cssi/SciSciGPT-SciSciNet huggingface dataset:
Chronostratigraphy of the Miocene-Pliocene Sagantole Formation, Middle Awash Valley, Afar rift, Ethiopia

The Sagantole Formation comprises more than 200 m of lacustrine, alluvial, and volcaniclastic sediments, plus compositionally bimodal tephras and basaltic lavas, exposed in a domelike horst named the Central Awash Complex in the southwestern Afar rift of Ethiopia. The Sagantole Formation is widely known for abundant vertebrate faunas, including the 4.4 Ma primitive hominid Ardipithecus ramidus . New lithostratigraphic data are used to subdivide the Sagantole Formation into the Kuseralee, Gawto, Haradaso, Aramis, Beidareem, Adgantole, and Belohdelie Members, in ascending order. The members are defined on the basis of lithologic differences and laterally continuous bounding tephras. 40 Ar/ 39 Ar dating of 12 intercalated volcanic units firmly establishes the age of the Sagantole Formation to be 5.6 to 3.9 Ma, significantly older than previous proposals based on erroneous correlations. Magnetostratigraphic data reveal eight paleomagnetic polarity zones, which can be correlated unambiguously with the Thvera, Sidufjall, Nunivak, and Cochiti Subchrons of the Gilbert Chron. Thus, by reference to the geomagnetic polarity time scale, seven additional chronological datums can be placed in the Sagantole Formation. With a total of 19 such datums, the age resolution anywhere in the Sagantole Formation is better than ±100 k.y., making this the best-dated Miocene–Pliocene succession in Africa.
Cloning and In Vitro Expression and Characterization of the Androgen Receptor and Isolation of Estrogen Receptor α from the Fathead Minnow (Pimephales promelas)

In vitro screening assays designed to identify hormone mimics or antagonists typically use mammalian (rat, human) estrogen (ER) and androgen receptors (AR). Although we know that the amino acid sequences of steroid receptors in nonmammalian vertebrates are not identical to the mammalian receptors, a great deal of uncertainty exists as to whether these differences affect interactions of potential endocrine-disrupting chemicals (EDC) with the receptors. This leads to substantial uncertainty with respect to the utility of mammalian-based screening assays to predict possible effects of EDCs in nonmammalian wildlife. This paper describes preparation of a cDNA library from a small fish model commonly used in ecological risk assessments, the fathead minnow (Pimphales promelas). The cDNA library was subsequently used to isolate and sequence both AR and ERalpha. In addition, the fathead minnow (fh)AR was expressed and characterized with respect to function using saturation and competitive binding assays in COS monkey kidney cells. Saturation experiments along with subsequent Scatchard analysis determined that the Kd of the fhAR for the potent synthetic androgen R1881 was 1.8 nM, which is comparable to that for the human AR in the same assay system. In COS whole cell competitive binding assays, potent androgens such as dihydrotestosterone and 11-ketotestosterone were also shown to be high affinity ligands for the fhAR. We also report affinity of the receptor for a number of environmental contaminants including the AR agonists androstenedione and 17a- and 17beta-trenbolone;AR antagonists such as p,p'-DDE, linuron, and vinclozolin; and the ER agonist 17beta-estradiol. Future plans include comparison of binding affinities of the fhAR to those of the human AR, also expressed in COS cells, using a range of EDCs.
Photophysical studies of amorphous orientation in poly(ethylene terephthalate) films

Abstract The effects of uniaxial and biaxial extension on the intrinsic fluorescence of poly(ethylene terephthalate) (PET) films have been investigated. A power law relationship, valid for both uniaxially and biaxially deformed samples, was found between the fluorescence emission at 368 nm and the planar extension, which is defined as the product of the extension ratios in the transverse and machine directions. Dimethyl terephthalate (DMT) model compound studies indicate that the fluorescent species in the PET films is not the monomeric unit. The dependence of emission intensity at 368 nm on orientation was greater when the films were excited with 300 nm light than with 340 nm. However, the absolute emission intensity was an order of magnitude larger when the excitation wavelength was 340 nm as compared to 300 nm. Transient fluorescence measurements show that the 368 nm emission has an average lifetime of 1.3 ns when using 340 nm excitation, and an average lifetime of 3.8 ns when exciting at 300 nm. A model incorporating energy migration in the non-crystalline region has been proposed to explain these results.
Dehydrogenases of Neurospora crassa

Malate, isocitrate, glucose-6-phosphate, and 6-phosphogluconate dehydrogenases of the homogenate prepared from the mycelia of several wild strains of Neurospora crassa have been subjected to zone electrophoresis in starch gel. Four electrophoretically different malate dehydrogenases, a single isocitrate dehydrogenase, three glucose-6-phosphate dehydrogenases, and two 6-phosphogluconate dehydrogenases were obtained regardless of the strain or the media in which the organism was grown.
Detection of pulmonary perfusion patterns in patients with pulmonary embolism by ultrafast CT

