Studies of cycles for liquid-metal magnetohydrodynamic generation of power

Studies of liquid-metal magnetohydrodynamic power cycles indicate that the overall efficiency of a binary cycle, employing a liquid-metal topping cycle and a bottoming steam cycle, may reach 60 percent. Details of analyses and data on cycles are presented, and the commercial potential of the binary cycle is discussed

A legacy of learning at Whiskeytown Environmental School: Fieldnotes from an interview with Ellen Petrick

An interview with a leading NPS environmental educator

Using Pareto Fronts to Evaluate Polyp Detection Algorithms for CT Colonography

We evaluate and improve an existing curvature-based region growing algorithm for colonic polyp detection for our CT colonography (CTC) computer-aided detection (CAD) system by using Pareto fronts. The performance of a polyp detection algorithm involves two conflicting objectives, minimizing both false negative (FN) and false positive (FP) detection rates. This problem does not produce a single optimal solution but a set of solutions known as a Pareto front. Any solution in a Pareto front can only outperform other solutions in one of the two competing objectives. Using evolutionary algorithms to find the Pareto fronts for multi-objective optimization problems has been common practice for years. However, they are rarely investigated in any CTC CAD system because the computation cost is inherently expensive. To circumvent this problem, we have developed a parallel program implemented on a Linux cluster environment. A data set of 56 CTC colon surfaces with 87 proven positive detections of polyps sized 4 to 60 mm is used to evaluate an existing one-step, and derive a new two-step region growing algorithm. We use a popular algorithm, the Strength Pareto Evolutionary Algorithm (SPEA2), to find the Pareto fronts. The performance differences are evaluated using a statistical approach. The new algorithm outperforms the old one in 81.6% of the sampled Pareto fronts from 20 simulations. When operated at a suitable sensitivity level such as 90.8% (79/87) or 88.5% (77/87), the FP rate is decreased by 24.4% or 45.8% respectively

Hybrid Committee Classifier for a Computerized Colonic Polyp Detection System

We present a hybrid committee classifier for computer-aided detection (CAD) of colonic polyps in CT colonography (CTC). The classifier involved an ensemble of support vector machines (SVM) and neural networks (NN) for classification, a progressive search algorithm for selecting a set of features used by the SVMs and a floating search algorithm for selecting features used by the NNs. A total of 102 quantitative features were calculated for each polyp candidate found by a prototype CAD system. 3 features were selected for each of 7 SVM classifiers which were then combined to form a committee of SVMs classifier. Similarly, features (numbers varied from 10-20) were selected for 11 NN classifiers which were again combined to form a NN committee classifier. Finally, a hybrid committee classifier was defined by combining the outputs of both the SVM and NN committees. The method was tested on CTC scans (supine and prone views) of 29 patients, in terms of the partial area under a free response receiving operation characteristic (FROC) curve (AUC). Our results showed that the hybrid committee classifier performed the best for the prone scans and was comparable to other classifiers for the supine scans

Obesity, diabetes, serum glucose, and risk of primary liver cancer by birth cohort, race/ethnicity, and sex: Multiphasic health checkup study

Obesity and diabetes have been associated with liver cancer. However, recent US-based studies have suggested a lack of association between obesity and liver cancer among blacks and women

Effectiveness of Internal vs. External SEU Scrubbing Mitigation Strategies in a Xilinx FPGA: Design, Test, and Analysis

We compare two scrubbing mitigation schemes for Xilinx FPGA devices. The design of the scrubbers is briefly discussed along with an examination of mitigation limitations. Proton and Heavy Ion data are then presented and analyzed

STIRAP transport of Bose-Einstein condensate in triple-well trap

The irreversible transport of multi-component Bose-Einstein condensate (BEC) is investigated within the Stimulated Adiabatic Raman Passage (STIRAP) scheme. A general formalism for a single BEC in M-well trap is derived and analogy between multi-photon and tunneling processes is demonstrated. STIRAP transport of BEC in a cyclic triple-well trap is explored for various values of detuning and interaction between BEC atoms. It is shown that STIRAP provides a complete population transfer at zero detuning and interaction and persists at their modest values. The detuning is found not to be obligatory. The possibility of non-adiabatic transport with intuitive order of couplings is demonstrated. Evolution of the condensate phases and generation of dynamical and geometric phases are inspected. It is shown that STIRAP allows to generate the unconventional geometrical phase which is now of a keen interest in quantum computing.Comment: 9 pages, 6 figures. To be published in Laser Physics (v. 19, n.4, 2009

Body mass index and risk of head and neck cancer by race: the Carolina Head and Neck Cancer Epidemiology Study

Most studies, primarily conducted in populations of European ancestry, reported increased risk of head and neck cancer (HNC) associated with leanness (body mass index (BMI) 30 kg/m2, respectively), compared to normal weight (18.5-<25.0 kg/m2)

Risk factors for severe outcomes in Extended-Spectrum Beta-Lactamase (ESBL) Bacteremia: a single-center study

Expanded-spectrum beta-lactamase (ESBL) bacteremia often leads to severe outcomes like mortality and treatment failure. This study aimed to identify risk factors in patients with ESBL bacteremia. A retrospective cohort analysis was conducted among patients aged 13 years and above who were admitted to Hospital Canselor Tuanku Muhriz (HCTM) due to ESBL bacteremia between the period of January 2015 and August 2019. Patients with polymicrobial bacteremia were excluded. The all-cause in HCTM mortality rate was 30.2%, while the infection-related mortality rate was 22.5%. The risk factors of all-cause in-hospital mortality include hypertension, diabetes mellitus, skin and soft tissue infections (SSTIs), urinary catheterisation and mechanical ventilation. The independent risk factor associated with mortality was mechanical ventilation (AOR 3.12; CI 1.06- 9.18; p = 0.04). No association found between appropriate empirical antibiotic treatment with mortality (p = 0.74), treatment success (p = 0.71) or length of hospital stay (p = 0.84). However, appropriate definitive treatment was associated with a lower mortality rate (p<0.01) and higher treatment success (p<0.01). Mechanical ventilation was the only independent risk factor significantly associated with mortality, while appropriate definitive treatment was associated with a lower mortality rate and higher treatment success