cssi/SciSciGPT-SciSciNet huggingface dataset:
Mechanism of Polykaryocytosis Associated with Noncytopathic Infection by Measles Virus

Abstract Atherton, John G. (University of Southern California, Los Angeles), Sotiros G. Chaparas, Martha Cremer, and Irving Gordon. Mechanism of polykaryocytosis associated with noncytopathic infection by measles virus. J. Bacteriol. 90:213–219. 1965.—Infection with a measles virus variant resulted not only in formation of polykaryocytes (PK) but also in formation of multicellular immunofluorescent foci (IFF) in which no cytopathic effect could be detected. The ratio of IFF to PK changed from 27 to 4 during the first passage and remained 4 after a second passage. PK were plaques. Plaque assay was linear in the presence of IFF. To investigate the mechanism of PK formation, radioautography was done on cells pulse-labeled with tritiated thymidine before virus multiplication began. The results showed that PK were formed by fusion; there were no PK whose nuclei contained no label, and the proportion of labeled nuclei (32%) and distribution of grain counts was the same in PK as in uninvolved cells, ruling out nuclear replication without concomitant cytoplasmic membrane formation as the mechanism of formation of these PK. Early in PK development, neutral red uptake was markedly increased (“red” plaques). As PK matured, hyperchromicity disappeared (“white” plaques). This sequence provided an index of rate of evolution of PK. Rate of PK maturation was more rapid at 37 than at 32 C.
Genomic profiling associated with recurrence in patients with rectal cancer treated with chemoradiation.

Purpose: Stage II and III adenocarcinoma of the rectum has an overall 5-year survival rate of approximately 50%, and tumor recurrence remains a major problem despite an improvement in local control through chemotherapy and radiation. The efficacy of chemoradiation therapy may be significantly compromised as a result of interindividual variations in clinical response and host toxicity. Therefore, it is imperative to identify those patients who will benefit from chemoradiation therapy and those who will develop recurrent disease. In this study, we tested whether a specific pattern of 21 polymorphisms in 18 genes involved in the critical pathways of cancer progression (i.e., drug metabolism, tumor microenvironment, cell cycle regulation, and DNA repair) will predict the risk of tumor recurrence in rectal cancer patients treated with chemoradiation. Patients and methods: A total of 90 patients with Stage II or III rectal cancer treated with chemoradiation were genotyped using polymerase chain reaction (PCR)-b...
Carrier density and quantum efficiency measurements in conjugated polymers: ultrafast photoinduced IRAV absorption

Abstract Ultrafast measurements of transient excited-state absorption in the spectral region spanning the infrared active vibrational active (IRAV) modes in the prototypical luminescent polymers, poly(phenylene vinylene), PPV, and poly[2–methoxy–5–(2–ethyl–hexyloxy)–(phenylenevinylene)], MEH-PPV, reveal charge carrier generation within 100 fs after photoexcitation. The relatively large photocarrier quantum efficiency in MEH-PPV, φ 0 ≈0.1 in zero applied electric field, implies primary photogeneration of charge carriers. Comparison of the recombination dynamics in MEH-PPV and PPV indicates that the carrier recombination rate is sensitive to the strength of the inter-chain interaction.
Microfracturing, paleostress and the growth of faults

Abstract We have analyzed the microfractures in samples taken near one thrust fault and five normal faults of known displacement to test the dependence of microfracture density and distribution on fault slip. We have also recorded the orientation of microfractures as a function of distance from the associated fault surface. In order to control as many parameters as possible, shallow faults with similar lithologies were chosen. They showed the same kind of deformation, namely, microfracturing without block rotation, recrystallization, extensive granulation or crystal plasticity. The results of over 8000 microfracture measurements suggest that maximum microfracture density is independent of net slip. We interpret this relationship as indicating that the preponderance of microfracturing occurs in proximity to the propagating fault tip. The angular relationship between the shear plane and microfractures was commonly found to be between 5° and 20°, significantly less than the ≈30° expected between the far-field maximum principal stress and the shear surface. This low angle between microfracture orientation and shear plane orientation is predicted for a local stress field associated with a propagating mode II fault tip. Other possible explanations for the small angle for tensional microfractures and the shear surface are: (1) the effective confining pressure was very low; or (2) shear strength at failure was much larger than expected.
Modeling latent and patent failures of electronic products

Abstract Burn-in and stress screening are becoming increasingly popular in the commercial electronics industry as customers become increasingly sensitive to failures occurring in the useful life of a product or system. For example, thermal stress screening (TSS) is an assembly-level electronics manufacturing process that evolved from the burn-in processes used in NASA and DoD programs. While burn-in subjects the product to expected field extremes to expose infant mortalities (patent failures), TSS briefy exposes a product to fast temperature rate-of-changes and out-of-specifications temperatures to expose failures that would occur during the useful life of the product. As a result, TSS ages the product in hopes of bringing out defects that would otherwise occur in the field (called latent defects). In support of this known failure behavior, the classical bathtub curve should be modified to aid in the economic modeling of various screen types. We have conducted extensive modeling efforts that have resulted in a systematic approach to explicitly model the latent failures in the bathtub curve. In this paper, we describe the efforts that have been dedicated to modeling latent failures known to exist in many products and systems. The resulting failure distribution is a truncated, mixed Weibull distribution. This model is proving to be an effective and relatively simple means to model the complex nature of failures of a system. With this increased flexibility, we can measure the impact of stress screens in varying conditions and ultimately design optimal screens.
Thermal analysis of solar thermal energy storage in a molten-salt thermocline

