Search

Northern corn leaf blight INCLB). caused by Exserohihun turcicum, a devastating disease of corn in China. To enhance our understanding NCLB epidemiology, the temporal progress and spatial patterns NCLB were investigated. A susceptible corn cultivar, Xianyu 335, planted in a field in Beijing in 2()16 and 2017. Leaf lesions of NCLB each plant were counted twice a week during the growing seasons. addition. temporal disease progress was monitored for 8 weeks in three patcommercial corn fields in each of Yanqing. Miyun, Daxing, and Haidian Districts of Beijing in 2017, and the spatial patterns of diseased plants and NCLB [esion counts per plant were assessed in three commercial corn fields with moderate to high NCLB incidence in Yanqing District. The results demonstrated that a logistic model was the most appropriate describe the temporal progress of NCLB incidence. The initial disease incidence was the key factor affecting disease epidemics under various conditions in the four districts of Beijing during the study. The higher the initial incidence of NCLB, the higher the final incidence. Thus, the earlier in the season NCLB incidence attained 1 %. the higher was the final disease incidence. Greater than 1.0 variance-to-mean ratios suggested that the leaf lesions of NCLB tended to be aggregated on a plant. According to results from join-counts, variance of moving window averages, and semivariogram analysis. diseased corn plants and lesion numbers on each plant were aggregated in the field. The clustered patcommercial tern of NCLB lesions and infected plants suggested that conidia produced locally on diseased plants were important for disease spread within the field. The aggregated pattern of diseased plants suggested that plants should be sampled from more sites iii a field to accurately estimate incidence of NCLB. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa is a major opportunistic pathogen in hospital-acquired infections and exhibits increasing antibiotic resistance. A rapid and sensitive molecular method for its detection in clinical samples is needed to guide therapeutic treatment and to control P. aeruginosa outbreaks. In this study, we established a polymerase spiral reaction (PSR) method for rapid detection of P. aeruginosa by targeting the toxA gene, which regulates exotoxin A synthesis. Real-time turbidity monitoring and a chromogenic visualization using hydroxynaphthol blue were used to assess the reaction. All 17 non- P. aeruginosa strains tested negative, indicating the high specificity of the PSR primers. The detection limit was 2.3 pg/μl within 60 min at isothermal temperature (C°65), 10- fold more sensitive than conventional PCR. Then, the PSR assay was applied to a clinical surveillance of P. aeruginosa in three top hospitals in Beijing, China. Of the 130 sputum samples collected from ICU patients with suspected multi-resistant infections, 37 P. aeruginosa isolates were identified from the positive samples. All clinical strains belonged to 10 different P. aeruginosa multilocus sequence typing groups and exhibited high resistance to carbapenems, cephalosporins, and aminoglycosides. Interestingly, of the 33 imipenem-resistant isolates, 30 (90.9%) had lost the outer membrane porin oprD gene. Moreover, isolate SY-95, containing multiple antibiotic resistance genes, possessed the ability to hydrolyze all antibiotics used in clinic and was susceptible only to polymyxin B. Our study showed the high level of antibiotic resistance and cooccurrence of resistance genes in the clinical strains, indicating a rapid and continuing evolution of P. aeruginosa. In conclusion, we developed a P. aeruginosa PSR assay, which could be a useful tool for clinical screening, especially in case of poor resources, or for point-of-care testing. [ABSTRACT FROM AUTHOR]

Concurrent screening has been proven to provide a comprehensive approach for management of congenital deafness and prevention of ototoxicity. The SLC26A4 gene is associated with late-onset hearing loss and is of great clinical concern. For much earlier detection of newborns with deafnesscausing mutations in the SLC26A4 gene, the Beijing Municipal Government launched a chip for optimized genetic screening of 15 variants of 4 genes causing deafness based on a chip to screen for 9 variants of 4 genes, and 6 variants of the SLC26A4 gene have now been added. To ascertain the advantage of a screening chip including 15 variants of 4 genes, the trends in concurrent hearing and genetic screening were analyzed in 2019 and 2020. Subjects were 76,460 newborns who underwent concurrent hearing and genetic screening at 24 maternal and child care centers in Beijing from January 2019 to December 2020. Hearing screening was conducted using transiently evoked otoacoustic emissions (TEOAEs), distortion product otoacoustic emissions (DPOAE), or the automated auditory brainstem response (AABR). Dried blood spots were collected for genetic testing and 15 variants of 4 genes, namely GJB2, SLC26A4, mtDNA 12S rRNA, and GJB3, were screened for using a DNA microarray platform. The initial referral rate for hearing screening decreased from 3.60% (1,502/41,690) in 2019 to 3.23% (1,124/34,770) in 2020, and the total referral rate for hearing screening dropped form 0.57% (236/41,690) in 2019 to 0.54% (187/34,770) in 2020, indicating the reduced false positive rate of newborn hearing screening and policies to prevent hearing loss conducted by the Beijing Municipal Government have had a significant effect. Positivity according to genetic screening was similar in 2019 (4.970%, 2,072/41,690) and 2020 (4.863%,1,691/34,770), and the most frequent mutant alleles were c.235 del C in the GJB2 gene, followed by c.919-2 A > G in the SLC26A4 gene, and c.299 del AT in the GJB2 gene. In this cohort study, 71.43% (5/7) of newborns with 2 variants of the SLC26A4 gene were screened for newly added mutations, and 28.57% (2/7) of newborns with 2 variants of the SLC26A4 gene passed hearing screening, suggesting that a screening chip including 15 variants of 4 genes was superior at early detection of hearing loss, and especially in early identification of newborns with deafness-causing mutations in the SLC26A4 gene. These findings have clinical significance. [ABSTRACT FROM AUTHOR]

This study estimates the economic values of and the dominant contributors to five key ecosystem services of wetlands in Beijing, by using the wetland inventory data in 2014 and economic valuation methods. Results indicate that the 51,434 ha of wetlands in Beijing annually provide 2.07 billion m3 of flood regulation, 944.01 million m3 of water provision, 42,154 tons of chemical oxygen demand (COD) purification, 3.03 PJ of heat absorption, and 9587 ha of habitat. Their economic values are estimated to be 15.89 billion RMB, 1.19 billion RMB, 169 million RMB, 421 million RMB, and 1.08 billion RMB in 2014 (RMB: Chinese currency, US$1 = RMB 6.14), respectively. The total values of five key wetland ecosystem services reach 18.76 billion RMB. In addition, the reservoir and river wetlands in Miyun, Yanqing, Fangshan, Huairou, and Mentougou Districts contribute 78% of key ecosystem services, whereas the urban wetlands in Xicheng, Dongcheng, Haidian, Chaoyang, and Tongzhou Districts more conveniently serve densely local people, hence they should be given particular attentions. In this paper, we develop the valuation methods of wetland ecosystem services, and recommend diversified strategies, regulations, and programs to protect the remaining wetlands in Beijing. This work can also provide a reference for the valuating of wetland ecosystem services for other urban-rural areas. [ABSTRACT FROM AUTHOR]