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Winter is a long period of the annual cycle of many lakes in the northern hemisphere. Low irradiance, ice, and snow cover cause poor light penetration into the water column of these lakes. Therefore, in northern lakes, respiration often exceeds primary production leading to low dissolved oxygen concentrations. This study aimed to quantify under‐ice metabolic processes during winter in an arid zone lake with little snow cover.This study was carried out in a mid‐latitude lake in Inner Mongolia, northern China. The study lake receives relatively high incoming solar radiation on the ice in mid‐winter, and radiation can penetrate down to the bottom sediment as the lake is shallow and the ice lacks snow cover.Primary production and respiration were estimated during two winters using high‐frequency sensor measurements of dissolved oxygen. To quantify under‐ice metabolic processes, sensors were deployed to different depths. During both winters, sensors collected data every 10 min over several weeks.The amount of solar radiation controlled photosynthesis under ice; temperature and photosynthesis together appeared to control respiration. The balance between gross primary production and ecosystem respiration was especially sensitive to changes in snow cover, and the balance between P and R decreased.Our data suggest that photosynthesis by plankton, submerged plants, and epiphytic algae may continue over winter in shallow lakes in mid‐latitudes when there is no snow cover on the ice, as may occur in arid climates. The continuation of photosynthesis under ice buffers against dissolved oxygen depletion and prevents consequent harmful ecosystem effects. [ABSTRACT FROM AUTHOR]

To improve the understanding of the seasonal evolution of the mass and heat budget of ice-covered lakes in the cold and arid climate zone, in-situ observations were collected during two winters (2016–2017 and 2017–2018) in Lake Wuliangsuhai, Inner Mongolia, China. The mean snow thickness was 5.2 and 1.6 cm in these winters, due to low winter precipitation. The mean ice thickness was 50.9 and 36.1 cm, and the ice growth rate was 3.6 and 2.1 mm day−1 at the lower boundary of ice. Analyses of mass and heat balance data from two winters revealed that the surface heat budget was governed by solar radiation and terrestrial radiation. The net heat flux loss of the ice was 9–22 W m−2, affected by the snow and ice thickness. Compared to boreal lakes, Lake Wuliangsuhai received more solar radiation and heat flux from the water. The ice temperature had a strong diurnal variation, which was produced by the diurnal cycles of solar radiation, and air and water temperatures. These results expand our knowledge of the evolution of mass and heat balance in temperate lakes of mid-latitude arid areas. [ABSTRACT FROM AUTHOR]

Background: Pre-hospital delay was a critical factor affecting stroke patients receiving intravenous thrombolytic therapy. The aim of this study was to explore the factors associated with pre-hospital delay and thrombolysis in China., Methods: Patient data were obtained from emergency department (ED), and the factors of patient pre-hospital delay were recorded through a well-designed form., Results: A total of 630 patients were eventually included in the study. 317 patients were admitted to the ED during the thrombolysis time window, and only 105 patients received intravenous thrombolytic therapy. In the univariate analysis, transportation (OR: 0.15; 95% CI: 0.44 - 0.518; p = 0.001), atrial fibrillation (OR: 0.555; 95% CI: 0.372-0.828; p = 0.004) and response of symptoms (OR: 0.002; 95% CI: 0.000-0.013; p = 0.000) were associated with early arrival. Speech disturbances (OR: 2.095; 95% CI: 1.294-3.391; p = 0.002), smoking (OR: 2.563; 95% CI: 1.527-4.304; p = 0.000), alcohol consumption (OR: 2.155; 95% CI: 1.159-4.005; p = 0.014) and referral presentation (OR: 2.837; 95% CI: 1.584-5.082; p = 0.000) were associated with thrombolysis. In the logistic regression analysis, direct visiting to the hospital after onset and rushing to emergency after onset were independent predictor of early arrival of AIS and intravenous thrombolytic., Conclusions: The pre-hospital delay of acute ischemic stroke in China was still serious. Strengthening the ability to identify stroke-related symptoms and establishing a mutual referral medical support service model between lower and upper hospitals may effectively shorten the pre-hospital delay of stroke patients., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflict interests., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Plutella xylostella (L.) is a worldwide pest of crucifer crops. Chlorfenapyr has been used extensively to manage several insect pests in vegetables, including P. xylostella. In this study, 48 field populations were collected from 11 geographic locations of China from 2008 to 2017 for resistance monitoring to chlorfenapyr. Inheritance and synergism of chlorfenapyr resistance were characterized in a field-derived population., Results: Compared with the susceptible SZ strain, 33 of 39 populations collected from Eastern China were susceptible or developed low levels of resistance to chlorfenapyr (< 10-fold), five populations developed mid-level resistance (11-33-fold), and only one population had high level resistance (208-fold). However, seven of nine populations sampled from Southern China evolved 136-334-fold resistance. Interestingly, the dynamic of the median lethal concentration (LC 50 ) values from four continuous sampling sites (NJ, HF, JN and KS) showed a sharp increase in 2009, which implies that adults may have immigrated from chlorfenapyr-resistant regions. A highly resistant field population (GZ15) was further studied. By crossing the GZ15 and susceptible SZ strains we showed that resistance to chlorfenapyr was autosomally inherited and incompletely dominant. Synergism bioassays revealed that metabolic detoxification might not be responsible for chlorfenapyr resistance in the GZ15 population., Conclusions: Some field populations of P. xylostella from China have evolved high levels of resistance to chlorfenapyr. Field-evolved resistance to chlorfenapyr is autosomal and dominant in the GZ15 population. These findings provide useful information for the design of effective resistance management strategies against P. xylostella in the field. © 2018 Society of Chemical Industry., (© 2018 Society of Chemical Industry.)

Background: Diarrheagenic Escherichia coli (DEC) is a major cause of bacterial gastroenteritis in children. Also, antibiotic resistance among DEC is becoming a critical area of concern in clinical settings., Methods: This study was conducted in 4 hospitals in Shanghai from June 2012 to October 2013. DEC isolates from stool samples of patients with diarrhea were examined to determine their antimicrobial susceptibilities and presence of virulence genes, in order to identify high risk clones., Results: A total of 735 (10.2%) DEC isolates were identified from 7204 stool samples from patients with diarrhea, including 374 enteropathogenic E. coli, 318 enterotoxigenic E. coli, 36 Shigella/enteroinvasive E. coli and 7 Shiga toxin-producing E. coli (STEC). Among the 735 DEC isolates, 299 (40.7%) were isolated from children less than 5 years old. High resistance rates were observed to streptomycin (90.7%), ampicillin (63.4%), nalidixic acid (61.1%), sulfisoxazole (49.1%), tetracycline (41.2%), trimethoprim (35.6%), trimethoprim-sulfamethoxazole (35.4%), followed by amoxicillin-clavulanic acid (27.2%), cefotaxime (24.5%), cefepime (23.5%), gentamicin (16.7%), ceftazidime (12.4%), chloramphenicol (10.6%), ciprofloxacin (7.2%) and ofloxacin (3.4%). All the isolates were susceptible to imipenem. In addition, potential virulence genes were screened by polymerase chain reaction. A total of 15 enterotoxigenic E. coli belonging to the same clone were identified to be associated with nosocomial neonatal diarrhea and resistant to greater than 10 antimicrobials., Conclusion: Our findings suggest that active surveillance programs combining both phenotypic and genetic data would help identify disease outbreaks and strengthen antibiotic management.