Variant forms ofα-2-l-fucosyltransferase in human submaxillary glands from blood group ABH “secretor” and “non-secretor” individuals

The properties of the -2-l-fucosyltransferases in submaxillary gland preparations from blood group ABH secrefors and non-secretors were compared. The level of activity in the non-secretor gland homogenates amounted to about 5% only of that found in the secretor gland preparations. The enzymes from the two sources differed in solubility properties, charge and affinities for donor and acceptor substrates. The enzyme from secretor glands showed a preference for acceptors with Type 1 [d-galactosyl(1–3)-N-acetyl-d-glucosamine] structures whereas the enzyme from non-secretor glands had a preference for Type 2 [d-galactosyl(1–4)-N-acetyl-d-glucosamine] structures.These results demonstrate that expression of the secretor gene (Se) is associated with a molecular form of the -2-l-fucosyltransferase that is different from the species present in the same tissue when theSe gene is not expressed.     

A model for light adaptation: Producing Weber's law with bleaching-type kinetics

An adaptation model having two stages is introduced and its mathematical properties are examined. The two stages are the adaptive process (parameter K _b), which has bleaching-type kinetics, and the response function (parameters K _r and n), which incorporates response saturation. In order to study the increment threshold functions generated by the adaptation model the concept of a detector is required. It is demonstrated that without an adaptive process the compression hypothesis, in the form of the difference equation, produces increment threshold functions which saturate and do not obey Weber's law. It is then shown that an adaptive process with bleaching-type kinetics can prevent saturation and produce Weber's law behavior provided that the adaptive strength of the system exceeds the detector sensitivity.     

A comparison and evaluation of some phytosociological techniques

Summary In three areas of vegetation (dune, mountain heath and salt marsh) the following phytosociological techniques have been tested and compared, using the same data: the Braun-Blanquet method; association and inverse analysis ofWilliams &Lambert; cluster analysis (agglomerative classification) based on different coefficients of similarity; and ordination (principal components analysis performed on matrices of different coefficients).The Braun-Blanquet method is considered to combine several advantages of the other methods and to be most economical in terms of efficiency (ratio of time input to information emerging).

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Zusammenfassung Auf drei verschiedenen Vegetationsflächen (Bergheide, Küstendünen und Salzwiesen) sind die folgenden pflanzensoziologischen Methoden geprüft und verglichen worden: die Methode von Braun-Blanquet; association analysis vonWilliams &Lambert (1959, 1961); Ordination (principal components analysis); und cluster analysis (Sokal &Sneath, 1963). Die letzteren beiden wurden mit verschiedenen Ähnlichkeitskoeffizienten geprüft.Auf Grund solchen Erfahrungen, zeigte sich die Braun-Blanquetische Methode leistungsfähiger als die anderen Methoden (d.h. optimale Einsicht in der Vegetation pro Arbeitsstunde). Sie vereinigte viele Vorteile der anderen Methoden.

     

Microaerophily

Objections to previous definitions of anaerobiosis and micro-aerophily are discussed, and a new definition of micro-aerophily is proposed. A survey of physiological characteristics of the micro-aerophilic bacterium Campylobacter sputorum spp. bubulus is given, and the concept of micro-aerophily is illustrated by the results of a study on the oxygen metabolism and oxygen sensitivity of this bacterium.     

Mitotic cycle time and somatic selection after neutron irradiation of germinating tomato seeds

Mitotic cycle time was estimated by means of a natural method in control and irradiated material of a dwarf tomato line in order to express the intensity of somatic selection in terms of this biological factor. In the natural method the mitotic index is estimated in relation to the number of hours after germination. The time interval between successive peaks in the mitotic index is considered to be an indication of mitotic cycle time. In control material mitotic cycle time was also estimated by the continuous colchicine method and compared with the natural method.The investigations reported here were performed at the Genetics Department, Catholic University, Nijmegen, Director Prof. Dr. S. J. Geerts and the Institute for the Application of Atomic Energy in Agriculture, Wageningen, Director Dr. D. de Zeeuw.     

Niche,habitat, and related ecological concepts

Summary Darwin's phrase place in natural economy, andSpencer's term correspondence can be regarded as first attempts to express the organism-environment relationships. The same concept has more recently been approached from the point of view of (1) life-form, (2) external activities, and (3) habitat. Though all these points are interlocking, they have been stressed differently in the writings of American and European ecologists. It is proposed that the term niche would be most useful and rational if applied to the total of relationships between a living organism (population, species) and its complete environment, both biotic and abiotic.     

