15 research outputs found

    How Prosecutors and Defense Attorneys Differ in Their Use of Neuroscience Evidence

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    Much of the public debate surrounding the intersection of neuroscience and criminal law is based on assumptions about how prosecutors and defense attorneys differ in their use of neuroscience evidence. For example, according to some commentators, the defense’s use of neuroscience evidence will abdicate criminals of all responsibility for their offenses. In contrast, the prosecution’s use of that same evidence will unfairly punish the most vulnerable defendants as unfixable future dangers to society. This “double- edged sword” view of neuroscience evidence is important for flagging concerns about the law’s construction of criminal responsibility and punishment: it demonstrates that the same information about the defendant can either be mitigating or aggravating depending on who is raising it. Yet empirical assessments of legal decisions reveal a far more nuanced reality, showing that public beliefs about the impact of neuroscience on the criminal law can often be wrong. This Article takes an evidence-based and multidisciplinary approach to examining how courts respond to neuroscience evidence in capital cases when the defense presents it to argue that the defendant’s mental state at the time of the crime was below the given legal requisite due to some neurologic or cognitive deficiency

    Invasive Malaria Vector Anopheles stephensi Mosquitoes in Sudan, 2016–2018

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    Anopheles stephensi mosquitoes are urban malaria vectors in Asia that have recently invaded the Horn of Africa. We detected emergence of An. stephensi mosquitoes in 2 noncontiguous states of eastern Sudan. Results of mitochondrial DNA sequencing suggest the possibility of distinct invasions, potentially from a neighboring country

    Field-Caught Permethrin-Resistant Anopheles gambiae Overexpress CYP6P3, a P450 That Metabolises Pyrethroids

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    Insects exposed to pesticides undergo strong natural selection and have developed various adaptive mechanisms to survive. Resistance to pyrethroid insecticides in the malaria vector Anopheles gambiae is receiving increasing attention because it threatens the sustainability of malaria vector control programs in sub-Saharan Africa. An understanding of the molecular mechanisms conferring pyrethroid resistance gives insight into the processes of evolution of adaptive traits and facilitates the development of simple monitoring tools and novel strategies to restore the efficacy of insecticides. For this purpose, it is essential to understand which mechanisms are important in wild mosquitoes. Here, our aim was to identify enzymes that may be important in metabolic resistance to pyrethroids by measuring gene expression for over 250 genes potentially involved in metabolic resistance in phenotyped individuals from a highly resistant, wild A. gambiae population from Ghana. A cytochrome P450, CYP6P3, was significantly overexpressed in the survivors, and we show that the translated enzyme metabolises both alpha-cyano and non–alpha-cyano pyrethroids. This is the first study to demonstrate the capacity of a P450 identified in wild A. gambiae to metabolise insecticides. The findings add to the understanding of the genetic basis of insecticide resistance in wild mosquito populations

    Dissecting the organ specificity of insecticide resistance candidate genes in Anopheles gambiae : known and novel candidate genes

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    Background The elevated expression of enzymes with insecticide metabolism activity can lead to high levels of insecticide resistance in the malaria vector, Anopheles gambiae. In this study, adult female mosquitoes from an insecticide susceptible and resistant strain were dissected into four different body parts. RNA from each of these samples was used in microarray analysis to determine the enrichment patterns of the key detoxification gene families within the mosquito and to identify additional candidate insecticide resistance genes that may have been overlooked in previous experiments on whole organisms. Results A general enrichment in the transcription of genes from the four major detoxification gene families (carboxylesterases, glutathione transferases, UDP glucornyltransferases and cytochrome P450s) was observed in the midgut and malpighian tubules. Yet the subset of P450 genes that have previously been implicated in insecticide resistance in An gambiae, show a surprisingly varied profile of tissue enrichment, confirmed by qPCR and, for three candidates, by immunostaining. A stringent selection process was used to define a list of 105 genes that are significantly (p ≤0.001) over expressed in body parts from the resistant versus susceptible strain. Over half of these, including all the cytochrome P450s on this list, were identified in previous whole organism comparisons between the strains, but several new candidates were detected, notably from comparisons of the transcriptomes from dissected abdomen integuments. Conclusions The use of RNA extracted from the whole organism to identify candidate insecticide resistance genes has a risk of missing candidates if key genes responsible for the phenotype have restricted expression within the body and/or are over expression only in certain tissues. However, as transcription of genes implicated in metabolic resistance to insecticides is not enriched in any one single organ, comparison of the transcriptome of individual dissected body parts cannot be recommended as a preferred means to identify new candidate insecticide resistant genes. Instead the rich data set on in vivo sites of transcription should be consulted when designing follow up qPCR validation steps, or for screening known candidates in field populations

