cssi/SciSciGPT-SciSciNet huggingface dataset:
The Gag Domain of the Gag-Pol Fusion Protein Directs Incorporation into the L-A Double-stranded RNA Viral Particles inSaccharomyces cerevisiae

The L-A double-stranded RNA virus of yeast encodes its major coat protein, Gag, and a Gag-Pol fusion protein made by a −1 ribosomal frameshift, a coding strategy used by many retroviruses. We find that cells expressing only Gag from one plasmid and only Gag-Pol (in frame) from a separate plasmid can support the propagation of M1 double-stranded RNA, encoding the killer toxin. We use this system to separately investigate the functions of Gag and the Gag part of Gag-Pol. L-A contains two fusion protein molecules per particle, and although N-terminal acetylation of Gag is essential for viral assembly, it is completely dispensable for function of Gag-Pol. In general, the requirements on Gag for viral assembly and propagation are more stringent than on the Gag part of Gag-Pol. Finally, we directly show that it is Gag that instructs the incorporation of Gag-Pol into the viral particles.
Ultratrace Analysis of Nine Macrolides, Including Tulathromycin A (Draxxin), in Edible Animal Tissues with Minicolumn Liquid Chromatography Tandem Mass Spectrometry

The analysis of nine macrolides is presented, including tulathromycin A (Draxxin), in beef, poultry, and pork muscle with a simple multiresidue extraction and analysis method using high-performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry. The sample preparation method involves extraction with acetonitrile and defatting with hexane followed by dilution of the extracts for analysis. Separation of the nine macrolides was performed using an Atlantis dC18, 3 μm, 3.9 mm × 20 mm minicolumn (guard column). Detection was carried out with two multiple reaction monitoring experiments per macrolide. The method detection limits (MDLs) were based on three times standard deviation of eight repeat spikes at 3.0 ng/g of a mix of the nine macrolides in the various tissues. The MDLs and retention times for the macrolides were as follows: lincomycin, 0.19 ng/g (tR = 5.00 min); tulathromycin, 0.46 ng/g (tR = 5.63 min); spiramycin, 0.21 ng/g (tR = 6.06 min); pirlimycin, 0.10 ng/g (tR =...
Distributed effect in GaAs MESFET

In order to obtain higher output power, the width of a single cell MESFET must be large. When it becomes too large the distributed effect along the width direction tends to limit the output power. It is found that the distributed effect is important when the gate width not less than 150 microns and that the gain decreases with gate width. Also found is that spurious oscillations occur due to line resonances at much higher frequencies than can be accounted for by the instability factor in the discrete device model.
Dollars and sense: Collecting fees and dismissing patients

Abstract Money and ethics often conflict. But being effective in collecting what you are owed is not in conflict with being ethical. There is nothing unethical about charging a fair fee, rendering competent services, and collecting your fee. This article explores issues that impact on fee collection efforts from three different perspectives: legal, practical, and ethical. The legal nuances associated with fee collections and the process for terminating nonpaying patients from your practice is discussed.
Proton shell-model potentials for lead and the stability of superheavy nuclei☆

Abstract Nuclear potentials for heavy nuclei have been determined by performing a least-squares fit to recent stripping and pickup data in the lead region for the single particle and hole energies. The well parameters were applied to the super-heavy region (A ∼ 300) and yielded no significant magic gap.
Face adaptation without a face.

Summary Prolonged viewing of a stimulus results in a subsequent perceptual bias [1–3]. This perceptual adaptation and the resulting aftereffect reveal important characteristics regarding how perceptual systems are tuned [2, 4–6]. These aftereffects occur not only for simple stimulus features but also for high-level stimulus properties [7–10]. Here we report a novel cross-category adaptation aftereffect demonstrating that prolonged viewing of a human body without a face shifts the perceptual tuning curve for face gender and face identity. This contradicts a central assumption underlying perceptual adaptation: that adaptation depends on physical similarity between how the adapting and the adapted features are perceived [5]. Additionally, this aftereffect was not due to response bias, because its dependence on adaptation duration resembled traditional perceptual aftereffects. These body-to-face adaptation results demonstrate that bodies alone can alter the tuning properties of neurons that code for the gender and identity of faces. More generally, these results reveal that high-level perceptual adaptation can occur when the property or features being adapted are automatically inferred rather than perceived in the adapting stimulus.
Polarity Limits of the Sphere Gap

It is found that (10-cycle polarity characteristics correlate with the positive and negative impulse calibration curves for grounded sphere gaps sufficiently well to use them for determining the polarity limits for sphere gaps. The available data show that the maximum spacing at which a grounded sphere gap has equal positive and negative spark-over is a linear function of the size of the spheres. From this relation, it follows that the maximum sparking distance for equal positive and negative sparkover, expressed as a per cent of the diameter of the spheres, is not constant for all sphere diameters. Therefore, arbitrary polarity limits expressed in terms of the diameter of the sphere cannot apply to all sizes of sphere gaps.
Is no news bad news? Information transmission and the role of ''early warning'' in the principal-agent model

