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  • Springer  (18)
  • Wiley  (7)
  • Wiley-Blackwell  (2)
  • 1985-1989  (15)
  • 1980-1984  (12)
  • 1
    Electronic Resource
    Electronic Resource
    Effects of seed size on seedling size in Virola surinamensis; a within and between tree analysis (1982)
    Springer
    Oecologia 53 (1982), S. 347-351 
    Details
    ISSN: 1432-1939
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We conducted a greenhouse study of the effects of initial seed mass on seedling characteristics in a Panamanian population of Virola surinamensis, a canopy tree in which mean seed mass of different individuals ranges from 1.34 to 4.04g. The system is of particular interest because birds preferentially eat fruits of small-seeded plants, leaving seedlings of large-seeded individuals under conditions of potentially severe sibling competition (Howe and Vande Kerckhove 1980). Effects of differences of mean seed mass between trees are explored using an analysis of variance, while effects of seed-mass variation within crops are demonstrated with a regression analysis. A two-way analysis of variance decisively shows effects of parental source and light condition on seedling height, leaf length, and dry shoot mass (all P〈0.0001). A posteriori tests show that differences in seedling characteristics reflect differences in initial seed mass, with especially strong differences apparent in shoot mass. Regression of seedling characteristics on initial seed mass shows that variation of seed size within a crop is sufficient to influence shoot mass at 15 weeks (P〈0.0001). Effects of size differences of seeds that land adjacent to each other, either under the parent or in monkey droppings, are documented with growth of pairs of seedlings in pots. Differences in shoot height and mass at 15 weeks are evident when seeds of average size differ by only 0.2 g, and dramatic differences are evident when paired seeds differ by an average of 1.5 g. Seedlings grow more when isolated than when planted with conspecifics. These experimental results offer indirect support for the hypothesis that small-seeded Virola parents secure an advantage in reproduction through differential dispersal, while large-seeded plants produce more competitive seedlings under their own crowns — an advantage most likely to be of importance when frugivores are scarce.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00389011
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  • 2
    Electronic Resource
    Electronic Resource
    Conditioning honeybees to discriminate between heritable odors from full and half sisters (1986)
    Springer
    Journal of comparative physiology 159 (1986), S. 251-256 
    Details
    ISSN: 1432-1351
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Differential conditioning of the proboscis extension reflex in honeybees is used to assess whether worker honeybees can be trained to discriminate between volatile odors emanating from different kin groups consisting of 2 or 20 workers. These odor source group workers are all reared and maintained under identical environmental conditions. They are the progeny of a queen that has been instrumentally inseminated so that eclosing adult workers can be sorted into colormorph full sister patrilines (workers are half sisters across patrilines). We demonstrate that workers are able to discriminate between the odors from groups of 20 individuals only if the groups represent individuals from different patrilines. However, discrimination occurs between groups of 2 individuals even if groups do not represent different patrilines. A number of environmental control experiments are also conducted. From our results we infer that there is heritable variation in the production of volatile odors by worker honeybees at a level that can be detected by the workers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00612307
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  • 3
    Electronic Resource
    Electronic Resource
    Olfactory sensitivity and discrimination of mixtures in the honeybeeApis mellifera (1987)
    Springer
    Journal of comparative physiology 160 (1987), S. 239-245 
    Details
    ISSN: 1432-1351
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The work reported here is motivated by questions relating to the perception of olfactory cues in the discrimination of nestmates and kin in the honeybeeApis mellifera. Two sets of experiments are discussed. The first deals with the perception of individual compounds in mixtures made up from various pairs of volatile (citral, geraniol, linalool, and limonene) and nonvolatile (un- and dodecanoic acids) compounds. The second deals with the ability of worker honeybees to discriminate between mixtures made up from the same two compounds (un- and dodecanoic acids; tri- and pentacosane) combined in different proportions. All experiments employ differential conditioning of the proboscis extension reflex as an assay of the ability of workers to discriminate between two odors. Results show that workers can relate mixtures to their component parts, and that workers can discriminate between mixtures of two very similar compounds as long as the proportions are relatively dissimilar.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00609729
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  • 4
    Electronic Resource
    Electronic Resource
    Isolation, characterization and sequence analysis of a full-length cDNA clone encoding NADH-dependent hydroxypyruvate reductase from cucumber (1989)
    Springer
    Plant molecular biology 13 (1989), S. 139-150 
    Details
    ISSN: 1573-5028
    Keywords: cDNA ; gene expression ; hydroxypyruvate reductase ; light regulation ; peroxisomal enzyme
