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531.
532.
Min B. Rayamajhi Thai K. Van Paul D. Pratt Ted D. Center 《Wetlands Ecology and Management》2006,14(4):303-316
Melaleuca quinquenervia dominates large areas of the Florida Everglades in the southeastern USA where it has transformed sedge-dominated marshes
into melaleuca forests. Despite its prevalence, very little is known about the ecology and stand dynamics of this invasive
tree. We delineated large-, intermediate-, and small-tree stands in non-flooded, seasonally flooded and permanently flooded
areas of Florida in 1997, measured their biological attributes, and then quantified litterfall components for 3–4 year periods.
Melaleuca wood components and mature seed-capsules comprised the largest and the smallest portions of aboveground biomass,
respectively, while leaves, fine stems, mature fruits, bud scales, floral structures, and residues represented decreasingly
smaller fractions of the litter during the succeeding year. Dry weight proportion of leaves in litter was greatest (80.9%)
in non-flooded and least (69.1%) in permanently flooded habitats. It was also greatest in small (85.6%) and least in large
(64.7%) tree stands. Reproductive structures and mature-fruit fractions in litter were highest in large-tree stands whereas
the bud-scale fraction showed no relationship to tree size. Seasonally flooded habitats had the most litterfall, wherein small-,
intermediate-, and large-tree stands generated 0.662, 0.882, and 1.128 kg m−2 yr−1, respectively. Dry weight of stems, leaves, bud–scales, floral structures, and mature fruit fractions in litter increased
as the predominant size of the trees in the stand increased. Total annual litter production was highest during 1999–2000.
Leaf fall occurred year-round with maximal amount during April, July, and October. Highest amounts of bud scales and floral
structures fell during October–January, which corresponded with flushes of vegetative growth and major flowering events. Overall,
melaleuca alone accounted for nearly 99% of the total litterfall dry weight in all habitats and months sampled. The amount
of non-melaleuca litter was greater in small-tree stands than in intermediate- or large-tree stands. Litterfall data of this
nature will be helpful in detecting changes occurring in melaleuca canopies in response to biological control impact and in
prescribing site-specific management strategies. 相似文献
533.
The first brackish levels of the Aquitanian (s. lat.) of Cap Janet (B. du Rh.), contemporaneous with thoseof Carry-le-Rouet, have provided rodents and continental molluscs. They belong to the same level as the mammals of Coderet and so are correlated to the “série grise” of Barrême, the “calcaire de Reillanne”, the marls and limestones of Rougier, the gypsun of Aix. Older faunas found in the localities of “St-Henri” and “Les Milles” show that they belong to the same detritic flow as the “marnes de Viens”. 相似文献
534.
Correlation table of the different units at the oligocene-miocene boundary; paleogeographical and paleoclimatical results; discussion. 相似文献
535.
Zhexi Chi Truc Phan Hoang Le Sang Ki Lee Erling Guo Dongsoo Kim Sanha Lee Seung‐Yong Seo Sook Young Lee Jae Hyung Kim Sang Yoon Lee 《Journal of cellular and molecular medicine》2020,24(18):10663-10676
Hypertension and endothelial dysfunction are associated with various cardiovascular diseases. Hydrogen sulphide (H2S) produced by cystathionine γ‐lyase (CSE) promotes vascular relaxation and lowers hypertension. Honokiol (HNK), a natural compound in the Magnolia plant, has been shown to retain multifunctional properties such as anti‐oxidative and anti‐inflammatory activities. However, a potential role of HNK in regulating CSE and hypertension remains largely unknown. Here, we aimed to demonstrate that HNK co‐treatment attenuated the vasoconstriction, hypertension and H2S reduction caused by angiotensin II (AngII), a well‐established inducer of hypertension. We previously found that histone deacetylase 6 (HDAC6) mediates AngII‐induced deacetylation of CSE, which facilitates its ubiquitination and proteasomal degradation. Our current results indicated that HNK increased endothelial CSE protein levels by enhancing its stability in a sirtuin‐3‐independent manner. Notably, HNK could increase CSE acetylation levels by inhibiting HDAC6 catalytic activity, thereby blocking the AngII‐induced degradative ubiquitination of CSE. CSE acetylation and ubiquitination occurred mainly on the lysine 73 (K73) residue. Conversely, its mutant (K73R) was resistant to both acetylation and ubiquitination, exhibiting higher protein stability than that of wild‐type CSE. Collectively, our findings suggested that HNK treatment protects CSE against HDAC6‐mediated degradation and may constitute an alternative for preventing endothelial dysfunction and hypertensive disorders. 相似文献
536.
537.
The human gene for aromatic L-amino acid decarboxylase (DDC) was previously assigned to chromosome 7 by analysis of a panel of somatic cell hybrids. We report here refinement of this localisation, by in situ hybridisation, to 7p13-->p11. 相似文献
538.