cssi/SciSciGPT-SciSciNet huggingface dataset:
Gene structure in the tryptophan operon of Escherichia coli: Nucleotide sequence of trpC and the flanking intercistronic regions

Abstract We have determined the DNA sequence for the portion of the Escherichia coli tryptophan (trp) operon spanning trpC, which codes for the bifunctional enzyme N-(5′-phosphoribosyl)-anthranilic acid isomerase/indole-3-glycerol phosphate synthetase. The coding region consists of 1356 nucleotides, directing the synthesis of a polypeptide 452 amino acids in length. The predicted protein sequence is consistent with the amino acid composition of the pure enzyme, and with all known partial peptide sequences derived from this molecule. The enzyme is of particular functional interest, because it contains the catalytic activities for two sequential reactions in tryptophan biosynthesis in a single polypeptide chain. The nucleotide sequences of the junctions between trpC and its flanking genes, trpD and trpB, have also been determined. The trpD-trpC junction consists of six untranslated nucleotides and translation of trpC initiates at the second of two adjacent AUG codons. The trpC termination codon is separated from trpB by 11 nucleotides. The short non-translated regions flanking trpC distinguish it from trpA and trpD, whose initiation codons overlap the termination codons of the preceding genes (trpB and trpE), respectively. These differences in the intercistronic regions may reflect functional relationships between the products of adjacent genes in the operon.
Post‐industrial society and third world development

Abstract Post‐industrial society and equivalent concepts such as the Scientific‐Technological Revolution (STR) and the Information Revolution point to the decisive role science and science‐technology systems play in the development of industrialized societies. A serious gap in these formulations is the lack of any significant discussion of how post‐industrial developments impact Third World countries. In East Europe and the Soviet Union it is recognized that STR will exert a strong influence on the Third World and, conversely, that the problems of the latter may prove fateful for the course of the STR. This article explores some of the impacts of computerization, central to the post‐industrial/information society, on the Third World. It suggests that the promise of computerization hinges on the values which enframe its development and on the sharing of knowledge and the willingness of Third World societies to undertake their own social revolutions.
Radiosurgery for Brain Metastases From Unknown Primary Cancers

Purpose We evaluated the role of Gamma Knife stereotactic radiosurgery in the multidisciplinary management of brain metastases from an undiagnosed primary cancer. Methods and Materials Twenty-nine patients who had solitary or multiple brain metastases without a detectable primary site underwent stereotactic radiosurgery between January 1990 and March 2007 at the University of Pittsburgh. The median patient age was 61.7 years (range, 37.9–78.7 years). The median target volume was 1.0 cc (range, 0.02–23.6 cc), and the median margin radiosurgical dose was 16 Gy (range, 20–70 Gy). Results After radiosurgery, the local tumor control rate was 88.5%. Twenty four patients died and 5 patients were living at the time of this analysis. The overall median survival was 12 months. Actuarial survival rates from stereotactic radiosurgery at 1 and 2 years were 57.2% and 36.8%, respectively. Factors associated with poor progression-free survival included large tumor volume (3 cc or more) and brainstem tumor location. Conclusions Radiosurgery is an effective and safe minimally invasive option for patients with brain metastases from an unknown primary site.
Justified True Belief as Knowledge

After almost a decade, the discussion initiated by Professor Edmund Gettier's provocative paper “Is Justified True Belief Knowledge?” continues. The most recent contribution to this discussion is Professor John Turk Saunders' attempt to counter Professor Irving Thalberg's claim that a principle that Gettier employs in reaching his notorious negative conclusion is unjustified. I am moved to add to the discussion at this time because it seems to me that the principle in question is unjustified. But more fundamentally, Gettier's argument fails because the putative counter-examples on which it rests fail to make their intended point. I shall discuss these claims in turn. The epistemic principle which I consider unjustified is the one which Thalberg has called the Principle of Deducibility for Justification (PDJ) and which Gettier formulates as follows: “for any proposition P, if S is justified in believing P, and P entails Q, and S deduces Q from P and accepts Q as a result of this deduction, then S is justified in believing Q.”
Clinical and Economic Outcomes of Rabbit Antithymocyte Globulin Induction in Adults Who Received Kidney Transplants from Living Unrelated Donors and Received Cyclosporine-Based Immunosuppression

48%, p 0.05). For the no induction versus induction groups, no significant differences in cytomegalovirus disease (5% vs 6%), malignancy (3% vs 2%), graft failures (5% vs 6%), mortality (5% vs 4%), and serum creatinine concentrations (mean ± SD 1.4 ± 0.3 vs 1.5 ± 0.3 mg/dl) were observed at 12 months (p>0.05 for all comparisons). Conclusion. Five-day TMG induction effectively reduced the 1-year acute rejection rate without significantly increasing total inpatient costs or posttransplantation complications among recipients of kidney transplants from living unrelated donors.
The Troubled Frame Narrative: Bad Listening in Late Imperial Russia

Technological change, the appearance of a new entertainment market, the great reforms, and the rise of new professions all required the subjects of the Russian Empire to listen differently in the final decades of the nineteenth century. As demonstrated in recent explorations by historians of the anglophone and francophone worlds, people react to what is perceived as an intolerable increase of noise in modernity by refusing to listen. This article contends that the new listening practices of the 1870s gave rise to a new literary genre, the “troubled frame narrative,” in which listening is thematized and portrayed as difficult and unpleasant; listeners yearn to escape. Close readings of Dostoevskii's “The Meek One,” Chekhov's “Drama,” and Tolstoy's “Kreutzer Sonata” describe the interactions between new genres of listening and a new literary phenomenon.
Plasma Edge Cooling During rf Heating.

