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Competition and the evolution of imperfect mimicry

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Current Zoology 2012年第4期58卷 608-619页

作者： david W. PFENNIG david W. KIKUCHI Department of Biology University of North Carolina Chapel Hill NC 27599-3280 USA

Mimicry is widely used to exemplify natural selection＇s power in promoting adaptation. Nonetheless, it has become increasingly clear that mimicry is frequently imprecise. Indeed, the phenotypic match is often poor between mimics and models in many Batesian mimicry complexes and among co-mimics in many Mtillerian mimicry complexes. Here, we consider whether such imperfect mimicry represents an evolutionary compromise between predator-mediated selection favoring mimetic conver- gence on the one hand and competitively mediated selection favoring divergence on the other hand. Specifically, for mimicry to be effective, mimics and their models/co-mimics should occur together. Yet, co-occurring species that are phenotypically similar often compete for resources, successful reproduction, or both. As an adaptive response to minimize such costly interactions, in-teracting species may diverge phenotypically through an evolutionary process known as character displacement. Such divergence between mimics and their models/co-mimics may thereby result in imperfect mimicry. We review the various ways in which character displacement could promote imprecise mimicry, describe the conditions under which this process may be especially likely to produce imperfect mimicry, examine a possible case study, and discuss avenues for future research. Generally, character displacement may play an underappreciated role in fostering inexact mimicry .

关键词： Batesian mimicry Character displacement Hybridization MtUlerian mimicry Reproductive interference Selectivetrade-off

Current state-of-the-art review of footwear–ground friction

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Friction 2024年第10期12卷 2188-2204页

作者： david REBENDA Tomáš SÁHA Footwear Research Centre University InstituteTomas Bata University in ZlinZlin 76001Czech Republic Faculty of Mechanical Engineering Brno University of TechnologyBron 61600Czech Republic

The most important role of footwear is to ensure safe,functional walking,and foot *** the proper functionality of not only the work shoes,the anti-slip behavior of the shoe under various conditions and environments plays an important role in the prevention of slips,trips,falls,and consequent *** article is intended to review the current understanding of the frictional mechanisms between shoe outsoles and various counterfaces that impact the evaluation of outsole *** research focuses on the mechanisms driving outsole friction on different ground surfaces or the definition and description of parameters that influence outsole ***,the review discusses the effect of various surface contaminants on footwear ***,challenges and outlooks in the field of footwear outsoles are briefly mentioned.

关键词： shoe outsole composite slipperiness coefficient of friction(COF) adhesion safe walk

A Batesian mimic and its model share color production mechanisms

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Current Zoology 2012年第4期58卷 658-667页

作者： david W. KIKUCHI david W. PFENNIG Department of Biology University of North Carolina at Chapel Hill Chapel Hill NC 27599-3280 USA

Batesian mimics are harmless prey species that resemble dangerous ones （models）, and thus receive protection from predators. How such adaptive resemblances evolve is a classical problem in evolutionary biology. Mimicry is typically thought to be difficult to evolve, especially if the model and mimic produce the convergent phenotype through different proximate mecha- nisms. However, mimicry may evolve more readily if mimic and model share similar pathways for producing the convergent phenotype. In such cases, these pathways can be co-opted in ancestral mimic populations to produce high-fidelity mimicry with- out the need for major evolutionary innovations. Here, we show that a Batesian mimic, the scarlet kingsnake Larnpropeltis elap-soides, produces its coloration using the same physiological mechanisms as does its model, the eastern coral snake Micrurus fulvius. Therefore, precise color mimicry may have been able to evolve easily in this system. Generally, we know relatively little about the proximate mechanisms underlying mimicry .

