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  • 1985-1989  (12)
  • 1965-1969  (2)
  • Chemistry  (11)
  • Fishery management  (3)
  • Cichlidae  (2)
  • 1
    Electronic Resource
    Electronic Resource
    A framework for understanding the consumptive orientation of recreational fishermen (1986)
    Springer
    Environmental management 10 (1986), S. 221-227 
    Details
    ISSN: 1432-1009
    Keywords: Recreational fishing ; Fishery management ; Fishing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Fishermen were aggregated into high-, mid-, and low-consumptive groups according to the importance they placed on catching fish. Analysis of variance indicated that each consumptive group was unique in the importance it placed on other fish-related variables. Low-consumptive fishermen rated most other aspects of the fishing experience, such as interacting with nature, relaxation, and escaping the daily routine, more important than did high-consumptive fishermen. Low-consumptive fishermen also fished more frequently and were generally more satisfied with their most recent fishing trip than were high-consumptive-oriented fishermen. The three groups can be viewed as different fishing constituencies. By understanding their characteristics, we can gain additional insights into the impacts of management decisions on recreational fishermen and their experiences.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01867360
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  • 2
    Electronic Resource
    Electronic Resource
    Unique qualities and special problems of the African Great Lakes (1986)
    Springer
    Environmental biology of fishes 17 (1986), S. 161-183 
    Details
    ISSN: 1573-5133
    Keywords: Meromictic ; Evolution ; Diversity ; Cichlidae ; Productivity ; Aquatic reserves ; Flushing ; Pollution ; Fish introductions ; Lake development ; Limnology ; Fishery management ; Conservation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis The African Great Lakes consist of large, deep rift valley lakes (e.g. Malawi & Tanganyika) and shallower lakes between the Eastern and Western Rifts (e.g. Victoria). They are a group comparable in size to the North American Great Lakes, but are old. Most are seasonally thermally stratified, and wind is the decisive factor that determines the annual cycle of cooling and mixing. Lakes Tanganyika, Malawi and Kivu are meromictic, with deep relict hypolimnia. Large magnitudes and time scales of periodic internal motion, where these have been measured, appear unique among lakes. These lakes harbour the world's richest lacustrine fish faunas, and the family Cichlidae provides the supreme example of geographically circumscribed vertebrate evolution. The lakes provide a unique comparative series of natural laboratories for evolutionary studies. Primary production is generally high, but in the deeper lakes standing stocks of plankton and of small fish species are low. These pelagic populations are characterised by very high P:B ratios. The fisheries are productive and of socio-economic importance. Large-scale mechanised fishing is not compatible with the survival of the diverse fish communities. Cichlids appear especially vulnerable to unselective fishing. Aquatic reserves might offer a means of survival for at least some communities. Various pollution threats exist. Because water retention times are long, extremely long for some deep lakes, and flushing rates are low, the lakes are vulnerable to pollution which would be long-lasting. Introductions of alien fishes have mostly had undesirable or disastrous results. While the faunas are one of the significant natural heritages of mankind, their conservation must realistically be linked to the legitimate development of the lakes for the well-being of the people who live there. Scientific value alone will not protect the lakes. Just as survival of African terrestrial wildlife in extensive reserves depends heavily upon tourism, so also might the cichlid flocks in underwater reserves. Greater interest from the international scientific community is needed to further rational development and conservation of these great lakes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00002094
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  • 3
    Electronic Resource
    Electronic Resource
    Unique qualities and special problems of the African Great Lakes (1986)
    Springer
    Environmental biology of fishes 17 (1986), S. 161-183 
    Details
    ISSN: 1573-5133
    Keywords: Meromictic ; Evolution ; Diversity ; Cichlidae ; Productivity ; Aquatic reserves ; Flushing ; Pollution ; Fish introductions ; Lake development ; Limnology ; Fishery management ; Conservation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis The African Great Lakes consist of large, deep rift valley lakes (e.g. Malawi & Tanganyika) and shallower lakes between the Eastern and Western Rifts (e.g. Victoria). They are a group comparable in size to the North American Great Lakes, but are old. Most are seasonally thermally stratified, and wind is the decisive factor that determines the annual cycle of cooling and mixing. Lakes Tanganyika, Malawi and Kivu are meromictic, with deep relict hypolimnia. Large magnitudes and time scales of periodic internal motion, where these have been measured, appear unique among lakes. These lakes harbour the world's richest lacustrine fish faunas, and the family Cichlidae provides the supreme example of geographically circumscribed vertebrate evolution. The lakes provide a unique comparative series of natural laboratories for evolutionary studies. Primary production is generally high, but in the deeper lakes standing stocks of plankton and of small fish species are low. These pelagic populations are characterised by very high P:B ratios. The fisheries are productive and of socio-economic importance. Large-scale mechanised fishing is not compatible with the survival of the diverse fish communities. Cichlids appear especially vulnerable to unselective fishing. Aquatic reserves might offer a means of survival for at least some communities. Various pollution threats exist. Because water retention times are long, extremely long for some deep lakes, and flushing rates are low, the lakes are vulnerable to pollution which would be long-lasting. Introductions of alien fishes have mostly had undesirable or disastrous results. While the faunas are one of the significant natural heritages of mankind, their conservation must realistically be linked to the legitimate development of the lakes for the well-being of the people who live there. Scientific value alone will not protect the lakes. Just as survival of African terrestrial wildlife in extensive reserves depends heavily upon tourism, so also might the cichlid flocks in underwater reserves. Greater interest from the international scientific community is needed to further rational development and conservation of these great lakes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00698196