Why the aristocrats were ‘heavy’ or how ethnopsychology legitimized inequality among the Tlingit

Conclusion Even a cursory look at the ethnographic literature on other Northwest Coast societies reveals some striking similarities with the Tlingit way of conceptualizing aristocrats as special persons. Thus the Kwakiutl referred to their chiefs as real or complete people, who were heavier than commoners. The Coast Tsimshian called their highest aristocrats real or ripe persons, in contrast to the low-ranking ones, who were described as unhealed or green. The Coast Tshimshian also referred to their chiefs as strong, heavy, and solid like a rock. The neighboring Gitksan contrasted the chiefs, described as people who were good and clean and stayed put, with the commoners, who were said to be dirty, ignorant, and always moving around. Because spirits of the dead liked to return to persons who were clean and showed respect by giving away wealth and feasts, there was considerable moral and practical pressure on the aristocrats to remain pure, train knowledgeable and clean heirs, and continue potlatching. Finally, among the Haida, rank was tied to a wider system of symbolic classification, associating aspects of food, space, clothing, ritual pollution and the ethic of industry with attributes of seniority.While some of the symbolic associations of aristocratic status are culture specific, others are present in several, if not all, of the NWC cultures. What we need is a comparative symbology of aristocratic status, which would combine the reanalysis of the existing ethnographic data with the introduction of some new materials that can still be obtained in the field. Such work would be the best tribute to Irving Goldman himself and to our common illustrious ancestors—Franz Boas and Marcel Mauss.Sergei Kan is Professor of Anthropology at Dartmouth College.     

Essentialistisches und evolution?res Denken in der systematischen Ornithologie des 19. und 20. Jahrhunderts

Zusammenfassung Die Ablösung des essentialistischen (typologischen) Denkens bei Vertretern der systematischen Ornithologie durch das darwinistische (evolutionäre) Populationsdenken um die letzte Jahrhundertwende bildete eine scharfe historische Diskontinuität. Die essentialistische Denkweise, die in Europa während des 19. Jahrhunderts dominierend war, erreichte ihr Ende im Werk vonOtto Kleinschmidt (1870–1954), dem letzten Vertreter derPallas-Schlegel Schule. In den ersten Jahrzehnten dieses Jahrhunderts wurde die evolutionäre Denkweise der Ornithologen der nordamerikanischenBaird-Coues Schule und der europäischenSeebohm-Harter Schule bestimmend. Die weite taxonomische Begrenzung von Arten durch die Ornithologen der essentialistischenPallas-Schlegel Schule und der evolutionären Mikrotaxonomie täuscht Gemeinsamkeiten dieser Schulen vor; im theoretischen Denken ihrer Vertreter bestanden fundamentale Unterschiede. Gegenwärtig ist eine Entwicklung innerhalb der evolutionären Mikrotaxonomie erkennbar, die möglicherweise in naher Zukunft zu einer Trennung in zwei Schulen mit verschiedenen Artkonzepten und unterschiedlicher Artabgrenzung führen wird: (a) Weite Artabgrenzung (mit relativ wenigen polytypischen Arten) und (b) enge Artabgrenzung (mit relativ vielen monotypischen Arten). Dazwischen vermitteln intermediäre Vorschläge. Der wissenschaftliche Naturschutz bezieht sich heute auf evolutionär signifikante Einheiten und ist unabhängig von den verschiedenen systematischen Konzeptionen über die Art.

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Essentialistic and evolutionary thinking in the field of systematic ornithology during the 19^th and 20^th century

Essentialistic thinking dominated systematic ornithology in North America during the first half of the 19^th century and in Europe until the beginning of this century, when evolutionary thinking superseded it marking a sharp historical discontinuity. Evolutionary thinking of the ornithologists of the North AmericanBaird-Coues school and of the EuropeanSeebohm-Hartert school prevailed increasingly from the late 19^th century and early 20^th century onward, respectively. The representatives of the essentialisticPallas-Schlegel school and of evolutionary microtaxonomy delimited species taxa broadly which common procedure concealed the fundamental differences in their theoretical thinking. Within the near future, evolutionary microtaxonomy may split into two different schools supporting different species concepts and a different delimitation of species taxa: (a) Wide species limits resulting in relatively few polytypic species taxa and (b) narrow species limits resulting in numerous monotypic species taxa; intermediate views connect these extremes. Conservation biology refers to evolutionarily significant units and is independent of the different views of systematists as to what constitutes a species.

