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131.
A novel mechanism of persistent facilitation induced by serotonin at Aplysia synapses depends upon rapid postsynaptic protein synthesis and increased responsiveness to glutamate; whereas the memory for this synaptic change is postsynaptic, the initiating signal may be an increase in spontaneous release of glutamate from the presynaptic terminals. 相似文献
132.
Jadhav AS Taylor DC Giblin M Ferrie AM Ambrose SJ Ross AR Nelson KM Irina Zaharia L Sharma N Anderson M Fobert PR Abrams SR 《Phytochemistry》2008,69(15):2678-2688
Developing seeds of Brassica napus contain significant levels of ABA and products of oxidation at the 7'- and 9'-methyl groups of ABA, 7'- and 9'-hydroxy ABA, as well stable products of oxidation of the 8'-methyl group, phaseic acid and dihydrophaseic acid. To probe the biological roles of the initially formed hydroxylated compounds, we have compared the effects of supplied ABA and the hydroxylated metabolites in regulating oil synthesis in microspore-derived embryos of B. napus, cv Hero that accumulate long chain fatty acids. Uptake into the embryos and metabolism of each of the hormone metabolites was studied by using deuterium labeled analogs. Supplied ABA, which was rapidly metabolized, induced expression of oleosin and fatty acid elongase genes and increased the accumulation of triacylglycerols and very long chain fatty acids. The metabolites 7'- and 9'-hydroxy ABA had similar effects, with the 9'-hydroxy ABA having even greater activity than ABA. The principal catabolite of ABA, 8'-hydroxy ABA, also had hormonal activity and led to increased oil synthesis but induced the genes weakly. These results indicate that all compounds tested could be involved in lipid synthesis in B. napus, and may have hormonal roles in other ABA-regulated processes. 相似文献
133.
Classification of cell death: recommendations of the Nomenclature Committee on Cell Death 2009 总被引:1,自引:0,他引:1
Kroemer G Galluzzi L Vandenabeele P Abrams J Alnemri ES Baehrecke EH Blagosklonny MV El-Deiry WS Golstein P Green DR Hengartner M Knight RA Kumar S Lipton SA Malorni W Nuñez G Peter ME Tschopp J Yuan J Piacentini M Zhivotovsky B Melino G;Nomenclature Committee on Cell Death 《Cell death and differentiation》2009,16(1):3-11
134.
Renato M Salgado Luciane P Capelo Rodolfo R Favaro Jocelyn D Glazier John D Aplin Telma MT Zorn 《Reproductive biology and endocrinology : RB&E》2009,7(1):60
Background
Remodeling of the extracellular matrix is one of the most striking features observed in the uterus during the estrous cycle and after hormone replacement. Versican (VER) is a hyaluronan-binding proteoglycan that undergoes RNA alternative splicing, generating four distinct isoforms. This study analyzed the synthesis and distribution of VER in mouse uterine tissues during the estrous cycle, in ovariectomized (OVX) animals and after 17beta-estradiol (E2) and medroxyprogesterone (MPA) treatments, either alone or in combination. 相似文献135.
136.
Chambers RJ Abrams K Castleberry TA Cheng JB Fisher DA Kamath AV Marfat A Nettleton DO Pillar JD Salter ED Sheils AL Shirley JT Turner CR Umland JP Lam KT 《Bioorganic & medicinal chemistry letters》2006,16(3):718-721
Nicotinamide (2) is a potent and selective inhibitor of the PDE4D isozyme and as a chemical tool selectively blocks eosinophil mediator release and chemotaxis thus linking the role of PDE4D to eosinophil function. 相似文献
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139.
Strecker AL Casselman JM Fortin MJ Jackson DA Ridgway MS Abrams PA Shuter BJ 《Oecologia》2011,166(3):819-831
Species present in communities are affected by the prevailing environmental conditions, and the traits that these species
display may be sensitive indicators of community responses to environmental change. However, interpretation of community responses
may be confounded by environmental variation at different spatial scales. Using a hierarchical approach, we assessed the spatial
and temporal variation of traits in coastal fish communities in Lake Huron over a 5-year time period (2001–2005) in response
to biotic and abiotic environmental factors. The association of environmental and spatial variables with trophic, life-history,
and thermal traits at two spatial scales (regional basin-scale, local site-scale) was quantified using multivariate statistics
and variation partitioning. We defined these two scales (regional, local) on which to measure variation and then applied this
measurement framework identically in all 5 study years. With this framework, we found that there was no change in the spatial
scales of fish community traits over the course of the study, although there were small inter-annual shifts in the importance
of regional basin- and local site-scale variables in determining community trait composition (e.g., life-history, trophic,
and thermal). The overriding effects of regional-scale variables may be related to inter-annual variation in average summer
temperature. Additionally, drivers of fish community traits were highly variable among study years, with some years dominated
by environmental variation and others dominated by spatially structured variation. The influence of spatial factors on trait
composition was dynamic, which suggests that spatial patterns in fish communities over large landscapes are transient. Air
temperature and vegetation were significant variables in most years, underscoring the importance of future climate change
and shoreline development as drivers of fish community structure. Overall, a trait-based hierarchical framework may be a useful
conservation tool, as it highlights the multi-scaled interactive effect of variables over a large landscape. 相似文献
140.
This article uses simple models to explore the impact of adaptive movement by consumers on the population dynamics of a consumer-resource metacommunity consisting of two identical patches. Consumer-resource interactions within a patch are described by the Rosenzweig-MacArthur predator-prey model, and these dynamics are assumed to be cyclic in the absence of movement. The per capita movement rate from one patch to the other is an increasing function of the difference between the per capita birth minus death rate in the destination patch and that in the currently occupied patch. Several variations on this model are considered. Results show that adaptive movement frequently creates anti-phase cycles in the two patches; these suppress the predator-prey cycle and lead to low temporal variation of the total population sizes of both species. Paradoxically, even when movement is very sensitive to the fitness difference between patches, perfect synchrony of patches is often much less likely than in comparable systems with random movement. Under these circumstances adaptive movement of consumers often generates differences in the average properties of the two patches. In addition, mean global densities and responses to global perturbations often differ greatly from similar systems with no movement or random movement. 相似文献