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  • Springer  (477,767)
  • Wiley-Blackwell  (93,603)
  • American Association for the Advancement of Science (AAAS)
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  • 101
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 341-347 
    ISSN: 1476-5535
    Keywords: Auerobasidium ; Color variants ; Xylanase ; Hemicellulase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The yeast-like fungusAureobasidium is a promising source of xylanase (EC 3.2.1.8) with an exceptionally high specific activity. For enzyme production in volumes of several liters, xylose was the preferred carbon source and inducer. Xylanase in clarified cultures was concentrated by reversible adsorption to cation-exchange matrix to 5% of the initial volume, and recovered at nearly 2 million IU/1. Selective conditions permitted 97% recovery of xylanase with a 1.8-fold enrichment in specific activity, to 70% of purity. The predominant xylanase species (20 kDa) was subsequently purified to 〉99% of homogeneity by gel filtration chromatography. Purified enzyme exhibited an isoelectric point of 8.5, and specific activity of 2100 IU/mg under optimal conditions, determined to be pH 4.5 and 45°C. The activity of purified enzyme was specific for polymeric xylan.
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  • 102
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 375-402 
    ISSN: 1476-5535
    Keywords: Toxicity ; Organotins ; Tin ; Methiltins ; Butyltins ; Tributyltin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Organotins are used for industrial and agricultural purposes and in antibiologic agents. They are significantly more toxic than inorganic tins, and eventually reach the environment where they can be toxic to a wide variety of organisms. Particular attention has been given to tributyltins which are highly toxic components of antifouling paints. Realization that the molecular species of organotin influences fate and effects of organotins led to development of sensitive methods for quantifying individual molecular species. Even though such methods are now available, little information has been obtained on the ability of microorganisms to bioaccumulate tin compounds. Trisubstituted alkyl and aryltins (R3Sn's) are more toxic than disubstituted compounds (R2Sn's) while monosubstituted organotins (RSn's) are still less toxic. R4Sn's are toxic only if they are metabolized to R3Sn's. Among trisubstituted compounds propyl-, butyl-, pentyl-, phenyl-, and cyclohexyl Sn's are generally the most toxic to microorganisms. Toxicity in the R3Sn series is related to total molecular surface area of the tin compound and to the octanol:water partition coefficient,K ow, which is a measure of hydrophobicity; a highK ow indicates greater hydrophobicity and predicts greater toxicity. Care must be taken when testing the toxicity of tin compounds, for a number of biological, physical and chemical factors can influence the apparent toxicity. Although little is known of the effects of tin compounds on microbial processes, a number of bacterial processes can be inhibited by organotins and all relate to membrane functions. They include effects on energy transduction, solute transport and retention and oxidation of substrates. Very little is known of how organotins exert their toxic effects on algae and fungi; Information on effects on chloroplasts and mitochondria stems principally from animal systems and from higher plants. Triorganotins act against chloroplasts and mitochondria by causing swelling, by acting as ionophores and by acting against ATPase, while diorganotins appear to act by binding to dithiol groups on enzymes and cofactors. Nucleic acids do not seem to be affected at environmentally relevant concentrations. Virtually nothing is known of the action of tin compounds on microbial enzymes, but resistant mutants are easy to obtain and should facilitate work to understand modes of microbial interaction with tin compounds and mechanisms of resistance.
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  • 103
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 419-428 
    ISSN: 1476-5535
    Keywords: Bacillus ; Paper and board machines ; Starch degrading enzymes ; Cellulase ; Proteases ; Slimicides ; Food packaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Aerobic spore-forming bacteria were found dominant in the microflora of food packaging paper and board. Twenty-five strains of bacteria belonging to the genusBacillus were isolated from these paper and board machines, papermaking chemicals, and final products of papermaking. Nineteen strains were analyzed for production of α-amylase, α-glucosidase, glucoamylase, pullulanase, β-glucanase, carboxymethyl cellulase, and caseinase, and also for resistance towards industrial biocides. pH and temperature optima for the activity of the enzymes were determined. All strains were found to produce one or more of the enzymes studied. The amylolytic enzymes of most strains had high temperature optima for activity. Vegetative cells of all strains were found very resistant towards the different commercial slimicides used in paper and board mills. This property together with the ability to survive through the dry end of the machine to the final board and paper, and the production of enzymes degrading papermaking chemicals makes these bacteria potentially harmful in paper and board mills.
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  • 104
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 441-446 
    ISSN: 1476-5535
    Keywords: DNS hybridization ; Gene probe ; Environmental survival ; Pseudomonas cepacia AC1100 ; Alcaligenes A5
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The effectiveness of gene probe methods for tracking genetically engineered microorganisms (GEMs) in the environment was tested by inoculating nutrient-supplemented freshwater microcosms withAlcaligenes A5 (a naturally occurring 4-chlorobiphenyl degrader) orPseudomonas cepacia AC1100 (a genetically engineered 2, 4, 5 T-degrader) and following the fates of the introduced bacterial populations. Colony hybridization of the viable heterotrophic bacterial populations and dot blot hybridization of DNA recovered from the total microcosm microbial communities showed persistence of bothAlcaligenes A5 andP. cepacia AC1100 in the microcosms in the presence and absence of the xenobiotic substrates that these organisms biodegrade. Although there was a gradual decline in the added populations, both of the bacterial populatins were still detected in the microcosms two months after their introduction into the microcosms. Addition of 2, 4, 5-T enhanced the survival ofP. cepacia AC1100 — and 4-chlorobiphenyl addition resulted in increased levels ofAlcaligenes A5. The results indicate that both organisms may persist for very long periods in freshwater habitats.
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  • 105
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 181-187 
    ISSN: 1476-5535
    Keywords: Nocardia amarae ; Surface tension ; Hydrocarbon affinity ; Montmorillonite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Cultures ofNocardia amarae give rise to cell-stabilized foams in a laboratory scale foaming apparatus. The organism produces a surfactant and the cells are very hydrophobic; factors which, in terms of froth flotation theory, are essential for foam production and transport of the cells from the aqueous to the bubble phase. The addition of montmorillonitic clay to the culture prior to foaming prevents foam stabilization. The results obtained suggest the formation of a salt-dependent, reversible, bacterium-montmorillonite complex which prevents transport of cells to the bubble phase.
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  • 106
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 195-207 
    ISSN: 1476-5535
    Keywords: Coal leaching ; Desulfurization ; Thiobacilli
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The leaching of six Eastern coals was investigated using experimental coal columns subjected to simulated leaching events. Measurements of CO2 assimilation and specific enrichment cultures indicated that the microbial communities of all leachates were dominated by iron- and sulfur-oxidizing chemoautotrophic bacteria. Comparison of CO2 assimilation rates in leachates and core samples of leached coal indicated that most chemoautotrophs remained within coal columns during leaching. Mean numbers of chemoautotrophic bacteria in leachate samples were correlated with concentrations of dissolved iron and sulfate. Leachates from unwashed, run-of-mine coals contained more chemoautotrophs and more iron and sulfate than did leachates from washed, final product coals. After several leachings, the ratio of sulfur oxidizers to iron oxidizers tended to increase. These data suggest that the chemoautotrophic community of final product coals may be pyritelimited. Aerobic heterotrophs constituted a minor component of the microbial community in leachates from the six coals and their abundance and metabolic activity were apparently not influenced by the beneficiation history of the coal. Changes in rates of acetate metabolism may have been related to microbial succession within the heterotrophic community of coal columns. In all leachates, rates of tritiated methylthymidine assimilation were correlated with rates of acetate incorporation but not with CO2 assimilation, even though autotrophs dominated the microflora. Thus, thymidine assimilation rates appear to reflect activities or growth of mainly heterotrophic microorganisms in leachate.
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  • 107
    ISSN: 1476-5535
    Keywords: Metabolism ; Acetate ; Alginate ; Carbon balance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Some metabolic properties of both suspended and immobilized aerobically and anaerobically growingEscherichia coli cells were investigated. Metabolic activity was found to be substantially different whenE. coli cells were immobilized in alginate. Cells grown immobilized in alginate, and then released from the gel, synthesized 1.6 (aerobic growth) and 4.9 (anaerobic growth) times as much β-galactosidase per cell in response to induction as did suspended cells. Under both aerobic and anaerobic conditions, the cell yield from glycerol for immobilized cells was half that for suspended cells. At specific growth rates that were not significantly different from those of suspended cells, immobilized cells consumed glycerol at twice the rate of suspended cells. Immobilized cells produced elevated quantities of acetate, pyruvate, and lactate. Interpretation of these findings is discussed in terms of the kinetics of energy metabolism and the regulation of inducible protein synthesis inE. coli.
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  • 108
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 267-274 
    ISSN: 1476-5535
    Keywords: Glucose isomerase ; Immobilization ; K-carrageenan ; Glucose ; Fructose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary ImmobilizedArthrobacter cells (NRRL-B-3728) were used for continuous isomerization of glucose to fructose in a bioreactor system. The system utilized stationary phase (55h) cells (2.2×109 CFU/ml saline) immobilized onto K-carrageenan (3% w/v) beads [cells were heated at 65°C for 10 min to inactivate endogenous proteolytic enzymes]. Immobilized-cell preparations were hardened using three different glutaraldehyde systems. Glutaraldehyde (0.2 M) treated-immobilized cells (pH 7.0, 5°C for 30 min) exhibited good gel strength and high glucose isomerase activities. Maximal bioreactor isomerization of 44% was achieved when a buffered feedstock containing 40% glucose was fed into the column (60°C) at a flow rate of 0.2 ml/min. The biological half-life of glucose isomerase activities in this system was 400 h. Scanning electron microscopy revealed large numbers of cells distributed within the beads. A thin layer surrounding the beads following glutaraldehyde treatment was mainly due to cross-linking reactions between cell proteins and glutaraldehyde. This layer prevented leaking of cells during continuous isomerization reaction.
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  • 109
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 289-298 
    ISSN: 1476-5535
    Keywords: Biodegradation ; Landfarming ; Metal-working coolants ; Waste-oil emulsions ; On-site oil disposal
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The use of land treatment for disposal of a dilute waste oil emulsion generated by an aluminum rolling industry was investigated. Major components of the waste, identified by gas chromatography and mass spectrometry, were linear and branched (C12−C25) and fatty acid emulsifiers (primarily, isomers of oleic acid). Hexadecane and pristane were readily biodegraded in vitro when added to soil collected from the waste disposal site. Hydrocarbons and fatty acids extracted from the waste were similarly, biodegraded, however, the rate of decomposition may have depended on the history of waste applications to soil collected from the land treatment site. The apparent half-life of resolvable waste hydrocarbons and fatty acids was 9.5 days in soil which had received waste applications averaging 25.4l m−2 wk−1. In contrast, soil receiving either 50.8l m−2 wk−1 or no waste application during summer 1987 apparent exhibited half-lives of 28.1 and 60.3 days, respectively. Waste components were restricted to the upper 48 cm of the soil cores collected from the disposal site. Core samples also provided evidence for biodegradation of hydrocarbons and fatty acids as well as an accumulation of other compounds not readily resolvable by gas chromatography
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  • 110
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 315-323 
    ISSN: 1476-5535
    Keywords: Sugar uptake ; Yeast ; Brewer's wort
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary When glucose and fructose are fermented separately, the uptake profiles indicate that both sugars are utilized at similar rates. However, when fermentations are conducted in media containing an equal concentration of glucose and fructose, glucose is utilized at approximately twice the rate of fructose. The preferential uptake of glucose also occurred when sucrose, which was first rapidly hydrolyzed into glucose and fructose by the action of the enzyme invertase, was employed as a substrate. Similar results were observed in the fermentation of brewer's wort and wort containing 30% sucrose and 30% glucose as adjuncts. In addition, the high levels of glucose in the wort exerted severe catabolite repression on maltose utilization in theSaccharmyces uvarum (carlsbergensis) brewing strain. Kinetic analysis of glucose and fructose uptake inSaccharomyces cerevisiae revealed aK m of 1.6 mM for glucose and 20 mM for fructose. Thus, the yeast strain has a higher affinity for glucose than fructose. Growth on glucose or fructose had no repressible effect on the uptake of either sugar. In addition, glucose inhibited fructose uptake by 60% and likewise fructose inhibited, glucose uptake by 40%. These results indicate that glucose and fructose share the same membrane transport components.
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  • 111
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 403-408 
    ISSN: 1476-5535
    Keywords: Bromochlorodimethylhydantion ; Legionella pneumophila ; Industrial cooling water
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Free residual chlorine and bromine can be generated in water from bromochlorodimethylhydantoin (BCDMH). Efficacy of chlorine from inorganic sources has been studied extensively, but there is much less information on the efficacy of bromine againstL. pneumophila; only a few efficacy studies of organically-derived. halogen appear in the literature and the results from different studies conflict or are difficult to interpret. This paper describes the efficacy of halogen from BCDMH against planktonic, pure cultureL. pneumophila in an industrial cooling water. There was no difference in efficacy between halogen derived from organic or inorganic sources in controlled laboratory experiments. Effective doses in laboratory studies cannot be translated directly to field applications because of significant differences in the microbiology. However, the data suggest that disinfection (〉99.9% reduction in viability within 10 min) of planktonic, pure cultureL. pneumophila can be achieved with about 1 ppm free residual halogen (expressed as chlorine) from BCDMH in a typical industrial cooling water.
