cssi/SciSciGPT-SciSciNet huggingface dataset:
Sonolytic Destruction of Methyl tert-Butyl Ether by Ultrasonic Irradiation: The Role of O3, H2O2, Frequency, and Power Density

The kinetics of degradation of methyl tert-butyl ether (MTBE) by ultrasonic irradiation in the presence of ozone as functions of applied frequencies and applied power are investigated. Experiments are performed over the frequency range of 205−1078 kHz. The higher overall reaction rates are observed at 358 and 618 kHz and then at 205 and 1078 kHz. The observed pseudo-first-order rate constant, k0, for MTBE degradation increases with increasing power density up to 250 W L-1. A linear dependence of the first-order rate constant, kO3, for the simultaneous degradation of O3 on power density is also observed. Naturally occurring organic matter (NOM) is shown to have a negligible effect on observed reaction rates.
Multiple circular inclusion problems in longitudinal shear deformation

An exact analytic solution is given for a case of antiplane deformation of an clastic solid containing an arbitrary number of circular cylindrical inclusions. The solution takes into account nonuniform spacing between the inclusions, which can have different radii. An example of interest to workers in composite materials is discussed.
Isotropic moments over integer lattices

Abstract Many modern edge and corner detection algorithms use moment transforms, which convolve images with tensor-valued filters, namely the product of a window function with a monomial. Over continuous domains, one may easily show that such transforms are isotropic. We generalize these continuous results to digital images, that is, to functions over the canonical integer lattice in a finite-dimensional real space. In particular, we first introduce a mathematically well-behaved method for the dilation and rotation of digital images, and then show these operations commute with discrete moment transforms in a manner consistent with the continuous results.
Akathisia in Parkinson's disease

This study evaluated the prevalence and clinical characteristics of akathisia in a tertiary care Parkinson's disease (PD) practice, and assessed the agreement between investigators for the diagnosis of akathisia in PD, and the sensitivity and specificity of a brief patient questionnaire. Fifty-six consecutive PD patients completed an akathisia questionnaire and then were clinically evaluated for akathisia by two examiners blinded to the patient questionnaire. Overall, 45% of PD patients had akathisia as determined by clinical evaluation. Interrater reliability for the diagnosis of akathisia was high (K = 0.89). Patient self-report of restlessness agreed with examiner diagnosis in 89% of the patients. The presence of akathisia was associated with the severity and age of onset of PD. Symptoms most frequently affected the legs, and associated movements were suppressible for brief periods.
Modeling of Lithography Related Yield Losses for CAD of VLSI Circuits

In this paper, a modeling technique, describing IC manufacturing yield losses in terms of parameters characterizing lithography related point defects and line registration errors, is presented. Optimization of geometrical design rules, evaluation of VLSI IC artwork, and maximization of the wafer yield are discussed as examples illustrating applications and advantages of the proposed modeling technique.
Gas-phase rotational spectroscopy of AlCCH (X∼1Σ+): A model system for organo-aluminum compounds

Abstract The pure rotational spectrum of AlCCH in its ground electronic state ( X ∼ 1 Σ + ) has been measured using Fourier transform microwave (FTMW) and mm/sub-mm direct absorption spectroscopy. AlCCH was created in a DC discharge from HCCH and aluminum vapor, either produced by a Broida-type oven, or generated from Al(CH3)3 in a supersonic jet source. Rotational transitions were measured for five isotopologues of AlCCH, with 13C and deuterium substitutions. From these data, rotational and Al and D quadrupole parameters were determined, as well as an accurate structure. AlCCH appears to exhibit an acetylenic arrangement with significant covalent character in the Al–C single bond.
Atmospheric transmittance of an absorbing gas: a computationally fast and accurate transmittance model for absorbing gases with constant mixing ratios in inhomogeneous atmospheres.

At a given pressure level the atmospheric transmittance for an absorbing gas with a constant mixing ratio varies only with the temperature profile of the atmosphere. A simple transmittance model based on temperature differences is derived for monochromatic radiation. This model then is extended to the more important case of polychromatic radiation through the use of scaling approximations. The resulting algorithm for calculating transmittances for an arbitrary temperature profile is simple to use, accurate, and computationally fast because only arithmetic operations are required. In fact, resulting transmittances agreed with line-by-line calculations to within 0.0031 for the cases tried. Details for calculating the expansion coefficients are provided.
The Growth of English Shipping 1572–1922

Nature of the data, — Tonnage of the merchant fleet, Table I, 466. — Shipping cleared in foreign trade, Table II, 469. — Entrances at London, Table III, 470. — Synoptic graph, 473. — Size of vessels, Tables IV and V, 475, 476. — Conclusion, 478.
Parental Conceptual Systems, Home Play Environment, and Potential Creativity in Children.

