Alpine grassland greening on the Northern Tibetan Plateau driven by climate change and human activities considering extreme temperature and soil moisture.

Alpine grassland is among the world's most vulnerable ecosystems, characterized by a high sensitivity to climate change (CC) and human activities (HA). Quantifying the relative contributions of CC and HA to grassland change plays a crucial role in safeguarding grassland ecological security and devising sustainable grassland management strategies. Although there were adequate studies focusing on the separate impacts of CC and HA on alpine ecosystem, insufficient attention has been given to investigating the effects of extreme temperatures and soil moisture. In this study, the spatiotemporal variations of alpine grassland were analyzed based on MODIS NDVI during the growing season from 2000 to 2020 in Naqu, using partial least squares regression and residual analysis methods to analyze the importance of climate factors and the impacts of CC and HA on grassland change. The results show that the NDVI during the growing season in Naqu exhibited an increasing trend of 0.0046/10a. At the biome scale, the most significant and rapid increase was observed in alpine desert and alpine desert grassland. Extreme temperature and soil moisture (SM) exerted a more significant importance on alpine grassland at whole scale. SM always showed a significant importance at biome and grid scale. The contributions of CC and HA to the change during the growing season were calculated as 0.0032/10a and 0.0015/10a, respectively, accounting for 68.05 % and 31.05 %. CC dominated the increase in NDVI during the growing season; HA contributed positively to NDVI in most areas of Naqu. The results are expected to enhance our understanding of grassland variations under CC and HA and provide a scientific basis for future ecological conservation in alpine regions.

Opto-Electronic Hybrid Network Based on Scattering Layers.

Owing to the disparity between the computing power and hardware development in electronic neural networks, optical diffraction networks have emerged as crucial technologies for various applications, including target recognition, because of their high speed, low power consumption, and large bandwidth. However, traditional optical diffraction networks and electronic neural networks are limited by long training durations and hardware requirements for complex applications. To overcome these constraints, this paper proposes an innovative opto-electronic hybrid system that combines optical diffraction networks with electronic neural networks. Using scattering layers to replace the diffraction layers in traditional optical diffraction networks, this hybrid system circumvents the challenging training process associated with diffraction layers. Spectral outputs of the optical diffraction network were processed using a simple backpropagation neural network, forming an opto-electronic hybrid network exhibiting exceptional performance with minimal data. For three-class target recognition, this network attains a classification accuracy of 93.3% within a substantially short training time of 9.2 s using only 100 data samples (training: 70 and testing: 30). Furthermore, it demonstrates exceptional insensitivity to position errors in scattering elements, enhancing its robustness. Therefore, the proposed opto-electronic hybrid network presents substantial application prospects in the fields of machine vision, face recognition, and remote sensing.

A Novel Tandem Differential Edge Sensor Layout for Segmented Mirror Telescopes.

The performance of an active control system, crucial for the co-phase maintenance of segmented mirrors, is closely related to the spatial layout of sensors and actuators. This article compares two types of edge sensor layouts, vertical and horizontal, and proposes a novel tandem differential sensor layout that saves layout space and reduces the number of positioning references. The control performance of this scheme is analyzed in terms of error propagation, mode representation, and the scalable construction of the control matrix. Finally, we constructed a tandem differential-based sensor detection system to examine the performance of edge sensors and the effect of laboratory environmental variables on sensor measurements. Simulations and experiments demonstrate that this scheme has the same ability to fully characterize actuator modification modes as the Keck edge sensor layout. Although the total error multiplier is slightly larger than the latter, it has fewer scalable control matrix types and stronger spatial and segmental shape adaptation capabilities. Actual measurements show that the sensor's own noise in a tandem differential layout is less than 20 nm, which meets the requirements for future segmented co-phase maintenance. This layout type can potentially be applied to future small and medium-sized segmented splices.

Experimental Study on the Effect of Background Interference on Tennis Players' Serving Performance / Estudio experimental sobre el efecto de la interferencia de fondo en el rendimiento del servicio de los tenistas

The learning of tennis movement skills is rather complex and requires repeated practice and body coordination. It is difficult to master standardized technical movements in a short period of time. Therefore, a variety of training methods have been developed to facilitate the learning of tennis movement skills. In particular, the theory of background interference has been discussed by many scholars in recent years. Whether background interference is beneficial or detrimental to the learning of tennis movement skills requires further validation by scholars. Based on research methods such as literature, experiments, expert interviews and mathematical statistics, the effect of background interference on tennis players' serving technique training was examined using 15 Level 2 tennis players with no significant difference as subjects in a sports institute. They were divided into three groups of 5, each by serpentine grouping. The experiment was conducted for 4 weeks, with 3 sessions per week, for a total of 12 sessions of training. Four experimental indices (serving performance, accuracy, inside-angle accuracy, and speed) were selected for testing. The results showed that: (1) During skill acquisition, the players comprehended tennis serves more deeply. Moreover, they improved the power and speed of the serve and controlled the direction of the drop better. (2) The results of the retention test reflected the performance characteristics of effective learning, with the persistent practice effects. High background-interference practice facilitated long-term memory and also clarified each serve more distinctly. (3) After high background-interference exercises, athletes tolerated stress better in migration tests, enabling themselves to adapt to new operating environments quickly.(AU)

A Portable and Flexible Self-Powered Multifunctional Sensor for Real-Time Monitoring in Swimming.