The standard principal-agent model neglects the potentially important role of information transmission from agent to principal. We study optimal incentive contracts when the agent has a private signal of the likelihood of the project’s success. We show that the principal can costlessly extract this signal if and only if this does not lead her to intervene in the project in any way that will influence its outcome. Intervention undermines incentives by weakening the link between the agent’s initial effort and the project’s outcome. If possible, the principal commits not to cancel some projects with negative expected payoffs. To elicit early warning, contracts must reward agents for coming forward with bad news. I want you to tell me exactly what’s wrong with me and M.G.M., even if it means losing your job.
Direct evidence for an SN1CB mechanism. III. Observations of deprotonated mixed ligand chelates of N-acetamidoiminodiacetatocopper(II). Evidence for the intermediate

Preuve de l'existence de [Cu(H −1 ADA) (β-alanine) 2− ]. Donnees potentiometriques, visible et RPE
Characterization of the core and accessory genomes of Pseudomonas aeruginosa using bioinformatic tools Spine and AGEnt

Pseudomonas aeruginosa is an important opportunistic pathogen responsible for many infections in hospitalized and immunocompromised patients. Previous reports estimated that approximately 10% of its 6.6 Mbp genome varies from strain to strain and is therefore referred to as “accessory genome”. Elements within the accessory genome of P. aeruginosa have been associated with differences in virulence and antibiotic resistance. As whole genome sequencing of bacterial strains becomes more widespread and cost-effective, methods to quickly and reliably identify accessory genomic elements in newly sequenced P. aeruginosa genomes will be needed. We developed a bioinformatic method for identifying the accessory genome of P. aeruginosa. First, the core genome was determined based on sequence conserved among the completed genomes of twelve reference strains using Spine, a software program developed for this purpose. The core genome was 5.84 Mbp in size and contained 5,316 coding sequences. We then developed an in silico genome subtraction program named AGEnt to filter out core genomic sequences from P. aeruginosa whole genomes to identify accessory genomic sequences of these reference strains. This analysis determined that the accessory genome of P. aeruginosa ranged from 6.9-18.0% of the total genome, was enriched for genes associated with mobile elements, and was comprised of a majority of genes with unknown or unclear function. Using these genomes, we showed that AGEnt performed well compared to other publically available programs designed to detect accessory genomic elements. We then demonstrated the utility of the AGEnt program by applying it to the draft genomes of two previously unsequenced P. aeruginosa strains, PA99 and PA103. The P. aeruginosa genome is rich in accessory genetic material. The AGEnt program accurately identified the accessory genomes of newly sequenced P. aeruginosa strains, even when draft genomes were used. As P. aeruginosa genomes become available at an increasingly rapid pace, this program will be useful in cataloging the expanding accessory genome of this bacterium and in discerning correlations between phenotype and accessory genome makeup. The combination of Spine and AGEnt should be useful in defining the accessory genomes of other bacterial species as well.
Entry-Level Marketing Research Recruits: What do Recruiters Need?

The marketing research industry offers numerous entry-level positions to marketing majors. However, because of poor and inappropriate choice of courses and inadequate internship experiences, recruiters find the graduating student ill-equipped to fill marketing research positions. This article reports a survey of research suppliers, advertising agencies, and other organizations that conduct marketing research. The findings provide useful information to academic and career advisors on college campuses who are in a position to counsel students in their pursuit of careers in marketing research.
The Hen Who Sang: Swordbearing Women in Eastern European Fairytales

(1990). The Hen Who Sang: Swordbearing Women in Eastern European Fairytales. Folklore: Vol. 101, No. 2, pp. 178-184.
Physical mechanism of silicon ablation with long nanosecond laser pulses at 1064 nm through time-resolved observation

Abstract Nanosecond (ns) laser ablation can provide a competitive solution for silicon micromachining in many applications. However, most of the previous studies focus on ns lasers at visible or ultraviolet (UV) wavelengths. The research is very limited for ns lasers at infrared (e.g., 1064 nm) wavelengths (which often have the advantage of much lower cost per unit average output power), and the research is even less if the ns laser also has a long pulse duration on the order of ∼100 ns. In this paper, time-resolved observation using an ICCD (intensified charge-coupled device) camera has been performed to understand the physical mechanism of silicon ablation by 200-ns and 1064-nm laser pulses. This kind of work has been rarely reported in the literature. The research shows that for the studied conditions, material removal in laser silicon ablation is realized through surface vaporization followed by liquid ejection that occurs at a delay time of around 200–300 ns. The propagation speed is on the order of ∼1000 m/s for laser-induced plasma (ionized vapor) front, while it is on the order of ∼100 m/s or smaller for the front of ejected liquid. It has also been found that the liquid ejection is very unlikely due to phase explosion, and its exact underlying physical mechanism requires further investigations.
Coping with Stress: Supporting the Needs of Military Families and Their Children

