NnaR

  • 文章类型: Journal Article
    脓肿分枝杆菌(Mab)是一种机会性病原体,困扰着患有潜在肺部疾病的个体,例如囊性纤维化(CF)或免疫缺陷。目前针对Mab感染的治疗策略受限于其固有的抗生素抗性和在其体内生态位中获得Mab的有限药物,导致30-50%的差的治愈率。Mab在巨噬细胞内存活的能力,肉芽肿和CF肺充满粘液的气道需要通过转录重塑来适应,以抵消缺氧等应激,硝酸盐含量增加,亚硝酸盐,和反应性氮中间体。已知结核分枝杆菌(Mtb)通过硝酸还原酶narGHJI诱导呼吸道硝酸盐同化来协调低氧适应。Mab,另一方面,不编码呼吸硝酸还原酶。此外,我们最近对Mab对缺氧的转录反应的研究揭示了含有推定的硝酸盐同化基因的基因座的明显下调,包括孤儿反应调节剂nnaR(硝酸盐/亚硝酸盐同化调节剂)。这些推定的硝酸盐同化基因,narK3(硝酸盐/亚硝酸盐转运蛋白),nirBD(亚硝酸还原酶),nnaR,和sirB(铁螯合酶)连续排列,而nasN(在这项工作中鉴定出的同化硝酸还原酶)在不同的基因座中编码。Mab中缺乏呼吸性硝酸还原酶和低氧中氮代谢基因的下调表明,低氧适应与硝酸盐同化之间的相互作用与Mtb中先前记录的不同。Mab在胁迫(例如缺氧)的背景下微调氮代谢的转录调节的机制,特别是NnaR的作用,仍然知之甚少。为了评估NnaR在硝酸盐代谢中的作用,我们构建了MabnnnaR敲除菌株(MabΔnnnaR)和补体(MabΔnnnaRC)来研究转录调控和表型。qRT-PCR显示NnaR对于调节硝酸盐和亚硝酸盐还原酶以及推定的硝酸盐转运蛋白是必需的。NnaR的损失损害了Mab吸收硝酸盐或亚硝酸盐作为唯一氮源的能力,这凸显了其必要性。这项工作为MabNnaR的作用提供了第一个见解,为未来研究NnaR对发病机理的贡献奠定了基础。
    Mycobacterium abscessus (Mab) is an opportunistic pathogen afflicting individuals with underlying lung disease such as Cystic Fibrosis (CF) or immunodeficiencies. Current treatment strategies for Mab infections are limited by its inherent antibiotic resistance and limited drug access to Mab in its in vivo niches resulting in poor cure rates of 30-50%. Mab\'s ability to survive within macrophages, granulomas and the mucus laden airways of the CF lung requires adaptation via transcriptional remodeling to counteract stresses like hypoxia, increased levels of nitrate, nitrite, and reactive nitrogen intermediates. Mycobacterium tuberculosis (Mtb) is known to coordinate hypoxic adaptation via induction of respiratory nitrate assimilation through the nitrate reductase narGHJI. Mab, on the other hand, does not encode a respiratory nitrate reductase. In addition, our recent study of the transcriptional responses of Mab to hypoxia revealed marked down-regulation of a locus containing putative nitrate assimilation genes, including the orphan response regulator nnaR (nitrate/nitrite assimilation regulator). These putative nitrate assimilation genes, narK3 (nitrate/nitrite transporter), nirBD (nitrite reductase), nnaR, and sirB (ferrochelatase) are arranged contiguously while nasN (assimilatory nitrate reductase identified in this work) is encoded in a different locus. Absence of a respiratory nitrate reductase in Mab and down-regulation of nitrogen metabolism genes in hypoxia suggest interplay between hypoxia adaptation and nitrate assimilation are distinct from what was previously documented in Mtb. The mechanisms used by Mab to fine-tune the transcriptional regulation of nitrogen metabolism in the context of stresses e.g. hypoxia, particularly the role of NnaR, remain poorly understood. To evaluate the role of NnaR in nitrate metabolism we constructed a Mab nnaR knockout strain (MabΔnnaR ) and complement (MabΔnnaR+C ) to investigate transcriptional regulation and