Prediction of collapse process and tipping points for mutualistic and competitive networks with k-core method

Ecosystems generally have the self-adapting ability to resist various external pressures or disturbances,which is always called resilience.However,once the external disturbances exceed the tipping points of the system resilience,the consequences would be catastrophic,and eventually lead the ecosystem to complete collapse.We capture the collapse process of ecosystems represented by plant-pollinator networks with the k-core nested structural method,and find that a sufficiently weak interaction strength or a sufficiently large competition weight can cause the structure of the ecosystem to collapse from its smallest k-core towards its largest k-core.Then we give the tipping points of structure and dynamic collapse of the entire system from the one-dimensional dynamic function of the ecosystem.Our work provides an intuitive and precise description of the dynamic process of ecosystem collapse under multiple interactions,and provides theoretical insights into further avoiding the occurrence of ecosystem collapse.

地基微波辐射计Tipping定标效果及误差分析

地基多通道微波辐射计采用了Tipping定标方法来实现自动定标,它是维持微波辐射计观测亮温数据可靠性的重要措施之一。为了说明Tipping自动定标过程,从Tipping标定的原理出发,详细介绍了微波辐射计Tipping自动定标过程及使用条件,同时对定标误差的基本来源进行了定量分析。最后利用微波辐射计实际观测资料进行了Tipping定标试验,并利用探空资料对Tipping定标效果进行了对比验证。结果表明Tipping定标方法使得亮温定标精度小于1 K,能够有效提高亮温观测精度和湿度廓线的反演效果。该方法对微波辐射计亮温数据观测的长期稳定性有着显著的作用。

Will the summer sea ice in the Arctic reach a tipping point?

The Arctic sea-ice cover has decreased in extent,area,and thickness over the last six decades.Most global climate models project that the summer sea-ice extent(SIE)will decline to less than 1 million(mill.)km^(2) in this century,ranging from 2030 to the end of the century,indicating large uncertainty.However,some models,using the same emission scenarios as required by the Paris Agreement to keep the global temperature below 2°C,indicate that the SIE could be about 2 mill.km^(2) in 2100 but with a large uncertainty of±1.5 mill.km^(2).Here,the authors take another approach by exploring the direct relationship between the SIE and atmospheric CO_(2) concentration for the summer-fall months.The authors correlate the SIE and In(CO_(2)/CO_(2)r)during the period 1979-2022,where CO_(2)r is the reference value in 1979.Using these transient regression equations with an R2 between 0.78 and 0.87,the authors calculate the value that the CO_(2) concentration needs to reach for zero SIE.The results are that,for July,the CO_(2) concentration needs to reach 691±16.5 ppm,for August 604±16.5 ppm,for September 563±17.5 ppm,and for October 620±21 ppm.These values of CO_(2)for an ice-free Arctic are much higher than the targets of the Paris Agreement,which are 450 ppm in 2060 and 425 ppm in 2100,under the IPCC SSP1-2.6 scenario.If these targets can be reached or even almost reached,the "no tipping point"hypothesis for the summer SIE may be valid.

On the Image Reconstruction of Zhuge Liang in ACGN Games Based on the Perspective of the Tipping Point Theory

Zhuge Liang,a well-known figure with rich cultural implications in Chinese history,has exerted profound influences on the spiritual life of the Chinese nation.In the ACGN context,new cultural implications have been attached to him,which offset some of the classic implications of the character forged over a long history.Meanwhile,the inherent traditional cultural spirit embodied by him is being reconstructed.In terms of content design,the ACGN games based on traditional realism tend to refresh people’s collective memories of Zhuge Liang to enhance the stickiness factor of the games,thus creating a sense of familiarity to make the transmitted information easier for the game players to accept.The modern fashionable games,however,are good at leveraging the advantages of technologies to form a tipping point and incorporating fashion elements into the traditional image of Zhuge Liang to attract players,thus enhancing the communication effect.In terms of environmental construction,the ACGN games have created a new industrial environment featuring“ACGN+traditional culture,”which changes the traditional image of Zhuge Liang by means of ACGN game technology while retaining its basic cultural characteristics to provide players with a better immersive and interactive experience.

Female Body Discourse in Tipping the Velvet

Being known as the lesbian-themed novel,Tipping the Velvet has always been analyzed with queer theory and Judith But?ler’s sexual performance.Female body discourse is a new perspective to analyze it with the combination of the text analysis and feminine writing put forward by Helene Cixous.Narrating the female body in a novel is a way to deconstruct the patriarchal society and to awaken women to fight against it.It is still of significance in 21st society where gender inequality and discrimination exist everywhere.

Tipping Point

LIBYA is rapidly joining the ranks of Africa＇s better-known failed states： the Central African Re- public, Somalia and South Sudan. The North African country, once boasting one of the continent＇s highest per-capita GDPs, is a shadow of its former self： torn apart by armed conflict and now felled by falling oil prices and declining production.

