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Runkle Laura S.; Wells Kentwood D.; Robb Catherine C.; Lance Stacey L. 《Behavioral ecology》1994,5(3):318-325
We investigated individual, nightly, and seasonal variationin calling behavior of a population of gray tree frogs (Hylaversicolor) from Connecticut, USA. Repeated recordings of individualmales on seven nights revealed significant differences amongmales in calling rate on all but one night and differences innumber of pulses per call and number of pulses produced perhour (pulse effort) on four nights. Most males reduced callingactivity late at night (after 2230 h), but some maintained arelatively steady rate of call production before dropping outof the chorus. Data collected for 26 individuals recorded onthree or more nights throughout the breeding season revealedsignificant differences among males in calling rate, numberof pulses per call, and pulse effort, but repeatabilities forall three variables were low (0.17, 0.35, and 0.12, respectively).The highest repeatability was for number of pulses per call,a variable strongly influenced by proximity to calling neighbors,probably because males often interacted with neighbors at similardistances on several successive nights. Males tended to reducethe number of pulses per call as the season progressed and thedistance between neighbors decreased, but they showed no clearseasonal change in calling rate or pulse effort. There was asubstantial seasonal decline in the number of hours of chorusactivity, resulting in a median decrease of 43% in nightly energyexpenditure by calling males. 相似文献
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Comparison of cytotoxicity and thin-layer chromatography methods for detection of mycotoxins 总被引:1,自引:0,他引:1
Thirty-three standard mycotoxins were assayed by thin-layer chromatography and by cytotoxicity in HEp-2 and Chang cells. Various levels of detection were found. The cytotoxicity test was significantly more sensitive than thin-layer chromatography for the trichothecenes and should be useful for screening extracts from animal feedstuffs for the presence of unknown mycotoxins. 相似文献
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A C Warren N K Robakis N Ramakrishna E H Koo C A Ross A S Robb M F Folstein D L Price S E Antonarakis 《Genomics》1987,1(4):307-312
Recently, it has been suggested that Alzheimer's disease is associated with a duplication of the amyloid precursor protein gene localized to chromosome 21q21. In this study, a cloned DNA probe (B2.3), complementary to the sequence coding the beta-amyloid peptide, and DNA polymorphisms adjacent to this sequence were used to determine the number of copies of the beta-amyloid gene in DNA isolated from human blood and brain. Individuals with trisomy 21 (Down syndrome) who were heterozygous for the polymorphisms showed a gene-dosage effect, with one allele exhibiting twice the autoradiographic intensity as the other. Heterozygous individuals with Alzheimer's disease and controls showed equal intensities of the two allelic bands, suggesting that there are only two copies of the beta-amyloid gene in these individuals. In individuals with Alzheimer's disease and in controls who were homozygous for these polymorphisms, the number of copies of the beta-amyloid gene was determined by comparing the autoradiographic intensity of beta-amyloid alleles to that of DNA fragments detected by a reference probe. No difference was detected between these two groups. 相似文献
769.
SplitsTree: analyzing and visualizing evolutionary data 总被引:15,自引:0,他引:15
MOTIVATION: Real evolutionary data often contain a number of different and
sometimes conflicting phylogenetic signals, and thus do not always clearly
support a unique tree. To address this problem, Bandelt and Dress (Adv.
Math., 92, 47-05, 1992) developed the method of split decomposition. For
ideal data, this method gives rise to a tree, whereas less ideal data are
represented by a tree-like network that may indicate evidence for different
and conflicting phylogenies. RESULTS: SplitsTree is an interactive program,
for analyzing and visualizing evolutionary data, that implements this
approach. It also supports a number of distances transformations, the
computation of parsimony splits, spectral analysis and bootstrapping.
相似文献
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