Abstract It was hypothesized that parents differing along a concreteness-abstractness dimension of conceptual development, as defined by the model of Harvey, Hunt, and Schroder, would differ in their attitudes and practices regarding the playfulness of their children's home play environment. It was also hypothesized that these parental differences would be systematically related to differences among the children in potential creativity. Parents' attitudes and their reported conditions of play in the home were determined by giving questionnaires to the parents. Potential creativity of the 3- and 4-year-old children was measured by indicators of complexity and variety of performance on a laboratory play task. The data for fathers showed no significant results. The results for mothers supported the hypotheses, in that conceptually abstract mothers were more likely than concrete mothers to enhance the playfulness of the home play environment, and the children of more abstract mothers showed evidence of greater creative potential on the performance task. These results were unrelated to differences among parents on certain demographic variables—age, income, education, and occupational prestige. The results were discussed in terms of the roles of parental conceptual systems and the home play environment in affecting the child's repertoire of potential responses and his motivation to respond to novelty.
Edge Effects and the Extinction of Populations Inside Protected Areas

Theory predicts that small populations may be driven to extinction by random fluctuations in demography and loss of genetic diversity through drift. However, population size is a poor predictor of extinction in large carnivores inhabiting protected areas. Conflict with people on reserve borders is the major cause of mortality in such populations, so that border areas represent population sinks. The species most likely to disappear from small reserves are those that range widely-and are therefore most exposed to threats on reserve borders-irrespective of population size. Conservation efforts that combat only stochastic processes are therefore unlikely to avert extinction.
High deferral rate for maternal-neonatal donor pairs for an allogeneic umbilical cord blood bank.

BACKGROUND: To fully evaluate the safety and efficacy of umbilical cord blood (UCB) as a source of hematopoietic progenitor cells, UCB banks are being established worldwide to provide a readily accessible resource of stem and progenitor cells for allogeneic transplantation. Guidelines for UCB donor criteria have been proposed to minimize the possibility of disease transmission to UCB recipients. STUDY DESIGN AND METHODS: In preparation for the establishment of an allogeneic UCB bank, 285 maternal–neonatal donor pairs were evaluated in our tertiary-care hospital, which was chosen because of the high percentage of African Americans among the maternal population. Maternal, neonatal, and family histories were obtained by confidential interview and medical record review to determine the number of eligible donor pairs on the basis of a conservative interpretation of proposed donor criteria. RESULTS: Only 44 percent of donor pairs were considered eligible. The most common deferral factors were maternal, and they included fever at delivery, history of chronic disease, and history of sexually transmitted disease. In most cases, more than one deferral factor was identified. CONCLUSIONS: High-risk maternal populations, which may provide access to ethnic minorities targeted for some UCB banks, may contain low percentages of eligible donors. Further refinement of donor criteria will be important in the evolution of UCB banking and transplantation.
A New Species of Cyathura (Isopoda, Anthuridae) From Coastal Waters Off Georgia, U.S.a. 1)

[Description et figuration de la nouvelle espece, Cyathura burbancki, qui, ecologiquement separee des autres Cyathura, vit au large des cotes de Georgie. Elle se distingue de C. polita, seule espece du genre connue des cotes atlantiques des U.S.A., par les larges exopodites des uropodes, qui passent au dessus du telson et se rencontrent ou se recouvrent dorsalement, et par le bord posterieur libre du sixieme pleonite, qui n'est pas fusionne avec le telson et presente une profonde incision medio-dorsale., Description et figuration de la nouvelle espece, Cyathura burbancki, qui, ecologiquement separee des autres Cyathura, vit au large des cotes de Georgie. Elle se distingue de C. polita, seule espece du genre connue des cotes atlantiques des U.S.A., par les larges exopodites des uropodes, qui passent au dessus du telson et se rencontrent ou se recouvrent dorsalement, et par le bord posterieur libre du sixieme pleonite, qui n'est pas fusionne avec le telson et presente une profonde incision medio-dorsale.]
STIM and Orai: Dynamic Intermembrane Coupling to Control Cellular Calcium Signals

Ca2+ signals controlling a vast array of cell functions involve both Ca2+ store release and external Ca2+ entry. These two events are coordinated through a dynamic intermembrane coupling between two distinct membrane proteins, STIM and Orai. STIM proteins are endoplasmic reticulum (ER) luminal Ca2+ sensors that undergo a profound redistribution into discrete junctional ER domains closely juxtaposed with the plasma membrane (PM). Orai proteins are PM Ca2+ channels that migrate and become tethered by STIM within the ER-PM junctions, where they mediate exceedingly selective Ca2+ entry. We describe a new understanding of the nature of the proteins and how they function to mediate this remarkable intermembrane signaling process controlling Ca2+ signals.
Inconclusive Hepatitis C Virus Antibody Results in African Sera

Abstract : In Africa, the prevalence of hepatitis C virus antibody (anti-HCV) is low compared to the frequency of serologic markers of hepatitis B, but high levels of false-positive anti-HCV ELISA results have been reported. To investigate the causes of false-positive results, sera from 688 outpatients living on the eastern coast of Kenya were evaluated. These data suggest that hepatitis C infection is very infrequent in eastern Kenya; however, false- positive ELISA results and inconclusive confirmatory assay results are common but unrelated to flavivirus infection (dengue, West Nile) and antibody to P. falciparum. False positivity and inconclusive reactions could be related to prolonged storage of samples, cross-reacting antibody to unknown antigens, or infection by HCV variants
Investigations of the differential affinity of antifreeze glycoprotein for single crystals of ice