关键词： Adaptation Coloration Convergent evolution Pteridine Pigment

Synthesis and biological activity of 3,6-diaryl-7H-thiazolo[3,2-b][1,2,4]triazin-7-one derivatives as novel acetylcholinesterase inhibitors

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Science China Chemistry 2010年第11期53卷 2297-2303页

作者： WAN david ChiCheong Department of Biochemistry Chinese University of Hong Kong

Acetylcholinesterase inhibitors played significant roles in treatment of Alzheimer's *** on the research foundation of our previous work and molecular modeling,twelve 3,6-diaryl-7H-thiazolo[3,2-b][1,2,4]triazin-7-one derivatives were synthesized and characterized by mass spectra,infrared spectra,NMR and elemental *** study of AChE inhibitory activity was carried out using the Ellman colorimetric assay with huperzine-A as the positive *** target compounds exhibited more than 40% inhibition at 10 μ*** target compounds showed good inhibition against *** preliminary structure-activity relationships were the halogen atoms at the phenyl ring at the C6 position,the hydroxy groups and the long side chains at the phenyl ring at the C3 position of the parent nucleus played significant roles in the AChE inhibitory activity of the target compounds.

关键词： acetylcholinesterase,inhibitor thiazole,1,2,4-triazine,heterocycle,synthesis,docking,MVD

TDP-43 and amyloid precursor protein processing: implications for Alzheimer's disease

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Neural Regeneration Research 2021年第7期16卷 1402-1403页

作者： david A.Hicks Division of Neuroscience and Experimental Psychology School of Biological SciencesFaculty of BiologyMedicine and HealthUniversity of ManchesterManchester Academic Health Science CentreManchesterUK RBMOnline Bourn HallBournCambridgeUK

In this perspective article,I will discuss our recent publication(Hicks et al.,2020),specifically its major findings and integration with the published ***'s disease(AD)is a progressive neurodegenerative disease of predominantly unknown *** neuropathological hallmarks are extracellular plaques formed of the amyloid beta(Aβ)peptide and neurofibrillary tangles of tau protein.

关键词： Alzheimer Aβ tau

Roles of secreted frizzled-related proteins in cancer

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Acta Pharmacologica Sinica 2007年第9期28卷 1499-1504页

作者： david M JABLONS Thoracic Oncology Laboratory Department of SurgeryComprehensive Cancer CenterUniversity of CaliforniaSan FranciscoCA 94115USASRI International333 Ravenswood AvenueMenlo ParkCA 94025 USA

The Wnt signaling pathway is implicated in a variety of biological processesranging from developmental cell fate to human *** components involvedin Wnt signaling have been under intense investigation over the last 2 *** canonical Wnt activation has been linked to tumor formation andinvolves activation of effector molecules or loss of tumor suppressor *** frizzled-related proteins (sFRPs) are Wnt *** recent years,accumulating evidence has suggested that sFRPs act as tumor suppressorsbecause their expression is frequently silenced in cancer by promoter ***,sFRPs may also promote cell growth in some ***,wefocus on the known knowledge of sFRPs in tumorigenesis.

关键词： Wnt signaling pathway secreted frizzledrelated proteins cancer

Numerical simulations for MHD coronal seismology

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Research in Astronomy and Astrophysics 2014年第7期14卷 805-830页

作者： david James Pascoe Centre for Fusion Space and AstrophysicsPhysics DepartmentUniversity of WarwickUK

Magnetohydrodynamic（MHD） processes are important for the transfer of energy over large scales in plasmas and so are essential to understanding most forms of dynamical activity in the solar atmosphere. The introduction of transverse structuring into models for the corona modifies the behavior of MHD waves through processes such as dispersion and mode coupling. Exploiting our understanding of MHD waves with the diagnostic tool of coronal seismology relies upon the development of sufficiently detailed models to account for all the features in observations. The development of realistic models appropriate for highly structured and dynamical plasmas is often beyond the domain of simple mathematical analysis and so numerical methods are employed. This paper reviews recent numerical results for seismology of the solar corona using MHD.

