[Remote Sensing Estimation of Plant Litter Cover Based on the Spectra of Plant Litter-Soil Mixed Scenes].

Quantifying plant litter cover is important to evaluate the effectiveness of vegetation to protect soil against soil erosion. Field campaign was carried out in the Loess Hilly-gully Region of Northern Shaanxi to acquire the spectral reflectance data of plant-soil mixed scenes for two broadleaf forests and rehabilitated grassland. Spectral behavior of plant-soil mixed scenes was analyzed and the effectiveness of hyperspectral indexes NDLI (normalized difference lignin index) and CAI (cellulose absorption index) for quantifying plant litter cover was evaluated based on lab and field experiments. The results showed spectra reflectance of plant-soil mixed scenes with different proportions of litter and soil varied greatly by the influence of color and water content. The NDLI and CAI values increased with the rise of proportion of litter within the mixed scene under dry and wet status, regression analysis between the two indexes and plant litter cover of mixed scenes showed that the obviously better result for CAI (R2=0.98, rehabilitated grassland and broadleaf forests under dry status). The discrimination between mixed scenes and soil using CAI significantly outperformed NDLI under dry status; the estimation of plant litter cover by CAI is more effective compared to NDLI. Lab analysis was validated by field measuring: R2=0.90 showed highest correlation between CAI and plant litter cover for rehabilitated grassland. The validity of estimation of plant litter cover by both two indexes reduced to some degree in the field. The research enhanced the scientific basis for remote sensing estimation of plant litter cover.

[Spatio-temporal variations of vegetation cover in semi-arid regions and its response to climate change: A case study of Xilin Gol, Inner Mongolia, China]. / åŠå¹²æ—±åŒºæ¤è¢«è¦†ç›–æ—¶ç©ºå˜åŒ–ç‰¹å¾åŠå ¶å¯¹æ°”å€™å˜åŒ–çš„å“åº”: 以锡林郭勒盟为例.

The quantitative analysis of spatio-temporal variations of vegetation cover and its correlation with climate are of great significance for understanding of ecological environment, ecological civilization construction, and sustainable development in semi-arid areas. We investigated the spatio-temporal variations of normalized difference vegetation index (NDVI) and its response to climate change during 2000-2020 in Xilin Gol, Inner Mongolia, by using trend analysis, regression analysis and partial correlation analysis based on the data of MODIS-NDVI, tempe-rature, precipitation, digital elevation model. The results showed that vegetation cover in Xilin Gol had been increased from 2000 to 2020, which generally included three phases, i.e., stable fluctuation, rapid growth, and steady growth. The mean NDVI showed a zonal increasing distribution from southwest to northeast, and had a strong correlation with elevation and population density in Xilin Gol region. The high values of NDVI were mainly in the east, with a significant increasing trend, and the low values were in the southwest, with a local degradation. The sensitivity of vegetation cover to climate change showed spatial and temporal variations. The spatial variation of vegetation was more sensitive to temperature and the interannual variation was sensitive to annual precipitation. In summary, vegetation cover improved overall in Xilin Gol, but there was degradation in some areas. We should formulate differentiated and precise vegetation restoration and ecological environmental protection policies.

Virtual ecological technology: Concepts, systems, and application perspectives.

Virtual ecological technology is a new technology that builds the foundation of a digital ecological system, simulates the process of ecological evolution, and establishes a global knowledge analysis system based on a unified spatio-temporal benchmark. It is a new direction for the interdisciplinary integration and development of eco-logy, geographic information science, computer science and other subjects towards modernization, informatization, and intelligence. Research, development, and application of virtual ecological technology is of great significance for the development of ecology as a discipline, ecosystem management, and regional sustainable development. Curren-tly, research on virtual ecological technology is still in its infancy and lacks a complete and clearly defined framework, making it difficult to support systematic iterative development and scientific analysis. In this paper, starting from the main theories and objectives of modern ecology, we summarized the main contents and technical requirements of virtual ecological construction, and proposed a key technical system of virtual ecology that integrated vir-tual geography and digital twin technology. From the perspective of application scenarios, we analyzed the application capabilities of virtual ecological technology in air pollution and energy analysis. Finally, we summarized the deve-lopment potential of virtual ecological technology in the digital construction of the ecological environment, intelligent computing, and realistic expression of different levels of ecological space resources transformation under the background of new generation of information technology, both at the local computing point breakthrough and the global technology point fusion aspects. This would enrich and advance the technical capabilities that support China's ecological space resource transformation.