This report outlines a method of automatically segmenting pulmonary perfusion regions from ultrafast CT data. Segmenting was performed by a k-means clustering of unenhanced, maximal enhancement and both parameters. Time density curves from distinct regions were generated and perfusion determined. In two example subjects with pulmonary embolism hypoperfused regions were identified. In a normal subject slight gravity related gradient hypoperfusion was also detected. These preliminary results suggest that automated segmentation of UFCT pulmonary perfusion scans is possible and could greatly improve the clinical utility of the scanning technology.
A constraint programming approach to designing a newspaper distribution system

Abstract This paper presents a constraint programming approach using a modeling language and CP optimizer to aid in the coordination of the production and delivery of multi-product newspapers to bulk delivery locations. The distribution problem is modeled as an open vehicle routing problem with time windows and zoning constraints. The use of a high level modeling language eliminates the need to develop custom low-level computer codes to solve the problem. The methodology is applied to the newspaper production and distribution problem in a major metropolitan area. Computational results are presented and show significant improvement relative to a previous metaheuristic approach using tabu search.
Estimating phospholipid membrane-water partition coefficients using comprehensive two-dimensional gas chromatography.

Recent studies have shown that membrane–water partition coefficients of organic chemicals can be used to predict bioaccumulation and type I narcosis toxicity more accurately than the traditional KOW-based approach. In this paper, we demonstrate how comprehensive two-dimensional gas chromatography (GC × GC) can be used to estimate such membrane–water partition coefficients (KPLWs), focusing in particular on phosphatidyl choline based lipids. This method performed well for a set of 38 compounds, including polycyclic aromatic hydrocarbons, polychlorinated benzenes and biphenyls, and substituted benzenes including some phenols and anilines. The average difference between the estimated and the measured log KPLW values of 0.47 log units is smaller than in the case of a log KOW correlation approach but larger than seen using a polyparameter linear free energy relationship based approach. However, the GC × GC based method presents the advantage that it can be applied to mixtures of chemicals that are not complete...
Examination of methylphenidate-mediated behavior regulation by glycogen synthase kinase-3 in mice.

Abnormalities in dopaminergic activity have been implicated in psychiatric diseases, such as attention deficit hyperactivity disorder (ADHD), and are treated with therapeutic stimulants, commonly methylphenidate or amphetamine. Amphetamine administration increases glycogen synthase kinase-3 (GSK3) activation, which is necessary for certain acute behavioral responses to amphetamine, including increased locomotor activity and impaired sensorimotor gating. Here, we tested if modulating GSK3 by administration of the GSK3 inhibitor lithium or expression of constitutively active GSK3 altered behavioral responses to methylphenidate administered to mice acutely or daily for 8 days. Methylphenidate or amphetamine was administered to mice intraperitoneally for 1 or 8 days. Open-field activity and pre-pulse inhibition (PPI) were measured. In contrast to lithium’s blockade of acute amphetamine-induced locomotor hyperactivity, lithium treatment did not significantly reduce methylphenidate-induced locomotor hyperactivity in wild-type mice after acute or 8 days of repeated methylphenidate administration. Lithium treatment significantly increased the impairment in PPI caused by methylphenidate, but significantly reduced the amphetamine-induced PPI deficit. In GSK3 knockin mice, expression of constitutively active GSK3β, but not GSK3α, significantly increased locomotor hyperactivity after acute methylphenidate treatment, and significantly impaired PPI, preventing further methylphenidate-induced impairment of PPI that was evident in wild-type mice and GSK3α knockin mice. Lithium does not counteract locomotor activity and PPI responses to methylphenidate as it does these responses to amphetamine, indicating that different mechanisms mediate these behavioral responses to methylphenidate and amphetamine. Only active GSK3β, not GSK3α, modulates behavioral responses to MPH, indicating selectivity in the actions of GSK3 isoforms.
Photochemical attachment of reactive cross-linked polymer films to Si/SiO2 surfaces and subsequent polymer brush growth

Thin films consisting of a mixture of acrylate/methacrylate monomers were photochemically attached to modified silicon wafer surfaces. Reactive functionality was embedded into the photopolymer film by adding alkoxyamine monomers (inimers) that facilitate polymer brush growth in subsequent polymerization reactions. We present a careful examination of each of the steps, from substrate preparation to silane coupling agent coating, photopolymer attachment, and polymer brush growth. Several 3-methacryloxypropyl silanes were evaluated as silane coupling reagents. The surface roughness of wafers increased from 0.2 to 0.6 nm after treatment with silane. Curing of a thin photopolymer film did not increase the surface roughness. Interestingly, brushes of d8 polystyrene grown from the photopolymer surface displayed half the roughness of the underlying polymer layer, displaying a smoothing effect. All photopolymer films attached to the wafers utilizing a silane layer had excellent adhesion. We studied the film surfac...
Interaction of boron with tungsten single crystal substrates

Abstract A low-energy electron diffraction (LEED) study of the interaction of a thin (ca. 10A) deposit of “amorphous” boron with (100), (110), (111), (211), and (310) tungsten single crystal surfaces is reported. Because of the disordered state of the B deposit it was possible to follow the effect of the interaction on the W lattice as the crystals were heated to successively higher temperatures. The interaction was found to proceed in steps as follows: (a) strong chemical bonding at 500 °C with an accompanying distortion of the top layer of the lattice; (b) penetration and disordering of the W lattice by the B at 600 to 700 °C; (c) reordering of the W lattice at 800 °C accompanied by ordered structures at the (100) surface; and (d) completion of ordering of the W lattice at 800 to 1000 °C and diffusion of the B into the bulk of the crystals. In the final step an expansion of the (110) surface in the [√2 a 0 ] direction is attributed to surface B atoms residing in particular crystallographic positions thereby producing anisotropic distortions of the top layer of W atoms.
A survey of financial planning models for health care organizations.

