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1.
New Phytol ; 237(6): 2054-2068, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36226674

RESUMEN

Spatial redistribution of nutrients by atmospheric transport and deposition could theoretically act as a continental-scale mechanism which counteracts declines in soil fertility caused by nutrient lock-up in accumulating biomass in tropical forests in Central Africa. However, to what extent it affects carbon sinks in forests remains elusive. Here we use a terrestrial biosphere model to quantify the impact of changes in atmospheric nitrogen and phosphorus deposition on plant nutrition and biomass carbon sink at a typical lowland forest site in Central Africa. We find that the increase in nutrient deposition since the 1980s could have contributed to the carbon sink over the past four decades up to an extent which is similar to that from the combined effects of increasing atmospheric carbon dioxide and climate change. Furthermore, we find that the modelled carbon sink responds to changes in phosphorus deposition, but less so to nitrogen deposition. The pronounced response of ecosystem productivity to changes in nutrient deposition illustrates a potential mechanism that could control carbon sinks in Central Africa. Monitoring the quantity and quality of nutrient deposition is needed in this region, given the changes in nutrient deposition due to human land use.


Asunto(s)
Secuestro de Carbono , Ecosistema , Humanos , Árboles/fisiología , Fósforo , Bosques , Suelo , Nitrógeno , África Central , Clima Tropical
2.
Food Chem ; 368: 130802, 2022 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-34411866

RESUMEN

This study aimed to investigate the influences of microwave (MV) exposure to flaxseed on the physicochemical stability of oil bodies (OBs) focused on the interface remodeling. The results showed that the intracellular OBs subjected to absolute rupture and then partial dispersion by protein bodies visualized by TEM following MV exposure (1-5 min; 700 W). After aqueous extraction, native flax OBs manifested excellent spherical particles with completely intact surface and wide particle size distribution (0.5-3.0 µm) examined by cryo-SEM. Upon 1-5 min of MV exposure, the defective interface integrity and beaded morphology were successively observed for flax OBs, accompanied by the impaired physical stability and rheological behavior due to the newly assembled phospholipid/protein interface. Notably, the profitable migration of phenolic compounds effectively suppressed the lipid peroxidation and protein carbonylation in flax OBs. Thus, MV exposure (1-5 min; 700 W) was unfavorable for improving the physical stability of flax OBs.


Asunto(s)
Lino , Aceite de Linaza , Gotas Lipídicas , Microondas , Fenoles , Fosfolípidos
3.
Nat Commun ; 11(1): 355, 2020 01 17.
Artículo en Inglés | MEDLINE | ID: mdl-31953430

RESUMEN

Global fish production (capture and aquaculture) has increased quickly, which has altered global flows of phosphorus (P). Here we show that in 2016, [Formula: see text] Tg P yr-1 (mean and interquartile range) was applied in aquaculture to increase fish production; while [Formula: see text] Tg P yr-1 was removed from aquatic systems by fish harvesting. Between 1950 and 1986, P from fish production went from aquatic towards the land-human systems. This landward P peaked at 0.54 Tg P yr-1, representing a large but overlooked P flux that might benefit land activities under P scarcity. After 1986, the landward P flux decreased significantly, and became negative around 2004, meaning that humans spend more P to produce fish than harvest P in fish capture. An idealized pathway to return to the balanced anthropogenic P flow would require the mean phosphorus use efficiency (the ratio of harvested to input P) of aquaculture to be increased from a current value of 20% to at least 48% by 2050 - a big challenge.


Asunto(s)
Productos Agrícolas , Explotaciones Pesqueras , Fósforo , Contaminantes Químicos del Agua/análisis , Animales , Bases de Datos Factuales , Ecología , Peces , Agua Dulce/química , Historia del Siglo XX , Historia del Siglo XXI , Humanos , Alimentos Marinos , Contaminantes Químicos del Agua/historia
4.
Exp Physiol ; 102(8): 974-984, 2017 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-28590038

RESUMEN

NEW FINDINGS: What is the central question of this study? We investigated the effects of oestrogen and Cimicifuga racemosa on the stellate ganglion, cardiac noradrenaline pathway and Ca2+ -calmodulin-dependent protein kinase II in ovariectomized rats. What is the main finding and its importance? The right stellate ganglion, but not the left, may be associated with decreased left ventricular noradrenaline content in ovariectomized rats. Oestrogen can reverse all changes caused by ovariectomy. Cimicifuga racemosa did not affect left ventricular noradrenaline, but decreased protein expression of ß1 -adrenergic receptor and Ca2+ -calmodulin-dependent protein kinase II. The results might explain potential effects of C. racemosa on the cardiovascular system and provide new insights into cardiovascular protection. The aim of this study was to investigate the effects of oestrogen and Cimicifuga racemosa on the stellate ganglion, cardiac noradrenaline (NA) pathway and Ca2+ -calmodulin-dependent protein kinase II (CaMK II). Forty adult female Sprague-Dawley rats were randomly divided into the following four groups: sham operated (SHAM); ovariectomized (OVX); ovariectomized with oestrogen treatment (E2); and ovariectomized with C. racemosa treatment (iCR). After 4 weeks of treatment, the NA content was determined by high-performance liquid chromatography, and dopamine ß-hydroxylase (DBH) and noradrenaline transporter (NET) expression were detected by immunohistochemistry. Western blotting was used to determine NET, ß1 -adrenergic receptor (ß1 -AR) and CaMK II expression. Compared with the SHAM group, body weights, DBH and NET expression in the right stellate ganglia, and NET, ß1 -AR and CaMK II expression in the left ventricles of the OVX group were increased, whereas left ventricular NA content was decreased; DBH and NET expression in the left stellate ganglion was not significantly different. The indexes of the E2 group were similar to those of the SHAM group. Moreover, in the iCR group, DBH, NET, ß1 -AR and CaMK II expression was decreased; NET expression and NA content of the left ventricle remained unchanged. Our conclusions are as follows. First, the right stellate ganglion, but not the left, may be associated with decreased left ventricular NA content in OVX rats. Second, oestrogen increases the left ventricular NA content and adjusts the expression of DBH and NET in the right stellate ganglion and restores ß1 -AR and CaMK II protein expression to normal levels. Third, C. racemosa does not affect left ventricular NA, but decreases the protein expression of ß1 -AR and CaMK II.


Asunto(s)
Cimicifuga/química , Estrógenos/farmacología , Ventrículos Cardíacos/efectos de los fármacos , Norepinefrina/metabolismo , Extractos Vegetales/farmacología , Animales , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/metabolismo , Dopamina beta-Hidroxilasa/metabolismo , Femenino , Proteínas de Transporte de Noradrenalina a través de la Membrana Plasmática/metabolismo , Ovariectomía/métodos , Ratas , Ratas Sprague-Dawley , Receptores Adrenérgicos beta 1/metabolismo , Ganglio Estrellado/efectos de los fármacos
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