Use of quantitative ultrasound scans of the calcaneus to diagnose osteoporosis in patients with rheumatoid arthritis

Background: Patients with rheumatoid arthritis are recognized as being at risk for osteoporosis as a result of the disease process as well as the medication used to treat it. This study was conducted to consider the use of calcaneal scanning with quantitative ultrasound—contact ultrasound bone analysis (CUBA)—to diagnose osteoporosis in patients with rheumatoid arthritis.Methods: Forty-six patients (11 men and 35 women) with established rheumatoid arthritis underwent dual-energy x-ray absorptiometry (DEXA) of the nondominant wrist andCUBA of the nondominant heel. Sensitivity, specificity, and positive and negative predictive values were used to determine the correlation between osteoporosis as diagnosedby the CUBA heel scan compared with the DEXA wrist scan given that DEXA is widely seen as the gold standard for the diagnosis of osteoporosis.Results: The CUBA heel scan revealed a sensitivity of 90% and a specificity of 44% for a diagnosis of osteoporosis compared with DEXA. The positive predictive value of theCUBA scan was 31%, and the negative predictive value was 94%. Therefore, if normal bone density is found using CUBA, there is 94% certainty this is correct. However, if osteoporosis is diagnosed using CUBA, there is only 31% certainty this is correct. In such instances a secondary scan using a different method (eg, DEXA) would be required. Future work should consider the effect of minor alterations to the equipment or scanning protocol, because this may improve diagnosis.Conclusions: The CUBA unit could be used as a primary screening device. Given the cost and accessibility issues associated with DEXA, quantitative ultrasound may have arole in screening for osteoporosis in the primary-care setting to determine the most appropriate routes of referral for patients requiring further investigations. <br/

Development of reliability methodology for systems engineering. Volume III - Theoretical investigations - An approach to a class of reliability problems Final report

Random quantities from continuous time stochastic process with application to reliability and probabilit

On certain functionals of normal processes Technical report no. 1

Probabilistic modeling and stochastic process investigations to provide measures of quality of performance and reliability for systems engineering - Chebyshev approximatio

Enhancing caBIG™ workflow for multi-tier distribution

posterIntroduction caBIG™ Integration caBIG™ provides a GRID based application environment with data abstraction and vocabulary services, workflow management and a security framework. Sensor Abstraction Interface It is proposed to provide a sensor abstraction interface, using caDSR, enabling caBIG™ workflow aware applications to obtain local and global access to sensor data. Applications from any caGRID accessible node will be able to utilize the collected data. Example Application We have chosen a disaster scenario using radiation level sensors to illustrate how sensors mounted in static facilities and first responder vehicles can be relayed via an adhoc wireless network to various hospital or government facilities. Data can be analyzed locally, for local planning and health care provisioning purposes, or accessed via the GRID by a hierarchy of city, county, state, and federal agencies. Application Hierarchy Proposed architecture is designed to use existing low cost infrastructure as a highly resilient mechanism for relaying sensor data. The network will piggy-back on the first responder networking systems and the applications layer will utilize caBIG™ services

ca! - emergency and disaster recovery system extensions to caBIG™

posterDuring Hurricane Katrina, US Federal and State Agencies had disparate data acquisition systems, separate data networks and unique incompatible applications. •System incompatibilities exist even between various Federal agencies. •Consistent data available to one agency should be available to another. Data must be portable and with a common vocabulary. •Katrina illustrated the need for a common data system to underpin applications at the first responder, local medical facility and state health care department level, plus federal safety and law enforcement

Cauchy Biorthogonal Polynomials

The paper investigates the properties of certain biorthogonal polynomials appearing in a specific simultaneous Hermite-Pade' approximation scheme. Associated to any totally positive kernel and a pair of positive measures on the positive axis we define biorthogonal polynomials and prove that their zeroes are simple and positive. We then specialize the kernel to the Cauchy kernel 1/{x+y} and show that the ensuing biorthogonal polynomials solve a four-term recurrence relation, have relevant Christoffel-Darboux generalized formulae, and their zeroes are interlaced. In addition, these polynomial solve a combination of Hermite-Pade' approximation problems to a Nikishin system of order 2. The motivation arises from two distant areas; on one side, in the study of the inverse spectral problem for the peakon solution of the Degasperis-Procesi equation; on the other side, from a random matrix model involving two positive definite random Hermitian matrices. Finally, we show how to characterize these polynomials in term of a Riemann-Hilbert problem.Comment: 38 pages, partially replaces arXiv:0711.408

Comparative Analyses of Two Methods of Backstroke Starting: Conventional and Whip

Generally, when a new skill, technique, or style is introduced into a sport, the first attempt to describe the change is by the coach or athlete. The biomechanist will then make a careful review of the mechanics involved, test the principles against the given theory, propose directions for future improvements, or reject the change. This procedure often occurs in the sport of swimming. During the last decade, techniques of competitive swimming have improved, resulting in several record-producing performances by the swimmers. This improvement may be attributed, in part, to coaches, researchers, and authors like Counsilman (1977) and Maglischo (1982), Hay (1985), Kreighbaum and Barthels (1985), among others. Backstroke swimming techniques have benefited from the investiveness of coaches, swimmers, and researchers. Probably much of the credit for initiating change in technique belongs to the backstrokers of the time. Two examples are Olympic champions John Naber in 1976 with his «headabove-water spin» turn and Rick Carey in 1984 with his «whip» start. These methods of turning and starting have been adopted by many coaches and swimmers. Even though the Naber turn and the Carey whip start have gained in popularity, little research has been conducted regarding the mechanics of such techniques. For instance, one of the few studies conducted was on the backstroke turns. Benson (1979) filmed two subjects: John Naber executing his unique turn and Peter Rocca (second to Naber in the 1976 Olympics) doing his standard backstroke turn. An elementary comparative eine analysis was made. Benson determined that the Naber turn was more efficient than the standard backstroke turn. Since scientific information about the backstroke whip start is limited. this study was conducted to fill that void and to serve as a basic for further research