cssi/SciSciGPT-SciSciNet huggingface dataset:
Risk factors for early onset elevated intraocular pressure after pterygium surgery.

Purpose In this study, we aimed to identify the risk factors for early postoperative elevation of intraocular pressure (IOP) after pterygium surgery. Patients and methods All patients in this retrospective cohort study were evaluated for inclusion from a single tertiary care center at Boston Medical Center. Their pre- and postoperative IOP measurements (day 1, week 1, month 1, month 3, and when clinically necessary) were compared. Patients with postoperative IOP measurement of >22 mmHg or with an increase in IOP by ≥10 mmHg compared with the preoperative measurement value were grouped as "Ocular Hypertension" group; otherwise, patients were grouped in the "No Ocular Hypertension" group. Age, sex, race, baseline IOP, cup-to-disc (C/D) ratio, history of glaucoma, and frequency of use of postoperative steroid drops in all patients were compared. Chi square test was performed to compare the categorical variables, whereas Student's t-test was performed to compare continuous variables. We performed a multivariate logistic regression analysis of categorical data with a significance level of p Results In total, 240 patient charts were reviewed for inclusion in this study. Twenty-six patients required pterygium surgery on both eyes; for these patients, the eye with higher IOP was analyzed. Two patients were discontinued from this study because of elevated IOP in the contralateral, nonsurgical eye. Fortyeight out of 212 eyes (22.64%) developed postsurgical elevation of IOP within the first 3 months of operation. No significant differences were found between age, sex, baseline IOP, C/D ratio, history of glaucoma diagnoses, and frequency of use of postoperative steroid drops. However, Hispanic/Latino race (p = 0.036) and lack of application of steroid ointment (p = 0.001) were found to be the significant risk factors for the development of "Ocular Hypertension" in multivariate analysis. Conclusion Early elevation of IOP is a risk of pterygium surgery. One nonmodifiable risk factor, Hispanic/Latino race, and one modifiable risk factor, lack of application of steroid ointments, were identified as potential causes of early postoperative IOP elevation.
Dynamic Learning Rate for Neural Networks: A Fixed-Time Stability Approach

Neural Networks (NN) have become important tools that have demonstrated their value solving complex problems regarding pattern recognition, natural language processing, automatic speech recognition, among others. Recently, the number of applications that require running the training process at the front-end in an online manner have increased dramatically. Unfortunately, in state-of-the-art (SoA) methods, this training process is an unbounded function of the initial conditions. Thus, there is no insight on the number of epochs required, making the online training a difficult problem. Speeding up the training process plays a key role in machine learning. In this work, an algorithm for dynamic learning rate is proposed based on recent results from fixed-time stability of continuous-time nonlinear systems, which ensures a convergence time bound to the equilibrium point independently of the initial conditions. We show experimentally that our discrete-time implementation presents promising results, proving that the number of epochs required for the training remains bounded, independently of the initial weights. This constitutes an important feature toward learning systems with real-time constraints. The efficiency of the method proposed is illustrated under different scenarios, including the public database MNIST, which shows that out algorithm outperforms SoA methods in terms of the number of epoch required for the training.
CB2 distinguishes cells from background barcodes in 10x Genomics data

An important challenge in pre-processing data from the 10x Genomics Chromium platform is distinguishing barcodes associated with real cells from those binding background reads. Existing methods test barcodes individually, and consequently do not leverage the strong cell-to-cell correlation present in most datasets. To improve the power to identify real cells and rare subpopulations, we introduce CB2, a cluster-based approach for distinguishing real cells from background barcodes.
Recessivity of pyrethroid resistance and limited interspecies hybridization across Hyalella clades supports rapid and independent origins of resistance

Abstract Several populations of the amphipod, Hyalella azteca, have developed resistance to pyrethroid insecticides due to non-target exposure, but the dominance of the resistance trait is unknown. The current study investigated the dominance level of point mutations in natural populations of insecticide-resistant H. azteca and determined whether H. azteca from different clades with and without resistant alleles can hybridize and produce viable offspring. A parent generation (P0) of non-resistant homozygous wild type H. azteca was crossbred with pyrethroid-resistant homozygous mutant animals and the tolerance of the filial 1 (F1) generation to the pyrethroid insecticide, permethrin, was measured. Then the genotypes of the F1 generation was examined to assure heterozygosity. The resistant parents had permethrin LC50 values that ranged from 52 to 82 times higher than the non-resistant animals and both crossbreeding experiments produced heterozygous hybrid offspring that had LC50 values similar to the non-resistant H. azteca parent. Dominance levels calculated for each of the crosses showed values close to 0, confirming that the L925I and L925V mutations were completely recessive. The lack of reproduction by hybrids of the C x D breeding confirmed that these clades are reproductively isolated and therefore introgression of adaptive alleles across these clades is unlikely. Potential evolutionary consequences of this selection include development of population bottlenecks, which may arise leading to fitness costs and reduced genetic diversity of H. azteca.
Increased long-term health risks attributable to select volatile organic compounds in residential indoor air in southeast Louisiana.