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  • 112
    ISSN: 1476-5535
    Keywords: Coriolus versicolor ; Wood-decay fungus ; Polyphenol oxidase ; Substrate specificity ; de novo Synthesis ; Partial purification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Coriolus versicolor, a white-rot Basidiomycete, secretes cellulolytic and ligninolytic enzymes as well as polyphenol oxidase (PPO). Whereas the former degrade wood polymers, the latter can convert diphenols to diquinones and oligomerize syringic acid, a lignin derivative. Certain phenolic compounds can serve as disease-resistance factors controlling the proliferation of wood-decay fungi within host tissues. BecauseC. vesicolor can be ‘batch-cultured’, overproduction and enhanced secretion of enzymes of biological and commercial interests are feasible. Reported here are the results of attempts to define the timed appearances of intracellular and extracellular PPO, to assess substrate specificity as well as distinguish synthesis versus activation of intracellular PPO and to partially purify extracellular PPO. These efforts were to provide data enabling cell-free synthesis of PPO, cloning of the gene(s) for the oxidase and the establishment of its subcellular route of secretion. Whereas two protein peaks (6 and 12 days in a 16 day time-course) were observed for dialyzed mycelial homogenates, the homogenates' PPO specific activity rose between 4 and 12 days and then declined. Total extracellular protein content climbed from 6 to 15 days for dialyzed growth medium and the medium's PPO specific activity rose at 4 days post-inoculation and except at 9 days increased linearly to 15 days. When aliquots of dialyzed 12 and 15 day media were added to PPO assay mixtures containing catechol and either syringic or gallic acids, statistically significant differences in PPO specific activity between phenolic substrates were noted. Supplementation of cultures with 1.91 μg cycloheximide ml growth medium−1 (control, growth medium only) together with 0.5 μCi [14C]-leucine revealed that cycloheximide inhibited PPO activity and suppressed [14C]-leucine incorporation into TCA-insoluble cytoplasmic protein. As for PPO partial purification, growth medium dialysis followed by 0–30% (NH4)2SO4 fractionation and subsequent 12 000×g dialyzate centrifugation yielded a 3.27-fold enhancement in PPO specific activity within the 12 000×g supernatant. Chromatography of the latter upon DEAE-Sephadex indicated that PPO exchanged with the DEAE counterion as it could be eluted with high ionic strength salt. These results suggest that: the occurrences of intracellular and extracellular PPO are time-dependent, intracellular PPO is de novo synthesized, the preferred substrate for extracellular PPO appears to be catechol and extracellular PPO can be partially purified by a combination of dialysis and ammonium sulfate fractionation as well as possibly DEAE chromatography and/or Sephadex G-150 gel filtration.
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  • 113
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 429-434 
    ISSN: 1476-5535
    Keywords: Sampling ; Biofilm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Quantitative sampling of periphyton from natural substrates is difficult and uncommon due to the nonhomogenous and irregular nature of most natural substrates. This paper describes an experimentally verified method for quantitative sampling of periphyton directly from the relatively homogenous and regular upper deck of a cooling tower.
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  • 114
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 71-75 
    ISSN: 1476-5535
    Keywords: Lactobacillus bulgaricus ; Whey permeate ; Peptide average molecular weight
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The batch fermentation of whey permeate to lactic acid was improved markedly by the addition of enzymehydrolyzed whey protein. Acid concentrations greater than 90 g/l were achieved at a productivity of 4.3 g/l per h and a 98% substrate use. Cell mass concentration reached 6 g/l. The acid productivity achieved is somewhat higher than that typical for fermentation of whole whey. The process economics, based on in-house hydrolyzate preparation, look promising. Presented in this paper are the experimental results showing the effects of hydrolyzate concentration on acid and cell mass production.
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  • 115
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 127-133 
    ISSN: 1476-5535
    Keywords: Salt-tolerant enzyme ; Heat-tolerant enzyme ; Depolymerase ; Lyase ; Oligosaccharide ; Viscosity breaker
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary A new high-temperature, salt-tolerant xanthanase suitable as an enzymic viscosity breaker for xanthanbased hydraulic fracture fluids was obtained by soil enrichment growth on xanthan gum incubated at 45°C in the presence of 3% NaCl. The mixed culture produces exoenzymes functional up to 65°C in the presence of salts. Degradation products include the pyruvic acetal of mannose and branched oligosaccharides derived from cleavage of main-chain β-(1→4)-d-glucosyl linkages. Release of the terminal pyruvic acetal ofd-mannose leads to oligosaccharide products that evidently contain the ene-4,5-unsaturated glucuronic acid residue.
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  • 116
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 145-154 
    ISSN: 1476-5535
    Keywords: Disinfectant ; Hypochlorite ; Chlorine dioxide ; Iodine ; Hydrogen peroxide ; Glutaraldehyde ; Quaternary ammonium compound ; Phenol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The activity of eleven disinfectants againstStaphylococcus aureus, Pseudomonas aeruginosa, andSaccharomyces cerevisiae was determined using a method based on the A.O.A.C. germicidal and detergent sanitizer assay. Based on the activity against the test organisms after 30-and 60-s exposures to each disinfectant, the disinfectant containing chlorine dioxide had the highest biocidal activity in this assay, on a mg/l basis. In addition, a disinfectant containing sodium hypochlorite and a disinfectant containing sodium chlorite performed well, at concentrations below label specifications. The results illustrate the importance of testing disinfectants in the context of their intended use.
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  • 117
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 173-180 
    ISSN: 1476-5535
    Keywords: Arabinan-degrading enzyme ; Arabanase ; p-Nitrophenyl-α-l-arabinosidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary A variety of thermophilic organisms andBacillus species were screened in shake flask culture for arabanase andp-nitrophenyl-α-l-arabinosidase activities. Highest arabanase activity was produced by strains ofThielavia terrestris andSporotrichum cellulophilum. Thermoascus aurantiacus and severalBacillus species were most active producers of arabinosidase. Arabinosidases fromBacillus strains had pH optima in the range 5.9–6.7. pH optima of fungal arabinosidases ranged from ≤2.9 to 6.7.Bacillus arabanases had neutral pH optima, whereas fungal arabanases had pH optima in the range 3.7–5.1. In general, arabinosidases were found to be relatively thermostable, retaining 〉70% activity for 3 h at 60°C. TheT. aurantiacus enzyme retained 98% activity at 70°C after 3 h.Bacillus arabanases were relatively unstable. All fungal arabanases except theT. aurantiacus enzyme were fully denatured at 70°C after 3 h.
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  • 118
    ISSN: 1476-5535
    Keywords: Isocoumarin ; Phosphodiesterase ; Enzyme inhibitor ; cGMP phosphodiesterase ; Secondary metabolite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Three isocoumarins have been isolated from a strain ofStreptoverticillium sp. and all inhibit the calmodulin-sensitive cyclic guanosine 3′,5′-monophosphate phosphodiesterase (EC 3.1.4.17, Boehringer Mannheim). Two of the compounds, 6,8-dihydroxy-7-methoxy-3-methyl isocoumarin and 6,7,8-trihydroxy-3-methyl isocoumarin have previously been isolated fromStreptomyces. The third fermentation product, 6,8-dihydroxy-3-methyl isocoumarin, was also found as a metabolite ofCeratocystis minor, a fungal species associated with the blue stain disease of pine [2,3].
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  • 119
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 215-229 
    ISSN: 1476-5535
    Keywords: Microbial enhanced oil recovery ; Microbial selective plugging ; Petroleum microbiology ; Permeability ; Biofouling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The ability of indigenous populations of microorganisms in Berea sandstone to improve the volumetric sweep efficiency and increase oil recovery by in situ growth and metabolism following the injection of nutrients was studied. Cores of differing permeabilities connected in parallel without crossflow and slabs of sandstone with differing permeabilities in capillary contact to allow crossflow were used. The addition of a sucrosenitrate mineral salts medium stimulated the growth and metabolism of microorganisms in the sandstone systems. This resulted in a preferential decrease in permeability in the core or slab with the higher initial permeability, diverted flow into the lower-permeability core or slab and improved the volumetric sweep efficiency. Injectivity into the slab with the lower initial permeability in the crossflow system increased during subsequent nutrient injections. Thus, microbial selective plugging does occur in laboratory systems that have the complex flow patterns observed in petroleum reservoirs without losing the ability to inject fluids into the formation. In situ microbial growth and metabolism increased oil recovery 10 to 38% of the original oil in place. Biogenic gas production accompanied oil production, and much of the gas was entrained within the produced oil suggesting that gas production was an important factor leading to increased oil recovery. Quantitation of the amount of phospholipid in the core confirmed that microbial growth preferentially occurred throughout the core with the higher initial permeability. These data showed that in situ microbial growth in the high-permeability regions improved not only the volumetric sweep efficiency but also the microscopic oil displacement efficiency.
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  • 120
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 255-266 
    ISSN: 1476-5535
    Keywords: Sulfate-reduction ; Anaerobic biodegradation ; Ground water ; Bacterial enrichment ; Phenol ; Cresol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Sulfate-reducing bacterial enrichments were obtained from a shallow anoxic aquifer for their ability to metabolize eithero-, m-, orp-cresol. GC/MS and simultaneous adaptation experiments suggested that the anaerobic decomposition ofp-cresol proceeds by the initial oxidation of the aryl methyl group to formp-hydroxybenzoic acid. This intermediate was then converted to benzoic acid. Benzoic acid and a hydroxybenzaldehyde were also found in spent culture fluids from ano-cresol-degrading enrichment culture. This result, in addition to others, suggested thato-cresol may also be anaerobically degraded by the oxidation of the methyl substituent. An alternate pathway for anaerobicm-cresol decomposition might exist. Enrichment cultures obtained with eitherp- oro-cresol degraded both of these substrates but notm-cresol. In contrast, am-cresol enrichment culture did not metabolize theortho orpara isomers. Anaerobic biodegradation in all enrichment cultures was inhibited by molybdate and oxygen, and was dependent on the presence of sulfate as a terminal electron acceptor. The stoichiometry of sulfate-reduction and substrate depletion by the various enrichment cultures indicated that the parent cresol isomers were completely mineralized. This result was confirmed by the conversion of14C-labeledp-cresol to14CO2. These results help clarify the fate of alkylated aromatic chemicals in anoxic aquifers.
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  • 121
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 279-288 
    ISSN: 1476-5535
    Keywords: Lead ; Organotins ; Organoleads ; Tin ; Tributyltin ; Yeasts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Four methods were used to screen nine organotin and two organolead compounds for toxicity to 29 yeasts, representing 10 genera. Center well diffusion plates were useful in comparing the sensitivity of yeasts to the most toxic organometals but were not useful for comparisons between compounds because of differences in diffusion rates and lack of sensitivity. Two-layer diffusion plates (density gradient plates) were also of limited use for comparisons between compounds but provided quantitative information on toxicity and allowed comparisons between organisms. Two-dimensional diffusion plates were useful for estimating the effect of pH on organometal toxicity. Release of K+ from cell suspensions measured using a K+-electrode provided quantitative information and allowed comparisons between compounds and organisms. The presence of 3% NaCl in cell suspensions decreased the rates and extent of organotin-induced K+ release. Yeasts varied in their sensitivity from strain to strain, but tributyltin was the most toxic compound tested. Mono- and dimethyltins were the least toxic. Triphenyltin, dibutyltin, monobutyltin, trimethyltin, triethyltin, diethyllead, diethyltin, and dimethylleads showed intermediate toxicity, but triphenyltin and monobutyltin were the most toxic among the group.
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  • 122
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    European journal of wildlife research 35 (1989), S. 137-137 
    ISSN: 1439-0574
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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    European journal of wildlife research 35 (1989), S. 151-163 
    ISSN: 1439-0574
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Description / Table of Contents: Summary The present report is part of a larger investigation aimed at differentiation among regional Hungarian red deer populations with the aid of morphological antler characteristics of shot red deer. However, this presentation is based on the use of morphological characteristics of cast off antlers as an extension of the previous work and encompasses a broader spectrum of antler formation. From a total of 418 cast off antlers from 4 different Hungarian red deer reserves, 14 morphological parameters were chosen. In order to characterize the distribution of mass along the antlers, a new parameter, the antler focal point was selected. The relationships among the parameters defining the cast off antlers were uniformly investigated within designated limits using simple correlation and regression calculations as well as with factorial analysis. The differences among the individual populations were investigated using graduated discrimination analysis. In numerous cases close positive correlations were demonstrated between the individual parameters; for example, between the selected parameter pairs — antler mass and antler length (r=0.84–0.92), lower antler circumference and antler mass (r=0.79–0.87), as well as upper antler circumference and antler mass (r=0.86–0.95). A comparison of the populations on the basis of the relationships existing between the parameter pairs showed only minimal differences. The factorial analysis demonstrated that the form variability of the cast off antlers can be characterized by the parameters of the lower and the upper antler masses, as well as by the relationship of the two — the antler focal point. For the investigated range of mass (0.3≤×≤3.0 kg), significant differences were in part determined between the individual populations from the results of the discrimination analysis. These differences, however, were very low. The antler focal point was also represented among the 6 parameters selected to differentiate respectively among the 6 different regions investigated. In 50% of the cases the individual cast off antlers were re-assigned to their correct areas of origin. Characteristic antler types could not be demonstrated. The results of the investigations of the antlers and cast off antlers were described. Other ways to compare red deer populations were discussed, whereby the complex investigations between morphological and biochemical-genetic parameters were emphasized.
