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  • Springer  (33,802)
  • 1990-1994
  • 1970-1974  (33,802)
  • 1950-1954
  • 1971  (33,802)
  • 1
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Three non-homologous structures act as intromittent organs: ligula (Zygoptera), hamuli posteriores (Anisozygoptera, ), vesica spermalis (Anisoptera). Ligula and vesica spermalis are anchored by means of hydraulically working “gland”-structures, Ligula-Schwellkörper and Vesica spermalis-Schwellkörper respectively. A sperm-pump (Ausspritzkammer) extends the function of Vesica spermalis-Schwellkorper in non-aeschnoid Anisoptera, a group found to be monophyletic. The study includes a depiction of the peripheral abdominal nerves of larva and imago.
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  • 2
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Skeletal differences in the lateral thoracico-abdominal regions of fifth instar and adult Notonecta appear to reflect respiratory differences in the two stages. Changes in the epidermis of this region during the last instar are described, and the possible relationships between the epidermis, nymphal cuticle, and imaginal cuticle are discussed.
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  • 3
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    Zoomorphology 69 (1971), S. 273-282 
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Coelo-rectal pygidial pores were found in the anal area of marine enchytraeids (Lumbricillus lineatus, Marionina spicula, Enchytraeus albidus) from the mud-flats of the Isle of Sylt. The structure and function of these pores have been discussed.
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  • 4
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    Zoomorphology 70 (1971), S. 229-237 
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The omasal surface with a range of horny papillae and stratum corneum has been examined using scanning electron microscopy. Other features of interest described include pits or holes in the surface of these corneal cells and hair-like structures associated with the lamina.
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  • 5
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    Zoomorphology 70 (1971), S. 253-280 
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The microanatomy of the dorsal giant fibers of Lumbricus terrestris is described systematically. Moreover, two afferent giant interneurons and 4 pairs of giant motor neurons are individually identified. The results are compared with the physiological data so far available.
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  • 6
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    Wood science and technology 5 (1971), S. 17-26 
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Specimens of Eucalyptus delegatensis timber showing different degrees of shrinkage and recovery on reconditioning have been examined by staining and analysed for lignin and polyphenol content. Collapsed specimens did not stain normally for lignin but this was shown to be caused by masking of staining reactions by polyphenol. Cross sectional area shrinkage before reconditioning did not show any significant correlation with either lignin or polyphenol content but shrinkage after reconditioning showed highly significant negative correlation with lignin and polyphenol content. Amount of recovery showed positive correlation with both lignin and polyphenol content. It is clear that low lignin and low polyphenol content is associated with lack of recovery and that polyphenol does tend to promote recovery. No evidence could be found to support the hypothesis that the rheological properties of the collapse specimens were influenced by esterification of the lignin with extraneous substances causing blocking of the normal lignin-polysaccharide bonding. The evidence suggests that polyphenol acts only as a bulking agent.
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  • 7
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    Wood science and technology 5 (1971), S. 49-62 
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary The distribution of lignin in normal and compression wood of loblolly pine (Pinus taeda L.) has been studied by the technique of lignin skeletonizing. Hydrolysis of the wood carbohydrates with hydrofluoric acid left normal wood tracheids with a uniform distribution of lignin in the S1 and S2 cell wall layers. However, the S3 region of both earlywood and latewood tracheids consistently retained a dense network of unhydrolyzable material throughout, perhaps lignin. Lignin content in compression wood averaged about 7% more than in normal wood and appears to be concentrated in the outer zone of the S2 layer. The inner S2 region, despite helical checking, is also heavily lignified. The S1 layer, although thicker than normal in compression wood tracheids, contains relatively little lignin. Ray cells, at least in normal wood, appear to be lignified to the same extent, if not more so in certain cases, than the longitudinal tracheids. Other locations where lignin may be concentrated include initial pit border regions and the membranes of bordered pits.
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  • 8
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    Wood science and technology 5 (1971), S. 40-48 
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary A method of rapidly determining the longitudinal growth stress present on the surface of logs and standing trees is described. Application of the technique will enable detailed examination of stress present about the circumference and along the length of trees and logs. In addition it will enable comparisons to be made between trees, as well as monitoring changes occurring in a particular log as the result of treatment to reduce stress. Finally, its use will enable the selection of low stressed trees for genetic studies and propagation trials.
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  • 9
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    Wood science and technology 5 (1971), S. 27-39 
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Spectra resulting from chemical changes in white spruce [Picea glauca (Moench) Voss] microsections heated in air or nitrogen at high temperatures (100 to 240°C) were continuously recorded on an infrared spectrophotometer. A significant change occurred in the intensity of the 1730 cm-1 band which indicates a carbonyl absorption of carboxyl and ester groups of wood. This intensity initially decreased and the increased at a greater rate. The time periods to reach the minimum inflection point, termed the times to initiate a significant oxidative carboxylation or oxidation, showed a good curvilinear relationship with heating temperatures. Quantification of this time-temperature relationship required to reach a significant level of oxidation was achieved, using wood microsections that had extractives removed to varying degrees. It was concluded that the extractives served only as catalysts for oxidation. When drying wood at temperatures over 180°C, in addition to oxidation, pyrolytic degradation occurred. Chemical evidence was further confirmed by tests of plywood panels bonded with phenolformaldehyde glue. Three separate types of veneers were investigated—non-extracted, acetone extracted, and veneer with the surface chemically stabilized by treatment with sodium borohydride. The results suggest that the time period to reach a significant level of oxidative carboxylation is also the time period to initiate a wood surface inactivated to polymer adhesion.
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  • 10
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    Zoomorphology 69 (1971), S. 318-362 
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The present contribution deals with the exoskeleton of Notiothauma reedi MacLachlan. A special attention has been paid to the external male genital apparatus with particular reference to the sperm-pump. Finally the structures, which have a bearing on the phylogeny of the order Mecoptera have been duly discussed.
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  • 11
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    Zoomorphology 70 (1971), S. 1-72 
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Skeleton, muscles, and functioning of the egg-laying systems of 38 species out of 16 subfamilies are studied. A development sequence toward a soil chamber to coat the eggs (b, c) can be characterized by the sternite 8: a) its inward position (Geroninae), b) its erection (9 subfamilies), c) its shell-shaped cavity (Exoprosopinae). Systropodinae and Heterotropinae cannot be fitted into this system.
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  • 12
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    Zoomorphology 70 (1971), S. 119-127 
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung 1. Das Auge von Pantodon buchholzi wird durch ein bei Fischen erstmals beschriebenes horizontal verlaufendes Septum zweigeteilt, welches stark pigmentiert and vaskularisiert ist. Es ist dem Conus papillaris der Reptilien vergleichbar. 2. In der unteren Retinahälfte befinden sich mehr als doppelt soviel Zapfen als in der oberen. Das Verhältnis von Receptoren zu den Schaltbzw. Ganglionzellen beträgt in der oberen Hälfte 13,8:7:1 und in der unteren 4:5,5: 1. 3. Beim bevorzugten Aufenthalt der Fische an der Wasseroberfläche wird letztere im Auge genau auf das Septum projeziert. Gegenstände über Wasser werden nur auf der unteren, solche im Wasser nur auf der oberen Retinahälfte abgebildet.
    Notes: Abstract A horizontal septum subdivides the eye of the surface feeding fish Pantodon buchholzi into an upper and lower part. The numbers and ratio of the receptor cells and succeeding neurons are different in both parts. The functional importance of these facts is discussed.
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  • 13
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In the mouth of the honey bee several types of sensory organs are found: Sensillae chaeticae on the tongue, sensillae trichodeae on the epipharynx and sensillae basiconicae on the hypopharynx. These organs usually are built up by a trichogen and a tormogen cell and they possess primary bipolar sensory cells in a varying number.
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  • 14
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    Zoomorphology 69 (1971), S. 1-8 
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An account is given of the morphology and function of the notal and postnotal organ in Mecoptera. The phylogenetic significance of these structures is discussed.
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  • 15
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    Zoomorphology 69 (1971), S. 115-183 
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The walls of the ampulla, mucous gland, albumen gland, prostate, bursa copulatrix and receptaculum seminis have been investigated in 28 species of Nudibranchs with the light microscope and in 11 species with the electron microscope. The structure of these organs is described and their function discussed.
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  • 16
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    Zoomorphology 69 (1971), S. 201-272 
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This paper is a condensation of our knowledge on the eyes of the Araneae with respect to anatomy and ontogeny. After the addition of new observations, generalizations are allowed at the present state of our knowledge. On the basis of the structure of the eyes a change in a part of the system of the Araneae has to be proposed.
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  • 17
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    Zoomorphology 69 (1971), S. 363-384 
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The histological larval anatomy of Oxygyrus keraudreni Lesueur, Carinaria lamarcki Péron and Lesueur, Pterotrachea coronata Forskal and Firoloida desmaresti Lesuour relating to the veliger organisation of Atlanta is described at the stages close to the metamorphosis.
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  • 18
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    Zoomorphology 70 (1971), S. 73-102 
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract For the first time 16 subfamilies (26 genera) of the Bombyliidae are analyzed for their phylogenetic relationship, using the egg-laying system as principal criterion. It is concluded that the generally held division of the family into two subgroups should be abandoned, because a monophyletic group is only represented by the B. tomophthalmae. The assemblage of all Bombyliidae possessing a soil chamber to coat the eggs is proposed as “B. psammophoridae”.
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  • 19
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    Zoomorphology 70 (1971), S. 183-200 
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A detailed study of the vermiform larva of Schistocerca gregaria was made using film analysis in combination with morphological studies. The adaptations of the body are illustrated, and the use of these in digging up to the surface of the ground is described. The means of orientation were investigated, and unusual club-tipped hairs are suggested as important mechanoreceptors.
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  • 20
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Yolk-cytoplasma-movements are described before, during and after appearance of the cleavage nuclei on the outer layer of the living egg and are compared with movements on the outer layer of eggs which are free of nuclei.
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  • 21
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    Wood science and technology 5 (1971), S. 6-16 
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Bacteria and actinomycetes are probably the most common wood-inhabiting microorganisms, certainly they are the most adaptable in terms of environmental influences. When considering them as factors in wood decay they may be roughly classified into four groups for convenience and ease of comparison. 1. Those bacteria which affect the permeability to liquids of wood but have no significant effect on strength properties.—2. Those types which attack the wood structure.—3. Bacteria which only function as integral members of the total microflora and are associated in the ultimate breakdown of the wood.—4. The “passive” colonizers which have no effect upon the wood at all but which have a marked influence on the remainder of the population by their antagonistic activities.—As bacteria and actinomycetes cetes have previously been held to be of minor importance in the field of wood degradation, these microorganisms are discussed in terms of the above four groups in an attempt to bring out their true importance.
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  • 22
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    Wood science and technology 5 (1971), S. 95-100 
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Values of moduli of rigidity (G LR andG LT), obtained from static bending tests of small southern yellow pine beams with square cross sections and true radial and tangential surfaces, are not significantly different. Values of moduli of elasticity and rupture of small southern pine beams at span-to-depth ratio of 14: 1 loaded on a true radial surface are not significantly different from values obtained from matched beams loaded on a true tangential surface.
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  • 23
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    Wood science and technology 5 (1971), S. 159-175 
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Summary The prolysis of cellulose, hemicelluloses, lignin preparations, and wood was studied by differential calorimetric analysis (DCA) for the range of 25° to 800° C. The test samples included powdered and filter paper celluloses; hardwood xylan; softwood galactoglucomannans, compression wood galactan, and arabinogalactan; a synthetic (DHP), sulfuric acid, Björkman, Brownell, and cellulase lignins; and unextracted and extracted hardwoods and softwoods. Heats of reaction were determined from the DCA thermal transition areas. Distinct differences were found between the thermograms of each hemicellulose and lignin sample. Although wood species could not be separated thermally, hardwood and softwood thermograms differed because of the hemicellulose degradation pattern.