Abstract A comprehensive, two-temperature model is developed to investigate energy storage in a molten-salt thermocline. The commercially available molten salt HITEC is considered for illustration with quartzite rocks as the filler. Heat transfer between the molten salt and quartzite rock is represented by an interstitial heat transfer coefficient. Volume-averaged mass and momentum equations are employed, with the Brinkman–Forchheimer extension to the Darcy law used to model the porous-medium resistance. The governing equations are solved using a finite-volume approach. The model is first validated against experiments from the literature and then used to systematically study the discharge behavior of thermocline thermal storage system. Thermal characteristics including temperature profiles and discharge efficiency are explored. Guidelines are developed for designing solar thermocline systems. The discharge efficiency is found to be improved at small Reynolds numbers and larger tank heights. The filler particle size strongly influences the interstitial heat transfer rate, and thus the discharge efficiency.
Error correction with feedback for asymmetric errors

This paper introduces a type-I hybrid ARQ scheme for the Z-channel, based on a class of codes which can correct t asymmetric errors and further detect d (d > t) more. The specific parameters of the ARQ schemes are considered and an upper bound on the probability of undetected error is derived. We give a couple of detailed examples based on classic inner error correcting codes. They show good behavior of this scheme in terms of error rate and throughput
Evidence for long-range repulsive atomic interactions in metals from bond energy calculations

The first and second nearest neighbor bond energies are calculated for a variety of liquid metals from heat of vaporization, density, and surface tension data using a simple pair-wise interaction model of cohesive forces. The first nearest neighbor interaction is found to be attractive, while the second nearest neighbor interaction is repulsive. This longer range repulsive interaction is not surprising, in view of the Friedel oscillations known to exist in the potential function for ion-ion interactions in a metal. It is suggested that γ-plot calculations for solid metals take this repulsion into account.
Multi-tasking on chromatin with the SAGA coactivator complexes

Abstract Over the past 10 years, much progress has been made to understand the roles of the similar, yet distinct yeast SAGA and SLIK coactivator complexes involved in histone post-translational modification and gene regulation. Many different groups have elucidated functions of the SAGA complexes including identification of novel components, which have conferred additional distinct functions. Together, recent studies demonstrate unique attributes of the SAGA coactivator complexes in histone acetylation, methylation, phosphorylation, and deubiquitination. In addition to roles in transcriptional activation with the 19S proteasome regulatory particle, recent evidence also suggests functions for SAGA in elongation and mRNA export. The modular nature of SAGA allows this ∼1.8 MDa complex to organize its functions and carry out multiple roles during transcription, particularly under conditions of cellular stress.
Montemayor's Diana: a novel pastoral

Jorge de Montemayor never called his Siete Libros de la Diana a ‘novela pastoril’ nor indeed was the word novela applied by anyone in the sixteenth century to any works other than Italianate short stories. Nevertheless it seems clear that Montemayor was conscious of producing a new and even daring version of pastoral, by combining it with narrative in the tradition of the Italian novella. In this sense the term ‘pastoral novel’ is valid for La Diana, and attention to its hybrid nature provides a clue to understanding the work's enormous popularity in terms of continuations, adaptations and translations in the sixteenth and seventeeth centuries, as well as its importance in the history of the modern European novel.
High-mobility electrons in modulation-doped AlAs quantum wells

Abstract We report on magnetoresistance measurements of two-dimensional electrons in AlAs quantum wells with mobilities up to 19 m 2 / V s . Fractional quantum Hall states at first- and second-order filling factors, and up to ν= 11 3 , are observed. Shubnikov–de Haas oscillations of high-density samples reveal that electrons occupy two X-point valleys.
Nanostructured palladium membrane synthesis by magnetron sputtering

Abstract Palladium membranes are of technological interest since they show a very high selectivity for hydrogen. Diffusion through the palladium is often the rate-limiting step in hydrogen transport through the membrane. Hydrogen flux can be improved by reducing the membrane thickness and increasing the hydrogen diffusivity. Nanostructured palladium has a higher hydrogen diffusivity than conventional palladium due to its large volume fraction of grain boundaries. They were generated as ultrathin membranes by d.c. magnetron sputtering onto porous Vycor ® glass substrates in an argon atmosphere. The nanostructured films exhibited no cracks on the submicron scale when examined with environmental scanning electron microscopy. The membranes delaminated from the substrates when exposed to hydrogen at room temperature, owing to the α → β phase transition. Heating the ultrathin nanostructured palladium membranes to 200 °C led to some grain growth. Stabilization against the phase transition and grain coarsening is critical to applications of nanostructured membranes in hydrogen separations, and can be achieved by the alloying of palladium with another metal.
Comparison of Simplex Designs for Quadratic Mixture Models

