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981.
张浩彬 (2022-04-23 15:36):
#paper Salinas, D., Flunkert, V., Gasthaus, J., & Januschowski, T. (2020). DeepAR: Probabilistic forecasting with autoregressive recurrent networks. International Journal of Forecasting, 36(3), 1181–1191. https://doi.org/10.1016/j.ijforecast.2019.07.001 2020的DeepAR算法,个人觉得还是蛮有启发性的。相比于大部分在时序问题这种的点预测,DeepAR用概率模型的思路,在每个时间点去预测期概率分布;这其实也可能更符合显示,毕竟本身时序过程就是有非常强的随机属性,概率分布本身也更贴近本质。文章本身对鲁棒性讨论不多,但DeepAR的鲁棒性应该比较好。另外就是DeepAR自身强调的是,他可以很方便地对多个相关的序列(数千上万)个进行建模并提取其中的关系,这一点确实也是比较强的。所以作者也特别提到,仅需要少量的特征工程及超参数调整,即能获得比传统模型更好的效果。(论文中的模型对比,我个人觉得确实也相对规范)。 论文本身写得很精炼,但是因为是Amazon的论文,所以亲生儿子是用Mxnet上搭建的,用起来确实有点不太方便。Pytprch和TF倒是有实现,但是实现细节也有些魔改的地方。方便性来看,确实比不过Prophet,哈哈
Abstract:
Probabilistic forecasting, i.e., estimating a time series’ future probability distribution given its past, is a key enabler for optimizing business processes. In retail businesses, for example, probabilistic demand forecasts are … >>>
Probabilistic forecasting, i.e., estimating a time series’ future probability distribution given its past, is a key enabler for optimizing business processes. In retail businesses, for example, probabilistic demand forecasts are crucial for having the right inventory available at the right time and in the right place. This paper proposes DeepAR, a methodology for producing accurate probabilistic forecasts, based on training an autoregressive recurrent neural network model on a large number of related time series. We demonstrate how the application of deep learning techniques to forecasting can overcome many of the challenges that are faced by widely-used classical approaches to the problem. By means of extensive empirical evaluations on several real-world forecasting datasets, we show that our methodology produces more accurate forecasts than other state-of-the-art methods, while requiring minimal manual work. <<<
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982.
张德祥 (2022-04-19 21:45):
#paper http://dx.doi.org/10.31234/osf.io/tdw82 逆向海马体高级认知: 作者分析了生物高级slam功能是生物高级认知的基础,论文第三部分调查梳理了大量生物认知文献,论文第二部分提到了作者之前实现的类生物的slam框架,更多介绍可以参考https://mp.weixin.qq.com/s/R7doxKN6ylz7QXAIMiWQlQ
Abstract:
Simultaneous localization and mapping (SLAM) represents a fundamental problem for autonomous embodied systems, for which the hippocampal/entorhinal system (H/E-S) has been optimized over the course of evolution. We have developed … >>>
Simultaneous localization and mapping (SLAM) represents a fundamental problem for autonomous embodied systems, for which the hippocampal/entorhinal system (H/E-S) has been optimized over the course of evolution. We have developed a biologically-inspired SLAM architecture based on latent variable generative modeling within the Free Energy Principle and Active Inference (FEP-AI) framework, which affords flexible navigation and planning in mobile robots. We have primarily focused on attempting to reverse engineer H/E-S ‘design’ properties, but here we consider ways in which SLAM principles from robotics may help us better understand nervous systems and emergent minds. After reviewing LatentSLAM and notable features of this control architecture, we consider how the H/E-S may realize these functional properties not only for physical navigation, but also with respect to high-level cognition understood as generalized simultaneous localization and mapping (G-SLAM). We focus on loop-closure, graph-relaxation, and node duplication as particularly impactful architectural features, suggesting these computational phenomena may contribute to understanding cognitive insight (as proto-causal-inference), accommodation (as integration into existing schemas), and assimilation (as category formation). All these operations can similarly be describable in terms of structure/category learning on multiple levels of abstraction. However, here we adopt an ecological rationality perspective, framing H/E-S functions as orchestrating SLAM processes within both concrete and abstract hypothesis spaces. In this navigation/search process, adaptive cognitive equilibration between assimilation and accommodation involves balancing tradeoffs between exploration and exploitation; this dynamic equilibrium may be near optimally realized in FEP-AI, wherein control systems governed by expected free energy objective functions naturally balance model simplicity and accuracy. With respect to structure learning, such a balance would involve constructing models and categories that are neither too inclusive nor exclusive. We propose these (generalized) SLAM phenomena may represent some of the most impactful sources of variation in cognition both within and between individuals, suggesting that modulators of H/E-S functioning may potentially illuminate their adaptive significances as fundamental cybernetic control parameters. Finally, we discuss how understanding H/E-S contributions to G-SLAM may provide a unifying framework for high-level cognition and its potential realization in artificial intelligences. <<<
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983.
张浩彬 (2022-04-19 21:09):
#paper 10.7287/peerj.preprints.3190v1 Taylor, S. J., & Letham, B. (2017, August 25). Forecasting at Scale. PeerJ Prepr 17年Facebook开源的Prophet。原理不复杂,时序分成3个部分,趋势项,周期项,节假日项。之前用在我司的一个预测模型里面,但是最近算是正儿八经的把论文给读了。Prophet被诟病最多应该还是没啥理论,尤其是趋势项的部分分解过于粗暴了,把时序上的所有点,分解的所有项都看作是t的函数,确实带有一股工业界浓浓的ML气息。虽然粗暴,但不得不说使用体验却是很好。prophet特别适用于商业时间序列的预测,并且这个包中集成了很多方便使用的工具,例如可以方便地定义节假日,方便地定于周期,中间时间序列有缺失值也不仅要,集成了异常检测识别,模型评估方法,时间序列分解图,所以说,即使不是很了解理论的人,也能够很容易使用这个包,简单而言,对数据分析师,非常友好。
Abstract:
Forecasting is a common data science task that helps organizations with capacity planning, goal setting, and anomaly detection. Despite its importance, there are serious challenges associated with producing reliable and … >>>
Forecasting is a common data science task that helps organizations with capacity planning, goal setting, and anomaly detection. Despite its importance, there are serious challenges associated with producing reliable and high quality forecasts — especially when there are a variety of time series and analysts with expertise in time series modeling are relatively rare. To address these challenges, we describe a practical approach to forecasting “at scale” that combines configurable models with analyst-in-the-loop performance analysis. We propose a modular regression model with interpretable parameters that can be intuitively adjusted by analysts with domain knowledge about the time series. We describe performance analyses to compare and evaluate forecasting procedures, and automatically flag forecasts for manual review and adjustment. Tools that help analysts to use their expertise most effectively enable reliable, practical forecasting of business time series. <<<
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984.