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  • 24
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    Wood science and technology 5 (1971), S. 200-210 
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Wood is considered as a continuum whose behaviour must comply with basic laws of nonequilibrium thermodynamics. This provides a unifying point of view for explaining different processes in wood in terms of basic laws and constitutive assumptions. The equations governing the behaviour of wood under different circumstances (e.g. sorption, swelling, transport of moisture, build up of stresses) are derived from specific constitutive assumptions. More general constitutive assumptions compatible with requirements of non-equilibrium thermodynamics can lead to more realistic mathematical models.
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  • 25
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    Wood science and technology 5 (1971), S. 190-199 
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary The hydrophobic properties of benzene-soluble extractives from the bark of Pinus radiata were studied by determining the water-solid-air contact angle and the resistance to water penetration. The material contained in the bark extract possessed wax-like and film-forming properties. It was highly hydrophobic with a contact angle with water of about 98°. Wood samples were impregnated with bark extract in order to study the ability of the hydrophobic bark extractives to prevent preferential wetting with water and the displacement of the impregnant from the hydrophilic wood surface. The wax-like material deposited from the bark extracts showed a remarkable affinity for wood as revealed by the high degree of resistance to water penetration and wetting of the treated wood even after several wetting-drying cycles which otherwise tend to break down the bonds and adhesion between a hydrophilic solid and a hydrophobic coating. Hydrophobic or film-forming additives did not improve the ability of bark extractives to protect a hydrophilic solid from water. The properties of the bark extractives as a water repellent and a water barrier could therefore be assumed to be as near perfect as possible. Nature seems to have solved the problem of producing one single, although complex, material with two properties which are extremely difficult, maybe impossible, to combine in a single synthetic material: one of high affinity for a hydrophilic solid and another of extreme water repellency and resistance to water. The in situ conditions prevailing in the bark tissue, combining bark extractives and cell walls of various anatomical structures, must therefore represent a rather unique and for this specific purpose highly efficient two-phase hydrophobic-hydrophilic solid system.
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  • 26
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    Wood science and technology 5 (1971), S. 221-231 
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    Source: Springer Online Journal Archives 1860-2000
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    Notes: Summary A first approximation model for the mechano-sorptive deformation of wood is used to predict the deformation behaviour of beam-columns. An experimental check showed that the theory provides a good estimate of the lateral deflections that occur during the first drying cycle of initially green beam-columns.
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  • 27
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    Wood science and technology 5 (1971), S. i 
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  • 28
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    Wood science and technology 5 (1971), S. 272-289 
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    Notes: Summary In the future, wood will be used largely for the manufacture of fibre products and particle board. The quality of wood used to meet increasing world demand will vary considerably. One feature of quality that can affect utilisation is the amount and type of wood extractives present. The distribution and variation in composition of extractives in the tree, as well as their effect on pulp manufacture, durability and surface films, are summarized. Methods to reduce the effects of some extractives in existing trees are described. Extractives can be reduced in plantation material by minimizing heartwood formation and by using silvicultural methods which result in small amounts of extractives being formed in this tissue. Current knowledge on heartwood formation is summarized.
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  • 29
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    Wood science and technology 5 (1971), S. 313-314 
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  • 30
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    Wood science and technology 5 (1971), S. 255-271 
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    Notes: Summary A review of possible changes in wood morphology through genetic manipulation of the southern pines showed that: 1. Significant changes can be obtained by modifying tree form, growth rate and disease resistance. (a) Compression wood can be reduced by developing straighter trees. The inheritance of straightness is so strong that one generation of selection has resulted in enough improvement to enable deemphasis of this characteristic in second-generation breeding. (b) Branch size affects the final product by knot volume and the associated compression wood, included bark and resin; it is moderately genetically controlled. (c) Use of disease-resistant trees not only results in greater wood volume but in higher quality wood. Logs infected with fusiform rust give lower pulp yields and lower mullen and tensile strength in the paper. (d) Growth rate has a limited effect on wood qualities in mature loblolly pine. It is possible to have fast growth combined with either high or low specific gravity wood, since these characteristics are not closely related genetically. 2. Inheritance of wood qualities per se is strong enough to obtain meaningful changes in both yield and quality of pulp and paper. (a) Wood specific gravity, which is really a complex of several characteristics, has responded well to selection. Specific gravity differences affect yield, quality and cost from harvesting to the end product. (b) Cell wall thickness appears to be the most important morphological characteristic that affects pulp and paper qualities; it is moderately genetically controlled directly and also controlled through specific gravity. (c) Pulp yield per unit volume increases when specific gravity is increased; also, 1 to 7 percent greater yields are found per unit weight dry wood. (d) Parent trees with juvenile wood of high or low specific gravity produce progeny with juvenile wood similar to the parents. Pulping tests showed high gravity juvenile wood had characteristics similar to mill run chips. (e) Moisture content inheritance closely parallels that of specific gravity. (f) All important wood morphological characteristics tested are under enough genetic control to obtain useful gains. A review of the inheritance of chemical characteristics revealed the existence of few definitive studies. Cellulose yield is inherited in such a manner that selection will not be effective, whereas, oppositely, resin content is inherited in a manner allowing gains to be made through selection. Because of the relationship between chemical characteristics and wood morphological characteristics such as specific gravity, breeding for one will generally affect the other. A previously unreported study of six trees from six control-pollinated families, all of which had the same mother but different fathers, showed that the sugar contents of the six families were essentially constant; glucose varied from 65 to 70 percent but this difference was not statistically meaningful. Polysaccharide differences were not closely related to specific gravity. Because of the close relationship between morphological and chemical characteristics it is the author's opinion that breeding for chemical differences should be limited to those instances in which it is specially useful for yield improvement. It is possible to manipulate wood in a desired direction by breeding for characteristics that affect wood or by breeding for the wood characteristics directly. Enough is now known about the effect of differing wood properties on the final product so that the worth of changes obtained can be assessed in terms of economic or utilization values.
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    Wood science and technology 5 (1971), S. 236-246 
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    Source: Springer Online Journal Archives 1860-2000
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    Notes: Summary Wood-destroying insects react to and depend regarding their nutrition on compounds contained in wood or produced by microorganisms in wood. This relation is a complex matter in the biology of the insects and the chemistry of wood and of the metabolism of woodinhabiting microorganisms. Results on the reaction of Coleoptera and Isoptera to attractive or repellent compounds in wood species or substances produced by fungi in wood are reviewed with emphasis to differences among various insect species. Nutrition of wood-destroying insects depends on nitrogen compounds of the wood; the content of nitrogen can be increased by the presence of fungi. Existing results on the relation between microorganisms and insects are also summarized including toxicity or parasitic influence of part of the microorganisms on insects. The survey may stimulate further investigations which are necessary for better knowledge of the complex interrelations.
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  • 32
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    Wood science and technology 5 (1971), S. 247-254 
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    Source: Springer Online Journal Archives 1860-2000
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    Notes: Summary Wood has continued to serve from the earliest days of history as an efficient and economical material for construction and for industry; so much so, in fact, that it has remained competitive even though research and technological improvements have been at a very low level. This is evident from the low efficiency being attained in the harvesting, processing, and use of forest products. Technological advances attainable through research and the implementation of its results can potentially add 3.1 billion cubic feet per year to the yield of products to be obtained from the present United States volume of forest products of about 12-/12 billion cubic feet annually. Such more complete use of our timber resources will aid greatly, and in fact is essential to meeting future needs for forest products. Many qualitative improvements are also attainable through research, to produce stronger, more durable, and more serviceable products. In competition with other materials of industry, that are not renewable and that are produced at a very high cost to society in terms of energy consumed and environmental degradation caused by their recovery and processing, wood is likely to assume a more prominent role in the future.
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    Wood science and technology 5 (1971), S. 290-312 
    ISSN: 1432-5225
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary A comparative histological investigation of 52 bamboo species from 14 genera, collected in seven Asian countries, was carried out; 1200 internodes from 250 culms were examined therein. The anatomical structure of the culms is characterized exclusively by the collateral vascular bundles embedded in parenchymatous ground tissue which exhibits four basic types. A classification system was devised for these vascular bundle types and their combinations within the culm; it was found to correlate well with the system of Holttum based on the structure of the ovary. A comprehensive description of the marked variability of the vascular bundle structure within one culm and between culms of a single species is given. The implications of such a representative description of a singles pecies and the introduction of an identification key are discussed.
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    Wood science and technology 5 (1971), S. 315-316 
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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    Marine biology 8 (1971), S. 30-34 
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    Topics: Biology
    Notes: Abstract Kinetic properties such as the Michaelis-Menten constant and the activation energy of the flexor muscle myosin ATPase were investigated in the estuarine crab Scylla serrata. These properties varied at different salinities, but the extractability of the enzyme remained unaltered. The qualitative changes upon salinity adaptation are discussed with reference to estuarine conditions.
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    Marine biology 8 (1971), S. 12-29 
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    Notes: Abstract Four species of balanomorph barnacles, Balanus crenatus Brugière, B. balanoides (L.), Elminius modestus Darwin and Chthamalus stellatus (Poli), were studied to assess the susceptibility of intertidal barnacle species to desiccation. Known sized samples of barnacles were exposed to controlled desiccating conditions and subsequent survival and water loss were determined. It is clear that the ability to live high on the shore is dependent on a reduction of the overall permeability to water loss. Because of greater surface area to volume ratios, small stages are particularly prone to desiccation. In normal intertidal emersion periods, small stages of B. crenatus particularly, and also of B. balanoides and E. modestus which are similar in their desiccation resistance, would be susceptible to desiccation at normal temperatures and low humidities. Large barnacles would be more prone to death from high temperatures when the tide is out. The spat of C. stellatus, although surviving much longer than spat of larger dimensions of the other species, must also be prone to prolonged emersion conditions at high shore levels.
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    Marine biology 8 (1971), S. 7-11 
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    Topics: Biology
    Notes: Abstract The activity of crude muscle lactate dehydrogenase (LDH) of several species of bathypelagic and shallow-water fishes has been measured at pressures between 1 and 578 atm and at temperatures of 15° and 25°C. No relationship has been found between the effect of pressure on enzyme activity and the hydrostatic pressure of the organism's environment. Applied hydrostatic pressure reduced activity at both temperatures. The decrease at 25°C was double the decrease at 15°C in LDH from shallow-water fishes. However, enzymes from 2 bathypelagic fishes showed approximately the same reduction at both temperatures. Thus, the interaction of temperature and pressure was less in deep-sea than in shallow-water fish LDH. Decreasing temperature and increasing pressure would both reduce the activity of LDH. That is, deep-sea conditions are noncompensatory in this instance. It is possible that the dissociation of the effects of temperature and pressure could be an adaptive feature of deep-sea life.
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    Marine biology 8 (1971), S. 57-59 
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    Notes: Abstract A direct and a diffusion method to be applied when measuring 14C labelled carbon dioxide by productivity measurements in natural water have been described. The labelled carbonate was trapped by 1 N solutions of NaOH, KOH or Ba(OH)2. Results comparable to those obtainable the biological method are achieved when using 100 μl of a 1 N KOH solution as a fixation reagent. The radiocarbonate fixed in this way was found to be stable for several days when dried, cooled, and stored in a desiccator. The reliability of these methods was demonstrated by analysing solutions containing various amounts of 14C labelled carbonate.
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    Notes: Abstract The main food reserve of the intertidal hebivorous isopod Dynamene bidentata is lipid. Only algal-dwelling juveniles exhibit rhythms of oxygen consumption and defecation related to the tidal cycle. Males undergo the moult to maturity in the algal habitat and are, therefore, able to replenish their food reserves before entering upon a nonfeeding reproductive phase in empty barncle tests and erevices. Storage sites are increased at this moult so that males are able to survive on their food reserves for 2 breeding seasons. Females enter the reproductive habitat in the preovigerous stage and cease to feed. Lipid food reserves are largely used up in the formation of eggs and the final stage cuticle. Consequently, after the ovigerous moult, females are required to utilise lipoprotein-containing tissue as an energy source, and are able to survive only for a single breeding season. At the final moult, the posterior end of the male becomes highly thickened, rugose, and supplied with tegumental glands. These modifications are correlated with the need for self protection, and protection of the vulnerable females, against various physical and biological factors in the intertidal zone. There is a large increase in the dry weight of the brood over the period of incubation, and this is due mainly to the development of the exoskeleton at the last marsupial moult. The source of materials for the weight increase is attributable to a combination of factors, of which salt uptake probably plays the major part.