This paper describes “what if?” financial planning models developed for health care administrators and financial managers to study and evaluate the economic impact of changes in a health care organization's charge structure, operating policies, reimbursement plans, and services and resources. Models for inpatient and outpatient care systems are presented. The models are described in terms of input, output, and application. An assessment of the state of the art of financial planning and prospects for the future of what if? models are given.
Cancer genomics identifies determinants of tumor biology

Unbiased sequencing and analysis of human tumors is revealing unsuspected somatic changes that, upon further study, are elucidating aspects of tumor biology and identifying new biomarkers.
Alkaline Hydrolysis of Mouse-Adapted Scrapie for Inactivation and Disposal of Prion-Positive Material

Prion diseases such as bovine spongiform encephalopathy, chronic wasting disease, and scrapie pose serious risks to human and animal health due to a host of disease-specific factors, including the resistance of infectious prions (PrP(Sc)) to natural degradation and to most commercial inactivation procedures. In an attempt to address this concern, a mouse model was used to compare the efficacy of an alkaline hydrolysis process with a simulated continuous-flow rendering treatment for disposal of PrP(Sc)-infected biological material. Female C57/BL6 mice (N = 120) were randomly divided into 4 treatment groups (n = 30), and each mouse was injected intraperitoneally with their designated treatment inoculum. Treatment groups 1 and 2 served as the positive and negative controls, respectively. Group 3 was inoculated with rendered scrapie-positive mouse brain material to investigate the effectiveness of simulated continuous-flow rendering practices to reduce or eliminate PrP(Sc). Group 4 was inoculated with hydrolyzed scrapie-positive mouse brain material to determine the sterilizing effect of alkaline hydrolysis on PrP(Sc). Mice were monitored for overt signs of disease, and those showing clinical signs were killed to prevent undue suffering. Brains were obtained from all mice that died (or were killed) and analyzed with an ELISA for the presence of PrP(Sc). Results indicated that the simulated continuous-flow rendering treatment used for preparing the rendering treatment group inoculum failed to completely eliminate PrP(Sc). Rendering delayed, but did not stop, clinical mouse-adapted scrapie transmission. Compared with positive controls, the rendering treatment group experienced an approximate 45-d average delay in days to death (250 vs. 205 d for positive controls; P < 0.0001) and a death loss of 73.9% (P = 0.0094). Positive controls suffered 100% death loss. The results validated the efficacy of the alkaline hydrolysis treatment to inactivate all PrP(Sc) because no alkaline hydrolysis treatment group mice succumbed to the disease (P < 0.0001). Based on our results, alkaline hydrolysis should be considered by the animal rendering and beef packing industries as an alternative to incineration, landfill burial, and rendering for disposing of biological material potentially infected or contaminated with prion disease.
N-Acetylcysteine in experimental and clinical acute lung injury

Clinically, lung injury is characterized by one or more of the following: altered gas exchange, dyspnea, decreased static compliance, and nonhydrostatic pulmonary edema. Although many antioxidants have been investigated in in vitro systems and in animal models, only some are at the developmental stage, or safe for clinical trials. Considerable evidence has recently accumulated supporting the hypothesis that leukocyte activation involves release of large quantities of highly reactive oxygen radicals, and hydrogen peroxide is partially responsible for diffuse microvascular and tissue injury in septic patients. Granulocyte depletion in animal models reduces the degree of fall in dynamic lung compliance and the increase in airflow resistance, lymph flow, and hypoxemia secondary to endotoxin administration. We hypothesized that the partial benefit derived from granulocyte depletion was due to the effective removal of a major source of oxygen radicals. Among the list of free radical scavengers, N-acetylcysteine stands out, because of its established usefulness in at least one human disease thought to be secondary to free radical organ damage (acetaminophen or paracetamol overdose). It is an extremely safe agent with a wide toxic-therapeutic window. An increasing number of animal studies indicate efficacy for this agent in the prevention and therapy of lung injury involving toxic oxygen species. We developed a randomized, double-blind protocol for the study of intravenous N-acetylcysteine in patients with established adult respiratory distress syndrome (ADRS). Results of this trial are preliminary. Nevertheless, they indicate that plasma and red cell glutathione levels are decreased in ADRS patients, and that N-acetylcysteine increases plasma cysteine as well as plasma and red cell glutathione. There are also indications that cardiopulmonary physiology is favorably affected by such therapy including improvements in chest radiograph edema scores, pulmonary vascular resistance, static compliance, oxygen delivery, and oxygen consumption.
Dose distributions in bifurcated coronary vessels treated with catheter-based photon and beta emitters in intravascular brachytherapy.

