Relationships between macroalgal functional form groups and substrata stability in a subtropical rocky-intertidal system

The general hypothesis that morphological, physiological, and ecological adaptations of macro algal functional-form groups can be related to the level of disturbance encountered in a natural environment was examined. Two articulated calcareous coralline algae (Amphiroa van-bosseae Lemoine, 24% cover and Corallina frondescens Post. & Rupr. 20%) and one non-articulated coralline alga (Lithophyllum sp., 16%), all late-successional predation-tolerant strategists, comprise most of the community cover on stable bedrock substrata at Punta Las Cuevitas, Sonora, Mexico. Conversely, Ulva rigida C. ag. (26% cover) and a ralfsioid crust (23%), shows to be early-successional opportunistic strategists, cover more of the disturbed boulder habitat. Porolithon sonorense Daws., a stress-tolerant strategist, is uniquely abundant on both substratum types (13% cover on boulders, 10% on bedrock). The sheet-like and filamentous algae, prevalent in the temporally unstable habitat, generally show greater productivity (>2×) than the thicker and calcareous forms conspicuous in the more constant environment. It appears that selection for delicate thalli with high productivities, as well as selection for tougher morphologies having lower photosynthetic rates due to greater proportions of structural tissues, are widespread, divergent evolutionary forces among marine algae. Experiments with captive sea urchins (Echinometra vanbrunti Agassiz), in conjunction with fish-preference data published for some of the same algae studied here, offer strong support for the functional-form model. Parrotfishes, rudderfishes, surgeonfishes, damselfishes and E. vanbrunti, in the Gulf of California, preferentially feed on delicate, early-successional, sheet-like, and filamentous algae, while rejecting or ignoring the more structured, late-successional and calcareous algae. There is no significant (P > 0.05) gradation in calorific content between the first four of the six functional groups (i.e., Sheet-, Filamentous-, Coarsely Branched- and Thick Leathery-Groups), but the mean value for these fleshy forms (2.6 kcal · g ash-free dry wt^?1) is significantly greater than that for the last two groups (0.3 kcal, Jointed Calcareous- and Crustose-Groups). The approach used in this study demonstrates a realistic technique for predicting macrophyte community composition from knowledge of the disturbance levels in a given habitat or the reverse. The form group-disturbance relationship has important implications for future biological monitoring of rocky-inter-tidal and subtidal systems.     

Immunocytochemistry of magnocellular neurons of supraoptic and paraventricular nuclei of normal and Brattleboro rats with vasopressin anti-idiotype antibody

Summary A vasopressin anti-idiotype antibody was generated by immunization with purified IgG of a primary vasopressin antiserum. The anti-idiotype antibody immunostained neurons in the supraoptic and paraventricular nuclei of the hypothalamus of normal and Brattleboro rats. The distribution of immunostained perikarya in these hypothalamic nuclei together with the staining of fibers in median eminence and neural lobe was similar to that observed in normal rats with anti-vasopressin and suggests strongly that vasopressinergic neurons are being stained. Absorption studies with vasopressin and a vasopressin-binding receptor protein further indicate that a receptor associated with vasopressinergic neurons is recognized by the anti-idiotype antibody.Supported by NIH grants ES03239, NS18626 and NSF grant BNS-8310914. D.T.P. is the receipient of RCDA award NS00869     

Enumeration of chlorine-stressed organisms with acridine orange 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyl tetrazolium chloride (AOINT)

Direct microscopic enumeration ofEnterobacter cloacae with the acridine orange 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyl tetrazolium chloride technique (AOINT) was compared with spread plate counts on nonselective media to establish the usefulness of the former technique in the enumeration of chlorine-stressed cells. Results indicate that the techniques are comparable when the organisms are not stressed. However, AOINT is more sensitive than are plate counts in the detection of chlorine-stressed cells.     

Arylamidase of Cephalosporium acremonium and Its Specificity for Cephalosporin C

Three aggregational forms of arylamidase are produced by Cephalosporium acremonium. The exocellular enzyme, with an approximate molecular weight of 60,000, was purified 300-fold by diethylaminoethyl cellulose chromatography, gel filtration, and gel electrophoresis. With l-leucyl-beta-naphthylamide as the substrate, the K(m) is 4.2 x 10(-4)m; the optimum pH, 7.7; and the temperature optimum, 35 C. The enzymatic hydrolysis of l-leucyl-beta-naphthylamide is inhibited by a number of cephalosporins, whereas a variety of penicillins show no effect. Alternatively, the enzyme specifically catalyzes the beta-lactam hydrolysis of a number of cephalosporins; a number of penicillins are resistant. The K(m) for cephalosporin C is 9.09 x 10(-4)m.     

Surfactants as Stimulants of Enzyme Production by Microorganisms

The addition of Tween 80 and sucrose monopalmitate, nonionic surfactants, to fungal cultures resulted in marked increases in yields of the enzymes cellulase, amylase, sucrase, beta-1 --> 3 glucanase, xylanase, purine nucleosidase, and benzoyl esterase. The action appears to be an effect of the surfactant on cell permeability.     

Detection of Lymphocytic Choriomeningitis Virus Antibody in Murine Sera by Immunofluorescence

An immunofluorescence technique developed for detection of antibody in murine sera to lymphocyitc choriomeningitis virus is described.     

Bacterial Interference with L-Forms

During the course of studying the effect of normal nasal flora on the growth of L-forms, a clear zone of inhibition was observed around colonies of many coagulase-negative staphylococci. Subsequent investigation demonstrated that Staphylococcus aureus and some S. albus strains produce a substance which is capable of markedly inhibiting the growth of stable staphylococcal and streptococcal L-forms. This interfering substance is separable from the staphylococcal organism and is diffusible through 1.5% agar, but not through a dialysis membrane. It is heat-stable.     

Purine Ribonucleosidase g from Aspergillus foetidus

Nucleosidase g was prepared by growing Aspergillus foetidus on bran, and was purified by passage through a diethylaminoethyl-Sephadex column. The enzyme acted on the purine ribosides (except xanthosine) and on their 5'-phosphates. Action on the latter was a good means for preparing ribose-5-phosphate.     

Lung edema formation following inhalation injury: role of the bronchial blood flow

We investigated the contribution of the bronchial blood flow to the lung lymph flow (QL) and lung edema formation after inhalation injury in sheep (n = 18). The animals were equally divided into three groups and chronically prepared by implantation of cardiopulmonary catheters and a flow probe on the common bronchial artery. Groups 1 and 2 sheep were insufflated with 48 breaths of cotton smoke while group 3 received only room air. Just before injury, the bronchial artery of group 2 animals was occluded. The occlusion was maintained for the duration of the 24-h study period. At the end of the investigation, samples of lung were taken for determination of blood-free wet weight-to-dry weight ratio (W/D). Inhalation injury induced a sevenfold increase in QL in group 1 (7 +/- 1 to 50 +/- 9 ml/h; P less than 0.05) but only a threefold increase in group 2 (10 +/- 2 to 28 +/- 7 ml/h; P less than 0.05). The mean W/D value of group 1 animals was 23% higher than that of group 2 (5.1 +/- 0.4 vs. 3.9 +/- 0.2; P less than 0.05). Our data suggest that the bronchial circulation contributes to edema formation in the lung that is often seen after the acute lung injury with smoke inhalation.