Detection of arabis mosaic virus using the polymerase chain reaction (PCR)

A new method is described for detecting arabis mosaic virus (ArMV) in infected plants. Specific sequences of ArMV-RNA present in total nucleic acid extracts of infected Vitis vinifera or Chenopodium quinoa were initially reverse-transcribed into a complementary DNA (cDNA), then amplified by PCR using specific oligonucleotide-primers. Different primer combinations distinguished between an ArMV infection and an infection with grapevine fanleaf or raspberry ringspot virus. The amount of nucleic acids obtained from 5 mg grapevine leaves resp. 1 mg leaves of Ch. quinoa were sufficient for detecting ArMV

Study on cycle-slip detection and repair methods for a single dual-frequency global positioning system (GPS) receiver

In this work, we assessed the performance of the cycle-slip detection methods: Turbo Edit (TE), Melbourne-Wübbena wide-lane ambiguity (MWWL) and forward and backward moving window averaging (FBMWA). The TE and MWWL methods were combined with ionospheric total electron content rate (TECR), and the FBMWA with second-order time-difference phase ionosphere residual (STPIR) and TECR. Under different scenarios, 10 Global Positioning System (GPS) datasets were used to assess the performance of the methods for cycle-slip detection. The MWWL-TECR delivered the best performance in detecting cycle-slips for 1 s data. The relative comparisons show that the FBMWA-TECR method performed slightly better than its original version, FBMWA-STPIR, detecting 100% and 73%, respectively. For data with a sample rate of 5 s, the FBMWA-TECR performed better than MWWL-TECR. However, the FBMWA is suitable only for post-processing, which refers to applications where the data are processed after the fact

Human physiologically based pharmacokinetic model for propofol

BACKGROUND: Propofol is widely used for both short-term anesthesia and long-term sedation. It has unusual pharmacokinetics because of its high lipid solubility. The standard approach to describing the pharmacokinetics is by a multi-compartmental model. This paper presents the first detailed human physiologically based pharmacokinetic (PBPK) model for propofol. METHODS: PKQuest, a freely distributed software routine , was used for all the calculations. The "standard human" PBPK parameters developed in previous applications is used. It is assumed that the blood and tissue binding is determined by simple partition into the tissue lipid, which is characterized by two previously determined set of parameters: 1) the value of the propofol oil/water partition coefficient; 2) the lipid fraction in the blood and tissues. The model was fit to the individual experimental data of Schnider et. al., Anesthesiology, 1998; 88:1170 in which an initial bolus dose was followed 60 minutes later by a one hour constant infusion. RESULTS: The PBPK model provides a good description of the experimental data over a large range of input dosage, subject age and fat fraction. Only one adjustable parameter (the liver clearance) is required to describe the constant infusion phase for each individual subject. In order to fit the bolus injection phase, for 10 or the 24 subjects it was necessary to assume that a fraction of the bolus dose was sequestered and then slowly released from the lungs (characterized by two additional parameters). The average weighted residual error (WRE) of the PBPK model fit to the both the bolus and infusion phases was 15%; similar to the WRE for just the constant infusion phase obtained by Schnider et. al. using a 6-parameter NONMEM compartmental model. CONCLUSION: A PBPK model using standard human parameters and a simple description of tissue binding provides a good description of human propofol kinetics. The major advantage of a PBPK model is that it can be used to predict the changes in kinetics produced by variations in physiological parameters. As one example, the model simulation of the changes in pharmacokinetics for morbidly obese subjects is discussed

The Second Generation Intact Stability Criteria: An Overview of Development

This paper describes the current state of development of the second generation of International Maritime Organization (IMO) intact stability criteria. The objective of the paper is three-fold. First, it is a brief review of the recent history of related IMO development with emphasis on the question: why is the second generation of stability criteria needed? Second, the paper describes the framework of the new criteria in which they are complementary to the existing IMO criteria. The new criteria are applied only to those designs that may be susceptible to one of the modes of stability failure considered (parametric roll, pure loss of stability, surf-riding/ broaching). This is achieved through a set of formalized procedures of vulnerability checks. The ideas, proposals, and justifications of these procedures represent the novel contents of the paper. Last, the paper reviews available technologies for development of direct stability assessment methods or performance-based criteria that should be available for those rare cases when susceptibility to these modes of failures is too high