龙海晨 (2022-04-10 12:28):
#paper Heat Shock Protein Beta 1 is a Prognostic Biomarker and Correlated with Immune Infiltrates in Hepatocellular Carcinoma PMID: 34531676 PMCID: PMC8439715 DOI: 10.2147/IJGM.S330608 推荐理由,最近在尝试自己做生信分析,这是我尝试复现文中生信分析方法的文章,文章使用生信分析和自己做免疫组化验证相结合的方法进行实验。 文章研究目的:研究旨在阐明HSPB1在肝癌中的表达及其潜在的治疗和预后价值。方法:从癌症基因组图谱和基因表达综合数据库中收集了肝癌和正常肝组织中HSPB1表达水平的数据。用免疫组织化学(IHC)对其进行了验证。ROC和Kaplan-Meier 生存曲线研究分析HSPB1在肝癌预后中的作用。生信分析部分包含:RNA-Sequencing Data and Bioinformatics(使用TCGA数据库数据GEO分析,免疫组化实验验证)ROC和Kaplan-Meier 生存曲线分析HSPB1在肝癌患者中的预后。单变量和多变量回归分析,分析HSPB1表达与肝癌生存率之间的相关性。用(STRING) 构建HSPB1的蛋白质相互作用(PPI)网络。HSPB1和HSPB1基因信号通路预测使用Gene Ontology (GO)和Kyoto Encyclopedia of Genes and Genomes (KEGG).用Tumor Immune Estimation Resource (TIMER) 和single sample Gene Set Enrichment Analysis (ssGSEA)分析HSPB1与肿瘤之间的关系。免疫细胞,包括B细胞、中性粒细胞、巨噬细胞、CD4+T细胞和CD8+T细胞。文章结论:HSPB1表达和免疫细胞浸润和肝癌患者预后之间存在显著相关性。HSPB1的表达可能对肝癌患者有明显的预后价值,而且可能是肝癌免疫治疗的潜在靶点。
Abstract:
BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most serious malignancies. The main features of HCC are vascular invasion and drug resistance. Ferroptosis is a novel cell program that is … >>>
BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most serious malignancies. The main features of HCC are vascular invasion and drug resistance. Ferroptosis is a novel cell program that is involved in several diseases, such as cancer. Heat shock protein beta 1 (HSPB1) is a major component of heat shock proteins. A recent study showed that HSPB1 could be a new therapeutic target for colorectal cancer with 5-fluorouracil-acquired resistance. However, the functional role of HSPB1 in HCC remains unclear.AIM: The aim of this study is to clarify HSPB1 expression in HCC and its potential therapeutic and prognostic value.METHODS: We collected data on HSPB1 expression levels in HCC and normal liver tissues from The Cancer Genome Atlas and Gene Expression Omnibus databases. We then validated it using immunohistochemistry (IHC). Receiver operating characteristic and Kaplan-Meier survival curves were used to investigate the role of HSPB1 in the prognosis analysis of HCC. Further, we used the online Search Tool for the Retrieval of Interacting Genes/Proteins website, Gene Ontology, and Kyoto Encyclopedia of Genes and Genomes to conduct enrichment analysis and identify the predictive signaling pathways. Meanwhile, we used the TIMER and GSVA package of R (v3.6.3) to analyze the association between HSPB1 and immunocyte infiltration.RESULTS: Compared to normal tissues, there was differential expression of HSPB1 in pan-cancers. HSPB1 expression was higher in HCC tissues than in normal tissues (p<0.05). There was an evident significant difference between HSPB1 mRNA levels and histologic grade, vascular invasion, and alpha-fetoprotein level (all p values<0.05). Univariate analysis indicated that HCC patients with high HSPB1 levels had shorter overall survival rates than those with low HSPB1 levels (p<0.05). MAPK14, HSPA8, MAPKAPK3, MAPKAPK5, and MAPKAPK2 are essential proteins that interact with HSPB1. There was a significant correlation between HSPB1 expression levels and immune cell infiltration, including CD4+ T cells (r=0.203, p<0.05).CONCLUSION: High HSPB1 expression is closely associated with a worse prognosis in HCC patients, and HSPB1 may be a target of immunotherapy in HCC. <<<
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985.
魏魏魏 (2022-04-05 00:36):
#paper doi:10.1007/s10826-015-0349-6 Journal of Child and Family Studies, (2016), Emotion Regulation in Relation to Emerging Adults’ Mental Health and Delinquency: A Multi-informant Approach. 父母的教养方式是其教养态度和价值观的反映,并体现在其具体的教养行为中,最终影响子女各方面的发展。此前研究证实,权威型教养方式有更多优点能促进子女积极发展,而威权型教养方式和溺爱型教养方式则会带来更多消极结果。当前研究探讨了父母教养方式与子女情绪调控技能和心理健康及越轨行为的关系,以及情绪调控的中介作用。不过,当前研究的被试不同于此前研究中的儿童或青少年被试,该研究以刚刚成年的子女为研究对象。该研究采用的是问卷法。结果发现,被试报告的情绪调控能力部分中介了权威型教养方式与心理健康的关系,而权威型教养方式通过情绪调控间接与子女的越轨行为发生关系。威权型和溺爱型两种消极的教养方式没有与情绪调控能力发生关系。这一结果提示家庭教育工作者,父母权威型教养方式是有利于子女情绪调控能力发展和心理健康的,不过,未来研究需要建立在干预研究或者追踪研究的基础上才更好。
Abstract:
Relative to the merits of authoritative parenting, potential adverse outcomes are well documented for authoritarian and permissive parenting. However, conclusions are typically drawn from single informants. The ability of youths’ … >>>
Relative to the merits of authoritative parenting, potential adverse outcomes are well documented for authoritarian and permissive parenting. However, conclusions are typically drawn from single informants. The ability of youths’ emotion regulation skills to mediate outcomes in emerging adults has also not been fully explored. This study investigated whether emotion regulation mediated parenting style history and potential outcomes of mental health and delinquency. Parenting style history and emerging adults’ emotion regulation ability were reported by 110 youth and their caregivers; youth reported on mental health functioning and delinquency. Emerging adults’ emotion regulation ability partially mediated the association between authoritative parenting history and mental health functioning and authoritative parenting history was indirectly related to delinquency through emotion regulation; however, based on all reporters, emotion regulation ability was not associated with authoritarian or permissive parenting style history. Results support that the merits of authoritative parenting may lie in fostering better emotion regulation skills. <<<
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986.
