Microfluidic method for rapid turbidimetric detection of the DNA of Mycobacterium tuberculosis using loop-mediated isothermal amplification in capillary tubes

We describe a microfluidic method for rapid isothermal turbidimetric detection of the DNA of Mycobacterium tuberculosis. Loop-mediated isothermal amplification is accomplished in capillary tubes for amplifying DNA in less than 15 min, and sensitivity and specificity were compared to conventional loop-mediated isothermal amplification (LAMP). The method can detect as little as 1 pg mL−1 DNA in a sample. Results obtained with clinical specimens indicated 90 % sensitivity and 95 % specificity for microfluidic LAMP in comparison to culture methods. No interference occurred due to the presence of nonspecific DNAs. The findings demonstrate the power of the new microfluidic LAMP test for rapid molecular detection of microorganisms even when using bare eyes. © 2014, Springer-Verlag Wien

Price determination in monopolistic markets with inventory adjustment

This paper presents a practical model for the analysis of the price determination mechanism in raw materials markets that are characterized by the dominance of a large firm. The model takes explicit note of the influence of inventory adjustments; it is postulated that the dominant firm?s decision on price and production levels is negatively related to the difference between actual and desired inventory levels. In a first empirical test, the model is applied to an analysis of the nickel industry. The empirical results support the hypothesized role of inventories and show the importance of inventory adjustments relative to the other factors determining price and production behavior.

Learning Representations in Model-Free Hierarchical Reinforcement Learning

Common approaches to Reinforcement Learning (RL) are seriously challenged by large-scale applications involving huge state spaces and sparse delayed reward feedback. Hierarchical Reinforcement Learning (HRL) methods attempt to address this scalability issue by learning action selection policies at multiple levels of temporal abstraction. Abstraction can be had by identifying a relatively small set of states that are likely to be useful as subgoals, in concert with the learning of corresponding skill policies to achieve those subgoals. Many approaches to subgoal discovery in HRL depend on the analysis of a model of the environment, but the need to learn such a model introduces its own problems of scale. Once subgoals are identified, skills may be learned through intrinsic motivation, introducing an internal reward signal marking subgoal attainment. In this paper, we present a novel model-free method for subgoal discovery using incremental unsupervised learning over a small memory of the most recent experiences (trajectories) of the agent. When combined with an intrinsic motivation learning mechanism, this method learns both subgoals and skills, based on experiences in the environment. Thus, we offer an original approach to HRL that does not require the acquisition of a model of the environment, suitable for large-scale applications. We demonstrate the efficiency of our method on two RL problems with sparse delayed feedback: a variant of the rooms environment and the first screen of the ATARI 2600 Montezuma's Revenge game

Experimental study on stability and rheological properties of aqueous foam in the presence of reservoir natural solid particles

The authors would like to acknowledge the school of engineering at the University of Aberdeen and University Technology Malaysia (UTM) to provide required materials and facilities to complete this research.Peer reviewedPostprin

The preparation and properties of metal-Schiff bare complexes as model intermediates in the reactions of Vitamin B₆ and related compounds

The aim of this research was to isolate metal-Schiff base complexes which occur as intermediates in the metal catalysis of the transamination reaction of Vitamin B6 (and its analogues) and amino acids (glycine and ethylenediamine). Metal ions used were: FeIII, CoII , NiII, CuII, ZnII, Cd II and AgI. The spectral absorption maxima of the complexes have been measured at various pH values using ultraviolet techniques. The infrared and ultraviolet-visible spectra of the complexes have been discussed and assignments of bands are made. Mass spectra were obtained for all of the complexes, and fragmentation patterns have been evaluated. The electron spin resonance technique was applied to copper complexes only, and In each case the "g" and "A" parameters were calculated satisfactorily. In most of the complexes, the ratio of metal ion to Schiff base was found to be 1:1, but in a few the ratio was found to be 2:1 (e.g. Cu2(PLGIy),3H 20) and 1:2 (e.g. Cu(PNen)2(SO4)2Cl2,5H 20). The remaining positions around the metal ion are occupied by either water or an amino acid molecule, or anions (such as OH&macr; or SO -4). The kinetics of the transamination reaction of pyridoxamine phosphate with alpha-ketoglutaric acid and copperII ion have been investigated spectro-photometrically. The reaction products were analysed by paper chromatography. The reaction was found to be preceded by an induction period and to be first order in alpha-ketoglutaric acid. It exhibits a maximum rate at a copper concentration of twice that of pyridoxamine phosphate. This maximum is justified mathematically by assuming that the concentration of a complex of copper" and the Schiff's base from pyridoxamine phosphateand alpha-ketoglutarate is very low, and that the complex accepts a further copper" ion at high concentrations of copperII. This makes the ratio 1:1:2 (1PMP:1 alpha-KG:2Cu 2+). The rates of formation of metal-Schiff base complexes of pyridoxal phosphate-glycine with CuII, CoII, CdII, Mn II and AlIII were measured at various pH values spectrophotometrically. The rates are dependent on the concentration of pyridoxal phosphate and of amino acid. The metal concentration has no effect on the rate, which would be consistent with the metal ion trapping the Schiff base as soon as it is formed. The rate of formation of metal-Schiff base complexes of pyridoxal phosphate-glycine-Aluminium III is dependent, however, on the concentration of aluminium when its concentration is in excess over the other species.<p

CAPABILITY SOURCING: A SERVICE- DOMINANT LOGIC VIEW

Sourcing is evolving into a strategic process for organizing and fine-tuning the firm’s value chain. Companies need to strategic sourcing in order to survive within the industry, particularly hospitals which are facing rapidly competition to provide high quality services in healthcare. Healthcare organizations need to leverage the right capabilities from the right source, and the right shore, at the right cost to improve their competitive position. Capability sourcing is an organizing process to execute strategic sourcing and improve the firm’s competitive position through gaining access to best-in-class capabilities across the value chain to ensure long-term competitive advantage. The main problem is a lack of technique to explore sourcing alternatives (insourcing, co-sourcing and outsourcing) and choose the right sourcing model. Our research solution is applying conceptual modeling as a technique to create schematic descriptions of alternative solutions based on organization’s capabilities to facilitate strategic sourcing decision making. The fundamental requirement of capability sourcing conceptual modelling is a language as a carrier for modeling intermediate artifacts of sourcing alternatives. Our position is introducing service-dominant logic conceptualisation as a well-defined language for capability sourcing conceptual modeling