9,079 research outputs found

    Phase locked phase modulator including a voltage controlled oscillator Patent

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    Phase locked phase modulation system with voltage controlled oscillator for final phase linearit

    Simultaneous reconstruction of evolutionary history and epidemiological dynamics from viral sequences with the birth-death SIR model

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    The evolution of RNA viruses such as HIV, Hepatitis C and Influenza virus occurs so rapidly that the viruses' genomes contain information on past ecological dynamics. Hence, we develop a phylodynamic method that enables the joint estimation of epidemiological parameters and phylogenetic history. Based on a compartmental susceptible-infected-removed (SIR) model, this method provides separate information on incidence and prevalence of infections. Detailed information on the interaction of host population dynamics and evolutionary history can inform decisions on how to contain or entirely avoid disease outbreaks. We apply our Birth-Death SIR method (BDSIR) to two viral data sets. First, five human immunodeficiency virus type 1 clusters sampled in the United Kingdom between 1999 and 2003 are analyzed. The estimated basic reproduction ratios range from 1.9 to 3.2 among the clusters. All clusters show a decline in the growth rate of the local epidemic in the middle or end of the 90's. The analysis of a hepatitis C virus (HCV) genotype 2c data set shows that the local epidemic in the C\'ordoban city Cruz del Eje originated around 1906 (median), coinciding with an immigration wave from Europe to central Argentina that dates from 1880--1920. The estimated time of epidemic peak is around 1970.Comment: Journal link: http://rsif.royalsocietypublishing.org/content/11/94/20131106.ful

    Exploratory Meeting on Airborne Doppler Lidar Wind Velocity Measurements

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    The scientific interests and applications of the Airborne Doppler Lidar Wind Velocity Measurement System to severe storms and local weather are discussed. The main areas include convective phenomena, local circulation, atmospheric boundary layer, atmospheric dispersion, and industrial aerodynamics

    Pm receiver rf test console, appendix f final rep

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    Technical description of phase-modulation receiver developed in radio-frequency console progra

    Development of autoclave moldable addition-type polyimides

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    Chemistry and processing modifications of the poly(Diels Alder) polyimide (PDA) resin were performed to obtain structural composites suitable for 589 K (600 F) service. This work demonstrated that the PDA resin formulation is suitable for service at 589 K (600 F) for up to 125 hours when used in combination with Hercules HTS graphite fiber. Sandwich panels were autoclave molded using PDA/HTS skins and polyimide/glass honeycomb core. Excellent adhesion between honeycomb core and the facing skins was demonstrated. Fabrication ease was demonstrated by autoclave molding three-quarter scale YF-12 wing panels

    Spacelab 3: Research in microgravity

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    The Spacelab 3 mission, which focused on research in microgravity, took place during the period April 29 through May 6, 1985. Spacelab 3 was the second flight of the National Aeronautics and Space Administration's modular Shuttle-borne research facility. An overview of the mission is presented. Preliminary scientific results from the mission were presented by investigators at a symposium held at Marshall Space Flight Center on December 4, 1985. This special issue is based on reports presented at that symposium

    Mapping maternity services in Australia: Location, classification and services

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    Objective. To describe maternity services available to Australian women and, in particular, the location, classification of services and support services available. Design. A descriptive study was conducted using an online survey that was emailed to eligible hospitals. Inclusion criteria for the study included public and private maternity units with greater than 50 births per year. In total, 278 maternity units were identified. Units were asked to classify their level of acuity (Levels 26). Results. A total of 150 (53%) maternity units responded. Those who responded were reasonably similar to those who did not respond, and were representative of Australian maternity units. Almost three-quarters of respondents were from public maternity units and almost 70% defined themselves as being in a rural or remote location. Maternity units with higher birth rates were more likely to classify themselves as providing higher acuity services, that is, Levels 5 and 6. Private maternity units were more likely to have higher acuity classifications. Interventions such as induction of labour, either using an artificial rupture of membranes (ARM) and oxytocin infusion or with prostaglandins, were common across most units. Although electronic fetal monitoring (EFM) was also widely available, access to fetal scalp pH monitoring was low. Conclusion. Maternity service provision varies across the country and is defined predominately by location and annual birth rate. What is known about the topic? In 2007, over 99% of the 289496 women who gave birth in Australia did so in a hospital. It is estimated that there are more than 300 maternity units in the country, ranging from large tertiary referral centres in major cities to smaller maternity units in rural towns, some of which only provide postnatal care with the woman giving birth at a larger facility. Geographical location, population and ability to attract a maternity workforce determine the number of maternity units within a region, although the means of determining the number of maternity units within a region is often unclear. In recent years, a large number of small maternity units have closed, particularly in rural areas, often due to difficulties securing an adequate workforce, particularly midwives and general practitioner obstetricians. There is a lack of understanding about the nature of maternity service provision in Australia and considerable differences across states and territories. What does this paper add? This paper provides a description of the geographic distribution and level of maternity services, the demand on services, the available obstetric interventions, the level of staffing (paediatric and anaesthetic) and support services available and the private and public mix of maternity units. The paper also provides an exploration of the different interventions and discusses whether these are appropriate, given the level of acuity and access to emergency Caesarean section services. What are the implications for practitioners? This study provides useful information particularly for policy-makers, managers and practitioners. This is at a time when considerable maternity reform is underway and changes at a broader level to the health system are planned. Understanding the nature of maternity services is critical to this debate and ongoing planning decisions. © 2011 AHHA

    Development of a high-altitude airborne dial system: The Lidar Atmospheric Sensing Experiment (LASE)

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    The ability of a Differential Absorption Lidar (DIAL) system to measure vertical profiles of H2O in the lower atmosphere was demonstrated both in ground-based and airborne experiments. In these experiments, tunable lasers were used that required real-time experimenter control to locate and lock onto the atmospheric H2O absorption line for the DIAL measurements. The Lidar Atmospheric Sensing Experiment (LASE) is the first step in a long-range effort to develop and demonstrate an autonomous DIAL system for airborne and spaceborne flight experiments. The LASE instrument is being developed to measure H2O, aerosol, and cloud profiles from a high-altitude ER-2 (extended range U-2) aircraft. The science of the LASE program, the LASE system design, and the expected measurement capability of the system are discussed

    No-vent fill pressurization tests using a cryogen simulant

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    The results are described of an experimental program which studied the performance of various no-vent fill techniques for tank-to-tank liquid transfer. The tests were performed using a cryogen simulant (Freon-114) and a test bed consisting of a multiple tank/plumbing network that enabled studies of a variety of different inlet flow and active mixing regimes. Several results and conclusions were drawn from the 26 transfer experiments comprising the program. Most notable was the significant improvement in fill performance (i.e., minimized fill time and maximized fill fraction) with increased agitation of the liquid surface. Another was the close correlation between measured condensation rates and those predicted by recent theories which express condensation as a function of turbulent eddy effects on the liquid surface. In most cases, test data exhibited strong agreement with an analytical model which accounts for tank heat transfer and thermodynamics in a 1 g environment
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