魏魏魏 (2022-04-04 23:41):
#paper doi:10.1007/s10802-021-00833-w Research on Child and Adolescent Psychopathology, (2021), Adolescent Emotionality and Emotion Regulation in the Context of Parent Emotion Socialization Among Adolescents with Neurodevelopmental Disorders: A Call to Action with Pilot Data. 父母的情绪社会化影响儿童和青少年的神经发展障碍,该领域的研究目前并不多,该研究也只是一个预备性研究,而且被试量也并不多,只有18个有神经发育障碍的青少年和他们的抚养者。研究中的青少年被试有注意力缺陷多动障碍(ADHD)以及系列共生障碍,比如焦虑、抑郁以及自闭症谱系障碍。当前研究采用了冲突讨论任务、观察法和问卷法。最后发现,父母支持性的情绪社会化行为与观察得到的子女适应性的情绪调控策略显著相关,与观察得到的负性情绪以及青少年报告的负性情绪的减少正相关,而父母非支持性情绪社会化行为与观察到的消极情绪相关。因此,当前研究发现支持了适应性父母情绪社会化抚养行为有助于减少有神经发育障碍子女的消极情绪体验,或者使之能更好地进行情绪调控。当前研究对探讨父母教养行为与子女神经发育障碍的关系提供了一个启发,希望后续能够看到更多此类研究。
Abstract:
To date, only three studies have examined the role of emotion socialization in the emotional functioning of youth with neurodevelopmental disorders. As such, this review article with pilot data sought … >>>
To date, only three studies have examined the role of emotion socialization in the emotional functioning of youth with neurodevelopmental disorders. As such, this review article with pilot data sought to provide a call to action and first step in addressing this limited research body. Pilot data was collected with 18 adolescents (Mage = 13.5, SD = 1.6; 70% male) with a neurodevelopmental disorder and their primary caregiver. All adolescents were diagnosed with attention-deficit/hyperactivity disorder and displayed a range of comorbid disorders: autism spectrum disorder (27.8%), anxiety (66.7%), depression (44.4%), and disruptive behavior disorders (50%). Adolescents and caregivers completed a conflict discussion task while physiological, observational, and self-report measures of emotion socialization and emotional functioning were measured. Observed supportive parent emotion socialization behaviors were significantly associated with more observed adaptive emotion regulation strategies, and decreased observed and adolescent-reported negative affect, whereas non-supportive emotion socialization behaviors were associated with more observed negative affect and less observed adaptive emotion regulation strategies. Our pilot findings support growing research suggesting that adaptive parent emotion socialization practices can help foster less negative emotionality and better emotion regulation in youth with neurodevelopment disorders. We make a call to action for more emotion socialization research focused on youth with neurodevelopmental disorders, and propose four important directions for future research: 1) Research examining emotion socialization behaviors during daily life, 2) Understanding the nuanced role of emotion socialization practices, 3) Considering diversity in emotion socialization practices with clinical populations, and 4) Longitudinal and intervention research studies. <<<
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987.
吴增丁 (2022-04-02 17:54):
#paper Lang, F., Schrörs, B., Löwer, M. et al. Identification of neoantigens for individualized therapeutic cancer vaccines. Nat Rev Drug Discov 21, 261–282 (2022). https://doi.org/10.1038/s41573-021-00387-y 这篇最近发表在Nat Rev Drug Discov的综述文章用较长的篇幅介绍了新抗原neoantigen疫苗在肿瘤临床个性化治疗的应用。核心内容包括三个方面:1.新抗原能够产生免疫治疗效果前提与机理,即新抗原的呈递和被免疫细胞的识别;2.提出了一种新的新抗原的分类;3.鉴定新抗原的方法。 篇幅有限,此处1/3两点不做更多详述。重点介绍下第2点--新抗原的分类。传统上一般根据产生新抗原的somatic 突变类型进行分类的,比如SNV/INDEL/FUSION/splice variants等。但是作者根据临床表现来将新抗原分为Guarding neoantigen、Restrained neoantigen、Ignored neoantigen。 其中Guarding Neo是能够自然天然的帮助身体产生对肿瘤细胞的免疫反应,再不需要而外干预的情况抑制了肿瘤细胞的生长。这主要两种情况,一是肿瘤细胞正好有很强的免疫原性,激活了native T,并进一步激活了整个免疫反应;二是由于cross- reactive 效果,即机体可能再产生肿瘤细胞前因为病原感染产生了对某种多肽的免疫,并有了记忆T细胞,正好新生肿瘤中的新抗原含有这个多肽;其二Restrained neoantigen,这个是为什么PD-L1抑制剂能起作用的原因;其三Ignored neoantigen ,这是最有潜力用于免疫治疗的新抗原。
Abstract:
Somatic mutations in cancer cells can generate tumour-specific neoepitopes, which are recognized by autologous T cells in the host. As neoepitopes are not subject to central immune tolerance and are … >>>
Somatic mutations in cancer cells can generate tumour-specific neoepitopes, which are recognized by autologous T cells in the host. As neoepitopes are not subject to central immune tolerance and are not expressed in healthy tissues, they are attractive targets for therapeutic cancer vaccines. Because the vast majority of cancer mutations are unique to the individual patient, harnessing the full potential of this rich source of targets requires individualized treatment approaches. Many computational algorithms and machine-learning tools have been developed to identify mutations in sequence data, to prioritize those that are more likely to be recognized by T cells and to design tailored vaccines for every patient. In this Review, we fill the gaps between the understanding of basic mechanisms of T cell recognition of neoantigens and the computational approaches for discovery of somatic mutations and neoantigen prediction for cancer immunotherapy. We present a new classification of neoantigens, distinguishing between guarding, restrained and ignored neoantigens, based on how they confer proficient antitumour immunity in a given clinical context. Such context-based differentiation will contribute to a framework that connects neoantigen biology to the clinical setting and medical peculiarities of cancer, and will enable future neoantigen-based therapies to provide greater clinical benefit. <<<
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988.
白义民 (2022-04-02 13:40):
#paper 《密契经验的比较研究》,对神秘主义感兴趣的同学可能比较关心,密契经验是从哲学跃迁到宗教的必经步骤,有助于你切身感受到另外维度空间的存在,或曰彼岸或曰净土或曰天堂地狱;如果缺乏宗教经验,哲学理性的归宿基本上都是悖论死胡同,走向不可知论;密契的非理性突破是走出死胡同,打开新世界天地的钥匙。本文是神学博士的比较宗教学研究作品,很合学术章法。对相关主题想深度研究的同学,可读书《宗教经验种种》
2012.
Abstract:
在本文当中,我们首先定义密契经验的内涵、特质以及说明为何选择此四人的主要原因。其次,则分别阐析王重阳等四人之生平大要、开悟的详细经过及开悟的内涵与特质。最后,则进一步分析及比较此四人之密契经验的异同以及我们可以从此探讨当中归纳出的重要结论。藉由如是的探讨,除了可以具体了解中印宗教、哲学的内涵、特质以及其形成与发展的一种重要途径外,也可使我们对于哲学、宗教学及心理学等学科中的重要问题,带来关键的启发。最后,密契经验做为一种了悟真理及彻底解决生命问题的可能方式,对其探讨,亦能给人类的生命,带来重要的启示及指引。 >>>
在本文当中,我们首先定义密契经验的内涵、特质以及说明为何选择此四人的主要原因。其次,则分别阐析王重阳等四人之生平大要、开悟的详细经过及开悟的内涵与特质。最后,则进一步分析及比较此四人之密契经验的异同以及我们可以从此探讨当中归纳出的重要结论。藉由如是的探讨,除了可以具体了解中印宗教、哲学的内涵、特质以及其形成与发展的一种重要途径外,也可使我们对于哲学、宗教学及心理学等学科中的重要问题,带来关键的启发。最后,密契经验做为一种了悟真理及彻底解决生命问题的可能方式,对其探讨,亦能给人类的生命,带来重要的启示及指引。 <<<
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989.
