629 research outputs found
Large-scale structure of brown rat (Rattus norvegicus) populations in England: effects on rodenticide resistance
The brown rat (Rattus norvegicus) is a relatively recent (<300 years) addition to the British fauna, but by association with negative impacts on public health, animal health and agriculture, it is regarded as one of the most important vertebrate pest species. Anticoagulant rodenticides were introduced for brown rat control in the 1950s and are widely used for rat control in the UK, but long-standing resistance has been linked to control failures in some regions. One thus far ignored aspect of resistance biology is the population structure of the brown rat. This paper investigates the role population structure has on the development of anticoagulant resistance. Using mitochondrial and microsatellite DNA, we examined 186 individuals (from 15 counties in England and one location in Wales near the WalesâEngland border) to investigate the population structure of rural brown rat populations. We also examined individual rats for variations of the VKORC1 gene previously associated with resistance to anticoagulant rodenticides. We show that the populations were structured to some degree, but that this was only apparent in the microsatellite data and not the mtDNA data. We discuss various reasons why this is the case. We show that the population as a whole appears not to be at equilibrium. The relative lack of diversity in the mtDNA sequences examined can be explained by founder effects and a subsequent spatial expansion of a species introduced to the UK relatively recently. We found there was a geographical distribution of resistance mutations, and relatively low rate of gene flow between populations, which has implications for the development and management of anticoagulant resistance
Four problems with global carbon markets: a critical review
This article offers a critique of global carbon markets and trading, with a special focus on the Clean Development Mechanism of the Kyoto Protocol. It explores
problems with the use of tradable permits to address climate change revolving around four areas: homogeneity, justice, gaming, and information. Homogeneity problems arise from the non-linear nature of climate change and sensitivity of emissions, which complicate attempts to calculate carbon offsets. Justice problems involve issues of dependency and the concentration of wealth among the rich, meaning carbon trading often counteracts attempts to reduce poverty. Gaming problems include pressures to promote high-volume, least-cost projects and the
consequences of emissions leakage. Information problems encompass transaction costs related to carbon trading and market participation and the comparatively weak institutional capacity of project evaluators
Analytic Metaphysics versus Naturalized Metaphysics: The Relevance of Applied Ontology
The relevance of analytic metaphysics has come under criticism: Ladyman & Ross, for instance, have suggested do discontinue the field. French & McKenzie have argued in defense of analytic metaphysics that it develops tools that could turn out to be useful for philosophy of physics. In this article, we show first that this heuristic defense of metaphysics can be extended to the scientific field of applied ontology, which uses constructs from analytic metaphysics. Second, we elaborate on a parallel by French & McKenzie between mathematics and metaphysics to show that the whole field of analytic metaphysics, being useful not only for philosophy but also for science, should continue to exist as a largely autonomous field
A multi-jurisdictional outbreak of Salmonella Typhimurium infections linked to backyard poultryâAustralia, 2020
Zoonotic salmonellosis can occur either through direct contact with an infected animal or through indirect contact, such as exposure to an infected animal's contaminated environment. Between May and August 2020, a multi-jurisdictional outbreak of Salmonella Typhimurium (STm) infection due to zoonotic transmission was investigated in Australia. In total, 38 outbreak cases of STm with a median age of 5âyears were reported. Epidemiological investigation showed contact with live poultry to be a common risk factor with most cases recently purchasing one-week old chicks from produce/pet stores. Traceback investigation of cases identified 25 product/pet stores of which 18 were linked to a single poultry breeder farm. On farm environmental sampling identified the same STm genotype as identified in cases. Whole genome sequencing of both environmental and human outbreak isolates found them to be highly related by phylogenetic analysis. This investigation describes the first documented widespread zoonotic salmonellosis outbreak in Australia attributed to backyard poultry exposure and identified potential risk factors and prevention and control measures for future outbreaks. Prevention of future outbreaks will require an integrated One Health approach involving the poultry industry, produce/pet store owners, animal healthcare providers, public health and veterinary health agencies and the public
Counting Yang-Mills Dyons with Index Theorems
We count the supersymmetric bound states of many distinct BPS monopoles in
N=4 Yang-Mills theories and in pure N=2 Yang-Mills theories. The novelty here
is that we work in generic Coulombic vacua where more than one adjoint Higgs
fields are turned on. The number of purely magnetic bound states is again found
to be consistent with the electromagnetic duality of the N=4 SU(n) theory, as
expected. We also count dyons of generic electric charges, which correspond to
1/4 BPS dyons in N=4 theories and 1/2 BPS dyons in N=2 theories. Surprisingly,
the degeneracy of dyons is typically much larger than would be accounted for by
a single supermultiplet of appropriate angular momentum, implying many
supermutiplets of the same charge and the same mass.Comment: 34 pages, 1 figure, LaTe
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Precision farming and archaeology
With a significant growth in the agricultural technology industry a vast amount of agricultural data is now being collected on farms throughout the world. Farmers aim to utilise these technologies to regularly record and manage the variation of crops and soils within their fields, to reduce inputs, increase yields and enhance environmental sustainability. In this paper we aim to highlight the variety of different data types and methodological processes involved in modern precision farming and explore how potentially interconnected these systems are with the archaeological communit
Ancient DNA Resolves Identity and Phylogeny of New Zealand's Extinct and Living Quail (Coturnix sp.)
BACKGROUND: The New Zealand quail, Coturnix novaezealandiae, was widespread throughout New Zealand until its rapid extinction in the 1870's. To date, confusion continues to exist concerning the identity of C. novaezealandiae and its phylogenetic relationship to Coturnix species in neighbouring Australia, two of which, C. ypsilophora and C. pectoralis, were introduced into New Zealand as game birds. The Australian brown quail, C. ypsilophora, was the only species thought to establish with current populations distributed mainly in the northern part of the North Island of New Zealand. Owing to the similarities between C. ypsilophora, C. pectoralis, and C. novaezealandiae, uncertainty has arisen over whether the New Zealand quail is indeed extinct, with suggestions that remnant populations of C. novaezealandiae may have survived on offshore islands. METHODOLOGY/PRINCIPAL FINDINGS: Using fresh and historical samples of Coturnix sp. from New Zealand and Australia, DNA analysis of selected mitochondrial regions was carried out to determine phylogenetic relationships and species status. Results show that Coturnix sp. specimens from the New Zealand mainland and offshore island Tiritiri Matangi are not the New Zealand quail but are genetically identical to C. ypsilophora from Australia and can be classified as the same species. Furthermore, cytochrome b and COI barcoding analysis of the New Zealand quail and Australia's C. pectoralis, often confused in museum collections, show that they are indeed separate species that diverged approximately 5 million years ago (mya). Gross morphological analysis of these birds suggests a parallel loss of sustained flight with very little change in other phenotypic characters such as plumage or skeletal structure. CONCLUSION/SIGNIFICANCE: Ancient DNA has proved invaluable for the detailed analysis and identification of extinct and morphologically cryptic taxa such as that of quail and can provide insights into the timing of evolutionary changes that influence morphology
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