2,912 research outputs found
Study of mosquito fauna in rice ecosystems around Hanoi, Northern Vietnam
Species of the Culex vishnui subgroup, Cx. fuscocephala and Cx. gelidus, which are known Japanese encephalitis (JE) vectors, are distributed in rice agroecosystems in Asian countries. Hence, although ecological studies of rice agroecosystems in northern Vietnam are necessary, very few integrated studies of breeding habitats of mosquitoes, including JE vectors, have been conducted. We carried out a field study and investigated the mosquito fauna in six rice production areas in northern Vietnam during the rainy and dry seasons of 2009. Mosquitoes and potential mosquito predators were collected from aquatic habitats by using larval dippers. We collected 1780 Culex individuals (including 254 Cx. tritaeniorhynchus; 113 Cx. vishnui, 58 Cx. vishnui complex, consisting of Cx. vishnui and Cx. pseudovishnui; 12 Cx. gelidus; 1 Cx. bitaeniorhynchus; and 1 Cx. fuscocephala), 148 Anopheles individuals (including 5 An. vagus), 1 Mansonia annulifera, and 1 Mimomyia chamberlaini during the rainy season. During the dry season, we collected 176 Culex individuals (including 33 Cx. vishnui, 24 Cx. tritaeniorhynchus, 8 Cx. vishnui complex, and 1 Cx. gelidus) and 186 Anopheles individuals (including 9 An. tessellatus, 2 An. kochi, and 2 An. barbumbrosus). We found mosquitoes in all aquatic habitats, namely, rice fields, ditches, ponds, wetlands, irrigation canals, and rice nurseries, and Cx. tritaeniorhynchus and Cx. vishnui complex were found in all the above six areas. Heteroptera such as Micronecta, Veliidae, and Pleidae were abundant and widely distributed in both the seasons. The abundance of mosquito larvae was higher in the rice fields, ditches, and ponds during the rainy season than during the dry season. Cx. tritaeniorhynchus, Cx. vishnui complex, Cx. fuscocephala, and Cx. gelidus were abundant in rice agroecosystems (rice fields, ditches, ponds, and wetlands) in northern Vietnam, and their abundance was high during the rainy season. These findings deepen our understanding of mosquito ecology and strengthen mosquito control strategies to be applied in rice ecosystems Vietnam in the future
Evidence synthesis and decision modelling to support complex decisions: stockpiling neuraminidase inhibitors for pandemic influenza usage
Objectives: The stockpiling of neuraminidase inhibitor (NAI) antivirals as a defence against pandemic influenza is a significant public health policy decision that must be made despite a lack of conclusive evidence from randomised controlled trials regarding the effectiveness of NAIs on important clinical end points such as mortality. The objective of this study was to determine whether NAIs should be stockpiled for treatment of pandemic influenza on the basis of current evidence.Methods: A decision model for stockpiling was designed. Data on previous pandemic influenza epidemiology was combined with data on the effectiveness of NAIs in reducing mortality obtained from a recent individual participant meta-analysis using observational data. Evidence synthesis techniques and a bias modelling method for observational data were used to incorporate the evidence into the model. The stockpiling decision was modelled for adults (≥16 years old) and the United Kingdom was used as an example. The main outcome was the expected net benefits of stockpiling in monetary terms. Health benefits were estimated from deaths averted through stockpiling.Results: After adjusting for biases in the estimated effectiveness of NAIs, the expected net benefit of stockpiling in the baseline analysis was £444 million, assuming a willingness to pay of £20,000/QALY ($31,000/QALY). The decision would therefore be to stockpile NAIs. There was a greater probability that the stockpile would not be utilised than utilised. However, the rare but catastrophic losses from a severe pandemic justified the decision to stockpile.Conclusions: Taking into account the available epidemiological data and evidence of effectiveness of NAIs in reducing mortality, including potential biases, a decision maker should stockpile anti-influenza medication in keeping with the postulated decision rule
Awareness and preparedness of healthcare workers against the first wave of the COVID-19 pandemic: A cross-sectional survey across 57 countries.
