ARMA

arma
  • 文章类型: Journal Article
    ISCR28是IS91样插入序列家族的全功能和活性成员。ISCR28长1,708-bp,包含一个1,293-bp长的推定开放阅读框,编码转座酶。来自GenBank的60个包含ISCR28的序列产生了27个非重复遗传背景,所有这些都代表了在广泛的革兰氏阴性生物中发生的自然发生的生物事件。将ISCR28插入靶DNA优选在其terIS(复制终止子)末端存在5'-GXXT-3'序列。其oriIS(复制起点)的前4bp的丢失可能导致ISCR28被困在基于ISApl1的转座子或类似结构中。terIS的丢失和与上游可移动元件的融合可能会促进ISCR28和下游抗性基因的共转移。可以从重组pKD46质粒中切除ArmA及其下游完整的ISCR28,形成环状中间体,进一步阐明其作为转座酶的活性。
    ISCR28 is a fully functional and active member of the IS91-like family of insertion sequences. ISCR28 is 1,708-bp long and contains a 1,293-bp long putative open reading frame that codes a transposase. Sixty ISCR28-containing sequences from GenBank generated 27 non-repeat genetic contexts, all of which represented naturally occurring biological events that had occurred in a wide range of gram-negative organisms. Insertion of ISCR28 into target DNA preferred the presence of a 5\'-GXXT-3\' sequence at its terIS (replication terminator) end. Loss of the first 4 bp of its oriIS (origin of replication) likely caused ISCR28 to be trapped in ISApl1-based transposons or similar structures. Loss of terIS and fusion with a mobile element upstream likely promoted co-transfer of ISCR28 and the downstream resistance genes. ArmA and its downstream intact ISCR28 can be excised from recombinant pKD46 plasmids forming circular intermediates, further elucidating its activity as a transposase.
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  • 文章类型: Journal Article
    耐碳青霉烯类肺炎克雷伯菌(CRKP)的迅速出现和新抗生素的开发相对有限,对公众健康构成了重大威胁。氨基糖苷是与β-内酰胺药物联合治疗可有效降低死亡率的重要选择。然而,在这项研究中,我们观察到两种多重耐药(MDR)肺炎克雷伯菌,命名为1632和1864,对碳青霉烯类和氨基糖苷类都表现出高度耐药.通过全基因组测序(WGS),rmtB的异常共现,arma,和blaKPC-2基因,与两个关键的抗性质粒相关联,在两个分离株中观察到。值得注意的是,我们还发现arma抗性基因和毒力因子iuc操纵子共同出现在肺炎克雷伯菌1864的同一质粒上。详细的比较遗传分析表明,所有这些质粒都被认为是可移动的质粒,因为它们都带有基本的orit站点。结合实验结果表明,两个分离株的armA阳性质粒均能有效自转移至大肠杆菌J53,尤其是,p1864-1质粒,可以将高毒力和多药耐药表型共同转移给其他分离株。此外,在重要的抗性基因周围还发现了多个插入序列(ISs)和转座子(Tns),这甚至可以形成一个大的抗生素抗性岛(ARI),并可以刺激抗性决定簇的动员。总的来说,我们报道了arma质粒的罕见共存,rmtB-blaKPC-2质粒,甚至在肺炎克雷伯菌分离物中编码iuc毒力操纵子的质粒,这大大增加了这些高风险表型的传播,这是非常令人担忧的。重要性产生碳青霉烯酶的肺炎克雷伯菌已成为抗菌化疗的巨大挑战,而氨基糖苷类与它们联合治疗可有效降低死亡率。不幸的是,我们从患者的血液样本中分离出两种肺炎克雷伯菌,这些患者不仅对碳青霉烯类和氨基糖苷类表现出高水平的耐药性,而且还表现出rmtB的异常共现,arma,和blaKPC-2基因.这些元件都位于移动质粒上,两侧是多态移动遗传元件(MGEs)。最糟糕的是,我们还鉴定了一种共轭毒力MDR质粒,共同拥有多个抗性决定因素,和iuc操纵子,证实可以将这种高风险表型转移到其他分离株。这种共轭毒力质粒的出现可以促进毒力编码元件在革兰氏阴性病原体中的快速传播。这种罕见的rmtB共存,arma,肺炎克雷伯菌blaKPC-2和iuc毒力操纵子编码质粒,给临床治疗带来了巨大的威胁。有必要进行未来的研究以评估此类分离株的患病率。
    The rapid emergence of carbapenem-resistant Klebsiella pneumoniae (CRKP) and the comparatively limited development of new antibiotics pose a major threat to public health. Aminoglycosides are important options that can lower the mortality rate effectively in combination therapy with β-lactam agents. However, in this study, we observed two multidrug-resistant (MDR) K. pneumoniae named 1632 and 1864 that exhibited high-level resistance to both carbapenems and aminoglycosides. Through whole-genome sequencing (WGS), the unusual co-occurrence of rmtB, armA, and blaKPC-2 genes, associating with two key resistance plasmids, was observed in two isolates. Notably, we also found that the armA resistance gene and virulence factor iuc operon co-occurred on the same plasmid in K. pneumoniae 1864. Detailed comparative genetic analysis showed that all these plasmids were recognized as mobilizable plasmids, as they all carry the essential oriT site. Results of conjugation assay indicated that armA-positive plasmids in two isolates could self-transfer