Noise Feedback Coding Revisited： Refurbished Legacy Codecs and New Coding Models

Noise feedback coding(NFC) has attracted renewed interest with the recent standardization of backward-compatible enhancements for ITU-T G.711 and G.722.It has also been revisited with the emergence of proprietary speech codecs,such as BV16,BV32,and SILK,that have structures different from CELP coding.In this article,we review NFC and describe a novel coding technique that optimally shapes coding noise in embedded pulse-code modulation(PCM) and embedded adaptive differential PCM(ADPCM).We describe how this new technique was incorporated into the recent ITU-T G.711.1,G.711 App.III,and G.722 Annex B(G.722B) speech-coding standards.     

Clinical and Molecular Characterization of Patients with Mucopolysaccharidosis Type I in an Algerian Series

Mucopolysaccharidoses (MPS’s) represent a subgroup of lysosomal storage diseases related to a deficiency of enzymes that catalyze glycosaminoglycans degradation. Mucopolysaccharidosis type I (MPS I) is a rare autosomal recessive disorder caused by a deficiency of α-l-iduronidase encoded by the IDUA gene. Partially degraded heparan sulfate and dermatan sulfate accumulate progressively and lead to multiorgan dysfunction and damage. The aim of this study is to describe the clinical, biochemical, and molecular characteristics of 13 Algerian patients from 11 distinct families. MPS I diagnosis was confirmed by molecular study of the patients’ IDUA gene. Clinical features at the diagnosis and during the follow-up are reported. Eighty-four percent of the studied patients presented with a mild clinical phenotype. Molecular study of the IDUA gene allowed the characterization of four pathological variations at the homozygous or compound heterozygote status: IDUA NM_00203.4:c.1598C>G-p.(Pro533Arg) in 21/26 alleles, IDUA NM_00203.4:c.532G>A-p.(Glu178Lys) in 2/26 alleles, IDUA NM_00203.4:c.501C>G-p.(Tyr167*) in 2/26 alleles, and IDUA NM_00203. 4: c.1743C>G-p.(Tyr581*) in 1/26 alleles. This molecular study unveils the predominance of p.(Pro533Arg) variation in our MPS I patients. In this series, the occurrence of some clinical features linked to the Scheie syndrome is consistent with the literature, such as systematic valvulopathies, corneal opacity, and umbilical hernia; however, storage signs, facial dysmorphic features, and hepatomegaly were more frequent in our series. Screening measures for these debilitating diseases in highly consanguineous at-risk populations must be considered a priority health problem.     

Mayonnaise production in batch and continuous process exploiting magnetohydrodynamic force

Mayonnaise currently is produced using high shear stirrers. Here we present a new production method using a magnetic emulsification device. According to the new method a stable oil-in-water emulsion is formed by pumping the two immiscible liquids through a magnetohydrodynamic dispersion device consisting of a Venturi provided with an orthogonal permanent magnetic field. As a proof of concept, magnetically emulsified highly viscous mayonnaise was produced in a batch process and in a continuous process. The viscosity of the mayonnaise was significantly enhanced by applying the magnetic field. The oil droplet size distribution of mayonnaise produced using the magnetic emulsification method was similar to mayonnaise produced with conventional high shear mixers. In contrast to conventional processes no fast moving mixers were needed in this new mayonnaise production scheme.     

Social influences related to college students’ use of Macintosh computers on an all-PC campus

In the present qualitative research study, 35 Mac users were interviewed in a university campus that exclusively supports PC machines. We particularly explored the Mac-users’ social influences, saving technological and other influences for future reports. Results showed Mac users to possess significant connections with other Mac users on the university campus. The Mac users in our study indicated that positive, past exposure, including Apple’s advertising of Macs, had sharp influences on their decisions to become and remain Mac users.     

Assessment of bottom-up sectoral and regional mitigation potentials

The greenhouse gas mitigation potential of different economic sectors in three world regions are estimated using a bottom-up approach. These estimates provide updates of the numbers reported in the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR4). This study is part of a larger project aimed at comparing greenhouse gas mitigation potentials from bottom-up and top-down approaches. The sectors included in the analysis are energy supply, transport, industry and the residential and service sector. The mitigation potentials range from 11 to 15 GtCO₂eq. This is 26–38% of the baseline in 2030 and 47–68% relative to the year 2000. Potential savings are estimated for different cost levels. The total potential at negative costs is estimated at 5–8% relative to the baseline, with the largest share in the residential and service sector and the highest reduction percentage for the transport and industry sectors. These (negative) costs include investment, operation and maintenance and fuel costs and revenues at moderate discount rates of 3–10%. At costs below 100 US$/tCO₂, the largest potential reductions in absolute terms are estimated in the energy supply sector, while the transport sector has the lowest reduction potential.     

