Showing papers in "Naturwissenschaften in 1971"

Selforganization of matter and the evolution of biological macromolecules

Abstract: IA. Cause and Effect . . . . . . . . . . . . . . 465 1.2. Prerequisites of Selforganization . . . . . . . 467 1.2.3. Evolut ion Must S ta r t f rom R andom Even ts 467 1.2.2. Ins t ruc t ion Requires In format ion . . . . 467 1.2.3. In format ion Originates or Gains Value by S e l e c t i o n . . . . . . . . . . . . . . . 469 1.2.4. Selection Occurs wi th Special Substances under Special Conditions . . . . . . . . 470

Regeneration of whole plants from isolated mesophyll protoplasts of tobacco

Abstract: (1963). [5] v. Sengbusch, R., in: Vortragsveranstaltung fiber neue Methoden der Fischzflchtung und -haltung. Hamburg: MPI f. KulturpflanzenzClchtung t 9 6 7 . [6~ Langhans, V. : NachrichtenbI. Fischzucht Fischerei 1, 122 (t928). [7] Krupauer, V.: Ryb~stvi H. 6, 85 (t963). [8] v. Sengbusch, R., Meske, Ch., Szablewski, W.: Experientia 21, 614 (1965). --. [9] v. Sengbusch, R., et al.: Z. Fiscberei 15 N. F., 45 (1967). [10]Meske, Ch.: Fischwirt 16, 309 (1966). [il~ I(oBmann, H.: ibid. 20, 255 ( 1 9 7 0 ) . ~t2~ SchS~perclaus, W.: Lehrbuch der Teichwirtschaft. Berlin-Hamburg: Paul Parey 1961. [13] Jancarik, A.: Z. Fischerei 12 N. t~'., 602 (1964). [t4~ Lflhr, B., in : Vortragsveranstaltung fiber neue Methoden der Fischzflchtung und -haltung. Hamburg: MPI f. t,~ulturpflanzenzflchtung 1 9 6 7 . [15~ Meske, Ch.: Fischwirt 18, 310 (t968). [t6] 3/Ieyer-Waarden, P. F., in: Der Aal. Hamburg: A. Keune 1 9 6 5 . [171 M~ller, H. : Dtsch. Fischerei-Z. 14, t (t967). r t81 Meske, Ch.: Arch. Fischereiwiss. 20, 26 (1969). [191 Suworow, I~.: Grundlagen der Ichthyologie. Moskau 1 9 4 8 . [20] Ihering, G.: Zool. Anz. 3 (t935). [2t] Gerbilski, H. L.: Vesti. Leningrad un.-ta Mr. (zitiert nach Woyn~rovich 1963). (t951). [22] Woyn~rovich, E.: Beitr. Gew/~sserforsch. 4, 210 ( 1 9 6 4 ) . [23] Meske, Ch., et al.: Theoret. Appl. Genetics 38, 47 ( t 9 6 8 ) . [24~ Kof3mann, H.: Zuchthygiene, im Druck. [25] Meske, Ch., Lflhr, B., Szablewski, \"vV.: Naturwissenschaften 54, 291 (1967). [26] v. Sengbusch, R., Meske, Ch.: Zflchter 37, 271 ( 1 9 6 7 ) . [27] KoBmann, H., Szablewski, W.: Fischwirt 21, 49 (1971): ~281 Denkschrift der DLG-Tierzuchtabteilung ( t 9 6 7 ) . [29] Meske, Ch. : Fischwirt 19, 244 (t969).

Phasenumwandlungen in Lipiden Mögliche Schaltprozesse in biologischen Membranen

Abstract: Recent experiments on phase transitions of lipid model membranes in aqueous medium are reviewed: the phase transition has been studied by optical methods using flourescence or absorption indicators and the kinetics of the transition by means of the temperature jump relaxation technique. Under certain conditions the transition curves show hysteresis phenomena. The ion binding and ion exchange properties of lipid structures are influenced by the phase transition. These phenomena may be important in memory and nerve excitation processes.

