Decoding river pollution trends and their landscape determinants in an ecologically fragile karst basin using a machine learning model.

Karst watersheds accommodate high landscape complexity and are influenced by both human-induced and natural activity, which affects the formation and process of runoff, sediment connectivity and contaminant transport and alters natural hydrological and nutrient cycling. However, physical monitoring stations are costly and labor-intensive, which has confined the assessment of water quality impairments on spatial scale. The geographical characteristics of catchments are potential influencing factors of water quality, often overlooked in previous studies of highly heterogeneous karst landscape. To solve this problem, we developed a machining learning method and applied Extreme Gradient Boosting (XGBoost) to predict the spatial distribution of water quality in the world's most ecologically fragile karst watershed. We used the Shapley Addition interpretation (SHAP) to explain the potential determinants. Before this process, we first used the water quality damage index (WQI-DET) to evaluate the water quality impairment status and determined that CODMn, TN and TP were causing river water quality impairments in the WRB. Second, we selected 46 watershed features based on the three key processes (sources-mobilization-transport) which affect the temporal and spatial variation of river pollutants to predict water quality in unmonitored reaches and decipher the potential determinants of river impairments. The predicting range of CODMn spanned from 1.39 mg/L to 17.40 mg/L. The predictions of TP and TN ranged from 0.02 to 1.31 mg/L and 0.25-5.72 mg/L, respectively. In general, the XGBoost model performs well in predicting the concentration of water quality in the WRB. SHAP explained that pollutant levels may be driven by three factors: anthropogenic sources (agricultural pollution inputs), fragile soils (low organic carbon content and high soil permeability to water flow), and pollutant transport mechanisms (TWI, carbonate rocks). Our study provides key data to support decision-making for water quality restoration projects in the WRB and information to help bridge the science:policy gap.

Arabidopsis Novel Microgametophyte Defective Mutant 1 Is Required for Pollen Viability via Influencing Intine Development in Arabidopsis.

The pollen intine layer is necessary for male fertility in flowering plants. However, the mechanisms behind the developmental regulation of intine formation still remain largely unknown. Here, we identified a positive regulator, Arabidopsis novel microgametophyte defective mutant 1 (AtNMDM1), which influences male fertility by regulating intine formation. The AtNMDM1, encoding a pollen nuclei-localized protein, was highly expressed in the pollens at the late anther stages, 10-12. Both the mutations and the knock-down of AtNMDM1 resulted in pollen defects and significantly lowered the seed-setting rates. Genetic transmission analysis indicated that AtNMDM1 is a microgametophyte lethal gene. Calcofluor white staining revealed that abnormal cellulose distribution was present in the aborted pollen. Ultrastructural analyses showed that the abnormal intine rather than the exine led to pollen abortion. We further found, using transcriptome analysis, that cell wall modification was the most highly enriched gene ontology (GO) term used in the category of biological processes. Notably, two categories of genes, Arabinogalactan proteins (AGPs) and pectin methylesterases (PMEs) were greatly reduced, which were associated with pollen intine formation. In addition, we also identified another regulator, AtNMDM2, which interacted with AtNMDM1 in the pollen nuclei. Taken together, we identified a novel regulator, AtNMDM1 that affected cellulose distribution in the intine by regulating intine-related gene expression; furthermore, these results provide insights into the molecular mechanisms of pollen intine development.

[Effect of lateral position ventilation combined with vibration sputum drainage on patients with acute respiratory distress syndrome: a prospective randomized controlled trial].

