150 research outputs found

    RETRACTED: Asymptotic constancy for a differential equation with multiple state-dependent delays

    Get PDF
    This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).This article has been retracted at the request of the Journal Editor.The article is very similar to the following papers: (1)'Asymptotic behavior of solutions to a system of differential equations with state-dependent delays', by Lijuan Wang, published in J. Comput. Appl. Math., 228 (2009) 226–230. (2) 'Asymptotic behavior of solutions to a differential equation with state-dependent delay' by Lequn Peng, published in Comput. Math. Appl., 57 (2009) 1511–1514.All these articles were written using the same Latex file, treating very similar problems in exactly the same way. The authors of the papers knew about the similarity between the papers, but did not make any reference to each other, and therefore violated the Ethical Rules of Publishing, at the time the papers were submitted for publication. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process

    Optimum Spraying Time and Management Guidelines for Soybean Aphid Control

    Get PDF
    In Liaoning Province, the population of soybean aphid, Aphis glycines Matsumura, increases the most rapidly in late June, which is the critical period for aphid control. The current guideline for spraying is 10,000 aphids per100 plants. This guideline may be relaxed to 23,800 - 40,700 for cultivar Tiefeng #18 and to 26,500 – 33,000 for cultivar Liaodou #3 in the plains region found in the middle and lower reaches of Liaohe River. It is difficult to use aphid numbers as a management guideline in agricultural practice. According to our studies, the ratio of infested plants with rolled leaves is closely correlated to the aphid number per 100 plants. The linear regression equation is ? = 4.283 + 1.8419x (r = 0.90), where ? is the rolled leaf ratio and x is the aphid numbers per 100 plants. Therefore, instead of aphid numbers per 100 plants, we propose to use the ratio of plants with rolled leaves as the management guideline for large-scale field control of soybean aphids, which is 10% for Tiefeng #18 and 8% for Liaodou #3.Originating text in Chinese.Citation: He, Fugang, Yan, Fanyyue, Xin, Wanmin, Lii, Xiaoping, Wang, Yanqin, Zhang, Guangxue. (1991). Optimum Spraying Time and Management Guidelines for Soybean Aphid Control. Acta Phytophylacica Sinica, 18(2), 155-159

    Synthesis of CoSe2-SnSe2 nanocube-coated nitrogen-doped carbon (NC) as anode for lithium and sodium ion batteries

    Get PDF
    CoSe2-SnSe2/NC nanocubes (CSNC@NC) coated by nitrogen-doped carbon (NC) were synthesized successfully by an ordinary pyrazole polymerization and carbonization process. In comparison with bare CSNC, the CSNC@NC composite exhibited good structural stability and improved electrical conductivity when used as anode. The CSNC@NC electrode showed a stable Li storage capacity (730.41 mAh g−1 over 100 cycles at 0.2 A g−1) and excellent rate performance (402.10 mAh g−1 at 2 A g−1). For Na storage, the discharge capacity could be maintained 279.3 mAh g−1 over 100 cycles at 0.2 A g−1; the lower capacity than that for Li storage maybe caused by the larger size of Na+ ions. The excellent cycling stability for both Li and Na storage cycle ability may be attributed to the carbon layer, which could tolerated the volume fluctuations and ensured the structural integrity of the CSNC during the charge/discharge process; Moreover, the improved electrical conductivity accelerated the diffusion rate of both Li+ and Na+, which is conducive to the electrochemical reactions in their respective batteries. This unique structure and preeminent electrochemical performance of CSNC@NC show that CSNC@NC is a promising anode material for high-efficiency Li ion and Na ion batteries

    Greenhouse gas emissions from municipal wastewater treatment facilities in China from 2006 to 2019

    Get PDF
    Wastewater treatment plants (WWTPs) alleviate water pollution but also induce resource consumption and environmental impacts especially greenhouse gas (GHG) emissions. Mitigating GHG emissions of WWTPs can contribute to achieving carbon neutrality in China. But there is still a lack of a high-resolution and time-series GHG emission inventories of WWTPs in China. In this study, we construct a firm-level emission inventory of WWTPs for CH4, N2O and CO2 emissions from different wastewater treatment processes, energy consumption and effluent discharge for the time-period from 2006 to 2019. We aim to develop a transparent, verifiable and comparable WWTP GHG emission inventory to support GHG mitigation of WWTPs in China

    Environmental impact of the effluents discharging from full-scale wastewater treatment plants evaluated by a hybrid fuzzy approach

    Get PDF
    Increasing attention is being paid to the environmental impacts of wastewater treatment plant (WWTP) effluent. In this study, comprehensive environmental impact analyses (EIAs) were performed for the secondary treatment processes, tertiary treatment processes, and entire plants at five full-scale WWTPs in Kunming, China. The EIAs took into account greenhouse gas (GHG) emissions, potential for the effluent to cause eutrophication, ecological risks posed by endocrine disrupting compounds (EDCs) in treated effluent, and the risks posed by heavy metals in excess sludge. A comprehensive assessment toward environmental sustainability was performed using a fuzzy approach. The results indicated that the biological treatment process made the largest contribution (>68% of the total) of the secondary treatment processes to GHG emissions and that electricity consumption made the largest contribution (>64% of the total) of the tertiary treatment processes to GHG emissions. Large numbers of EDCs were removed during the secondary treatment processes, but the potential ecological risks posed by EDCs still require attention. High mercury concentrations were found in excess sludge. The plant that removed the largest proportion of pollutants and produced effluent posing the least ecological risks gave the best comprehensive EIA performance

