EXTRACTION OF URANYL IONS BY SYNERGISTIC MIXTURES OF THENOYLTRIFLUOROACETONE AND MACROCYCLIC DONORS

A linear polyether, 1, 13-bis[8-qulnoly]-l,4,7,10,13-pentaoxa-trldecane (K-5) and an aza-crown ether, 4,13-didodecyl-1,7,10,16-tetraoxadiazacyclooctadecane (K22DD) when combined with thenoyltrlfluoroacetone (HTTA) have been shown to exhibit a synergistic effect on the extraction of uranyl ion. The effects of the addition to the organic phase of K-5, K22DD, and tert-butylcyclohexyl-15-crown-5 (15-C-5) on the extraction of UO₂ ⁺² by HTTA in chloroform from 0.5 M NaNO₃ at 25°C have been measured. The results indicate the extraction is enhanced by the formation of an adduct, UO₂(TTA)₂S for K-5 and K22DD. No enhancement of the extraction was seen with the crown ether. The organic phase stability constants for both K-5 and K22DD were evaluated and found to be similar in magnitude. These results suggest that the major factor in the formation of the synergistic adduct is the presence of the nitrogen atom in the synergist.     

Evolutionary Interactions Between Visual and Chemical Signals: Chemosignals Compensate for the Loss of a Visual Signal in Male <Emphasis Type="Italic">Sceloporus</Emphasis> Lizards

Animals rely on multimodal signals to obtain information from conspecifics through alternative sensory systems, and the evolutionary loss of a signal in one modality may lead to compensation through increased use of signals in an alternative modality. We investigated associations between chemical signaling and evolutionary loss of abdominal color patches in males of four species (two plain-bellied and two colorful-bellied) of Sceloporus lizards. We conducted field trials to compare behavioral responses of male lizards to swabs with femoral gland (FG) secretions from conspecific males and control swabs (clean paper). We also analyzed the volatile organic compound (VOC) composition of male FG secretions by stir bar extraction and gas chromatography-mass spectrometry (GC-MS) to test the hypothesis that loss of the visual signal is associated with elaboration of the chemical signal. Males of plain-bellied, but not colorful-bellied species exhibited different rates of visual displays when exposed to swabs of conspecific FG secretions relative to control swabs. The VOC composition of male Sceloporus FG secretions was similar across all four species, and no clear association between relative abundances of VOCs and evolutionary loss of abdominal color patches was observed. The emerging pattern is that behavioral responses to conspecific chemical signals are species- and context-specific in male Sceloporus, and compensatory changes in receivers, but not signalers may be involved in mediating increased responsiveness to chemical signals in males of plain-bellied species.     

Differentiation of two strains of Mycoplasma gallisepticum with monoclonal antibodies and flow cytometry

Identification of infecting Mycoplasma spp. is difficult and not routine for strain. This paper describes a procedure for the rapid identification of the strain of M. gallisepticum. Monoclonal antibodies were prepared against M. gallisepticum F and M. gallisepticum S6. Aliquots of 24-hour broth cultures of these organisms were incubated briefly with either of the monoclonal antibodies. A second incubation was made with anti-mouse immunoglobulin conjugated to fluorescein isothiocyanate. Fluorescent intensity associated with the organisms was measured with a flow cytometer. The criterion for identification was a comparative increase in fluorescent intensity when the strain and monoclonal antibody were homologous. The procedure correctly differentiated the F and S6 strains of M. gallisepticum in a blind study.     

Reduction of variation in the gasoline blending process —A case study

In an attempt to reduce the release of gasoline vapors into the atmosphere, the U.S. Environmental Protection Agency (EPA) has placed restrictions on the volatility of commercial gasoline. In particular, they have set an upper specification limit on the gasoline's volatility as measured by the Reid vapor pressure (RVP). Exceeding the EPA's upper specification limit may result in a fine to the refiner. While there is no lower specification limit imposed by the EPA, lower RVP values require greater production costs. This article describes the efforts of one refiner to meet the EPA requirements with minimum economic disbenefit. Various statistical tools were used during this effort. The paper demonstrates a variety of successful SPC applications in the continuous process industry.     