Abstract Two distinctively different experiments showing the differential affinity of antifreeze glycoproteins (AFGP) for the facets of ice crystals are presented. In free growth studies of single seed crystals of ice into solutions of AFGP, clear distinction between crystals growing into the AFGP solution and similar crystals growing into pure water is found. Immediately upon going below the temperature of freezing depression, crystals grow along the c-axis as long spicules, not dendrites within the basal plane as is the case of growth into pure water. The rates of growth of the spicules are higher than growth velocity of dendrites in pure water. As the supercooling is increased, both morphology and rate become more like that of growth in pure water. We also conducted dynamic light scattering studies of the ice-solution interface. In these experiments, the local concentration of AFGP in the neighborhood of the interface was monitored by the effect of these molecules on microbubbles present near the growing interface; AFGP molecules showed preference towards the prismatic facets. All of these experimental observations support the idea of a dynamic adsorption/desorption equilibrium that is facet dependent.
Models and Strategies for Blending Nuclear Wastes to Minimize Immobilized Waste Volume

Hanford tank waste will be separated into high-level and low-level portions; each portion will then be vitrified to produce a stable glass form for disposal. Because of the wide variability in the tank waste compositions, blending is being considered as a way to reduce the number of distinct compositions that must be vitrified and to minimize the resultant volume of vitrified waste. This paper discusses several approaches to blending and models developed to formulate blends for each approach. The models produce optimized blends which minimize the volume of glass required such that all composition and property constraints on the glass are satisfied. The paper will discuss several blending strategies, and will provide the results of calculations comparing the approaches and strategies. Finally, an overall strategy for retrieving, blending, and vitrifying Hanford tank waste will be briefly discussed. Results of the calculations for high-level waste show that an effective blending strategy can greatly reduce the volume of glass required to immobilize the waste.
Timing of colonoscopy: impact on length of hospital stay in patients with acute lower intestinal bleeding

Timing of colonoscopy: impact on length of hospital stay in patients with acute lower intestinal bleeding
Learning basic concepts of telecommunications: an experiment in multimedia and learning

Abstract This paper reports on learning as it is related to use of a multimedia-based tutorial. The tutorial is designed to teach basic concepts of telecommunications to University students. The experiment described analyzes test scores of two sets of students, the first group using the aforementioned tutorial and the second learning in a traditional setting. Although learning, in both cases, occurs, there is no significant difference between the amount learned by students in the control group and those in the experimental group.
Chemoprevention of prostate cancer: agents and study designs.

Purpose: With the completion of the Prostate Cancer Prevention Trial and the ongoing performance of several additional large-scale prostate cancer prevention trials interest in this intervention has increased. We review promising agents for prostate cancer prevention, clinical trial designs and how these agents may be used clinically.Materials and Methods: We reviewed current and completed randomized chemoprevention trials for prostate cancer as well as the most promising agents for which evidence suggests that a decreased prostate cancer risk may result from their use.Results: Evidence suggests that lycopene, decreased dietary fat, antioxidants such as α-tocopherol and selenium, nonsteroidal anti-inflammatory drugs and selective estrogen receptor modulators such as toremifene and 5α-reductase inhibitors may prove useful for decreasing the risk of prostate cancer in a man. Ongoing studies are examining these agents in the 3 general scenarios of 1) general population studies (finasteride, α-tocopherol and ...
Detection of antibody responses and delayed dermal hypersensitivity with Blastomyces dermatitidis yeast and mycelial lysate antigens

Yeast cell lysate and mycelial lysate antigens prepared from one strain (T-58) of Blastomyces dermatitidis were evaluated with respect to the detection of antibodies and delayed dermal hypersensitivity. Comparable ELISA sensitivity values were evidenced with the two antigens when assayed against serum specimens from dogs with blastomycosis, sera from non-infected dogs residing in endemic and nonendemic areas for blastomycosis and sera from rabbits that were hyperimmunized with B. dermatitidis antigens. Specificity determinations with anti -Histoplasma capsulatum rabbit sera indicated that both reagents exhibited only minimal cross-reactivity; the mycelial antigen was slightly more specific than the yeast phase reagent. Similar sensitivity and specificity results were experienced when the two antigens were used to detect delayed dermal hypersensitivity in guinea pigs previously sensitized with B. dermatitidis or H. capsulatum.
Inhibition of calcite crystal growth by Mg2+ at 100°C and 100 bars: Influence of growth regime

