cssi/SciSciGPT-SciSciNet huggingface dataset:
Effective communication coalescing for data-parallel applications

Communication coalescing is a static optimization that can reduce both communication frequency and redundant data transfer in compiler-generated code for regular, data parallel applications. We present an algorithm for coalescing communication that arises when generating code for regular, data-parallel applications written in High Performance Fortran (HPF). To handle sophisticated computation partitionings, our algorithm normalizes communication before attempting coalescing. We experimentally evaluate our algorithm, which is implemented in the dHPF compiler, in the compilation of HPF versions of the NAS application benchmarks SP, BT and LU. Our normalized coalescing algorithm improves the performance and scalability of compiler-generated code for these benchmarks by reducing the communication volume up to 55% compared to a simpler coalescing strategy and enables us to match the communication volume and frequency in hand-optimized MPI implementations of these codes.
Evolution of the pili nut genus (Canarium L., Burseraceae) and its cultivated species

Seeds from species of Canarium L. (Burseraceae) have been recommended as a potential nut crop for global trade that, if adopted, would be the first ‘new’ nut commodity since the introduction of the Macadamia nut in the early 20th century. The present study addresses several knowledge gaps about the evolutionary biology of Canarium species in order to explore their phylogeny and cultivation history in greater detail. The phylogeny of select Canarium species (16 spp.) from the three taxonomic sections of the genus was reconstructed using DNA sequence data from seven regions and included cultivated species C. album (Lour.) Raeusch., C. decumanum Gaertn., C. harveyi Seem., C. indicum L., C. ovatum Engl., C. tramdenum C.D. Dai et Yakovlev, and C. vulgare Leenh.. Sequence data from the nuclear genome (rDNA external transcribed spacer (ETS), the third intron of nitrate reductase (NIA-i3)) and the chloroplast genome (rbcL, rps16 intron, psbA-trnH spacer, trnL intron and trnL-F spacer) were analyzed using parsimony and Bayesian inference. Results indicate that Canarium comprises at least two distantly related evolutionary lineages within its tribe, desirable fruit characteristics of cultivated and wild-harvested edible species have evolved multiple times, and autopolyploidization rather than allopolyploidization may have been associated with speciation in Canarium sensu stricto. The markers ETS, NIA-i3, rps16 intron, and psbA-trnH spacer will provide the most informative variation for future expanded studies of Canarium phylogeny, although detailed morphological study and taxonomic revision of the genus will be necessary as well.
The relationship between secondary sulfate and primary regional signatures in northeastern aerosol and precipitation

Abstract Regional apportionment of 3 years of aerosol and precipitation samples from Narragansett, RI, demonstrates that the relationship between secondary sulfate and primary signatures is functionally linear, at least for the main northeastern and midwestern source regions. Furthermore, the relationship for local (northeastern) sources appears to be no more variable than for the more-distant (midwestern) sources. The correlation of sulfate with regional signatures shows that the regionafity of secondary sulfate is not significantly greater than that of the primary tracer elements.
The influence of β-lactoglobulin on the growth and dissolution kinetics of hydroxyapatite

Abstract The growth rate of hydroxyapatite (HAP) crystallites has been studied at pH 7.4, using the dual constant composition method. Addition of β-lactoglobulin (β-Lg) at concentrations greater than about 2 p.p.m. reduces the growth rate, and the degree of inhibition increases with additive concentration, up to a value of about 100 p.p.m. Above this level, however, there is no further decrease in the rate, suggesting a limiting adsorption of β-Lg at the HAP surface. β-Lg also reduces the constant composition dissolution rate of HAP, almost completely inhibiting the reaction after only 25% dissolution at a concentration of 800 p.p.m. In the absence of the additive the dissolution stops after 60% reaction.
Scanning laser tomography: influence of working distance

The purpose of this study is to determine the effects of the working distance on the accuracy of confocal scanning laser tomography using the Heidelberg Retina Tomograph II. Twenty eyes of normal patients were imaged and the topographies of the retinal surfaces were recorded. Each eye was imaged first at the optimum working distance, establishing the baseline exam, and then re-imaged at four different working distances (one at a shorter distance than optimum, three more at longer distances than optimum, variation done in 2 mm increments). The recorded data at various working distances was compared to the baseline data. The deviation from the baseline was compared to the normal standard deviation for the instrument reported in the literature. Data is within the normal standard deviation when staying between -2 mm and +4 mm of optimum working distance. Some stereometric parameters vary greater than the normal standard deviation if working distance is more than +4 mm from optimum. To minimize error in recorded data, the operator of the Heidelberg Retinal Tomograph II should image the patient’s eye between -2 mm and +4 mm of optimum working distance. Staying in this range should provide results that vary within the normal standard deviation.
Bringing culture to the uncultured: Coxiella burnetii and lessons for obligate intracellular bacterial pathogens.

