971-54 A Non-invasive Method of Visually Assessing Renal Perfusion Using a Newly Developed Intravenous Ultrasound Contrast

Present methods of quantifying renal artery blood flow (RABF) in renovascular disease require either radionuclide techniques or invasive delivery of radiographic or ultrasound contrast. Perfluoropropane is a gas routinely used for intraocular injections which, when sonicated with dextrose albumin (PESDA). produces microbubbles with prolonged survival in blood. We hypothesized, therefore, that this prolonged ultrasound contrast effect could be utilized to non-invasively evaluate RABF and perfusion, Accordingly, we gave intravenous injections (IVI) of PESDA (0.06 cc/kg) to seven dogs while imaging with an external 4.5 MHz linear array transducer RABF was monitored using a Transonic Doppler probe placed around the renal artery. Contrast two-dimensional enhancement was quantified off-line. Both echo and color Doppler enhancement were also qualitatively graded as 0=no enhancement, 1+=mild, 2+=marked enhancement.Following all 36 (100%) IVI of PESDA, there was 2+ contrast ultrasound enhancement of the renal cortex. A linear correlation existed between Doppler renal artery flow and peak renal cortex videointensity follOWing IV PESDA (r=0.65, P<0.001), Color Doppler signals were also enhanced following IV PESDA, and resulted in excellent visualization of the main renal artery as well as segmental and lobar arteries. When renal artery stenosis was induced to decrease RABF to less than 10% of baseline, the segmental and lobar arteries were not visualized with color Doppler following IV PESDA, and peak renal cortex videointensity was reduced from 26 ± 10 to 15 ± 8 units (p<0.05). These data demonstrate that renal artery and cortical blood flow abnormalities can be detected using intravenous PESDA. This ultrasound contrast agent could be a new non-invasive method to detect renal artery stenosis or abnormal renal perfusion

Improving Loss Estimation for Woodframe Buildings. Volume 2: Appendices

This report documents Tasks 4.1 and 4.5 of the CUREE-Caltech Woodframe Project. It presents a theoretical and empirical methodology for creating probabilistic relationships between seismic shaking severity and physical damage and loss for buildings in general, and for woodframe buildings in particular. The methodology, called assembly-based vulnerability (ABV), is illustrated for 19 specific woodframe buildings of varying ages, sizes, configuration, quality of construction, and retrofit and redesign conditions. The study employs variations on four basic floorplans, called index buildings. These include a small house and a large house, a townhouse and an apartment building. The resulting seismic vulnerability functions give the probability distribution of repair cost as a function of instrumental ground-motion severity. These vulnerability functions are useful by themselves, and are also transformed to seismic fragility functions compatible with the HAZUS software. The methods and data employed here use well-accepted structural engineering techniques, laboratory test data and computer programs produced by Element 1 of the CUREE-Caltech Woodframe Project, other recently published research, and standard construction cost-estimating methods. While based on such well established principles, this report represents a substantially new contribution to the field of earthquake loss estimation. Its methodology is notable in that it calculates detailed structural response using nonlinear time-history structural analysis as opposed to the simplifying assumptions required by nonlinear pushover methods. It models physical damage at the level of individual building assemblies such as individual windows, segments of wall, etc., for which detailed laboratory testing is available, as opposed to two or three broad component categories that cannot be directly tested. And it explicitly models uncertainty in ground motion, structural response, component damageability, and contractor costs. Consequently, a very detailed, verifiable, probabilistic picture of physical performance and repair cost is produced, capable of informing a variety of decisions regarding seismic retrofit, code development, code enforcement, performance-based design for above-code applications, and insurance practices

A physiologist observing and reporting supra-pharmacologic dobutamine stress testing: can we trust them, and can we trust the results?

