复杂文摘翻译第二期-(摘自Complex Digest 2016.5月文章)

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Complex Digest 复杂文摘翻译第二期-(摘自Complex Digest 2016.5月文章)


有益属性流行的动力学 (Dynamics of beneficial epidemics)

May 1, 12:50 AM From arxiv.org

by Andrew Berdahl, Christa Brelsford, Caterina De Bacco, Marion Dumas, Vanessa Ferdinand, Joshua A. Grochow, Laurent Hébert-Dufresne, Yoav Kallus, Christopher P. Kempes, Artemy Kolchinsky, Daniel B. Larremore, Eric Libby, Eleanor A. Power, Caitlin A. Stern, Brendan Tracey

(Translated by - xiaomuqiu)

Pathogens can spread epidemically through populations. Beneficial contagions, such as viruses that enhance host survival or technological innovations that improve quality of life, also have the potential to spread epidemically. How do the dynamics of beneficial biological and social epidemics differ from those of detrimental epidemics? We investigate this question using three theoretical approaches as well as an empirical analysis of concept propagation. First, in evolutionary models, we show that a beneficial horizontally-transmissible element, such as viral DNA, spreads super-exponentially through a population, substantially more quickly than a beneficial mutation. Second, in an epidemiological social network approach, we show that infections that cause increased connectivity lead to faster-than-exponential fixation in the population. Third, in a sociological model with strategic rewiring, we find that preferences for increased global infection accelerate spread and produce super-exponential fixation rates, while preferences for local assortativity halt epidemics by disconnecting the infected from the susceptible. Finally, in an investigation of the Google Ngram corpus, we find that new words and phrases spread super-exponentially, as anticipated by our models. We conclude that the dynamics of beneficial biological and social epidemics are characterized by the remarkably rapid spread of beneficial elements, which can be facilitated in biological systems by horizontal transmission and in social systems by active spreading strategies of infected individuals.

病原体可以在种群中流行性传播。有益属性的传播,例如可以增强宿主生存能力的病毒,或者可以提高生存质量的技术创新,也拥有流行性传播的潜质。那么,有益的生物或社会属性的流行与有害属性的流行,其动力学有什么不同呢?我们采用以下三个方法进行理论研究,并对概念传播进行实证分析。首先,我们在演化模型中发现,一个有益的水平传播元素(例如病毒DNA)在种群中呈指数级传播,实质上比一个有益突变的传播快得多。其次,在一个社交网络的流行过程研究中,我们发现那些能够引起连接度增加的感染会导致人群中的超指数速度的固化。第三,在一个依策略重链接(strategic rewiring)的社会学模型中,我们发现选择偏好于那些可以加速传播以及产生超指数固化率的全局感染,以及那些能够通过去链接将感染者与疑似病例隔开从而终止疾病传播的局域同配性(local assortativity)。最后,我们在对谷歌Ngram语料库的研究中发现新单词和短语会超指数传播,和我们模型的预期相符。因此,我们得出结论,即有益的生物属性和社会属性的流行动力学是由有益元素的快速传播导致的,这些元素可以通过生物系统中的横向传播,以及社会系统中被感染个体的活跃传播策略所实现。


“社会比特币”撑起民主数字世界的天空(A "Social Bitcoin" could sustain a democratic digital world)

May 3, 3:06 PM From arxiv.org

by Kaj-Kolja Kleineberg, Dirk Helbing

(Translated by -李宇峰)

A multidimensional financial system could provide benefits for individuals, companies, and states. Instead of top-down control, which is destined to eventually fail in a hyperconnected world, a bottom-up creation of value can unleash creative potential and drive innovations. Multiple currency dimensions can represent different externalities and thus enable the design of incentives and feedback mechanisms that foster the ability of complex dynamical systems to self-organize and lead to a more resilient society and sustainable economy. Modern information and communication technologies play a crucial role in this process, as Web 2.0 and online social networks promote cooperation and collaboration on unprecedented scales. Within this contribution, we discuss how one dimension of a multidimensional currency system could represent socio-digital capital (Social Bitcoins) that can be generated in a bottom-up way by individuals who perform search and navigation tasks in a future version of the digital world. The incentive to mine Social Bitcoins could sustain digital diversity, which mitigates the risk of totalitarian control by powerful monopolies of information and can create new business opportunities needed in times where a large fraction of current jobs is estimated to disappear due to computerisation.

一个多维度的金融系统能够使个人、公司和国家都能从中获益。自上而下的控制结构在这个互联世界终将被淘汰,取而代之的是一种自下而上的价值创造,它将释放创造潜能和创新驱动。多种货币维度可以代表不同的外部性,因此这就使得那些能够培育出复杂动力系统自组织能力,并导致社会稳定和经济可持续的激励和反馈机制设计更有效。现代信息与通信的技术在这之中发挥着重要作用,例如Web 2.0和社交网络正前所未有地促进着人们的合作。 在这篇文章中,我们讨论了一个未来数字化世界的可能版本,即多维货币系统中的某一个维度是如何代表了一种由大量个体通过执行搜索和导航任务从而自下而上地生成了一个社会-数字化资本(社会比特币)的。开采比特币的动机能够维持数据的多样性,从而减轻信息垄断带来的极权控制压力,并创造了一个在这个大量现职工作将会因为计算机化而消失的时代所需的商机。


幂律之外:复杂系统及其受限多样性的极限定律 (Past the power law: Complex systems and the limiting law of restricted diversity)

May 4, 2:28 PM From onlinelibrary.wiley.com

by Brian Castellani and Rajeev Rajaram

(Translated by - xiaomuqiu)

Probability distributions have proven effective at modeling diversity in complex systems. The two most common are the Gaussian normal and skewed-right. While the mechanics of the former are well-known; the latter less so, given the significant limitations of the power-law. Moving past the power-law, we demonstrate that there exists, hidden-in-full-view, a limiting law governing the diversity of complexity in skewed-right systems; which can be measured using a case-based version of Shannon entropy, resulting in a 60/40 rule. For our study, given the wide range of approaches to measuring complexity (i.e., descriptive, constructive, etc), we examined eight different systems, which varied significantly in scale and composition (from galaxies to genes). We found that skewed-right complex systems obey the law of restricted diversity; that is, when plotted for a variety of natural and human-made systems, as the diversity of complexity (primarily in terms of the number of types; but also, secondarily, in terms of the frequency of cases) a limiting law of restricted diversity emerges, constraining the majority of cases to simpler types. Even more compelling, this limiting law obeys a scale-free 60/40 rule: when measured using , 60%(or more) of the cases in these systems reside within the first 40% (or less) of the lower bound of equiprobable diversity types—with or without long-tail and whether or not the distribution fits a power-law. Furthermore, as an extension of the Pareto Principle, this lower bound accounts for only a small percentage of the total diversity; that is, while the top 20% of cases constitute a sizable percentage of the total diversity in a system, the bottom 60% are highly constrained. In short, as the central limit theorem governs the diversity of complexity in normal distributions, restricted diversity seems to govern the diversity of complexity in skewed-right distributions.

