Quantitative characterization of flaws near a surface using inverse born approximation

Quantitative reconstruction of volumetric flaws near a surface of an elastic solid has been carried out experimentally by analyzing the scattered ultrasonic waves. The inverse Born approximation (developed for flaws in bulk materials) was tested for the first time in the determination of the size, shape, and orientation of near-surface flaws. We have studied spherical solid inclusions at various depths below the surface. In addition we examined an approximately 2:1 prolate spheroidal inclusion which was located one major axis below the surface. The determination of the flaw's size, shape, and orientation in terms of an equivalent ellipsoid is realized by performing nonlinear least-squares iteration of the one-dimensional Born inversion results obtained at various scattering directions within a finite aperture. The reconstruction is in good agreement with the actual parameters of the flaw.     

Reviews

READING LANDSCAPE; COUNTRY-CITY-CAPITAL, Simon Pugh, ed., Manchester : Manchester University Press, 1990, pp. 245, £35.00 HB, £9.95 PB, ISBN 0-7190-2979-1, 0-7190-3189-3.

ENVISIONING INFORMATION

by Edward R. Tufte, Cheshire, Connecticut, The Graphics Press, 1990, £30.00.

THE MAKING OF THE AMERICAN LANDSCAPE, Michael P. Conzen, ed., Boston and London: Unwin Hyman, 1990. pp. xvi + 434. ISBN 0-04-917010-4. £14.95 PB.

THE EFFECTS OF THE GREAT STORM: REPORT OF A TECHNICAL COORDINATION COMMITTEE AND THE GOVERNMENT'S RESPONSE, London: HMSO, 1988, 43pp, £5.00, P.B., ISBN 011 752144 2.

THE 1987 STORM: IMPACTS AND RESPONSES, A. J. Grayson (ed.), London: HMSO, 1989, 46pp, £4.00, P.B., ISBN 011 752144 2.

VIEWS OF AMERICAN LANDSCAPES, edited by Mick Gidley and Robert Lawson-Peebles, Cambridge: Cambridge University Press, 1989, £27.50; $39.50, H.B., 228pp.

TAMING THE FLOOD: A HISTORY AND NATURAL HISTORY OF RIVERS AND WETLANDS by Jeremy Purseglove, Oxford: Oxford University Press in association with Channel 4, 1989, 291pp, ISBN 0 19 286091 7, £9.95, P.B.

THE ITALIAN RENAISSANCE GARDEN FROM THE CONVENTIONS OF PLANTING, DESIGN, AND ORNAMENT TO THE GRAND GARDENS OF SIXTEENTH-CENTURY CENTRAL ITALY, Claudia Lazzaro with photographs by Ralph Lieberman, New Haven and London, Yale University Press, 1990, pp. i-ix + 342, £45.00, $65.00, ISBN 0-300-4765-7.

LANDSCAPE OR LAND?, poems for Devon, Mark Beeson and Christopher Southgate, Wheal Press, Devon, ISBN 0-9511588-1-3.     

Extended input-output models: progress and potential

"This article presents a critical survey of research on extended input-output models, emphasizing recent developments in demographic-economic and socio-economic analysis. Basic principles of model design and construction are reviewed, by reference to a representative selection of extended models. Two research themes--labor market analysis and income distribution--are pursued in greater detail as examples of the directions of current work. A comparison is made between extended models and social accounting matrices."     

Environmental tobacco smoke exposure in the home and worksite and health effects in adults: results from the 1991 National Health Interview Survey

It is generally accepted that genetics play a significant role in the pathogenesis of hypertension. Since hypertension often follows kidney transplantation, candidate genes have been sought and found in the kidneys of rats and humans. One well-recognized, inherited influence on blood pressure (BP) occurs via abnormal renal sodium handling in vivo. Further, abnormal renal sodium handling is seen in isolated kidneys of genetically hypertensive rats. People who have a relative inability to handle a sodium load properly, and retain it inappropriately, often develop high BP and are referred to as "salt-sensitive". More than half of patients diagnosed with essential hypertension are salt-sensitive. In contrast to the deleterious effects associated with high sodium intake, many believe that ingestion of more potassium, calcium, and magnesium may influence BP favorably. The beneficial effects of these ions work, at least in part, through an effect on sodium balance, i.e. a diuretic influence. In support of this concept, they lower BP more effectively in salt-sensitive hypertensives. Refined carbohydrates and saturated fats are also associated with salt retention and hypertension. Thus, dietary factors, working directly on their own and/or indirectly via effects on genetic mechanisms, may alter BP favorably or unfavorably.     

