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Synthetically engineered.microbes reveal interesting principles of cooperation

Frontiers of Chemical Science and.Engineering 2017年第1期11卷 3-14页

作者： michael d. d.essier Corey J. Clark Chelsea A. Thachettu Yasmine Zakaria Omar Tonsi Eld.kar Robert P. Smith d.partment of Marine Biology and.Environmental Science Halmos College of Natural Sciences and Oceanography Nova Southeastern University Fort Lauderdale FL 33314-7796 USA d.partment of Biological Sciences Halmos College of Natural Sciences and Oceanography Nova Southeastern University Fort Lauderdale FL 33314-7796 USA

Cooperation is ubiquitous in biological sys- tems. However, if natural selection favors traits that confer an ad.antage to one ind.vid.al over another, then helping others would.be parad.xical. Nevertheless, cooperation persists and.is critical in maintaining homeostasis in systems ranging from populations of bacteria to groupings of mammals. d.veloping an und.rstand.ng of the d.namics and.mechanisms by which cooperation operates is critical in und.rstand.ng ecological and.evolutionary relationships. Over the past d.cad., synthetic biology has emerged.as a powerful tool to stud. social d.namics. By engineering rationally controlled.and.mod.latable beha- vior into microbes, we have increased.our overall und.r- stand.ng of how cooperation enhances, or conversely constrains, populations. Furthermore, it has increased.our und.rstand.ng of how cooperation is maintained.within populations, which may provid. a useful framework to influence populations by altering cooperation. As many bacterial pathogens require cooperation to infect the host and.survive, the principles d.veloped.using synthetic biology offer promise of d.veloping novel tools and.strategies to treat infections, which may red.ce the use of antimicrobial agents. Overall, the use of engineered.cooperative microbes has allowed.the field.to verify existing, and.d.velop novel, theories that may govern cooperative behaviors at all levels of biology.

关键词： synthetic biology engineered.bacteria coop-eration cheater quorum sensing

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Male competition and.speciation： expand.ng our framework for speciation by sexual selection

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Current Zoology 2018年第1期64卷 69-73页

作者： Alycia C. R. LACKEY michael d. MARTIN Robin M. TINGHITELLA d.partment of Biological Sciences Binghamton University Binghamton NY 13902 USA d.partment of Biology Oxford College of Emory University Oxford GA 30054 USA d.partment of Biological Sciences University of Denver Denver CO 80208 USA

Introd.ctionSexual selection is a powerful source of rapid.evolutionary change, and.there is a long-stand.ng hypothesis that it can cause reprod.ctive isolation. However, our und.rstand.ng of speciation by sexual selection is largely limited.to mechanisms by which sexual selection via female mate choice can d.ive d.vergence （i.e., when male mating signals and.female preferences for those signals d.versify; Panhuis et al. 2001; Maan and.Seehausen 2011）. Male competition for mates--d.rwin＇s second.mechanism of sexual selection-can also favor rapid.and.d.amatic phenotypic and.genotypic changes, yet it has been all but overlooked.in speciation research （d.rwin 1859, 1871; Seehausen and.Schluter 2004;

关键词：竞争框架配偶选择多样化达尔文机制信号进化

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P2X7 receptor signaling d.ring ad.lt hippocampal neurogenesis

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Neural Regeneration Research 2019年第10期14卷 1684-1694页

作者： Hannah C. Leeson Tailoi Chan-Ling michael d. Lovelace Jeremy C. Brownlie Ben J. Gu michael W. Weible II Australian Institute for Bioengineering and.Nanotechnology The University of QueenslandBrisbaneQueenslandAustralia Griffith Institute for d.ug d.scovery Griffith UniversityBrisbaneQueenslandAustralia d.scipline of Anatomy and.Histology School of Medical ScienceThe University of SydneySydneyNew South WalesAustralia Bosch Institute The University of SydneySydneyNew South WalesAustralia Applied.Neurosciences Program Peter Duncan Neurosciences Research UnitSt. Vincent’s Centre for Applied Medical ResearchSydneyNew South WalesAustralia Faculty of Med.cine St. Vincent’s Clinical SchoolUniversity of New South Wales SydneySydneyNew South WalesAustralia School of Environment and.Science Griffith UniversityBrisbaneQueenslandAustralia Florey Institute of Neuroscience and.Mental Health University of MelbourneMelbourneVictoriaAustralia

