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Journal of Integrative Plant Biology 2014年第3期56卷 271-280页

作者： matthew J.Milner Nicole S.Pence Jiping Liu Leon V.Kochian Robert W.Holley Center for Agriculture and Health USDA‐ARS Cornell University Department of Plant Biology Cornell University

To gain a better understanding of the regulation of Zn homeostasis in plants and the degree of conservation of Zn homeostasis between plants and yeast, a cDNA library from the Zn/Cd hyperaccumulating plant species, Noccaea caerulescens, was screened for its ability to restore growth under Zn limiting conditions in the yeast mutant zaplA. ZAP1 is a transcription factor that activates the Zn dependent transcription of yeast genes involved in Zn uptake, including ZRT1, the yeast high affinity Zn transporter. from this screen two members of the E2f family of transcription factors were found to activate ZRT1 expression in a Zn independent manner. The activation of ZRTI by the plant E2f proteins involves E2f- mediated activation of a yeast GATA transcription factor which in turn activates ZRT1 expression. A ZRT1 promoter region necessary for activation by E2f and GATA proteins is upstream of two zinc responsive elements previously shown to bind ZAP1 in ZRT1. This activation may not involve direct binding of E2f to the ZRT1 promoter. The expression of E2f genes in yeast does not replace function of ZAP1; instead it appears to activate a novel GATA regulatory pathway involved in Zn uptake and homeostasis that is not Zn responsive.

关键词： E2f transcription factor GATA transcription factor ZRT1 Znhomeostasis

Bolstering integrity in environmental data science and machine learning requires understanding socioecological inequity

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frontiers of Environmental Science & Engineering 2024年第5期18卷 171-179页

作者： Joe f.Bozeman III School of Civil and Environmental Engineering Georgia Institute of TechnologyAtlantaGA30332USA School of Public Policy Georgia Institute of TechnologyAtlantaGA30332USA

Socioecological inequity in environmental data science—such as inequities deriving from data-driven approaches and machine learning(ML)—are current issues subject to debate and *** is growing consensus around embedding equity throughout all research and design domains—from inception to administration,while also addressing procedural,distributive,and recognitional ***,practically doing so may seem onerous or daunting to *** current perspective helps to alleviate these types of concerns by providing substantiation for the connection between environmental data science and socioecological inequity,using the Systemic Equity framework,and provides the foundation for a paradigmatic shift toward normalizing the use of equity-centered approaches in environmental data science and ML *** the integrity of environmental data science and ML is just beginning from an equity-centered tool development and rigorous application *** this end,this perspective also provides relevant future directions and challenges by overviewing some meaningful tools and strategies—such as applying the Wells-Du Bois Protocol,employing fairness metrics,and systematically addressing irreproducibility;emerging needs and proposals—such as addressing data-proxy bias and supporting convergence research;and establishes a ten-step path ***,the work that environmental scientists and engineers do ultimately affect the well-being of us all.

关键词： Equity Bias Machine Learning Data Science Justice Systemic Equity

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金属原子之间的键——过渡金属化学的新模式

有机化学 1983年第2期 147-155页

作者： f.A.Cotton M.H.chisholm 徐珍娥美国德州农工大学美国印第安纳大学

自从第二次世界大战以来,过渡金属化学一直在无机化学中占据了主导地位。奇怪的是,经历了这么多年以后,这些元素仍然是化学研究中的丰富领域。不论在理论上或是实际应用上,过渡金属都是化学研究的前沿。在过渡金属化学的各个方面,最吸... 详细信息

自从第二次世界大战以来,过渡金属化学一直在无机化学中占据了主导地位。奇怪的是,经历了这么多年以后,这些元素仍然是化学研究中的丰富领域。不论在理论上或是实际应用上,过渡金属都是化学研究的前沿。在过渡金属化学的各个方面,最吸引人的是多核金属簇化合物。它们包含二个或更多的金属原子互相成键,以及和非金属元素成键。在这些金属簇中,称为Chevrel面的是迄今发现的,强磁场中最好的超导材料。其它簇可用为重要有机反应的催化剂。有些则是光敏络合物,在把太阳能转化为更有用的能量中,有潜在的作用。当然对很多化学家来说,这些金属簇之令人注意,只是因为它们的存在。它们中有的很稳定,易于制备,但只是在最近才对它们的化学开始有所了解。本报告是由这一领域中两位杰出的化学家撰写的。他们讨论了这些络合物以及可能的应用。

关键词：金属原子氧化态过渡金属化学离子成键多重键化合物络合物配位化合物

Phylogenetic reconstruction of Chirita and allies (Gesneriaceae) with taxonomic treatments

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Journal of Systematics and Evolution 2011年第1期49卷 50-64页

