Chemical characterization of dissolved organic matter released by limed and unlimed forest soil horizons

1997 ◽  
Vol 77 (3) ◽  
pp. 405-413 ◽  
Author(s):  
M. Susan Erich ◽  
Georgette M. Trusty
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Charge Density ◽  
Forest Soil ◽  
Negative Charge ◽  
Fluorescence Emission ◽  
Water Extracts ◽  
Forest Practices ◽  
Organic Horizons ◽  
Negative Charge Density

Liming of forest soils, currently practiced in Europe, may be necessary in the future in North America to counteract calcium (Ca) depletion due to whole tree harvesting. With current concerns over increasing carbon dioxide (CO2) levels in the atmosphere, the effects of forest practices such as liming on carbon (C) cycling in forest ecosystems has been receiving increasing attention. This laboratory study investigated the effect of an increase in pH on dissolved organic matter (DOM) in water extracts of organic horizons. Organic horizons were collected from nine forested sites, some predominantly hardwood and some predominantly softwood stand types. The soils were chemically characterized. Water extracts of limed and unlimed treatments of nine organic horizons were analyzed for pH, Al, Fe, Ca, C, and DOM negative charge density. Total luminescence fluorescence spectra were also obtained for each extract. The addition of lime (CaCO3) to organic horizons caused an average of 55% more C to be released than in unamended samples. Liming caused no significant changes in negative charge density of the DOM. Liming decreased organically-complexed aluminum (Al) and increased organically-complexed Ca. There was a negative correlation between Al concentration of extracts and fluorescence intensity. Chemical changes in the DOM released by liming were suggested by decreased fluorescence emission and excitation wavelengths due to liming. Hardwood samples did not respond differently than softwood samples with respect to DOM concentration, functional group concentration, or spectroscopic characteristics. However, there was a suggestion that particular tree species, such as cedar, may have unique effects on C concentrations and DOM chemistry. Key words: Lime, forest soil, dissolved organic matter, fluorescence

The effect of the negative charge density on switchable properties of pseudoisocyanine dye

2017 ◽  
Vol 144 ◽  
pp. 54-59 ◽  
Author(s):  
Marián Matejdes ◽  
Daisuke Himeno ◽  
Yasutaka Suzuki ◽  
Jun Kawamata
Keyword(s):  
Charge Density ◽  
Negative Charge ◽  
Negative Charge Density

Characterisation of dissolved organic matter in water extracts of thermally altered plant species found in box - ironbark forests

Soil Research ◽  
2010 ◽  
Vol 48 (8) ◽  
pp. 693 ◽  
Author(s):  
Eben S. Quill ◽  
Michael J. Angove ◽  
David W. Morton ◽  
Bruce B. Johnson
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Chemical Structure ◽  
Water Extracts ◽  
Central Victoria ◽  
Reducing Conditions ◽  
Extraction Period ◽  
Kaolinite Surface ◽  
Fire Residues ◽  
Trees And Shrubs

This study investigated the chemical structure of extracted dissolved organic matter (DOM) derived from thermally altered plant material found in the box–ironbark environments of central Victoria, namely: Eucalyptus tricarpa, Pinus pinaceae, Isolepsis nodosa, Acacia pycnantha, and Cassinia arcuata. Samples taken from the plants were burnt at 150, 300, and 400°C, under oxidising and reducing conditions in order to represent the variable combustion undergone by plants during bushfire events. The extraction of DOM from the burnt residues into water was conducted over 96 h. During the extraction period, solution concentrations of DOM were measured using HPLC and TOC methods, while the chemistry of the extracted DOM was characterised using ATR-IR. The nature of the extracted DOM depended on the originating species and whether burnt under oxidising or reducing conditions. DOM derived from the residues of the Australian native trees and shrubs (E. tricarpa, A. pycnantha, and C. arcuata) were generally more aromatic and conjugated than the materials extracted from herbaceous I. nodosa and introduced dendrophyte P. pinaceae. When burnt under reducing conditions, fire residues were less polar, indicated by the fact that they were significantly less soluble and ATR-IR spectra spectroscopy showed little OH stretching compared with the extracts obtained under oxidising conditions. Water extracts from the burnt residues sorbed strongly to the mineral goethite, but had less affinity for the kaolinite surface.

scholarly journals Peripheral Cytoplasmic Characteristics of Leukocytes in Monocytic Leukemia: Relationship To Clinical Manifestations

Blood ◽  
1972 ◽  
Vol 40 (1) ◽  
pp. 52-61 ◽  
Author(s):  
Marshall A. Lichtman ◽  
Robert I. Weed
Keyword(s):  
Charge Density ◽  
Cell Population ◽  
Negative Charge ◽  
High Surface ◽  
Clinical Manifestations ◽  
Homogeneous Distribution ◽  
Blood Monocytes ◽  
Monocytic Leukemia ◽  
Negative Charge Density ◽  
Cytoplasmic Maturation

