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21.
Krešimir Begović Jonathan S. Schurman Marek Svitok Jakob Pavlin Thomas Langbehn Kristyna Svobodová Martin Mikoláš Pavel Janda Michal Synek William Marchand Lucie Vitková Daniel Kozák Ondrej Vostarek Vojtech Čada Radek Bače Miroslav Svoboda 《Global Change Biology》2023,29(1):143-164
In a world of accelerating changes in environmental conditions driving tree growth, tradeoffs between tree growth rate and longevity could curtail the abundance of large old trees (LOTs), with potentially dire consequences for biodiversity and carbon storage. However, the influence of tree-level tradeoffs on forest structure at landscape scales will also depend on disturbances, which shape tree size and age distribution, and on whether LOTs can benefit from improved growing conditions due to climate warming. We analyzed temporal and spatial variation in radial growth patterns from ~5000 Norway spruce (Picea abies [L.] H. Karst) live and dead trees from the Western Carpathian primary spruce forest stands. We applied mixed-linear modeling to quantify the importance of LOT growth histories and stand dynamics (i.e., competition and disturbance factors) on lifespan. Finally, we assessed regional synchronization in radial growth variability over the 20th century, and modeled the effects of stand dynamics and climate on LOTs recent growth trends. Tree age varied considerably among forest stands, implying an important role of disturbance as an age constraint. Slow juvenile growth and longer period of suppressed growth prolonged tree lifespan, while increasing disturbance severity and shorter time since last disturbance decreased it. The highest age was not achieved only by trees with continuous slow growth, but those with slow juvenile growth followed by subsequent growth releases. Growth trend analysis demonstrated an increase in absolute growth rates in response to climate warming, with late summer temperatures driving the recent growth trend. Contrary to our expectation that LOTs would eventually exhibit declining growth rates, the oldest LOTs (>400 years) continuously increase growth throughout their lives, indicating a high phenotypic plasticity of LOTs for increasing biomass, and a strong carbon sink role of primary spruce forests under rising temperatures, intensifying droughts, and increasing bark beetle outbreaks. 相似文献
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Our experiments showed that the activity of -glutamyltransferase (-GT) did not remarkably change in homogenates of mouse, rat, and bovine brains during the first four days post mortem. In the course of that period, the brain microvessels also retained their -GT activity. -GT of microvessels from bovine brain cortex, solubilized with sodium deoxycholate, was eluted in the void volume Vo when chromatographed on a Sephadex G-200 column with the detergent Triton X-100. In human post mortem brains, the specific activity of -GT in choroid plexi was found to be about five times higher than that in the cerebral cortex, white matter, basal ganglia, pons, and cerebellum but about four times lower than that in the microvessels obtained from the studied brain regions. Our findings suggest that it is possible to study the components of the blood-brain barrier on material from deceased subjects. 相似文献
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The rat NMDAR1 (N-methyl-D-aspartate receptor) was expressed transiently in human embryonic kidney cells. Transfected cell homogenates showed saturable [3H]MK-801 binding activity that was best fit by a single high-affinity site with a KD of 9 nM and a Bmax of 113 fmol of binding sites/mg of protein. Antibodies raised against the peptide sequence NMDAR1 (929-938) coupled to keyhole limpet haemocyanin specifically recognised a single band with M(r) 117,000 in immunoblots from adult rat brain. In the transfected cells, the antibody recognised two bands: one with M(r) 117,000, which was coincident with that from brain membranes, and one with M(r) 97,000, which was identified as nonglycosylated NMDAR1 subunit. These results identify the NMDAR1 of rat brain and further show that the homooligomer binds MK-801, albeit at low efficiency. 相似文献
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Antisera (B10.129×A)F1 anti-P and (B10×A)F1 anti-B10.P contain antibodies that define, in the PVP hemagglutination test, an antigen originally described as G or H-2.7. Of the independentH-2 haplotypes, the H-2.7 antigen is present inf, j, k, p, ands. In addition, the antisera also contain a weak cytotoxic antibody, distinct from anti-H-2.7. The cytotoxic antibody reacts with antigens controlled by theK orI regions. The hemagglutinating H-2.7 antibody does not have cytotoxic activity. The genetic determinant coding for antigen H-2.7 can be mapped into the chromosomal segment between theS andD regions. The H-2.7 antigen thus serves as a marker for a new region of theH-2 complex. The locus coding for antigen H-2.7 is designatedH-2 G and the correspondingH-2 regionG. The H-2.7 antigen has a tissue distribution distinct from that of the H-2 antigens controlled by theK orD regions. So far it could be detected primarily on erythrocytes. 相似文献
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Antoaneta Trendafilova Victoria Ivanova Miroslav Rangelov Milka Todorova Gulmira Ozek Suleyman Yur Temel Ozek Ina Aneva Ralitza Veleva Veselina Moskova‐Doumanova Jordan Doumanov Tanya Topouzova‐Hristova 《化学与生物多样性》2020,17(4)
Chlorogenic (5‐CQA), 1,5‐, 3,5‐, 4,5‐ and 3,4‐dicaffeoylquinic (DCQA) acids were identified and quantified in the methanol extracts of Inula oculus‐christi L., I. bifrons L., I. aschersoniana Janka var. aschersoniana, I. ensifolia L., I. conyza (Griess .) DC. and I. germanica L. by HPLC analysis. The amount of 5‐CQA varied from 5.48 to 28.44 mg/g DE and the highest content was detected in I. ensifolia. 1,5‐DCQA (4.05–55.25 mg/g DE) was the most abundant dicaffeoyl ester of quinic acid followed by 3,5‐DCQA, 4,5‐DCQA and 3,4‐DCQA. The extract of I. ensifolia showed the highest total phenolic content (119.92±0.95 mg GAE/g DE) and exhibited the strongest DPPH radical scavenging activity (69.41±0.55 %). I. bifrons extract was found to be the most active sample against ABTS.+ (TEAC 0.257±0.012 mg/mL) and the best tyrosinase inhibitor. The studied extracts demonstrated a low inhibitory effect towards acetylcholinesterase and possessed low cytotoxicity in concentration range from 10 to 300 μg/mL toward non‐cancer (MDCK II) and cancer (A 549) cells. 相似文献
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Milosavljevic Isidora Jakovljevic Vladimir Petrovic Dejan Draginic Nevena Jeremic Jovana Mitrovic Miroslav Zivkovic Vladimir Srejovic Ivan Stojic Vladislava Bolevich Sergey Andjelkovic Nebojsa 《Molecular and cellular biochemistry》2021,476(11):4167-4175
Molecular and Cellular Biochemistry - The aim of our study was to investigate the effects of one-month consumption of polyphenol-rich standardized Aronia melanocarpa extract (SAE) on redox status... 相似文献
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