作者： James f. SMITH Department of Biological Sciences Boise State University

Chirita D. Don, a large genus in the subfamily Cyrtandroideae of Gesneriaceae, has been the subject of much debate whether it is a natural group or not. In addition, the highly heterogeneous Chirita has also been very problematic with regard to delimitation and subdivision. Here we used the nrDNA internal transcribed spacer and cpDNA trnL-f for molecular phylogenetic analaysis, combined with morphological data. Our results suggest that Chirita is an artificial, polyphyletic genus. The most important character that defines Chirita, the dorso-ventrally oblique and bilamellar stigma, has evolved convergently in different clades of diandrous Cyrtandroideae. Chirita sensu stricto only includes the species of Chirita sect. Chirita, whereas Chirita sect. Microchirita is an independent clade located at the basal node of the phylogenetic tree. Chirita sect. Liebigia is closely related to Didymocarpus with an entire stigma unlike other species of Chirita. The species of Chirita sect. Gibbosaccus, Chiritopsis, Primulina, and Wentsaiboea form a monophyletic group that is sister to a strongly supported clade comprising four monotypic genera Paralagarosolen, Calcareoboea, Petrocodon, and Tengia. We further analyzed the morphological evolution of Chirita and identified a series of morphological synapomorphies for the monophyletic groups revealed herein, and thereby provide a taxonomic treatment in this study.

关键词： Chirita D. Don morphological evolution phylogenetic reconstruction polyphyly taxonomic treatment.

Phase Stability, Kinetic Diagrams and Diffusion Path in High Temperature Oxidation of Binary Solid-Solution Alloys

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Journal of Materials Science & Technology 2003年第6期19卷 545-552页

作者： YanNIU f.Gesmundo StateKeyLaboratoryforCorrosionandProtection InstituteofMetalResearchShenyang110016China DipartimentodiIngegneriaChimicaediProcesso UniversityofGenova16129GenovaItaly

The phase diagrams of ternary systems involving two metal components and one oxidant are considered first, the limitations to their use is discussed in relation to the high temperature oxidation of binary alloys. Kinetic diagrams, which are useful to predict the conditions for the stability of the two mutually insoluble oxides as the external scale, are then calculated on the basis of thermodynamic and kinetic data concerning both the alloys and the oxides, assuming the validity of the parabolic rate law. A combination of the two types of diagrams provides a more detail information about the oxidation behavior of binary alloys. The calculation of the diffusion paths, which relate the oxidant pressure to the composition of the system in terms of the alloy components both in the alloy and in the scale during an initial stage of the reaction in the presence of the parabolic rate law, is finally developed.

关键词： Binary alloys Oxidation Therniodynamic and kinetic diagrams Diffusion path

Dose-Dependent AGO1-Mediated Inhibition of the miRNA165/166 Pathway Modulates Stem Cell Maintenance in Arabidopsis Shoot Apical Meristem

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Plant Communications 2020年第1期1卷 179-189页

作者： fei Du Wen Gong Sonia Bosca matthew Tucker Herve Vaucheret Thomas Laux Signalling Research Centres BIOSS and CIBSS Faculty of BiologyUniversity of FreiburgSchanzlestrasse 179104 FreiburgGermany Institut Jean-Pierre Bourgin INRAAgroParisTechCNRSUniversite Paris-Saclay78000 VersaillesFrance Sino-German Joint Research Center on Agricultural Biology Shandong Agricultural UniversityTai’anShandongChina State Key Laboratory of Plant Genomics Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China School of Agriculture Food and WineUniversity of AdelaideWaite CampusUrrbraeSAAustralia

Pluripotent stem cells localized in proliferating growth centers, the meristems, are the origin of life-long organ formation and growth in higher plants. In the shoot apical meristem of Arabidopsis thaliana, the closelyrelated ARGONAUTE proteins AGO1 and ZLL/AGO10 bind miR165/166 species to regulate mRNAs of HDZIP III transcription factors that are essential to maintaining stem cells. Several genetic studies showed thatAGO1 and ZLL/AGO10 act redundantly to maintain stem cells. By contrast, the reported biochemical datasuggested antagonistic functions: AGO1 utilizes miR165/166 to slice HD-ZIP III mRNAs, whereas ZLL/AGO10 promotes degradation of miR165/166 and thus stabilizes HD-ZIP III mRNAs. How these differentfunctions are balanced in stem cell regulation has remained enigmatic. Here, we show that autorepressionof AGO1 through miR168-mediated slicing of its own RNA is required to maintain the ability of AGO1 to suppress HD-ZIP III mRNAs. Increased AGO1 expression, either in the miR168a-2 mutant or by transgenicexpression, inhibits this ability despite the presence of high levels of miR165/166, effectively uncouplingHD-ZIP III and miR165/166 expression. AGO1 activity can be restored, however, by increasing the levelsof chaperones SQN and HSP90, which promote assembly of RNA-induced silencing complex (RISC). Thissuggests that cellular abundance of SQN and HSP chaperones limits AGO1-mediated RNA interferencein shoot meristem stem cell regulation. Localized misexpression of AGO1 indicates that the cells surrounding the shoot meristem primordium play a crucial role in stem cell development. Taken together, our studyprovides a framework that reconciles biochemical and genetic data, showing that restriction of AGO1 levelsby miR168-mediated autorepression is key to RISC homeostasis and the function of AGO1 in stem cellregulation.