A remote management system for control and surveillance of echinococcosis: design and implementation based on internet of things.

BACKGROUND: As a neglected cross-species parasitic disease transmitted between canines and livestock, echinococcosis remains a global public health concern with a heavy disease burden. In China, especially in the epidemic pastoral communities on the Qinghai-Tibet Plateau, the harsh climate, low socio-economic status, poor overall hygiene, and remote and insufficient access to all owned dogs exacerbate the difficulty in implementing the ambitious control programme for echinococcosis. We aimed to design and implement a remote management system (RMS) based on internet of things (IoT) for control and surveillance of echinococcosis by combining deworming devices to realise long-distance smart deworming control, smooth statistical analysis and result display. New methods and tools are urgently needed to increase the deworming coverage and frequency, promote real-time scientific surveillance, and prevent transmission of echinococcosis in remoted transmission areas. METHODS: From 2016 to 2019, we had cooperated and developed the smart collar and smart feeder with the Central Research Institute of Shanghai Electric Group Co., Ltd. (Shanghai, China) and Shenzhen Jizhi Future Technology Co., Ltd. (Shenzhen, China). From September 2019 to March 2020, We had proposed the RMS based on IoT as a novel tool to control smart deworming devices to deliver efficient praziquantel (PZQ) baits to dogs regularly and automatically and also as a smart digital management platform to monitor, analyse, and display the epidemic trends of echinococcosis dynamically, in real time in Hezuo City, Gannan Tibetan Autonomous Prefecture, Gansu Province, China. Starting from January 2018, The RMS has been maintained and upgraded by Shanghai Yier Information Technology Co., Ltd (Shanghai, China). The database was based on MySQL tools and the Chi-square test was used to probe the difference and changes of variables in different groups. RESULTS: The smart collars are fully capable of anti-collision, waterproof, and cold-proof performance, and the battery's energy is sufficient, the anti-collision rate, water-proof rate, cold-proof rate and voltage normal rate is 99.6% (521/523), 100.0% (523/523), 100.0% (523/523) and 100.0% (523/523), respectively. The RMS can accurately analyse the monitoring data and parameters including positive rates of canine faeces, and the prevalence of echinococcosis in the general population livestock, and children. The data of dogs deworming and surveillance for echinococcosis is able to be controlled using RMS and has expanded gradually in townships to the whole Hezuo region. The automatic delivering PZQ rate, collar positioning rate, deliver PZQ reminding rate, and fault report rate is 91.1% (1914/2102), 92.1% (13 580/14 745), 92.1% (1936/2102) and 84.7% (1287/1519), respectively. After using the RMS from 2019, the missing rate of monitoring data decreased from 32.1% (9/28) to 0 (0/16). A total of 48 administrators (3, 3, 8, 11, 23 at the provincial, municipal, county, township, village levels, respectively) participated in the questionnaire survey, with 93.8% of its overall satisfaction rate. CONCLUSIONS: The existing difficulties and challenges in the way of prevention and control for echinococcosis can partially be resolved using the innovative, IoT-based technologies and tools. The proposed RMS advance the upgrade of existing manual prevention and control models for echinococcosis, especially in the current ongoing COVID-19 pandemic, as social distance and community blockade continue.

Global survey of miRNAs and tRNA-derived small RNAs from the human parasitic protist Trichomonas vaginalis.

