Livestock grazing modifies soil nematode body size structure in mosaic grassland habitats.

Body size is closely related to the trophic level and abundance of soil fauna, particularly nematodes. Therefore, size-based analyses are increasingly prominent in unveiling soil food web structure and its responses to anthropogenic disturbances, such as livestock grazing. Yet, little is known about the effects of different livestock on the body size structure of soil nematodes, especially in grasslands characterized by local habitat heterogeneity. A four-year field grazing experiment from 2017 to 2020 was conducted in a meadow steppe characterized by typical mosaics of degraded hypersaline patches and undegraded hyposaline patches to assess the impacts of cattle and sheep grazing on the body size structure of soil nematodes within and across trophic groups. Without grazing, the hypersaline patches harbored higher abundance of large-bodied nematodes in the community compared to the hyposaline patches. Livestock grazing decreased large-bodied nematodes within and across trophic groups mainly by reducing soil microbial biomass in the hypersaline patches, with sheep grazing resulting in more substantial reductions compared to cattle grazing. The reduction in large-bodied nematode individuals correspondingly resulted in decreases in nematode community-weighted mean (CWM) body size, nematode biomass, and size spectra slopes. However, both cattle and sheep grazing had minimal impacts on the CWM body size and size spectra of total nematodes in the hyposaline patches. Our findings suggest that livestock grazing, especially sheep grazing, has the potential to simplify soil food webs by reducing large-bodied nematodes in degraded habitats, which may aggravate soil degradation by weakening the bioturbation activities of soil fauna. In light of the widespread land use of grasslands by herbivores of various species and the ongoing global grassland degradation of mosaic patches, the recognition of the trends revealed by our findings is critical for developing appropriate strategies for grassland grazing management.

Responses of plant biomass and yield component in rice, wheat, and maize to climatic warming: a meta-analysis.

MAIN CONCLUSION: Responses of plant biomass and yield components to warming are species-specific and are shifted as increased warming magnitude rises; this finding improves the results of IPCC AR5. The responses of crop yields to climatic warming have been extensively reported from experimental results, historical yield collections, and modeling research. However, an integrative report on the responses of plant biomass and yield components of three major crops to experimental warming is lacking. Here, a meta-analysis based on the most recent warming experiments was conducted to quantify the climatic warming responses of the biomass, grain yield (GY), and yield components of three staple crops. The results showed that the wheat total aboveground biomass (TAGB) increased by 6.0% with general warming, while the wheat GY did not significantly respond to warming; however, the responses shifted with increases in the mean growing season temperature (MGST). Negative effects on wheat TAGB and GY appeared when the MGSTs were above 15 °C and 13 °C, respectively. The wheat GY and the number of grains per panicle decreased by 8.4% and 7.5%, respectively, per degree Celsius increase. Increases in temperature significantly reduced the rice TAGB and GY by 4.3% and 16.6%, respectively, but rice straw biomass increased with increasing temperature. However, the rice grain weight and the number of panicles decreased with continuous increasing temperature (ΔTa). The maize biomass, GY, and yield components all generally decreased with climatic warming. Finally, the crop responses to climatic warming were significantly influenced by warming time, warming treatment facility, and methods. Our findings can improve the assessment of crop responses to climatic warming and are useful for ensuring food security while combating future global climate change.

Comparison of a Newly Developed HPV Genotyping Assay (Mojin HPV Kit) with Cobas 4800 HPV Test for Detection of High-Risk HPV in Specimens Collected in SurePath Solution.