The dose distributions in the bifurcated vessels treated with intravascular brachytherapy line sources are complicated and depend on the bifurcation geometry consisting of a main and a branch vessel at different angles. To investigate the dosimetric effects at the bifurcation, calculations were performed on branching vessels of various bifurcation angles ranging from 20° to 90°. Two catheter based delivery systems were considered in the calculations using a 40 mm long radioactive sources of 192 Ir or 90 Sr/Y . It was assumed that the bifurcated vessel was treated in two separate source insertions, once for the main vessel and later for the branch vessel. Calculations were performed for different values of source gap from 0 to 9 mm, at the junction of main and branch vessels. Our results indicate that main vessel always receives a higher dose (up to 200%) when the branch vessel is also treated. Hot spots at portions of the main vessel near the junction cannot be totally avoided without severely underdosing the branch vessel. For bifurcation angle greater than 45°, a 4 mm source gap can almost ensure that overdosing of the main vessel does not exceed 60% and underdosing of the branch vessel does not exceed 10% for 192 Ir . However, for 90 Sr/Y , the same is not possible unless the bifurcation angle is larger than 70°. Dose heterogeneity using 90 Sr/Y is more sensitive to the value of source gap than 192 Ir because 90 Sr/Y source provides a sharper dose-fall-off than 192 Ir . For both photon and beta emitters, there is no acceptable solution for bifurcation angles less than 30°, where the activity of the line source has a uniform distributions. Appropriate choice of gap at the junction can only help to reduce either overdosing of the main vessel or underdosing of the branch vessel, but not both.
La pression barométrique: Paul Bert's hypoxia theory and its critics

Abstract Just one hundred years ago, Paul Bert published his most famous book, La Pression barometrique... , summarizing his work on the physiological effects of altering barometric pressure. After a summary of Bert's life and contributions, this paper focuses on his experimental demonstration of the hypoxic etiology of altitude sickness. Bert showed that functional impairment or death occurred in each of a variety of species at a certain inspired oxygen pressure regardless of what combination of barometric pressure and oxygen percentage was used to achieve it. He further showed that the oxygen pressures impairing function were those producing arterial hypoxemia, and that raising the inspired oxygen percentage protected against the effects of altitudes that would otherwise endanger life. For the next several decades some other physiologists were unable to confirm these points. The criticisms of Setschenow, of Cyon, of Fraenkel and Geppert, of Mosso, and of Kronecker are analyzed in the light of modern knowledge.
COMPARATIVE ONTOGENETIC STUDIES IN YOUNG SPOROPHYTES OF TREE FERNS. I. A PRIMITIVE AND AN ADVANCED TAXON

A B S T R A C T Ontogenetic studies of young sporophytes were undertaken to determine anatomical and morphological differences between a primitive (Lophosoria quadripinnata) and an advanced (Sphaeropteris elongata) tree fern. In both species the first leaf is simple, fanshaped, and possesses dichotomous venation. Later-formed leaves exhibit either a pinnate or bipinnate pattern of laminar dissection. As the sporophyte matures, the stelar pattern changes from a protostele to an amphiphloic siphonostele, and finally to a dictyostele in Sphaeropteris. Medullation of the protostele occurs either prior to or after the formation of the first leaf trace in both species. Differentiation of xylem in the shoot is acropetal and the appearance of mature protoxylem occurs closer to the apical meristem in Sphaeropteris. The nodal pattern varies within each species with a no gap 1-trace pattern characteristic for the first two or three leaves, depending upon the taxon. In Lophosoria subsequent leaves possess a unilacunar 1trace nodal pattern, whereas a complete nodal series (1 gap 1-trace to 1 gap 6-trace) occurs in Sphaeropteris. Fusiform leaf gaps are noted in both species. The shoot apical meristem is dominated by a single apical cell, with an organized apical cell first found in P2. Stem, root, and petiole anatomy are discussed.
Implement an adjustable delay time digital trigger for an NI data acquisition card in a high-speed demodulation system

A National Instruments (NI) DAQ card PCI 5105 is installed in a high-speed demodulation system based on Fiber Fabry-Perot Tunable Filter. The instability of the spectra of Fiber Bragg Grating sensors caused by intrinsic drifts of FFP-TF needs an appropriate, flexible trigger. However, the driver of the DAQ card in the current development environment does not provide the functions of analog trigger but digital trigger type. Moreover, the high level of the trigger signal from the tuning voltage of FFP-TF is larger than the maximum input overload voltage of PCI 5105 card. To resolve this incompatibility, a novel converter to change an analog trigger signal into a digital trigger signal has been reported previously. However, the obvious delay time between input and output signals limits the function of demodulation system. Accordingly, we report an improved low-cost, small-size converter with an adjustable delay time. This new scheme can decline the delay time to or close to zero when the frequency of trigger signal is less than 3,000 Hz. This method might be employed to resolve similar problems or to be applied in semiconductor integrated circuits.
Surgical strategy for severe tricuspid valve regurgitation complicated by advanced mitral valve disease: long-term outcome of tricuspid valve supra-annular implantation in eighty-eight cases.

