Model reduction method for a class of 2-D systems, A

Includes bibliographical references.A decomposition-aggregation scheme for reduction of dimensionality for a class of 2-D systems is introduced. This method, which is based upon the extension of the singular perturbation method in two dimensions, is used to decompose the original 2-D system into two reduced-order 2-D subsystems. These reduced order subsystems are shown to effectively capture the dynamical behavior of the original full-order system. Two numerical examples are provided that indicate the effectiveness of this method when used in image modeling applications.This work was supported in part by the Natural Sciences and Engineering Research Council of Canada, and by Fonds Pour la Formation de Chercheurs et L'aide la Recherche, Programme E'tablissment de Nouveaux Chercheurs

Reduced order strip Kalman filtering using singular perturbation method

Includes bibliographical references.Strip Kalman filtering for restoration of images degraded by linear shift invariant (LSI) blur and additive white Gaussian (WG) noise is considered. The image process is modeled by a 1-D vector autoregressive (AR) model in each strip. It is shown that the composite dynamic model that is obtained by combining the image model and the blur model takes the form of a singularly perturbed system owing to the strong-weak correlation effects within a window. The time scale property of the singularly perturbed system is then utilized to decompose the original system into reduced order subsystems which closely capture the behavior of the full order system. For these subsystems the relevant Kalman filtering equations are given which provide the suboptimal filtered estimates of the image and the one-step prediction estimates of the blur needed for the next stage. Simulation results are also provided

Assessing 2 D-dimer age-adjustment strategies to optimize computed tomographic use in ED evaluation of pulmonary embolism

STUDY OBJECTIVE: Validate the sensitivity and specificity of 2 age adjustment strategies for d-dimer values in identifying patients at risk for pulmonary embolism (PE) compared with traditional D-dimer cutoff value (500 ng/mL) to decrease inappropriate computed tomography pulmonary angiography (CTPA) use. METHODS: This institutional review board-approved, Health Insurance Portability and Accountability Act-compliant retrospective study included all adult emergency department patients evaluated for PE over a 32-month period (1/1/11-8/30/13). Only patients undergoing CTPA and D-dimer testing were included. We used a validated natural language processing algorithm to parse CTPA radiology reports and determine the presence of acute PE. Outcome measures were sensitivity and specificity of 2 age-adjusted D-dimer cutoffs compared with the traditional cutoff. We used chi2 tests with proportional analyses to assess differences in traditional and age-adjusted (agex10 ng/mL) D-dimer cutoffs, adjusting both by decade and by year. RESULTS: A total 3063 patients with suspected PE were evaluated by CTPA during the study period, and 1055 (34%) also received d-dimer testing. The specificity of age-adjusted D-dimer values was similar or higher for each age group studied compared with traditional cutoff, without significantly compromising sensitivity. Overall, had decade age-adjusted cutoffs been used, 37 CTPAs could have been avoided (19.6% of 189 patients aged \u3e60 years with Wells score50 years with Wells scor

Comparison between in vitro and in vivo antibacterial activity of Curcuma zedoaria from Malaysia

The antimicrobial activity of the extracts of Curcuma zedoaria from Malaysia was compared using in vitro and in vivo systems. The comparison was performed against four bacterial strains including two gram negative strains (Escherichia coli and Pseudomonas aeruginosa) and two gram positive strains (Bacillus cereus and Staphylococcus aureus) using the agar well diffusion method. Petroleum ether, chloroform and methanol were used as solvents for preparing the plant extracts. Growth hormones namely indole-3-butyric acid (IBA) and 6-Benzylaminopurine (BAP) were used in the in vitro system separately between the range of 0.25 and 3.5 mg/l for IBA and 0.5 and 4 mg/l for BAP and a mix formula containing both hormones using the best ranges after rapid tests. The results showed that the in vitro system was more capable of inhibiting S. aureus growth compared with in vivo system on the agar plate. P. aeruginosa and E. coli growth were only inhibited by the in vitro system on the agar plate, while B. cereus was the only strain in the in vivo system which produced higher inhibition zone on the agar plate against its growth compared with the in vitro system.Key words: Curcuma zedoaria, antibacterial activity

The use of decision support to measure documented adherence to a national imaging quality measure

RATIONALE AND OBJECTIVES: Present methods for measuring adherence to national imaging quality measures often require a resource-intensive chart review. Computerized decision support systems may allow for automated capture of these data. We sought to determine the feasibility of measuring adherence to a national quality measure (NQM) regarding computed tomography pulmonary angiograms (CTPAs) for pulmonary embolism using measure-targeted clinical decision support and whether the associated increased burden of data captured required by this system would affect the use and yield of CTs. MATERIALS AND METHODS: This institutional review board-approved prospective cohort study enrolled patients from September 1, 2009, through November 30, 2011, in the emergency department (ED) of a 776-bed quaternary-care adults-only academic medical center. Our intervention consisted of an NQM-targeted clinical decision support tool for CTPAs, which required mandatory input of the Wells criteria and serum D-dimer level. The primary outcome was the documented adherence to the quality measure prior and subsequent to the intervention, and the secondary outcomes were the use and yield of CTPAs. RESULTS: A total of 1209 patients with suspected PE (2.0% of 58,795 ED visits) were imaged by CTPA during the 12-month control period, and 1212 patients were imaged in the 12 months after the quarter during which the intervention was implemented (2.0% of 59,478 ED visits, P = .84). Documented baseline adherence to the NQM was 56.9% based on a structured review of the provider notes. After implementation, documented adherence increased to 75.6% (P \u3c .01). CTPA yield remained unchanged and was 10.4% during the control period and 10.1% after the intervention (P = .88). CONCLUSIONS: Implementation of a clinical decision support tool significantly improved documented adherence to an NQM, enabling automated measurement of provider adherence to evidence without the need for resource-intensive chart review. It did not adversely affect the use or yield of CTPAs

Mainstreaming road safety in the regional integration of the East African Community to reduce road traffic injuries

The East African Community (EAC) comprising of five states: Burundi, Kenya, Rwanda, Tanzania and Uganda bear a disproportionate burden of the global public health burden for road traffic injuries (RTIs). In response to this, each state has devised its own road safety measures, but not at the EAC level. This paper aims to explore how differing road safety policies could be aligned as part of EAC regional integration so that they become one mainstream policy in the EAC. This is done after exploring the rate of RTIs; the existing road safety initiatives; and the impact of RTIs on the EAC integration in the four EAC states excluding Burundi. A desk-based review of data and information from different sources between 2009 and 2015 for Kenya, Rwanda, Tanzania and Uganda was conducted. This revealed that the rate of RTIs in the four EAC states significantly exceeds the African and global average rates. This is associated with large numbers of fatalities, debilitating injuries and economic costs which hamper the EAC integration–especially its main pillar of a common market. All the four states have independently adopted different road safety laws and policies in line with the United Nations Decade of Action for Road Safety initiative. A unified road safety policy and road safety lead agency for the EAC as a whole is urgently needed. This should be based on cooperation and commitment, and take into account the region’sgeopolitical dynamics.Keywords: Road safety, road traffic injuries, regional integration, East African Communit