This paper used a multi-period DID model with panel data from 283 Chinese cities between 2006 and 2019 to investigate the emission reduction effects and mechanisms of China's carbon trading scheme. ...The research revealed that China's Carbon Emissions Trading Scheme not only stimulated businesses to reduce emissions as a market-based environmental regulation policy but also influenced local governments' governance objectives. As a result, the Hawthorne effect inevitably manifested during the experimental period of China's Carbon Emissions Trading Scheme. Further analysis indicated that China's CETS encouraged local authorities to take a more proactive stance towards the balance between environmental preservation and economic growth, aiming to achieve a mutually beneficial outcome. Based on the political stance of local governments, they are likely to simultaneously increase their focus on both economic growth and environmental protection. However, when faced with the conflict between economic advancement and environmental safeguarding, pilot regions prioritized ecological conservation in their practical steps, leading to a modest decline in economic growth. In other words, the government's high-profile announcements may not always manifest in actual deeds. In practice, local authorities tend to allocate more administrative resources to areas highly prioritized by the central government. Furthermore, the extended analysis reveals that China's CETS has resulted in a reduction in social welfare due to a shift in governance priorities influenced by political incentives. Therefore, fine-tuning the performance evaluation mechanism, preventing any bias towards the target preferences of local authorities, and guaranteeing the successful operation of the market mechanism are imperative to achieve truly low-cost and sustainable emissions reductions objectives for CETS.
Atmospheric CO2 and global climate are closely coupled. Since 800ka CO2 concentrations have been up to 50% higher during interglacial compared to glacial periods. Because of its dependence on ...temperature, humidity, and erosion rates, chemical weathering of exposed silicate minerals was suggested to have dampened these cyclic variations of atmospheric composition. Cooler and drier conditions and lower non-glacial erosion rates suppressed in situ chemical weathering rates during glacial periods. However, using systematic variations in major element geochemistry, Sr–Nd isotopes and clay mineral records from Ocean Drilling Program Sites 1143 and 1144 in the South China Sea spanning the last 1.1Ma, we show that sediment deposited during glacial periods was more weathered than sediment delivered during interglacials. We attribute this to subaerial exposure and weathering of unconsolidated shelf sediments during glacial sealevel lowstands. Our estimates suggest that enhanced silicate weathering of tropical shelf sediments exposed during glacial lowstands can account for ∼9% of the carbon dioxide removed from the atmosphere during the glacial and thus represent a significant part of the observed glacial–interglacial variation of ∼80ppmv. As a result, if similar magnitudes can be identified in other tropical shelf-slope systems, the effects of increased sediment exposure and subsequent silicate weathering during lowstands could have potentially enhanced the drawdown of atmospheric CO2 during cold stages of the Quaternary. This in turn would have caused an intensification of glacial cycles.
Intestinal microbiota dysregulation is considered the primary trigger of low-grade inflammation responsible for weight loss due to heat stress. 1,8-Cineole is the major bacteriostatic agent in ...eucalypt and possesses remarkable anti-inflammatory properties. However, the mechanisms of its effect on intestinal microbiota remain unclear. In this study, 1,8-cineole was prepared into microcapsules prior to use as feed supplement in chickens. The microencapsulation efficiency and chemical stability of 1,8-cineole microcapsules were evaluated. The chicken treatment with 1,8-cineole microcapsules (1 or 3%) for 45 days, in the presence or absence of heat stress for fifteen days, commenced on Day 31, with or without an antibiotics mix (Abx) for three days on Day 27. Performance parameters were measured once a week from Day 30 through Day 45. Surface and entrapped concentration of 1,8-cineole was estimated as 7.89 g/100 g powder in the microcapsules. The time to maximal concentration (T
, terminal half-life (T
), and the area under plasma concentration-time curve (AUC
) of the encapsulated 1,8-cineole were higher than those of the nonencapsulated in treated chickens, although the maximal concentrations (C
) were similar. Chickens treated under higher temperatures with 1,8-cineole microcapsules exhibited lower levels of grade inflammation and higher body weight gain. Dietary 1,8-cineole microcapsules recovered the normal structure of upper ileum and altered the ratio of gut microbiota under heat stress and increased the ratio of
and
, whereas the proportion of
decreased based on 16S rRNA analysis of the upper ileum microbiota.