Family dynamics and the individual differences of each family member can impact their stress. For families in the military, stress occurs regularly due to factors such a reassignments, deployments, and the frequency of changes. For some families, the stress that occurs over time helps family members to develop resiliency. Learning to cope with stress can teach skills in adapting to stressful lifestyle factors (e.g., mobility and relocation). Members of many military families develop these skills, while other families need a strong supportive network to facilitate their adjustment to military lifestyle stress. This is a review of the literature on the issues of how families and their children cope with and adapt to the stress of the military lifestyle. Suggestion are given for how families and school can work together to support children in military families to adapt to the military lifestyle. These suggestions can be applied to other types of transient families.
Acidification of the young phagosomes of Paramecium is mediated by proton pumps derived from the acidosomes

Although it is generally accepted that phagosome acidification is induced through the activity of a vacuolar proton pump (V-ATPase) present on the phagosome membrane, exactly how these pumps are delivered to the phagosomes is not well understood. To study this question inParamecium, it was necessary to first show that an authentic V-ATPase was present on their phagosomal membranes. Three antibodies raised against V-ATPases or their subunits were each found to label one or two large digestive vacuoles (DVs) inParamecium multimicronucleatum when immunofluorescence microscopy was used. Using horseradish peroxidase immunocytochemistry to increase sensitivity, about 10 DVs were shown to contain a V-ATPase. In high magnification images and cryoultramicrotomy these proton pumps were found to be located on the acidosomes, suggesting the vacuolar proton pumps on the DVs originate from the acidosomes. The authenticity of the V-ATPase was further confirmed by its sensitivity to cold temperature and to the V-ATPase specific inhibitor, concanamycin B, which at 10 nM doubled the t1/2 for vacuole acidification. Thus, we conclude that (1) acidosomes and some DVs ofParamecium have a bona-fide concanamycin B-sensitive and cold-sensitive V-ATPase, (2) the V-ATPase is delivered to the young DVs during acidosome fusion, and (3) the V-ATPase is involved in vacuole acidification. Finally, we have now determined thatParamecium has two immunologically related V-ATPases that are involved in two very different functions, (1) the acidification of phagosomes and (2) fluid segregation in the contractile vacuole complexes.
Review of Magnetic Neurosurgery Research

Image guided surgical techniques are often used to provide useful localizing information during the course of otherwise "standard" surgical procedures. In this review, a magnetic surgery system (MSS) is described that couples image guidance methods with a novel magnetic treatment delivery system. The MSS was designed with the unique capacity to manipulate an implant remotely, to follow complex curvilinear paths, and to implement serial movements over time without reoperation. Magnetically tipped intracerebral implants are placed on the brain surface and then directed along a target trajectory by means of externally generated magnetic gradients. The location of the implant is calculated by comparing preoperative magnetic resonance imaging (MRI) imaging data with intraoperative biplanar fluoroscopic images. A command computer presents the surgeon with relevant MRI-derived images and implements movement commands by sending currents of various strength to the six superconducting magnets suspended about the subject's head. The results of multidisciplinary preclinical research and development work are reviewed.
Mediation of Trypanosoma cruzi invasion by heparan sulfate receptors on host cells and penetrin counter-receptors on the trypanosomes

Abstract Trypanosoma cruzi attaches and invades a large variety of mammalian cells by receptor-mediated interactions, one of them involving the binding of parasite trans-sialidase to host sialyl receptors. Three proteoglycan-deficient mutants of Chinese hamster ovary (CHO) cells were used to probe the role of host heparin and heparan sulfate glycosaminoglycans (GAG) in T. cruzi invasion. All three mutants supported adhesion and infection to a much lower extent than the parental CHO cells. One of the mutants, pgsD-677, did not express beparan sulfate while containing three- to four-fold excess chondroitin sulfate, yet the cell line was a poor substrate for T. cruzi adhesion. Proteoglycan-deficient cells obtained by inhibiting GAG synthesis in parental cells with p -nitrophenyl-β- d -xyloside, were also poor hosts for T. cruzi invasion. Furthermore, digestion of parental cells with heparinase and heparitinase, two lyases that specifically depolymerize heparin and heparan sulfate, reduced the potential of the cells to support T. cruzi adhesion and growth. Lyases that digested chondroitin sulfate and other GAGs did not affect T. cruzi invasion. These results suggest that heparin/heparan sulfate epitopes are receptors for T. cruzi invasion. The corresponding counter-receptor on T. cruzi appears to be penetrin, a heparin-binding protein that promotes trypanosome penetration into cells. Purified penetrin caused agglutination of red blood cells, and the hemagglutination was exquisitely sensitive to heparin and heparan sulfate. However, sialic acid and sialyl compounds did not inhibit penetrin-induced hemagglutination. Recombinant penetrin competitively inhibited T. cruzi invasion of proteoglycan-containing parental cells, but not of proteoglycan-deficient mutants nor of heparitinase-treated cells. Furthermore, consistent with the sugar specificity of penetrin as a hemagglutinin, recombinant penetrin competed for trypanosome invasion of a CHO cell mutant (Lec2) that expresses heparan sulfate but not sialyl residues. Given that the release of sialic acid from the proteoglycan-deficient mutants further reduced T. cruzi invasion, as did the removal of heparan sulfate from the Lec2 mutant, and given that penetrin does not bind to sialic acid with high affinity, the results indicate that the penetrin-heparan sulfate pathway for T. cruzi invasion is distinct from the trans-sialidase-sialic acid route.
Monoalkylidene Derivatives of Meldrum's Acid