Designs for quadratic regression are considered when the possible values of the controlable variable are mixtures x = (x 1, x 2, …, x q + 1) of nonnegative components x i with Σ q + 1 1 x i = 1. The designs that are optimum with respect to the D-, A-, and E-optimality criteria are compared in their performance relative to these and other criteria. Computational routines for obtaining these designs are developed, and the geometry of optimum structures is discussed. Except when q = 2, the A-optimum design is supported by the vertices and midpoints of edges of the simplex, as is the case for the previously known D-optimum design. Although the E-optimum design requires more observation points, it is more robust in its efficiency, under variation of criterion: but all three designs perform reasonably well in this sense.
Update on master's genetic counseling training programs: Survey of curriculum content and graduate analysis summary.

The field of genetic counseling is a recognized specialty in medical genetics with the primary practitioners being masters degree prepared individuals. Since the inception of the first master's degree genetic counseling (MGC) training program in 1969, more than 1000 genetic counselors have graduated from established training programs in United States and Canada. The MGC programs involve a 2-year academic curriculum of both didactic course work and supervised clinical field work (clinical praticums). A recent survey of 17 existing MGC training programs (16 U.S. and 1 Canadian) reveals that MGC graduates average a total of 1349 actual contact hours (range 854–1952 hours) during their 2-year degree program course of study. Clinical experience gained through clinical practica accounts for 58% of required coursework, followed by didactic coursework in basic science (21%) and counseling (16%), respectively. A few programs also have requisite laboratory practica, which accounts for 5% of overall content hours. The 17 existing MGC programs produce approximately 100 graduates annually. Although the number of programs has grown since inception of the first MGC program in 1969, the mean number of graduates per program remains fairly constant. By year 2002, the estimated total number of master's degree trained genetic counselors will approach 2200.
Echocardiographic Demonstration of Right Atrial Rupture in a Patient with Right-sided Cardiac Tumor

Two-dimensional echocardiographic evaluation of a young man with recent drainage of a hemorrhagic pericardial effusion revealed persistent fluid and a massive tumor involving the right atrium, tricuspid valve, and right ventricle. Echocardiographic demonstration of right atrial wall rupture was confirmed at surgery; pathologic analysis showed a spindle cell sarcoma.
Fiber Composition and Digestion Kinetics in Grass Stem Internodes as Influenced by Particle Size

Abstract Our objective was to characterize discrete particle fractions in ground grass forage and determine the influence of differences in particle size among fractions on fiber composition and digestion kinetics. Three replicates of reed canarygrass and switchgrass were harvested and the fourth and fifth stem internodes below the panicle were removed, dried, and ground (3 mm). Samples were sieved to a constant weight and particles retained on .3, .425, .6, and .85-mm sieves were analyzed with half of each particle fraction reground to pass a 1-mm Udy mill screen. Particles were analyzed for length, width, and area using an image analyzer, and particle thickness was determined using a light microscope. Volume, surface area, and density measurements of defined particle fractions had an approximate geometric distribution for the four particle fractions, indicating that these measurements are related to particle size estimates based on logarithmic normal distributions. The four particle fractions were similar in composition based on density, crude protein, and fiber estimates. Digestion rate constants were not affected by particle size within the range of the four particle fractions. However, regrinding to pass a 1-mm Udy screen increased digestion rates, indicating that small particle size can affect digestion kinetics. Fiber values from sequential analysis of forage particles not ground to pass a 1-mm screen must be evaluated cautiously, because some potentially soluble components may remain in the residue after each extraction step and result in high analytical values.
Mass transfer of oxygen in poly(2-hydroxyethyl methacrylate)

The diffusion coefficient of oxygen in poly(2-hydroxyethyl methacrylate) has been explicitly measured using an optical technique based on fluorescence quenching. This measurement represents the first explicit determination of D in PHEMA. A diffusion coefficient of oxygen in PHEMA of 1.36 × 10−7 cm2/s at 20°C was obtained from this measurement. This value is shown to agree well with permeability data for PHEMA, the free volume theory of diffusion, and with values of D that have been explicitly measured in other methacrylate hydrogels.
Effects of amino-glutethimide on adrenal function in man.

