, P=0.05; 2019 vs. 2021: 2.26% vs. 4.99%, P=0.03). In the first 5 months of 2021, there were 26 cases of vaccine-induced immune thrombotic thrombocytopenia (VITT), resulting in six deaths.
Conclusions: During the 1st year of the COVID-19 pandemic, CVT hospitalization volume and CVT in-hospital mortality did not change compared to the prior year. COVID-19 diagnosis was associated with higher CVT in-hospital mortality. During the first 5 months of 2021, there was an increase in CVT hospitalization volume and increase in CVT-related mortality, partially attributable to VITT
Global Impact of the COVID-19 Pandemic on Cerebral Venous Thrombosis and Mortality.
BACKGROUND AND PURPOSE: Recent studies suggested an increased incidence of cerebral venous thrombosis (CVT) during the coronavirus disease 2019 (COVID-19) pandemic. We evaluated the volume of CVT hospitalization and in-hospital mortality during the 1st year of the COVID-19 pandemic compared to the preceding year. METHODS: We conducted a cross-sectional retrospective study of 171 stroke centers from 49 countries. We recorded COVID-19 admission volumes, CVT hospitalization, and CVT in-hospital mortality from January 1, 2019, to May 31, 2021. CVT diagnoses were identified by International Classification of Disease-10 (ICD-10) codes or stroke databases. We additionally sought to compare the same metrics in the first 5 months of 2021 compared to the corresponding months in 2019 and 2020 (ClinicalTrials.gov Identifier: NCT04934020). RESULTS: There were 2,313 CVT admissions across the 1-year pre-pandemic (2019) and pandemic year (2020); no differences in CVT volume or CVT mortality were observed. During the first 5 months of 2021, there was an increase in CVT volumes compared to 2019 (27.5%; 95% confidence interval [CI], 24.2 to 32.0; P<0.0001) and 2020 (41.4%; 95% CI, 37.0 to 46.0; P<0.0001). A COVID-19 diagnosis was present in 7.6% (132/1,738) of CVT hospitalizations. CVT was present in 0.04% (103/292,080) of COVID-19 hospitalizations. During the first pandemic year, CVT mortality was higher in patients who were COVID positive compared to COVID negative patients (8/53 [15.0%] vs. 41/910 [4.5%], P=0.004). There was an increase in CVT mortality during the first 5 months of pandemic years 2020 and 2021 compared to the first 5 months of the pre-pandemic year 2019 (2019 vs. 2020: 2.26% vs. 4.74%, P=0.05; 2019 vs. 2021: 2.26% vs. 4.99%, P=0.03). In the first 5 months of 2021, there were 26 cases of vaccine-induced immune thrombotic thrombocytopenia (VITT), resulting in six deaths. CONCLUSIONS: During the 1st year of the COVID-19 pandemic, CVT hospitalization volume and CVT in-hospital mortality did not change compared to the prior year. COVID-19 diagnosis was associated with higher CVT in-hospital mortality. During the first 5 months of 2021, there was an increase in CVT hospitalization volume and increase in CVT-related mortality, partially attributable to VITT
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