to Escherichia coli J53 effectively, especially, the p1864-1 plasmid, which could cotransfer hypervirulent and multidrug-resistant phenotypes to other isolates. Moreover, multiple insertion sequences (ISs) and transposons (Tns) were also found surrounding the vital resistant genes, which could even form a large antibiotic resistance island (ARI) and could stimulate mobilization of resistant determinants. Overall, we report the uncommon coexistence of armA plasmid, rmtB-blaKPC-2 plasmid, and even iuc virulence operon-encoding plasmid in K. pneumoniae isolates, which greatly increased the spread of these high-risk phenotypes and which are of great concern. IMPORTANCE Carbapenemase-producing Klebsiella pneumoniae have become a great challenge for antimicrobial chemotherapy, while aminoglycosides can lower the mortality rate effectively in combination therapy with them. Unfortunately, we isolated two K. pneumoniae from blood sample of patients that not only exhibited high-level resistance to carbapenems and aminoglycosides but also showed the unusual co-occurrence of the rmtB, armA, and blaKPC-2 genes. These elements were all located on mobile plasmids and flanked by polymorphic mobile genetic elements (MGEs). What\'s worse most, we also identified a conjugative virulent MDR plasmid, coharboring multiple resistant determinants, and iuc operon, which was confirmed could transfer such high-risk phenotype to other isolates. The emergence of such conjugative virulence plasmids may promote the rapid dissemination of virulence-encoding elements among Gram-negative pathogens. This uncommon coexistence of rmtB, armA, blaKPC-2, and iuc virulence operon-encoding plasmids in K. pneumoniae, presents a huge threat to clinical treatment. Future studies are necessary to evaluate the prevalence of such isolates.
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  • 文章类型: Journal Article
    股指是衡量股市波动的重要指标,对投资者决策具有指导作用,因此成为许多研究的对象。然而,股票市场受到不确定性和波动性的影响,使准确的预测成为一项具有挑战性的任务。我们提出了一种新的基于时间序列分解和混合模型的股指预测模型。具有自适应噪声的完整集合经验模式分解(CEEMDAN)将股票指数分解为一系列具有不同特征尺度和趋势项的内在模式函数(IMFs)。增强迪基富勒(ADF)方法判断每个顶F和趋势项的稳定性。自回归移动平均(ARMA)模型用于平稳时间序列,长短期记忆(LSTM)模型提取不稳定时间序列的抽象特征。对每个时间序列的预测结果进行重构,得到最终的预测值。对四个股指时间序列进行了实验,结果表明,与7个参考模型相比,该模型的预测更接近真实值,并具有较好的量化投资参考价值。
    The stock index is an important indicator to measure stock market fluctuation, with a guiding role for investors\' decision-making, thus being the object of much research. However, the stock market is affected by uncertainty and volatility, making accurate prediction a challenging task. We propose a new stock index forecasting model based on time series decomposition and a hybrid model. Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN) decomposes the stock index into a series of Intrinsic Mode Functions (IMFs) with different feature scales and trend term. The Augmented Dickey Fuller (ADF) method judges the stability of each IMFs and trend term. The Autoregressive Moving Average (ARMA) model is used on stationary time series, and a Long Short-Term Memory (LSTM) model extracts abstract features of unstable time series. The predicted results of each time sequence are reconstructed to obtain the final predicted value. Experiments are conducted on four stock index time series, and the results show that the prediction of the proposed model is closer to the real value than that of seven reference models, and has a good quantitative investment reference value.