Volatile organic compounds (VOCs) represent a broad class of chemicals, many of which can be found in indoor air including residential indoor air. VOCs derive from a variety of sources including cleaning products, cooking practices, fragrances and fresheners, hobbies and at-home work behaviors. This study examined residential indoor air in homes (n = 99) in southeast Louisiana using passive organic vapor monitors and gas chromatography/mass spectrometry to determine if select VOCs were present, at what concentrations, and if those posed any potential long-term health risks. Twenty-nine VOCs were targeted in cross-sectional analyses using a 48-h sampling period. Twelve VOCs were detected in most of the homes sampled including xylenes, pinenes, benzene, toluene, ethylbenzene, hexane, pentane, chloroform, and carbon tetrachloride. Concentrations of alkanes and BTEX compounds were highly correlated (Spearman’s r > 0.63, p < 0.0001). Using health risk measures (i.e. reference concentrations [RfCs] and inhalation unit risks [IURs]) available from the USEPA non-cancer risk assessments and cancer risk assessments were developed for some of these VOCs. Alkanes and BTEX compounds likely come from the same indoor source(s). Using existing health standards published by the USEPA, no unacceptable non-cancer risks were evident except under extremely high concentrations. Lifetime cancer risks, on the other hand, may well be considered unacceptable for chloroform and benzene (upper IUR) and for the combination of chloroform, benzene, and carbon tetrachloride. These exceeded a 1 in 10,000 cancer risk threshold in 35–50% of our simulations. Further study of residential indoor air in low-income women’s homes in this area is needed. Including a larger number of VOCs may reveal yet more potential health risks.
Establishing New Endoscopic Programs in the Unit Pitfalls and Tips for Success

Abstract Gastroenterology is a field that is rapidly evolving and its success hinges on its technological evolution. Endoscopy units around the world must attempt to stay current by introducing new techniques and endoscopic programs. In order to successfully launch a new endoscopy program, one must consider individual physician and staff training, engaging strategic partners, building out long-term business plans, and showing flexibility in addressing unforeseen circumstances such as the COVID-19 pandemic. Finally, there are specific issues that women face when advocating for their ideas to be considered in the endoscopy unit, gastroenterology practice, or medical center. Issues related to implicit bias can be overcome through preparedness, utilizing connections in your center and beyond, and accessing resources. Ultimately, having a well thought out strategy that incorporates the finances, partnerships and overall benefit to your practice can allow successful implementation of any new endoscopic program into your unit.
The Human Leukocyte Antigen Class II Immunopeptidome of SARS-CoV-2 Spike Glycoprotein

The precise elucidation of the antigen sequences for T-cell immunosurveillance greatly enhances our ability to both understand and modulate humoral responses to viral infection or active immunization. Mass spectrometry was used to identify 529 unique sequences from SARS-CoV-2 spike glycoprotein extracellular domain in a complex with human leukocyte antigen class II molecules on antigen presenting cells from a panel of healthy donors selected to represent a majority of allele usage from this highly polymorphic molecule. The identified sequences span the entire spike protein and several sequences were isolated from a majority of the donors sampled indicating promiscuous binding. Importantly, many peptides derived from the receptor binding domain used for cell entry were identified. This work represents the most precise and comprehensive immunopeptidomic investigation with SARS-CoV-2 spike glycoprotein and allows detailed analysis of features which may aid vaccine development to end the current COVID-19 pandemic. Funding: This work was supported by Eli Lilly and Company. Conflict of Interest: The authors declare no competing interests. Ethical Approval: Frozen PBMCs were obtained from 9 informed consent healthy donors (Discovery Life Sciences) according to local ethical practice.
Sources and Health Impacts of Chronic Exposure to Naturally Occurring Radioactive Material of Geologic Origins

The average person in the U.S. receives 6.2 mSv year−1 in combined radiation dose, whereas the average person worldwide receives 3.0 mSv year−1. The difference in these doses is primarily due to greater exposure to radon/thoron gas and a greater use of radiation in medicine in the U.S. Of this exposure, in the U.S. and worldwide, 3.1 and 2.4 mSv are absorbed per year from natural sources, respectively. Of all sources of radiation exposure to the public, exposure to radon and thoron make up the largest dose source comprising up to 36% and 42% of total annual absorbed dose in the U.S. and worldwide, respectively. Due to the carcinogenic nature of radiation and its ubiquity in the environment, the sources of natural exposure must be understood and controlled to improve public health worldwide.
Robots That Run their Own Human Experiments: Exploring Relational Humor with Multi-Robot Comedy