Should Apple Charge Fees for Tipping on Social Networking Apps?

Recently, Apple＇s decision to start taking a 30-percent cut on tips given by users of socia networking apps has sparked heated debates in China.

Tipping Point

A MAFIA-LIKE criminal order inspired by a totalitarian ideology threatens North Africa and the Sahel, with Libya now as its centerpiece. As this radical, obscurantist and brutal form of Islam spreads and displaces traditional Islam in Libya, the emergence of the Benghazi Defense Brigades （BDB）, formed in June 2016 to oppose the Libyan national army, has plunged the coun- try into further chaos. The BDB is locked in con- flict with the Libyan army led by Major General Khalifa Haftar.

The Tipping Point

THE worst year on record for rhino poaching in South Africa＇s history makes 2013 a dismal period for the endangered animal. Figures released by the South African Department of Environmental Affairs in January show that in 2013, just over 1,000 rhinos were illegally killed in South Africa - the equivalent of nearly three animals a day. The figure is more than 1.5 times the official figure of 668 rhinos killed for their horns in 2012. This brings South Africa＇s white rhino population ever closer to the tipping point, where deaths outnumber births and the population begins a serious decline.

Hunt for the tipping point during endocrine resistance process in breast cancer by dynamic network biomarkers

Acquired drug resistance is the major reason why patients fail to respond to cancer therapies.It is a challenging task to deter.mine the tipping point of endocrine resistance and detect the associated molecules.Derived from new systems biology theory, the dynamic network biomarker (DNB) method is designed to quantitatively identify the tipping point of a drastic system transition and can theoretically identify DNB genes that play key roles in acquiring drug resistance.We analyzed time-course mRNA sequence data generated from the tamoxifen-treated estrogen receptor (ER)-positive MCF-7 cell line, and identified the tipping point of endocrine resistance with its leading molecules.The results show that there is interplay between gene mutations and DNB genes, in which the accumulated mutations eventually affect the DNB genes that subsequently cause the change of transcriptional landscape, enabling full-blown drug resistance. Survival analyses based on clinical datasets validated that the DNB genes were associated with the poor survival of breast cancer patients.The results provided the detection for the pre-resistance state or early signs of endocrine resistance.Our predictive method may greatly benefit the scheduling of treatments for complex diseases in which patients are exposed to considerably different drugs and may become drug resistant.

SMAD7 and SERPINE1 as novel dynamic network biomarkers detect and regulate the tipping point of TGF-beta induced EMT

Epithelial–mesenchymal transition(EMT) is a complex nonlinear biological process that plays essential roles in fundamental biological processes such as embryogenesis, wounding healing, tissue regeneration,and cancer metastasis. A hallmark of EMT is the switch-like behavior during state transition, which is characteristic of phase transitions. Hence, detecting the tipping point just before mesenchymal state transition is critical for understanding molecular mechanism of EMT. Through dynamic network biomarkers(DNB) model, a DNB group with 37 genes was identified which can provide the early-warning signals of EMT. Particularly, we found that two DNB genes, i.e., SMAD7 and SERPINE1 promoted EMT by switching their regulatory network which was further validated by biological experiments. Survival analyses revealed that SMAD7 and SERPINE1 as DNB genes further acted as prognostic biomarkers for lung adenocarcinoma.

Landscape dynamic network biomarker analysis reveals the tipping point of transcriptome reprogramming to prevent skin photodamage

Skin,as the outmost layer of human body,is frequently exposed to environmental stressors including pollutants and ultraviolet(UV),which could lead to skin disorders.Generally,skin response process to ultraviolet B(UVB)irradiation is a nonlinear dynamic process,with unknown underlying molecular mechanism of critical transition.Here,the landscape dynamic network biomarker(lDNB)analysis of time series transcriptome data on 3D skin model was conducted to reveal the complicated process of skin response to UV irradiation at both molecular and network levels.The advanced l-DNB analysis approach showed that:(i)there was a tipping point before critical transition state during pigmentation process,validated by 3D skin model;(ii)13 core DNB genes were identified to detect the tipping point as a network biomarker,supported by computational assessment;(iii)core DNB genes such as COL7A1 and CTNNB1 can effectively predict skin lightening,validated by independent human skin data.Overall,this study provides new insights for skin response to repetitive UVB irradiation,including dynamic pathway pattern,biphasic response,and DNBs for skin lightening change,and enables us to further understand the skin resilience process after external stress.

Do abrupt cryosphere events in High Mountain Asia indicate earlier tipping point than expected?

