7,227 research outputs found

    Optimal population-level infection detection strategies for malaria control and elimination in a spatial model of malaria transmission

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    Mass campaigns with antimalarial drugs are potentially a powerful tool for local elimination of malaria, yet current diagnostic technologies are insufficiently sensitive to identify all individuals who harbor infections. At the same time, overtreatment of uninfected individuals increases the risk of accelerating emergence of drug resistance and losing community acceptance. Local heterogeneity in transmission intensity may allow campaign strategies that respond to index cases to successfully target subpatent infections while simultaneously limiting overtreatment. While selective targeting of hotspots of transmission has been proposed as a strategy for malaria control, such targeting has not been tested in the context of malaria elimination. Using household locations, demographics, and prevalence data from a survey of four health facility catchment areas in southern Zambia and an agent-based model of malaria transmission and immunity acquisition, a transmission intensity was fit to each household based on neighborhood age-dependent malaria prevalence. A set of individual infection trajectories was constructed for every household in each catchment area, accounting for heterogeneous exposure and immunity. Various campaign strategies (mass drug administration, mass screen and treat, focal mass drug administration, snowball reactive case detection, pooled sampling, and a hypothetical serological diagnostic) were simulated and evaluated for performance at finding infections, minimizing overtreatment, reducing clinical case counts, and interrupting transmission. For malaria control, presumptive treatment leads to substantial overtreatment without additional morbidity reduction under all but the highest transmission conditions. Selective targeting of hotspots with drug campaigns is an ineffective tool for elimination due to limited sensitivity of available field diagnostics

    Verifying continuous variable entanglement of intense light pulses

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    Three different methods have been discussed to verify continuous variable entanglement of intense light beams. We demonstrate all three methods using the same set--up to facilitate the comparison. The non--linearity used to generate entanglement is the Kerr--effect in optical fibres. Due to the brightness of the entangled pulses, standard homodyne detection is not an appropriate tool for the verification. However, we show that by using large asymmetric interferometers on each beam individually, two non-commuting variables can be accessed and the presence of entanglement verified via joint measurements on the two beams. Alternatively, we witness entanglement by combining the two beams on a beam splitter that yields certain linear combinations of quadrature amplitudes which suffice to prove the presence of entanglement.Comment: 11 pages, 7 figures, to appear in Phys. Rev.

    Untangling the Recombination Line Emission from HII Regions with Multiple Velocity Components

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    HII regions are the ionized spheres surrounding high-mass stars. They are ideal targets for tracing Galactic structure because they are predominantly found in spiral arms and have high luminosities at infrared and radio wavelengths. In the Green Bank Telescope HII Region Discovery Survey (GBT HRDS) we found that >30% of first Galactic quadrant HII regions have multiple hydrogen radio recombination line (RRL) velocities, which makes determining their Galactic locations and physical properties impossible. Here we make additional GBT RRL observations to determine the discrete HII region velocity for all 117 multiple-velocity sources within 18deg. < l < 65deg. The multiple-velocity sources are concentrated in the zone 22deg. < l < 32deg., coinciding with the largest regions of massive star formation, which implies that the diffuse emission is caused by leaked ionizing photons. We combine our observations with analyses of the electron temperature, molecular gas, and carbon recombination lines to determine the source velocities for 103 discrete H II regions (88% of the sample). With the source velocities known, we resolve the kinematic distance ambiguity for 47 regions, and thus determine their heliocentric distances.Comment: 44 pages, 5 figures, 16 pages of tables; Accepted by ApJ

    Variations Electrical Resistance of the Skin in Newborn Infants

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    Measurements were made of the large variations in apparent electrical resistance of the skin of fifteen newborn infants. Readings were taken every five minutes over two hour periods using a unidirectional current technique. The purpose of the experiment was to check Richter\u27s hypothesis that increases in palmar resistance afford an objective criterion of sleep

    Malaria elimination campaigns in the Lake Kariba region of Zambia: a spatial dynamical model

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    Background As more regions approach malaria elimination, understanding how different interventions interact to reduce transmission becomes critical. The Lake Kariba area of Southern Province, Zambia, is part of a multi-country elimination effort and presents a particular challenge as it is an interconnected region of variable transmission intensities. Methods In 2012-13, six rounds of mass-screen-and-treat drug campaigns were carried out in the Lake Kariba region. A spatial dynamical model of malaria transmission in the Lake Kariba area, with transmission and climate modeled at the village scale, was calibrated to the 2012-13 prevalence survey data, with case management rates, insecticide-treated net usage, and drug campaign coverage informed by surveillance. The model was used to simulate the effect of various interventions implemented in 2014-22 on reducing regional transmission, achieving elimination by 2022, and maintaining elimination through 2028. Findings The model captured the spatio-temporal trends of decline and rebound in malaria prevalence in 2012-13 at the village scale. Simulations predicted that elimination required repeated mass drug administrations coupled with simultaneous increase in net usage. Drug campaigns targeted only at high-burden areas were as successful as campaigns covering the entire region. Interpretation Elimination in the Lake Kariba region is possible through coordinating mass drug campaigns with high-coverage vector control. Targeting regional hotspots is a viable alternative to global campaigns when human migration within an interconnected area is responsible for maintaining transmission in low-burden areas

    On the phase diagram of QCD at finite isospin density

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    Using a canonical formalism, we determine the equation of state and the phase diagram of eight-flavour QCD, as a function of temperature and isospin density. Two mechanisms are at work: Bose condensation of pions at high density, and deconfinement at high temperature. We study their interplay and find that on our small and coarse lattice the first order deconfinement transition appears to end at a critical point at finite density. We investigate the strength of the overlap and of the sign problems and discuss implications for the baryonic density case.Comment: 7 pages, 4 figures, Contribution to Lattice 2007, Regensburg, Germany, 30 July - 4 August 200

    The Relationship between the UniProt Knowledgebase (UniProtKB) and the IntAct Molecular Interaction Databases

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    IntAct provides a freely available, open source database system and analysis tools for protein interaction data. All interactions are derived from literature curation or direct user submission and all experimental information relating to binary protein-protein&#xd;&#xa;interactions is entered into the IntAct database by curators, via a web-based editor. Interaction information is added to the SUBUNIT comment and the RP line of the relevant publication within the UniProtKB entry. There may be a single INTERACTION comment present within a UniProtKB entry, which conveys information relevant to binary protein-protein interactions. This is automatically derived from the IntAct database and is updated on a triweekly basis. Interactions can be derived by any appropriate experimental method but must be confirmed by a second interaction if resulting from a single yeast2hybrid experiment. For large-scale experiments, interactions are considered if a high confidence score is assigned by the authors. The INTERACTION line contains a direct link to IntAct that provides detailed information for the experimental support. These lines are not changed manually and any discrepancy is reported to IntAct for updates. There is also a database crossreference line within the UniProtKB entry i.e.: DR IntAct _UniProtKB AC, which directs the user to additional interaction data for that molecule. &#xd;&#xa;UniProt is supported by grants from the National Institutes of Health, European Commission, Swiss Federal Government and PATRIC BRC.&#xd;&#xa;IntAct is funded by the European Commission under FELICS, contract number 021902 (RII3) within the Research Infrastructure Action of the FP6 &#x22;Structuring the European Research Area&#x22; Programme
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