2,566 research outputs found
Xanthomonas campestris pv. campestris race 1 is the main causal agent of black rot of Brassicas in Southern Mozambique
Severe outbreaks of bacterial black rot caused by Xanthomonas campestris pv. campestris (Xcc) were observed in Brassica production fields of Southern Mozambique. The causal agent of the disease in the Mahotas and Chòkwé districts was identified and characterised. In total, 83 Xanthomonas-like strains were isolated from seed samples and leaves of cabbage and tronchuda cole with typical symptoms of the disease. Forty-six out of the 83 strains were found to be putative Xcc in at least one of the tests used: Classical biochemical assays, enzyme-linked immunosorbent assay (ELISA) with monoclonal antibodies, Biolog identification system, polymerase chain reaction (PCR) with specific primers and pathogenicity tests. The ELISA tests were positive for 43 strains. Biolog identified 43 strains as Xanthomonas, but only 32 as Xcc. PCR tests with primers targeting a fragment of the hrpF gene were positive for all 46 strains tested. Three strains were not pathogenic or weakly pathogenic and all other strains caused typical black rot symptoms in brassicas. Race type differentiation tests revealed the Xcc strains from Mozambique as members of race 1. The prevalence of this pathogenic race of the Xcc pathogen in Mozambique should be considered when black rot resistant cultivars are evaluated or introduced into the production regions of this country
Inequality, material well-being, and subjective well-being: Exploring associations for children across 15 diverse countries
Children's material well-being, and the levels of wealth and inequality in societies within which children live, are important factors in determining outcomes. However, less is known about the extent to which these factors have an impact children's subjective well-being, especially in an internationally comparative context. This study draws on data from the Children's Worlds survey, an international study of child subjective well-being, to explore links between national level indicators of wealth and inequality (GDP and Gini coefficients), individual indicators of material well-being (the material resources children report having access to), and subjective well-being. The survey covers 15 diverse countries covering the continents of Europe, Asia, Africa and South America, with samples of at least 3000 per country, ages 8, 10 and 12. Analysis takes the form of a multilevel, varying intercepts and slopes model, examining the association between financial and material resources and inequality and subjective well-being across and between countries. Findings suggest that material resources that children report are significantly associated with subjective well-being, while indicators of financial resources and inequality at the national level are not. While a significant association between material resources and subjective well-being is found across the whole sample, the magnitude of this association, and the association between school- and country-level material resources, varies markedly. Within different countries, the strongest material resources-related predictor of overall subjective well-being may be either at the individual, school or country level
Reply to the Comment by B. Andresen
All the comments made by Andresen's comments are replied and are shown not to
be pertinent. The original discussions [ABE S., Europhys. Lett. 90 (2010)
50004] about the absence of nonextensive statistical mechanics with q-entropies
for classical continuous systems are reinforced.Comment: 5 pages. This is Reply to B. Andresen's Comment on the paper entitled
"Essential discreteness in generalized thermostatistics with non-logarithmic
entropy", Europhys. Lett. 90 (2010) 5000
A high-efficiency spin-resolved phototemission spectrometer combining time-of-flight spectroscopy with exchange-scattering polarimetry
We describe a spin-resolved electron spectrometer capable of uniquely
efficient and high energy resolution measurements. Spin analysis is obtained
through polarimetry based on low-energy exchange scattering from a
ferromagnetic thin-film target. This approach can achieve a similar analyzing
power (Sherman function) as state-of-the-art Mott scattering polarimeters, but
with as much as 100 times improved efficiency due to increased reflectivity.
Performance is further enhanced by integrating the polarimeter into a
time-of-flight (TOF) based energy analysis scheme with a precise and flexible
electrostatic lens system. The parallel acquisition of a range of electron
kinetic energies afforded by the TOF approach results in an order of magnitude
(or more) increase in efficiency compared to hemispherical analyzers. The lens
system additionally features a 90{\deg} bandpass filter, which by removing
unwanted parts of the photoelectron distribution allows the TOF technique to be
performed at low electron drift energy and high energy resolution within a wide
range of experimental parameters. The spectrometer is ideally suited for
high-resolution spin- and angle-resolved photoemission spectroscopy
(spin-ARPES), and initial results are shown. The TOF approach makes the
spectrometer especially ideal for time-resolved spin-ARPES experiments.Comment: 16 pages, 11 figure
Production of antihydrogen at reduced magnetic field for anti-atom trapping
We have demonstrated production of antihydrogen in a 1T solenoidal
magnetic field. This field strength is significantly smaller than that used in
the first generation experiments ATHENA (3T) and ATRAP (5T). The
motivation for using a smaller magnetic field is to facilitate trapping of
antihydrogen atoms in a neutral atom trap surrounding the production region. We
report the results of measurements with the ALPHA (Antihydrogen Laser PHysics
Apparatus) device, which can capture and cool antiprotons at 3T, and then
mix the antiprotons with positrons at 1T. We infer antihydrogen production
from the time structure of antiproton annihilations during mixing, using mixing
with heated positrons as the null experiment, as demonstrated in ATHENA.