关键词： MHD -- methods: numerical -- Sun: corona -- Sun: magnetic fields --Sun: oscillations -- waves

Evolutionary responses to climate change and contaminants： Evidence and experimental approaches

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Current Zoology 2015年第4期61卷 690-701页

作者： david A. KIMBERLY Department of Biology Westminster College 442 Meldrum Science Center Salt Lake City UT 84105 USA Department of Environmental Toxicology The Institute of Environmental and Human Health Texas Tech University 1207 Gilbert Drive Lubbock Texas 79416 USA Environmental Science and Studies Program Towson University 8000 York Rd. Towson MD 21252 USA

A fundamental objective within ecotoxicology lies in understanding and predicting effects of contaminants. This ob- jective is made more challenging when global climate change is considered as an environmental stress that co-occurs with con- taminant exposure. In this multi-stressor context, evolutionary processes are particularly important. In this paper, we consider several non-＂omic＂ approaches wherein evolutionary responses to stress have been studied and discuss those amenable to a mul- tiple stressor context. Specifically, we discuss common-garden designs, artificial and quasi-natural selection, and the estimation of adaptive potential using quantitative genetics as methods for studying evolutionary responses to contaminants and climate change in the absence of expensive molecular tools. While all approaches shed light on potential evolutionary impacts of stressor exposure, they also have limitations. These include logistical constraints, difficulty extrapolating to real systems, and responses tied strongly to specific taxa, populations, and/or testing conditions. The most effective way to lessen these inherent limitations is likely through inclusion of complementary physiological and molecular tools, when available. We believe that an evolutionary context to the study of contaminants and global climate change is a high priority in ecotoxicology and we outline methods that can be implemented by almost any researcher but will also provide valuable insights [Current Zoology 61 （4）： 690-701, 2015].

关键词： Climate change Multiple stressors Adaptation Experimental evolution Quantitative genetics

Re-Establishing the Merits of Thermal Maturity and Petroleum Generation Multi-Dimensional Modeling with an Arrhenius Equation Using a Single Activation Energy

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Journal of Earth Science 2017年第5期28卷 804-834页

作者： david A.Wood DWA Energy Limited

Thermal maturation and petroleum generation modeling of shales is essential for suc- cessful exploration and exploitation of conventional and unconventional oil and gas plays. For basin- wide unconventional resource plays such modeling, when well calibrated with direct maturity meas- urements from wells, can characterize and locate production sweet spots for oil, wet gas and dry gas. The transformation of kerogen to petroleum is associated with many chemical reactions, but models typically focus on first-order reactions with rates determined by the Arrhenius Equation. A miscon- ception has been perpetuated for many years that accurate thermal maturity modeling of vitrinite re- flectance using the Arrhenius Equation and a single activation energy, to derive a time-temperature index （~TTIARa）, as proposed by Wood （1988）, is flawed. This claim was initially made by Sweeney and Burnham （1990） in promoting their ＂EasyRo＂ method, and repeated by others. This paper dem- onstrates through detailed multi-dimensional burial and thermal modeling and direct comparison of the ~TTIARR and ＂EasyRo＂ methods that this is not the case. The ~TTIA^R method not only provides a very useful and sensitive maturity index, it can reproduce the calculated vitrinite reflectance values derived from models based on multiple activation energies （e.g., ＂EasyRo＂）. Through simple expres- sions the ~TTIAaa method can also provide oil and gas transformation factors that can be flexibly scaled and calibrated to match the oil, wet gas and dry gas generation windows. This is achieved in a more-computationally-efficient, flexible and transparent way by the ~TTIARR method than the ＂EasyRo＂ method. Analysis indicates that the ＂EasyRo＂ method, using twenty activation energies and a constant frequency factor, generates reaction rates and transformation factors that do not realisti- cally model observed kerogen behaviour and transformation factors over geologic time scales.

关键词： time-temperature maturity index kerogen activation energies kerogen reaction rates multi-dimensional thermal maturity models petroleum generation versus vitrinite reflectance burial/ thermal history analysis.