Biocybernetic and thermodynamic perspectives of landscape functions and land use patterns

This paper develops and applies two concepts which are fundamental to landscape ecology. These concepts concern biocybernetics, which is the theory of regulation of biological and ecological systems, and thermodynamics, especially the flux of energy and the production of entropy. The landscape state factors, including site conditions and fluxes of energy, materials, and organisms, are shaped by the biocybernetic and thermodynamic processes. This theory provides us a way of understanding and discussing complex human interactions with landscape systems, expressing our concept of the whole landscape system (what I have termed the Total Human Ecosystem), and linking landscape ecology with several of the most powerfully creative ideas in modern science.     

P. M. Huang,D. L., Sparks and S. A. Boyd (eds.), Future Prospects for Soil Chemistry. SSSA Special Publication No. 55

Water, Air, &; Soil Pollution -     

Monosodium L-glutamate: its pharmacology and role in the Chinese restaurant syndrome

Monosodium L-glutamate is the cause of the Chinese restaurant syndrome and can precipitate headaches. In appropriate doses it causes burning sensations, facial pressure, and chest pain. These are pharmacological effects obeying a dose-effect relationship. There is considerable variation in oral threshold does among individuals.     

Red grapefruit positively influences serum triglyceride level in patients suffering from coronary atherosclerosis: studies in vitro and in humans

The contents of the bioactive compounds in red and blond grapefruits and their influence on humans suffering from hypertriglyceridemia were studied. It was found that red grapefruit has a higher content of bioactive compounds and a higher antioxidant potential than blond grapefruit, determined by oxygen radical scavenging capacity, 1,1-diphenyl-2-picrylhydrazyl, carotenoid bleaching, and Folin-Ciocalteu assays. Fifty-seven hyperlipidemic patients, ages 39-72 years, after coronary bypass surgery, recruited from the Institute's pool of volunteers, were randomly divided into three equal in number (19) groups: two experimental (red and blond groups) and one control group (CG). During 30 consecutive days of the investigation the diets of the patients of the red and blond dietary groups were daily supplemented with one equal in weight fresh red or blond grapefruit, respectively. Before and after this trial, serum lipid levels of all fractions and serum antioxidant activity were determined. It was found that serum lipid levels in patients of the red and blond groups versus the CG after treatment were decreased: (a) total cholesterol, 6.69 versus 7.92 mmol/L, 15.5%, and 7.32 versus 7.92 mmol/L, 7.6%, respectively; (b) low-density lipoprotein cholesterol, 5.01 versus 6.29 mmol/L, 20.3%, and 5.62 versus 6.29 mmol/L, 10.7%, respectively; (c) triglycerides, 1.69 versus 2.32 mmol/L, 17.2%, and 2.19 versus 2.32 mmol/L, 5.6%, respectively. No changes in the serum lipid levels in patients of the CG were found. In conclusion, fresh red grapefruit contains higher quantities of bioactive compounds and has significantly higher antioxidant potential than blond grapefruit. Diet supplemented with fresh red grapefruit positively influences serum lipid levels of all fractions, especially serum triglycerides and also serum antioxidant activity. The addition of fresh red grapefruit to generally accepted diets could be beneficial for hyperlipidemic, especially hypertriglyceridemic, patients suffering from coronary atherosclerosis.     

Adsorption,decomposition and movement of oxamyl in soil

A study was conducted of the behaviour of oxamyl in Israeli soils of varying clay and organic matter contents. The adsorption isotherms for oxamyl were linear, and the adsorption coefficient (K_d) could be correlated to the clay content of the soils, as well as to the organic matter content of the soil. Oxamyl adsorption was underestimated by using published correlations between the adsorption and the chemical properties of pesticides, such as their solubility or octan-1-ol-water partition coefficient. The decomposition of oxamyl in soils followed first-order kinetics. The half-life ranged from 4 to 33 days in a Bet Dagan soil. The reaction rate increased with increasing moisture content of the soil until field capacity was reached, at which point it levelled off. The Arrhenius relationship was followed, with degradation proceeding more rapidly at higher temperatures. In several soils of varying composition, which were kept at field capacity, no difference in the degradation rates was observed. Oxamyl was applied to a Bet Dagan soil from a point source in a single pulse, as a split application, and on a continuous basis. The distribution patterns of oxamyl under the various treatments differed significantly. After the single-pulse application, oxamyl was leached out of the emitter zone. While the split application decreased the oxamyl-free zone, the best results were obtained by continuous application, which gave a nearly uniform distribution of oxamyl in the soil.