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A novel image-based approach for interactive characterization of rock fracture spacing in a tunnel face

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第4期14卷 1077-1088页

作者： Jiayao Chen Yifeng Chen Anthony G.cohn Hongwei Huang Jianhong Man Lijun Wei Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education Department of Geotechnical EngineeringTongji UniversityShanghai200092China School of Computing University of LeedsLeedsLS29JTUK Department of Computer Science and Technology Tongji UniversityShanghai211985China School of Civil Engineering Shandong UniversityJinan250061China Luzhong Institute of Safety Environmental Protection Engineering and Materialsand School of Mechanical and Electrical EngineeringQingdao University of Science and TechnologyQingdao255000China

This paper presents a novel integrated method for interactive characterization of fracture spacing in rock tunnel *** main procedure includes four steps:(1)Automatic extraction of fracture traces,(2)digitization of trace maps,(3)disconnection and grouping of traces,and(4)interactive measurement of fracture set spacing,total spacing,and surface rock quality designation(S-RQD)*** evaluate the performance of the proposed method,sample images were obtained by employing a photogrammetrybased scheme in tunnel *** were then conducted to determine the optimal parameter values(*** threshold,angle threshold,and number of fracture trace grouping)for characterizing rock fracture *** applying the identified optimal parameters involved in the model,the proposed method could lead to excellent qualitative results to a new tunnel *** perform a quantitative analysis,three methods(***,straightening,and the proposed method)were employed in the same study and comparisons were *** proposed method agrees well with the field measurement in terms of the maximum and average values of measured spacing ***,the proposed method has reasonably good accuracy and interactive advantage for estimating the ultimate fracture spacing and *** can be a possible extension of existing methods for fracture spacing characterization for two-dimensional(2D)rock tunnel faces.

关键词： Fracture spacing Rock tunnel Image processing Fracture set grouping

Best Constants for Moser-Trudinger Inequalities,Fundamental Solutions and One-Parameter Representation Formulas on Groups of Heisenberg Type

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Acta Mathematica Sinica,English Series 2002年第2期18卷 375-390页

作者： cohn William S. Department of Mathematics.Wayne State University.Detroit.MI 48202 USA

We derive the explicit fundamental solutions for a class of degenerate(or singular)one- parameter subelliptic differential operators on groups of Heisenberg(H)*** extends the result of Kaplan for the sub-Laplacian on H-type groups,which in turn generalizes Folland's result on the Heisenberg *** an application,we obtain a one-parameter representation formula for Sobolev functions of compact support on H-type *** choosing the parameter equal to the homogeneous dimension Q and using the Mose-Trudinger inequality for the convolutional type operator on stratified groups obtained in[18].we get the following theorem which gives the best constant for the Moser- Trudiuger inequality for Sobolev functions on H-type groups. Let G be any group of Heisenberg type whose Lie algebra is generated by m left invariant vector fields and with a q-dimensional *** Q=m+2q.Q'=Q-1/Q and Then. with A_Q as the sharp constant,where ▽G denotes the subelliptic gradient on G. This continues the research originated in our earlier study of the best constants in Moser-Trudinger inequalities and fundamental solutions for one-parameter subelliptic operators on the Heisenberg group [18].

关键词： Heisenberg group Groups of Heisenberg type Sobolev inequalities Moser-Trudinger inequalities Best constants One-Parameter representation formulas Fundamental solutions

Intervertebral disc degeneration is rescued by TGFβ/BMP signaling modulation in an ex vivo flamin B mouse model

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Bone Research 2022年第3期10卷 524-535页

