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61.
Gargan Laura M. Brooks Paul R. Vye Siobhan R. Ironside Joseph E. Jenkins Stuart R. Crowe Tasman P. Carlsson Jens 《Biological invasions》2022,24(3):635-648
Biological Invasions - Artificial coastal structures associated with coastal defences, energy generation, ports, marinas and other developments, are known to support lower levels of biodiversity... 相似文献
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M D Keppler M A Read P J Perry J O Trent T C Jenkins A P Reszka S Neidle K R Fox 《European journal of biochemistry》1999,263(3):817-825
We have used quantitative DNase I footprinting to measure the relative affinities of four disubstituted and two monosubstituted amidoanthraquinone compounds for intermolecular DNA triplexes, and have examined how the position of the attached base-functionalized substituents affects their ability to stabilize DNA triplexes. All four isomeric disubstituted derivatives examined stabilize DNA triplexes at micromolar or lower concentrations. Of the compounds studied the 2,7-disubstituted amidoanthraquinone displayed the greatest triplex affinity. The order of triplex affinity for the other disubstituted ligands decreases in the order 2,7 > 1,8 = 1,5 > 2,6, with the equivalent monosubstituted compounds being at least an order of magnitude less efficient. The 1,5-disubstituted derivative also shows some interaction with duplex DNA. These results have been confirmed by molecular modelling studies, which provide a rational basis for the structure-activity relationships. These suggest that, although all of the compounds bind through an intercalative mode, the 2,6, 2,7 and 1,5 disubstituted isomers bind with their two side groups occupying adjacent triplex grooves, in contrast with the 1,8 isomer which is positioned with both side groups in the same triplex groove. 相似文献
65.
R. T. Yamamoto R. Y. Jenkins R. K. McClusky 《Entomologia Experimentalis et Applicata》1969,12(5):504-508
A generalized scheme concerning the oviposition behavior of Manduca sexta (Johan.) moths was constructed according to observations and experiments conducted in large cages. There are two phases in the orientation to plants, the approach and the landing. The approach appears non-discriminatory and the moths utilize visual cues during this phase. The landing is discriminatory and is based on fixed or learned responses to olfactory stimuli. After landing, contact chemostimulation elicits deposition of eggs.
Zusammenfassung Auf Grund von Beobachtungen und Versuchen in großen Käfigen wird ein allgemeines Schema des Eiablageverhaltens von Manduca sexta (Johan.) entworfen. Es bestehen zwei Phasen in der Orientierung auf die Pflanzen, die Annäherung und die Landung. Die Annäherung scheint unterschiedslos ungerichtet zu erfolgen; die Schwärmer benutzen während dieser Phase visuelle Schlüsselreize. Die Landung ist entscheidend gerichtet und beruht auf erlernten Reaktionen auf spezifische Geruchsreize. Nach der Landung löst ein chemischer Kontaktreiz die Ablage der Eier aus.相似文献
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Following the discovery of synergistic action between oxacillin and manuka honey against methicillin-resistant Staphylococcus aureus, this study was undertaken to search for further synergistic combinations of antibiotics and honey that might have potential in treating wounds. Fifteen antibiotics were tested with and without sublethal concentrations of manuka honey against each of MRSA and Pseudomonas aeruginosa using disc diffusion, broth dilution, E strip, chequerboard titration and growth curves. Five novel antibiotic and manuka honey combinations were found that improved antibacterial effectiveness in vitro and these offer a new avenue of future topical treatments for wound infections caused by these two important pathogens. 相似文献
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Levels of androgens and oestradiol in dogfish, Scyliorhinus canicula , plasma, measured by radioimmunoassay, decrease markedly after ovariectomy (OVX). The magnitude and latency of these responses varies according to length of captivity preceding the operation and the time of year at which ovariectomy is performed. Androgens are cleared more rapidly than oestradiol from plasma following OVX, and levels of both steroids are reduced after laparotomy (LAP) in November but not in March. An extract of ventral lobes of the dogfish pituitary induces a significant increase in the circulating androgen levels in LAP fish but not in OVX fish, indicating that the ovary is the major site of androgen production in response to stimulation by dogfish gonadotrophin. Intramuscular injections of oestradiol benzoate (2.5 mg per fish) into LAP fish produce a significant reduction in the gonadotrophin content of the pituitary ventral lobe, measured in the quail testicular cell bioassay, when compared to LAP and unoperated controls. However, no significant changes in the gonadotrophin content of the ventral lobe were seen five days after OVX in June. 相似文献
69.
The “balance” argument suggests that if sex were maladaptive at the individual level, it would be quickly lost from species with asexual/sexual alternation. Williams has suggested an “Aphid-Rotifer” model for such species. It has the following characteristics (a) parthenogenesis is favoured when the environment is stable (b) when the environment changes qualitatively, sex generates offspring with an increased fitness variance compared to parthenogenetic progeny (c) if selection is intense and sib competition occurs then sex is favoured. It is argued here that condition (b) is not essential to the model. An increased fitness variance may be generated by the recombination of unfavourable mutations when one or more of the following occur; (1) founder effects (2) inbreeding (3) haplo-diploidy (4) intra-male competition. Parthenogenesis sustains an advantage when selection is relaxed and the possession of mutations is not reflected in differences in fitness. Sex is favoured when selection is intense and fitness reflects the possession of unfavourable mutations. 相似文献
70.
Sean Martin Andrew Vincent Anne W. Taylor Evan Atlantis Alicia Jenkins Andrzej Januszewski Peter O’Loughlin Gary Wittert 《PloS one》2015,10(10)