A portable and flexible self-powered biosensor based on ZnO nanowire arrays (ZnO NWs) and flexible PET substrate has been designed and fabricated for real-time monitoring in swimming. Based on the piezoelectric effect of polar ZnO NWs, the fabricated biosensor can work in both air and water without any external power supply. In addition, the biosensor can be easily attached to the surface of the skin to precisely monitor the motion state such as joint moving angle and frequency during swimming. The constant output piezoelectric signal in different relative humidity levels enables actual application in different sports, including swimming. Therefore, the biosensor can be utilized to monitor swimming strokes by attaching it on the surface of the skin. Finally, a wireless transmitting application is demonstrated by implanting the biosensor in vivo to detect angiogenesis. This portable and flexible self-powered biosensor system exhibits broad application prospects in sport monitoring, human-computer interaction and wireless sport big data.

Comparisons between minimally invasive and open esophagectomy for esophageal cancer with cervical anastomosis: a retrospective study.

BACKGROUND: As an extensive surgery, minimally invasive esophagectomy (MIE) has advantages in reducing morbidity and improving quality of life for patients suffering from esophageal cancer. This study aims to investigate differences between MIE and open esophagectomy (OE) for considerations of the safety of procedures, rate of tumor resection, postoperative complications, and quality of life. This paper also tends to provide some references for MIE on esophageal cancer therapy. METHODS: A retrospective data analysis was undertaken on 140 patients who either underwent MIE or OE for esophageal cancer with cervical anastomosis from March 2013 to May 2014 by our surgical team. Preoperative characteristics were analyzed for both groups. Differences in perioperative and oncologic outcomes were compared in operation time, intraoperative blood loss, lymph nodes retrieved, and R0-resection rate. Accordingly, a comparative analysis was conducted on complications namely anastomotic leakage, pulmonary infection, in-hospital mortality, and short-term (3 months) postoperative EORTC C30 Global health as well. RESULTS: A total of 140 patients (87 with MIE and 53 with OE) were enrolled and the two groups were homogeneous in terms of patient- and tumor-related data. There was no difference on postoperative ICU stay (21.15 ± 1.54 h vs 21.75 ± 1.68 h, p = 0.07) and R0-resection rate (100% vs 100%, p = 1.00). The operation time for MIE was significantly shorter (146.08 ± 17.35 min vs 200.34 ± 14.51 min, p <  0.0001), the intraoperative blood loss was remarkably saved (MIE vs OE, 83.91 ± 24.72 ml vs 174.53 ± 35.32 ml, P <  0.0001) and more lymph nodes were retrieved (MIE vs OE, 38.89 ± 4.31 vs 18.42 ± 3.66, P <  0.0001). There was no difference between the groups to postoperative complications and mortality. However, pulmonary infection in MIE was higher than in OE and the difference was not statistically significant (MIE vs OE, 20.75% vs 31.03%, P = 0.24). Complications such as in-hospital mortality and short-term (3 months) postoperative EORTC C30 Global health displayed no difference between both groups as well. CONCLUSIONS: The number of lymph nodes and intraoperative blood loss were significantly ameliorated in MIE. A 4-5 cm longitudinal incision below the xiphoid process was made to create the gastric conduit under direct vision assisting in shortening the total operation time significantly.

Culture and Identification of Bone Marrow Mesenchymal Stem Cells from Enhanced Green Fluorescent Protein-transgenic Rats.

OBJECTIVE: To isolate, culture, and identify bone marrow mesenchymal stem cells (BMSCs) from enhanced green fluorescent protein (EGFP)-transgenic rats in vitro. METHODS: Bone marrows were isolated from tibia and femur of healthy EGFP-transgenic rats of specific pathogen free (SPF) grade. Then,the whole bone marrow adherent method was used for isolation,culture,and purification of BMSCs. The morphological change was noted by continuous observation under inverted fluorescence microscope. The growth curve of cells was drawn through the method of CCK-8 and the proliferation compared with wild type BMSCs. The surface markers of BMSCs were detected by flow cytometry. The BMSCs were induced to differentiate into osteoblasts, adipocytes, and chondrocytes lineages. The EGFP-BMSCs were transplanted into the rats intravenously, and the expression of GFP was detected. RESULTS: BMSCs stably expressing EGFP gene were obtained successfully, with the fusiform-shaped appearance and the forming of circinate cell colonies. The growth curve of EGFP-MSCs showed the characteristic of active proliferation, showing no significant difference compared with the wild-type BMSCs. The expression rates of the surface markers of BMSCs CD29, CD90, CD34, CD49d, and CD45 were 99.4%, 96.4%, 0.171%, 0.049%, and 0.038%. The GFP were detected in lung 3 days after transplantation. After osteogenic, adipogenic, and chondrogenic induction, oil red-O and alizarin red positive signals and toluidine blue positive cells were detected. CONCLUSIONS: High-purity BMSCs stably expressing green fluorescent protein gene can be cultured using the whole bone marrow adherent method. EGFP does not affect the stem cell properties and expresses stably after transplantation. The cells can be used as seed cells for subsequent research.