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A full-length cDNA encoding NADH-dependent hydroxypyruvate reductase (HPR), a photorespiratory enzyme localized in leaf peroxisomes, was isolated from a λgt11 cDNA library made by reverse transcription of poly(A)+ RNA from cucumber cotyledons. In vitro transcription and translation of this clone yielded a major polypeptide which was identical in size, 43 kDA, to the product of in vitro translation of cotyledonary poly(A)+ RNA and subsequent immunoprecipitation with HPR antiserum. Escherichia coli cultures transformed with a plasmid construct containing the cDNA insert were induced to express HPR enzyme activity. RNA blot analysis showed that HPR transcript levels rise significantly in the first eight days of light-grown seedling development. This closely resembles the pattern seen for HPR-specific translatable mRNA. DNA blot analysis indicated that a single HPR gene is likely present per haploid genome. Nucleotide sequence analysis revealed an open reading frame of 1146 bases which encodes a polypeptide with a calculated molecular weight of 41.7 kDa. The derived amino acid sequence from this open reading frame is 26% identical and 50% similar to the amino acid sequence of the E. coli enzyme phosphoglycerate dehydrogenase, which catalyzes a similar reaction and functions in a related pathway. Statistical analyses show that this similarity is significant (z〉10). The derived amino acid sequence for HPR also contains the characteristics of an NAD-binding domain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00016133
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  • 5
    Electronic Resource
    Electronic Resource
    Kin structure and the swarming behavior of the honey bee Apis mellifera (1982)
    Springer
    Behavioral ecology and sociobiology 10 (1982), S. 265-270 
    Details
    ISSN: 1432-0762
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Experimental hives obtained from cordovan queens that were instrumentally inseminated with semen from one cordovan and one Italian drone were set up and allowed to swarm. Cordovan provides a resessive genetic marker system (cuticle color) so that the workers from the cordovan and Italian male lines are distinguishable. Our results show that these patrilineal worker groups segregate non-randomly during colony fission and this segregation cannot be explained by observed age structure. Evidence of innate kin recognition in bees has been previously established. We argue that kin recognition could be responsible for the observed non-random grouping of kin during swarming.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00302815
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  • 6
    Electronic Resource
    Electronic Resource
    Evolutionarily stable dispersal of a waterstrider in a temporally and spatially heterogeneous environment (1989)
    Springer
    Evolutionary ecology 3 (1989), S. 283-298 
    Details
    ISSN: 1573-8477
    Keywords: Evolutionarily stable strategy ; risk-spreading ; dispersal behavior ; flight muscle histolysis ; waterstrider
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Evolutionary stable dispersal and wing muscle histolysis strategies are studied in the waterstriderGerris thoracicus. These strategies relate to spreading reproductive risk. Overwintering individuals have the choice of dispersing to either a brackish sea bay or a rock pool habitat. The former is reproductively more favorable than the latter during warm dry years and less favorable during cool wet years. After spring migration, individuals may histolyse their flight muscles and lay all their eggs in one pool or they may retain their flight ability and lay fewer eggs in total but spread them in several pools. We use a simple two-habitat model to examine the question of habitat dispersal. Our results indicate that, although the value of the evolutionary stable dispersal depends on the degree of variability in the environment and on the probability of local extinctions in either habitat, the population always disperses to both habitats as a consequence of density dependent growth. We use a more detailed multiple-rockpool habitat model to examine the question of wing muscle histolysis as a response to density dependence. Our results indicate that a wing muscle histolysis response to population density is an evolutionarily stable strategy when compared with the two alternatives of females always histolysing or never histolysing their flight muscles. The application of evolutionarily stable theory to stochastic problems presents a number of difficulties. We discuss these difficulties in the context of computing evolutionarily stable strategies for the problems at hand.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02285260
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  • 7
    Electronic Resource
    Electronic Resource
    Light-stimulated accumulation of the peroxisomal enzymes hydroxypyruvate reductase and serine:glyoxylate aminotransferase and their translatable mRNAs in cotyledons of cucumber seedlings (1987)
    Springer
    Plant molecular biology 9 (1987), S. 259-275 
    Details
    ISSN: 1573-5028
    Keywords: cucumber ; gene expression ; hydroxypyruvate reductase ; light regulation ; peroxisomal enzymes ; serine:glyoxylate aminotransferase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The development of peroxisomal enzymes in cotyledons of cucumber seedlings is strongly dependent on light. In light-grown seedlings, activities of two peroxisomal enzymes, hydroxypyruvate reductase (HPR) and serine: glyoxylate aminotransferase (SGAT), were barely detectable until three days postimbibition, after which time both activities increased rapidly and linearly for at least three days. In the dark, the activities of these enzymes increased slightly over the same time period, but only to about 5% to 10% of 7-day light-induced levels. When 51/2-day dark-grown seedlings were transferred into white light, activities of HPR and SGAT began to increase after approximately 8 h. HPR protein was shown by an immunoprecipitation assay to increase concurrently with enzymatic activity in both light- and dark-grown cotyledons. Immunoblotting results suggested that the amounts of SGAT-A and SGAT-B, the two subunits of SGAT, also developed along with SGAT activity. The relative levels of translatable mRNAs encoding HPR, SGAT-A, and SGAT-B were also light-dependent, and increased with a developmental pattern similar to enzyme activity and protein levels in light- and dark-grown cotyledons. In 51/2-day dark-grown cotyledons that were transferred to the light, translatable mRNAs for SGAT-A and SGAT-B began to increase within 1 h of illumination and continued of increase rapidly and linearly for the next 24 h in the light to a new steady-state level that was 45 times that of dark controls. Translatable HPR mRNA exhibited a biphasic pattern of accumulation, with a three-fold increase during the first 6 h of illumination, followed by an additional six-fold increase between 8 and 24 h. The accumulation of translationally active mRNA for both enzymes preceded the accumulation of the corresponding protein and enzyme activity by about 8 h. Our data suggest that the rise in enzyme activity depends on an increase in translatable mRNA for these enzymes and is regulated at a pretranslational level, most likely involving transcription of new mRNA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00166462