Abstract We were in need of several aliphatic monoalkylidene derivatives of Meldrum's acid (1) for use in conjunction with a current synthetic problem. Implementation of base1,2 or Lewis acid3 initiated Knoevenagel conditions were found to be unsatisfactory, in our hands, due to the intercedence of subsequent Michael addition of Meldrum's acid to the desired product. We reasoned, therefore, that a method should be employed which generates the alkylidene derivative in the absence of Meldrum's acid.
Argon retention properties of silicate glasses and implications for 40 Ar/ 39 Ar age and noble gas diffusion studies

Sized aggregates of glasses (47–84 wt% SiO2) were fused from igneous-derived cohesive fault rock and igneous rock, and step-heated from ~400 to >1,200 °C to obtain their 39Ar diffusion properties (average E=33,400 cal mol−1; D o=4.63×10−3 cm2 s−1). At T ~1 mm) are analyzed, glasses with compositions similar to ours may preserve their formation ages.
Effect of disinfectants on Giardia cysts

Due to a misstatement in the early literature, Giardia cysts have been considered for many years to be extremely resistant to disinfection. Recent studies using in vitro excystation as the criterion of viability have demonstrated that this concept is inaccurate. Several studies have shown that as little as 2 mg of chlorine per liter can kill greater than 99.8% of the Giardia cysts, while another study has suggested that only a slightly higher concentration of iodine than chlorine was equally cysticidal. Much lower concentrations were cysticidal when ozone (0.03 to 0.48 mg/l) was used as the disinfectant. Ultraviolet irradiation in excess of what can be feasibly generated commercially was ineffective against Giardia cysts. Several small‐quantity water disinfection methods have been tested against Giardia cysts following the manufacturer's recommendations for use. Halazone® and Emergency Drinking Water Germicidal Tablets® were effective under all conditions, while the Globaline®, bleach, and I2 methods suff...
Environmental trade-offs with the adoption of cogeneration technologies

Abstract Current U.S. Department of Energy strategies for meeting energy crises include efforts to promote the cogeneration of energy. One cogeneration allocation is the energy-saving potential involved in the cogeneration of process heat and electricity. However, cogeneration technologies often face an unfavorable economic climate due to increasingly stringent environmental standards. This paper investigates the policy options which might encourage the adoption of cogeneration technologies and still provide for an adequate level of environmental protection.
The immunopathology of myasthenia gravis

Experimental autoimmune myasthenia gravis, induced by immunization with solubilized acetylcholine receptors, has proven an excellent animal model for the study of myasthenia gravis. The role of the thymus in myasthenia gravis is not yet known. Its content of skeletal muscle elements and acetylcholine receptors and the presence of germinal centers in myasthenia gravis suggest that the thymus could be a site of autoimmunization. An effector role has not been demonstrated for T cells in the pathogenesis of experimental autoimmune or clinical myasthenia gravis, but helper T cells participate in the rat's autoantibody response to acetylcholine receptors. Antibodies and lymphocytes reactive with acetylcholine receptors are demonstrable in the peripheral blood of patients with myasthenia gravis and appear to be specific for this disease. Parallel studies of both experimental autoimmune and clinical myasthenia gravis have provided evidence for an autoimmune basis for the pathophysiology in myasthenia gravis. Antiacetylcholine receptor antibodies appear to play a central role in impairing neuromuscular transmission. Numerous antibody specificities have been described, but none seems to be directed at the acetylcholine binding site of the receptor. Addition of antiacetylcholine receptor antibodies to cultured muscle cells, in the absence of complement, causes redistribution of the receptors on the membranes of myotubes, accelerated receptor degradation, apparent impairment of ionophore function, and loss of sensitivity to acetylcholine. In vivo complement appears to be an important mediator of antiacetylcholine receptor antibody pathogenicity. Its presence is essential for the passive transfer of experimental autoimmune myasthenia gravis with antibodies. In muscle biopsy specimens from patients with myasthenia gravis, IgG and C3 have been demonstrated on the postsynaptic membrane and on degenerated fragments of membrane in the synaptic cleft. This suggests that complement activation in vivo is associated with focal lysis of the postsynaptic membrane. A causal relationship appears to exist between the binding of antibody to acetylcholine receptors, the reduction in muscle acetylcholine receptors, and impairment of neuromuscular transmission.
Cervical cancer survival in a high risk urban population.

