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  • 1
    Electronic Resource
    Electronic Resource
    Reproduction of the estuarine mysid Taphromysis bowmani (Crustacea: Malacostraca) in fresh water (1977)
    Springer
    Marine biology 42 (1977), S. 253-257 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Taphromysis bowmani, previously considered to be an estuarine species, is shown to reproduce and complete its life cycle in fresh water. Both sexes and all life history stages were collected from March to June 1975, in the Wakulla River, Florida (USA), where chlorinity, alkalinity and total hardness were relatively high. Development was synchronous within a brood but not between broods. Brood size was positively correlated with female size, and ripe ovaries of brooding females suggest that at least 2 broods per female are possible. Breeding appears to occur throughout the year. The relatively high ion content, especially chloride, in the Wakulla River may account for the presence of T. bowmani. Other estuarine mysids reported from fresh water are noted.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00397749
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  • 2
    Electronic Resource
    Electronic Resource
    On the mechanisms of frost injury and frost hardening of spruce chloroplasts (1977)
    Springer
    Planta 137 (1977), S. 195-201 
    Details
    ISSN: 1432-2048
    Keywords: Chloroplast membranes ; Frost-hardening ; Photochemical activities ; Picea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Hill reaction and noncyclic photophosphorylation of isolated class C chloroplasts of spruce (Picea abies (L.) Karst.), as well as 14CO2 fixation by whole needles at constant laboratory conditions proceeded at high rates during spring and early summer, declined during late summer and autumn by about 60%, remained at this level during winter, and recovered quickly in early spring. During summer, the whole needles proved to be frost labile, since after exposure to-20°C and careful thawing, fast chlorophyll degradation occurred. In addition, only photosynthetically inactive chloroplasts could be isolated from those precooled needles. On the contrary, during winter the photochemical activities of plastids from freshly harvested needles did not differ from those of artificially frozen-thawed needles. When isolated spruce chloroplasts were exposed to the same subfreezing temperatures as the whole needles, no influence of freezing on the photochemical activities was observed, irrespective of whether the plastids were isolated from frost sensitive or frost hardened needles. It is concluded that frost damage to spruce chloroplasts is due to an attack of membrane toxic compounds or lytic enzymes which were liberated upon freezing from more labile compartments. Frost hardening of the chloroplasts, as determined by the stability of chlorophyll after exposure of the needles to low temperatures, as well as by the isolation of photosynthetically active chloroplasts from such precooled needles, appeared to depend at least on 2 processes: (i) an alteration of the composition of the photosynthetically active membranes and (ii) and additional stabilization of these membranes by protecting substances. The first process was indicated by a large increase (decrease) of the capability of isolated chloroplasts for PMS-mediated photophosphorylation which accompanied natural or artificial frost hardening (dehardening). Production of cryoprotecting compounds was suggested by a significant higher stability against NaCl observed with class C chloroplasts isolated from frost hardened needles as compared to that of plastids from frost labile material. The decrease of the capability for both, the ferricyanide dependent photoreactions of the plastids and the CO2 fixation by whole needles, which was observed during the frost hardening phase, cannot be due to freezing injuries; it rather appears to be a consequence of the frost hardening process.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00388150
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  • 3
    Electronic Resource
    Electronic Resource
    Morphologie, Larvalentwicklung und Haarsensillen des Tastbeinpaares der Gei\elspinneHeterophrynus longicornis Butler (Arach., Amblypygi) (1977)
    Springer
    Zoomorphology 88 (1977), S. 259-276 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die Gei\elspinneHeterophrynus longicornis orientiert sich überwiegend mit Hilfe von cuticularen Haarsensillen. Borstenhaare und Trichobothrien treten besonders an den Beinen auf. Das zu einem Tastbein umgeformte, vielfach gegliederte 1. Beinpaar trÄgt au\erdem 5 weitere Typen von Haarsensillen- und 3 anders gestaltete cuticulare Sinnesorgane. Die Haarsensillen der verschiedenen Entwicklungsstadien der Gei\elspinne wurden licht und rasterelektronenmikroskopisch untersucht und ausgezÄhlt. Anschlie\ende elektronenmikroskopische Untersuchungen erlauben die Zuordnung folgender physiologischer Funktionen: Borstenhaare — Kontaktchemo- und Mechanorezeptoren; Trichobothrien — Mechanorezeptoren („Ferntastsinnesorgane“); Porenhaare (2 Typen) — olfaktorische Chemorezeptoren; Kölbchenhaare — Chemorezeptoren i.w.S. (auch hygrosensitiv?); StÄbchenhaare (2 Typen) — Chemorezeptoren i.w.S. Die umgeformten Krallen sowie das „Gruben“- und das „Plattenorgan“ sind vermutlich ebenfalls Chemorezeptoren i.w.S. (auch hygro-thermosensitiv?). Aus der Anzahl der Sensillen des Tastbeintarsus ergibt sich eine theoretische Axonzahl von 2250 an der Spitze bzw. 21 500 an der Basis. AuszÄhlungen von EM-Schnittbildern stimmen damit gut überein. Alle Fasern (Φ um 0,2 Μm) sind wahrscheinlich afferent und ziehen getrennt zum ZNS. Daneben finden sich in jedem Tarsalnerv eine oder mehrere Riesenfasern (Φ 10–20Μm), auf die kleinere Axone bereits vom Glied 1 an aufgeschaltet werden. Wahrscheinlich handelt es sich hier um ein „Schnelleitsystem“, das periphere Reize möglichst rasch zum ZNS bringt. Ein Vergleich mit Untersuchungen an anderen Arten macht wahrscheinlich, da\ die Ausstattung mit Sinnesorganen innerhalb der Ordnung Amblypygi sehr Ähnlich ist und damit der Ähnlichen Lebensweise der Arten entspricht.