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    Notes: Abstract Zostera marina L. was studied at the Izembek Lagoon, Alaska Peninsula. Two morphologically different forms, tidepool and subtidal, can be distinguished. Both show a high tolerance to different salinities and temperatures. The plasmatic resistance was found in a range of distilled H2O up to 3.0 seawater (24 h) and between-6° and 34°C (12 h). Within these resistance limits, the photosynthesis, which has its maximum in normal (1.0) seawater, decreases nearly to zero not only in distilled H2O but even in 2.0 seawater, and increases with the temperature in the tidepool form up to 35°C, but in the subtidal form up to 30°C only. At higher temperatures photosynthesis declines sharply in both forms. Respiration has its minimum in distilled H2O and at 0°C and increases with increasing salinity and temperature.
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    Marine biology 8 (1971), S. 82-87 
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    Topics: Biology
    Notes: Abstract Five species of Sepiola and Sepictta were reared in the laboratory from egg to adult size. Spawning was achieved in 3 species of Sepiola after 5 to 7 months. The growth rate of the species reared did not depend upon temperature, which ranged from 12.5° to 20°C. A fairly constant size increase (2.5 mm mantle length/month) was observed in Sepiola during the 5 months after hatching. In Sepietta, the same growth rate was observed until the fourth month after hatching, when it increased to the rate of 5 mm mantle length/month.
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    Marine biology 8 (1971), S. 89-95 
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    Topics: Biology
    Notes: Abstract Estimation of the silica balance in the ocean requires clarification of the trend of dissolution of biogenous silica. We used biogenous silica in our experiments to compare silica gel and opal. From the results, convenient methods can be devised to estimate the easily soluble parts of biogenous silica. The soluble parts of diatomaceous silica vary considerably with the different species and the characteristics of organic body matter. X-ray diffraction patterns of the biogenous silica suggests an amorphous silica gel form. All different kinds of diatomaceous silica used show infra-red spectra patterns similar to that of silica gel. In the dissolution trends, there exist differences between recent and ancient silica frustules, the former resembling silica gel, the latter opaline silica. Silicious sponge spicules show characteristics similar to that of opaline silica in respect to dissolution and infra-red spectrum pattern. It would, therefore, be reasonable to conclude that there are many forms of biogenous silica ranging from silica gel to pseudo-opaline silica.
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    Marine biology 8 (1971), S. 96-98 
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    Topics: Biology
    Notes: Abstract The blood serum of 4 Tilapia species were analyzed electrophoretically for protein components, and the percentage of proteins in each fraction was determined. Sera from Tilapia nilotica Linnaeus, T. zillii Gervais, T. galilaea Artedi, and T. aurea (Steindachner) were studied. Characteristic protein fractions for each species were obtained. The species differed in the number of protein fractions and in the final mobilities; T. nilotica sera migrate 120 mm, T. zillii sera 95 mm, T. galilaea sera 90 mm, and T. aurea sera 118 mm. The mobilities for fractions 1 and 2 were similar for the 4 species' sera. Inter-specific differences in the amount of protein occurred. Diet may be a major contributing factor to the variations observed in the amount of total protein.
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    Marine biology 8 (1971), S. 105-108 
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    Topics: Biology
    Notes: Abstract A vigorous strain of Tintinnopsis beroidea was established in vitro by mixing several isolates obtained during the period January to March, 1969. More than 1,000 cells/ml were routinely obtained within a few weeks. On one occasion 3,000 cells/ml were obtained in just over a month. The period required for ciliate populations to double was 2.5 to 6 days. Growth curve data has been obtained with cultures receiving single doses of food at the time the flasks were inoculated with protozoa. The initial concentration of food had a noticeable effect on ciliate growth. Excessive amounts of food were somewhat inhibitory; insufficient amounts resulted in rapid starvation. Conjugation patterns characteristic of wild populations of tintinnids were not observed. However, there was evidence of sexual activity in the cultures: (1) pairing of cells occurred; (2) protrusions were seen in the oral region indicative of preconjugation activity; (3) very high cell yields and rapid division rates were obtained after more than 1.5 years in culture.
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    Marine biology 8 (1971), S. 109-117 
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    Notes: Abstract Analyses of bottom trawl samples and feeding experiments in the laboratory revealed a reproduction period ranging from late March to early August in Eledone cirrosa of the Catalonian Sea (Western Mediterranean). The embryonic development, studies for the first time on eggs laid in the laboratory, shows no basic difference from that of other Octopodidae. The newly hatched animals are planktonic; morphologically, this feature is expressed by a relatively small arm-length.
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  • 46
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    Notes: Abstract The ostracod fauna of Baltic brackish-water rockpools is made up of two groups: permanent members of the pools, and occasional guests from the littoral zone. The former group consists of Heterocypris salinus, H. incongruens and Cypridopsis aculeata. These species are characterized by rapid development (which starts when the water temperature approaches 15°C), a short life span, and 2 or 3 separate generations during the summer and autumn. The number of generations is determined by water temperature. Hibernation always takes place as eggs. Hatching and development during the late spring or early summer has been found to be mostly simultaneous. The spawning of the 3 species always starts epidemically. Reproduction is entirely parthenogenetic in the investigated area. Under natural conditions, C. aculeata may be found with either H. salinus or H. incongruens, but these two latter species have never been recorded together. H. incongruens is less tolerant to high salinities than the other 2 species and, even after successive adaptation, it does not resist salinities higher than 16‰. H. salinus has been found in 35.2‰ S in the field, and has been kept in 30‰ S in the laboratory after successive adaptation. The optimum salinity-temperature range for this species is 5 to 10‰ S and 15°C, when both survival and development are considered. Corresponding figures for C. aculeata are 0.5 to 20‰ S and 15°C, although this species, like H. salinus, survives longest at 5°C. The very rapid development, parthenogenetic reproduction and short life span of these species must be considered as favourable adaptations to the variable and unstable environment of the rockpool ecosystems.
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    Marine biology 8 (1971), S. 280-307 
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    Notes: Abstract An extensive study was conducted on the settlement and seasonal succession of fouling bryozoans in and around Cochin Harbour during the period 1965 to 1966; it was the first study of its kind performed in Indian waters. A total of 14 species was recorded from localities which were ecologically dissimilar. A distinct succession of species, mainly of a seasonal character, was observed. Seasonal succession usually occurs in localities where seasons are well marked, and where different species of animals with short life spans settle during particular times of the year. The study has shown that a distinct seasonal succession of bryozoans occurs in this locality; out of the 14 species which appeared on the panels not one species settled throughout the year. This was due to seasonal differences in the ecological conditions which prevailed in the area investigated. The significant seasonal influences on the incidence of bryozoans led to a categorisation of the species into the following patterns (a) typical brackish-water forms not encountered in purely marine localities; (b) typical brackish-water forms which may occur in marine localities; (c) typical marine forms never found in localities where low salinity conditions prevail.
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    Marine biology 8 (1971), S. 344-350 
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    Topics: Biology
    Notes: Abstract Fungi inhabiting Sargassum spp. from the Sargasso Sea were examined. Three ascomycetes were found, two of which are new records for this environment. Haloguignardia oceanica (Ferdinandsen et Winge) Kohlm. comb. nov. was collected only once before, over 50 years ago. Haloguignardia tumefaciens (Cribb et Herbert) Cribb et Cribb was known only from Australia and New Zealand. Imperfect states of these ascomycetes and fruiting bodies (acervuli) of a hyperparasitic deuteromycete (cf. Sphaceloma sp.) were found for the first time in the galls of the two species. Lindra thalassiae Orpurt et al., previously known only from the sea grass Thalassia testudinum Köngig, develops in air bladders of Sargassum sp., causing a shedding of infested vesicles. Possible reasons for the rarity of fungal species and diseased plants in the Sargasso Sea are diseussed.
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    Marine biology 8 (1971), S. 308-343 
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    Topics: Biology
    Description / Table of Contents: Résumé 1. La structure des populations microplanctoniques du Golfe de Marseille en 1964 a été appréciée au moyen de diverses mesures de diversité: indices de diversité spécifique, indices de diversité relative, diagrammes de fréquences, indice de diversité pigmentaire. 2. Les variations saisonnières et verticales des populations microplanctoniques ont été décrites en 2 stations en tenant compte des divers résultats des numérations et des concentrations de chlorophylle a. Des indications ont été également données sur la composition spécifique et la succession écologique du microplancton. 3. Divers indices de diversité spécifique ont été comparés et appliqués au microplancton du Golfe de Marseille. L'évolution annuelle de la diversité spécifique de ce plancton a été décrite et ses rapports avec la succession écologique envisagés. 4. De même, des évaluations de dominance, de redondance et d'équitabilité renseignant sur les fréquences relatives des diverses espèces ont été comparées entre elles et aux mesures de diversité globale. Ces évaluations ont été appliquées à l'étude de la structure et de l'évolution du microplancton marin. 5. Cette structure et cette évolution ont été représentées graphiquement au moyen de diagrammes de fréquences dont l'usage semble très prometteur. 6. Enfin la diversité pigmentaire du phytoplancton a été envisagée et comparée à la diversité spécifique, sans donner de résultats réellement probants. 7. En conslusion, il peut être recommandé d'utiliser de préférence les indices dérivés de la théorie de l'information ( $$\bar D$$ ou $$\bar D\prime $$ d'une part, R ou J d'autre part). En leur absence, un indice simple comme l'indice de diversité spécifique d de Gleason-Margalef peut aussi être utilisé avec profit (surtout s'il est amélioré par la méthode de raréfaction de Sanders). Quant à l'indice de diversité pigmentaire, son emploi demande plus de précautions car il dépend étroitement de certaines conditions. L'usage des diagrammes de fréquences permet une description plus détaillée et une meilleure interprétation de l'évolution de la structure de l'écosystème et de la succession écologique.
    Notes: Abstract The structure of microplankton populations sampled in the Gulf of Marseilles during 1964 has been estimated by means of various diversity measurements. Numerical results and chlorophyll a concentrations have been used to describe the seasonal cycle and vertical distribution of microplankton at two stations. Data are also given upon species composition and ecological succession. A comparison is made between different species diversity indices applied to microplankton of the Gulf of Marseilles. Annual fluctuations in species diversity of the plankton are described, together with its relationship with ecological succession. Dominance, redundancy and equitability estimates of the relative species frequencies are compared with each other and with total species diversity measurements. These estimates have been applied to the study of marine microplankton structure and evolution. Structure and evolution have been graphically represented by means of frequency diagrams, which appear promising. Finally, phytoplankton pigment diversity has been taken and compared with species diversity. As a result, the use of indices derived from the information theory ( $$\bar D$$ or $$\bar D\prime $$ on the one hand, R or J on the other hand) is recommended. A simple index such as the Gleason-Margalef species diversity index d can also be profitably used (especially if improved by the Sanders rare-faction faction method). Use of the pigment diversity index, however, calls for more caution. The use of frequency diagrams permits a more detailed description and a better interpretation of the evolution of the ecosystem structure and of ecological succession.
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    Marine biology 8 (1971), S. 351-355 
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    Description / Table of Contents: Zusammenfassung 1. Während der Expedition mit dem FS „Meteor” 1964/1965 ist im Persischen Golf eine Population von Pseudeuphausia latifrons (G. O. Sars, 1883) festgestellt worden, die von der Population im Arabischen Meer isoliert ist und morphologische Unterschiede aufweist. 2. Die adulten Individuen der Population im Persischen Golf sind mit einer Körperlänge von 7 bis 16 mm wesentlich größer als die im übrigen Verbreitungsgebiet (6 bis 12 mm). 3. Morphologische Unterschiede am Petasma der männlichen Individuen im Persischen Golf können nur zum Tiel als Allometrie gedeutet werden, was mit der extremen Länge der Tiere im Zusammenhang stehen könnte. Offensichtlich hat sich unter den besonderen ökologischen Bedingungen des Persischen Golfes und in räumlicher Isolation auch eine genetische Veränderung der Population herausgebildet, so daß von einer geographischen Variation oder Rasse gesprochen werden muß. 4. Durch die Analyse von Vergleichsmaterial aus dem Roten Meer konnte gezeigt werden, daß die von dort beschriebene Pseudeuphausia colosii Torelli, 1934 ein Synonym zu Pseudeuphausia latifrons (G. O. Sars, 1883) ist.
