232 research outputs found

    A comparative study of the use of tiger-specific and heterologous microsatellite markers for population genetic studies of the Bengal tiger (Panthera tigris tigris)

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    Comparison of genetic diversity indices of heterologous and species-specific microsatellite loci within a species may provide a panel of appropriate markers for genetic studies, but few studies have carried out such comparisons. We examined and compared the genetic characteristics of tiger-specific and heterologous loci in eight captive Bengal tigers. The mean polymorphic information content (PIC) value of the tiger-specific microsatellite loci (n = 15) was 0.447, and the number of alleles was from 2 to 4 per locus. In comparison, the heterologous microsatellite loci (n = 15) had a mean PIC value of 0.539, and the number of alleles per locus was three to five. Our findings indicate that the heterologous markers have a higher frequency (n = 11) of polymorphic microsatellite loci and number of alleles per locus compared with tiger-specific loci. We pooled the highly polymorphic (PIC > 0.5) tiger-specific loci (n = 5) and heterologous microsatellite loci (n = 11) except one and noted a higher mean observed heterozygosity and PIC values of 0.668 and 0.575, respectively, compared with the heterologous and tiger-specific loci taken alone. Using a locus selection criterion of PIC > 0.5, we recommend a combined panel of 16 highly polymorphic loci for genetic studies of the wild population of the Bengal tigers and suggest that either a combination of tiger-specific and heterologous microsatellite primers or heterologous primers be used in genetic studies related to the ecology, biology, socio-biology and behavior of Bengal tigers as >13 loci are needed in such studies.Keywords: Bengal tiger, highly polymorphic, tiger-specific, heterologous, microsatellite loci

    Macroscopic Dynamics of Multi-Lane Traffic

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    We present a macroscopic model of mixed multi-lane freeway traffic that can be easily calibrated to empirical traffic data, as is shown for Dutch highway data. The model is derived from a gas-kinetic level of description, including effects of vehicular space requirements and velocity correlations between successive vehicles. We also give a derivation of the lane-changing rates. The resulting dynamic velocity equations contain non-local and anisotropic interaction terms which allow a robust and efficient numerical simulation of multi-lane traffic. As demonstrated by various examples, this facilitates the investigation of synchronization patterns among lanes and effects of on-ramps, off-ramps, lane closures, or accidents.Comment: For related work see http://www.theo2.physik.uni-stuttgart.de/helbing.htm

    Adaptability and AMMI biplot analysis for yield and agronomical traits in scented rice genotypes under diverse production environments

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    550-562The crucial aspect of the identification of the genotypes adaptable to different production environments (systems) for the thirty-six popular scented rice varieties was countered via adaptability and AMMI biplot analysis. The varieties were evaluated for several agronomical traits (twelve) under four production environments namely, direct-seeded rice (DSR), the system of rice intensification (SRI), chemical-free cultivation (CFC) and transplanted rice (TPR). Among different production environments, SRI was found on the top followed by TPR, CFC and DSR. Genotype × environment interactions were significant for all of the traits. Based on the AMMI biplot technique, Pusa Sugandh 3, HKR -11-509 and Pusa Sugandh 5 were found suitable for grain yield per plant and general adaptation to all the environments

    Modeling and Simulation of Multi-Lane Traffic Flow

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    A most important aspect in the field of traffic modeling is the simulation of bottleneck situations. For their realistic description a macroscopic multi-lane model for uni-directional freeways including acceleration, deceleration, velocity fluctuations, overtaking and lane-changing maneuvers is systematically deduced from a gas-kinetic (Boltzmann-like) approach. The resulting equations contain corrections with respect to previous models. For efficient computer simulations, a reduced model delineating the coarse-grained temporal behavior is derived and applied to bottleneck situations.Comment: For related work see http://www.theo2.physik.uni-stuttgart.de/helbing.htm

    A perspective on multinational enterprise’s national identity dilemma

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    This conceptual paper identifies gaps and contributes to the literature on ‘identity’ dilemmas faced by multinational enterprises operating in a globalised world. Various characteristics and business strategies of multinational enterprises are delineated and analysed through the lens of social identity theory and international business concepts such as market and institutional logic. Our analysis, based on multiple cases, and derived from a variety of industries and countries, associates the identity dilemma to informed business strategy. Our findings suggest that while multinational enterprises face identity dilemmas that they sometimes use to their advantage, it also poses several challenges. Through our conceptualisation, we derive five distinct propositions to shape future research directions

    On sound transmission loss across a Helmholtz resonator in a low Mach number flow duct

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    A simplified physical model, which described the generation of sound by a Helmholtz resonator upon flow excitation at its neck, was developed in the present investigation to study the drop in sound power transmission loss across such a resonator mounted on the wall of a duct conveying a low Mach number mean flow. Experiments were derived to validate the model. Mitigation methods derived according to the model were also tested experimentally. Results showed that the simplified model gave predictions which agreed with experimental observations. The proposed mitigation methods were also proved to be effective for building services application. It was also found that the sound intensity generated by the flow excited resonator scaled with approximately the ninth power of the flowvelocity inside the duct.Department of Building Services EngineeringAuthor name used in this publication: S. K. Tan

    Gas-kinetic derivation of Navier-Stokes-like traffic equations

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    Macroscopic traffic models have recently been severely criticized to base on lax analogies only and to have a number of deficiencies. Therefore, this paper shows how to construct a logically consistent fluid-dynamic traffic model from basic laws for the acceleration and interaction of vehicles. These considerations lead to the gas-kinetic traffic equation of Paveri-Fontana. Its stationary and spatially homogeneous solution implies equilibrium relations for the `fundamental diagram', the variance-density relation, and other quantities which are partly difficult to determine empirically. Paveri-Fontana's traffic equation allows the derivation of macroscopic moment equations which build a system of non-closed equations. This system can be closed by the well proved method of Chapman and Enskog which leads to Euler-like traffic equations in zeroth-order approximation and to Navier-Stokes-like traffic equations in first-order approximation. The latter are finally corrected for the finite space requirements of vehicles. It is shown that the resulting model is able to withstand the above mentioned criticism.Comment: For related work see http://www.theo2.physik.uni-stuttgart.de/helbing.htm

    Potential therapeutic effects of branched-chain amino acids supplementation on resistance exercise-based muscle damage in humans

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    Branched-chain amino acids (BCAA) supplementation has been considered an interesting nutritional strategy to improve skeletal muscle protein turnover in several conditions. In this context, there is evidence that resistance exercise (RE)-derived biochemical markers of muscle soreness (creatine kinase (CK), aldolase, myoglobin), soreness, and functional strength may be modulated by BCAA supplementation in order to favor of muscle adaptation. However, few studies have investigated such effects in well-controlled conditions in humans. Therefore, the aim of this short report is to describe the potential therapeutic effects of BCAA supplementation on RE-based muscle damage in humans. The main point is that BCAA supplementation may decrease some biochemical markers related with muscle soreness but this does not necessarily reflect on muscle functionality
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