Showing papers by "University of Göttingen published in 1968"

[Maternal care, pre- and postnatal, behavioral ontogeny, and circadian activity of the European wild boar (Sus scrofa L)].

Abstract: Zusammenfassung 1In verschiedenen Wildgattern und in einem Grosgehege (Lainzer Tiergarten) wurde das Brutfursorge- und Brutpflegeverhalten, die Ontogenese des Verhaltens sowie die Aktivitatsperiodik des Europaischen Wildschweines untersucht. 2Grundeinheit der sozialen Organisation ist die Mutterfamilie. Mehrere Mutterfamilien vereinigen sich zu groseren Familienverbanden. Zu Beginn der Wurfzeit sondern sich die beschlagenen Bachen von den Gruppen ab. 3Die Bachen bringen ihre Frischlinge in Wurfnestern zur Welt. Sie haben durchschnittlich 5 Jungtiere pro Wurf. Neben den Wurfnestern werden Ruhe- oder Schlafnester angelegt. 4Die Bachen gebaren und saugen ihre Frischlinge in Seitenlage, was fur die Nesthocker typisch ist. 5In den ersten Tagen nach der Geburt bleiben die Muttertiere mit ihren Jungen im Wurfnest. Die Bindung an das Nest vermindert sich danach allmahlich. Die wichtigste Mutter-Kind-Beziehung sind das Saugen und der Nasenkontakt zwischen den Frischlingen und der Bache. 6Der Saugakt gliedert sich in Vormassage, Milchflus und Nachmassage. Den Jungen fehlen die fur die Nesthocker typischen Suchautomatismen; sie finden die Zitzen mit einem “oralen Einstellmechanismus”. Das Saugen ist ein Lecksaugen. 7Die Entwicklung der Verhaltensweisen in den verschiedenen Funktionskreisen wird beschrieben. Auser dem Walzen und dem Suhlen sind alle Verhaltenselemente bereits in den ersten Tagen nach der Geburt entwikkelt oder reifen bald heran. Selbst das Paarungsverhalten und die Grundelemente des Nestbauverhaltens laufen bei wenige Tage alten Tieren voll koordiniert ab. Die Entwicklung des Kampfverhaltens durchlauft verschiedene Phasen. Die Verhaltensweisen des Fusstemmens und des Totschuttelns, die dem Funktionskreis der Nahrungsaufnahme angehoren, sowie das Gahnen und Schutteln im Sitzen sind formal mit denen der Raubtiere zu vergleichen. 8Wildschweine sind in storungsfreien Gebieten vorwiegend tagaktiv. Ruheund Aktivitatsphase sind klar getrennt. Der entscheidende Zeitgeber durfte der Licht-Dunkel-Wechsel sein. 9Der Ubergang von der Ruhe zur Aktivitat und umgekehrt vollzieht sich in verschiedenen Stufen, denen typische Verhaltensweisen zugeordnet sind.

Correlation Coefficients for Electronic Wave Functions

Abstract: Electron correlation in atoms and molecules can be analyzed in terms of correlation coefficients similar to those used in probability theory and mathematical statistics. Different correlation coefficients can be defined for angular, radial, and momentum correlation in atoms and for axial (left-right), equatorial, and radial (in-out) correlation in molecules. The correlation coefficients are closely related to certain coefficients of the so-called natural expansion of the wave function. Nonvanishing correlation coefficients are obtained for the Fermi correlation in the independent-particle model as well as for electron correlation proper. Numerical examples show that the correlation coefficients for atoms are of the order of -0.05, suggesting that the correlation is usually small and negative, as compared with \ifmmode\pm\else\textpm\fi{}1 for "perfect" correlation. However, positive correlation coefficients may occur, in particular for excited states. Correlation in supersystems consisting of two nonoverlapping systems at large distances, and the distinction between interorbital and intraorbital correlation, are also discussed.

