scholarly journals Incidence of Rio Grande Gummosis of Grapefruit Is Not Associated with Concentrations of Anions in Soil Water

HortScience ◽  
1998 ◽  
Vol 33 (7) ◽  
pp. 1186-1187 ◽  
Author(s):  
Y.C. Li ◽  
A.K. Alva ◽  
D.V. Calvert ◽  
R.M. Sonoda ◽  
R.R. Pelosi ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Samples ◽  
Rio Grande ◽  
Sour Orange ◽  
Citrus Paradisi ◽  
High Concentrations ◽  
Depth Water ◽  
Chloride Concentrations ◽  
Suction Lysimeters

The objective of this study was to evaluate the role of chloride (Cl-) and other anions in soil water on the incidence and severity of Rio Grande Gummosis (RGG) in grapefruit (Citrus paradisi MacFadyen) trees. White `Marsh' grapefruit trees on sour orange (C. aurantium Lush.) rootstock were grown on two-row raised beds. Due to differential rates of K application (as KCl), the trees received various rates of Cl- ranging from 0 to 156 kg·ha-1 per year. Soil water was sampled using suction lysimeters at 120- and 180-cm depths. The severity of RGG was evaluated 18 months following the application of various rates of KCl. The concentration of Cl- in soil water samples varied from 16.2 to 617 mg·L-1, with mean concentrations across all treatments of 160.7 and 188.4 mg·L-1 for 120- and 180-cm depth water samples, respectively. The concentrations of Cl- and other anions (\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NO}_{3}^{-}\) \end{document}, \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{PO}_{4}^{3-}\) \end{document}, \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{SO}_{4}^{2-}\) \end{document}) in soil water at either 120- or 180-cm depth were poorly related to the incidence or severity of RGG (R = -0.10 to -0.28). Chloride concentrations in the soil water ranged from 20 to 617 mg·L-1 near the RGG-free trees, and from 16.7 to 310 mg·L-1 near the trees that were affected by RGG. This suggests that under the conditions of this study, neither the incidence nor the severity of RGG was influenced by high concentrations of Cl- in the soil water.

Origin of the waters sourced by trees in a pre-Alpine forested catchment

2020 ◽  
Author(s):  
Giulia Zuecco ◽  
Chiara Marchina ◽  
Amin Anam ◽  
Michael Engel ◽  
Jay Frentress ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Samples ◽  
Vacuum Distillation ◽  
Stream Water ◽  
Bulk Soil ◽  
Water Isotopes ◽  
Stable Water Isotopes ◽  
Forested Catchment ◽  
Cryogenic Vacuum ◽  
Suction Lysimeters

<p>Stable water isotopes have proven to be useful tracers to determine the origin of water taken up by plants, quantify the relative contributions of water sources to stream runoff and investigate water flow paths. However, the presence of different water pools in a catchment and soil water allocation complicates our understanding of water cycling, and calls for research on processes governing soil water movement and storage, as well as interactions between soil and plants.</p><p>In this study, we used isotopic data from a forested catchment in the Italian pre-Alps to i) investigate the spatial and temporal variability of the isotopic signature of various water sources, and ii) determine which waters are used by beech and chestnut trees in the study area.</p><p> </p><p>Ecohydrological and hydrometeorological monitoring took place in the 2.4-ha Ressi catchment (Northern Italy). Elevations range from 598 to 721 m a.s.l., while average slope is 31°. Average annual precipitation is about 1695 mm, while average annual temperature is 9.7 °C. The entire catchment is covered by deciduous forest, with beech, chestnut, hazel and maple as the main tree species.</p><p>Water samples for isotopic analysis were taken monthly from bulk precipitation, approximately bi-weekly from stream water, groundwater and soil water by two suction lysimeter cups in the riparian zone. Bulk soil water samples and twigs for xylem water extraction by cryogenic vacuum distillation were collected starting in June, 2017. All water samples were analysed by laser spectroscopy, except xylem water that was analysed by mass spectrometry.</p><p> </p><p>Stream water, groundwater and soil water extracted by suction lysimeters were isotopically similar to precipitation and aligned to the local meteoric water line. Bulk soil water obtained by cryogenic vacuum distillation showed an evaporation signature, especially on the hillslope where soil moisture was lower and soil water had been extracted by suction lysimeters only during or just after a large rainfall event. This indicates that soil water sampled by suction lysimeters and extracted by cryogenic vacuum distillation is stored differently in the soil layers due to the different soil tension, and hillslopes tend to store less mobile soil water compared to the riparian zone. At greater depths, bulk soil water extracted by cryogenic vacuum distillation was slightly less evaporated and less enriched in heavy isotopes compared to soil water extracted from shallower layers. The isotopic composition of xylem water had a large temporal and tree-species variability, with chestnut xylem water samples more enriched in heavy isotopes than samples obtained from beech trees. Xylem water was more similar to soil water obtained by cryogenic vacuum distillation, suggesting that in the study area trees likely use more bulk soil water than the mobile soil water, groundwater and stream water.</p><p> </p><p>Keywords: stable water isotopes; soil water; xylem water; forested catchment.</p>