     

Mitochondrial genetic damage induced in yeast by a photoactivated furocoumarin in combination with ethidium bromide or ultraviolet light

Summary Ethidium bromide (EB) and ultraviolet light (UV) in combination are known to produce a synergistic induction of petite mutants in yeast. Two other agents were combined with EB, 3-Carbethoxypsoralene (3 CPs) activated by 365 nm light or rays. EB in combination with 3 CPs also resulted in an enhanced production of petite mutants. After the photoaddition of 3 CPs in exponential phase cells, recovery of the petite mutation during dark liquid holding was inhibited by the presence of EB producing an enhanced number of petite mutants. The behavior of mitochondrial antibiotic resistance markers after individual and combined treatments with EB and 3 CPs indicates a random loss of markers after EB and a preferential loss of a certain region for the 3 CPs photoaddition. The combination of the two agents leads to an additivity of total drug marker losses rather than a synergistic loss. The combination of EB with rays produced no enhancement in petite induction. A combination of UV and 3 CPs showed a synergistic interaction for petite induction. These results indicate that the three agents, EB, UV and 3 CPs photoaddition may share a common repair step for mitochondrial lesions.     

Evolution alpiner Populationen vonEuphrasia (Scrophulariaceae): Die mittel- bis kleinblütigen,drüsenhaarigen Arten

A more precise taxonomic concept ofE. hirtella and its infraspecific synonymy is presented. Its diploid nature (2n = 22) is confirmed. Within the European area ofE. hirtella five different races may be recognised: typical, brandisii, capitulata, Rofan and Bretagne. Taxonomic rank is not yet attributed to these races. The heterogeneous taxonomic assembly E. drosocalyx is disentangled. The type refers to products of hybrid introgression ofE. rostkoviana-characters (long glandular hairs) intoE. minima.

Former contributions of this series areEhrendorfer & Vitek (1984) andGreilhuber & al. (1984).     

Vom Einfluß des Phytochroms auf die Xylemdifferenzierung im Hypokotyl des Senfkeimlings (Sinapis alba L.)

Zusammenfassung P₇₃₀, das aktive Phytochrom, bewirkt eine vermehrte Bildung von Gefäßen (Tracheen und Tracheiden) im Hypokotyl des Senfkeimlings. Das Differenzierungsmuster der Leitbündel und der Verlauf der Leitbahnen sind im belichteten und im etiolierten Keimling gleich. Es wird geschlossen, daß auch bezüglich der Ausbildung der Leitbahnen das P₇₃₀ lediglich im Rahmen einer sekundären Differenzierung als Auslöser wirkt. Die primäre Differenzierung (vgl. Wagner und Mohr, 1966 b) wird durch P₇₃₀ offenbar nicht beeinflußt.

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Phytochrome-mediated control of xylem differentiation in the hypocotyl of the mustard seedling (Sinapis alba L.)

Summary P₇₃₀, the active phytochrome, causes an increased formation of xylem elements (tracheids and vessel elements) in the hypocotyl of the mustard seedling (Figs. 3,4). On the other hand, the pattern of differentiation of the bundles and the course of the bundles within the hypocotyl (Figs. 1,2) are the same in etiolated as well as in illuminated seedlings.—It has been concluded that in connection with bundle differentiation P₇₃₀ acts only as a trigger at the level of secondary differentiation. The pattern of differentiation is laid down in the course of primary differentiation which apparently is not influenced by P₇₃₀. The same problem has been dealt with more in detail in a foregoing paper (Wagner and Mohr, 1966b).

     

Hexagonally ordered “rosettes” of particles in the plasma membrane ofMicrasterias denticulata Bréb. and their significance for microfibril formation and orientation

Summary Cells ofMicrasterias denticulata Bréb. at the stage of secondary wall formation have been studied by freeze-etching. It was found that the plasma membrane exhibits oval areas in which arrays of membrane particles occur. These particles form rosettes which are arranged in a hexagonally ordered lattice with a center to center spacing of 25 nm. Nearly the same periodicities can be found between microfibrils. It is concluded that the rosettes probably together with the thickened area of the plasma membrane below them represent the apparatus for the production and orientation of microfibrils. The hypothesis suggesting the incorporation of membrane templates functional in microfibril formation, originally advanced byKiermayer andDobberstein (1973) has received further support.     

