Development and comparison of loop-mediated isothermal amplification and quantitative polymerase chain reaction assays for the detection of Mycoplasma bovis in milk

Bovine mastitis is an economic burden for dairies worldwide. Mycoplasma species, and especially Mycoplasma bovis, are among the most important causative agents, and rapid, precise, and low-cost methods for Mycoplasma detection are urgently needed. For this purpose, loop-mediated isothermal amplification (LAMP) and quantitative PCR (qPCR) assays were developed and compared. The LAMP assay was designed and primer concentrations optimized to M. bovis oppD, encoding oligopeptide permease D. For qPCR, a Taqman assay (Applied Biosystems, Carlsbad, CA) targeting M. bovis gltX, encoding glutamate transfer RNA ligase, was optimized for primer concentration, annealing temperature, and DNA polymerase. Both assays were similarly sensitive, with a detection limit of approximately 10⁴ to 10⁵ M. bovis cells/mL. Both assays were also successful in confirming M. bovis identity in laboratory culture suspensions and in bovine milk. The LAMP and qPCR assays combined with the MoBio DNA extraction kit (MoBio Laboratories Inc., Carlsbad, CA) resulted in the correct detection of 13 out of 13 M. bovis isolates and 14 out of 16 M. bovis-positive milk samples collected from commercial dairies in California. When combined with the PrepMan Ultra reagent (Applied Biosystems), the qPCR assay resulted in confirming 21 out of 21 M. bovis-positive milk samples. Comparison of the assays to milk containing either Mycoplasma arginini, Mycoplasma bovigenitalium, Mycoplasma californicum, M. alkalescens, or Acholeplasma laidlawii or milk lacking any detectable Mycoplasma species or relatives resulted in 3 out of 17 (LAMP with MoBio), 1 out of 17 (qPCR with MoBio), and 2 out of 36 (qPCR with PrepMan Ultra) false positives. Overall, the qPCR assay was more robust than LAMP and could be used on DNA recovered from milk prepared with the PrepMan Ultra reagent, a method that does not include a DNA purification step. The use of this qPCR method enables M. bovis detection in bovine milk in 40 to 55 min, and therefore provides new opportunities to accelerate and simplify M. bovis detection in unpasteurized milk to reduce the incidence of M. bovis mastitis outbreaks.     

Probiotics for cure of Helicobacter pylori infection: A review

Human physiology normally contains pathogenic and non-pathogenic microorganisms in the gastrointestinal flora. Disturbance of these microorganism balance results in the formation of infection. Extensive use of antibiotics for cure of these disturbances like Helicobacter pylori (H. pylori) infection leads to patient discomfort and associated side-effects. There is a need to adopt adjunct or alternative approach in order to minimize such conditions. Probiotics is one of the potential therapies to cure gastrointestinal discomforts especially associated with H. pylori. It competes through non-immune and immune systems. This review article concludes that probiotics are used to eradicate the infection at increased rate, and decreased associated side-effects are caused by triple therapy. A proper evaluation of these probiotics is demanded before their use in future as a commercial product. Furthermore, their effect on immune system requires more research work so that their usage for other chronic disorders can also be considered.     

Space Efficient Quantization for Deep Convolutional Neural Networks

Deep convolutional neural networks (DCNNs) have shown outstanding performance in the fields of computer vision, natural language processing, and complex system analysis. With the improvement of performance with deeper layers, DCNNs incur higher computational complexity and larger storage requirement, making it extremely difficult to deploy DCNNs on resource-limited embedded systems (such as mobile devices or Internet of Things devices). Network quantization efficiently reduces storage space required by DCNNs. However, the performance of DCNNs often drops rapidly as the quantization bit reduces. In this article, we propose a space efficient quantization scheme which uses eight or less bits to represent the original 32-bit weights. We adopt singular value decomposition (SVD) method to decrease the parameter size of fully-connected layers for further compression. Additionally, we propose a weight clipping method based on dynamic boundary to improve the performance when using lower precision. Experimental results demonstrate that our approach can achieve up to approximately 14x compression while preserving almost the same accuracy compared with the full-precision models. The proposed weight clipping method can also significantly improve the performance of DCNNs when lower precision is required.

     

Observation of non-chemical equilibrium effect on Ar-CO2-H2 thermal plasma model by changing pressure

The authors developed a two-dimensional one-temperature chemical non-equilibrium (1T-NCE) model of Ar-CO₂-H₂ inductively coupled thermal plasmas (ICTP) to investigate the effect of pressure variation. The basic concept of one-temperature model is the assumption and treatment of the same energy conservation equation for electrons and heavy particles. The energy conservation equations consider reaction heat effects and energy transfer among the species produced as well as enthalpy flow resulting from diffusion. Assuming twenty two (22) different particles in this model and by solving mass conservation equations for each particle, considering diffusion, convection and net production terms resulting from hundred and ninety eight (198) chemical reactions, chemical non-equilibrium effects were taken into account. Transport and thermodynamic properties of Ar-CO₂-H₂ thermal plasmas were self-consistently calculated using the first-order approximation of the Chapman-Enskog method. Finally results obtained at atmospheric pressure (760 Torr) and at reduced pressure (500, 300 Torr) were compared with results from one-temperature chemical equilibrium (1T-CE) model. And of course, this comparison supported discussion of chemical non-equilibrium effects in the inductively coupled thermal plasmas (ICTP).     