    Abstract: Résumé Le présent travail se situe dans le cadre de nos recherches sur les possibilités de différencier les souches régionales du Cerf en Hongrie par l'analyse de caractères morphologiques des bois recueillis sur des cerfs abattus. Ces recherches se poursuivent par l'examen des caractéristiques des mues grâce auxquelles un spectre beaucoup plus étendu du développement des bois peut être pris en considération. Sur un total de 418 mues provenant de quatre territoires hongrois colonisés par le Cerf, 14 paramètres morphologiques ont été relevés. Afin de caractériser la répartition des masses sur les mues, on a fait appel à un nouveau paramètre défini comme «centre de gravité du merrain». Les corrélations existant entre les caractères des mues ont été uniformément analysées, dans des limites définies, au moyen de corrélations simples, de calculs de régression et d'analyses factorielles; les différences entre les populations, quant à elles, ont fait l'objet d'une analyse discriminante par degrés. Dans de nombreux cas, des liens positifs étroits ont pu être constatés entre les différents caractères examinés, par exemple, entre les couples de paramètres suivants: masse des merrains et longueur des merrains (r=0,84–0,92), périmètre inférieur des merrains et longueur des merrains (r=0,79–0,87) de même que périmètre supérieur des merrains et masse des merrains (r=0,86–0,95). Une comparaison des populations sur base des corrélations existant entre des différents couples de paramètres ne révèle que de faibles différences. L'analyse factorielle démontra que la variabilité des conformations des merrains pouvait être définie par les caractéristiques de la masse inférieure et de la masse supérieure de même que par le rapport des ces dernières à savoir le centre de gravité. L'analyse discriminante permit de dégager certaines différences significatives entre les différentes populations dans la fourchette observée au niveau des masses des merrains (0,3〈×〈3,0 kg); ces différences étaient cependant peu marquées. Parmi les six caractères départageant les territoires étudiés figurait également le centre de gravité des merrains. Dans 50% des cas en moyenne, les différentes mues purent être classées selon leur territoire d'origine effectif. Des types caractéristiques de bois ne purent être mis en évidence. Les résultats des recherches effectuées sur les bois et sur les mues font l'objet d'une discussion. D'autres études comparatives sur les populations de cerfs sont suggérées en particulier celles, complexes, relevant de caractères morphologiques ainsi que de caractères biochimiques et génétiques.
    Notes: Zusammenfassung Die vorliegende Arbeit nimmt im Rahmen unserer Untersuchungen zur regionalen Differenzierbarkeit ungarischer Rotwildvorkommen anhand morphologischer Geweihmerkmale erlegter Hirsche als Fortsetzung die Merkmale von Abwurfstangen zur Grundlage, mit welchen ein breiteres Spektrum der Geweihbildung erfaßt werden kann. An insgesamt 418 Abwurfstangen aus vier ungarischen Rotwildgebieten wurden jeweils 14 morphologische Parameter aufgenommen. Zur Charakterisierung der Massenverteilung an der Abwurfstange wurde der „Stangenschwerpunkt“ als neuer Parameter eingeführt. Die zwischen den Abwurfstangenmerkmalen bestehenden Zusammenhänge wurden einheitlich in definierten Grenzbereichen mit Hilfe der einfachen Korrelations- und Regressionsrechnung sowie der Faktorenanalyse, die Unterschiede zwischen den Einzelpopulationen mit der Methode der stufenweisen Diskriminanzanalyse untersucht. In zahlreichen Fällen konnten enge positive Korrelationen zwischen den Einzelmerkmalen nachgewiesen werden. So zum Beispiel bei den ausgewählten Parameterpaaren; Stangenmasse und Stangenlänge (r=0,84–0,92), unterer Stangenumfang und Stangenlänge (r=0,79–0,87) sowie oberer Stangenumfang und Stangenmasse (r=0,86–0,95). Ein Vergleich der Populationen auf Grundlage der zwischen den Parameterpaaren bestehenden Zusammenhänge erbrachte nur geringe Unterschiede. Die Faktorenanalyse zeigte, daß die Formenvariabilität der Abwurfstangen durch die Merkmale der unteren und der oberen Stangenmasse sowie durch das Verhältnis der beiden, den Stangenschwerpunkt charakterisiert werden kann. Im Ergebnis der Diskriminanzanalyse konnten im untersuchten Massebereich (0,3≤x≤3,0 kg) zum Teil zwischen den einzelnen Populationen signifikante Unterschiede ermittelt werden, welche jedoch gering waren. Unter den sechs die Untersuchungsgebiete abgrenzenden Merkmalen war auch der Stangenschwerpunkt vertreten. Die einzelnen Abwurfstangen wurden in durchschnittlich 50 % der Fälle richtig ihren eigentlichen Herkunftsgebieten zugeordnet. Charakteristische Geweihtypen konnten nicht nachgewiesen werden. Es werden die Ergebnisse der Geweih- und der Abwurfstangenuntersuchungen erörtert. Weitere Wege der vergleichenden Betrachtung zwischen Rotwildpopulationen werden aufgezeigt, wobei die komplexe Untersuchung morphologischer und biochemisch-genetischer Merkmale hervorgehoben wird.
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    European journal of wildlife research 35 (1989), S. 235-244 
    ISSN: 1439-0574
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Description / Table of Contents: Summary The present paper is concerned with research carried out in the Emmental area in Switzerland in a selection forest of the silver fir-beech typ(Abieti-Fagetum). The basis was a random survey, assessing density and browsing intensity for each species of the young forest trees. A total of 199 random samplings were taken, distributed systematically over 176 ha and comprising 30 young forest trees each. A regression and correlation analysis of the data showed that, on small browsing areas, browsing intensity of a specific tree species is highly influenced by the availability of any other browse plants. If beech and spruce are numerous, silver fir is subjected to increased browsing. On the other hand, a high density of silver fir can effectively ease the strain of browsing on both beech and spruce. A reduction of the browse impact on all tree species can be achieved by a high supply of sycamore maple, common ash, and mountain ash. Browsing by roe deer has now reached such proportions in the area investigated that silver fir suffers heavy losses through mortal browsing. The subsequent steady decline in the number of silver fir is further accelerated by the continued shift of the browse supply to beech and spruce.
    Abstract: Résumé La présente étude a été réalisée dans une forêt jardinée de l'Emmental (Suisse) sise dans le domaine de la hêtraie à sapins(Abieti-Fagetum). Les données de base ont été fournies à l'aide d'un relevé par échantillonnage, pour chaque essence, de la densité et de l'intensité de l'abroutissement sur de jeunes arbres forestiers. Il s'agit au total de 199 placettes réparties systématiquement sur 176 ha et contenant chacune 30 jeunes plantes. A l'aide d'une analyse de régression et de corrélation, la preuve a été faite que sur de petites surfaces de gagnage, l'intensité de l'abroutissement d'une essence donnée est fortement influencée par la quantité et la qualité des autres plantes susceptibles d'être abrouties. Une quantité importante de hêtres et d'épicéas induit un abroutissement plus intense du sapin blanc. Inversément, une forte densité de sapins blancs peut soulager efficacement de l'abroutissement tant le hêtre que l'épicéa. Une forte présence de l'érable de montagne, du frêne et du sorbier des oiseleurs provoque une diminution de la pression de l'abroutissement sur l'ensemble des essences. L'abroutissement du chevreuil atteint actuellement, pour la région étudiée, une proportion élevée qui a pour conséquence d'importantes défections dues à l'abroutissement létal. La régression continue du sapin blanc ainsi provoquée est de plus accélérée par le déplacement persistant de la proportion des essences au profit du hêtre et de l'épicéa.
    Notes: Zusammenfassung Die vorliegende Untersuchung wurde im Emmental (Schweiz) in einem Plenterwaldgebiet des Tannen-Buchenwaldes(Abieti-Fagetum) ausgeführt. Die Grundlage dazu lieferte eine Stichprobenerhebung, mit der baumartenweise die Dichte und Verbißintensität der jungen Waldbäume erfaßt worden waren. Insgesamt handelte es sich um 199, systematisch über 176 ha verteilte Stichproben zu je 30 jungen Waldbäumen. Mit Hilfe einer Regressions- und Korrelationsanalyse konnte der Nachweis erbracht werden, daß auf kleinen Äsungsflächen die Verbißintensität einer bestimmten Baumart vom Angebot der übrigen Verbißpflanzen erheblich beeinflußt wird. Ein hohes Angebot von Buche und Fichte zieht einen verstärkten Verbiß der Weißtanne nach sich. Umgekehrt kann eine hohe Dichte der Weißtanne sowohl die Buche als auch die Fichte wirkungsvoll vom Verbiß entlasten. Ein hohes Angebot von Bergahorn, Esche und Vogelbeere bewirkt bei sämtlichen Baumarten eine Verminderung der Verbißbelastung. Der Verbiß durch das Reh erreicht gegenwärtig im Untersuchungsgebiet einen Wert, der bei der Weißtanne hohe Abgänge durch Totverbiß zur Folge hat. Der dadurch ausgelöste stetige Rückgang der Weißtanne wird durch die anhaltende Verlagerung des Angebotes auf Buche und Fichte zusätzlich beschleunigt.
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    European journal of wildlife research 35 (1989), S. 252-256 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Description / Table of Contents: Summary Presented is a case of periodontitis apicalis purulenta in the mandible of a roe buck, aged 16 to 18 months. The anomaly was caused by a 90 degrees rotation of the right P4 and the resulting failure to resorb the distal root of the right Pd4, which was not shed. In the course of the resorption of its mesial root the pulpal cavity of the Pd4 was exposed and invaded by bacteria. Through the apical foramen of the tooth's distal root the inflammation later extended into the periapical space.
    Abstract: Résumé Sont décrites les altérations pathologiques résultant d'un abcès périapical(Parodontitis apicalis purulenta) au niveau du rumen inférieur droit du maxillaire d'un brocard de 16 à 18 mois. L'altération résulte d'une rotation à 90° de la P4 par rapport à sa position normale dans le maxillaire et l'absence consécutive de résorption de la racine distale de la Pd4 restée en place. Lors de l'évacuation de la dent de lait, la cavité pulpaire de cette dent, en s'ouvrant, donne accès à une infection bactérienne. L'inflammation gagne ensuite l'espace périapical par leForamen apicale de la racine distale de la Pd4.
    Notes: Zusammenfassung Beschrieben werden die als Folge eines periapicalen Abszesses (Parodontitis apicalis purulenta) entstandenen pathologischen Veränderungen in der rechten Unterkieferhälfte eines 16 bis 18 Monate alten Rehbockes. Ursache der Erkrankung war die Rotation des P4 um 90 Grad gegenüber seiner normalen Position im Kiefer und das daraus resultierende Ausbleiben der Resorption der distalen Wurzel des stehengebliebenen Pd4. Im Zuge des Milchzahnabbaues erfolgte die Eröffnung der Pulpahöhle dieses Zahnes, in die anschließend bakterielle Infektionserreger eindrangen. Später dehnte sich der Entzündungsprozeß dann über das Foramen apicale der distalen Wurzel des Pd4 auf den periapicalen Raum aus.
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    European journal of wildlife research 35 (1989), S. 271-279 
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    European journal of wildlife research 35 (1989), S. 280-280 
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 1-5 
    ISSN: 1476-5535
    Keywords: Xylose isomerase ; Enzyme expression ; thermally inducible ; Hollow fiber bioreactor ; Escherichia coli
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary TheEscherichia coli xylose isomerase (EC 5.3.1.5) has been expressed under the control of a thermal inverting promotor system (att-nutL-p-att-N block) and its performance in a hollow fiber bioreactor measured. The conversion of xylose to xylulose was inversely proportional to the flow rate and the system operated up to 60°C. The maximum conversion efficiency observed was 19.05% at 55°C.
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 13-17 
    ISSN: 1476-5535
    Keywords: Streptococcus lactis ; UV irradiation ; Liquid holding recovery ; Photoreactivation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Repair of ultraviolet-light-induced DNA damage inStreptococcus lactis has been examined. The wild-type strain and its derivative Lac− possess a dark repair system (maximal increase in survival of 4-fold). Enzymatic photoreactivation exists in the two strains but a weaker photoreactivability was found in the Lac− derivative (4 and 2-fold, respectively). Concomitant reduction of UV-induced mutagenesis (Rifr marker) was also studied during these two repair phenomena. The absence of dark repair after saturation of photoreactivation suggests that photoreactivation is much more efficient with pyrimidine dimers as substrate.
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 37-42 
    ISSN: 1476-5535
    Keywords: Exported recombinant protein ; Recombinant protein ; β-Galactosidase ; Leader peptide ; Thaumatin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary To produce and direct the export inStreptomyces lividans of the sweet plant protein thaumatin, thaumatin II cDNA was fused in the correct reading frame to the β-galactosidase leader peptide, under the control of the β-galactosidase promoter and ribosome binding site. The export of the recombinant thaumatin may allow the correct formation of the thaumatin disulfide bonds. The recombinant thaumatin was purified from the medium on an S-Sepharose column and detected with western blots by sheep α-thaumatin antibodies. The recombinant thaumatin was the same size as authentic thaumatin and changed position on an acrylamide gel in response to reduction by 2-mercaptoethanol in the same manner.