概率分布是已经被反复验证过的有效的模拟复杂系统多样性的模型。最常见的分布就是是高斯正态和右偏(skewed-right)这两种分布。由于正态分布的产生机理众所周知,而后者则在给定了幂律显著局限性的前提下比较少闻。所以,幂律之外,我们发现,在右偏系统的全景视图中隐藏了一个掌控着复杂系统多样性的极限定律。我们可以通过基于个体的香农熵来测量,并可导出60/40准则。我们在研究中使用了一系列的测度复杂性的方法(类似描述性的、构造性的方法等),测试了8种在尺度上和组成上都很不同的系统(从星系到基因)。我们发现遵循右偏分布的复杂系统遵循受限的多样性法则,也就是说,当描述自然和人工系统时,作为复杂性的多样性(主要指种类的数量,但其次也指个体出现的频率),一个受限多样性的极限定律开始涌现出来,致使大部分的个体趋于更简单的类型。更令人信服的是,这个限制法则同样遵循60/40的无尺度法则:即当测量时,60%(或者更多)的个体在系统中存在于40%(或更少)的等概率多样性类型的下限之中——无论有没有长尾或者是否遵循幂律分布。此外,作为扩展的帕累托原则, 这个下限只占总多样性的一小部分,亦即,虽然顶端20%的个体占据了系统总多样性构成的相当大一部分,底部的60%个体则是高度受限的。总之,作为决定正态分布复杂系统多样性的核心约束法则,受限多样性法则似乎制约了右偏分布的复杂系统中的多样性。


繁华路段收费 缓解城市拥堵 (Decongestion of urban areas with hotspot-pricing)

May 4, 3:07 PM From arxiv.org

by Albert Solé-Ribalta, Sergio Gómez, Alex Arenas

(Translated by -苏格兰)

The rapid growth of population in urban areas is jeopardizing the mobility and air quality worldwide. One of the most notable problems arising is that of traffic congestion which in turn affects air pollution. With the advent of technologies able to sense real-time data about cities, and its public distribution for analysis, we are in place to forecast scenarios valuable to ameliorate and control congestion. Here, we propose a local congestion pricing scheme, hotspot-pricing, that surcharges vehicles traversing congested junctions. The proposed tax is computed from the estimation of the evolution of congestion at local level, and the expected response of users to the tax (elasticity). Results on cities' road networks, considering real-traffic data, show that the proposed hotspot-pricing scheme would be more effective than current mechanisms to decongest urban areas, and paves the way towards sustainable congestion in urban areas.



非神经生物体中的习惯性学习:来自黏菌的证据 (Habituation in non-neural organisms: evidence from slime moulds)

May 4, 8:27 PM From rspb.royalsocietypublishing.org

by Romain P. Boisseau, David Vogel, Audrey Dussutour

(Translated by - 高德华,edited by 傅渥成)

Learning, defined as a change in behaviour evoked by experience, has hitherto been investigated almost exclusively in multicellular neural organisms. Evidence for learning in non-neural multicellular organisms is scant, and only a few unequivocal reports of learning have been described in single-celled organisms. Here we demonstrate habituation, an unmistakable form of learning, in the non-neural organism Physarum polycephalum. In our experiment, using chemotaxis as the behavioural output and quinine or caffeine as the stimulus, we showed that P. polycephalum learnt to ignore quinine or caffeine when the stimuli were repeated, but responded again when the stimulus was withheld for a certain time. Our results meet the principle criteria that have been used to demonstrate habituation: responsiveness decline and spontaneous recovery. To distinguish habituation from sensory adaptation or motor fatigue, we also show stimulus specificity. Our results point to the diversity of organisms lacking neurons, which likely display a hitherto unrecognized capacity for learning, and suggest that slime moulds may be an ideal model system in which to investigate fundamental mechanisms underlying learning processes. Besides, documenting learning in non-neural organisms such as slime moulds is centrally important to a comprehensive, phylogenetic understanding of when and where in the tree of life the earliest manifestations of learning evolved.

学习,作为由经验所诱发的一种行为上的变化,迄今已经在几乎所有的多细胞神经生物中得到研究。但是,有关多细胞非神经生物体学习的证据仍存在不足,而只有少数确切的报告对单细胞生物体中的学习作了描述。本文中,我们展示了多头绒泡菌(Physarum polycephalum)这一非神经生物体中的习惯性行为,并将其看作是一种毋容置疑的学习形式。在我们的实验中,通过将趋化性(chemotaxis)作为行为的输出并且将奎宁(quinine)或咖啡因(caffeine)作为刺激物,我们发现:当刺激重复出现时,多头绒泡菌学会了忽略奎宁或咖啡因的作用。但是当这些刺激被抑制特定的时间之后,它们又能够重新作出反应。我们的研究结果符合反应性下降(responsiveness decline)和自然恢复(spontaneous recovery)等被运用于证实适应性的原则标准。为了将习惯性学习与感觉适应或运动性疲劳相区分,我们也对刺激的特异性(stimulus specificity)进行了研究。相关的结果显示:缺乏神经元的生物体的多样性,可能表现出一种至今仍未被识别的学习能力;并且认为,黏菌可能是用来研究学习过程的基本机制的理想模型系统。此外,对诸如黏菌之类的非神经生物体学习机制的揭示,对于全面、系统地理解生命之树(tree of life)中的学习的早期表现形式在何时何地发生的演化也至关重要。


Remark by 傅渥成

通常,adaptation 是”适应“,而 Habituation 更强调”习惯性学习“,属于”学习行为“中的一类。学习行为包括习惯性学习、模仿学习、印随、联想学习、推理学习等。 Wiki: Habituation is a form of learning in which an organism decreases or ceases to respond to a stimulus after repeated presentations. Habituation 和 adaptation 的一个主要区别在于”repeated presentations“,即重复性(文中还提到了特异性)。举个例子就可以明白适应性跟习惯性学习之间的区别,当眼睛进入到黑暗的房间,瞳孔会缩小,这个就是适应性行为,人不用反复刺激几次才学会缩小瞳孔,而药物成瘾等则是这种”习惯性学习“。其实这个摘要里面也提到了”To distinguish habituation from sensory adaptation or motor fatigue,“强调这二者之间是有区别的。

用热点定价策略来缓解城市拥堵问题(Decongestion of urban areas with hotspot-pricing)

May 4, 3:07 PM From arxiv.org

by Albert Solé-Ribalta, Sergio Gómez, Alex Arenas

(Translated by - HSAH_CHOI)

The rapid growth of population in urban areas is jeopardizing the mobility and air quality worldwide. One of the most notable problems arising is that of traffic congestion which in turn affects air pollution. With the advent of technologies able to sense real-time data about cities, and its public distribution for analysis, we are in place to forecast scenarios valuable to ameliorate and control congestion. Here, we propose a local congestion pricing scheme, hotspot-pricing, that surcharges vehicles traversing congested junctions. The proposed tax is computed from the estimation of the evolution of congestion at local level, and the expected response of users to the tax (elasticity). Results on cities' road networks, considering real-traffic data, show that the proposed hotspot-pricing scheme would be more effective than current mechanisms to decongest urban areas, and paves the way towards sustainable congestion in urban areas.

城市人口的快速增长正危及全球范围内的移动出行和空气质量,由此产生的最显著问题之一是交通拥堵又转而加剧了空气污染。随着对城市数据的实时检测技术的出现,我们可以通过分析这些公开的数据预测可能发生的情景,从而帮助改善和控制拥堵问题。在文章中,我们提出了一种针对局部拥堵的定价方案,热点定价,即对穿越拥堵路口的车辆征收附加费。该附加费是根据用户局部区域的拥堵演化以及其对税务的弹性预期估计出来的。结合城市的交通路网以及实际交通数据得到以下结果,我们的热点定价方案相较现有的机制能更好地缓解城市拥堵问题,并给出了一个缓解城市拥堵的可持续调控方向(paves the way towards sustainable congestion in urban areas)。


众包解决城里的罗宾汉效应 (Crowdsourcing the Robin Hood effect in cities)

May 5, 7:11 PM From arxiv.org

by Thomas Louail, Maxime Lenormand, Juan Murillo Arias, José J. Ramasco

(Translated by - F7,edited by 傅渥成)

Socioeconomic inequalities in cities are embedded in space and result in neighborhood effects, whose harmful consequences have proved very hard to counterbalance efficiently by planning policies alone. Considering redistribution of money flows as a first step toward improved spatial equity, we study a bottom-up approach that would rely on a slight evolution of shopping mobility practices. Building on a database of anonymized credit card transactions in Madrid and Barcelona, we quantify the mobility effort required to reach a reference situation where commercial income is evenly shared among neighborhoods. The redirections of shopping trips preserve key properties of human mobility, including travel distances. Surprisingly, for both cities only a small fraction (∼5%) of trips need to be altered to reach equity situations, improving even other sustainability indicators. The method could be implemented in mobile applications that would assist individuals in reshaping their shopping practices, to promote the spatial redistribution of opportunities in the city.