BACKGROUND: Human papillomavirus (HPV) detection based on cervical cytology specimens is useful for cervical cancer screening. The aim of this study was to compare Mojin HPV kit (a newly developed HPV genotyping assay) with the Cobas 4800 HPV test in detecting high-risk (HR) HPV. METHODS: A total of 347 cervical exfoliated cell specimens were tested using the Mojin HPV kit and Cobas 4800 HPV test. When the results from the two tests were inconsistent, gene sequencing was performed for correction. RESULTS: For HR-HPV, the results of the two assays agreed by 96.3% [Kappa = 0.911; 95% confidence interval (CI): 0.863 - 0.958)]. The positive and negative coincidence rates between the two tests were 96.0% (95% CI: 92.7% - 98.0%) and 97.0% (95% CI: 91.5% - 99.4%), respectively. Of the 13 samples with discordant results, 3 samples were false positive and 10 samples were true negative for Mojin HPV test, according to the identification by sequencing. For HPV16 genotyping, the total coincidence rate between the 2 tests was 100% (Kappa = 1.000), and 99.7% (Kappa = 0.973; 95% CI: 0.905 - 1.000) for HPV18. CONCLUSIONS: Mojin HPV kit may be as effective as Cobas 4800 HPV assay in detecting the total HR-HPV, especially HPV16 or HPV18.

Serum microRNA-205 as a novel biomarker for cervical cancer patients.

OBJECTIVE: Serum microRNAs (miRNAs) are a novel class of diagnostic and prognostic biomarkers for numerous cancers. However, the level and clinical relevance of circulating miR-205 transcripts in human serum of cervical cancer patients are unclear. The purpose of this study was to determine serum miR-205 levels in cervical cancer patients and explore its association with clinicopathological factors and prognosis. METHODS: Serum miR-205 expression was investigated in 60 cervical cancer patients and 60 healthy normal controls by using real-time PCR. Correlations between miR-205 expression and the clinicopathological features and prognosis of cervical cancer patients were then evaluated. Receiver operating characteristic curves were used to evaluate the sensitivity and specificity of serum miR-205. RESULTS: Serum miR-205 was significantly upregulated in cervical cancer patients compared with healthy donors (p < 0.01), and a high level of miR-205 expression was correlated with poor tumor differentiation (p = 0.009), lymph node metastasis (p = 0.015) and increased tumor stage (p = 0.001). The serum miR-205 level was capable of separating advanced stage from early stage metastatic cervical cancer from non-metastatic samples and poorly differentiated tumors from differentiated tumors with an area under the curve values of 0.74, 0.694 and 0.717, respectively. The expression of miR-205 was also higher in the cervical cancer tissues compared with the para-carcinoma tissues. In addition, Kaplan-Meier survival analysis showed that cervical cancer patients with high miR-205 expression tended to have shorter overall survival. In multivariate Cox regression analysis, miR-205 was identified as an independent prognostic marker. CONCLUSIONS: Serum miR-205, which is upregulated in cervical cancer, represents a predictive biomarker for the prognosis of cervical cancer patients.

Soil microbial responses to large changes in precipitation with nitrogen deposition in an arid ecosystem.

Climatic change severely affects terrestrial ecosystem functioning by modifying soil microbial communities, especially in arid ecosystems. However, how precipitation patterns affect soil microbes and the underlying mechanisms remain largely unclear, particularly under long-term dry-wet cycling and vice versa in field settings. In this study, a field experiment was conducted to quantify soil microbial responses and resilience to precipitation changes with nitrogen addition. We established five levels of precipitation with nitrogen addition over the first 3 years and then balanced this with compensatory precipitation in the fourth year (i.e., reversed the precipitation treatments), to recover to the levels expected over 4 years in a desert steppe ecosystem. Soil microbial community biomass increased with increasing precipitation, and the reversed precipitation reversed these responses. The soil microbial response ratio was constrained by the initial reduction in precipitation, whereas the resilience and limitation/promotion index of most microbial groups tended to increase. Nitrogen addition reduced the response rates of most microbial groups, depending on the soil depth. The soil microbial response and limitation/promotion index could be distinguished by antecedent soil features. The precipitation regime can regulate the responses of soil microbial communities to climatic change via two potential mechanisms: (1) concurrent nitrogen deposition and (2) soil chemical and biological mediation. Soil microbial behaviors and their associations with soil properties should be considered when assessing the responses of terrestrial ecosystems to climatic change.

Climatic warming enhances soil respiration resilience in an arid ecosystem.

