506 research outputs found

    ACLAS – a method to define geologically significant lineaments from potential fields data

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    Geological features, such as faults, dikes and contacts appear as lineaments in gravity and magnetic data. The Automated Coherent Lineament Analysis and Selection (ACLAS) method is a new approach to automatically compare and combine sets of lineaments or edges derived from two or more existing enhancement techniques applied to the same gravity or magnetic data set. ACLAS can be applied to the results of any edge detection algorithms and overcomes discrepancies between techniques to generate a coherent set of detected lineaments, which can be more reliably incorporated into geological interpretation. We demonstrate that the method increases spatial accuracy, removes artefacts not related to real edges, increases stability and that it is fast to implement and execute. The direction of lower density or susceptibility can also be automatically determined representing, for example, the downthrown side of a fault. Here, ACLAS is demonstrated on magnetic anomalies calculated from a simple slab model and from a synthetic continental margin model with noise added to the result. The approach helps to identify and discount artefacts of the different techniques, although the success of the combination is limited by the appropriateness of the individual techniques and their inherent assumptions. ACLAS has been applied separately to gravity and magnetic data from the NW Australia shelf displaying results from the two data sets together helps the appreciation of similarities and differences between gravity and magnetic results and indicates the application of the new approach to large scale structural mapping. Future developments could include refinement of depth estimates for ACLAS lineaments

    Comparison of social resistance to Ebola response in Sierra Leone and Guinea suggests explanations lie in political configurations not culture

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    Sierra Leone and Guinea share broadly similar cultural worlds, straddling the societies of the Upper Guinea Coast with Islamic West Africa. There was, however, a notable difference in their reactions to the Ebola epidemic. As the epidemic spread in Guinea, acts of violent or everyday resistance to outbreak control measures repeatedly followed, undermining public health attempts to contain the crisis. In Sierra Leone, defiant resistance was rarer. Instead of looking to ‘culture’ to explain patterns of social resistance (as was common in the media and in the discourse of responding public health authorities) a comparison between Sierra Leone and Guinea suggests that explanations lie in divergent political practice and lived experiences of the state. In particular, the structures of authority in which the government-sanctioned epidemic response was channeled relate very differently to communities of trust in each country. Predicting and addressing social responses to epidemic control measures should assess such political-trust configurations when planning interventions

    Using Mobile Phones to Improve Vaccination Uptake in 21 Low- and Middle-Income Countries: Systematic Review

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    Background: The benefits of vaccination have been comprehensively proven, however disparities in coverage persist due to poor health system management, limited resources and parental knowledge and attitudes. Evidence suggests that health interventions that engage local parties in communication strategies improve vaccination uptake. As mobile technology is widely used to improve health communication, mobile health (mHealth) interventions might be used to increase coverage. Objective: To conduct a systematic review of the available literature on the use of mHealth to improve vaccination in low and middle income countries with large numbers of unvaccinated children. Methods: In February 2017, MEDLINE, Scopus and Web of Science, and three health organization websites; Communication Initiative Network, TechNet-21, and PATH, were searched to identify mHealth intervention studies on vaccination uptake in 21 countries. Results: Ten peer-reviewed studies and eleven studies from white or grey literature were included. Nine took place in India, three in Pakistan, two each in Malawi and Nigeria, and one each in Bangladesh, Zambia, Zimbabwe and Kenya. Ten peer-reviewed studies and seven white/grey studies demonstrated improved vaccination uptake after interventions, including appointment reminders, mobile phone apps and pre-recorded messages. Conclusions: While the potential for mHealth interventions to improve vaccination coverage seems clear, the evidence for such interventions is not. The dearth of studies in countries facing the greatest barriers to immunization impedes the prospects for evidence-based policy and practice in these settings.The study was funded by the Medical Research Council, British Heart Foundation, and Homerton College, Cambridge

    Generating a high-resolution global magnetic model for oil and mineral exploration

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    This is the final contribution to the trilogy of articles on global potential-field data compilations. Getech's continental and national magnetic data compilations commenced in 1989 and were designed specifically for use in petroleum and mineral exploration. These studies complemented the continental-scale gravity-compilation studies that were the subject of the TLE “Meter Reader” contributions in March and May of this year. The success of these projects resulted from strategic partnerships, especially with Paterson, Grant and Watson Ltd. (PGW), and links to a wide range of national organizations. Early compilations covering the whole of Africa, South America, and China were followed by large-scale, small-scale, and national compilations and continue to this day with compilations of U. S. surveys. The projects spawned a range of technical developments, including approaches to remove survey-line noise, the integration of survey grids and disparate ship-track data, and the preservation of the longest-wavelength anomalies associated with the crustal magnetic field. The resulting global gravity and magnetic grids now form an invaluable resource for resource exploration

    Constraints on non-minimally coupled curved space electrodynamics from astrophysical observations

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    We study interactions of electro-magnetic fields with the curvature tensor of the form λRμναβFμνFαβ\lambda R_{\mu \nu \alpha \beta}F^{\mu \nu}F^{\alpha \beta}. Such coupling terms though are invariant under general coordinate transformation and CPT, however violate the Einstein equivalence principle. These couplings do not cause any energy dependent dispersion of photons but they exhibit birefringence. We put constraints on the coupling constant λ\lambda using results from solar system radar ranging experiments and millisecond-pulsar observations. We find that the most stringent constraint comes from pulsar observations and is given by λ<1011cm2 \lambda < 10^{11} cm^2 obtained from the timing of binary pulsar PSR B1534+12.Comment: 9 pages latex, accepted in CQ