A new approach to prevent the influx of high-$Z$ impurities into the core of a tokamak discharge by using rf power to modify the edge plasma temperature profile is discussed. This concept is based on spectroscopic measurements on PLT (Princeton Large Torus) during ohmic heating and ATC (Adiabatic Toroidal Compressor) during rf heating.
Coupling the dynamics of two actin networks--new views on the mechanics of cell protrusion.

We study how mechanical forces integrate spatially and temporally with regulatory signals at the leading edge of migrating cells. To probe the dynamics of this system, we developed quantitative fluorescent speckle microscopy, which maps out actin cytoskeleton transport, assembly and disassembly with high spatial resolution. Statistical processing of single speckle properties revealed two kinetically, kinematically and molecularly distinct, yet spatially overlapping, actin arrays at the leading edge of migrating epithelial cells. The first network, referred to as the lamellipodium, polymerizes and depolymerizes 1–2 μm from the edge in an Arp2/3 (actin-related protein 2/3)- and cofilin-dependent fashion. The second network, referred to as the lamella, exhibits Arp2/3-independent polymerization. To elucidate the dynamic relationship between the two networks, we have begun to examine how assembly and flow are temporally modulated with respect to a protrusion event. In control cells we found bursts of protrusion preceding bursts of F-actin assembly. The time lag disappears in cells where Arp2/3-function is impaired. This and other results allowed us to propose a model in which tropomyosin protects lamella filaments from branching and severing, and to conjecture that Arp2/3-mediated lamellipodium assembly is a natural consequence of lamella expansion, but not the initiator of cell protrusion.
A simultaneous probit model of earnings, migration, job change with wage heterogeneity

In this study, earnings are decomposed in order to measure the effects due to individual characteristics and to unobserved heterogeneity. These effects are shown to work in opposite directions, complicating the effect of earnings on migration. The use of aggregate earnings masks the two separate effects. Those earning more because of productive characteristics are less likely to move. However, higher earnings due to other reasons that are more qualitative act as an impetus for migration. Job change is often part of the decision to migrate. In our analysis we recognize the endogeneity of job change in the migration equation and estimate it separately in the model. Job change is found to have a significantly positive influence on migration. Moreover, the separate estimation of job change brings out the important role of both explained and unexplained earnings on the decision to switch jobs, both factors decreasing the perceived necessity of changing jobs.
Expediting the Institutional Review Board Process for Exercise Protocols

(2011). Expediting the Institutional Review Board Process for Exercise Protocols. Research Quarterly for Exercise and Sport: Vol. 82, No. 1, pp. 129-134.
Effects of repeated light-dark phase shifts on voluntary ethanol and water intake in male and female Fischer and Lewis rats.

Several lines of evidence implicate reciprocal interactions between excessive alcohol (ethanol) intake and dysregulation of circadian biological rhythms. Thus, chronic alcohol intake leads to widespread circadian disruption in both humans and experimental animals, while in turn, chronobiological disruption has been hypothesized to promote or sustain excessive alcohol intake. Nevertheless, the effects of circadian disruption on voluntary ethanol intake have not been investigated extensively, and prior studies have reported both increased and decreased ethanol intake in rats maintained under ‘‘shift-lag’’ lighting regimens mimicking those experienced by shift workers and transmeridian travelers. In the present study, male and female inbred Fischer and Lewis rats were housed in running wheel cages with continuous free-choice access to both water and 10% (vol/vol) ethanol solution and exposed to repeated 6-h phase advances of the daily lightedark (LD) cycle, whereas controls were kept under standard LD 12:12 conditions. Shift-lag lighting reduced overall ethanol and water intake, and reduced ethanol preference in Fischer rats. Although contrary to the hypothesis that circadian disruption would increase voluntary ethanol intake, these results are consistent with our previous report of reduced ethanol intake in selectively bred high-alcohol-drinking (HAD1) rats housed under a similar lighting regimen. We conclude that chronic circadian disruption is a form of chronobiological stressor that, like other stressors, can either increase or decrease ethanol intake, depending on a variety of poorly understood variables. 2010
Impacts of Free Trade Agreement on US State Vegetable and Fruit Trade Flows

A few studies have shown that free trade agreements have affected the pattern of state exports. This paper examines the effects of free trade agreements on US state vegetable and fruit trade flows. We propose a single commodity gravity equation to overcome a common shortcoming of most gravity models, which are applied to aggregate trade flows. Our results show significant gross trade creation effects of NAFTA and APEC that are greater than the EU gross trade creation effects. In addition, our findings reveal that the Asian Pacific Rim region is a significant destination of many vegetables and fruits from US states.
Automatically RESTful web applications: marking modular serializable continuations