Human diseases caused by obligate intracellular bacterial pathogens result in significant morbidity and mortality. Obligate intracellular bacteria that replicate in the cytoplasm of host endothelial cells include Rickettsia prowazekii, Rickettsia rickettsii, and Orientia tsutsugamushi (etiologic agents of epidemic typhus, Rocky Mountain spotted fever, and scrub typhus, respectively). Residing in specialized vacuolar compartments are Anaplasma phagocyophilum and Ehrlichia chaffensis (agents of febrile illnesses that have tropisms for neutrophils and monocytes, respectively) and Chlamydia trachomatis, which targets mucosal epithelia and causes blinding trachoma and sexually transmitted diseases. Coxiella burnetii preferentially colonizes mononuclear phagocytes during natural infection where it inhabits a specialized vacuole with properties of a phagolysosome [1]. The pathogen causes a debilitating influenza-like illness in humans called Q (query) fever, a disease that has received recent notoriety due to a large outbreak in the Netherlands [2]. The absolute reliance of obligates on a eucaryotic host cell for growth imposes significant experimental constraints, not the least of which is difficulty in establishing pathogen genetic systems. However, C. burnetii was recently liberated from its host cell by a medium that supports axenic (host cell–free) growth. Here, we provide a brief overview of the systematic approach used in C. burnetii media development and discuss how insight gained from this success could facilitate development of axenic media for other obligate intracellular bacterial pathogens.
Vascular Recruitment of Human Retinoblastoma Cells by Multi-Cellular Adhesive Interactions with Circulating Leukocytes

Retinoblastoma (RB) is a retinal cancer of childhood. RB survivors tend to develop additional tumors later in life, although the physical mechanisms of RB metastatic spread are largely unknown. One step in metastasis through the blood stream is tumor cell adherence to the blood vessel wall through specific receptor:ligand interactions. Yet, human RB cell lines RB143 and WERI-Rb27 do not express selectin ligands or beta-2 integrins and cannot directly interact with inflamed endothelium. In this study, we show that RB cells express ICAM-1, a beta-2 integrin ligand that correlates with metastasis and is preferentially co-expressed on RB cells that also express ABCG2, a stem cell marker associated with chemoresistance and metastasis. Based on the presence of ICAM-1+ RB cells, we tested the hypothesis that RB cells could be recruited to an E-selectin surface via attachment to activated polymorphonuclear cells (PMNs). We characterized the dynamic adhesion between RB cells and PMNs within E-selectin coated microtubes under a physiological range of wall shear stress values (0.2–5 dyn/cm2). We show that activated PMNs are necessary for the recruitment of RB cells through ICAM-1:LFA-1 binding. Results from this work may lead to new strategies that target the metastatic spread of tumor cells.
Prostatic carcinoma metastasizing to skin and subcutaneous tissues

Abstract Carcinoma of the prostate metastasizing to the skin and subcutaneous tissues is extremely uncommon; only 14 cases are reported in the English literature, including our 2 cases. One of our cases demonstrated macular formation followed by nodular appearance. Both patients died within eight to twelve weeks after appearance of skin nodules, indicating the severity of its prognosis.
The spectrum of Ebstein's anomaly☆

Abstract Seventeen cases of Ebstein's anomaly have been presented; the diagnosis was confirmed by autopsy in 6, and made on clinical grounds in the other 11. The series includes the youngest patient dying of the lesion, a stillborn infant, and the fifth oldest patient thus far reported (64 years). The features associated with this condition are presented as found in this series and compared with those observed by previous authors. It is emphasized that the history and physical and laboratory examinations are sufficiently characteristic to allow the diagnosis to be made with a high degree of accuracy in the majority of cases. As with any condition, the entity is represented by a spectrum in every regard; and as to the cases on either end of the spectrum, one must combine a high degree of suspicion with a knowledge of the spectrum, else the true diagnosis will only be made at the autopsy table or at the time of ill-advised operative procedures. Particular emphasis is given to the group of patients over 50 years of age who represent about 5 per cent of the patients with Ebstein's anomaly. They may be, and in fact generally are, unusual in all respects when compared to the “typical” case. Comments are made on the natural history of the young patient, and it is urged that extensive diagnostic or surgical procedures be delayed until signs of deterioration appear, since tolerance of such procedures may be poor. The etiology of the anomaly remains obscure, and a practical and satisfactory therapeutic approach remains for the future.
Searching geometric libraries using generalized epsilon-congruence

