•An integrated framework for ecological protection and restoration is proposed.•Recreational service is estimated by considering spatial accessibility.•Priority areas of protection are identified ...based on trade-off of ecosystem service.•Ecological protection and restoration pattern is identified at the two scales.•Land management measures are proposed for ecological protection and restoration.
Ecological protection and restoration is an important bridge to adjust the contradiction between ecological protection and economic development, and it is essential for ecological security and sustainable development. An integrated evaluation framework for multiscale ecological protection and restoration based on multi-scenario trade-offs of ecosystem services was proposed in this study, and the city of Nanjing was taken as an example to identify key areas and land strategies for ecological protection and restoration. In our framework, carbon storage, habitat quality, nitrogen retention, and water conservation services were quantified by InVEST model, and recreational service was quantified as the total areas of green spaces within ecological land accessibility. The ordered weighted averaging model was used to simulate the priority areas of ecological protection under 11 scenarios of trade-offs of ecosystem services, and ecological sources, ecological corridors, ecological pinch points and ecological barriers at the Nanjing city scale and the main urban scale were identified based on circuit theory. We also nested the ecological conservation and restoration patterns at two scales and analyzed the coincidence degree between two scales. Our results showed that the S7 scenario had the highest average conservation efficiency among the 11 scenarios. The priority areas for ecological protection in this scenario had an area of 1582 km2 and are mainly distributed in the central and southern parts of Nanjing. In our study, 50 ecological sources (with an area of 1153.36 km2), 77 ecological corridors (with a length of 443.04 km), 25 key nodes for ecological protection and 31 key nodes for ecological restoration were identified in Nanjing. By nesting the ecological protection and restoration patterns of two scales, we found that the overlap of ecological sources and ecological pinch points at two scales is 100%, and the overlap of ecological corridors and ecological barriers is 45.28% and 57.14%, respectively, which means that the ecological protection and restoration patterns at the two scales in Nanjing were well connected, but the ecological network at the large scale cannot fully reflect the real ecological problems and needs at the small scale. We suggest regarding the ecological protection and restoration pattern at large scale as the basis and the pattern at small scale as the supplement. We also propose that priority should be given to the protection and restoration of key areas where the two scales overlap, and strictly control their land development to promote sustainable development. This framework and these strategies are applicable to other rapidly urbanizing regions of the world.
Xylanase is an important enzyme involved in degrading xylan. In this study, an extracellular cellulase-free, thermostable endo-xylanase which was produced by Streptomyces griseorubens LH-3 with ...bagasse semi-cellulose as a carbon source was purified and characterized. The xylanase was purified 4-fold with a recovery yield of 21.6% by precipitation with 25–55% (NH4)2SO4, Mono Q ion exchange chromatography and sephacryl S-200 HR gel filtration chromatography. It appeared as a monomeric protein on SDS-PAGE gel and had an apparent molecular weight of 45.5 kDa with specific activity of 434 IU/mg. Using birchwood xylan as substrate, the maximum velocity (Vmax) and Michaelis–Menten constant (Km) were found to be 1.44 mg/ml and 2.05 μmol/min mg, respectively. The purified xylanase was active at pH 4.0–8.0 with an optimum pH of 5.0. It was stable at temperatures between 30°C and 50°C, exhibiting maximum activity at 60°C. Hg2+ and Al3+ inhibited the enzyme activity significantly. Enzymatic product analysis indicated that the enzyme was an endo-xylanase, whose hydrolysis products were mainly a series of short-chain xylooligosaccharides. Furthermore, it was used for biobleaching of eucalyptus kraft pulp, and results showed that this purified xylanase increased the brightness of the pulp by 14.5% and reduced the kappa number by 24.5%. All these industrially relevant characteristics made it had potential application in the pulp and paper industry as a biobleaching agent.
