A component‐based framework for radio‐astronomical imaging software systems

This paper describes a component‐based framework for radio‐astronomical imaging software systems. We consider optimal re‐use strategies for packages of disparate architectures brought together within a modern component framework. In this practical case study, the legacy codes include both procedural and object‐oriented architectures. We consider also the special requirements on scientific component middleware, with a specific focus on high‐performance computing. We present an example application in this component architecture and outline future development planned for this project. Copyright © 2007 John Wiley & Sons, Ltd.     

Cognitive operations and the generation effect.

The present experiments were designed to test a cognitive operations hypothesis of the generation effect, or memorial advantage for stimuli that are generated rather than simply read. In two experiments two aspects of generation were manipulated independently: (a) whether the to-be-remembered stimulus was absent (and therefore produced by the subject) or present (and therefore not produced) and (b) whether the relevant cognitive operations were performed by the subject or were instead performed by another agent. Specifically, subjects were given simple multiplication problems with the answers either absent or present in the original problems and with the calculations performed either by themselves or by another agent (either the experimenter or a calculator). The first experiment tested immediate recall of the answers, and the second experiment tested both recall and recognition of the answers after retention intervals up to a week. In all cases, a highly significant retention advantage was found for the tasks requiring multiplication operations by the subjects themselves as opposed to another agent, but there was no main effect for whether the answer was absent or present in the original problem. We discuss the theoretical implications of these results with respect to the generation effect as well as the practical implications with respect to using a calculator in learning the multiplication facts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Network implications of multicast in electronic commerce

Electronic commerce (EC) systems have been in existence for many years. In the financial industry, for example, electronic trading has been in place for well over a decade. Momentum has gathered pace to the point where EC is considered at least an essential adjunct to a company's business or, in some cases, the primary means of connecting vendors to their customers. This momentum has been at least, partly inspired by the convergence of content, commerce, communication, and the Internet. In many EC systems, the state of the market (current value and availability of goods and services) or another event needs to be disseminated to consumers so that they can take actions based on the information. IP multicasting is an emerging network technology that can greatly improve the efficiency of providing such information     

Conversion of Fusaric Acid to Fusarinol by Aspergillus tubingensis: A Detoxification Reaction

The fungus Fusarium oxysporum causes wilt diseases of plants and produces a potent phytotoxin fusaric acid (FA), which is also toxic to many microorganisms. An Aspergillus tubingensis strain with high tolerance to FA was isolated from soil and designated as CDRAt01. HPLC analysis of culture filtrates from A. tubingensis isolate CDRAt01 grown with the addition of FA indicated the formation of a metabolite over time that was associated with a decrease of FA. Spectral analysis and chemical synthesis confirmed the compound as 5-butyl-2-pyridinemethanol, referred to here as fusarinol. The phytotoxicity of fusarinol compared to FA was measured by comparing necrosis induced in cotton (Gossypium hirsutum L. cv. Coker 312) cotyledons. Fusarinol was significantly less phytotoxic than FA. Therefore, the A. tubingensis strain provides a novel detoxification mechanism against FA which may be utilized to control Fusarium wilt.     

Ticks and tick-borne diseases in Oklahoma

Tick-borne diseases are common in Oklahoma, especially the eastern part of the state where tick prevalence is highest. Three species of hard ticks are present in Oklahoma that are known vectors of human disease--the American dog tick (Rocky Mountain spotted fever; RMSF), the lone star tick (ehrlichiosis) and the black-legged tick (Lyme disease). Oklahoma consistently ranks among the top states in numbers of reported RMSF cases, and Ehrlichiosis may be as prevalent as RMSF. Although Lyme disease is frequently reported in Oklahoma, over-diagnosing of this disease due to false-positive test results is common; positive or equivocal screening tests should be confirmed by Western immunoblot. At present, it is unclear whether the disease seen here is Lyme disease or another Lyme-like disease. If true Lyme disease is present in the state, it is probably rare. Physicians should be aware of the most recent recommendations for diagnosis, therapy and prevention of tick-borne diseases.     

Alkyldimethylamine oxides as synergistic fabric softeners

The interaction of solid alkyldimethylamine oxide and ditallowdimethylammonium chloride (DTMAC) and ditallow dimethylammonium sulfate (DTMAS) quats in representative types of fabric softener systems was studied with particular focus on synergistic behavior. Softening, whiteness retention, wetting, static build-up and detersiveness were evaluated for laundry rinses, laundry detergents and dryer sheets. In laundry rinses, blends of amine oxide and DTMAC proved to be synergistic for improving the wetting of cotton towels. Although no synergism was observed in laundry detergents, formulations containing amine oxide gave better detersiveness than systems with DTMAC without the splotching associated with the quaternary salt. In dryer sheets, it was discovered that blends of amine oxide and DTMAS gave synergistic softening of cotton towels and were unexpectedly effective in preventing static charge build-up on polyester fabric.     

Microbial Resistance Mechanisms to the Antibiotic and Phytotoxin Fusaric Acid

Fusaric acid (FA) produced by Fusarium oxysporum plays an important role in disease development in plants, including cotton. This non-specific toxin also has antibiotic effects on microorganisms. Thus, one expects a potential pool of diverse detoxification mechanisms of FA in nature. Bacteria and fungi from soils infested with Fusarium and from laboratory sources were evaluated for their ability to grow in the presence of FA and to alter the structure of FA into less toxic compounds. None of the bacterial strains were able to chemically modify FA. Highly FA-resistant strains were found only in Gram-negative bacteria, mainly in the genus of Pseudomonas. The FA resistance of the Gram-negative bacteria was positively correlated with the number of predicted genes for FA efflux pumps present in the genome. Phylogenetic analysis of predicted FA resistance proteins (FUSC, an inner membrane transporter component of the efflux pump) revealed that FUSC proteins having high sequence identities with the functionally characterized FA resistance protein FusC or Fdt might be the major contributors of FA resistance. In contrast, most fungi converted FA to less toxic compounds regardless of the level of FA resistance they exhibited. Five derivatives were detected, and the detoxification of FA involved either oxidative reactions on the butyl side chain or reductive reactions on the carboxylic acid group. The production of these metabolites from widely different phyla indicates that resistance to FA by altering its structure is highly conserved. A few FA resistant saprophytic or biocontrol strains of fungi were incapable of altering FA, indicating a possible involvement of efflux transporters. Deployment of both efflux and derivatization mechanisms may be a common feature of fungal FA resistance.     

Connection management for an ATM network

The facilities required to control and manage multiservice applications in asynchronous transfer mode (ATM) networks are discussed. An overview of the hardware aspects of ATM networks is presented. Requirements and architectural models for multiservice applications and an architecture for connection management are described. The requirements at each layer of the connection management architecture are discussed, and the services and protocols are outlined