Mesoscale finite element prediction of concrete failure

The present paper studies the failure of concrete from the mesoscopic point of view. Biphasic cubic concrete samples containing spherical aggregates embedded in a homogenized mortar have been simulated using standard finite element method. Linear elasticity and damage-plasticity hypotheses are considered for the aggregates and mortar, respectively. Various triaxial loading conditions are assumed for each sample to generate adequate discrete failure points within the stress space. In the next step, the approximated failure surfaces of specimens are constructed using the Delaunay triangulation technique. The effects of mesostructural features such as aggregate grading curve, aggregate volumetric share, and more importantly the controlling parameters of mortar’s damage-plasticity constitutive model have been investigated. Finally, the failure modes of some selected samples have been reported and discussed.     

A human-assisted knowledge extraction method for machining operations

This paper deals with a human-assisted knowledge extraction method to extract “if…then…” rules from a small set of machining data. The presented method utilizes both probabilistic reasoning and fuzzy logical reasoning to benefit from the machining data and from the judgment and preference of a machinist. Using the extracted rules, one can determine the values of operational parameters (feed, cutting velocity, etc.) to ensure the desired machining performance (keep surface roughness within the stipulated range (e.g., moderate)). Applying the presented method in a real-life machining knowledge extraction situation and comparing it with the inductive learning based knowledge extraction method (i.e., ID3), the usefulness of the method is demonstrated. As the concept of manufacturing automation is shifting toward “how to support humans by computers”, the presented method provides some valuable hints to the developers of futuristic computer integrated manufacturing systems.     

Characterization of the ocular antiallergic and antihistaminic effects of olopatadine (AL-4943A), a novel drug for treating ocular allergic diseases

Olopatadine (AL-4943A; KW-4679) [(Z)-11-[3-(dimethylamino)propylidene]-6, 11-dihydrodibenz[b,e]oxepine-2-acetic acid hydrochloride] is an antiallergic/antihistaminic drug under development for topical ocular use. The effects of the compound on release of proinflammatory mediators (histamine, tryptase and prostaglandin D2) from monodispersed human conjunctival mast cells were assessed. Histamine receptor subtype binding affinities and functional potencies were determined with ligand binding and phosphoinositide turnover assays, respectively. Olopatadine inhibited the release of histamine, tryptase and prostaglandin D2, in a concentration-dependent manner (IC50 = 559 microM). Evaluation of the interaction of olopatadine with histamine receptors revealed a relatively high affinity for the H1 receptor (Ki = 31.6 nM, pKi = 7.5 +/- 0.1, n = 7) but lower affinities for H2 receptors (Ki = 100 microM, pKi = 4.0 +/- 0.19, n = 7) and H3 receptors (Ki = 79.4 microM, pKi = 4.1 +/- 0.16, n = 7). The H1 selectivity of olopatadine was superior to that of other ocularly used antihistamines studied, such as ketotifen, levocabastine, antazoline and pheniramine. The profiling of olopatadine in 42 nonhistamine receptor binding assays revealed that olopatadine interacts with only two nonhistamine receptor/uptake sites to any significant degree (pIC50 < or = 5-6). Olopatadine inhibited histamine-induced phosphoinositide turnover in human conjunctival epithelial cells (IC50 = 10 nM, pIC50 = 8.0, n = 4) and in other human ocular cells (IC50 = 15.8-31.6 nM, pIC50 = 7.5-7.8) and exhibited apparent noncompetitive antagonist properties in these cells, with an estimated dissociation constant (Kb) of 19.9 nM (pKb = 7.7, n = 6). This combination of mast cell mediator release inhibition and selective H1 receptor antagonism suggests that olopatadine may be particularly useful in the treatment of ocular allergic diseases. Indeed, olopatadine has recently shown clinical efficacy in an allergic conjunctivitis model in human subjects.     

Soft X-Ray Emission Optimization Study with Nitrogen Gas in a 1.2 kJ Plasma Focus

Measurement of soft x-ray emission from a low-energy plasma focus operated with nitrogen within the pressure range of 0.1–1.0 mbar is presented. The x-rays are detected by using an assembly of Quantrad Si PIN-diodes with differential filtering and with a multipinhole camera. In the 1.0–1.3 keV and 1.0–1.5 keV windows, the x-ray yield in 4 geometry is 1.03 J and 14.0 J, respectively, at a filling pressure of 0.25 mbar and the corresponding efficiencies are 0.04% and 1.22%. The total x-ray emission in 4 geometry is estimated at 21.8 J, which corresponds to the system efficiency of about 1.9%. The soft x-ray emission is found dominantly as a result of electron beam activity on the anode tip, which is confirmed by the images recorded by a pinhole camera.     

Extended Virtual Boundary and Its Application in Dynamic Spectrum Allocation

This paper presents an efficient dynamic spectrum allocation （DSA） scheme in a flexible spectrum licensing environment where multiple networks coexist and interfere with each other. In particular, an extension of virtual boundary concept in DSA is proposed, which is spectrally efficient than the previous virtual boundary concept applied to donor systems only. Here, the same technique is applied to both donor and rental systems so as to further reduce the occurrences where the insertion of guard bands is obligatory and as a result provides better spectral efficiency. The proposed extension improves the spectrum utilization without any compromise on interference and fairness issues.     

Estimation of the thermohydraulic efficiency of swirlers at small Reynolds numbers

To estimate the thermohydraulic efficiency of different types of swirlers of heat exchange in pipes, we have generalized the experimental data, which has made it possible to determine the optimal range of Reynolds numbers and the optimal geometric sizes of swirlers. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 82, No. 1, pp. 23–30, January–February, 2009.