    Notes: Abstract During the expedition of RV “Meteor” in 1964/1965 a population of Pseudeuphausia latifrons (G. O. Sars, 1883) was found in the Persian Gulf; this population is isolated and morphologically different from a population of the same species in the Arabian Sea. The adults of the Persian Gulf population are between 7 and 16 mm long which means that they are considerably larger than those found elsewhere. Morphological differences of the copulatory appendages of the male specimens from the Persian Gulf can only partly be regarded as allometric, which may be due to the abnormal length of these specimens. It is possible that isolation and the particular ecological conditions in the Persian Gulf have led to genetic changes in this population so that it can be regarded as a distinct geographical variation. Comparative analysis has shown that Pseudeuphausia colosii Torelli, 1934, described from the Red Sea, is synonymous with Pseudeuphausia latifrons (G. O. Sars, 1883).
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    Marine biology 9 (1971), S. 1-3 
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    Marine biology 9 (1971), S. 38-50 
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    Notes: Abstract Studies employing Scuba techniques were carried out on populations of 3 species of tropical demosponges to determine in situ patterns of water-pumping activity. Short-term changes in individual activity of deep-water species (15 to 55 m) were determined from continuous recordings of exhalant current velocities. Long-term changes were determined by repeated measurements of oscular velocity and oscular area. Mycale sp. was found to maintain constant levels of pumping activity in both short and long-term studies. Verongia gigantea underwent periodic cessations of activity averaging 42 min, at random intervals of approximately 19 h. Cessations were asynchronous throughout the population and inherent in origin. Long-term activity variations appeared to be cyclic, but were explainable by environmental events. Shallow-water populations of Tethya crypta exhibited a synchronized diurnal cycle of contraction and dilation, probably tied to the diurnal cycle of illumination. A longer term (average 15.8 days) cycle of activity-inactivity, also involving contraction and dilation, was asynchronous throughout the population during the calm season. Each individual maintained a fairly uniform cyclic period ranging from 9 to 21 days. Changes of T. crypta activity were probably due to changes in flagellar activity. With the onset of the stormy season, the activity of all members of the population was brought into synchrony by the effects of approximately biweekly storms. The behavior of Verongia archeri, Agelas sp., and other species indicates that constant activity (e.g. Mycale sp.) may be restricted to thin-walled species working at low pressures and velocities. Activity patterns are consistent within species, but variable in higher taxa. Behavioral activity patterns of sponges must be taken into account in ecological and physiological studies of these animals.
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    Description / Table of Contents: Résumé 1. La production d'oeufs de Centropages typicus Kröyer, Acartia clausi Giesbrecht et Temora stylifera Dana a été étudiée sous différentes conditions nutritielles à divers moments de l'année. 2. L'abondance du phytoplancton joue un rôle inducteur sur le déclenchement de la ponte. 3. La nature spécifique des algues proposées agit aussi sur la fertilité. 4. Une variation saisonnière de l'importance de la ponte a pu être établie. 5. Quelques observations sont faites sur la disposition des oeufs pondus et leur développement ultérieur.
    Notes: Abstract Egg-laying of 3 common copepod species from the Gulf of Marseilles (Centropages typicus Kröyer, Acatia clausi Giesbrecht, Temora stylifera Dana) has been studied under various trophic conditions, at different periods of the year. The role of phytoplankton abundance in the induction and importance of egg-laying is indicated. The specific quality of the algal suspension used for feeding affected also fertility. A seasonal variation in the importance of egg-laying is established. Some observations are made on egg deposition and development.
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    Description / Table of Contents: Zusammenfassung 1. Bei Dredgefängen auf der Großen Meteorbank (Mittelatlantik) wurde auf einem Einzelexemplar von Sigalion squamatum (Polychaeta, Sigalioninae) ein starker Bewuchs mit dem obligatorisch epizoischen Kamptozoon Loxomespilon perezi Bobin et Prenant (Loxosomatidae) festgestellt; diese Gattung war bisher nur aus Flachseebiotopen an der bretonischen Küste (Roscoff) und bei Plymouth als Epöke von Sthenelais boa (Polychaeta, Sigalioninae) bekannt. 2. Geringfügige aber signifikante morphologische Unterschiede zwischen den bretonischen und englischen Tieren einerseits und den Meteor-Tieren andererseits rechtfertigen vermutlich die Abgrenzung einer Lokalvariation (var. meteoris). 3. Die auffällige Wirtsgleichheit selbst in anscheinend voneinander unabhängigen Faunengebieten —Loxomespilon wurde bis jetzt ausschließlich auf Sigalioninen gefunden — wirft die Frage der Wirtsspezifität dieser Art und allgemein der Loxosomatiden auf. 4. Der Fund des „Synökenpaares” Sigalion/Loxomespilon auf der tiergeographisch isolierten Großen Meteorbank gibt Anlaß zu Überlegungen über die mögliche Herkunft der Bankfauna: Da Formen, die zu den typischen Bewohnern des Archibenthos und Abyssal gehören, einen wesentlichen Teil der Bankfauna ausmachen, ist man versucht, anzunehmen, daß zumindest ein großer Teil der Bankfauna der Tiefsee entstammt und auch in Schüben von dort immer wieder ergänzt wird. Auf diesem Wege dürfte auch das Paar Sigalion und Loxomespilon auf die Bank gelangt sein.
    Notes: Abstract In dredge-hauls on the Great Meteor Seamont (Canary Basin), the loxosomatid entoproct Loxomespilon perezi Robin et Prénant has been found growing under the elytra of the aphroditid polychaete Sigalion squamatum; L. perezi was attached to the dorsal surface of the polychaete. This is the third find of Loxomespilon, a genus first described from the coastal waters of Bretagne (France) and later from the Plymouth region (England); in all 3 places Loxomespilon was associated only with sigalionid polychaetes as hosts. The question of specificity in the host relationship of Loxosomatidae in general, and this genus in particular, is discussed. Because the Meteor Seamount has little primary production and a very poor fauna, which spreads sporadically over its plateau, there is believed to be little chance for the associated species of Sigalion and Loxomespilon to exist permanently on that bank. It is assumed that there must be a faunal reservoir in the surrounding deep sea. The possible pathways of benthos settlement on the Great Meteor Seamount are discussed.
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    Description / Table of Contents: Résumé 1. Cette note expose les résultats préliminaires d'une étude expérimentale du phototropisme d'Anomalocera patersoni en éclairage horizontal. 2. Les paramètres décrivant le comportement de ce copépode sont la vitesse moyenne du déplacement et le coefficient de polarisation définissant le sens de l'orientation vis à vis de la source lumineuse. 3. Le coefficient de polarisation semble varier selon un rythme interne chez les adultes, lesquels sont plus photopositifs le matin que l'après midi. 4. Les variations expérimentales d'intensité lumineuse ne semblent pas affecter le sens du mouvement chez les mâles alors qu'une diminution de l'intensité lumineuse a pour conséquence une augmentation du nombre de femelles photopositives. 5. Les mâles sont en général plus rapides que les femelles et les jeunes. La vitesse de déplacement peut varier en fonction de l'heure et de l'éclairement chez les femelles; chez les mâles elle semble indépendante de l'heure.
    Notes: Abstract This paper summarizes some preliminary results on phototropic reactions of Anomalocera patersoni under experimental conditions. Velocity and polarization coefficient are used to describe the activity and orientation of animals. The polarization coefficient may change with an intrinsic rhythm: during the morning, the phototropic reaction is generally more positive than during the afternoon. The variations of light intensity do not directly affect male orientation, but females are more positive in reduced light conditions. Velocity is generally higher in males than in females or immature copepods; it is influenced by the hour of experimentation and by light intensity with females; with males, the hour seems to have no effect on the velocity.
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    Marine biology 9 (1971), S. 78-85 
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    Notes: Abstract Several aspects of asexual reproduction in Glossobalanus crozieri (a species first found in Bermuda, but occurring also on the coast of Brazil) have been observed. The results are compared with those by earlier authors on other species of Enteropneusta. A revision of asexual reproduction in the Enteropneusta (Hemichordata) is made. Developmental rates and regeneration were studied in branchiogenital individuals, hepatic individuals and regenerands. The habitat where these forms are found is described. Possible meaning of gonad maturation and sexual reproduction in relation to asexual reproduction in different species is discussed. The need for further studies on the variation of forms which reproduce both sexually and asexually is emphasized, with a view to taxonomic problems, based both upon the proportions of the different body regions and on the number of branchial pores. The present findings indicate that, when compared to the results reported for other species, asexual reproduction in all ptychoderids (Balanoglossus, Glossobalanus and Ptychodera) follows the same general pattern. The phenomenon of asexual reproduction in this group is also confirmed to be worldwide.
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    Marine biology 9 (1971), S. 109-114 
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    Notes: Abstract Some aspects of the habitat zones, distribution pattern, and population density with reference to tidal levels of the tropical limpet Cellana radiata (Born) are presented. Observations have also been made on the ‘homing’ behaviour of the limpet. Unlike the temperate limpets, no migration to different tidal levels during different seasons was observed in C. radiata.
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    Notes: Abstract Wax esters, which function as reserve fuels, account for 25 to 40% of the lipid of the pelagic copepod Calanus helgolandicus (Copepoda, Calanoida). In laboratory experiments with these crustaceans, diatoms (Lauderia borealis, Chaetoceros curvisetus, and Skeletonema costatum) and dinoflagellates (Gymnodinium splendens), which contained no wax esters, were used as food. Changes in the food concentration affected both the amount of lipid and the composition of the wax esters. Since the fatty acids of the triglycerides and wax esters of C. helgolandicus resembled the dietary fatty acid composition, it appeared that copepods incorporated their dietary fatty acids largely unchanged into their wax esters. The polyunsaturated alcohols of the wax esters did not correspond in carbon numbers or degrees of unsaturation to the dietary fatty acids. We postulate two different metabolic pools to explain the origin of these long chain alcohols. The phospholipid fatty acids were not affected by changes in the amount or type of food, probably because of their structural function.
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    Marine biology 9 (1971), S. 92-98 
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    Notes: Abstract The problem of vertical distribution and the movements of copepods was studied from several plankton samples collected by vertical hauls in the Saronic Bay, Greece during two cruises (8 to 17 August and 21 November to 1 December, 1969). The species, whose vertical movements were analyzed, were divided into 3 groups: (1) Those which perform diurnal vertical migration (generally psychrophilic species found in summer samples in deeper layers and in reduced numbers). In autumn, the number of specimens is generally increased and many individuals reach the surface at night. From surface hauls it is known that these species abound in night surface hauls during the cold period. (2) Those species which execute a seasonal vertical migration. These, too are, in general, psychrophilic and found in summer in the deep water layers. In autumn, the population of the upper layers increases. From surface hauls it is known that these species abound in day and night surface samples. (3) Copepods which remained at the surface layer in both seasons of our cruises. These species are thermophilic and are absent from surface hauls during the cold period.
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  • 60
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    Notes: Abstract Linuparus trigonus V. Siebold were placed in a tank, with a hydrophone suspended in one corner, in order to investigate the mechanism of sound production and the under-water sounds released. Sounds were recorded by tape recorder and analyzed by means of sound spectrograph. L. trigonus emits creaky sounds by rubbing the protuberance of the antennal coxa against the white tubercle in front of its optic stalk. The protuberance of the coxa molds a hollow, with the opening covered by a thin membrane; this facilitates the production of under-water sounds. However, these sounds are produced only when the antenna is lifted. It is also possible to produce these sounds artificially using dead lobsters. When disturbed by external stimulus, L. trigonus flaps back and accelerates the repitition rate. The under-water sounds produced are a series of pulses, which can be divided into 2 groups: (1) The A type sound; this has a relatively slow repetition rate (10 to 80 times/sec) and is weak at the low frequency range below 3 kHz; the sounds, therefore, are manifested on the sonagram in a pattern consisting of some layers of frequencies which are almost constant. (2) The B type sound; this comprises a series of pulses which are powerful even at low frequency. The repetition rate is very high, and not recognizable on the sonagram.
