1,257 research outputs found

    In-vitro comparison of the larvicidal activity of moxidectin and abamectin against Onthophagus gazella (F.) (Coleoptera Scarabaeidae) and Haematobia irritans exigua De Meijere (Diptera Muscidae)

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    When incorporated directly into cattle dung, a formulation of moxidectin was less toxic to larvae of the dung beetle Onthophagus gazella and the buffalo fly, Haematobia irritans exigua, than an abamectin formulation. Concentrations of moxidectin 64-fold greater than abamectin concentrations were required to produce equivalent toxicities. Neither moxidectin nor abamectin reduced oviposition by O. gazella. Moxidectin may consequently be less likely than abamectin to affect the decomposition of cattle dung but may have less effect on buffalo fly infestations

    Modelling the impact of ground planes on aircraft transmission cable impedance

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    With the recent movement in the aircraft industry to have a more electric based secondary power system, new challenges are being uncovered, particularly with the electrical wiring interconnect system. These systems and their insulation are expected to be exposed to significantly higher voltage and frequency stresses. Complicating matters, aircraft power transmission cables are often unshielded, yet are located in close proximity to a ground plane due to the aircraft metallic structure. Electromagnetic interactions between the two in this environment are poorly understood, particularly with respect to how the cable impedance changes for higher frequency signals. Using finite element analysis (FEA), this paper investigates how field stress conditions for high frequency components change as the cable-ground distance changes. A wider discussion of the impact of the mapped behavior on future aircraft electrical wiring design and airframe integration will also be presented. Findings demonstrate that despite cable-ground plane distance being within the standard limits, the cable characteristics can still significantly change, with a 3 cm distance leading to a 15% change in impedance

    Genomic evolution and polymorphism: Segmental duplications and haplotypes at 108 regions on 21 chromosomes

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    We describe here extensive, previously unknown, genomic polymorphism in 120 regions, covering 19 autosomes and both sex chromosomes. Each contains duplication within multigene clusters. Of these, 108 are extremely polymorphic with multiple haplotypes.We used the genomic matching technique (GMT), previously used to characterise the major histocompatibility complex (MHC) and regulators of complement activation (RCA).This genome-wide extension of this technique enables the examination of many underlying cis, trans and epistatic interactions responsible for phenotypic differences especially in relation to individuality, evolution and disease susceptibility.The extent of the diversity could not have been predicted and suggests a new model of primate evolution based on conservation of polymorphism rather than de novo mutation

    Asymptotic Expansions for Stationary Distributions of Perturbed Semi-Markov Processes

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    New algorithms for computing of asymptotic expansions for stationary distributions of nonlinearly perturbed semi-Markov processes are presented. The algorithms are based on special techniques of sequential phase space reduction, which can be applied to processes with asymptotically coupled and uncoupled finite phase spaces.Comment: 83 page

    Student perspectives on creating a positive classroom dynamic: science education in prison

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    Detailed student perspectives on their involvement in prison education are limited in published literature, yet such contributions are invaluable to education practitioners wanting to create inclusive learning environments. This article focuses on the student experience of taking part in a science outreach programme teaching science in prison in England, which was designed to build confidence in students who face challenges in accessing education pathways. Here, former students share their experiences of the programme, as well as other education courses in prison, and offer guidance on best practices for those engaging in outreach or research with the prison population. In particular, their reflections highlight that by creating and maintaining an environment that is accessible, inclusive and relatable, students from all backgrounds are able to engage in course content, and overcome hidden barriers to accessing education. Furthermore, based on their lived experience, the students offer practical advice with regard to improving future access to education in prison. The aim of this article is to give a voice to students in prison about their education experience, highlighting which aspects of this outreach programme (and other education courses) were impactful for them

    Particle physics models of inflation

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    Inflation models are compared with observation on the assumption that the curvature perturbation is generated from the vacuum fluctuation of the inflaton field. The focus is on single-field models with canonical kinetic terms, classified as small- medium- and large-field according to the variation of the inflaton field while cosmological scales leave the horizon. Small-field models are constructed according to the usual paradigm for beyond Standard Model physicsComment: Based on a talk given at the 22nd IAP Colloquium, ``Inflation +25'', Paris, June 2006 Curve omitted from final Figur

    Investigating the Effect of the Environment on Prey Detection Ability in Humans.

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    Visual search experiments used in the field of psychology may be applied to investigate the relationship between environments and prey detection rates that could influence hunting behaviours in ancient humans. Two lab-based experiments were designed to examine the effects of differing virtual environments, representing Marine Isotope Stage 3 (MIS3) in Europe, on participants' ability to locate prey. The results show that prey detection performance is highly influenced by vegetation structure, both in terms of the biome type (wooded vs. grassland environments) and the density of the vegetation (trees in wooded and shrubs in grassland environments). However, the density of vegetation has a greater relative effect in grassland than in wooded biomes. Closer examination of the transition between biomes (relative percentages of trees vs. shrubs) at the same vegetative density shows a non-linear relationship between prey detection performance and the relative tree to shrub percentages. Changes in the distribution of biomes occurred throughout the Quaternary. The composition of those biomes will have likely affected hominin hunting behaviours because of their intermediary effects on prey detection performance. This may, therefore, have played a role in the turn-overs of hunter-gatherer hominin populations during MIS3 and at other times in the Quaternary

    Volcanic air pollution and human health: recent advances and future directions

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    Volcanic air pollution from both explosive and effusive activity can affect large populations as far as thousands of kilometers away from the source, for days to decades or even centuries. Here, we summarize key advances and prospects in the assessment of health hazards, effects, risk, and management. Recent advances include standardized ash assessment methods to characterize the multiple physicochemical characteristics that might influence toxicity; the rise of community-based air quality monitoring networks using low-cost gas and particulate sensors; the development of forecasting methods for ground-level concentrations and associated public advisories; the development of risk and impact assessment methods to explore health consequences of future eruptions; and the development of evidence-based, locally specific measures for health protection. However, it remains problematic that the health effects of many major and sometimes long-duration eruptions near large populations have gone completely unmonitored. Similarly, effects of prolonged degassing on exposed populations have received very little attention relative to explosive eruptions. Furthermore, very few studies have longitudinally followed populations chronically exposed to volcanic emissions; thus, knowledge gaps remain about whether chronic exposures can trigger development of potentially fatal diseases. Instigating such studies will be facilitated by continued co-development of standardized protocols, supporting local study teams and procuring equipment, funding, and ethical permissions. Relationship building between visiting researchers and host country academic, observatory, and agency partners is vital and can, in turn, support the effective communication of health impacts of volcanic air pollution to populations, health practitioners, and emergency managers
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