Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 2000-2004
  • 1990-1994  (2)
  • 1935-1939
  • 1905-1909
  • B-form representations associated with irregular triangles  (1)
  • Host-plant preference  (1)
  • 1
    ISSN: 1432-1939
    Keywords: Herbivore performance ; Host phenology ; Host-plant preference ; Phyllonorycter ; Populus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Larvae of the aspen blotch miner, Phyllonorycter salicifoliella Chambers (Lepidoptera: Gracillariidae), feed within leaves of three host-tree species in north-central Minnesota, USA. Far more individuals occur on Populus tremuloides than on P. balsamifera or P. grandidentata. We tested whether this pattern of host use reflected variable performance among alternative hosts by examining survivorship, sources of mortality, pupal mass, feeding efficiency, and development time of miners on each tree species. We also determined foliar water, nitrogen, condensed tannin, and phenolic glycoside content of host trees to test if host-tree chemical attributes were responsible for differences in performance. There was no significant difference in egg-to-adult survival among miners on different hosts, although dominant sources of mortality did vary. Miners on P. grandidentata suffered less parasitism and more predation than those on the other hosts, even though most parasitoid species attacked miners on all hosts. The other performance parameters varied among host species, but not in a consistent pattern. Pupal mass was greatest on P. tremuloides and P. balsamifera, the hosts with comparatively high foliar nitrogen and low phenolic glycoside concentrations. However, feeding efficiency was greatest and development time shortest for miners on P. grandidentata. Thus, pupal mass was the only index of performance maximized on P. tremuloides, the most commonly used host. Infrequent occurrence of Phyllonorycter salicifoliella on P. grandidentata results in part from phenological differences between this and the other host species. Low oviposition rates on P. balsamifera are correlated with low abundance of this host at the study site and a phenolic glycoside profile different from that of the other host species.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Mathematical geology 22 (1990), S. 723-742 
    ISSN: 1573-8868
    Keywords: constrained Delaunay triangulation ; interpolation ; approximation ; B-form representations associated with irregular triangles ; simplex splines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Mathematics
    Notes: Abstract In the practice of administrative or engineering geosciences, the problem of deriving a digital surface representation from a map displaying contour lines of the interesting quantity is quite often encountered. First, alpha-numerical data are retrieved from the map by digitizing these contour lines pointwise into polygons. However, common “gridding” algorithms are known to fail at adequately reproducing the input contour lines due to the inhomogeneous and anisotropic areal distribution of the sites of the data sampled from given contour lines. Therefore, we suggest a new algorithm; the basic elements of its first stage are a constrained Delaunay triangulation of the data sites honoring their natural neighborhood relationship—i.e., whether they belong to the same contour line or not, and linear interpolation according to this triangulation of the data domain. In a second stage, a Bezier-Bernstein or simplex B-spline representation is easily achieved if a C1 or C2 smooth representation is required. At this stage, also, discontinuities of the function or its first directional derivatives with known locations in the data domain may be represented, provided this additional information has been taken into account when the triangulation was performed. The algorithm is numerically stable and efficient, and allows external interaction by the user to introduce his/her additional knowledge of the phenomenon to be studied, which may not be explicitly inherent in the available data.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...