城市中的社会经济学的不平等内嵌于地理空间之中,并将导致邻里效应(neighborhood effects),其弊端已经被证明单用计划性政策是很难去有效平衡解决的。考虑到资金流的再分配可以作为改善不平等的的第一步,我们研究提出了一个自下而上的解决方法,该方法需要一些购物流动性上的改变。通过建立马德里和巴塞罗那的匿名信用卡交易数据库,我们量化了达到一个在邻里之间商业收入比较均等的参考水平所需要的移动耗费量。购物出行的重新定向保存了人类移动的一些关键性质,包括移动的距离。令人惊奇的是,这两个城市都只需要非常少(大约5%)的移动改变就能达到较为平等的水平,同时甚至也改进了其他的可持续性指标。该方法可以在移动应用程序中实现,并且将有助于个人重塑购物习惯,以促进城市内的机会在空间上的重新分布。


Remark by 傅渥成 邻里效应(http://wiki.mbalib.com/zh-cn/%E9%82%BB%E9%87%8C%E6%95%88%E5%BA%94 ) 另”均衡“会让人想到 equilibrium,equity 最好翻译成”平等“。

综合复杂网络和数据挖掘:原因和方法 (Combining complex networks and data mining: why and how)

May 6, 3:10 AM From arxiv.org

by M. Zanin, D. Papo, P. A. Sousa, E. Menasalvas, A. Nicchi, E. Kubik, S. Boccaletti

(Translated by 蔡嘉文, edited by 傅渥成)

The increasing power of computer technology does not dispense with the need to extract meaningful information out of data sets of ever growing size, and indeed typically exacerbates the complexity of this task. To tackle this general problem, two methods have emerged, at chronologically different times, that are now commonly used in the scientific community: data mining and complex network theory. Not only do complex network analysis and data mining share the same general goal, that of extracting information from complex systems to ultimately create a new compact quantifiable representation, but they also often address similar problems too. In the face of that, a surprisingly low number of researchers turn out to resort to both methodologies. One may then be tempted to conclude that these two fields are either largely redundant or totally antithetic. The starting point of this review is that this state of affairs should be put down to contingent rather than conceptual differences, and that these two fields can in fact advantageously be used in a synergistic manner. An overview of both fields is first provided, some fundamental concepts of which are illustrated. A variety of contexts in which complex network theory and data mining have be used in a synergistic manner are then presented. Contexts in which the appropriate integration of complex networks metrics can lead to improved classification rates with respect to classical data mining algorithms and, conversely, contexts in which data mining can be used to tackle important issues in complex network theory applications are illustrated. Finally, ways to achieve a tighter integration between complex networks and data mining, and open lines of research are discussed.



研究多部门(Multi-sector)协调及自组织的一个演化博弈理论方法 (An Evolutionary Game Theoretic Approach to Multi-Sector Coordination and Self-Organization)

May 6, 12:16 AM From www.mdpi.com

by Fernando P. Santos, Sara Encarnação, Francisco C. Santos, Juval Portugali and Jorge M. Pacheco

(Translated by -麟凤兰草-ATC-ABM-Canton)

Coordination games provide ubiquitous interaction paradigms to frame human behavioral features, such as information transmission, conventions and languages as well as socio-economic processes and institutions. By using a dynamical approach, such as Evolutionary Game Theory (EGT), one is able to follow, in detail, the self-organization process by which a population of individuals coordinates into a given behavior. Real socio-economic scenarios, however, often involve the interaction between multiple co-evolving sectors, with specific options of their own, that call for generalized and more sophisticated mathematical frameworks. In this paper, we explore a general EGT approach to deal with coordination dynamics in which individuals from multiple sectors interact. Starting from a two-sector, consumer/producer scenario, we investigate the effects of including a third co-evolving sector that we call public. We explore the changes in the self-organization process of all sectors, given the feedback that this new sector imparts on the other two.

协调博弈为我们研究人类行为特征,例如信息的交换传输、习俗和语言、社会经济过程和各种社会机构的形成,提供了一种通用的相互作用范式。而通过诸如演化博弈这样的动态方法,我们能够从细节上了解大量个体通过相互协作而形成一种特定行为的自组织过程。 然而,在真实的社会经济情形中,众多具有自己独特观念的部门(Multi-sector)会共同演化、共同发展,这就需要构建更加普适和精妙的数学模型。在本文中,笔者尝试使用一种一般的演化博弈模型来处理协调动力学,其中个体来自多个部门并可以相互作用。从两个部类(消费者/生产者)开始,我们研究公众部门加入之后的影响,公众作为第三个部门也一同演进。在给定这个新加入部门对另外两个部门的影响的反馈之后,我们探究了三个部门自组织进程中的所有变化。



作为一种气候信号关键滤波器的河流网络自组织过程 (Self-organization of river channels as a critical filter on climate signals)

May 6, 4:09 PM From science.sciencemag.org

by Colin B. Phillips1,*, Douglas J. Jerolmack

(Translated by Cicely)

Large floods should seemingly influence the depth and width of rivers. Phillips and Jerolmack, however, suggest that the self-organization of bedrock river channels blunts the impact of extreme rainfall events. River channel geometries from a wide range of course-grained rivers across the United States show that larger floods have very limited additional impact on channel geometry. River channel sculpting does increase as flood size increases, but the effect is most pronounced for moderate floods. This relationship may explain the long-term stability of rivers across shifts in climate.



大数据如何造成虚假信心 (How Big Data Creates False Confidence)

May 6, 10:20 PM From nautil.us

by Jesse Dunietz

(Translated by -阎赫)

Although no one can quite agree how to define it, the general idea is to find datasets so enormous that they can reveal patterns invisible to conventional inquiry. The data are often generated by millions of real-world user actions, such as tweets or credit-card purchases, and they can take thousands of computers to collect, store, and analyze. To many companies and researchers, though, the investment is worth it because the patterns can unlock information about anything from genetic disorders to tomorrow’s stock prices. But there’s a problem: It’s tempting to think that with such an incredible volume of data behind them, studies relying on big data couldn’t be wrong. But the bigness of the data can imbue the results with a false sense of certainty. Many of them are probably bogus—and the reasons why should give us pause about any research that blindly trusts big data.

虽然对如何定义大数据,没有达成十分一致意见,但是,其总体思路是找到足够庞大的数据集,以揭示常规调查不可见的模式。这些数据常常由数以百万计现实生活中的用户行为所产生,如发微博或信用卡购物等,人们需要动用数以千计的计算机收集,储存和分析这些数据。虽然如此,对于许多公司和研究人员而言,这些投资还是值得的,因为这个模式能够破解从家族遗传病到明天的股市价格相关信息的任何事情。但有个问题: 它使人自然地认为,由这些研究背后惊人的数据量,所以这些依托于如此大数据的研究是不会有错误的。但巨大的数据可能会以虚假的确定感影响研究结果。许多研究结果可能都是虚假的 – 而这也是为什么使我们不再盲目相信大数据研究的理由。


人工智能可以帮我们找到下一个优良的新材料吗? (Can artificial intelligence create the next wonder material?)

May 7, 4:14 PM From www.nature.com

by Nicola Nosengo

(Translated by - 彭程,edited by 傅渥成)

Instead of continuing to develop new materials the old-fashioned way — stumbling across them by luck, then painstakingly measuring their properties in the laboratory — Marzari and like-minded researchers are using computer modelling and machine-learning techniques to generate libraries of candidate materials by the tens of thousands. Even data from failed experiments can provide useful input1. Many of these candidates are completely hypothetical, but engineers are already beginning to shortlist those that are worth synthesizing and testing for specific applications by searching through their predicted properties — for example, how well they will work as a conductor or an insulator, whether they will act as a magnet, and how much heat and pressure they can withstand.

