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[en] In a model of human neuroblastoma (NB) cell lines persistently infected with human cytomegalovirus (HCMV) we previously showed that persistent HCMV infection is associated with an increased malignant phenotype, enhanced drug resistance, and invasive properties. To gain insights into the mechanisms of increased malignancy we analyzed the global changes in cellular gene expression induced by persistent HCMV infection of human neuroblastoma cells by use of high-density oligonucleotide microarrays (HG-U133A, Affymetrix) and RT-PCR. Comparing the gene expression of different NB cell lines with persistently infected cell sub-lines revealed 11 host cell genes regulated in a similar manner throughout all infected samples. Nine of these 11 genes may contribute to the previously observed changes in malignant phenotype of persistently HCMV infected NB cells by influencing invasive growth, apoptosis, angiogenesis, and proliferation. Thus, this work provides the basis for further functional studies
[en] A pulse shaping mechanism applied to mode-locked lasers is proposed. By adding a linear (forcing) term in the power energy saturation model, we are able to control the resulting pulses in both energy and shape. In fact, this term also provides a focusing effect keeping most of the pulse’s energy confined within the width of the forcing. The appropriate condition for which mode-locking occurs is also derived and links the physical parameters of the system (gain, loss, filtering) to those of the pulse (amplitude, width, energy). Thus, given the desired pulse one only needs to fix the laser’s parameters accordingly, so as to obey this condition, and mode-locking will occur. (letter)
[en] In recent years, low-cost micro and nano fabrication process have gain intention from the manufacturing industry. Biochip is a platform of miniaturized microarrays arranged on a solid substrate that allows various biological tests to achieve immediate results. The development of biochip has established a new platform in biomedical industry. However, to fulfill the demands and availability in the market with affordable cost requires high volume manufacturing techniques for the fabrication of the biochips. In this article we will discuss the fabrication of PDMS mould for replicating microelectrode array of biochip. The fabrication of the microelectrodes utilizes the Nanoimprint lithography (NIL) technique. Finally, the fabrication of PDMS mould has been demonstrated successfully for using Nanoimprint lithography (NIL) technique and achieved 13% of size difference in overall. (paper)
[en] A new scheme of the external cavity of a diode laser is described. The scheme provides emission of two closely spaced (Δλ < 10-3 nm) orthogonally polarised modes, which can be tuned within the gain line, with the mode interval continuously changed. (lasers)
[en] A summing network of FitzHugh–Nagumo model neurons, immersed in the background of both external noise and internal noise, is studied in the context of array stochastic resonance. An aperiodic Gaussian stimulus, assisted by collective internal array noise, stimulates the summing network for a more efficient response. This form of array stochastic resonance can be characterized by a correlation coefficient for an aperiodic input signal. Moreover, the correlation gain of the ensembles of neuronal models is investigated for finite and infinite array sizes. The nonmonotonic behavior of the correlation gain and the regions of the correlation gain beyond unity, i.e. the two main features of array SR, are demonstrated numerically and theoretically. These results suggest that certain levels of both external noise and internal noise contribute in a beneficial way to the neuronal coding strategy
[en] We apply signal processing analysis to the information spreading in a scale-free network. To reproduce typical behaviours obtained from the analysis of information spreading in the World Wide Web, we use a modified SIS (from ‘susceptible–infectious–susceptible’) model where synergy effects and influential nodes are taken into account. This model depends on a single free parameter that characterizes the memory time of the spreading process. We show that by means of fractal analysis it is possible—from aggregated easily accessible data—to gain information on the memory time of the underlying mechanism driving the information spreading process. (paper)
[en] Design conditions for existence of the H_∞ linear state feedback control for discretetime stochastic systems with state-multiplicative noise and polytopic uncertainties are presented in the paper. Using an enhanced form of the bounded real lemma for discrete-time stochastic systems with state-multiplicative noise, the LMI-based procedure is provided for computation of the gains of linear, as well as nonlinear, state control law. The approach is illustrated on an example demonstrating the validity of the proposed method. (paper)
[en] This paper describes a gain stabilization technique for a RF signal measurement system. A sinusoidal signal of known amplitude, phase and close enough in frequency is added to the main, to be measured RF signal at the input of the analog section. The system stabilizes this offset tone in the digital domain, as it is sampled at the output of the analog section. This process generates a correction factor needed to stabilize the magnitude of the gain of the analog section for the main RF signal. With the help of a simple calibration procedure, the absolute amplitude of the main RF signal can be measured. The technique is especially suited for a system that processes signals around a single frequency, employs direct signal conversion into the digital domain, and processes subsequent steps in an FPGA. The inherent parallel signal processing in an FPGA-based implementation allows a real time stabilization of the gain. The effectiveness of the technique is derived from the fact, that the gain stabilization stamped to the main RF signal measurement branch requires only a few components in the system to be inherently stable. A test setup, along with experimental results is presented from the field of RF instrumentation for particle accelerators. Due to the availability of a phase synchronized RF reference signal in these systems, the measured phase difference between the main RF and the RF reference is also stabilized using this technique. A scheme of the signal processing is presented, where a moving average filter has been used to filter out not only the unwanted frequencies, but also to separate the main RF signal from the offset tone signal. This is achieved by a suitable choice of sampling and offset tone frequencies. The presented signal processing scheme is suitable to a variety of RF measurement applications
[en] This paper considers a multi-step output feedback robust model predictive control (OFRMPC) approach for the linear parameter varying (LPV) systems with bounded changes of scheduling parameters and bounded disturbance. Less conservative bounds of future estimation error sets and system parametric uncertain sets are predicted by considering bounded changes of scheduling parameters in LPV systems. In the multi-step OFRMPC approach, an optimization problem is solved to obtain a sequence of controller gains, which considers predictions of future bounds of estimation error sets and system parametric uncertain sets. The optimized sequence of controller gains corresponding to a sequence of Lyaponov matrices have less constraint conditions and also introduce more degree of freedom for the optimization. The proposed multi-step OFRMPC guarantees robust uniform ultimately bounded of the estimation error and robust stability of the observer system. A numerical example is given to demonstrate the effectiveness of the approach.
[en] Surface wave methods gained in the past decades a primary role in many seismic projects. Specifically, they are often used to retrieve a 1D shear wave velocity model or to estimate the VS,30 at a site. The complexity of the interpretation process and the variety of possible approaches to surface wave analysis make it very hard to set a fixed standard to assure quality and reliability of the results. The present guidelines provide practical information on the acquisition and analysis of surface wave data by giving some basic principles and specific suggestions related to the most common situations. They are primarily targeted to non-expert users approaching surface wave testing, but can be useful to specialists in the field as a general reference. The guidelines are based on the experience gained within the InterPACIFIC project and on the expertise of the participants in acquisition and analysis of surface wave data.