In computer vision, one of the major problems is how to identify an observed object in an image by comparing it to a set of models in a library. The comparison is made using a shape metric which measures the similarity between different shapes. The observed object is classified as the library object with which it minimizes the shape metric. This paper looks at algorithms for efficiently searching a geometric library to identify an observed object in the image. All objects are modeled as points and (epsilon) -congruence is used as the shape metric. Algorithms are presented for searching two classes of geometric libraries, ordered linear libraries and convex linear libraries. The complexity of the algorithms is expressed in terms of the number of objects in the library, the size of the objects, the error in the optimal match, and the geometric structure.
Life span differences in digoxin uptake and excretion.

Abstract Little is known about the underlying mechanisms for the altered susceptibility to digitalis with age. To this end, we investigated the digoxin uptake and excretion in mice and rats of different ages through the life span, including the periods of growth, maturity, and aging. Digoxin uptake by cardiac slices was linear from 0 to 15 min, with steady state occuring at 45 min. The rate in the mature 12-month mouse was significantly less than that of the senescent 30-month mouse. The kinetic parameters revealed a significant decrease in Km with a concomitant increase in Vmax during senescense. On the other hand uptake by renal cortical slices was highest during growth, decreased to a maturation plateau and then declined further during senescence. Renal clearance and the secretory capacity for digoxin increased 30 and 62%, respectively, during growth and progressively decreased from maturity through senescence and were 59 and 77%, respectively, during aging. In summary, there was an increase in digoxin clearance and tubular activity during growth, and in increase in myocardial uptake of digoxin and a decrease in renal excretion during aging. Thus, these results may explain the clinical observations of altered susceptibility to digitalis with age.
Meta-terphenyls as building blocks for pyridinophanes

Abstract Pyridinophanes 6 and 7 were prepared in good yield from bis(thiomethyl)-m-terphenyls 2 and 12 and bis (chloromethyl) pyridine derivative 11.
LYRAN: A program for the analysis of linac beam dynamics

Abstract The FORTRAN program LYRAN has been written for use in analyzing the beam dynamics of superconducting heavy ion linacs. The program is based on the program LYRA developed by A.H. Scholldorf at SUNY Stony Brook, but that original program has been extensively extended, modified, and restructed. LYRAN transports a group of input particles randomly distributed on a selected distribution function through linac elements which include rf accelerating and bunching elements, dipole and quadrupole magnets, electrostatic elements, and drift spaces. Second order corrections to dipole and quadrupole fields are included. A nonlinear optimization routine is incorporated, providing fast and efficient determination of accelerator configurations and parameter settings that provide desired beam properties. Beam envelope plotting is also included to provide a graphic display of beam characteristics.
Analysis of Laser-Enhanced Adsorption/Desorption Processes on Semiconductor Surfaces via Electronic Surface State Excitation

Abstract : Electronic surface states in semiconductors often lie between the valence and conduction bands and give rise to charge densities confined to the surface region. Laser radiation of frequency less than the energy gap can excite electrons from delocalized valence band states to these localized surface states leading to large changes in the charge distribution at the surface. Selective enhancement of adsorption/desorption processes involving ionic or polar adspecies can result from such a charge redistribution. Using a one-dimensional model for silicon, the cross-section for the laser-induced electronic transition to surface states is show to be large. The interaction energy of an adspecies with the surface changes significantly with direct excitation of surface states in a semiconductor. For a one-dimensional metal, however, direct transitions between bulk and surface states are not allowed, but phonon-mediated transitions coupled with laser radiation lead to substantial charge transfer as for semiconductors.
Degradability of an Acrylate-Linked, Fluorotelomer Polymer in Soil

Fluorotelomer polymers are used in a broad array of products in modern societies worldwide and, if they degrade at significant rates, potentially are a significant source of perfluorooctanoic acid ...
Interaction between gene II protein and the DNA replication origin of bacteriophage f1

Abstract The origin of DNA replication of the filamentous bacteriophage f1 binds its initiator protein (gene II protein) in vitro to form a complex that can be trapped on nitrocellulose filters. The binding occurs with both superhelical form DNA and linear DNA fragments. A number of defective mutants of the origin were tested for the ability to bind gene II protein. The region of DNA required for the binding is around a second palindrome downstream from the palindrome that contains the DNA replication initiation site. It overlaps, but is not identical to, the region required for the nicking reaction by the protein. The nicking site itself was dispensible for the binding. In vivo , a number of defective deletion mutants of the origin, when in a plasmid, inhibited growth of superinfecting phage if the intracellular level of gene II protein was low. In addition, these defective origins inhibited the activity of the functional phage origin located on the same replicon. The domain of the DNA sequence required for inhibition in vivo was consistent with that for the binding in vitro .
Correlation of primary production as measured aboard ship in Southern California Coastal waters and as estimated from satellite chlorophyll images