    Cyclin D1-mediated microRNA expression signature predicts breast cancer outcome

    Get PDF
    Background: Genetic classification of breast cancer based on the coding mRNA suggests the evolution of distinct subtypes. Whether the non-coding genome is altered concordantly with the coding genome and the mechanism by which the cell cycle directly controls the non-coding genome is poorly understood. Methods: Herein, the miRNA signature maintained by endogenous cyclin D1 in human breast cancer cells was defined. In order to determine the clinical significance of the cyclin D1-mediated miRNA signature, we defined a miRNA expression superset from 459 breast cancer samples. We compared the coding and non-coding genome of breast cancer subtypes. Results: Hierarchical clustering of human breast cancers defined four distinct miRNA clusters (G1-G4) associated with distinguishable relapse-free survival by Kaplan-Meier analysis. The cyclin D1-regulated miRNA signature included several oncomirs, was conserved in multiple breast cancer cell lines, was associated with the G2 tumor miRNA cluster, ERα+ status, better outcome and activation of the Wnt pathway. The coding and non-coding genome were discordant within breast cancer subtypes. Seed elements for cyclin D1-regulated miRNA were identified in 63 genes of the Wnt signaling pathway including DKK. Cyclin D1 restrained DKK1 via the 3\u27UTR. In vivo studies using inducible transgenics confirmed cyclin D1 induces Wnt-dependent gene expression. Conclusion: The non-coding genome defines breast cancer subtypes that are discordant with their coding genome subtype suggesting distinct evolutionary drivers within the tumors. Cyclin D1 orchestrates expression of a miRNA signature that induces Wnt/β-catenin signaling, therefore cyclin D1 serves both upstream and downstream of Wnt/β-catenin signaling

    Small RNA zippers lock miRNA molecules and block miRNA function in mammalian cells.

    Get PDF
    MicroRNAs (miRNAs) loss-of-function phenotypes are mainly induced by chemically modified antisense oligonucleotides. Here we develop an alternative inhibitor for miRNAs, termed \u27small RNA zipper\u27. It is designed to connect miRNA molecules end to end, forming a DNA-RNA duplex through a complementary interaction with high affinity, high specificity and high stability. Two miRNAs, miR-221 and miR-17, are tested in human breast cancer cell lines, demonstrating the 70∼90% knockdown of miRNA levels by 30-50 nM small RNA zippers. The miR-221 zipper shows capability in rescuing the expression of target genes of miR-221 and reversing the oncogenic function of miR-221 in breast cancer cells. In addition, we demonstrate that the miR-221 zipper attenuates doxorubicin resistance with higher efficiency than anti-miR-221 in human breast cancer cells. Taken together, small RNA zippers are a miRNA inhibitor, which can be used to induce miRNA loss-of-function phenotypes and validate miRNA target genes

    Bayesian geoacoustic parameters inversion for multi-layer seabed in shallow sea using underwater acoustic field

    Get PDF
    Seabed geoacoustic parameters play an important role in underwater acoustic channel modeling. Traditional methods to determine these parameters, for example, drilling, are expensive and are being replaced by acoustic inverse technology. An inversion method based on Bayesian theory is presented to derive the structure and geoacoustic parameters of a layered seabed in a shallow sea. The seabed was considered a layered elastic medium. The objective of this research was to use the sound pressure detected by underwater acoustic sensors at different positions and to use nonlinear Bayesian inversion to estimate the geoacoustic parameters and their uncertainties in the multi-layer seabed. Specifically, the thickness, density, compression wave speed, shear wave speed, and the attenuation of these two wave speeds were determined. The maximum a posterior (MAP) model and posterior probability distribution of each parameter were estimated using the optimized simulated annealing (OSA) and Metropolis-Hastings sampling (MHS) methods. Model selection was carried out using the Bayesian information criterion (BIC) to determine the optimal model that thoroughly explained the experimental data for different parameterizations. The results showed that the OSA is much more capable of delivering high-accuracy results in multi-layer seabed models. The compression wave speed and shear wave speed were less uncertain than the other parameters, and the parameters in the upper layer had less uncertainty than those in the lower layer

    miR-17/20 sensitization of breast cancer cells to chemotherapy-induced apoptosis requires Akt1.

    Get PDF
    The serine threonine kinase Akt1 has been implicated in the control of cellular metabolism, survival and growth. Herein, disruption of the ubiquitously expressed member of the Akt family of genes, Akt1, in the mouse, demonstrates a requirement for Akt1 in miRNA-mediated cellular apoptosis. The miR-17/20 cluster is known to inhibit breast cancer cellular proliferation through G1/S cell cycle arrest via binding to the cyclin D1 3\u27UTR. Here we show that miR-17/20 overexpression sensitizes cells to apoptosis induced by either Doxorubicin or UV irradiation in MCF-7 cells via Akt1. miR-17/20 mediates apoptosis via increased p53 expression which promotes Akt degradation. Akt1-/- mammary epithelial cells which express Akt2 and Akt3 demonstrated increased apoptosis to DNA damaging agents. Akt1 deficiency abolished the miR-17/20-mediated apoptosis. These results demonstrated a novel pathway through which miR17/20 regulate p53 and Akt controlling breast cancer cell apoptosis
    • …
    corecore