Abstract Objective: Although annuloplasty has been the most commonly performed surgical modality for severe tricuspid regurgitation, tricuspid valve supra-annular implantation has been performed in our hospital for more than a decade. The aim of this study was to assess the long-term outcome of tricuspid valve supra-annular implantation in a subgroup of patients with severe tricuspid regurgitation, those who also had advanced mitral valve disease. Methods: Mitral valve replacement in conjunction with tricuspid valve supra-annular implantation was performed on 88 patients at our hospital between 1984 and 1998. The patients (mean age 57 ± 11 years) were followed up for an average of 7.2 ± 4.5 years after the operation (range 0-14 years); total follow-up was 643.1 patient-years. All patients except 2 (97.6%) were included in the follow-up. We evaluated the mortality, the cause of death, survival, the freedom from structural valve deterioration and reoperation, postoperative complications, and long-term echocardiographic findings. Results: Overall survival at 14 years was 69% ± 7.7%. Freedom from structural valve deterioration at 14 years was 100% and from reoperation, 88% ± 9.4%. There were no instances of pulmonary thromboembolism or of complications associated with fatal arrhythmias. Echocardiography showed little residual tricuspid regurgitation, no atrophic and stenotic change in the native tricuspid valve, and no thrombus formation between native valve and the implanted bioprosthesis. Conclusions: The procedure's simplicity, the good long-term durability of the bioprosthesis, and the absence of fatal arrhythmias and pulmonary thromboembolism indicate that tricuspid valve supra-annular implantation is a useful procedure for patients with severe tricuspid regurgitation complicated by advanced mitral valve disease. (J Thorac Cardiovasc Surg 2000;120:280-3)
A scalable double in-memory checkpoint and restart scheme towards exascale

As the size of supercomputers increases, the probability of system failure grows substantially, posing an increasingly significant challenge for scalability. It is important to provide resilience for long running applications. Checkpoint-based fault tolerance methods are effective approaches at dealing with faults. With these methods, the state of the entire parallel application is checkpointed to reliable storage. When a failure occurs, the application is restarted from a recent checkpoint. In previous work, we have demonstrated an efficient double in-memory checkpoint and restart fault tolerance scheme, which leverages Charm++'s parallel objects for checkpointing. In this paper, we further optimize the scheme by eliminating several bottlenecks caused by serialized communication. We extend the in-memory checkpointing scheme to work on MPI communication layer, and demonstrate the performance on very large scale supercomputers. For example, when running a one million atom molecular dynamics simulation on up to 64K cores of a BlueGene/P machine, the checkpoint time was in milliseconds. The restart time was measured to be less than 0.15 seconds on 64K cores.
The charge‐flow transistor: A new MOS device

A new device, the charge‐flow transistor (CFT), has been developed to achieve integrated MOS compatibility in sensor applications, such as gas, humidity, and fire detection, where one is interested in monitoring the transverse resistance of a thin film. The resistive material is incorporated into the gate structure of the CFT in such a way that there is a time delay between the application of the gate‐to‐source voltage and the appearance of a complete channel. This time delay depends on the resistivity of the thin film. A theory of device operation is presented, together with experimental results on the first CFT’s. These results confirm the principles of operation, and demonstrate the utility of the CFT for making fully integrated sensing devices.
Surgery of skull base tumors

Differential diagnosis of tumours at the cranial base clinical neurophysiologic and radiologic diagnosis of skull base lesions special anaesthetic challenges in skull base tumour surgery anterior craniofacial resection transpalatal and transmandibular approaches to the skull base lateral, preauricular (transparotid) approaches to the skull base infratemporal approaches to the skull base lateral transtemporal approaches to the skull base malignancies of the temporal bone and ear canal intracranial extension of cranial base tumours and combined resection the neurosurgical perspective reconstruction of skull base surgical defects post-operative management and rehabilitation of cranial nerve deficits.
Measuring employment among substance-using offenders

Employment has been identified as an important predictor of drug abuse treatment outcome; however, employment has been measured in a variety of different ways in the drug abuse literature and typically with community samples. The present IRB-approved study used factor analysis to identify commonalities among several employment measures collected from a sample of drug court offenders who entered one of two Kentucky drug courts between March 2000 and November 2002. Measures included demographics, employment, substance use, and criminality. The factor analysis produced four employment factors: status, earnings, duration, and stability. These factors had different correlation patterns with substance use and criminality. Study limitations are noted. This study was supported by a grant from the National Institute on Drug Abuse.
Flame inhibition by ferrocene and blends of inert and catalytic agents