吴增丁 (2022-04-02 11:39):
#paper  Sahin, U., Oehm, P., Derhovanessian, E. et al. An RNA vaccine drives immunity in checkpoint-inhibitor-treated melanoma. Nature 585, 107–112 (2020).  doi:org/10.1038/s41586-020-2537-9 这篇2020年发表在Nautre文章介绍了BioNtech关于FixVac BNT111的I期临床结果,它是2016年pre-clinical 研究( doi.org/10.1038/nature18300)的clinical 研究的延续。该文章首先介绍了临床研究设计: 1.药物核心还是用临川前验证有效的RNA-LPX载体递送四个TAA (NY-ESO-1/Tyrosinase/MAGE-A3/TPTE); 2.通过总共纳入了89例黑色素瘤患者,做了 a.剂量爬坡 、b.剂量范围(7.2-400ug totalRNA)、c. 单用及联合PD-1 抑制剂分别进行cohort验证药效和安全性分析。 最终结果显示单独或与PD1抑制剂联用,都可以介导晚期无法手术的患者产生客观缓解(OR)。通过进一步研究分析产生客观缓解的患者体内伴随着很强的CD4+和CD8+ T 细胞,这个水平几乎和T-cell治疗的水平相当,并且有持久效果。综合显示,TAA BNT111对治疗黑色素瘤取得较好效果。
IF:50.500Q1 Nature, 2020-09. DOI: 10.1038/s41586-020-2537-9 PMID: 32728218
Abstract:
Treating patients who have cancer with vaccines that stimulate a targeted immune response is conceptually appealing, but cancer vaccine trials have not been successful in late-stage patients with treatment-refractory tumours. … >>>
Treating patients who have cancer with vaccines that stimulate a targeted immune response is conceptually appealing, but cancer vaccine trials have not been successful in late-stage patients with treatment-refractory tumours. We are testing melanoma FixVac (BNT111)-an intravenously administered liposomal RNA (RNA-LPX) vaccine, which targets four non-mutated, tumour-associated antigens that are prevalent in melanoma-in an ongoing, first-in-human, dose-escalation phase I trial in patients with advanced melanoma (Lipo-MERIT trial, ClinicalTrials.gov identifier NCT02410733). We report here data from an exploratory interim analysis that show that melanoma FixVac, alone or in combination with blockade of the checkpoint inhibitor PD1, mediates durable objective responses in checkpoint-inhibitor (CPI)-experienced patients with unresectable melanoma. Clinical responses are accompanied by the induction of strong CD4 and CD8 T cell immunity against the vaccine antigens. The antigen-specific cytotoxic T-cell responses in some responders reach magnitudes typically reported for adoptive T-cell therapy, and are durable. Our findings indicate that RNA-LPX vaccination is a potent immunotherapy in patients with CPI-experienced melanoma, and suggest the general utility of non-mutant shared tumour antigens as targets for cancer vaccination. <<<
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吴增丁 (2022-04-01 16:41):
#paper Kranz, L., Diken, M., Haas, H. et al. Systemic RNA delivery to dendritic cells exploits antiviral defence for cancer immunotherapy. Nature 534, 396–401 (2016). DOI:10.1038/nature18300 该文章是BioNtech在2016年发表的,展示了其公司开发的RNA-LPX递送载体技术,以及利用该提送技术成功地将包含四个Tumor associate antigen (NY-SYO-1,MAGE-A3,tyrosinase,TPTE)的FixVac panel,成功推到了临床研究阶段。1.该研究在pre-clinical阶段:a.探索了LPX载体的生产工艺,包括其电荷比,mRNA:Lipid比例等关键参数等。b.探索了mRNA在老鼠体内的表达位置,通过调整DOTAM/DOPE比例,将mRNA的表达主要局限在spleen和骨髓中;c.通过注射能表达流感免疫原的mRNA,评估确定了mRNA能正常表达,且在老鼠体内产生了免疫反应;d.在小鼠体内也能对肿瘤产生免疫反应;2. 在clinical阶段,采用了四个在黑色素瘤中特异高表达的Tumor associate antigen (NY-SYO-1,MAGE-A3,tyrosinase,TPTE),并对纳入临床研究的几例patien分析评估其产生了免疫反应。
IF:50.500Q1 Nature, 2016-06-16. DOI: 10.1038/nature18300 PMID: 27281205
Abstract:
Lymphoid organs, in which antigen presenting cells (APCs) are in close proximity to T cells, are the ideal microenvironment for efficient priming and amplification of T-cell responses. However, the systemic … >>>
Lymphoid organs, in which antigen presenting cells (APCs) are in close proximity to T cells, are the ideal microenvironment for efficient priming and amplification of T-cell responses. However, the systemic delivery of vaccine antigens into dendritic cells (DCs) is hampered by various technical challenges. Here we show that DCs can be targeted precisely and effectively in vivo using intravenously administered RNA-lipoplexes (RNA-LPX) based on well-known lipid carriers by optimally adjusting net charge, without the need for functionalization of particles with molecular ligands. The LPX protects RNA from extracellular ribonucleases and mediates its efficient uptake and expression of the encoded antigen by DC populations and macrophages in various lymphoid compartments. RNA-LPX triggers interferon-α (IFNα) release by plasmacytoid DCs and macrophages. Consequently, DC maturation in situ and inflammatory immune mechanisms reminiscent of those in the early systemic phase of viral infection are activated. We show that RNA-LPX encoding viral or mutant neo-antigens or endogenous self-antigens induce strong effector and memory T-cell responses, and mediate potent IFNα-dependent rejection of progressive tumours. A phase I dose-escalation trial testing RNA-LPX that encode shared tumour antigens is ongoing. In the first three melanoma patients treated at a low-dose level, IFNα and strong antigen-specific T-cell responses were induced, supporting the identified mode of action and potency. As any polypeptide-based antigen can be encoded as RNA, RNA-LPX represent a universally applicable vaccine class for systemic DC targeting and synchronized induction of both highly potent adaptive as well as type-I-IFN-mediated innate immune mechanisms for cancer immunotherapy. <<<
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Ricardo (2022-04-01 00:05):
#paper https://doi.org/10.1016/j.neuroimage.2020.117161 NeuroImage, 2020 Cortical surface registration using unsupervised learning 由于我们经常需要在不同被试间或者同一个被试的不同时间点的脑图像上建立空间映射关系,因此非线性配准是脑影像分析中非常重要的一步。这几年时间里,大家开始使用深度学习开发新的脑图像配准算法,但是大都关注于基于volume空间下的配准算法的研究,鲜少有研究关注于脑皮层的点云空间下的配准。这篇文章通过将卷积操作拓展到极坐标空间下,实现了在球面空间上的卷积操作,从而开发了针对于脑皮层的配准算法。
IF:4.700Q1 NeuroImage, 2020-11-01. DOI: 10.1016/j.neuroimage.2020.117161 PMID: 32702486 PMCID:PMC7784120
Abstract:
Non-rigid cortical registration is an important and challenging task due to the geometric complexity of the human cortex and the high degree of inter-subject variability. A conventional solution is to … >>>