Monster zooids inCryptosula pallasiana (bryozoa,cheilostomata ascophora)

In the ascophoran bryozoanCryptosula pallasiana (Moll) many examples of regenerative growth and of abnormal zooids have been observed. Most of the different forms of monsters are caused by fusion of zooids or zooid buds respectively. Zooids may often fuse laterally but in a few cases also distally. Some monster zooids have two polypides and combined opercula caused by various degrees of fusion of the apertures. Lack of sufficient space may lead to the formation of dwarf zooids or remainder cystids.     

Histoenzymatic characterization of sub-types of Type I fibres in fast muscles of rats

Summary The histochemical activities of succinic dehydrogenase (SDH), myofibrillar Adenosine triphosphatase (ATPase) and alpha glycerophosphate dehydrogenase were studied in serial sections of rat vastus lateralis (red) (RVL), gastrocnemius and diaphragm muscles. Three main fibre-types were distinguished. The Type I fibres of RVL and gastrocnemius muscles fell into two distinct groups: one category-Type IA showed very low ATPase activity. The second category of Type IB fibres displayed moderate ATPase reaction. The Type IA fibres were divisible into two sub-groups when tested for SDH reaction. Type IA₁ fibres possessed a homogenous distribution of diformazan·granules throughout the fibre: Type IA₂ fibres displayed characteristic moth-eaten pattern of diformazan localization. The diaphragm muscle did not show either Type IB or Type IA₂ varieties. The great majority of Type I fibres were sub-type IA₁ in the three fast muscles studied. It is also demonstrated here that an inherent heterogeneity exists between Type I fibres of diaphragm and leg muscles in regard to -GPD localization. This histochemical data emphasizes the fact that subdivision of Type I striated muscle fibres of mammalian animals into two sub-types is only approximate and that a further subcategorization is possible.     

Influence of molecular variations of ionophore and lipid on the selective ion permeability of membranes: I. Tetranactin and the methylation of nonactin-type carriers

Summary The manner in which the molecular structure of the carrier and the lipid composition of the membrane modulate the membrane selectivity among monovalent cations has been investigated for nonactin, trinactin, and tetranactin, which differ only in their degrees of methylation, and for membranes made of two lipids, phosphatidyl ethanolamine and glyceryl dioleate, in which equilibrium and kinetic aspects of permeation, respectively, are emphasized. Bilayer permeability ratios for Li, Na, K, Rb, Cs, Tl, and NH₄ have been characterized and resolved into equilibrium and kinetic components using a model for carrier-mediated membrane transport which includes both a trapezoidal energy barrier for translocation of the complex across the membrane interior and a potential-dependence of the loading and unloading of ions at the membrane-solution interfaces. The bilayer permeability properties due to tetranactin have been characterized in each of these lipids and found not only to be regular but to be systematically related to those of the less methylated homologues, trinactin and nonactin. This analysis has led to the following conclusions: (1) The change in lipid composition alters the relative contributions of kineticvs. equilibrium components to the observed carrier-mediated selectivity. (2) Increased methylation of the carrier increases the contribution of the kinetic component to the selectivity relative to that of the equilibrium component and additionally alters the equilibrium component sufficiently that an inversion in Cs–Na selectivity occurs between trinactin and tetranactin. (3) For all ions and carriers examined, the reaction plane for ion-carrier complexation and the width for the diffusion barrier can be represented by the same two parameters, independent of the ion or carrier, so that in all cases the complexation reaction senses 10% of the applied potential and the plateau of the diffusion barrier extends across 70% of the membrane interior.     

Unique sequences for two HLA-DRB1 genes expressed on distinct DRw6 haplotypes

We have used restriction fragment length polymorphism (RFLP) analysis and DNA sequencing to characterize two distinct DRB1 alleles expressed on DRw52 and DQw7-associated haplotypes but not readily defined by conventional DR serology. These two haplotypes, designated HLA-D HAG and PEV, react variably with DRw13(w6), DRw14(w6), and the more broad DR 3+6 antisera. Analysis of RFLP revealed that HLA-D HAG and PEV are associated with different DRw52 variants, and that HAG is indistinguishable from DRw18(3) haplotypes. Sequencing of the HAG and PEV DRB1 genes showed each to represent novel alleles. Nevertheless, these sequences show similarities with the other alleles of the DR5, w6, and w8 family. HAG (DRB1*1303) appears to have arisen either from two recombinational events involving at least three DRB1 sequences (DRB1*1101, DRB1*0803, DRB1*0401) or from a single recombinational event together with multiple point mutational events. PEV appears to represent a DRB1*1301-1302/DRB1*1101 recombinant allele, with recombination having occured in the region of bases 175 – 198. The results of this study suggest that the DRw52 family haplotypes is derived from a relatively restricted number of ancestral sequences, with diversity among DRB1 alleles within this family arising through gene conversion or recombination events.     