phenotypes. qRT-PCR revealed NnaR is necessary for regulating nitrate and nitrite reductases along with a putative nitrate transporter. Loss of NnaR compromised the ability of Mab to assimilate nitrate or nitrite as sole nitrogen sources highlighting its necessity. This work provides the first insights into the role of Mab NnaR setting a foundation for future work investigating NnaR\'s contribution to pathogenesis.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    背景:预测模型在各个领域中对于决策目的具有极大的重要性。在网球的背景下,仅仅依靠赢得一场比赛的概率可能不足以预测球员未来的表现或排名。网球运动员的表现受他们全年比赛时间的影响,必须将时间作为一个关键因素。这项研究旨在专注于绩效指标的预测模型,该模型可以帮助网球运动员和体育分析师预测未来比赛中的运动员排名。
    方法:要预测球员的表现,本研究采用了一种动态技术,使用线性和非线性时间序列模型分析性能的结构。采取了一种新颖的方法,将非线性神经网络自回归(NNAR)模型与传统随机线性和非线性模型(例如自回归积分移动平均(ARIMA))的性能进行比较,指数平滑(ETS),和TBATS(三角季节分解时间序列)。
    结果:研究发现,基于均方根误差(RMSE)的较低值,NNAR模型优于所有其他竞争模型,平均绝对误差(MAE),和平均绝对百分比误差(MAPE)。绩效指标的这种优越性表明,NNAR模型是预测网球运动员表现的最合适方法。此外,从NNAR模型获得的预测结果表明,95%的置信区间较窄,表明预测的准确性和可靠性更高。
    结论:结论:这项研究强调了在预测网球运动员表现时将时间作为一个因素的重要性。它强调了使用NNAR模型预测比赛中未来球员排名的潜在好处。研究结果表明,与ARIMA等传统模型相比,NNAR模型是一种推荐的方法,ETS,和TBATS。通过将时间视为关键因素并采用NNAR模型,网球运动员和体育分析师都可以对运动员的表现做出更准确的预测。
    BACKGROUND: Prediction models have gained immense importance in various fields for decision-making purposes. In the context of tennis, relying solely on the probability of winning a single match may not be sufficient for predicting a player\'s future performance or ranking. The performance of a tennis player is influenced by the timing of their matches throughout the year, necessitating the incorporation of time as a crucial factor. This study aims to focus on prediction models for performance indicators that can assist both tennis players and sports analysts in forecasting player standings in future matches.
    METHODS: To predict player performance, this study employs a dynamic technique that analyzes the structure of performance using both linear and nonlinear time series models. A novel approach has been taken, comparing the performance of the non-linear Neural Network Auto-Regressive (NNAR) model with conventional stochastic linear and nonlinear models such as Auto-Regressive Integrated Moving Average (ARIMA), Exponential Smoothing (ETS), and TBATS (Trigonometric Seasonal Decomposition Time Series).
    RESULTS: The study finds that the NNAR model outperforms all other competing models based on lower values of Root Mean Squared Error (RMSE), Mean Absolute Error (MAE), and Mean Absolute Percentage Error (MAPE). This superiority in performance metrics suggests that the NNAR model is the most appropriate approach for predicting player performance in tennis. Additionally, the prediction results obtained from the NNAR model demonstrate narrow 95% Confidence Intervals, indicating higher accuracy and reliability in the forecasts.