    An integrated genetic and physical map for the malaria vector Anopheles funestus

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    We have constructed a genetic map of the major African malaria vector, Anopheles funestus, using genetic markers segregating in F-2 progeny from crosses between two strains colonized from different field sites. Genotyping was performed on 174 progeny from three families using 33 microsatellite markers, a single RFLP, and 15 single nucleotide polymorphism (SNP) loci. Four linkage groups were resolved and these were anchored to chromosomes X and 2 and chromosomal arms 3R and 3L by comparison with a physical map of this species. Five markers were linked to the X chromosome, 16 markers to chromosome 2, and 10 and 11 markers to chromosomal arms 3R and 3L, respectively. This significantly increases the number of chromosomally defined genetic markers for this species and will facilitate the identification of genes controlling epidemiologically important traits such as resistance to insecticides or vector competence

    Insecticide resistance levels and mechanisms in Aedes aegypti populations in and around Ouagadougou, Burkina Faso.

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    BACKGROUND:Recent outbreaks of dengue and other Aedes aegypti-borne arboviruses highlight the importance of a rapid response for effective vector control. Data on insecticide resistance and underlying mechanisms are essential for outbreak preparedness, but are sparse in much of Africa. We investigated the levels and heterogeneity of insecticide resistance and mechanisms of Ae. aegypti from contrasting settings within and around Ouagadougou, Burkina Faso. METHODOLOGY/PRINCIPAL FINDINGS:Bioassays were performed on larvae and adults to diagnose prevalence of resistance, and to assess levels where resistance was detected. Investigation of resistance mechanisms was performed using synergist bioassays, knockdown resistance (kdr) target site mutation genotyping and quantitative PCR expression analysis of candidate P450 genes. Larval dose-response assays indicated susceptibility to the organophosphates tested. Adult females were also susceptible to organophosphates, but resistance to carbamates was suspected in urban and semi-urban localities. Females from all localities showed resistance to pyrethroids but resistance prevalence and level were higher in urban and especially in semi-urban areas, compared to the rural population. Environment was also associated with susceptibility: adults reared from larvae collected in tires from the semi-urban site were significantly less resistant to pyrethroids than those collected from large outdoor drinking water containers ('drums'). Susceptibility to both pyrethroids tested was largely restored by pre-exposure to Piperonyl Butoxide (PBO), suggesting a strong metabolic basis to resistance. The 1534C kdr mutation was nearly fixed in semi-urban and urban areas but was far less common in the rural area, where the 1016I kdr mutation frequency was also significantly lower. P450 gene analysis detected limited over-expression of single candidates but significantly elevated average expression in the semi-urban site compared to both a susceptible laboratory colony, and females from the other collection sites. CONCLUSIONS/SIGNIFICANCE:Our results reveal pyrethroid resistance and paired kdr mutations in both urban and semi-urban sites at levels that are unprecedented for mainland Africa. The combination of target site and metabolic mechanisms is common in Ae. aegypti populations from other continents but is a worrying finding for African populations. However, organophosphate insecticides are still active against both larvae and adults of Ae. aegypti, providing useful insecticidal options for control and resistance management

    Towards a Genetic Map for Anopheles albimanus: Identification of Microsatellite Markers and a Preliminary Linkage Map for Chromosome 2

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    Fifty microsatellite loci were identified in the malaria vector Anopheles albimanus. Markers segregating in F2 progeny of crosses between laboratory stains of An. albinanus were used to construct a preliminary genetic map. More than 300 progeny were genotyped, but the resolution of the map was limited by the lack of polymorphisms in the microsatelite alleles. A robust linkage map for chromosome 2 was established and additional markers were assigned to the third and X chromosomes by linkage to morphological markers of known physical location. Addtional non-informative microsatellite sequencies are provided including some showing similarity to those of An. gambiae. This study significantly increases the number of genetic markers available for An. albinmanus and provides useful tools for population genetics and genetic mapping studies in this important malaria vector
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