Comparison of agar gel immunodiffusion test, enzyme-linked immunosorbent assay and PCR in diagnostics of enzootic bovine leukosis

Bovine leukaemia virus (BLV) is a retrovirus that induces a chronic infection in cattle. Once infected, cattle remain virus carriers for life and start to show an antibody response within a few weeks after infection. Eradication and control of the disease are based on early diagnostics and segregation of the carriers. The choice of a diagnostic method depends on the eradication programme, money resources and characteristics of the herd to be analysed. The agar gel immunodiffusion (AGID) test has been the serological test of choice for routine diagnosis of serum samples. Nevertheless, in more recent years, the enzyme-linked immunosorbent assay (ELISA) has replaced the AGID for large scale testing. For this purpose, commercially available BLV-ELISA kits were compared to the AGID and to the polymerase chain reaction (PCR) method performed with two sets of primers, amplifying env region. The ELISA kit based on the p24 core protein was found to be less specific and served as a screening test. The ELISA kit based on the envelope glycoprotein (gpSI) served as a verification test and gave a good correlation with the AGID test and PCR method. However, ELISA showed a higher sensitivity than AGID. The p24 based ELiSA was useful for screening a large number of samples, whereas gp51 based ELISA, AGID and PCR were more important for detecting the antibody response against the individual BLV-proteins and therefore for verification of the infection with BLV

Production/maintenance cooperative scheduling using multi-agents and fuzzy logic

Within companies, production is directly concerned with the manufacturing schedule, but other services like sales, maintenance, purchasing or workforce management should also have an influence on this schedule. These services often have together a hierarchical relationship, i.e. the leading function (most of the time sales or production) generates constraints defining the framework within which the other functions have to satisfy their own objectives. We show how the multi-agent paradigm, often used in scheduling for its ability to distribute decision-making, can also provide a framework for making several functions cooperate in the schedule performance. Production and maintenance have been chosen as an example: having common resources (the machines), their activities are actually often conflicting. We show how to use a fuzzy logic in order to model the temporal degrees of freedom of the two functions, and show that this approach may allow one to obtain a schedule that provides a better compromise between the satisfaction of the respective objectives of the two functions

Acoustic Properties of Soybeans

Acoustic transmission and impact force response methods were investigated for classification of soybeans. The transmission method was slow and not suitable for real-time application. A polynomial was fitted to the deconvolved frequency spectrum of acoustic impulse data for soybeans. The curve fitting procedure successfully predicted the mass of each soybean. The size of soybeans was related to the bandwidth. Diseased soybeans consistently showed narrower bandwidths than healthy soybeans. The diseased and damaged soybeans had broad variations in low frequency which was quantifiable by threshholding the error of fit in the curve fitting procedure

Strange form factors of the nucleon in a two-component model

The strange form factors of the nucleon are studied in a two-component model consisting of a three-quark intrinsic structure surrounded by a meson cloud. A comparison with the available experimental world data from the SAMPLE, PVA4, HAPPEX and G0 collaborations shows a good overall agreement. The strange magnetic moment is found to be positive, 0.315 nm.Comment: 11 pages, 2 tables, 5 figures, accepted for publication in J. Phys. G. Revised version, new figures, extra table, new results, updated reference

A Model for the Global Quantum Efficiency for a TPB-based Wavelength-Shifting System used with Photomultiplier Tubes in Liquid Argon in MicroBooNE

We present a model for the Global Quantum Efficiency (GQE) of the MicroBooNE optical units. An optical unit consists of a flat, circular acrylic plate, coated with tetraphenyl butadiene (TPB), positioned near the photocathode of a 20.2-cm diameter photomultiplier tube. The plate converts the ultra-violet scintillation photons from liquid argon into visible-spectrum photons to which the cryogenic phototubes are sensitive. The GQE is the convolution of the efficiency of the plates that convert the 128 nm scintillation light from liquid argon to visible light, the efficiency of the shifted light to reach the photocathode, and the efficiency of the cryogenic photomultiplier tube. We develop a GEANT4-based model of the optical unit, based on first principles, and obtain the range of probable values for the expected number of detected photoelectrons ($N_{\rm PE}$) given the known systematic errors on the simulation parameters. We compare results from four measurements of the $N_{\rm PE}$ determined using alpha-particle sources placed at two distances from a TPB-coated plate in a liquid argon cryostat test stand. We also directly measured the radial dependence of the quantum efficiency, and find that this has the same shape as predicted by our model. Our model results in a GQE of $0.0055\pm0.0009$ for the MicroBooNE optical units. While the information shown here is MicroBooNE specific, the approach to the model and the collection of simulation parameters will be widely applicable to many liquid-argon-based light collection systems.Comment: final version accepted for publication by JINS

