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91.
92.
Microsaurs as possible apodan ancestors 总被引:1,自引:0,他引:1
The specific ancestry and nature of the relationships of modern amphibians have not yet been established. Detailed comparisons of the anatomy of the skull roof, palate and braincase of living apodans and the Paleozoic microsaur Goniorhynchus demonstrate greater similarities than between apodans and any other group of amphibians, fossil or recent. Unlike any other amphibians, extensive pleurosphenoid ossifications are developed in the area of the Vth nerve, uniting the otic capsule with the sphenethmoid. Other important features that they share (although not uniquely) include the presence of all the primitive dermal elements of the palate, a solidly roofed temporal region, a row of palatal teeth parallel to the marginal dentition and a row of teeth on the medial surface of the lower jaw. The stapes has a similar configuration and position, totally different from that of frogs and salamanders. Such similarities do not necessarily prove close relationship, but indicate the necessity for considering that apodans may have an ancestry distinct from that of frogs and salamanders. 相似文献
93.
T. H. THOMAS J. E. CARROLL F. M. R. ISENBERG ANN PENDERGRASS LYDIA HOWELL 《Physiologia plantarum》1975,33(1):83-86
Chromatography of partially purified extracts of Danish cabbage (Brassica oleracea var. capitata L.) heads on polyvinylpyrrolidone columns using a weak phosphate buffer indicated a cytokinin complex containing nine components active in the modified Amaranthus betacyanin bioassay. Similar elution patterns were obtained with extracts of four different cabbage varieties but varietal differences occurred in the biological activity from each component peak. Paper and thin-layer chromatography indicated the presence of both zeatin and zeatin riboside in the extracts but the other cytokinin-active components were not identified. Separation of sweet-corn extracts by this technique indicated that most of the cytokinin activity occurred in the elution volume where zeatin and zeatin riboside would normally occur. 相似文献
94.
BRIAN M. SHAMBLIN BRANT C. FAIRCLOTH MARK DODD ALICIA WOOD‐JONES STEVEN B. CASTLEBERRY JOHN P. CARROLL C. JOSEPH NAIRN 《Molecular ecology resources》2007,7(5):784-787
We describe primers and polymerase chain reaction conditions to amplify 15 tetranucleotide microsatellite loci from the loggerhead sea turtle (Caretta caretta). The primers were tested on 30 individuals that nested along the Georgia, USA coast. The primer pairs developed in this study yielded an average of 13.9 alleles per locus (range of 10–21), an average observed heterozygosity of 0.91 (range 0.79–1.00), and an average polymorphic information content of 0.88 (range 0.84–0.92). 相似文献
95.
Mosquitoes and ticks are blood‐feeding pests of humans and animals that can vector many important aetiological agents of disease. Previous research demonstrated that TT‐4302 (Guardian® Wilderness) containing 5% geraniol applied to human subjects gave 5–6 h of repellency against mosquitoes (depending on species) and was repellent to ticks in vitro. This study was conducted to obtain an independent third‐party evaluation of TT‐4302 against Stegomyia aegypti (= Aedes aegypti) (Diptera: Culicidae) mosquitoes and to test the efficacy of the product in the field against ticks. TT‐4302 provided an average of 6.5 h of repellency of ≥ 95% [Weibull mean protection time: 7.4 h, 95% confidence interval (CI) 5.8–11.3 h] for St. aegypti, whereas a 15% DEET formulation provided 4.7 h of repellency (Weibull mean protection time: 5.2 h, 95% CI 3.7–6.9 h). In tick field trials, the efficacy of TT‐4302 did not differ significantly from that of a 25% DEET formulation against Amblyomma americanum (Ixodida: Ixodidae). TT‐4302 was 81.3% repellent at 2.5 h after application, whereas DEET was 77.2% repellent at the same time‐point. Results at 3.5 h after application were 71.4% for TT‐4302 and 72.9% for DEET. 相似文献
96.
1. The coffee berry borer Hypothenemus hampei (Coleoptera, Curculionidae) (Ferrari) is the most important pest of coffee production worldwide. 2. The hypothesis that the tropical fire ant, Solenopsis geminata Westwood, indirectly protects the coffee berry borer by suppressing other ant species that are the coffee berry borer's primary predators was tested. 3. It was found that removing S. geminata from coffee plots significantly increased the disappearance of adult coffee berry borer beetles from coffee berries compared with control plots. An average of 6% of beetles disappeared from plots with S. geminata whereas 23% of beetles disappeared from plots from which S. geminata was removed. This pattern was observed on two shade coffee farms with marked differences in ant species composition, one in the rainforest in central Costa Rica and one in the cloudforest in northwest Costa Rica. 4. If the results of this small‐scale study can be replicated on the farm level, then S. geminata suppression may represent a new management technique for the coffee berry borer throughout Central and South America. 相似文献
97.
NICHOLAS P. MCCANN RON A. MOEN GERALD J. NIEMI 《The Journal of wildlife management》2008,72(4):955-958
Abstract: We calibrated snowshoe hare (Lepus americanus) numbers with pellet counts in Minnesota, USA, to understand the relationship between hare numbers and pellets in the central portion of the hare range. We found a strong and significant correlation between hare numbers and pellet counts using either linear or functional regression with either annual or semiannual pellet counts. Equations we developed using linear or functional regression predicted >1 hare/ha at similar pellet-density thresholds. These equations can be used to efficiently identify habitats that support hare numbers necessary for Canada lynx (Lynx canadensis) persistence in Minnesota. 相似文献
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100.
ERIC L. STALLER WILLIAM E. PALMER JOHN P. CARROLL RYAN P. THORNTON D. CLAY SISSON 《The Journal of wildlife management》2005,69(1):124-132
Abstract: We identified nest predators of northern bobwhites (Colinus virginianus) on private lands in northern Florida and southern Georgia, USA, using continuous infrared micro-video cameras, 1999–2001, and compared these results to predictions based on diagnostic sign at nests. Mammals (59%), snakes (29%), and ants (12%) accounted for known bobwhite nest depredations. Mammalian predators, in order of importance, were the raccoon (Procyon lotor), nine-banded armadillo (Dasypus novemcinctus), Virginia opossum (Didelphis virginiana), bobcat (Lynx rufus), hispid cotton rat (Sigmodon hispidus), and coyote (Canis latrans). Using diagnostic sign, technicians correctly classified 30% of mammalian depredations to species and overestimated nest depredations by snakes. A classification tree model correctly classified 75% of the test sample (n = 33) into “mammal” or “snake” categories, but still overestimated depredations by snakes. We documented a broader predator community upon bobwhite eggs than previously known for northern Florida and southern Georgia and confirmed that snakes were significant nest predators in some years. We conclude that diagnostic sign at depredated nests was unreliable for identifying nest predators of northern bobwhites. 相似文献