The production of the fire suppressant CF3Br has been banned, and finding a replacement with all of its desirable properties is proving difficult. Iron pentacarbonyl has been found to be up to several orders of magnitude more effective than CF3Br, but it is flammable and highly toxic. Ferrocene [Fe(C5H5)2], which is much less toxic and flammable than Fe(CO)5, can also be used to introduce iron into a flame. We present the first experimental data and numerical modeling for flame inhibition by ferrocene and find it to behave similarly to Fe(CO)5. A ferrocene mole fraction of 200 ppm reduced the burning velocity of slightly preheated premixed methane/air flames by a factor of two, and the effectiveness dropped off sharply at higher mole fractions. For air with a higher oxygen mole fraction, the burning velocity reduction was less. We also present experimental data and modeling for flames with ferrocene blended with CO2 or CF3H. The combination of the thermally acting agent CO2 with ferrocene mitigated the loss of effectiveness experienced by ferrocene alone at higher mole fractions. An agent consisting of 1.5% ferrocene in 98.5% CO2 performed as effectively as CF3Br in achieving a 50% reduction in burning velocity. Likewise, four times less CO2 was required to achieve the 50% reduction if 0.35% ferrocene was added to the CO2. In contrast, addition of 0.35% ferrocene to the hydrofluorocarbon CF3H reduced the CF3H required to achieve the 50% reduction in burning velocity by only about 25%. Thermodynamic equilibrium calculations predict that the formation of iron/fluoride compounds can reduce the concentrations of the iron-species oxide and hydroxide intermediates which are believed to be responsible for the catalytic radical recombination cycles.
Spatial and temporal patterns of intracellular calcium in colonic smooth muscle.

Intracellular calcium [Ca2+] i measurements in cell suspension of gastrointestinal myocytes have suggested a single [Ca2+] i transient followed by a steady-state increase as the characteristic [Ca2+] i response of these cells. In the present study, we used digital video imaging techniques in freshly dispersed myocytes from the rabbit colon, to characterize the spatiotemporal pattern of the [Ca2+] i signal in single cells. The distribution of [Ca2+] i in resting and stimulated cells was nonhomogeneous, with gradients of high [Ca2+] i present in the subplasmalemmal space and in one cell pole. [Ca2+] i gradients within these regions were not constant but showed temporal changes in the form of [Ca2+] i oscillations and spatial changes in the form of [Ca2+] i waves. [Ca2+] i oscillations in unstimulated cells (n = 60) were independent of extracellular [Ca2+] and had a mean frequency of 12.6 +1.1 oscillations per min. The baseline [Ca2+], was 171 ± 13 nm and the mean oscillation amplitude was 194 ± 12 nm. Generation of [Ca2+] i waves was also independent of influx of extracellular Ca2+. [Ca2+] i waves originated in one cell pole and were visualized as propagation mostly along the subplasmalemmal space or occasionally throughout the cytoplasm. The mean velocity was 23 +3 μm per sec (n = 6). Increases of [Ca2+] i induced by different agonists were encoded into changes of baseline [Ca2+] i and the amplitude of oscillations, but not into their frequency. The observed spatiotemporal pattern of [Ca2+] i regulation may be the underlying mechanism for slow wave generation and propagation in this tissue. These findings are consistent with a [Ca2+] i regulation whereby cell regulators modulate the spatiotemporal pattern of intracellularly generated [Ca2+] i oscillations.
Learning algorithms for repeated bimatrix Nash games with incomplete information

The purpose of this paper is to study a particular recursive scheme for updating the actions of two players involved in a Nash game, who do not know the parameters of the game, so that the resulting costs and strategies converge to (or approach a neighborhood of) those that could be calculated in the known parameter case. We study this problem in the context of a matrix Nash game, where the elements of the matrices are unknown to both players. The essence of the contribution of this paper is twofold. On the one hand, it shows that learning algorithms which are known to work for zero-sum games or team problems can also perform well for Nash games. On the other hand, it shows that, if two players act without even knowing that they are involved in a game, but merely thinking that they try to maximize their output using the learning algorithm proposed, they end up being in Nash equilibrium.
Effects of bleach constituents on the performance of silver-halide holograms

A factorial design approach to optimizing rehalogenating bleaches for silver-halide holograms is presented. An advantage of this technique is that it allows simultaneous improvement to a number of hologram performance characteristics as a function of several input parameters. Interactive effects of combinations of input parameters can also be examined. A specific experiment is described in which diffraction efficiency, average light loss, thickness change, and noise grating efficiency are optimized as a function of the rehalogenating agent, oxiding agent, and acid concentrations of a rehalogenating bleach. Results for both Agfa 8E75HD and Ilford SP673 films are presented.© (1990) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Surface Preparation and Characterization Techniques for Quartz Resonators

Abstract : CHNIQUES. The polishing processes which to date produced the most defect-free surfaces are described. The surface crystallinities were investigated by high energy electron diffraction (HEED). Clearly defined Kikuchi lines were observed indicating that if there is a disturbed surface layer, its thickness is less than 100A. The effectiveness of the hydrogen peroxide based cleaning procedure was investigated by Auger electron spectroscopy. A fraction of a monolayer of carbon was the only observable contaminant on the surface after this procedure was used. Atomically clean quartz surfaces could be produced by ion bombardment cleaning, but the ion bombardment itself produced some undesired side effects. The effects of the electron beam and of the ion beam are discussed. (Modified author abstract)
Adsorption with axial diffusion in deep beds