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    Marine biology 9 (1971), S. 138-144 
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    Notes: Abstract The winkle Littorina littorea (L.) feeds mainly when moistened by the tide and is quiescent when exposed to the drying effects of the wind and sun. Upper shore winkles thus experience a reduced feeding time compared with individuals living lower in the intertidal zone, but are able to completely compensate by an increased rate of radular activity when immersed. The rate of radular activity is influenced by the body size of winkles, by experimental temperature and by acclimation temperature, but is mainly modified by the duration of exposure to air which directly controls the rate of radular activity on immersion.
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    Notes: Abstract Phytoplankton samples were collected from a large area of the West Indian Ocean and 237 different species identified. The object of this study was to define structure in the species distributions and to relate this to environmental factors. Numerical methods of cluster analysis are described, with adaptation and application to this ecological study of phytoplankton. The phytoplankton stations were grouped according to their phytoplankton populations; these groupings were related firstly to the monsoon seasons, and secondly to the hydrology, in order to derive phytohydrographic regions. The species were then grouped according to hydrographical distribution in order to derive the floral elements (species associations) which typify the different regions. The samples divided seasonally into 2 overlapping clusters, those sampled prior to the South West Monsoon, and those sampled subsequently. In both seasonal groups 4 main phytohydrographic regions were isolated from (1) equatorial subsurface water; (2) the equatorial undercurrent boundary; (3) the South Equatorial Current; (4) the surface tropical water. A total of 11 different floral elements were derived to account for the phytohydrographic groupings. The distribution of the largest element (50 species) was centred in equatorial subsurface water. This element dominated all samples, and was considered to comprise the endemic Indian Ocean flora. The effects of the other minor floral elements were superimposed on the dominance or otherwise of this element in the samples. These different minor floral elements were characteristic of (a) different seasonal divisions; (b) regional differences in equatorial subsurface water; (c) traversing currents; (d) nutrientrich regions of instability.
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    Marine biology 9 (1971), S. 202-204 
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    Notes: Abstract The knowledge that the initial mating in planktonic copepods may be inadequate to permit realization of a female's total reproductive potential, and that remating can occur, has important implications for both population dynamics and speciation studies. Acartia tonsa Dana females in controlled laboratory experiments were successfully remated after becoming totally infertile following approximately 3 weeks of highly fertile production. Large numbers of viable nauplii resulted from these second matings.
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    Marine biology 9 (1971), S. 205-212 
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    Notes: Abstract Two types of secretory cell have been found in the cement glands of the cypris larva of Balanus balanoides (L.). Histochemical tests show the presence of proteins, phenols and the enzyme polyphenol oxidase in both the glands and secreted cement. It is proposed that cyprid cement is composed of tanned protein, all the components of which are derived from the cement glands.
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    Marine biology 9 (1971), S. 183-201 
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    Notes: Abstract The biological effects of 5 surface active agents (the anionic ABS, LAS and LES 3 EO and the nonionic NP 10 EO and TAE 10 EO) on marine fishes, crustaceans and bivalves have been tested in, continuous-flow systems. Concentrations from 100 to 0.5 ppm were normally used. Fishes were found to be more susceptible (96 hLC 50 range: 0.8 to 6.5 ppm) than bivalves (96 hLC50 range: 5 to 〉100 ppm) while crustaceans were considerably more resistant (96 h LC 50 range: 25 to 〉 100 ppm). Within each of these 3 systematic groups, more active species were found to be more sensitive than less active species. Developmental stages were also more sensitive than adults. The resistance of crustaceans to surfactants decreases immediately after moulting. The most toxic agent for fishes and decapods was the “soft” anionic LAS, and for bivalves and barnacles the “hard” nonionic NP 10 EO. Ability to recover normal behaviour after exposure decreases with increasing concentration and time, and ceases earlier in anionic than in nonionic surfactants. The first reaction to the surfactants is increased activity (avoidance reaction of mobile species), followed successively by inactivation, immobilization and death. Nonionic surfactants affect the equilibrium in fishes. Sublethal effects appear as impaired locomotory activity and breathing rate in fishes and crustaceans, impaired byssus activity and shell closure in Mytilus edulis, burrowing in Cardium edule, Astarte montagui and Astarte sulcata. Siphon retraction is affected in Mya arenaria and Cardium edule, as is also the response to food of the Leander spp.
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    Marine biology 9 (1971), S. 213-218 
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    Notes: Abstract The uptake of a polychlorinated biphenyl preparation containing 5 to 7 chlorine atoms/molecule, solubilized in a nonionic surfactant in sea water, by Gammarus oceanicus was measured spectrophotometrically. Uptake occurred in living animals across the general integument. It is suggested that uptake rates are dependent upon the total surface area of the integument, although no accurate method of determining this is known. The rate of uptake decreased after 4 to 6 hours exposure and uptake was dependent upon concentration of polychlorinated biphenyls in sea water. The stage of the intermoult of G. oceanicus did not affect uptake rates.
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    Marine biology 9 (1971), S. 219-223 
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    Notes: Abstract Several concentrations of extracts prepared from the eyestalks of a specimen of Uca pugilator were injected into other U. pugilator individuals. The distal pigment of the eyes first became light adapted and then dark adapted, the whole process lasting 6 h. The mean integrated response for light adaptation increased progressively up to the highest tested extract (3 eyestalk equivalents/dose), but with the darkadapting response the maximal effect was produced by the extract containing 2 eyestalk equivalents/dose. Gel filtration of eyestalk extracts in Sephadex G-50 showed that the fractions associated with greatest light adaptation were also associated with greatest pigment dispersion in the melanophores. Almost no light or dark adaptation of the retinal pigment resulted from injections of eyestalk extracts treated with α-chymotrypsin which supports the interpretation that these substances are polypeptides of neurosecretory origin.
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    Marine biology 9 (1971), S. 145-182 
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    Description / Table of Contents: Zusammenfassung 1. Die Einwirkung von Salzgehalt und Temperatur auf verschiedene Lebensprozesse von Artemia salina (L.) aus dem Großen Salzsee, Utah, USA, wurde untersucht in 16 Faktorkombinationen: 5; 15; 32; 70‰S und 10°; 15°; 20°; 30°C. Als Futter wurde der Phytoflagellat Dunaliella tertiolecta verwendet. Die Untersuchungen befaßten sich mit Schlüpfrate, Schlüpferfolg, Energiebilanz und Stoffwechsel des Schlüpfprozesses, Wachstumsrate, Maturationsrate und Reproduktionsrate. 2. Die Schlüpfrate wird durch erhöhte Temperatur beschleunigt, durch erhöhte Salinität vermindert. 3. Der Schlüpferfolg ist optimal bei 20°C und 32‰ S; in den beiden Salzgehaltsstufen 15 und 70‰ war er jedoch nur geringfügig schlechter, ebenso bei 30°C in 15, 32 und 70‰S. 4. Zwischen 20° und 15°C und unterhalb 15‰S vermindert sich die Schlüpfrate erheblich. 5. Mit steigender Temperatur nimmt die Wachstumsrate bis 20°C zu und fällt dann wieder leicht ab. 6. Mit steigendem Salzgehlt verbessert sich das Wachstum bis 32‰S und fällt dann wieder leicht ab. 7. Das Wachstumsoptimum bei 32‰S und 20°C bezieht sich nur auf heranwachsende Individuen. larven gedeihen besser bei 15‰S und 30°C. Weibliche A. salina werden größer und sind von Umweltbedingungen stärker beeinflußbar als männliche. 8. Mit fallender Temperatur vermindert sich die Fähigkeit, in geringer Salinität zu leben. Nur bei hohem Salzgehalt konnten sich die Tiere trotz niedriger Temperatur fortpflanzen. 9. Die Zeit bis zur Geschlechtsreife ist abhängig von der Temperatur, kaum aber vom Salzgehalt. 10. Die Zeitspannen bis zum Ablegen des ersten Geleges und die Intervalle zwischen den folgenden Eiablagen werden mit zunehmender Temperatur verkürzt, durch zunehmenden Salzgehalt geringfügig verlängert. 11. Bei höheren Salzgehalten sind die Gelege größer als bei niedrigeren; unterhalb 20°C vermindert sich die Gelegegröße. 12. Die Nachkommenschaft pro Weibchen steigt mit zunehmender Temperatur. Unterhalb 32‰S nimmt die Nachkommenzahl ab. 13. Zwischen Umweltbedingungen und Zystenbildung konnte kein ursächlicher Zusammenhang festgestellt werden. Dauer- und Subitaneier, wie auch Nauplien, wurden unter gleichen Versuchsbedingungen produziert. Nur bei 10°C und 70‰S kam es ausschließlich zur Produktion von Nauplien. 14. Fortpflanzung und Fortpflanzungsrate werden durch nicht-genetische Adaptation nicht merklich beeinflußt. 15. Biochemische und kalorimetrische Untersuchungen wurden an Zysten, Schalen und Nauplien durchgeführt. Die Embryonalentwicklung fand ebenfalls bei verschiedenen Salzgehalts-Temperatur-Kombinationen statt. Da der Embryo energiemäßig ein geschlossenes System darstellt, waren Unterschiede im Verbrauch einzelner biochemischer Komponenten auf die verschiedenen Umweltbedingungen zurückzuführen. 16. Mit steigendem Salzgehalt, und zu einem geringeren Ausmaß mit fallender Temperatur, steigt der Energieverbrauch und dabei fällt das Gewicht des Nauplius. 17. Der Kohlehydratverbrauch ist unter allen Bedingungen gewichtsmäßig am größten, doch der energiemäßige Anteil an der Gesamtbilanz verringert sich mit zunehmendem Energieverbrauch. 18. Der zusätzliche Energiebedarf wird durch zunehmenden Stoffwechsel von Fetten und Proteinen gedeckt, wobei Fett als Hauptenergiereserve zu betrachten ist. 19. Zwei grundlegend verschiedene Phasen des Schlüpfvorgangs unterscheiden sich hinsichtlich des Stoffwechselsubstrats. In der ersten Phase wird vorwiegend Kohlehydrat metabolisiert, in der zweiten dagegen vorwiegend Fett und Protein. 20. Die Optimalkombinationen von Salzgehalt und Temperatur sind je nach den biologischen Kriterien und für die verschiedenen Stadien des Lebenszyklus verschieden.
    Notes: Abstract The influence of salinity and temperature on various life processes of Artemia salina (L.) from the Great Salt Lake, Utah, USA, was investigated. Hatching rate, hatching success, energetics and metabolism of hatching, growth rate, maturation rate and reproductive rate were measured at all combinations of 4 temperature levels (10°, 15°, 20°, 30°C) and 4 salinity levels (5, 15, 32, 70‰S). Optimal temperature-salinity combinations differ for different life cycle stages and parameters. The hatching rate rises with increased temperature and sinks with increased salinity. Hatching success is optimal at 20°C and 32‰S. Larval growth is best at 30°C and 15‰S; however, the maximum growth is attained at 20°C and 32‰S. Maturation rate, onset of reproduction, interval between clutches as well as the total number of offspring are primarily influenced by temperature, whereas the clutch size is a function of salinity. As the temperature is lowered, the capacity to survive low salinities is decreased. At low temperature, reproduction is only possible at high salinity. The energy consumption of the hatching embryo is primarily determined by the salinity level of the medium and is directly proportional to it. Carbohydrate consumption is under all conditions greatest by weight, but measured by its caloric contribution the relative importance decreases with increased energy drain. Additional energy requirements, particularly during the later stages of hatching, are met by raising fat and protein metabolism, fat being the main energy reserve.