Continuation-based Web servers provide distinct advantages over traditional Web application development: expressive power and modularity. This power leads to fewer errors and more interesting applications. Furthermore, these Web servers are more than prototypes; they are used in some real commercial applications. Unfortunately, they pay a heavy price for the additional power in the form of lack of scalability.We fix this key problem with a modular program transformation that produces scalable, continuation-based Web programs based on the REST architecture. Our programs use the same features as non-scalable, continuation-based Web programs, so we do not sacrifice expressive power for performance. In particular, we allow continuation marks in Web programs. Our system uses 10 percent (or less) of the memory required by previous approaches.
Time-average reflection-moiré method for vibration analysis of plates

A moire method is described whereby time-average slope contours are obtained from vibrating plates. It has an advantage over deflection contouring methods in that only first-order differentiation of experimental data is needed for stress calculations.
Vector continued fractions

Abstract By exploiting an isomorphism between vectors and certain matrices, the theory of vector-valued continued fractions is developed as a special case of the theory of matrix-valued continued fractions. It is shown that if a given power series has coefficient vectors lying in Hilbert space, then the vector-valued Pade quotients derived from this series also lie in Hilbert space. Properties of the matrices occuring in the vector-matrix isomorphism are examined; in particular, it is shown that the numerical values of certain norms of a vector are equal to those of the corresponding norms of its companion matrix. The concept of a functional Pade table is introduced, and one of its properties is derived.
Instrumental Neutron Activation Analysis Of French Geochemical Reference Samples

Instrumental neutron activation analytical data, for eighteen trace elements (Ba, Co, Cr, Cs, Hf, Rb), Sb, Sc, Ta, Th, La, Ce, Nd, Sm, Eu, Tb, Yb, Lu), Hd2O and Fe203 in eleven French geoche-mical reference samples are presented and discussed briefly.
Two types of pigeon key pecking: suppression of long- but not short-duration key pecks by duration-dependent shock

The key pecking of eight pigeons was maintained on a variable-interval 1-minute schedule of food reinforcement. Sometimes, all responses between 35 and 50 milliseconds in duration produced a shock; sometimes, all responses between 10 and 25 milliseconds produced a shock; sometimes, shocks were produced by pecks without regard to duration (nondifferential punishment), and sometimes shocks were delivered independently of responding. Punishment of 35- to 50-millisecond responses selectively suppressed those responses, while punishment of 10- to 25-millisecond responses and nondifferential punishment suppressed responding overall but did not suppress responses of particular duration. Punishment of 35- to 50-millisecond responses suppressed key pecking slightly less than did nondifferential punishment. Punishment of 10- to 25-millisecond responses and response-independent shock produced roughly equal amounts of suppression, substantially less than the other punishment procedures. The data support the view that there are at least two kinds of key peck, identifiable on the basis of duration, one of which (short duration) is insensitive to its consequences.
Safety and Efficacy of Clopidogrel Reloading in Patients on Chronic Clopidogrel Therapy Who Present With an Acute Coronary Syndrome and Undergo Percutaneous Coronary Intervention

The clinical safety and efficacy of clopidogrel reloading in patients receiving long-term clopidogrel therapy who present with acute coronary syndromes and undergo percutaneous coronary intervention have not yet been evaluated. The study cohort comprised 1,368 consecutive patients receiving long-term clopidogrel therapy (75 mg/day) who had presented with acute coronary syndromes and underwent coronary artery stent implantation. In total, 926 patients were given a 600-mg clopidogrel loading dose (reload cohort) before cardiac catheterization, while 442 patients were not reloaded (no-reload cohort). Patients who had presented with cardiogenic shock or stable angina were excluded. The 2 cohorts were well matched for the conventional risk factors for coronary artery disease. The analyzed clinical end points of death (1.1% vs 0.9%, p = 0.77), death or Q-wave myocardial infarction (0.9% vs 0.9%, p = 1.0), target lesion revascularization (0.2% vs 0.8%, p = 0.45), target vessel revascularization (1.1% vs 1.1%, p = 1.0), and major adverse cardiac events (2.0% vs 1.8%, p = 0.8) were similar between the no-reload and reload groups at 30 days. The in-hospital rates of major bleeding and gastrointestinal bleeding were also similar between the 2 cohorts. There were no cases of definite stent thrombosis. In conclusion, patients receiving long-term clopidogrel therapy who present with acute coronary syndromes do not gain any clinical benefit from additional reloading with clopidogrel.
Appetite regulation: Shedding new light on obesity

Several genes involved in the regulation of appetite and energy metabolism have been cloned and characterized recently. Each seems to form part of the complex regulatory network, centred in the hypothalamus, that is responsible for striking a balance between food intake and energy expenditure.
Voluntary control of penile tumescence.

