Plant roots fuel tropical soil animal communities.

Belowground life relies on plant litter, while its linkage to living roots had long been understudied, and remains unknown in the tropics. Here, we analysed the response of 30 soil animal groups to root trenching and litter removal in rainforest and plantations in Sumatra, and found that roots are similarly important to soil fauna as litter. Trenching effects were stronger in soil than in litter, with an overall decrease in animal abundance in rainforest by 42% and in plantations by 30%. Litter removal little affected animals in soil, but decreased the total abundance by 60% in rainforest and rubber plantations but not in oil palm plantations. Litter and root effects on animal group abundances were explained by body size or vertical distribution. Our study quantifies principle carbon pathways in soil food webs under tropical land use, providing the basis for mechanistic modelling and ecosystem-friendly management of tropical soils.

Litter nitrogen concentration changes mediate effects of drought and plant species richness on litter decomposition.

Biodiversity loss, exotic plant invasion and climatic change are three important global changes that can affect litter decomposition. These effects may be interactive and these global changes thus need to be considered simultaneously. Here, we assembled herbaceous plant communities with five species richness levels (1, 2, 4, 8 or 16) and subjected them to a drought treatment (no, moderate or intensive drought) that was factorially combined with an invasion treatment (presence or absence of the non-native Symphyotrichum subulatum). We collected litter of these plant communities and let it decompose for 9 months in the plant communities from which it originated. Drought decreased litter decomposition, while invasion by S. subulatum had little impact. Increasing species richness decreased litter decomposition except under intensive drought. A structural equation model showed that drought and species richness affected litter decomposition indirectly through changes in litter nitrogen concentration rather than by altering quantity and diversity of soil meso-fauna or soil physico-chemical properties. The slowed litter decomposition under high species diversity originated from a sampling effect, specifically from low litter nitrogen concentrations in the two dominant species. We conclude that effects on litter decomposition rates that are mediated by changing concentrations of the limiting nutrient in litter need to be considered when predicting effects of global changes such as plant diversity loss.

Molecular epidemiology and clinical characteristics of Clostridioides difficile infection in patients with inflammatory bowel disease from a teaching hospital.

BACKGROUND: Clostridioides difficile infection (CDI) in patients with inflammatory bowel disease (IBD) is of increasing concern. This study aimed to investigate the molecular epidemiology and antimicrobial susceptibilities of toxigenic C. difficile isolated from IBD patients and to evaluate the risk factors for CDI in IBD population. METHODS: Loose or watery stools from IBD patients were tested for glutamate dehydrogenase, C. difficile toxins A&B and anaerobic culture. Toxigenic C. difficile isolates were characterized by multi-locus sequence typing, ribotyping and antimicrobial susceptibility testing. RESULTS: The prevalence of CDI in IBD patients was 13.6% (43/317). The dominant sequence types (STs) were ST35 (20.9%), ST2 (18.6%) and ST37 (16.3%). The most common ribotypes (RTs) were RT 017 (18.6%), RT 012 (14.0%), and RT 220 (14.0%), whereas RT 027 and RT 078 were not detected in this study. All the isolates were susceptible to vancomycin and metronidazole. The multidrug resistance rate of C. difficile RT 017 was higher (p < 0.01) than that of other RT strains. Recent hospitalization, use of corticosteroids and proton pump inhibitors were related to increased risk of CDI in IBD patients; of these, recent hospitalization and proton pump inhibitors use were independent risk factors. CONCLUSION: Patients with IBD have a relatively high incidence rate of CDI. C. difficile RT 017 is most frequently isolated from IBD patients in this region and warrants more attention to its high resistance rate. Clinicians should pay greater attention to CDI testing in IBD patients with diarrhea to ensure early diagnosis and initiation of effective treatment.

Study on the COVID-19 infection status, prevention and control strategies among people entering Shenzhen.