Background. Cervical cancer remains an important public health problem, particularly for the urban minority population. To the authors' knowledge, determinants of cervical cancer survival have not been studied in this high risk population. Methods. This study included all 158 women diagnosed and treated for invasive cervical cancer from January 1, 1986, through December 31, 1992, at the Grady Memorial Hospital and Clinics (Atlanta, GA). Medical records were abstracted to determineage at diagnosis, race, International Federation of Gynecology and Obstetrics (FIGO) clinical stage, treatment, and survival. Pathologic material was reviewed to confirm the diagnosis. Results. Most patients (80%) were African American, and the stage distribution was similar for African American and white patients. Sixty-six (42%) had FIGO Stage I disease: 50%, Stage II or III; and 8%, Stage IV. Four-year actuarial survival differed significantly according to clinical stage (Ia = 94%, Ib = 79%, II = 39%, III = 26%, IV = 0%). Overall survival was lower for patients with glandular carcinomas than for those with squamous cell carcinomas (26% vs. %%, P = 0.09). This difference was almost entirely due to increased mortality in patients with Stage Ib adenocarcinomas (53% vs. 88% for squamous cell carcinoma, Stage Ib, P = 0.03). Conclusions. The major prognostic markers for cervical cancer survival in this high risk patient population were clinical stage and histology, factors identical to those identified for other populations.
Influence of Contraction Section Shape and Inlet Flow Direction on Supersonic Nozzle Flow and Performance

Wall static pressure measurements and performance parameters are presented for axisymmetric supersonic nozzles with relatively steep convergent sections and comparatively small radius-of-curvature throats. The nozzle walls were essentially adiabatic. These results are compared with those obtained in other nozzles tested previously to appraise the influence of contraction shape on performance. Both the flow coefficient and the thrust were less than the corresponding values for one-dimensional, isentropic, plane flow for both the axial and radial inflow nozzles considered, but the specific impulse, the most important performance parameter, was found to be relatively unchanged. The thrust decrement for the axial inflow nozzles was established primarily by the shape of the contraction section, and could be estimated reasonably well from a conical sink flow consideration. The radial inflow nozzle has a potential advantage from a cooling point of view if used in a rocket engine.
Effect of humic acids on iron analyses in natural waters

Abstract Florida river samples containing high and low concentrations of humic acids, naturally occurring chelators, were analyzed for iron content. The samples were subjected to automated microanalysis of soluble iron. Through statistical analyses of many replicate samples, it was possible to evaluate the error of analysis of low and high concentrations of iron in waters containing low and high concentrations of humic acid. Statistical evidence is presented to show that the presence of humic acid does not interfere in the precision of analysis of soluble iron and that changes in the iron content can be detected after storage for 2 months at -10°C.
Calculation of the EPR Spectrum of a Small Nitroxide from Molecular Dynamics Simulations

Algorithms have been developed for calculating the continuous wave electron paramagnetic resonance (EPR) spectrum of a nitroxide spin label from a free-induction decay (FID) derived from a molecular dynamics (MD) simulation. These algorithms have been successfully used to simulate the EPR spectra of two spin-labeled mutants of T4 lysozyme, T4L F153R1 and T4L K65R1 [DeSensi et al., Biophys. J. 94, 3798-3809 (2008)]. In this previous work, MD simulations were performed using the AMBER suite of programs, the all-atom AMBER99 force field, the particle mesh Ewald (PME) method for treating long-range electrostatic interactions, and the SPC/E water model. In order to test the effect of the water model used in the AMBER-based molecular dynamics simulations, calculations for a small nitroxide [3-hydroxymethyl-(1-oxy-2,2,5,5-tetramethylpyrroline) or 3MeOHSL] are being performed using a variety of different water models (SPC/E, TIP3P, TIP4P). The EPR spectra calculated from these molecular dynamics simulations of 3MeOHSL will be compared to experimental data.
Dynamic scaling of coupled nonequilibrium interfaces

We propose a simple discrete model to study the nonequilibrium fluctuations of two locally coupled (1+1)-dimensional systems (interfaces). Measuring numerically the tilt-dependent velocity we construct a set of stochastic continuum equations describing the fluctuations in the model. The scaling predicted by the equations is studied analytically using dynamic-renormalization-group theory and compared with simulation results.
Interacting Coronal Mass Ejections and Solar Energetic Particles

We studied the association between solar energetic particle (SEP) events and coronal mass ejections (CMEs) and found that CME interaction is an important aspect of SEP production. Each SEP event was associated with a primary CME that is faster and wider than average CMEs and originated from west of E45°. For most of the SEP events, the primary CME overtakes one or more slower CMEs within a heliocentric distance of ∼20 R⊙. In an inverse study, we found that for all the fast (speed greater than 900 km s^(-1)) and wide (width greater than 60°) western hemispheric frontside CMEs during the study period, the SEP-associated CMEs were ∼4 times more likely to be preceded by CME interaction than the SEP-poor CMEs; i.e., CME interaction is a good discriminator between SEP-poor and SEP-associated CMEs. We infer that the efficiency of the CME-driven shocks is enhanced as they propagate through the preceding CMEs and that they accelerate SEPs from the material of the preceding CMEs rather than from the quiet solar wind. We also found a high degree of association between major SEP events and interplanetary type II radio bursts, suggesting that proton accelerators are also good electron accelerators.
Assessing School Climate: An Important Step for Enhancing School Quality:

How can the administrator encourage students to attend and remain in school? How can one offset feelings of detachment? How can the adminis trator support faculty members in their daily work? How c...
Cyanogen as a selective probe for carbonic anhydrase hydrolase activity.