OBJECTIVE: To investigate the curative effect of lateral position ventilation combined with vibration sputum drainage on the patients with acute respiratory distress syndrome (ARDS). METHODS: A prospective randomized controlled trial was conducted. The patients with ARDS undergoing mechanical ventilation (MV) admitted to intensive care unit (ICU) of Linyi Central Hospital from January 2013 to June 2017 were enrolled, and they were divided into simple ventilation group and combined treatment group according to random number table. The patients in both groups received etiological treatment, protective ventilation strategy, sensitive antibiotics for anti-infection, and calefacient and humidifying treatment. The patients in the simple ventilation group received bilateral discontinuous alternative lateral position ventilation [pressure controlled ventilation (PCV), tidal volume (VT) ≤ 6 mL/kg, the inhaled oxygen concentration (FiO2) and positive end expiratory pressure (PEEP) was adjusted to maintain the airway plateau pressure (Pplat) ≤ 30 cmH2O (1 cmH2O = 0.098 kPa)], and those in the combined treatment group received lateral position ventilation combined with vibration sputum drainage, twice a day, 15 minutes each time. The parameters of respiratory function and inflammation as well as excretion of sputum before and after treatment were compared between the two groups, and the complication and prognosis were recorded. RESULTS: A total of 200 patients with ARDS were included, 4 patients were excluded because of severe pneumothorax, massive hemorrhage of the digestive tract, or elevated intracranial pressure, so 196 patients were finally enrolled in the analysis. There were 98 patients in the simple ventilation group and the combined treatment group, respectively. There were no significant differences in parameters of respiratory function and inflammation as well as excretion of sputum before treatment between the two groups. After treatment, the above parameters in both groups were improved, and the effect of combined treatment was more significant. Compared with the simple ventilation group, white blood cell count (WBC), procalcitonin (PCT), C-reactive protein (CRP) at 24 hours of treatment in the combined treatment group were significantly decreased [WBC (×109/L): 9.1±1.6 vs. 11.8±3.6, PCT (µg/L): 14.5±2.4 vs. 22.7±3.2, CRP (mg/L): 32.2±6.3 vs. 67.2±7.2, all P < 0.01], the quantity of sputum excretion was significantly increased (mL: 49.3±12.5 vs. 36.8±11.8, P < 0.01); 72 hours after treatment, the oxygenation index (PaO2/FiO2) in the combined treatment group was significantly increased [mmHg (1 mmHg = 0.133 kPa): 278±28 vs. 238±39, P < 0.01], and PEEP, FiO2, airway resistance (Raw) were significantly lowered [PEEP (cmH2O): 5±2 vs. 7±3, FiO2: 0.40±0.11 vs. 0.49±0.12, Raw (cmH2O): 12.8±0.7 vs. 16.2±0.8, all P < 0.01]. There was no significant difference in static lung compliance (Cst) or Pplat between the two groups. Compared with the simple ventilation group, the duration of MV (days: 5.5±3.0 vs. 8.6±2.1), the length of ICU stay (days: 7.5±5.4 vs. 11.3±4.6) and the extraction time of artificial airway (days: 6.6±2.8 vs. 9.4±3.3) in the combined treatment group were significantly shortened (all P < 0.01). However, there was no significant difference in the 28-day mortality rate [4.1% (4/98) vs. 3.1% (3/98)], the rate of tracheotomy [2.0% (2/98) vs. 3.1% (3/98)] or the incidence of I-II skin pressure sore [1.0% (1/98) vs. 2.0% (2/98)] between simple ventilation group and the combined treatment group (all P > 0.05). No artificial airway disappearance, pneumothorax, grade III or IV pressure sore was found in the two groups. CONCLUSIONS: Compared with lateral position ventilation alone, the treatment of combined with vibration sputum drainage is more effective for improving the respiratory function of patients with ARDS, reducing infection action, shortening the duration of MV and the length of ICU stay, and improve the recovery, promote the rehabitation of patients.

[Global proteomic and phosphoproteomic analysis of the premature maize anther].

Reversible phosphorylation plays a crucial role in regulating protein activities and functions. Sexual reproduction directly affects yield of most agricultural crops. As the male reproductive organ, anther generates microspores (pollen), delivering gametes (sperms) to complete double fertilization in higher plants. Here, we took the advantage of Nano UHPLC-MS/MS to analyze maize (Zea mays, B73) early anthers at proteomic and phosphoproteomic levels, to explore the protein and phosphorylation modification regulatory networks controlling maize anther development. Our proteomic analysis identified 3 016 unique peptides, belonging to 1 032 maize proteins. MapMan analysis revealed variously potential proteins associated with maize anther development, such as receptor-like kinases (GRMZM2G082823_P01 and GRMZM5G805485_P01). Using phospho-peptides enriched by TiO2 affinity chromatography, our phosphoproteomic analysis detected 257 phospho-peptides from 210 phosphoproteins, discovering 223 phosphosites. Compared to the 86 maize phosphoproteins collected in the Plant Protein Phosphorylation Data Base (P3DB), we found that 203 phosphoproteins and 218 phosphosites were not revealed before. Further bioinformatics analysis revealed that phosphorylation of 14-3-3 proteins, kinases, phosphatases, transcription factors, cell cycle and chromatin structure related proteins might play important roles in regulating normal anther development in maize. Our findings not only enlarged the maize phosphoproteome data, but also provided information for analyzing the molecular mechanism controlling maize anther development at genetic and biochemical levels.

Proteomic and phosphoproteomic analyses reveal extensive phosphorylation of regulatory proteins in developing rice anthers.

Anther development, particularly around the time of meiosis, is extremely crucial for plant sexual reproduction. Meanwhile, cell-to-cell communication between somatic (especial tapetum) cells and meiocytes are important for both somatic anther development and meiosis. To investigate possible molecular mechanisms modulating protein activities during anther development, we applied high-resolution mass spectrometry-based proteomic and phosphoproteomic analyses for developing rice (Oryza sativa) anthers around the time of meiosis (RAM). In total, we identified 4984 proteins and 3203 phosphoproteins with 8973 unique phosphorylation sites (p-sites). Among those detected here, 1544 phosphoproteins are currently absent in the Plant Protein Phosphorylation DataBase (P3 DB), substantially enriching plant phosphorylation information. Mapman enrichment analysis showed that 'DNA repair','transcription regulation' and 'signaling' related proteins were overrepresented in the phosphorylated proteins. Ten genetically identified rice meiotic proteins were detected to be phosphorylated at a total of 25 p-sites; moreover more than 400 meiotically expressed proteins were revealed to be phosphorylated and their phosphorylation sites were precisely assigned. 163 putative secretory proteins, possibly functioning in cell-to-cell communication, are also phosphorylated. Furthermore, we showed that DNA synthesis, RNA splicing and RNA-directed DNA methylation pathways are extensively affected by phosphorylation. In addition, our data support 46 kinase-substrate pairs predicted by the rice Kinase-Protein Interaction Map, with SnRK1 substrates highly enriched. Taken together, our data revealed extensive protein phosphorylation during anther development, suggesting an important post-translational modification affecting protein activity.