ABSTRACT The effects of amino-glutethimide on adrenocortical function have been studied in 24 subjects, including 10 patients with Cushing's syndrome, 3 with primary aldosteronism and 1 with secondary hyperaldosteronism. Aminoglutethimide inhibited adrenal secretion of both cortisol and aldosterone. Inhibition of cortisol secretion was most clearly demonstrable in a patient with Cushing's syndrome caused by autonomous steroid secretion from an adrenal adenoma. In normal subjects, administration of large doses of amino-glutethimide was accompanied by consistent increases in plasma ACTH, and it is likely that these “compensatory” increases in ACTH were responsible for maintaining near-normal cortisol secretion rates and plasma 17-hydroxycorticosteroid (17-OHCS) concentrations in these subjects. Decreases in cortisol secretion occurred in 7 of 9 patients with Cushing's disease given amino-glutethimide, and this was of modest therapeutic value in 4 of these patients treated for several months. The most consis...
Non-Additive Increases in Sediment Stability Are Generated by Macroinvertebrate Species Interactions in Laboratory Streams

Previous studies have shown that biological structures such as plant roots can have large impacts on landscape morphodynamics, and that physical models that do not incorporate biology can generate qualitatively incorrect predictions of sediment transport. However, work to date has focused almost entirely on the impacts of single, usually dominant, species. Here we ask whether multiple, coexisting species of hydropsychid caddisfly larvae have different impacts on sediment mobility compared to single-species systems due to competitive interactions and niche differences. We manipulated the presence of two common species of net-spinning caddisfly (Ceratopsyche oslari, Arctopsyche californica) in laboratory mesocosms and measured how their silk filtration nets influence the critical shear stress required to initiate sediment grain motion when they were in monoculture versus polyculture. We found that critical shear stress increases non-additively in polycultures where species were allowed to interact. Critical shear stress was 26% higher in multi-species assemblages compared to the average single-species monoculture, and 21% greater than levels of stability achieved by the species having the largest impact on sediment motion in monoculture. Supplementary behavioral experiments suggest the non-additive increase in critical shear stress may have occurred as competition among species led to shifts in the spatial distribution of the two populations and complementary habitat use. To explore the implications of these results for field conditions, we used results from the laboratory study to parameterize a common model of sediment transport. We then used this model to estimate potential bed movement in a natural stream for which we had measurements of channel geometry, grain size, and daily discharge. Although this extrapolation is speculative, it illustrates that multi-species impacts could be sufficiently large to reduce bedload sediment flux over annual time scales in streams where multiple species of caddisfly are present.
Heat Shock Proteins and Protection Against Myocardial Ischemia

The incidence of myocardial infarcts has significantly decreased in the past decade. Research aimed at identifying the cause of atherosclerosis and efforts to prevent it have contributed to this decrease in myocardial infarction, tIowever in spite of early reperfusion, loss of functional myocardium leading to subsequent severe cardiac failure still remains a significant medical problem (American tteart Association, 1990). The salvage of additional myocardinm is, therefore, a highly desirable aim. Recent evidence indicates that endogenous protective mechanisms are activated in the ischemic cardiomyocyte. A better understanding of these endogenous protective mechanisms will most likely lead to additional myocardial salvage in the reperfused myocardium. Ischemia is known to produce a number of intracellular changes within the cardiomyocyte. These changes include among others increased cel-lular calcium levels, altered osmotic control, membrane damage, free radical production, decreased intracellular pit, depressed ATP levels, oxygen depletion, decreased intracellular glucose levels, etc. (Bonventre, 1988). These events represent a form of metabolic or hypoxic stress which is known to produce protein denaturation within the cell. Interestingly, an increase in denatured proteins in the cell has been reported to result in the onset of the heat shock response which increased the synthesis of the so-called heat shock proteins (HSPs) (Ananthan et al., 1986). The heat shock response has been shown to occur in all organisms examined to date. This heat shock response consists of a transient rearrangement of cellular activities to cope with the stress period by protecting essential components within the cell so as to permit it lo resume normal activity during recovery /i'om the slress (Lindquist, 1986). This ability of the cell for self-preservation has attracted the attention of several investigators in the field. Several studies have shown that a hyperthermic treatment of experimental animals can result in a signitlcantly improved myocardial salvage lbllowing c(~ronary occlusion and reperfusion in vhTo (Donnelty et al., 1992; Currie et aL, 1993) as well as in an isolated perfused heart model (Walker et al., 1993). Interestingly, recent studies have now demonstrated a direct correlation between the amount of one of tlhese iheat shock proteins (HSP70) and the degree of myocardkd protection following a hyperthermic treatment in experimental animals ( t tu t te re t al., 1994; Marber et aL, 1994). A closer examination of this group of proteins (liSPs) and their involvement in cardioprotection during myocardial infarction is then extremely important as a means to understand the cardiac cell's ability to protect itself against ischemic injury. The present review will attempt to cover what is known about these proteins and the more recent studies related to their expression and myocardial protection.
Selection of novel forms of a functional domain within the Tetrahymena ribozyme

P5abc is an RNA structure within the self-splicing Tetrahymena group I intron that provides an activation function to the remainder of the ribozyme, either when present in cis or when added in trans. This 69-nucleotide activator domain was replaced with randomized sequence of 20 or 40 nt in length, and individuals among these pools with sequences that could functionally replace P5abc were selected. The basis of selection was a reaction in which two separate halves of the ribozyme became joined; selection was completed by reverse transcription and the polymerase chain reaction, using primers with sequence from either side of the ligation junction. Selectant sequences fell into three families that appear unrelated to P5abc; for example they lack the A-rich bulge thought to be a important feature of P5abc. Thus, rather than defining some consensus sequence for activator domains, this result reveals a certain tolerance in the ribozyme in its ability to derive activation function from diverse sequence types. In the context of splicing precursor RNA, the new sequences supported self-splicing, but failed to activate a related reaction, hydrolysis of the 3' splice site, implying that this region of the intron can differentially control two related reactions.
Photophysics and redox behavior of chiral transition metal polymers.