作者： Jennifer Zieba Kimberly N.Forlenza Kelly Heard Jorge H.Martin Michaela Bosakova Daniel H.cohn Stephen P.Robertson Pavel Krejci Deborah Krakow Department of Orthopedic Surgery Los AngelesCA 90095USA Department of Biology Faculty of MedicineMasaryk University62500 BrnoCzech Republic International Clinical Research Center St.Anne’s University Hospital65691 BrnoCzech Republic Institute of Animal Physiology and Genetics Czech Academy of Sciences60200 BrnoCzech Republic Department of Molecular Cell and Developmental Biology University of CaliforniaLos AngelesLos AngelesCA 90095USA Department of Women’s and Children’s Health Dunedin School of MedicineUniversity of OtagoDunedinNew Zealand Department of Human Genetics Los AngelesCA 90095USA Department of Obstetrics and Gynecology Los AngelesCA 90095USA Department of Pediatrics David Geffen School of Medicine at University of CaliforniaLos AngelesLos AngelesCA 90095USA

Spondylocarpotarsal syndrome(SCT) is a rare musculoskeletal disorder characterized by short stature and vertebral, carpal, and tarsal fusions resulting from biallelic nonsense mutations in the gene encoding filamin B(FLNB). Utilizing a FLNB knockout mouse,we showed that the vertebral fusions in SCT evolved from intervertebral disc(IVD) degeneration and ossification of the annulus fibrosus(AF), eventually leading to full trabecular bone formation. This resulted from alterations in the TGFβ/BMP signaling pathway that included increased canonical TGFβ and noncanonical BMP signaling. In this study, the role of FLNB in the TGFβ/BMP pathway was elucidated using in vitro, in vivo, and ex vivo treatment methodologies. The data demonstrated that FLNB interacts with inhibitory Smads 6 and 7(i-Smads) to regulate TGFβ/BMP signaling and that loss of FLNB produces increased TGFβ receptor activity and decreased Smad 1 ubiquitination. Through the use of small molecule inhibitors in an ex vivo spine model, TGFβ/BMP signaling was modulated to design a targeted treatment for SCT and disc degeneration. Inhibition of canonical and noncanonical TGFβ/BMP pathway activity restored Flnb-/-IVD morphology. These most effective improvements resulted from specific inhibition of TGFβand p38 signaling activation. FLNB acts as a bridge for TGFβ/BMP signaling crosstalk through i-Smads and is key for the critical balance in TGFβ/BMP signaling that maintains the IVD. These findings further our understanding of IVD biology and reveal new molecular targets for disc degeneration as well as congenital vertebral fusion disorders.

关键词： TGFβ vivo BMP treatment

Phytochrome Signaling in Green Arabidopsis Seedlings： Impact Assessment of a Mutually Negative phyB-PIF Feedback Loop

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Molecular Plant 2012年第3期5卷 734-749页

作者： Pablo Leivar Elena Monte Megan M. cohn Peter H. Quail Department of Plant and Microbial Biology University of California Berkeley CA 94720 USA United States Department of Agriculture Plant Gene Expression Center Albany CA 94710 USA Department of Molecular Genetics Center for Research in Agricultural Genomics （CRAG） CSIC-IRTA-UAB-UB Campus UAB Bellaterra （Cerdanyola del Valles） 08193 Barcelona Spain

The reversibly red （R）/far-red （FR）-Iight-responsive phytochrome （phy） photosensory system initiates both the deetiolation process in dark-germinated seedlings upon first exposure to light, and the shade-avoidance process in fully deetiolated seedlings upon exposure to vegetational shade. The intracellular signaling pathway from the light-activated photoreceptor conformer （Pfr） to the transcriptional network that drives these responses involves direct, physical inter- action of Pfr with a small subfamily of bHLH transcription factors, termed Phy-lnteracting Factors （PIFs）, which induces rapid PIF proteolytic degradation. In addition, there is evidence of further complexity in light-grown seedlings, whereby phyB-PIF interaction reciprocally induces phyB degradation, in a mutually-negative, feedback-loop configuration. Here, to assess the relative contributions of these antagonistic activities to the net phenotypic readout in light-grown seedlings, we have examined the magnitude of the light- and simulated-shade-induced responses of a pentuple phyBpiflpif3pif4pif5 （phyBpifq） mutant and various multiple pif-mutant combinations. The data （1） reaffirm that phyB is the predominant, if not exclusive, photoreceptor imposing the inhibition of hypocotyl elongation in deetiolating seedlings in response to pro- longed continuous R irradiation and （2） show that the PIF quartet （PIF1, PIF3, PIF4, and PIF5） retain and exert a dual capacity to modulate hypocotyl elongation under these conditions, by concomitantly promoting cell elongation through intrinsic transcriptional-regulatory activity, and reducing phyB-inhibitory capacity through feedback-loop-induced phyB degrada- tion. In shade-exposed seedlings, immunoblot analysis shows that the shade-imposed reduction in Pfr levels induces increases in the abundance of PIF3, and mutant analysis indicates that PIF3 acts, in conjunction with PIF4 and PIF5, to promote the known shade-induced acceleration of hypocotyl elongation. Conversel