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 55-64 
    ISSN: 1476-5535
    Keywords: Rifampicin ; Bacitracin ; Exopolysaccharide ; Productivity ; Viscosity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Two classes of mutants ofXanthomonas campestris B1459 were isolated that accumulate more xanthan gum than the parental wild-type in culture broths of shake flask cultures and both batch and fed-batch fermentations. The first mutant class was resistant to the antibiotic rifampicin and accumulated, on average, about 20% more xanthan gum than wild-type. The second mutant class, a derivative of the first, was resistant to both bacitracin and rifampicin, and accumulated about 10% more xanthan than its parent. On a weight basis, the viscosities of the polysaccharides made by each strain were not distinguishable. Only a subset of the drug-resistant mutants were overproducers of xanthan. The biochemical basis for the overproduction of xanthan by the mutant strains has not been determined. Both new strains served as recipients for recombinant plasmids bearing ‘xanthan’ genes and further augmented the effects of multiple copies of those genes on xanthan productivity.
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 77-80 
    ISSN: 1476-5535
    Keywords: Lactobacillus bulgaricus ; Endoprotease ; Peptide average molecular weight
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The batch fermentation of whey permeate to lactic acid was improved by supplementing the broth with enzyme-hydrolyzed whey protein. Hydrolyzates prepared with endoprotease were more stimulatory to acid production rates than were those prepared with exo/endo protease. The effect of hydrolyzate average molecular weight on acid production is presented. Results show that the hydrolyzate having an average molecular weight of 700 is the most stimulatory to acid production rates.
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 121-125 
    ISSN: 1476-5535
    Keywords: Clostridium acetobutylicum ; Granulose ; Capsule ; Exopolysaccharide ; Oxido-reduction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The production of granulose (an intracellular reserve polygranule), capsule and exopolysaccharide was investigated in a synthetic medium in which the oxido-reduction level was modified by the addition of acetic or butyric acid. After addition of the acids, granulose synthesis increased from 150 to 300 mg glucose equivalents ·1−1 and capsular synthesis decreased by 25%. Exopolysaccharide production was unchanged under these conditions. A hypothesis that attributes a role to the polymer in the oxido-reduction sequences is discussed.
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 135-144 
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    Keywords: Xanthomonas campestris ; Xanthan gum ; Secretion ; Cellulase ; Amylase ; Pathogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Mutants ofXanthomonas campestris B 1459 were isolated that are defective in secretion of both cellulase and amylase. Both enzymes accumulated in the periplasmic space. The defects in secretion of cellulase or amylase were partly overcome by introducing into the mutants specific multiple copies of DNA cloned fromX. campestris, and presumed to code for cellulase or amylase enzymes. The mutant strains also showed reduced amounts of extracellular pectinase and protease activities, as if the mutants were generally defective for secretion of extracellular enzymes. The mutants showed reduced pathogenesis for turnip seedlings. The secretion-defective mutants may allow production of xanthan gum with reduced cellulose, pectin, protein and starch-degrading enzyme activities, thereby allowing more widespread mixing of microbially produced xanthan gum with these commercially important water-soluble polymers.
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 155-161 
    ISSN: 1476-5535
    Keywords: Rhizopus arrhizus ; Fungal growth ; Filamentous growth ; Hyphal morphology ; Fermentation medium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Rhizopus arrhizus biomass attached itself to fermentor walls, baffles and impellers when grown in casein/ glucose media. In shake flasks, dispersed filamentous growth was produced in media containing certain concentrations of glucose and soya flour. Other media tested produced pelleted or clumpy growth. Medium initial pH did not affect morphology type. Dispersed growth could not be obtained by addition of detergents, oils and polymers to a clear glucose/soya peptone medium. Addition of maize solids to this medium resulted in dispersed growth which occurred even in the presence of calcium, which in most media caused pellet formation. Mycelia appeared to bind to the maize particles and use these as growth centres thereby preventing pellet or clump formation. Mycelial pellets appeared to originate either from a single spore or by interaction of branched hyphae from different spores. Medium composition and macro-morphology type correlate with differences in hyphal structures.
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 189-193 
    ISSN: 1476-5535
    Keywords: Gastroenteritis ; Cytotoxin ; Food safety
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The lethality of 16 clinical or food isolates ofAeromonas hydrophila was assessed by determination of LD50 (i.p.) in mice and goldfish. In mice LD50 values for the variousA. hydrophila strains were similar, ranging from 1.2–21.0×108 cells/animal. A wider range of LD50 values, 0.03–11.8×108 cells/animal, was observed with goldfish. Lethality was not correlated between the two test animals. Further, cytotoxic response in Y-1 adrenal cells did not correlate with lethality in either test animal. It appears that lethality is not a good measure of potential enterotoxigenicity, but may be useful in assessing the invasive character of isolates causing systemic infections in immunocompromised hosts.
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 231-237 
    ISSN: 1476-5535
    Keywords: Avermectin ; Streptomyces avermitilis ; Biosynthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The biosynthesis of avermectins was studied further inStreptomyces avermitilis MA5502 by feeding experiments with labeled precursors.13C-NMR analysis of the compounds biosynthesized from [2-13C]acetate, [1,2-13C2]acetate, [3-13C]propionate and [2,3-13C2]propionate confirmed that the aglycone of avermectins is made from seven intact acetate and five propionate units. Feeding experiments with [1-13C]2-methylbutyrate and [1-13C]isobutyrate have shown that 2-methylbutyrate and isobutyrate are immediate precursors of the starter units of the polyketide chains of avermectin ‘a’ and ‘b’ components, respectively. The3H/14C doublelabeling experiments suggest that the two oleandrose moieties are derived from glucose.
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 7-12 
    ISSN: 1476-5535
    Keywords: Photoreactivation ; Streptomyces lividans ; UV survival ; Visible light
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Biological systems can repair damage induced in their DNA by ultraviolet light (UV). Most cells contain at least three DNA repair pathways, each of which has a marked effect on UV survival. Excision repair and recombinational (postreplication) repair are light-independent whereas photoreactivation (PR), whether enzyzmatic or photochemical, is light-dependent. The specificity of photoreactivation for UV-induced DNA damage allows it to be used as a tool for examining whether premutational DNA lesions are preferred sites for photoreversal; it therefore plays an important role in mutagenesis studies. Evidence is presented here that PR occurs in a time-dependent fashion in three strains ofStreptomyces lividans 66. The effect appears to be independent of temperature and is observed only when PR treatment is given after UV irradiation. The present experiments do not discriminate between enzymatic and photochemical protection.
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 29-35 
    ISSN: 1476-5535
    Keywords: Methane-utilizing bacteria ; Halogenated hydrocarbons ; Trichloroethylene ; Chloroform ; Dichloromethane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Soil was taken from the top 10 cm of a soil column that removed halogenated aliphatic hydrocarbons in the presence of natural gas. This soil was used as an enrichment inoculum to determine that the removals seen in the soil column were in fact of a microbiological nature. Methane served as the source of carbon and energy and was consumed immediately by the enrichments. After several transfers of the enrichments, a stable consortium of at least three bacterial types was obtained. The predominant bacterium was a non-motile, gram-negative coccus. This stable consortium was able to remove chlorinated methanes, ethanes, and ethylenes when grown with methane and oxygen in the headspace. Methane was required for the removals to be observed. Acetylene inhibited the removals, which further suggests the involvement of methanotrophs. Benzene and toluene were removed by the mixed culture with or without methane in the headspace. Fatty acid analysis of the mixed culture resulted in a profile that indicated that the predominant organism was a type II methanotroph. This study provides further evidence that methanotrophic bacteria are capable of cometabolizing a wide range of chlorinated methanes, ethanes, and ethylenes.
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 49-53 
    ISSN: 1476-5535
    Keywords: l-Phenylacetyl carbinol ; Saccharomyces cerevisiae ; Yeast ; Benzaldehyde ; Biotransformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The rate of production ofl-phenylacetyl carbinol bySaccharomyces cerevisiae in reaction mixtures containing benzaldehyde with sucrose or pyruvate as cosubstrate was investigated in short 1 h incubations. The effect of yeast dose rate, sucrose and benzaldehyde concentration and pH on the rate of reaction was determined. Maximum biotransformation rates were obtained with concentrations of benzaldehyde, sucrose and yeast of 6 g, 40 g and 60 g/l, respectively. Negligible biotransformation rates were observed at a concentration of 8 g/l benzaldehyde. The reaction had a pH optimum of 4.0–4.5. Rates of bioconversion of benzaldehyde and selected substituted aromatic aldehydes using both sucrose and sodium pyruvate as cosubstrate were compared. The rate of aromatic alcohol production was much higher when sucrose was used rather than pyruvate.o-Tolualdehyde and 1-chlorobenzaldehyde were poor substrates for aromatic carbinol formation although the latter produced significant aromatic alcohol in sucrose-containing media. Yields of 2.74 and 3.80 g/l phenylacetyl carbinol were produced from sucrose and pyruvate, respectively, in a 1 h reaction period.
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 81-84 
    ISSN: 1476-5535
    Keywords: Ethanol fermentation ; Wheat starch ; Saccharomyces cerevisiae ; immobilization ; Continuous dynamic immobilized biocatalyst bioreactor ; Biocatalyst bioreactor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary A simple and efficient method of conversion of wheat starch B to ethanol was investigated. Employing a two-stage enzymatic saccharification process, 95% of the wheat starch was converted to fermentable sugars in 40 h. From 140 g/l total sugars in the feed solution, 63.6 g/l ethanol was produced continuously with a residence time of 3.3 h in a continuous dynamic immobilized biocatalyst bioreactor by immobilized cells ofSaccharomyces cerevisiae. The advantages and the application of this bioreactor to continuous alcoholic fermentation of industrial substrates are presented.
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  • 142
    ISSN: 1476-5535
    Keywords: Fermentation development ; Cholecystokinin
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    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The natural product asperlicin is the first nonpeptide antagonist of cholecystokinin isolated from a microbial source. At discovery, production of asperlicin by the original soil isolate ofAspergillus alliaceus was between 15 and 30 mg/l. Selection of natural variants ofA. alliaceus, use of Plackett & Burman and Simplex experimental designs; formulation of synthetic media; amino acid supplementation of production media; analysis of complex nitrogen sources for their amino acid content; evaluation of promising media in fermentors; substitution of glycerol for glucose as a carbon source and rational mutant selection all contributed to titer increases to 〉900 mg/l.
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  • 143
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 109-120 
    ISSN: 1476-5535
    Keywords: Ground water ; Biodegradation ; Hydrocarbon ; Adaptation ; Subsurface ; Creosote ; Microorganism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The microbial ecology of pristine, slightly contaminated, and heavily contaminated subsurface materials, and four subsurface materials on the periphery of the plume at an abandoned creosote waste site was investigated. Except for the unsaturated zone of the heavily contaminated material, mineralization of glucose (13.5 ppb) indicated a metabolically active microflora in all subsurface materials. However, mineralization (〈40%) of naphthalene, phenanthrene, and 2-methylnaphthalene was observed in contaminated material and material from the periphery of the plume, but not in pristine material. Pentachlorophenol was mineralized in material from the periphery of the plume. Inorganic and organic nutrient amendments and changes in pH and temperature did not increase the extent of mineralization of the aromatic compounds. An array of organic compounds found in creosote were biotransformed in contaminated ground water; however some compounds were still detected after 7 months of incubation. The data suggest that the subsurface microflora in slightly and heavily contaminated subsurface materials and materials from the periphery of the plume has adapted to degrade many compounds found in creosote.
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  • 144
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 163-171 
    ISSN: 1476-5535
    Keywords: Bacteriocin ; Plasmid curing ; Phenotype ; Pediococcus acidilactici
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Pediococcus acidilactici strains E, F and H isolated from fermented sausages produced bacteriocins which were protein in nature and inhibitory to a variety of spoilage and pathogenic microorganisms often encountered in foods. These strains harbored two to three plasmids ranging in size from 7.4 to 40.2 megadaltons. Curing experiments and plasmid profile analysis indicated the involvement of plasmid DNA with bacteriocin activity in all three strains. Carbohydrate fermentation and antibiotic resistance phenotypes did not appear to be associated with bacteriocin plasmids. Both bacteriocin activity and resistance determinants were linked in strain H and mediated by a 7.4-megadalton plasmid, whereas in strains E and F these two traits were not linked.
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  • 145
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    Stochastic environmental research and risk assessment 3 (1989), S. 1-16 
    ISSN: 1436-3259
    Keywords: Width function ; instantaneous unit hydrograph ; peak ; regression ; birth-death process
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract We investigate optimal predictors of the peak (S) and distance to peak (T) of the width function of drainage networks under the assumption that the networks are topologically random with independent and exponentially distributed link lengths. Analytical results are derived using the fact that, under these assumptions, the width function is a homogeneous Markov birth-death process. In particular, exact expressions are derived for the asymptotic conditional expectations ofS andT given network magnitudeN and given mainstream lengthH. In addition, a simulation study is performed to examine various predictors ofS andT, includingN, H, and basin morphometric properties; non-asymptotic conditional expectations and variances are estimated. The best single predictor ofS isN, ofT isH, and of the scaled peak (S divided by the area under the width function) isH. Finally, expressions tested on a set of drainage basins from the state of Wyoming perform reasonably well in predictingS andT despite probable violations of the original assumptions.