关键词： Arabidopsis ARGONAUTE1 ZWILLE(ARGONAUTE10) HD-ZIP III stem cell shoot meristem

A closed form of a kurtosis parameter of a hypergeometric-Gaussian type-Ⅱ beam

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Chinese Physics B 2016年第4期25卷 154-160页

作者： Khannous f Ebrahim A A A Belafhal A adida Morocco

Based on the irradiance moment definition and the analytical expression of waveform propagation for hypergeometric- Gaussian type-II beams passing through an ABCD system, the kurtosis parameter is derived analytically and illustrated numerically. The kurtosis parameters of the Gaussian beam, modified Bessel modulated Gaussian beam with quadrature radial and elegant Laguerre-Gaussian beams are obtained by treating them as special cases of the present treatment. The obtained results show that the kurtosis parameter depends on the change of the beam order m and the hollowness parameter p, such as its decrease with increasing m and increase with increasing p.

关键词： Kurtosis parameter hypergeometric-Gaussian type-II beams paraxial optical ABCD system

fifty years of character compatibility concepts at work

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植物分类学报 2008年第2期46卷 109-129页

作者： George f.ESTABROOK Department of Ecology and Evolutionary Biology The University of Michigan Ann Arbor MI 4809-1048 USA

In the mid 19th century, systematic biologists realized that observable similarities and differences among a group of related species could be the basis for hypotheses about the evolutionary relationships among the species and their ancestors. Such hypotheses can be expressed as characters. A character is comprised of two or more character states of species considered to be similar with respect to a basis for comparison. The states of a character may also be arranged into a character state tree to hypothesize speciation events associated with changes from one character state to another. In the mid 20th century, some systematists realized that sometimes pairs of characters （or character state trees） could be incompatible as hypotheses, i.e., they could not both be true. Through the 1950s, ＇60s and ＇70s, tests for, and ways to resolve, incompatibilities were used to estimate an ancestor rela-tion based on mutually compatible characters. An estimate was often shown as a diagram connecting ancestors to their immediate descendants （not quite correctly） called a phylogenetic tree. More recently, other applications of compatibility concepts have been developed, including： identify characters that appear to be random in the context of their data set; combine estimates of ancestor relations for subsets of taxa in a larger collection into a single estimate （a so-called supertree） for the whole collection; and interpret geographic patterns in an evolutionary context.

关键词： biogeography character compatibility character evaluation convex groups phylogenetic trees,reciprocal illumination speciation supertrees

Inference of phylogenetic relationships among key angiosperm lineages using a compatibility method on a molecular data set

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植物分类学报 2008年第2期46卷 130-141页

作者： George f.ESTABROOK Department of Ecology & Evolutionary Biology The University of Michigan Ann Arbor MI 48109-1048 USA

Phylogenetic relationships among the five key angiosperm lineages, Ceratophyllum, Chloranthaceae, eudicots, magnoliids, and monocots, have resisted resolution despite several large-scale analyses sampling taxa and characters extensively and using various analytical methods. Meanwhile, compatibility methods, which were explored together with parsimony and likelihood methods during the early development stage of phylogenetics, have been greatly under-appreciated and not been used to analyze the massive amount of sequence data to recon-struct the basal angiosperm phylogeny. In this study, we used a compatibility method on a data set of eight genes (mitochondrial atp1, matR, and nad5, plastid atpB, matK, rbcL, and rpoC2, and nuclear 18S rDNA) gathered in an earlier study. We selected two sets of characters that are compatible with more of the other characters than a random character would be with at probabilities of pMf the 8 gene pMf other compatible site matrices produced different topologies that were all weakly sup-ported. The topology reconstructed in the parsimony analyses agrees with the one recovered in the previous study using both parsimony and likelihood methods when no character was eliminated. Parts of this topology have also been recovered in several earlier studies. Hence, this topology plausibly reflects the true relationships among the five key angiosperm lineages.

关键词：系统发育被子植物形态特征数据库

Regulation of Cytochrome P450 Enzymes by Reversible Oxidation of Thiols to Sulfenic Acids

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Regulation of Cytochrome P450 Enzymes by Reversible Oxidatio...