Abstract Breakthrough behavior is analyzed for adsorption in deep beds with axial diffusion, assuming that a constant pattern wave has developed upstream of the bed outlet. Fluid-solid equilibria are described by both Langmuir and Freundlich isotherms. Breakthrough curves are shown to be much sharper than corresponding constant pattern profiles, especially for very favorable isotherms, as the result of a change in the velocity of the fluid-phase concentration wave during breakthrough. In an appendix, a brief derivation is given of the proper boundary condition for the outlet of a fixed-bed adsorber.
Grazer identity changes the spatial distribution of cascading trophic effects in stream pools

Non-lethal effects of predators on prey behavior can mediate trophic cascades, but the extent of effects depends on habitat characteristics and risk sensitivity of prey. Furthermore, predation risk for stream organisms varies along the depth gradient and strongly influences their behavior. Grazing minnows (Campostoma anomalum) and crayfish (Orconectes virilis) are both prey for largemouth bass (Micropterus salmoides) in streams, but differ in their predator-avoidance behavior. This study contrasts the effects and mechanisms of non-lethal trophic cascades on the spatial distribution of filamentous green algae among stream pools and along a depth gradient within pools. Presence/absence of a largemouth bass was crossed with four combinations of the two grazer species (0 grazers, 30 minnows, 30 crayfish, and 15 each) in outdoor, experimental streams. Grazer densities were maintained by restocking. I used geostatistics to quantify spatial patterns of predator and grazer habitat use, height of filamentous algae in the water column, and spatial covariation of water depth with algal height, and depth with grazer habitat use. In streams with only minnows, bass were sedentary, and hid within tall algae in a single "bass pool". In pools with grazed algae, bass actively pursued prey within and among pools and used deeper water. This set up a hierarchy of risk to grazers along the depth gradient from bass in deep water to potential risk from terrestrial predators in shallow water. Thus, minnows were more sensitive than crayfish to predation risk from bass, but less sensitive than crayfish to risk from terrestrial predators. Minnows mediated cascades at the scale of whole pools by avoiding "bass pools", but only if crayfish were absent. Crayfish avoided potential interactions both with terrestrial predators and bass by grazing and burrowing in deeper water at night (when bass were inactive), and by hiding in burrows during daytime. Crayfish without burrows avoided bass and crayfish defending burrows by using shallow edges of pools as corridors, but did not graze there. Thus, crayfish-mediated cascades were limited to pool edges. Effects of grazer identity may extend to other consumers via modification of risk for biota that use filamentous algae as either foraging or refuge habitat.
An inside-out exploration of contemporary Chinese public relations education

Abstract This study provides an inside-out examination of contemporary Chinese public relations education. Particularly, it seeks to explore (1) how Chinese public relations educators make meaning of the imported U.S. body of knowledge of public relations; (2) how Chinese educators conceptualize Chinese public relations; and (3) the connection and disconnection between academia and industry. We conducted 49 face-to-face in-depth interviews and performed content analysis of 22 Web sites of Chinese universities with public relations programs. Research findings reflected the movement of Chinese PR from a merely technical function to a more strategic function centering on relationship building, reputation, social responsibility, and organizational identity. The findings also suggested significant influence of the U.S. PR education on the development of Chinese public relations education manifested through textbook adoption and core curricular design. However, the study has also shown that educators have undertaken substantial effort to localize the imported knowledge in accordance with China's unique cultural, economic, and political systems.
NUTRIENT AND GROWTH RESPONSES OF LEERSIA ORYZOIDES, RICE CUTGRASS, TO VARYING DEGREES OF SOIL SATURATION AND WATER NITROGEN CONCENTRATION

Leersia oryzoides (rice cutgrass) is an obligate wetland plant common to agricultural drainage ditches. The objective of this greenhouse study was to expose plants to various flooding and aqueous nitrogen (N) concentrations and then to quantify the allocation of nutrients and biomass to plant components. Plants in the continuously flooded treatment (CF) had the highest tissue concentrations of copper (Cu), sulfur (S), zinc (Zn), potassium (K), sodium (Na), and manganese (Mn) in one or more plant components. Plants in the partially flooded treatment (PF) had the highest concentrations of magnesium (Mg) in leaves. The N input affected phosphorus (P) and S concentrations in roots. Leaf, stem, and root biomass were highest in PF plants. Rhizome biomass was the lowest in CF plants. These results indicate that L. oryzoides may significantly affect elemental concentrations in surface waters by its ability to uptake various elements and subsequent sequestration in various biomass components.
A Model of Solar Flares and Their Homologous Behavior

