444 research outputs found

    RNAi as a management tool for the western corn rootworm, \u3ci\u3eDiabrotica virgifera virgifera\u3c/i\u3e

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    The western corn rootworm (WCR), Diabrotica virgifera virgifera, is the most important pest of corn in the US Corn Belt. Economic estimates indicate that costs of control and yield loss associated with WCR damage exceed $US 1 billion annually. Historically, corn rootworm management has been extremely difficult because of its ability to evolve resistance to both chemical insecticides and cultural control practices. Since 2003, the only novel commercialized developments in rootworm management have been transgenic plants expressing Bt insecticidal proteins. Four transgenic insecticidal proteins are currently registered for rootworm management, and field resistance to proteins from the Cry3 family highlights the importance of developing traits with new modes of action. One of the newest approaches for controlling rootworm pests involves RNA interference (RNAi). This review describes the current understanding of the RNAi mechanisms in WCR and the use of this technology for WCR management. Further, the review addresses ecological risk assessment of RNAi and insect resistance management of RNAi for corn rootworm

    RNAi as a management tool for the western corn rootworm, \u3ci\u3eDiabrotica virgifera virgifera\u3c/i\u3e

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    The western corn rootworm (WCR), Diabrotica virgifera virgifera, is the most important pest of corn in the US Corn Belt. Economic estimates indicate that costs of control and yield loss associated with WCR damage exceed $US 1 billion annually. Historically, corn rootworm management has been extremely difficult because of its ability to evolve resistance to both chemical insecticides and cultural control practices. Since 2003, the only novel commercialized developments in rootworm management have been transgenic plants expressing Bt insecticidal proteins. Four transgenic insecticidal proteins are currently registered for rootworm management, and field resistance to proteins from the Cry3 family highlights the importance of developing traits with new modes of action. One of the newest approaches for controlling rootworm pests involves RNA interference (RNAi). This review describes the current understanding of the RNAi mechanisms in WCR and the use of this technology for WCR management. Further, the review addresses ecological risk assessment of RNAi and insect resistance management of RNAi for corn rootworm

    PARENTAL RNAI SUPPRESSION OF KRUPPEL GENE TO CONTROL HEMIPTERAN PESTS

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    This disclosure concerns nucleic acid molecules and methods of use thereof for control of hemipteran pests through RNA interference - mediated inhibition of target coding and transcribed non - coding sequences in hemipteran pests. The disclosure also concerns methods for making transgenic plants that express nucleic acid molecules useful for the control of hemipteran pests, and the plant cells and plants obtained thereby

    PARENTAL RNAI SUPPRESSION OF HUNCHBACK GENE TO CONTROL HEMIPTERAN PESTS

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    This disclosure concerns nucleic acid molecules and methods of use thereof for control of hemipteran pests through RNA interference-mediated inhibition of target coding and transcribed non-coding sequences in hemipteran pests. The dis closure also concerns methods for making transgenic plants that express nucleic acid molecules useful for the control of hemipteran pests, and the plant cells and plants obtained thereby

    PARENTAL RNAI SUPPRESSION OF HUNCHBACK GENE TO CONTROL HEMIPTERAN PESTS

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    This disclosure concerns nucleic acid molecules and methods of use thereof for control of hemipteran pests through RNA interference-mediated inhibition of target coding and transcribed non-coding sequences in hemipteran pests. The dis closure also concerns methods for making transgenic plants that express nucleic acid molecules useful for the control of hemipteran pests, and the plant cells and plants obtained thereby

    PARENTAL RNAI SUPPRESSION OF CHROMATIN REMODELING GENES TO CONTROL COLEOPTERAN PESTS

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    This disclosure concerns nucleic acid molecules and meth ods of use thereof for control of hemipteran pests through RNA interference - mediated inhibition of target coding and transcribed non - coding sequences in hemipteran pests. The disclosure also concerns methods for making transgenic plants that express nucleic acid molecules useful for the control of hemipteran pests, and the plant cells and plants obtained thereby

    Control of western corn rootworm via RNAi traits in maize: Lethal and sublethal effects of Sec23 dsRNA