BACKGROUND: Since the COVID-19 pandemic began, there have been concerns related to the preparedness of healthcare workers (HCWs). This study aimed to describe the level of awareness and preparedness of hospital HCWs at the time of the first wave. METHODS: This multinational, multicenter, cross-sectional survey was conducted among hospital HCWs from February to May 2020. We used a hierarchical logistic regression multivariate analysis to adjust the influence of variables based on awareness and preparedness. We then used association rule mining to identify relationships between HCW confidence in handling suspected COVID-19 patients and prior COVID-19 case-management training. RESULTS: We surveyed 24,653 HCWs from 371 hospitals across 57 countries and received 17,302 responses from 70.2% HCWs overall. The median COVID-19 preparedness score was 11.0 (interquartile range [IQR] = 6.0-14.0) and the median awareness score was 29.6 (IQR = 26.6-32.6). HCWs at COVID-19 designated facilities with previous outbreak experience, or HCWs who were trained for dealing with the SARS-CoV-2 outbreak, had significantly higher levels of preparedness and awareness (p<0.001). Association rule mining suggests that nurses and doctors who had a 'great-extent-of-confidence' in handling suspected COVID-19 patients had participated in COVID-19 training courses. Male participants (mean difference = 0.34; 95% CI = 0.22, 0.46; p<0.001) and nurses (mean difference = 0.67; 95% CI = 0.53, 0.81; p<0.001) had higher preparedness scores compared to women participants and doctors. INTERPRETATION: There was an unsurprising high level of awareness and preparedness among HCWs who participated in COVID-19 training courses. However, disparity existed along the lines of gender and type of HCW. It is unknown whether the difference in COVID-19 preparedness that we detected early in the pandemic may have translated into disproportionate SARS-CoV-2 burden of disease by gender or HCW type
Early Planet Formation in Embedded Disks (eDisk). II. Limited Dust Settling and Prominent Snow Surfaces in the Edge-on Class I Disk IRAS 04302+2247
While dust disks around optically visible, Class II protostars are found to
be vertically thin, when and how dust settles to the midplane are unclear. As
part of the Atacama Large Millimeter/submillimeter Array (ALMA) large program,
Early Planet Formation in Embedded Disks, we analyze the edge-on, embedded,
Class I protostar IRAS 04302+2247, also nicknamed the ``Butterfly Star." With a
resolution of 0.05" (8~au), the 1.3 mm continuum shows an asymmetry along the
minor axis which is evidence of an optically thick and geometrically thick disk
viewed nearly edge-on. There is no evidence of rings and gaps, which could be
due to the lack of radial substructure or the highly inclined and optically
thick view. With 0.1" (16~au) resolution, we resolve the 2D snow surfaces,
i.e., the boundary region between freeze-out and sublimation, for CO
=2--1, CO =2--1, CO =2--1, CO
=--, and SO =--, and constrain the CO
midplane snow line to au. We find Keplerian rotation around a
protostar of using CO. Through forward
ray-tracing using RADMC-3D, we find that the dust scale height is au
at a radius of 100~au from the central star and is comparable to the gas
pressure scale height. The results suggest that the dust of this Class~I source
has yet to vertically settle significantly.Comment: 33 pages, 21 figures. Accepted for publication in ApJ as one of the
first-look papers of the eDisk ALMA Large Progra
Early Planet Formation in Embedded Disks (eDisk) III: A first high-resolution view of sub-mm continuum and molecular line emission toward the Class 0 protostar L1527 IRS
Studying the physical and chemical conditions of young embedded disks is
crucial to constrain the initial conditions for planet formation. Here, we
present Atacama Large Millimeter/submillimeter Array (ALMA) observations of
dust continuum at 0.06" (8 au) resolution and molecular line emission at
0.17" (24 au) resolution toward the Class 0 protostar L1527 IRS from the
Large Program eDisk (Early Planet Formation in Embedded Disks). The continuum
emission is smooth without substructures, but asymmetric along both the major
and minor axes of the disk as previously observed. The detected lines of
CO, CO, CO, HCO, c-CH, SO, SiO, and DCN trace
different components of the protostellar system, with a disk wind potentially
visible in CO. The CO brightness temperature and the HCO line
ratio confirm that the disk is too warm for CO freeze out, with the snowline
located at 350 au in the envelope. Both molecules show potential evidence
of a temperature increase around the disk-envelope interface. SO seems to
originate predominantly in UV-irradiated regions such as the disk surface and
the outflow cavity walls rather than at the disk-envelope interface as
previously suggested. Finally, the continuum asymmetry along the minor axis is
consistent with the inclination derived from the large-scale (100" or 14,000
au) outflow, but opposite to that based on the molecular jet and envelope
emission, suggesting a misalignment in the system. Overall, these results
highlight the importance of observing multiple molecular species in multiple
transitions to characterize the physical and chemical environment of young
disks.Comment: 27 pages, 16 figures, 2 tables, 10 pages appendix with 12 figures.