The absorption and emission spectra, excited-state lifetimes, quantum yields, and electrochemical measurements have been obtained for a new series of chiral complexes based on three different chiral 2,2‘:6‘,2‘ ‘-terpyridine ligands, (−)-ctpy, (−)-[ctpy-x-ctpy], and (−)-[ctpy-b-ctpy], with one, two, or multiple Ru metal centers. The room-temperature absorption and emission maxima of {[((−)-ctpy)Ru]-(−)-[ctpy-b-ctpy]-[Ru((−)-ctpy)]}(PF6)4 and ((−)-[ctpy-b-ctpy])-{[Ru((−)-[ctpy-b-ctpy])](PF6)2}n were shifted to lower energies and also exhibited significantly longer luminescence lifetimes when compared to [Ru((−)-ctpy)2](PF6)2, {[((−)-ctpy)Ru]-(−)-[ctpy-x-ctpy]-[Ru((−)-ctpy)]}(PF6)4, and ((−)-[ctpy-x-ctpy])-{[Ru((−)-[ctpy-x-ctpy])](PF6)2}n. In terms of their electrochemical behavior, all of the complexes studied exhibited one Ru-centered and two ligand-centered redox waves and the {[((−)-ctpy)Ru]-(−)-[ctpy-x-ctpy]-[Ru((−)-ctpy)]}(PF6)4, ((−)-[ctpy-x-ctpy])-{[Ru((−)-[ctpy-x-ctpy])](PF6)2}n, and ((−)-[ctpy-b-ct...
Working in the legislature: perspectives on injury prevention in the United States.

National, state, and local policies to prevent and control injury can benefit from the knowledge and expertise that researchers can bring to policymaking; however, researches are often absent from this process. The lack of interaction between researchers and legislators results in a chasm between two parties with a common interest in reducing injuries, and a potentially missed opportunity for injury prevention and control. The purpose of this paper is to describe two state-level injury-related bills that were considered during the 2008 Maryland General Assembly. Our goal is to illustrate one approach to translating and disseminating research findings to legislators. We describe how researchers contributed to the deliberative processes surrounding these two injury-related legislative proposals. We also discuss the critical role of researchers in the policymaking process, and conclude with recommendations for how researchers can be more involved with legislative initiatives to prevent and control injury. Although legislators formulate policy interventions by passing laws, including those that address injury, their efforts are not always informed by the best available research. Legislators generally do not have access to research or the training needed to critically appraise and synthesise research findings accurately.1 In order to develop evidence-based policies, some legislators rely on researchers to synthesise and translate scientific literature into succinct points that can be shared with advocates and used to inform policy debates. Researchers can be an important information source in the legislative process. They have knowledge relevant to agenda setting; they can be advocates for empirically-based policies;2 and they can provide a level of depth that complements the broad knowledge base generally required of legislators. Despite the potential benefits that can result from researchers interacting with legislators, direct and regular communication between researchers and legislators is uncommon. This lack of interaction has implications for public health. It results in …
Differentiation of creatine phosphokinase during myogenesis: quantitative fractionation of isozymes.

Abstract A technique is described for the quantitative measurement of creatine phosphokinase (CPK) isozymes in extracts of chick muscle. The isozymes are fractionated by stepwise elution with increasing salt concentrations from DEAE-Sephadex minicolumns. Isozyme separation was confirmed by polyacrylamide gel electrophoresis followed by enzyme staining. We used this method to determine changes in CPK isozymes during the course of myogenesis in culture. The total specific activity of CPK increases about 20-fold during myogenesis. Quantative analysis of isozyme changes shows that the muscle-specific form (MM) accounts for virtually all of this increase. Activity of MM-CPK is undetectable in 1-day cultures, increases rapidly after myoblast fusion, and comprises more than 70% of total CPK in mature cultures. In contrast, the specific activity of the brain-specific isozyme (BB) remains constant throughout myogenesis. This was interpreted as indicating that the B subunit is expressed in both mononucleated cells and myotubes. We confirmed this by analyzing CPK isozymes in fibroblast cultures and in myotube-enriched cultures. Elimination of most of the mononucleated cells in the cultures produced an increase in the specific activity of CPK, but had no effect on the isozyme pattern and did not decrease the relative amount of the BB isozyme. Pure fibroblast cultures contained very low CPK activity, predominantly the BB isozyme.
A semiclassical quantization of area-preserving maps

Abstract A semiclassical path integral formalism is developed for a class of area-preserving maps. The quasi-energy spectrum of these systems is represented as a sum over closed orbits in the manner of Gutzwiller. The method is illustrated with some numerical tests of the “standard map”.
A Study of the Secretion of Iodine in Milk of Dairy Cows, Using Daily Oral Doses of I131,