This paper proposes a street-style study method to conduct human-robot interaction studies in-the-wild where the robots conduct their own experiments by recruiting their audience, conducting the study and gathering data. This street-style study method was implemented using multi-robot comedy as the platform deployed at an arts and technology festival to validate the concept. Twelve robot comedy shows occurred over seven hours with two robots on stage, who queried the audience during and at the end of each show. The multi-robot aspect enabled the robots to act out interactions relative each other, oneself and the audience. The final street-style study method evolved from pilots at a local farmer’s market, with hardware designed for portability and easy replication. The robots conducted their own human experiments in that they queried the audience after displaying experimentally balanced episodes of relational humor, with permutations of who was the ‘butt of the joke.’ Our study results explore the relational humor of the two robots and the audience, asking the audience to agree or disagree with particular perspectives. Delivered as part of the show, the robots invite the audience to vote via a show of hands. ANOVA analyses of the percent-agreement results find that (1) audiences were generally positive about all aspects of the show unless both robots were being negative, and (2) audiences were more ready to protect the robot comedian’s ego than their own, strongly supporting the statement that the robot was doing a good job.New Abstract
The Effects of Induced Arousal on Learning and Performance of a Pursuit Motor Skill

Abstract To examine the effects of induced-arousal on learning and performance of a motor skill, 42 subjects were administered practice on a pursuit rotor task over 2 days. Fifteen trials were given on Day 1 and 10 trials were administered 24 hr. later. Subjects were randomly assigned to one of three conditions: related arousal, unrelated arousal, or control. Arousal was enhanced by administering electric shock during trials 6-15 on Day 1. Subjects in the related arousal group received shock if their performance did not reach an established criterion, whereas subjects in the unrelated arousal group received shock on a random schedule regardless of their performance. The control group received no shock. To determine if the induced-arousal was anxiety evoking, the A-State form of the State-Trait Anxiety Inventory was administered. Analysis of the results indicated that electric shock administration significantly enhanced arousal of the related arousal group over the control group but not the unrelated arous...
Weighted Rayleigh quotients for minor and principal component extraction

New criteria are proposed for extracting in parallel multiple minor and principal components associated with the covariance matrix of an input process. The proposed minor and principal component analyzer (MCA/PCA) algorithms are based on optimizing a weighted inverse Rayleigh quotient so that the optimum equilibrium points are exactly the desired eigenvectors of a covariance matrix instead of an arbitrary orthonormal basis of the minor subspace. Variations of the derived MCA/PCA learning rules are obtained by imposing orthogonal and quadratic constraints and change of variables. Similar criteria are proposed for component analysis of the generalized eigenvalue problem. Some of the proposed MCA algorithms can also perform PCA by merely changing the sign of the step-size. These algorithms may be seen as generalization of Oja's and Xu's systems for computing multiple principal components.
Herfindahl Concentration with an Import Fringe and with Supply Constraints

The widely used Herfindahl index of concentration measures market power incorrectly in cases where a core of sellers faces a competitive fringe or where some subset of sellers is supply-constrained. These cases arise, for example, where domestic sellers face a small fringe of imports, or where import supply of any magnitude is limited by natural or artificial constraints. Returning to the theoretical roots of the Herindahl, this paper demonstrates how the index should be modified to deal with such circumstances.
Measurement of bone erosion cavities from CT scans

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease characterized by progressive joint destruction resulting from chronic synovial inflammation. Progression of this disease is noted by decreases in bone mineral density and joint space width, and increases in hand erosion count. Clinical scoring methods, however, are highly variable and may not be comparable between patients or across different scoring tests. Computer aided diagnostics may offer a more standardized and comparable method to measure progression of this disease. Three dimensional imaging techniques such as CT provide an accessible alternative to radiography for objectively assessing disease progression. The focus of this research was to develop and validate a method to measure the volume of cavities created in bone assessed with CT imaging.
Surface‐enhanced Raman spectroscopy in art and archaeology

Since its introduction in the cultural heritage field, nearly 30 years ago, surface-enhanced Raman spectroscopy (SERS) has emerged as a promising analytical technique that is particularly suitable for the detection and identification of organic colorants. Its great molecular selectivity and specificity, and unparalleled sensitivity compared to other instrumental methods, have allowed researchers to successfully characterize a wide number of natural dyes and a few synthetic ones in microscopic samples from objects of artistic, historical, and archaeological significance. Continued research over the course of the past decade has led to the construction of comprehensive databases of dyes, whose adsorption and spectral properties have been investigated at length; to the comparative study of the efficiency and performance of various metal substrates; and to the evaluation of several sample treatment methods and ad-hoc analytical protocols. In addition, recent literature in the field of SERS for art and archaeology has described instrumentation and technique advancements aimed at solving the unique challenges posed by the analysis of irreplaceable objects, namely, quasi non-destructive sampling, spatial resolution improvement, examination of insoluble compounds, and resolution of dye mixtures. Reviewing the most salient methodological and technological milestones that have traced the history of SERS for cultural heritage to date, the present article is intended as a practical resource for those researchers who would like to undertake systematic characterization of organic colorants from artworks using this powerful technique. Copyright © 2015 John Wiley & Sons, Ltd.
The Most Collimated Outflows of Planetary Nebulae

I characterize the common properties of highly collimated bipolar outflows and identify the most plausible mechanisms that create and maintain them.
An information theoretic approach to network tomography

In this article, we formulate an information theoretic approach to information recovery for a network flow transportation problem as an ill-posed inverse problem and use nonparametric information theoretic methods to recover the unknown adaptive-intelligent behaviour traffic flows. We indicate how, in general, information theoretic methods may provide a solution to the ill-posed inverse information flow problems, when a function must be inferred from insufficient sample information. As an application, we examine a data set which comprised traffic volumes at Bell Labs.
An analysis of the relationship of malignant lesions of the kidney to hypertension.