Non-rigid cortical registration is an important and challenging task due to the geometric complexity of the human cortex and the high degree of inter-subject variability. A conventional solution is to use a spherical representation of surface properties and perform registration by aligning cortical folding patterns in that space. This strategy produces accurate spatial alignment, but often requires high computational cost. Recently, convolutional neural networks (CNNs) have demonstrated the potential to dramatically speed up volumetric registration. However, due to distortions introduced by projecting a sphere to a 2D plane, a direct application of recent learning-based methods to surfaces yields poor results. In this study, we present SphereMorph, a diffeomorphic registration framework for cortical surfaces using deep networks that addresses these issues. SphereMorph uses a UNet-style network associated with a spherical kernel to learn the displacement field and warps the sphere using a modified spatial transformer layer. We propose a resampling weight in computing the data fitting loss to account for distortions introduced by polar projection, and demonstrate the performance of our proposed method on two tasks, including cortical parcellation and group-wise functional area alignment. The experiments show that the proposed SphereMorph is capable of modeling the geometric registration problem in a CNN framework and demonstrate superior registration accuracy and computational efficiency. The source code of SphereMorph will be released to the public upon acceptance of this manuscript at https://github.com/voxelmorph/spheremorph. <<<
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Donny (2022-03-31 23:39):
#paper Deep Learning-Based Multi-Omics Integration Robustly Predicts Survival in Liver Cancer  DOI: 10.1158/1078-0432.CCR-17-0853 识别肝细胞癌(HCC)鲁棒的生存亚组对于改善病人护理十分重要。当前,仍然缺乏整合多组学数据以从不同病人队列中明确预测HCC生存状况的尝试。为了填补这一空白,作者开发了针对HCC基于深度学习的模型并能够鲁棒地将病人的生存亚群分为六个队列。作者使用来自TCGA的RNA-seq、miRNA-seq和甲基化数据构建了基于深度学习的生存敏感的模型。该模型对预后的预测能够取得与同时考虑基因组与临床数据的模型相当的效果。该基于深度学习的模型提供了两个有明显生存区别和模型拟合的最优的病人亚组。更为恶性的亚型与频繁的TP53抑制突变、干细胞特性标志物(KRT19、EPCAM)及肿瘤标志物(BIRC5)的高表达及Wnt和Akt信号通路的激活相关。作者在五个不同组学数据类型的外部数据集上验证了该多组学模型,LIRI-JP队列(n=230,C-index=0.75),NCI队列(n=221, C-index=0.67),Chinese队列(n=166,C-index=0.69),E-TABM-36 队列(n=40, C-index=0.77)及Hawaiian队列(n=27, C-index=0.82)。这是第一次采用深度学习来识别与HCC病人不同生存相关联的多组学特征的研究。考虑到该模型在不同队列的鲁棒性,研究人员期望该工作流能够对HCC预后的预测发挥作用。
Abstract:
Identifying robust survival subgroups of hepatocellular carcinoma (HCC) will significantly improve patient care. Currently, endeavor of integrating multi-omics data to explicitly predict HCC survival from multiple patient cohorts is lacking. … >>>
Identifying robust survival subgroups of hepatocellular carcinoma (HCC) will significantly improve patient care. Currently, endeavor of integrating multi-omics data to explicitly predict HCC survival from multiple patient cohorts is lacking. To fill this gap, we present a deep learning (DL)-based model on HCC that robustly differentiates survival subpopulations of patients in six cohorts. We built the DL-based, survival-sensitive model on 360 HCC patients' data using RNA sequencing (RNA-Seq), miRNA sequencing (miRNA-Seq), and methylation data from The Cancer Genome Atlas (TCGA), which predicts prognosis as good as an alternative model where genomics and clinical data are both considered. This DL-based model provides two optimal subgroups of patients with significant survival differences ( = 7.13e-6) and good model fitness [concordance index (C-index) = 0.68]. More aggressive subtype is associated with frequent inactivation mutations, higher expression of stemness markers ( and ) and tumor marker , and activated Wnt and Akt signaling pathways. We validated this multi-omics model on five external datasets of various omics types: LIRI-JP cohort ( = 230, C-index = 0.75), NCI cohort ( = 221, C-index = 0.67), Chinese cohort ( = 166, C-index = 0.69), E-TABM-36 cohort ( = 40, C-index = 0.77), and Hawaiian cohort ( = 27, C-index = 0.82). This is the first study to employ DL to identify multi-omics features linked to the differential survival of patients with HCC. Given its robustness over multiple cohorts, we expect this workflow to be useful at predicting HCC prognosis prediction. . <<<
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993.
旺旺小小酥 (2022-03-31 23:18):
#paper 看不见的家庭教育投资:子女升学压力与母亲收入损失[J].经济研究,2021,56(09):73-89. 本篇文章抓住了社科研究追逐热点地习惯,通过研究子女升学压力与母亲收入损失地因果关系,针对我国教育内卷化现象进行深入探究,但是给出的建议大多宽泛没有实质性的建议,这也是社科研究的通病。文章的难点在于数据的获取和前期处理,因此,本篇文章作者以2005年的1%人口抽样调查数据作为分析的主要数据来源,理由是该调查数据包含了个体工资收入信息,贴合本文所研究的重点,但是否贴合现在的情况还是很值得进一步讨论的。对于本文的数据前期处理可以作为参考,特别是探究因果效益的分析或者研究具备较大的参考价值。作者在文章下半部分进行了内在的机制分析,认为子女升学压力会使得母亲降低工作时长、增加家庭照料时间等方式,进行隐性投资教育。我本人虽然不是做相关议题研究的,但该论文若是可以进一步分析潜在的正负反馈机制或许会有更具价值的指导性建议
经济研究, 2021.
Abstract:
在家庭教育投资中,除现金性的显性教育支出外,家庭也会通过放弃潜在收入并增加子女陪护时间的方式进行隐性教育投资。这种看不见的家庭教育投资行为尚未得到学术界的广泛关注,但其对理解中国家庭的教育行为具有重要现实意义。本文利用子女升学压力对家庭教育重视程度的外生冲击作为识别框架,估计了母亲由于子女教育压力而放弃的潜在收入,为识别家庭隐性教育投资行为提供了微观证据。本文实证结果表明,子女升学压力会使母亲月收入显著下降19%,同时父亲收入没有显著变化。异质性分析发现,高学历、非国有行业、育有男孩或独生子女的母亲收入更容易受到子女升学压力的影响。机制分析表明,在子女升学压力下母亲会通过降低劳动参与率、降低工作时长以及增加家庭照料时间等方式进行隐性教育投资。进一步利用地区重点高校录取率反映地区升学压力,发现子女升学压力越大的地区,母亲收入下降幅度越大。本文研究识别了子女升学压力下的家庭隐性教育投资行为,为更好理解中国人力资本积累和家庭劳动供给决策提供了新的观察视角。 >>>
在家庭教育投资中,除现金性的显性教育支出外,家庭也会通过放弃潜在收入并增加子女陪护时间的方式进行隐性教育投资。这种看不见的家庭教育投资行为尚未得到学术界的广泛关注,但其对理解中国家庭的教育行为具有重要现实意义。本文利用子女升学压力对家庭教育重视程度的外生冲击作为识别框架,估计了母亲由于子女教育压力而放弃的潜在收入,为识别家庭隐性教育投资行为提供了微观证据。本文实证结果表明,子女升学压力会使母亲月收入显著下降19%,同时父亲收入没有显著变化。异质性分析发现,高学历、非国有行业、育有男孩或独生子女的母亲收入更容易受到子女升学压力的影响。机制分析表明,在子女升学压力下母亲会通过降低劳动参与率、降低工作时长以及增加家庭照料时间等方式进行隐性教育投资。进一步利用地区重点高校录取率反映地区升学压力,发现子女升学压力越大的地区,母亲收入下降幅度越大。本文研究识别了子女升学压力下的家庭隐性教育投资行为,为更好理解中国人力资本积累和家庭劳动供给决策提供了新的观察视角。 <<<
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草莓味儿 (2022-03-31 21:36):
