367 research outputs found
Antimicrobial susceptibility testing of Clostridium difficile using EUCAST epidemiological cut-off values and disk diffusion correlates
AbstractWith the emergence of reduced susceptibility of Clostridium difficile to metronidazole and vancomycin the value of antimicrobial susceptibility testing has increased. The aim of our study was to evaluate disk diffusion for susceptibility testing of C. difficile by comparing disk diffusion results with MICs from gradient tests and to propose zone diameter breakpoint correlates for the EUCAST epidemiological cut-off values (ECOFFs) recently published. We tested 211 clinical isolates of C. difficile, from patients with diarrhoea hospitalized at Aarhus and Odense University Hospitals, Denmark. Furthermore, ten clinical isolates of C. difficile from the Anaerobe Reference Laboratory, University Hospital of Wales, with known reduced susceptibility to either metronidazole or vancomycin, were included. Isolates were tested with Etest gradient strips and disk diffusion towards metronidazole, vancomycin and moxifloxacin on Brucella Blood Agar supplemented with hemin and vitamin K. We found an excellent agreement between inhibition zone diameter and MICs. For each MIC value, the inhibition zones varied from 0 to 8 mm, with 93% of values within 6 mm for metronidazole, 95% of values within 4 mm for vancomycin, and 98% of values within 4 mm for moxifloxacin. With proposed zone diameter breakpoints for metronidazole, vancomycin and moxifloxacin of WT ≥ 23 mm, WT ≥ 19 and WT ≥ 20 mm, respectively, we found no very major errors and only major errors below 2%. In conclusion, we suggest that disk diffusion is an option for antimicrobial susceptibility testing of C. difficile
Is Fairtrade in commercial farms justifiable?: its impact on commercial and small-scale producers in South Africa
Fairtrade initially was limited to improving the lives of small-scale and peasant farmers, but later on it embraced commercial farmers, which attracted criticism. While there are a number of justifications for the Fairtrade organization's decision, there are authors who feel that meaningful “fair trade” cannot be achieved with the inclusion of commercial farms. This paper investigates the impact of Fairtrade on commercial farms and small-scale farmer cooperatives in South Africa. Fairtrade on South African commercial farms embraces a number of policy concerns related to land reform, BEE and sustainable development. The results of the study show that when commercial farms are included in the Fairtrade model, communities in which these farmers live benefit from developmental projects. In addition, in some instances, farm workers gain shares in the commercial farms, and benefit from the farm owners’ knowledge and capital
The provenance of Borneo's enigmatic alluvial diamonds:A case study from Cempaka, SE Kalimantan
Gem-quality diamonds have been found in several alluvial deposits across central and southern Borneo. Borneo has been a known source of diamonds for centuries, but the location of their primary igneous source remains enigmatic. Many geological models have been proposed to explain their distribution, including: the diamonds were derived from a local diatreme; they were brought to the surface through ophiolite obduction or exhumation of UHP metamorphic rocks; they were transported long distances southward via major Asian river systems; or, they were transported from the Australian continent before Borneo was rifted from its northwestern margin in the Late Jurassic. To assess these models, we conducted a study of the provenance of heavy minerals from Kalimantan's Cempaka alluvial diamond deposit. This involved collecting U–Pb isotopic data, fission track and trace element geochemistry of zircon as well as major element geochemical data of spinels and morphological descriptions of zircon and diamond. The results indicate that the Cempaka diamonds were likely derived from at least two sources, one which was relatively local and/or involved little reworking, and the other more distal which records several periods of reworking. The distal diamond source is interpreted to be diamond-bearing pipes that intruded the basement of a block that: (1) rifted from northwest Australia (East Java or SW Borneo) and the diamonds were recycled into its sedimentary cover, or: (2) were emplaced elsewhere (e.g. NW Australia) and transported to a block (e.g. East Java or SW Borneo). Both of these scenarios require the diamonds to be transported with the block when it rifted from NW Australia in the Late Jurassic. The local source could be diamondiferous diatremes associated with eroded Miocene high-K alkaline intrusions north of the Barito Basin, which would indicate that the lithosphere beneath SW Borneo is thick (~ 150 km or greater). The ‘local’ diamonds could also be associated with ophiolitic rocks that are exposed in the nearby Meratus Mountains
FGF receptor genes and breast cancer susceptibility: results from the Breast Cancer Association Consortium
Background:Breast cancer is one of the most common malignancies in women. Genome-wide association studies have identified FGFR2 as a breast cancer susceptibility gene. Common variation in other fibroblast growth factor (FGF) receptors might also modify risk. We tested this hypothesis by studying genotyped single-nucleotide polymorphisms (SNPs) and imputed SNPs in FGFR1, FGFR3, FGFR4 and FGFRL1 in the Breast Cancer Association Consortium.
