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91.
Changiz Geula Sara R. Dunlop Ivan Ayala Allegra S. Kawles Margaret E. Flanagan Tamar Gefen Marek-Marsel Mesulam 《Journal of neurochemistry》2021,158(6):1394-1411
92.
Tamar Keasar Muriel Ney-Nifle Marc Mangel Sean Swezey 《Entomologia Experimentalis et Applicata》2001,98(2):123-132
Parasitoids learn olfactory and visual cues that are associated with their hosts, and use these cues to forage more efficiently. Classical conditioning theory predicts that encounters with high-quality hosts will lead to better learning of host-associated cues than encounters with low-quality hosts. We tested this prediction in a two-phase laboratory experiment with the parasitoid Trichogramma thalense Pinto & Oatman (Hymenoptera: Trichogrammatidae) and the host Anagasta kuehniella Zeller (Lepidoptera: Pyralidae).Host quality during the first exposure to hosts affected later foraging behavior for some experimental treatments, as predicted. We used a learning model, followed by patch-time optimization, to interpret our findings. We first simulated the parasitoids' host encounters during the experiment, and predicted their estimate of patch quality after each encounter. We then used dynamic optimization to predict the parasitoids' optimal patch residence times. The model reproduces the trends of the experimental results. 相似文献
93.
Morphological relationship among sympatric animal species have often been seen as indirect evidence for competition. Many early ecomorphological studies revealed patterns that were taken as indicating character displacement and character release, driven by competition or lack thereof. These patterns may result from a coevolutionary morphological response or from species sorting according to size. Thus, the relationship between morphology and competition may be crucial for understanding both the morphological evolution of animals and the role of competition in structuring communities. Some earlier research perceived as indicating morphological relationships conditioned by interaction of species was conducted on mammals, particularly carnivores. Subsequent criticism in the ecological literature demonstrated that many of the perceived patterns could not be statistically confirmed, thus calling into question this line of evidence for competition. More recent ecological literature relies on strong statistical analyses and careful consideration both of guild composition and of which morphological traits should be examined. This literature, resting largely on mammals, includes several cases that suggest a coevolutionary morphological response to interspecific competition. These studies have focused on the thropic apparatus directly related to food procurement by mammals — the teeth. Island mammals often show striking morphological patterns, some of which have been interpreted as resulting from release from competition with mainland species that have not reached islands. However, few of these patterns were critically evaluated to demonstrate their support for the hypothesis of character release. Despite several decades of interest and research, many questions regarding competitively induced morphological patterns remain unresolved and require further research. Mammals are especially promising subjects for such researh. 相似文献
94.
Chuanlin Zheng Atiako Kwame Acheampong Zhaowan Shi Amichay Mugzech Tamar Halaly‐Basha Felix Shaya Yufei Sun Violeta Colova Assaf Mosquna Ron Ophir David W. Galbraith Etti Or 《Plant, cell & environment》2018,41(10):2490-2503
The molecular mechanism regulating dormancy release in grapevine buds is as yet unclear. It was formerly proposed that dormancy is maintained by abscisic acid (ABA)‐mediated repression of bud–meristem activity and that removal of this repression triggers dormancy release. It was also proposed that such removal of repression may be achieved via natural or artificial up‐regulation of VvA8H‐CYP707A4, which encodes ABA 8′‐hydroxylase, and is the most highly expressed paralog in grapevine buds. The current study further examines these assumptions, and its experiments reveal that (a) hypoxia and ethylene, stimuli of bud dormancy release, enhance expression of VvA8H‐CYP707A4 within grape buds, (b) the VvA8H‐CYP707A4 protein accumulates during the natural transition to the dormancy release stage, and (c) transgenic vines overexpressing VvA8H‐CYP707A4 exhibit increased ABA catabolism and significant enhancement of bud break in controlled and natural environments and longer basal summer laterals. The results suggest that VvA8H‐CYP707A4 functions as an ABA degrading enzyme, and are consistent with a model in which the VvA8H‐CYP707A4 level in the bud is up‐regulated by natural and artificial bud break stimuli, which leads to increased ABA degradation capacity, removal of endogenous ABA‐mediated repression, and enhanced regrowth. Interestingly, it also hints at sharing of regulatory steps between latent and lateral bud outgrowth. 相似文献
95.