scholarly journals Deutsche Schule urbana - Collegio Allemão de Pelotas na rota da Verein Für das Deutschtum im Ausland (V.D.A.), 1921-1925, 1933 / Urban Deutsche Schule – German College of Pelotas on the Verein Für das Deutschtum im Ausland (V.D.A.) Route, 1921-1925, 1933

2019 ◽  
Vol 2 (6) ◽  
pp. 80
Author(s):  
Maria Angela Peter da Fonseca ◽  
Elomar Antonio Callegaro Tambara
Keyword(s):  
School Culture ◽  
Rio Grande ◽  
Rio Grande Do Sul ◽  
The South ◽  
Educational Project ◽  
Cultura Escolar ◽  
Didactic Material ◽  
German College

Neste artigo enfoca-se o papel dos visitantes que chegavam à Deutsche Schule urbana, Collegio Allemão de Pelotas, no sul do Rio Grande do Sul, provenientes da Verein für das Deutschtum im Ausland (V.D.A.), (Sociedade de Apoio ao Deutschtum no Exterior), em 1921, 1923, 1924, 1925 e 1933, situada em Hamburgo e Berlim, na Alemanha. O objetivo desses visitantes era inspecionar o projeto educacional alemão e a manutenção do Deutschtum, que mesclava elementos do nacionalismo alemão, vigente, à cultura escolar deste educandário em tempos de Nacionalização do Ensino no Brasil. Consequência dessas visitas era o envio de livros, material didático e professores alemães, bem como a troca de correspondência entre os alunos do educandário de Pelotas e alunos alemães. Trata-se de pesquisa qualitativa, bibliográfica e documental cujas fontes principais são os Relatórios Escolares da Deutsche Schule de Pelotas dos anos 1921, 1923, 1924, 1925 e 1933.* * *This paper focuses on the role of visitors arriving at the urban Deutsche Schule, German College of Pelotas, in the south of Rio Grande do Sul from the Verein für das Deutschtum im Ausland (VDA), a Society for Supporting Deutschtum Abroad, in 1921, 1923, 1924, 1925 and 1933, located in Hamburg and Berlin, Germany. The purpose of these visitors was to inspect the German educational project and the maintenance of the Deutschtum, which merged elements of German nationalism, in force, into the school culture of this educandário in times of Nationalization of Teaching in Brazil. The consequence of these visits was the sending of books, didactic material and German teachers, as well as the exchange of correspondence between the students of the educator of Pelotas and German students. It is a qualitative, bibliographical and documentary research whose main sources are the School Reports of the Deutsche Schule of Pelotas of years 1921, 1923, 1924, 1925 and 1933.

scholarly journals Spatial Variation of Water Chemistry in Aries River Catchment Western Romania

2021 ◽  
Vol 11 (14) ◽  
pp. 6592
Author(s):  
Ana Moldovan ◽  
Maria-Alexandra Hoaghia ◽  
Anamaria Iulia Török ◽  
Marius Roman ◽  
Ionut Cornel Mirea ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Water Quality ◽  
Water Chemistry ◽  
Water Samples ◽  
Mine Drainage ◽  
Pollution Indices ◽  
Mining Activities ◽  
River Catchment ◽  
High Concentrations ◽  
The Impact

This study aims to investigate the quality and vulnerability of surface water (Aries River catchment) in order to identify the impact of past mining activities. For this purpose, the pollution and water quality indices, Piper and Durov plots, as well vulnerability modeling maps were used. The obtained results indicate that the water samples were contaminated with As, Fe, Mn, Pb and have relatively high concentrations of SO42−, HCO3−, TDS, Ca, K, Mg and high values for the electrical conductivity. Possible sources of the high content of chemicals could be the natural processes or the inputs of the mine drainage. Generally, according to the pollution indices, which were correlated to high concentrations of heavy metals, especially with Pb, Fe and Mn, the water samples were characterized by heavy metals pollution. The water quality index classified the studied water samples into five different classes of quality, namely: unsuitable for drinking, poor, medium, good and excellent quality. Similarly, medium, high and very high vulnerability classes were observed. The Durov and Piper plots classified the waters into Mg-HCO3− and Ca-Cl− types. The past and present mining activities clearly change the water chemistry and alter the quality of the Aries River, with the water requiring specific treatments before use.