Tipping points of about 16 elements have been identified in Earth system,yet cryospheric tipping point of specific Alpine region has not been studied.Here we analyzed three tipping elements(mountain glacier,snow cover,and permafrost)identified in recent years,evidenced by the facts of frequent occurrence of abrupt massive collapse of glacier mass and the widespread thermakarst of permafrost.Since 2015,strikingly abrupt cryosphere events(ACEs)have been consistently observed over a large range of High Mountain Asia(HMA).Those events were un-precedentedly significant in history,leading to collapses of glaciers following by disconnection of glacier tongue from accumulation basin and recession of thermakarst towards higher elevation.Strong decreasing of snow depth in 2022 was also observed since 2021/2022 winter,coinciding with extreme warming of the year.The widespread high warming rates in the last two decades over HMA might have triggered above ACEs.The dynamic thresholds of ACEs depend largely on high temperature,especially extreme heat wave,for both glaciers and permafrost,closely related to meltwater as a key factor for reaching initial conditions of abrupt changes,suggesting HMA cryosphere is a tipping element under the global warming level of 1.1℃.The ACEs can cause tremendous damage to local ecosystem and socioeconomy,measures to mitigate risks should be taken when the tipping points are reached.

Significant tipping points of sediment microeukaryotes forewarn increasing antibiotic pollution

Antibiotic pollution imposes urgent threats to public health and microbial-mediated ecological processes.Existing studies have primarily focused on bacterial responses to antibiotic pollution,but they ignored the microeukaryotic counterpart,though microeukaryotes are functionally important(e.g.,predators and saprophytes)in microbial ecology.Herein,we explored how the assembly of sediment microeukaryotes was affected by increasing antibiotic pollution at the inlet(control)and across the outlet sites along a shrimpwastewater discharge channel.The structures of sedimentmicroeukaryotic community were substantially altered by the increasing nutrient and antibiotic pollutions,whichwere primarily controlled by the direct effects of phosphate and ammonium(−0.645 and 0.507,respectively).In addition,tetracyclines exerted a large effect(0.209),including direct effect(0.326)and indirect effect(−0.117),on the microeukaryotic assembly.On the contrary,the fungal subcommunity was relatively resistant to antibiotic pollution.Segmented analysis depicted nonlinear responses of microeukaryotic genera to the antibiotic pollution gradient,as supported by the significant tipping points.We screened 30 antibiotic concentration-discriminatory taxa of microeukaryotes,which can quantitatively and accurately predict(98.7%accuracy)the in-situ antibiotic concentration.Sediment microeukaryotic(except fungal)community is sensitive to antibiotic pollution,and the identified bioindicators could be used for antibiotic pollution diagnosis.

Critical transitions and tipping points in EMT

Background:Phase transition and phase separation as well as their tipping points are penetrating phenomena in biology and are intrinsic properties of biological systems ranging from basic molecule complexes to cells and all way up to entire ecosystems.Results:For example,phase separation has been established as a key mechanism for biological molecules such as protein or RNA to form membraneless organelles to perform complex biological functions.Phase transitions are commonly observed during cellular differentiation,and generally,there are the tipping points or critical states just before the phase transitions.And the stability of ecosystem and extinction of species are systematic manifestation of phase transitions.All phase transition and phase separation phenomena display switch-like behavior and critical transitions.Conclusion:Here we summarize the concepts regarding the epithelial-to・mesenchymal transition(EMT)as a type of phase changes and the implication of critical transitions in EMT,and discuss open questions and challenges in this fast-moving field.

Tipping points among social learners： Tools from varied disciplines

There is a long and rich tradition in the social sciences of using models of collective behavior in animals as jump- ing-off points for the study of human behavior, including collective human behavior. Here, we come at the problem in a slightly different fashion. We ask whether models of collective human behavior have anything to offer those who study animal behavior. Our brief example of tipping points, a model first developed in the physical sciences and later used in the social sciences, suggests that the analysis of human collective behavior does indeed have considerable to offer

NO FLY Tipping啥意思

在欧洲，不少大街小巷上会出现No Fly Tipping的标牌，你可千万别误以为是“别给小费”的意思，那样就要闹笑话了。它是英语中的一个俚语，意思是“不要随便扔垃圾”。

9%Ni锻造钢管焊接接头性能研究

针对用于海上油气平台的9%Ni锻造钢管,通过无损检测、力学性能测试及硫化物应力腐蚀试验对焊接接头进行测试,并对比了其在不同浓度硫化氢气体下的腐蚀行为。结果表明,采用TIP TIG焊方法并保持层间温度在150℃以下,能有效保证焊缝的低温力学性能与在微量硫化氢环境中的抗腐蚀能力,但在高浓度硫化氢环境中焊缝发生断裂失效。

基于团队协作的旅游服务与管理专业“TIPS”实践教学模式创新路径研究-以沈阳市旅游学校为例

文章在梳理文献成果、提炼相关理论的基础上,以沈阳市旅游学校为例,以中职学校旅游服务与管理专业的实践教学模式为研究对象,通过对文旅企业、中职旅游学校进行调研,针对中职旅游服务与管理专业学生职业能力有限、企业人才流失率高、学生职业自信度低等问题,对基于团队协作的旅游服务与管理专业“TIPS”实践教学模式创新路径进行深入研究。