Magnetic resonance imaging of coronary arteries and coronary stenosis

Coronary artery imaging is an important investigation for the management of coronary artery disease. Alternative noninvasive imaging would be useful, but the small caliber and tortuosity of the coronary vessels and cardiac and respiratory motion create formidable imaging problems. We first studied 21 normal subjects and 5 with coronary artery disease established by X-ray contrast angiography, of whom 2 had undergone bypass grafting. Of these, 22 were imaged successfully. Identification of the artery was possible for the left main stem, left anterior descending, right coronary, and left circumflex arteries respectively in 95%, 91%, 95%, and 76%. The arterial diameter at the origin could be measured in 77%, 77%, 81%, and 63%. The mean ±SD arterial diameter in each case (4.8±0.8, 3.7±0.5, 3.9±0.9, and 2.9±0.6 mm) was not significantly different from reference values (allp=ns). The mean length of artery visualized was 10.4±5.2,46.7±22.8,53.7±27.9, and 26.3±17.5 mm. In 12 normal males, the total coronary area was 30.9±9.2 mm² and the ratio compared with body surface area was 16.4±4.4 mm² m^–2 (bothp=ns compared with reference values). In seven patients, with X-ray contrast coronary angiography, the proximal arterial diameter measured by magnetic resonance was 3.9±1.1 mm, and by X-ray contrast angiography 3.7±1.0 mm (p=ns). We then studied 17 patients with angina. Imaging of just the relevant artery was performed and analysis was blinded to the X-ray angiography results. Stenosis was identified on the magnetic resonance (MR) images by localized reduction in vessel signal intensity. Stenosis location by MR was assessed by measurement of its distance from a reference vessel, with correlation to the X-ray findings. X-ray coronary angiography showed 23 stenoses of which 15 (65%) were correctly located by blind assessment of the MR images. Of the eight remaining stenoses, a further 5 (63%) were correctly located on the MR images after retrospective comparison (overall sensitivity 87%). There were three lesions thought to represent stenosis by MR, which on review of the X-ray angiogram proved to be a minor stenosis <50% (two cases) or a tortuous vessel (one case). Greater signal loss was seen in the more severe stenoses. The stenosis length by MRI was greater than by X-ray (8.4 versus 5.1 mm,p<0.001). The overestimation of stenosis length may be due to turbulence.     

MR high-resolution imaging of arterial intimal hyperplasia at 1.5 T

Intimal hyperplasia is the earliest microscopic change detectable in the arterial wall in the development of arteriosclerosis and atherosclerosis. To enable high-resolution imaging of this, a standard 1.5-T machine was modified using inserted gradient coils of 30 cm internal diameter and surface radio-frequency coils. Six rabbit aorta specimens with injury-induced intimal hyperplasia and two normal rabbit aorta specimens were imaged using a spin-echo sequence of TE 40. Pixel sizes as small as 20 µ×20 µ could be obtained and the area of intimal hyperplasia could be measured at 80 µ×40 µ. The results were compared with those made by a computer-linked microscope. In the injured aortas, there was a low-signal region on magnetic resonance imaging which corresponded to the media of the vessel wall when compared with the histology.T ₁ andT ₂ constants for the media were determined and compared with those of a normal specimen. TheT ₁ constant was shorter for the media of the injured aorta than in the normal. This could be related to the disruption of the internal elastic lamina and migration of muscle cells to the intima which occurs following injury. The popliteal artery of four normal volunteers was imaged and the area of the wall could be measured at a pixel size of 312 µ×160 µ. This suggests thatin vivo studies of intimal hyperplasia arteriosclerosis and atherosclerosis could be made.     

Kinetics of heavy metal vaporization from model wastes in a fluidized bed

Metal vaporization experiments were carried out in an atmospheric fluidized bed to study the influence of operating conditions on the extent of heavy metal (HM) release in fumes from municipal solid waste incinerators. Modelwastes spiked with compounds of Pb, Cd, and Zn were used. The parameters studied were temperature, treatment duration, matrix of the model waste (mineral and organic), HM initial speciation, and gas composition (N2, air, air + HCl, gas mixture simulating the incinerators). The extent of vaporization was measured by solid sample analysis and on-line analysis of the gaseous effluent, after customization of the ICP technique for gas analysis. The results indicate the metal vaporization rate is very high initially and then slows. The results with mineral matrices give the decreasing order of volatility Cd > Pb > Zn, but in industrial incinerators Zn volatilizes slightly more than Pb. Temperature (especially for porous alumina) and mineral matrix have a strong influence on the HM vaporization, but HCl concentration and HM initial speciation do not. The gas composition and the initial metal concentration are significant parameters. The matrix influence clearly denoted the mass transfer limitations in the vaporization process from mineral matrix.