Search

Abstract Assessing the impact of past and future urban land expansion on ecosystem services (ESs) is essential for the sustainable management of urban landscapes. Despite recent progress, it remains challenging to determine the influence mechanism of different urbanization stages and areas on ESs and their trade-offs/synergies. Here, we analyzed the responses of four ESs and their trade-offs/synergies to the spatial and temporal differentiation of urbanization in the Su-Xi-Chang region of China from 1990 to 2050. The results showed that the relationship between ESs and urbanization followed a U-shaped curve from 1990 to 2050. Between 1990 and 2020, urbanization weakened trade-offs and enhanced lose-lose situations, exhibiting an S-shaped curve. From 2020 to 2050, lose-lose situations are expected to diminish, and the curve is projected to display a downward trend. Our findings suggest the implementation of compact urban development, sustainable agricultural practices, reforestation, and the conversion of farmland to lakes.

Abstract Background Chickens are one of the most widely farmed animals worldwide and play a crucial role in meat and egg production. Gut microbiota is essential for chickens’ health, disease, growth, and egg production. However, native chickens such as Jianghan chickens have better meat and egg production quality than centralized chickens, their intestinal microbial diversity is richer, and the potential gut microbial resources may bring health benefits to the host. Results The bacterial species composition in the gut microbiota of Jianghan chickens is similar to that of other chicken breeds, with Phocaeicola and Bacteroides being the most abundant bacterial genera. The LEfSe analysis revealed significant differences in species composition and functional profiles between samples from Jingzhou and the other three groups. Functional annotation indicated that the gut microbiota of Jianghan chickens were dominated by metabolic genes, with the highest number of genes related to carbohydrate metabolism. Several antibiotic resistance genes (ARGs) were found, and the composition of ARGs was similar to that of factory-farmed chickens, suggesting that antibiotics were widely present in the gut microbiota of Jianghan chickens. The resistance genes of Jianghan chickens are mainly carried by microorganisms of the Bacteroidota and Bacillota phylum. In addition, more than 829 isolates were selected from the microbiota of Jianghan chickens. Following three rounds of acid and bile tolerance experiments performed on all the isolated strains, it was determined that six strains of Pediococcus acidilactici exhibited consistent tolerance. Further experiments confirmed that three of these strains (A4, B9, and C2) held substantial probiotic potential, with P. acidilactici B9 displaying the highest probiotic potential. Conclusions This study elucidates the composition of the intestinal microbiota and functional gene repertoire in Jianghan chickens. Despite the absence of antibiotic supplementation, the intestinal microbial community of Jianghan chickens still demonstrates a profile of antibiotic resistance genes similar to that of intensively reared chickens, suggesting resistance genes are prevalent in free-ranging poultry. Moreover, Jianghan and intensively reared chickens host major resistance genes differently, an aspect seldom explored between free-range and pastured chickens. Furthermore, among the 829 isolates, three strains of P. acidilatici exhibited strong probiotic potential. These findings provide insights into the unique gut microbiota of Jianghan chickens and highlight potential probiotic strains offering benefits to the host. Video Abstract

Obesity, a global public health challenge, is closely associated with gut microbiota alterations. Probiotics have the potential to prevent obesity, but their effectiveness can vary depending on the specific strain. This study focused on evaluating the anti-obesity and probiotic properties of four Bifidobacterium species isolated from healthy Chinese individuals in vitro. The findings indicated that Bifidobacterium lactis YGMCC2013 showed notable cholesterol assimilation ability, bile salt hydrolase activity, gastrointestinal tolerance, cellular adhesion, and production of short-chain fatty acids. The anti-obesity effect of YGMCC2013 was then assessed in mice fed a high-fat diet. The results demonstrated that YGMCC2013 reduced body and liver weight, adipose tissue hypertrophy and inflammation, and influenced specific microbial genera associated with adipose tissue characteristics. Notably, the study observed associations between certain microbial genera and different types of adipose tissue, indicating that YGMCC2013 may impact the balance and function of adipose tissue through its effects on the gut microbiota. Furthermore, YGMCC2013 enhanced the thermogenic capacity of brown and beige adipocytes, and improved the structure and function of the gut microbiota. These improvements were reflected by an increase in short-chain fatty acids produced by beneficial bacteria in the intestine, and the activation of metabolic pathways related to energy and carbohydrate metabolism. Moreover, YGMCC2013 modulated the expression of il-27 and tgr5 signaling pathways in adipose tissue, which might be involved in regulating adipose tissue inflammation and energy expenditure, respectively. These findings collectively demonstrate that YGMCC2013 has potential as a probiotic candidate for preventing obesity and improving metabolic health by influencing the gut-adipose tissue axis.