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  • 文章类型: Journal Article
    碳价格及其相关成分的波动能够有效反映整体经济状况。本文探讨了碳价格的波动及其影响因素。首先,采用集合经验模态分解(EEMD)方法对8个试点项目的碳价序列进行多时间尺度分解。第二,根据八个试点项目的历史交易记录,本文构建了各种情景下的全国碳价。最后,根据八个试点市场每日交易数据集的平均值,全国碳价建设,并进行了短期预测。结果表明:(1)北京和湖北试点项目易受短期外部因素的影响,北京试点的内部市场机制对碳价格有很大影响;(2)在大多数情况下,全国物价波动,最高碳价接近70CNY/tCO2,最低碳价低于10CNY/tCO2;(3)中国碳价未来仍有充足的上涨空间。本文为我国碳价格的预测提供了理论依据和实践指导。
    The fluctuation of the carbon price and its related components can effectively reflect the overall economy. This paper explores the fluctuation of the carbon price and its influencing factors. First, the ensemble empirical mode decomposition (EEMD) method is used to decompose the carbon price series of eight pilot projects at multiple timescales. Second, according to the historical trading records in the eight pilot projects, this paper constructs a national carbon price under a variety of scenarios. Finally, based on the average of the eight pilot market daily trading datasets, the national carbon price is constructed, and a short-term prediction is made. The results show that: (1) the pilot projects in Beijing and Hubei are susceptible to short-term external factors, and Beijing\'s pilot internal market mechanism has a large impact on the carbon price; (2) in most scenarios, the national price fluctuates, with the highest carbon price approaching 70 CNY/tCO2 and the lowest falling below 10 CNY/tCO2; and (3) China\'s carbon price is still has ample room to rise in the future. This paper provides a theoretical basis and practical guidance for the prediction of carbon prices in China.
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  • 文章类型: Journal Article
    在本文中,我们提出了一种新颖的混合模型,该模型通过使用模糊熵和极限学习机(ELM)方法来扩展涉及集成经验模式分解(EEMD)的先验工作。我们通过将其应用于以混沌和复杂性为特征的碳期货价格预测来证明该三阶段模型。首先,我们采用EEMD方法将碳期货价格分解为几个内在模式函数(IMFs)和一个残差。第二,利用模糊熵和K-均值聚类方法对IMFs和残差进行重构,得到3个重构分量,特别是高频系列,低频系列,和趋势系列。第三,ARMA模型是为固定的高频和低频系列实现的,而极限学习机(ELM)模型用于非平稳趋势序列。最后,所有的成分预测被汇总以形成每个模型的碳价的最终预测。实证结果表明,在相同的预测框架下,与传统的细粗重构算法相比,本文提出的重构算法可以带来40%以上的预测精度提升。本文提出的混合预测模型也很好地抓住了价格变动的方向,具有强大而强大的预测能力,显著优于单一预测模型和其他混合预测模型。
    In this paper, we propose a novel hybrid model that extends prior work involving ensemble empirical mode decomposition (EEMD) by using fuzzy entropy and extreme learning machine (ELM) methods. We demonstrate this 3-stage model by applying it to forecast carbon futures prices which are characterized by chaos and complexity. First, we employ the EEMD method to decompose carbon futures prices into a couple of intrinsic mode functions (IMFs) and one residue. Second, the fuzzy entropy and K-means clustering methods are used to reconstruct the IMFs and the residue to obtain three reconstructed components, specifically a high frequency series, a low frequency series, and a trend series. Third, the ARMA model is implemented for the stationary high and low frequency series, while the extreme learning machine (ELM) model is utilized for the non-stationary trend series. Finally, all the component forecasts are aggregated to form final forecasts of the carbon price for each model. The empirical results show that the proposed reconstruction algorithm can bring more than 40% improvement in prediction accuracy compared to the traditional fine-to-coarse reconstruction algorithm under the same forecasting framework. The hybrid forecasting model proposed in this paper also well captures the direction of the price changes, with strong and robust forecasting ability, which is significantly better than the single forecasting models and the other hybrid forecasting models.
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  • 文章类型: Journal Article
    BACKGROUND: Accurate and timely prediction of regional winter wheat maturity date can provide essential information to improve the management of agriculture and avoid declines in the yield and quality of crops. In this paper, we propose the use of an autoregressive moving-average model to predict vegetation indices on 1, 9, and 17 May each year, and applied them to the methods of evaluating crop maturity based on vegetation indices. Growing degree days and a widely applied local empirical method were selected to explore and compare the feasibility of several methods. We analyzed winter wheat harvested from the Guanzhong Plain during 2003-2013 and used leave-one-out cross-validation to compare and verify the performance of the maturity prediction methods.