与传统的开发新材料方法不同,Marzari 和志同道合的研究者们不再凭借偶然发现新材料的运气在实验室精心测试材料性能,而是利用计算机建模和机器学习技术通过数以万计次的训练生成候选材料库 。即使来自失败实验的数据也能够提供有效的输入。虽然很多候选材料都是完全假设的,但是工程师们已经开始通过搜索那些预测出来的性能(例如材料作为导体或者绝缘体时的工作效果、能否作为磁体、以及耐高温或高压的性质等),将那些值得合成和测试的具有特定功能的材料列入候选名单。


Remark by 傅渥成


从成功度中理清技能表现的影响 (Untangling performance from success)

May 8, 9:10 AM From epjdatascience.springeropen.com

by Burcu Yucesoy, Albert-László Barabási

(Translated by - jeffersonchou)

Fame, popularity and celebrity status, frequently used tokens of success, are often loosely related to, or even divorced from professional performance. This dichotomy is partly rooted in the difficulty to distinguish performance, an individual measure that captures the actions of a performer, from success, a collective measure that captures a community’s reactions to these actions. Yet, finding the relationship between the two measures is essential for all areas that aim to objectively reward excellence, from science to business. Here we quantify the relationship between performance and success by focusing on tennis, an individual sport where the two quantities can be independently measured. We show that a predictive model, relying only on a tennis player’s performance in tournaments, can accurately predict an athlete’s popularity, both during a player’s active years and after retirement. Hence the model establishes a direct link between performance and momentary popularity. The agreement between the performance-driven and observed popularity suggests that in most areas of human achievement exceptional visibility may be rooted in detectable performance measures.



网络中社区数目的估算 (Estimating the number of communities in a network)

May 11, 6:18 PM From arxiv.org

by M.E.J.Newman, Gesine Reinert

(Translated by - 张皓 人机环境 南京,edited by 傅渥成)

Community detection, the division of a network into dense subnetworks with only sparse connections between them, has been a topic of vigorous study in recent years. However, while there exist a range of powerful and flexible methods for dividing a network into a specified number of communities, it is an open question how to determine exactly how many communities one should use. Here we describe a mathematically principled approach for finding the number of communities in a network using a maximum-likelihood method. We demonstrate this approach on a range of real-world examples with known community structure, finding that it is able to determine the number of communities correctly in every case.



remark by 傅渥成

在生态学里面用「群落」,在复杂网络上,Community detection 通常还是用「社区识别」。

合作还是不合作:为什么行为机制很重要 (To Cooperate or Not to Cooperate: Why Behavioural Mechanisms Matter)

May 12, 3:15 PM From journals.plos.org

by Arthur Bernard, Jean-Baptiste André, Nicolas Bredeche

(Translated by - boboyang,edited by 傅渥成)

Mutualistic behaviours wherein several individuals act together for a common benefit, such as a collective hunt, are often deemed of minor interest by theoreticians in evolutionary biology. These behaviours benefit all the individuals involved, and therefore, so the argument goes, their evolution is straightforward. However, mutualistic behaviours do pose a specific kind of evolutionary problem: they require the coordination of several partners. Indeed, a single individual expressing a preference for cooperation cannot benefit if others wish to remain solitary. Here we use simulations in evolutionary robotics to study the consequences of this problem. We show that it constitutes a far more serious obstacle for the evolution of cooperation than was previously thought on the basis of game theoretical analyses. We find that the transition from solitary to cooperative strategies is very unlikely, and we also observe that successful cooperation requires the evolution of a specific and rather complex behaviour, necessary for individuals to coordinate with each other. This reveals the critical role of the practical mechanics of behaviour in evolution.



开源数据揭示网络和街头抗议活动之间的关联 (Open source data reveals connection between online and on-street protest activity)

May 12, 6:56 PM From epjdatascience.springeropen.com

by Hong Qi, Pedro Manrique, Daniela Johnson, Elvira Restrepo and Neil F Johnson

(Translated by - F7,edited by 唐璐)

There is enormous interest in inferring features of human behavior in the real world from potential digital footprints created online - particularly at the collective level, where the sheer volume of online activity may indicate some changing mood within the population regarding a particular topic. Civil unrest is a prime example, involving the spontaneous appearance of large crowds of otherwise unrelated people on the street on a certain day. While indicators of brewing protests might be gleaned from individual online communications or account content (e.g. Twitter, Facebook) societal concerns regarding privacy can make such probing a politically delicate issue. Here we show that instead, a simple low-level indicator of civil unrest can be obtained from online data at the aggregate level through Google Trends or similar tools. Our study covers countries across Latin America during 2011-2014 in which diverse civil unrest events took place. In each case, we find that the combination of the volume and momentum of searches from Google Trends surrounding pairs of simple keywords, tailored for the specific cultural setting, provide good indicators of periods of civil unrest. This proof-of-concept study motivates the search for more geographically specific indicators based on geo-located searches at the urban level.

根据上网记录推断人类的行为特征——尤其是在群体层面上——引起了很多兴趣,在线活动的突然转向的规模可能表明群体对特定话题的情绪发生了变化。民众动乱就是一个典型的例子,大批互不相识的人同时聚集到街上。而抗议活动正在酝酿的苗头可以从个人在线聊天的内容或者账户内容(比如Twitter, Facebook)获取,不过对个人隐私的社会关切会让这种做法充满争议。在此,我们提出了一个替代办法,利用Google Trend或类似工具的总体在线数据就可以获得一个简单的民众骚乱的低层次预测指标。我们研究了拉美地区2011-2014年间发生了各种民众骚乱的地区。在每一个案例里,我们发现Google Trend上围绕几个简单关键词的搜索数量和趋势的组合,在排除特定的文化设定后,为民众骚乱的时期提供了很好的指标。这一实证结果启发我们基于搜索的城市级别地理位置寻找更具地理针对性的指标。


复杂性实验室 (Complexity Labs)

May 12, 9:28 PM From complexitylabs.io

by Complexity Labs

(Translated by -庞博,edited by 唐璐)

Complexity Labs is an online resource dedicated to the area of complex systems providing a wide variety of users with information, research, learning and media content relating to this exciting new area. Our mission statement is to assist in the development of a coherent, robust and accessible framework for modelling, designing and managing complex systems.

复杂性实验室(Complexity Labs:http://complexitylabs.io/) 是一个关于复杂系统的在线资源,它为多个领域的用户提供了有关这个令人兴奋的新领域的讯息、研究进展、学习材料等内容。该网站的使命是为复杂系统的建模、设计及管理开发出一个一致、稳健且易于使用的框架。


肠道微生物内部合作的演化 (The evolution of cooperation within the gut microbiota)

May 13, 4:17 PM From www.nature.com

by Seth Rakoff-Nahoum, Kevin R. Foster & Laurie E. Comstock

(Translated by 秦德盛)

Little is known about cooperative behaviour among the gut microbiota; here, limited cooperation is demonstrated for Bacteroides thetaiotaomicron, but Bacteroides ovatus is found to extracellularly digest a polysaccharide not for its own use, but to cooperatively feed other species such as Bacteroides vulgatus from which it receives return benefits.

人们对肠道微生物之间的合作行为所知甚少。本文中,多型拟杆菌(Bacteroides thetaiotaomicron)有限的合作行为被证实,研究人员们发现卵型拟杆菌(Bacteroides ovatus)消化胞外多糖不是为了自己使用,而是为了给其他种群——例如普通拟杆菌(Bacteroides vulgatus)——提供食物,并从这些种群那里获取回报。


具有一个对称轴的四体中心构型 (Central configurations of four bodies with an axis of symmetry)

May 18, 4:14 PM From link.springer.com

by Bálint Érdi, Zalán Czirják

(Translated by -阎赫,edited by 傅渥成)

A complete solution is given for a symmetric case of the problem of the planar central configurations of four bodies, when two bodies are on an axis of symmetry, and the other two bodies have equal masses and are situated symmetrically with respect to the axis of symmetry. The positions of the bodies on the axis of symmetry are described by angle coordinates with respect to the outside bodies. The solution is such, that giving the angle coordinates, the masses for which the given configuration is a central configuration, can be computed from simple analytical expressions of the angles. The central configurations can be described as one-parameter families, and these are discussed in detail in one convex and two concave cases. The derived formulae represent exact analytical solutions of the four-body problem.