    Notes: Summary The whip spiderHeterophrynus longicornis uses cuticular hair sensilla for orientation. Bristles and trichobothria occur mainly on the walking legs. The first pair of legs, which are modified appendages, bear five additional types of sensilla as well as three other sensory structures. The hair sensilla of different developmental stages were studied by light- and scanning electron microscopy for quantitative evaluations. Transmission electron microscopy permitted to attribute the following tentative functions to certain sensilla: bristles — contact chemoreception and mechanoreception; trichobothria — mechanoreception (‘touch-at-a-distance’); porous sensilla (2 types)— olfaction; club sensilla — chemoreception (hygroreception?); rod sensilla — chemoreceptors. The modified claws, the ‘pit organ’ and the ‘plate organ’ are supposedly also chemoreceptors (eventually humidity and/or thermoreceptors). Based on the number of sensilla on the tarsus of a first leg we calculated a theoretical number of 2250 axons for the first tarsal segment and 21 500 axons for the level of the last tarsal segment. Actual counts done on EM-pictures yielded very similar numbers. This means that practically all nerve fibres (0.2/gmm diameter) are afferent and that all of them proceed toward the CNS. Furthermore, each tarsal nerve contains one or several giant fibres (10–20Μm diameter) which receive synapses from small axons already in the distalmost segment 1. We interpret this findings as a fast conduction pathway to relate peripheral stimuli quickly to the CNS. A comparison with the few studies on other Amblypygi renders it likely that their sensory equipment is rather similar, which corresponds to their similar life habits.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00995476
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  • 4
    Electronic Resource
    Electronic Resource
    Transition-metal complexes in the prebiotic soup (1977)
    Springer
    Naturwissenschaften 64 (1977), S. 91-91 
    Details
    ISSN: 1432-1904
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00437354
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  • 5
    Electronic Resource
    Electronic Resource
    Über Mittelwerte aus Potenzproduktsummen (1977)
    Springer
    Monatshefte für Mathematik 83 (1977), S. 177-189 
    Details
    ISSN: 1436-5081
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract Using symmetric forms $$M_{k_1 ,...,k_p } : = (1/A(n))\,\sum\limits_{v_1 ,...,v_p } {a_{v_1 }^{k_1 } ...a_{v_p }^{k_p } } $$ A(n)=number of terms of the sum,a ν〉0,k i≠0,i=1,...,n) the meansm k 1,...,kp:=(Mk 1,...,kp1/(k1+...+kp)(k1+...+kp≠0) are formed and investigated as to monotonicity under the hypothesis that the exponentsk 1,...,k p are certain linear functions of only one parameterk(k i =λ i k+β 1,λ i 〉0,β 1+...β p =0). (The means $$m_{\lambda _1 k_1 ,...,\lambda _1 k_p } $$ , e. g., are increasing ifk is increasing.) The proofs are elementary and use the known method of positive logarithmically convex (or concave) sequences and certain generalizations of Muirhead's theorem.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01541634
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  • 6
    Electronic Resource
    Electronic Resource
    Bleidioxid als Lösungselektrode (1977)
    Springer
    Colloid & polymer science 255 (1977), S. 515-515 
    Details
    ISSN: 1435-1536
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01536501
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  • 7
    Electronic Resource
    Electronic Resource
    Ermittlung der Wärmeübergangszahl beim Erspinnen monofiler Fäden aus der Schmelze bei freier Konvektion (1977)
    Springer
    Colloid & polymer science 255 (1977), S. 1156-1164 
    Details
    ISSN: 1435-1536