Introducing the new industrial engineer

During the last couple of decades, we industrial engineers have typically learned FORTRAN, plus a simulation language or two, gathered together a few optimization programs, and have proclaimed ourselves computer users and, in some cases, even computer experts. Ours has been a somewhat passive expertise, however. That is, with the possible exception of contributions to simulation language development, industrial engineers have not been in the forefront of the wave of computer developments. This has not been entirely our fault. Computers were expensive and hard to justify; utilization was often inconvenient; processing and turnaround was slow; input and output media were few and often unreliable; program development via cards was lengthy, painstaking and cumbersome; and implementation was usually suspect and unpopular.But a funny thing happened in the last few years. Computers, which are so necessary for so many IE-type functions, suddenly became…(a) inexpensive, (b) acceptable, (c) abundant, (d) popular, (e) prominent and most important of all (f) necessary. Industry's key catchword of “profitability” was replaced by “productivity” and suddenly the IE and his stock-in-trade were once more thrust into the forefront. But the tools of days past are no longer enough. The computer will be our constant companion from now on, not as it has been in the past, but as we are innovative enough to make it in the future.This paper is about the computer, computer languages, computer innovations and computer uses, but mostly it is about the new industrial engineer and the environment in which he must exist. It is about the challenges, the opportunities and the direction of the trully modern IE and the role he must play.     

IPM: A computer Interactive Project Management teaching tool

Project management deals with all phases of a project, from the initiation of the planning procedure to the physical completion of the entire effort. The process of teaching the quantitative approaches to project management (i.e. Critical-Path Method and Program Evaluation and Review Technique) is a fairly straightforward task that has been performed for many years. However, teaching the principles of project management is a different task altogether. The project management process involves a sequence of planning, decision making, follow-up activities and reevaluation followed by a repeat of the sequence. That is, in order to truly examine and teach the process of project management (i.e. not just the tools), it is necessary to view the activities in a dynamic projectlike environment. With this idea in mind, the Interactive Project Management game (IPM) was developed. IPM was created with the intent of teaching project management principles in a simulated project environment using the computer. This paper describes IPM, its characteristics and its capabilities, and includes an IPM gaming session.     

Evaluation of natural Psoroptes ovis (Acarina: Psoroptidae) soluble proteins as candidate vaccine immunogens

In this study potential vaccine candidate immunogens were identified and evaluated in a vaccine challenge trial. Calves vaccinated with a partially purified fraction of Psoroptes ovis-soluble proteins had 8 of 14 calves free of palpable lesions 8 wk after a challenge infestation. A self-grooming behavioral response elicited by a pruritic immediate-type allergic reaction was believed to be an effector in protecting the vaccinated calves from a clinical P. ovis infestation.     

The lack of long-term detrimental effects on liver allografts caused by donor-specific anti-HLA antibodies

Recent reports indicate a higher incidence of both acute and chronic liver allograft rejection when, at the time of transplantation, the recipients serum contains donor-specific anti-HLA antibodies. From 9/89 to 5/91, 133 liver allografts were performed at our institution. Thirteen liver recipients had donor-specific IgG anti-HLA antibodies (complement-fixing) at the time of transplantation. In eleven patients, antibodies reacted to donor class I antigens while in 1 patient the donor-specific antibody had class II reactivity. Twelve patients have been followed for a minimum of 12 months (median 18 months, range 28-12 months). No hyperacute rejection was seen in any of the cases and four patients had acute rejections. Thus far only one of the twelve patients has biopsy evidence suggestive of chronic liver injury. The remaining have normal liver enzymes and bilirubin. Three of these twelve patients died (one from a myocardial infarction and the others from sepsis) accounting for a one-year graft survival of 75%. There was no significant statistical difference in the one-year graft survival in those recipients without donor-specific antibodies (i.e., 80.5%). In eight of the twelve patients, pretransplant preformed antibody level (PRA) was > 50%. In six of the thirteen patients donor-specific antibody was present at dilutions greater than 1:64. As previously reported, the donor-specific antibody disappeared from the serum posttransplant within hours and did not reappear. In vitro studies demonstrated no factor in portal or hepatic artery blood that could inhibit rabbit complement mediated lysis of anti-HLA antibodies. We conclude that it is not a contraindication to do liver transplants in the presence of donor-specific anti-HLA antibodies.     

An electronic device for triggering a stimulator during membraneresponsiveness determinations in cardiac tissues

A device is described that monitors the repolarization phase of a cardiac action potential and compares the membrane potential to a voltage selected by the investigator. When the voltages are the same, the device triggers a stimulator that injects the stimulus at the desired membrane potential. The device can stimulate tissue at any membrane potential during the repolarization phase of the action potential between 0 and -100 mV without regard to action potential duration. When it is precisely calibrated, its accuracy is within ±1.0 mV