This study investigated the voluntary control of penile tumescence in the absence of external erotic stimulation. Twelve experimental subjects were given analogue visual feedback and monetary rewards for increase in penile diameter as measured by a strain gauge. Twelve control subjects were given no analogue feedback and noncontingent rewards but the same instructions to maximize erections. While both groups were capable of voluntary penile tumescence, significantly improved performance was observed in the experimental group. Two distinct psychophysiological patterns of voluntary penile tumescence were observed. A "tension" pattern was associated with marked heart rate acceleration, irregular respiration, and variable penile response. A "relaxation" pattern was associated with stable heart rate, regular respiration, and smooth tumescence curves. In using these procedures for the treatment of sexual dysfunctions, it is suggested that feedback and reward be given for a combined pattern of sexual and autonomic responses. Language: en
WISC‐R: The first five years

Since its introduction five years ago (1974), 113 articles or papers have appeared regarding the WISC-R, including empirical investigations of its nature, as well as its comparability with a variety of other measures of intelligence and achievement, including the WISC. While not all this research has been carefully done, two general conclusions can be derived from the review. First, although the WISC-R involves modification in administration, design, and presentation of items, as well as a complete restandardization, the literature substantially suggests that it remains very similar in nature to its predecessor, the WISC. Investigations of factor analytic structures, standard errors, reliability coefficients, and subtest intercorrelations support the conclusion that individuals perform on the WISC-R largely the same as they do on the WISC. The second conclusion points out (with few exceptions): consistently lower scores were obtained on the WISC-R than on several other measures, including the WISC, the WAIS, the Slosson Intelligence Test, the Peabody Picture Vocabulary Test, and the Stanford Binet, which was revised shortly before the WISC. These lower scores on the WISC-R may be due to a variety of influences, including examiner variance, an artifact of design leading to inflated scores on the WISC, and finally and most obviously, the restandardization of the scale. The amount of literature that has appeared over the five-year period suggests that practitioners and researchers are as interested in learning about the WISC-R as they were about the WISC. Despite this fact and the conclusion that the WISC and WISC-R are substantially similar, the present authors encourage caution in the overgeneralization of findings until additional literature develops.
Shedding of Tumor Necrosis Factor Type 1 Receptor after Experimental Spinal Cord Injury

In a number of stress conditions, the biological effects of tumor necrosis factor–α (TNF-α), such as the induction of neuronal apoptosis, are presumably attenuated by the soluble fragments of TNF receptors (sTNFRs). Within 1 h after spinal cord injury, increased synthesis and/or secretion of TNF-α is detectable at the injury site. However, the shedding of ectodomains of TNFRs in the traumatized spinal cord has not yet been reported. In the present study, adult Sprague-Dawley rats were subjected to acute spinal cord injury (ASCI) by applying a 25-g Walsh-Tator aneurysm clip at the C8-T1 level. Sham-injured animals underwent laminectomy and facetectomy only. A PE10 catheter was placed in the subarachnoid space to collect the samples of cerebrospinal fluid (CSF) from near the injury site. These CSF samples were analyzed by ELISA for the presence of TNF-α and soluble TNFR1 and TNFR2 (sTNFR1 and sTNFR2, respectively). The spinal cord tissue was analyzed by immunohistochemistry for the expression of TNF-α, TNFR...
Effects of the Add-A-Word spelling program on test accuracy, grades, and retention of spelling words with fifth and sixth grade regular education students

ABSTRACT This study compares the Add-A-Word spelling program to a traditional basal spelling program in an intermediate grade school classroom. The participants were 16 fifth and sixth grade students enrolled in a private parochial school. A counterbalanced time series design was employed to evaluate the effects of the Add-A-Word program across two groups of students. The overall results indicate that students' weekly tests significantly increased during the Add-A-Word program each time it was in effect. The participants received higher quarterly letter grades in spelling during the Add-A-Word condition than during basal instruction. Retention rates on 9-week, 50 word tests were not affected by either the Add-A-Word or basal procedures but gradually increased over time. Benefits to students as well as the difficulties of implementing the Add-A-Word Spelling program are outlined.
Stationary optimal control of a stochastic system with stable environmental interferences

In this paper, we consider a class of nonstationary control systems. We obtain some conditions for stationary optimal controls of such systems. The results are then applied to a linear-quadratic system.
Myology of the shoulder of Pontoporia blainvillei, including a review of the literature on shoulder morphology in the cetacea

The purpose of this paper is to describe in detail the shoulder myology of the La Plata River Dolphin, Pontoporia blainvillei, and to review the literature on cetacean shoulder myology. Three fetal and one adult animal were used for the collection of morphological information. Pontoporia is less specialized in its shoulder anatomy that most delphinid cetaceans, and shares several characteristics with some mysticetes. The omohyoid and anterior serratus anterior muscles are found in both Pontoporia and the mysticete Balaenoptera, but are absent in most delphinids. The pectoralis abdominalis and three rhomboideus divisions are found in Pontoporia and Kogia, but in only a few delphinid species described in the literature. It is suggested that these characteristics are associated with a generalized use of the forelimb in Pontoporia.
A simple method for detecting genetically modified maize in common food products

