A New Species of Halophilous Collembola (Insecta) from Korea

Three species of interstitial Collembola in Entomobryidae were identified from South Korean coast. One of them, Sinella (Coecobrya) maritima, is new to science. So far 21 halophilous species in 10 families of Collembola, including the new species in this paper, were reported from the Korean peninsula.     

Taxonomy of the Genus Zeadolopus Broun (Coleoptera: Leiodidae: Leiodinae) in Korea

A taxonomic study of the genus Zeadolopus Broun in Korea is presented. Two species, Zeadolopus chaosicus Daffner and Z. japonica (Champion), are recognized and the latter is recorded for the first time in Korea. A key, diagnoses, and illustrations of diagnostic characters are provided.     

VARIATION IN ALCOHOL DEHYDROGENASE ACTIVITY AND FLOOD TOLERANCE IN WHITE CLOVER,TRIFOLIUM REPENS

Flooding results in induction of anaerobic metabolism in many higher plants. As an important component of anaerobic energy production, alcohol dehydrogenase (ADH) activity increases markedly in response to flooding in white clover, Trifolium repens. Significant inter-individual variation in flood-induced ADH activity exists in natural populations of T. repens. The genetic basis of this variation was analyzed by offspring-midparent regression of data from 75 greenhouse reared families; the estimated heritability of flood-induced ADH activity was 0.55 (±0.13). Genetic variation in flood-induced ADH activity has pronounced effects on physiological response and flood tolerance in this species. ADH activity is positively correlated with the rate of ethanol production, indicating that observed in vitro activity differences are manifested in in vivo physiological function. T. repens plants with higher ADH activities during flooding have greater flood tolerance (measured as growth rate when flooded/unflooded growth rate). Variation in ADH activity during flooding accounts for more than 79% of the variance in flood tolerance. On the basis of a limited field survey of populations occupying three sites differing in exposure to flooding conditions, individuals from site C, the most frequently flooded site, expressed significantly higher average ADH activity when flooded than individuals from site A, a site with no history of flooding. Since ADH activity levels are not correlated with electrophoretic mobility variation in T. repens, this work supports previous suggestions that regulatory variation in enzyme activity may play a central role in biochemical adaptations to environmental stress.     

Four New Species of Xenylla (Collembola: Hypogastruridae) from Korea

ABSTRACT Four new species of the collembolan genus Xenylla, X. convexopyga, X. longistriata, X. dotata and X. marina from Korea are described. X. convexopyga is characterized by an absence of the dorsal seta m₃ on Th. II-III. While the other three new species share similarities in dorsal chaetotaxic characters. However, they are dissimilar in the following respects: ventral chaetotaxy, body colour, presence or absence of inner teeth on unguis, the length proportion of abdominal segments and thoracic segments, arrangement of anal papillae and the general shape of apical bulb of fourth antennal segment. As a result of this study, a total of 25 species in 6 genera of Hypogastruridae have been recorded from the Korean Peninsula.     

Big Moose Basin: simulation of response to acidic deposition

The ILWAS model has been enhanced for application to multiple-lake hydrologic basins. This version of the model has been applied to the Big Moose basin, which includes Big Moose Lake and its tributary streams, lakes, and watersheds. The basin, as defined, includes an area of 96 km², with over 20 lakes and ponds, and 70 km of streams. Hydrologic and chemical calibrations have been made using data from seven sampling stations. When total atmospheric sulfur loading to the basin is halved, the model predicts, after four years of simulation, a decreasing sulfate concentration and to a lesser extent a rising alkalinity at Big Moose Lake outlet. At the end of four years, the results show an increase in pH of 0.1 to 0.5 pH units depending upon season.     

Soluble minerals in chemical evolution

The adsorption of 5-AMP and 5-CMP was studied in saturated solutions of several soluble mineral salts (NaCl, Na₂SO₄, MgCl₂·6H₂O, MgSO₄·7H₂O, CaCl₂·2H₂O, CaSO₄·2H₂O, SrCl₂·6H₂O, SrSO₄, and ZnSO₄·7H₂O) as a function of pH, ionic strength, and surface area of the solid salt. The adsorption shows a pH dependence; this can be correlated with the charge on the nucleotide molecule which is determined by the state of protonation of the N-1 nitrogen of 5-AMP or N-3 nitrogen of 5-CMP and the phosphate oxygens. The adsorption which results from the binding between the nucleotide molecule and the salt surface is proposed as being due to electrostatic forces. It was concluded that the adsorption was reversible in nature. The adsorption shows a strong dependence upon ionic strength and decreases with increasing ionic strength. Surface area is shown to be an important factor in evaluating and comparing the magnitude of adsorption of nucleotides onto various mineral salts. The implications of the results of the study are discussed in terms of the importance of soluble mineral salts as adsorption sites in the characterization of the adsorption reactions of an adsorbed template in biogeochemical cycles.     

Chemical modification of human alpha 1-proteinase inhibitor by tetranitromethane. Structure-function relationship.

Nitration of tyrosine residues of alpha 1-proteinase inhibitor (alpha 1-PI) by tetranitromethane yielded a product that maintained its inhibitory activity against trypsin but lost most of its inhibitory activity against elastase. Chemical analysis of the product showed that four out of the six tyrosine residues in alpha 1-PI had been nitrated to various degrees: Tyr-38 and Tyr-297 were not nitrated, whereas Tyr-138, Tyr-160, Tyr-187 and Tyr-244 were nitrated to extents in the range 40-80%. We interpreted these data to mean that modification of these tyrosine residues decreased the association constant between alpha 1-PI and the proteinases and that the decrease differs from one proteinase to the other. When either alpha 1-PI-trypsin or alpha 1-PI-elastase complex was nitrated, nitration took place only to a very slight extent at these latter four tyrosine residues. On the other hand, Tyr-38 and Tyr-297 underwent nitration to about 20%. We concluded that Tyr-138, Tyr-160, Tyr-187 and Tyr-244 were located on the surface of alpha 1-PI that interacts with either trypsin or elastase in the formation of complexes, and were therefore protected from nitration.     

Acute inflammation in gram-negative infection: endotoxin, interleukin 1, tumor necrosis factor, and neutrophils

Experimental bacterial infection of the dermis induced with gram-negative microorganisms is associated with an acute inflammatory reaction, which represents the principal local defense against spread of the infection. When the inflammatory reaction is quantitated with radiolabeled cells and proteins, the kinetics resemble acute inflammation induced with other agents, such as immune complexes or chemotaxins. There is an interrelationship between the components or events of the inflammatory reaction; inasmuch as vascular injury is neutrophil-dependent, neutrophils must migrate to the site where the bacteria multiply. In neutropenic animals there is no such emigration and bacterial multiplication is not inhibited. The microorganisms shed endotoxin, which in turn induces secretion of interleukin 1 (IL 1) and probably tumor necrosis factor. Endotoxin is the most potent agent (10(-15) mol vs. 10(-12) mol of C5ades Arg) capable of inducing a neutrophil influx. Desensitization or tachyphylaxis of the tissues (probably of postcapillary venular endothelium) to IL 1 seems to control cessation of the neutrophil influx (also in vitro evidence). Phagocytosis of the bacteria by neutrophils is associated with release of oxygen radicals and lysosomal proteases from the neutrophils. These are instrumental in eliciting microvascular injury, which is characterized by enhanced vasopermeability, hemorrhage, and thrombosis.