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Zusammenfassung Mit in der Literatur veröffentlichten Angaben wird der Fadenbildungsvorgang aus der Schmelze für Polyamid 6 und Polyäthylenterephthalat bei der freien Konvektion untersucht. Mit dem Spinnwegx s, der dem Glasumwandlungspunkt zugeordnet ist, werden der mittlere Fadendurchmesser und die Oberfläche des Polymerstrahles bestimmt. Die mittlere Wärmeübergangszahl ergibt sich aus der Wärmemenge der Polymerschmelze des monofilen Fadens, die zur Oberfläche und zur mittleren Fadentemperatur ins Verhältnis gesetzt wird. Nach dem gefundenen Ergebnis ist die mittlere Wärmeübergangszahl zum mittleren Fadendurchmesser umgekehrt proportional. Für Polyamid 6 und Polyäthylenterephthalat sind Gleichungen angegeben, die zeigen, daß die mittlere Wärmeübergangszahl zur Wärmeleitzahl des jeweiligen Polymers proportional ist. Bei den 30 ausgewerteten Meßwetten aus der Literatur wird gefunden, daß die Fadenkühlung, die sich aus dem Verhältnis der mittleren Fadentemperatur zum Spinnwegx s ergibt, bei der freien Konvektion zur Durchsatzmenge des monofilen Fadens umgekehrt proportional ist. Der Nachweis wird geführt, wie relevant der Durchmesser der Kapillârbohrung der Düse für den mittleren Fadendurchmesser und damit die mittlere Wärmeübergangszahl ist. Gleichungen zur Berechnung des mittleren Fadendurchmessers, des Spinnwegesx s, der mittleren Wärmeübergangszahl und der Fadenkühlung sind angegeben. In der Abbildung 1 läßt sich zum mittleren Fadendurchmesser die mittlere Wärmeübergangszahl ablesen. Bei der freien Konvektion ist die mittlere Wärmeübergangszahl für Polyamid 6 größer als für Polyäthylenterephthalat. Die Fadenkühlung dagegen ist für Polyamid 6 kleiner als für Polyäthylenterephthalat, da der Wärmeinhalt des Polymerstrahles des monofilen Fadens bei Polyamid 6 größer ist.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01447583
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  • 8
    Electronic Resource
    Electronic Resource
    Unsaturated dicarboxylic acids as substrates in oscillating reactions involving bromate, sulfuric acid and a catalyst (1977)
    Springer
    Reaction kinetics and catalysis letters 6 (1977), S. 275-279 
    Details
    ISSN: 1588-2837
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Abstract Наблюдалась гомогенная осциллирующая реакция нового типа в системе бромат калия — ацетилендикарбоксильная кислота — ферроин — серная кислота. Это доказывает, что присутствие “активной” метиленовой группы не является необходимым условием осциллирующей реакции, включающей карбоксильные кислоты. Малоновая кислота может быть частично замещена малеиновой и фумаровй кислотами в реакции Белоусова. В мягких экспериментальных условиях осциллирующей реакции малеиновая кислота иэомеризуется в фумаровую кислоту.
    Notes: Abstract A new type of homogeneous oscillating reaction has been observed in the potassium bromate-acetylenedicarboxylic acid-ferroin-sulfuric acid system. This proves that the presence of an “active” methylene group is not a necessary condition for oscillating reactions involving carboxylic acids. Malonic acid can be partly replaced by maleic and fumaric acid in the Belousov reaction. Under the mild experimental conditions of the oscillating reaction, maleic acid undergoes isomerization to fumaric acid.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02070220
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  • 9
    Electronic Resource
    Electronic Resource
    The redox mechanism of the chelate-catalysed oxygen cathode (1977)
    Springer
    Journal of applied electrochemistry 7 (1977), S. 239-245 
    Details
    ISSN: 1572-8838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The electro-reduction of oxygen is effectively catalysed by metal chelates of the N4-type. The mechanism of this process has been found to be a modified ‘redox catalysis’. O2 molecules and the products of their reaction, at least up to H2O2, remain strongly co-ordinated to the central metal ion of the chelates XMeII. The potential-determining step, which regenerates the reduced form, is the following: (XMeIII...O2H)++H++ 2e→XMeII+H2O2. H2O2 is further decomposed via the catalase action of the electrocatalyst. The mechanism is confirmed by experimental results with iron phthalocyanine (FePc) and cobalt-dibenzotetraazaannulene (CoTAA) as a O2-slurry electrode at various O2 pressures. The latter shows anodic reaction-limited currents, which seem to involve also oxygen-containing intermediates. The implication of the presented mechanism in regard to other electrochemical processes is discussed briefly.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00618991
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  • 10
    Electronic Resource
    Electronic Resource
    Auslaufvorgänge aus wasserbehältern-eine anwendungsorientierte einführung in die analysis (1977)
    Springer
    Educational studies in mathematics 8 (1977), S. 439-460 
    Details
    ISSN: 1573-0816
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00310947
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