The salt bridge probe cyanogen (ethanedinitrile, C2N2; NC–-CN) inhibits the bovine carbonic anhydrase (EC 4.2.1.1.) hydrolase activity toward various types of esters without significant effect on its hydrolyase activity. Two sets of pyridine derivatives that were isosteric substrates for the two activities were differentially affected. Acetazolamide and salamide are reversible inhibitors of the enzyme; only salamide affords protection of the hydrolase activity against the action of C2N2. Since each is known to bind in different positions within the active site, the selective effect of salamide may arise from its position covering one CO2 site as well as a site important for hydrolase activity. The C2N2 concentration dependence of the time course of hydrolase inhibition is consistent with the existence of a high C2N2 affinity site with slow covalent change and a second site with lower C2N2 affinity, but higher rate of covalent modification of the enzyme. © 1993 John Wiley & Sons, Inc.
Driver Behavior Model of Saturation Flow

Traditional estimates of saturation flow rates have been based on a hypothesis that the time headways between successive vehicles entering an intersection from a traffic signal are constant after the first three to five vehicles are discharged. This model of constant flow has been challenged by recent field observations in which average headways between vehicles continue to decrease through the last queued vehicle entering an intersection, causing a marginal saturation flow rate that increases progressively with each entering vehicle. Large variations in saturation flow measurements also have cast doubt on the presumption that the base saturation flow rate of 1,900 passenger cars per hour of green time per lane (specified in the Highway Capacity Manual) is either stable or a constant value. The human factors that underlie the rate at which successive queued vehicles enter an intersection at a traffic signal are considered. A model based on driver behavior is formulated in a manner that can be calibrated w...
Global Local Edge Coincidence Segmentation For Medical Images

Object location in computed tomography images is a preliminary step required for automated measurements which may be useful in many diagnostic procedures. Most object location, image processing techniques are either globally based such as histogram segmentation or locally based such as edge detection. The method described in this paper uses both local and global information for object location. The technique has been applied to the location of suspected tumors in CT lung and brain images. Sorting and merging steps are required for eliminating noise regions but all suspected tumor regions have been located. Measurements such as boundary roughness or density statistics may also be made on the objects and used to identify suspicious regions for further study by the radiologists. Algorithms for chain-encoding the object boundaries and locating the vertices on the boundaries is also presented and compared. These methods are useful for shape analysis of the regions. The significance of this technique is that it demonstrates important additional capability which could be added to the software libraries of most CT systems.
Assessment of operator trust in and utilization of automated decision-aids under different framing conditions

Abstract Computerized aids may be used to support decision-making and control in a variety of complex, dynamic arenas. For instance, such systems have been introduced into industrial settings as the means to implement automated control or support decision-making activities such as fault detection and recovery. Of interest in these systems is the extent to which operators utilize and trust such systems, in terms of their ability to successfully control systems, or the information or decision support they provide, particularly under conditions of potential failure. A theoretical framework to describe potential factors affecting these issues, and an experiment to investigate the role of failure cause on trust and system utilization, are described. Results provide some support for factors in the theoretical framework, and also demonstrated the use of an empirically developed trust scale. Relevance to industry As manufacturing environments increasingly rely on computerized and automated systems for control and human operator support, it is necessary to understand the situational factors which could impact operators’ use of such systems. This paper describes a framework which could be used to investigate trust in industrial automation settings, as well as a rating scale which could be applied.
Cardiovascular and metabolic effects of adenosine 3',5'-monophosphate in vivo.

CATECHOLAMINES activate the enzyme, adenyl cyclase, which forms cyclic adenosine 3′,5′-monophosphate (3′,5′-AMP) in a variety of animal tissues1. This reaction system has been thought to control several metabolic processes, including glycogenolysis, steroidogenesis, keto-genesis, lipolysis and antidiuresis1–8. The positive ino-tropic and chronotropic effects of catecholamines on the heart are generally attributed to catechol interaction with the beta adrenergic receptor site. Rall and Sutherland2 and Mayer et al.9 have proposed that 3′, 5′-AMP might directly affect cardiac beta receptors by mediating hormone-induced changes in contractile force without necessarily involving glycogenolysis. During the course of investigations in the isolated perfused rat liver, 3′,5′-AMP was observed to induce delayed vasomotor changes unrelated to its glycogenolytic action10. This suggested that 3′, 5′-AMP might have a direct vascular effect on smooth muscle. Although 3′,5′-AMP produces hypergly-caemia in intact animals1,10–13, correlation of its metabolic action with possible regulation of cardiac activity has not been previously investigated.
Nullarbor 018: a new L6 chondrite from Australia.