#paper DNA methylation loss promotes immune evasion of tumours with high mutation and copy number load DOI: 10.1038/s41467-019-12159-9 本篇文章的研究者对各种肿瘤类型的TCGA数据进行了大规模的系统分析,研究了全局甲基化水平与细胞增殖,突变负荷,SCNA水平,浸润性免疫细胞标记和免疫应答基因活性之间的关系。结果表明作为免疫治疗中重要的预测标志物,基因组去甲基化与表观遗传调控有关,可以作为精确免疫治疗的联合方案。 主要研究内容包括:通过细胞系数据,确定了与正常细胞相比在癌症中更早或更晚复制的基因;另外,晚期复制区的甲基化缺失也称为部分甲基化结构域(PMD),与免疫基因抑制相关;全局甲基化预测免疫疗法的反应:采用肺癌队列测试了由分子分析得出的假设,需要指出的是这是第一项针对癌症免疫疗法的分子和临床数据中的DNA甲基化模式的研究;全局去甲基化排除了非整倍性的影响。总的来说,表观遗传调节和检查点阻断相结合,可以作为一种潜在的精准免疫治疗方案。
IF:14.700Q1 Nature communications, 2019-09-19. DOI: 10.1038/s41467-019-12159-9 PMID: 31537801 PMCID:PMC6753140
Abstract:
Mitotic cell division increases tumour mutation burden and copy number load, predictive markers of the clinical benefit of immunotherapy. Cell division correlates also with genomic demethylation involving methylation loss in … >>>
Mitotic cell division increases tumour mutation burden and copy number load, predictive markers of the clinical benefit of immunotherapy. Cell division correlates also with genomic demethylation involving methylation loss in late-replicating partial methylation domains. Here we find that immunomodulatory pathway genes are concentrated in these domains and transcriptionally repressed in demethylated tumours with CpG island promoter hypermethylation. Global methylation loss correlated with immune evasion signatures independently of mutation burden and aneuploidy. Methylome data of our cohort (n = 60) and a published cohort (n = 81) in lung cancer and a melanoma cohort (n = 40) consistently demonstrated that genomic methylation alterations counteract the contribution of high mutation burden and increase immunotherapeutic resistance. Higher predictive power was observed for methylation loss than mutation burden. We also found that genomic hypomethylation correlates with the immune escape signatures of aneuploid tumours. Hence, DNA methylation alterations implicate epigenetic modulation in precision immunotherapy. <<<
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Marvel (2022-03-31 20:46):
#paper Challenges of CRISPR-Based Gene Editing in Primary T Cells doi: 10.3390/ijms23031689 Link# https://www.mdpi.com/1422-0067/23/3/1689 过继性细胞疗法在白血病以及某些类型癌症的成功治疗中取得了很大希望,近来其也在免疫抑制患者的慢性病毒感染中显示出疗效。而这些自体或异体的T细胞往往要经过基因修饰以表达新的TCR或CAR,在此过程中无可避免或多或少要用到CRISPR/Cas系统,以达到基因组上特定位点的增删。此篇综述中,研究者总结了对这些基因修饰比较重要的方法学突破,操作中需要考虑的关键点,并强调了这些方法的潜在缺陷。 文章总结了1. CRISPR/Cas系统的起源、结构以及基因组编辑的分子机制 2. CRISPR/Cas系统进行T细胞基因编辑应用流程及各环节的注意事项 ( T细胞的培养与活化、gRNA的选择<设计与脱靶检测>、RNP形式的选择) 3. 递送方式的选择与优劣 4. 系统引起的非同源末端链接导致DSB修复。 文章同时总结了截至到2021.12.31基于CRISPR基因编辑T细胞的临床试验,统计了其编辑靶点、适应症与临床分期。其他包括基于Cas9敲入的注意事项包括gRNA和HDR的设计与选择等等。 总的来说,这篇文章与其说是综述,更像是综述的综述。对于细分领域的研发人员来讲,真的是一篇不可多的的好文章!
Abstract:
Adaptive T-cell immunotherapy holds great promise for the successful treatment of leukemia, as well as other types of cancers. More recently, it was also shown to be an effective treatment … >>>
Adaptive T-cell immunotherapy holds great promise for the successful treatment of leukemia, as well as other types of cancers. More recently, it was also shown to be an effective treatment option for chronic virus infections in immunosuppressed patients. Autologous or allogeneic T cells used for immunotherapy are usually genetically modified to express novel T-cell or chimeric antigen receptors. The production of such cells was significantly simplified with the CRISPR/Cas system, allowing for the deletion or insertion of novel genes at specific locations within the genome. In this review, we describe recent methodological breakthroughs that were important for the conduction of these genetic modifications, summarize crucial points to be considered when conducting such experiments, and highlight the potential pitfalls of these approaches. <<<
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June (2022-03-31 18:24):
#paper doi: 10.1038/s41556-021-00820-9. Epub 2022 Feb 10.Cancer-cell-derived GABA promotes β-catenin-mediated tumour growth and immunosuppression 在此项工作中,研究人员通过分析大量病人的肿瘤病理切片,证实了GABA在肺癌和结肠癌中的异常积累。通过统计,他们发现GABA的含量随着临床分期的提升而逐渐增加,并且与病人的生存时间呈现明显的负相关性。这些都提示GABA可能在肿瘤的发生发展中充当了“帮凶”。 为了找出GABA在肿瘤中积累的原因,研究人员结合肿瘤病人临床样品,小鼠肿瘤模型和体外肿瘤细胞,发现肺癌和结肠癌细胞通过异常表达谷氨酸脱羧酶家族成员GAD1从而利用肿瘤环境中丰富的谷氨酰胺进行代谢并合成GABA。通过干预GAD1在肿瘤细胞内的表达,不仅可以显著减少肿瘤细胞所产生的GABA,还能够在一定程度上抑制肿瘤的生长。 为了更加清晰地了解GABA在肿瘤中的作用机制,他们发现肿瘤细胞分泌到环境中的GABA将被同样表达于细胞表面的一种名叫GABA B型受体的蛋白所识别,其产生的细胞内信号最终增强了一种在发育和肿瘤等方面发挥着重要作用的通路调节蛋白β-catenin。有意思的是,这种增强的β-catenin信号不仅可以通过调节下游相关基因的表达帮助肿瘤细胞体外增殖,还能通过抑制免疫细胞对肿瘤的渗入促进体内肿瘤生长。利用不同的小鼠模型,研究者们发现阻断GABA的肿瘤能够通过抑制β-catenin通路而激活肿瘤中特定细胞因子的表达,而这将有助于树突状细胞对肿瘤的渗入,从而进一步影响T细胞进入肿瘤并对肿瘤进行杀伤。最后,研究人员发现将抑制GABA类药物与免疫检查点抑制剂结合使用能够明显改善对于单独免疫检查点抑制剂具有抗性的肿瘤治疗效果,并且显著提升小鼠的存活时间。 总体而言,此项工作揭示了GABA在神经系统之外发挥了调控肿瘤自身增殖和免疫逃逸的重要作用。由于一部分GABA抑制剂已作为药物在临床运用,此项研究也揭示了GABA抑制剂与免疫疗法相结合治疗肿瘤的潜在应用价值。
IF:17.300Q1 Nature cell biology, 2022-02. DOI: 10.1038/s41556-021-00820-9 PMID: 35145222 PMCID:PMC8852304
Abstract:
Many cancers have an unusual dependence on glutamine. However, most previous studies have focused on the contribution of glutamine to metabolic building blocks and the energy supply. Here, we report … >>>
Many cancers have an unusual dependence on glutamine. However, most previous studies have focused on the contribution of glutamine to metabolic building blocks and the energy supply. Here, we report that cancer cells with aberrant expression of glutamate decarboxylase 1 (GAD1) rewire glutamine metabolism for the synthesis of γ-aminobutyric acid (GABA)-a prominent neurotransmitter-in non-nervous tissues. An analysis of clinical samples reveals that increased GABA levels predict poor prognosis. Mechanistically, we identify a cancer-intrinsic pathway through which GABA activates the GABA receptor to inhibit GSK-3β activity, leading to enhanced β-catenin signalling. This GABA-mediated β-catenin activation both stimulates tumour cell proliferation and suppresses CD8 T cell intratumoural infiltration, such that targeting GAD1 or GABAR in mouse models overcomes resistance to anti-PD-1 immune checkpoint blockade therapy. Our findings uncover a signalling role for tumour-derived GABA beyond its classic function as a neurotransmitter that can be targeted pharmacologically to reverse immunosuppression. <<<