Methods:Data were combined from 49 studies, including 53 835 cases and 50 156 controls, of which 89 050 (46 450 cases and 42 600 controls) were of European ancestry, 12 893 (6269 cases and 6624 controls) of Asian and 2048 (1116 cases and 932 controls) of African ancestry. Associations with risk of breast cancer, overall and by disease sub-type, were assessed using unconditional logistic regression.
Results:Little evidence of association with breast cancer risk was observed for SNPs in the FGF receptor genes. The strongest evidence in European women was for rs743682 in FGFR3; the estimated per-allele odds ratio was 1.05 (95 confidence interval=1.02-1.09, P=0.0020), which is substantially lower than that observed for SNPs in FGFR2.
Conclusion:Our results suggest that common variants in the other FGF receptors are not associated with risk of breast cancer to the degree observed for FGFR2. © 2014 Cancer Research UK
Evidence of Color Coherence Effects in W+jets Events from ppbar Collisions at sqrt(s) = 1.8 TeV
We report the results of a study of color coherence effects in ppbar
collisions based on data collected by the D0 detector during the 1994-1995 run
of the Fermilab Tevatron Collider, at a center of mass energy sqrt(s) = 1.8
TeV. Initial-to-final state color interference effects are studied by examining
particle distribution patterns in events with a W boson and at least one jet.
The data are compared to Monte Carlo simulations with different color coherence
implementations and to an analytic modified-leading-logarithm perturbative
calculation based on the local parton-hadron duality hypothesis.Comment: 13 pages, 6 figures. Submitted to Physics Letters
Efficient and Correct Stencil Computation via Pattern Matching and Static Typing
Stencil computations, involving operations over the elements of an array, are a common programming pattern in scientific computing, games, and image processing. As a programming pattern, stencil computations are highly regular and amenable to optimisation and parallelisation. However, general-purpose languages obscure this regular pattern from the compiler, and even the programmer, preventing optimisation and obfuscating (in)correctness. This paper furthers our work on the Ypnos domain-specific language for stencil computations embedded in Haskell. Ypnos allows declarative, abstract specification of stencil computations, exposing the structure of a problem to the compiler and to the programmer via specialised syntax. In this paper we show the decidable safety guarantee that well-formed, well-typed Ypnos programs cannot index outside of array boundaries. Thus indexing in Ypnos is safe and run-time bounds checking can be eliminated. Program information is encoded as types, using the advanced type-system features of the Glasgow Haskell Compiler, with the safe-indexing invariant enforced at compile time via type checking
Search for electroweak production of single top quarks in collisions.
We present a search for electroweak production of single top quarks in the electron+jets and muon+jets decay channels. The measurements use ~90 pb^-1 of data from Run 1 of the Fermilab Tevatron collider, collected at 1.8 TeV with the DZero detector between 1992 and 1995. We use events that include a tagging muon, implying the presence of a b jet, to set an upper limit at the 95% confidence level on the cross section for the s-channel process ppbar->tb+X of 39 pb. The upper limit for the t-channel process ppbar->tqb+X is 58 pb. (arXiv
Mapping disparities in education across low- and middle-income countries
Analyses of the proportions of individuals who have completed key levels of schooling across all low- and middle-income countries from 2000 to 2017 reveal inequalities across countries as well as within populations. Educational attainment is an important social determinant of maternal, newborn, and child health(1-3). As a tool for promoting gender equity, it has gained increasing traction in popular media, international aid strategies, and global agenda-setting(4-6). The global health agenda is increasingly focused on evidence of precision public health, which illustrates the subnational distribution of disease and illness(7,8); however, an agenda focused on future equity must integrate comparable evidence on the distribution of social determinants of health(9-11). Here we expand on the available precision SDG evidence by estimating the subnational distribution of educational attainment, including the proportions of individuals who have completed key levels of schooling, across all low- and middle-income countries from 2000 to 2017. Previous analyses have focused on geographical disparities in average attainment across Africa or for specific countries, but-to our knowledge-no analysis has examined the subnational proportions of individuals who completed specific levels of education across all low- and middle-income countries(12-14). By geolocating subnational data for more than 184 million person-years across 528 data sources, we precisely identify inequalities across geography as well as within populations.Peer reviewe
Hard Single Diffraction in pbarp Collisions at root-s = 630 and 1800 GeV
Using the D0 detector, we have studied events produced in proton-antiproton
collisions that contain large forward regions with very little energy
deposition (``rapidity gaps'') and concurrent jet production at center-of-mass
energies of root-s = 630 and 1800 Gev. The fractions of forward and central jet
events associated with such rapidity gaps are measured and compared to
predictions from Monte Carlo models. For hard diffractive candidate events, we
use the calorimeter to extract the fractional momentum loss of the scattered
protons.Comment: 11 pages 4 figures. submitted to PR
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