Lake tanganyika: Water chemistry, sediments, geological structure

Abstract: The water chemistry of the lake is uniform throughout its entire length and depth except for the nutrient minerals ammonia, nitrate, phosphate, and silica. Sediment fill in the lake is very massive. Because the sediments are almost entirely composed of biological debris, changes in the fossil inventory can be linked to the chemical and in turn biological evolution of the lake. Rates of depositions are about 30 to 50 cm per 1 000 years in the deep basins and 5 cm per 1 000 years in the sill area separating the southern and northern basins. Seismic profiles indicate graben-type structures. Magnetic surveys reveal no magnetic lineation typical of rifting. Free air and simple Bouguer anomalies suggest that lake and land structures are grossly similar. Low heat flow and similarity with surrounding values in Africa is consistent with a lack of active volcanicity and sea-floor spreading in Lake Tanganyika. A new concept on the evolution of a rift is proposed.

Periodische Signale steuern die Musterbildung in Zellverbänden

Abstract: Aggregating cells of the cellular slime mold, Dictyostelium discoideum, are guided by an intercellular signal system comprising chemotaxis, cell contact formation and transmission of periodic stimuli from cell to cell. This has been studied as a model system for morphogenetic cell interactions in which spatial patterns are formed by self-organization, starting from a homogeneous layer of essentially identical cells.

The olfactory and auditory mediated sex attraction in Achroia grisella (Fabr.).

Abstract: (t966). [45] Strausfeld, N. J. : Phil. Trans. Roy. Soc. (London) Set. B. 258, 135 (t970). [46] Mi~ller, J.: Zur vergleichenden Physiologic des Gesichtssinnes. Leipzig: C. Cnobloch 1 8 2 6 . [47] Seitz, G.: Verh. Dtsch. Zool. Ges. (Innsbruck) 1968, 361. [483 Burkhardt, D., et al., in: The functional organization of the compound eye. Ed. C. G. Bernhard. Vol. 7, p. 5t. Oxford: Pergamon Press 1966. [49] Washizu, Y., et aI.: Z. vergl. Physiol. 48, 413 (1964). [50] Scholes, J.: Kybernetik 6, t49 ( t 9 6 9 ) . [5t] Langer, H.: Z. vergl. Physiol. 55, 354 ( t 9 6 7 ) . [52] Langer, H. : Umschau Wiss. Techn. 67, 1t2 ( t 9 6 7 ) . [53] G6tz, K. G. : Kybernetik 2, 77 (t964). [54] G6tz, K. G.: ibid. 2, 215 (1965). [55] Kirschfeld, K., Franceschini, N.: ibid. 5, 47 ( t 9 6 8 ) . [56] Seitz, G.: Verh. Dtsch. Zool. Ges. (K61n) 1970, t69. [ 5 7 ] Kirschfeld, K., Franceschini, N. : Kybernetik 6, 13 (I969).

Electrochromism of chlorophylls and carotenoids in multilayers and in chloroplasts

Abstract: Some of the l ight-induced t ransient changes in the absorpt ion of chloroplasts are though t to be due to a l ight-induced electric field which alters the absorpt ion spectra of the bulk pigments in the photosynthet ic membrane [t, 2]. In order to tes t this interpretat ion, the influence of an electric field on the absorpt ion spectra (electrochromism) of chlorophyll and carotenoid multi layers bui l t up on slides has been measured [3-5]. The spectrum of the light-induced field-indicating absorption changes of spinach chloroplasts as published in [2] is shown in Fig. t top. The spectra of the electrically induced absorption changes of a) chlorophyll a, b) chlorophyll b, and c) carotenoids are shown in Fig. I bot tom. The spectrum c) is a superposition of the electrochromic spectra of hitein, t -carot in , violaxanthin, and neoxan th in in their na tura l molar ratio. The electrochromic spectrum of lutein has been measured directly; the

Stimulability, adenosine triphosphatases and their control by cellular redox processes.