A model describing physical processes of solar flares and their homologous behavior is presented based on resistive MHD simulations of magnetic arcade evolution subject to continuous shear-increasing footpoint motions. It is proposed in our model that the individual flaring process encompasses magnetic reconnection of arcade field lines, generation of magnetic islands in the magnetic arcade, and coalescence of magnetic islands. When a magnetic arcade is sheared, a current sheet is formed and magnetic reconnection can take place to form a magnetic island. A continuing increase of magnetic shear can trigger a new reconnection process and create another island in the underlying arcade below the original magnetic island. The newborn island rises faster than the preceding island and merges with it to form one island. Before completing the merging process, the newborn island exhibits two different phases of rising motion: the first phase with a slower rising speed and the second phase with a faster rising speed. This is consistent with the Yohkoh observation by Ohyama & Shibata (1998) of X-ray plasma ejecta motion. The first phase, in which reconnection of line-tied field in the underlying arcade is important, can be regarded as being related with the preflare phase. In the second phase, the island coalescence takes place, which creates an elongated current sheet below and enhances the reconnection rate of the line-tied arcade field. This phase is interpreted as the impulsive phase or the flash phase of flares. The obtained reconnection electric field is large enough to accelerate electrons to an energy level higher than 10 keV, which is necessary for observed X-ray emissions. After merging of the islands is completed, magnetic reconnection continues in the current sheet under the integrated island for rather a long period, which can be considered as the main phase of flares. The sequence of all these processes is repeated with some time interval while a shear-increasing motion continues. We propose that a series of these flaring processes constitutes a set of homologous flares. The time interval between successive flaring events depends on the energy input rate into the system, which is governed by the nature of the footpoint motion and the flux reconnecting rate. We also have investigated the destruction of a magnetic island in a system undergoing a decrease of magnetic shear. The result suggests that there is a critical value of magnetic shear for existence of a magnetic island in an arcade-like field configuration.
Solution of adiabatic and nonadiabatic combustion problems using step-function reaction models

We consider the use of step-functions to model Arrhenius reaction terms for traveling wave solutions to combustion problems. We develop a methodology by which the Arrhenius reaction rate term is replaced by a suitably normalized step-function. The resulting model introduces interior interfaces and allows the conservation equations for energy and species to be solved explicitly within the subdomains bounded by the interfaces. The problem can then be reduced to a small number of nonlinear algebraic equations governing appropriate interface conditions. We apply this methodology to a variety of single-reaction problems and show that the resulting solutions agree with those obtained by the well-known front δ-function) approximations for large Zeldovich numbers. We then consider multiple reaction problems, specifically problems involving two independent reactions and problems involving sequential reactions. For these problems we compare the results with simpler front models as well as with Arrhenius kinetics. We show that the step-function models are generally superior to the front models where available and agree, both qualitatively and with reasonable quantitative accuracy, with solutions obtained via full Arrhenius kinetics.
Constructing a Worker Identity Class, Experience, and Organizing in Workers'Awaaz

This article examines the debates over the meaning of ‘worker’ in Workers' Awaaz, a female domestic workers' group in New York City, at three moments in the organization's history.Workers' Awaaz se...
Subcellular fractions of bovine brain degrade phosphatidylcholine by sequential deacylation of the sn-1 and sn-2 positions

Phosphatidylcholine (PC) metabolism was investigated using cytosol (fraction I) and particulate fractions of bovine brain that were enriched with microsomes (fraction II), plasma membranes (fraction III) or mitochondria (fraction IV). Fractions I–III incubated with 1-palmitoyl-2-[14C]arachidonoyl-sn-glycero-3-phosphocholine yielded [14C]arachidonic acid at near equal rates, whereas only fraction I accumulated significant amounts of 2-[14C]arachidonoyl-sn-glycero-3-phosphocholine. Much slower rates of arachidonic acid release were observed using an ether PC (1-O-hexadecyl-2-[3H]arachidonoyl-sn-glycero-3-phosphocholine). Moreover, arachidonic acid yield from the diacyl, but not ether PC was slowed by pretreating fractions I–III, but not IV, with phenylmethylsulfonyl fluoride (PMSF). Coincident with this decreased arachidonic acid, 2-[14C]arachidonoyl-sn-glycero-3-phosphocholine was increased, indicating high PLA1 activity. Taken together these data suggest that arachidonic release was largely dependent on initial deacylation of position sn-1. Incubating each untreated fraction with 2-[3H]arachidonoyl-sn-glycero-3-phosphocholine yielded [3H]arachidonic acid (lysophospholipase A2 activity) at rate that was substantially greater than that using the comparable PMSF-treated fraction. Thus, the large effect of PMSF on arachidonic acid release can be accounted for if much of the fatty acid formation arose from the sequential sn-1 and sn-2 deacylation of diacyl-PC by phospholipase A1 and lysophospholipase A2. When PMSF-treated fractions were incubated with 2-[3H]arachidonoyl-sn-glycero-3-phosphocholine, [3H]PC accumulated at low rates that were enhanced by adding coenzyme A or stearoyl-coenzyme A. Thus, the lysophospholipid was also reacylated to form PC, but this reaction was negligible in the absence of PMSF and added cofactors. In summary, we conclude that, in brain subcellular fractions, deacylation of the sn-1 position of diacyl-PC proceeded more rapidly than sn-2 hydrolysis. There was substantial further metabolism of 2-acyl lysophospholipids due to the combined activities of a PMSF-sensitive and -insensitive lysophospholipase. Finally, the sequential deacylation of diacyl-PC by phospholipase A1 and lysophospholipase A2 probably accounted for the major portion of arachidonic acid produced.