Brain tissue segmentation based on MP2RAGE multi-contrast images in 7 T MRI.

We proposed a method for segmentation of brain tissues-gray matter, white matter, and cerebrospinal fluid-using multi-contrast images, including a T1 map and a uniform T1-weighted image, from a magnetization-prepared 2 rapid acquisition gradient echoes (MP2RAGE) sequence at 7 Tesla. The proposed method was evaluated with respect to the processing time and the similarity of the segmented masks of brain tissues with those obtained using FSL, FreeSurfer, and SPM12. The processing time of the proposed method (28 ± 0 s) was significantly shorter than those of FSL and SPM12 (444 ± 4 s and 159 ± 2 s for FSL and SPM12, respectively). In the similarity assessment, the tissue mask of the brain obtained by the proposed method showed higher consistency with those obtained using FSL than with those obtained using SPM12. The proposed method misclassified the subcortical structures and large vessels since it is based on the intensities of multi-contrast images obtained using MP2RAGE, which uses a similar segmentation approach as FSL but is not based on a template image or a parcellated brain atlas, which are used for FreeSurfer and SPM12, respectively. However, the proposed method showed good segmentation in the cerebellum and white matter in the medial part of the brain in comparison with the other methods. Thus, because the proposed method using different contrast images of MP2RAGE sequence showed the shortest processing time and similar segmentation ability as the other methods, it may be useful for both neuroimaging research and clinical diagnosis

Development of simulation-based testing environment for safety-critical software

Recently, a software program has been used in nuclear power plants (NPPs) to digitalize many instrumentation and control systems. To guarantee NPP safety, the reliability of the software used in safety-critical instrumentation and control systems must be quantified and verified with proper test cases and test environment. In this study, a software testing method using a simulation-based software test bed is proposed. The test bed is developed by emulating the microprocessor architecture of the programmable logic controller used in NPP safety-critical applications and capturing its behavior at each machine instruction. The effectiveness of the proposed method is demonstrated via a case study. To represent the possible states of software input and the internal variables that contribute to generating a dedicated safety signal, the software test cases are developed in consideration of the digital characteristics of the target system and the plant dynamics. The method provides a practical way to conduct exhaustive software testing, which can prove the software to be error free and minimize the uncertainty in software reliability quantification. Compared with existing testing methods, it can effectively reduce the software testing effort by emulating the programmable logic controller behavior at the machine level

Analysis of Rating Appropriateness and Patient Outcomes in Cataract Surgery

Purpose: Using the RAND/UCLA methodology to create the appropriateness criteria, we assessed that the appropriate ratings in cataract surgery can be a better prognosis of outcomes in postoperative 12 months than uncertain or inappropriate ratings. In addition, we indentified the degree of the appropriate rating surgery associated with the outcome changes in postoperative 12 months. Materials and Methods: The patients in this study were followed up prospectively in preoperative and postoperative 12 months periods. The 20 ophthalmologists in 14 hospitals were asked to refer about 20 patients who were scheduled to undergo cataract surgery from March and June of 1997. A multiple regression analysis was used to identify the degree of the appropriate surgery associated with the changes of outcomes. The outcomes were designed as the clinical and functional outcomes (visual acuity, visual function, satisfaction with vision, and satisfaction with overall care). Results: The outcome changes of vision acuity (p < 0.001), vision function-14 (p < 0.001), and symptom score (p < 0.006) were significantly different between four appropriateness ratings (crucial, appropriate, uncertain, and inappropriate). There was a trend that the appropriate rating surgeries were related to the successful change of the vision function (2.29, p = 0.015) and satisfaction with vision (3.84, p = 0.014) in 12 month postoperative period. Conclusion: The crucial or appropriate rating surgeries may indicate better outcomes than uncertain or inappropriate rating surgeries do. The appropriate rating surgeries were more closely related to functional outcome vision function, VF-14 and subjective outcom

Influence of dietary conjugated linoleic acid (CLA) on lipid and fatty acid composition in liver and flesh of Atlantic salmon (Salmo salar)

The aim of the present study was to determine the effects of conjugated linoleic acid (CLA) on lipid and fatty acid metabolism in Atlantic salmon. The overall objective being to test the hypotheses that CLA has beneficial effects in salmon including growth enhancement, improved flesh quality through decreased adiposity and lipid deposition thereby minimising detrimental effects of feeding high fat diets, and increased nutritional quality through increased levels of beneficial fatty acids including n-3 highly unsaturated fatty acids (HUFA) and CLA itself. Salmon smolts were fed diets containing two levels of fish oil (low, ~18% and high, ~34%) containing three levels of CLA (a 1:1 mixture of 9-cis,trans-11 and trans-10,cis-12. at 0, 1 and 2% of diet) for 3 months and the effects on growth performance, liver and muscle (flesh) lipid contents and class compositions, and fatty acid compositions determined. The diets were also specifically formulated to investigate whether the effects of CLA, if any, were more dependent upon absolute content of CLA in the diet (as percentage of total diet) or the relative level of CLA to other fatty acids. Dietary CLA in salmon smolts had no effect on growth parameters or biometric parameters. However, there was a clear trend of increased total lipid and triacylglycerol contents in both liver and flesh in fish fed CLA, particularly in fish fed the high oil diets. Finally, CLA was incorporated into tissue lipids, with levels in flesh being 2-fold higher than in liver, but importantly, incorporation in liver was at the expense of saturated and monounsaturated fatty acids whereas in flesh it was at the expense of n-3HUFA