Follow ing Shiraki and Brantley (1995), who found different growth mechanisms for calcite crystal growth at 100°C and 100 bars total pressure, we investigated the inhibition of calcite crystal growth by Mg 2+ under the same conditions of temperature, pressure, and composition. The results showed that the Mg 2+ inhibition depends on the growth regime. For growth in the exponential rate regime, the growth of calcite is almost totally inhibited, and aragonite grows instead. For growth in the linear rate regime, both aragonite and calcite precipitate. On the other hand, for experiments best described by a parabolic growth model, Mg inhibits the growth rate of calcite, but no aragonite precipitates. The study also showed that Mg inserts into the calcite structure but not into the aragonite structure to any significant extent during growth. The aragonite growth, which is controlled by primary nucleation, suggests that neither nucleation nor growth are inhibited by Mg. Discrepant observations concerning Mg inhibition documented in the literature may be explained by such differences in the growth mechanism. Copyright © 1997 Elsevier Science Ltd
Generalized maximum entropy deconvolution of spectral segments

Abstract A maximum entropy Fourier spectral deconvolution (MEFSD) program capable of selecting segments of larger spectra is used to deconvolute overlapping peaks in experimental and synthetic test cases. Low signal-to-noise features in spectra which also have very large features (dynamic ranges 100:1, 1000:1, or more) can be selected for maximum entropy processing by performing calculations on a pseudo-FID constructed from the selected region. Results show efficient and powerful deconvolution with simultaneous noise suppression for spectral segments, even when relatively crowded. Quantitative tests of MEFSD on low signal-to-noise synthetic test spectra, modeled after experimental examples, showed accuracies which were at least as good, or better, in relative peak integrations, over conventional FFT processing followed by Lorentzian curve fitting, for segments from several different test cases with dynamic ranges of 1000:1 to 3:1.
Astronomical results from SHARC-II

Abstract The Submillimeter High Angular Resolution Camera (SHARC-II) is a facility instrument for far-infrared (350 μm) imaging at the Caltech Submillimeter Observatory (CSO). With 384 pixels, SHARC-II uses the world's largest bolometer array for astronomical observations. SHARC-II is most efficiently utilized for observations of extended sources and for deep sky surveys. The low 1/ f detector noise allows total power measurements without the need to observe an emission free “off position”. This is possible because the sky emission can be distinguished from the celestial emission when the array scans over the sky at sufficient speed. Here we present a representative set of SHARC-II observations, which highlight the capabilities of the instrument. The observations show the submillimeter continuum emission from our own Galactic center, the nearby galaxy M51, and the gravitationally lensed high- z Cloverleaf galaxy H1413+1143.
CHIMERAS CONTAINING INFLUENZA NS1 AND HIV-1 REV PROTEIN SEQUENCES : MECHANISM OF THEIR INHIBITION OF NUCLEAR EXPORT OF REV PROTEIN-RNA COMPLEXES

Nuclear RNA export mediated by the HIV-1 Rev protein is inhibited by chimeric proteins in which the wild-type Rev protein is covalently linked to amino acid sequences of the NS1 protein of influenza A virus (NS1A protein), a protein that inhibits nuclear RNA export. These chimeric molecules function not only in cis but also in trans: they inhibit nuclear RNA export mediated by Rev protein molecules that are not covalently linked to the NS1A protein sequence. Here we show that inhibition occurs with a NS1-Rev chimera in which the 78 amino-terminal amino acids of the NS1A protein comprising its entire RNA-binding domain is deleted, thereby establishing that this carboxyl portion of the NS1A protein can function as an independent effector domain. The mechanism by which this NS1-Rev chimera inhibits Rev function in trans was determined. The Rev sequence in this chimera oligomerizes with Rev molecules in trans, and the resulting mixed oligomers are retained in the nucleus because the nuclear retention activity of the NS1 effector domain is dominant over the nuclear transport activity of the Rev effector domain. Binding of the FG-containing nucleoporin-like Rab protein to this NS1-Rev chimera, as measured in yeast two-hybrid assays, is much stronger than that to the Rev protein itself, yet nuclear export does not occur in the presence of the chimera. Unexpectedly, the introduction of specific mutations into the NS1A portion of this NS1-Rev chimera not only restores Rev-mediated unclear export of RNA but also eliminates detectable Rab binding, indicating that this nuclear export can occur without detectable Rab binding. A different NS1-Rev chimera, one in which the NS1A protein is full-length but contains a mutated RNA-binding domain, effectively inhibits Rev-mediated nuclear export of RNA without blocking the nuclear export of the Rev protein, indicating that nuclear export of the carrier Rev protein can be uncoupled from nuclear export of its passenger RNA.
Issues in programming language design: an overview

The past few years have witnessed an increased understanding of the relationship between programming languages and problem solving. Programming is now understood to be a rather difficult task which requires the simultaneous application of principles, skills, and art. Computer scientists have recognized that the features of a programming language can have a significant effect upon the ease with which reliable programs can be developed. It has also been observed that certain languages and language features are particularly well suited for the use of systematic programming techniques, while others hinder or discourage such discipline. Of course, it is possible to write well-structured, clearly organized programs in any programming language, but such programs have often been the exception rather than the rule.
Sexual experiences and condom use of heterosexual, low-income African American and Hispanic youth practicing relative monogamy, serial monogamy, and nonmonogamy.

