4,454 research outputs found
Quantitative detection of atropine-delayed gastric emptying in the horse by the <sup>13</sup>C-octanoic acid breath test
The <sup>13</sup>C-octanoic acid breath test has been correlated significantly to radioscintigraphy for measurement of gastric emptying indices in healthy horses. The objective of this study was to investigate the validity of the test for measurement of equine delayed gastric emptying, prior to its potential clinical application for this purpose. A model of atropine- induced gastroparesis was used. Gastric emptying rate was measured twice in 8 horses using concurrent radioscintigraphy and/or breath test after treatment i.v. with either atropine (0.035 mg/kg bwt) or saline in randomised order. Analysis of both data sets demonstrated that the atropine treatment had caused a significant delay in gastric emptying rate. Paired breath test data showed an atropine-induced delay in gastric half-emptying time t(1/2)), with no overlap in the 99% Cl range (P<0.001). Significant correlations were found between scintigraphy and <sup>13</sup>C-octanoic acid breath test for calculation of both t(1/2) (P<0.01) and lag phase duration (P<0.05) in the atropine-delayed emptying results. The mean (s.d.) bias in breath test t(1/2) when compared with scintigraphy was 1.78 (0.58) h. The results demonstrated that the <sup>13</sup>C-octanoic acid breath test was an effective diagnostic modality for the measurement of equine delayed gastric emptying. The technique offers advantages to existing methods for clinical investigation, as it is noninvasive, not radioactive, quantitative and requires minimal equipment or training to perform
Towards a shared method to classify contaminated territories in the case of an accidental nuclear event: the PRIME project
The analysis of the management of the accidentally radioactive contaminated areas such as those around Chernobyl nuclear power plant highlights the fact that the current spatial classification methods hardly help in recovering proper use of the contaminated territory.
The cause is mainly to be searched for in the traditional construction of risks assessment methods; these methods rest on criteria defined by institutional experts, which are not applicable in practise because they are not shared by all the stakeholders involved in the management of the contaminated territories.
Opposite such top-down tentative management, local efforts supported by Non-Governmental Organizations to restore life in the contaminated area seem to be more fruitful but very time and resources consuming and limited to the specific areas where they are experimented. The aim of the PRIME project, in progress at the French Institute for Radioprotection and Nuclear Safety, is to mix the advantages of both approaches in building a multicriteria decision tool based on the territorial specificities.
The criteria of the method are chosen and weighted with representatives of the territory’s stakeholders (decision makers, local actors and experts) to warrant that all the points of view are taken into account and to enable the risk managers to choose the appropriate strategy in case of an accident involving radioactive substances.
The area chosen for the pilot study is a 50 km radius territory around the nuclear sites of Tricastin-Pierrelatte in the lower valley of RhĂ´ne (France). One of the exploration questions of the PRIME project is whether a multicriteria method may be an appropriate tool to treat the data and make them visible and accessible for all the stakeholders
Use and abuse of the quasi-steady-state approximation
The transient kinetic behaviour of an open single enzyme, single substrate reaction is examined. The reaction follows the Van Slyke–Cullen mechanism, a spacial case of the Michaelis–Menten reaction. The analysis is performed both with and without applying the quasi-steady-state approximation. The analysis of the full system shows conditions for biochemical pathway coupling, which yield sustained oscillatory behaviour in the enzyme reaction. The reduced model does not demonstrate this behaviour. The results have important implications in the analysis of open biochemical reactions and the modelling of metabolic systems
Unemployment Duration, Schooling and Property Crime
It is well known that there is no consensus with respect to the relationship between unemployment and crime. As well, there is very little research on the linkages between crime and the educational experiences of young people. In this paper we show a very strong positive relationship between criminal activity and the extent of youth male long-term unemployment. We also show that criminal activity is negatively associated high school completions, and positively associated with high school non-completion rates. The analysis suggests that labour market and education policies have the potential to significantly reduce property crime. However, increased high school participation of the targeted group only decreases crime if it results in graduation. This suggests that the effectiveness of education policy is a critical influence on crime activity, a unique finding for the literature
Thulium and ytterbium-doped titanium oxide thin films deposited by ultrasonic spray pyrolysis
Thin films of thulium and ytterbium-doped titanium oxide were grown by
metal-organic spray pyrolysis deposition from titanium(IV)oxide
bis(acetylacetonate), thulium(III) tris(2,2,6,6-tetramethyl-3,5-heptanedionate)
and ytterbium(III) tris(acetylacetonate). Deposition temperatures have been
investigated from 300{\deg}C to 600{\deg}C. Films have been studied regarding
their crystallity and doping quality. Structural and composition
characterisations of TiO2:Tm,Yb were performed by electron microprobe, X-ray
diffraction and Fourier transform infrared spectroscopy. The deposition rate
can reach 0.8 \mum/h. The anatase phase of TiO2 was obtained after synthesis at
400{\deg}C or higher. Organic contamination at low deposition temperature is
eliminated by annealing treatments.Comment: 6 pages, 6 figure
Fresh concrete pumping arrest investigation for thixotropy by a CFD modelling apporach
Concrete pumping operations determine construction speed, finishing
quality, durability and even structural integrity. When pumping operations
cannot be continued, most problems occur due to complex time-dependent
transformations. This causes significant industrial costs (e.g. material and delay).
Since time-dependent aspects are currently not fully understood and cannot be
predicted, a way to quantify time-dependent aspects is needed. Therefore, we
make an attempt by numerical simulation by comparing thixotropic cases with
different pumping arresting times. After an introduction to fresh concrete rheology
and numerical modelling, ten representative thixotropy cases are analysed.
Despite some unresolved numerical instabilities, the numerical framework
allows to estimate pumping pressure peaks after resting time. The results
evaluate a thixotropy model, which is generally applicable for less thixotropic
SCC’s. It is clear that flow re-initiation after rest in concrete pumping is poorly
understood. Numerical simulation could be one approach for further analysis
and is potentially important for practice. Future work such as simulation of
concrete mixers, pressure increase after pumping arrest, formwork pressure
decay and leakage are therefore recommended
Protein container disassembly pathways depend on geometric design
The majority of viruses are organised according to the structural blueprints
of the seminal Caspar-Klug theory. However, there are a number of notable
exceptions to this geometric design principle. Prominent examples are the
cancer-causing papilloma viridae and the \textit{de novo} designed AaLS cages
that exhibit non-quasiequivalent capsid structures with protein numbers
excluded by Caspar-Klug theory. The biophysical properties of these
geometrically distinct architectures and the fitness advantages driving their
evolution are currently unclear. We investigate here the resilience to
fragmentation and disassembly behaviour of these capsid geometries by
introducing a percolation theory on weighted graphs. We show that these cage
architectures follow one of two distinct disassembly pathways, preferring
either hole formation or capsid fragmentation. This suggests that preference
for specific disassembly scenarios could be a driving force for the evolution
of the non Caspar-Klug protein container architectures.Comment: 15 pages, 10 figure
Establishment of a new method for rapid and precise estimation of apple proliferation phytoplasma concentration in periwinkle.
Preliminary development of real time PCR for quantification of Erwinia species infecting potato tubers.
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