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Background In patients with systolic chronic heart failure (CHF) clinical signs of congestion cannot always be evident at clinical examination. Right atrial pressure (RAP) measured by right heart catheterization (RHC) is an accurate and reproducible marker of blood volume. A non-invasive accurate tool to identify CHF patients with normal RAP would be desirable to tailor therapy. Purpose To validate an ultrasound (US)-assessed internal jugular vein distensibility (JVD) ratio to identify patients with normal mean RAP (defined as 7 mmHg or less) measured by RHC. Methods We first identify the JVD ratio that allows the most accurate identification of patients with normal RAP in a prospective calibration cohort of 100 patients with systolic CHF. Then, we tested the JVD ratio threshold to identify patients with normal RAP in a validation cohort of 101 consecutive patients with systolic CHF. All patients had a left ventricular ejection fraction (LVEF) Results In the calibration cohort (mean age 53 years, 13% female; median LVEF 25%, 81% in NYHA class III/IV) we define the best threshold of the JVD ratio to identify patients with normal RAP that has 1.6 with an area under the curve (AUC of 0.74; p1.6, n=42; median RAP 4 mmHg). High JVD ratio and low JVD ratio groups had similar clinical and laboratory characteristics. In the validation cohort (mean age 55 years, 13% female; median LVEF 25%; 56% in NYHA class III/IV) using the previously defined 1.6 JVD ratio threshold, we identified 51 patients with low JVD ratio (median RAP 8 mmHg) and 50 patients with high JVD ratio (median RAP 3 mmHg; p Conclusions We found that US-assessed JVD ratio is a convenient and accurate diagnostic tool to identify patients with advanced systolic CHF with normal vs. increased RAP. This tool could be tested in the ambulatory setting to modulate therapies, particularly diuretics and vasodilators. Figure 1 Funding Acknowledgement Type of funding source: None

Introduction The Insomnia Severity Index is a commonly used instrument to assess the presence of insomnia symptoms as well as an outcome measure following an intervention. Longitudinal measurement invariance is a necessary property of an assessment instrument when it is repeated over time. The validity of conclusions regarding change in the construct ‘insomnia severity’ depend on scale equivalence at each measurement timepoint. Assessment of measurement invariance of the ISI in sleep apnea patients has never been performed. Methods Veterans with sleep apnea (n=654; AHI=36±28; 93% male; age=52±12; BMI=33±6) completed the ISI on the night of their overnight PSG and again when they picked up their PAP device. Invariance was determined by imposing a series of more restrictive equivalence constraints on a 2-factor model of the ISI. The series of constraints tested for configural, weak, strong and strict invariance. Invariance testing was modeled with exploratory structural equation modeling in Mplus (v. 7.0). Results The 2-factor model that emerged from the analysis showed items relating to nighttime symptoms loading on factor 1 and daytime symptoms loading on factor 2. The sleep ‘satisfaction’ item, however, had weak but similar loadings on both factors. The increasingly restrictive constraints imposed on the model revealed no decrement in model fit (RMSEA=.039 to.043; CFI=.987 to .980; TLI=.981-.977; SRMR=.027-.041). Conclusion The ISI met strict criteria for longitudinal measurement invariance demonstrating that it is a valid instrument to be used in repeated measures study designs of insomnia in sleep apnea patients. Change over time on the ISI is not due to the changing measurement characteristics of the ISI but to true changes in the ‘insomnia severity’ construct. Support None

Studies have shown that joint acquisition programs are prone to experience larger cost and schedule overruns than single service programs, but that cost growth is not related to their generally larger sizes. This paper explains the unique and substantial cost growth of joint programs by describing an underlying causal mechanism that drives the observable schedule delays and cost overruns. Through analysis of actual joint program performance data and the use of that data in a system dynamics model of acquisition program behavior, we characterize two primary sources of joint program cost growth: (1) requirements growth and rework due to a social dilemma that occurs for the Joint Program Office due to interactions among stakeholder programs, and (2) rework driven by more traditional causes such as contract underbidding and the resulting schedule pressure increasing defect levels, and then effectively depressing productivity through the resultant rework. The combination of the two effects diminishes joint program performance significantly, explaining the previously identified degree of severity. In joint programs, the slowing performance manifests itself as a cascade of departing stakeholder programs who are unwilling to accept the growing schedule and cost, ultimately resulting in the cancellation of the program.

Excerpt from the Proceedings of the Tenth Annual Acquisition Research Symposium Acquisition Management

Aiming at improving the knowledge on the source areas of shallow landslides, this research deals with the geotechnical characterization of the debris slope cover of arenaceous formations, by means of low cost dynamic penetration tests (Dynamic Probing – DP).

A typical hardware-in-the-loop (HWIL) lab normally integrates a wide array of digital equipment, each driven by its own internal oscillator. While the various equipment designers may strive to utilize high-precision oscillators in their products, if no synchronization scheme is employed, then time-base drift between the various HWIL components is inevitable. If real-time communications between components is required, such as between the motion simulator controller and the simulation (host) computer, this time-base drift, exacerbated by timing jitter in the communication channel and each component's internal processing loop, can degrade the simulation fidelity. By designing the motion simulator controller to synchronize to an externally provided, facility-wide, standards-based site timing reference such as the Global Positioning System (GPS), the relative time-base drift can be completely eliminated. This paper discusses the advantages of this approach for improving HWIL simulation performance.

