149 research outputs found
Cost and cost-effectiveness of indoor residual spraying with pirimiphos-methyl in a high malaria transmission district of Mozambique with high access to standard insecticide-treated nets
Background:
As malaria cases increase in some of the highest burden countries, more strategic deployment of new and proven interventions must be evaluated to meet global malaria reduction goals.
Methods:
The cost and cost-effectiveness of indoor residual spraying (IRS) with pirimiphos-methyl (ActellicÂź300 CS) were assessed in a high transmission district (Mopeia) with high access to pyrethroid insecticide-treated nets (ITNs), compared to ITNs alone. The major mosquito vectors in the area were susceptible to primiphos-methyl, but resistant to pyrethoids. A decision analysis approach was followed to conduct deterministic and probabilistic sensitivity analyses in a theoretical cohort of 10,000 children under five years of age (U5) and 10,000 individuals of all ages, separately. Model parameters and distributions were based on prospectively collected cost and epidemiological data from a cluster-randomized control trial and a literature review. The primary analysis used health facility-malaria incidence, while community cohort incidence and cross-sectional prevalence rates were used in sensitivity analyses. Lifetime costs, malaria cases, deaths and disability-adjusted life-years (DALYs) were calculated to determine the incremental costs per DALY averted through IRS.
Results:
The average IRS cost per person protected was US400 (95% CI 399â402) per DALY averted. In the all-age cohort, the ICER was higher: US7.06) and IRS was highly cost-effective in children U5 (ICERâ=âUS1,431), compared to ITNs alone.
Conclusion:
This study provides robust evidence that IRS with pirimiphos-methyl can be cost-effective in high transmission regions with high pyrethroid ITN coverage where the major vector is susceptible to pirimiphos-methyl but resistant to pyrethroids. The finding that insecticide cost is the main driver of IRS costs highlights the need to reduce the insecticide price without jeopardizing effectiveness.
Trial registration: ClinicalTrials.gov identifier NCT02910934 (Registered 22 September 2016). https://clinicaltrials.gov/ct2/show/NCT02910934?term=NCT02910934&draw=2&rank=
Radial Velocity Discovery of an Eccentric Jovian World Orbiting at 18 au
Based on two decades of radial velocity (RV) observations using Keck/High Resolution Echelle Spectrometer (HIRES) and McDonald/Tull, and more recent observations using the Automated Planet Finder, we found that the nearby star HR 5183 (HD 120066) hosts a 3 minimum mass planet with an orbital period of yr. The orbit is highly eccentric (e â 0.84), shuttling the planet from within the orbit of Jupiter to beyond the orbit of Neptune. Our careful survey design enabled high cadence observations before, during, and after the planet\u27s periastron passage, yielding precise orbital parameter constraints. We searched for stellar or planetary companions that could have excited the planet\u27s eccentricity, but found no candidates, potentially implying that the perturber was ejected from the system. We did identify a bound stellar companion more than 15,000 au from the primary, but reasoned that it is currently too widely separated to have an appreciable effect on HR 5183 b. Because HR 5183 b\u27s wide orbit takes it more than 30 au (1\u27\u27) from its star, we also explored the potential of complimentary studies with direct imaging or stellar astrometry. We found that a Gaia detection is very likely, and that imaging at 10 ÎŒm is a promising avenue. This discovery highlights the value of long-baseline RV surveys for discovering and characterizing long-period, eccentric Jovian planets. This population may offer important insights into the dynamical evolution of planetary systems containing multiple massive planets
Comparative study of the analysis of seized samples by GC-MS, 1H NMR and FT-IR spectroscopy within a Night-Time Economy (NTE) setting
Rapid analysis of surrendered or seized drug samples provides important intelligence for health (e.g. treatment or harm reduction), and custodial services. Herein, three in-situ techniques, GC-MS, 1H NMR and FT-IR spectroscopy, with searchable libraries, are used to analyse 318 samples qualitatively, using technique specific library-based searches, obtained over the period 24th â 29th August 2019. 259 samples were identified as consisting of a single component, of which cocaine was the most prevalent (n = 158). Median match scores for all three techniques were â„ 0.84 and showed agreement except for metformin (n = 1), oxandrolone (identified as vitamin K by IR (n = 4)), diazepam (identified as zolpidem by FT-IR (n = 2)) and 2-Br-4,5-DMPEA (n = 1), a structural isomer of 2C-B identified as a polymer of cellulose (cardboard) by FT-IR. 51 samples were found to consist of two or more components, of which 49 were adulterated cocaine samples (45 binary and 4 tertiary samples). GC-MS identified all components present in the 49 adulterated cocaine samples, whereas IR identified only cocaine in 88 % of cases (adulterant only = 12 %). The breakdown for 1H NMR spectroscopy was all components identified (51 %), cocaine only (33 %), adulterant only (10 %), cocaine and one adulterant (tertiary mixtures only, 6 %)