当两个质点在一个对称轴上,而其它两个质点具有相等的质量、并相对于对称轴对称分布时,就会赋予四体的平面中心构型问题的在对称情况下的一个完全解。 位于对称轴上的质点用其相对于外侧质点的夹角为坐标进行描述。 本问题的解是这样的:给定角坐标,在假定中心构型的情况下,质量的解可以通过角度的简单解析表达式进行计算。中心构型可以描述为单参数族,且其性质可以被详细地讨论,它可能表现为一种凸的情况和两种凹的情况。推导的公式代表四体问题的精确解析解。


remark by 傅渥成

body 是“N-体问题”中的“体”,但是用作“二体/三体/四体问题”时非常顺,说“两个体”读起来总觉得奇怪,这里意译成“质点”似乎更好一点(或者可以翻译为「天体」)。 这里的 one convex and two concave cases 更可能是作为「凸多边形」的意思,而不是「凸面」的意思。

进化中的稳式非平衡:大小基本固定的种群在进化中的无穷动力学 (Evolutionarily stable disequilibrium: endless dynamics of evolution in a stationary population)

May 19, 9:19 PM From rspb.royalsocietypublishing.org

by Nobuto Takeuchi, Kunihiko Kaneko, Paulien Hogeweg

(Translated by 孟庆业,edited by 傅渥成)

Evolution is often conceived as changes in the properties of a population over generations. Does this notion exhaust the possible dynamics of evolution? Life is hierarchically organized, and evolution can operate at multiple levels with conflicting tendencies. Using a minimal model of such conflicting multilevel evolution, we demonstrate the possibility of a novel mode of evolution that challenges the above notion: individuals ceaselessly modify their genetically inherited phenotype and fitness along their lines of descent, without involving apparent changes in the properties of the population. The model assumes a population of primitive cells (protocells, for short), each containing a population of replicating catalytic molecules. Protocells are selected towards maximizing the catalytic activity of internal molecules, whereas molecules tend to evolve towards minimizing it in order to maximize their relative fitness within a protocell. These conflicting evolutionary tendencies at different levels and genetic drift drive the lineages of protocells to oscillate endlessly between high and low intracellular catalytic activity, i.e. high and low fitness, along their lines of descent. This oscillation, however, occurs independently in different lineages, so that the population as a whole appears stationary. Therefore, ongoing evolution can be hidden behind an apparently stationary population owing to conflicting multilevel evolution.

通常认为进化是种群在一代代繁衍中所产生的性质改变。这种观念涵盖了所有可能的进化动力学了吗?生命是层次化地组织起来的,而且进化有可能在相互之间存在冲突性倾向的多个层次上发挥其影响。我们用一个最简单的层次间有冲突的多层次进化模型,展示了可能存在一种新的不同于上述观念的的进化模式。在通常的进化观念中,个体会在一代代繁衍中不停的改变它们由基因遗传的表现型和适应度,但并不会使种群的性质产生明显变化。这个模型基于一群原始细胞(简写为 protocells),每个原始细胞都包含了很多具有催化能力的可复制分子。原始细胞因自然选择趋向于使内部分子的催化活性最强,而内部分子为了最大化在原始细胞内的相对适应度,趋向于使自己的催化活性最差。这种在不同层次上有所冲突的进化趋势和遗传漂变会使原始细胞后代中的内部分子所具有的催化活性(亦即适应度)在一代代中高高低低来回震荡。然而,这种震荡在不同后代中都会发生,以至于种群大小基本保持不变。因此,表面上大小保持不变的种群会因为相互冲突的多层次进化模式而不断进化。


向自然学习如何让无人机着陆 (Learning from nature how to land aerial robots)

May 19, 9:27 PM From science.sciencemag.org

by Mirko Kovac

(Translated by 阿勺,edited by 唐璐)

One of the main challenges for aerial robots is the high-energy consumption of powered flight, which limits flight times to typically only tens of minutes for systems below 2 kg in weight (1). This limitation greatly reduces their utility for sensing and inspection tasks, where longer hovering times would be beneficial. Perching onto structures can save energy and maintain a high, stable observation or resting position, but it requires a coordination of flight dynamics and some means of attaching to the structure. Birds and insects have mastered the ability to perch successfully and have inspired perching robots at various sizes. On page 978 of this issue, Graule et al. (2) describe a perching robotic insect that represents the smallest flying robot platform that can autonomously attach to surfaces. At a mass of only 100 mg, it combines advanced flight control with adaptive mechanical dampers and electro-adhesion to perch on a variety of natural and artificial structures.



建造功能性城市 (Building functional cities)

May 19, 11:36 PM From science.sciencemag.org

by J. Vernon Henderson, Anthony J. Venables, Tanner Regan, Ilia Samsonov

(Translated by - 刘清晴, edited by 傅渥成)

The literature views many African cities as dysfunctional with a hodgepodge of land uses and poor “connectivity.” One driver of inefficient land uses is construction decisions for highly durable buildings made under weak institutions. In a novel approach, we model the dynamics of urban land use with both formal and slum dwellings and ongoing urban redevelopment to higher building heights in the formal sector as a city grows. We analyze the evolution of Nairobi using a unique high–spatial resolution data set. The analysis suggests insufficient building volume through most of the city and large slum areas with low housing volumes near the center, where corrupted institutions deter conversion to formal sector usage.

许多文献资料都指出:非洲的许多城市都是功能失调的,它们在土地利用方面一团糟,而且在“连接性(connectivity)”方面也很差劲。导致土地低效利用的一个因素是由于坚固耐用的住宅的施工是在脆弱的体制下决策的。我们使用一种全新的手段建立了城市生长模型,用正规社区(formal sector)中较高建筑的高度来描述既有正规民居又有贫民窟的城市土地使用的动力学特征,以及城市持续不断的再发展情况。我们用一个独特的具有较高空间分辨率的数据库分析了Nairobi(译注:肯尼亚首都)的演化过程。分析结果表明,该城市的大部分地区建筑容积(housing volume)不足,同时市中心附近存在大片的贫民窟,住宅容积低。混乱的城市规划阻碍了这些区域向正规社区的转变。



Remark by 傅渥成:

(1)weak/corrupted institutions 表示脆弱的、腐败的国家机构(体制)。 (2)“正规社区”的翻译我也不确定是否是最好的, 在国内的一些论文中,Informal_sector (https://en.wikipedia.org/wiki/Informal_sector) 被译作“非正规部门”(城中村)http://www.mur.cn/nsfiles/f99d1fcf6a0fff0a8243fb6d1805c0ac09-03-06.pdf 但我觉得在本文这里 sector 翻译成空间意义的“区域”或者“社区”其实比”部门“更好些,如果用正规经济跟灰色地带经济作比较的时候,用”部门“可能更好一些。

行为经济学有潜力造福病人、保险公司和雇主 (Behavioral Economics Holds Potential To Deliver Better Results For Patients, Insurers, And Employers)

May 20, 4:15 PM From content.healthaffairs.org

by George Loewenstein, David A. Asch and Kevin G. Volpp

(Translated by -Frank,edited by 唐璐)

Many programs being implemented by US employers, insurers, and health care providers use incentives to encourage patients to take better care of themselves. We critically review a range of these efforts and show that many programs, although well-meaning, are unlikely to have much impact because they require information, expertise, and self-control that few patients possess. As a result, benefits are likely to accrue disproportionately to patients who already are taking adequate care of their health. We show how these programs could be made more effective through the use of insights from behavioral economics. For example, incentive programs that offer patients small and frequent payments for behavior that would benefit the patients, such as medication adherence, can be more effective than programs with incentives that are far less visible because they are folded into a paycheck or used to reduce a monthly premium. Deploying more-nuanced insights from behavioral economics can lead to policies with the potential to increase patient engagement and deliver dividends for patients and favorable cost-effectiveness ratios for insurers, employers, and other relevant commercial entities.