Theoretical description of phase coexistence in model C60

We have investigated the phase diagram of the Girifalco model of C60 fullerene in the framework provided by the MHNC and the SCOZA liquid state theories, and by a Perturbation Theory (PT), for the free energy of the solid phase. We present an extended assessment of such theories as set against a recent Monte Carlo study of the same model [D. Costa et al, J. Chem. Phys. 118:304 (2003)]. We have compared the theoretical predictions with the corresponding simulation results for several thermodynamic properties. Then we have determined the phase diagram of the model, by using either the SCOZA, or the MHNC, or the PT predictions for one of the coexisting phases, and the simulation data for the other phase, in order to separately ascertain the accuracy of each theory. It turns out that the overall appearance of the phase portrait is reproduced fairly well by all theories, with remarkable accuracy as for the melting line and the solid-vapor equilibrium. The MHNC and SCOZA results for the liquid-vapor coexistence, as well as for the corresponding critical points, are quite accurate. All results are discussed in terms of the basic assumptions underlying each theory. We have selected the MHNC for the fluid and the first-order PT for the solid phase, as the most accurate tools to investigate the phase behavior of the model in terms of purely theoretical approaches. The overall results appear as a robust benchmark for further theoretical investigations on higher order C(n>60) fullerenes, as well as on other fullerene-related materials, whose description can be based on a modelization similar to that adopted in this work.Comment: RevTeX4, 15 pages, 7 figures; submitted to Phys. Rev.

Results of Colorectal Cancer Screening of the National Cancer Screening Program in Korea, 2008

PURPOSE: This study aims to investigate the current situation of national colorectal cancer screening by analyzing participation rates, positive rates of screening methods and screening rate of secondary screening tests in colorectal screening of the national cancer screening program in 2008.0aMATERIALS AND METHODS: With database about target population and screened individuals of the national cancer screening program, the results of target population and participants of colorectal cancer screening in 2008 were analyzed. Among adults aged over 50 years of medical aid and beneficiaries of national health insurance paying lower 50% premiums in the total subscribers, 4,640,365 were target population of colorectal cancer screening and the data of 984,915 undergoing fecal occult blood test (FOBT) as a primary screening were analyzed.0aRESULTS: The colorectal cancer screening rate was 21.2% and the rates of national health insurance subscribers, females and the elderly aged 60-64 years were higher than those of others. The recipients with a positive result in FOBT recorded approximately 7.5%. Medical aid beneficiaries (7.9%), males (8.8%) and seniors aged over 75 years (9.1%) showed higher positive rates than the average one. Out of the FOBT positive recipients, 43.0% took a secondary screening and the rate undergoing colonoscopy (31.4%) was higher than that of doing double-contrast barium enema test (11.6%).0aCONCLUSION: Colorectal cancer screening rate of medical aid beneficiaries and people paying lower 50% premiums among national health insurance subscribers, was different according to demographic characters (gender, age and types of health insurance). This finding meant that screening for the vulnerable needed to be encouraged by considering socio-demographic characters. Additionally, more efforts were necessary to increase the secondary screening rate of people with a positive result in primary one.ope

Accidental benzene release risk assessment in an urban area using an atmospheric dispersion model

This study applied the American Meteorological Society and Environmental Protection Agency Regulatory Model (AERMOD) to assess the risk caused by an accidental release and dispersion of the toxic chemical benzene in the vicinity of a highly populated urban area. The modeling domain encompasses the Korean megacity of Ulsan, which includes two national industrial complexes and is characterized by a complex coastal terrain. Multiple AERMOD simulations were conducted for an assumed emission scenario using background wind data from August between 2009 and 2013. The series of experiments produced the spatial accident probability patterns for different concentration levels during daytime and nighttime scenarios based on the corresponding dominant wind patterns. This study further quantifies the potential accident risk based on the number of affected individuals by combining the accident probability with the indoor and outdoor population estimates. The chemical gas dispersion characteristics depend on various local meteorological conditions, such as the land-sea breeze direction, which alternates between daytime and nighttime, and the atmospheric stability. The results reveal that benzene dispersion affects a much larger area during the nighttime owing to the presence of a nocturnal stable boundary layer with significant temperature stratification. The affected area is smaller during the daytime owing to decreased stability and enhanced vertical mixing in the boundary layer. The results include a high degree of uncertainty during the nighttime owing to weak wind speeds and the lack of a prevailing wind direction, which impact the vulnerable area. However, vulnerable areas are more effectively identified during the daytime, when more consistent meteorological conditions exist. However, the potential risk becomes much lower during the nighttime owing to a substantial reduction of the outdoor population.ope