Abstract This study, designed in a “blind” fashion, presents, for the first time, a relationship of the histopathology of the kidneys with mean arterial blood pressure (MAP) and age in hypertensive species. Kidneys from 46 spontaneously hypertensive rats (SHR) aged 8–104 weeks were studied using light and electron microscopy (LM and EM, respectively), and their findings were compared with those in age-matched 35 normotensive Wistar rats (NR) and 28 Wistar-Kyoto rats (WKY). A scoring system for the severity of the renal changes (index scores) was developed, and the grading of the renal changes was made without any knowledge of age, MAP, or strain of rat from which kidneys were obtained. The severe (or malignant) renal lesions were found only in old SHR (av: 91 weeks), in contrast to mild or moderate renal lesions (benign) in young SHR (52 weeks or less). The findings of highly significant ( P P
Differential Labeling by Monoclonal Antibodies Adnab-9 and Anti-α-Defensin 5 Based on the Distribution and Adenomatous Tissue Content of Colonic Polyps

We sought a correlation between site and morphology of colonic polyps by labeling with neoplastic and general Paneth cell markers, monoclonal antibodies Adnab-9 and anti-α-defensin 5, respectively. Proportions labeled by Adnab-9 and anti-α -defensin 5 were, respectively, 42 and 85% for adenomas, 39 and 63% for early tubular adenomas, 41 and 44% for serrated, 34 and 20% for mixed, and 11 versus 2.7% for hyperplastic polyps. Compared with hyperplastic polyps, the proportion of other polyps labeled by Adnab-9 or anti-α-defensin 5 was higher but this difference was more significant for distal (P = 0.008 for Adnab-9 and P = 0.0001 for anti-α-defensin 5) than proximal (P = 0.645 and P = 0.154, respectively) polyps. While increased labeling of all proximal polyps compared to distal ones mirrored the colonic distribution of Paneth cells, distal adenomas tended to have a higher proportion labeled by Adnab-9, suggesting that Adnab-9 labels Paneth cells associated with increased neoplastic potential.
The war and the new world order

No country has ever managed to be a great power and a great debtor at the same time, and two great powers ‐ Britain in this century and Spain in the 16th century ‐ lost their stature as world leaders when they moved from creditor to debtor status. Joint Economic Committee of the US Congress, 1988. The United States has a new credibility. What we say goes. George Bush, speaking at a US military base, February 2, 1991.
Travelling waves for a reaction–diffusion system in population dynamics and epidemiology

The existence and uniqueness of travelling-wave solutions is investigated for a system of two reaction–diffusion equations where one diffusion constant vanishes. The system arises in population dynamics and epidemiology. Travelling-wave solutions satisfy a three-dimensional system about (u, u′, ν), whose equilibria lie on the u-axis. Our main result shows that, given any wave speed c > 0, the unstable manifold at any point (a, 0, 0) on the u-axis, where a ∈ (0, γ) and γ is a positive number, provides a travelling-wave solution connecting another point (b, 0, 0) on the u-axis, where b:= b(a) ∈ (γ, ∞), and furthermore, b(·): (0, γ) → (γ, ∞) is continuous and bijective
Personal space in a virtual community

This paper explores whether the societal norm of personal space influences behaviour during interaction and communication in a virtual environment. An online virtual world was explored using a participatory-observer approach over a period of 3 months. The results parallel personal space and physical distance literature: personal space exists; influences behaviour; produces discomfort and possible flight when violated. Future research should explore whether these results indicate identification with one’s avatar or another influence.
Effects of mortality salience and perceived vulnerability on HIV testing intentions and behaviour

Objective: Research indicates that death thoughts that occur in response to health threats affect subsequent health behaviour. The present study examined the effects of mortality salience on HIV testing.Design: After reading an article that was intended to make them perceive that they had high or low vulnerability to HIV, participants wrote about death or an aversive control topic. Participants then indicated their intentions to get tested for HIV and were given the opportunity to take an HIV test at the end of the study.Results: Results showed that mortality salience increased testing behaviour among participants who were made to feel vulnerable to HIV, but decreased testing behaviour among participants who were not made to feel vulnerable to HIV infection.Conclusion: This research suggests that HIV prevention programmes must carefully consider how the association many people make between HIV and death may interact with people’s perceptions of their vulnerability to HIV infection to affect their willingn...
Novel preparation of poly (vinyl alcohol) microparticles without crosslinking agent for controlled drug delivery of proteins

