The seeds of ecological recovery in urbanization-Spatiotemporal evolution of ecological resiliency of Dianchi Lake Basin, China

As a result of years of monitoring the ecological resiliency of natural areas and cities, it has become clear that it is both important and often feasible to implement ecological and environmental restoration in conjunction with ongoing processes of landscape change development and urbanization. Ecological resiliency and spatiotemporal evolution studies can objectively reveal the resiliency of ecosystems to external disturbances. Ecological monitoring and assessment can also help planners understand regional ecological spatial differentiation patterns and provided data support for planning. In this paper we have analyzes quantitatively the interrelationships of ecological factors in Dianchi Lake Basin (DLB) over the past 30 years and explored the spatial and temporal dynamics of ecological resiliency. Based on remote sensing images and primary data in 1995, 2005, 2010, 2015, 2018, and 2022, we used the center of gravity migration and kernel density analysis to explore the spatial and temporal changes of ecological resiliency. We built the overall resiliency evaluation system using entropy weight in the TOPSIS model, and finally simulate the future changes based on CA-Markov (CA-MC) model. The results show that from 1995 to 2022, the ecological resiliency of land use and vegetation cover in DLB decreased substantially. An important finding was that the ecological resiliency of riparian buffer zone and landscape pattern were generally increasing. The distribution of barycenter movement and kernel density of different levels of ecological resiliency differed significantly and showed fluctuating changes. The extreme low resiliency and extremely resilient areas shift to the northeast, the mildly resilient areas shift to the northwest, and the highly resilient areas shift to the southeast. The overall resiliency level of DLB is predicted to slowly increase from 2022 to 2030 by deduction of the CA-MC model. Our analysis suggests that the study of the evolution of regional ecological resiliency can provide a timely understanding of regional ecological evolution patterns and propose ecological protection strategies

Exogenous H2S Inhibits Autophagy in Unilateral Ureteral Obstruction Mouse Renal Tubule Cells by Regulating the ROS-AMPK Signaling Pathway

Background/Aims: The induction of excessive autophagy by increased levels of oxidative stress is one of the main mechanisms underlying unilateral ureteral obstruction (UUO)-induced vascular endothelial cell dysfunction. Hydrogen sulfide (H2S) has been shown to have an anti-oxidative effect, but its mode of action on excessive autophagy in vascular endothelial cells is unclear. Methods: Surgery was used to induce UUO in male C57BL/6 mice as an in vivo model. Human renal epithelial cells (HK-2) were treated with H2O2 as an in vitro model. NaHS was used as an exogenous H2S donor. Transmission electron microscopy was applied to observe the structure of renal autophagosomes. The expression of proteins related to autophagy and apoptosis was detected by western blot analysis in vivo and in vitro. Flow cytometry (DCFH-DA) was used to examine the levels of intracellular reactive oxygen species (ROS). The terminal deoxynucleotidyl transferase dUTP nick end labeling assay was used to detect cell apoptosis. Compound C was used to analyze the association of AMPK with autophagy. Results: Compared with the sham group, in which the ureter was exposed but not ligated, the cell apoptosis index, number of autophagosomes, protein expression of microtubule-associated protein 1 light-chain 3 (LC3)-II/I, beclin-1, and p-AMPK/AMPK were significantly increased in the UUO group. On the other hand, p62, cystathionine β-synthase, and cystathionine γ-lyase protein expression levels and H2S concentration were significantly decreased (p < 0.05). These alterations were ameliorated by the addition of NaHS (p < 0.05). Similar results were observed in vitro. By using the AMPK inhibitor compound C, it was indicated that AMPK was involved in ROS-induced autophagy. In addition, using tissue from patients with obstructive nephropathy, excessive autophagy was observed by an increased LC3-II/LC3-I ratio. Conclusion: NaHS-treatment may exert a protective effect on mouse kidney against UUO by suppressing the ROS-AMPK pathway. ROS-AMPK-mediated autophagy may represent a promising therapeutic target for obstructive nephropathy

Reutilization of Green Waste as Compost for Soil Improvement in the Afforested Land of the Beijing Plain