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  • 146
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    Stochastic environmental research and risk assessment 3 (1989), S. 68-69 
    ISSN: 1436-3259
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
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  • 147
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    Stochastic environmental research and risk assessment 3 (1989), S. 281-292 
    ISSN: 1436-3259
    Keywords: Generalised Pareto distribution ; Peaks over threshold ; Probability weighted moments ; Regionalisation
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    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract A peaks over threshold (POT) method of analysing daily rainfall values is developed using a Poisson process of occurrences and a generalised Pareto distribution (GPD) for the exceedances. The parameters of the GPD are estimated by the method of probability weighted moments (PWM) and a method of combining the individual estimates to define a regional curve is proposed.
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  • 148
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    Stochastic environmental research and risk assessment 3 (1989), S. 31-49 
    ISSN: 1436-3259
    Keywords: Reservoir operation ; prediction ; Kalman filtering ; flood prevention ; fuzzy control
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract Japan has traditionally performed flood prevention through the construction and use of dikes, storage reservoirs, and basins which are costly and time consuming options. Another non-structural option is to operate the flood control system appropriately with a view to reducing flood damage. In this paper, a flood control system combining the runoff prediction model in the whole river basin with the reservoir operation is discussed. Different models of the runoff process are introduced in order to compare their accuracies and the computational time for the flood forecasting system. The reservoir operational rule is formulated in terms of fuzzy inference theory. Historical data are applied in a case study for verification of the proposed theories.
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  • 149
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    Stochastic environmental research and risk assessment 3 (1989), S. 69-69 
    ISSN: 1436-3259
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    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
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  • 150
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    Stochastic environmental research and risk assessment 3 (1989), S. 154-154 
    ISSN: 1436-3259
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
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  • 151
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    Stochastic environmental research and risk assessment 3 (1989), S. 155-178 
    ISSN: 1436-3259
    Keywords: Stochastic differential equations ; Stochastic Taylor formula ; Numerical methods ; Simulations ; Strong convergence ; Weak convergence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract The development of numerical methods for stochastic differential equations has intensified over the past decade. The earliest methods were usually heuristic adaptations of deterministic methods, but were found to have limited accuracy regardless of the order of the original scheme. A stochastic counterpart of the Taylor formula now provides a framework for the systematic investigation of numerical methods for stochastic differential equations. It suggests numerical schemes, which involve multiple stochastic integrals, of higher order of convergence. We shall survey the literature on these and on the earlier schemes in this paper. Our discussion will focus on diffusion processes, but we shall also indicate the extensions needed to handle processes with jump components. In particular, we shall classify the schemes according to strong or weak convergence criteria, depending on whether the approximation of the sample paths or of the probability distribution is of main interest.
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    Stochastic environmental research and risk assessment 3 (1989), S. 217-226 
    ISSN: 1436-3259
    Keywords: Stochastic integral equation method ; rainfall-runoff models ; confidence interval
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    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract The stochastic integral equation method (S.I.E.M.) is used to evaluate the relative performance of a set of both calibrated and uncalibrated rainfall-runoff models with respect to prediction errors. The S.I.E.M. is also used to estimate confidence (prediction) interval values of a runoff criterion variable, given a prescribed rainfall-runoff model, and a similarity measure used to condition the storms that are utilized for model calibration purposes. Because of the increasing attention given to the issue of uncertainty in rainfall-runoff modeling estimates, the S.I.E.M. provides a promising tool for the hydrologist to consider in both research and design.
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  • 153
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    Stochastic environmental research and risk assessment 3 (1989), S. 241-260 
    ISSN: 1436-3259
    Keywords: Hat matrix ; Mahalanobis distance ; Additive outliers ; Innovation outliers ; Influential data ; Autoregressive models ; Threshold autoregression ; Lake Huron
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract A practical method is developed for outlier detection in autoregressive modelling. It has the interpretation of a Mahalanobis distance function and requires minimal additional computation once a model is fitted. It can be of use to detect both innovation outliers and additive outliers. Both simulated data and real data re used for illustration, including one data set from water resources.
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  • 154
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    Stochastic environmental research and risk assessment 3 (1989), S. 293-316 
    ISSN: 1436-3259
    Keywords: Confined aquifer ; Transmissivity identification ; Geostatistics ; Inverse problem ; Ill-posedness ; Ill-conditioning ; Stability analysis ; Regularization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract In recent years, geostatistical concepts have been applied to the inverse problem of transmissivity estimation from piezometric head data. It has been claimed that such methods overcome various difficulties encountered in other approaches. However, the reconstruction of transmissivity from head measurements is ill-posed as it depends on derivatives of the head field. Consequently, any accurate method for its solution is likely to encounter numerically ill-conditioned systems. This paper reviews the geostatistical approach, and uses the stability analyses of linear algebra to show that, as the amount of available data increases and the discretization of the system is refined, both a numerically ill-conditioned parameter estimation problem and ill-conditioned cokriging equations may appear. Therefore, while the geostatistical approach does have conceptual appeal, it does not avoid the fundamental difficulties arising out of the ill-posed nature of transmissivity identification. Instead, the method is likely to be quite sensitive to these difficulties, so care must be taken in its formulation to minimize their effects. A means to stabilize the geostatistical method is suggested and numerical experiments that highlight key points of our analysis are given.
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    Mathematical programming 43 (1989), S. 31-44 
    ISSN: 1436-4646
    Keywords: Affine-scaling ; Karmarkar's algorithm ; dual algorithm ; feasibility algorithm
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    Topics: Computer Science , Mathematics
    Notes: Abstract The affine-scaling modification of Karmarkar's algorithm is extended to solve problems with free variables. This extended primal algorithm is used to prove two important results. First the geometrically elegant feasibility algorithm proposed by Chandru and Kochar is the same algorithm as the one obtained by appending a single column of residuals to the constraint matrix. Second the dual algorithm as first described by Adler et al., is the same as the extended primal algorithm applied to the dual.
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    Mathematical programming 45 (1989), S. 35-47 
    ISSN: 1436-4646
    Keywords: Facets ; ternary ; covering ; packing
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    Topics: Computer Science , Mathematics
    Notes: Abstract We consider ternary matrices, i.e., integer matrices having all entries 0, 1 or 2. Three associated problems—the group problem, covering, and packing—are studied. General classes of vertices and facets are discussed in each case. Certain lifting procedures are also described. For all three problems techniques used are natural extensions of those used in the binary case.
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    Mathematical programming 45 (1989), S. 407-435 
    ISSN: 1436-4646
    Keywords: 49D05 ; 65K05 ; Conjugate gradient ; diagonal updates ; Hilbert spaces ; large-scale problems ; limited memory ; numerical experiments ; unconstrained optimization ; variable-metric algorithms ; variablestorage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mathematics
    Notes: Abstract This paper describes some numerical experiments with variable-storage quasi-Newton methods for the optimization of some large-scale models (coming from fluid mechanics and molecular biology). In addition to assessing these kinds of methods in real-life situations, we compare an algorithm of A. Buckley with a proposal by J. Nocedal. The latter seems generally superior, provided that careful attention is given to some nontrivial implementation aspects, which concern the general question of properly initializing a quasi-Newton matrix. In this context, we find it appropriate to use a diagonal matrix, generated by an update of the identity matrix, so as to fit the Rayleigh ellipsoid of the local Hessian in the direction of the change in the gradient. Also, a variational derivation of some rank one and rank two updates in Hilbert spaces is given.
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    Mathematical programming 45 (1989), S. 529-546 
    ISSN: 1436-4646
    Keywords: Nonlinear optimization ; parallel computing ; block iterative methods ; truncated-Newton methods
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    Topics: Computer Science , Mathematics
    Notes: Abstract Truncated-Newton methods are a class of optimization methods suitable for large scale problems. At each iteration, a search direction is obtained by approximately solving the Newton equations using an iterative method. In this way, matrix costs and second-derivative calculations are avoided, hence removing the major drawbacks of Newton's method. In this form, the algorithms are well-suited for vectorization. Further improvements in performance are sought by using block iterative methods for computing the search direction. In particular, conjugate-gradient-type methods are considered. Computational experience on a hypercube computer is reported, indicating that on some problems the improvements in performance can be better than that attributable to parallelism alone.
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    Computing 41 (1989), S. 205-217 
    ISSN: 1436-5057
    Keywords: 65Q05 ; 65L15 ; 65N25 ; 65N35 ; Functional differential eigenvalue problems ; differential equations ; partial differential equations ; eigenvalues ; Tau Method ; collocation ; Legendre or Chebyshev series methods ; spectral Tau method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Description / Table of Contents: Zusammenfassung Mit Hilfe einer neuen Formulierung der Tau-Methode werden Eigenwertprobleme für gewöhnliche und partielle Funktional-Differentialgleichungen auf verallgemeinerte algebraische Eigenwertprobleme reduziert. Ein einfacher Algorithmus liefert genaue numerische Ergebnisse, die wir an Hand einiger konkreter Beispiele diskutieren. Zur weiteren Verbesserung der Ergebnisse wird Extrapolation verwendet.
    Notes: Abstract We apply a recent new formulation of the Tau Method to reduce the numerical treatment of eigenvalue problems for ordinary and partialfunctional-differential equations to that of generalized algebraic eigenvalue problems. We find accurate numerical results through the use of a simple algorithm which we discuss in applications to several concrete examples. Extrapolation is used to refine the results already obtained.
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    Computing 41 (1989), S. 163-166 
    ISSN: 1436-5057
    Keywords: Primary 65 C 10 ; Random variables ; acceptance-rejection ; logarithm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Description / Table of Contents: Zusammenfassung Bei der Erzeugung nicht-gleichverteilter Zufallszahlen muß häufig der Logarithmus einer gleichverteilten Zufallszahl mit einer Testgröße verglichen werden. Es wird gezeigt, daß dieser Vergleich ohne den Aufruf einer Logarithmusroutine effizient durchführbar ist; zwei Prozeduren für diese Aufgabe werden vorgestellt und verglichen.
    Notes: Abstract In many algorithms for sampling from non-uniform distributions the logarithm of a uniform deviate must be compared with some test quantity. It is shown that all these comparisons can be done efficiently without calling a logarithm subprogram: two procedures for this task are presented and compared.
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    Computing 41 (1989), S. 219-235 
    ISSN: 1436-5057
    Keywords: 65L05 ; Numerical analysis ; stiff problems ; Rosenbrock methods ; B-convergence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Description / Table of Contents: Zusammenfassung Es werden die Konvergenzeigenschaften der ROW-Verfahren bei ihrer Anwendung auf das steife Differentialgleichungsmodell von Prothero und Robinson untersucht. Dabei zeigt es sich, daß es Barrieren für die tatsächlich erreichbare Konvergenzordnung gibt. Ferner existieren ROW-Verfahren, deren Genauigkeit asymptotisch mit der Steifheit des Modells zunimmt. Die theoretischen Ergebnisse werden an numerischen Beispielen demonstriert.
    Notes: Abstract The convergence of ROW methods is studied when these methods are applied to the stiff model equation of Prothero and Robinson. It turns out that there are barriers of the attainable order of convergence. Furthermore, the existence of ROW methods is shown the accuracy of which increases asymptotically with the stiffness of the model. The theoretical results are demonstrated by numerical examples.
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    Computing 41 (1989), S. 267-274 
    ISSN: 1436-5057
    Keywords: 65R20 ; Integral equations ; transmission problems ; projection methods
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Description / Table of Contents: Zusammenfassung Das Verfahren besteht in der Entkopplung in zwei Randwertprobleme, welche mit bekannten Verfahren gelöst werden können. Der Konvergenzbeweis wird mit Hilfe der Integralgleichungsmethode und Konvergenzaussagen über Projektionsverfahren geführt.
    Notes: Abstract This method consists in decoupling the transmission problem into two boundary value problems, which can be solved separately by well known procedures. A convergence proof is given with the help of the integral equation method and convergence results on projection methods.
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    Computing 41 (1989), S. 261-265 
    ISSN: 1436-5057
    Keywords: 65V05 ; 65K10 ; 68C25 ; Automatic differentiation ; complexity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Description / Table of Contents: Zusammenfassung Die Arbeit behandelt ein spezielles Problem des Automatischen Differenzierens. Seif eine rationale Funktion vonn Variablen, sei #(f) die Anzahl der Operationen in der Auswertung vonf(x), seig der Gradient vonf. Viele Algorithmen zur Minimierung vonf(x) benötigen das Skalarproduktg(u) tv. In der Standardmethode zur Berechnung vong(u) tv wächst der Arbeitsaufwand mitn·#(f). In der vorliegenden Arbeit wird eine neue Methode zur Berechnung vong(u) tv angegeben. Die neue Methode erweist sich als wesentlich schneller, ihr Arbeitsaufwand wächst nur mit #(f).
    Notes: Abstract The paper deals with a special problem in Automatic Differentiation. Letf be a rational function ofn variables, let #(f) denote the number of operations to evaluatef(x), letg denote the gradient off. Many algorithms for minimizingf(x) require the scalar productg(u) tv. In the standard method for computingg(u) tv the amount of work grows withn·#(f). In this note a new method for computingg(u) tv is presented. The new method is considerably faster, its amount of work only grows with #(f).
