3,899 research outputs found
Target product profiles for protecting against outdoor malaria transmission.
BACKGROUND\ud
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Long-lasting insecticidal nets (LLINs) and indoor residual sprays (IRS) have decimated malaria transmission by killing indoor-feeding mosquitoes. However, complete elimination of malaria transmission with these proven methods is confounded by vectors that evade pesticide contact by feeding outdoors.\ud
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METHODS\ud
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For any assumed level of indoor coverage and personal protective efficacy with insecticidal products, process-explicit malaria transmission models suggest that insecticides that repel mosquitoes will achieve less impact upon transmission than those that kill them outright. Here such models are extended to explore how outdoor use of products containing either contact toxins or spatial repellents might augment or attenuate impact of high indoor coverage of LLINs relying primarily upon contact toxicity.\ud
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RESULTS\ud
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LLIN impact could be dramatically enhanced by high coverage with spatial repellents conferring near-complete personal protection, but only if combined indoor use of both measures can be avoided where vectors persist that prefer feeding indoors upon humans. While very high levels of coverage and efficacy will be required for spatial repellents to substantially augment the impact of LLINs or IRS, these ambitious targets may well be at least as practically achievable as the lower requirements for equivalent impact using contact insecticides.\ud
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CONCLUSIONS\ud
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Vapour-phase repellents may be more acceptable, practical and effective than contact insecticides for preventing outdoor malaria transmission because they need not be applied to skin or clothing and may protect multiple occupants of spaces outside of treatable structures such as nets or houses
Knowledge as peacebuilder : an external review of the Peace Building and Reconstruction Programme Initiative
Studentsâ perceptions of video-conferencing in the classrooms in higher education
AbstractVideoconferencing technology is now considered as an advantageous way to connect with people anywhere in the world. Literature has indicated that it improves learning by meeting people that were previosly inaccessible due to several problems such as time and financial constraints (Dogget, 2008; Jian-Xiang, 1998; Martin, 2005). Despite its benefits, its success depends on various factors like tutors, students, and their attitudes to educational technology. This study aims to find out studentsâ perceptions of video-conferencing in higher education. Within the framework of this study, the second and third year students from English Language Teaching Department at Yildiz Technical University attended a videoconferencing class delivered by a native speaker of English related to their field for about thirty minutes. Adapted from Ashley's study (2010), pre -session and post-session surveys which included both short-answer and likert-scale type of questions were used. The results indicated that students tend to have a negative attitude towards both using video-conferencing in the class themselves and having videoconferencing in their classes at the university. The study is of vital importance as it can reveal how prospective English teachers will deal with technology in their own classes in the future
Characterization of Cadmium-Zinc Telluride Crystals Grown by 'Contactless' PVT Using Synchrotron White Beam Topography
Crystals of Cd(1-x)Zn(x)Te grown by Physical Vapor Transport (PVT) using self-seeding 'contactless' techniques were characterized using synchrotron radiation (reflection, transmission, and Laue back-reflection X-ray topography). Crystals of low (x = 0.04) and high (up to x approx. = 0.4) ZnTe content were investigated. Twins and defects such as dislocations, precipitates, and slip bands were identified. Extensive inhomogeneous strains present in some samples were found to be generated by interaction (sticking) with the pedestal and by composition gradients in the crystals. Large (up to about 5 mm) oval strain fields were observed around some Te precipitates. Low angle grain boundaries were found only in higher ZnTe content (x greater than or equal to 0.2) samples
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3D modelling of angiogenesis and vascular tumour growth
This paper was presented at the 3rd Micro and Nano Flows Conference (MNF2011), which was held at the Makedonia Palace Hotel, Thessaloniki in Greece. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, Aristotle University of Thessaloniki, University of Thessaly, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute
Modelling and observation of transionospheric propagation results from ISIS II in preparation for ePOP
The enhanced Polar Outflow Probe (ePOP) is scheduled to be launched as part of the Cascade Demonstrator Small-Sat and Ionospheric Polar Explorer (CASSIOPE) satellite in early 2008. A Radio Receiver Instrument (RRI) on ePOP will receive HF transmissions from various ground-based transmitters. In preparation for the ePOP mission, data from a similar transionospheric experiment performed by the International Satellites for Ionospheric Studies (ISIS) II satellite has been studied. Prominent features in the received 9.303-MHz signal were periodic Faraday fading of signal intensity at rates up to 13 Hz and a time of arrival delay between the O- and X-modes of up to 0.8 ms. Both features occurred when the satellite was above or south of the Ottawa transmitter. Ionospheric models for ray tracing were constructed using both International Reference Ionosphere (IRI) profiles and local peak electron density values from ISIS ionograms. Values for fade rate and differential mode delay were computed and compared to the values observed in the ISIS II data. The computed values showed very good agreement to the observed values of both received signal parameters when the topside sounding <I>fo</I>F2 values were used to scale IRI profiles, but not when strictly modelled IRI profiles were used. It was determined that the primary modifier of the received signal parameters was the <I>fo</I>F2 density and not the shape of the profile. This dependence was due to refraction, at the 9.303-MHz signal frequency, causing the rays to travel larger distances near the peak density where essentially all the mode splitting occurred. This study should assist in interpretation of ePOP RRI data when they are available
The Campbells: lordship, literature and liminality
The Campbells have the potential to offer much to the theme of literature and borders, given that the kindredâs astonishing political success in the late medieval and early modern period depended heavily upon the ability to negotiate multiple frontiers: between Highlands and Lowlands; between Gaelic Scotland and Ireland, and, especially after the Reformation, with England and the matter of Britain. This paper will explore the literary dimension to Campbell expansionism, from the Book of the Dean of Lismore in the earlier sixteenth century, to poetry addressed to dukes of Argyll in the earlier eighteenth century. Particular attention will be paid to the literary proclivities of the household of the Campbells of Glenorchy on either side of what appears to be a major watershed in 1550; and to the agenda of the Campbell protĂ©gĂ© John Carswell, first post-Reformation bishop of the Isles, and author of the first printed book in Gaelic in either Scotland or Ireland, Foirm na n-Urrnuidheadh (âThe Form of Prayersâ), published at Edinburgh in 1567
CFS prediction of winter persistent inversions in the Intermountain Region
A recent study by Gillies and others of persistent inversion events in the Intermountain West of the United States found a substantive linkage between the intraseasonal oscillation (ISO) and the development of persistent inversion events. Given that NCEPâs Climate Forecast System (CFS) has demonstrated skill in the prediction of the ISO as far out as 1 month, it was decided to examine the CFS forecastâs capability in the prediction of such winter persistent inversions. After initial analysis, a simple regression scheme is proposed that is coupled to the CFS output of geopotential height as a way to predict the occurrence of persistent inversion events for Salt Lake City, Utah. Analysis of the CFS hindcasts through the period 1981â2008 indicates that the regression coupled with the CFS can predict persistent inversion events with lead times of up to 4 weeks. The adoption of this coupled regressionâCFS prediction may improve the forecasting of persistent inversion events in the Intermountain West, which is currently restricted to the more limited time span (;10 days) of medium-range weather forecast models
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