Malaria control-two years' use of insecticide treated bednets compared with insecticide house spraying in KwaZulu-Natal

Objectives. The objective of this study was to produce data indicating whether insecticide-treated bednets should replaced insecticide house spraying as a malaria control method in South Africa. We report 2 years of preliminary data on malaria incidence comparing areas receiving insecticidetreated bednets and those subjected to house spraying in northern KwaZulu-Natal.Design, setting and subjects. In order to measure significant reductions in malaria incidence between the two interventions, a geographical information system (GIS) was used to identify and create seven pairs of geographical blocks (areas) in the malaria high-risk areas of Ndumu and Makanis in Ingwavuma magisterial district, KwaZulu-Natal. Individual blocks were then randomly allocated to either insecticide-treated bednets or house spraying with  deltamethrin. Malaria cases were either routinely recorded by surveillance agents at home or were reported to the nearest health facility.Results and conclusions. The results show that 2 years' use of insecticide-treated bednets by communities in Ndumu and Makanis, KwaZulu-Natal, significantly reduced the malaria incidence both in 1997 (rate ratio (RR) = 0.879, 95% confidence interval (CI) 0.80- 0.95, P = 0.04) and in 1998 (RR = 0.667, CI 0.61 - 0.72, P= 0.0001). Using a t-test, these significant reductions were further confirmed by an assessment of the rate of change between 1996 and 1998, showing a 16% reduction in malaria incidence in blocks using  treated bednets and an increase of 45% in sprayed areas (t =2.534, P = 0.026 (12 df)). In order to decide whether bednets should replace house spraying in South Africa, we need more data on the efficacy of treated bednets, their long-term acceptability and the cost of the two interventions

Malaria control – two years' use of insecticide treated bednets compared with insecticide house spraying in Kwazulu-Natal

Objectives_ The objective of this study was to produce data indicating whether insecticide-treated bednets should replac insecticide house spraying as a malaria control method in South Africa_ We report 2 years of preliminary data on malaria incidence comparing areas receiving insecticidetreated bednets and those subjected to house spraying in northern KwaZulu-Natal.Design, setting and subjects. In order to measure significant reductions in malaria incidence between the two interventions, a geographical information system (GIS) was used to identify and create seven pairs of geographical blood ; (areas) in the malaria high-risk areas of Ndumu and Makani in Ingwavuma magisterial district, KwaZulu-Natal, Individual blocks were then randomly allocated to either insecticide-treated bednets or house spraying with deltamethrin. Malaria cases were either routinely recorded by surveillance agents at home or were reported to the nearest health facility_Results and conclusions. The results show that 2 years' use of insecticide-treated bednets by communities in Ndumu and Makanis, KwaZulu-Natal, significantly reduced the malaria incidence both in 1997 (rate ratio (RR) =0_879, 95% confidence interval (Cn 0.80 - 0.95, P =0.04) and in 1998 (RR = 0.667, Cl 0_61 - 0.72, P = 0.0001). Using a t-test, these significant reductions were further confirmed by an assessment of the rate of change between 1996 and 1998, showing a 16% reduction in malaria incidence in blocks using bednets and an increase of 45% in sprayed areas (t = 2.534, P = 0.026 (12 df». In order to decide whether bednets : should replace house spraying in South Africa, we need more : data on the efficacy of treated bednets, their long-term acceptability and the cost of the two interventions

Building development and roads: implications for the distribution of stone curlews across the Brecks

Background: Substantial new housing and infrastructure development planned within England has the potential to conflict with the nature conservation interests of protected sites. The Breckland area of eastern England (the Brecks) is designated as a Special Protection Area for a number of bird species, including the stone curlew (for which it holds more than 60% of the UK total population). We explore the effect of buildings and roads on the spatial distribution of stone curlew nests across the Brecks in order to inform strategic development plans to avoid adverse effects on such European protected sites. Methodology: Using data across all years (and subsets of years) over the period 1988 – 2006 but restricted to habitat areas of arable land with suitable soils, we assessed nest density in relation to the distances to nearest settlements and to major roads. Measures of the local density of nearby buildings, roads and traffic levels were assessed using normal kernel distance-weighting functions. Quasi-Poisson generalised linear mixed models allowing for spatial auto-correlation were fitted. Results: Significantly lower densities of stone curlew nests were found at distances up to 1500m from settlements, and distances up to 1000m or more from major (trunk) roads. The best fitting models involved optimally distance-weighted variables for the extent of nearby buildings and the trunk road traffic levels. Significance : The results and predictions from this study of past data suggests there is cause for concern that future housing development and associated road infrastructure within the Breckland area could have negative impacts on the nesting stone curlew population. Given the strict legal protection afforded to the SPA the planning and conservation bodies have subsequently agreed precautionary restrictions on building development within the distances identified and used the modelling predictions to agree mitigation measures for proposed trunk road developments

