Vertical trends in morphological variability of sea urchins of the genus Echinus from the Northeast Atlantic and Arctic

A study of the morphological variability of seven species of sea urchins of the genus Echinus from the Northeast Atlantic and Arctic with different depth preferences showed that in the group of species E. tenuispinus, E. esculentus, E. melo, E. acutus, E. elegans, E. affinis, and E. alexandri, arranged based on increasing depth of occurrence, the maximum test diameter decreases, the diameter of the apical system increases, the ratio of the number of interambulacral plates to the number of ambulacral plates increases, buccal and periproctal spines tend to disappear, and the number of ambulacral plates lacking a primary tubercle sharply decreases. At the same time, the test height decreases, while the number of secondary tubercles on coronal plates and number of lateral teeth on the valves of the globiferous pedicellariae increases. The change in the first six characters reflects the process of retention of juvenile features in deep-water Echinus. Similar trends in test height, apical system diameter and the ratio of the number of interambulacral plates to the number of ambulacral plates are recorded while comparing shallow-water and deep-sea populations of the eurybathic species E. acutus. This suggests that this species may currently be in the process of speciation.     

Tropical Vine Growth and the Effects on Forest Succession: A Review of the Ecology and Management of Tropical Climbing Plants

The climbing habit has evolved independently in many plant taxa, offering vines the ability to compete with non-climbing vegetation for resources such as light, nutrients, and water. This review examines the structural and functional characteristics that allow climbing plants to (1) achieve widespread dispersal, (2) transport large amounts of water throughout vessels, (3) maintain high photosynthesis levels through a large leaf area to biomass ratio, (4) achieve rapid vertical and horizontal expansion by fast growth rates and various climbing mechanisms and (5) survive and recover from disturbances. Due to the competitive effects of vines on trees, management of vine growth is used to preserve tropical timber plantations, combat invasive weeds, and promote rainforest recovery. In order to sustainably manage the vines into the future, it is necessary to understand the mechanisms by which they can alter tropical forest succession and the impacts of various management techniques.     

Erythrocytic diagnostic agents for determining antibodies to Proteus O antigens

Highly sensitive and specific erythrocyte diagnostic agents (ED) for the determination of antibodies to Proteus O-antigens have been obtained by the sensitization of formolated sheep red blood cells (SPBC) with activated lipopolysaccharides (LPS) without the use of mediators. The tannin treatment of formolated SRBC and/or the increase of temperature from 45 degrees C to 100 degrees C in the process of the preparation of ED have been found to produce no increase in effectiveness. Antibody ED permitting the detection of Proteus O- and H-antigens has been obtained by the sensitization of formolated chick red blood cells with immunoglobulin preparations to Proteus hydroxylamine antigens, carried out with the use of amidol. The experiments have shown the possibility of using this antibody ED for the determination of O-antibodies in the antigen neutralization test with nonactivated LPS used as an agglutinating agent. The passive hemagglutination test with antibody ED has proved to be a more sensitive method for the detection of O-antibodies than the antigen neutralization test with antigenic ED. The determination of Proteus etiology in the passive hemagglutination test with the use of antigenic ED has been shown to be highly effective in the examination of patients with chronic osteomyelitis at the stage of exacerbation.     

Selective electric-current inhibition of signals from the C fibers in nerve fiber microbundles: a method for identifying A and C afferents

Direct electric current of 3 microA applied through platinum electrode during 10 s to a fine strand teased mechanically from saphenous nerve, inhibits selectively C-fibre spikes in the strand and does not inhibit A-fiber spikes. The selective inhibition of C-fibers spikes in a fine strand is proposed as a method to identify a type of a single nerve fiber.     

Phenylalanine hydroxylase of human embryos: its homology with the enzyme from the liver of adults

Phenylalanine hydroxylase (PH) activity was discovered in the liver of 7-12 week old human embryos. Embryonic and adult PHs were identical, as shown by immunoelectrophoresis. Unlike the adult liver PH, the PH content of the extract of cytoplasmic proteins of embryonic liver was reduced but the specific activity was increased more than by one order of magnitude. H (57,000 D) and L (55,000 D) subunits were detected by immunoblotting. The L subunit predominates in the extract of membrane proteins of embryonic liver. Hence, the major part of phenylalanine oxidizing activity in the embryonic liver is related to the enzyme immunochemically identical with the PH of adult liver but differing from it in some structural and functional properties.     

Immunoperoxidase localization of fibronectin during odontoblast differentiation. An ultrastructural study

Immunoperoxidase labeling of fibronectin in one-day-old mouse first lower molars allowed to visualize a striking redistribution of this glycoprotein during terminal cytodifferentiation of odontoblasts. The modifications involved both extracellular and cell surface localizations. The possible roles of these modifications in terminal differentiation of odontoblasts are discussed.