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    Marine biology 9 (1971), S. 228-234 
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    Notes: Abstract Sergestes lucens Hansen, a mesopelagic shrimp fished commercially in Suruga Bay, Japan, was successfully reared from egg to post-larval stage V under laboratory conditions. Chaetoceros ceratosporum and Artemia nauplii were found to be satisfactory food in the laboratory during rearing. Growth, mortality, food preference, and feeding and swimming activities during the various developmental stages were investigated. Temperature changes greatly affected the speed of development and the mortality of the larvae. The optimum temperature range for larval development was 18° to 25°C. The growth rate (length) of larval stages was as rapid as 0.16mm/ day at 20 °C and 0.21 mm/day at 23 °C. The larvae first started feeding on phytoplankton at elaphocaris stage I, and then gradually became predators in the post-larval stages. It is suggested that the critical period for the species occurs in the elaphocaris stages. Environmental data, vertical distribution of the species, and data obtained from laboratory experiments suggest that the fluctuation in the abundance of S. lucens is greatly influenced by the water temperature at around 50 m from June to August. Feeding mechanisms observed in the post-larval stages are described.
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    Marine biology 9 (1971), S. 224-227 
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    Description / Table of Contents: Zusammenfassung 1. Mit Hilfe von Pt-Aspiratioselektroden wurden die Herzfrequenzen ungestörter, frei beweglicher Carcinus maenas L. registriert und bei Konstanz der übrigen Faktoren der Einfluß des O2-Gehalts auf die Herzfrequenz untersucht. 2. Die Herzfrequenz von C. maenas zeigt eine deutliche Abhängigkeit vom O2-Gehalt des Meerwassers. 3. Zwischen 0 und 6 ml O2/l Meerwasser besteht eine statistisch in hohem Maße gesicherte Korrelation zwischen O2-Gehalt und Herzfrequenz: mit steigendem Sauerstoffgehalt werden die Herzfrequenzen erhöht. Oberhald dieses Sättigungspunktes konnte keine Abhängigkeit mehr gefunden werden. Es wird vermutet, daß dieses Phänomen mit der neurogenen Tätigkeit des Krebsherzens in Verbindung steht.
    Notes: Abstract Heart beats of unrestrained Carcinus maenas L. have been recorded by means of aspiration electrodes. The heart rate shows a clear dependence upon the oxygen content of the sea water under otherwise constant conditions. There is a high degree of correlation between heart rate and oxygen concentration in the range between 0 cm3 and ca. 6 cm3 O2/I sea water. From this point upwards no further dependence could be found. Very low (beneath 0.5 cm3 O2/I water) and very high (over 12 cm3 O2/I water) concentrations lead to arrhythmia and often to long lasting intervals in the heart beats. It is suggested that this correlation is due to the oxygen-dependent excitability of the neurones generating the beats in the neurogenic hearts of crustaceans.
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    Marine biology 9 (1971), S. 235-241 
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    Notes: Abstract A major adaptive problem among comatulid crinoids is the need for a system of articulation and muscularization of the skeleton which provides rigidity in the cirri, arms, and pinnules for maintaining position and feeding in moving water masses, and also the ability to undergo occasional rapid flexions. Most skeletal ossicles of comatulids are united by so-called ligament fibers, while arm articulations possess masses of muscle as well as ligament. Light and electron microscopic work shows that the ligament consists primarily of collagen fibers. Similarity of this dual system of crinoid arm musculature to the muscles and collagenous catch apparatus of echinoid spines suggests that the crinoid ligaments may provide the needed rigidity to the crinoid skeleton, in a manner similar to that by which the echinoid catch apparatus can hold the spine tightly to the test in one position.
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    Notes: Abstract The frequencies of certain electrophoretic fractions of esterases, transferrins and haemoglobins in an American sample of eels (Anguilla rostrata Le Sueur) are compared to those in a sample from Iceland [A. anguilla (L.)]. A number of quantitative differences were established as well as 6 contrasts of a qualitative all-or-none type. The bearing of these differences and contrasts on theories concerning a separate or a single gene pool for Atlantic eels is discussed.
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    Marine biology 9 (1971), S. 250-252 
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    Notes: Abstract Red cell osmotic fragility was studied in 50 blood samples of the fish Scomberomorus maculatus (Mitchill). High levels of mean corpuscular fragility were found and hypotheses are presented to explain this phenomenon.
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    Marine biology 9 (1971), S. 267-273 
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    Notes: Abstract The perennial bryozoan Flustra foliacea L. has annual growth-checks which leave lines across the fronds. These growth-checks have been used to determine the age and the pattern of growth of the colonies in terms of height and numbers of zooids. Monthly samples have been used to find the annual growth cycle. Heavy encrustations of epizoites on the F. foliacea colonies reduce growth rate. As the fronds increase in height, frontal budding of zooids thickens, and thereby strengthens, the holdfast.
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    Notes: Abstract A comparative study was made of the entrained (12:12 LD) and endogenous (DD) respiratory rhythms of 8 species of cardinal fishes. Volumetric respirometers, designed specifically for long-term measurements of oxygen uptake by small fishes under controlled conditions, were used during standard 5 day experiments. Despite some individual variation, certain species-specific and genus-specific patterns of respiration emerged. Each species showed a persistant (advancing) rhythm of oxygen consumption during 3 days of DD. Light appeared to be the “Zeitgeber”, with the light-dark transition phasing the nocturnal peaks and the dark-light transition possibly phasing the diurnal ones. Genus-specific and species-specific trends in field behavior, habitat selection, and distribution were studied. There were correlations between the field behavior and the entrained respiratory rhythms of these nocturnally active fishes. Entrained and endogenous rhythms of each species showed characteristic similarities and were interpreted as integral components of a level of organization evolved for nocturnal life in the shallow marine environment.
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    Notes: Abstract Monhystera disjuncta Bastian 1865 and Theristus pertenuis Bresslau and Schuubmans Stekhoven 1935 were cultured on sea-water agar in Boveri dishes at various temperatures. Generation time was measured as the period elapsing in two consecutive generations between the first egg deposit, the first hatching, or the first appearance of sexual characters. M. disjuncta has a generation time of 13 days at 17° to 22°C, 15 days at 13° to 15°C, 17 days at 9° to 12°C, 22 days at 7°C, 77 days at 0° to 2°C, and 135 days at -1° to 1°C. Low temperatures result sometimes in vivipary. T. pertenuis has a generation time of 23 days at 17° to 22°C, 41 days at 13° to 15°C, 47 days at 9° to 12°C, and 71 days at 7°C. M. disjuncta females live for up to 61 days at 17° to 22°C, T. pertenuis females up to 208 days at 7°C. Under North Sea temperature conditions, 17 generations of M. disjuncta and 7 generations of T. pertenuis could occur during the course of 1 year (calculation based upon experiments giving the shortest possible generation time). Females deposit eggs over a couple of days, therefore, the medium generation time is longer, and there will be fewer generations per year in the sea.
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    Marine biology 9 (1971), S. 281-289 
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    Notes: Abstract Species diversity and trophic structure of plankton communities have been considered as most important biological features. The Fisher (α) and Simpson (λ) indices and the information index H=-Σ pi log2 pi (Margalef) were used for evaluation of species diversity. The indices have been calculated within the group of filter feeders by numbers (α and H′) and biomass (λ and H″) of the species; the best results were obtained in the latter case. The index H=-Σ pi log2 pi is proposed for the quantitative evaluation of trophic structure, where a portion of an individual trophic group is taken as pi. The plankton material was collected by the R.V. “Vityaz” in the northern Indian Ocean in January through February, 1960. Analysis of characteristics of zooplankton distribution, species and trophic diversity in connection with characteristics of the water regime resulted in the definition of 3 types of the plankton communities: (a) those in intensive divergence zones; (b) those in poor divergence zones; (c) those in regions with stable water stratification or with feebly marked convergence, distiguished by different values of biomass, species diversity, and trophic group ratios.
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    Marine biology 9 (1971), S. 290-299 
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    Topics: Biology
    Notes: Abstract Nerita undata, N. plicata, N. polita, N. albicilla and N. textilis are common intertidal gastropods on Aldabra Atoll. Each species prefers a different level on the shore and/or different degrees of exposure to wave action. Patterns of zonation, population size-frequency structure and biomass are given. N. undata exhibits 2 distinct ecophenotypes. Normal types occur on expsed to moderately sheltered shores but are replaced by ‘type B’ in extremely sheltered conditions. Differences in shell morphology and population structure are also noted. Foraging by all species was confined to hours of darkness, generally at low tide. Activity of N. polita was induced slightly on overcast days. N. undata and N. textilis are cryptically coloured and often visible during the day. N. plicata is conspicuous, but is protected by a strong shell. N. polita and N. albicilla are often brightly and variably coloured, but both are concealed during daylight. No Nerita were found infected with trematodes, suggesting that the degree of infection was extremely low. Habitats of the Aldabran Nerita are compared with 3 species on Barbados, West Indies.
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    Marine biology 9 (1971), S. 315-322 
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    Notes: Abstract Gut analyses of the green sea urchin Strongylocentrotus droebachiensis (O. F. Müller) demonstrated that perennial phaeophytes, mostly fucoids and Alaria esculenta, were predominant in the diet. Ephemeral species, coralline algae and animals, were consumed in smaller amounts when available. Grazing by the urchins is evidently responsible for the dearth of non-coralline sublittoral algae in Newfoundland waters. Lobsters, rock crabs, purple sea stars, other urchins, and a variety of fishes and birds feed on S. droebachiensis, but predation is apparently not effective in limiting the abundance of the urchin.
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    Marine biology 9 (1971), S. 323-327 
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    Notes: Abstract Blood sugar metabolism of the isopod Ligia exotica Roux was studied in relation to chitin synthesis during the moult cycle. The blood sugars were found to occur free, as well as bound with blood proteins, during all moult stages, as in Emerita asiatica. The variety of free blood sugars is smaller in L. exotica; it comprises only glucose and glucose-6-phosphate. The protein-bound blood sugars are glucose and glucosamine. The blood-volume values do not differ markedly during the moult cycle. Estimations of blood sugars showed a marked rise of sugar levels in the blood during the premoult phase, and a subsequent fall during the freshmoult phase, when chitin is actively synthesised. The chitin values also showed a definite correlation with the blood-sugar values. The increased resorption of chitin during the premoult stage, and its liberation into the blood stream as glucosamine, is indicative of its reutilisation in chitin synthesis as in E. asiatica and the genus Cecropia. As more immediate precursors of chitin, such as uridine diphosphate and uridine diphophate acetylglucosamine compounds, were absent in the blood, a thorough biochemical study of the epidermis is suggested to locate the intermediate precursors of chitin which are possibly derived from blood sugars.
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  • 81
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    Description / Table of Contents: Zusammenfassung 1. Eine Schleimdrüse in der Schwanzspitze einiger Röhrenaale (Heterocongridae) wird beschrieben. 2. Nach Verhaltensbeobachtungen kann angenommen werden, daß das Sekret dieser Drüse zur Verfestigung der Wohnröhrenwände dient. 3. Die Schleimsubstanz besteht vorwiegend aus neutralen und zu einem geringen Anteil aus sauren Mucopolysacchariden. 4. Die Drüsenzellen werden mit den Schleimzellen in der Haut der Körpermitte und mit denen der Schwanzspitze der Jungtiere zweier Arten verglichen.
    Notes: Abstract A gland in the tip of the tail of the garden eel (Heterocongridae) is described. This gland produces a mixture of neutral and, to a lesser extent, acidic mucopolysaccharides. These slime substances appear to be used to glue the sand grains forming the tube walls in which the semi-sedentary eels live. The structure of the gland is described in relation to the normal mucous-containing goblet cells in the body epidermis of the garden eels. In the tail of young individuals, in two species, only goblet-like cells could be found. These differ in shape and histochemical reaction from the tail gland of the adult eels.
