Publications by authors named "Samantha O'Loughlin"

With reductions in the malaria burden stalling in the past years, gene drive holds promise as a novel way of reducing disease transmission. Governance and decision-making processes are pivotal aspects of the legitimate adoption of this technology. Here, the authors explore Target Malaria's journey in developing a community agreement model for the release of non-gene drive genetically modified mosquitoes.

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Background: Intensive deployment of insecticide based malaria vector control tools resulted in the rapid evolution of phenotypes resistant to these chemicals. Understanding this process at the genomic level is important for the deployment of successful vector control interventions. Therefore, longitudinal sampling followed by whole genome sequencing (WGS) is necessary to understand how these evolutionary processes evolve over time.

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Article Synopsis
  • The study investigates ultra-conserved elements (UCEs) in Anopheles mosquito genomes, identifying sequences that have remained unchanged for over 100 million years.
  • UCEs are likely under strong functional constraints, making them useful for pinpointing regulatory regions in the genome and may help in developing gene drives for controlling mosquito populations.
  • The research found over 8000 UCEs, with many associated with important biological functions, and 15% of these UCEs showed no genetic variation in wild-caught mosquitoes, making them promising targets for gene-drive modification to combat malaria transmission.
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Introduction: Electromagnetic interference (EMI) due to a mobile phone device has been reported to produce a detrimental effect on the function of a gamma camera system. This effect provides evidentiary support of potential bans or restrictions regarding mobile phone use within a nuclear medicine department.

Methodology: A 3G Apple iPhone 6 was tested against a thyroid phantom in four operating modes, in three positions.

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Genetic control aims to reduce the ability of insect pest populations to cause harm via the release of modified insects. One strategy is to bias the reproductive sex ratio towards males so that a population decreases in size or is eliminated altogether due to a lack of females. We have shown previously that sex ratio distortion can be generated synthetically in the main human malaria vector Anopheles gambiae, by selectively destroying the X-chromosome during spermatogenesis, through the activity of a naturally-occurring endonuclease that targets a repetitive rDNA sequence highly-conserved in a wide range of organisms.

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Background: Population genomic features such as nucleotide diversity and linkage disequilibrium are expected to be strongly shaped by changes in population size, and might therefore be useful for monitoring the success of a control campaign. In the Kilifi district of Kenya, there has been a marked decline in the abundance of the malaria vector Anopheles gambiae subsequent to the rollout of insecticide-treated bed nets.

Methods: To investigate whether this decline left a detectable population genomic signature, simulations were performed to compare the effect of population crashes on nucleotide diversity, Tajima's D, and linkage disequilibrium (as measured by the population recombination parameter ρ).

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Background: In many locations malaria is transmitted by more than one vector species. Some vector control interventions, in particular those using genetic approaches, are likely to be targeted against a single species or species complex, at least initially, and it would therefore be useful to be able to predict the epidemiological impact of controlling a single species when multiple vector species are present.

Methods: To address this issue, the classical Ross-McDonald model of malaria epidemiology is expanded to account for multiple vector species, giving expressions for the equilibrium prevalence, sporozoite rates and reproductive number.

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Variation in vectorial capacity for human malaria among Anopheles mosquito species is determined by many factors, including behavior, immunity, and life history. To investigate the genomic basis of vectorial capacity and explore new avenues for vector control, we sequenced the genomes of 16 anopheline mosquito species from diverse locations spanning ~100 million years of evolution. Comparative analyses show faster rates of gene gain and loss, elevated gene shuffling on the X chromosome, and more intron losses, relative to Drosophila.

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Unlabelled: Warming patients by changing the ambient environment (rather than core temperature) has been reported to reduce brown adipose tissue activity, thereby reducing artifacts in (18)F-FDG PET. Nonetheless, a reduction in cardiac uptake of (18)F-FDG has been incidentally noted during ambient warming. This study examined the impact of seasonal variations in ambient temperatures on cardiac uptake of (18)F-FDG.

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The role of nuclear medicine diagnostic bone scanning is well established and the influence of coregistration between single-photon emission computed tomography and computed tomography well documented. This case provides an insight into a less frequently encountered pathology in which the combination of single-photon emission computed tomography and computed tomography permitted the differentiation of potential pathology.

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Background: Anopheles baimaii is a primary vector of human malaria in the forest settings of Southeast Asia including the north-eastern region of India. Here, the genetic population structure and the basic population genetic parameters of An. baimaii in north-east India were estimated using DNA sequences of the mitochondrial cytochrome oxidase sub unit II (COII) gene.

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South-East Asia is one of the world's richest regions in terms of biodiversity. An understanding of the distribution of diversity and the factors shaping it is lacking, yet essential for identifying conservation priorities for the region's highly threatened biodiversity. Here, we take a large-scale comparative approach, combining data from nine forest-associated Anopheles mosquito species and using statistical phylogeographical methods to disentangle the effects of environmental history, species-specific ecology and random coalescent effects.

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Molecular studies of population divergence and speciation across the Oriental Region are sparse, despite the region's high biodiversity and extensive Pliocene and Pleistocene environmental change. A molecular phylogenetic study of the Neocellia Series of Anopheles mosquitoes was undertaken to identify patterns of diversification across the Oriental Region and to infer the role of Pleistocene and Pliocene climatic change. A robust phylogeny was constructed using CO2 and ND5 mitochondrial genes and ITS2 and D3 nuclear ribosomal markers.

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There are 3 recognized chromosomal forms (B, E, K) in the taxon of Anopheles maculatus, 1 of the 8 members of the Anopheles maculatus group. Previous studies suggested that forms B and E are cytotypes of the species, but genetic characteristics of form K are unknown. The present study used crossing experiments, and polytene chromosomes of the ovarian nurse cell in F1 hybrids to show that form K is genetically distinct from forms B and E.

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The sibling species composition of the Anopheles minimus and Anopheles dirus complexes is poorly known in the highly malarious north-eastern region of India where these two vector taxa are accountable for most of the malaria transmission among 30.7 million inhabitants. Prevalent members of these two complexes in this part of India were identified using sequences for the second internal transcribed spacer (ITS2) of ribosomal DNA.

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Background: A genealogy based on gene sequences within a species plays an essential role in the estimation of the character, structure, and evolutionary history of that species. Because intraspecific sequences are more closely related than interspecific ones, detailed information on the evolutionary process may be available by determining all the node sequences of trees and provide insight into functional constraints and adaptations. However, strong evolutionary correlations on a few lineages make this determination difficult as a whole, and the maximum parsimony (MP) method frequently allows a number of topologies with a same total branching length.

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