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41.
L. P. Lefkovitch 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1985,70(6):585-589
Summary Significant genotype-environment interactions in an ANOVA can be found for a number of reasons: one is the differences in
the among-environments variances for each genotype, another is the differences in the ordering of the environments by each
genotype. Using conditional clustering, groups may be formed in which the means, variances and patterns are used simultaneously
but separately to decide on group homogeneity.
Contribution No. I-685 from the Engineering and Statistical Research Institute 相似文献
42.
Synopsis Aspects of the life history of Barbus anoplus were studied in Lake le Roux, a turbid man-made lake on the Orange River, South Africa. This minnow underwent a population
explosion and successfully colonized the shoreline of the newly-formed lake during the early phases of reservoir filling.
Male and female B. anoplus reach sexual maturity in one year at about 40 mm fork length. They have a multiple spawning habit with the first spawning
in November–January and the second in February–March. The growth of the two resulting cohorts is discussed. It is proposed
that the offspring from the second spawning not only acts as a ‘back-up’ but is capable of prolonging the life of that year-class
into an additional reproductive season. Most of the minnows die after their second summer, but more offspring from the second
spawning, especially females, live into a third summer. Females attain a larger maximum size (73 mm FL) and age (3–4 years)
than males (60 mm FL, 2–3 years). B. anoplus is small and short-lived with a high seasonal reproductive potential, which is in contrast to the larger Barbus species in the Orange River system. These life-history traits enable the species to colonize and successfully inhabit unstable
environments and probably account for its widespread distribution. 相似文献
43.
Multiple discriminant analysis is a useful multivariate technique in vegetation studies that can be employed for several purposes, even if the underlying statistical assumptions are not satisfied. An example of application of this method is discussed: multiple discriminant analysis was successfully used for evaluating the predictivity of forest types defined by numerical classification of vegetation data with respect to soil variables.Species nomenclature follows Pignatti (1982) for vascular plants and Augier (1966) for mosses.The research has been supported by the IDROSER (Bologna, Italy) and by the Italian C. N. R. (Grant no. 83.02548.04, resp. Prof. A. Pirola). We wish to thank Prof. E. Feoli, Prof. E. van der Maarel, Prof. L. Orlóci and Prof. A. Pirola for suggestions. We are also indebted to Dr N. Filippi who analyzed the soil samples. 相似文献
44.
The vegetation succession on the dunes near Oostvoorne, The Netherlands has been followed by means of a novel combination of repeated large-scale vegetation mapping and air photograph interpretation. Vegetation units have been discerned on the formation level because these could be distinguished fairly easily on the photographs and because the rates of change are appropriate to the time interval chosen. Nineteen formations were distinguished. Five 1:6250 maps were constructed, reflecting the formation pattern in 1934, 1943, 1959, 1972 and 1980. An overlay with 2736 grid points at 25 m field distance was used to quantify changes in the formation pattern.The results suggest a pronounced multiple pathway succession with nevertheless three principal trajectories of succession from pioneer to woodland vegetation. The outer dunes, which have originated since 1910, are distinct in successional characteristics from the inner dunes, which already existed but were released from heavy grazing pressure in 1910. The rate of change in the outer dunes was high in the beginning and is slowly decreasing eversince. In the inner dunes it went the other way around. Through visual extrapolation the likely formation patterns in 1910 and in 2000 were estimated.Transition frequencies proved highly variable for most formations. Moreover, strong spatial dependence was found. Limitations in the use of Markov models in cases of long-term succession in heterogeneous environments are discussed.Nomenclature follows the same sources as in van der Maarel et al. (1984).Field work carried out 1980–1981 when the authors were at the Division of Geobotany, University of Nijmegen. We thank Jos Rijntjes, Nijmegen, for his cooperation in the field. Vegetation maps were prepared and calculations performed at Uppsala. We thank the Foundation Het Zuid-Hollands Landschap, Rotterdam, for providing facilities and a grant for fieldwork as well as additional means to reproduce the vegetation maps. Two reviewers gave useful comments. 相似文献
45.
46.
Kawalek J. C., Rew R. S. and Heavner J. 1984. Glutathione-S-transferase, a possible drug-metabolizing enzyme in Haemonchus contortus: comparative activity of a cambendazole-resistant and a susceptible strain. International Journal for Parasitology14: 173–175. A drug metabolizing enzyme (DME), glutathione-S-transferase, was detected in homogenates of a cambendazole-susceptible and a cambendazole-resistant strain of Haemonchus contortus. The activity was 1.5–1.8 times higher in the resistant strain. DME activation is a possible mechanism for anthelmintic resistance in H. contortus. 相似文献
47.
Esmail K. Shubber David Jacobson-Kram Dr. Jerry R. Williams 《Cell biology and toxicology》1986,2(3):379-399
Seven antischistosomal drugs, two antimalarial drugs, and one antiamoebic drug were tested in all five Ames strains for induction of mutation, as well as for induction of cytotoxicity, inhibition of cellular progression, and the induction of sister chromatid exchanges in two cultured mammalian cell lines. We found that two agents shown to be negative in the Ames test were positive for sister chromatid exchange induction. Based on qualitative and quantitative evaluation, we find that all but three of the pharmaceuticals should be considered to be potential human carcinogens.Abbreviations AA
2-aminoanthracene
- 9AACC
9-aminoacridine
- AM
amoscanate
- BrdUU
bromodeoxyuridine
- CA
chloroquine diphosphate
- CHO
Chinese hamster ovary
- CQ
chloroquine
- DAPI
46-diamidino-2-phenylindole
- DHY
dehydroemetine
- DMSO
dimethyl sulfoxide
- EB
ethidium bromide
- FCS
fetal calf serum
- FN
4-fluoro-3-nitrophenyl azide
- HY
hycanthone
- ICP
inhibiting cell progression
- LU
lucanthone
- MEM
minimal essential medium
- 2NF
2-nitrofurantoin
- 4NPD
4-nitro-O-phenylenediamine
- NZ
niridazole
- OL
oltipraz
- OX
oxaminiquine
- PBS
phosphate buffered saline
- PQ
primaquine
- PZ
praziquantel
- SA
sodium azide
- SCE
sister chromatid exchange 相似文献
48.
Dr. Dimitrij A. Kuznetsov Nikolay V. Zavijalov Gennadij J. Kelman Alexander V. Govorkov 《Cell biology and toxicology》1986,2(3):337-340
A variety of methylated 4-oxypiperidine derivatives were tested for their ability to inhibit protein synthesis in vitro. A direct correlation was found between the extent of methylation of these compounds and their inhibitory activity in a rabbit reticulocyte lysate cell-free translation system.Abbreviation IC50
50% inhibitory concentration 相似文献
49.
Venkataraman Amarnath Traci L. Miller Arthur D. Broom 《Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression》1983,741(2):224-229
Poly(5-fluoro-2′-deoxyuridylic acid) was synthesized and its properties were compared with those of poly(dT) and poly(dU). It readily complexed with poly(dA). The 1:1 complex melted at about 20°C lower than poly(dA) · poly(dT). A triple-stranded helix, poly(dA)·2 poly(dF5U) was formed only in high salt (2.0 M NaCl). 相似文献
50.
A multivariate t probability integral 总被引:2,自引:0,他引:2