An understanding of differences in contraceptive use patterns among monogamous serially monogamous and nonmonogamous adolescents is essential to the design and targeting of condom promotion interventions. Interviews were conducted in Detroit Michigan (US) in 1991 with a probability sample of 1062 heterosexual low-income African American and Hispanic youth 15-24 years of age. 577 were categorized as relatively monogamous 171 as serially monogamous and 278 as nonmonogamous. Monogamous youth were most likely to be female Hispanic married and to have engaged in unprotected intercourse. Those who practiced serial monogamy were likely to be younger and to have used condoms at last intercourse. Nonmonogamous youth initiated intercourse earlier were most likely to have experienced oral and anal intercourse tended not to use contraception and had the highest use rates of alcohol and marijuana. Condom use at last intercourse was reported by 38.6% of monogamous youth 57.3% of the serially monogamous and 38.2% of nonmonogamous youth; consistent condom use during the past year was reported by only 3.0% 3.1% and 2.5% respectively. Discriminant analysis indicated that age at first intercourse experience with oral sex and number of partners best distinguished monogamous youth from serial and nonmonogamous youth. The 3 groups differed significantly in their perceived susceptibility to HIV; 11.0% 17.8% and 23.6% respectively had ever worried about contracting HIV from a partner. Risk reduction programs should be tailored to accommodate the different needs of these 3 subgroups. For example nonmonogamous youth tend to be sensation seekers and may be more responsive to condom promotion campaigns that emphasize pleasure enhancement than to fear-based interventions.
Consistent and compact data management in distributed storage systems

In this paper we consider the problem of maintaining a consistent mapping of a virtual object space to a set of memory modules, i.e. the object space can be decomposed into a set of ranges where every module is responsible for exactly one range. A module owning some range R is responsible for storing all objects in R. Besides consistency, we require the mapping to be compact, i.e. any object or consecutive range of objects should be spread out over as few memory modules as possible. A compact mapping is important for many applications such as efficiently executing programs using a large amount of space or complex search queries such as semi-group range queries. Our main result assumes a static set of memory modules of uniform capacity, but we also show how to extend this to a dynamic set of memory modules of non-uniform capacity in a decentralized environment.In both settings, new objects may be added, old objects may be deleted, or objects may be modified over time. Each object consists of a set of data blocks of uniform size. So insert, delete, or modify operations on objects can be seen as insert or delete operations of data blocks. Each module can send or receive at most one data block in each unit of time and the injection of insert or delete requests for data blocks is under adversarial control. We prove asymptotically tight upper and lower bounds on the maximum rate at which the adversary can inject requests into the system so that a consistent and compact placement can be preserved without exceeding the capacity of a module at any time. Specifically, we show that in a (1-e)-utilized system (i.e. the available space is used up to an e fraction) the maximum injection rate that can be sustained is Θ(e).
Evidence for a new phospholipid intermediate in rat liver subcellular systems

Abstract A glycerol phosphatide termed GPX is highly labeled from [ 32 P]orthophosphate, [ 32 P i ], [ 14 C]glycerol or 14 C-labeled fatty acids in rat liver systems. This lipid has properties similar to but not identical with phosphatidic acid. It has different chromatographic mobilities in several solvent systems than does phosphatidic acid and forms a dissociable complex with fluorodinitrobenzene under conditions where phosphatidic acid does not form such a complex. Both GPX and phosphatidic acid yield α-glycero-phosphate on alkaline hydrolysis, both yield one lyso-product on phospholipase A 1 (EC 3.1.1.4) hydrolysis, and both are not hydrolyzed by phospholipases C (EC 3.1.4.3) and D (EC 3.1.4.4), It is postulated that GPX is a diacyl glycerol phosphate compound having a labile polar group attached to the phosphate moiety. The nature of this group is not known.
Clear cell carcinoma of the endometrium

In a clinical-pathologic review of 825 cases of endometrial carcinoma diagnosed between 1955 and 1984, 735 cases were confirmed as endometrial carcinoma. From this group 29 cases of clear cell carcinoma of the endometrium were found representing a 4% frequency. Clear cell carcinoma of the endometrium was found in an older group of women, all postmenopausal. No relationship to the use of estrogen could be demonstrated. The frequency of clear cell carcinoma of the endometrium dropped from 6% in the group diagnosed between 1955 and 1969 to 3% in the group diagnosed between 1970 and 1984, although the numbers of cases of endometrial cancer rose from 194 to 525 in the comparative time span. Clear cell carcinoma of the endometrium has a poorer prognosis, with a 64% 5-year survival rate compared with an 80% 5-year survival rate for adenocarcinoma, not otherwise stated. Three patients died after 5 years of disease. Treatment is still not satisfactory, but the proved therapy remains total abdominal hysterectomy plus salpingo-oophorectomy. The role of adjunctive therapy has not been established.
Evidence for developmental plasticity of the rubrospinal tract. Studies using the North American opossum.