对基于Twitter的政治集体运动研究中的偏见的一个有偏的回顾 A Biased Review of Biases in Twitter Studies on Political Collective Action

May 20, 6:21 PM From arxiv.org

by Peter Cihon, Taha Yasseri

(Translated by Cancy,edited by 傅渥成)

In recent years researchers have gravitated to social media platforms, especially Twitter, as fertile ground for empirical analysis of social phenomena. Social media provides researchers access to trace data of interactions and discourse that once went unrecorded in the offline world. Researchers have sought to use these data to explain social phenomena both particular to social media and applicable to the broader social world. This paper offers a minireview of Twitter-based research on political crowd behavior. This literature offers insight into particular social phenomena on Twitter, but often fails to use standardized methods that permit interpretation beyond individual studies. Moreover, the literature fails to ground methodologies and results in social or political theory, divorcing empirical research from the theory needed to interpret it. Rather, papers focus primarily on methodological innovations for social media analyses, but these too often fail to sufficiently demonstrate the validity of such methodologies. This minireview considers a small number of selected papers; we analyze their (often lack of) theoretical approaches, review their methodological innovations, and offer suggestions as to the relevance of their results for political scientists and sociologists.

近年来,研究人员被社交媒体平台所吸引,尤其是作为社会现象实证分析沃土的 Twitter。除非离线没有记录,社交媒体源源不断的为研究人员提供了交互和话语的访问跟踪数据。研究人员试图使用这些数据来解释特定社交媒体和适用于更广泛的社会的社会现象。本文提供了一个基于 Twitter 研究的政治群体行为简述。这些已有的文献常常提供了在 Twitter 上的特定社会现象的洞察,然而经常无法使用标准化的方法去解释超出个体的研究。此外,现有的文献通常未能提出基础性的方法用于解释社会或政治理论,从而割裂了实证研究与理论。相反,现有的文献主要侧重于社交媒体分析方法论的创新,但这些往往不能充分证明这些方法的有效性。这个简述选取了较少的文章进行分析,我们分析了这些文章中提到的理论方法(通常这些文章是缺乏理论方法的),回顾他们在方法上的创新,并且为政治学家与社会学家提供与研究结果相关的建议。


走向智慧、可持续、健康城市的基本原则 (Meta-principles for developing smart, sustainable, and healthy cities)

May 20, 9:34 PM From science.sciencemag.org

by Anu Ramaswami, Armistead G. Russell, Patricia J. Culligan, Karnamadakala Rahul Sharma, Emani Kumar

(Translated by 陈立群,edited by 唐璐)

Policy directives in several nations are focusing on the development of smart cities, linking innovations in the data sciences with the goal of advancing human well-being and sustainability on a highly urbanized planet. To achieve this goal, smart initiatives must move beyond city-level data to a higher-order understanding of cities as transboundary, multisectoral, multiscalar, social-ecological-infrastructural systems with diverse actors, priorities, and solutions. We identify five key dimensions of cities and present eight principles to focus attention on the systems-level decisions that society faces to transition toward a smart, sustainable, and healthy urban future.



开放创新2.0的十二条准则 (Twelve principles for open innovation 2.0)

May 21, 4:07 PM From www.nature.com

by Martin Curley

(Translated by -胡鹏博,edited by 唐璐)

A new mode of innovation is emerging that blurs the lines between universities, industry, governments and communities. It exploits disruptive technologies — such as cloud computing, the Internet of Things and big data — to solve societal challenges sustainably and profitably, and more quickly and ably than before. It is called open innovation 2.0. The promise is sustainable, intelligent living: innovations drive economic growth and improve quality of life while reducing environmental impact and resource use. For example, a dynamic congestion-charging system can adjust traffic flow and offer incentives to use park-and-ride schemes, guided by real-time traffic levels and air quality. Car-to-car communication could manage traffic to minimize transit times and emissions and eliminate road deaths from collisions. Smart electricity grids lower costs, integrate renewable energies and balance loads. Health-care monitoring enables early interventions, improving life quality and reducing care costs.

一种新出现的创新模式模糊了大学、工业、政府和公众的界限。它利用了一些颠覆性技术,例如云计算,物联网和大数据,来持续有效的解决一些社会问题,而且要比之前更加快速和精妙。这个创新模式被称为开放创新2.0(open innovation 2.0)。目标是一个可持续的、智能的生活:创新驱动的经济增长和生活质量的改善,同时减少对环境的影响和资源的消耗。例如,动态堵车收费系统能够调整交通流量并且会激励人们更多的去使用停车换乘方案,而这个方案是由实时交通状况和空气质量引导的。车间通信可以调控交通,将换乘时间和尾气排放降到最低,并且避免由碰撞引起的道路交通死亡事故。智能电网可以降低耗费、整合可再生能源和平衡负载。卫生保健监控可以实现早期介入,从而改善生活质量和减少保健费用。


城市决定未来 (Cities are the Future)

May 22, 5:38 AM From science.sciencemag.org

by Nicholas S. Wigginton, Julia Fahrenkamp-Uppenbrink, Brad Wible, David Malakoff

(Translated by -陈开壮,edited by 唐璐)

Earth has become an urban planet. More than half of the world's people now live in cities, and the proportion is growing. And urban areas are sprawling even faster than they are adding people, swallowing up both farmland and wildlands. The implications are sobering. The land area needed to provide city residents with food, energy, and materials is expanding; this ecological footprint is often 200 times greater than the area of a city itself. The resulting carbon emissions, added to those from cities themselves, mean that urbanization is now the main driver of climate change.

地球已成为一颗城市星球。如今有一半的世界人口生活在城市中,这个比例还在不断增长。城区面积的扩张甚至比新增人口还来得迅猛,吞噬农地和荒地。 这其中的启示发人深省。用于为城市居民提供食物、能量、和原材料所需的土地面积在不断扩张,这个生态区域常常比城区本身的面积大200倍。由此导致碳排放,再加上城市本身的碳排放,意味着城市化现在成了气候变化的主要推动力。


空荡的大脑 (The empty brain)

May 23, 9:21 PM From aeon.co

by Pam Weintraub

(Translated by -Frank)

Your brain does not process information, retrieve knowledge or store memories. In short: your brain is not a computer.



物质,能量...知识,如何利用物理世界这些魔鬼般的力量(Matter, energy… knowledge: How to harness physics’ demonic power)

May 23, 11:29 PM From www.newscientist.com

by Stephen Battersby

(Translated by -Maggie)

Running a brain-twisting thought experiment for real shows that information is a physical thing – so can we now harness the most elusive entity in the cosmos?



最大聚集活动中的人类社会和空间聚类研究 (Social and Spatial Clustering of People at Humanity's Largest Gathering)

May 24, 7:53 PM From arxiv.org

by Ian Barnett, Tarun Khanna, Jukka-Pekka Onnela

(Translated by -辛,edited by 傅渥成)

Macroscopic behavior of scientific and societal systems results from the aggregation of microscopic behaviors of their constituent elements, but connecting the macroscopic with the microscopic in human behavior has traditionally been difficult. Manifestations of homophily, the notion that individuals tend to interact with others who resemble them, have been observed in many small and intermediate size settings. However, whether this behavior translates to truly macroscopic levels, and what its consequences may be, remains unknown. Here, we use call detail records (CDRs) to examine the population dynamics and manifestations of social and spatial homophily at a macroscopic level among the residents of 23 states of India at the Kumbh Mela, a 3-month-long Hindu festival. We estimate that the festival was attended by 61 million people, making it the largest gathering in the history of humanity. While we find strong overall evidence for both types of homophily for residents of different states, participants from low-representation states show considerably stronger propensity for both social and spatial homophily than those from high-representation states. These manifestations of homophily are amplified on crowded days, such as the peak day of the festival, which we estimate was attended by 25 million people. Our findings confirm that homophily, which here likely arises from social influence, permeates all scales of human behavior.