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    Marine biology 8 (1971), S. 238-242 
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    Topics: Biology
    Description / Table of Contents: Résumé 1. Cette étude décrit les différents traitements auxquels sont soumises les récoltes micronectoniques en vue de leur étude qualitative et quantitative. 2. A bord du bateau, aucune manipulation particulière n'est effectuée, si ce n'est, après le lavage du filet et le vidage du collecteur, le stockage dans une solution de formol neutralisé à 10%. Au laboratoire, les récoltes font l'objet d'une succession de traitements mécaniques qui s'effectuent dans un courant d'eau. 3. Le passage dans une colonne de 1,60 m de hauteur permet, par différence de densité, d'isoler les organismes gélatineux; la fraction restante passe alors sur une suite de tamis, dont le fond est constitué de baguettes de verre régulièrement espacées, qui permettent d'isoler des fractions homogènes en tailles. 4. Le tri manuel, qui aboutit à la séparation par taxa puis aux différentes pesées, s'en trouve grandement facilité, les organismes étant bien séparés les uns des autres et leurs tailles équivalentes dans chaque fraction. 5. Il semble qu'à l'avenir des efforts importants devront être faits dans cette voie qui permet, de traiter un grand nombre de prélèvements du fait d'un considérable gain de temps.
    Notes: Abstract This paper deals with some mechanical treatments of micronektonic samples which enable easier sorting into taxa. At sea, it is only possible to hose the net intensively before being brought on board ship; organisms are then washed into a bucket, the bucket emptied, and the samples preserved in a 10% buffered formaldehyde solution. A laboratory method for sorting gelatinous organisms based on differential specific gravity is described. The sorter consists of a cylinder 1.60 m high, supplied with running water. The remaining fraction is then sorted into 3 size groups. The device consists of a set of grills made from equidistant glass rods, through which organisms are sieved by the reciprocating motion of the grills into a large jar filled with running water. As this method results in higher sorting efficiency, it is recommended that further research be made in this direction.
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    Marine biology 8 (1971), S. 224-231 
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    Topics: Biology
    Notes: Abstract The elimination of 3 radionuclides from Euphausia pacifica was measured over a 5 month period. The biological half-lives for 65Zn, 137Cs, and 144Ce, calculated after the euphausiids had ingested radioactive Artemia nauplii, were found to be 140 days, 6 days, and 7.5 h, respectively. The percentages of body burdens lost in molts were greatest for the fission products, 144Ce (21%) and 137Cs (7%), and least for 65Zn (1%). Elimination of the isotopes in the feces could not be followed because of the difficulty in collecting fecal material for analysis; however, 1 sample collected 2 months after the beginning of the elimination experiment had no measurable radioactivity. Loss of 65Zn from molts and time to disintegration of the molts were found to be temperature dependent over a 5° to 15°C range, and the sinking rate of molts was both temperature and salinity dependent. Calculations showed that, in areas in the North Pacific outside the influence of upwelling, percentage 65Zn loss from sinking molts (before disintegration of the molts) was likely to be the same throughout the year, since the molts would be exposed to about the same mean temperature in the water column in all seasons. Even though temperature structure in the upper layers changes with season, mean temperatures change very little when calculated over the sinking distance of intact molts. Intact molts would sink to slightly over 400 m in the absence of turbulence, and would lose 87% of their 65Zn by the time they reached this depth. Sinking molts thus might contribute substantially to the vertical transport of 65Zn in the sea. If loss of 65Zn in fecal pellets is assumed to be small under our experimental conditions, and molting loss is only 1% of 65Zn body burden, the major mechanism of 65Zn loss from euphausiids feeding on non-radioactive food must be isotopic exchange with the water. Approximately 96% of the initial body burden was eliminated over a period of 5 months.
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    Marine biology 8 (1971), S. 243-259 
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    Notes: Abstract Oogenesis in polychaetes has, in most species, two main phases: a coelomic phase during which vitellogenesis occurs, and an ovarian phase. Details of the latter are known in very few species. Efficient reproduction requires coordination between these two phases of oocyte differentiation. The ovaries of Cirratulus cirratus (O. F. Müller) occur 2/segment throughout the fertile region of the body; 5 main stages of oocyte differentiation can be recognised on them: stem cells, oogonia, premeiotic oocytes, early oocytes and terminal oocytes. A quantitative study of the composition of the ovary throughout the reproductive cycle shows that the ovary size is approximately constant, but that the percentage of cells in the terminal oocyte stage is reduced to zero prior to spawning. This stage in oocyte differentiation is therefore a critical one, at which oogenesis may be arrested. The ovary alternates between a proliferative phase when the terminal oocytes are present, and a non-proliferative phase when they are absent. The overall rate of germ cell production for each ovary is low, less than 1 cell/ovary/day, and the, ovary tissue turnover time is greater than 2 years. A qualitative model describing the production of oocytes is presented, and the implications of the low rate of germ cell production are discussed. A low rate of germ cell proliferation, as in Cirratulus cirratus, implies that the rate of oocyte output into the coelom will be controlled by factors influencing the later stages of ovarian oocyte differentiation.
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  • 85
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    Notes: Abstract A Zürich-Montpellier analysis provided more detailed information about pelecypod associations in two sediment beds than either a traditional subjective approach or a cluster analysis based on Jaccard's coefficient. The Zürich-Montpellier test separated till and sand pelecypod associations, and indicated distinguishing species and atypical samples. Species distinguishing the till association were Cardita ventricosa, Yoldia myalis, Semele rubropicta, Venerupis kennerlyi, Clinocardium nuttallii, Nuculana minuta and Macoma incongrua. Species distinguishing the sand were Macoma elimata, Compsomyax subdiaphana, Yoldia ensifera, Macoma calcarea, M. lipara, M. brota, Yoldia limatula and Macoma alaskana. Two samples contained species from both associations plus some species rare elsewhere. Combined R-and Q-type grouping procedures, of which the Zürich-Montpellier approach is an example, are useful in evaluating benthic faunal similarities, but the suitability of various forms of the procedure needs further study.
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    Marine biology 8 (1971), S. 267-269 
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    Topics: Biology
    Description / Table of Contents: Zusammenfassung 1. Der freilebende Meeresnematode Ixonema sordidum gen.n., sp.n. wird aus sublitoralem Grobsand bei Helgoland beschrieben. 2. I. sordidum ist durch viele ursprüngliche und Sondermerkmale charakterisiert. Diese Merkmale werden diskutiert.
    Notes: Abstract A new nematode species, Ixonema sordidum, gen.n., sp.n. is described. Special characters are discussed: smooth cuticle, separate outlet of the caudal glands, a gelatinous rod rising from the amphids, a thin layer of sediment particles around the body, and a leftward bent tail.
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    Marine biology 9 (1971), S. 4-8 
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    Topics: Biology
    Notes: Abstract Viable heterotrophic microorganisms were enumerated to be 3.7±7.3 bacterial cells per microbial clump during summer in the euphotic zone of Saanich Inlet, British Columbia, Canada. Large microbial aggregates were observed, especially after the phytoplankton bloom, when the phytoplankton biomass formed about 1/2 the total suspended organic matter in the sea. The cell number per microbial clump was minimal when the phytoplankton fraction in the total suspended organic matter was almost 0 (i.e., before the phytoplankton bloom), and again when the phytoplankton bloom occurred. The size of the microbial clumps is discussed, particularly in reference to the food chain in the sea.
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    Marine biology 9 (1971), S. 9-25 
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    Topics: Biology
    Notes: Abstract A technique for rearing the loliginid squids Sepioteuthis sepioidea and Doryteuthis plei is reported. Specimens of the former were reared from eggs to sexually mature adults, and maintained for a maximum of 146 days; adult D. plei were maintained for 38 days. Choice and quantity of food was most important for the survival of all sizes, particularly young squid. Newly hatched specimens thrived on Mysidium columbiae. Both species fed at a rate of 30 to 60% of their body weight daily; starvation occurred when intake fell below 10 to 15%. Food conversion efficiency averaged between 10 to 20%. Growth was rapid and steady. S. sepioidea grew to a maximum of 105 mm and 77 g in less than 5 months; D. plei grew an estimated 20 mm/month. Experimental data indicate a lethal minimum salinity for both species at about 27‰. Lethal minimum and maximum temperatures for young S. sepioidea are 17.5° to 18.0°C, and 32.5° to 33.0°C, respectively. Young consume 0.64μl O2/mg wet weight/h. Opaque tanks, with a semi-natural bottom substrate and special ultra-violet (UV) illumination, are advantageous for rearing and maintenance.
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  • 89
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    Notes: Abstract In the laboratory, Balanus balanoides (L.) barnacles maintained without food at 5°C over the winter to summer period remained cold-tolerant. Winter animals maintained at 5°C and fed Artemia nauplii under a controlled light-dark regime until mid-summer lost this cold-tolerance. Summer animals, maintained without food at 5° or 15°C until midwinter, became cold-tolerant. Summer and winter animals subjected to increased (or decreased) ambient salinity for 48 h showed a small decrease (or increase) in their lower median lethal temperature (MLT—defined as the temperature at which 50% of the animals die after 18 h exposure to air). Summer animals subjected to desiccation for 48 h also showed a small decrease in their lower MLT. It is concluded that the seasonal changes in cold-tolerance of adult barnacles are probably induced by a combination of environmental factors including food availability, light intensity, day-length and changes in ambient sea-water temperatures. Development of cold-tolerance in the winter did not depend upon fertilisation. Changes in intra-cellular solute concentration which accompany adaptation to changes in ambient salinity or desiccation do not appear to be related to the seasonal changes in cold-tolerance.
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    Marine biology 9 (1971), S. 31-37 
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    Topics: Biology
    Notes: Abstract Individuals of the oriental brown shrimp Penaeus japonicus Bate, were raised separately (1 shrimp per rearing cage) with surplus food, in almost dark, non-sediment conditions. Results were obtained regarding growth of each part of the body in conjunction with exuviation and molting cycle. Increases in carapace, body length and body weight conformed to the general pattern discribed by Hiatt (1948), with no difference in growth resulting from sex, or inflexion point in juvenile stage. The molting cycle of shrimp weighing 1.5 to 15 g was 6 to 17 days at a water temperature of 20° to 28°C. The molting cycle was prolonged in proportion to the size of the shrimp; shortened as the water temperature increased.
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    Marine biology 9 (1971), S. 63-64 
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    Topics: Biology
    Notes: Abstract The plovers Charadrius hiaticula and C. alexandrinus feed on the mysid shrimp Gastrosaccus sanctus (van Beneden, 1861). They hunt at random along the sandy seashore, on the sites of the densest mysid population, regardless of the size of the mysids.
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    Marine biology 9 (1971), S. 347-354 
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    Topics: Biology
    Notes: Abstract Over a period of 6 weeks in aquaria, Portuguese oysters Crassostrea angulata, accumulate 65Zn to a greater extent than do native Ostrea edulis, although intake rates for any particular organ in either species are quite similar. The general distribution pattern of radioactivity in the tissues is similar to that observed for stable zine and 65Zn in other oyster species, concentration occurring to the greatest extent in gills and mantle, and least in muscle. The observed equilibrium concentrations and biological half-lives are considerably less than those measured in the natural environment, and the significance of this and its bearing on the mechanism of uptake is discussed. Cobalt and iron depress the rate of 65Zn uptake by both oyster soft tissues and the shell. The limiting effect in soft tissues is probably due to competition for sites at the actual point of uptake. The distribution of 65Zn in tissue subcellular fractions separated by centrifugation shows the greatest concentration of the radioisotope in the insoluble tissue components of gills, mantle and heart. Appreciable amounts of 65Zn are associated with tissue proteins.
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    Marine biology 9 (1971), S. 328-338 
    ISSN: 1432-1793
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    Topics: Biology
    Description / Table of Contents: Zusammenfassung 1. In Eilat, Israel, am Roten Meer wurden 9 Fischarten aus 3 Familien (Tabelle 1) beim Erbeuten von Diadema-Seeigeln unter Wasser beobachtet und fotografiert. Die Beutefangmethoden werden beschrieben. Lethriniden und Labriden-Arten fressen den Seeigel mit Stacheln ganz auf. Einige Labriden zerschlagen größere Seeigel am felsigen Untergrund. Balistiden haben besonders spezialisierte Methoden und können auch versteckt lebende Seeigel erbeuten. 2. Die Fische können zwischen großen und kleinen Diadem-Seeigeln unterscheiden und meiden einige andere Seeigel-Arten. 3. Im Attrappenversuch erkennt Balistes fuscus Seeigel and optischen Reizen (Stachelwald und Körper) und Verhaltensweisen (Stachelbewegung). 5. Für die Ausbildung der differenzierten Jagdmethoden waren offenbar morphologische und ethologische Präadaptationen erforderlich, die erst die Vorzugsverschiebung in der Nahrungswahl ermöglichten. 5. Die Bedeutung des Verhaltens im Ökosystem Korallenriff und die wechselseitigen Einflüsse im Räuber-Beute-Verhältnis werden kurz diskutiert.