关键词： Light regulation light signaling genetics molecular biology transcriptional control and transcription fac- tors photomorphogenesis

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法国值得一去的美丽地方

英语画刊(高中版) 2023年第20期 16-17页

作者： Lindsay cohn

除了著名的凯旋门、埃菲尔铁塔、凡尔赛宫和卢浮宫,法国还有哪些值得一去的地方呢?Gordes戈尔德斯Gordes is one of the most beautiful small towns in the *** of tourists are drawn in the hopes of capturing the perfect shot of its cobbled lanes,time-worn churches,and 12th-century Sénanque Abbey framed by lavender fields.戈尔德斯是世界上最美的小镇之一。大批游客被吸引前来,希望能捕捉到鹅卵石小道、古老的教堂和被薰衣草田环绕的12世纪塞南克修道院的完美镜头。

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Critical Climate Change—Minority Report on 21st Century Western Studies

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Comparative Literature:East & West 2007年第2期 1-10页

作者： Tom cohn State University of New York

本文论述了21世纪西方的文化研究中出现的转向:从"他者的他者性"向"全然他者"的转向。这种转向不仅同全球"气候变化"有关,还同体制自身内部的转变有关。作者首先针对中国学者提出的"另类现代性"阐明了自己的观点,接着具体阐述了当今文... 详细信息

本文论述了21世纪西方的文化研究中出现的转向:从"他者的他者性"向"全然他者"的转向。这种转向不仅同全球"气候变化"有关,还同体制自身内部的转变有关。作者首先针对中国学者提出的"另类现代性"阐明了自己的观点,接着具体阐述了当今文化研究中的新动向,认为这同"后民主时代"的政治转向密不可分,标志着传统文化研究模式的终结,转向对"伦理"、"人权"和"技术"的关注,极大地改变了人们对当今"全球"现状的理解,体现出对"全然他者"的关注。作为文化批判的人文学科,显然应该直面人类自身的弱点和局限性。最后,作者对新的文化研究提出了几点初步设想,并附带提出了新的研究视野中的文本阅读和"理论消费"问题。

关键词：传统文化研究文本阅读文化批判人文学科气候变化现代性 horizon invention t

手术室自动化机器人辅助手术器材提升医疗效率

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空中英语教室（高级版．彭蒙惠英语） 2022年第9期 24-25,46,47页

作者： Meredith cohn 陈信宏(译) 不详

工程师打造无医生陪同的手术机器人在约翰霍普金斯大学位于马里兰州巴尔的摩市的霍姆伍德校区一间高科技实验室里,工程师正打造部机器人,它也许能缝合你肚子里断裂的血管,有朝一日甚至还能缝合你的大脑,而且不需要有医生在场。这部机器... 详细信息

工程师打造无医生陪同的手术机器人在约翰霍普金斯大学位于马里兰州巴尔的摩市的霍姆伍德校区一间高科技实验室里,工程师正打造部机器人,它也许能缝合你肚子里断裂的血管,有朝一日甚至还能缝合你的大脑,而且不需要有医生在场。这部机器人的一支手臂上有个高科技摄像机,另一支手臂,上有一部高科技缝合机。它已经能把被切成两半的猪肠缝合起来。

关键词：机器人医疗效率马里兰州手术室高科技摄像机自动化工程师