In a study, published in this issue of Echo Research and Practice, Ntoskas et al. retrospectively analyzed the safety of a cardiac physiologist performing, and interpreting, Dobutamine stress echocardiography (DSE) in of 300 patients undergoing DSE for the detection of inducible reversible ischemia, myocardial viability and valvular heart disease. While safety during the tests themselves did not appear to be compromised with this unsupervised approach, the interpretation of these DSEs causes concerns regarding broad patient safety relative to misread results

In Vitro Maturation of a Humanized Shark VNAR Domain to Improve Its Biophysical Properties to Facilitate Clinical Development

Acknowledgments: The authors would like to acknowledge the funding support for this work from Scottish Enterprise [VNAR_001(2012)] and the Biotechnology and Biological Sciences Research Council (BB/K010905/1).Peer reviewedPublisher PD

On the presence of nonjet "higher harmonic" components in 2D angular correlations from high energy heavy ion collisions

It is conjectured that several higher harmonic flows $v_m$ may result from initial-state geometry fluctuations in \aa collisions coupled to a radially-expanding medium. But as with "elliptic flow" $v_2$ measurements, non-hydrodynamic mechanisms such as jet production may contribute to other higher azimuth multipoles $v_m$ as biases. Careful distinctions should be maintained between jet-related and nonjet (possibly hydrodynamic) contributions to $v_m$ (e.g., "nonflow" and "flow"). In this study we consider several questions: (a) To what extent do jet-like structures in two-dimensional (2D) angular correlations contribute to azimuth multipoles inferred from various $v_m$ methods? (b) If a multipole element is added to a 2D fit model is a nonzero amplitude indicative of a corresponding flow component? and (c) Can 2D correlations establish the necessity of nonjet contributions to some or all higher multipoles? Model fits to 2D angular correlations are used to establish the origins of azimuth multipoles inferred from 1D projections onto azimuth or from nongraphical numerical methods. We find that jet-like angular correlations, and specifically a 2D peak at the angular origin consistent with jet production, constitute the dominant contribution to inferred higher multipoles, and the data do not {\em require} higher multipoles in isolation from the jet-like 2D peak. Inference of "higher harmonic flows" results from identifying certain nominally jet-like structure as flow manifestations through unjustified application of 1D Fourier series analysis. Although the peak structure at the angular origin is strongly modified in more-central collisions some properties remain compatible with relevant pQCD theory expectations for jet production.Comment: 14 pages, 11 figure

Prognostic value of high-dose dipyridamole stress myocardial contrast perfusion echocardiography

The addition of myocardial perfusion (MP) imaging during dipyridamole real-time contrast echocardiography improves the sensitivity to detect coronary artery disease, but its prognostic value to predict hard cardiac events in large numbers of patients with known or suspected coronary artery disease remains unknown

Multimode bolometer development for the PIXIE instrument

The Primordial Inflation Explorer (PIXIE) is an Explorer-class mission concept designed to measure the polarization and absolute intensity of the cosmic microwave background. In the following, we report on the design, fabrication, and performance of the multimode polarization-sensitive bolometers for PIXIE, which are based on silicon thermistors. In particular we focus on several recent advances in the detector design, including the implementation of a scheme to greatly raise the frequencies of the internal vibrational modes of the large-area, low-mass optical absorber structure consisting of a grid of micromachined, ion-implanted silicon wires. With $\sim30$ times the absorbing area of the spider-web bolometers used by Planck, the tensioning scheme enables the PIXIE bolometers to be robust in the vibrational and acoustic environment at launch of the space mission. More generally, it could be used to reduce microphonic sensitivity in other types of low temperature detectors. We also report on the performance of the PIXIE bolometers in a dark cryogenic environment.Comment: 10 pages, 7 figure

Capital Structure Choices and Survival in a Deregulated Environment

We examine the impact of capital structure choices for survival in a deregulated industry. Financial leverage in particular has been identified by numerous prior studies as a major determinant of the probability of survival in most industries. In the course of a deregulation, the debt overhang effect stemming from high leverage negatively affects the ability of existing firms to survive when a regulatory shock occurs (Zingales, 1998). Following such a regulatory shock, and consistent with the tradeoff and debt overhang theories of capital structure, firms are more likely to reduce their level of leverage (Ovtchinnikov, 2010). This causes the expected costs of financial distress to rise higher and we can expect a negative association between leverage and survival in a deregulated industry. However, in a highly competitive setting, firms may signal their level of quality by contracting for more debt instead of equity (Ross, 1977). This signaling perspective can therefore induce the existence of a positive association between leverage and survival in a deregulated context. Using a sample of private trucking firms, we test this hypothesis and find a negative association between leverage and survival. In a refined analysis aimed at distinguishing high “quality” versus low “quality” firms, we adopt the “excess capacity” approach of De Vany and Saving (1977). Consistent with our initial findings, we find that the negative association between leverage and survival increases with the level of excess capacity