    Notes: Abstract The techniques used by 9 species of fish (representing 3 families) to capture Diadema sea urchins were observed under water in the Red Sea at Eilat, Israel. Different species displayed different techniques. Fish belonging to the Lethrinidae and Labridae families devoured the entire urchin after capture; Labridae alone were also capable of breaking up large sea urchins by banging them on rocks. The fish did this by shaking its head while holding the urchin in its mouth. Under experimental conditions, fish can distinguish between large and small urchins, and show a preference for the small urchin. The fish also shun contact with some other species of urchins. The trigger fish Balistes fuscus exposed to a dummy sea urchin responds to optical stimuli (body shape and spines); when exposed to a living sea urchin it responds to both optical and behavioural stimuli (movements of the spines). Morphological and ethological preadaptation of the fish to alter its preference for other food is essential before it can develop differentiated capture techniques. The ecological significance of the behaviour of fish in the coral reef ecosystem and the alternating influences in the predator-prey-relationship are discussed.
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  • 94
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    Description / Table of Contents: Résumé 1. Durant la croisière “Alizé” faite le long de l'équateur dans l'Océan Pacifique de 86° 20 W à 151° 01 E, 33 traits furent exécutés à l'aide d'un filet à plancton ordinaire dans la couche 0 à 200 m, de nuit. 2. Ces échantillons montrent 3 types dedistribution pour les copépodes; la principale présente la décroissance bien connue qui existe d'est en ouest. 3. Les différentes distributions, à maximum oriental, semblent être contrôlées par: (a) l'abondance du phytoplancton de surface pour Eucalanus subtenuis; (b) la température et la thermocline pour Euchaeta media et Pleuromamma quadrungulata; (c) les proies pour Euchaeta marina; (d) l'upwelling et le courant du Pérou pour Eucalanus elongatus hyalinus et Rhincalanus nasutus. Les 3 espèces d'eaux chaudes (Rhincalanus calanus cornutus, Eucalanus attenatus et Eucalanus subcrassus) sont plus abondantes dans la région occidentale où la température est plus élevée. Les 2 espèces cosmopolites Pleuromamma xiphias et Pleuromamma abdominalis n'offrent aucune corrélation nette avec le biotope. La présence de certaines espèces dans les eaux superficielles de la zone A, où la divergence est intense et où existe un upwelling, accentue probablement la décroissance des effectifs, observée vers l'ouest dans la couche 0 à 200 m. 4. Quatre zones délimitées par la distribution du phytoplancton, les courants, la circulation verticale et les propriétés physicochimiques du biotope, coïncident avec la zonation des copépodes vérifiée par un test de rangement au niveau des espèces. 5. Dans ces limites, les diversités spécifiques d'après I=-Σ pi log2 pi et les “équitabilités” ont été calculées. Les variations de la diversité rendent compte de l'évolution de l'écosystème d'après la théorie de Margalef. La faible, diversité dans la zone orientale est liée à la divergence bien développée aux taux élevés de sels nutritifs, à la production intense de phytoplancton, à l'instabilité dans le temps et à l'arrivée d'eaux du sud. Là, l'écosystème est dans un stade jeune de succession de populations avec un fort pourcentage d'herbivores tel qu'Eucalanus subtenuis (45%). La diversité confirme les changements dus aux vents Alizés le long de l'équateur, surtout dans la région orientale de l'Océan Pacifique.
    Notes: Abstract During the cruise “Alizé” along the Equator in the Pacific Ocean from 86° 20 W to 151° 01 E (Fig.1), 33 night tows were made with a 1 m plankton net, in the 0 to 200 m layer. The samplings show, 3 types of copepod distribution (Figs. 2 to 5); the main type presents the well-documented decrease from east to west. The different distributions seem controlled by: suface phytoplankton abundance in the case of Eucalanus sublenuis temperature and the thermocline in Euchaeta media and Pleuromamma quadrungulata; type and availability of prey in Euchaeta marina; upwelling and the Peru current in Eucalanus elongatus hyalinus and Rhincalanus nasutus. The 3 warm-water species Rhincalanus cornutus, Eucalanus attenuata and Eucalanus subcrassus are more abundant in the western part of the Pacific Ocean, where temperature is higher. The 2 cosmopolitan species Pleuromamma xiphias and P. abdominalis do not show any clear relationship with the biotope. Probably the presence of some species in the upper water layer in the zone of intense divergence and upwelling emphasizes the westward decrease. It has been possible to define 4 zones by phytoplankton distribution, currents, vertical circulation, and the physical and chemical properties of the biotope; these zones agree with the zonation of the copepods in accordance with the results of a rank test. Within these limits, the 4 indices of specific diversity I=-Σ pi log2 pi and the equitibility have been calculated. The diversity variations account for the ecosystem evolution after Margalef's theory. The lower specific diversity in the oriental zone is related to the well developed divergence, the high rates of nutrients, the intense phytoplankton production, the instability in time and the southern water inflow; in this zone, the ecosystem is in an early stage of succession with a percentage of herbivores such as Eucalanus subtenuis (45%) present. The diversity index confirms the changes introduced by the trade winds along the Equator, mainly in the eastern part of the Pacific Ocean.
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    Radiation and environmental biophysics 7 (1971), S. 85-94 
    ISSN: 1432-2099
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    Topics: Biology , Physics
    Notes: Summary By means of a formal kinetic model, an analysis of the behavior of a certain type of unbranched sequences of biomolecular reactions is made. The main results are in (i) the characterization of the steady-state, (ii) the specification of a condition under which the largest physically admissible invariant set, containing the steady-state as invariant subset, can be obtained, and (iii) the deduction of parameter restrictions sufficient to assure asymptotic stability in the large in the given invariant set with respect to the steady-state.
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    Radiation and environmental biophysics 7 (1971), S. 106-114 
    ISSN: 1432-2099
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    Topics: Biology , Physics
    Notes: Summary X-ray irradiation of aqueous ferredoxin solutions isolated fromClostridium pasteurianum causes a rapid destruction of the ferredoxin molecule. The destruction is manifested by the decrease of the absorption at 390 nm, the liberation of ferric iron and hydrogen sulfide, and concommittant loss of biological activity in the phosphoroclastic reaction ofC. pasteurianum. The biological activity decreases parallel with the iron liberation, and was found to be dose and pH dependent. The yield of biological inactivation (G-value) and the yield of iron liberation showed the same value of 0.8. OH-radical scavengers like p-amino-benzoic acid and cysteine in low concentrations of 2×10−3 M, protect ferredoxin effectively against radiation, suggesting that OH-radicals are mainly responsible for the inactivation.
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    Radiation and environmental biophysics 7 (1971), S. 95-105 
    ISSN: 1432-2099
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Summary Expressions are derived for the decrease of the conductivity of lipid bilayer membranes caused by diffusion polarization in the aqueous solutions near the membrane. It is assumed that after a sudden change in the voltage or current, the reestablishment of the stationary state within the membrane is fast as compared to the change of ion concentration in the solutions. The time course of the diffusion polarization, then, can be calculated for experiments where either the voltage or the current are controlled. Criteria are given to distinguish diffusion polarization from other relaxation processes, and several limiting cases of experimental interest are discussed.
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  • 98
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    Springer
    Radiation and environmental biophysics 7 (1971), S. 120-125 
    ISSN: 1432-2099
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Description / Table of Contents: Zusammenfassung Lymphozytenkulturen werden nach Zugabe von Glyzerin als Gefrierschutzsubstanz zunächst gemeinsam mit ungefähr 1 °C/min Abkühlgeschwindigkeit bis zum vollständigen Erstarren eingefroren und dann mit verschiedener Geschwindigkeit (∼ 200 °C pro min und 3 bis 5 °C/min) auf verschieden tiefe Temperaturen (−22, −80 und −196 °C) gebracht. Alle eingefrorenen Proben weisen nach 24 h Kulturdauer eine kleinere, nach 48 h Kulturdauer eine wesentlich höhere Mitoserate als die Kontrollgruppe (unbehandelte, nicht eingefrorene Plasmaproben) auf. In den schnell auf −196 °C abgekühlten Proben wurden in beiden Fällen (24 h und 48 h Kulturdauer) keine Metaphaseplatten gefunden. Die Zellkonzentrationen waren nur bei den schnell auf −196 °C abgekühlten Kulturen stark verringert. Die Chromosomenaberrationsrate der eingefrorenen Kulturen ist nicht signifikant erhöht.
    Notes: Summary Peripheral human lymphocytes were cooled to the temperature of solidification at a rate of less than 1 °C/min using glycerol as a protective agent against the effects of freezing. After solidification at temperatures of −10 to −15 °C and cooling to about −22 °C one group of the samples was thawn and the others were cooled rapidly to −80 or −196 °C by immersion into solid carbon dioxide or liquid nitrogen. Other samples of the frozen cell suspension were cooled down to the same temperatures much slower at a cooling rate of 3 to 5 °C/min. After rapid thawing in a 25 °C water bath the cell suspensions were removed from glycerol and cultured for 24 or 48 h before stopping mitoses by adding colchicine. The samples frozen at −22 °C, the samples cooled both rapidly and slowly to −79 °C, and the ones cooled slowly to −196 °C showed a lower rate of mitosis when colchicine was added after 24 h and a significantly higher rate of mitosis after 48 h of incubation before adding colchicine as compared to the controls (untreated, unfrozen plasma). In the culture frozen rapidly to −196 °C no metaphases could be found. The cell concentrations before and after freezing showed no significant differences except those of the culture frozen rapidly to −196 °C. The chromosome aberration rate is not significantly increased.
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  • 99
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    Springer
    Radiation and environmental biophysics 7 (1971), S. 146-151 
    ISSN: 1432-2099
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Description / Table of Contents: Zusammenfassung Untersuchungen an thermischen Polymeren vonα-Aminosäuren in festem Zustand zeigen, daß in diesen insbesondere Tryptophan, Histidin, Cystin, Lysin und Methionin eine höhere Strahlenempfindlichkeit als in den bisher untersuchten Proteinen aufweisen. Diese Ergebnisse werden verglichen mit ähnlichen Untersuchungen an Filmen von Aminosäuremischungen, die in noch stärkerem Umfang auf einen beträchtlichen Energietransfer oder Chargetransfer in Richtung auf die vier genannten Aminosäuren schließen lassen. Die Ergebnisse werden auch in Hinsicht auf die Strahlenempfindlichkeit von Aminosäuren in Proteinen und auf die Inaktivierung von Enzymen diskutiert.
    Notes: Summary Irradiation of thermal polymers ofα-amino acids with X-rays in the solid state produces a significantly increased destruction of tryptophan, histidine, cystine, lysine and methionine as compared with the response of constituent amino acids in proteins. These results are discussed with respect to related results obtained by irradiation of dry films of amino acid mixtures which indicate an even stronger energy or charge transfer towards the four amino acids mentioned. The results are also discussed with respect to the radiation sensitivity of constituent amino acids in proteins and the inactivation of enzymes.
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  • 100
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    Springer
    Radiation and environmental biophysics 7 (1971), S. 169-180 
    ISSN: 1432-2099
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Summary In dogs the changes in the plasma concentration following the injection and/or infusion of labeled glucose reveal the “labeled glucose system” to be a linear system. Based on a simple chemical model it was shown that the rate of removal from the system of any tracer injected as single impulse can be described by a first order chemical reaction, even in systems from which the tracee is removed by a process of a higher order, provided the tracee is in the steady state and the concentration of tracer in the plasma is low compared to that of the tracee. The validity of the commonly used formulae for the calculations of the rates of disappearance from systems in a steady state is based on this first order process.
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