BACKGROUND: Small non-coding RNAs play critical regulatory roles in post-transcription. However, their characteristics in Trichomonas vaginalis, the causative agent of human sexually transmitted trichomoniasis, still remain to be determined. METHODS: Small RNA transcriptomes from Trichomonas trophozoites were deep sequenced using the Illumina NextSeq 500 system and comprehensively analyzed to identify Trichomonas microRNAs (miRNAs) and transfer RNA (tRNA)-derived small RNAs (tsRNAs). The tsRNA candidates were confirmed by stem-loop quantitative reverse transcription-PCR, and motifs to guide the cleavage of tsRNAs were predicted using the GLAM2 algorithm. RESULTS: The miRNAs were found to be present in T. vaginalis but at an extremely low abundance (0.0046%). Three categories of endogenous Trichomonas tsRNAs were identified, namely 5'tritsRNAs, mid-tritsRNAs and 3'tritsRNAs, with the 5'tritsRNAs constituting the dominant category (67.63%) of tsRNAs. Interestingly, the cleavage site analysis verified both conventional classes of tRNA-derived fragments (tRFs) and tRNA-halves in tritsRNAs, indicating the expression of tRNA-halves in the non-stress condition. A total of 25 tritsRNAs were experimentally confirmed, accounting for 78.1% of all tested candidates. Three motifs were predicted to guide the production of tritsRNAs. The results prove the expression of tRFs and tRNA-halves in the T. vaginalis transcriptome. CONCLUSIONS: This is the first report of genome-wide investigation of small RNAs, particularly tsRNAs and miRNAs, from Trichomonas parasites. Our findings demonstrate the expression profile of tsRNAs in T. vaginalis, while miRNA was barely detected. These results may promote further research aimed at gaining a better understanding of the evolution of small non-coding RNA in T. vaginalis and their functions in the pathogenesis of trichomoniasis.

Smart deworming collar: A novel tool for reducing Echinococcus infection in dogs.

Echinococcosis is a serious zoonotic parasitic disease transmitted from canines to humans and livestock. Periodic deworming is recommended by the WHO/OIE as a highly effective measure against echinococcosis. However, manual deworming involves significant challenges, particularly in remote areas with scarce resources. The insufficient awareness delivering praziquantel (PZQ) baits for dogs leads to low compliance rate. The aim of this study was therefore to develop a novel smart collar for dogs to address these challenges. We developed a smart Internet of Things (IoT)-based deworming collar which can deliver PZQ baits for dogs automatically, regularly, quantitatively with predominant characteristics of being waterproof, anti-collision, cold-proof and long life battery. Its performance was tested in two remote locations on the Tibetan Plateau. A cross-sectional survey was conducted to evaluate the compliance of the dog owners. Further, a randomized controlled study was performed to evaluate the difference between smart-collar deworming and manual deworming. The collar's effectiveness was further assessed on the basis of Generalized Estimation Equations (GEE). The testing and evaluation was done for 10 smart deworming collars in factory laboratory, 18 collars attached for 18 dogs in Seni district, Tibet Autonomous Region, China, and 523 collars attached for 523 dogs in Hezuo city, Gansu province, China. The anti-collision, waterproof, and coldproof proportion of the smart collars were 100.0%, 99.5%, and 100.0%, respectively. When compared to manual deworming, the dogs' risk of infection with Echinococcus on smart-collar deworming is down to 0.182 times (95% CI: 0.049, 0.684) in Seni district and 0.355 (95%CI: 0.178, 0.706) in Hezuo city, the smart collar has a significant protective effect. The owners' overall compliance rate to attach the smart collars for their dogs was 89%. The smart deworming collar could effectively reduce the dogs' risk of infection with Echinococcus in dogs, significantly increase the deworming frequency and coverage and rapidly remove worm biomass in dogs. Thus, it may be a promising alternative to manual deworming, particularly in remote areas on the Tibetan Plateau.

[Spatial heterogeneity of soil fungal diversity in area with presence of Stellera chamaejasme on the degraded alpine meadow]. / é€€åŒ–é«˜å¯’è‰ç”¸ç‹¼æ¯’å‘ç”ŸåŒºåœŸå£¤çœŸèŒå¤šæ ·æ€§çš„ç©ºé—´å˜å¼‚.

