The borrelidin polyketide synthase (PKS) begins with a carboxylated substrate and, unlike typical decarboxylative loading PKSs, retains the carboxy group in the final product. The specificity and tolerance of incorporation of carboxyacyl substrate into type I PKSs have not been explored. Here, we show that the first extension module is promiscuous in its ability to extend both carboxyacyl and non-carboxyacyl substrates. However, the loading module has a requirement for substrates containing a carboxy moiety, which are not decarboxylated in situ. Thus, the loading module is the basis for the observed specific incorporation of carboxylated starter units by the borelidin PKS.
Some of the physico-electrochemical properties of passive oxide films that form on reactive metal and alloy surfaces, and which protect the underlying metals from reaction with corrosive environments, are reviewed within the context of the Point Defect Model (PDM). This model yields analytical expressions for the steady state current and film thickness and for the transients in these properties that can be used to predict deterministically the accumulation of general corrosion damage to metal surfaces, provided that the evolutionary path to the future state is continuous and can be specified. The conditions under which passivity may exist are defined in terms of Phase Space Analysis (PSA) of the PDM and it is found that passivity is invariably a meta-stable phenomenon. PSA leads to the development of Kinetic Stability Diagrams (KSDs) as alternatives to the equilibrium thermodynamic Pourbaix diagrams that are now used to describe the conditions under which passivity is observed.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructure and reactions of oxametallacyclobutanes and oxametallacyclobutenes of rutheniumJohn F. Hartwig, Robert G. Bergman, and Richard A. AndersenCite this: Organometallics 1991, 10, 9, 3344–3362Publication Date (Print):September 1, 1991Publication History Published online1 May 2002Published inissue 1 September 1991https://pubs.acs.org/doi/10.1021/om00055a061https://doi.org/10.1021/om00055a061research-articleACS PublicationsRequest reuse permissionsArticle Views622Altmetric-Citations69LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts
Received 4 December 2009DOI:https://doi.org/10.1103/PhysRevLett.103.259902©2009 American Physical Society
I am grateful to my four critics for taking kindly to my intrusion into the social science of race and human brutality in history and for responding to my sketch of “The Checkerboard of Ethnoracial Violence” (Wacquant 2023a) with earnest and productive comments. In the spirit of their articles, I will rejoin to their propositions and then enroll them to suggest further pathways to a better understanding of the specificity and historicity of racialized violence, individual and collective.
Este artigo reflete sobre a recepção internacional ao livro Prisões da miséria como reveladora da expansão penal nas sociedades avançadas na década de 2000. Ele revela que a tempestade global da "lei e ordem" inspirada pelos Estados Unidos, que o livro detectou em 1999, continuou a espalhar-se por toda a parte. Na verdade, ela estendeu-se dos países do Primeiro Mundo para os do Segundo Mundo e alterou a política e as práticas de punição em todo o globo de uma forma que ninguém previa e que ninguém teria pensado como possível há cerca de 15 anos. O artigo estende a análise para o papel dos institutos de consultoria (em especial o Manhattan Institute) na difusão das noções de combate ao crime e das panacéias no estilo estadunidense na América Latina como um elemento da circulação internacional dos pacotes de política pró-mercado que alimentam a gerência punitiva da pobreza. O artigo elabora e revê o modelo original do nexo entre neoliberalismo e penalidade punitiva, levando a análise da montagem do Estado na era da insegurança social, desenvolvida no livro Punindo os pobres.
Optical spectra having moderately high resolution (~ 2 — 5 Å) are being used to study the profiles of narrow emission lines in active galactic nuclei (AGNs). It is often found that forbidden lines associated with high critical densities for collisional deexcitation are the broadest. A good example is [O III] λ4363 [ n e (crit) ≈ 3 × 10 7 cm −3 ], whose width can be more than twice that of [O III] λ5007 [ n e (crit) ≈ 8 × 10 5 cm −3 ]. The tight correlation between line width and n e (crit) implies that a much larger range of densities (∼ 10 2 — 10 7 cm −3 ) must be present among clouds in the narrow-line region than was previously believed. At times there almost appears to be a continuity between the narrow- and broad-line regions. In some objects the dense, high-velocity clouds are optically thick to ionizing radiation, since they emit [O I] λ6300 as well as species of much higher ionization (such as [Ne V] λ3426). These results help eliminate several difficulties in photoionization models of LINERs. It may also be possible to use the observed line widths as probes of the gravitational potential in AGNs.