BACKGROUND: The novel coronavirus disease 2019 (COVID-19) confirmed cases overseas have continued to rise in the last months, and many people overseas have chosen to return to China. This increases the risk of a large number of imported cases which may cause a relapse of the COVID-19 outbreak. In order to prevent imported infection, the Shenzhen government has implemented a closed-loop management strategy using nucleic acid testing (NAT) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and requiring 14 days of medical observation for individuals with an overseas tour history (Hong Kong, Macao, Taiwan province and other countries). Our study aims to describe the status of COVID-19 infection among people entering Shenzhen, and to evaluate the effect of the closed-loop management strategy. METHODS: We undertook a descriptive study and risk analysis by the entry time, time of reporting, and local confirmed cases in countries of origin. The NAT were completed in Shenzhen Center for Disease Control and Prevention (CDC), ten district-level CDCs, and fever clinics. RESULTS: A total of 86,844 people from overseas entered Shenzhen from January 1 to April 18, 2020; there were 39 imported COVID cases and 293 close contacts. The infection rate of people entering was 4.49‰ [95% Confidence interval (CI): 3.26‰-6.05‰]. Fourteen imported cases (35.9%) came from the UK, and nine (23.08%) came from the USA. People entering from the USA since March 9 or from the UK since March 13 are the high-risk population. As of July 17, there have been no new confirmed cases in Shenzhen for 153 days, and the numbers of confirmed case, close contacts, and asymptomatic cases are 0. CONCLUSIONS: The closed-loop management has been effective in preventing imported infection and controlling domestic relapse. The distribution of entry time and report time for imported cases overseas was similar. This shows that it is important to implement closed-loop management at the port of entry.

Lumen degradation analysis of LED lamps based on the subsystem isolation method.

The lumen degradation of LED lamps undergoing an accelerated aging test is investigated. The entire LED lamp is divided into three subsystems, namely, driver, lampshade, and LED light source. The parameters of output power [Watts (W)], transmittance (%), and lumen flux (lm) are adopted in the analysis of the degradation of the driver, lampshade, and LED light source, respectively. Two groups of LED lamps are aged under the ambient temperatures of 25°C and 85°C, respectively, with the aging time of 2000 h. The lumen degradation of the lamps is from 3.8% to 4.9% for the group under a temperature of 25°C and from 10.6% to 12.7% for the group under a temperature of 85°C. The LED light source is the most aggressive part of the three subsystems, which accounts for 70.5% of the lumen degradation of the LED lamp on average. The lampshade is the second degradation source, which causes 21.5% of the total amount on average. The driver is the third degradation source, which causes 6.5% under 25°C and 2.8% under 85°C of the total amount on average.

Prevalence of Undernutrition and Related Dietary Factors among People Aged 75 Years or Older in China during 2010-2012.

OBJECTIVE: Undernutrition is highly prevalent among older people. The aim of this study was to estimate the prevalence of undernutrition in elderly Chinese residents and explore the relationship between undernutrition and dietary factors. METHODS: Data were collected from 2,552 elderly people aged 75 years and over from the Chinese Nutrition and Health Surveillance during 2010-2012 using questionnaires, anthropometric measurement, and individual consecutive 3-day 24-hour dietary records. RESULTS: The present study showed that 10.5% of participants had undernutrition. The prevalence was higher among the population living in rural areas, those living in the South region, those who smoked, and those with low income levels. Most participants failed to meet the Chinese Dietary Reference Intakes for energy (66.1%) and protein (72.1%). When comparing quartiles of food intake, high rice consumption [odds ratio (OR) = 2.44, 95% confidence interval (CI): 1.35-4.40)], animal oil intake (OR = 1.60, 95% CI: 1.18-2.17), and high fat intake from animal sources (OR = 1.56, 95% CI: 1.06-2.31) were positively associated with underweight whereas high wheat consumption (OR = 0.44, 95% CI: 0.26-0.74), a proper proportion (24%-32%) of energy intake from fat (OR = 0.54, 95% CI: 0.35-0.83), and high fat intake from plant sources (OR = 0.67, 95% CI: 0.46-0.99) were inversely related. CONCLUSION: The prevalence of undernutrition was high among elderly Chinese people, especially in rural areas. Dietary factors, such as high consumption of rice, were associated with undernutrition.