Abstract Using axonal tracing techniques we have shown that rubral axons are capable of growing around lesions of the rubrospinal tract during early stages of development in the North American opossum and that a critical period for such growth exists. The opossum was employed for study because it is born in a very immature state 12–13 days after conception and the entire development of its rubrospinal tract occurs postnatally.
Cadmium and manganese flux in eelgrass Zostera marina II. Metal uptake by leaf and root-rhizome tissues

Cadmium and manganese radionuclide uptake by Zostera marina L. tissues and translocation between rootrhizomes and leaves was examined. Cadmium concentrations in root-rhizomes increased with incubation time but appeared to reach saturation levels at 24 h of exposure. Translocation of cadmium between root-rhizomes and leaves occurred in both directions. A greater flux of cadmium downward suggested that root-rhizomes were a cadmium sink. Cadmium flux in either direction could be enhanced by a salt gradient. Cadmium appears to move through eelgrass by diffusion or mass flow through vascular tissues and apparent free spaces. Manganese is less mobile but is more readily fixed by leaves. Manganese mobility is not enhanced by salt gradients. Incorporation of cadmium and manganese into root-rhizomes from labelled anoxic sediments was several orders of magnitude less than that from labelled anoxic seawater media.
NUMERICAL COMPUTATION OF HEAT AND MOMENTUM TRANSFER IN TURBULENT FLOWS ALONG A PLATE USING LARGE TRANSVERSAL INTERVALS

A hybrid computational method has been developed for the step-by-step calculation of both momentum and heat transfer in turbulent boundary layer flows along flat plates. Basically, the proposed procedure relies on the method of lines (MOL), which replaces a partial differential equation in two independent variables by an appropriate system of ordinary differential equations in one of these variables. This convenient transformation is accomplished by constructing a “control volume” being infinitesimal in the axial direction and finite in the transversal direction of the fluid stream. Using the customary assumptions for modellirg the turbulent diffusivity of momentum and heat for gases, the resulting system of ordinary differential equations of first order may be readily integrated utilizing a fourth-order Runge-Kutta algorithm. In general, for a typical boundary layer calculation, a maximum number of sixteen lines is necessary at the trailing edge of the flat plate. As a consequence, computing time and sto...
Availability of organic carbon for denitrification of nitrate in subsoils

Previous work in our laboratory indicated that the slow rate of denitrification in Iowa subsoils is not due to a lack of denitrifying microorganisms, but to a lack of organic C that can be utilized by these microorganisms for reduction of NO 3 − . This conclusion was supported by studies showing that drainage water from tile drains under agricultural research plots contained only trace amounts of organic C and had very little, if any, effect on denitrification in subsoils. Aqueous extracts of surface soils promoted denitrification when added to subsoils, and their ability to do so increased with increase in their organic C content. Amendment of surface soils with corn and soybean residues initially led to a marked increase in the amounts of organic C in aqueous extracts of these soils and in the ability of these extracts to promote denitrification in subsoils, but these effects were short-lived and could not be detected after incubation of residue-treated soils for a few days. We conclude from these observations that water-soluble organic C derived from plant residues is decomposed so rapidly in surface soils that very little of this C is leached into subsoils, and that this largely accounts for the slow rate of denitrification of nitrate in subsoils.
On the rate of acquisition of visual information about space, time, and intensity

The temporal course of acquisition of visual information was mapped by measuring the speed and accuracy With which Ss could discriminate the position, intensity, or duration of a stimulus that was varied independently on these three binary dimensions. The speed-accuracy tradeoff was different for each of the three discrimination tasks, with performance substantially superior in the position discrimination task. In the intensity and duration discrimination tasks, there were systematic changes with RT in the relative influences of the three stimulus variables over the two alternative responses, suggesting .three phases of the corresponding perceptual processes: an initial dominance by position of the stimulus, a subsequent, joint influence by both intensity and duration, and finally an exclusive control by the correct dimension. The results demonstrate that Ss can selectively attend to various dimensions of the same stimulus, with concommitantly varying time constants. The perceptual processes being tapped by a discrimination task depend upon instructions and upon RT.
Majoring in fashion: a theoretical framework for understanding the decision-making process

Choosing a college major can be a complex decision and one that has the potential to determine an individual's professional future. The purpose of this study was to develop a theoretical framework for mapping the decision-making process. Grounded in findings from a previously published study of interviews with students majoring in fashion and the existing literature on the process of major selection, an interpretation of factors influencing students' decision-making was developed. Findings provided the foundation for a theoretical framework that permits an in-depth understanding of the decision process that currently does not exist within the literature. Further empirical use and development of the framework would provide assessment of its applicability across a variety of college majors and within countries other than the USA.
U.S. FDA Perspective on the Regulation of Cyanoacrylate Polymer Tissue Adhesives in Clinical Applications

