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861.
Thomas W. H. Aspin Kieran Khamis Thomas J. Matthews Alexander M. Milner Matthew J. OCallaghan Mark Trimmer Guy Woodward Mark E. Ledger 《Global Change Biology》2019,25(1):230-244
Functional traits are increasingly being used to predict extinction risks and range shifts under long‐term climate change scenarios, but have rarely been used to study vulnerability to extreme climatic events, such as supraseasonal droughts. In streams, drought intensification can cross thresholds of habitat loss, where marginal changes in environmental conditions trigger disproportionate biotic responses. However, these thresholds have been studied only from a structural perspective, and the existence of functional nonlinearity remains unknown. We explored trends in invertebrate community functional traits along a gradient of drought intensity, simulated over 18 months, using mesocosms analogous to lowland headwater streams. We modelled the responses of 16 traits based on a priori predictions of trait filtering by drought, and also examined the responses of trait profile groups (TPGs) identified via hierarchical cluster analysis. As responses to drought intensification were both linear and nonlinear, generalized additive models (GAMs) were chosen to model response curves, with the slopes of fitted splines used to detect functional thresholds during drought. Drought triggered significant responses in 12 (75%) of the a priori‐selected traits. Behavioural traits describing movement (dispersal, locomotion) and diet were sensitive to moderate‐intensity drought, as channels fragmented into isolated pools. By comparison, morphological and physiological traits showed little response until surface water was lost, at which point we observed sudden shifts in body size, respiration mode and thermal tolerance. Responses varied widely among TPGs, ranging from population collapses of non‐aerial dispersers as channels fragmented to irruptions of small, eurythermic dietary generalists upon extreme dewatering. Our study demonstrates for the first time that relatively small changes in drought intensity can trigger disproportionately large functional shifts in stream communities, suggesting that traits‐based approaches could be particularly useful for diagnosing catastrophic ecological responses to global change. 相似文献
862.
Alexander Geurds 《The journal of the Royal Anthropological Institute》2019,25(4):851-852
863.
S. Amat D. Baines E. Timsit J. Hallewell T.W. Alexander 《Journal of applied microbiology》2019,126(6):1668-1682
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865.
866.
Gorman Daniel Pucci Marinella Soares Lucy S. H. Turra Alexander Schlacher Thomas A. 《Ecosystems》2019,22(4):796-804
Ecosystems - Land–ocean coupling in the form of riverine inputs of terrestrial matter can constitute an energetic subsidy to food webs in nearshore coastal areas. In regions with distinctly... 相似文献
867.
Sandipan Roy Chowdhury Steven Kennedy Kai Zhu Rama Mishra Patrick Chuong Alyssa-uyen Nguyen Stefan G. Kathman Alexander V. Statsyuk 《Bioorganic & medicinal chemistry letters》2019,29(1):36-39
Here we present a virtual docking screen of 1648 commercially available covalent fragments, and identified covalent inhibitors of cysteine protease cathepsin L. These inhibitors did not inhibit closely related protease cathepsin B. Thus, we have established virtual docking of covalent fragments as an approach to discover covalent enzyme inhibitors. 相似文献
868.
Anton Shetnev Angelina Osipyan Sergey Baykov Alexander Sapegin Zhanna Chirkova Michail Korsakov Anél Petzer Idalet Engelbrecht Jacobus P. Petzer 《Bioorganic & medicinal chemistry letters》2019,29(1):40-46
Series of structurally diverse 2-imidazoline derivatives have been synthesized by condensation of substituted aldehydes with ethylenediamine, Pd-catalyzed N-arylation of 2-imidazolines and by the formation of 1,2,4-oxadiazoles and benzoxazepines from 2-imidazoline-containing precursors. The 2-imidazoline derivatives were evaluated as potential inhibitors of human monoamine oxidase (MAO) A and B. Among the 2-imidazolines, good potency inhibitors were discovered with compound 9p (IC50?=?0.012?µM) being the most potent MAO-B inhibitor, while compound 9d (IC50?=?0.751?µM) was the most potent MAO-A inhibitor of the series. These potencies are in the same range as those of reference MAO inhibitors used in the clinic. Among 33 compounds evaluated, 13 exhibited IC50 values in the submicromolar range for the inhibition of an MAO isoform. It is postulated that the imidazoline moieties of some of these inhibitors may be recognized by the imidazoline I2-binding site of MAO. Good potency MAO inhibitors may be useful for the treatment of neuropsychiatric and neurodegenerative disorders such as depression and Parkinson’s disease, and future application for the treatment of prostate cancer, congestive heart failure and Alzheimer’s disease. In addition, high potency 2-imidazoline-derived MAO inhibitors may be used as potential probes for the imidazoline binding sites of the MAOs, as well as to determine alternative binding regions of imidazoline within the MAO active site. 相似文献
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870.