Implications for antihydrogen trapping are discussed
Antihydrogen formation dynamics in a multipolar neutral anti-atom trap
Antihydrogen production in a neutral atom trap formed by an octupole-based
magnetic field minimum is demonstrated using field-ionization of weakly bound
anti-atoms. Using our unique annihilation imaging detector, we correlate
antihydrogen detection by imaging and by field-ionization for the first time.
We further establish how field-ionization causes radial redistribution of the
antiprotons during antihydrogen formation and use this effect for the first
simultaneous measurements of strongly and weakly bound antihydrogen atoms.
Distinguishing between these provides critical information needed in the
process of optimizing for trappable antihydrogen. These observations are of
crucial importance to the ultimate goal of performing CPT tests involving
antihydrogen, which likely depends upon trapping the anti-atom
Search For Trapped Antihydrogen
We present the results of an experiment to search for trapped antihydrogen
atoms with the ALPHA antihydrogen trap at the CERN Antiproton Decelerator.
Sensitive diagnostics of the temperatures, sizes, and densities of the trapped
antiproton and positron plasmas have been developed, which in turn permitted
development of techniques to precisely and reproducibly control the initial
experimental parameters. The use of a position-sensitive annihilation vertex
detector, together with the capability of controllably quenching the
superconducting magnetic minimum trap, enabled us to carry out a
high-sensitivity and low-background search for trapped synthesised antihydrogen
atoms. We aim to identify the annihilations of antihydrogen atoms held for at
least 130 ms in the trap before being released over ~30 ms. After a three-week
experimental run in 2009 involving mixing of 10^7 antiprotons with 1.3 10^9
positrons to produce 6 10^5 antihydrogen atoms, we have identified six
antiproton annihilation events that are consistent with the release of trapped
antihydrogen. The cosmic ray background, estimated to contribute 0.14 counts,
is incompatible with this observation at a significance of 5.6 sigma. Extensive
simulations predict that an alternative source of annihilations, the escape of
mirror-trapped antiprotons, is highly unlikely, though this possibility has not
yet been ruled out experimentally.Comment: 12 pages, 7 figure
Decreasing the Peril of Antimicrobial Resistance Through Enhanced Health Literacy in Outpatient Settings: An Underrecognized Approach to Advance Antimicrobial Stewardship
© 2020, The Author(s). Globally, antimicrobial resistance (AMR) is a serious problem causing 700,000 deaths annually. By 2050, AMR is expected to cause approximately 10 million deaths globally each year if allowed to increase at the present rate. Many individuals have limited knowledge regarding appropriate antibiotic use and AMR. Most antibiotic use occurs in the outpatient setting, with approximately 30% of antibiotics prescribed deemed unnecessary. Antimicrobial stewardship (AMS) is a means to reduce inappropriate antibiotic use and AMR. While existing AMS efforts generally focus on the inpatient setting, a significant gap is present in the outpatient setting. A common theme across various national action plans to reduce AMR is the need for education and awareness. The importance of communicating information in a manner easily comprehended by the patient in addition to productive clinician–patient dialogue cannot be overestimated. Enhancing the public’s and patients’ AMS health literacy is an underrecognized approach to help address AMR. We describe Four Core Elements of Enhancing AMS Health Literacy in the Outpatient Setting, utilizing the Centers for Disease Control and Prevention’s framework: (1) leadership commitment, (2) intervention/action, (3) tracking/reporting, and (4) education/expertise. We call upon leaders in outpatient settings to embrace this approach to curb inappropriate antimicrobial use
Newborn screening for medium chain acyl-CoA dehydrogenase deficiency in England: prevalence, predictive value and test validity based on 1.5 million screened babies
Medium chain acyl-CoA dehydrogenase deficiency (MCADD) is a rare, life-threatening condition. Early diagnosis by screening asymptomatic newborns may improve outcome, but the benefit to newborns identified with variants not encountered clinically is uncertain
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