Abstract: This review suggests that oxidation of reduced glutathione in the cell has a profound effect on active and passive cation permeability as well as on the chemical stimulaiion of excitable cells. Since permeabilities are presumably regulated by ATP-ases, it is speculated that the pentose shunt, glutathione, and the lipid environment, regulate the activity of different ATP-ases, and hence the permeability and chemical stimulability of cells. A hypothesis of this type might provide a link between the metabolic state of the cell and certain functions of the cell membrane.

Pyruvate P i dikinase in crassulacean acid metabolism

Abstract: Some of the l ight-induced t ransient changes in the absorpt ion of chloroplasts are though t to be due to a l ight-induced electric field which alters the absorpt ion spectra of the bulk pigments in the photosynthet ic membrane [t, 2]. In order to tes t this interpretat ion, the influence of an electric field on the absorpt ion spectra (electrochromism) of chlorophyll and carotenoid multi layers bui l t up on slides has been measured [3-5]. The spectrum of the light-induced field-indicating absorption changes of spinach chloroplasts as published in [2] is shown in Fig. t top. The spectra of the electrically induced absorption changes of a) chlorophyll a, b) chlorophyll b, and c) carotenoids are shown in Fig. I bot tom. The spectrum c) is a superposition of the electrochromic spectra of hitein, t -carot in , violaxanthin, and neoxan th in in their na tura l molar ratio. The electrochromic spectrum of lutein has been measured directly; the

Visualisation of single heavy atoms with the electron microscope

Abstract: In order to examine the cont ras t of a single h e a v y a tom in the electron microscope, the s ter ica l ly well-defined \"disc-like\" molecule t r i a ce toxy -mercu ry aurine (TAMA) was synthesized. The compound was sp rayed on \" low-no i se\" a luminum oxide suppor t films. On micrographs a p p r o x i m a t e l y 1 000 A in the underfocus the expected t r i angu la r a r rangement of dense dots 8 to 9 A a p a r t could clear ly be recognized. The con t ras t of these dots was between 5 and 6% above background. These results suggest t ha t single mercu ry a toms wi th in TAMA molecules can be localized wi th reasonable p robab i l i t y using a luminum oxide suppor t films. Equ iva l en t results were ob ta ined with the compounds descr ibed b y Crewe et al. [2]. The results of these authors , however, could not be confirmed.

Inhibition ofDendroctonus frontalis response to frontalin by isomers of brevicomin

Abstract: Die La rven der Aleoehara-Arten leben, soweit bekannt , raubparas i t i sch in Pupar i en cyclor rhapher Dipteren. ObwohI Superparas i t i smus vo rkommt , entwickel t sich s te ts nur eine der in das F l iegenpupar ium e ingedrungenen Aleochara-Eil a rven ektoparas i t i sch an der F l iegenpuppe [t, 2]. Von den bet A. bilineata und A. curtula beobach te t en Konkur renze rscheinungen ist eine so auffallend, dab sie mi t der leicht zug/inglichen A. curtula als Paras i t und Calliphora erythrocephata Ms Wir t un t e r such t wurde. Das Ph~Lnomen: Von der Pr im~rlarve wird bet Einfachparas i t i e rung (pro Versuchsrbhrchen t P u p a r i u m ill Normalpos i t ion in Erde + 1 l~ilarve, ]Befallskontrolle nach 12 h) die Eingangs6ffnung s te ts in e inem Vorzugsbereich ven t ra l am I l in t e rende des Pupa r iums genagt [3]. Se tz t m a n zu dem gleichen Pupa r ium innerhalb einer Zei t spanne yon t 2 7 2 h nach ]Befallskontrol le eine weitere Ei larve (Sekund~rlarve), so dr ingt diese in der Regel n ich t im Vorzugsbere ich ein (Fig. I a).

The lower Omo Basin: Geology, fauna and hominids of Plio-Pleistocene formations

Abstract: The international Omo Research Expedition, working in the southwestern Ethiopia t966--70, has established a unique late Pliocene to early Holocene sedimentary sequence, dating from before 4.2 to about t.8 million years. Older than the classical Olduvai formations, these strata have provided a complex faunal stratigraphy for this poorly-known time range. At the same time, two, contemporary, hominid lineages, one a hyperrobust australopithecine, the other a gracile form, have been established as far back as 3-5 million years, extending the known time span and the enigmatic dichotomy of these early hominids.

