9,351 research outputs found

    Long-term radiographic and clinical-functional outcomes of isolated, displaced, closed talar neck and body fractures treated by ORIF: the timing of surgical management

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    Background: The main purpose of this retrospective case series study was to evaluate long-term radiographic and clinical outcomes of a consecutive series of patients diagnosed with isolated, displaced, closed talar neck or body fractures treated by open reduction and internal fixation (ORIF). Secondly, the aim was to verify the influence of the location of talar fractures on the outcomes, the prognostic value of the Hawkins sign, whether operative delays promote avascular necrosis (AVN) and if the fractures require emergent surgical management. Methods: From January 2007 to December 2012, at our institution, 31 patients underwent ORIF through the use of screws. On the basis of Inokuchi criteria, the injuries were divided between neck and body fractures, which were classified according to Hawkins and Sneppen, respectively. The patients included were divided into two groups in relation to fracture location and complexity. Radiographic assessment focused on reduction quality, bone healing, the Hawkins sign and post-traumatic arthritis (PTA) development. For the clinical evaluation, clinical-functional scores (AOFAS Ankle-Hindfoot Score; MFS; FFI-17; SF-36) and VAS were determined, and statistical analysis was performed. Results: 27 patients, 19 males and 8 females, mean age 38.3 years, were included with an average follow-up period of 83.2 months (range 49\u2013119). There were 9 neck and 19 body fractures; their reduction was anatomical or nearly anatomical in 22 cases, and all reached radiographic consolidation after a mean period of 3.4 months (range 1.7\u20137). The Hawkins sign was observed in 9 cases, in which necrosis did not develop. With a 0\u201311 day surgical timing interval, more than 60% of the patients obtained good or fair results with different scores, while 18 (66.7%) were completely satisfied (VAS: 9\u201310). The early complications included malunions (21.4%) and wound problems (25%); the late complications involved AVN (25%) and PTA (78.6%). Conclusions: Despite a high rate of long-term complications, satisfactory clinical results were achieved. Talar fracture location did not influence the outcomes, the Hawkins sign was confirmed as a positive prognostic factor, and operation timing did not influence AVN development. Hence, these injuries do not require emergent surgical management by ORIF

    Restart-Based Fault-Tolerance: System Design and Schedulability Analysis

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    Embedded systems in safety-critical environments are continuously required to deliver more performance and functionality, while expected to provide verified safety guarantees. Nonetheless, platform-wide software verification (required for safety) is often expensive. Therefore, design methods that enable utilization of components such as real-time operating systems (RTOS), without requiring their correctness to guarantee safety, is necessary. In this paper, we propose a design approach to deploy safe-by-design embedded systems. To attain this goal, we rely on a small core of verified software to handle faults in applications and RTOS and recover from them while ensuring that timing constraints of safety-critical tasks are always satisfied. Faults are detected by monitoring the application timing and fault-recovery is achieved via full platform restart and software reload, enabled by the short restart time of embedded systems. Schedulability analysis is used to ensure that the timing constraints of critical plant control tasks are always satisfied in spite of faults and consequent restarts. We derive schedulability results for four restart-tolerant task models. We use a simulator to evaluate and compare the performance of the considered scheduling models

    Previous reproductive history and post-natal family planning among HIV-infected women in Ukraine