Accepted for publication in ApJ as one of the first-look papers of the eDisk
ALMA Large Progra
Early Planet Formation in Embedded Disks (eDisk). IV. The Ringed and Warped Structure of the Disk around the Class I Protostar L1489 IRS
Constraining the physical and chemical structure of young embedded disks is
crucial to understanding the earliest stages of planet formation. As part of
the Early Planet Formation in Embedded Disks Atacama Large
Millimeter/submillimeter Array Large Program, we present high spatial
resolution (0.\!\!^{\prime\prime}1 or 15 au) observations of the
1.3 mm continuum and CO 2-1, CO 2-1, and SO
- molecular lines toward the disk around the Class I protostar L1489
IRS. The continuum emission shows a ring-like structure at 56 au from the
central protostar and a tenuous, optically thin emission extending beyond
300 au. The CO emission traces the warm disk surface, while the
CO emission originates from near the disk midplane. The coincidence of
the radial emission peak of CO with the dust ring may indicate a
gap-ring structure in the gaseous disk as well. The SO emission shows a highly
complex distribution, including a compact, prominent component at 30
au, which is likely to originate from thermally sublimated SO molecules. The
compact SO emission also shows a velocity gradient along a slightly
() tilted direction with respect to the major axis of the dust
disk, which we interpret as an inner warped disk in addition to the warp around
200 au suggested by previous work. These warped structures may be formed
by a planet or companion with an inclined orbit, or by a gradual change in the
angular momentum axis during gas infall.Comment: 24 pages, 12 figures. Accepted for publication in The Astrophysical
Journal as one of the first-look papers of the eDisk ALMA Large Progra
Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS
The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ψγ (with J/ψ → μ + μ −) where photons are reconstructed from γ → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured
Measurements of fiducial and differential cross sections for Higgs boson production in the diphoton decay channel at s√=8 TeV with ATLAS
Measurements of fiducial and differential cross sections are presented for Higgs boson production in proton-proton collisions at a centre-of-mass energy of s√=8 TeV. The analysis is performed in the H → γγ decay channel using 20.3 fb−1 of data recorded by the ATLAS experiment at the CERN Large Hadron Collider. The signal is extracted using a fit to the diphoton invariant mass spectrum assuming that the width of the resonance is much smaller than the experimental resolution. The signal yields are corrected for the effects of detector inefficiency and resolution. The pp → H → γγ fiducial cross section is measured to be 43.2 ±9.4(stat.) − 2.9 + 3.2 (syst.) ±1.2(lumi)fb for a Higgs boson of mass 125.4GeV decaying to two isolated photons that have transverse momentum greater than 35% and 25% of the diphoton invariant mass and each with absolute pseudorapidity less than 2.37. Four additional fiducial cross sections and two cross-section limits are presented in phase space regions that test the theoretical modelling of different Higgs boson production mechanisms, or are sensitive to physics beyond the Standard Model. Differential cross sections are also presented, as a function of variables related to the diphoton kinematics and the jet activity produced in the Higgs boson events. The observed spectra are statistically limited but broadly in line with the theoretical expectations
Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector
The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30
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