On the Robustness of Question Rewriting Systems to Questions of Varying Hardness

In conversational question answering (CQA), the task of question rewriting~(QR) in context aims to rewrite a context-dependent question into an equivalent self-contained question that gives the same answer. In this paper, we are interested in the robustness of a QR system to questions varying in rewriting hardness or difficulty. Since there is a lack of questions classified based on their rewriting hardness, we first propose a heuristic method to automatically classify questions into subsets of varying hardness, by measuring the discrepancy between a question and its rewrite. To find out what makes questions hard or easy for rewriting, we then conduct a human evaluation to annotate the rewriting hardness of questions. Finally, to enhance the robustness of QR systems to questions of varying hardness, we propose a novel learning framework for QR that first trains a QR model independently on each subset of questions of a certain level of hardness, then combines these QR models as one joint model for inference. Experimental results on two datasets show that our framework improves the overall performance compared to the baselines.Comment: ACL'22, main, long pape

Observation of the effectiveness of whole course of comprehensive nursing in clinical care after the surgery for benign prostatic hyperplasia

This study discussed the effect of whole course of comprehensive nursing after the operation for benign prostatic hyperplasia (BPH). Eighty-six patients with BPH who were to undergo prostatic hyperplasia surgery were divided into a control group and a study group based on therapeutic method. 43 patients in each group were postoperatively given usual care in the control group and comprehensive nursing in the study group. The mental status, prostate symptoms, quality of life, complications and degree of satisfaction were compared before and after the interventions. The mental status, prostate symptoms, and quality of life (QOL) of the patients were relatively similar (p > 0.05) before the intervention. The scores of self-rating anxiety scale (SAS), self-rating depression scale (SDS), international prostate symptom scale (IPSS) and QOL of patients in the study group were significantly lower than those in the control group after the intervention (p < 0.05). The incidence of complications in the study group was 4.65%, which was significantly lower than that of the control group at 18.60% (p < 0.05), while the satisfaction rate in the study group was 95.35%, which was significantly higher than that of the control group at 69.77% (p < 0.05) . The whole course of comprehensive nursing after the operation for BPH surgery was effective in improving patients’ mental status, promoting the recovery of prostate, improving patients’ quality of life, reducing the incidence of complications, and improving patients’ satisfaction

Effects of sunlight on tundra nitrous oxide and methane fluxes in maritime Antarctica

The relationships of nitrous oxide (N2O) and methane (CH4) emissions to other environmental parameters have been studied extensively in Antarctic terrestrial ecosystems. However, the effects of sunlight on soil N2O and CH4 fluxes are neglected across the Antarctic tundra. Here, fluxes of N2O and CH4 from maritime Antarctic tundra soils were measured in the absence and presence of sunlight during three summers. The N2O fluxes averaged −4.6±1.2 μg·m−2·h−1 in the absence of sunlight and 5.7±1.5 μg·m−2·h−1 in its presence; CH4 fluxes averaged 119.8±24.5 μg·m−2·h−1 (absence) and −40.5±28.3 μg·m−2·h−1 (presence). The correlations between N2O and CH4 fluxes and other environmental variables (e.g., soil moisture, temperature, organic and inorganic material) were not statistically significant (P>0.05) at all sites. On average, sunlight significantly increased N2O emissions and CH4 uptake by 10.3 μg·m−2·h−1 and 160.3 μg·m−2·h−1, respectively. This study indicates that sunlight is critical for accurately estimating N2O and CH4 budgets from maritime Antarctica and necessary for constraining the role of their emissions from tundra soil

Tradeoffs in soil carbon protection mechanisms under aerobic and anaerobic conditions

Oxygen (O2) limitation is generally understood to suppress soil carbon (C) decomposition and is a key mechanism impacting terrestrial C stocks under global change. Yet, O2 limitation may differentially impact kinetic or thermodynamic vs. physico-chemical C protection mechanisms, challenging our understanding of how soil C may respond to climate-mediated changes in O2 dynamics. Although O2 limitation may suppress decomposition of new litter C inputs, release of physico-chemically protected C due to iron (Fe) reduction could potentially sustain soil C losses. To test this tradeoff, we incubated two disparate upland soils that experience periodic O2 limitation—a tropical rainforest Oxisol and a temperate cropland Mollisol—with added litter under either aerobic (control) or anaerobic conditions for one year. Anoxia suppressed total C loss by 27% in the Oxisol and by 41% in the Mollisol relative to the control, mainly due to the decrease in litter-C decomposition. However, anoxia sustained or even increased decomposition of native soil-C (11.0% vs. 12.4% in the control for the Oxisol and 12.5% vs. 5.3% in the control for the Mollisol, in terms of initial soil C mass), and it stimulated losses of metal- or mineral-associated C. Solid-state 13C nuclear magnetic resonance spectroscopy demonstrated that anaerobic conditions decreased protein-derived C but increased lignin- and carbohydrate-C relative to the control. Our results indicate a tradeoff between physico-chemical and kinetic/thermodynamic C protection mechanisms under anaerobic conditions, whereby decreased decomposition of litter C was compensated by more extensive loss of mineral-associated soil C in both soils. This challenges the common assumption that anoxia inherently protects soil C and illustrates the vulnerability of mineral-associated C under anaerobic events characteristic of a warmer and wetter future climate