LXR agonists promote the proliferation of neural progenitor cells through MEK-ERK pathway.

The liver X receptors (LXRs) are transcriptional regulators of lipid homeostasis and may be critical for neurodegeneration and neurogenesis in vivo. However, it remains largely unknown about the role of LXRs and its agonists in the in vitro proliferation of neural progenitor cells (NPCs). Here we revealed for the first time that LXRs were markedly expressed in mouse NPCs and were critical for the in vitro proliferation. LXR agonists GW3965 and LXR623 promoted the proliferation of wildtype NPCs, but not NPCs from LXR double-knockout mice. Mechanistically, phosphorylation of MEK1/2 and ERK1/2 in NPCs was enhanced upon LXR agonist treatment, while abrogation of MEK/ERK phosphorylation by the inhibitors PD98059 and U0126 impaired the proliferation of wildtype NPCs in the presence or absence of LXR agonists. Collectively, our findings suggest that LXR agonists GW3965 and LXR623 can stimulate the NPC proliferation in LXR- and MEK/ERK-dependent manner.

Synchronous gastrointestinal cancer and gastrointestinal stromal tumors: a single-institution experience.

BACKGROUND: A study was conducted to investigate the clinicopathological features and survival outcomes of gastrointestinal stromal tumors (GISTs) that are synchronous with other gastrointestinal cancers. METHODS: Clinical and pathological data of 286 patients with primary GIST from a single institution from January 2009 to December 2014 were reviewed. RESULTS: The entire study population comprised 286 patients with GISTs. Of these patients, 167 (58.4%) were males and 119 (41.6%) were females. The median age was 58 years old (in the range 29-86 years). A total of 47 patients were diagnosed with GISTs synchronous with other digestive tract malignancies (synchronous group), whereas 239 patients were diagnosed with non-synchronous disease (non-synchronous group). The concomitant digestive tumors in 27, 12, 7, and 1 patients were diagnosed as gastric carcinoma, esophageal carcinoma, colorectal carcinoma, and pancreatic adenocarcinoma, respectively. Compared with the synchronous group, the non-synchronous group exhibited a higher percentage of increased mitotic count (P = 0.011). The difference in tumor diameter between the two groups was statistically significant (P < 0.001). Patients in the non-synchronous group exhibited larger tumor size than the patients in the synchronous group (5.9 ± 3.5 cm vs. 1.6 ± 0.4 cm, P < 0.001). The majority of GIST lesions in the synchronous group were located in the stomach (P = 0.020). Lower risk stratifications and worse ECOG performance statuses were observed in the synchronous group (P < 0.001) than in the non-synchronous group. The 5-year overall survival rate was significantly higher in patients with no synchronous digestive tract malignancies than in patients with synchronous disease (70.8 vs. 34.1%, P < 0.001). CONCLUSIONS: Patients with GIST synchronous with other gastrointestinal cancers show worse prognosis than those with non-synchronous tumors. Clinicians should pay more attention to this subgroup.

[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.

Plantation forestry under global warming: hybrid poplars with improved thermotolerance provide new insights on the in vivo function of small heat shock protein chaperones.

Climate-driven heat stress is a key factor affecting forest plantation yields. While its effects are expected to worsen during this century, breeding more tolerant genotypes has proven elusive. We report here a substantial and durable increase in the thermotolerance of hybrid poplar (Populus tremula×Populus alba) through overexpression of a major small heat shock protein (sHSP) with convenient features. Experimental evidence was obtained linking protective effects in the transgenic events with the unique chaperone activity of sHSPs. In addition, significant positive correlations were observed between phenotype strength and heterologous sHSP accumulation. The remarkable baseline levels of transgene product (up to 1.8% of total leaf protein) have not been reported in analogous studies with herbaceous species. As judged by protein analyses, such an accumulation is not matched either by endogenous sHSPs in both heat-stressed poplar plants and field-grown adult trees. Quantitative real time-polymerase chain reaction analyses supported these observations and allowed us to identify the poplar members most responsive to heat stress. Interestingly, sHSP overaccumulation was not associated with pleiotropic effects that might decrease yields. The poplar lines developed here also outperformed controls under in vitro and ex vitro culture conditions (callus biomass, shoot production, and ex vitro survival), even in the absence of thermal stress. These results reinforce the feasibility of improving valuable genotypes for plantation forestry, a field where in vitro recalcitrance, long breeding cycles, and other practical factors constrain conventional genetic approaches. They also provide new insights into the biological functions of the least understood family of heat shock protein chaperones.

