RESUMEN
Watershed ecosystems play a pivotal role in maintaining the global carbon cycle and reducing global warming by serving as vital carbon reservoirs for sustainable ecosystem management. In this study, we based on the "quantity-mechanism-scenario" frameworks, integrate the MCE-CA-Markov and InVEST models to evaluate the spatiotemporal variations of carbon stocks in mid- to high-latitude alpine watersheds in China under historical and future climate scenarios. Additionally, the study employs the Geographic Detector model to explore the driving mechanisms influencing the carbon storage capacity of watershed ecosystems. The results showed that the carbon stock of the watershed increased by about 15.9 Tg from 1980 to 2020. Fractional Vegetation Cover (FVC), Digital Elevation Model (DEM), and Mean Annual Temperature (MAT) had the strongest explanatory power for carbon stocks. Under different climate scenarios, it was found that the SSP2-4.5 scenario had a significant rise in carbon stock from 2020 to 2050, roughly 24.1 Tg. This increase was primarily observed in the southeastern region of the watersheds, with forest and grassland effectively protected. Conversely, according to the SSP5-8.5 scenario, the carbon stock would decrease by about 50.53 Tg with the expansion of cultivated and construction land in the watershed's southwest part. Therefore, given the vulnerability of mid- to high-latitude mountain watersheds, global warming trends continue to pose a greater threat to carbon sequestration in watersheds. Our findings carry important implications for tackling potential ecological threats in mid- to high-latitude watersheds in the Northern Hemisphere and assisting policymakers in creating carbon sequestration plans, as well as for reducing climate change.
Asunto(s)
Carbono , Cambio Climático , Ecosistema , Monitoreo del Ambiente , China , Carbono/análisis , Secuestro de Carbono , Ciclo del Carbono , Conservación de los Recursos Naturales , Modelos TeóricosRESUMEN
The objective of this study was to compare the effects of nanoselenium (NS) and selenium yeast (SY) on the performance, egg selenium (Se) concentration, and anti-oxidative capacity of hens. A total of 216 Brown Hy-line hens (29-week old) were randomly allocated into three treatments (6 replicate/treatment, 12 hens/replicate). The pre-trial period lasted 7 days, and the experimental period lasted 35 days. Dietary treatments included corn-soybean meal basal diet (containing 0.16 µg Se/g, as control group), and basal diet supplemented with 0.3 mg Se/kg diet (Se was from NS or SY), called as SY group or NS group, respectively. At the end of the experiment, one hen per replicate from each treatment was slaughtered. Liver, spleen, and kidney tissues were sampled for the determination of Se concentrations. The results showed that NS or SY supplement significantly improved feed conversion ratio (P < 0.05), soft broken egg rate (P < 0.05), and the serum T-AOC value (P < 0.05) when compared with control group. Remarkably, the deposition of Se increased significantly (P < 0.05) and equivalently in egg, liver, and kidney of hens supplemented with both NS and SY. Interestingly, SY supplement also enhanced the serum CAT and SOD activities (P < 0.05), NS but not SY significantly reduced serum MDA (P < 0.05), whereas RT-PCR results did not show significant differences in the mRNA levels of antioxidant genes among three groups (P > 0.05). Taken together, dietary supplemented with SY or NS improved the Se deposition in eggs, liver and kidney of laying hens, increased antioxidant activity, and NS supplement had greater Se deposition in the kidney tissue than SY supplement. SY or NS supplement could be considered to be applied for Se-enriched egg production.
Asunto(s)
Selenio , Levadura Seca , Alimentación Animal/análisis , Animales , Pollos , Dieta , Suplementos Dietéticos , Huevos , Femenino , Saccharomyces cerevisiae , Selenio/farmacologíaRESUMEN
Supplementation of selenium (Se) is a common practice in the poultry industry via sodium selenite (SS) and selenium yeast (SY), while the effects of nano-selenium (NS) on laying hens are poorly known. This study aimed to compare the effects of NS, SS, and SY on productivity; selenium (Se) deposition in eggs; and antioxidant capacity in laying hens. A total of 288 30-week-old Brown Hy-line laying hens were randomly assigned into four dietary treatments, which included corn-soybean meal basal diet (Con) without Se sources and basal diets supplemented with 0.3 mg Se/kg as SS, SY, or NS, respectively. The results exhibited that Se-supplemented treatments achieved greater egg production, egg weight, and daily egg mass, also better feed conversion ratio than Con group (p < 0.05). Se supplementation significant increased egg Se concentration and decreased the egg Se deposition efficiency (p < 0.05), while SY or NS supplementation had higher Se deposition efficiency than SS group at 35 days (p < 0.05). Moreover, serum glutathione peroxidase (GSH-Px) activity increased in SS or NS group compared to Con group (p < 0.05). The glutathione peroxidase 4 (GPX-4) mRNA levels in liver were significantly higher (p < 0.05) in SS or SY group than in NS group, and mRNA levels of the methionine (Met) metabolism gene glycine N-methyltranserfase (GNMT) were markedly upregulated (p < 0.05) in SY group compared to SS or NS group. Taken together, the results revealed Se from SY is deposited into eggs more efficiently than Se from NS or SS, probably via enhancing the route of Met metabolism. Meanwhile, it might be concluded that SS or SY supplementation directly regulated GSH-Px activity via enhancing GPx4 level, whereas NS via GPx1, thus affecting body oxidation and development.
Asunto(s)
Antioxidantes/metabolismo , Selenio/análisis , Selenio/metabolismo , Animales , Pollos , Suplementos Dietéticos , Huevos , Femenino , Glutatión Peroxidasa/metabolismo , Selenito de Sodio/análisis , Selenito de Sodio/metabolismoRESUMEN
OBJECTIVE: To investigate the antitumor effect of lycorine on renal cell carcinoma ACHN cells and explore the possible mechanism. METHODS: We used flow cytometry to examine the effect of lycorine on ACHN cell cycle and apoptosis. The cell proliferation, migration and invasion were assessed with MTS assay, wound healing assay, and Transwell assay, respectively. Colony forming assay was performed, and the mRNA and protein levels of Bax, Bcl-2, survivin, caspase-3, cyclin D1 and CDK4 were measured with qRT-PCR and Western blotting. RESULTS: Lycorine obviously inhibited the proliferation of ACHN cells with an IC(50) of 24.34 µmol/L. Lycorine also induced apoptosis of ACHN cells, caused cell cycle arrest at G(0)/G(1) phase, and suppressed the colony forming ability of the cells in a dose-dependent manner. The migration and invasion of ACHN cells were significantly inhibited by 5 µmol/L lycorine. Lycorine up-regulated the mRNA levels of CDK4, Bax, caspase-3 while down-regulated the levels of survivin, Bcl-2 and Cyclin D1; the protein levels of CDK4 and Bax were increased and cyclin D1, Bcl-2 and surviving expressions were decreased, but caspase-3 expression showed no significant changes following the treatment. CONCLUSION: Lycorine has obvious antitumor effect against ACHN cells, suggesting its value as a new therapeutic agent for renal cell carcinoma.