Experimental investigation of the reaction forsterite + H2O ⇌ serpentine + brucite

Abstract: A new determination of the equilibrium reaction: $$\begin{gathered} 2{\text{ Mg}}_{\text{2}} [{\text{SiO}}_{\text{4}} ] + 3{\text{ H}}_{\text{2}} {\text{O}} \rightleftharpoons {\text{1 Mg}}_{\text{3}} [({\text{OH)}}_{\text{4}} |{\text{Si}}_{\text{2}} {\text{O}}_{\text{5}} ] + 1{\text{ Mg(OH)}}_{\text{2}} \hfill \\ \hfill \\ {\text{ forsterite serpentine brucite}} \hfill \\ \end{gathered} $$ yielded equilibrium temperatures which lie (at identical H2O-pressures) about 60° C lower than all previously published data (Bowen and Tuttle, 1949; Yoder, 1952; Kitahara et al., 1966; Kitahara and Kennedy, 1967). It has been shown that the above authors have determined not the stable equilibrium curve but instead a metastable “synthesis boundary”. The actual (stable) equilibrium curve is located at 0,5 kb and 350° C 2,0 kb and 380° C 3,5 kb and 400° C 5,0 kb and 420° C 6,5 kb and 430° C.

Ultrastructural analysis of individual layers in the lateral geniculate body of the monkey.

Abstract: 1. The cellular and synaptic pattern of the lateral geniculate body of the monkey has been studied electronmicroscopically by using microdissected portions from individual layers. For general orientation and comparison the Golgi technique has been utilised extensively. 2. This technique revealed four different types of neuron whose distribution differs in the various layers. The first type has 3–4 stem dendrites, which possess tiny side branches or appendages. The second type is smaller and has 8–10 stem dendrites. The third type is a Golgi type II cell with very long dendrites with bushy terminal arborisations. The fourth type are very small neurons and it is difficult to separate them from glial cells with certainty. 3. The synaptic organisation has been examined in great detail, in particular the different composition of the glomeruli in different layers. Seven components of a glomerulus have been found whose individual contributions vary in different layers. These components are: main axon, main dendrite, peripheral axons, peripheral dendrites, dendritic and axonal thorns and glia lamellae. 4. In addition to this synaptic pattern a further interesting synapse has been found, an axo-axonal type in contact with the initial segment of a large axon of a geniculate cell.

Der Einfluß von Cytokininen auf die Bildung von Photosyntheseenzymen in Roggenkeimlingen

Abstract: 1. Factors were investigated which control the formation of photosynthetic enzymes during germination. Enzymes of the reductive pentose phosphate cycle like carboxydismutase (EC 4.1.1.39) and NADP-dependent glyceraldehydephosphate dehydrogenase (EC 1.2.1.9.) are formed in the primary leaves of dark-grown rye seedlings. The rate of their synthesis is determined by the level of cytokinins. This rate can be increased by treatment of normal seedlings with kinetin. After application of kinetin to dark-grown seedlings, the investigated enzymes finally reach the same activity as they do in untreated light-grown plants. The formation of these photosynthetic enzymes can be strongly reduced by excision of the roots early in the development, a treatment which is known to lower the supply of cytokinins. A high rate of enzyme formation can be restored by feeding kinetin to rootless seedlings. Neither adenosine nor gibberellic acid have this effect on enzyme formation. 2. Changes in the content of cytokinins preferentially influence the formation of the investigated photosynthetic enzymes. Some cytoplasmic enzymes are not affected by the decrease of the cytokinin level which is achieved by excision of the roots. At the beginning of germination only cytoplasmic enzymes are promoted by application of kinetin, whereas in later stages, after 96 hours of germination, only the formation of photosynthetic enzymes is increased. The formation of photosynthetic and cytoplasmic enzymes seem to differ in their cytokinin requirements. 3. Cytokinins seem to be necessary for the formation of enzymes of the reductive pentose phosphate cycle. However, the cytokinins do not alter the time of appearance of these enzymes. Also the suppressing action which is exerted on the formation of photosynthetic enzymes by low temperature cannot be prevented by the application of kinetin. The action of cytokinins probably does not induce the derepression of the genes, but the level of cytokinins determines the extent of the manifestation of the genes. 4. The formation of the photosynthetic enzymes is also promoted by phytochrome. Phytochrome and cytokinin act as independent factors in a multiplicative system. The rate of synthesis of these enzymes in the dark, which corresponds to the cytokinin level of the seedlings (rootless, normal or treated with kinetin) can be increased by a constant factor via the phytochrome system by continuous irradiation with far-red light. In the case of carboxydismutase this factor is nearly 2. 5. After excision of the roots carboxydismutase and NADP-dependent glyceraldehydephosphate dehydrogenase reach higher activity in red and blue light than in far-red light, under which no chlorophyll is formed. In this case formation of carboxydismutase in red and blue light seems to proceed in close correlation with chlorophyll synthesis.

