4,430 research outputs found

    Effects of Hazardous Waste Risks on Property Transfers: Legal Liability vs. Direct Regulation

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    Process, Ideology, and Willingness to Pay for Reducing Childhood Poverty

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    We investigated the perceived value of government programs on early-childhood development as a means of reducing childhood poverty. We incorporated preferences for the process as well as the outcome by developing two stated-preference survey instruments. One survey directly elicited respondents’ willingness to pay specifically for high-quality, intensive, early-childhood development programs at federal and state levels. A second survey elicited respondents’ preferences for increasing or decreasing taxes and reallocating expenditures between other government programs and early-childhood programs. We found that respondents cared greatly about how childhood poverty was reduced, not just reducing poverty per se. The perceived effectiveness of a program and ideological perspective were found to be important determinants of preferences for a poverty-reduction program. Respondents across all groups, including conservatives and respondents who perceived the effectiveness of early-childhood programs to be low, were not in favor of reducing the early-childhood program.</jats:p

    High-Fidelity Readout in Circuit Quantum Electrodynamics Using the Jaynes-Cummings Nonlinearity

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    We demonstrate a qubit readout scheme that exploits the Jaynes-Cummings nonlinearity of a superconducting cavity coupled to transmon qubits. We find that in the strongly-driven dispersive regime of this system, there is the unexpected onset of a high-transmission "bright" state at a critical power which depends sensitively on the initial qubit state. A simple and robust measurement protocol exploiting this effect achieves a single-shot fidelity of 87% using a conventional sample design and experimental setup, and at least 61% fidelity to joint correlations of three qubits.Comment: 5 pages, 4 figure

    Ebola Virus Localization in the Macaque Reproductive Tract during Acute Ebola Virus Disease.

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    Sexual transmission of Ebola virus (EBOV) has been demonstrated more than a year after recovery from the acute phase of Ebola virus disease (EVD). The mechanisms underlying EBOV persistence and sexual transmission are not currently understood. Using the acute macaque model of EVD, we hypothesized EBOV would infect the reproductive tissues and sought to localize the infection in these tissues using immunohistochemistry and transmission electron microscopy. In four female and eight male macaques that succumbed to EVD between 6 and 9 days after EBOV challenge, we demonstrate widespread EBOV infection of the interstitial tissues and endothelium in the ovary, uterus, testis, seminal vesicle, epididymis, and prostate gland, with minimal associated tissue immune response or organ pathology. Given the widespread involvement of EBOV in the reproductive tracts of both male and female macaques, it is reasonable to surmise that our understanding of the mechanisms underlying sexual transmission of EVD and persistence of EBOV in immune-privileged sites would be facilitated by the development of a nonhuman primate model in which the macaques survived past the acute stage into convalescence

    Linear vs. nonlinear effects for nonlinear Schrodinger equations with potential

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    We review some recent results on nonlinear Schrodinger equations with potential, with emphasis on the case where the potential is a second order polynomial, for which the interaction between the linear dynamics caused by the potential, and the nonlinear effects, can be described quite precisely. This includes semi-classical regimes, as well as finite time blow-up and scattering issues. We present the tools used for these problems, as well as their limitations, and outline the arguments of the proofs.Comment: 20 pages; survey of previous result

    COVID-19 Health Preference Research: 4 Lessons Learned

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    Like the rest of the world, the pandemic has reshaped the lives and livelihoods of scientists in the health economics and outcomes research community. Many investigators in health preference research reacted by conducting empirical studies to better understand the value of health and health-related alternatives affected by COVID-19. The group identified 18 health preference studies currently under review or ongoing. On 17 June 2020, the first COVID-19 health preference research roundtable was held as an open meeting of the minds, allowing a healthy exchange of ideas between these study teams and other attendees interested in the area. From that discussion, this summary characterizes the state of science for the broader scientific community and for regulators and other decision makers looking for preference evidence regarding COVID-19

    Subclinical infection of macaques and baboons with a baboon simarterivirus

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    Simarteriviruses (Arteriviridae: Simarterivirinae) are commonly found at high titers in the blood of African monkeys but do not cause overt disease in these hosts. In contrast, simarteriviruses cause severe disease in Asian macaques upon accidental or experimental transmission. Here, we sought to better understand the host-dependent drivers of simarterivirus pathogenesis by infecting olive baboons (n = 4) and rhesus monkeys (n = 4) with the simarterivirus Southwest baboon virus 1 (SWBV-1). Surprisingly, none of the animals in our study showed signs of disease following SWBV-1 inoculation. Three animals (two rhesus monkeys and one olive baboon) became infected and sustained high levels of SWBV-1 viremia for the duration of the study. The course of SWBV-1 infection was highly predictable: plasma viremia peaked between 1 × 107 and 1 × 108 vRNA copies/mL at 3–10 days post-inoculation, which was followed by a relative nadir and then establishment of a stable set-point between 1 × 106 and 1 × 107 vRNA copies/mL for the remainder of the study (56 days). We characterized cellular and antibody responses to SWBV-1 infection in these animals, demonstrating that macaques and baboons mount similar responses to SWBV-1 infection, yet these responses are ineffective at clearing SWBV-1 infection. SWBV-1 sequencing revealed the accumulation of non-synonymous mutations in a region of the genome that corresponds to an immunodominant epitope in the simarterivirus major envelope glycoprotein GP5, which likely contribute to viral persistence by enabling escape from host antibodies

    Interactions between vaccinia virus and sensitized macrophages in vitro

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    The action of peritoneal exudate cells (PEC) from normal and vaccinia virus infected mice on infectious vaccinia virus particles was investigatedin vitro. PEC from immune mice showed a significantly higher infectivity titre reduction (virus clearance, VC) than normal cells. This effect could be clearly attributed to the macrophage. Vaccinia virus multiplied in PEC from normal animals while there was no virus propagation in cells from immunized mice. The release of adsorbed or engulfed virus was reduced significantly in PEC from immunized animals. Anti-vaccinia-antibodies seem to activate normal macrophages to increased virus clearance. This stimulating effect was demonstrable only in the IgG fraction of the antiserum. The activity of macrophages from mice injected three times over a period of 14 days with vaccinia virus could be entirely blocked with anti-mouse-IgG, while PEC from mice injected one time six days previously were not inhibited

    Sufficient conditions for two-dimensional localization by arbitrarily weak defects in periodic potentials with band gaps

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    We prove, via an elementary variational method, 1d and 2d localization within the band gaps of a periodic Schrodinger operator for any mostly negative or mostly positive defect potential, V, whose depth is not too great compared to the size of the gap. In a similar way, we also prove sufficient conditions for 1d and 2d localization below the ground state of such an operator. Furthermore, we extend our results to 1d and 2d localization in d dimensions; for example, a linear or planar defect in a 3d crystal. For the case of D-fold degenerate band edges, we also give sufficient conditions for localization of up to D states.Comment: 9 pages, 3 figure
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