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Delineating the respective impacts of stochastic curl- and grad-forces in a family of idealized core genetic commitment circuits

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Frontiers of Electrical and Electronic Engineering in China 2016年第2期4卷 69-83页

作者： Marc turcotte Department of Mathematics The University of Texas at Arlington Arlington TX 76109 USA Biological Sciences The University of Texas at Dallas Richardson TX-75080 USA

Stochastic dynamics pervades gene regulation. Despite being random, the dynamics displays a kind of innate structure. In fact, two stochastic forces combine driving efforts： one force originates from the gradient of the underlying stochastic potential, and the other originates from the mathematical curl of the probability flux. The curl force gives rise to rotation. The gradient force gives rise to drift. Together they give rise to helical behavior. Here, it is shown that around and about the vicinity of attractive fixed points, the gradient force naturally wanes but the curl force is found to remain high. This leads to a locally noticeably different type of stochastic track near and about attractive fixed points, compared to tracks in regions where drift dominates. The consistency of this observation with the experimental fact that, in biology, fate commitment appears to not be a-priory locked-in, but rather necessitating active maintenance, is discussed. Hence attractive fixed-points are not only fuzzy, but may effectively be, locally, ＂more free＂.

关键词： systems biology theoretical biology gene regulation nonlinear dynamics stochasticity

Parameter asymmetry and time-scale separation in core genetic commitment circuits

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Frontiers of Electrical and Electronic Engineering in China 2015年第1期10卷 19-45页

作者： Hongguang Xi Marc turcotte Department of Mathematics University of Texas at Arlington Arlington TX 76109 USA Biological Sciences University of Texas at Dallas Richardson TX 75080 USA

Theory allows studying why Evolution might select core genetic commitment circuit topologies over alternatives. The nonlinear dynamics of the underlying gene regulation together with the unescapable subtle interplay of intrinsic biochemical noise impact the range of possible evolutionary choices. The question of why certain genetic regulation circuits might present robustness to phenotype-delivery breaking over others, is therefore of high interest. Here, the behavior of systematically more complex commitment circuits is studied, in the presence of intrinsic noise, with a focus on two aspects relevant to biology： parameter asymmetry and time-scale separation. We show that phenotype delivery is broken in simple two- and three-gene circuits. In the two-gene circuit, we show how stochastic potential wells of different depths break commitment. In the three-gene circuit, we show that the onset of oscillations breaks the commitment phenotype in a systematic way. Finally, we also show that higher dimensional circuits （four-gene and five-gene circuits） may be intrinsically more robust.

关键词： systems biology theoretical biology gene regulation nonlinear dynamics stochasticity

Time-scale separation and stochasticity conspire to impact phenotypic dynamics in the canonical and inverted Bacillus subtilis core genetic regulation circuits

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Frontiers of Electrical and Electronic Engineering in China 2019年第1期7卷 54-68页

作者： lijie Hao Zhuoqin Yang Marc turcotte School of Mathematics and Systems Science and lMIB Beihang UniversityBeijing 100191China University of Texas at Dallas RichardsonTX 75080USA

Backgrounds In this work, we study two seemingly unrelated aspects of core genetic nonlinear dynamical control of the competence phenotype in Bacillus subtilis, a common Gram-positive bacterium living in the soil. Methods: We focus on hitherto unchartered aspects of the dynamics by exploring the effect of time-scale separation between transcription and translation and, as well, the effect of intrinsic molecular stochasticity. We consider these aspects of regulatory control as two possible evolutionary handles. Results: Hence, using theory and computations, we study how the onset of oscillations breaks the excitability-based competence phenotype in two topologically close evolutionary-competing circuits: the canonical "wild-type" regulation circuit selected by Evolution and the corresponding indirect-feedback inverted circuit that failed to be selected by Evolution, as was shown elsewhere, due to dynamical reasons. Conclusions^ Relying on in-silico perturbation of the living state, we show that the canonical core genetic regulation of excitability-based competence is more robust against switching to phenotype-breaking oscillations than the inverted feedback organism. We show how this is due to time-scale separation and stochasticity.