道路使用者交互仿真---委内瑞拉交通复杂性一瞥 (Simulating the interaction of road users: A glance to complexity of Venezuelan traffic)

May 24, 7:55 PM From arxiv.org

by Juan C. Correa, Mario I. Caicedo, Ana L. C. Bazzan, Klaus Jaffe

(Translated by -苏格兰)

Automotive traffic is a classical example of a complex system, being the simplest case the homogeneous traffic where all vehicles are of the same kind, and using different means of transportation increases complexity due to different driving rules and interactions between each vehicle type. In particular, when motorcyclists drive in between the lanes of stopped or slow-moving vehicles. This later driving mode is a Venezuelan pervasive practice of mobilization that clearly jeopardizes road safety. We developed a minimalist agent-based model to analyze the interaction of road users with and without motorcyclists on the way. The presence of motorcyclists dwindles significantly the frequency of lane changes of motorists while increasing their frequency of acceleration-deceleration maneuvers, without significantly affecting their average speed. That is, motorcyclist "corralled" motorists in their lanes limiting their ability to maneuver and increasing their acceleration noise. Comparison of the simulations with real traffic videos shows good agreement between model and observation. The implications of these results regarding road safety concerns about the interaction between motorists and motorcyclists are discussed.

公路交通是复杂系统的经典案例,所有人出行都使用同一种车辆的单一交通方式是其最简单的形式;而多种交通方式同时使用则增加了复杂性,因为每一种交通工具的驾驶规则不同,相互之间的交互方式也不同。尤其是当摩托车穿行于路边停车道或慢车道之间的车道时,后一种驾驶模式在委内瑞拉相当普遍,显然危害了道路安全。我们开发了一款基于 agent 的简化模型,用于分析路上有摩托车和没有摩托车两种情况下道路使用者之间的互动。摩托车的出现明显减少了汽车驾驶员变道的频率,增加了他们加速—减速操作的频率,但并未显著影响其平均速度。也就是说,摩托车驾驶员将汽车驾驶员“围堵”在他们的车道上,限制其操作能力,提高了他们加速时的噪音。实际交通监控视频与模拟结果的对比,显示了模型对实地观察的良好拟合。考虑到汽车驾驶者和摩托车驾驶者之间的相互作用,以上结果对道路安全的启示也在文中加以讨论。



(1)agent 可以译成「主体」,在有些场合也基于上下文翻译成「个体」「代理人」「基本单元」……,或者在大量场合,其实不翻译也可以的,例如 http://www.swarmagents.cn/swarma/detail.php?id=1155

(2)interaction 通常翻译成「相互作用」,但是这里根据上下文,我觉得翻译灵活地处理成「互动」和「相互作用」非常好。

活细胞背后的数学如何来帮助我们解码大脑 (How the hidden mathematics of living cells could help us decipher the brain)

May 26, 7:20 PM From theconversation.com

by Chrystopher Nehaniv

(Translated by Haven Feng, edited by 傅渥成)

So will we ever be able to model something as complex as the human brain using computers? After all, biological systems use symmetry and interaction to do things that even the most powerful computers cannot do – like surviving, adapting and reproducing. This is one reason why binary logic often falls short of describing how living things or human intelligence work. But our new research suggests there are alternatives: by using the mathematics that describe biological networks in the computers of the future, we may be able to make them more complex and similar to living systems like the brain.

在未来,我们是否有能力利用计算机建模和人脑一样复杂的事物呢?毕竟, 生物系统利用对称性和相互作用可以实现的事即使最强大的计算机也无法完成,例如:生存,适应和繁衍。这是二进制逻辑总不能描述生命活动或者人类智能如何运作的一个原因。但我们的新研究给出了其他思路:通过将描述生物网络的数学引入到未来的计算机中,我们也许可以使它们变得更具复杂性,而且也更为贴近像大脑一样的活体系统。


策略不确定性的专家管理中的信息加密 (Information encryption in the expert management of strategic uncertainty)

May 26, 9:21 PM From arxiv.org

by Seth Frey, Paul L.Williams, Dominic K.Albino

(Translated by -Jamie, edited by 傅渥成)

Strategic agents in incomplete-information environments have a conflicted relationship with uncertainty: it can keep them unpredictable to their opponents, but it must also be overcome to predict the actions of those opponents. We use a multivariate generalization of information theory to characterize the information processing behavior of strategic reasoning experts. We compare expert and novice poker players --- "sharks" and "fish" --- over 1.75 million hands of online two-player No-Limit Texas Hold'em (NLHE). Comparing the effects of privately known and publicly signaled information on wagering behavior, we find that the behavior of sharks coheres with information that emerges only from the interaction of public and private sources --- "synergistic" information that does not exist in either source alone. This implies that the effect of public information on shark behavior is better encrypted: it cannot be reconstructed without access to the hidden state of private cards. Integrative information processing affects not only one's own strategic behavior, but the ability of others to predict it. By characterizing the informational structure of complex strategic interactions, we offer a detailed account of how experts extract, process, and conceal valuable information in high-uncertainty, high-stakes competitive environments.

不完全信息(incomplete-information)环境内的策略主体(strategic agents)间存在一种具有不确定性的矛盾关系:这让他们对于对手来说不可预测,但这也使得对手的行动预测变成一个需要克服的问题。我们采用了一种信息论的多变量推广形式来描述策略推论专家的信息处理行为。我们比较专家和新手纸牌玩家——“鲨鱼和小鱼”——在超过175万手在线一对一无限制德州扑克压赌游戏中。在赌注行为中比较私人信息和公开讯号的效应,我们发现鲨鱼玩家们只利用在公开资源与私有资源交融后浮现出来的内容——“协同的”信息在任何一方资源的内部不存在。这意味着公开信息的效应在鲨鱼玩家行为中被更好地加密了:当隐藏的私人牌面内容不可得时,它不能得出新的解读。信息的综合处理过程不仅影响一个人自身的策略行为,也影响其他人预测这些行为的能力。通过描述这些复杂策略互动的信息结构,我们为专家如何在高度不确定且高风险的竞争环境中提取、处理和隐藏有价值的信息提供了一种细节化的解释。


生命初始的类辅酶世界模型 (Coenzyme world model of the origin of life)

May 26, 11:21 PM From www.sciencedirect.com

by Alexei A.Sharov

(Translated by Remi ,edited by 傅渥成)

The origin of life means the emergence of heritable and evolvable self-reproduction. However the mechanisms of primordial heredity were different from those in contemporary cells. Here I argue that primordial life had no nucleic acids; instead heritable signs were represented by isolated catalytically active self-reproducing molecules, similar to extant coenzymes, which presumably colonized surfaces of oil droplets in water. The model further assumes that coenzyme-like molecules (CLMs) changed surface properties of oil droplets (e.g., by oxidizing terminal carbons), and in this way created and sustained favorable conditions for their own self-reproduction. Such niche-dependent self-reproduction is a necessary condition for cooperation between different kinds of CLMs because they have to coexist in the same oil droplets and either succeed or perish together. Additional kinds of hereditary molecules were acquired via coalescence of oil droplets carrying different kinds of CLMs or via modification of already existing CLMs. Eventually, polymerization of CLMs became controlled by other polymers used as templates; and this kind of template-based synthesis eventually resulted in the emergence of RNA-like replicons. Apparently, oil droplets transformed into the outer membrane of cells via engulfing water, stabilization of the surface, and osmoregulation. In result, the metabolism was internalized allowing cells to accumulate free-floating resources (e.g., amino acids, ATP), which was a necessary condition for the development of protein synthesis. Thus, life originated from simple but already functional molecules, and its gradual evolution towards higher complexity was driven by cooperation and natural selection.