    RESULTS: The results demonstrated that (i) the vegetation index methods and growing degree days methods predicted maturity with higher accuracy than did the widely applied local empirical method, and (ii) the two-step filtering method based on future meteorological data from The Observing System Research and Predictability Experiment Interactive Grand Global Ensemble exhibited the highest prediction accuracy on 1 May and had the lowest error fluctuation range on 17 May.
    CONCLUSIONS: These results provide new insights for predicting regional crop maturity, deploying agricultural harvesting equipment in various regions, and avoiding decreases in crop yields caused by adverse weather.
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  • 文章类型: Journal Article
    With the development of human motion capture (MoCap) equipment and motion analysis technologies, MoCap systems have been widely applied in many fields, including biomedicine, computer vision, virtual reality, etc. With the rapid increase in MoCap data collection in different scenarios and applications, effective segmentation of MoCap data is becoming a crucial issue for further human motion posture and behavior analysis, which requires both robustness and computation efficiency in the algorithm design. In this paper, we propose an unsupervised segmentation algorithm based on limb-bone partition angle body structural representation and autoregressive moving average (ARMA) model fitting. The collected MoCap data were converted into the angle sequence formed by the human limb-bone partition segment and the central spine segment. The limb angle sequences are matched by the ARMA model, and the segmentation points of the limb angle sequences are distinguished by analyzing the good of fitness of the ARMA model. A medial filtering algorithm is proposed to ensemble the segmentation results from individual limb motion sequences. A set of MoCap measurements were also conducted to evaluate the algorithm including typical body motions collected from subjects of different heights, and were labeled by manual segmentation. The proposed algorithm is compared with the principle component analysis (PCA), K-means clustering algorithm (K-means), and back propagation (BP) neural-network-based segmentation algorithms, which shows higher segmentation accuracy due to a more semantic description of human motions by limb-bone partition angles. The results highlight the efficiency and performance of the proposed algorithm, and reveals the potentials of this segmentation model on analyzing inter- and intra-motion sequence distinguishing.
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  • 文章类型: Journal Article
    沙门氏菌是社区获得性食源性感染的主要原因,所以它对抗菌药物的抗性,如氨基糖苷类,是一个公共卫生问题。令人担忧的是,沙门氏菌对氨基糖苷类药物的耐药性正在迅速增加。这里,我们进行了一项回顾性研究,评估了在社区获得性感染和食物或环境来源中携带arma介导的氨基糖苷类耐药的沙门氏菌的患病率.在门诊和食品/环境分离株中,携带arma的沙门氏菌菌株的患病率分别为1.1/1,000(13/12,095)和8.7/1,000(32/3,687),分别。所有携带arma的沙门氏菌菌株对多种药物都有抗药性,包括氟喹诺酮和/或超广谱头孢菌素,大多数(34/45)属于印第安纳州血清型。这些菌株的arma基因都携带在质粒上,它跨越了五种复制子类型,其中IncHI2是主要的质粒类型。所有携带armA的质粒均可转移到大肠杆菌和鲍曼不动杆菌受体中。结合实验结果表明,携带armA的S.Indiana菌株获得armA携带质粒的能力相对较高。它们的脉冲场凝胶电泳模式的相似性较低,表明携带armA的沙门氏菌菌株不太可能起源于单个流行病克隆,表明广泛的军备扩散。此外,从门诊患者中分离出的携带arma的沙门氏菌菌株的遗传背景与从家禽中分离出的菌株比从猪中分离出的菌株具有更高的相似性,表明家禽消费可能是感染源。这些发现强调了迫切需要监测携带armA的沙门氏菌的流行和传播,尤其是印第安纳州,更好地了解潜在的公共卫生威胁,并防止这些菌株的进一步传播。
    Salmonella is the primary cause of community-acquired foodborne infections, so its resistance to antimicrobials, such as aminoglycosides, is a public health issue. Of concern, aminoglycoside resistance in Salmonella is increasing rapidly. Here, we performed a retrospective study evaluating the prevalence of Salmonella harboring armA-mediated aminoglycoside resistance in community-acquired infections and in food or environmental sources. The prevalence rates of armA-harboring Salmonella strains were 1.1/1,000 (13/12,095) and 8.7/1,000 (32/3,687) in outpatient and food/environmental isolates, respectively. All the armA-harboring Salmonella strains were resistant to multiple drugs, including fluoroquinolone and/or extended-spectrum cephalosporins, and most (34/45) belonged to serovar Indiana. The armA gene of these strains were all carried on plasmids, which spanned five replicon types with IncHI2 being the dominant plasmid type. All the armA-carrying plasmids were transferable into Escherichia coli and Acinetobacter baumannii recipients. The conjugation experiment results revealed that the armA-harboring S. Indiana strains had a relatively higher ability to acquire armA-carrying plasmids. The low similarity of their pulsed field gel electrophoresis patterns indicates that the armA-harboring Salmonella strains were unlikely to have originated from a single epidemic clone, suggesting broad armA spread. Furthermore, the genetic backgrounds of armA-harboring Salmonella strains isolated from outpatients exhibited higher similarity to those isolated from poultry than to those isolated from swine, suggesting that poultry consumption maybe an infection source. These findings highlight an urgent need to monitor the prevalence and transmission of armA-harboring Salmonella, especially S. Indiana, to better understand the potential public health threat and prevent the further spread of these strains.