关键词： Bacillus subtilis competence gene regulation deterministic dynamics stochastic dynamics

Impact Assessment and Mitigation Techniques for High Penetration levels of Renewable Energy Sources in Distribution Networks:Voltage-control Perspective

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Journal of Modern Power Systems and Clean Energy 2022年第2期10卷 450-458页

作者： Ahmed S.A.Awad Dave turcotte Tarek H.M.El-Fouly Natural Resources Canada Can-metENERGYVarennesCanadaon leave from the Electrical Power and Machines DepartmentFaculty of EngineeringAin Shams UniversityCairo 11566Egyp Natural Resources Canada CanmetENERGYVarennesCanada Advanced Power and Energy Center Khalifa UniversityAbu DhabiUnited Arab Emirates

The integration of renewable distributed generation(RDG)into distribution networks is promising and increasing ***,high penetration levels of distributed generation(DG)are often limited as they may have an adverse effect on the operation of distribution *** of the operation challenges is the interaction between DG and voltage-control equipment,e.g.,an under-load tap changer(UlTC),which is basically designed to compensate for voltage changes caused by slow load *** integration of variable DGs leads to rapid voltage fluctuations,which can negatively affect the tap operation of *** paper investigates the impact of high penetration levels of RDG on the tap operation of UlTC in distribution networks through *** mitigation techniques that can alleviate this impact are also *** these techniques,constant power-factor mode is regarded as the best trade-off between the simplicity and effectiveness of minimizing the number of tap *** are performed on a Canadian benchmark rural distribution feeder using OpenDSS software.

关键词： Renewable energy distributed generation(DG) voltage regulator load tap changer distribution network.

Recurrent cyclops lesion after primary anterior cruciate ligament reconstruction using bone tendon bone allograft:A case report

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World Journal of Orthopedics 2023年第11期14卷 836-842页

作者： Grayson Kelmer Andrea H Johnson Justin J turcotte Daniel E Redziniak Orthopedic Research Anne Arundel Medical CenterAnnapolisMD 21401United States Medical School Campbell University School of Osteopathic MedicineLillingtonNC 27546United States Orthopedic Surgery Anne Arundel Medical CenterAnnapolisMD 21401United States

BACKGROUND Cyclops lesions are a known complication of anterior cruciate ligament(ACl)reconstruction,with symptomatic cyclops syndrome occurring in up to 11%of *** cyclops lesions have been rarely documented;this case study documents the successful treatment of a recurrent cyclops *** SUMMARY A 28-year-old female presented following a non-contact injury to the right *** and clinical exam revealed an ACl tear,and arthroscopic reconstruction was *** years later a cyclops lesion was discovered and removed via arthroscopic *** months postoperatively,the patient presented with pain,stiffness,and difficulty achieving terminal extension.A smaller recurrent cyclops lesion was diagnosed,and a repeat synovectomy was *** patient recovered *** To the best of our knowledge,this is the first documented case of recurrent cyclops lesion after bone-patellar tendon-bone allograft ACl reconstruction presenting as cyclops syndrome.

关键词： Anterior cruciate ligament Cyclops lesion Cyclops syndrome Knee arthroscopy Anterior cruciate ligament reconstruction Case report

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地壳形变与分形

世界地震译丛 1996年第2期27卷 1-8页

作者： D.l.turcotte 蒋海昆吴琼山东省地震局山东省轻工业学院

众所周知,地震的频度-震级统计关系满足古登堡-里克特关系式。易知,这一关系是分形的,分维数D=1.8～2.0。既然每条断层都有其特征地震这一观点已被普遍接受,那么断层的频数-尺度统计关系也将是分形的。有限的野外研究表明,断层的出露部... 详细信息

众所周知,地震的频度-震级统计关系满足古登堡-里克特关系式。易知,这一关系是分形的,分维数D=1.8～2.0。既然每条断层都有其特征地震这一观点已被普遍接受,那么断层的频数-尺度统计关系也将是分形的。有限的野外研究表明,断层的出露部分是D≈1.6的二维分形(地震和断层的分维数并不要求一定相等,因为地震的复发时间亦具有依赖于标度的幂律关系)。断块在很宽的尺度范围内具有D≈2.5的分形频数-尺度关系。关于构造形变的一个模型就是碎裂,这样一个标度不变的模型似乎与上述讨论的分形关系是一致的。地震活动性具有许多“自组织临界现象”的显著特性,能量(应变)被持续不断地施加于地壳上,又以离散事件的形式(地震)被释放掉,而这些离散的事件具有分形的频数-尺度分布。这样,认为大陆地壳的所有地方均处于这样一种临界状态似乎是有道理的(类似于与完全塑性有关的临界应力),其证据来源于板内地震的分布,以及差不多是任何一个地方的人工水库蓄水后所发生的诱发地震。