, 1,8-cineole effectively inhibited the growth of
as demonstrated by inhibition zone assay. In summary, our findings elucidated the interaction between 1,8-cineole and intestinal microbiota as a new mechanism for the anti-heat stress effect of 1,8-cineole in preventing low-grade inflammation and weight loss. The results suggest that 1,8-cineole microcapsules may be a good feed supplement to protect against heat stress injury.
In the work, a numerical method of the 2D Helmholtz equation with meshless interpolation collocation method is developed, which is defined in arbitrary domain with irregular shape. In our numerical ...method, based on the Chebyshev points, the partial derivatives and the spatial variables are discretized by the barycentric rational form basis function. After that the differential equations are simplified by employing differential matrix. To verify the the accuracy, effectiveness and stability in our method, some numerical tests based on the three types of different test points are adopted. Moreover, we can also verify that present method can be applied to both variable wave number problems and high wave number problems.
Gut microbiota play important roles in their co-evolution with mammals. However, little is understood about gut bacterial community of Tibetan sheep compared with other sheep breeds. In this study, ...we investigated the gut bacterial community in 4 different sheep breeds living in the Qinghai-Tibetan Plateau (QTP) of China using high-throughput sequencing (HTS) technique.
The results suggested that bacterial community abundance and breeds diversity of Tibetan sheep (TS) were significantly lower than that of the other three breeds of sheep Dorset sheep (DrS), Dorper sheep (DrS) and Small Tail Han sheep (STHS) (p < 0.05). Principal coordinates analysis (PCoA) and nonmetric multidimensional scaling (NMDS) analysis indicated that microbiome composition of TS was significantly different from that of other three sheep breeds (p < 0.01). Firmicutes was the most predominant microbial phylum in the gut, followed by Bacteroidetes. The gut bacterial community of TS showed higher proportions of phylum Spirochaetes, Proteobacteria and Verrucomicrobia, compared to the other three sheep breeds, but the Deferribacteres was absent in TS. At the genus level, Treponema, Succinivibrio, 5-7 N15 and Prevotella showed significantly higher abundance in TS than in the other three sheep breeds (p < 0.05).
In this study, we first employed HTS to understand the gut microbiomes among different sheep breeds in QTP of China.
We aimed to reuse the propylene oxide sludge (POS). Propylene oxide sludge shell-aggregate (POSS-A) and propylene oxide sludge gradient shell-aggregate (POSGS-A) whose main hydrated phase is ...tobermorite were successfully manufactured by the hydrothermal synthesis of POS and silica materials under the condition of autoclaved (180 °C, 1.0 MPa) curing. Influences of pre-wetting time of coarse aggregate and pressure application mode on the different concretes were investigated. The experimental results show that the concrete with POSS-A as coarse aggregate (POSS-A concrete), the concrete with POS gradient shell-aggregate as coarse aggregate (POSGS-A concrete), sintered aggregate concrete and common concrete, all have excellent impermeability performance whatever the pre-wetting time of coarse aggregate is 0.5 h or 24 h, and the pre-wetting time of coarse aggregate has a negligible influence on the concrete. The influence degree of pressure application mode on the impermeability performance of the sintered aggregate concrete is the greatest among three kinds of concrete, which has a negligible influence on impermeability performance of the other concretes. POSGS-A can be used as a green building light aggregate in hydraulic concrete.
Change detection for remote sensing images is an indispensable procedure for many remote sensing applications, such as geological disaster assessment, environmental monitoring, and urban development ...monitoring. Through this technique, the difference in certain areas after some emergencies can be determined to estimate their influence. Additionally, by analyzing the sequential difference maps, the change tendency can be found to help to predict future changes, such as urban development and environmental pollution. The complex variety of changes and interferential changes caused by imaging processing, such as season, weather and sensors, are critical factors that affect the effectiveness of change detection methods. Recently, there have been many research achievements surrounding this topic, but a perfect solution to all the problems in change detection has not yet been achieved. In this paper, we mainly focus on reducing the influence of imaging processing through the deep neural network technique with limited labeled samples. The attention-guided Siamese fusion network is constructed based on one basic Siamese network for change detection. In contrast to common processing, besides high-level feature fusion, feature fusion is operated during the whole feature extraction process by using an attention information fusion module. This module can not only realize the information fusion of two feature extraction network branches, but also guide the feature learning network to focus on feature channels with high importance. Finally, extensive experiments were performed on three public datasets, which could verify the significance of information fusion and the guidance of the attention mechanism during feature learning in comparison with related methods.