scholarly journals Environmentally persistent free radicals are ubiquitous in wildfire charcoals and remain stable for years

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Gabriel Sigmund ◽  
Cristina Santín ◽  
Marc Pignitter ◽  
Nathalie Tepe ◽  
Stefan H. Doerr ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Free Radicals ◽  
Reactive Oxygen ◽  
Resonance Spectroscopy ◽  
Oxygen Species ◽  
Pyrogenic Carbon ◽  
Spin Resonance ◽  
Long Time ◽  
High Concentrations

AbstractGlobally landscape fires produce about 256 Tg of pyrogenic carbon or charcoal each year. The role of charcoal as a source of environmentally persistent free radicals, which are precursors of potentially harmful reactive oxygen species, is poorly constrained. Here, we analyse 60 charcoal samples collected from 10 wildfires, that include crown as well as surface fires in forest, shrubland and grassland spanning different boreal, temperate, subtropical and tropical climate. Using electron spin resonance spectroscopy, we measure high concentrations of environmentally persistent free radicals in charcoal samples, much higher than those found in soils. Concentrations increased with degree of carbonization and woody fuels favoured higher concentrations. Moreover, environmentally persistent free radicals remained stable for an unexpectedly long time of at least 5 years. We suggest that wildfire charcoal is an important global source of environmentally persistent free radicals, and therefore potentially of harmful reactive oxygen species.

Singlet oxygen feedback delayed fluorescence of protoporphyrin IX in organic solutions

2017 ◽  
Vol 16 (4) ◽  
pp. 507-518 ◽  
Author(s):  
Ivo S. Vinklárek ◽  
Marek Scholz ◽  
Roman Dědic ◽  
Jan Hála
Keyword(s):  
Partial Pressure ◽  
Singlet Oxygen ◽  
Protoporphyrin Ix ◽  
Clinical Applications ◽  
Delayed Fluorescence ◽  
Diagnostic Tools ◽  
Partial Pressure Of Oxygen ◽  
High Concentrations ◽  
Organic Solutions

The PpIX DF show the significant role of SOFDF mechanism at high concentrations and at atmospheric partial pressure of oxygen and should be considered when developing diagnostic tools for clinical applications.

scholarly journals Synthesis of Platinum Nanocrystals within Iodine Ions Mediated

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Jiamao Li ◽  
Jingwei Hou ◽  
Yu Gong ◽  
Chengjian Xiao ◽  
Lei Yue ◽  
...  
Keyword(s):  
Shape Control ◽  
Growth Process ◽  
Growth Stage ◽  
Nucleation Stage ◽  
Platinum Nanocrystals ◽  
High Resolution Tem ◽  
Pt Nanocrystals ◽  
High Concentrations ◽  
Insight Into

A liquid-phase reducing method of synthesizing Pt nanocrystals was demonstrated, and dendrite-, cube-, and cuboctahedron-shaped Pt nanocrystals (NCs) with well-defined monomorphic were successfully synthesized through iodine ions mediated with the CTAB agent. When the KI concentration was increased to thirty times of K2PtCl4 at the nucleation stage, the high-quality Pt nanodendrites could be obtained. However, no matter how many KI were added at the growth age, only cube- and cuboctahedron-shaped Pt nanocrystals formed. The results of high-resolution TEM, EDX, and XRD indicated that the size and shape of Pt NCs could be turned by changing the concentration and time of KI. In the nucleation stage, it might be due to that some iodine ions adsorb on the surfaces of Pt NCs, which probably cause the rapid growth process resulting in the formation of Pt nanodendrites. In the growth stage, although high concentrations of I− ions could contribute to the shape control and generate bigger particles of Pt NCs, small Pt particles do not grow into dendrites. The insight into the role of I− ions in synthesis of Pt NCs reported here provided a viewpoint for clearly understanding the formation mechanism of anisotropic platinum nanostructures.

scholarly journals A thermodynamic formulation of root water uptake

2016 ◽  
Vol 20 (8) ◽  
pp. 3441-3454 ◽  
Author(s):  
Anke Hildebrandt ◽  
Axel Kleidon ◽  
Marcel Bechmann
Keyword(s):  
Soil Water ◽  
Water Uptake ◽  
Water Distribution ◽  
Bound Water ◽  
Root Water Uptake ◽  
Flow Path ◽  
Thermodynamic Evaluation ◽  
Entire Flow ◽  
Soil Water Distribution