关键词：地壳形变分形地震地质地震活性

Occupational injuries and burn out among orthopedic oncology surgeons

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World Journal of Orthopedics 2022年第12期13卷 1056-1063页

作者： Abdulrahman M Alaseem Robert E turcotte Nathalie Ste-Marie Mohammad M Alzahrani Saad M Alqahtani Krista A Goulding Department of Orthopedic Surgery College of MedicineKing Saud UniversityRiyadh 12372Saudi Arabia Department of Orthopedic Surgery McGill University Health CentreMontreal H4A3J1Canada Department of Orthopedic Surgery College of MedicineImam Abdulrahman Bin Faisal universityDammam 34212Saudi Arabia Department of Orthopaedic Surgery Mayo ClinicPhoenixArizona 85054USA

BACKGROUND Orthopedic oncology surgeons commonly engage in prolonged and complex surgical *** types of surgeries increase the risk of physical and psychological stressors,which may in turn make these physicians prone to workrelated occupational *** The aim of this study was to explore in orthopedic oncologists,the prevalence of work-related physical injuries and psychological *** A modified version of the physical discomfort survey was developed to assess occupational injuries among orthopedic oncology surgeon members of the Musculoskeletal Tumor Society,the Canadian Orthopedic Oncology Society and European Musculoskeletal Oncology *** survey was sent by email,and it explored musculoskeletal complaints,psychological disturbances,treatment required for these complaints and the requirement of time off *** A total of 67 surgeon responses were collected.A high number of orthopedic oncologists(84%)reported an occupational *** back pain(39%)was the most prevalent musculoskeletal condition,followed by lumbar disk herniation(16%),shoulder tendinitis(15%)and lateral epicondylitis(13%).Of the cohort,46%required surgery and 31%required time off work due to their ***-three respondents reported a psychological ***(27%),anxiety(20%)and insomnia(20%)were the most commonly *** required off work due to injury was associated with old age and years in *** Orthopedic oncology surgeons report a high prevalence of work-related *** back related injury and burnout were the most reported *** operative room ergonomics and prevention of stress related to the work environment should be areas to explore in upcoming research.

关键词： Orthopedic oncology Surgeons Occupational Musculoskeletal Injuries

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流体力学中的分形

力学进展 1988年第4期 511-517页

作者： D.l.turcotte,李家春美国康乃尔大学地质科学系

1 引言统计分布在物理学中有许多十分重要的应用。统计力学就是一例;宏观量如温度和熵是微观层次上随机分布的统计平均。在量子力学中,原子的位置与动量具有统计分布。愈来愈多的事实证明,为了了解各种宏观现象,可能要直接应用统计方... 详细信息

1 引言统计分布在物理学中有许多十分重要的应用。统计力学就是一例;宏观量如温度和熵是微观层次上随机分布的统计平均。在量子力学中,原子的位置与动量具有统计分布。愈来愈多的事实证明,为了了解各种宏观现象,可能要直接应用统计方法。人们发现微分方程可以有浑沌解,这就说明使用统计方法的必要性。象奇怪吸引子这样的解往往呈现分形行为。重正化群的方法已应用于研究具有突变性质的连续介质问题;例如相变,磁性的突然发生。上述这些解往往具有分形性态的统计分布。

关键词：分形定义分维数方程分形分布尺度不变性白噪声序列奇怪吸引子湍流边界层湍流附面层统计分布流体力学

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沉积盆地的演化模式

地球与环境 1984年第3期 18-21页

作者： D.l.turcotte 黄惠林同济大学海洋地质系

引言沉积盆地发育的最简单模式是地形低地被沉积物所充填。由于沉积物负载而发生沉降,从而使沉积盆地的深度大于原始低地的深度。低地可能与洋壳有关。洋壳上沉积物充填的一个例子是象亚马孙河和尼日尔河那样的大河三角洲。在其他情况下... 详细信息

引言沉积盆地发育的最简单模式是地形低地被沉积物所充填。由于沉积物负载而发生沉降,从而使沉积盆地的深度大于原始低地的深度。低地可能与洋壳有关。洋壳上沉积物充填的一个例子是象亚马孙河和尼日尔河那样的大河三角洲。在其他情况下,如加利福

关键词：沉积盆地大洋岩石圈岩石圈厚度密执安盆地挠曲热沉降