Chlorophyll images suitable for the regional analysis of the Southern California Bight were obtained by satellite (Nimbus-7 Coastal Zone Color Scanner) on 27 February, 6 March and 11 March 1979. An algorithm to convert satellite chlorophyll data to primary production has been developed. In addition, primary production was measured along with other biological and physical factors from ships cruising in the Southern California Bight during late February and early March 1979. There was fair agreement between shipboard measurements and satellite estimations; for example, primary production (mg carbon m-2 d-1) averaged 554 mg from shipboard measurement and 403 mg from satellite estimation when averaged for the entire Bight for the course of the study. The high standard error associated with the variance in productivity index used in our algorithm prevented more accurate conversion of chlorophyll concentrations into primary productivity. However, the synoptic data provided by concurrent ship and satellite measurements can be used to quantify, and perhaps reduce, sampling errors associated with ship sampling alone and to provide estimates of the accuracy of primary productivity on a regional basis.
Unified Fermi-Yang and Chew-Low Models

We consider a unified bootstrap theory which incorporates the features of the Chew-Low and Fermi-Yang models. The baryons are treated as being much heavier than the mesons. In this approximation the self-consistent baryon-meson vertices are shown to incorporate simultaneously the $\mathrm{SU}{(6)}_{\mathrm{JJ}}$ and $\mathrm{SU}{(6)}_{W}$ relations. It is pointed out that if the baryons are taken as very heavy, a nearly degenerate sequence of excited rotational states must exist in the crossed channel (baryon-antibaryon); the Chew-Low model is not really self-consistent unless these mesons are all included. The rotational sequence includes exactly the same states as are obtained in the quark model. However, it may be possible to distinguish the two theories through some differences in detail (for example, in the predicted mass splittings).
Room-temperature yellow–amber emission from InGaP quantum wells grown on an InGaP metamorphic buffer layer on GaP(1 0 0) substrates

Abstract In this paper we present a systematic investigation of the structural and optical properties of InGaP using a metamorphic In x Ga 1− x P buffer layer grown on GaP(1 0 0) substrates. When grown at 400 °C, the simpler constant-composition metamorphic buffer layer has a smoother surface morphology, as compared to that grown at 500 °C, and results in comparable structural quality of the top layers as a linearly graded metamorphic buffer layer. In 0.5 Ga 0.5 P quantum wells with In 0.3 Ga 0.3 P barriers grown on a constant-composition metamorphic buffer layer exhibit room-temperature bright photoluminescence in the amber wavelength at 610 nm.
Utilization of interfacial engineering to produce novel emulsion properties: Pre-mixed lactoferrin/β-lactoglobulin protein emulsifiers

Abstract The interfacial coatings around lipid droplets can be tailored in a number of ways to alter the functionality of emulsion-based delivery systems. In this study, a “premix” approach was utilized that involved mixing two globular proteins with different isoelectric points prior to emulsion formation: β-lactoglobulin (BLG) and lactoferrin (LF). The influence of environmental stresses (pH, ionic strength and temperature) on the physicochemical properties of the emulsions produced using this approach was examined. Droplets coated by BLG were unstable to aggregation near their isoelectric point (pH ≈ 5), whereas those coated by LF were stable across the whole pH range. The stability of emulsions to pH induced aggregation improved as the ratio of LF-to-BLG in the mixed systems was increased. Lipid droplets coated by either LF or BLG were unstable to aggregation at high salt concentrations (500 mM NaCl, pH 6.5), but those stabilized by mixed protein coatings (LF and BLG) were stable, which was attributed to an increase in interfacial thickness and steric repulsion. Droplets coated by BLG were stable to droplet aggregation after thermal treatment (30 to 90 °C, 0 mM, NaCl pH 7), whereas those coated by LF were highly unstable when heated above their thermal denaturation temperature. The thermal stability of the droplets depended on the amount of LF in the mixed systems. Overall, this study shows that mixtures of LF and BLG are able to modulate the physicochemical properties and stability of protein-coated lipid droplets in oil-in-water emulsions. This study provides useful information for designing emulsion-based delivery systems for use in functional food and beverage products.
Glucocorticoids inhibit osteocalcin transcription in osteoblasts by suppressing Egr2/Krox20-binding enhancer.

