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Mucopolysaccharidosis IVA (MPS IVA), also known as Morquio-Brailsford or Morquio A syndrome, is a lysosomal storage disorder caused by a deficiency of the enzyme N-acetyl-galactosamine-6-sulphate sulphatase (GALNS). MPS IVA is multisystemic but manifests primarily as a progressive skeletal dysplasia. Spinal involvement is a major cause of morbidity and mortality in MPS IVA. Early diagnosis and timely treatment of problems involving the spine are critical in preventing or arresting neurological deterioration and loss of function. This review details the spinal manifestations of MPS IVA and describes the tools used to diagnose and monitor spinal involvement. The relative utility of radiography, computed tomography (CT) and magnetic resonance imaging (MRI) for the evaluation of cervical spine instability, stenosis, and cord compression is discussed. Surgical interventions, anaesthetic considerations, and the use of neurophysiological monitoring during procedures performed under general anaesthesia are reviewed. Recommendations for regular radiological imaging and neurologic assessments are presented, and the need for a more standardized approach for evaluating and managing spinal involvement in MPS IVA is addressed.

Introduction Each year, the DISAM Journal publishes a summary of the legislation that impacts U.S. security assistance and other related international programs. This report is intended to alert all security [...]

Sample-time error among the channels of a time-interleaved analog-to-digital converter (ADC) is the main reason for significant degradation of the effective resolution of the high-speed time-interleaved ADC. A calibration technique for sample-time mismatches has been proposed and implemented at a low level of complexity. The calibration method uses random data and is especially suitable for ADCs used in digital data communication systems. An 800-MS/s four-channel, time-interleaved ADC system has been implemented to evaluate the performance of the technique. The experimental results show that the spurious-free dynamic range of the ADC system is improved to 58.1 dB at 350 MHz. The ADC system achieves a signal-to-noise and distortion ratio of 59.6 dB at 5 MHz and 50.1 dB at 350 MHz after calibration. Index Terms--Analog-to-digital converter (ADC), calibration, sample-time mismatch, skew, time interleaved.

Complex transfer functions are not restricted to having complex-conjugate symmetry in the frequency-domain, as is the case for real filters. This gives them more flexibility when they are used in communication systems with complex signals, such as intermediate frequency signals of wireless communication systems. This paper describes a set of algorithms and procedures that can be used in solving the approximation problem involved in deriving complex infinite-impulse-response bandpass transfer functions directly, without the requirement of first designing a real-transfer-function prototype filter, which is then frequency translated. Because the requirement for a real prototype filter is eliminated, the filters need not have arithmetic symmetry; this results in superior stopbands with smaller filter orders. The procedures can be used for both continuous and discrete-time filters, can allow for arbitrary stopband specifications, and can be used for either equiripple or monotonic passbands. Index Terms--Complex signal processing, filter approximation, quadrature signal processing, transfer functions.

Wireless systems often make use of the quadrature relationship between pairs of signals to effectively cancel out-of-band and interfering in-band signal components. The understanding of these systems is often simplified by considering both the signals and system transfer functions as 'complex' quantities. The complex approach is especially useful in highly integrated multistandard receivers where the use of narrow-band fixed-coefficient filters at the RF and high IF must be minimized. This paper first presents a tutorial review of complex signal processing for wireless applications. The review emphasizes a graphical and pictorial description rather than an equation-based approach. Next, a number of classical modulation architectures are described using this formulation. Finally, more recent developments such as complex filters, image-reject mixers, low-IF receivers, and oversampling analog--digital converters are discussed. Index Terms--Communication systems, complex signal processing, filters, frequency modulation, mixers, wireless receivers.