Objective Cervical cancer is linked with the constitutive activation of growth factors and gene mutations-induced pro-survival signaling pathways. Herein, we purposed to explore the possible molecular mechanism of Foxo3a-mediated DNMT3B in the proliferation and migration of cervical cancer cells via mediating the PTEN promoter methylation. Methods Foxo3a expression in cervical cancer was tested by qRT-PCR and western blot experiments. The cervical cancer cell biological functions with overexpression of Foxo3a were evaluated by CCK-8 assay, Transwell experiment, and flow cytometry, respectively. MS-PCR was utilized for testing the PTEN methylation levels, and ChIP experiment was implemented for evaluating the enrichment of DNMT3B in the PTEN promoter region and the binding of Foxo3a and DNMT3B. The PTEN methylation and interference with Foxo3a expression were performed in cervical cancer cells, and then their impacts on cervical cancer cell biological functions were observed. Results FOXO3a was expressed at a low level in cervical cancer, and its overexpression contributed to a reduction in cell proliferative, migratory and invasive capabilities, and an elevation in apoptosis rate. Foxo3a blocked its methylation with the PTEN promoter by repressing DNMT3B activity. Upon treatment with methyltransferase inhibitor (5-aza-dc), the malignant phenotypes of cervical cancer cells were diminished. 5-aza-dc neutralized the impacts of silencing Foxo3a on malignant phenotypes. Conclusion This research underlines that Foxo3a blocks its methylation with the PTEN promoter by inhibiting DNMT3B activity, which subsequently impedes cervical cancer cell progression.

Vegetation Net Primary Productivity (NPP) plays a crucial role in terrestrial carbon sinks and the global carbon cycle. Investigating the spatiotemporal dynamics and influencing factors in the Yangtze River Delta (YRD) region can furnish a solid scientific foundation for green, low-carbon, and sustainable development in China, as well as a reference for other rapidly urbanizing regions. This study focuses on the YRD region as an illustration and utilizes the Carnegie–Ames–Stanford Approach (CASA model) to quantify NPP in this region from 2000 to 2018. Investigation into the spatiotemporal dynamics and influencing factors was conducted using Theil–Sen median trend analysis and scenario analysis. The results indicate that the NPP in the YRD region from 2000 to 2018 exhibited pronounced spatial differentiation characteristics, typically exhibiting a spatial distribution pattern of being high in the south and low in the north, high in the west and low in the east. Additionally, the expansion of built-up areas and the reduction in cultivated land have the potential to reduce NPP in the YRD region. Moreover, the influence of land-use and land-cover change (LULCC) is anticipated to be relatively limited compared to that of climate change. Furthermore, changes in precipitation were found to be positively correlated with changes in NPP, with the effect being relatively more pronounced. The correlation between temperature and NPP demonstrated spatial differentiation, with a mainly positive correlation in the central and southern parts of the YRD and a mainly negative correlation in the northern part. Changes in solar radiation had a negative correlation with changes in NPP. Based on these results, it is recommended that local governments strictly enforce urban development boundaries and manage the disorderly expansion of built-up areas, enhance the regional irrigation infrastructure, and address air pollution, so as to ensure the necessary conditions for the growth of vegetation, reduce greenhouse gas emissions, and control regional temperature rises. This study can provide stronger evidence for revealing the influencing mechanisms of NPP through the control of impact conditions and the exclusion of confounding factors via scenario analysis. The policy implications can offer insights into NPP enhancement and environmental management for the YRD and other rapidly urbanizing regions.