Resource utilization of urban green waste compost for soil improvement in afforested land is an important way of digesting urban green waste. In this study, artificial Sophora japonica Linn. Woodland in the Beijing plain, where the million mu (66,700 ha) afforestation project was carried out, was taken as an experimental area to investigate the influences of urban green waste composting on soil improvement and soil microorganisms. Application amounts of green waste composts for each tree were as follows: CK treatment: no application of fertilizer; T1 treatment: 5 kg/each tree; T2 treatment: 10 kg/each tree; T3 treatment: 15 kg/each tree. Results showed that the application of green waste had a significant effect on soil improvement, such as improving of organic matter, available phosphorus, and available potassium content (p < 0.05). The high-level application amount (T3 treatment) had a greater effect on soil improvement. Compared with the control treatment (CK), soil pH in T3 treatment decreased to 7.28–7.45, Soil organic matter contents reached more than 35 g·kg−1, and soil total nitrogen, soil available phosphorus, and soil available potassium increased by 25–28%, 200–400%, and 80–177%, respectively. Soil carbon–nitrogen ratio has increasing to 15.61–24.38 in the three treatments, which would not obviously slow down the decomposition of organic matter by microorganisms in the soil. After the application of green waste compost, the soil microbial structure was changed. From the operational taxonomic unit (OTU) level, bacterial abundance increased by 12–13%, but the change in bacterial diversity was not significant. The influences of pH and contents of organic matter content, available phosphorus, and rapidly available potassium on the bacterial community were greater. This study will provide the necessary scientific basis for the application of green waste compost in the improvement of soil on afforested land in the Beijing plain

Adaptive Haar-Like Features for Head Pose Estimation

International audienceThis paper presents a work on head pose estimation. Here, face images are tagged with head pose information. To achieve head pose estimation, anatomic regions (eyes, nose and mouth) are extracted using a facial descriptor. Candidates for these regions are extracted from an energy map based on Haar-like features. Then, a multi-threshold analysis is applied to find the position and the size of each region. Region projections on vertical and horizontal axis enable to define a set of rules in order to estimate head pos

The Integration of Photodiode and Camera for Visible Light Positioning by Using Fixed-Lag Ensemble Kalman Smoother

Visible Light Positioning (VLP) has become one of the most popular positioning and navigation systems in this decade. Filter-based VLP systems can provide real-time solutions but have limited accuracy. On the contrary, fixed-interval smoothers can help VLP achieve higher accuracy but require post-processing. In this article, a trade-off solution, Fixed-Lag Ensemble Kalman Smoother (FLEnKS), is proposed for VLP to achieve a semi-real-time and accurate positioning solution. The forward part of the FLEnKS is based on the Ensemble Kalman Filter (EnKF), which uses stochastic sampling with ensemble members and enables a better reflection of the features of nonlinear systems. The backward filter in the FLEnKS compensates for the estimation error from the forward filter using the linearization based on error states and further reduces the estimation error. Furthermore, multiple data from both photodiode (PD) and camera are fused in the proposed FLEnKS for VLP, which further improves the accuracy of conventional VLP with a single data source. Preliminary field test results show that the proposed FLEnKS provides a semi-real-time positioning solution with the average 3D positioning accuracy of 15.63 cm in dynamic tests

The forming region and mechanical properties of SiO2-Al2O3-MgO glasses

International audienceThe glasses of 93.9% (xSiO(2)-yAl(2)O(3)-zMgO)-5% CaO-1% B2O3-0.1% Fe2O3 were prepared, and the relationship between mechanical properties and structural stability were characterized by means of Raman spectroscopy and optical band gap values. The glass forming region is found to be x = 50-70%, y = 10-25% and z = 15-32%. As x = 65%, y = 10% and z = 25% (SAM-4), the investigated glass possesses the optimum volume density, oxygen packing density, optical band gap, banding strength, compression strength and compression modulus, which are 2.517 g/cm(3), 77.047 mol/l, 3.56 eV, 77.04 MPa, 202.74 MPa and 106.70 GPa, respectively. Meanwhile, starting from the representative point of SAM-4 to radiate around, the volume density, oxygen density, Raman intensity and mechanical properties of the glasses are all decreasing constantly, and the optical band gap of the glasses is increasing on the contrary. Moreover, the optical band gap value and Raman spectroscopy of SAM-4 all prove that the number of oxygen bonds in the bridge reach the maximum and the highest structural stability is achieved, which further shows that it is an important reason why its mechanical properties is significantly improved

Thermal and luminescent properties of 2 mu m emission in thulium-sensitized holmium-doped silicate-germanate glass

International audienceIn this paper, we present the luminescent properties of Tm3+/Ho3+ co-doped new glass. A series of silicate-germanate glass was prepared by the conventional melt-quenching method. In the Tm3+/Ho3+ co-doped silicate-germanate glass, a strong emission of 2 mu m originating from the Ho3+:I-5(7) -> I-5(8) transition can be observed under conventional 808 nm pumping. The characteristic temperatures, structure, and absorption spectra have been measured. The radiative properties of Ho-3+ in the prepared glass were calculated. The emission cross section of Ho3+ ions transition can reach 4.78 x 10(-21) cm(2) around 2 mu m, and the FWHM is as high as 153 nm. The energy transfer efficiency between Ho3+ and Tm3+ has a large value (52%), which indicates the Tm3+/Ho3+ co-doped silicategermanate glass is a suitable candidate for the 2 mu m laser. Moreover, the energy transfer mechanism between Tm(3+)and Ho3+ ions was investigated. (C) 2016 Chinese Laser Pres