    CONCLUSIONS: In conclusion, this study highlights the significance of incorporating time as a factor when predicting player performance in tennis. It emphasizes the potential benefits of using the NNAR model for forecasting future player standings in matches. The findings suggest that the NNAR model is a recommended approach compared to conventional models like ARIMA, ETS, and TBATS. By considering time as a crucial factor and employing the NNAR model, both tennis players and sports analysts can make more accurate predictions about player performance.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    预测对各国做出明智的商业决策和制定数据驱动战略很有价值。豆类的生产是农业多样化举措的一个组成部分,因为它为减少发展中国家的农村贫困和失业提供了有希望的经济机会。豆类是人类健康所需的最便宜的蛋白质来源。印度的豆类生产指南必须基于准确和最佳的预测模型。比较基于不同科学数据系列的经典统计和机器学习模型是当今高级研究的主题。这项研究的重点是预测印度豆类生产的行为,卡纳塔克邦,中央邦,马哈拉施特拉邦,拉贾斯坦邦和北方邦。将数据序列拆分为训练数据集(1950-2014)和测试数据集(2015-2019),用于模型构建和验证,分别。阿丽玛,使用NNAR和混合模型,并在基于拟合优度的训练和验证数据集上进行比较(RMSE,MAE和MASE)。这项研究表明,由于印度不同省份的农业条件不同,没有一个单一的模型可以准确预测所有地区的脉冲产生。本研究的最高精度模型是ARIMA。ARIMA优于NAR,机器学习模型。印度的脉冲生产,拉贾斯坦邦,中央邦将扩大26.11%,12.62%,从2020年到2030年,将下降0.51%,而下降6.5%,-6.21%,卡纳塔克邦为6.76%,马哈拉施特拉邦,北方邦,分别。目前的预测结果可以让政策制定者在未来制定更积极的粮食安全和可持续性计划,以及更好的印度豆类生产政策。
    Forecasts are valuable to countries to make informed business decisions and develop data-driven strategies. The production of pulses is an integral part of agricultural diversification initiatives because it offers promising economic opportunities to reduce rural poverty and unemployment in developing countries. Pulses are the cheapest source of protein needed for human health. India\'s pulses production guidelines must be based on accurate and best forecast models. Comparing classical statistical and machine learning models based on different scientific data series is the subject of high-level research today. This study focused on the forecasting behaviour of pulses production for India, Karnataka, Madhya Pradesh, Maharashtra, Rajasthan and Uttar Pradesh. The data series was split into a training dataset (1950-2014) and a testing dataset (2015-2019) for model building and validation purposes, respectively. ARIMA, NNAR and hybrid models were used and compared on training and validation datasets based on goodness of fit (RMSE, MAE and MASE). This research demonstrates that due to the diverse agricultural conditions across different provinces in India, there is no single model that can accurately predict pulse production in all regions. This study\'s highest accuracy model is ARIMA. ARIMA outperforms NNAR, a machine learning model. Pulse production in India, Rajasthan, and Madhya Pradesh will expand by 26.11%, 12.62%, and 0.51% from 2020 to 2030, whereas it would decline by - 6.5%, - 6.21%, and - 6.76 per cent in Karnataka, Maharashtra, and Uttar Pradesh, respectively. The current forecast results could allow policymakers to develop more aggressive food security and sustainability plans and better Indian pulses production policies in the future.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    癌症仍然是全球死亡的主要原因,并且正在增长,多方面的全球负担。因此,预防癌症和降低癌症死亡率是21世纪最紧迫的公共卫生问题之一。反过来,癌症发病率和死亡率的准确预测对于强有力的决策至关重要,旨在建立有效和包容性的公共卫生系统,并建立基线以评估新引入的公共卫生措施的影响。在欧洲联盟(欧盟)内,罗马尼亚一直报告所有类型癌症的死亡率高于欧盟平均水平,由低效和资金不足的公共卫生系统和较低的经济发展造成的,这反过来又造成了“生态旅游”现象。本文旨在根据官方统计数据和人口网络搜索习惯反映的发病率和死亡率之间的历史联系,开发新的癌症发病率/癌症死亡率模型。随后,它使用网络查询索引的估计值来预测罗马尼亚的癌症发病率和死亡率。各种统计和机器学习模型-自回归综合移动平均模型(ARIMA),基于Box-Cox变换的指数平滑状态空间模型,ARMA错误,趋势,和季节性成分(TBATS),和前馈神经网络非线性自回归模型,或NNAR-通过自动算法进行估计,以评估网络查询量数据的样本内拟合和样本外预测准确性。预测是在样本外背景下使用表现优异的模型(即,NNAR)并纳入新的发病率/死亡率模型。结果表明,到2026年,罗马尼亚的癌症发病率和死亡率继续呈上升趋势,预计年龄标准化的癌症总发病率为313.8,年龄标准化的死亡率为233.8,增加了2%。and,分别,相对于2019年的水平,3%。因此,研究结果表明,在不变假设下,在罗马尼亚,癌症仍将是一个巨大的负担,并强调了改善罗马尼亚公共卫生系统现状的必要性和紧迫性。