In addition to mechanical alignments, precision machine interfaces, and accurate readout transducers, the servo controller is a key component in producing reliable and improved position accuracies. Sub-arc-second accuracies are possible by transducer interpolation and axis calibration. This level of position accuracy is less than a fraction of an inch in angular attitude heading error in one mile of travel. To achieve this accuracy with reliability and repeatability, a new generation of servo controller is needed: one that uses the latest in digital sampling techniques to improve signal fidelity by eliminating noise-prone feedback signals. Position feedback signals consist of a random and a deterministic error. New digital sampling techniques can reduce random errors, while manipulation of stored position calibration data within the controller’s memory can reduce deterministic errors. These techniques have produced a position accuracy of 0.05 arc-seconds and a position resolution of 0.01 arc-seconds. This improved position accuracy relates to an improvement in other specifications as a 0.02% rate error over a one-degree interval.

A case of unexpected death associated with an aneurysm of the left ventricle caused by nonpenetrating chest trauma is described. A review of the more recent literature on the incidence, pathological course, and prognosis of the posttraumatic ventricular aneurysm pointed out the necessity of suspecting cardiac damage in cases of blunt chest trauma especially when major injuries may obscure heart involvement.

Between 1999 and 2001, 355 hospital laboratories in Italy were asked to complete a questionnaire addressing mycobacterial test methods, 1-year workloads and laboratory safety features. Analysis of the data showed that rapid methods for mycobacterial testing were being used by most larger laboratories; however, sub-optimal methods were still in use in small and medium-size laboratories. In a country such as Italy, which has a low prevalence of tuberculosis cases, implementation of rapid technologies, combined with regionalisation of mycobacterial diagnostic services, seems to be the most reasonable and costeffective strategy.

This paper describes one of the capstone engineering design projects implemented by Penn State Altoona BSEMET (baccalaureate degree in electro-mechanical engineering technology) students during their senior year. This project is titled "Design and Implementation of a Vending Machine". At Penn State Altoona, the vending machine is designed and built by individual students in one semester. The paper begins with a description of the BSEMET program. Next, the paper describes the BSEMET capstone project design course (EMET 440). Finally, the paper provides a description of one of the EMET 440 capstone design projects recently completed by students. The project consists of design and implementation of a vending machine using a PLC. The paper presents the design specifications of this vending machine and provides details regarding its design and implementation. Recommendations for design improvement are presented.

Advances in inertial guidance testing place increasing demands upon accuracy, resolution, and response of motion-based test tables and simulators. These test tables are typically controlled via closed-loop servomechanisms utilizing precision axis position transducers (e.g. Inductosyns® 1 , resolvers, optical encoders, etc.) to measure axis motion. A new method of acquiring data from these transducers provides greater resolution, repeatability, and accuracy of axis position measurements, enabling more precise control of the axis. The enhanced data acquisition method has been implemented in the Carco Advanced Servo Controller And Decoding Electronics (CASCADE), and is based upon the delta-sigma data conversion process found in high-end data conversion products. Analog signals from the transducer (typically in the form of quadrature sinusoids) are sampled and digitized at a high rate using a high-speed, high-accuracy, medium-resolution data converter. These samples are processed digitally using FPGA and DSP technology to produce a high-accuracy, high-resolution axis measurement at a lower sample rate. The resulting axis measurement provides superior accuracy resulting from the minimization of analog signal processing stages and the errors (offset, gain errors, etc.) that they introduce.

Seroepidemiological investigations are essential for assessing the efficacy of measles vaccination programmes. However, when large-scale sampling is needed, a major difficulty is the problem of taking venous blood, especially in children. An alternative method is the collection of capillary blood samples spotted on filter papers. The eluted extract from these 'blood' spots can be used instead of serum samples for measles laboratory diagnosis or investigations. Measles antibody detection is readily carried out by ELISA on serum samples. The same technique can be used on eluates from capillary blood spots. Measles antibody titres determined on matched serum and blood spot samples from 27 children were compared. A strong correlation was found between the results obtained with the two methods of blood sampling.

In Italy, although vaccination has been recommended for a number of years, vaccination coverage for mumps is still sub-optimal. The objective of the present study was to evaluate the seroprevalence of mumps antibodies in the Italian population, stratified by age, gender and geographical area. The proportion of individuals positive for mumps antibodies remained stable in the age classes 0–11 months and 1 year (25.4% and 30.8%, respectively) and showed a continuous increase after the second year of life. The percentage of susceptible individuals was higher than 20% in persons 2–14 years of age and exceeded 10% in persons 15–39 years of age. No statistically significant differences were observed by gender or geographical area. Comparison between these results and the data obtained from a 1996 survey showed a statistically significant increase in seroprevalence in the age class 2–4 years. No changes were observed in the other age-groups. The results of this study confirm that the efforts made in recent years to improve vaccination coverage within the second year of life should be strengthened.