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  • 8
    Electronic Resource
    Electronic Resource
    Validity and reliability of biostereometric measurement of the human female breast (1986)
    Springer
    Annals of biomedical engineering 14 (1986), S. 1-14 
    Details
    ISSN: 1573-9686
    Keywords: Stereophotogrammetry ; Validity ; Reliability ; Breast volume
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract A measurement technique has been developed for application in the area of noninvasive breast cancer detection. The measurement process involves the use of closerange stereophotogrammetry as a data acquisition device necessary for determination of breast volume and volume distribution. This report details the methodology used to acquire and analyze stereopair photographs necessary to document the validity and reliability of this application. The volume of a test object was determined by both water displacement and stereophotogrammetric analysis to estimate the precision of the proposed methodology. Additionally, the reliability component of the study was documented by analyzing variability of coordinates representing a series of locations marked on the surface of an irregularly shaped object. Both tests confirm that this stereometric analysis is a reliable and valid method of measurement and may be well suited for further development in the field of breast cancer detection.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02364645
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  • 9
    Electronic Resource
    Electronic Resource
    Variability of chemosensory stimuli within honeybee (Apis mellifera) colonies: Differential conditioning assay for discrimination cues (1988)
    Springer
    Journal of chemical ecology 14 (1988), S. 253-264 
    Details
    ISSN: 1573-1561
    Keywords: Chemosensory cues ; olfaction ; kin recognition ; honeybees ; Apis mellifera ; Hymenoptera ; Apidae ; differential conditioning ; proboscis extension reflex ; learning
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Differential training of honeybee workers using the proboscis extension reflex is applied to the problem of evaluating compounds that may potentially provide cues for kin recognition in the honeybeeApis mellifera. These cues were obtained by contaminating glass rods and steel needles with different materials found in the hive. In particular it is shown that workers discriminate between: cuticular waxes from different adult workers; eggs from the same and different hives; similar aged larvae within the same hive; and needles contaminated with the Nasonov gland secretions of different adult workers. It appears that some of these differences are due to phenotypic variation among individuals that cannot be directly attributed to environmental factors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01022545
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  • 10
    Electronic Resource
    Electronic Resource
    Production and efficiency of protozoa (1980)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 22 (1980), S. 1415-1440 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Despite the chronic and debilitative nature of the infection they cause, several species of microsporidia and neogregarines offer a good potential as microbial control agents, particularly against insect pests of high economic thresholds. Techniques for mass production of protozoa have usually involved per os, inoculation or injection of the protozoa into their usual or alternate hosts. The spores are harvested subsequently from heavily infected host tissues by grinding, filtration, and differential centrifugation. Although fresh spores are used in most field tests, the spores of many species can be stored with high survival either frozen or in water at low temperatures (0-4°C) for up to several months. Sunlight or ultraviolet (UV) radiation is a serious factor limiting spore persistence. However, the protozoa do not appear to be significantly limiting spore persistence. However, the protozoa do not appears to be significantly more susceptible to UV radiation than other insect pathogens and persistence can be prolonged with UV protectants. Most field tests with protozoa have involved the application of spores in sprays and have usually resulted in a high degree of infection in the target host species. The potential for control of few species has been improved by formulation of spores in to baits, and the potential of other species will likely increase if suitable bait formulation can be devised in the future. One species, Nosema locustae, formulated as a bait, has been successfully used to control grasshoppers on rangelands. Limited laboratory and field studies have also suggested that increased short-term control might be obtained if candidate protozoan species can be combined with certain insecticides. While recent and increased efforts have been devoted to assess the potential of protozoa as microbial control agents, potential hazards to nontarget organism have been investigated for only three species. Their close relation taxonomically to protozoa pathogenic for mammals will necessitate careful evaluation of the safety of candidate control species for nontarget organisms.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260220709
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