    INPOP08, a 4-D planetary ephemeris: From asteroid and time-scale computations to ESA Mars Express and Venus Express contributions

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    The latest version of the planetary ephemerides developed at the Paris Observatory and at the Besancon Observatory is presented here. INPOP08 is a 4-dimension ephemeris since it provides to users positions and velocities of planets and the relation between TT and TDB. Investigations leading to improve the modeling of asteroids are described as well as the new sets of observations used for the fit of INPOP08. New observations provided by the European Space Agency (ESA) deduced from the tracking of the Mars Express (MEX) and Venus Express (VEX) missions are presented as well as the normal point deduced from the Cassini mission. We show the huge impact brought by these observations in the fit of INPOP08, especially in terms of Venus, Saturn and Earth-Moon barycenter orbits.Comment: 14 pages. submitted to A&A. accepted in A&

    Synthesis and characterization of a 29-amino acid residue DNA-binding peptide derived from α/β-type small, acid-soluble spore proteins (SASP) of bacteria

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    AbstractA 29-amino acid residue peptide (SASP-peptide) derived from the sequence of the putative DNA-contacting portion at the carboxyl terminus of an α/β-type small, acid-soluble spore protein (SASP) of Bacillus subillis has been synthesized by automated solid-phase methods and tested for its ability to interact with DNA. Circular dichroism (CD) spectroscopy reveals an interaction between this SASP-peptidc and DNA, both by an increase in α-helix content of the peplide (which alone has a mostly random conformation) and by enhancement of the 275-nm CD band of the DNA. In contrast to results with intact α/β-type SASP, however, the peptide does not induce a B → A cenformational transition in the DNA. The SASP-peptide also binds to poly(dG)·poly(dC) and prtects this polynucleotide against DNase I digestion and UV light-induced cylosine dimer formation, parallel to Findings made previously with native α/β-type SASP. The results confirm the hypothesis that the carboxyl-terminal region of the α/β-type SASP directly contacts DNA and possesses some, but not all, or the functional characteristics of the intact molecule

    Introducing a new breed of wine yeast: interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast and Saccharomyces mikatae

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    Interspecific hybrids are commonplace in agriculture and horticulture; bread wheat and grapefruit are but two examples. The benefits derived from interspecific hybridisation include the potential of generating advantageous transgressive phenotypes. This paper describes the generation of a new breed of wine yeast by interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast strain and Saccharomyces mikatae, a species hitherto not associated with industrial fermentation environs. While commercially available wine yeast strains provide consistent and reliable fermentations, wines produced using single inocula are thought to lack the sensory complexity and rounded palate structure obtained from spontaneous fermentations. In contrast, interspecific yeast hybrids have the potential to deliver increased complexity to wine sensory properties and alternative wine styles through the formation of novel, and wider ranging, yeast volatile fermentation metabolite profiles, whilst maintaining the robustness of the wine yeast parent. Screening of newly generated hybrids from a cross between a S. cerevisiae wine yeast and S. mikatae (closely-related but ecologically distant members of the Saccharomyces sensu stricto clade), has identified progeny with robust fermentation properties and winemaking potential. Chemical analysis showed that, relative to the S. cerevisiae wine yeast parent, hybrids produced wines with different concentrations of volatile metabolites that are known to contribute to wine flavour and aroma, including flavour compounds associated with non-Saccharomyces species. The new S. cerevisiae x S. mikatae hybrids have the potential to produce complex wines akin to products of spontaneous fermentation while giving winemakers the safeguard of an inoculated ferment.Jennifer R. Bellon, Frank Schmid, Dimitra L. Capone, Barbara L. Dunn, Paul J. Chamber

    Array-Based Whole-Genome Survey of Dog Saliva DNA Yields High Quality SNP Data

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    Background: Genome-wide association scans for genetic loci underlying both Mendelian and complex traits are increasingly common in canine genetics research. However, the demand for high-quality DNA for use on such platforms creates challenges for traditional blood sample ascertainment. Though the use of saliva as a means of collecting DNA is common in human studies, alternate means of DNA collection for canine research have instead been limited to buccal swabs, from which dog DNA is of insufficient quality and yield for use on most high-throughput array-based systems. We thus investigated an animal-based saliva collection method for ease of use and quality of DNA obtained and tested the performance of saliva-extracted canine DNA on genome-wide genotyping arrays. Methodology/Principal Findings: Overall, we found that saliva sample collection using this method was efficient. Extractions yielded high concentrations (,125 ng/ul) of high-quality DNA that performed equally well as blood-extracted DNA on the Illumina Infinium canine genotyping platform, with average call rates.99%. Concordance rates between genotype calls of saliva- versus blood-extracted DNA samples from the same individual were also.99%. Additionally, in silico calling of copy number variants was successfully performed and verified by PCR. Conclusions/Significance: Our findings validate the use of saliva-obtained samples for genome-wide association studies i
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