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masion (2022-03-31 18:15):
#paper doi: 10.1126/science.aad0408 Science, 2015, The Symbiodinium kawagutii genome illuminates dinoflagellate gene expression and coral symbiosis. 甲藻是海洋生态系统和珊瑚共生体的重要组成部分,但对它们的基因组却知之甚少。我们报告了一个来自共生菌Symbiodinium kawagutii的1180Mb碱基的高质量组装基因组,对蛋白质编码基因进行了注释,并确定了共生菌种特异性的基因家族。没有观察到全基因组复制,但我们发现了活跃(追溯) 转位和基因家族扩张,尤其是在对与珊瑚成功共生过程相关的基因族表达。此外,我们还记录了可能控制有性繁殖及休眠体形成、新启动子元件和microRNA系统相关的基因,后者可能在调节共生体和珊瑚中的基因表达中都起作用。我们发现了S.kawagutii和顶孢珊瑚虫anthozoan Acropora基因组之间存在生化反应的互补性,揭示了宿主-共生体的共进化,为研究珊瑚共生的分子基础和进化提供资料。
Abstract:
Dinoflagellates are important components of marine ecosystems and essential coral symbionts, yet little is known about their genomes. We report here on the analysis of a high-quality assembly from the … >>>
Dinoflagellates are important components of marine ecosystems and essential coral symbionts, yet little is known about their genomes. We report here on the analysis of a high-quality assembly from the 1180-megabase genome of Symbiodinium kawagutii. We annotated protein-coding genes and identified Symbiodinium-specific gene families. No whole-genome duplication was observed, but instead we found active (retro)transposition and gene family expansion, especially in processes important for successful symbiosis with corals. We also documented genes potentially governing sexual reproduction and cyst formation, novel promoter elements, and a microRNA system potentially regulating gene expression in both symbiont and coral. We found biochemical complementarity between genomes of S. kawagutii and the anthozoan Acropora, indicative of host-symbiont coevolution, providing a resource for studying the molecular basis and evolution of coral symbiosis. <<<
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998.
白云飞 (2022-03-31 16:24):
#paper 31st Conference on Neural Information Processing Systems (NIPS 2017), Long Beach, CA, USA. 论文地址:https://proceedings.neurips.cc/paper/2017/file/6449f44a102fde848669bdd9eb6b76fa-Paper.pdf 项目文档:https://lightgbm.readthedocs.io/en/latest/Features.html 在LightGBM提出之前,最有名的GBDT工具就是XGBoost了,它是基于预排序方法的决策树算法。这种构建决策树的算法基本思想是:首先,对所有特征都按照特征的数值进行预排序。其次,在遍历分割点的时候用O(#data)的代价找到一个特征上的最好分割点。最后,在找到一个特征的最好分割点后,将数据分裂成左右子节点。 这样的预排序算法的优点是能精确地找到分割点。但是缺点也很明显:首先,空间消耗大。这样的算法需要保存数据的特征值,还保存了特征排序的结果(例如,为了后续快速的计算分割点,保存了排序后的索引),这就需要消耗训练数据两倍的内存。其次,时间上也有较大的开销,在遍历每一个分割点的时候,都需要进行分裂增益的计算,消耗的代价大。最后,对cache优化不友好。在预排序后,特征对梯度的访问是一种随机访问,并且不同的特征访问的顺序不一样,无法对cache进行优化。同时,在每一层长树的时候,需要随机访问一个行索引到叶子索引的数组,并且不同特征访问的顺序也不一样,也会造成较大的cache miss。 为了避免上述XGBoost的缺陷,并且能够在不损害准确率的条件下加快GBDT模型的训练速度,lightGBM在传统的GBDT算法上进行了如下优化: 基于Histogram的决策树算法。 单边梯度采样 Gradient-based One-Side Sampling(GOSS):使用GOSS可以减少大量只具有小梯度的数据实例,这样在计算信息增益的时候只利用剩下的具有高梯度的数据就可以了,相比XGBoost遍历所有特征值节省了不少时间和空间上的开销。 互斥特征捆绑 Exclusive Feature Bundling(EFB):使用EFB可以将许多互斥的特征绑定为一个特征,这样达到了降维的目的。 带深度限制的Leaf-wise的叶子生长策略:大多数GBDT工具使用低效的按层生长 (level-wise) 的决策树生长策略,因为它不加区分的对待同一层的叶子,带来了很多没必要的开销。实际上很多叶子的分裂增益较低,没必要进行搜索和分裂。LightGBM使用了带有深度限制的按叶子生长 (leaf-wise) 算法。 直接支持类别特征(Categorical Feature) 支持高效并行 Cache命中率优化 其中两个加速GBDT训练的算法:Gradient-based One Side Sampling (GOSS) 和 Exclusive Feature Bundling (EFB)。在不影响精度的情况下,两个算法分别减少了GBDT训练中所需的数据量和特征量,从而加速了GBDT的训练。 GOSS: 在每一次迭代前,利用了GBDT中的样本梯度和误差的关系,对训练样本进行采样: 对误差大(梯度绝对值大)的数据保留;对误差小的数据采样一个子集,但给这个子集的数据一个权重,让这个子集可以近似到误差小的数据的全集。这么采样出来的数据,既不损失误差大的样本,又在减少训练数据的同时不改变数据的分布,从而实现了在几乎不影响精度的情况下加速了训练。 EFB:在特征维度很大的数据上,特征空间一般是稀疏的。利用这个特征,我们可以无损地降低GBDT算法中需要遍历的特征数量,更确切地说,是降低构造特征直方图(训练GBDT的主要时间消耗)需要遍历的特征数量。在稀疏的特征空间中,很多特征是exclusive的(即在同一个样本里,这一组特征里最多只有一个特征不为0)。每一组exclusive feature都可以无损地合并成一个“大特征”。构造直方图的时候,遍历一个“大特征”可以得到一组exclusive feature的直方图。这样只需要遍历这些“大特征”就可以获取到所有特征的直方图,降低了需要遍历的特征量。这里还需要解决的是Exclusive feature的分组问题,这是一个NP问题,可以转成Graph Coloring (Graph coloring - Wikipedia) 问题,并用贪心的近似方法来求解。 值得一提的是,XGBoost 也实现了 histogram 算法,比原来presorted算法快了不少。但相比LightGBM,还是慢了一些,且内存占用还是比较大。
Abstract:
Gradient Boosting Decision Tree (GBDT) is a popular machine learning algorithm, and has quite a few effective implementations such as XGBoost and pGBRT. Although many engineering optimizations have been adopted … >>>
Gradient Boosting Decision Tree (GBDT) is a popular machine learning algorithm, and has quite a few effective implementations such as XGBoost and pGBRT. Although many engineering optimizations have been adopted in these implementations, the efficiency and scalability are still unsatisfactory when the feature dimension is high and data size is large. A major reason is that for each feature, they need to scan all the data instances to estimate the information gain of all possible split points, which is very time consuming. To tackle this problem, we propose two novel techniques: Gradient-based One-Side Sampling (GOSS) and Exclusive Feature Bundling (EFB). With GOSS, we exclude a significant proportion of data instances with small gradients, and only use the rest to estimate the information gain. We prove that, since the data instances with larger gradients play a more important role in the computation of information gain, GOSS can obtain quite accurate estimation of the information gain with a much smaller data size. With EFB, we bundle mutually exclusive features (i.e., they rarely take nonzero values simultaneously), to reduce the number of features. We prove that finding the optimal bundling of exclusive features is NP-hard, but a greedy algorithm can achieve quite good approximation ratio (and thus can effectively reduce the number of features without hurting the accuracy of split point determination by much). We call our new GBDT implementation with GOSS and EFB LightGBM. Our experiments on multiple public datasets show that, LightGBM speeds up the training process of conventional GBDT by up to over 20 times while achieving almost the same accuracy. <<<
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999.