Impairment of energy metabolism and excitotoxic cell death in Huntington disease

The gene for Huntington's disease is widely expressed in brain and yet the illness is characterized pathologically by a distinct regional pattern of cell death. Various theories for this selective vulnerability have been offered but the most compelling remains that of abnormal energy metabolism. These issues are reviewed.     

Evaluation of the uncertainty of molecular mass measurement by electrospray ionization mass spectrometry

Electrospray ionization (ES) is a novel method used in mass spectrometry (MS) for producing gas-phase ions from substances in solutions. Common practices for molecular mass estimation from ES spectra summarize the spectrum as a single peak giving no estimate of uncertainty or treat each peak as an independent molecular mass measurement. ES-MS data analysis showed that each peak in an ES spectrum does not always provide an independent measure of molecular mass. Underestimation of measurement uncertainty is a possible result. An elementary time series method, the Yule-Walker equations, was applied to molecular mass estimation from ES data.     

Characterization of unconventional MYO6, the human homologue of the gene responsible for deafness in Snell's waltzer mice

Deafness is the most common form of sensory impairment in humans. Mutations in unconventional myosins have been found to cause deafness in humans and mice. The mouse recessive deafness mutation, Snell's waltzer, contains an intragenic deletion in an unconventional myosin, myosin VI (locus designation, Myo6). The requirement for Myo6 for proper hearing in mice makes this gene an excellent candidate for a human deafness disorder. Here we report the cloning and characterization of the human unconventional myosin VI (locus designation, MYO6) cDNA. The MYO6 gene maps to human chromosome 6q13. The isolation of the human gene makes it now possible to determine if mutations in MYO6 contribute to the pathogenesis of deafness in the human population.     

Osteopontin in chronic puromycin aminonucleoside nephrosis

Increased expression of osteopontin (OPN) associated with interstitial monocyte infiltration has been demonstrated in the early phase of a variety of experimental renal diseases. Whether these changes occur in the chronic phase of progressive glomerular disease is unknown. Chronic puromycin aminonucleoside nephrosis (PAN) was induced in 16 rats by the injection of a single bolus of PA into the internal jugular vein, which results in a triphasic disease characterized by minimal glomerular change and marked proteinuria, peaking at about 10 to 14 d and subsiding by 28 d, followed by a quiescent 4-wk period of no or minimal proteinuria and then the development of progressive focal glomerulosclerosis (FGS) and increasing proteinuria. Fifteen rats injected similarly with normal saline served as controls. At 11 d after injection, PA rats demonstrated significantly greater urinary protein excretion (P = 0.0107), cortical tubular OPN expression (P = 0.0086), and intraglomerular (P = 0.0009) and interstitial (P = 0.0212) monocyte infiltration than did the controls. At 42 d, no significant differences between the two groups with respect to the above parameters were detected. At 98 d, PA rats had FGS and showed a definite trend to increased proteinuria, cortical tubular OPN, and intraglomerular monocyte infiltration. Although the cortical interstitial monocyte count was not elevated in PA rats compared with controls, there were significantly more monocytes around OPN-positive cortical tubules than around OPN-negative ones (P = 0.0011). Cortical tubular OPN expression correlated well with urinary protein excretion (r = 0.932, P < 0.0001), cortical tubular proliferating cell nuclear antigen (r = 0.796, P < 0.0001), and intraglomerular monocyte count (r = 0.552, P = 0.0013). The results are consistent with a monocyte chemoattractant role for OPN and suggest that OPN is upregulated in the chronic phase of PAN and that this increase in expression is a result of glomerular events.