A new meteorite find from the Nullarbor Plain in Australia was studied using optical, scanning electron microscopy (SEM), and electron microprobe techniques. The meteorite, Nullarbor 018, is an orthodox L6 chondrite that experienced minor-to-moderate alteration of metal during terrestrial weathering (grade A-B to B). During weathering, trolite was preferentially altered, and roughly 20% of the original complement of S in the meteorite was removed. Shock metamorphic effects corresponding to shock stage S4 (or shock facies d) are found, including the presence of some diaplectic feldspar (maskelynite). The meteorite is not obviously paired with other finds from the Nullarbor region, but the possibility that it is paired cannot be excluded.
Potentiation of the dorsal immobility response following intrastriatal injections of enkephalins

Abstract The effects of bilateral intrastriatal injections (1.0 μg/side) of leucine5- and methionine5-enkephalins and their related nonopiate fragments upon three measures of immobility over a time course were investigated. Both leucine5-enkephalin and des-Tyr1-leucine-enkephalin potentiated the duration of the dorsal immobility response (DIR) 15 min postinjection and over a 1-h time course. On the other hand, methionine5-enkephalin and des-Tyr1-methionine-enkephalin potentiated the duration of the DIR at 5 and 15 min. These enkephalins and their fragments had no effect upon vertical cling and bar catalepsy. In a second study, an SC injection of 4 mg/kg naloxone 15 min prior to the central injections blocked the potentiation of the DIR effects of the enkephalins.
Comparisons of Galerkin and finite difference methods for solving highly nonlinear thermally driven flows

Abstract The equations of motion for a high Prandtl number Boussinesq fluid in a square 2-D cavity with side-wail heating and cooling and perfectly conducting end walls have been solved by means of Galerkin as well as ADI (alternating-direction-implicit) finite difference methods for Rayleigh numbers up to 8 × 10 6 and two angles of tilt. The finite difference solutions for the conductive flux at the heated wall converge monotonically from above with increasing numbers of mesh points; whereas, the Galerkin solutions converge from below and undergo modest oscillations with long period as additional terms are included. The nearly quiescent core and associated hydrodynamic boundary layers are, for given numbers of mesh points/terms, better represented by the finite difference method. With increasing precision in the wall heat flux and/or shear, the computational costs for both methods become comparable; however, for errors in excess of 2–3%, the Galerkin method is more economical.
Micromechanics of the velocity and normal stress dependence of rock friction

Among the second-order effects on friction the most important are those of variable normal stress and of slip velocity. Velocity weakening, which is usually considered the source of the stick-slip instability in rock friction, has been observed in velocity stepping experiments with Westerly granite. The friction change, Δμ, was −0.01 to −0.008 for a tenfold velocity increase. Using normal closure measurements, we observed dilation upon each increase in sliding rate. We also observed, for the first time, time-dependent closure between surfaces during static loading. The dilation that occurred during the velocity stepping experiment was found to be that expected from the static time-dependent closure phenomenon. This change in closure was used to predict friction change with an elastic contact model. The calculated friction change which results from a change in contact area and asperity interlocking, is in good agreement with the observed velocity dependence of steady-state friction. Variable normal stress during sliding has two effects, first in creating new partial slip contacts and locking some existing fully sliding contacts and second in increasing interlocking, for instance when normal load is suddenly increased. As a result, a transient change in friction occurs upon a sudden change in normal load.
A NEW SPECIES OF LISTRUS FROM CAJON PASS, CALIFORNIA (COLEOPTERA, MELYRIDAE)

Form parallel-oblong to elongate-subovate, about three times as long as wide. Color black; second antennal segments and protrochanters more or less rufo-testaceous; tarsi and distal two-thirds of tibiae rufous. Luster slightly aeneous and somewhat shining.
Combining conditional and unconditional recruitment incentives could facilitate telephone tracing in surveys of postpartum women

Abstract Background and Objective To compare tracing and contact rates using alternative incentives in a computer-assisted telephone interview (CATI) survey among postpartum women. Methods In a randomized trial of 1,061 postpartum women 18–49 years of age selected from four Iowa counties, we compared the effects of: (1) unconditional $5 telephone card incentive enclosed with the introductory letter followed by $25 incentive conditional upon successful telephone tracing, contact, and completion of CATI (Group 1, n = 530) vs. (2) $30 incentive conditional upon subject completion of CATI (Group 2, n = 531). Results Overall telephone tracing and contact rates achieved were 67.8% and 66.6%, respectively. Tracing (70.2 vs. 65.4%, P = .09) and contact (68.5 vs. 64.8%, P = .26) rates were consistently higher among subjects assigned the combination of a conditional and an unconditional incentive. The combined incentive type had a greater impact on telephone tracing success rates for subjects on whom we could not initially locate an active telephone number (16.7 vs. 7.3%, P = .07) when compared to subjects for whom we found an active telephone number at the time of mailing the introductory letter (78.9 vs. 75.9%, P = .30). Conclusions Combining conditional and unconditional recruitment incentives can facilitate telephone tracing efforts in surveys conducted among recently postpartum women.
Level of photosynthetic intermediates in isolated spinach chloroplasts.