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    Background: RNA interference (RNAi) triggered by maize plants expressing RNA hairpins against specific western corn rootworm ( WCR) transcripts have proven to be effective at controlling this pest. To provide robust crop protection, mRNA transcripts targeted by double-stranded RNA must be sensitive to knockdown and encode essential proteins. Results: Using WCR adult feeding assays, we identified Sec23 as a highly lethal RNAi target. Sec23 encodes a coatomer protein, a component of the coat protein (COPII) complex that mediates ER-Golgi transport. The lethality detected in WCR adults was also observed in early instar larvae, the life stage causing most of the crop damage, suggesting that WCR adults can serve as an alternative to larvae for dsRNA screening. Surprisingly, over 85% transcript inhibition resulted in less than 40% protein knockdown, suggesting that complete protein knockdown is not necessary for Sec23 RNAi-mediated mortality. The efficacy of Sec23 dsRNA for rootworm control was confirmed in planta; T0maize events carrying rootwormSec23 hairpin transgenes showed high levels of root protection in greenhouse assays. A reduction in larval survival and weight were observed in the offspring of WCR females exposed to Sec23 dsRNA LC25in diet bioassays. Conclusion: We describe Sec23 as RNAi target for in planta rootworm control. High mortality in exposed adult and larvae and moderate sublethal effects in the offspring of females exposed to Sec23 dsRNA LC25, suggest the potential for field application of this RNAi trait and the need to factor in responses to sublethal exposure into insect resistance management programs. Includes supplemental materials

    Cascades of subharmonic stationary states in strongly non-linear driven planar systems

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    The dynamics of a one-degree of freedom oscillator with arbitrary polynomial non-linearity subjected to an external periodic excitation is studied. The sequences (cascades) of harmonic and subharmonic stationary solutions to the equation of motion are obtained by using the harmonic balance approximation adapted for arbitrary truncation numbers, powers of non-linearity, and orders of subharmonics. A scheme for investigating the stability of the harmonic balance stationary solutions of such a general form is developed on the basis of the Floquet theorem. Besides establishing the stable/unstable nature of a stationary solution, its stability analysis allows obtaining the regions of parameters, where symmetry-breaking and period-doubling bifurcations occur. Thus, for period-doubling cascades, each unstable stationary solution is used as a base solution for finding a subsequent stationary state in a cascade. The procedure is repeated until this stationary state becomes stable provided that a stable solution can finally be achieved. The proposed technique is applied to calculate the sequences of subharmonic stationary states in driven hardening Duffing's oscillator. The existence of stable subharmonic motions found is confirmed by solving the differential equation of motion numerically by means of a time-difference method, with initial conditions being supplied by the harmonic balance approximation.Comment: 37 pages, 11 figures, revised material on chaotic motio

    Books in the News in Cromwellian England

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    This article offers detailed analysis of the patterns of book advertising in Marchamont Nedham’s government-sponsored newsbook, Mercurius Politicus. It contends that, for a brief period, Politicus was the nearest thing that the mid-seventeenth century had to a literary periodical and contests standard accounts that Politicus was only successful because government monopoly made it so. Instead I show that Politicus was instrumental in creating an image of the Commonwealth and Protectorate as a Republic of Letters; the cheap print of its small advertisements insisted that the publication of a book was an event, that London was a city of the book, and that its inhabitants might respond to the uncertainty of political revolution by eagerly imagining a future comprised of new books as yet unread

    LibertĂ  politica e virtĂą civile. Significati e percorsi del repubblicanesimo classico

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    Tra storia e filosofia della politica, il volume analizza il ruolo delle idee politiche repubblicane nella formazione delle repubbliche moderne e propone spunti di riflessione sul significato del repubblicanesimo per il futuro delle democrazie.- Indice #5- Introduzione, Maurizio Viroli #9- Il repubblicanesimo di Machiavelli, Maurizio Viroli #19- Declino e durata delle repubbliche e delle idee repubblicane nell’Italia del Cinquecento, Elena Fasano Guarini #49- Patriottismo e riforma politica, Rosario Villari #113- Le idee repubblicane e la Rivoluzione inglese, Blair Worden #127- Cittadini, clienti e creditori: la repubblica come critica del mutamento storico, John G. A. Pocock #151- Le trasformazioni del repubblicanesimo classico nella Francia del Settecento, Keith Michael Baker #167- Virtù e Vittorianesimo. I valori repubblicani del liberalismo inglese, 1860/1890, Eugenio F. Biagini #195- Tra virtù e libertà: percorsi dell’idea repubblicana nella Francia ottocentesca (1830/1875), Mirella Larizza #217- La tradizione repubblicana nell’Italia dell’Ottocento e del Novecento, Massimo L. Salvadori #245- Considerazioni sulla libertà repubblicana, Quentin Skinner #267- “Moderno repubblicanesimo”? La promessa della società civile, Benjamin R. Barber #279- La moderna repubblica: mito o realtà?, Jean Fabien Spitz #30
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