Interventional Radiology Readiness Assessment Tool for Global Health

The Interventional Radiology Readiness Assessment Tool for Global Health is a new tool to methodically evaluate the environment of a medical institution for interventional radiology services given the existing infrastructure. Global health provides an exciting opportunity for interventional radiology to impact health outcomes in developing countries. A systematic and thoughtful approach to integrating interventional radiology services in the health care institutions of resource poor countries is needed in order to maximize global health efforts and outcomes. The IR Readiness Assessment Tool is available as on online form and in PDF format under Additional Files below

Diffractive effects in spin-flip pp amplitudes and predictions for relativistic energies

We analyze the diffractive (Pomeron) contribution to pp spin-flip amplitude and discuss the possible scenarios for energies available at the Relativistic Heavy-Ion Collider (RHIC). In particular, we show that RHIC data will be instrumental in assessing the real contribution of diffraction to spin amplitudes.Comment: 11 pages, 12 Encapsulated PostScript files, LaTeX2e use

Multivariate Granger Causality and Generalized Variance

Granger causality analysis is a popular method for inference on directed interactions in complex systems of many variables. A shortcoming of the standard framework for Granger causality is that it only allows for examination of interactions between single (univariate) variables within a system, perhaps conditioned on other variables. However, interactions do not necessarily take place between single variables, but may occur among groups, or "ensembles", of variables. In this study we establish a principled framework for Granger causality in the context of causal interactions among two or more multivariate sets of variables. Building on Geweke's seminal 1982 work, we offer new justifications for one particular form of multivariate Granger causality based on the generalized variances of residual errors. Taken together, our results support a comprehensive and theoretically consistent extension of Granger causality to the multivariate case. Treated individually, they highlight several specific advantages of the generalized variance measure, which we illustrate using applications in neuroscience as an example. We further show how the measure can be used to define "partial" Granger causality in the multivariate context and we also motivate reformulations of "causal density" and "Granger autonomy". Our results are directly applicable to experimental data and promise to reveal new types of functional relations in complex systems, neural and otherwise.Comment: added 1 reference, minor change to discussion, typos corrected; 28 pages, 3 figures, 1 table, LaTe

Reflected Shock Tunnel Noise Measurement by Focused Differential Interferometry

A series of experiments is conducted where a quantitative non-intrusive optical technique is used to investigate disturbances in the free-stream of T5, the free-piston driven reflected shock tunnel at Caltech. The optical technique, focused laser differential interferometry (FLDI), measures fluctuations in density. In the test matrix, reservoir enthalpy is varied while the reservoir pressure is held fixed. The results show the perturbations in density are not a strong function of the reservoir enthalpy. During one experiment, exceptional levels of noise were detected; this unique result is attributed to non-ideal operation of the shock tunnel. The data indicate that rms density fluctuations of less than 0.75% are achievable with attention to tunnel cleanliness. In addition, the spectral content of density fluctuation does not change throughout the test time

Low-dimensional dynamics embedded in a plane Poiseuille flow turbulence : Traveling-wave solution is a saddle point ?

The instability of a streak and its nonlinear evolution are investigated by direct numerical simulation (DNS) for plane Poiseuille flow at Re=3000. It is suggested that there exists a traveling-wave solution (TWS). The TWS is localized around one of the two walls and notably resemble to the coherent structures observed in experiments and DNS so far. The phase space structure around this TWS is similar to a saddle point. Since the stable manifold of this TWS is extended close to the quasi two dimensional (Q2D) energy axis, the approaching process toward the TWS along the stable manifold is approximately described as the instability of the streak (Q2D flow) and the succeeding nonlinear evolution. Bursting corresponds to the escape from the TWS along the unstable manifold. These manifolds constitute part of basin boundary of the turbulent state.Comment: 5 pages, 6 figure

Evidence That the Clinical Impairment Assessment (CIA) Subscales Should Not Be Scored: Bifactor Modelling, Reliability, and Validity in Clinical and Community Samples

Aim: The Clinical Impairment Assessment (CIA 3.0) is the most widely used instrument assessing psychosocial impairment secondary to eating disorder symptoms. However, there is conflicting advice regarding the dimensionality and optimal method of scoring the CIA. We sought to resolve this confusion by conducting a comprehensive factor analytic study of the CIA in a community sample (N = 301) and clinical sample comprising patients with a diagnosed eating disorder (N = 209). Convergent and discriminant validity were also assessed. Method: The CIA and measures of eating disorder symptoms were administered to both samples. Results: Factor analyses indicated there is a general impairment factor underlying all items on the CIA that is reliably measured by the CIA Global score. CIA Global demonstrated good convergent and discriminant validity. Conclusions: CIA Global is a reliable and valid measure of psychosocial impairment secondary to eating disorder symptoms; however, subscale scores should not be computed

Compressible flow structures interaction with a two-dimensional ejector: a cold-flow study

An experimental study has been conducted to examine the interaction of compressible flow structures such as shocks and vortices with a two-dimensional ejector geometry using a shock-tube facility. Three diaphragm pressure ratios ofP4 =P1 = 4, 8, and 12 have been employed, whereP4 is the driver gas pressure andP1 is the pressure within the driven compartment of the shock tube. These lead to incident shock Mach numbers of Ms = 1:34, 1.54, and 1.66, respectively. The length of the driver section of the shock tube was 700 mm. Air was used for both the driver and driven gases. High-speed shadowgraphy was employed to visualize the induced flowfield. Pressure measurements were taken at different locations along the test section to study theflow quantitatively. The induced flow is unsteady and dependent on the degree of compressibility of the initial shock wave generated by the rupture of the diaphragm

How do Alternative Pressures Affect the Accuracy of the Pressed Juice Percentage (PJP) at Predicting Consumer Juiciness Rating?

Texture is the most important sensory trait when evaluating meat products (Gomes et al., 2014). In beef products, tenderness and juiciness interact to form overall texture and mouthfeel. As a result, beef juiciness is one of the most important factors in creating a satisfactory beef eating experience. A recent study by Woolley (2014) developed an instrumental technique for measuring beef juiciness and predicting consumer beef juiciness satisfaction. The method utilizes a texture analyzer to compress cooked beef samples for a period of 8 seconds at 17.6 lb of force and quantifies the percentage of moisture lost as Pressed Juice Percentage (PJP), a predictor of beef juiciness. Results from the initial study found PJP accounts for 20% of the variation in consumer juiciness scores; however, an evaluation of additional pressures is needed to determine if the PJP method can account for an even greater percentage of variation. Thus, the objective of this study was to evaluate the PJP method utilizing three different pressures and determine the relationship of these values to consumer sensory scores for juiciness