A commercially available leaf DNA extraction and amplification kit has been adapted for the detection of genetically modified material in common food products containing maize. Amplification using published primer pairs specific for the Bacillus thuringiensis delta-endotoxin and maize invertase genes results in a 226-bp invertase PCR product in all samples (an internal positive control) plus a 184-bp product in samples that are genetically modified with the endotoxin gene. The ease and rapidity of DNA extraction and PCR make this exercise especially suitable for advanced-placement high school or lower division college biology students.
Diagnostics for Group Effects in Regression Analysis

The diagnostic tools examined in this article are applicable to regressions estimated with panel data or cross-sectional data drawn from a population with grouped structure. The diagnostic tools considered include (a) tests for the existence of group effects under both fixed and random effects models, (b) checks for outlying groups, and (c) specification tests for comparing the fixed and random effects models. A group-specific counterpart to the studentized residual is introduced. The methods are illustrated using a hedonic housing price regression.
Kinetic analysis of [36Cl]-, [22Na]- and [3H]mannitol uptake into the in vivo choroid plexus-cerebrospinal fluid brain system: Ontogeny of the blood-brain and blood-CSF barriers

Abstract The kinetics of penetration of radioactive [36Cl]-, [22Na]- and [3H]mannitol into the choroid plexus-CSF brain system was investigated in 1-week, 2-week and adult Sprague-Dawley rats. For adults rats (5 weeks), 36Cl and 22Na uptake by the choroid plexus of lateral ventricle (LVCP) and fourth ventricle (4VCP) resolved into a fast component (t 1 2 0.02–0.05 h) representing isotope distribution within the extracellular and residual erythrocyte compartments, and a slow component ( t 1 2 0.8–1.9 h ) representing isotope movement into the epithelial cell compartment. From steady-state distribution data, choroid cell [Cl] in both LVCP and 4VCP was calculated to be 67 mmol/kg cell H2O, a level nearly 4 times greater than that predicted by the membrane potential for passive distribution. In 1-week immature rats cell [Cl] and [Na] in the choroid plexuses were even greater than the corresponding levels in adults, probably because ion transport across the basolateral membrane is not yet coupled with ion movement from cell to CSF. In mature rats the 36Cl and 22Na uptake into the CSF resolved into 2 components ( t 1 2 0.18 h , fractional volume 0.24 and t 1 2 1.2 h , fractional volume 0.76); however, the fast component of CSF uptake, which likely represents isotope movement across the choroid plexuses, was negligible in the 1-week animals. Permeability-surface area products (PA) were determined for the blood-CSF barrier (i.e. the choroid plexuses) as well as the blood-brain barrier (cerebral cortex and cerebellum). The PA values for 36Cl and 22Na as determined by the fast component of CSF uptake (choroid plexus secretion?) were an order of magnitude less in the 1-week rats than in adults. In contrast, the effective permeability of the blood-CSF barrier as well as the the blood-brain barrier, as evaluated by changes in PA of [3H]mannitol, decreased steadily with advancing age.
Photophysics of Tryptophan Fluorescence: Link with the Catalytic Strategy of the Citrate Synthase from Thermoplasma acidophilum†

The formation of all major intermediates in the reaction catalyzed by the citrate synthase from Thermoplasma acidophilum is accompanied by changes in tryptophan fluorescence. The largest change is the strong quenching observed on formation of the binary complex with substrate, oxaloacetate (OAA). The four tryptophan residues present in the enzyme have been changed to nonfluorescent ones in various combinations without major perturbations in protein stability, enzyme mechanism, or other physical properties. W348, residing in the hydrophobic core of the protein behind the active site wall ca. 9 A from OAA, is responsible for the majority of the protein's intrinsic fluorescence and all of the quenching that accompanies OAA binding. Lifetime studies show that all of the quenching results from excited-state processes. The lack of solvent isotope effects on the quantum yields excludes a quenching mechanism involving proton transfer to an acceptor. There are no significant changes in fluorescence properties in single site mutants of residues near W348 that change conformation and/or interactions when OAA binds. This result excludes these changes from a direct role. Electron transfer from the indole excited state to some acceptor is the major quenching mechanism; the reduced quenching observed in the 5F-W-substituted protein strengthens this conclusion. Using the X-ray structures of the unliganded enzyme and its OAA binary complex, hybrid quantum mechanics-molecular dynamics (QM-MM) calculations show that OAA itself is the most likely quencher with the OAA carbonyl as the electron acceptor. This conclusion is strengthened by the ability of an alpha-keto acid model compound, trimethylpyruvate, to act as a diffusional quencher of indole fluorescence in solution. The theoretical calculations further indicate that the positive electrostatic potential surrounding the OAA carbonyl within the enzymes' active site is essential to its ability to accept an electron from the excited state of W348. These same environmental factors play a major role in activating OAA to react with the carbanion of acetyl-CoA. Since carbonyl polarization plays a role in the catalytic strategies of numerous enzymes whose reactions involve this functional group, tryptophan fluorescence changes might be useful as a mechanistic probe for other systems.
Minimum Color Differences for Discriminating Mismatch between Composite and Tooth Color

