Short-term changes in amino acid pool of neurospora mycelium

Short-term changes in amino acid poo

Continuous and Segmented Flow Microfluidics: Applications in High-throughput Chemistry and Biology

This account highlights some of our recent activities focused on developing microfluidic technologies for application in high-throughput and high-information content chemical and biological analysis. Specifically, we discuss the use of continuous and segmented flow microfluidics for artificial membrane formation, the analysis of single cells and organisms, nanomaterial synthesis and DNA amplification via the polymerase chain reaction. In addition, we report on recent developments in small-volume detection technology that allow access to the vast amounts of chemical and biological information afforded by microfluidic systems

MRI radiomic features are independently associated with overall survival in soft tissue sarcoma

Purpose: Soft tissue sarcomas (STS) represent a heterogeneous group of diseases, and selection of individualized treatments remains a challenge. The goal of this study was to determine whether radiomic features extracted from magnetic resonance (MR) images are independently associated with overall survival (OS) in STS. Methods and Materials: This study analyzed 2 independent cohorts of adult patients with stage II-III STS treated at center 1 (N = 165) and center 2 (N = 61). Thirty radiomic features were extracted from pretreatment T1-weighted contrast-enhanced MR images. Prognostic models for OS were derived on the center 1 cohort and validated on the center 2 cohort. Clinical-only (C), radiomics-only (R), and clinical and radiomics (C+R) penalized Cox models were constructed. Model performance was assessed using Harrell\u27s concordance index. Results: In the R model, tumor volume (hazard ratio [HR], 1.5) and 4 texture features (HR, 1.1-1.5) were selected. In the C+R model, both age (HR, 1.4) and grade (HR, 1.7) were selected along with 5 radiomic features. The adjusted c-indices of the 3 models ranged from 0.68 (C) to 0.74 (C+R) in the derivation cohort and 0.68 (R) to 0.78 (C+R) in the validation cohort. The radiomic features were independently associated with OS in the validation cohort after accounting for age and grade (HR, 2.4; Conclusions: This study found that radiomic features extracted from MR images are independently associated with OS when accounting for age and tumor grade. The overall predictive performance of 3-year OS using a model based on clinical and radiomic features was replicated in an independent cohort. Optimal models using clinical and radiomic features could improve personalized selection of therapy in patients with STS

Controlling chaotic transport in a Hamiltonian model of interest to magnetized plasmas

We present a technique to control chaos in Hamiltonian systems which are close to integrable. By adding a small and simple control term to the perturbation, the system becomes more regular than the original one. We apply this technique to a model that reproduces turbulent ExB drift and show numerically that the control is able to drastically reduce chaotic transport

Application of semantic control to a class of pursuer-evader problems

AbstractIn this article, we describe our work in developing a comprehensive software system for tactical decision aiding for an evader faced with multiple pursuers. The objective is to provide the evader with defensive maneuver decisions that maximize its chances of survival.We have developed a hierarchical semantic controller consisting of a System Identifier, a Goal Selector and an Adapter. This system is implemented on a 386DX personal computer via object-oriented programming, knowledge-based systems, Analytical Hierarchy Process, optimal control, and differential game methodologies.The viability of our Semantic Control approach to the evasive action selection problem has been shown and its operation has been tested against pursuers which follow either pure pursuit or proportional guidance strategies. The user is included in the decision process via approval of setpoints. Displays of the engagement and effect of coverage by countermeasures provide a visual reinforcement of the recommendation made. Use of semantic controllers as TDA support systems for man-in-the-loop, pursuer-evader problems on a PC with current software and hardware technology is feasible. The ability to deploy the system on a portable PC permits the use of the technology in a wide variety of applications

Optimization of a mega-ampere spherical tokamak for beta-limit and confinement studies