The excessive use of cultivated land for non-grain production activities is considered a threat to grain security. This study presents an analysis framework on unraveling the causal mechanisms for ...non-grain production of cultivated land. We apply the analysis framework in Liyang, which is located in the Yangtze River Delta and is also an important “national grain base” county of China. We first determine four non-grain production categories as immediately recoverable (IMR), simple-engineering recoverable (SER), engineering recoverable (ENR), and irrecoverable (IR) based on the effect of non-grain activities on the degree of soil damage of the cultivated land, especially the difficulty of restoring the capacity for grain production. Then, we analyze the spatial pattern features for non-grain production of four given categories at the village scale. Furthermore, we reveal the mechanisms of the four categories using multiple linear regression modeling with geophysical, demographic, economic, and policy variables. The results show that the total non-grain area of cultivated land in Liyang is 28,158.38 hectares, and the non-grain rate is 48.09%, ranging from 10.59% to 96.75% among villages. The IMR, SER, ER, and IR rates are 11.81%, 17.76%, 15.07%, and 3.45%, respectively. There is also a significant neighborhood effect among the four categories, indicating that non-grain production activities have a stimulating effect on the surrounding operators of cultivated land. Farming conditions such as the proportion of irrigated farmland and economic variables such as the tourism scale have stronger effects on non-grain production than demographic variables. Policy variables, especially the cultivated land transfer policy, neither inhibit nor promote non-grain production. Based on these findings, we make policy suggestions for reducing non-grain production activities and protecting cultivated land. This analysis framework contributes to a new perspective for unraveling the causal mechanisms and making categorical governance decisions of non-grain production on cultivated land at the village level.
To understand and respond to the common ecological and environmental challenges faced by human beings, this study investigated the relationship between territorial spatial development (TSD), ...eco-environmental responses, and territorial spatial planning (TSP) from the perspective of human-environment interactions and explores a feasible way to modulate these human-environment interactions by taking China’s TSP practice as an illustrative case. The research results show that (1) the interplay between territorial development, resource utilization, and environmental feedback forms the crux of human-environment interactions. Notably, eco-environment responses, one of which is the spread of germs, coupled with human development and utilization behavior constitute a complete negative feedback loop. Human beings’ adjustment to the unbalanced conditions in these interactions, employing institutions, technology, planning, and other tools, constitutes a positive cycle within human-environment interactions. (2) TSP can regulate the whole process of human-environment interactions through mechanisms such as coordination and control, adaptation and mitigation, and consolidation and restoration. (3) Unreasonable agricultural development and urban expansion have triggered intense negative feedback on the ecological environment. (4) The Chinese government has carried out a top-down TSP reform initiative to establish a unified planning system. This aims to alleviate the adverse ecological and environmental effects caused by TSD and build a more secure territory space pattern. Therefore, nations around the globe should innovate their spatial planning management systems and spatial planning systems, standardize and guide the development and utilization of spatial resources, and coordinate the relationship between humans and the environment.
In this study, decolorized pectic polysaccharides (D-ACLP) with molecular weight (Mw) distribution of 3483– 2,023,656 Da were prepared from Amaranth caudatus leaves. Purified polysaccharides (P-ACLP) ...with the Mw of 152,955 Da were further isolated from D-ACLP through gel filtration. The structure of P-ACLP was analyzed by 1D and 2D NMR spectra. P-ACLP were identified as rhamnogalacturonan-I (RG-I) containing dimeric arabinose side chains. The main chain of P-ACLP was composed of →4)-α-GalpA-(1→, →2)-β-Rhap-(1→, →3)-β-Galp-(1→ and →6)-β-Galp-(1→. There was a branched chain of α-Araf-(1→2)-α-Araf-(1→ connected to the O-6 position of →3)-β-Galp-(1→. The GalpA residues were partially methyl esterified at O-6 and acetylated at O-3. The 28-day consecutive gavage of D-ALCP (400 mg/kg) significantly elevated the hippocampal glucagon-like peptide-1 (GLP-1) levels in rats. The concentrations of butyric acid and total short chain fatty acids in the cecum contents also increased significantly. Moreover, D-ACLP could significantly increase the gut microbiota diversity and dramatically up-regulated the abundance of Actinobacteriota (phylum) and unclassified Oscillospiraceae (genus) in intestinal bacteria. Taking together, D-ACLP might promote the hippocampal GLP-1 level through the beneficial regulation of butyric acid-producing bacteria in gut microbiota. This study contributed to making full use of Amaranth caudatus leaves for cognitive dysfunction intervention in food industry.
