224 research outputs found

    Expression of T4 Lysozyme Gene (gene e) in Streptococcus salivarius subsp. Thermophilus

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    In present study, we aimed to express T4 Lysozyme gene (gene e) in Streptococcus salivarus subsp. thermophilus to create better probiotics for poultry. The Esherichia coli plasmid, Bluescript II SK +/-harboring gene e named pL1, was converted to a new E. coli-Streptococcus sp. shuttle vector (pL2) by cloning and inserting Streptococcal replication origin of pTRW10 vector into pL1. pL2 plasmid isolated from E. coli was introduced into S. salivarius subsp. thermophilus and Lactococcus lactis cells by electro-transformation. The lysozyme enzymes expressing by these bacteria were found to be active on Micrococcus luteus cells and thereby preventing their growth on assay plates. Thermostability of these enzymes from the recombinant bacteria was also found different from each other. The lysozyme expressed by S. salivarius subsp. thermophilus cells seemed to increase its capacity for thermoresistance and was not denaturated at 70°C for 15 min. In contrast, the enzyme expressed by L.lactis and E. coli cells were easily denaturated when exposed to the same temperature treatment

    Estimation and measurement of effective line mobility on a non-deterministic thin plate excited by a piezoelectric patch

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    This paper derived the expression to estimate the effective line moment mobility of a non-deterministic thin plate under moment excitation by a piezoelectric patch actuator. The piezoelectric patch actuator is assumed to generate purely line moments at each of its edges and regarded as a finite number of point moments acting on an infinite plate, which is achieved by integration method. The theoretical model is validated using MATLAB simulation and compared with experimental measurements on a randomized thin plate. The derived effective line moment mobility managed to closely estimate high-frequency response while cutting significant computational time and resource. Results from this study can be used in many applications ranging from vibration isolation where power transmission between the isolator with an area distribution and its host structure can be determined more accurately, and to design the optimal shunt circuit of a piezoelectric shunt damper for maximum power dissipation in order to reduce vibration of a non-deterministic thin plate

    Active vibration control using piezoelectric actuator: implementation of ant colony optimization technique in virtual experimentation

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    This paper demonstrates the implementation of virtual experiment using COMSOL Mutiphysics – MATLAB integration for optimization in active vibration control system. The benchmark model is a simply supported thin plate excited and attenuated by two piezoelectric patches. Instead of using equation-based modeling to represent the system, optimization of the sensor-actuator location and controller gains are conducted directly on the finite element model in COMSOL Multiphysics via Livelink for MATLAB function. The optimization is based on the average energy reduction across a frequency range between 11 Hz to 50 Hz, which covers the first three modes. It is found that the maximum attenuation achieved is 68.31% using optimal values of ensor -actuator location and controller gains

    Lettuce Supply Chains and Marketing Margins in Benguet, Philippines

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    Understanding value chains requires knowledge of the needs of customers and how these needs are met by different suppliers of marketing or value-adding services. The need for these marketing services and costs of supplying these are reflected in marketing margins or the difference in the prices of the various marketing levels in the chain. This study analyzed lettuce supply chains in Benguet and mapped 3 chains, including the value-adding activities and the governance mechanisms such as contracts and payment terms that exist in the chain. Some new roles have emerged due to recent developments in the market. Some wholesalers became “commissioners” and “disposers,” and some individuals played dual roles along the chain. A few farmers became “disposers,” and a few “disposers” eventually became farmers. Marketing margins were also computed for a sample chain including the cost of value-adding activities to show a more accurate distribution of benefits across key actors in the chain. Higher gross margins were due to higher costs of providing marketing services, which indicates a competitive market. There are opportunities in the lettuce chains to respond to increasing demand for salad vegetables. While lettuce producers and other actors in the chain respond to these market requirements such as producing new lettuce varieties, there are issues that need to be addressed to improve efficiency and performance of the chain

    Intelligent glove for suppression of resting tremor in Parkinson’s disease

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    One of the significant symptoms in Parkinson’s disease is resting tremor. Resting tremor occurs when the muscle is relaxed, causing the limb to shake. Rhythmic muscle movement of the patients commonly happens within the range of 4 Hz to 6 Hz. Thus, reducing this type of tremor will help improve patients’ quality of life. In this paper, to suppress resting tremors, an intelligent glove was designed utilizing the concepts of vibrations and gyro effect. A rotating brass disc attached to the glove creates a gyroscopic effect of the smart glove. Therefore, the disc will do their utmost to stay upright and counter any input forces instantaneously by providing the counterforce. A reduction of more than 50 % with the intelligent glove is also shown

    Estimating ensemble average power delivered by a piezoelectric patch actuator to a non-deterministic subsystem