PURPOSE: The purpose of this study was to determine if there are differences between patients and dental professionals in their ability to identify small color differences (deltaE) in composite resin restorative materials in vitro and to determine the deltaE that would indicate acceptability of color match between a restoration and an adjacent tooth. MATERIALS AND METHODS: Subjects were asked to evaluate composite resin disks to distinguish acceptability of deltaE between disk pairs. Color difference discrimination of dental professionals groups D1 (dentists, n = 12) and D2 (dental auxiliaries, n = 12) was compared to that of dental patient groups P1 (patients, n = 12) and P2 (scientists, n = 12). Each group was pretested for normal color vision. Color differences between a standard and restoration disks of composite were measured in Colour Measurement Committee (CMC) (1:1) color units. Data were analyzed by logistic regression, and results were used to calculate a probability level for minimal acceptance or rejection of AE for all observers. Mean 50:50 deltaE replacement points (RP) for each group were obtained and analyzed by analysis of variance, and the Tukey pairwise comparison test was applied (alpha = 0.05 for all statistical analyses). RESULTS: There were significant differences found between the experimental groups (p = .020). Group D2 (mean 50:50 deltaE RP = 1.78) proved to be more discriminating in accepting differences between tooth and composite resin restorative material color than group P1 (mean 50:50 deltaE RP = 2.69). The mean 50:50 deltaE RP for all subjects was 2.29 CMC (1:1) units. CLINICAL SIGNIFICANCE: The ability to generate an excellent color match between a tooth-colored restoration and the tooth is critical to esthetic success. This study demonstrates that patients are not as discriminating in their ability to identify small color differences between composite restorations and the tooth as are dental professionals. Dental auxiliaries proved to be more discriminating in accepting differences between tooth and composite resin restorative material color than were patients.
Multi-residue method for the determination of chlorinated phenol metabolites in urine.

Electron-capture-gas chromatographic (EC-GC) methods for the determination of chlorinated phenol metabolites of hexachlorobenzene (HCB) and pentachlorophenol (PCP) in urine are presented. After extraction the sample was reacted with diazomethane to produce the methyl ether of each metabolite prior to determination by EC-GC. An acid alumina column was used for cleanup and separation of methylated phenols into groups. Average recoveries of greater than 80% were obtained from urine fortified with known amounts of the phenol metabolites under investigation. A level of 1 ppb1 was established as minimum detection limit for each phenol metabolite. Previously unreported urinary metabolites of HCB and PCP were found as a result of a rat feeding study. Levels of chlorinated phenol residues from (a) human general population and (b) a worker occupationally exposed to PCP are also included.
Microstructural evaluation of as-solidified and heat-treated γ-TiAl based powders

Powders with nominal compositions (in atomic %) Ti-48Al and Ti-48Al-2Nb-2Cr were prepared by the plasma rotating electrode process (PREP) and gas atomization (GA) techniques. As-solidified and heat treated (1000{degrees} C/3 hr) powder samples were examined by metallography, SEM, X-ray diffraction, and TEM. The microstructures of the powders were characterized as a function of atomization technique, alloy content, powder particle size (solidification rate), and thermal history. All of the as-solidified powders were comprised of disordered {alpha}, and ordered {alpha}{sub 2}-Ti{sub 3}Al and {gamma}-TiAl. For both alloys, a larger volume fraction of {alpha} and {alpha}{sub 2} was observed in the PREP powders relative to GA powders of comparable size. Additionally, for both alloys and both atomization techniques, the volume fraction of {alpha}{sub 2} was observed to increase with decreasing powder particle size. In general, the PREP powders appeared to solidify more rapidly than the GA powders. Possible reasons for the differences in microstructures and solidification rates observed for the two atomization techniques will be discussed. Upon heat treatment, the microstructure of the powders was similar. The heat treated powders were comprised predominently of equiaxed {gamma} grains with limited amounts of lamellar {alpha}{sub 2}/{gamma} grains also present. The GA powders did exhibit amore » slightly higher volume fraction of {alpha}{sub 2} than the PREP powders, possibly due to slight differences in the Al content of the alloys or the higher oxygen content of the GA alloys.« less
Nucleotide sequence of the genetically labile repeated elements 5′ to the origin of mouse rRNA transcription

We have determined the complete nucleotide sequence of a cloned Balb/c mouse rDNA NTS fragment containing 13 tandem copies of a 135 bp subrepeating segment. This repetitious region (VrDNA) lies close to the origin of ribosomal RNA transcription. Analyses of these VrDNA subrepeats from Balb/c and a related species, Mus pahari, reveal regions of inverted repeat DNA as well as large poly T tracts, either of which may be significant to the generation of the high levels of VrDNA copy number variation found in wild and inbred mice and/or the modulation of rRNA synthesis. Unlike the highly homogeneous subrepeats in the Xenopus laevis NTS repetitious regions, the VrDNA subrepeats differ from one another on the average by about 13%. Sequence analysis and Southern hybridization studies have also shown that, unlike the Xenopus and Drosophila NTS, extensive duplications of sequences found surrounding the mouse rRNA initiation site are found neither in the VrDNA region nor 6 kb further upstream in the NTS.
Vascular surgery-associated ureteral injury: Zebras do exist