A brief description of the uses and clinical applications of synthetic cyanoacrylate polymer adhesive/glues that have been cleared and/or approved as medical devices by FDA since the Medical Device Amendments of 1976 were enacted. This includes cyanoacrylate Class I devices (Exempt and not Exempt devices), Class II cyanoacrylate devices such as Dental Cements and Orthodontic Bracket Adhesives, and Class III (PMA) devices such as Dermabond™, Indermil™ Tissue Adhesive, and Trufill® n-Butyl Cyanoacrylate Embolic Agent. By citing an example of recently FDA approved Class III (PMA) devices in the Cyanoacrylate technology, the author provides a brief discussion of the FDA approval process of medical devices. It includes the FDA issues regarding the published guidance document for "Cyanoacrylate Topical Tissue Adhesives" that will provide guidance to regulatory personnel and manufacturers in the preparation of IDE applications and in the development of valid scientific evidence to support PMA applications for cyanocrylate tissue adhesives intended for topical approximation of skin and others. Also, the author provides a short regulatory description of US FDA; under what laws its operates, how FDA evaluates new devices for marketing, and how the device regulatory system works, for example, Class I, Class II, and Class III cyanoacrylate medical devices.
The time-domain behavior of power-law noises

The power spectra of many geophysical phenomena are well approximated by a power-law dependence on frequency or wavenumber. A simple expression for the root-mean-square variability of a process with such a spectrum over an interval of time or space is derived. The resulting expression yields the powerlaw time dependence characteristic of fractal processes, but can be generalized to give the temporal variability for more general spectral behaviors. The method is applied to spectra of crustal strain (to show what size of strain events can be detected over periods of months to seconds) and of sea level (to show the difficulty of extracting long-term rates from short records).
A 17 dBm 64 GHz voltage controlled oscillator with power amplifier in a 0.13 /spl mu/m SiGe BiCMOS technology

A 64 GHz voltage controlled oscillator with power amplifier is presented. It uses an LC type oscillator with a capacitively degenerated negative resistance core, and a class AB power amplifier to output 17 dBm of power with a phase noise of -100 dBc/Hz (at 600 kHz). The stand alone oscillator delivers 5 dBm of output power (8 dBm balanced) with phase noise of between -95 dBc/Hz and -100 dBc/Hz (at 600 KHz offset) and 2 GHz tuning range. Separate voltage rails of 4 V, 2 V, and 1 V are provided for the two stages of buffering and core, respectively, for a total power consumption of 130 mW. The PA is a class-AB push-pull amplifier made from two unbalanced cascode amplifiers with 15 dB power gain and 17 dBm saturated output power. The PA operates off the same 4 V rail as the VCO buffer, consuming up to 500 mW of power for power added efficiencies of between 6-10%.
Computation of low-speed flow with heat addition

A perturbation expansion is used to obtain a system of conservation laws for compressible flows that is valid at arbitrarily low Mach numbers. These equations are rendered hyperbolic by adding an artificial time derivative to the energy equation, thus introducing pseudoacoustic waves with a speed the same order as the particle velocity. Traditional time-iterative schemes are shown to be effective in solving this system numerically. Stability calculations of the complete vector system indicate unconditional stability at all Mach numbers in the absence of gravity, but the source term introduced by buoyancy becomes destabilizing at Froude numbers below about 1. This instability is amplified by approximate factorization thus precluding solutions with gravity below this Mach number level. Computations of strong heat addition in low-Mach-number flow both with and without gravity confirm the stability predictions. Convergent solutions are maintained and are used to show the effect of gravity on such flowfields.
Abrupt changes (Heinrich events) in late Quaternary North Atlantic marine environments: a history and review of data and concepts

In the last several years evidence has mounted that a series of abrupt changes in sediment delivery and palaeoceanography effected the North Atlantic; they are recorded in a variety of proxy records but most dramatically in changes of grain-size and mineralogy associated with postulated iceberg rafting events, specifically Heinrich (H) events. This review paper examines the evidence for such evidence prior to the development of the ‘Heinrich event’ concept (1988–1992), and then examines the explosion of data and correlations that stemmed from the acceptance and use of this paradigm. Specific attention is focused on ideas pertaining to the cause(s) of glaciological mechanisms, sediment delivery, and sediment source, and major gaps in our understanding of the underlying glaciological, glacial geological, and glacial marine processes are stressed. Abrupt changes across boundaries associated with H-2 in the Labrador Sea are illustrated from core HU87033-009LCF. The case is made that correlations between records need to be more rigorous, especially within the range of radiocarbon dating, but it appears that abrupt changes in the delivery of iceberg rafted debris, which characterize these intervals, are multisourced. It is unclear how global ‘climate’ can simultaneously influence the abrupt behaviour of ice margins in different parts of the world—for marine-based margins, changes in relative sea-level are one possibility. A qualitative model is presented for triggering H events, which includes global changes in mass balance, changes in relative sea-level at ice margins due to glacial isostasy, and changes in the basal thermal regime of tidewater ice-streams. © 1998 John Wiley & Sons, Ltd.
Faults, symptoms, and software fault tolerance in the Tandem GUARDIAN90 operating system

The authors present a measurement-based study of software failures and recovery in the Tandem GUARDIAN90 operating system using a collection of memory dump analyses of field software failures. They identify the effects of software faults on the processor state and trace the propagation of the effects to other areas of the system. They also evaluate the role of the defensive programming techniques and the software fault tolerance of the process pair mechanism implemented in the Tandem system. Results show that the Tandem system tolerates nearly 82% of reported field software faults, thus demonstrating the effectiveness of the system against software faults. Consistency checks made by the operating system detect 52% of software problems and prevent any error propagation in 31% of software problems. Results also show that 72% of reported field software failures are recurrences of known software faults and 70% of the recurrence groups have identical characteristics.
Chimeric nature of two plasmids of Hafnia alvei encoding the bacteriocins alveicins A and B