The authors have traced the secretion of iodine to the fat and nonfat fractions of milk, through the normal pathways of excretion and to its retention in the blood and thyroid. They have also demonstrated the usefulness of the isotope dilution method for studying trace mineral metabolism. Editor. The metabolism of iodine by the dairy cow has been of interest for many years. However, owing to the lack of reliable techniques adaptable to routine analyses, the secretion of iodine into milk has not been studied in detail. The advent of nuclear fission markedly increased the amount of research concerning iodine metabolism by providing radioactive nuclides which, though chemically indistinguishable from the nonradioactive iodine, are readily detected by their reactions. Also, the observation of Van Middlesworth (16) that radioactive iodine with a half-life of 8 days could be detected in the thyroids of cattle in many parts of the country in the summer of 1954, made it of more than academic interest to learn more about the secretion of iodine into milk. The secretion of I TM in milk has been studied by Honour et al. (7) in hmnans, in a rabbit and goats by Wright et al. (19), and in a dairy cow by Glascoek (3). All of these studies charted the fate of a single administration of I TM. Since exposure of grazing animals to radioactive fall-out is likely to be for a period of several days, it is desirable to know how continuous administration affects the secretion of I TM in milk. The daily administration of a radioactive isotope has been used by Van Middlesworth (17) to study iodine metabolism in the rat, by Visek et al. (18) using Ca 45 in dairy cattle, and by Comar et al. (2) with Sr 9° in rats. The experiments reported in this paper show a comparison of the results of single administrations of I TM with the results of daily dosing experiments. An
Photoemission study of the adsorption of O2, CO and H2 on GaAs(110)

Abstract Ultraviolet photoemission spectroscopy with hv 2 , CO, and H 2 adsorption on the cleaved GaAs(110) face. It was found that O 2 exposures above 10 5 L(1LM = 10 −6 Torr sec) were required to produce changes in the energy distribution curves. At O 2 exposures of 10 6 L on p-type and 10 8 L on n-type an oxide peak is observed in the EDC's located 4 eV below the valence band maximum. On p-type GaAs, O 2 exposures cause the Fermi level at the surface to move up to a point 0.5 eV above the valence band maximum, while on n-type GaAs O 2 exposures do not remove the Fermi level pinning caused by empty surface states on the clean GaAs. CO was found to stick to GaAs, but to desorb over a period of hours, and not to change the surface Fermi level position. H 2 did not affect the EDC's, but atomic H lowered the electron affinity and raised the surface position of the Fermi level on p-type GaAs. A correlation is found in which gases which stick to the GaAs cause an upward movement of the Fermi level at the surface on p-type GaAs, while gases which stick only temporarily do not change the surface position of the Fermi level.
Thermophysics of alkali and related azides II. Heat capacities of potassium, rubidium, cesium, and thallium azides from 5 to 350 K,

Abstract The heat capacities of potassium, rubidium, cesium, and thallium azides were determined from 5 to 350 K by adiabatic calorimetry. Although the alkali-metal azides studied in this work exhibited no thermal anomalies over the temperature range studied, thallium azide has a bifurcated anomaly with two maxima at (233.0±0.1) K and (242.04±0.02) K. The associated excess entropy was 0.90 calth K−1 mol−1. The thermal properties of the azides and the corresponding structurally similar hydrogen difluorides are nearly identical. Both have linear symmetrical anions. However, thallium azide shows a solid-solid phase transition not exhibited by thallium hydrogen difluoride. At 298.15 K the values of Cpo, So, and −{G o (T)−H o (0)} T , respectively, are 18.38, 24.86, and 12.676 calth K−1 mol−1 for potassium azide; 19.09, 28.78, and 15.58 calth K−1 mol−1 for rubidium azide; 19.89, 32.11, and 18.17 calth K−1 mol−1 for cesium azide; and 19.26, 32.09, and 18.69 calth K−1 mol−1 for thallium azide. Heat capacities at constant volume for KN3 were deduced from infrared and Raman data.
Transverse momentum distributions from effective field theory with numerical results

We derive a factorization theorem for the differential distributions of electroweak gauge bosons in Drell-Yan processes, valid at low transverse momentum, using the soft-collinear effective theory. We present the next-to-leading logarithmic transverse momentum distribution for the Z-boson and find good agreement with Tevatron data collected by the CDF and D0 collaborations. We also give predictions for the Higgs boson differential distributions at next-to-leading logarithmic accuracy based on a factorization theorem derived in earlier work. We derive formulas for all quantities needed to study low transverse momentum production of color-neutral particles within the effective theory. This effective field theory approach is free of Landau poles and can be formulated entirely in momentum space. Consequently, our results are free of the Landau-pole prescriptions necessary in the standard approach.
Lens distortion in optically coupled digital x-ray imaging