Studies on the decomposition of amino acids in soils

Summary 1. Anaerobic amino-acid breakdown in a garden soil was accompanied by the formation of large quantities of volatile fatty acid and ammonia (plus indole in the case of tryptophan).2. Hydroxyproline, leucine, methionine, phenylalanine, proline, threonine, tryptophan, tyrosine, and valine were found to be resistant and decomposed more slowly than did alanine, arginine, aspartic acid, cystine, glutamic acid, glycine, histidine lysine, and serine. Casein hydrolysate was rapidly and completely deaminated.3. The slow rates of breakdown of the resistant acids when tested singly could not be attributed either to the effects of adsorption on the soil surface or to elimination of an essential Stickland reaction.4. The effect of glucose and of nitrate on anaerobic amino-acid metabolism have been tested. With the exception ofdl-methionine nitrate acted as an hydrogen acceptor in the anaerobic deamination of the resistant acids, glucose had no effect on their anaerobic metabolism.     

Silver staining the chromosome scaffold

Cytological silver-staining procedures reveal the presence of a core running along the chromatid axes of isolated HeLa mitotic chromosomes. In this communication we examine the relationship between this core and the nonhistone chromosome scaffolding, isolated and characterized in previous publications from this laboratory. When chromosomes on coverslips were subjected to the steps used for scaffold isolation in vitro and subsequently stained with silver, the characteristic core staining was unaffected. Control experiments suggested that the core does not contain large amounts of DNA. When scaffolds were isolated in vitro, centrifuged onto electron microscope grids, and stained with silver, they were found to stain selectively under conditions where specific core staining was observed in intact chromosomes. These results suggest that the nonhistone scaffolding is the principal target of the silver stain in chromosomes.     

Electrogenic properties of the sodium-alanine cotransporter in pancreatic acinar cells: II. Comparison with transport models

Summary In this paper, the results of the preceding electrophysiological study of sodium-alanine cotransport in pancreatic acinar cells are compared with kinetic models. Two different types of transport mechanisms are considered. In the simultaneous mechanism the cotransporterC forms a ternary complexNCS with Na⁺ and the substrateS; coupled transport of Na⁺ andS involves a conformational transition between statesNCS andNCS with inward- and outward-facing binding sites. In the consecutive (or ping-pong) mechanism, formation of a ternary complex is not required; coupled transport occurs by an alternating sequence of association-dissociation steps and conformational transitions. It is shown that the experimentally observed alanine- and sodium-concentration dependence of transport rates is consistent with the predictions of the simultaneous model, but incompatible with the consecutive mechanism. Assuming that the association-dissociation reactions are not rate-limiting, a number of kinetic parameters of the simultaneous model can be estimated from the experimental results. The equilibrium dissociation constants of Na⁺ and alanine at the extracellular side are determined to beK _N <-64mm andK _S <-18mm. Furthermore, the ratioK _N /K _N ^S of the dissociation constants of Na⁺ from the binary (NC) and the ternary complex (NCS) at the extracellular side is estimated to be <-6. This indicates that the binding sequence of Na⁺ andS to the transporter is not ordered. The current-voltage behavior of the transporter is analyzed in terms of charge translocations associated with the single-reaction steps. The observed voltage-dependence of the half-saturation concentration of sodium is consistent with the assumption that a Na⁺ ion that migrates from the extracellular medium to the binding site has to traverse part of the transmembrane voltage.     

Die Lebensformen der Laubmoose

Zusammenfassung Im Gegensatz zu dem morphologischen Begriff Wuchsform wird der ökologische Begriff Lebensform definiert als der Habitus einer Pflanze in Einklang mit ihren Lebensbedingungen. Es werden 10 Lebensformen der Laubmoose unterschieden, ihr Anteil an verschiedenen Pflanzenformationen und Moosgesellschaften dargelegt und ihre Abhängigkeit von den ökologischen Bedingungen erörtert.

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Summary In opposition to the morphological term growth-form the ecological term life-form is defined as the organization of a plant in correspondence with its life conditions. Ten life-forms of mosses are discerned, their part within various plant-formations and moss-associations is explained, and their dependence on ecological conditions is discussed.

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Herrn Prof. Dr. Carl Troll in herzlicher Verehrung zum 70. Geburtstag gewidmet.