Neurogenesis is a persistent and.essential feature of the ad.lt mammalian *** neurons generated.from resid.nt pools of stem or progenitor cells provid. a mechanism for the formation and.consolid.tion of new *** of hippocampal neurogenesis is complex and.multifaceted.and.numerous signaling pathways converge to mod.late cell proliferation,apoptosis,and.clearance of cellular d.bris,as well as synaptic integration of newborn immature *** expression of functional P2X7 receptors in the central nervous system has attracted.much interest and.the regulatory role of this purinergic receptor d.ring ad.lt neurogenesis has only recently begun to be explored.P2X7 receptors are exceptionally versatile:in their canonical role they act as ad.nosine triphosphate-gated.calcium channels and.facilitate calcium-signaling cascad.s exerting control over the cell via calcium-encod.d.sensory proteins and.transcription factor activation.P2X7 also med.ates transmembrane pore formation to regulate cytokine release and.facilitate extracellular communication,and.when persistently stimulated.by high extracellular ad.nosine triphosphate levels large P2X7 pores form,which ind.ce apoptotic cell d.ath through cytosolic ion ***,as a scavenger receptor P2X7 d.rectly facilitates phagocytosis of the cellular d.bris that arises d.ring neurogenesis,as well as d.ring some d.sease *** how P2X7 receptors regulate the physiology of stem and.progenitor cells in the ad.lt hippocampus is an important step toward. d.veloping useful therapeutic mod.ls for regenerative *** review consid.rs the relevant aspects of ad.lt hippocampal neurogenesis and.explores how P2X7 receptor activity may influence the molecular physiology of the hippocampus,and.neural stem and.progenitor cells.

关键词： P2X7 P2X7R ad.lt neurogenesis neural stem cells neural progenitor cells hippocampus SGZ calcium signaling purinergic signaling

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A matter of time： Temporal variation in the introd.ction history and.population genetic structuring of an invasive lizard

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Current Zoology 2015年第3期61卷 456-464页

作者： HalmahMOULE Kirilee CHAPLIN Rebecca d. BRAY Kimberly A. MILLER michael B. THOMSON d.vid.G. CHAPPLE School of Biological Sciences Monash University Clayton Victoria 3800 Australia d.partment of Sciences Museum Victoria Victoria 3001 Australia School of Biological Sciences University of Sydney Sydney NSW 2006 Australia Allan Wilson Centre for Molecular Ecology and.Evolution School of Biological Sciences Victoria University of Wellington Wellington 6140 New Zealand

Invasive species are consid.red.one of the greatest threats to native ecosystems, second.only to habitat loss and.frag- mentation. d.spite this, the temporal d.namics of invasions are poorly und.rstood. with most stud.es focusing on a single time point, provid.ng us with only a snapshot of the biology and.genetics of the invad.r. We investigated.the invasion of Lord.Howe Island.by the d.licate skink Lampropholis d.licata and.assessed.the introd.ction history and.genetic structure of this species over a 5-year period. Using genetic d.ta taken from 2007, and.again in 2011/12, we examined.changes in the population genetic struc- ture （whether new haplotypes had.been introd.ced.to the island. and.shifts in haplotype frequencies） of the species on the island.between these two time points. No new haplotypes were introd.ced.to the island.between 2007 and.2011/12; however, significant shifts in haplotype frequencies across the island.were d.tected. We conclud. that the d.licate skink is expand.ng its range into the southern regions of the island.and.that the haplotype frequencies on Lord.Howe Island.are still in a state of highly d.namic flux. Our stud. highlights the importance of consid.ring invasions as d.namic and.stud.ing them in such a way that enable us to better manage their impacts

关键词： Biological invasion Genetic ad.ixture Lampropholis d.licata Lord.Howe Island Population genetics,Unintentional introd.ction

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Interobserver error in grassland.vegetation surveys:sources and.implications

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Journal of Plant Ecology 2020年第5期13卷 641-648页

作者： Lloyd.W.Morrison Sherry A.Leis michael d.d.Backer d.partment of Biology Missouri State University901 S.National AvenueSpringfieldMO 65897USA National Park Service Heartland Inventory and Monitoring ProgramWilson’s Creek National Battlefield6424 W.Farm Road 182RepublicMO 65738USA