The objectives of this research are to analyze geometrical distortions introduced by relaylenses in optically coupled digital x-ray imaging systems and to introduce an algorithm to correct such distortions. Methods: The radial and tangential errors introduced by a relay lens in digital x-ray imaging were experimentally measured, using a lens-coupled CCD(charge coupled device) prototype. An algorithm was introduced to correct these distortions. Based on an x-rayimage of a standard calibration grid, the algorithm first identified the location of the optical axis, then corrected the radial and tangential distortions using polynomial transformation technique. Results: Lens distortions were classified and both radial and tangential distortions introduced by lenses were corrected using polynomial transformation. For the specific lens-CCD prototype investigated, the mean positional error caused by the relay lens was reduced by the correction algorithm from about eight pixels (0.69 mm) to less than 1.8 pixels (0.15 mm). Our investigation also shows that the fourth order of polynomial for the correction algorithm provided the best correction result. Conclusions: Lens distortions should be considered in position-dependant, quantitative x-ray imaging and such distortions can be minimized in CCDx-ray imaging by appropriate algorithm, as demonstrated in this paper.
Managing microcomputers and end-user computing: Some critical issues

Abstract The end-user computing is typically a non-data processing professional who accesses and performs analyses on data to support decision making. End-user computing is a prevalent wave in today's society. Software is being developed that is easy to use and does not require one to have a programming background. This paper examines managing microcomputers and end-user computing.
Performance analysis of test scheduling schemes for a multi-access communications network

In this paper, we investigate the performance of two implementable test scheduling schemes for a multi-access communication channel whose components are subject to failure or malfunction. We relate the reliability of the system design, as reflected by system failure rate parameters, and the frequency at which the system (or nodal subsystem) is tested for failure detection, to the underlying key message delay and throughput performance. We derive queue-size distribution results for a discreteGeom(X)/D/1 system, representing the operation of the multi-access channel, or of a network node operating as a communications or queueing processor, which is maintained by a periodic or near periodic test scheduling scheme. Explicit formulas are presented for the system behavior as exhibited by the generating functions of the system queue-size distributions. The mean message delay is then calculated. The mean delay (or mean system size/workload performance index) can then be optimized by selecting the proper scheme parameters, under specified system (and component) failure conditions, noting that performing a test at too high a rate leads to inefficient system bandwidth utilization, while if tests are not carried out often enough, excessive message (or task) retransmissions and delays ensue.
Validating Emergency Department Vital Signs Using a Data Quality Engine for Data Warehouse

Background: Vital signs in our emergency department information system were entered into free-text fields for heart rate, respiratory rate, blood pressure, temperature and oxygen saturation. Objective: We sought to convert these text entries into a more useful form, for research and QA purposes, upon entry into a data warehouse. Methods: We derived a series of rules and assigned quality scores to the transformed values, conforming to physiologic parameters for vital signs across the age range and spectrum of illness seen in the emergency department. Results: Validating these entries revealed that 98% of free-text data had perfect quality scores, conforming to established vital sign parameters. Average vital signs varied as expected by age. Degradations in quality scores were most commonly attributed logging temperature in Fahrenheit instead of Celsius; vital signs with this error could still be transformed for use. Errors occurred more frequently during periods of high triage, though error rates did not correlate with triage volume. Conclusions: In developing a method for importing free-text vital sign data from our emergency department information system, we now have a data warehouse with a broad array of quality-checked vital signs, permitting analysis and correlation with demographics and outcomes.
Macular hole formation, progression, and surgical repair: case series of serial optical coherence tomography and time lapse morphing video study

To use a new medium to dynamically visualize serial optical coherence tomography (OCT) scans in order to illustrate and elucidate the pathogenesis of idiopathic macular hole formation, progression, and surgical closure. Two patients at the onset of symptoms with early stage macular holes and one patient following repair were followed with serial OCTs. Images centered at the fovea and at the same orientation were digitally exported and morphed into an Audiovisual Interleaving (avi) movie format. Morphing videos from serial OCTs allowed the OCTs to be viewed dynamically. The videos supported anterior-posterior vitreofoveal traction as the initial event in macular hole formation. Progression of the macular hole occurred with increased cystic thickening of the fovea without evidence of further vitreofoveal traction. During cyst formation, the macular hole enlarged as the edges of the hole became elevated from the retinal pigment epithelium (RPE) with an increase in subretinal fluid. Surgical repair of a macular hole revealed initial closure of the macular hole with subsequent reabsorption of the sub-retinal fluid and restoration of the foveal contour. Morphing videos from serial OCTs are a useful tool and helped illustrate and support anterior-posterior vitreofoveal traction with subsequent retinal hydration as the pathogenesis of idiopathic macular holes.
Dynamic imaging of ictal rhythmic activity using dense-array EEG