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  • 文章类型: Journal Article
    Aminoglycosides are important options for treating life-threatening infections. However, high levels of aminoglycoside resistance (HLAR) among Klebsiella pneumoniae isolates have been observed to be increasing frequently. In this study, a total of 292 isolates of the K. pneumoniae complex from a teaching hospital in China were analyzed. Among these isolates, the percentage of HLAR strains was 13.7% (40/292), and 15 aminoglycoside resistance genes were identified among the HLAR strains, with rmtB being the most dominant resistance gene (70%, 28/40). We also described an armA-carrying Klebsiella variicola strain KP2757 that exhibited a high-level resistance to all aminoglycosides tested. Whole-genome sequencing of KP2757 demonstrated that the strain contained one chromosome and three plasmids, with all the aminoglycoside resistance genes (including two copies of armA and six AME genes) being located on a conjugative plasmid, p2757-346, belonging to type IncHI5. Comparative genomic analysis of eight IncHI5 plasmids showed that six of them carried two copies of the intact armA gene in the complete or truncated Tn1548 transposon. To the best of our knowledge, for the first time, we observed that two copies of armA together with six AME genes coexisted on the same plasmid in a strain of K. variicola with HLAR. Comparative genomic analysis of eight armA-carrying IncHI5 plasmids isolated from humans and sediment was performed, suggesting the potential for dissemination of these plasmids among bacteria from different sources. These results demonstrated the necessity of monitoring the prevalence of IncHI5 plasmids to restrict their worldwide dissemination.
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  • 文章类型: Journal Article
    UNASSIGNED: The aminoglycosides are widely used for the therapeutic management of infections caused by gram-negative bacteria, including the Acinetobacter baumannii strains. However, the resistance to the members of the aminoglycoside family, such as amikacin, gentamicin, and tobramycin, is increasingly being common among the clinical isolates.
    UNASSIGNED: This study aimed to investigate the presence of 16SrRNA methylases and aminoglycoside modifying enzymes (AMEs) genes among aminoglycoside resistant A. baumannii isolates and to study the genetic diversity of the clinical population of A. baumannii in local hospitals.
    UNASSIGNED: The 143 A. baumannii clinical strains were analyzed for antimicrobial susceptibility, genetic screening for enzymes conferring aminoglycosides resistance followed by the multilocus sequence typing.
    UNASSIGNED: The 133/143 (93%) isolates were non-susceptible to at least one of the tested aminoglycosides, including amikacin, gentamicin, and tobramycin. The MIC distribution has shown that 87.486.7% strains were resistant to amikacin and gentamicin, respectively. The aphA6, aadB, aacC1, and aphA1 were found in 74.1%, 59.4%, 16.1%, and 11.2% isolates, respectively, whereas the armA was found in 28% of the strains having a higher MIC value (MIC; ≥256µg/mL). The MLST data have shown that the ST589 and ST2 were the most common STs and corresponded to 51 (35.7%) and 38 (26.6%) isolates, respectively, and few of the isolates corresponding to these STs were found to harbor the armA gene with a variable genotypic profile for AMEs.
    UNASSIGNED: The study has reported the incidence of various enzymes conferring aminoglycoside resistance among the A. baumannii clones for the first time from Pakistan. The findings suggest the possibility of transmission of aminoglycoside resistance determinants through the lateral gene transfer as well as clonal dissemination.
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