The level of intermediates of the photosynthetic carbon cycle was measured in intact spinach chloroplasts in an attempt to determine the cause of the induction lag in CO(2) assimilation. In addition, transient changes in the level of the intermediates were determined as affected by a light-dark period and by the addition of an excess amount of bicarbonate during a period of steady photosynthesis. Assayed enzymically were: ribulose 1,5-diphosphate, pentose monophosphates (mixture of ribose 5-phosphate, ribulose 5-phosphate and xylulose 5-phosphate, hexose monophosphates (mixture of glucose 6-phosphate, glucose 1-phosphate, and fructose 6-phosphate), glyceraldehyde 3-phosphate, dihydroxyacetone phosphate, glycerate acid 3-phosphate, a mixture of fructose 1,6-diphosphate and sedoheptulose 1,7-diphosphate, adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP).The lag in CO(2) fixation appeared to be the result of low levels of pentose monophosphates. The level of ribulose 1,5-diphosphate was roughly equal in chloroplasts showing immediate linear kinetics with respect to CO(2) fixation and chloroplasts which exhibited an initial lag.Following a light-dark transition, CO(2) fixation ceased immediately but the level of glycerate 3-phosphate increased while ribulose 1,5-diphosphate was only slightly effected. The increase in level of glycerate 3-phosphate was correlated with a decrease in triose phosphate. Within 3 to 5 min in the light, ATP reached a maximum concentration while in darkness, all was utilized in 30 to 60 sec. The rapid loss of ATP was ascribed to an ATPase rather than to its utilization in kinase reactions.A rapid increase in CO(2) concentration enhanced the level of triose phosphate, but the level of glycerate 3-phosphate showed only a small overshoot and was considered as evidence that reducing power was not a rate limiting factor. Data were obtained indicating that triose phosphates similar to pentose monophosphates and in contrast to fructose 6-phosphate, glucose 6-phosphate and glucose 1-phosphate could be transported between chloroplast and suspending medium. Differential import and export of phosphorylated compounds may serve as routes alternative to starch and sucrose for the flow of carbon into biosynthetic pathways.
Validity of Ray-Optics Calculations in a Turbulent Atmosphere

The restrictions on the applicability of ray optics in the turbulent atmosphere are investigated. Within the single-scatter approximation, the requirement that amplitude fluctuations have negligible effect compared to phase fluctuations leads to the condition linner11/3louter1/3/λ2≫(L/27)2 where linner, louter are the inner and outer turbulence scales and L is the range. This criterion is a considerable relaxation of the criterion which has been employed (linner2/λ≫L).
Encode/decode: Electronic mailing of complex files

Abstract An Encode/Decode processor is described that enables sending complex documents such as binary ChemText DOC files, files containing special characters, or lines longer than 80 characters through BITNET and other electronic mail systems that normally only handle restricted ASCII messages. The Encode/Decode system is included on Disk 4 in subdirectory ENCODE.
Variable structure control of spacecraft reorientation maneuvers

A Variable Structure Control (VSC) approach is presented for multi-axial spacecraft reorientation maneuvers. A nonlinear sliding surface is proposed which results in an asymptotically stable, ideal linear sliding motion of Cayley-Rodriques attitude parameters. By imposing a desired equivalent dynamics on the attitude parameters, the approach is devoid of optimal control considerations. The single axis case provides a design scheme for the multiple axes design problem. Illustrative examples are presented.
Visual scanning and matching dysfunction in brain-damaged patients with drawing impairment.

Summary Visual matching and visual exploration were examined in 7 normal subjects and 20 brain-damaged patients with drawing impairment measured by the Bender Gestalt Visual-Motor Test. Right brain-damaged patients made significantly more errors of rotation and integration than left brain-damaged patients. Selected Bender figures were also used as stimuli for both visual matching and visual exploration tests. The ability to match Bender figures was found to be impaired in right but not left brain-damaged patients. All patients showed eye movement and fixation patterns different from those of normals. Patients essentially had more fixations and shorter fixation durations. Significant intercorrelations were found between the total Bender Gestalt score and visual matching and visual exploration scores. These findings indicate that visual matching and visual exploration measures can be used to evaluate perceptual impairment in individuals who do not have adequate motor responses or where impaired motor responses may confound interpretations about visual cognitive impairment.
Non-aversive procedures and their effect on cigarette smoking

Abstract The majority of smoking reduction studies have focused on the use of aversive control procedures to reduce or eliminate smoking behavior. Relatively few studies have analyzed the effect of positive reinforcement despite evidence which suggests that positive retraining may be more effective over the long run than aversive controls in reducing cigarette smoking. This study examines the long-term effect of non-aversive procedures to reduce smoking behavior and describes a low cost, reliable method for validating self-report data. Twenty-seven smokers were randomly assigned to experimental or control groups. Experimental subjects were divided into two groups which met for six consecutive weekly sessions and 2 bi-weekly sessions. Follow-up data was taken at 3, 6 and 12 months after treatment. A series of non-aversive stimulus control and positive reinforcement procedures comprised the treatment package. Included were alternate response training, gradual smoking reduction via individualized situational heirarchies, behavior rehearsal of verbal no-smoking requests, contingency contracting and in vivo practice of non-smoking in high anxiety situations. Significant differences in smoking reduction rates were noted at the 3 and 6 month follow-ups but not at the 12 months. Tests measuring serum thiocyanate levels in the blood revealed discrepancies in self-reported data.