Abstract Poly (vinyl alcohol) microparticles were prepared by a novel freezing-thawing process in the absence of a crosslinking agent. An aqueous PVA solution was dispersed in corn oil to which 1.25 wt% sodium lauryl sulfate was added. The system was agitated and the ensuing suspended droplets of PVA solution were solidified by a cyclic freezing-thawing process. Key parameters of the process were the PVA to corn oil ratio, amount of surfactant added, agitation speed, number of freeze cycles, temperatures of freezing and thawing, and presence of additional components. The particles were then loaded with bovine serum albumin by an absorption technique and release studies were performed in vitro.
The potent induction of intestinal heme oxygenase by the organotin compound, bis(tri-n-butyltin)oxide.

Abstract Oral administration of bis(tri-n-butyltin)oxide, an important organotin biocidal agent, produces a substantial elevation in heme oxygenase activity when measured at 16 hours in rat small intestine. An apparent Km for hemin of 100 μM is the same in both control and the organotin-induced 9,000 × g supernatant preparations. Concomitant with elevated heme oxygenase activity there occurs a substantial reduction in benzo(a)pyrene hydroxylase activity (∼20% of controls) and cytochrome P-450 concentration (∼60% of controls). These perturbations of heme metabolism in intestinal epithelium of the rat define an important new toxicological effect of organotins and raise the possibility that concurrent oral ingestion of environmental pollutants can directly affect the cytochrome P-450-dependent metabolism of other chemicals in the intestine.
Conditioned effects of heroin on the expression of inducible nitric oxide synthase in the rat are susceptible to extinction and latent inhibition.

The administration of heroin has been shown to inhibit the induction of nitric oxide, a molecule known to play a critical role in immune function. Previous research has shown that this alteration can be conditioned to environmental stimuli that have been associated with drug administration. However, it remains unknown whether the conditioned effects of heroin on nitric oxide formation follow accepted principles of learning. This study sought to determine whether manipulations that induce extinction and latent inhibition, two learning paradigms known to reduce the expression of conditioned responses, would alter heroin’s conditioned effects on the expression of inducible nitric oxide synthase (iNOS). The conditioning procedure involved repeated pairing of heroin administration with placement into a standard conditioning chamber. Rats were repeatedly exposed to the chambers without heroin reinforcement to determine whether the conditioned response would extinguish. To induce latent inhibition, rats received repeated exposure to the chamber before the start of conditioning to inhibit the acquisition of the conditioned response. Ten days after the final conditioning session, all rats were injected with lipopolysaccharide (LPS) to induce iNOS expression. Spleen and liver tissue were removed to determine iNOS expression using reverse transcriptase polymerase chain reaction. Blood was collected to determine the concentration of nitrite/nitrate. The results showed that both extinction and latent inhibition reduced the conditioned effects of heroin on the production of nitric oxide. This study provides the first evidence that the conditioned effects of heroin on nitric oxide production follow accepted principles of learning.
Kinetics of vapor-solvent growth in the system ZnS:HCl

The method of growing ZnS crystals in a closed tube containing HCl as a vapor solvent and located in a temperature gradient around 1000°C is investigated. Experiments show that net flux of solid is directly proportional to the cross sectional area of the container and practically unaffected by surface reaction rates. The flux of solid increases with the square root of the pressure up to about 2 atm and is thereafter almost independent of pressure, showing only a slight monotonic decrease with increasing pressure up to 15 atm. In the latter range, the process is essentially diffusion controlled and the pressure dependence can be explained by the concomitant action of two chemical equilibria, viz. ZnS+2HCl ⇄ ZnCl2+H2S and the dissociation of hydrogen sulfide H2S ⇄ H2+ 12S2. Experiments carried out with mixtures of HC1 and Ar, and of HC1 and H2S reveal effects on the transport rate. One arises from the change of diffusion coefficients in the case of HCL and Ar. In addition, there is the change of chemical equilibrium in the case of HCl and H2S.
Molecular Origins of Heavy Oil Interfacial Activity Part 1: Fundamental Interfacial Properties of Asphaltenes Derived from Heavy Crude Oils and Their Correlation To Chemical Composition

Fundamental interfacial properties of n-heptane insoluble asphaltenes derived from five heavy crude oils, HCO-A, HCO-B, HCO-C, HCO-D, and HCO-E, were determined at the oil−water interface. Two oils were used in the study, (a) a model oil made of 60/20/20 tridecane/toluene/cyclohexane, and (b) the corresponding deasphalted oil (DAO), from which the asphaltenes were separated. Use of the model oil has limitations in determining fundamental interfacial properties of extracted asphaltenes. The deasphalted oil is a better medium and provides more representative interfacial properties of asphaltenes in crude oil. The deasphalted oil composition and, in particular, the naphthenic acid content of the deasphalted oil influences the interfacial properties of the asphaltenes at the crude oil−water interface. We hypothesize that the basic nitrogen-containing asphaltenes and crude oil naphthenic acids interact with each other synergistically, leading to naphthenic acid−asphaltene acid−base complexes. The high propensi...
The effects of methadone on operant behavior maintained with and without conditioned reinforcement in the pigeon.