Aufnahme und Verarbeitung optischer Daten im Komplexauge von Insekten

Abstract: Special, striking neural connections in the optic ganglia of the compound eye of flies have been functionally interpreted by several authors. These functions proposed include colour vision, movement perception, pattern recognition and even vision of polarized light. A detailed study of the optical properties of the flies ommatidia and the “wiring diagram” of the first optic ganglion within the eye provide evidence that the special neural arrangement is not related to the functions mentioned above but is a means of increasing the light-gathering power in this type of compound eye by means of “neural superposition”.

Induzierung von optischer Aktivität und Zirkulardichroismus in nematischen Phasen durch chirale Moleküle

Abstract: Addition of chiralic non-mesomorphic molecules to a nematic mesophase produces an optical rotatory power which exceeds the specific rotation of the optically active solutes by a factor of several orders of magnitude. Further, a circular dichroism is induced which causes temperature-dependent selective reflection colours characteristic of cholesteric phases. From this, it may be deduced that chiralic molecules transform nematic into cholesteric phases. The screw-sense of the cholesteric arrangement is determined by the chirality of the optically active solute.

Pflanzenstoffe und Pflanzensystematik

Abstract: Some recent trends in the chemotaxonomy of plants are reviewed. It is often difficult to judge the systematic significance of chemical characters, due mainly to our still incomplete knowledge about the distribution, biosynthesis and function of most phytoconstituents. Three patterns of distribution (fairly general occurrence, “asystematic” occurrence, clear-cut “systematic” occurrence) are distinguished. They enable us to analyze the taxonomic possibilities and limitations of natural products. Each of these patterns is illustrated and exemplified by a number of secondary metabolites of vascular plants.

Relationship of structure and biological activity of bacterial endotoxins

Abstract: There are two factors which must be borne in mind before we start the discussion of the chemistry and biology of endotoxic bacterial lipopolysaccharides (LPS). The iirst is that the information available is limited to individual strains. I t is clear that different bacterial strains produce chemically dissimilar polysaccharides. There is some evidence which indicates that other parts of the LPS molecule, such as the lipid moiety, are not entirely identical in all strains either, and there is no reason to assume that they should be identical in their chemical composition, no mat ter how desirable this would be to us chemists. The only feature which seems to be shared by most gram-negative endotoxins is the /ascinating array o/ biological activities. But here again we cannot speak about identity, since some data Jn the literature can be interpreted as evidence for different degrees of activity in one or another biological parameter. Whether these are real differences or only apparent ones due to poor reproducibility in the measurement of different biological activities remains an open question. Nevertheless, generalizations about the structure or the biological activity of endotoxins should be avoided. Another even more disturbing factor we have to realize is the heterogeneity of endotoxic LPS preparations. I t has been detected that all endotoxic LPS preparations investigated thus far consist of a number of components. These materials are similar but still different in their chemical composition and they elicit different biological activities if injected into experimental animals. A review of the aspects of chemical and biological heterogeneity of endotoxins is in press [1]. Despite these factors, a picture of endotoxin structure with rather vague contours and some light about its mode of action emerges from the many years of study, and the overall pat tern seems to be similar in several gram-negative strains. Heterogeneity as well as individual variations from strain to strain may be restricted to certain features or smaller details of the architecture which may have limited bearing on the most characteristic structural or biological properties of all endotoxins. Although our knowledge of the

Biogenetic amino acid antagonists

Abstract: The mode of action of amino acid antagonists of biological origin ist surveyed und the enzymatic reactions with which these antibiotics interfere are described, thus also elucidating the various roles of amino acids in cell physiology. Several organisms, including the antibiotic producer, possess molecular devices for conferring resistance to some of these substances. These antibiotics may be of further value as research tools in molecular biology.