Stellera chamaejasme is one of the most serious weeds in Qinhai-Tibetan Plateau, the rapid expansion of which exerts an increasing effect on the alpine meadow ecosystem. With high-throughput sequencing technology, geostatistics and GIS method, the spatial heterogeneity of soil fungal diversity in Stellera occurrence area and the spatial correlation between Stellera coverage and soil fungal diversity were investigated in a typical degraded alpine meadow of the Qilian Mountain. Compared to no-Stellera area, the fungi richness in Stellera area decreased, the dominance increased, and the α-diversity reduced. The difference of fungal species composition enhanced and ß-diversity significantly increased. The spatial pattern of soil fungal diversity was affected by the invasion of Stellera, resulting in higher fragmentation in occurrence area. Spatial heterogeneity of species composition increased remarkably, and spatial stability of α-diversity and ß-diversity decreased. The portion of positive correlation and negative correlation interlaced, indicating no clear spatial correlation between Stellera coverage and soil fungal diversity. Our results indicate that the spatial pattern of soil fungal diversity was affected by the interaction of soil and vegetation in Stellera invaded meadows.

High expression of HLA-DQA1 predicts poor outcome in patients with esophageal squamous cell carcinoma in Northern China.

BACKGROUND: Our previous studies demonstrate that the major histocompatibility complex (MHC) is associated with the progression of esophageal squamous cell carcinoma (ESCC). HLA-DQA1, which belongs to the MHC Class II family, may be a potential biomarker in ESCC progression. However, the association between HLA-DQA1 and ESCC in high-incidence area of northern China has not been well characterized. The purpose of this study is to investigate the relationship of HLA-DQA1 expression with the progression and prognosis of ESCC. METHODS: We analyzed the expression profiles of HLA-DQA1 in esophageal cancer (EC) samples in the TCGA database and validated HLA-DQA1 expression by immunohistochemistry, western blotting, and quantitative reverse-transcription polymerase chain reaction in matched EC and normal tissues, respectively. The correlation between HLA-DQA1 expression and clinicopathologic characteristics of ESCC was further analyzed. RESULT: Immunohistochemical analysis indicated that the expression level of HLA-DQA1 in ESCC tissues was significantly higher than the matched normal tissues (P < .001). HLA-DQA1 mRNA and protein expression were significantly higher in ESCC tissues compared to the matched normal tissues. Patients with family history negative or with tumor sizes >4 cm were associated with higher HLA-DQA1 expression levels. A prognostic significance of HLA-DQA1 was also found by the Log-rank method, in which high expression of HLA-DQA1 was correlated with a shorter overall survival time. The receiver operating characteristic (ROC) curve analysis yielded the area under the ROC curve value of 0.693. Univariate and multivariate analyses also suggest that high expression of HLA-DQA1 is a potential indicator for poor prognosis of ESCC. CONCLUSIONS: Our results demonstrate that HLA-DQA1 plays an important role in ESCC progression and may be a biomarker for ESCC diagnosis and prognosis, as well as a potential target for the treatment of patients with ESCC.

Receptor-mediated gene delivery using polyethylenimine (PEI) coupled with polypeptides targeting FGF receptors on cells surface.

OBJECTIVE: To construct a novel kind of nonviral gene delivery vector based on polyethylenimine (PEI) conjugated with polypeptides derived from ligand FGF with high transfection efficiency and according to tumor targeting ability. METHODS: The synthetic polypeptides CR16 for binding FGF receptors was conjugated to PEI and the characters of the polypeptides including DNA condensing and particle size were determined. Enhanced efficiency and the targeting specificity of the synthesized vector were investigated in vitro and in vivo. RESULTS: The polypeptides were successfully coupled to PEI. The new vectors PEI-CR16 could efficiently condense pDNA into particles with around 200 nm diameter. The PEI-CR16/pDNA polyplexes showed significantly greater transgene activity than PEI/pDNA in FGF receptors positive tumor cells in vitro and in vivo gene transfer, while no difference was observed in FGF receptors negative tumor cells. The enhanced transfection efficiency of PEI-CR16 could be blocked by excess free polypeptides. CONCLUSION: The synthesized vector could improve the efficiency of gene transfer and targeting specificity in FGF receptors positive cells. The vector had good prospect for use in cancer gene therapy.