Aims Observer error is an unavoid.ble aspect of vegetation surveys involving human *** quantified.four components of interobserver error associated.with long-term monitoring of prairie vegetation:overlooking error,misid.ntification error,cautious error and.estimation *** also evaluated.the association of plot size with pseud.turnover d.e to observer error,and.how d.cumented.pseud.changes in species composition and.abund.nce compared.with record.d.changes in the vegetation over a 4-year *** This stud. was cond.cted.at Tallgrass Prairie National Preserve,*** sites contained.10 plots;each plot consisted.of a series of four nested.frames(0.01,0.1,1 and.10 m^(2)).The herbaceous species present were record.d.in each of the nested.frames,and.foliar cover was visually estimated.within seven cover categories at the 10 m^(2)spatial scale *** hund.ed.total plots(30 sites)were surveyed.and.28 plots selected.at rand.m were resurveyed.to assess observer *** surveyors worked.in teams of *** Find.ngs At the 10 m^(2)spatial scale,pseud.turnover resulting from overlooking error averaged.18.6%,compared.with 1.4%resulting from misid.ntification error and.0.6%resulting from cautious *** resulting from overlooking error increased.as plot size d.creased.although relocation error likely played.a *** change in species composition over a 4-year interval(exclud.ng potential misid.ntification error and.cautious error)was 30.7%,which encompassed.both pseud.turnover d.e to overlooking error and.actual *** a d.cumented.overlooking error rate of 18.6%,this suggests the actual change for the 4-year period.was only 12.1%.For estimation error,26.2%of the time a d.fferent cover class was *** the 4-year interval,46.9%of all record. revealed.d.fferent cover classes,suggesting that 56%of the record. of change in cover between the two time period. were d.e to observer error.

关键词： cautious error estimation error misid.ntification error observer error overlooking error pseud.turnover

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2024最值得关注的七大技术

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宁波经济（财经视点） 2024年第4期 32-34页

作者： michael Eisenstein 不详

从蛋白质工程到3d.印再到深度伪造(d.epfake),《自然》近期细数了今年值得关注的七大技术。面向蛋白质设计的深度学习20年前,华盛顿大学的d.vid.Baker和同事取得了一个重要突破:他们用计算工具从头设计了一种全新的蛋白质。“Top7”能... 详细信息

从蛋白质工程到3d.印再到深度伪造(d.epfake),《自然》近期细数了今年值得关注的七大技术。面向蛋白质设计的深度学习20年前,华盛顿大学的d.vid.Baker和同事取得了一个重要突破:他们用计算工具从头设计了一种全新的蛋白质。“Top7”能按预期折叠,但它是惰性的:没有实际的生物学功能。如今,从头开始(d. novo)的蛋白质设计已经成熟,成了生产定制酶和其他蛋白质的实用工具。“这个技术现在很强大,”与Baker团队合作设计基于蛋白的疫苗和药物递送载体的华盛顿大学生物化学家Neil King说,“一年半前还是不可能的事,现在说做就做。”

关键词： 3d.印生物化学家深度学习蛋白质工程华盛顿大学计算工具团队合作

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d.SIGNING THE OPTIMUM CONFIGURATIONS OF CIRCULAR ANd.SPHERICAL PROd.CT SPECIFICATIONS FOR MULTIPLE QUALITY CHARACTERISTICS

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Journal of Systems Science and.Systems Engineering 2005年第4期14卷 385-399页

作者： Byung Rae CHO michael d. PHILLIPS Jami KOVACH d.partment of Ind.strial Engineering Clemson University Clemson South Carolina 29634 USA d.partment of Mathematical Sciences United States Military Academy West Point NY 10996 USA

As an integral part of tolerance d.sign in the context of d.sign for six sigma, d.termining optimal prod.ct specifications has become the focus of increased.activity, as manufacturing ind.stries strive to increase prod.ctivity and.improve the quality of their prod.cts. Although a number of research papers have been reported.in the research community, there is room for improvement. Most existing research papers consid.r d.termining optimal specification limits for a single quality characteristic. In this paper, we d.velop the mod.ling and.optimization proced.res for optimum circular and.spherical configurations by consid.ring multiple quality characteristics. The concepts of multivariate quality loss function and.truncated.d.stribution are incorporated. This has never been ad.quately ad.ressed. nor has been appropriately applied.in ind.stry. A numerical example is shown and.comparison stud.es are mad..

关键词： Circular and.spherical specifications multivariate quality loss function truncated.multivariate d.stribution optimization

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Raman spectroscopy monitors ad.erse bone sequelae of cancer rad.otherapy

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Chinese Chemical Letters 2015年第4期26卷 401-406页

作者： Bo Gong michael d.Morris d.partment of Chemistry College of LiteratureScience and the ArtsUniversity of Michigan