Use of two-step grafting to fabricate dual-functional films and site-specific functionalized scaffolds.

Polycaprolactone (PCL) is a widely utilized bioresorbable polymer in tissue engineering applications. However, the absence of intrinsic functional groups in the polymer backbone necessitates the incorporation of functional chemistries to enable the further addition of bioactive molecules to PCL-based surfaces and scaffolds. The current study aimed to incorporate two different functional groups, amine and carboxylate, first on two-dimensional (2D) spin-coated PCL films and, thereafter, throughout all surfaces within three-dimensional (3D) porous PCL-based scaffolds, produced using the thermally induced phase separation (TIPS) method, but in a spatially separated manner. Specifically, gamma irradiation induced grafting of acrylic acid (AA) and 2-aminoethyl methacrylate hydrochloride (AEMA) onto PCL was performed in selected solvents and the resulting substrates were characterized using X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and contact angle measurements to determine the surface free energy. Results demonstrated that stepwise graft copolymerization of AEMA and AA allows the fabrication of dual-functional surfaces, with chemistry depending on the order of grafting of the two monomers. In addition, 3D scaffolds could be decorated exclusively with carboxylate groups in the interior, while the outer surface displayed dual-functionality. This simple surface modification methodology, with the ability to create spatially separated surface functional groups throughout 3D porous scaffolds post their fabrication, has the potential to be applied to many current and future scaffold systems being investigated in the field of tissue engineering.

Thrombin generation increasing with age and decreasing with use of heparin indicated by calibrated automated thrombogram conducted in Chinese.

OBJECTIVE: Calibrated Automated Thrombogram(CAT) is a test to monitor the generation of thrombin. It can be described by four parameters: lag time, peak thrombin, endogenous thrombin potential (ETP) and time to peak (ttPeak). This study aims to determine the normal ranges of CAT parameters in Chinese, and evaluate whether thrombin generation is correlated with the concentration of heparin/low molecular weight heparin. METHODS: Plasma from 120 healthy subjects were collected to determine the normal rangea of CAT parameters in Chinese. Normal plasma pool (NPP, n=25) spiked with different concentrations of heparin or enoxaparin were used to detecte CAT parameters. The overall and age specific normal ranges of CAT parameters were calculated using descriptive statistics method with mean±2SD. The correlation between CAT parameters and age or concentrations of heparin, enoxaparin were analyzed with linear regression model. RESULTS: The normal ranges for lag time, peak thrombin, ETP, ttPeak in the subjects were 3.648±2.465 min, 367.39±151.93 nmol/L, 2277±1030 nmol/L•min and 6.372±4.280 min respectively. Age was linearly correlated with lag time (r=-0.6583, P<0.0001), peak thrombin (r=0.4863, P<0.0001), ETP (r=0.3608, P<0.0014) and ttPeak (r=-0.6313, P<0.0001). The values of ETP/peak ratio were linearly correlated with concentrations of heparin. CONCLUSION: The normal ranges of four CAT parameters for Chinese were determined. CAT parameters are associated with age. ETP/peak ratio could be used to monitor the process of anticoagulation therapy.

Human papilloma viruses (HPVs) no co-existence in breast cancer and cervical cells in the same patient.

High-risk HPVs were detected in both breast cancer tissues and cervical cells from 56 breast cancer patients. The results suggested that HPV infection did not coexist in breast and cervical tissues. HPV infection of the breast cancer tissue is more likely to happen in patients without cervical infection.

Niche dimensions in soil oribatid mite community assembly under native and introduced tree species.