Precipitation plays a vital role in maintaining desert ecosystems in which rain events after drought cause soil respiration (Rs) pulses. However, this process and its underlying mechanism remain ambiguous, particularly under climatic warming conditions. This study aims to determine the magnitude and drivers of Rs resilience to rewetting. We conducted a warming experiment in situ in a desert steppe with three climatic warming scenarios-ambient temperature as the control, long-term and moderate warming treatment, and short-term and acute warming treatment. Our findings showed that the average Rs over the measurement period in the control, moderate and acute warming plots were 0.51, 0.30 and 0.30 µmol·CO2·m-2·s-1, respectively, and significantly increased to 1.72, 1.41 and 1.72 µmol·CO2·m-2·s-1, respectively, after rewetting. Both microbial and root respiration substantially increased by rewetting; microbial respiration contributed more than root respiration to total Rs. The Rs significantly increased with microbial biomass carbon and soil organic carbon (SOC) contents. The Rs increase by rewetting might be due to the greater microbial respiration relying heavily on microbial biomass and the larger amount of available SOC after rewetting. A trackable pattern of Rs resilience changes occurred during the daytime. The resilience of Rs in acute warming plots was significantly higher than those in both moderate warming and no warming plots, indicating that Rs resilience might be enhanced with drought severity induced by climatic warming. These results suggest that climatic warming treatment would enhance the drought resilience of soil carbon effluxes following rewatering in arid ecosystems, consequently accelerating the positive feedback of climate change. Therefore, this information should be included in carbon cycle models to accurately assess ecosystem carbon budgets with future climate change scenarios in terrestrial ecosystems, particularly in arid areas.

Cryopreserved mouse fetal liver stromal cells treated with mitomycin C are able to support the growth of human embryonic stem cells.

An immortalized mouse fetal liver stromal cell line, named KM3, has demonstrated the potential to support the growth and maintenance of human embryonic stem cells (hESCs). In this study, the characteristics of KM3 cells were examined following cryopreservation at -70°C and in liquid nitrogen for 15, 30 and 60 days following treatment with 10 µg/ml mitomycin C. In addition, whether the KM3 cells were suitable for use as feeder cells to support the growth of hESCs was evaluated. The inhibition of mitosis without cell death was observed when the KM3 cells were treated with 10 µg/ml mitomycin C for 2 h. The morphology of the KM3 cells cryopreserved in liquid nitrogen for 60 days was not markedly changed, and the cell survival rate was 84.60±1.14%. By contrast, the survival rate of the KM3 cells was 66.40±2.88% following cryopreservation at -70°C for 60 days; the cells readily detached, were maintained for a shorter time, and had a reduced expression level of basic fibroblast growth factor. hESCs cultured on KM3 cells cryopreserved in liquid nitrogen for 60 days showed the typical bird's nest structure, with clear boundaries and a differentiation rate of 16.33±2.08%. The differentiation rate of hESCs cultured on KM3 cells cryopreserved at -70°C for 60 days was 37.67±3.51%. These results indicate that the cryopreserved KM3 cells treated with mitomycin C may be directly used in the subculture of hESCs, and the effect is relatively good with -70°C short-term or liquid nitrogen cryopreservation.

Immortalized mouse fetal liver stromal cells support growth and maintenance of human embryonic stem cells.

Human embryonic stem cells (hESCs) are usually maintained in an undifferentiated state by co-culture with feeder cells. The feeder cells are important for the growth of hESCs. A novel spontaneously immortalizated mouse fetal liver stromal cell line, named KM3, was isolated from a 13.5­day mouse fetal liver. In this study, we examined whether KM3 cells could be used as feeders to support the growth of hESCs. hESCs cultured on KM3 cells showed a similar proliferation rate and characteristics to mouse embryonic fibroblasts (MEFs) after prolonged culture, including morphology, unlimited and undifferentiated proliferative ability, maintenance of normal karyotypes, formation of embryoid bodies in vitro and typically immature teratomas in vivo. Our results indicate that the immortalized KM3 cell line has the potential to support the growth and maintenance of hESCs. The cell line may be used for the large-scale expansion of hESCs in a low-cost and less labor-intensive manner.