Abstract. By extracting bound water from the soil and lifting it to the canopy, root systems of vegetation perform work. Here we describe how root water uptake can be evaluated thermodynamically and demonstrate that this evaluation provides additional insights into the factors that impede root water uptake. We derive an expression that relates the energy export at the base of the root system to a sum of terms that reflect all fluxes and storage changes along the flow path in thermodynamic terms. We illustrate this thermodynamic formulation using an idealized setup of scenarios with a simple model. In these scenarios, we demonstrate why heterogeneity in soil water distribution and rooting properties affect the impediment of water flow even though the mean soil water content and rooting properties are the same across the scenarios. The effects of heterogeneity can clearly be identified in the thermodynamics of the system in terms of differences in dissipative losses and hydraulic energy, resulting in an earlier start of water limitation in the drying cycle. We conclude that this thermodynamic evaluation of root water uptake conveniently provides insights into the impediments of different processes along the entire flow path, which goes beyond resistances and also accounts for the role of heterogeneity in soil water distribution.

The role of tree stem proximity in the spatial variability of soil water repellency in a eucalypt plantation in coastal Portugal

Soil Research ◽  
2005 ◽  
Vol 43 (3) ◽  
pp. 251 ◽  
Author(s):  
J. J. Keizer ◽  
A. J. D. Ferreira ◽  
C. O. A. Coelho ◽  
S. H. Doerr ◽  
M. C. Malvar ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Repellency ◽  
Soil Water Repellency ◽  
Individual Measurement ◽  
Hydrophobic Compounds ◽  
Ethanol Droplet ◽  
Central Portugal ◽  
Living Organisms ◽  
Tree Stem

Certain organic compounds derived from living organisms or their decaying parts are generally accepted to induce soil water repellency. Water repellency may therefore be expected to increase with proximity to organisms releasing hydrophobic compounds. This hypothesis is tested here for Eucalyptus globulus trees, since eucalypt species are frequently associated with elevated repellency levels. In a young, first-rotation plantation on coastal dune sands in central Portugal, repeat measurements of water repellency using the ‘Molarity of an Ethanol Droplet’ (MED) test were carried out in situ between April 2001 and May 2002. On 25 dates, repellency was measured at initially 2 and later 3 distances on 2 sides of 8–11 randomly selected trees. On 15 occasions, additional repellency measurements were performed within small grids aside 3 of the selected trees. The postulated decrease in topsoil water repellency with increased distance from eucalypt tree stems was found to apply on several individual measurement dates, as well as, more unexpectedly since repellency usually is a transient phenomenon, for the study period as a whole. The results confirm the general association of eucalypt trees with water repellency, and indicate that tree stem proximity is an important but not sufficient factor to explain repellency distribution in topsoil.

scholarly journals Colchicine-binding protein of the liver. Its characterization and relation to microtubules.

1975 ◽  
Vol 66 (3) ◽  
pp. 609-620 ◽  
Author(s):  
C Patzelt ◽  
A Singh ◽  
Y L Marchand ◽  
L Orci ◽  
B Jeanrenaud
Keyword(s):  
High Speed ◽  
Specific Binding ◽  
Electrophoretic Analysis ◽  
Binding Activity ◽  
Low Concentrations ◽  
Electrophoretic Behavior ◽  
High Affinity Binding Site ◽  
High Concentrations

Colchicine-binding activity of mouse liver high-speed supernate has been investigated. It has been found to be time and temperature dependent. Two binding activities with different affinities for colchicine seem to be present in this high-speed supernate, of which only the high-affinity binding site (half maximal binding at 5 x 10(-6) M colchicine) can be attributed to microtubular protein by comparison with purified tubulin. Vinblastine interacted with this binding activity by precipitating it when used at high concentrations (2 x 10(-3) M), and by stabilizing it at low concentrations (10(-5) M). Lumicolchicine was found not to compete with colchicine. The colchicine-binding activity was purified from liver and compared with that of microtubular protein from brain. The specific binding activity of the resulting preparation, its electrophoretic behavior, and the electron microscope appearance of the paracrystals obtained upon its precipitation with vinblastine permitted its identification as microtubular protein (tubulin). Electrophoretic analysis of the proteins from liver supernate that were precipitated by vinblastine indicated that this drug was not specific for liver tubulin. Preincubation of liver supernate with 5 mM EGTA resulted in a time-dependent decrease of colchicine-binding activity, which was partly reversed by the addition of Ca++. However, an in vitro formation of microtubules upon lowering the Ca++ concentration could not be detected. Finally, a method was developed enabling that portion of microtubular protein which was present as free tubulin to be measured and to be compared with the total amount of this protein in the tissue. This procedure permitted demonstration of the fact that, under normal conditions, only about 40% of the tubulin of the liver was assemled as microtubules. It is suggested that, in the liver, rapid polymerization and depolymerization of microtubules occur and may be an important facet of the functional role of the microtubular system.

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