    Cancer remains a leading cause of worldwide mortality and is a growing, multifaceted global burden. As a result, cancer prevention and cancer mortality reduction are counted among the most pressing public health issues of the twenty-first century. In turn, accurate projections of cancer incidence and mortality rates are paramount for robust policymaking, aimed at creating efficient and inclusive public health systems and also for establishing a baseline to assess the impact of newly introduced public health measures. Within the European Union (EU), Romania consistently reports higher mortality from all types of cancer than the EU average, caused by an inefficient and underfinanced public health system and lower economic development that in turn have created the phenomenon of \"oncotourism\". This paper aims to develop novel cancer incidence/cancer mortality models based on historical links between incidence and mortality occurrence as reflected in official statistics and population web-search habits. Subsequently, it employs estimates of the web query index to produce forecasts of cancer incidence and mortality rates in Romania. Various statistical and machine-learning models-the autoregressive integrated moving average model (ARIMA), the Exponential Smoothing State Space Model with Box-Cox Transformation, ARMA Errors, Trend, and Seasonal Components (TBATS), and a feed-forward neural network nonlinear autoregression model, or NNAR-are estimated through automated algorithms to assess in-sample fit and out-of-sample forecasting accuracy for web-query volume data. Forecasts are produced with the overperforming model in the out-of-sample context (i.e., NNAR) and fed into the novel incidence/mortality models. Results indicate a continuation of the increasing trends in cancer incidence and mortality in Romania by 2026, with projected levels for the age-standardized total cancer incidence of 313.8 and the age-standardized mortality rate of 233.8 representing an increase of 2%, and, respectively, 3% relative to the 2019 levels. Research findings thus indicate that, under the no-change hypothesis, cancer will remain a significant burden in Romania and highlight the need and urgency to improve the status quo in the Romanian public health system.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    The coronavirus disease (COVID-19) is a severe, ongoing, novel pandemic that emerged in Wuhan, China, in December 2019. As of January 21, 2021, the virus had infected approximately 100 million people, causing over 2 million deaths. This article analyzed several time series forecasting methods to predict the spread of COVID-19 during the pandemic\'s second wave in Italy (the period after October 13, 2020). The autoregressive moving average (ARIMA) model, innovations state space models for exponential smoothing (ETS), the neural network autoregression (NNAR) model, the trigonometric exponential smoothing state space model with Box-Cox transformation, ARMA errors, and trend and seasonal components (TBATS), and all of their feasible hybrid combinations were employed to forecast the number of patients hospitalized with mild symptoms and the number of patients hospitalized in the intensive care units (ICU). The data for the period February 21, 2020-October 13, 2020 were extracted from the website of the Italian Ministry of Health ( www.salute.gov.it ). The results showed that (i) hybrid models were better at capturing the linear, nonlinear, and seasonal pandemic patterns, significantly outperforming the respective single models for both time series, and (ii) the numbers of COVID-19-related hospitalizations of patients with mild symptoms and in the ICU were projected to increase rapidly from October 2020 to mid-November 2020. According to the estimations, the necessary ordinary and intensive care beds were expected to double in 10 days and to triple in approximately 20 days. These predictions were consistent with the observed trend, demonstrating that hybrid models may facilitate public health authorities\' decision-making, especially in the short-term.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

       PDF(Pubmed)

公众号