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    Computing 42 (1989), S. 61-67 
    ISSN: 1436-5057
    Keywords: 65L05 ; Stiff initial value problems ; B-convergence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Description / Table of Contents: Zusammenfassung Auf der Klasse von Anfangswertproblemen mit negativer einseitiger Lipschitzkonstante ist die Eigenschaft algebraischer Stabilität eines Runge-Kutta-Verfahrens notwendig und hinreichend für dessenB-Konvergenz.
    Notes: Abstract The property of algebraic stability turns out to be a sufficient and necessary condition for a Runge-Kutta method to beB-convergent on the class of problems with a negative one-sided Lipschitz constant.
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    Computing 42 (1989), S. 91-108 
    ISSN: 1436-5057
    Keywords: 68B99 (Software) ; Image processing ; standardization ; system design ; Ada
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Description / Table of Contents: Zusammenfassung Im folgenden stellen wir einen Gestaltungsentwurf für ein ikonisches Bildverarbeitungssystem vor und beschreiben eine virtuelle Maschine, die die hierfür notwendigen Operationen realisiert. Es werden sowohl Datentypen als auch die charakteristischen Operationen der Bildverarbeitung diskutiert, und es werden Datenobjekte sowie Bildverarbeitungsoperationen formal definiert. Abschließend wird eine mögliche Implementation skizziert, die auf den generischen Konstrukten der Programmiersprache Ada basiert.
    Notes: Abstract We present a proposal for the design of a kernel system for iconic image processing operations and construct a virtual machine for image processing. The data structures and typical operations in the field of digital image processing are discussed. Furthermore, we give a formal definition of the operations and data objects required and describe one way to implement them by using the generic features of Ada.
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    Computing 42 (1989), S. 171-186 
    ISSN: 1436-5057
    Keywords: 65G10 ; 65H10 ; 65W05 ; CR: G. 1.0 ; G.1.5 ; Parallel methods ; nonlinear systems ; enclosures ; error bounds ; interval iterative methods ; multisplittings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Description / Table of Contents: Zusammenfassung Für gewisse Systeme nichtlinearer GleichungenF(x)=0 entwicklen wir ein Verfahren, welches iterativ enge untere und obere Schranken für die Nullstellen vonF berechnet. Das Verfahren beruht auf einem Multisplitting für bestimmte Matrizen und weist so in natürlcher Weise Parallelität auf. Wir geben Kriterien für die Konvergenz der Schranken gegen die Nullstellen an und untersuchen die Konvergenzgeschwindigkeit.
    Notes: Abstract For some systems of nonlinear equationsF(x)=0 we derive an algorithm which iteratively constructs tight lower and upper bounds for the zeros ofF. The algorithm is based on a multisplitting of certain matrices thus showing a natural parallelism. We prove criteria for the convergence of the bounds towards the zeros and we investigate the speed of convergence.
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    Computing 42 (1989), S. 225-238 
    ISSN: 1436-5057
    Keywords: 65G10 ; 65G05 ; 65H15 ; Generalized eigenproblem ; inclusion of solution ; guaranteed results ; error bounds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Description / Table of Contents: Zusammenfassung Es wird eine Methode zur Berechnung garantierter Schranken für die Lösung des komplexen allgemeinen Eigenproblems beschrieben. Die Methode erweitert einen ähnlichen Ansatz für allgemeine nichtlineare Gleichungssysteme in der Art, daß für den vorliegenden speziellen Fall weitgehende Folgerungen aus schwächeren Voraussetzungen gezogen werden können.
    Notes: Abstract A method is described which produces guaranteed bounds for a solution of the generalized complex eigenproblem. The method extends a similar approach for general systems of nonlinear equations to the special case of complex pencils, where under weaker assumptions stronger assertions can be proved.
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    Computing 42 (1989), S. 341-352 
    ISSN: 1436-5057
    Keywords: 65L05 ; Initial-value problems ; error control ; tolerance proportionality ; local extrapolation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Description / Table of Contents: Zusammenfassung Toleranztreue wird als minimale Bedingung dafür erkannt, daß eine einheitliche Interpretation der vom Benutzer geforderten Genauigkeit bei der Lösung von Anfangswertaufgaben möglich ist. Es werden Ergebnisse angeführt, die zeigen, daß ein Code den lokalen Fehler pro Einheitsschritt kontrollieren muß, um Toleranztreue zu erreichen. In Mehrschritt-Codes kann dieser Effekt dadurch erreicht werden, daß ein Korrektor-Verfahren verwendet wird, das eine Ordnung genauer ist als das Prädiktor-Verfahren. Diese Strategie ist leicht anzuwenden und führt zu besserer Toleranztreue als die Strategie des lokalen Fehlers pro Schritt, die oft bei Software für steife Probleme verwendet wird. Numerische Ergebnisse wurden mit zwei Codes gewonnen, die auf die vorgeschlagene Strategie modifiziert wurden. Die Ergebnissezeigen, daß durch die Modifikation eine signifikante Verbesserung der Toleranztreue bei geringem zusätzlichen Aufwand erreicht werden kann.
    Notes: Abstract Tolerance proportionality is identified as a minimum requirement for a more uniform interpretation of the user's requested accuracy in software for the solution of initial-value problems. Results are quoted that show that a code must control the local error per unit step in order to achieve tolerance proportionality. This effect can be obtained in codes based on multistep formulas by using a corrector formula of one order higher than the predictor formula. This strategy is simple to implement and leads to better tolerance proportionality than the local error per step strategy often used in stiff software.Numerical results are obtained from two existing solvers that have been modified to use the proposed strategy. These results show that there is a significant improvement in tolerance proportionality in the modified codes at little extra cost over the original versions.
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    Computing 43 (1989), S. 37-45 
    ISSN: 1436-5057
    Keywords: 65 D 05 ; 65 D 32 ; Interpolation on the ball ; cubature formulae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Description / Table of Contents: Abstract Extremal fundamental systems are nodal systems with a small Lebesgue-constant (≤dimension). An exchange algorithm for their calculation in case of polynomial interpolation over the unit ballB r is realized. ForB 3 and algebraic degree 6, a system consisting of 84 nodes and with a Lebesgue-constant 〈26 is documented, the corresponding cubature leading to a relative error of ≈10−8 in case of analytic functions.
    Notes: Zusammenfassung Extremale Fundamentalsysteme sind Knotensysteme mit kleiner Lebesgue-Konstante (≤Dimension). Hier wird ein Austauschalgorithmus zu ihrer Berechnung für die Polynominterpolation über der VollkugelB r konkretisiert. Für dieB 3 und den Polynomgrad 6 wird ein aus 84 Knoten bestehendes System mit Lebesgue-Konstanten 〈26 numerisch angegeben. Die zugehörige Kubatur führt bei analytischen Funktionen auf einen relativen Fehler ≈10−8.
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  • 170
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    Computing 43 (1989), S. 85-92 
    ISSN: 1436-5057
    Keywords: 65K10 ; 65G10 ; Global optimization ; guaranteed error bounds ; interval analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Description / Table of Contents: Zusammenfassung Zur Bestimmung des globalen Maximums einer Funktion einer Veränderlichen auf einem abgeschlossenen Intervall [a, b] schlagen wir eine Intervall-Majoranten-Methode vor. Sie benützt die Vorteile und vermeidet die Nachteile zweier bekannter Verfahren. Numerische Resultate werden berichtet.
    Notes: Abstract For seeking the global maximum of a function of a single variable defined on a closed interval [a, b] an interval-majorant method is proposed. This method derives advantages and avoids defects from both the one-step strategy method and the interval method. Numerical results are given.
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  • 171
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    Computing 43 (1989), S. 141-157 
    ISSN: 1436-5057
    Keywords: 65D32 ; 41A55 ; cubature formula ; ideal theory ; integration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Description / Table of Contents: Zusammenfassung Es sind nur wenige Kubaturformeln bekannt, deren Knotenzahl Möllers unterer Schranke entspricht. In dieser Arbeit werden die Beziehungen zwischen reelen Idealen und Kubaturformeln ausgenutzt, um solche minimale Formeln mit beliebigem ungeraden Grad für zwei klassische Integrale zu bestimmen. Eine Basis der Ideale kann explizit angegeben werden, weiter können fast alle Knoten in geschlossener Form bestimmt werden. Es wird gezeigt, daß alle Knoten im Integrationsbereicht liegen.
    Notes: Abstract Cubature formulae with the number of nodes equal to Möller's lower bound are rare. In this paper, the relation between real polynomial ideals and cubature formulae is used to construct such minimal formulae of arbitrary odd degree for two classical integrals. We found general expressions for bases of these ideals and closed formulae for almost all nodes. We proved that all nodes are inside the domain of integration.
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  • 172
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    European journal of nutrition 28 (1989), S. 56-75 
    ISSN: 1436-6215
    Keywords: free radicals ; cataracts ; antioxidant vitamins ; vitamin C ; vitamin E ; β-carotene ; Katarakte ; antioxidative Vitamine ; Vitamin C und E ; Betakarotin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Die Augenlinse kann durch einfallendes Licht und Sauerstoff photooxidativ so geschädigt werden, daß eine Trübung bzw. ein Katarakt entsteht. Sauerstoffradikale schädigen nicht nur die Kristalline, spezialisierte Linsenproteine, die Aggregate bilden und präzipitieren, sondern sie greifen auch proteolytische Enzyme an, deren Funktion es wäre, die geschädigten Proteine zu eliminieren. Neben einem enzymatischen Abwehrsystem gegen Sauerstoffradikale, bestehend aus Superoxiddismutase, Katalase und Glutathionperoxidase, enthält die Linse die antioxidativen Vitamine C und E und evtl. Betakarotin. Tierversuche an verschiedenen Spezies haben sowohl in vitro als auch in vivo eine Schutzwirkung gegen lichtinduzierte Kataraktbildung aufgezeigt. Eine ähnliche Wirkung war gegen Zucker- und Steroidkatarakte nachweisbar. Epidemiologische Studien am Menschen haben gezeigt, daß Personen mit vergleichsweise höherer Einnahme bzw. höheren Blutkonzentrationen antioxidativer Vitamine ein vermindertes Risiko der Kataraktbildung haben. Diese positiven Befunde rechtfertigen die Durchführung breit angelegter Interventionsstudien mit antioxidativen Vitaminen am Menschen.
    Notes: Summary The ocular lens, which is continually exposed to light and ambient oxygen, is at high risk of photooxidative damage resulting in cataract. Oxygen free radicals appear to impair not only lens crystallins which will aggregate and precipitate forming opacities but also proteolytic enzymes whose function it would be to eliminate the damaged proteins. Apart from an enzymatic defense system consisting of superoxide dismutase, catalase and glutathione peroxidase against excited oxygen species the lens contains the antioxidant vitamins C, E and presumably β-carotene as another line of defense. In vitro and in vivo studies in different animal species have demonstrated a significant protective effect of vitamins C and E against light-induced cataract. Sugar and steroid cataracts were prevented as well. Epidemiological evidence in humans suggests that persons with comparatively higher intakes or blood concentrations of antioxidant vitamins are at a reduced risk of cataract development. These positive findings established by several research groups justify extensive intervention trials with antioxidant vitamins in humans using presenile cataract development as a model.
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    European journal of nutrition 28 (1989), S. 103-129 
    ISSN: 1436-6215
    Keywords: geeignete Spezies ; analoge Reaktionen ; optimale Standardisierung ; ethische Grundsätze ; spezifische Alternativen ; suitablespecies ; analogousreactions ; optimalstandardization ; ethicalprinciples ; specificalternatives
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary Experimental animals may serve as models for human beings, if analogies between animal and human functions exist. Therefore, the selection of species and strain plays an important role in the development of such models. Knowledge of the nutritional and physiological characteristics of a species is a prerequisite for the composition of complete diets. Often, preliminary work has to begin at the breeding farm in order to make use of such curative models possible. Only when the high requirements of standardization of experimental animals are met can clinical and subclinical symptoms be determined distinctly. By means of sensitive biochemical reactions, imbalances and interactions of nutritive and active ingredients, as well as successful substitutions, can be recorded. The study of absorption and metabolism of preparations is made possible by observing these reactions. However, negative influence on the results of analysis must be eliminated by correct selection of narcotics, and the proper excision and storage of organs. Because of its importance for the planning and evaluation of experiments, biometry is an integral part of every research project. The scientific information which must be gained from the whole experimental animal cannot be substituted by either isolated organs and cell cultures, or by means of computer simulation. A demanding effort, which includes biotechnological methods, is necessary to further reduce the number of experimental animals and, simultaneously, to enhance experimental evidence. In any case, all scientific aims must be in accordance with the ethical principles of the Society for the Prevention of Cruelty to Animals.