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    Engineering systems such as aircraft, ships and automotive are considered built-up structures. Dynamically they are taught of as being fabricated from many components that are classified as deterministic subsystems (DS) and non-deterministic subsystems (Non-DS). Structures’ response of the DS is deterministic in nature and analysed using deterministic modelling methods such as finite element method (FEM). The response of Non-DS is statistical in nature and estimated using statistical modelling technique such as statistical energy analysis (SEA). SEA method uses power balance equation, in which any external input to the subsystem must be represented in terms of power. Often, input force is taken as point force and ensemble average power delivered by point force is already well-established. However, the external input can also be applied in the form of moments exerted by a piezoelectric (PZT) patch actuator. In order to be able to apply SEA method for input moments, a mathematical representation for moment generated by PZT patch in the form of average power is needed, which is attempted in this paper. A simply-supported plate with attached PZT patch is taken as a benchmark model. Analytical solution to estimate average power is derived using mobility approach. Ensemble average of power given by the PZT patch actuator to the benchmark model when subjected to structural uncertainties is also simulated using Lagrangian method. These two results are compared and presented in this paper. The effects of size and location of the PZT actuators on the power delivered to the plate are later investigated

    SePCAR: A Secure and Privacy-Enhancing Protocol for Car Access Provision

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    We present an efficient secure and privacy-enhancing protocol for car access provision, named SePCAR. The protocol is fully decentralised and allows users to share their cars conveniently without sacrifising their security and privacy. It provides generation, update, revocation, and distribution mechanisms for access tokens to shared cars, as well as procedures to solve disputes and to deal with law enforcement requests, for instance in the case of car incidents. We prove that SePCAR meets its appropriate security and privacy requirements and that it is efficient: our practical efficiency analysis through a proof-of-concept implementation shows that SePCAR takes only 1.55 s for a car access provision

    Is TrpM5 a reliable marker for chemosensory cells? Multiple types of microvillous cells in the main olfactory epithelium of mice

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    <p>Abstract</p> <p>Background</p> <p>In the past, ciliated receptor neurons, basal cells, and supporting cells were considered the principal components of the main olfactory epithelium. Several studies reported the presence of microvillous cells but their function is unknown. A recent report showed cells in the main olfactory epithelium that express the transient receptor potential channel TrpM5 claiming that these cells are chemosensory and that TrpM5 is an intrinsic signaling component of mammalian chemosensory organs. We asked whether the TrpM5-positive cells in the olfactory epithelium are microvillous and whether they belong to a chemosensory system, i.e. are olfactory neurons or trigeminally-innervated solitary chemosensory cells.</p> <p>Results</p> <p>We investigated the main olfactory epithelium of mice at the light and electron microscopic level and describe several subpopulations of microvillous cells. The ultrastructure of the microvillous cells reveals at least three morphologically different types two of which express the TrpM5 channel. None of these cells have an axon that projects to the olfactory bulb. Tests with a large panel of cell markers indicate that the TrpM5-positive cells are not sensory since they express neither neuronal markers nor are contacted by trigeminal nerve fibers.</p> <p>Conclusion</p> <p>We conclude that TrpM5 is not a reliable marker for chemosensory cells. The TrpM5-positive cells of the olfactory epithelium are microvillous and may be chemoresponsive albeit not part of the sensory apparatus. Activity of these microvillous cells may however influence functionality of local elements of the olfactory system.</p

    Customisation of the Exome Data Analysis Pipeline Using a Combinatorial Approach

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    The advent of next generation sequencing (NGS) technologies have revolutionised the way biologists produce, analyse and interpret data. Although NGS platforms provide a cost-effective way to discover genome-wide variants from a single experiment, variants discovered by NGS need follow up validation due to the high error rates associated with various sequencing chemistries. Recently, whole exome sequencing has been proposed as an affordable option compared to whole genome runs but it still requires follow up validation of all the novel exomic variants. Customarily, a consensus approach is used to overcome the systematic errors inherent to the sequencing technology, alignment and post alignment variant detection algorithms. However, the aforementioned approach warrants the use of multiple sequencing chemistry, multiple alignment tools, multiple variant callers which may not be viable in terms of time and money for individual investigators with limited informatics know-how. Biologists often lack the requisite training to deal with the huge amount of data produced by NGS runs and face difficulty in choosing from the list of freely available analytical tools for NGS data analysis. Hence, there is a need to customise the NGS data analysis pipeline to preferentially retain true variants by minimising the incidence of false positives and make the choice of right analytical tools easier. To this end, we have sampled different freely available tools used at the alignment and post alignment stage suggesting the use of the most suitable combination determined by a simple framework of pre-existing metrics to create significant datasets
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