Multiple upwelling systems develop in the Indian Ocean during the summer monsoon. The Sri Lanka dome (SLD), which occurs in the open ocean off the east coast of Sri Lanka from June to September, is ...distinct from those near the coast. The SLD is characterized by uplifted thermocline and increased chlorophyll concentration. Mechanisms of the upwelling and its biogeochemical response are not well understood. Here, we explored the dynamics of the chlorophyll and sea-to-air CO2 flux in the SLD using ocean color and altimetry remote sensing data, together with other reanalysis products. We found that the occurrence of high chlorophyll concentration and sea-to-air CO2 flux happens along the pathway of the southwest monsoon current (SMC). The annual cycle of chlorophyll in the SLD has a one-month lag relative to that in the southern coast of Sri Lanka. The positive wind stress curl that forms in the SLD during the summer does not fully explain the seasonal chlorophyll maximum. Transport of the SMC, eddy activity, and associated frontal processes also play an important role in regulating the variability in chlorophyll. In the SLD, upwelled subsurface water has excess dissolved inorganic carbon (DIC) relative to the conventional Redfield ratio between DIC and nutrients; thus, upwelling and sub-mesoscale processes determine this region to be a net carbon source to the atmosphere.
How functional peptides may have arisen is a significant problem for the scenario of the RNA world. An attractive idea, the direct RNA template (DRT) hypothesis, proposes that RNA molecules can bind ...amino acids specifically and promote the synthesis of corresponding peptides, thereby starting the RNA/peptides world. To investigate the plausibility of this idea, we modeled the emergence of a "membrane-stabilizing peptide" in RNA-based protocells-such a peptide was suggested to have appeared early in the RNA world based on experimental evidence. The computer simulation demonstrated that the protocells containing the "RNA gene" encoding this peptide may spread in the system owing to the peptide's function. The RNA gene may either originate de novo in protocells or emerge in protocells already containing ribozymes-here we adopt a nucleotide synthetase ribozyme as an example. Furthermore, interestingly, we show that a "nucleotide synthetase peptide" encoded by RNA (also via the DRT mechanism) may substitute the nucleotide synthetase ribozyme in evolution, which may represent how "functional-takeover" in the RNA world could have occurred. Overall, we conclude that the transition from the RNA world towards an RNA/peptides world may well have been mediated by the DRT mechanism. Remarkably, the successful modeling on the emergence of membrane-stabilizing peptide in RNA-based protocells is per se significant, which may imply a "promising" way for peptides to enter the RNA world, especially considering the weak interaction between RNA and the membrane in chemistry.
The oxygen minimum zone has a significant effect on primary production, marine biodiversity, food web structure, and marine biogeochemical cycle. The Arabian Sea oxygen minimum zone (ASOMZ) is one of ...the largest and most extreme oxygen minimum zones in the world, with a positional decoupling from the region of phytoplankton blooms. The core of the ASOMZ is located to the east of the high primary production region in the western Arabian Sea. In this study, a coupled physical–biogeochemical numerical model was used to quantify the impact of ocean circulation and settling of particulate organic matters (POMs) on the decoupling of the ASOMZ. Model results demonstrate that the increased (decreased) dissolved oxygen replenishment in the western (central) Arabian Sea is responsible for decoupling. The oxygen-rich intermediate water (200–1,000 m) from the southern Arabian Sea enters the Arabian Sea along the west coast and hardly reaches the central Arabian Sea, resulting in a significant oxygen replenishment in the western Arabian Sea high-productivity region (Gulf of Aden) but only a minor contribution in the central Arabian Sea. Besides that, the POMs that are remineralized to consume central Arabian Sea dissolved oxygen comprises not only local productivity in winter bloom but also the transport from the western Arabian Sea high-productivity region (Oman coast) in summer bloom. More dissolved oxygen replenishment in the western Arabian Sea, and higher dissolved oxygen consumption and fewer dissolved oxygen replenishment in the central Arabian Sea could contribute to the decoupling of the ASOMZ and phytoplankton productive zone.
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