    Notes: Zusammenfassung Versuchstiere können als Modell für den Menschen herangezogen werden, wenn Analogien zwischen tierischen und menschlichen Funktionen bestehen. Deshalb kommt der Wahl von Spezies und Stamm bei der Entwicklung solcher Modelle eine besondere Bedeutung zu. Die Kenntnis der ernährungsphysiologischen Besonderheiten einer Spezies ist die Voraussetzung für die Herstellung vollwertiger Diäten. Oft sind Vorleistungen bereits in der Zuchtstation zu erbringen, um kurative Modelle überhaupt erst anwenden zu können. Nur wenn die hohen Anforderungen an die Standardisierung des tierexperimentellen Teiles einer Untersuchung erfüllt sind, können klinische und subklinische Symptome eindeutig zugeordnet werden. Mit empfindlichen biochemischen Reaktionen lassen sich sowohl Imbalanzen und Interaktionen von Nähr- und Wirkstoffen sowie Substitutionserfolge erfassen. Ebenso können die Resorption und der Stoffwechsel von Präparaten verfolgt werden. Negative Auswirkungen auf das Analysenergebnis sind bereits bei der Wahl des Narkotikums, der Entnahme und Lagerung von Organproben auszuschließen. Wegen ihrer Bedeutung für die Planung und Auswertung stellt auch die Biometrie einen integrierenden Bestandteil eines jeden Forschungsprojektes dar. Die am Ganztier erzielte wissenschaftliche Information kann weder mit isolierten Organen und Zellkulturen, noch mit Hilfe simulierender Computersysteme erreicht werden. Große Anstrengungen, auch unter Einbeziehung biotechnologischer Methoden, sind erforderlich, um die Tierzahlen weiterhin zu reduzieren und gleichzeitig die Aussagekraft der Experimente zu erhöhen. In jedem Fall jedoch müssen die wissenschaftlichen Zielsetzungen mit den ethischen Anliegen des Tierschutzes in Einklang gebracht werden.
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  • 174
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    Keywords: Fettemulsion ; MCT ; LCT ; Lipoproteine ; Elimination ; fat emulsion ; triglycerides ; medium chain (MCT) triglycerides ; long chain (LCT) ; lipoprotein elimination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary A fat emulsion containing 20% fat as medium chain triglycerides (MCT) and long chain triglycerides (LCT) (1∶1) was injected as a bolus in an amount of 0.2 g fat per kg body weight to six patients, three to five days after a serious injury. Triglyceride concentrations increased within two min in lipoprotein fractions d〈0.95 g/ml (Chylomicrons), d〈1.006 g/ml (VLDL), d〈1.063 g/ml (LDL) and d〈1.21 g/ml (HDL). Sixty minutes after injection triglyceride concentrations had again reached preexperimental values in all lipoprotein fractions. Cholesterol values did not change. According to the composition of the fat emulsion, linoleic acid content increased in triglycerides of all lipoprotein fractions, whereas octanoic and decanoic acid did so only in triglyceride-rich lipoproteins (d〈1.006). Half-life values of elimination of octanoic acid (3.3 min) and decanoic acid (3.9 min) in triglycerides of lipoprotein fraction d〈1.006 were nearly half as short as that of long chain fatty acids (linoleic acid, 6.4 min; oleic acid, 6.5 min; palmitic acid, 7.5 min). Thus in contrast to LCT, MCT are only found in triglyceride-rich lipoproteins (d〈1.006) and are also eliminated more rapidly.
    Notes: Zusammenfassung Eine Fettemulsion mit 20% Fett aus mittelkettigen Triglyceriden (MCT) und langkettigen Triglyceriden (LCT) (1∶1) wurde als Bolus in einer Menge von 0,2 g Fett pro kg Körpergewicht bei 6 Patienten 3–5 Tage nach einem schweren Unfall injiziert. Die Triglyceridkonzentrationen stiegen innerhalb von 2 Minuten in den Lipoproteinfraktionen d〈0,95 g/ml (Chylomikronen), d〈1,006 g/ ml (VLDL), d〈1,063 g/ml (LDL) und d〈1,21 g/ml (HDL) an. 60 Minuten nach der Injektion hatten die Triglyceridkonzentrationen bereits wieder in allen Lipoproteinfraktionen dsie Vorwerte erreicht. Die Cholesterinkonzentrationen änderten sich nicht. Entsprechend der Zusammensetzung der Fettemulsion nahm der Linolsäureanteil in den Triglyceriden aller Lipoproteinfraktionen zu, während Octansäure und Decansäure nur in den triglyceridreichen Lipoproteinen (d〈1,006) anstiegen. Die Halbwertszeiten der Elimination der Octansäure (3,3 min) und Decansäure (3,9 min) in den Triglyceriden der Lipoproteinfraktion d〈1,006 waren fast halb so kurz wie die der langkettigen Fettsäuren (Linolsäure, 6,4 min; Ölsäure, 6,5 min; Palmitinsäure, 7,5 min). Demzufolge findet man im Gegensatz zu den LCT die MCT nur in den triglyceridreichen Lipoproteinen (d〈1,006), und sie werden daraus auch rascher eliminiert.
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  • 175
    ISSN: 1436-6215
    Keywords: RBP secretion ; vitamin A ; carotenoids ; goat ; RBP-Sekretion ; Vitamin A ; Carotinoide ; Ziege
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Die Sekretion von retinolbindendem Protein (RBP) ins Blut von Ziegen wurde nach unterschiedlicher Verabreichung von Vitamin A (Retinylacetat), Β-Carotin und einer Mischung von pflanzlichen Carotinoiden untersucht. Die Zufuhr dieser Verbindungen — entweder in einer einzelnen hohen Dosis oder in der gleichen Menge gleichmäßig auf 4 Tagesdosen verteilt — führte zu einem deutlichen Anstieg der RBP-Sekretion. Diese Sekretion erfolgte in zwei Phasen, von denen eine früh und eine später einsetzte.
    Notes: Summary Studies were conducted on the secretion of retinol-binding protein (RBP) in blood of goats given different treatments of preformed vitamin A, Β-carotene and plant carotenoids. Administration of these sources either in a single massive dose or massive dose split into four equal doses, markedly increased the secretion of RBP in blood. The secretion of RBP in blood occurred at least in two phases, one at early periods and the other at later periods.
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    European journal of nutrition 28 (1989), S. 265-265 
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    Source: Springer Online Journal Archives 1860-2000
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    European journal of nutrition 28 (1989), S. 300-309 
    ISSN: 1436-6215
    Keywords: tobacco protein ; Arnes test ; micronucleus test ; chromosome aberration test ; SCE test ; Tabakprotein ; Ames-Test ; Mikrokerntest ; Chromosomenaberrationstest ; Schwesterstrangaustauschtest
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Tabakprotein wurde im Ames-Test und in drei In-vivo-Tests auf Mutagenität geprüft. In den Salmonellenstämmen TA 98 und TA 100 bewirkten Methanolextrakte des Tabakproteins und der Urin von Ratten, die mit Tabakprotein gefüttert waren, erhöhte Revertantenzahlen, nicht aber Fäzesextrakte. Im Mikrokerntest wurden durchgehend schwach positive Effekte des Tabakproteins in Chinesischen Hamstern und zwei Mäuse-Inzuchtstämmen erzielt, desgleichen im Chromosomenaberrationstest und im SCE-Test an Chinesischen Hamstern. Die in den analytischen Angaben des Tabakproteins ausgewiesenen Substanzen Nikotin, Chlorogensäure und Rutin wurden einzeln im Chromosomenaberrationstest geprüft. Dabei wurde das Nikotin als der verantwortliche Faktor oder einer der verantwortlichen Faktoren für die schwach positiven Testergebnisse erkannt.
    Notes: Summary Tobacco protein was assayed for mutagenicity using the Ames test and three in vivo tests. In the Salmonella strains TA 98 and TA 100 methanolic extracts of the tobacco protein and urine of rats fed tobacco protein exhibited increased revertant numbers, but extracts of feces did not. Using the micronucleus test throughout, weak mutagenic effects after feeding the tobacco protein were detected in Chinese hamsters and two inbred strains of mice, and again in Chinese hamsters when the chromosome aberration test and the SCE test were applied. The analytical specifications of the tobacco protein listed nicotine, chlorogenic acid and rutin as components. These were examined separately in a chromosome aberration test, and nicotine was discovered to be the factor or a factor responsible for the weak positive test results.
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    European journal of nutrition 28 (1989), S. 319-326 
    ISSN: 1436-6215
    Keywords: Tryptophanschädigung ; Tryptophangehalt im Brot ; Tryptophangehalt im Keks ; tryptophan degradation ; tryptophan content inbread ; tryptophan content incookie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary The change of tryptophan contents in proteins of bread and cookies under technological processing conditions were investigated. Tryptophan contents in all cookie samples were noted to be significantly (p=0.05) reduced in relation to corresponding dough. The relative decreases are significantly correlated with fat content and the degree of unsaturation of fats in the dough of cookies (r=0.802 and r=0.777, p=0.01), independently of various physical parameters during different cookie samples' processing. Tryptophan decrease in proteins of bread during baking was not significant.
    Notes: Zusammenfassung Es wurde der Einfluß des technologischen Herstellungsprozesses auf die Gehaltsveränderung von Tryptophan in Brot- und Kekseiweißen untersucht. Es wurde eine signifikante (p=0,05) Tryptophanabnahme bei dem Backen der verschiedenen Keksarten festgestellt. Diese Abnahme korreliert linear mit dem Lipidgehalt und dem Gehalt an ungesättigten Fettsäuren der entsprechenden Keksteige (r=0,802 bzw. r=0,777 bei p=0,01), unabhängig von bedeutenden Schwankungen der physikalischen Parameter im Produktionsprozeß der verschiedenen Keksarten. Bei Brot blieb der Tryptophangehalt während des Backens praktisch unverändert.
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    European journal of nutrition 28 (1989), S. 345-345 
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    European journal of nutrition 28 (1989), S. 263-264 
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    European journal of nutrition 28 (1989), S. 240-259 
    ISSN: 1436-6215
    Keywords: Data analysis ; health status ; food pattern ; nutrition behavior ; research strategy ; Gesundheitsstatus ; Ernährungsverhalten ; Forschungsstrategie ; Datenanalyse ; Nahrungsmuster ; Ernährungsepidemiologie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Die Beziehungen zwischen Ernährungsfaktoren und Gesundheit in epidemiologischen Studien sind oft inkonsistent. Eine der möglichen Ursachen für diese Gegebenheit kann darin liegen, daß die Vielzahl der potentiellen Ernährungsdimensionen in der spezifischen Untersuchungssituation in unzulänglichem Maße berücksichtigt wurden. Solche Dimensionsbereiche sind vor allem die physiologische Individualität von Menschen, deren verschiedenen Lebensumwelten und die zahlreichen Interdependenzen zwischen Ernährungsvariablen. Diese Tatsachen sollten in ernährungsepidemiologischen Studien dadurch besser erfaßt werden, daß sowohl die Studienmodelle als auch die Datenanalysen entsprechend ausgerichtet werden. Anstelle von Untersuchungen an heterogenen Stichproben ist es ratsam, sich auf spezifische „Typen“ zu konzentrieren, wobei gemäß dem jeweiligen Studienziel solche „Typen“ aus den physiologischen Besonderheiten (z. B. Cholesterinempfindlichkeit), aus biologisch-konstitutionellen Faktoren (z. B. Körperbau-Typus), aus Lebensstil-Eigenschaften oder anderen Faktorenbereichen abgeleitet werden können. Die Variationsbreite der Ernährungsfaktoren geht über die üblicherweise verwendeten Nährstoffdimensionen hinaus, doch sie läßt sich durch integrierte Indizes — die „Nahrungsmuster“ — zusammenfassen. Zu solchen „Nahrungsmustern“ kann man auf verschiedene Weise kommen. Sie können aus Theorien abgeleitet werden und zu bestimmten Bewertungsrastern führen. Man kann sie aber auch mittels multivariater statistischer Analyse suchen. Die prinzipiellen Wege, die zu „Nahrungsmustern“ führen, werden dargestellt und diskutiert. Die hier vorgestellten und diskutierten Ideen leiten zu einem verbesserten Untersuchungsmodell für ernährungsepidemiologische Studien über. Die „Nahrungsmuster“ nehmen dabei eine wichtige Position ein. Man kann annehmen, daß durch diesen Untersuchungsansatz neue Erkenntnisse über die Beziehungen zwischen Ernährung und Gesundheit sichtbar werden, die helfen, den bisher noch diffusen Untersuchungsbereichen klare Konturen zu geben.
    Notes: Summary The relation between nutritional factors and health investigated in epidemiological studies are often inconsistent. One of the reasons for such findings can be the improper addressing of the multitude of nutritional dimensions in the specific study situation such as physiological individuality of human beings, different living conditions, or numerous interdependencies between nutritional variables. Epidemiological research in nutrition and health should recognize such facts and work with appropiate study models and adequate data analyses. Instead of investigating heterogenous populations it is advisable to concentrate on specific “types” of people. Under consideration of the study goals such “types” can be compiled according to physiological properties, e.g., cholesterol sensitivity, or biological-constitutional factors such as body build, life-style entities, or other factors. The variety of nutrition factors far beyond the commonly applied nutrient values can be expressed in integrated indices of “food patterns”. Such “food patterns” can be derived in many ways. They can be deduced from theories by using specific criteria, but also explored by modern multivariate statistical analyses. The ways leading to “food patterns” are discussed. The ideas presented and discussed in this paper lead to an improved model for research in the field of nutrition and health with integrated indices of “food patterns” as the critical point. It is assumed that using this approach will generate new insight in the relation of nutrition and health, a currently still diffuse research area.