This report describes a case of direct ureteral injury sustained during retroperitoneal vascular surgery. The diagnosis was delayed and treatment was complicated by infection. To address the patient's problem initially and then to consolidate our impressions, a literature review was undertaken. The conclusions from this review suggest that direct ureteral injury during vascular surgery is rare but most common during redo surgery, is just as likely to be missed as discovered during surgery, and when missed may be so for months. The diagnostic delay is caused by a varied and often misleading presentation, and a ureteral contrast study is the ultimate diagnostic tool. In these delayed cases the typical ureteral treatment is a stented ureteroureterostomy or nephrectomy. In the present case the patient was otherwise healthy; therefore an aggressive attitude to renal salvage was taken. This is a unique case of ileal conduit replacement of the damaged ureter for this specific situation. Five years after repair, renal function is stable without infectious complications. The current literature would suggest that the vascular graft may be left undisturbed if the urine is sterile. If infection is present, graft removal appears the standard of care and was successful in the present case.
Recent advances in microfluidic cell separations

The isolation and sorting of cells has become an increasingly important step in chemical and biological analyses. As a unit operation in more complex analyses, isolating a phenotypically pure cell population from a heterogeneous sample presents unique challenges. Microfluidic systems are ideal platforms for performing cell separations, enabling integration with other techniques and enhancing traditional separation modalities. In recent years there have been several techniques that use surface antigen affinity, physical interactions, or a combination of the two to achieve high separation purity and efficiency. This review discusses methods including magnetophoretic, acoustophoretic, sedimentation, electric, and hydrodynamic methods for physical separations. We also discuss affinity methods, including magnetic sorting, flow sorting, and affinity capture.
IR-UWB transmitters synthesized from standard digital library components

This paper presents two impulse radio ultrawideband (IR-UWB) transmitters which are synthesized from standard digital library components. All functional blocks in the transmitters are implemented with digital standard cells, and placed-and-routed (PAR) by automatic design tools; therefore the transmitter is portable and scalable to other process technologies. To verify the feasibility of the architecture, the transmitter is implemented in a FPGA device, then, fabricated in a 65nm CMOS process. The 65nm CMOS transmitter occupies 0.0375mm2, and the active energy consumption while pulsing is 90pJ/pulse.
A framework for testing first-order logic axioms in program verification

Program verification systems based on automated theorem provers rely on user-provided axioms in order to verify domain-specific properties of code. However, formulating axioms correctly (that is, formalizing properties of an intended mathematical interpretation) is non-trivial in practice, and avoiding or even detecting unsoundness can sometimes be difficult to achieve. Moreover, speculating soundness of axioms based on the output of the provers themselves is not easy since they do not typically give counterexamples. We adopt the idea of model-based testing to aid axiom authors in discovering errors in axiomatizations. To test the validity of axioms, users define a computational model of the axiomatized logic by giving interpretations to the function symbols and constants in a simple declarative programming language. We have developed an axiom testing framework that helps automate model definition and test generation using off-the-shelf tools for meta-programming, property-based random testing, and constraint solving. We have experimented with our tool to test the axioms used in Auto-Cert, a program verification system that has been applied to verify aerospace flight code using a first-order axiomatization of navigational concepts, and were able to find counterexamples for a number of axioms.
Fast M-sequence transform for laser-Doppler-based mine detection

Low detector signals, acoustic coupling and speckle noise are challenging problems in the laser Doppler-based acoustic-to-seismic detection of land mines. Scanning insonified patches over buried targets with the spatial resolution required in minefield applications demands processing a large quantity of detection data. To achieve an efficient and robust detection, acoustic-to-seismic coupling on the ground is considered as a system under test (SUT), number-theoretical maximum-length sequences (M-sequences) have been applied as the acoustic excitation to the SUT. Exploiting their excellent auto-correlation property and high noise immunity due to high signal energy and noise suppression, a fast algorithm (so-called fast M-sequence transform) is implemented in the cross-correlation procedure to extract the impulse response of the SUT directly from laser Doppler vibrometer signals with a high signal-to-noise ratio. The advantage of directly obtaining impulse responses is also exploited in featuring a time windowing technique to isolate the acoustic coupling into the laser Doppler-based system.
How to calm hyperactive agents

System performance in multi-agent resource allocation systems can often improve if individual agents reduce their activity. Agents need a way to modulate their individual behavior in light of the system's state, preferably without centralized control. We illustrate the problem of hyperactive agents in two domains related to resource allocation. A simple, decentralized scheme, inspired by insect pheromones, enables individual agents to adjust their activity as the system operates, and suggests a general approach to dealing with approaching deadlines.
NK cells – From Bench to Clinic