Effects of methadone on key pecking supplemented with brief stimuli either correlated with or independent of unconditioned reinforcement was investigated. On average, key pecks by pigeons produced brief stimuli (BS) once per minute and food once per 4 min during both components of a multiple schedule (i.e., VI1:BS, VI4:Food). Brief stimuli were paired with food presentation during one component and not related to food during the second component. Acute methadone administration (0.56, 1.0, 1.7, and 3.0 mg/kg) decreased response rates during both components; however, the decrease was smaller by a constant amount during the paired brief stimulus component, regardless of drug dose. These results suggest conditioned reinforcement is not a primary mechanism through which methadone exerts behavioral effects and that reinforcer-correlated stimuli have potential for diminishing the reduced behavioral output observed following methadone administration.
Letter to the Editor---Note on a Paper by C. W. Marshall

In a paper by C. W. Marshall “Full Service Probability for Regular Arrangement,” Opns Res.9 186--199 1961., an error is made that, although not fundamental to his results, should be pointed out.
The empirical case for role-governed categories

Most theories of categorization posit feature-based representations. Markman and Stilwell (2001) argued that many natural categories name roles in relational systems and therefore they are role-governed categories. There is little extant empirical evidence to support the existence of role-governed categories. Three experiments examine predictions for ways that role-governed categories should differ from feature-based categories. Experiment 1 shows that our knowledge of role-governed categories, in contrast to feature-based categories, is largely about properties extrinsic to category members. Experiment 2 shows that role-governed categories have more prominent ideals than feature-based categories. Experiment 3 demonstrates that novel role-governed categories are licensed by the instantiation of novel relational structures. We then discuss broader implications for the study of categories and concepts.
Computed tomographic evaluation of C1–C2 in Pediatric cervical spine trauma

The supine open-mouth odontoid view required in most cervical spine trauma series often is difficult to obtain, especially in the pediatric or uncooperative patient. This retrospective study compared thin-section computed tomography with multiplanar reconstructions and the standard plain film cervical spine examination for evaluation of C1–C2 in a group of 31 pediatric patients age 6 years and under with combined craniocervical trauma. The plain film examination demonstrated adequate visualization of C1–C2 in only 58% of patients. The average number of anteroposterior odontoid films was 3.5 per examination (range, 1–6 films). Only 9% of anteroposterior open-mouth odontoid views were felt to be of adequate diagnostic quality vs. 60% of the Fuch’s odontoid view. The computed tomographic examination was diagnostic in 91% of examinations and could be acquired more rapidly.
Development of reaching in infancy

The development of reaching for stationary objects was studied longitudinally in 12 human infants: 5 from the time of reach onset to 5 months of age, 5 from 6 to 20 months of age, and 2 from reach onset to 20 months of age. We used linear mixed-effects statistical modeling and found a gradual slowing of reach speed and a more rapid decrease of movement jerk with increasing age. The elbow was essentially locked during early reaching, but was prominently used by 6 months. Differences between infants were distributed normally and no evidence of different types of reachers was found. The current work combined with other longitudinal studies of infant reaching shows that the increase in skill over the first 2 years of life is seen, not by an increase in reaching speed, but by an increase in reach smoothness. By the end of the second year, the overall speed profile of reaching is approaching the typical adult profile where an early acceleration of the hand brings the hand to the region of the target with a smooth transition to a lower-speed phase where grasp is accomplished.
Alignment of Metastable Helium Atoms by Unpolarized Resonance Radiation

Experiments in which helium atoms in the /sup 3/S/sub 1/ metastable state were aligned by the action of unpolarized optical resonance radiation are reported. The alignment was detected by resonance methods; the observed line widths are of the order of a milligauss with a raw signal-to-noise ratio of approximates 1OO: 1. The simplest experimental arrangement is described and the theory outlined. (W.D.M.)
Hippocampal neurotransmitter efflux during one-trial novel object recognition in rats

Several lines of evidence point to a role for the hippocampal formation and contiguous temporal lobe structures in a variety of learning and memory paradigms. Presumably, these cognitive phenomena are mediated (and accompanied) by dynamic changes in neurochemical transmission that may differ between learning and recall phases. However, the neurotransmitter correlates of most memory-related tasks have not been thoroughly investigated. Here we used a one-trial object recognition paradigm paired with in vivo microdialysis to assess hippocampal acetylcholine (ACh), glutamate and GABA efflux when rats were exposed to familiar objects, and when given the option to explore familiar and novel objects. Rats preferentially explored the novel object over the familiar one when presented with the option. Regardless of object familiarity, object exploration was accompanied by an increase in hippocampal ACh efflux, while GABA efflux was unaffected. However, glutamate efflux was not increased above baseline levels by presentation of familiar objects, but was significantly enhanced in the presence of the novel object. These data suggest that the hippocampus, and in particular, hippocampal glutamate, may be involved in memory processes during novelty recognition paradigms.
Pathogenesis of gastroduodenal injury due to nonsteroidal antiinflammatory drugs: implications for prevention and therapy