[Spatial-temporal process and characteristics of vegetation recovery after Wenchuan earthquake: A case study in Longxi River basin of Dujiangyan, China.] / 汶川地震区灾后植被恢复时空过程及特征­­ä»¥éƒ½æ±Ÿå °é¾™æºªæ²³æµåŸŸä¸ºä¾‹.

Quantitative evaluation on the vegetation recovery after the earthquake is of great scienti-fic significance for local ecological system rebuilding and regional social-economic sustainable deve-lopment. By taking the Longxi River Basin in Dujiangyan of Sichuan Province as an example, and employing the MODIS-NDVI time-series data, this paper illustrated the dynamic changes of the ve-getation cover rates in Longxi River basin before and after the 5.12 Wenchuan Earthquake by using Landsat data, and then time-space characters of the recovery rates of the damaged vegetation was quantified structurally by referring the factors of river-system and terrain. The results showed that the recovery of impaired vegetation coverage worked well from a holistic point of view, but the response of vegetation coverage to earthquake disaster showed a lagging-phenomenon. The recovery rate of damaged vegetation was significantly correlated to its distance to surrounding river systems, elevation, slope degree, and slope aspect. This finding could provide technical supports for decision-makers to intervene the recovering process after earthquake.

[Extraction of spectral difference characteristics of Stellera chamaejasme in Qilian County of Qinghai Province, Northwest China].

Stellera chamaejasme is one of the main poisonous weeds distributed in alpine meadow of Qinghai Province. Rapid spreading of S. chamaejasme has done serious harm to local animal husbandry and caused continuous grassland ecosystem degradation. This paper focused on the spectral differences between S. chamaejasme and herbage, taking the typical degraded alpine meadow dominated by S. chamaejasme in Qilian County of Haibei Region as the test site and using the spectral measurements acquired in the full-blossom period of S. chamaejasme from 2012 to 2014. The results showed that the spectral behavior of flowers of S. chamaejasme differed significantly from green background that included leaves of S. chamaejasme and herbage within 350-900 nm of VIS-NIR wavebands. The biggest reflectance difference between flowers of S. chamaejasme and green background was located in the red valley, followed by the blue valley. The reflectance of S. chamaejasme community increased with the rising of coverage, the biggest reflectance difference between S. chamaejasme and herbage communities lied in the near-infrared peak, and the best separability between S. chamaejasme communities with different coverage was also at the point. The difference of first derivative spectra between flowers of S. chamaejasme and green background located in amplitude of yellow edge was remarkable, followed by amplitude of blue edge, the same as differences between S. chamaejasme and herbage communities. Linear regression analysis between coverage of S. chamaejasme and spectral feature parameters showed best result for red valley (R2 = 0.94). Finally, the red valley, the blue valley and the near-infrared peak were proposed for discriminating S. chamaejasme from herbage in the full-blossom period of S. chamaejasme, and the combination of corresponding red, blue and near-infrared bands could be used to build sensitive indices for S. chamaejasme recognition.

[Preparation of mB7.1-GPI and SEA-TM dual-anchored tumor cell vaccine and its antitumor effect].