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    BACKGROUND: Ukraine has the highest antenatal HIV prevalence in Europe. The national prevention of mother-to-child transmission (MTCT) programme has reduced the MTCT rate, but less attention has been given to the prevention of unintended pregnancy among HIV-positive women. Our objectives were to describe the reproductive health, condom use and family planning (FP) practices of HIV-positive childbearing Ukrainian women and to identify factors associated with different methods of post-natal contraception. METHODS: HIV-infected childbearing women, diagnosed before or during pregnancy, were enrolled prospectively in a post-natal cohort study in four regional HIV/AIDS centres in Ukraine from December 2007. Logistic regression models were used to identify factors associated with post-natal FP practices. RESULTS: Data were available for 371 women enrolled by March 2009; 82% (n = 303) were married or cohabiting, 27% (97 of 363) reported a current HIV-negative sexual partner and 69% were diagnosed with HIV during their most recent pregnancy. Overall, 21% (75 of 349) of women were not using contraception post-natally (of whom 80% reported no current sexual activity), 50% (174 of 349) used condoms, 20% (74 of 349) relied solely/partially on coitus interruptus and 4% used hormonal methods or intrauterine device. Among married/cohabiting women, consistent use of condoms in the previous pregnancy [AOR 1.96 (95%CI 1.06–3.62)], having an HIV-positive partner [AOR 0.42 (0.20–0.87)], current sexual activity [AOR 4.53 (1.19–17.3)] and study site were significantly associated with post-natal condom use; 16% of those with HIV-negative partners did not use condoms. Risk factors for non-use of FP were lack of affordability [AOR 6.34 (1.73–23.2)] and inconsistent use of condoms in the previous pregnancy [AOR 7.25 (1.41–37.2)]. CONCLUSIONS: More than 40% of HIV-positive women in this population are at risk of unintended pregnancy and the one in six women in HIV-discordant couples not using barrier methods risk transmitting HIV to their partners. Our study results are limited by the observational nature of the data and the potential for both measured and unmeasured confounding

    AES-EPO study program, volume I Final study report

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    Conceptual study of possible solutions to long- term and time-critical reliability problems affecting Apollo command module guidance and control compute

    Systemic: A Testbed for Characterizing the Detection of Extrasolar Planets. II. Numerical approaches to the Transit Timing Inverse Problem

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    Transit timing variations - deviations from strict periodicity between successive passages of a transiting planet - can be used to probe the structure and dynamics of multiple-planet systems. In this paper, we examine prospects for numerically solving the so-called inverse problem, the determination of the orbital elements of a perturbing body from the transit timing variations it induces. We assume that the planetary systems under examination have a limited number of Doppler velocity measurements, and show that a more extensive radial velocity characterization with precision comparable to the semiamplitude of the perturber may remove degeneracies in the solution. We examine several configurations of interest, including (1) a prototypical non-resonant system, modeled after HD40307 b and c, which contains multiple super-Earth mass planets, (2) a hypothetical system containing a transiting giant planet with a terrestrial-mass companion trapped in low-order mean motion resonance, and (3) the HAT-P-13 system, in which forced precession by an outer perturbing body that is well characterized by Doppler radial velocity measurements can give insight into the interior structure of a perturbing planet, and for which the determination of mutual inclination between the transiting planet and its perturber is a key issue.Comment: 9 pages, 8 figures. Accepted for publication in Ap

    Two-dimensional batch linear programming on the GPU

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    This paper presents a novel, high-performance, graphical processing unit-based algorithm for efficiently solving two-dimensional linear programs in batches. The domain of two-dimensional linear programs is particularly useful due to the prevalence of relevant geometric problems. Batch linear programming refers to solving numerous different linear programs within one operation. By solving many linear programs simultaneously and distributing workload evenly across threads, graphical processing unit utilization can be maximized. Speedups of over 22 times and 63 times are obtained against state-of-the-art graphics processing unit and CPU linear program solvers, respectively

    Computation of cross-talk alignment by mixed integer linear programming

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    Noise analysis has been an important and difficult part of design flow of very large-scale integrated (VLSI) systems in many years. In this thesis, the problem of signal alignment resulting in possible maximum peak interconnect coupling noise and propose a variation aware technique for computing combined noise pulse taking into account timing constraints on signal transitions has been discussed. This work shows that the worst noise alignment algorithm can be formulated as mixed integer programming (MLIP) problem both in deterministic window cases and variational window cases. For deterministic window cases, it is assumed that timing windows are given for each aggressor inputs and the victim net is quite. It compares the results from proposed method with the most known and widely used method for computing the worst aggressor alignment - sweeping line algorithm, to verify its correctness and efficiency. For variation window cases, as variations of process and environmental parameters result in variation of start and end points of timing windows, linear approximation is used for approximating effect of process and environmental variations. One of the biggest advantages of MILP formulation of aggressor alignment problem has also been discussed, which is the ability to be easily extended to more complex cases such as non-triangle noise pulses, victim sensitivity window and discontinuous timing windows, this work shows that such extension can be solved by algorithm and does not require development of new algorithms. Therefore, this novel technique can handle noise alignment problem both in deterministic and variational cases and can be easily extended for more complex cases --Abstract, page iii
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