Sudden death in a 4-month-old infant associated with anomalous origin of the left coronary artery

We describe the autopsy findings of a 4 months-old boy, who died suddenly after an episode of high airway infection of 3 days time. Autopsy examination showed cardiomegaly (80 g) with widening of the left cavities and thick and white endocardial surface, besides a severe thinning of the cardiac apex at the level of the left ventricle. Left coronary origin was in the pulmonary artery trunk. Histologically, the myocardium shows endomyocardial fibroelastosis and also multiple and extensive areas of old and recent infarcts in the left ventricle. The collateral coronary arteries, were increased in number, and branches showed a marked intimal oedema and a reduction of the luminal diameter.     

A 5-V CMOS programmable acoustic front-end for ISDN terminals anddigital telephone sets

A 5-V CMOS programmable acoustic front-end IC for ISDN terminal and digital telephone set applications is presented. The chip performs PCM codec and filter functions, fulfilling all D3/D4 and CCITT specs. Moreover, it implements the main analog interfaces required for the speech channel (low-noise microphone preamplifier, earpiece and loudspeaker drivers, sidetone, antilarsen control) and tone/ring/DTMF generation without external components. The device can be controlled by a microprocessor or a HDLC controller via a four wire separated control interface or by means of a serial control channel multiplexed with the PCM voice/data channel in a GCI compatible format. Chip area is 30 mm ² in a 1.5-μm CMOS technology. The active/stand-by power consumption is 60 mW/0.2 mW from a single 5-V supply. All circuits are designed to meet performance objectives over a voltage range from 4.5 V to 5.5 V and a temperature range from -40°C up to 85°C     

A 3.3-V 800-nVrms noise, gain-programmable CMOSmicrophone preamplifier design using yield modeling technique

A 3.3-V CMOS low-noise gain-programmable microphone amplifier with a high-impedance balanced input is presented. The preamplifier allows gains from 20 to 35 dB to be set by software control in 1-dB steps with 0.05-dB accuracy. Typical measured V_OS is 0.8 mV, V_OS drift is 1 μV/C, input-referred p-weighted noise is 0.8 μV _rms and total harmonic distortion (THD) is -70 dB. The active area is about 350 mils², and power consumption is 1.7 mW at 3.3-V supply and 2.9 mW at 5-V supply. These results have been obtained through an intensive use of the yield modeling technique for yield-performance optimization during the design phase, and by applying a common-centroid cross-coupled strategy to the layout of all the ideally matched MOS transistors in the input stage     

New approach to the approximation of RC-active-filter transmission functions with low Q factor

A new polynomial class is considered for the design of the transmission functions of lowpass RC active filters. These transmission functions have higher degree but lower Q factors than those computed with the classical Cheby?shev method.     

Morphogenetic approach to system identification

In this paper, we propose a novel approach to system identification based on morphogenetic theory (MT). Given a context H defined by a set of M objects, each described by a set of N attributes, and a vector X of desired outputs for each object, MT combines notions from formal concept analysis and tensor calculus so as to generate a morphogenetic system (MS). The MS is defined by a set of weights s¹, …, s^N, one for each attribute. Given H and X, weights are computed so as to generate the projection Y of X on the space of the attributes with the minimum distance between Y and X. An MS can be represented as a neuron, morphogenetic neuron, with a number of synapses equal to the number of attributes and synaptic weights equal to s¹, …, s^N. Unlike traditional neural network paradigm, which adopts an iterative process to determine synaptic weights, in MT, weights are computed at once. We introduce a method to generate a morphogenetic neural network (MNN) for identification problems. The method is based on extending appropriately and iteratively the attribute space so as to reduce the error between desired output and computed output. By using four well‐known datasets, we show that an MNN can identify an unknown system with a precision comparable with classical multilayer perceptron with complexity similar to the MNN but reducing drastically the time needed to generate the neural network. Furthermore, the structure of the MNN is generated automatically by the method and does not require a trial‐and‐error approach often applied in classical neural networks. © 2009 Wiley Periodicals, Inc.     

Environmental and Ontogenetic Control of Accumulation of Brachycerine, a Bioactive Indole Alkaloid from Psychotria brachyceras

Brachycerine is a monoterpenoid indole alkaloid accumulated in Psychotria brachyceras plants (Rubiaceae). To better understand the accumulation patterns of this alkaloid, we investigated its content in different plant organs from field-grown trees, throughout the seasons, during seedling development, and in response to potential biotic factors regulating its biosynthesis. Quantification by RP-HPLC showed that aerial vegetative organs (green stems, young and old leaves) yielded similar amounts of brachycerine [0.1-0.2% dry weight (DW)]. Brachycerine was not detected in roots. In reproductive structures, the highest brachycerine amounts (0.3% DW) were found in inflorescences. Alkaloid concentration decreased in mature fruits (0.045% DW). The lowest concentration in reproductive organs was observed in quiescent seeds (0.004% DW). Apparently, brachycerine content dropped during radicle emission in germinating seeds. During seedling development, an increase in leaf content from 0.02 to 0.1% DW was observed between the stages of 2 and 14 leaves, respectively. Salicylic acid did not affect brachycerine content. A doubling of alkaloid content was observed in wounded plants, and a threefold induction occurred with jasmonic acid treatment, suggesting that brachycerine biosynthesis is regulated by jasmonate production.     

A CMOS bandgap reference for differential signal processing

A switched-capacitor fully differential bandgap reference that uses a standard double-poly CMOS process is presented. It generates a differential reference voltage of 6.2 V with a standard deviation of about 24 mV and a typical temperature stability of 15.2 p.p.m./°C over an extended temperature range from -40 to +85°C. These performance results are obtained without using any trimming in mass production. The bandgap reference only occupies 730 mil² and dissipates 4.8 mW at±5-V power supplies. A measured power supply rejection of about 90 dB until 500 kHz is the best ever reported at high frequency