OBJECTIVE: To prepare the SEA-TM and mB7.1-GPI dual-anchored EL-4 cell vaccine and to investigate its antitumor effects. METHODS: mB7.1-GPI-anchored EL-4 cell vaccine, SEA-TM-anchored EL-4 cell vaccine, SEA-TM and mB7.1-GPI dual-anchored EL-4 cell vaccine were prepared. In vitro the biological activities of these vaccines were measured using a lymphocyte proliferation assay and cytokine release assay on splenocytes derived from C57BL/6 mice. The splenocytes were co-cultured with EL-4 or EL-4/mB7.1-GPI or EL-4/SEA-TM or EL-4/SEA-TM + mB7.1-GPI (treated with Mitomycin C). Lymphocyte proliferation was determined with MTT assay, the concentrations of cytokines (IL-2 and IFN-gamma) were measured using a ELISA technique. Forty C57BL/6 mice were inoculated with EL-4 cells, after 3 days the mice were randomly divided into 5 groups with 8 in each and were treated with PBS, EL-4 cell vaccine, EL-4/mB7.1-GPI cell vaccine, EL-4/SEA-TM cell vaccine and EL-4/SEA-TM + mB7.1-GPI cell vaccine respectively, vaccines were injected three time with two-day interval. Animals were observed daily, tumor sizes were measured every third day. Twenty-five days after tumor challenge, 3 mice in each group were sacrificed and splenic lymphocytes were isolated to examine the activity of natural killer cells (NK) and cytolytic T lymphocytes (CTL). The survival of the remaining 5 mice in each group was observed till the 90th day. RESULTS: mB7.1-GPI or/and TM-SEA fusion protein was stably anchored onto the surface of EL-4 tumor cells. EL-4/mB7.1-GPI or EL-4/SEA-TM had a stronger ability to stimulate lymphocyte proliferation and IL-2 and IFN-gamma production than EL-4 (P < 0.05); while EL-4/SEA-TM + mB7.1-GPI showed a further increased ability than EL-4/mB7.1-GPI and EL-4/SEA-TM in stimulating lymphocyte proliferation and cytokine production in vitro (P < 0.05). Volume of tumor was smaller and survival time of mice was longer in EL-4/mB7.1-GPI vaccine group, EL-4/SEA-TM vaccine group and EL-4/SEA-TM + mB7.1-GPI vaccine group, comparing with PBS group and EL-4 cell vaccine group (P < 0.05). Tumor volume was much smaller and survival time of mice was much longer in EL-4/mB7.1-GPI + mB7.1-GPI vaccine group, comparing with EL-4/SEA-TM vaccine group and EL-4/mB7.1-GPI vaccine group (P < 0.05). Lymphocytes derived from the mice treated with EL-4/SEA-TM + mB7.1-GPI showed much higher NK activity and CTL activity than those derived from EL-4/mB7.1-GPI vaccine group and EL-4/SEA-TM vaccine group (P < 0.05), meanwhile the NK activity and CTL activity of EL-4/mB7.1-GPI vaccine group and EL-4/SEA-TM vaccine group was higher than EL-4 vaccine group (P < 0.05). CONCLUSION: mB7.1-GPI or/and SEA-TM fusion protein was stably anchored onto the surface of EL-4 tumor cells. The tumor cell vaccines prepared from these cells exhibited antitumor effect. The mB7.1-GPI and SEA-TM dual-anchored tumor cell vaccine had much stronger antitumor effect than the single-anchored tumor cell vaccine.

[Gene transfer by novel non-viral vector polyethylenimine].

OBJECTIVE: To investigate the influencing factors of polyethylenimine (PEI) in gene transfer in vitro. METHODS: Cytotoxic effects of PEI on in vitro cultured NIH 3T3 cells were quantified by MTT assay. The interaction between PEI and DNA at different charge ratios was analyzed by agarose gel electrophoresis retardation assay. The expression of gene transfer was monitored in Cos-7 cells using pEGFP and pSV beta plasmids as the reporter gene systems. Influences of chloroquine, albumin, serum, salt ion strength, and Mg(2+) ion and other factors on PEI/DNA transfer efficiency were evaluated. RESULT: The survival rate of NIH3T3 cells at 6 mg/L of PEI was 64.2% and at 7 mg/L of PEI was 54.4%. Gel electrophoresis retardation assays showed that PEI completely retarded DNA migration at 3.0 PEI nitrogen per DNA phosphate. Chloroquine enhanced the transfection efficiency of PEI. Albumin and serum in the culture medium decreased the transfection efficiency. HBS(HEPES buffered solution) or 150 mmol/L NaCl as the dilution solution of PEI/DNA was superior over 278 mmol/L glucose solution in the transfection efficiency. Mg(2+) in the dilution solution decreased the transfer efficiency of PEI/DNA. CONCLUSION: PEI is efficient gene transfer agent of eukaryotes in vitro, and can be possibly used in vivo.