Metagenomic insights into the abundance and composition of resistance genes in aquatic environments:Influence of stratification and geography

A global survey was performed with 122 aquatic metagenomic DNA datasets (92 lake water and 30 seawater) obtained from the Sequence Read Archive (SRA). Antibiotic resistance genes (ARGs) and metal resistance genes (MRGs) were derived from the dataset sequences via bioinformatic analysis. The relative abundances of ARGs and MRGs in lake samples were in the ranges ND (not detected)-1.34x10(0) and 1.22x10(-3) -1.98x10(-1) copies per 16S rRNA, which were higher than those in seawater samples. Among ARGs, multidrug resistance genes and bacitracin resistance genes had high relative abundances in both lake and sea water samples. Multimetal resistance genes, mercury resistance genes and copper resistance genes had the greatest relative abundance for MRGs. No significant difference was found between epilimnion and hypolimnion in abundance or the Shannon diversity index for ARGs and MRGs. Principal coordinates analysis and permutational multivariate analysis of variance (PERMANOVA) test showed that stratification and geography had significant influence on the composition of ARGs and MRGs in lakes (p < 0.05, PERMANOVA). Coastal seawater samples had significantly greater relative abundance and a higher Shannon index for both ARGs and MRGs than deep ocean and Antarctic seawater samples (p < 0.05, Kruskal-Wallis one-way ANOVA), suggesting that human activity may exert more selective pressure on ARGs and MRGs in coastal areas than those in deep ocean and Antarctic seawater

ATP6L promotes metastasis of colorectal cancer by inducing epithelial-mesenchymal transition

ATP6L, the C subunit of the V-ATPase V0 domain, is involved in regulating the acidic tumor micro-environment and may promote tumor progression. However, the expression and functional role of ATP6L in tumors have not yet been well explored. In this study, we found that ATP6L protein overexpression was related to colorectal cancer histological differentiation (P <0.001), presence of metastasis (P <0.001) and recurrence (P = 0.02). ATP6L expression in the liver metastatic foci was higher than in the primary foci (P = 0.04). ATP6L expression was notably concomitant with epithelial-mesenchymal transition (EMT) immunohistochemical features, such as reduced expression of the epithelial marker E-cadherin (P = 0.021) and increased expression of the mesenchymal marker vimentin (P = 0.004). Results of in vitro and in vivo experiments showed that ATP6L expression could alter cell morphology, regulate EMT-associated protein expression, and enhance migration and invasion. The effect of ATP6L on metastasis was further demonstrated in a tail vein injection mice model. In addition, the mouse xenograft model showed that ATP6L-overexpressing HCT116 cells grew into larger tumor masses, showed less necrosis and formed more micro-vessels than the control cells. Taken together, our results suggest that ATP6L promotes metastasis of colorectal cancer by inducing EMT and angiogenesis, and is a potential target for tumor therapy

Study of Histopathological and Molecular Changes of Rat Kidney under Simulated Weightlessness and Resistance Training Protective Effect

To explore the effects of long-term weightlessness on the renal tissue, we used the two months tail suspension model to simulate microgravity and investigated the simulated microgravity on the renal morphological damages and related molecular mechanisms. The microscopic examination of tissue structure and ultrastructure was carried out for histopathological changes of renal tissue morphology. The immunohistochemistry, real-time PCR and Western blot were performed to explore the molecular mechanisms associated the observations. Hematoxylin and eosin (HE) staining showed severe pathological kidney lesions including glomerular atrophy, degeneration and necrosis of renal tubular epithelial cells in two months tail-suspended rats. Ultrastructural studies of the renal tubular epithelial cells demonstrated that basal laminas of renal tubules were rough and incrassate with mitochondria swelling and vacuolation. Cell apoptosis in kidney monitored by the expression of Bax/Bcl-2 and caspase-3 accompanied these pathological damages caused by long-term microgravity. Analysis of the HSP70 protein expression illustrated that overexpression of HSP70 might play a crucial role in inducing those pathological damages. Glucose regulated protein 78 (GRP78), one of the endoplasmic reticulum (ER) chaperones, was up-regulated significantly in the kidney of tail suspension rat, which implied that ER-stress was associated with apoptosis. Furthermore, CHOP and caspase-12 pathways were activated in ER-stress induced apoptosis. Resistance training not only reduced kidney cell apoptosis and expression of HSP70 protein, it also can attenuate the kidney impairment imposed by weightlessness. The appropriate optimization might be needed for the long term application for space exploration