Financing methods for small-scale hardwood plantations in Queensland, Australia

Under Vision 2020, a target was set in 1997 for trebling the plantation area in Australia by the year 2020. Government subsidies and extension for plantation establishment have largely disappeared, hence forestry expansion is highly dependent on access to private finance. In the state of Queensland, plantation expansion has occurred predominantly through managed investment schemes and the joint venture scheme managed by Forestry Plantations Queensland, a government-owned corporation. Most of these plantings are relatively small-scale hardwood plantations, which are designed to replace the hardwood timber from the native forests that will be protected from further logging after 2024 under the South-East Queensland Regional Forestry Agreement. Views on financing methods for forestry expansion in Queensland were investigated through by an email survey of 12 forestry and finance professionals, followed by in-depth personal interviews of the same group of key informants. Some of the issues identified include lack of transparent information, inequitable taxation system between Managed Investment Scheme (MIS) companies and small-scale forest operators, the need for further R&D on all aspects of the industry, the potential impacts of carbon credit schemes on the industry, and the design of a strategic model for forestry investors. Participants took the view that adoption of a strategic alliance model would encourage further investment in small-scale forestry, arguing that this model could protect the interest of all the stakeholders through reducing investment risk and creating competitive advantage. The potential introduction of a carbon trading scheme also attracted interest from investors, who look for recognisable structures that may alleviate the risk of investing in an industry with which they are unfamiliar. The participants considered that further R&D should be the main focus for government participation in small-scale forestry

Extensive Copy-Number Variation of Young Genes across Stickleback Populations

MM received funding from the Max Planck innovation funds for this project. PGDF was supported by a Marie Curie European Reintegration Grant (proposal nr 270891). CE was supported by German Science Foundation grants (DFG, EI 841/4-1 and EI 841/6-1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

HIV-1 recombinants with multiple parental strains in low-prevalence, remote regions of Cameroon: Evolutionary relics?

<p>Abstract</p> <p>Background</p> <p>The HIV pandemic disseminated globally from Central West Africa, beginning in the second half of the twentieth century. To elucidate the virologic origins of the pandemic, a cross-sectional study was conducted of the genetic diversity of HIV-1 strains in villagers in 14 remote locations in Cameroon and in hospitalized and STI patients. DNA extracted from PBMC was PCR amplified from HIV(+) subjects. Partial <it>pol </it>amplicons (N = 164) and nearly full virus genomes (N = 78) were sequenced. Among the 3956 rural villagers studied, the prevalence of HIV infection was 4.9%; among the hospitalized and clinic patients, it was 8.6%.</p> <p>Results</p> <p>Virus genotypes fell into two distinctive groups. A majority of the genotyped strains (109/164) were the circulating recombinant form (CRF) known to be endemic in West Africa and Central West Africa, CRF02_AG. The second most common genetic form (9/164) was the recently described CRF22_01A1, and the rest were a collection of 4 different subtypes (A2, D, F2, G) and 6 different CRFs (-01, -11, -13, -18, -25, -37). Remarkably, 10.4% of HIV-1 genomes detected (17/164) were heretofore undescribed unique recombinant forms (URF) present in only a single person. Nearly full genome sequencing was completed for 78 of the viruses of interest. HIV genetic diversity was commonplace in rural villages: 12 villages each had at least one newly detected URF, and 9 villages had two or more.</p> <p>Conclusions</p> <p>These results show that while CRF02_AG dominated the HIV strains in the rural villages, the remainder of the viruses had tremendous genetic diversity. Between the trans-species transmission of SIV_cpzand the dispersal of pandemic HIV-1, there was a time when we hypothesize that nascent HIV-1 was spreading, but only to a limited extent, recombining with other local HIV-1, creating a large variety of recombinants. When one of those recombinants began to spread widely (i.e. became epidemic), it was recognized as a subtype. We hypothesize that the viruses in these remote Cameroon villages may represent that pre-epidemic stage of viral evolution.</p

Optimizing topological cascade resilience based on the structure of terrorist networks

Complex socioeconomic networks such as information, finance and even terrorist networks need resilience to cascades - to prevent the failure of a single node from causing a far-reaching domino effect. We show that terrorist and guerrilla networks are uniquely cascade-resilient while maintaining high efficiency, but they become more vulnerable beyond a certain threshold. We also introduce an optimization method for constructing networks with high passive cascade resilience. The optimal networks are found to be based on cells, where each cell has a star topology. Counterintuitively, we find that there are conditions where networks should not be modified to stop cascades because doing so would come at a disproportionate loss of efficiency. Implementation of these findings can lead to more cascade-resilient networks in many diverse areas.Comment: 26 pages. v2: In review at Public Library of Science ON

The regulatory mechanism of fungal elicitor-induced secondary metabolite biosynthesis in medical plants.

A wide range of external stress stimuli trigger plant cells to undergo complex network of reactions that ultimately lead to the synthesis and accumulation of secondary metabolites. Accumulation of such metabolites often occurs in plants subjected to stresses including various elicitors or signal molecules. Throughout evolution, endophytic fungi, an important constituent in the environment of medicinal plants, have known to form long-term stable and mutually beneficial symbiosis with medicinal plants. The endophytic fungal elicitor can rapidly and specifically induce the expression of specific genes in medicinal plants which can result in the activation of a series of specific secondary metabolic pathways resulting in the significant accumulation of active ingredients. Here we summarize the progress made on the mechanisms of fungal elicitor including elicitor signal recognition, signal transduction, gene expression and activation of the key enzymes and its application. This review provides guidance on studies which may be conducted to promote the efficient synthesis and accumulation of active ingredients by the endogenous fungal elicitor in medicinal plant cells, and provides new ideas and methods of studying the regulation of secondary metabolism in medicinal plants