Chemical Fractionation in the Sedimentary Environment

Abstract: Chemical data on the upper continental earth's crust (assumed composition: 44% granites; 34% granodiorites; 8% quartz diorites; 13% gabbros) have been compared with those on graywackes and ordinary shales. Both abundant sedimentary rock types show only little chemical differentiation relative to magmatic rocks as their ultimate source. In addition to weathering products of crustal rocks volatile elements from degassing concentrate in the sedimentary environment. A general predominance of mechanical accumulation over chemical precipitation is observed in this environment. Three types of processes have been primarily identified which chemically influence the composition of detrital sediments: (1) reaction of clay particles with seawater or adsorption on clay particles from sea-water. (2) Trapping of seawater during sediment accumulation plus diagenetic reactions between sediment and pore solution. (3) Admixture of chemical or biogenic precipitates or residues. Compilations of data on average magmatic rocks, ordinary shales, graywackes, seawater, freshwater, bituminous shales and pelagic clays are presented to show their specific chemical features.

Stabilitätsbeziehungen zwischen Chlorit, Cordierit und Almandin bei der Metamorphose

Abstract: The stability relations between cordierite and almandite in rocks, having a composition of CaO poor argillaceous rocks, were experimentally investigated. The starting material consisted of a mixture of chlorite, muscovite, and quartz. Systems with widely varying Fe2+/Fe2++Mg ratios were investigated by using two different chlorites, thuringite or ripidolite, in the starting mixture.

Anionische Silberzentren („B-Zentren“) in Alkalihalogeniden

Abstract: It is proposed that negatively charged silver ions on anion sites are responsible for theB bands found in silver doped alkalihalides. Experimental investigations confirming this model of theB center are presented. Optical absorption and emission ofB centers were measured in seven alkalihalides in the temperature range from 450 to 4 °K. Configuration coordinate diagrams were obtained for KCl, KBr, and KI.

Symmetry properties of natural orbitals and geminals I. Construction of spin‐ and symmetry‐adapted functions

Abstract: Natural spin-orbitals (NSO), natural spin-geminals (NSG) and their spinless counterparts are not always adapted to the symmetry group of the Hamiltonian. Alternative orbitals and geminals that are always symmetry adapted and as close as possible to the NSO and NSG are defined and their properties are discussed. The expansion of the one- and two- particle density matrices ρ1 and ρ2 in irreducible tensor components is considered and the relations between the tensor components of ρ2 and the spin coupling functions introduced previously are established. The totally symmetric components ρ and ρ of ρ1 and ρ2 are of particular interest, because their eigenfunctions are the required symmetry-adapted NSO'S and NSG'S, respectively. Les spin-orbitales naturelles (NSO) les spin-geminales naturelles (NSG) et les fonctions correspondantes sans spin ne sont pas toujours adaptees au groupe de symmetrie de l'Hamiltonien. On definie des orbitales et des geminales alternatives, qui sont toujours adaptees a la symmetrie et qui ressemblent aux NSO et NSG autant que possible, et on discute leurs proprietes. On decrit le developpement des matrices de densite a une et deux particules ρ1 et ρ2 en composantes de tenseurs irreductibles et on etablit des relations entre les composantes tensorielles de ρ2 et les fonctions de couplage du spin definies anterieurement. Les composantes completement symmetriques ρ et ρ de ρ1 et ρ2 sont particulierement interessantes, parce que leurs fonctions propres sont les NSO et les NSG cherchees, qui sont adaptees a la symmetrie. Die naturlichen Ein- (NSO) und Zweielektronenfunktionen (NSG) und ihre spinlose Gegenstucke sind nicht immer der Symmetriegruppe des Hamiltonoperators angepasst. Alternative Ein- und Zweielektronenfunktionen, die immer der Symmetrie angepasst sind, und die soweit wie moglich den NSO und NSG gleichen, werden definiert und ihre Eigenschaften werden diskutiert. Die Entwicklung der Dichtematrizen erster und zweiter Ordnung ρ1 und ρ2 in irreduziblen Tensorkomponenten wird beschrieben und gewisse Beziehungen zwischen den Tensorkomponenten von ρ2 und vorher eingefuhrten Spinkopplungsfunktionen werden hergeleitet. Die ganzlich symmetrischen Komponenten ρ und ρ von ρ1 und ρ2 sind von speziellem Interesse weil ihre Eigenfunktionen die gesuchten symmetrieangepassten NSO und NSG sind.