Forest soils are a critical component of terrestrial ecosystems and host a large number of animal decomposer species. One diverse and abundant decomposer taxon is oribatid mites (Acari: Oribatida), whose species composition varies with forest type and tree species composition. We used functional traits that indicate different niche dimensions, to infer assembly processes of oribatid mite communities in monocultures and mixed forests of native and introduced tree species. We found that coexisting species differed more in the resource-related niche dimension, i.e., reproductive mode and trophic guild, than in the morphological dimension, e.g., body length and width, sclerotization and concealability. These results suggest that both filtering and partitioning processes structure oribatid mite communities. In native European beech forests, but not in non-native Douglas fir forests, oribatid mites were mainly structured by filtering processes acting via traits related both to environmental tolerance and to resources. Furthermore, oribatid mite trait diversity, but not phylogenetic diversity, differed significantly between monocultures and mixed forests, demonstrating that multidimensional diversity indices provide additional information on soil biodiversity. Overall, the study provides evidence that traits representing different niche dimensions need to be considered for understanding assembly processes in soil animal communities and thereby soil biodiversity.

[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.

Identification of keystone taxa in rhizosphere microbial communities using different methods and their effects on compounds of the host Cinnamomum migao.

Exploring keystone taxa affecting microbial community stability and host function is crucial for understanding ecosystem functions. However, identifying keystone taxa from humongous microbial communities remains challenging. We collected 344 rhizosphere and bulk soil samples from the endangered plant C. migao for 2 years consecutively. Used high-throughput sequencing 16S rDNA and ITS to obtain the composition of bacterial and fungal communities. We explored keystone taxa and the applicability and limitations of five methods (SPEC-OCCU, Zi-Pi, Subnetwork, Betweenness, and Module), as well as the impact of microbial community domain, time series, and rhizosphere boundary on the identification of keystone taxa in the communities. Our results showed that the five methods, identified abundant keystone taxa in rhizosphere and bulk soil microbial communities. However, the keystone taxa shared by the rhizosphere and bulk soil microbial communities over time decreased rapidly decrease in the five methods. Among five methods on the identification of keystone taxa in the rhizosphere community, Module identified 113 taxa, SPEC-OCCU identified 17 taxa, Betweenness identified 3 taxa, Subnetwork identified 3 taxa, and Zi-Pi identified 4 taxa. The keystone taxa are mainly conditionally rare taxa, and their ecological functions include chemoheterotrophy, aerobic chemoheterotrophy, nitrate reduction, and anaerobic photoautotrophy. The results of the random forest model and structural equation model predict that keystone taxa Mortierella and Ellin6513 may have an effects on the accumulation of 1, 4, 7, - Cycloundecatriene, 1, 5, 9, 9-tetramethyl-, Z, Z, Z-, beta-copaene, bicyclogermacrene, 1,8-Cineole in C. migao fruits, but their effects still need further evidence. Our study evidence an unstable microbial community in the bulk soil, and the definition of microbial boundary and ecologically functional affected the identification of keystone taxa in the community. Subnetwork and Module are more in line with the definition of keystone taxa in microbial ecosystems in terms of maintaining community stability and hosting function.

Nickel Induces Pyroptosis via the Nrf2/NLRP3 Pathway in Kidney of Mice.

Nickel (Ni) is considered a toxic metal, and excessive exposure can cause kidney damage. This study was designed to explore whether nickel chloride (NiCl2) can induce cell pyroptosis and its possible mechanism. Here, we found that NiCl2 treatment could reduce the kidney index and result in kidney damage. Meanwhile, NiCl2 could obviously induce renal pyroptosis, which was characterized by an increase in IL-18, IL-1ß, NLRP3, and GSDMD expression. Furthermore, NiCl2 induced pyroptosis through the Nrf2/NLRP3 pathway which featured down-regulated protein and mRNA expression levels of Nrf2 and up-regulated protein and mRNA expression levels of Caspase-1, NLRP3, and GSDMD. In summary, excessive Ni exposure can induce renal cell pyroptosis, ultimately leading to kidney tissue damage and hindering normal development, and its possible mechanism may be due to the inhibition of the Nrf2 pathway.

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.