小擎子 (2022-03-31 15:29):
#paper doi: 10.1126/science.aah5043 Science, 2017, Potential role of intratumor bacteria in mediating tumor resistance to the chemotherapeutic drug gemcitabine. 先前已经有研究发现支原体感染的肿瘤细胞培养物中的核苷分解代谢酶会损害抗癌药物吉西他滨的细胞抑制活性。该文献对其机制进行进一步探索,发现人类真皮成纤维细胞(HDF) 的抗生素治疗消除了吉西他滨代谢活性,但用M. hyorhinis(猪支原体)再次感染这些相同的HDF恢复了细胞条件培养基对吉西他滨的代谢;为了确定除支原体以外的细菌是否可以对吉西他滨产生耐药性,文献将分析扩展到 27 种细菌, 27 个物种中有 13 个消除了吉西他滨对 RKO 人结肠直肠癌细胞的影响。经实验发现,CDD是细菌抗吉西他滨的关键基因,CDD的异构体会影响细菌对吉西他滨的代谢能力,CDD L会显著抗吉西他滨,CDD S只有部分代谢吉西他滨的能力。主要是属于Gammaproteobacteria的细菌具有赋予CDD L介导的吉西他滨抗性的潜力。吉西他滨通常用于治疗胰腺导管腺癌 (PDAC),文献假设肿瘤内细菌可能导致这些肿瘤的耐药性,进而对PDAC进行了采样和检测,在测试的 113 个人类 PDAC 中,86 个(76%)对细菌呈阳性,主要是 Gammaproteobacteria。
Abstract:
Growing evidence suggests that microbes can influence the efficacy of cancer therapies. By studying colon cancer models, we found that bacteria can metabolize the chemotherapeutic drug gemcitabine (2',2'-difluorodeoxycytidine) into its … >>>
Growing evidence suggests that microbes can influence the efficacy of cancer therapies. By studying colon cancer models, we found that bacteria can metabolize the chemotherapeutic drug gemcitabine (2',2'-difluorodeoxycytidine) into its inactive form, 2',2'-difluorodeoxyuridine. Metabolism was dependent on the expression of a long isoform of the bacterial enzyme cytidine deaminase (CDD), seen primarily in Gammaproteobacteria. In a colon cancer mouse model, gemcitabine resistance was induced by intratumor Gammaproteobacteria, dependent on bacterial CDD expression, and abrogated by cotreatment with the antibiotic ciprofloxacin. Gemcitabine is commonly used to treat pancreatic ductal adenocarcinoma (PDAC), and we hypothesized that intratumor bacteria might contribute to drug resistance of these tumors. Consistent with this possibility, we found that of the 113 human PDACs that were tested, 86 (76%) were positive for bacteria, mainly Gammaproteobacteria. <<<
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1000.
cellsarts (2022-03-31 14:25):
#paper  https://doi.org/10.1016/j.csbj.2021.03.019  title:Computational  prediction of secreted  proteins in  gram-negative bacteria abstract:Gram-negative bacteria harness multiple protein secretion systems and secrete a large proportion of the proteome. Proteins can be exported to periplasmic space, integrated into membrane, transported into extracellular milieu, or translocated into cytoplasm of contacting cells. It is important for accurate, genome-wide annotation of the secreted proteins and their secretion pathways. In this review, we systematically classified the secreted proteins according to the types of secretion systems in Gram- negative bacteria, summarized the known features of these proteins, and reviewed the algorithms and tools for their prediction. 题目:革兰氏阴性菌分泌蛋白的预测 摘要:革兰氏阴性菌控制多种蛋白质分泌系统,并分泌大量的蛋白质。蛋白质可以被输出到胞外周质空间,整合到细胞膜,运输到细胞外环境,或转运到接触细胞的细胞质中。其分泌蛋白的准确预测和分类对于细菌基因组的解读和细菌毒力、耐药等重要生物表型的分子机制研究都具有重要意义。全基因组注释的分泌蛋白质及其分泌途径非常的重要。本文根据革兰氏阴性菌分泌系统的类型,对革兰氏阴性菌分泌蛋白进行了系统分类,总结了这些蛋白的已知特征,并对其预测算法和工具进行了综述。在这篇综述中,总结了革兰氏阴性菌的蛋白质分泌系统和预测这些分泌蛋白的生物信息学工具。首先,计算科学家和实验生物学家之间经常存在差距。尽管开发人员证明了软件工具的高准确性,但基于非同源的效应预测器(特别是T3SEs、T4SEs和T6SEs)还很少被湿实验室研究者成功地应用于识别新的效应器。更多的热情被投入到新的算法而不是生物方面,例如新功能。大多数效应预测工具都是通用的,没有考虑特定的生物先验信息,如物种、分泌系统亚型和调节管道特异性。
Abstract:
Gram-negative bacteria harness multiple protein secretion systems and secrete a large proportion of the proteome. Proteins can be exported to periplasmic space, integrated into membrane, transported into extracellular milieu, or … >>>
Gram-negative bacteria harness multiple protein secretion systems and secrete a large proportion of the proteome. Proteins can be exported to periplasmic space, integrated into membrane, transported into extracellular milieu, or translocated into cytoplasm of contacting cells. It is important for accurate, genome-wide annotation of the secreted proteins and their secretion pathways. In this review, we systematically classified the secreted proteins according to the types of secretion systems in Gram-negative bacteria, summarized the known features of these proteins, and reviewed the algorithms and tools for their prediction. <<<
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