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    Paper (German National Licenses)
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  • 4
    Electronic Resource
    Electronic Resource
    Reaktionen an Indolderivaten, XI. Die stereoselektive Totalsynthese von DL-Ajmalicin, DL-19-epi-Ajmalicin, DL-Formosanin und Isoformosanin (1969)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 102 (1969), S. 3558-3572 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ausgehend vom ungesättigten Keton 1 gelingt die stereoselektive Totalsynthese mehrerer heterocyclischer Indol- und Oxindol-Alkaloide. Speziell der stereoselektive Aufbau der C-19-Konfiguration sowie der Einfluß dieses Zentrums auf die Folgereaktionen werden diskutiert. Die Massenspektren der verschiedenen stereoisomeren Zwischenprodukte werden gegenübergestellt.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19691021034
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  • 5
    Electronic Resource
    Electronic Resource
    Monitoring the quality of mix of polymer melts with particulate fillers using fluorescence spectroscopy (1989)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 29 (1989), S. 1759-1765 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Fluorescence spectroscopy has been employed to monitor the mixing of polymer melts with filler material. The polymer melts were low molecular weight polybutadiene and PBAN, a terpolymer consisting of 85% butadiene, 11% acrylonitrile, 4% acrylic acid, and the filler material was aluminum oxide. To carry out the fluorescence observations, a dopant chromophore was mixed into the polymer melt at very low concentrations, 10-4 to 10-6 molar or 11 to 0.11 ppm by weight. The mixing experiments were carried out using a small laboratory mixer which had glass walls for viewing the fluorescence spectra from the dopant chromophore. Fluctuations in fluorescence intensity were observed to decrease as a function of mixing time indicating that the spatial distribution of the fluorescent chromophores was becoming more uniform. Concerning the mixing of polymer melt and filler, we hypothesize that uniform mixing of ingredients is achieved when fluorescence intensity as a function of time is constant. In order to obtain quantitative support for this hypothesis, we used a fluorescence microscope to measure fluorescence intensity and optical transmittance from microscopic regions of well-mixed and poorly mixed specimens.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760292405
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  • 6
    Electronic Resource
    Electronic Resource
    Mechanism of accelerated photofading of thioether anthraquinone dyes in styrene butadiene resinsPresented, in part, at the IUPAC Photochemistry Symposium at Interlaken, Switzerland, July 1984. (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 36 (1988), S. 1205-1219 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Many anthraquinone dyes fade in visible light up to 100 times faster in styrene butadiene copolymers than in polyester resins or polystyrene. A mechanistic investigation of the photofading of 1,5-dihydroxy-2,6-diisobutyl-4-thiophenylanthraquinone has established that the dye sensitizes formation of singlet oxygen, a very reactive species, which attacks the double bonds in the styrene butadiene, resulting in extensive chain cleavage and peroxide formation. The major process is the oxidation of the polymer, and the dye fading is a minor process whereby the dye is apparently attacked by polymeric peroxides. The mechanism appears to be general for anthraquinone dyes, especially those with thioether, amino, hydroxy, or double-bond functionality. Unfortunately the fading is unaffected by most anticxidant stabilizers: the best result achieved was a doubling of half-life with 1 wt% Spinuvex A-36. This is still insufficient to give colored styrene butadiene copolymer resins the intrinsic dye stability available in other polymers, rendering styrene butadiene unsuitable for applications requiring high photostability of anthraquinone dyes.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1988.070360520
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  • 7
    Electronic Resource
    Electronic Resource
    Morphology of yeast cell wall as affected by genetic manipulation of β(1 → 6) glycosidic linkage (1986)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 28 (1986), S. 769-784 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The morphology of yeast cells as it is affected by the glycosidic linkages of constituent glucan was studied. Four different strains of Saccharomyces cerevisiae were studied. A cell wall matrix particle representing the intact original morphology and composed entirely of β-glucan was prepared. Using prepared cell wall glucan particles, the morphology and cell wall matrix structure were examined. Genetic modification of the cell wall structure during growth results in the alteration of the shape and hydrodnamic volume of the intact cell wall particles. The shape and hydrodynamic volume of the cell wall particles can also be modified by in vitro chemical and enzymatic treatment. The shape factor and hydrodynamic volume of the whole glucan cell wall matrix particles were evaluated quantitatively using a rheological analysis. An increased degree of β(1 → 6) cross-linking in the cell wall matrix induces a nearly 2-fold increase in the shape factor and a 10-fold increase in the compression modulus of the glucan particles. The disruption of β(1 → 6) glycosidic cross-linking causes the particles to swell by up to 18% of their original volume. This was used as a strategy to isolate a yeast mutant with a high β(1 → 6) glycosidic content in the cell wall glucan.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260280602