High-speed high-resolution [DELTA] [SIGMA] analog-to-digital converters (ADCs) for broad-band communication applications must be designed at a low oversampling ratio (OSR). However, lowering the OSR limits the efficiency of a [DELTA] [SIGMA] ADC in achieving a high-resolution A/D conversion. This paper presents several techniques that enable the OSR reduction in [DELTA] [SIGMA] ADCs without compromising the resolution. 1) Noise transfer function (NTF). In this paper, a single-stage multibit [DELTA] [SIGMA] modulator with a high-order finite-impulse-response NTF is proposed to achieve high signal-to-quantization-noise ratios at low OSRs. Its key features include: decreased circuit complexity, improved robustness to modulator coefficient variations, and reduced sensitivity to integrator nonlinearities. Its performance is validated through behavioral simulations and compared to traditional [DELTA] [SIGMA]. modulator structures. 2) Signal transfer function (STF). This paper describes how the STF of a [DELTA] [SIGMA] modulator can be designed, independently of the NTF, in order to significantly reduce the harmonic distortion due to opamp nonidealities and to help lower the power dissipation. 3) Dynamic element matching (DEM) is also presented. Data weighted averaging (DWA) has prevailed as the most practical DEM technique to linearize the internal digital-to-analog converter (DAC) of a multibit [DELTA] [SIGMA] modulator, especially when the number of DAC elements is large. However, the occurrence of in-band signal-dependent tones, when using DWA at a low OSR, degrades the spurious-free dynamic range. This paper proposes a simple technique, caned Pseudo DWA, to solve the DWA tone problem without sacrificing the signal-to-noise ratio. Its implementation adds no extra delay in the [DELTA] [SIGMA] feedback loop and requires only minimal additional digital hardware. Existing schemes for DWA tone reduction are also compared. Index Terms--[DELTA] [SIGMA] modulators, analog-to-digital converters (ADCs), data-weighted averaging (DWA), digital-to-analog conversion, dynamic element matching (DEM), mismatch shaping.

An approach for realizing filter banks having improved sidelobe performance compared to approaches such as those based on inverse Fourier transforms (IFT's), especially for greater frequency differences from the passband frequencies, is presented. The approach is based on using a weighted-sum of near-adjacent IFT filters to realize the individual channel-bank filters, but with constraints added that results in significantly improved stopband performance while still achieving small reconstruction errors. The proposed channel banks are suitable for realizing multitone digital data communication systems, such as Asymmetric Digital Subscriber Line (ADSL) systems, where stopband performance is critical. Under the conditions of maximal decimation, the reconstruction is not perfect, but aliasing errors are small enough to be negligible in practical communication systems. For some eases, the filter coefficients can be determined exactly without using optimization. Given the frequency-weighting coefficients reported herein, near-optimal multirate filter banks may be designed exactly without optimization for all even n. Index Terms - Data communications, filters, multirate.

A fully differential high-Q bandpass filter that uses lossy integrated inductors is presented. The circuit is implemented in a 0.8 [[micro]meter] BiCMOS technology and realizes a center frequency of 750 MHz with a Q-factor that is tunable from 10 to 490 while dissipating 80-100 mW from a single 5 V supply. Since the objective of the prototype was to explore the proposed Q-enhancement technique, the dynamic range is limited to 25 dB for Q = 20.

The new algorithm proposed is used in the spectral analysis of continuous signals with abruptly varying characteristics. The stopping of the adaptive filter, which has been operating only forward in time, and the re-operating of the filter forward and backward several times alternatively enables the fast acquisition of new characteristics with more accuracy. The algorithm is run only forward in time after the determination of the new characteristics under the condition that there is not much change in the input characteristics. The proposed algorithm can be tuned to specific applications, which results in faster adoption time rates.

[Please note that this summary is not legal advice. The reader should confer with one's assigned general counsel for any related legal analysis or advice.] Introduction Each year, the DISAM [...]

The article presents a recap of the U.S. security assistance and cooperation legislation for fiscal year 2015. Fiscal year 2015 appropriations legislation include Consolidated and Further Continuing Appropriations Act (CROmnibus), 2015, the Ukraine Freedom Support Act of 2014 and Carl Levin and the National Defense Authorization Act of Fiscal Year 2015.

The advantages of analog integrated Viterbi decoders over conventional digital decoders are evident in the creation of faster decoders with savings in size and power consumption. Furthermore, these advantages are extendible to other Viterbi decoders. Two partial-response signals Viterbi decoders were designed and constructed on a common silicon core to examine the feasibility of extending the implementation approach to complicated decoders. The implementation approach is general, thus, it may also be used in error-correction coding systems.