Electroencephalogram (EEG) is an important component of the pre-surgical evaluation in the treatment of medically intractable epilepsy. However, clinical EEG uses 19 to 32 electrodes that significantly limits its localization ability. Recent development of dense-array recording techniques has suggested that increased spatial sampling rate improves the accuracy of source localization. In the current study, we proposed a 76-channel EEG system for the long-term monitoring of epilepsy patients, and proposed a dynamic seizure imaging (DSI) technique to image the ictal rhythmic activity that may evolve through time, space and frequency. We tested the system in a cohort of 8 patients and our results show that the DSI estimated the seizure activity in good correlation with intracranial recordings, successful surgery outcomes and other clinical evidence. The proposed dense-array recording and DSI imaging approach enable a non-invasive but quantitative imaging of continuous seizure activity. The results suggest that DSI may potentially be useful to assist the pre-surgical evaluation in patients with intractable epilepsy.
Contact stresses in pin-loaded orthotropic plates

The effects of pin elasticity, friction, and clearance on the stresses near the hole in a pin-loaded orthotropic plate are described. The problem is modeled as a contact elasticity problem using complex variable theory, the pin and the plate being two elastic bodies interacting through contact. This modeling is in contrast to previous works which assumed that the pin is rigid or that it exerts a known cosinusoidal radial traction on the hole boundary. Neither of these approaches explicitly involves a pin. A collocation procedure and iteration were used to obtain numerical results for a variety of plate and pin elastic properties and various levels of friction and clearance. Collocation was used to enforce the boundary and iteration was used to find the contact and no-slip regions on the boundary. Details of the numerical scheme are discussed.
Relationships between the band gaps of the zinc-blende and wurtzite modifications of semiconductors

While the direct band gaps of wurtzite (W) and zinc-blende (ZB) structures are rather similar, the W and ZB gaps can differ enormously (e.g., \ensuremath{\sim}1 eV in SiC) in indirect gap materials. This large difference is surprising given that the structural difference between wurtzite and zinc blende starts only in the third neighbor and that total energy differences are only \ensuremath{\sim}0.01 eV/atom. We show that zinc-blende compounds can be divided into five types (I--V) in terms of the order of their ${\mathrm{\ensuremath{\Gamma}}}_{1\mathit{c}}$, ${\mathit{X}}_{1\mathit{c}}$, and ${\mathit{L}}_{1\mathit{c}}$ levels and that this decides the character (direct, indirect, pseudodirect) of the wurtzite band gap. The observation of small ${\mathit{E}}_{\mathit{g}}^{\mathrm{W}}$-${\mathit{E}}_{\mathit{g}}^{\mathrm{ZB}}$ differences in direct band-gap systems (``type II,'' e.g., ZnS), and large differences in indirect gap systems (``type IV,'' e.g., SiC) are explained. We further show that while both type-III systems (e.g., AIN) and type-V systems (e.g., GaP) have an indirect gap in the zinc-blende form, their wurtzite form will have direct and pseudodirect band gaps, respectively. Furthermore, a direct-to-pseudodirect transition is predicted to occur in type-I (e.g., GaSb) systems.
Morphology, structure, and growth of nanoparticles produced in a carbon arc.

The morphology and crystalline microstructure of carbon-encapsulated nanoparticles produced in a Huffman-Kr\"atschmer fullerene reactor are studied systematically as a function of location within the reactor. X-ray powder diffraction and high-resolution transmission electron microscopy are used to characterize powder harvested from the reactor walls and the inner and outer cores of the cathode deposit. We observe increased graphitization and crystallinity, more faceting, and more gaps between the nanoparticle and the encapsulating carbon cages in the cathode deposit when compared to the wall powder. We propose a growth model based on gas-phase nucleation to explain these observations, linking carbon arc nanoparticle synthesis to existing work on gas aggregation cluster sources.
A membrane-lytic immunoconjugate selective for human tumor T-lymphocytes

An immunoconjugate was constructed from a monoclonal antibody recognizing human T-lymphoblastoid cells and a membrane-lytic cytotoxin purified from the venom of the Thailand cobra. Activities of this novel immunoconjugate were compared using human and murine T-lymphocyte cell lines. The ability of the conjugate to inhibit human T-cell proliferation, as measured by incorporation of [3H]thymidine, was three to four times higher than its ability to inhibit proliferation of mouse L1210 cells. The immunoconjugate EC50 for human CEM cells was equivalent to 0.1 nmoles per 2×105 target cells. Immunoconjugate selectivity paralleled the monoclonal antibodys binding characteristics. Preincubation with free antibody blocked the effect of the conjugate, but only upon the human target cells. This study supports the feasibility of directing a toxic moiety to the surface of a cancer cell to accomplish cell destruction without requiring prior toxin internalization and uncoupling from its antibody carrier.
Effect of prostaglandin E 1 on leukocyte migration.

THE acute inflammatory response following many types of tissue injury involves principally an increase in vascular permeability and the migration of leukocytes towards the inflammatory focus1. Although the complement system is known to be involved in the acute inflammatory response to allergic causes2,3, the nature of non-immunologically induced inflammation, however, is still rather obscure. We recently reported that prostaglandin E1 (PGE1) increased vascular permeability in rat skin and rat cremasteric muscle to a degree and in a pattern, not unlike that produced by histamine or serotonin4.