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  • 8
    Electronic Resource
    Electronic Resource
    Recovery of biological materials through ultrafiltrationPresented at the 3rd International Fermentation Symposium, September 3-8, 1968, Rutgers University, New Brunswick, N.J. (1969)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 11 (1969), S. 987-1003 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Experiments were performed on a cellulose acetate ultrafiltration membrane (HF-200, ABCOR Inc., Cambridge, Mass.) to test its efficacy in concentrating and purifying a crude enzyme (trypsin) preparation. Studies were also made to determine the influence of inorganic salts, pressure, and temperature on the rate of ultrafiltration for this membrane. The results showed reductions in the rates will be encountered due to the presence of inorganic salts. However, the reduced rates were still sufficiently high to make this method extremely attractive. Operating at filtration pressures above 75 psi at, 20 to 30°C for this membrane does not show any beneficial effect in terms of ultrafiltration rates. However, at 10°C there were continual increases in the filtration rates up to 100 psi. Concentration and purification studies with trypsin yielded a concentration factor of 8.35 and a purification factor 2.35. It was shown concretely that the purification of the enzyme was due to the passage of low molecular weight proteins (below 20,000) through the membrane. Enzyme activity slightly greater than 90% was obtained: 70% was found in the concentrate and 20% in the filtrate. It is concluded that membrane ultrafiltration is an ideal simple, rapid, and economical method for the recovery of biological active substances.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260110520
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  • 9
    Electronic Resource
    Electronic Resource
    Acrylonitrile-based copolymers: Synthesis, characterization, and formation of ultrafiltration membranes utilized for the immobilization of proteinsFinal author approval January 15, 1985. (1985)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 30 (1985), S. 1113-1132 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Various high molecular weight copolymers of acrylonitrile and a vinyl comonomer containing an aryl amine, a pyridine, or an aliphatic hydroxyl group were synthesized via slurry polymerization techniques so as to contain from 1 to 15 mol % functional comonomer. The comonomer content was quantitated by ultraviolet absorbance, base titration of acid polymer salts, and/or relative chemical reactivity with trichloro-s-triazine. Thin films were cast from copolymer solutions, coagulated into unsupported ultrafiltration membrances, and characterized with respect to both water permeability and pore size distribution. Analysis by size exclusion chromatography of the membrane permeate of a pool of dextran fractions yielded a continuous distribution curve for membrane pore size over the range 1.5 to 70 nm. The ultrafiltration membranes were used for protein immobilization after appropriate chemical activation. The three distinct types of functional copolymers gave comparable results for α-chymotrypsin, with protein weight loadings of 6-12% and 40-65% retention of enzymatic specific activity.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1985.070300318
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  • 10
    Electronic Resource
    Electronic Resource
    Rat peritoneal macrophage adhesion to hydroxyethyl methacrylate-ethyl methacrylate copolymers and hydroxystyrene-styrene copolymers (1985)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 19 (1985), S. 1101-1115 
    Details
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Macrophage adhesion to a wide variety of substrates has been measured, but no systematic study of the influence of specific substrate chemical properties on adhesion is available. These studies were conducted using two series of materials, copolymers of hydroxyethyl methacrylate (HEMA) and ethyl methacrylate (EMA) and copolymers of hydroxystyrene and styrene, to determine the effect of a single chemical property, polar character, on adhesion. Rat periotoneal macrophages were allowed to contact polymer substrates for periods ranging from 1 to 240 min before being subjected to a shear stress of 60-120 dynes/cm2 in a thin-channel flow cell. Percentage adhesion was calculated from the number of cells that remained adherent to the substrate after 30 s of applied shear stress. Macrophages remained adherent to 100% EMA and all hydroxystyrene-styrene copolymer surfaces after only 1 min of contact. In copolymers of the HEMA-EMA series, the time required to attain peak adhesion levels increased with increasing substrate hydrophilicity (increasing HEMA content). Cells did not attach to the 20% EMA/80% HEMA copolymer and the 100% HEMA polymer. The results demonstrate that there is a time delay between contact and adhesion of the cells to surfaces of increasing hydrophilicity within the HEMA-EMA series and no time delay with the hydroxystyrene-styrene series. The time delay is thought to be a function of the excluded volume provided by polymers that are able to undergo significant chain rotation and or swelling in the solvent, water. Small excluded volumes present in copolymers of high EMA content and all hydroxystyrene-styrene copolymers offer little or no resistance to formation of adhesive bonds by macrophages, whereas copolymers with large excluded volumes (high HEMA content) prevent contact and/or adhesion. A mechanism based on the net excluded volumes of both the cell and substrate surface macromolecule is proposed to explain this phenomenon.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jbm.820190919
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