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  • 182
    ISSN: 1436-6215
    Keywords: dietarycalcium ; dietarymagnesium ; dietaryphosphorus ; serumcholesterol ; livercholesterol ; fecalbile acids ; rats ; Calcium ; Magnesium ; Phosphor ; Serumcholesterin ; Lebercholesterin ; Gallensäure im Kot ; Ratten
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Während 28 Tagen wurden an Ratten cholesterinfreie halbgereinigte Diäten, die verschiedene Konzentrationen von Calcium (0,13–0,75 g/100 g), Magnesium (0,02–0,04 g/100 g) oder Phosphor (0,2–0,8 g/100 g) enthielten, verabreicht. Die unterschiedlichen Mineralkonzentrationen hatten keinen Einfluß auf Serum- und Lebercholesterin oder die Ausscheidung von Gallensäuren im Kot.
    Notes: Summary Female rats were fed cholesterol-free, purified diets with different concentrations of calcium (0.13–0.75%, w/w), magnesium (0.02 or 0.04%) or phosphorus (0.2–0.8 %) as the only dietary variable. After 28 days, no effects of the minerals were found on liver cholesterol concentrations and rates of fecal excretion of bile acids.
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  • 183
    ISSN: 1436-6215
    Keywords: Meerschweinchen ; Ascorbinsäure ; Adaption im Stoffwechsel ; Vitamin C ; guinea pigs ; adaptation inascorbic acid metabolism ; blood ; liver ; spleen ; adrenal glands
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Eine Substitution mit 5 mg/100 g Vitamin C im Futter stellt für Meerschweinchen anscheinend die untere Grenze dar, um ein Überleben zu ermöglichen. Sie scheinen keine Möglichkeit zu haben, den Stoffwechsel der Ascorbinsäure an diese niedrige Substitution zu adaptieren. Meerschweinchen, die über lange Zeit (6–8 Wochen) 20 mg/100 g oder 680 mg/100 g Vitamin C im Futter erhalten hatten, zeigen, nachdem der Vitamin-C-Gehalt im Futter drastisch verändert worden ist, bei den Ascorbinsäurespiegeln mehrerer Organe das für eine ablaufende Adaptation typische Überbzw. Unterschwingen.
    Notes: Summary Guinea pigs supplied with 5 mg/100 g vitamin in the food seem to be at the marginal substitution for a survival and show no ability to adapt the ascorbic acid metabolism to this low support. Guinea pigs longlastingly (6–8 weeks) supplied with 20 mg/100g or 680 mg/100g vitamin C in the food show the typical symptoms of an evolving adaptation by an overshooting in the course of the ascorbic acid levels in several organs after a switch to an extremely different vitamin C supply.
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    OR spectrum 11 (1989), S. 1-2 
    ISSN: 1436-6304
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    Topics: Mathematics , Economics
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    OR spectrum 11 (1989), S. 42-42 
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    Topics: Mathematics , Economics
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    OR spectrum 11 (1989), S. 3-16 
    ISSN: 1436-6304
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Economics
    Description / Table of Contents: Zusammenfassung In diesem Beitrag wird ein Überblick über heuristische, prioritätsregelgestützte Auftragsreihenfolgeplanung gegeben. Prioritätsregeln sind in den letzten 30 Jahren eingehend anhand von Simulations-Experimenten untersucht worden. Sie haben ebenso in Programmsysteme zur Produktionsplanung und-steuerung Eingang gefunden. Der Beitrag bemüht sich um eine Klassifizierung, Charakterisierung und Beurteilung von elementaren Prioritätsregeln. Abschließend werden einige prioritätsregelrelevante Modellerweiterungen angeschnitten.
    Notes: Summary In this paper, we survey the literature on heuristic priority rule-based job shop scheduling. Priority rules have been intensively investigated over the last 30 years by means of simulation experiments. They are also used in Shop Floor Control software systems. We present a classification, a characterization, and an evaluation of elementary priority rules. Some priority rule-related model extensions are discussed.
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    OR spectrum 11 (1989), S. 17-24 
    ISSN: 1436-6304
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    Topics: Mathematics , Economics
    Description / Table of Contents: Zusammenfassung Betrachtet wird das Problem der Fahrplangestaltung im öffentlichen (Personen-)Nahverkehr mit dem Ziel der Minimierung der Summe der Wartezeiten für Umsteiger. Es werden heuristische Lösungsverfahren (Regret-Methoden, Verbesserungsverfahren, Simulated Annealing) sowie ein Branch-and- Bound-Algorithmus beschrieben. Die Verfahren wurden u. a. anhand von Daten aus der Praxis getestet.
    Notes: Summary The problem of minimizing waiting times of passengers who want to change communication routes at transfer stations is considered. The paper contains heuristics (regret-methods, improvement algorithms, simulated annealing) as well as a branch and boundalgorithm and provides computational results, some of them gained with practical data.
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    OR spectrum 11 (1989), S. 48-48 
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    OR spectrum 11 (1989), S. 25-41 
    ISSN: 1436-6304
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    Topics: Mathematics , Economics
    Description / Table of Contents: Summary A model is set up to simulate commercial flights in 4-D-mode. Basic data are standard flight tracks of German domestic flights; altitudes included range up to flightlevel FL 300. For simulation runs, flight times profiles are derived both from real flights and departure times respectively fly-over times of the Berlin gates. Aircraft movements are simulated with respect to airways, departure and arrival routes, air traffic control areas, starts and landings. Conflicts arise in the case of too short distances to other aircraft. They are solved dependently on flight attitude, e.g. en route state by changing the flight level, or by holding procedures if an aircraft cannot be sequenced for final approach. The simulation is carried out for 465 domestic flights per day. Some results and an outlook on suitable applications are given.
    Notes: Zusammenfassung Grundlagen des symbolischen Modells zur Simulation der Flugbewegungen in Zeit und Raum sind Standardrouten sowie Flughöhen bis FL 300. Flugzeiten und Flugprofile werden aus realen Flugeinsätzen abgeleitet. Die Nachbildung erfolgt in Luftstraßen, An- und Abflugrouten, CTA- und FIR-Gebieten sowie für Starts und Landungen. Vor jedem LFZ wird in Flugrichtung ein Sicherheitsbereich eingerichtet, dessen Unterschreitung durch andere LFZ Konflikte verursacht. Konfliktlösungen erfolgen unterschiedlich nach Flugzuständen, z. B. durch Flugflächenwechsel (Reiseflug) oder Warterunden (Platzanflug), falls ein LFZ zum Endanflug nicht in eine Landekette eingereiht werden kann. Die Simulation erfolgt für 465 Flüge eines Tages im nationalen Verkehr. Es werden einige Ergebnisse angegeben, ferner ein Ausblick auf mögliche Anwendungen des Modells.
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    OR spectrum 11 (1989), S. 43-47 
    ISSN: 1436-6304
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    Topics: Mathematics , Economics
    Description / Table of Contents: Zusammenfassung Die Klasse von sogenannten lexicographisch monotonen Verhandlungslösungen für Verhandlungsprobleme mit zwei Spielem wird in mehreren Weisen charakterisiert. Diese Lösungen sind nichtsymmetrische Verallgemeinerungen der lexicographisch egalitaren Lösung. In dieser Charakterisierung wird Monotonie der Lösung erfordert nur wenn der Lösungspunkt nicht ein Endpunkt der Pareto optimalen Menge ist. Diese Kondition wird interpretiert als Natürlichkeit oder Zwangslosigkeit der Übereinstimmung zwischen den Spielern.
    Notes: Summary The family of 2-person bargaining solutions called Lexicographic monotone path solutions — which are nonsymmetric generalizations of the lexicographic egalitarian solution — is characterized in several ways. Central in these characterizations is an interiority condition first introduced in [1] in order to characterize then-person lexicographic egalitarian solution. This condition means that a monotonicity property is required to hold only if the agreement is an interior Pareto optimal point, the interpretation being that in that case the agreement is “natural” or “unforced”.
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    OR spectrum 11 (1989), S. 63-63 
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    OR spectrum 11 (1989), S. 64-64 
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  • 193
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    Topics: Mathematics , Economics
    Description / Table of Contents: Summary The purpose of this article is twofold. In the first place it serves as an introduction the using of the simultaneous equations method as compare with step method of cost allocation in computer centre. The model is based on the principle that no expense any service department should be distributed unless all of its expenses, including services received from other service departments, are included. Using the simultaneous equations method, ratios for distributing expenses of service departments to production departments are established which take into consideration the interaction between and among the various service departments. In the second place, to illustrate the formulating a description of a problem in terms of mathematical equations and interpreting the results.
    Notes: Zusammenfassung Der Artikel verfolgt zwei Ziele. Zum einen wird der Gebrauch simultaner Gleichungsrechnungen in der innerbetrieblichen Leistungsverrechnung im Vergleich zur sukzessiven Kostenauflösung nach der Zuschlagmethode demonstriert. Es werden Leistungsaustauschvorgänge zwischen produzierenden und/oder verwaltenden Stellen aufgezeigt. Zum anderen wird die Lösung und die Interpretation der Ergebnisse gezeigt.
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    OR spectrum 11 (1989), S. 64-64 
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    OR spectrum 11 (1989), S. 65-66 
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    OR spectrum 11 (1989), S. 96-96 
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    OR spectrum 11 (1989), S. 83-88 
    ISSN: 1436-6304
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Economics
    Description / Table of Contents: Zusammenfassung Eine Verallgemeinerung von Fluß-spielen, nämlich solchen mit Komitee-Kontrolle, wird in der vorliegenden Arbeit betrachtet, um eine Darstellung nicht-negativer ausgewogener Spiele zu erhalten. Die Komitee-Kontrolle wird mit Hilfe einfacher Spiele modelliert. Ebenso werden lineare Produktionsspiele mit Komitee-Kontrolle untersucht, und Ergebnisse zur Ausgewogenheit solcher Spiele werden hergeleitet.
    Notes: Summary A generalization of flow games, namely, flow games with committee control is considered, to obtain a representation of non-negative balanced games. The committee control is modeled with the aid of simple games. Linear production games with committee control are also studied and results on the balancedness of such games are obtained.
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    OR spectrum 11 (1989), S. 89-95 
    ISSN: 1436-6304
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Economics
    Description / Table of Contents: Zusammenfassung Ein Fahrzeuggetriebe läßt sich als System modellieren, dessen Zustände (= Gänge) einen Markov-Prozeß darstellen. Jeder Gang benützt eine charakteristische Untermenge von Komponenten (= Zahnräder usw.). Die Ausfallrate jeder Komponente wächst linear mit der zurückgelegten Betriebszeit. Der erste Ausfall einer im Einsatz befindlichen Komponente führt zum Ausfall des Getriebes. Für die Überlebensfunktion werden Konvergenzresultate und Schranken angegeben. Mittelwert und Varianz der Systemlebensdauer streben mit fallenden Ausfallraten gegen die entsprechenden Werte einer Rayleighverteilung. Die bedingten Wahrscheinlichkeiten einer Komponente, einen Defekt nach Überleben der Zeitspanne τ zu verursachen, streben asymptotisch mit τ gegen die mittleren, stationären relativen Schadensakkumulationsraten. Ein Schätzverfahren für die Modellparameter bei gegebener stationärer Verteilung des Markov-Prozesses schließt die Untersuchung ab.
    Notes: Summary A vehicle transmission box is modeled as a system, whose operating states (= speeds) perform a Markov-process. Every speed uses its own subset of components (= gears etc.). The failure rate of a component increases linearly with its accumulated operating time. The first failure of a gear causes system failure. Asymptotic results and bounds are given for the system survival function. Mean value and variance of the system lifetime tend towards their counterparts in case of a Rayleigh distribution, as component failure rates converge towards 0. The conditional posterior culprit probabilities, i.e. the probabilities to cause a system failure, given survival of a time span τ, converge asymptotically towards the stationary expected relative damage accumulation rates as τ increases. Estimators for the model parameters are given for a known stationary distribution of the Markov-process.
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    OR spectrum 11 (1989), S. 101-110 
    ISSN: 1436-6304
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    Topics: Mathematics , Economics
    Description / Table of Contents: Zusammenfassung In dieser Arbeit wird ein mathematisches Modell zur Optimierung der Entladestrategie für Schiffe vorgestellt, die Schuttgüter transportieren. Unter Verwendung der Ergebnisse einer vorherigen Arbeit, die sich mit Entladeoperationen einer einzelnen Luke befaßte, wird hier die Minimierung der gesamten Entladezeit angestrebt, wobei Ablaufplanungsalgorithmen benutzt werden, die auf einer simplen Prioritätsregel basieren. Zur Validierung dieses heuristischen Ansatzes wird ebenfalls ein gemischt-ganzzahliges Optimierungsmodell eingeführt, welches Untergrenzen für die Entladezeit liefert durch Lockerung einzelner Ganzzahligkeitsrestriktionen.
    Notes: Summary A mathematical model for the optimization of the unloading strategy for ships transporting bulk goods will be presented in this paper. Using the results of a previous paper concerning the unloading operation of a single hatch, the minimization of the overall unloading time is striven for by using scheduling algorithms based on a simple priority rule. For validation of this heuristic approach a mixed-integer optimization model will also be introduced, which delivers lower bounds for the unloading time by relaxing some of the integrality constraints.
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    OR spectrum 11 (1989), S. 113-113 
    ISSN: 1436-6304
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    Topics: Mathematics , Economics
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