On phase equilibria in metamorphosed siliceous dolomites

Abstract: Basing on calculations and experiments the equilibrium curves of 15 reactions occuring during metamorphism of siliceous dolomites are presented. In a T—XCO2 diagram these curves intersect at four isobaric invariant points. This is consistent with the fact, that different reaction sequences are known from the nature.

Homing and ?ortsteue? (attachment to place) in Patella L. (Gastropoda, Prosobranchia)

Abstract: It is known that numerous gastropods show homing ability. Many limpets return to well defined sites. Patella L. acquires a home spot also on the smooth glass surfaces of aquarium. Before leaving, the limpet scrapes its home, particularly the anterior part of the footprint. After each return it makes characteristic movements with its shell. When homing Patella nearly always retraces its outward track, at least in part; sometimes it reaches its home over the shortest route possible. Site and tracks are marked by chemical substances. The animal orientates itself by contact chemoreception on the track and by distance chemoreception when near its home. Apparently there also exists a kinesthetic mechanism of orientation based on a measurement of distance on the outward journey. At the home spot Patella always manoeuveres exactly into the same position. Often it has to turn or to glide around slightly. It finally settles down with small movements of its shell. The footprint shows chemical differences in a wide marginal zone. Probably, different chemoreceptors on the sole of the foot are associated to the various regions of the footprint. The chemical differentiation of the footprint has the same orientation-value for all individuals of the same size group. In addition there exists an individual marking, shown e.g. by avoidance reactions of alien animals. The individual specificity of the foot's secretum is particularly marked on the tracks, for each Patella follows its own trail only and thus normally reaches its own home. On an uneven substratum this is the only place where the margin of its shell fits the ground exactly. For establishing a home site and keeping to it, several environmental conditions have to be met. Patella settles only on surfaces overgrown with small algae. In an aquarium it favours the sides most exposed to light. On vertical walls the animal is gravity-oriented. Most limpets are attached head-end down. Patella is able to perceive the distance from the water-line, and may orient itself with respect to fixed objects in the aquarium by means of a “Ferntastsinn”. When first choosing a home spot on an uneven substratum, the limpet often adjusts its position by turning movements, so that the contacts between shell and ground are as close as possible. Selective growth at the shell's margin then results in a perfect fit to the irregularities of the ground. All prerequisites for the establishment of a home site are also determining the animal's keeping to its home. If changes are introduced with respect to the fitting of the shell to the ground, to the position of neighbouring objects, to water-level, light, or direction of gravity, the animal may leave its home site and reorient itself in an equivalent new one. The attractiveness of the chemical markings of the old site nevertheless compete with all these conditions for some time. Rest and activity are controlled by light-dark and tidal cycles. — Inter-and intraspecific differences were obtained under experimental conditions. Almost all individuals were preferentially active in darkness. P. caerulea moved at high tide; P. vulgata was active either at low tide only, or both at high and low tide, or — rarely—at high tide only. All animals reacting to tidal rhythms were synchronized even by unnaturally frequent changes in the water-level. The tidal dependence of the activity of individual P. vulgata may perhaps be interpreted as the persistence of an adaptation to drought and submergence acquired at the original habitat. The reactive ability towards high and low tide can be modified. The activity-phase may be stopped prematurely by changing light or tidal conditions. Animals keeping constantly to their homes returned to them at once, whereas others — having no defined home —generally prolonged their excursions. When light and water-level are kept constant the locomotory activity of P. vulgata and P. caerulea has the characteristics of an endogenous tidal rhythm. Changes in water-level soon approximately catch the freerunning periodicity, alteration of light and darkness synchronize it less readily but more precisely.

Synthese von Cyclopropyläthern und Cyclopropanolen durch Carben‐Übertragung – Acetolyse von Cyclopropyltosylaten

