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  • 1
    Electronic Resource
    Electronic Resource
    Long-term dynamics of a predator used for biological control and decoupling from mosquito prey in a subtropical treehole ecosystem (1997)
    Springer
    Oecologia 111 (1997), S. 189-200 
    Details
    ISSN: 1432-1939
    Keywords: Key wordsAedes ; Extinction ; Long-term censuses ; Seasonality ; Weights
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We identified, staged and counted the immature stages of mosquitoes from 1,826 censuses (with replacement) of the aquatic contents of ten treeholes surveyed every 2 weeks between 1978 and 1993. These time series were used to examine the population dynamics and effect on prey of the predatory mosquito Toxorhynchites rutilus. The mean annual frequency of occurrence of T. rutilus ranged from 0.02 to 0.67 among holes, and no fourth instars were recovered during a 30-month dry period. Oviposition and pupation by this species were recorded in all months, but most commonly in the spring. Overwintering larvae of the predator increased in weight during the prolonged fourth instar that preceded pupation in the spring. Time series analyses showed that the presence of a fourth instar T. rutilus significantly reduced the abundances of late-stage Aedes triseriatus mosquitoes. Pupal numbers of this prey species were more negatively affected by T. rutilus than were numbers of fourth instar A. triseriatus. Long-term declines in mean annual abundance of A. triseriatus prey during 16 years of observations on two holes were not correlated with increases in the mean annual frequencies of T. rutilus. Local extinctions of the aquatic stages of A. triseriatus within treeholes were common, but in most holes not significantly associated with the presence of T. rutilus, suggesting that predation does not routinely drive mosquito prey locally extinct in this ecosystem. The decoupling of T. rutilus and A. triseriatus, as revealed through these complete and long-term censuses, is contrasted with other reports of generalist predators causing extinctions of mosquito prey. Discrepancies among reported outcomes probably result from differences in duration of sampling periods and statistical procedures along with real differences in the intensity of predation among systems and sites.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004420050225
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  • 2
    Electronic Resource
    Electronic Resource
    Finding Largest Subtrees and Smallest Supertrees (1998)
    Springer
    Algorithmica 21 (1998), S. 183-210 
    Details
    ISSN: 1432-0541
    Keywords: Key words. Subgraph isomorphism, Topological embedding, Largest common subtree, Smallest common supertree.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mathematics
    Notes: Abstract. As trees are used in a wide variety of application areas, the comparison of trees arises in many guises. Here we consider two generalizations of classical tree pattern matching, which consists of determining if one tree is isomorphic to a subgraph of another. For the embedding problems of subgraph isomorphism and topological embedding, we present algorithms for determining a largest tree embeddable in two trees T and T' (or a largest subtree) and a smallest tree in which each of T and T' can be embedded (or a smallest supertree). Both subtrees and supertrees can be used in a variety of different applications. For example, when each of the two trees contains partial information about a data set, such as the evolution of a set of species, the subtree or supertree corresponds to a structuring of the data in a manner consistent with both original trees. The size of a subtree or supertree of two trees can also be used to measure the similarity between two arrangements of data, whether images, documents, or RNA secondary structures. In this paper we present a general paradigm for sequential and parallel subtree and supertree algorithms for subgraph isomorphism and topological embedding. Our sequential algorithms run in time O(n 2.5 log n) and our parallel algorithms in time O(log 3 n) on a randomized crew pram using a polynomial number of processors. In addition, we produce better algorithms for these problems when the underlying trees are ordered, that is, when the children of each node have a left-to-right ordering associated with them. In particular, we obtain O(n 2 ) -time sequential algorithms and O(log 3 n) -time deterministic parallel algorithms on crew prams for both embeddings.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00009212
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  • 3
    Electronic Resource
    Electronic Resource
    In vivo absorbance spectra and the ecophysiology of reef macroalgae (1997)
    Springer
    Coral reefs 16 (1997), S. 21-28 
    Details
    ISSN: 1432-0975
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract.  In vivo absorbance spectra were obtained for 12 species of tropical macroalgae. Absorbance of UV irradiance was greater than absorbance of photosynthetically active radiation in most algal taxa. UV irradiance may be pre-emptively captured by UV absorbing compounds as indicated by the significant relationship between in vivo and extract absorbance characteristics. In vivo and extract absorbance characteristics indicated that concentrations of UV absorbing compounds were highest among rhodophytes. Additionally, a marked consistency was observed in the visible spectral region, 400 to 750 nm, for in vivo absorbance and fourth derivative maxima for species within specific taxonomic divisions. For Gracilaria salicornia, pigment and photosynthetic performance acclimation paralleled the sun to shade irradiance gradient established by its mat-like morphology. Regression relationships of in vivo absorbance for phycoerythrin and carotenoid-specific maxima with I k , I c , and P max were significant and may have utility in modeling algal photosynthetic parameters.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003380050055