After decades of mouse and human research, we now know that natural killer (NK) cells have unique properties including memory. Although initially described as major histocompatibility complex (MHC) unrestricted killers, NK cells have several families of receptors that directly recognize MHC including Ly49 receptors in the mouse and killer immunoglobulin-like receptors (KIR) in humans. The strength of this signal is determined by polymorphisms in NK cell inhibitory receptor genes and their MHC ligands inherited on different chromosomes. Inhibitory receptors protect "self"-expressing normal tissue from being killed by NK cells and protecting against autoimmunity. Therefore, for NK cells to kill and produce cytokines, they must encounter activating receptor ligands in the context of "missing self" that occurs with some viral infections and malignant transformation. The second property of inhibitory receptors is to educate or license NK cells to acquire function. This is best demonstrated in the mouse and in humans by enhanced function on self-inhibitory receptor-expressing NK cells when in a host expressing cognate ligate. In contrast, NK cells without inhibitory receptors or with nonself-inhibitory receptors are relatively hyporesponsive. The basic biology of NK cells in response to cytokines, education, and viruses will translate into strategies to manipulate NK cells for therapeutic purposes.
Histological manifestations of a magnesium deficiency in the rat and rabbit.

SummaryLow levels of magnesium in the diet of rabbits and rats produced chromatolysis and degeneration of the cells of Purkinje of the cerebellum in the rat and rabbit. Nephrosis and fibrosis of the kidney occurs in rabbits restricted to a diet deficient in magnesium.
Effect of pH on the solubility and release of furosemide from polyamidoamine (PAMAM) dendrimer complexes

The complexation of the practically insoluble drug furosemide (acidic pK(a) 3.22) with lower generation PAMAM dendrimers showed a significant release dependence on the ionization state of the drug. UV and FTIR studies suggested that the drug was localized in the interior of the dendrimer. The dendrimer amine, amide and ester groups, demonstrated pH-dependent ionization as did the drug carboxylic acid group and it was proven that the most efficient drug complexation was achieved in slightly acidic conditions (pH 4.0-6.0). At this pH, amide groups in the dendrimer cavities were at least partially ionized to expose a positive charge whilst the furosemide carboxylic acid ionized to great extent (pH>pK(a)) resulting in electrostatic complexation. Conversely, higher release rates were observed in acidic conditions (pH 1.2) where furosemide was virtually unionized, emphasizing the importance of the drug ionization state in the determination of drug release. Despite the complex interactions between the dendrimer and drug and its effects on release kinetics, the dendrimers resulted in higher solubility of the drug and contributed significantly to the array of available techniques to increase the solubility of poorly water-soluble drugs that are very abundant in industry today. Complexation with low generation PAMAM dendrimers (<generation 4) could provide opportunities to both increase drug solubility and tuning of the release profile for practically insoluble drugs.
PCR-amplification of mixed 16S rRNA genes from an anaerobic, cyanide-degrading consortium

The microorganisms participating in the anaerobic biodegradation of cyanide were characterized using 16S rRNA genes as genetic markers of diversity. Segments of mixed population 16S rRNA genes were amplified using the polymerase chain reaction (PCR) and prokaryote-specific amplification primers. Restriction fragment length polymorphism (RFLPs) and screening with the 926f universal sequencing primer were used to categorized the cloned PCR products. Six unique prokaryote sequence were obtained, including four similar to methanogens and two similar to Gram-positive eubacteria.
Discovery of N-(2,4-di-tert-butyl-5-hydroxyphenyl)-4-oxo-1,4-dihydroquinoline-3-carboxamide (VX-770, ivacaftor), a potent and orally bioavailable CFTR potentiator.

Quinolinone-3-carboxamide 1, a novel CFTR potentiator, was discovered using high-throughput screening in NIH-3T3 cells expressing the F508del-CFTR mutation. Extensive medicinal chemistry and iterative structure–activity relationship (SAR) studies to evaluate potency, selectivity, and pharmacokinetic properties resulted in the identification of N-(2,4-di-tert-butyl-5-hydroxyphenyl)-4-oxo-1,4-dihydroquinoline-3-carboxamide (VX-770, 48, ivacaftor), an investigational drug candidate approved by the FDA for the treatment of CF patients 6 years of age and older carrying the G551D mutation.
Production of mass-selected neutral clusters of rubidium

Abstract Charge neutralization of rubidium cluster ions (Rb N + ) by Rb atomic vapor is reported. The cluster ions are generated by a liquid metal ion source (LMIS). The ions and the neutrals are detected directly without any photoionization step. The extent of dissociative neutralization is negligible. This results in intense, mass-selected neutral cluster beams. The charge exchange cross sections for Rb 2 + and Rb 3 + with Rb, are 9.3× 10 −15 and 3.1 × 10 −15 cm 2 respectively.
Intensity noise reduction in semiconductor lasers by amplitude-phase decorrelation

Detuned operation of a laser results in coupling of field amplitude and phase fluctuations. In a semiconductor laser, this coupling is known to be very large. We demonstrate that it can be used to significantly reduce intensity noise below its intrinsic limit.