11,241 research outputs found

    Body Area Networks

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    Recent technological advances in integrated circuits, wireless networks, and physiological sensing have enabled miniature, lightweight, low power, intelligent monitoring devices to be integrated into a Body Area Network (BAN). This new type of technology hold much promise for future patient health monitoring. BANs promise inexpensive, unobtrusive, and unsupervised ambulatory monitoring during normal daily activities for long periods of time. However, in order for BANs to become ubiquitous and affordable, a number of challenging issues must be resolved, such as integration, standardisation, system design, customisation, security and privacy, and social issues. This paper presents an overview of many of these issues and indeed the background and rationale of body area networks

    ADVANCED RECEIVER ARCHITECTURES IN RADIOFREQUENCY APPLICATIONS

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    The general principles of several types of receivers fall under the two main headings of TRF (tuned radio frequency)receivers, where the received signal is processed at the incoming frequency right up to the detector stage, and the superhet(supersonic heterodyne) receiver, where the incoming signal is translated (sometimes after some amplification at theincoming frequency) to an intermediate frequency for further processing. There are however, a number of variants of each ofthese two main types. Regeneration (‘reaction’ or ‘tickling’) may be applied in a TRF receiver, to increase both its sensitivityand selectivity. This may be carried to the stage where the RF amplifier actually oscillates – either continuously, so that thereceiver operates as a synchrodyne or homodyne, or intermittently, so that the receiver operates as a super-regenerativereceiver, both of which have been described previously. The synchrodyne or homodyne may be considered alternatively as asuperhet, where the IF (intermediate frequency) is 0 Hz. In this paper we present the new type of receiver architectureswhich work in radiofrequencies.Keywords: supersonic heterodyne, tuned radio frequency

    Cellular and population plasticity of helper CD4(+) T cell responses

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    Vertebrates are constantly exposed to pathogens, and the adaptive immunity has most likely evolved to control and clear such infectious agents. CD4(+) T cells are the major players in the adaptive immune response to pathogens. Following recognition of pathogen-derived antigens naïve CD4(+) T cells differentiate into effectors which then control pathogen replication either directly by killing pathogen-infected cells or by assisting with generation of cytotoxic T lymphocytes (CTLs) or pathogen-specific antibodies. Pathogen-specific effector CD4(+) T cells are highly heterogeneous in terms of cytokines they produce. Three major subtypes of effector CD4(+) T cells have been identified: T-helper 1 (Th1) cells producing IFN-γ and TNF-α, Th2 cells producing IL-4 and IL-10, and Th17 cells producing IL-17. How this heterogeneity is maintained and what regulates changes in effector T cell composition during chronic infections remains poorly understood. In this review we discuss recent advances in our understanding of CD4(+) T cell differentiation in response to microbial infections. We propose that a change in the phenotype of pathogen-specific effector CD4(+) T cells during chronic infections, for example, from Th1 to Th2 response as observed in Mycobactrium avium ssp. paratuberculosis (MAP) infection of ruminants, can be achieved by conversion of T cells from one effector subset to another (cellular plasticity) or due to differences in kinetics (differentiation, proliferation, death) of different effector T cell subsets (population plasticity). We also shortly review mathematical models aimed at describing CD4(+) T cell differentiation and outline areas for future experimental and theoretical research. doi: 10.3389/fphys.2013.0020

    Comparative Analysis of PID and NARMA L2 Controllers for Shell and Tube Heat Exchanger

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    The application of this paper firstly simplified mathematical model for heat exchanger process has been developed and used for the dynamic analysis and control design. A conventional PID controller and Advanced Artificial Neural Network NARMA L2 Controller for Shell and Tube heat exchanger is proposed to control the cold water outlet temperature and test the best efficiency of NARMA L2 and PID controller.The control problem formulated as outlet cold water temperature is controlled variable and the inlet hot water temperature is manipulated variable the minimum possible time irrespective of load and process disturbances.Simulation and verified the mathematical model of the controller has been done in MATLAB Simulink. From the simulation results the prime controller has been chosen by comparing the criteria of the response such as settling time, rise time, percentage of overshoot and steady state error.The Neural NetworkNARMA L2 controller is founded to give finest performance for Shell and Heat exchanger problem like temperature control. Later Need to compare Conventional PID and Advance Artificial Neural NetworkNARMA L2 Controller results which lead to decide which one is best for Chosen has a better performance than other

    Histopathological Study of Stomatitis Nicotina

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    One hundred and thirteen biopsies of the palate in people accustomed to smoking cigars, most of them with the burning end of the cigar inside the mouth, have been studied
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