Abstract The increased prevalence of tissue infiltration in some cases of monocytic leukemia may represent an enhanced ability of monocytes for tissue entry, continued cell proliferation, an increased life span in the tissues, or a combination of these three factors. Studies in this laboratory have shown that the normal myeloblast undergoes a process of cytoplasmic maturation that adapts it for marrow egress, tissue emigration, and particle ingestion. These include a reduction in surface negative charge density, increased ability to adhere to negatively charged surfaces, increased cytoplasmic deformability, more rapid motility, and enhanced phagocytic rate. In a subject with monocytic leukemia in whom tissue infiltration was a striking feature of the clinical disease, blood monocytes were broadly distributed in regard to their peripheral cytoplasmic characteristics. One portion of the cell population had a high surface negative charge density, was weakly adherent, weakly phagocytic, and poorly deformable, akin to blast cells. A second portion of the cell population had lower surface negative charge density, was adhesive, phagocytic, and readily deformable, akin to mature blood phagocytes. In five patients with myeloblastic leukemia in whom tissue infiltration was not prominent and in whom 92% of cells were myeloblasts, the blood leukocytes had a more homogeneous distribution of surface properties, and these properties were characteristic of immaturity. The increased prevalence of tissue infiltration in some cases of monocytic leukemia may be due to the presence of cytoplasmic maturation, which normally adapts the monocyte for tissue entry.

The Changes of Surface Potential and Built-in Charge in Alumina Films After the Anodization Process

2019 ◽  
Vol 18 (03n04) ◽  
pp. 1940058
Author(s):  
Le Dinh Vi ◽  
V. V. Dudich ◽  
G. G. Rabatuev ◽  
A. S. Lazarouk ◽  
A. V. Korotkevich
Keyword(s):  
Charge Density ◽  
Surface Potential ◽  
Electric Charge ◽  
Negative Charge ◽  
Anodic Alumina ◽  
Substantial Decrease ◽  
Alumina Films ◽  
Anodization Process ◽  
Negative Charge Density

We have shown that the surface potential of anodic alumina films changes in time: immediately after the anodization process it was positively followed by the substantial decrease to negative values. Such variations of the surface potential can be associated with the negative built-in electric charge in alumina. The highest negative charge density occurs in the films formed in citric and phosphoric electrolytes.

Effect of pH and dissolved organic matter on the abundance of nirK and nirS denitrifiers in spruce forest soil

2010 ◽  
Vol 101 (1-3) ◽  
pp. 123-132 ◽  
Author(s):  
Jiří Bárta ◽  
Tereza Melichová ◽  
Daniel Vaněk ◽  
Tomáš Picek ◽  
Hana Šantrůčková
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Forest Soil ◽  
Spruce Forest ◽  
Effect Of Ph

Negative Charge Density of a Magnetized Presheath Plasma with Two-Dimensional Ion Flux

1983 ◽  
Vol 22 (Part 1, No. 5) ◽  
pp. 892-892
Author(s):  
Motoichi Kawaguchi ◽  
Hiroyoshi Tanaka ◽  
Shigeru Suzuki
Keyword(s):  
Charge Density ◽  
Negative Charge ◽  
Ion Flux ◽  
Two Dimensional ◽  
Negative Charge Density

Influence of the negative charge density of metalate nanosheets on their bottom-up synthesis

CrystEngComm ◽  
2018 ◽  
Vol 20 (25) ◽  
pp. 3559-3568 ◽  
Author(s):  
Takayuki Ban ◽  
Takahiro Wakita ◽  
Ryo Yokoyama ◽  
Tatsuya Miyake ◽  
Yutaka Ohya
Keyword(s):  
Aqueous Solution ◽  
Charge Density ◽  
Negative Charge ◽  
Solution Process ◽  
Bottom Up ◽  
Negative Charge Density

Low negative charge density is required for the bottom-up synthesis of metalate nanosheets by an aqueous solution process.

Heparin inhibits histamine release from canine mast cells

1993 ◽  
Vol 264 (4) ◽  
pp. L387-L390 ◽  
Author(s):  
N. Inase ◽  
R. E. Schreck ◽  
S. C. Lazarus
Keyword(s):  
Mast Cells ◽  
Charge Density ◽  
Histamine Release ◽  
Negative Charge ◽  
Calcium Ionophore ◽  
Inhibitory Effect ◽  
Calcium Ionophore A23187 ◽  
Ionophore A23187 ◽  
Similar Inhibitory Effect ◽  
Negative Charge Density

To determine the role of heparin in mast cell exocytosis, we studied the effect of heparin on histamine release induced by compound 48/80 or calcium ionophore A23187 in canine mastocytoma cells (BR). Heparin caused concentration-dependent inhibition of compound 48/80-induced histamine release from mast cells (n = 4; P < 0.05) with a mean inhibitory concentration of 0.14 +/- 0.01 U/ml (mean +/- SE). Mean maximal inhibition was 69.3 +/- 2.0%. In contrast, heparin had no effect on calcium ionophore A23187-induced histamine release. Although benzyl alcohol, a preservative of pharmaceutical heparin, had no effect, purified heparin produced a similar inhibitory effect on compound 48/80-induced histamine release (n = 4; P < 0.05). The inhibitory effect of heparin on histamine release was rapid and was eliminated by washing cells. Dextran sulfate, a polysaccharide with negative charge density, produced a similar inhibitory effect on compound 48/80-induced histamine release (n = 4; P < 0.05). We conclude that heparin inhibits compound 48/80-induced exocytosis in mast cells probably by its negative charge density.

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