Recent favorable results on the START experiment have caused renewed interest in the potential of low aspect ratio tokamaks. To aid in designing a next-step spherical tokamak to study confinement scaling, high beta, and high normalized beta plasmas for minimal cost, the authors have developed a transport scaling and device optimization code. This code STOP, benchmarked against START, includes 10 empirical confinement scaling laws and essential tokamak physics such as stability limits. Parameters are optimized separately for each scaling law and physical goal. Using STOP the authors find for R/a = 1.2 to 2.0 one can achieve {beta}{sub N} = 5, ({beta}) = 31--44%, and easily study predicted confinement degradation with auxiliary heating with just two neutral beams (P{sub NB} < 3.5 MW) for I{sub p} {ge} 0.75 MA, and R{sub 0} {ge} 0.6 m. In contrast, if one insists on using the nominal device parameters, i.e. I{sub p} = 1 MA and R{sub 0} = 0.8 m, with each scaling law, achieving {beta}{sub N} = 5 requires typically P{sub NB} {approx} 7.5 MW. They also conclude that while running D{sup 0} {yields} D{sup +} increases {tau}{sub E} {approx} 25%, with {tau}{sub E} already uncertain by 2--3{times}, one incurs restricted machine access and compromised physics operation

Characterization of heterogeneous vancomycin-intermediate resistance, MIC and accessory gene regulator (agr) dysfunction among clinical bloodstream isolates of staphyloccocus aureus

<p>Abstract</p> <p>Background</p> <p>The development of hVISA has been associated with vancomycin clinical failures and is commonly misidentified in clinical microbiology laboratories. Therefore, the objectives of this present study was to improve the reliability of methodologies and criteria for identifying hVISA, evaluate the prevalence of hVISA among clinical bloodstream isolates of <it>S. aureus </it>and determine if there exists a relationship between accessory gene regulator (<it>agr) </it>dysfunction and the hVISA phenotype.</p> <p>Methods</p> <p>The presence of hVISA in 220 clinical <it>S. aureus </it>isolates (121 MSSA, 99 MRSA) from bloodstream infections was examined by CLSI broth microdilution, Macro & Standard Etest. Isolates which were classified as hVISA by Macro Etest, were additionally evaluated using a modified PAP-AUC method using a modified starting inoculum of 10¹⁰CFU/mL, and growth on brain heart infusion agar with 4 mg/L vancomycin (BHIV4) at 10⁸and 10¹⁰CFU/mL, and <it>agr </it>function was assessed by delta-hemolysin production.</p> <p>Results</p> <p>Broth microdilution MIC_50/90of <it>S.aureus </it>and hVISA was 1.0/2.0 and 1.5/2.0 mg/L (<it>p</it>= 0.02), respectively. Macro Etest identified 12 (5.5%) hVISA isolates; higher among MRSA (9.1%) versus MSSA (2.5%) (<it>p </it>= 0.03). The mean modified PAP-AUC ratios (> 0.8) of 7 MRSA strains and 3 MSSA strains were significantly different (<it>p </it>= 0.001). 58% of hVISA strains were found to be <it>agr </it>dysfunctional when 21% of MRSA strains were <it>agr </it>dysfunctional. hVISA was detected among <it>S. aureus </it>bloodstream isolates, which were classified as susceptible among clinical microbiology laboratories.</p> <p>Conclusions</p> <p>Evaluating the correlation between Etest MICs and modified PAP-AUC ratio values will add further improvement of discriminating hVISA, and <it>agr </it>dysfunction may be predictive of strains which display a greater predilection to display the hVISA phenotype.</p

Compact tokamak reactors. Part 1 (analytic results)

We discuss the possible use of tokamaks for thermonuclear power plants, in particular tokamaks with low aspect ratio and copper toroidal field coils. Three approaches are presented. First we review and summarize the existing literature. Second, using simple analytic estimates, the size of the smallest tokamak to produce an ignited plasma is derived. This steady state energy balance analysis is then extended to determine the smallest tokamak power plant, by including the power required to drive the toroidal field, and considering two extremes of plasma current drive efficiency. The analytic results will be augmented by a numerical calculation which permits arbitrary plasma current drive efficiency; the results of which will be presented in Part II. Third, a scaling from any given reference reactor design to a copper toroidal field coil device is discussed. Throughout the paper the importance of various restrictions is emphasized, in particular plasma current drive efficiency, plasma confinement, plasma safety factor, plasma elongation, plasma beta, neutron wall loading, blanket availability and recirculating electric power. We conclude that the latest published reactor studies, which show little advantage in using low aspect ratio unless remarkably high efficiency plasma current drive and low safety factor are combined, can be reproduced with the analytic model