Nonsteroidal antiinflammatory drugs (NSAIDs) initiate gastroduodenal ulceration and promote complications such as bleeding and perforation by interfering with the ability of the proximal gastrointestinal tract to maintain its defensive capabilities. Mucosal defense is composed of three critical components: preepithelial, epithelial, and postepithelial. Preepithelial defense is composed of the mucous gel containing mucin, bicarbonate, and surface-active phospholipids. The epithelial component includes the surface cells, their apical tight junctions, and membrane transporters. Postepithelial defense is maintained by mucosal blood flow, which is essential for both defense and repair. NSAIDs interfere with each component of mucosal defense via direct toxic effects along with cyclooxygenase inhibition and depletion of endogenous prostaglandins. Although NSAID injury is dependent on luminal acid, attempts to prevent NSAID injury by acid suppression using H2-receptor antagonists in humans have had limited success, whereas complete inhibition of acid secretion with proton pump inhibition may have promise. Prostaglandins appear most effective for prevention of NSAID injury, sucralfate appears ineffective, and bismuth compounds have not been studied extensively. Recent evidence suggests that NSAID ulcers heal quickly with proton pump inhibitors compared with H2-receptor antagonists in patients who continue NSAID therapy.
EXPERIMENTS ON THE CULTIVATION OF THE ACTIVE AGENT OF MOSAIC DISEASE IN TOBACCO AND TOMATO PLANTS.

The results of the attempts here described to cultivate the incitant of mosaic disease of tobacco and tomato plants give good reason to suppose that this has been accomplished. The agent in the tissues of affected plants induces the disease not infrequently in a dilution of 1:10,000 but only very rarely at a higher dilution. During its transference from tube to tube of the special medium used in the present study it underwent a dilution far beyond these effective limits—in one experiment to 4 x 10–16. Nevertheless, the material of the remote subplants proved effective in inducing the disease, which appeared as rapidly and in as active a form as if the undiluted inoculum had been employed. Material derived from plants in which mosaic developed as result of inoculation with the culture fluid induced the disease in yet other plants, and from these again the agent could be propagated in vitro, or transfers to other plants could be made. In the course of the experiments a significant fact was noted; namely, that the agent present in remote subplants which can induce the disease was not readily filterable. The nature of the change thus indicated remains to be determined. No formed elements could at any time be distinguished in the medium. The conclusion seems justified that the incitant of mosaic disease of tobacco and tomatoes is a living microbic body which can be cultivated in an artificial medium.
Digital Career Portfolios: Expanding Institutional Opportunities.

Faculty at a small university discussed digital portfolios for technology support students who were entering the senior year without a portfolio that illustrated their knowledge and skills for potential employers. Business leaders expressed the need for graduates to demonstrate technological skills and other critical competency areas. Recent trends replace the traditional resumes and portfolios with digital portfolios, which capture student accomplishments by electronic methods. The authors note that smaller institutions may not have the funding, administrative support, or technical support necessary for such large-scale projects. They discuss how smaller institutions can provide students with opportunities to develop digital portfolios despite these constraints.
The Usage of Electronic Data Interchange in the Hotel Industry

This study investigates the major factors that can influence electronic data interchange (EDI) within the hotel industry. Results illustrate that some profile, channel, and task variables can influence EDI usage in the areas of purchasing, financing, and strategy. By identifying and testing relevant intraorganizational variables, this study offers insights to academics and practitioners regarding the usage of EDI within the hotel industry. Indications are EDI could become an important tool for hotels to use in conducting business in both an interorganizational and intraorganizational manner.
Mechanism of manganese-induced tolerance to cadmium lethality and hepatotoxicity☆