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  • 4
    Electronic Resource
    Electronic Resource
    Slow positron study on dielectric-coated mirror for free-electron-laser experiments (1996)
    Springer
    Journal of radioanalytical and nuclear chemistry 211 (1996), S. 47-52 
    Details
    ISSN: 1588-2780
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract A positron lifetime study has been done on dielectric multilayer cavity mirrors for free-electron-laser experiments by the use of a variable-energy pulsed positron beam. A long-lived ortho-positronium component has been observed at low positron energy region, corresponding to the depth of the top amorphous SiO2 layer. The intensity of the positronium component correlates with the degradation and restoration of the mirrors. We discuss the relation between the positronium intensity and degradation mechanism of the mirrors. The present studies revealed that the slow positron lifetime technique is highly sensitive to the properties of the mirrors and is useful for the evaluation of the mirrors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02036254
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  • 5
    Electronic Resource
    Electronic Resource
    Effect of microstructure of titanium surface on the behaviour of osteogenic cell line MC3T3-E1 (1998)
    Springer
    Journal of materials science 9 (1998), S. 99-102 
    Details
    ISSN: 1573-4838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract Three different microstructures were obtained on a titanium surface via immersion in HCl, H3PO4, or mixed acid of HNO3 and HF (HNO3/HF) solution. The microstructure and Rmax of the acid-treated surfaces were dependent on the acid type and immersion conditions. The growth rate of the osteogenic cell line MC3T3-E1 on each acid-treated sample, which was measured using MTT-formazan assay, was significantly higher than that of the standard which was ground with #400 SiC grit paper. Moreover, both the H3PO4 treated sample and the HNO3/HF-treated surface showed a tendency to enhance the alkaline phosphatase activity of MC3T3-E1 cells, which were grown on each acid-treated surface. These results suggest that the acid treatment of titanium is effective for the improvement of its osteocompatibility. © 1998 Chapman & Hall
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008851115846
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  • 6
    Electronic Resource
    Electronic Resource
    Canopy gap formation and replacement pattern of major tree species among developmental stages of beech (Fagus crenata) stands, Japan (1999)
    Springer
    Plant ecology 140 (1999), S. 167-176 
    Details
    ISSN: 1573-5052
    Keywords: Gap dynamics ; Old growth stands ; Primary stands ; Regeneration behavior ; Stand development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Gap characteristics and gap phase replacement of major tree species were examined in two primary old-growth (mean DBHs of the canopy trees were 45.2 and 56.1 cm) and four secondary developing (range of mean DBH of the canopy trees was 23.5–39.9 cm) beech (Fagus crenata) stands in the Daisen Forest Reserve, southwestern Japan, and these were analyzed in relation to stand development as expressed by the difference of mean DBH of canopy trees. Percentage gap area (percentage of total gap area to total surveyed area) and mean and maximum gap size varied widely and ranged from 1.7 to 20.0%, from 19.4 to 162.8 m2, and from 35.7 to 585.1 m2, respectively. Mean percentage gap area and mean gap size were significantly greater in old-growth than in developing stands. However, they and maximum gap size might not increase linearly with stand development, and the gap feature of less developed stands was greater than that of later stages in developing stands. The cause was a higher formation rate, in younger developing stands, of gaps formed by simultaneous death (multiple trees falling down in domino fashion) which tends to produce larger gaps. In developing stands mean DBH of gapmakers (canopy trees that formed a gap) was smaller than that of canopy trees, though the inverse trend might be found in old-growth stands. Three typical types of death or injury states of gapmakers such as standing dead, trunk broken and uprooted were found in every study stand and the difference in stand development may not cause stand-to-stand variations for them. Importance of F. crenata (the most dominant species) in the canopy layer increased and its importance in the understory layer decreased with stand development. Shade-intolerant Quercus mongolica in the canopy layer was more important in younger than in old-growth stands, and there was no Quercus regeneration in old-growth stands. Acer mono consistently appeared, though in much less abundance than other species, in both canopy and understory layers of all study stands. Sub-canopy layers, which are mainly formed by sub-canopy tree species such as Acanthopanax sciadophylloides and Acer japonicum, may gradually develop with stand development.p〉
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009713002039
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