Complete Genome Sequence and Characterization of a Protein-Glutaminase Producing Strain, Chryseobacterium proteolyticum QSH1265

Recently, an enzyme named protein-glutaminase (PG) has been identified as a new type of enzyme with significant potential for deamidation of food proteins. The enzyme is shown to be expressed as a pre-pro-protein with a putative signal peptide of 21 amino acids, a pro-sequence of 114 amino acids, and a mature PG of 185 amino acids. The microbial enzyme PG specifically catalyzes deamidation of proteins without protein hydrolysis pretreatment and only reacts with glutamine residues in the side-chains of proteins or long peptides. All these attributes suggest that it has a great potential for food industrial applications. However, until recently, there have been relatively few studies of the PG-producing strains. A strain named Chryseobacterium proteolyticum QSH1265 which can produce PG was isolated from a soil sample collected in Songjiang, Shanghai, China. Its enzyme activity was about 0.34 ± 0.01 U/mL when using carboxybenzoxy-Gln-Gly as a substrate. The strain can produce acid from D-glucose, maltose, L-arabinose sucrose, glycerol, and mannitol but not fructose, and it is also positive for indole production and urease. Here we describe the complete genome sequence of this strain via PacBio RSII sequencing. The C. proteolyticum QSH1265 genome consists of a circular chromosome with total length of 4,849,803 bp without any plasmids. All of 4563 genes were predicted including 4459 genes for protein-coding and 104 RNA-relative genes with an average G+C content of 36.16%. The KEGG and COG annotation provide information for the specific function of proteins encoded in the genome, such as proteases, chromoproteins, stress proteins, antiporters, etc. A highly conserved hypothetical protein shares a promoter with the gene encoding the protein-glutaminase enzyme. The genome sequence and preliminary annotation provide valuable genetic information for further study of C. proteolyticum

Global variations and drivers of nitrous oxide emissions from forests and grasslands

Nitrous oxide (N2O) emissions are highly variable due to the complex interaction of climatic and ecological factors. Here, we obtained in-situ annual N2O emission flux data from almost 180 peer-papers to evaluate the dominant drivers of N2O emissions from forests and unfertilized grasslands at a global scale. The average value of N2O emission fluxes from forest (1.389 kg Nha-1yr-1) is almost twice as large as that from grassland (0.675 kg Nha-1yr-1). Soil texture and climate are the primary drivers of global forest and grassland annual N2O emissions. However, the best predictors varied according to land use and region. Soil clay content was the best predictor for N2O emissions from forest soils, especially in moist or wet regions, while soil sand content predicted N2O emissions from dry or moist grasslands in temperate and tropical regions best. Air temperature was important for N2O emission from forest, while precipitation was more efficient in grassland. This study provides an overall understanding of the relationship between natural N2O emissions and climatic and environmental variables. Moreover, the identification of principle factors for different regions will reduce the uncertainty range of N2O flux estimates, and help to identify region specific climate change mitigation and adaptation strategies

High Glucose Enhances Cytotoxic T Lymphocyte-Mediated Cytotoxicity

Cytotoxic T lymphocytes (CTLs) are key players to eliminate tumorigenic or pathogen-infected cells using lytic granules (LG) and Fas ligand (FasL) pathways. Depletion of glucose leads to severely impaired cytotoxic function of CTLs. However, the impact of excessive glucose on CTL functions still remains largely unknown. Here we used primary human CD8+ T cells, which were stimulated by CD3/CD28 beads and cultured in medium either containing high glucose (HG, 25 mM) or normal glucose (NG, 5.6 mM). We found that in HG-CTLs, glucose uptake and glycolysis were enhanced, whereas proliferation remained unaltered. Furthermore, CTLs cultured in HG exhibited an enhanced CTL killing efficiency compared to their counterparts in NG. Unexpectedly, expression of cytotoxic proteins (perforin, granzyme A, granzyme B and FasL), LG release, cytokine/cytotoxic protein release and CTL migration remained unchanged in HG-cultured CTLs. Interestingly, additional extracellular Ca2+ diminished HG-enhanced CTL killing function. Our findings suggest that in an environment with excessive glucose, CTLs could eliminate target cells more efficiently, at least for a certain period of time, in a Ca2+-dependent manner