Evaluating the potential of a new murine gene drive for pre-emptive mouse plague control

Rodent outbreaks have significant ecological, agricultural and economic impacts around the world. Although they can occur with increasing frequency in some parts of the world, current management practices remain ineffective. Gene drives, which are genetic elements with positively biased transmission, have been theoretically shown to eradicate large populations of invasive mice on isolated islands and could potentially serve as pre-emptive tools against mouse plagues. Using a spatially explicit individual-based model, we investigated whether a recently developed murine gene drive, tCRISPR, is effective in suppressing mouse populations within an open agricultural setting that experiences plague-like conditions with varying intensity and duration. We simulated various release strategies involving different temporal and spatial release efforts and measured the reduction in maximum plague population sizes relative to scenarios where no control was applied. Early releases allowed more time for the drive to spread before the onset of plagues, making it the most effective strategy to reduce the impact of plagues. Repeated and spatially extensive release efforts, which were initiated 3 years earlier and continued up to the onset of plagues, resulted in up to 90% reductions in the maximum population sizes compared to plagues without control. Effectiveness declined with later releases; those initiated at the onset of the plagues or later did not result in a decrease in population sizes. We tested whether the total release effort of the most effective strategy can be reduced by incorporating periods without any releases. We showed that pulsed releases with no-release gaps could be similarly effective; however, the timing of both releases was critical. Surprisingly, the lowest release effort, which was the one-time release of a single individual to the release sites, had almost no impact on the first plague, but had a substantial impact on subsequent recurring plagues that occurred 10 years later and reduced the maximum population sizes by ~80%. A newly-developed murine gene drive, tCRISPR, could be an effective pre-emptive control tool for costly mice plagues. Early releases followed by supplementation could eliminate the need to predict or closely monitor their occurrence

Scalability of genetic biocontrols for eradicating invasive alien mammals

CRISPR-based gene drives offer novel solutions for controlling invasive alien species, which could ultimately extend eradication efforts to continental scales. Gene drives for suppressing invasive alien vertebrates are now under development. Using a landscape-scale individual-based model, we present the first estimates of times to eradication for long-lived alien mammals. We show that demography and life-history traits interact to determine the scalability of gene drives for vertebrate pest eradication. Notably, optimism around eradicating smaller-bodied pests (rodents and rabbits) with gene-drive technologies does not easily translate into eradication of larger-bodied alien species (cats and foxes).Aysegul Birand, Phillip Cassey, Joshua V. Ross, Paul Q. Thomas, Thomas A. A. Prows

Leveraging a natural murine meiotic drive to suppress invasive populations

Invasive rodents are a major cause of environmental damage and biodiversity loss, particularly on islands. Unlike insects, genetic biocontrol strategies including populationsuppressing gene drives with biased inheritance have not been developed in mice. Here, we demonstrate a gene drive strategy (tCRISPR) that leverages super-Mendelian transmission of the t haplotype to spread inactivating mutations in a haplosufficient female fertility gene (Prl). Using spatially explicit individual-based in silico modeling, we show that tCRISPR can eradicate island populations under a range of realistic field-based parameter values. We also engineer transgenic tCRISPR mice that, crucially, exhibit biased transmission of the modified t haplotype and Prl mutations at levels our modeling predicts would be sufficient for eradication. This is an example of a feasible gene drive system for invasive alien rodent population control.Luke Gierusa, Aysegul Birandc, Mark D. Buntinga, Gelshan I. Godahewa, Sandra G. Piltz Kevin P. Oh, Antoinette J. Piaggio, David W. Threadgill, John Godwin, Owain Edwards, Phillip Cassey, Joshua V. Ross, Thomas A. A. Prowse and Paul Q. Thoma

Turkey's EU candidacy and civil-military relations: Challenges and prospects

This article examines the Turkish case within the framework of theories that explain the impact of transnational factors upon civil-military relations in national contexts. The authors examine the impact of Turkey's European Union (EU) membership candidacy on civil-military relations in Turkey. More specifically, they elaborate on the challenges and prospects for more democratic civil-military relations in Turkey as triggered by the EU candidacy. In this regard, the article examines the notion of guardianship that characterizes the military's traditional role in Turkish politics and its institutional reflections

The effects of cardiac glucoside, digitoxin, on atrial electrocardiogram in healthy persons

Atrial electrocardiograms have been studied in 32 normal subjects both before and after digitalisation, where digitoxin was given for three successive days in a total dose of 1.2 mgr. Following a statistical analysis of the results obtained it has been concluded that the effects of digitoxin on the atrial electrocardiograms of normal subjects are insignificant

Editorial comment: Factors regulating exercise capacity in heart failure and effects of beta- receptor blockers on exercise tolerance [Editöryel Yorum: Kalp Yetersizliginde Egzersiz Kapasitesini Düzenleyen Etkenler ve Beta-Reseptör Blokerlerinin Egzersiz Toleransi Üzerindeki Etkileri]

PubMedID: 14675881[No abstract available

On the behavior and identification of collapsible soils

The objective of this paper is to present research first on the factors that control collapse, which are; the effect of silt content and the surcharge intensity and second, a comparative treatment of major methods of identification