2,031 research outputs found
A catalog of radio observations of Jupiter 1961-1964
Catalog of radio observations of Jupiter 1961 to 196
Efficient Toffoli Gates Using Qudits
The simplest decomposition of a Toffoli gate acting on three qubits requires
{\em five} 2-qubit gates. If we restrict ourselves to controlled-sign (or
controlled-NOT) gates this number climbs to six. We show that the number of
controlled-sign gates required to implement a Toffoli gate can be reduced to
just {\em three} if one of the three quantum systems has a third state that is
accessible during the computation, i.e. is actually a qutrit. Such a
requirement is not unreasonable or even atypical since we often artificially
enforce a qubit structure on multilevel quantums systems (eg. atoms, photonic
polarization and spatial modes). We explore the implementation of these
techniques in optical quantum processing and show that linear optical circuits
could operate with much higher probabilities of success
Fetal and early neonatal interleukin-6 response
In 1998, a systemic fetal cytokine response, defined as a plasma interleukin-6 (IL-6) value above 11 pg/mL, was reported to be a major independent risk factor for the subsequent development of neonatal morbid events even after adjustments for gestational age and other confounders. Since then, the body of literature investigating the use of blood concentrations of IL-6 as a hallmark of the fetal inflammatory response syndrome (FIRS), a diagnostic marker of early-onset neonatal sepsis (EONS) and a risk predictor of white matter injury (WMI), has grown rapidly. In this article, we critically review: IL-6 biological functions; current evidence on the association between IL-6, preterm birth, FIRS and EONS; IL-6 reference intervals and dynamics in the early neonatal period; IL-6 response during the immediate postnatal period and perinatal confounders; accuracy and completeness of IL-6 diagnostic studies for EONS (according to the Standards for Reporting of Diagnostic Accuracy statement); and recent breakthroughs in the association between fetal blood IL-6, EONS, and WMI
Water vapor radiometry research and development phase
This report describes the research and development phase for eight dual-channel water vapor radiometers constructed for the Crustal Dynamics Project at the Goddard Space Flight Center, Greenbelt, Maryland, and for the NASA Deep Space Network. These instruments were developed to demonstrate that the variable path delay imposed on microwave radio transmissions by atmospheric water vapor can be calibrated, particularly as this phenomenon affects very long baseline interferometry measurement systems. Water vapor radiometry technology can also be used in systems that involve moist air meteorology and propagation studies
Coherent analysis of quantum optical sideband modes
We demonstrate a device that allows for the coherent analysis of a pair of
optical frequency sidebands in an arbitrary basis. We show that our device is
quantum noise limited and hence applications for this scheme may be found in
discrete and continuous variable optical quantum information experiments.Comment: 3 pages, 3 figures, submitted to Optics Letter
A conditional-phase switch at the single-photon level
We present an experimental realization of a two-photon conditional-phase
switch, related to the ``-'' gate of quantum computation. This gate
relies on quantum interference between photon pairs, generating entanglement
between two optical modes through the process of spontaneous parametric
down-conversion (SPDC). The interference effect serves to enhance the effective
nonlinearity by many orders of magnitude, so it is significant at the quantum
(single-photon) level. By adjusting the relative optical phase between the
classical pump for SPDC and the pair of input modes, one can impress a large
phase shift on one beam which depends on the presence or absence of a single
photon in a control mode.Comment: 8 pages, 4 figure
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Assessing Health and Economic Outcomes of Interventions to Reduce Pregnancy-Related Mortality in Nigeria
Background: Women in Nigeria face some of the highest maternal mortality risks in the world. We explore the benefits and cost-effectiveness of individual and integrated packages of interventions to prevent pregnancy-related deaths. Methods: We adapt a previously validated maternal mortality model to Nigeria. Model outcomes included clinical events, population measures, costs, and cost-effectiveness ratios. Separate models were adapted to Southwest and Northeast zones using survey-based data. Strategies consisted of improving coverage of effective interventions, and could include improved logistics. Results: Increasing family planning was the most effective individual intervention to reduce pregnancy-related mortality, was cost saving in the Southwest zone and cost-effective elsewhere, and prevented nearly 1 in 5 abortion-related deaths. However, with a singular focus on family planning and safe abortion, mortality reduction would plateau below MDG 5. Strategies that could prevent 4 out of 5 maternal deaths included an integrated and stepwise approach that includes increased skilled deliveries, facility births, access to antenatal/postpartum care, improved recognition of referral need, transport, and availability quality of EmOC in addition to family planning and safe abortion. The economic benefits of these strategies ranged from being cost-saving to having incremental cost-effectiveness ratios less than $500 per YLS, well below Nigeria’s per capita GDP. Conclusions: Early intensive efforts to improve family planning and control of fertility choices, accompanied by a stepwise effort to scale-up capacity for integrated maternal health services over several years, will save lives and provide equal or greater value than many public health interventions we consider among the most cost-effective (e.g., childhood immunization)
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