Hypercholesterolemia, a risk factor for cardiovascular disease (CVD), often requires therapeutic agents with varying degrees of side effects. This has created a need for safe and natural alternatives such as medications or functional foods that can improve lipid metabolism and reduce cholesterol levels. In recent years, Next-generation probiotics (NGPs) have recently emerged as a potential solution, offering distinct mechanisms compared to traditional probiotics. Among the NGPs, Bacteroides, a dominant bacterial genus in the human gut, has gained significant attention due to its prevalence, ability to break down plant polysaccharides, and production of short-chain fatty acids (SCFAs). Recent evidence has demonstrated that Bacteroides effectively reduces cholesterol levels, prevents obesity, and lowers the risk of CVD. However, research on Bacteroides is currently limited to a few species, leaving rooms for exploration of the beneficial functions of different species in this genus. In this study, we isolated 66 Bacteroides strains, including 9 distinct species, from healthy adults’ fecal samples. By comparing their ability to assimilate cholesterol, we found that the transformation ability was not specific to any particular species. Notably, Bacteroides dorei YGMCC0564 revealed superior cholesterol-lowering capabilities and bile salt hydrolase (BSH) activity in vitro, surpassing that of Lactobacillus GG (LGG). YGMCC0564 exhibited favorable probiotic characteristics, including high survival rate in vitro simulation of gastrointestinal digestion, excellent adhesion ability, susceptibility to antibiotics, absence of hemolysis or virulence genes, and substantial production of SCFAs. The strain also demonstrated remarkable bile salt deconjugation activities and upregulation of the BT_416 gene associated with cholesterol, providing insights into a possible molecular mechanism underlying its cholesterol-reducing activity. These findings establish YGMCC0564 as a promising NPG candidate for improving cardiovascular health.

The silted-up sediment in the reservoir may have a significant influence on the propagation of dam-break flows. In this paper, a three-dimensional numerical simulation of the silted-up dam-break flow is carried out. In this paper, simulations of three-dimensional silted-up dam-break flow are carried out. A kind of Eulerian–Eulerian two-fluid model (TFM), coupled level set and volume of fluid (CLSVOF) methods, is presented. In order to calculate the motions of the air–water interface and the sediment simultaneously, kinetic particle theory (KPT) and computational fluid dynamics (CFD) are combined. The rheology-based constitutive equations of sediment are also considered to simulate scouring and deposition. In addition, a partial-slip boundary condition (BC) for the velocity of the sediment phase at stationary walls is implemented. The simulation results of the benchmark case demonstrate that the proposed model can effectively simulate the silted-up dam-break flow while taking into account multi-interface capturing problems. Subsequently, the simulations of the silted-up dam-break flow over dry are investigated numerically in a three-dimensional long channel. The simulated results reveal that, in the dam-break flows, the silted-up sediment height has a significant influence on wave propagation, dynamic pressure loads, sediment transport, and sediment deposition. HIGHLIGHTS Three-dimensional simulation of silted-up dam-break flow is carried out.; The air–water interface movement is captured by CLSVOF method.; A Eulerian–Eulerian multiphase model coupling kinetic particle theory and computational fluid dynamics is used.; The rheology-based constitutive equations of sediment are considered.; The effect of the silted-up sediment height during a dam-break flow is investigated.;

In order to explore the effect of forward and reverse rotation speeds of rockfall on normal restitution coefficient (Rn), three typical blocks of cube, disc and cylinder were customized, and the impact tests of each block with slope at different forward and reverse rotation speeds in X and Y axes were carried out through the specially developed rockfall impact test device. Results show that the rotation speed has no effect on Rn when the disc and the cylinder shaped blocks rotate around the Y-axis (approximately normal impact); when the three shaped blocks rotate along the X-axis (non-normal impact), there exists a certain correlation between the rotation speed and Rn, but Rn is also affected by the block shape and impact posture. Thus, a comprehensive variable - impact posture coefficient (IPC) was introduced to quantify the effect of rotation speed on Rn. In view of the difference of the mechanical action mechanism of normal impact force on Rn under different impact posture, the impact-rebound characteristics of the blocks were classified and discussed. For the type of rebounding after only one impact, IPC and Rn have linear positive correlation and negative correlation respectively when the mass center (C) is behind and in front of the contact point (CP) in the forward rotation test, and the results of the reverse rotation test were just the opposite. For the type of rebounding after two impacts, regardless of forward or reverse, whether C is behind or in front of CP during the first impact, Rn and IPC of each shaped block are strongly positive correlation, yet the relevant laws are not consistent under various working conditions. These conclusions basically reveal the influence of rotation speed on Rn, and provide a reference for accurate prediction of impact-rebound process of rotating irregular rockfall.