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•Pectic polysaccharides from Amaranth caudatus leaves are first characterized.•The pectic polysaccharides belong to rhamnogalacturonan-I (RG-I).•The pectic polysaccharides promote the hippocampal GLP-1 levels in rats.•Gut butyric acid-producing bacteria are related to the increased GLP-1 level.
A series of Cr and Fe promoted Rh-based silica supported catalysts were prepared by an incipient co-impregnation method. The performance of the catalysts was investigated by the hydrogenation of ...carbon monoxide to ethanol. The catalysts were characterized by N
2
adsorption-desorption, X-ray diffraction, transmission electron microscopy, H
2
temperature-programmed reduction, temperature programmed surface reaction, and Fourier transform infrared spectroscopy. The results revealed that addition of 0.2-0.4 wt% Cr to Rh/SiO
2
increased its activity significantly. However, further addition of 0.1-0.2 wt% Fe lowered CO conversion slightly, while the selectivity towards ethanol was enhanced significantly. Therefore, high catalytic activity and selectivity toward ethanol were achieved by simultaneous introduction of 0.4 wt% Cr and 0.2 wt% Fe to Rh/SiO
2
. This may be due to improved dispersion of Rh particles, moderate ability to dissociate CO molecules, and high ratio of Rh
+
sites to Rh
0
sites.
The mode of contact between Rh and Cr is different to that between Rh and Fe.
A polysaccharide CY-2 from C. yunnanensis was obtained through a process of consecutive water extraction, alcohol precipitation, and DEAE-52 fast-flow chromatography. CY-2, with an average molecular ...weight of 2.69 × 104 Da mainly consisted of glucose and mannose with a molar ratio of 33.5: 56.9. Infrared spectrum (IR), methylation analysis, and nuclear magnetic resonance (NMR) results revealed that CY-2 may have a backbone consisting of →6)-α-D-Manp-(1 → 3)-β-D-Glcp-(1→, and branch chain β-D-Glcp-(1→. Meanwhile, CY-2 had a higher inhibition rate on α-glucosidase activity compared with other fractions (CY-0, CY-1, and CY-4) and was a mixed competitive inhibitor. In addition, CY-2 at the concentration of 10 μg/mL presented a superior power to improve glucose consumption and metabolism in HepG2 cells compared with metformin. Overall, these findings highlight the potential value of CY-2 as a hypoglycemic agent.
A series of Cr and Fe promoted Rh-based silica supported catalysts were prepared by an incipient co-impregnation method. The performance of the catalysts was investigated by the hydrogenation of ...carbon monoxide to ethanol. The catalysts were characterized by N 2 adsorption–desorption, X-ray diffraction, transmission electron microscopy, H 2 temperature-programmed reduction, temperature programmed surface reaction, and Fourier transform infrared spectroscopy. The results revealed that addition of 0.2–0.4 wt% Cr to Rh/SiO 2 increased its activity significantly. However, further addition of 0.1–0.2 wt% Fe lowered CO conversion slightly, while the selectivity towards ethanol was enhanced significantly. Therefore, high catalytic activity and selectivity toward ethanol were achieved by simultaneous introduction of 0.4 wt% Cr and 0.2 wt% Fe to Rh/SiO 2 . This may be due to improved dispersion of Rh particles, moderate ability to dissociate CO molecules, and high ratio of Rh + sites to Rh 0 sites.
A series of Rh–Mn–Li/SiO
2
catalysts were prepared by the impregnation of a silica support with solutions containing metal precursors with different amounts of urea. Catalyst performance was ...investigated by the hydrogenation of carbon monoxide. The catalysts were characterized by X-ray diffraction, transmission electron microscopy, hydrogen chemisorption, diffuse reflectance ultraviolet–visible (DR UV–Vis) spectroscopy, and thermogravimetric analysis. The results revealed that the amount of urea had a significant effect on the particle size of Rh, which increased from approximately 2–5 nm with the increase in urea loading from 0 to 2.0 wt%. DR UV–Vis spectra indicated that the increase in the Rh particle size with increasing urea loading might be attributed to the coordination of Rh
3+
with urea or its derivatives during calcination. At a urea loading of 1.0 wt%, the particle size of Rh was 3.7 nm, and the space time yield of C
2+
oxygenates reached a maximum of 560.0 g kg
−1
h
−1
.
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