Coral Reefs - Ultraviolet radiation (UVR) can exacerbate the effects of elevated seawater temperatures concomitant with climate change. Such stressors can collapse the mutualism of scleractinian... 相似文献
96.
Tamar Katzav Gozansky Victoria Soroker Abraham Hefetz 《Invertebrate neuroscience : IN》1997,3(2-3):239-243
Chemical analysis of queen Dufour's gland by GC/MS revealed the presence of long chain esters and hydrocarbons. To evaluate
whether the biosynthesis of Dufour's gland components is modulated by physiological factors, we studied thede novo biosynthesis of esters and hydrocarbons in virgin and mated queen glandsin vivo andin vitro. Using [1-14C] sodium acetate as a precursor, it was shown thatin vivo, esters and hydrocarbons comprised the majorde novo products. The relative proportion of the hydrocarbon fraction was significantly higher in mated queens than in virgins, while
in esters the situation was reversed. Comparision between reproductive and non reproductive virgin queens revealed that mating
and not egg laying induced changes in glandular activity. Glands incubatedin vitro, on the other hand, synthesized mainly esters and alcohols but not hydrocarbons. These results suggest that either hydrocarbons
are produced elsewhere and subsequently sequestered by Dufour's gland, or that the gland biosynthetic expressionin vivo is modulated. Differences between the gland activityin vivo andin vitro further support the hypothesis of a physiological mechanism in regulation of glandular performance. 相似文献
97.
Graph representations have been widely used to analyze and design various economic, social, military, political, and biological networks. In systems biology, networks of cells and organs are useful for understanding disease and medical treatments and, in structural biology, structures of molecules can be described, including RNA structures. In our RNA-As-Graphs (RAG) framework, we represent RNA structures as tree graphs by translating unpaired regions into vertices and helices into edges. Here we explore the modularity of RNA structures by applying graph partitioning known in graph theory to divide an RNA graph into subgraphs. To our knowledge, this is the first application of graph partitioning to biology, and the results suggest a systematic approach for modular design in general. The graph partitioning algorithms utilize mathematical properties of the Laplacian eigenvector (µ2) corresponding to the second eigenvalues (λ2) associated with the topology matrix defining the graph: λ2 describes the overall topology, and the sum of µ2′s components is zero. The three types of algorithms, termed median, sign, and gap cuts, divide a graph by determining nodes of cut by median, zero, and largest gap of µ2′s components, respectively. We apply these algorithms to 45 graphs corresponding to all solved RNA structures up through 11 vertices (∼220 nucleotides). While we observe that the median cut divides a graph into two similar-sized subgraphs, the sign and gap cuts partition a graph into two topologically-distinct subgraphs. We find that the gap cut produces the best biologically-relevant partitioning for RNA because it divides RNAs at less stable connections while maintaining junctions intact. The iterative gap cuts suggest basic modules and assembly protocols to design large RNA structures. Our graph substructuring thus suggests a systematic approach to explore the modularity of biological networks. In our applications to RNA structures, subgraphs also suggest design strategies for novel RNA motifs. 相似文献
98.
99.
Effect of Metal-Rich Sewage Sludge Application on the Bacterial Communities of Grasslands 总被引:2,自引:7,他引:2 下载免费PDF全文
The effect of long-term application of heavy metal-laden sewage sludge on the total heterotrophic aerobic and the cadmium-resistant soil bacterial communities was studied. Gram-positive bacteria were completely absent from resistant communities. These findings suggest that this group is highly susceptible to Cd. Shannon's diversity indices estimated for total communities did not reveal negative effects on the communities that developed in the presence of sludge. However, Cd-resistant communities isolated from long-term sludge-amended soils were more diverse than the resistant communities from a control sample, suggesting that adaptation to Cd as a stressor had occurred in the presence of sludge constituents. This higher diversity was attributed to Cd resistance in pseudomonads and gram-negative fermenters. Resistance did not develop by dissemination of Cd resistance plasmids, because these were rarely detected in the genomes of resistant strains. 相似文献
100.