A passive localization algorithm based on UAV aerial images and Angle of Arrival (AOA) is proposed to solve the target passive localization problem. In this paper, the images are captured using fixed-focus shooting. A target localization factor is defined to eliminate the effect of focal length and simplify calculations. To synchronize the positions of multiple UAVs, a dynamic navigation coordinate system is defined with the leader at its center. The target positioning factor is calculated based on image information and azimuth elements within the UAV photoelectric reconnaissance device. The covariance equation is used to derive AOA, which is then used to obtain the target coordinate value by solving the joint UAV swarm positional information. The accuracy of the positioning algorithm is verified by actual aerial images. Based on this, an error model is established, the calculation method of the co-localization PDOP is given, and the correctness of the error model is verified through the simulation of the Monte Carlo statistical method. At the end of the article, the trackless Kalman filter algorithm is designed to improve positioning accuracy, and the simulation analysis is performed on the stationary and moving states of the target. The experimental results show that the algorithm can significantly improve the target positioning accuracy and ensure stable tracking of the target.

Improving our understanding of the patterns and drivers of regional carbon budgets is critical to mitigating climate change regionally and globally. Different from previous research, our study attempts to reveal the comprehensive impact of climate change and human activities factors on the carbon budget. Based on the Carnegie–Ames–Stanford approach (CASA) model, the IPCC inventory method, the ordinary least squares (OLS) regression model, the Geodetector model, and the geographically weighted regression (GWR) method, we investigated the spatiotemporal patterns of the carbon budget in the Yangtze River Delta (YRD) region from 2000 to 2015 and analyzed the effects of climate change and human activities on the carbon budget. The results showed that the carbon budget in the YRD region changed from 271.33 million tons in 2000 to −1193.76 million tons in 2015. During this period, the changes in the carbon budget per unit area in the four provinces all showed a decreasing trend, among which Shanghai decreased the most, followed by Jiangsu, Zhejiang and Anhui. In terms of spatial pattern, the carbon budget of the YRD region has a “core-edge” structural feature. The closer it is to Shanghai, the core area, the more severe the carbon budget deficit; the farther from it, the greater the carbon budget surplus. Overall, we found that human activities have a greater impact on the carbon budget than climate change. The top three drivers were, in order, changes in population density, GDP per capita, and unused land, with q values of 0.3317, 0.1202, and 0.0998, respectively. Locally, the impact of the drivers on the carbon budget shows obvious spatial heterogeneity. In particular, the population density was negatively correlated with carbon budget changes in the entire study area, and the coefficients of GDP per capita and unused land were negative in most counties. Based on the results, we put forward suggestions for restricting population flow among the core area and the peripheral area, promoting industrial innovation in the core area and ecological protection in the peripheral area, as well as implementing three-dimensional space development in the core area and controlling the expansion of construction land in the peripheral area. Our study can provide a scientific basis for low-carbon development in the YRD region. The methodology and findings of this study can provide references for similar studies in other urbanized regions around the world.