Simultaneously enhancing adsorbed hydrogen and dinitrogen to enable efficient electrochemical NH3 synthesis on Sm(OH)3
The electrochemical N2 reduction reaction (ENRR), driven by renewable electricity and run under ambient conditions, offers a promising sustainable avenue for carbon-neutral NH3 production. Yet, to efficiently bind and activate the inert N2 remains challenge. Herein, effective and stable electrochemical NH3 synthesis on Sm(OH)3 via enhanced adsorption of hydrogen and dinitrogen by dual integration of sulfur dopants and oxygen vacancies (VO) is reported. The resulting S-doped lanthanide electrocatalyst attains both a good NH3 yield rate, exceeding 21âÎŒgNH3âhâ1âmgcat.â1, and an NH3 faradaic efficiency of over 29% at â0.3âV (vs reversible hydrogen electrode) in an H-type cell using a neutral electrolyte, figures of merit that are largely maintained after 2âdays of consecutive polarization. Density functional theory calculations show that the adsorption energy barrier of N2 on S-Sm(OH)3(VO) is greatly lowered by the introduction of VO. In addition, the S sites improve the adsorption of hydrogen produced via the Volmer reaction, which is conducive to the formation of the *NâNH intermediate (i.e., the potential determining step, PDS) on adjacent Sm sites, and thereby significantly promotes the reaction kinetics of ENRR. The PDS free energy for the catalyst is comparable with the values at the peak of the ENRR volcano plots of leading transition metal catalyst surfaces
The TESS-Keck Survey. XV. Precise Properties of 108 TESS Planets and Their Host Stars
We present the stellar and planetary properties for 85 TESS Objects of
Interest (TOIs) hosting 108 planet candidates which comprise the TESS-Keck
Survey (TKS) sample. We combine photometry, high-resolution spectroscopy, and
Gaia parallaxes to measure precise and accurate stellar properties. We then use
these parameters as inputs to a lightcurve processing pipeline to recover
planetary signals and homogeneously fit their transit properties. Among these
transit fits, we detect significant transit-timing variations among at least
three multi-planet systems (TOI-1136, TOI-1246, TOI-1339) and at least one
single-planet system (TOI-1279). We also reduce the uncertainties on
planet-to-star radius ratios across our sample, from a median
fractional uncertainty of 8.8 among the original TOI Catalog values to
3.0 among our updated results. With this improvement, we are able to
recover the Radius Gap among small TKS planets and find that the topology of
the Radius Gap among our sample is broadly consistent with that measured among
Kepler planets. The stellar and planetary properties presented here will
facilitate follow-up investigations of both individual TOIs and broader trends
in planet properties, system dynamics, and the evolution of planetary systems.Comment: Accepted at The Astronomical Journal; 21 pages, 9 figure
The TESS-Keck Survey. III. A Stellar Obliquity Measurement of TOI-1726 c
We report the measurement of a spectroscopic transit of TOI-1726c, one of two planets transiting a G-type star with V = 6.9 in the Ursa Major Moving Group (~400 Myr). With a precise age constraint from cluster membership, TOI-1726 provides a great opportunity to test various obliquity excitation scenarios that operate on different timescales. By modeling the RossiterâMcLaughlin (RM) effect, we derived a sky-projected obliquity of â1^(+35)_(â32)â. This result rules out a polar/retrograde orbit and is consistent with an aligned orbit for planet c. Considering the previously reported, similarly prograde RM measurement of planet b and the transiting nature of both planets, TOI-1726 tentatively conforms to the overall picture that compact multitransiting planetary systems tend to have coplanar, likely aligned orbits. TOI-1726 is also a great atmospheric target for understanding differential atmospheric loss of sub-Neptune planets (planet b 2.2 Râ and c 2.7 Râ both likely underwent photoevaporation). The coplanar geometry points to a dynamically cold history of the system that simplifies any future modeling of atmospheric escape
The TESS-Keck Survey. XVI. Mass Measurements for 12 Planets in Eight Systems
With JWST's successful deployment and unexpectedly high fuel reserves,
measuring the masses of sub-Neptunes transiting bright, nearby stars will soon
become the bottleneck for characterizing the atmospheres of small exoplanets
via transmission spectroscopy. Using a carefully curated target list and more
than two years' worth of APF-Levy and Keck-HIRES Doppler monitoring, the
TESS-Keck Survey is working toward alleviating this pressure. Here we present
mass measurements for 11 transiting planets in eight systems that are
particularly suited to atmospheric follow-up with JWST. We also report the
discovery and confirmation of a temperate super-Jovian-mass planet on a
moderately eccentric orbit. The sample of eight host stars, which includes one
subgiant, spans early-K to late-F spectral types ( 5200--6200
K). We homogeneously derive planet parameters using a joint photometry and
radial velocity modeling framework, discuss the planets' possible bulk
compositions, and comment on their prospects for atmospheric characterization.Comment: Accepted for publication in The Astronomical Journal on 2023-Jun-22.
60 pages, 17 Tables, 28 Figure
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