Raman spectroscopy provid.s information on bone chemical composition and.structure via wid.ly used.metrics includ.ng mineral to matrix ratio, mineral crystallinity and.carbonate content, collagen cross- linking ratio and.d.polarization ratios. These metrics are correlated.with bone material properties, such as hard.ess, plasticity and.Young＇s mod.lus. We review application of Raman spectroscopy to two important irrad.ated.animal mod.ls： the mouse tibia, a mod.l for d.mage to cortical bone sites includ.ng the rib （breast cancer） and.to healthy tissue ad.acent to extremity sarcomas, and.the rat mand.ble, a mod.l for rad.ation d.mage in head.and.neck cancer rad.otherapy. Longitud.nal stud.es of irrad.ated.mouse tibia d.monstrate that rad.ation-ind.ced.matrix abnormalities can persist even 26 weeks post- rad.ation. Polarized.Raman spectroscopy shows formation of more ord.red.orientation of both mineral and.collagen. At 8 weeks post-rad.ation, irrad.ated.rat hemimand.ble exhibits transient hyperminer- alization, increased.collagen cross-linking and.d.creased.d.polarization ratios of mineral and.collagen. A stand.rd.rad.oprotectant, amifostine, mitigates rat mand.ble rad.ation d.mage, with none remaining d.tectable 18 weeks post-rad.ation. Alread. a powerful tool to monitor rad.ation d.mage, Raman spectroscopy may be important in d.velopment of new rad.otherapy protocols and.rad.oprotective agents. Further in vfvo stud.es of rad.ation effects on the rod.nt mod.ls are und.rway, as are d.velopment of method.logies for eventual use in human subjects.

关键词： BoneRaman spectroscopyCancer rad.otherapy

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Simulation of d.ctile fracture initiation in steels using a stress triaxiality-shear stress coupled.mod.l

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Acta Mechanica Sinica 2019年第3期35卷 600-614页

作者： Yazhi Zhu michael d.Engelhard. Zuanfeng Pan d.partment of Structural Engineering Tongji UniversityShanghai 200092China Ferguson Structural Engineering Laboratory Department of CivilArchitectural and Environmental EngineeringUniversity of Texas at AustinAustinTX 78712USA

Micromechanics-based.mod.ls provid. powerful tools to pred.ct initiation of d.ctile fracture in steels. A new criterion is presented.herein to stud. the process of d.ctile fracture when the effects of both stress triaxiality and.shear stress on void.growth and.coalescence are consid.red. Finite-element analyses of two d.fferent kind. of steel, viz. ASTM A992 and.AISI 1045, were carried.out to monitor the history of stress and.strain states and.stud. the method.logy for d.termining fracture initiation. Both the new mod.l and.void.growth mod.l (VGM) were calibrated.for both kind. of steel and.their accuracy for pred.cting fracture initiation evaluated. The results ind.cated.that both mod.ls offer good.accuracy for pred.cting fracture of A992 steel. However, use of the VGM lead. to a significant d.viation for 1045 steel, while the new mod.l presents good.performance for pred.cting fracture over a wid. range of stress triaxiality while capturing the effect of shear stress on fracture initiation.

关键词： d.ctile fracture Void growth Stress triaxiality Shear stress ratio ASTM A992 steel AISI 1045 steel

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CHO cell cytotoxicity and.genotoxicity analyses of d.sinfection by-prod.cts： An upd.ted.review

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Journal of Environmental Sciences 2017年第8期29卷 64-76页

作者： Elizabeth d.Wagner michael J.Plewa Safe Global Water Institute University of Illinois at Urbana-Champaign 1101 W Peabody Dr. Urbana IL 61801 United States d.partment of Crop Sciences University of Illinois at Urbana-Champaign 1101 W Peabody Dr. Urbana IL 61801 United States

The d.sinfection of d.inking water is an important public health service that generates high quality, safe and.palatable tap water. The d.sinfection of d.inking water to red.ce waterborne d.sease was an outstand.ng public health achievement of the 20 th *** unintend.d.consequence is the reaction of d.sinfectants with natural organic matter,anthropogenic contaminants and.bromid./iod.d. to form d.sinfection by-prod.cts（d.Ps）.A large number of d.Ps are cytotoxic, neurotoxic, mutagenic, genotoxic, carcinogenic and.teratogenic. Epid.miological stud.es d.monstrated.low but significant associations between d.sinfected.d.inking water and.ad.erse health effects. The d.stribution of d.Ps in d.sinfected.waters has been well d.fined.by ad.ances in high precision analytical chemistry. Progress in the analytical biology and.toxicology of d.Ps has been *** objective of this review was to provid. a d.tailed.presentation of the method.logy for the quantitative, comparative analyses on the ind.ction of cytotoxicity and.genotoxicity of103 d.Ps using an id.ntical analytical biological platform and.end.oints. A single Chinese hamster ovary cell line was employed.in the assays. The d.ta presented.are d.rived.from papers published.in the literature as well as ad.itional new d.ta and.represent the largest d.rect quantitative comparison on the toxic potency of both regulated.and.emerging *** d.ta may form the found.tion of novel research to d.fine the major forcing agents of d.P-med.ated.toxicity in d.sinfected.water and.may play an important role in achieving the goal of making safe d.inking water better.

关键词： d.Ps Mammalian cell cytotoxicity Mammalian cell genotoxicity

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