Background: This study was performed to determine the mRNA expression levels of limb-bud and heart (LBH) in peripheral blood mononuclear cells (PBMCs) from patients with rheumatoid arthritis (RA), and to assess the associations of LBH rs7579944 and rs906868 polymorphisms with RA in a Chinese population. Methods: Real-time transcription-polymerase chain reaction analysis was used to determine the LBH mRNA expression in PBMCs from 53 patients with RA and 58 healthy controls, and LBH rs7579944 and rs906868 polymorphisms were genotyped in 328 RA patients and 449 healthy controls. Results: The LBH mRNA expression levels were significantly decreased in RA patients compared with healthy controls (p = 0.02). However, non-significant correlation between LBH mRNA expression in PBMCs and ESR (r = 0.14, p = 0.36), CRP (r = 0.17, p = 0.27) or DAS28-ESR (r = 0.23, p = 0.12) was found. There was no significant difference in neither genotype (p = 0.90) nor allele (p = 0.97) distribution of the LBH rs7579944 polymorphism between RA patients and healthy controls. The relationships between the major allele T of LBH rs7579944 polymorphism and the risk of RA under dominant and recessive model were examined, whereas non-significant evidence was found. Similarly, a non-significant signal was detected for the association of LBH rs906868 polymorphism with RA. Conclusions: Decreased expression of LBH mRNA in PBMCs might contribute to the pathogenesis of RA. [ABSTRACT FROM AUTHOR]

In order to evaluate the effect of lactic acid (LA)-assisted low-temperature plasma on the preservation of yellow-feathered broiler carcass, single factor experiments and response surface methodology were used to investigate total viable count (TVC), coliform count (CC) and fat oxidation value as a function of three variables, namely LA concentration (V/V), discharge voltage, and discharge time. Microbiological, physicochemical, and quality indicators of chicken were determined during storage after sterilization under optimized conditions. The results showed that the optimal sterilization parameters were LA concentration of 2.0%, discharge voltage of 150 kV, and discharge time of 115 s. Under these conditions, the TVC and CC on the surface of chicken and its fat oxidation value were 3.02, 1.00 (lg(CFU/g)) and 0.58 mg/kg, respectively. On the 7th day of storage, the inhibitory effects of LA-assisted low-temperature plasma on TVC and CC increased by 26.75% and 19.72% compared with those of LA, by 34.51% and 24.87% compared with those of low-temperature plasma, respectively, and the combination decreased the total volatile basic nitrogen (TVB-N) content by 27.35% and 12.25% compared with single treatments with LA and low-temperature plasma, respectively. In addition, the combination treatment delayed the increase in pH of chicken during storage, improved the texture, and significantly slowed down the deterioration of sensory quality (P < 0.05). Low-temperature plasma treatment increased the fat oxidation value at the early stage (from day 1 to 3) of storage, but did not have a significant impact on the sensory evaluation of meat in terms of odor or color. Overall, LA combined with low-temperature plasma was more effective in preserving yellow-feathered broiler carcass than either alone.

In order to investigate the effect of low-temperature air cooling on the postmortem energy metabolism and meat quality of yellow-feathered broilers during mixed cooling (first water cooling and then air cooling), 85-day-old broilers were slaughtered and divided into three groups: treatment (water cooling at 0–4 ℃ followed by air cooling at −8, −18, −25 or −31 ℃), control (traditional water cooling at 0–4 ℃) and traditional mixed cooling (water cooling at 0–4 ℃ followed by air cooling at 0–4 ℃) groups. Finally, all carcasses were cooled to an internal temperature of 4 ℃, and the optimal air cooling temperature was determined by measuring cooling rate, pH, energy metabolism and quality indexes. The results showed that the cooling time of air cooling at −25 and −31 ℃ was 2 537 and 2 272 s, respectively, which was shortened by 27.78% and 35.33% compared with the traditional water cooling and by 51.87% and 56.90% compared with the traditional mixed cooling, respectively. Air cooling at −25 and −31 ℃ delayed the decrease in pH, reduced the drip loss and cooking loss of broiler breast muscle, significantly increased the shear force and the content of immobilized water compared with the control group (P < 0.05). Compared with the other groups, the activities of muscle hexokinases, phosphate-3-phosphate dehydrogenase and lactate dehydrogenase in the air cooling treatments at −25 and −31 ℃ were lower, and the consumptions of adenosine triphosphate (ATP) and glycogen, the production of lactic acid and adenosine monophosphate (AMP) and AMP/ATP ratio were the smallest (P < 0.05). The above findings showed that air cooling at −25 and −31 ℃ significantly inhibited the rate of anaerobic glycolysis during the early postmortem period in chicken meat, delayed the rate of pH decline, and effectively improved muscle water retention. From the perspective of industrial energy saving, −25 ℃ is determined as the best temperature for air cooling treatment.