生命诞生意味着这世界上出现了可遗传、可进化的自我繁衍。然而最原始的遗传机制与现今细胞的分裂大有不同。在本文中,我提出了这样的观点:原始生命不含有核酸,遗传的表达是由各自独立的、可催化自我繁殖的分子来完成。这些分子与现存的辅酶相似, 它们很可能粘附在水中油滴的表面。运用这个模型,我们进一步猜想类辅酶分子 (CLMs) 改变了油滴的表面特征(比如氧化末端碳原子),来创造并维持有利于它们本身生存的条件。因为不同类辅酶分子同兴同亡地存在于在一个油滴上,这种依赖于居地的自我繁殖是它们合作的必要前提。携带着各种类辅酶分子的油滴联结在一起,或是现有类辅酶分子变异,就会产生新品种的遗传分子。渐渐地,其他聚合物利用类辅酶分子的聚合作为模板,以这种模板为基础的合成最终促使类似于RNA复制机制的出现。油滴通过吸收水分子、稳定表面、渗透调节一系列步骤转变成了细胞膜。 最终,新陈代谢的内化让细胞可以获取自由流动的的物质(比如氨基酸和ATP),这为蛋白质合成的产生提供了必要条件。 因此,生命源自于简单但已具有功能性的分子,合作和自然选择促使它向更复杂生命体的逐步进化。


在自适应系统群落中的合作、竞争和临界涌现 (Cooperation, competition and the emergence of criticality in communities of adaptive systems)

May 27, 10:32 AM From iopscience.iop.org

by Jorge Hidalgo, Jacopo Grilli, Samir Suweis, Amos Maritan, Miguel A Muñoz

(Translated by - 女周瑜, edited by 傅渥成 )

The hypothesis that living systems can benefit from operating at the vicinity of critical points has gained momentum in recent years. Criticality may confer an optimal balance between too ordered and exceedingly noisy states. Here we present a model, based on information theory and statistical mechanics, illustrating how and why a community of agents aimed at understanding and communicating with each other converges to a globally coherent state in which all individuals are close to an internal critical state, i.e. at the borderline between order and disorder. We study—both analytically and computationally—the circumstances under which criticality is the best possible outcome of the dynamical process, confirming the convergence to critical points under very generic conditions. Finally, we analyze the effect of cooperation (agents trying to enhance not only their fitness, but also that of other individuals) and competition (agents trying to improve their own fitness and to diminish those of competitors) within our setting. The conclusion is that, while competition fosters criticality, cooperation hinders it and can lead to more ordered or more disordered consensual outcomes.



网络二元及三元关系中的同性偏好 (Gender homophily in online dyadic and triadic relationships)

May 27, 9:09 PM From epjdatascience.springeropen.com

by David Laniado, Yana Volkovich, Karolin Kappler and Andreas Kaltenbrunner

(Translated by Remi,edited by 傅渥成 )

Gender homophily, or the preference for interaction with individuals of the same gender, has been observed in many contexts, especially during childhood and adolescence. In this study we investigate such phenomenon by analyzing the interactions of the ∼10 million users of Tuenti, a Spanish social networking service popular among teenagers. In dyadic relationships we find evidence of higher gender homophily for women. We also observe a preference of users with more friends to connect to the opposite gender. A particularly marked gender difference emerges in signing up for the social networking service and adding the first friends, and in the interactions by means of wall messages. In these contexts we find evidence of a strong homophily for women, and little or no homophily for men. By examining the gender composition of triangle motifs, we observe a marked tendency of users to group into gender homogeneous clusters, with a particularly high number of male-only triangles. We show that age plays an important role in this context, with a tendency to higher homophily for young teenagers in both dyadic and triadic relationships. Our findings have implications for addressing gender gap issues, understanding adolescent online behavior and technology adoption, and modeling social networks.



Remark by 傅渥成

motif 在复杂网络研究中通常译作「模体」或「基序」。

一只同时生活在两个盒子中的薛定谔猫 (A Schrödinger cat living in two boxes)

May 27, 5:06 PM From science.sciencemag.org

by Chen Wang, Yvonne Y. Gao, Philip Reinhold, R. W. Heeres, Nissim Ofek, Kevin Chou, Christopher Axline, Matthew Reagor, Jacob Blumoff, K.M.Sliwa1, L.Frunzio, S. M. Girvin, Liang Jiang, M. Mirrahimi, M. H. Devoret1, R. J. Schoelkopf

(Translated by - 王继康, edited by 傅渥成)

Quantum superpositions of distinct coherent states in a single-mode harmonic oscillator, known as “cat states,” have been an elegant demonstration of Schrödinger’s famous cat paradox. Here, we realize a two-mode cat state of electromagnetic fields in two microwave cavities bridged by a superconducting artificial atom, which can also be viewed as an entangled pair of single-cavity cat states. We present full quantum state tomography of this complex cat state over a Hilbert space exceeding 100 dimensions via quantum nondemolition measurements of the joint photon number parity. The ability to manipulate such multicavity quantum states paves the way for logical operations between redundantly encoded qubits for fault-tolerant quantum computation and communication.



青春的真相:复杂 (The Real Secret of Youth Is Complexity)

May 27, 7:12 PM From nautil.us

by Lewis A.Lipsitz

(Translated by - dan, edited by 傅渥成)

“Simplicity, simplicity, simplicity!” Henry David Thoreau exhorted in his 1854 memoir Walden, in which he extolled the virtues of a “Spartan-like” life. Saint Thomas Aquinas preached that simplicity brings one closer to God. Isaac Newton believed it leads to truth. The process of simplification, we’re told, can illuminate beauty, strip away needless clutter and stress, and help us focus on what really matters. It can also be a sign of aging. Youthful health and vigor depend, in many ways, on complexity. Bones get strength from elaborate scaffolds of connective tissue. Mental acuity arises from interconnected webs of neurons. Even seemingly simple bodily functions like heartbeat rely on interacting networks of metabolic controls, signaling pathways, genetic switches, and circadian rhythms. As our bodies age, these anatomic structures and physiologic processes lose complexity, making them less resilient and ultimately leading to frailty and disease.


简单同时也是衰老的标志。很多方面体现出,青春之健康和活力都依赖于复杂。骨骼之力量依赖于复杂连接的组织结构,大脑之敏捷决定于精巧的神经元网络。甚至连看上去十分简单的人体生理功能,比如心跳,都依赖于代谢控制(metabolic controls)、细胞信号通路(signaling pathways)、遗传开关(genetic switches)和昼夜节律(circadian rhythms)的相互作用网络。当我们的身体开始衰老,人体解剖结构和生理过程都丧失其复杂性,也就失去复原的弹性,最终导致脆弱和疾病。


贫穷与表观遗传变异及精神疾病的关系 (Poverty linked to epigenetic changes and mental illness)

May 27, 12:41 PM From www.nature.com

by Sara Reardon

(Translated by -李宇峰, edited by 傅渥成)

Children from impoverished families are more prone to mental illness, and alterations in DNA structure could be to blame, according to a study published on 24 May in Molecular Psychiatry1. Poverty brings with it a number of different stressors, such as poor nutrition, increased prevalence of smoking and the general struggle of trying to get by. All of these can affect a child’s development, particularly in the brain, where the structure of areas involved in response to stress and decision-making have been linked to low socioeconomic status. Poor children are more prone to mental illnesses such as depression than their peers from wealthier families, but they are also more likely to have cognitive problems. Some of these differences are clearly visible in the brain structure and seem to appear at birth, which suggests that prenatal exposure to these stressors can be involved2.

根据5月24日发表在 Molecular Psychiatry 的一项研究,来自贫困家庭的孩子更容易出现心理疾病,而发生在DNA结构的改变可能是罪魁祸首。 贫困带来了各种不同的应激源,如营养不良,烟瘾成灾以及为了谋生所遭受的日夜操劳。它们会对孩子的发育造成影响,尤其是大脑的发育,较低的社会经济状况会与对大脑中参与应激与决策的区域的结构相关。 穷人家的孩子比富家的同龄人更容易出现抑郁症等精神疾病,同时他们也更容易有认知问题。这些差异在大脑结构中清晰可见,而且似乎在出生时就已经出现。这表明,即使在产前暴露于这些压力下,孩子也会受影响。


Remark by 傅渥成

翻译得非常好,很多地方都处理得非常好。 不过我个人建议翻译的时候有些关键的地方最好还是用更准确地直译,两个例子: (1)「它们会对孩子的成长潜移默化」,这个原文是”affect a child’s development“,其实只需要说「会影响孩子的发育」就可以了(development 在生物学里就是「发育」的意思)。 (2)类似的,「从出生开始就初露端倪(seem to appear at birth)」,这里「初露端倪」的说法比较模糊,不知道是从出生开始就「已经表现出来了」,还是出生时「只有一点微小的区别,此后表现越来越明显」。个人觉得这样的地方应该直译为「似乎在出生时就已经出现」。