The complete nucleotide sequences of two bacteriocin-encoding plasmids isolated from Hafnia alvei (pAlvA and pAlvB) were determined. Both plasmids resemble ColE1-type replicons and carry mobilization genes, as well as colicin-like bacteriocin operons. These bacteriocins appear to be chimeras consisting of translocation domains from Tol-dependent colicins, unique binding domains, and killing and immunity domains similar to those of the pore-forming colicin Ia. Just as is found for colicin Ia, these H. alvei bacteriocins (alveicins) lack lysis genes. The alveicins are unusually small at 408 and 358 amino acids for alveicin A and B, respectively, which would make alveicin B the smallest pore-forming bacteriocin yet discovered. The pattern of nucleotide substitution in the alveicins suggests that the dominant forces in the evolution of their killing domains and immunity genes are neutral mutation and random genetic drift rather than diversifying selection, which has been implicated in the evolution of other colicins. Five of six bacteriocinogenic isolates of H. alvei were found to carry plasmids identical to pAlvA. Comparisons of the levels of nucleotide divergence in five housekeeping genes to the levels of divergence in their respective plasmids led us to conclude that pAlvA is transferring laterally through the H. alvei population relatively rapidly.
Keynote 2: using randomized techniques to build scalable intrusion-tolerant overlay networks

Overlay networks provide important routing functionality not easily supported directly by the Internet. Distributed Hash Tables (DHTs) have been proposed to support such overlay networks. While it is often straightforward to support overlay networks on DHTs, this choice can be questioned. DHTs dictate routes that are not optimal, and DHTs are hard to secure. As overlay networks are beginning to be deployed for critical applications, efficiency and security are becoming important attributes. We present an alternative support structure called Fireflies. Fireflies provides each of its members with a complete view of its live peers. A small subset of these peers is marked as neighbors. With high probability, the mesh formed by the members and their neighbor links has a diameter logarithmic in the number of live members, and connects all the reachable members that are not Byzantine. Fireflies uses several randomized algorithms, which are briefly described. We also discuss how Fireflies may be used to build intrusion-tolerant overlay networks
Absorption Effects in STEM Microanalysis of Ceramic Oxides

A scanning transmission electron microscope (STEM) equipped with an X-ray energy dispersive spectrometer (EDS) was used for quantitative X-ray tnicroanalysis of an MgO-10 mol% NiO ceramic. Using the Cliff-Lorimer standardless ratio technique for quantitative X-ray microanalysis, absorption of the Mg characteristic X rays, particularly by oxygen in the specimen, was found to be a critical problem and corrections were required. This problem is characteristic of low atomic number oxide ceramics. However, preferential absorption of characteristic X rays by carbon contamination buildup during X-ray analysis was negligible. A grain-boundary composition profile, corrected for absorption, showed no segregation of the Ni to the grain boundary, in agreement with current segregation theory.
Effect of CD4+ T lymphocyte depletion on resistance of Gulf Coast Native lambs to Haemonchus contortus infection.

It has been reported that CD4 + T lymphocytes are important in acquired immunity to gastrointestinal nematode infection. Whether these lymphocytes are also involved in the immune response of naturally resistant Gulf Coast Native (GCN) sheep to Haemonchus contortus infection remains to be defined. The objective of this study was to determine the role of CD4 + T lymphocytes in this resistance. Ten GCN lambs were randomly assigned to a control (n = 5) or a treatment (n = 5) group. The treatment consisted of a series of IV injections with mouse anti-ovine CD4 + T lymphocyte monoclonal antibodies for a period of 3 weeks. After the second treatment, all lambs were experimentally infected with 10,000 H. contortus infective larvae by oral inoculation. All lambs were monitored for fecal egg counts, blood packed cell volumes, white blood cell differential counts and serum antibody responses on a weekly basis. Fluorescence-activated cell sorter (FACS) analysis was done biweekly to enumerate CD4 + T lymphocytes in peripheral blood. Necropsies were performed at the end of the study and 10% of the contents of the gastrointestinal tract were preserved for nematode enumeration and identification. Also at necropsy, mesenteric lymph nodes were extracted and FACS analysis was run on lymphoid cells. Mean fecal egg counts on day 21 and 28 post-infection and nematode counts at necropsy of the treated group were significantly (p < 0.05) higher than that of the control group. Percent CD4 + T lymphocytes in peripheral blood was significantly (p < 0.05) lower in the treatment group than in the control group from day 9 to the end of the study. No differences were found in blood packed cell volumes, white blood cell differential counts, antibody titer or lymph node CD4 + lymphocytes between groups. Lambs depleted of their CD4 + T lymphocytes were more susceptible to H. contortus infection than undepleted lambs. The results of this study suggest that CD4 + T lymphocytes are associated with the natural resistance of GCN sheep to H. contortus infection.