Abstract Pretreatment with Mn2+ is known to produce tolerance to Cd2+-induced lethality. This study was designed to determine the mechanism of tolerance to Cd2+-induced lethality and hepatotoxicity following Mn2+ pretreatment. Rats given 36 μmoles Cd2+/kg, i.v., died within 10–20 hr while only one of nine rats pretreated with Mn2+ (250 μmoles/kg, s.c., 48 and 24 hr prior to Cd2+ challenge) died. Ten hours after Cd2+, plasma aspartate aminotransferase and sorbitol dehydrogenase activities were elevated markedly, and extensive histopathologic lesions of the liver were evident in control rats but not in Mn2+- pretreated rats. To examine the mechanism of this tolerance, distribution of Cd2+ to fourteen organs and the subcellular distribution in six organs were determined in control and Mn2+-pretreated rats. Two hours after challenge (31 μmoles Cd2+/kg, i.v., 0.75 μCi 109Cd2+/μmole Cd2+), the distribution of Cd2+ to liver markedly increased after Mn2+ pretreatment with concomitant decreases in other tissues. Mn2+ pretreatment also resulted in a marked difference in the hepatic subcellular distribution of Cd2+ with more present in cytosol and less associated with organelles. Gel-filtration chromatography indicated that most cytosolic Cd2+ was bound to a low molecular weight protein. Isolation and partial characterization of this protein suggest that it is identical to metallothionein (MT); it had a similar relative elution following gel-filtration chromatography, had low absorbance at 280 nm and, after separation into two isoproteins by DEAE A-25 anion exchange chromatography, had the same mobility after electrophoresis on non-denaturing polyacrylamide gels as Cd2+-induced metallothioneins. These data suggest that Mn2+ pretreatment reduces Cd2+-induced hepatotoxicity by altering the hepatic subcellular distribution of Cd2+ with more Cd2+ binding to MT in the cytosol. This decreased hepatotoxicity is probably responsible for tolerance to Cd2+-induced lethality.
The Confirmation of Black's Theory of Lime

Abstract In 1756 Joseph Black published a new theory of the nature of lime, one that is now viewed as essentially correct. Black's theory was not immediately accepted, and a competing theory, published in 1764 by Johann Meyer, was widely preferred to Black's for some years. In this paper, probability theory is used to show that, and why, some of Black's evidence made his theory more probable than Meyer's.
THE QUANTUM YIELD OF OXYGEN PRODUCTION BY CHLOROPLASTS SUSPENDED IN SOLUTIONS CONTAINING FERRIC OXALATE

1. The quantum yield of oxygen liberation by spinach and Tradescantia chloroplasts suspended in solutions containing ferric oxalate and potassium ferricyanide varied from 0.013 to 0.080. 2. It was concluded that the nature of this oxygen liberation reaction is not fundamentally different from the formation of oxygen in normal photosynthesis, with respect to its light efficiency.
Performance Measures for Patients Hospitalized With Heart Failure: Are They Predictive of Clinical Outcomes?

Assessment of quality of care in heart failure (HF) has focused on the development and use of process of care-based performance measures. While it has been presumed that these process measures when applied in actual clinical practice are associated with improved clinical outcomes, this link has not been well-established. A recent analysis of the Organized Program to Initiate Lifesaving Treatment In Hospitalized Patients With Heart Failure (OPTIMIZE-HF) 1 registry/performance improvement program examined the relationship between current performance measures for patients hospitalized with HF and relevant patient clinical outcomes. This study found that none of the current HF performance measures were significantly associated with reduced early mortality risk and only angiotensin-converting enzyme inhibitor/angiotensin receptor blocker use at discharge was associated with 60- to 90-day postdischarge mortality or rehospitalization. b-Blocker therapy at the time of hospital discharge, currently not an HF performance measure, was strongly associated with reduced risk of mortality and mortality/rehospitalization postdischarge. To accurately identify health care providers and hospitals providing care that is associated with more optimal clinical outcomes, additional HF performance measures as well as better methodology for identifying and validating performance measures is needed. HF is the leading cause of hospitalization in persons older than 65 years, with almost 3.6 million hospitalizations attributed to HF as the primary or a secondary discharge diagnosis each year. 2 HF patients are at substantial risk for recurrent exacerbations of symptoms requiring intervention, with up to 50% of discharged patients being rehospitalized within 6 months. An estimated 11.6% of HF patients die within 30 days and 33.1% of patients die within 1 year after their first hospitalization for HF. 3 Uniform highquality health care might reasonably be expected to reduce this burden of morbidity and mortality associated with HF. Evidence-based guidelines for the diagnosis and treatment of patients with HF have been developed. 2,4 To facilitate the measurement of and improvement in quality of care in HF, components of these guidelines have been adapted by the various organizations as performance measures. 5,6 These performance measures are based on clinical practice guidelines but are intended to be confined to those structural aspects or processes of care for which the evidence is so strong that the failure to perform them reduces the likelihood of optimal patient outcomes. 5 It is impor
Kinetics of CO recombination to the heme in Geobacillus stearothermophilus nitric oxide synthase

We report the kinetics of CO rebinding to the heme in His134Ser, Ile223Val and His134Ser/Ile223Ser mutants of Geobacillus stearothermophilus nitric oxide synthase (gsNOS). The amplitudes of the two observed kinetics phases, which are insensitive to CO concentration, depend on enzyme concentration. We suggest that two forms of gsNOS are in equilibrium under the conditions employed (6.1–27 μM gsNOS with 20 or 100% CO atmosphere). The kinetics of CO rebinding to the heme do not depend on the identity of the NO-gate residues at positions 134 and 223.