Abstract: Durch Umsetzung von Chlormethylphenylather mit Butyllithium in Olefinen erhalt man Phenoxycyclopropane. Auf ahnlichem Wege sind, wenngleich in bescheidenen Ausbeuten, 1-Chlor-1-phenoxycyclopropane darstellbar. Alkoxycyclopropane entstehen, wenn man in Gegenwart von Olefinen Dichlormethylalkylather mit Methyllithium·Lithiumjodid behandelt. (β-Chlorathoxy)cyclopropane lassen sich mit Butyl- oder Athyllithium oder mit Basen in guten Ausbeuten in Cyclopropanole umwandeln. – Wie Acetolyseversuche mit sterisch definierten Cyclopropyltosylaten ergaben, vollzieht sich die Umwandlung eines Cyclopropylderivates in ein Allylkation in Ubereinstimmung mit den von Woodward und Hoffmann sowie DePuy formulierten Regeln. Fur die Solvolyse von exo-Bicyclo[n.1.0]-alkyltosylaten werden „halbgeoffnete” Zwischenstufen postuliert, die eine Mittelstellung zwischen einem Allylkation und einem Cyclopropylkation einnehmen.

Zur Fortpflanzung und Entwicklung der Macrodasyoidea (Gastrotricha)

Abstract: Comparative investigations of the reproduction and development of the Macrodasyoidea are made on the species Turbanella cornuta, Macrodasys caudatus, Cephalodasys muximus, Dactylopodalia baltica and some others The Macrodasyoidea have a direct development The divisions of the best studied species, Turbanella cornuta, is total, equal and bilateral The cell-lineage produces a 30-cell stage in which gastrulation by invagination of two entoderm cells followed by mesodermal cells occurs Two compact mesodermal strands segregate the germ cells and give rise to the muscular system and the y-organ Agreements in the embryology of the gastrotrichs and the nematodes support the postulation of a close relationship between them

[Regulation of glucose-6-phosphate dehydrogenase from Hydrogenomonas by ATP and reduced pyridine nucleotides].

Abstract: 1 Die Bildung der zum Fructoseabbau uber den Entner-Doudoroff-Weg dienenden Enzyme wird in Hydrogenomonas H 16 durch molekularen Wasserstoff reprimiert In volladaptierten, auf Fructose gewachsenen Zellen wird der Fructoseabbau durch H2 gehemmt Die durch H2 bewirkte Hemmung greift wahrscheinlich an der Glucose-6-phosphat-Dehydrogenase an 2 Die aus Hydrogenomonas H 16 100fach angereicherte Glucose-6-phosphat-Dehydrogenase unterscheidet sich vom Hefeenzym durch ihre geringe Substrataffinitat, durch die Fahigkeit sowohl mit NADP als auch mit NAD als Coenzym zu reagieren und durch den sigmoiden Verlauf der Substratsattigungskurve (G-6-P) 3 Das Enzym wird durch ATP und NADH2 gehemmt Durch ATP wird die Sigmoiditat der Substratsattigungskurve verstarkt Aus den gewonnenen kinetischen Daten ist zu schliesen, a) das die durch NADH2 bewirkte Hemmung vor allem auf einer Konkurrenzreaktion zwischen NADP und NADH2 um die Bindungsstelle des Coenzyms am Enzym beruht, b) das G-6-P-DH ein allosterisches Enzym ist, das aus mindestens vier Untereinheiten besteht und fur welches ATP ein negativer allosterischer Effector ist; c) das die Substratbindungsstellen fur G-6-P der Enzymuntereinheiten kooperative Wechselwirkungen aufeinander ausuben; d) das G-6-P-DH ein “K-System”, ist, d h das der allosterische Effector den apparenten K m -Wert,jedoch nicht die maximale Geschwindigkeit (vmax) der Enzymfunktion verandert 5 G-6-P-DH aus H 16 wird durch Magnesium-Ionen nicht aktiviert Hohe MgSO4-Konzentrationen hemmen das Enzym sogar Durch Zusatz von MgSO4 kann die “ATP-Hemmung” vollkommen aufgehoben werden, wenn G-6-P in hoher Konzentration im Reaktionsgemisch vorliegt Die Hemmung wird minimal, wenn das Verhaltnis Mg/ATP den Wert 1,3 ubersteigt

O−−-Lücken-Dipole in Alkalihalogenidkristallen

Abstract: Dielectric loss measurements are reported for KBr, KCl, and NaCl crystals containing O−− ions. The frequency and temperature dependences can be well represented by a Debye curve.

Kleine Mitteilungen über Flagellaten und Algen

Abstract: Porphyridium marinum ist mit P. cruentum identisch. Weder morphologische, noch physiologische Unterschiede liesen sich finden. Die Alge kann ohne organische Verbindungen auskommen und bedarf keiner Vitamine, wird aber durch Erddekokt und Hefeextrakt gefordert.