The Strayed Reveller, No. 1

The Strayed Reveller is a literary magazine of stories, songs, poems, essays, reviews and artwork by students at Stephen F. Austin State University. It is published monthly andsponsered by the School of Liberal Arts and Department of English.https://scholarworks.sfasu.edu/reveller/1000/thumbnail.jp

Signals for strange quark contributions to the neutrino (antineutrino) scattering in quasi-elastic region

Strange quark contributions to the neutrino (antineutrino) scattering are investigated on the elastic neutrino-nucleon scattering and the neutrino-nucleus scattering for 12C target in the quasi-elastic region on the incident energy of 500 MeV, within the framework of a relativistic single particle model. For the neutrino-nucleus scattering, the effects of final state interaction for the knocked-out nucleon are included by a relativistic optical potential. In the cross sections we found some cancellations of the strange quark contributions between the knocked-out protons and neutrons. Consequently, the asymmetries between the incident neutrino and antineutrino which is the ratio of neutral current to charged current, and the difference between the asymmetries are shown to be able to yield more feasible quantities for the strangeness effects. In order to explicitly display importance of the cancellations, results of the exclusive reaction 16O(\nu, \nu' p) are additionally presented for detecting the strangeness effects.Comment: 14 pages, 8 figures, submitted to Phys. Lett.

Measurement of nuclide cross-sections of spallation residues in 1 A GeV 238U + proton collisions

The production of heavy nuclides from the spallation-evaporation reaction of 238U induced by 1 GeV protons was studied in inverse kinematics. The evaporation residues from tungsten to uranium were identified in-flight in mass and atomic number. Their production cross-sections and their momentum distributions were determined. The data are compared with empirical systematics. A comparison with previous results from the spallation of 208Pb and 197Au reveals the strong influence of fission in the spallation of 238U.Comment: 20 pages, 10 figures, background information at http://www-wnt.gsi.de/kschmidt

Magic Numbers of Silicon Clusters

A structural model for intermediate sized silicon clusters is proposed that is able to generate unique structures without any dangling bonds. This structural model consists of bulk-like core of five atoms surrounded by fullerene-like surface. Reconstruction of the ideal fullerene geometry results in the formation of crown atoms surrounded by $\pi$-bonded dimer pairs. This model yields unique structures for \Si{33}, \Si{39}, and \Si{45} clusters without any dangling bonds and hence explains why these clusters are least reactive towards chemisorption of ammonia, methanol, ethylene, and water. This model is also consistent with the experimental finding that silicon clusters undergo a transition from prolate to spherical shapes at \Si{27}. Finally, reagent specific chemisorption reactivities observed experimentally is explained based on the electronic structures of the reagents.Comment: 4 pages + 3 figures (postscript files after \end{document}

Proton strangeness form factors in (4,1) clustering configurations

We reexamine a recent result within a nonrelativistic constituent quark model (NRCQM) which maintains that the uuds\bar s component in the proton has its uuds subsystem in P state, with its \bar s in S state (configuration I). When the result are corrected, contrary to the previous result, we find that all the empirical signs of the form factors data can be described by the lowest-lying uuds\bar s configuration with \bar s in P state that has its uuds subsystem in $S$ state (configuration II). Further, it is also found that the removal of the center-of-mass (CM) motion of the clusters will enhance the contributions of the transition current considerably. We also show that a reasonable description of the existing form factors data can be obtained with a very small probability P_{s\bar s}=0.025% for the uuds\bar s component. We further see that the agreement of our prediction with the data for G_A^s at low-q^2 region can be markedly improved by a small admixture of configuration I. It is also found that by not removing CM motion, P_{s\bar s} would be overestimated by about a factor of four in the case when transition dominates over direct currents. Then, we also study the consequence of a recent estimate reached from analyzing the existing data on quark distributions that P_{s\bar s} lies between 2.4-2.9% which would lead to a large size for the five-quark (5q) system, as well as a small bump in both G^s_E+\eta G^s_M and G^s_E in the region of q^2 =< 0.1 GeV^2.Comment: Prepared for The Fifth Asia-Pacific Conference on Few-Body Problems in Physics 2011 in Seoul, South Korea, 22-26 August 201