Objective Glucocorticoids are widely used for the management of rheumatoid arthritis. Osteoporosis is a major side effect of glucocorticoid therapy and is attributable to inhibition of bone formation. We developed an osteoblast culture system in which glucocorticoids strongly inhibit development of the osteoblast phenotype, including expression of the bone-specific osteocalcin (OC) gene. Using this gene as a model, the goal of this study was to discover glucocorticoid-sensitive transcriptional mechanisms in osteoblasts. Methods Dexamethasone (DEX; 1 μM) was administered to murine MC3T3-E1 osteoblastic cultures under conditions that inhibit mineralized extracellular matrix formation and OC messenger RNA levels by >10-fold. Because standard (short-term) transient transfection assays with OC promoter-reporter constructs did not recapitulate the strong DEX-mediated repression, mapping of OC negative glucocorticoid response elements (GREs) was performed initially by stable transfection and then with long-term transient transfection assays. Transcription factor binding to the OC negative GRE was studied by electrophoretic mobility shift assays. Results Several-fold repression of OC–luciferase constructs was recapitulated in stable and long-term transient transfection assays, in which the transfected cells were allowed to progress to a sufficiently advanced developmental stage. Analysis of a 5′ promoter deletion series mapped an OC negative GRE to a 15-bp G/C-rich motif (−161/−147) located just upstream of the binding site for the osteoblast master transcription factor Runx2. Oligonucleotides encompassing this element and MC3T3-E1 cell extracts formed a protein–DNA complex that contained an Egr/Krox family member(s). Complex formation was competed by either an oligonucleotide containing 2 consensus Egr motifs or by anti-Egr2/Krox20 antibodies. Three copies of this Krox-binding element conferred 20-fold transcriptional activation on the 147-bp basal OC promoter in osteoblasts, and the enhancer activity was inhibited by DEX. Enhancer activity was not observed in 10T1/2 fibroblasts unless these cells were cotransfected with Runx2. Conclusion An Egr2/Krox20-binding site located immediately upstream of the Runx2 site of the mouse OC promoter was identified as an enhancer in osteoblasts, whose activity is repressed by glucocorticoids. Sequence similarity suggests that such a mechanism is likely operative in both murine and human cells. Because glucocorticoids inhibit Egr2/Krox20 expression in osteoblasts, and because trabecular bone formation is arrested in Egr2/Krox20-knockout mice, the inhibition of Egr2/Krox20 activity likely contributes to glucocorticoid-induced osteoporosis.
Teachers' Strategies to Positively Connect Students to School

Abstract Background: School connectedness is a leading school-based protective factor against youth engagement in risky behaviors. Research on teachers' individual practices in fostering school connections with their students is currently lacking. Purpose: The purpose of the present study was to address gaps in the research by examining elementary and middle school teachers' use of specific strategies to positively connect students to school. Methods: An electronic survey was completed by 419 (60% response rate) elementary and middle school teachers. Results: On average, teachers reported using connection-building strategies at least once a week. The most frequently used strategies were acting like a positive role model for students and calling students by their first names. MANOVAs were conducted and found teachers who most frequently reported using connection-building strategies were elementary school teachers, those who had received training on school connectedness outside of/after college, and those w...
Three-dimensional pore connectivity in bi-axially stretched microporous composite membranes

Confocal laser scanning microscopy (CLSM) and three-dimensional (3D) image reconstruction were used to visualize the interconnecting pores that result from the bi-axial stretching of CaCO3/polyolefin composite membranes. The following three effects on pore connectivity were examined: (1) amount of membrane stretching—unstretched, low-stretched, and overstretched; (2) polymer matrices—polyethylene and polypropylene; (3) particle coatings—uncoated CaCO3 (calcite) and stearic acid coated calcite. The porosity of the membranes increased with quantifiable increases in their elongation. The pattern of the interconnecting pores depended on the polymer matrix and the particulate coating, where the change in the pattern was related to the stiffness of the composite material and the nature of the interaction at the polymer/calcite interface.
A fast algorithm for VLSI net extraction

Net extraction is crucial in VLSI design verification. Current algorithms for net extraction do not exploit the fact that the number, c, of different orientations of the line segments or polygon edges in a practical VLSI mask design is small relative to the number, n, of segments or edges. Instead, they rely on computing all intersections in the input and hence take time that is at least proportional to the number of intersections. In this paper we develop a simple and practical algorithm for net extraction that runs in O(cn log n) time and O(n) space, which is optimal for fixed c. Experiments indicate that the algorithm will generally outperform existing algorithms on practical VLSI designs. We expect that the techniques presented will be useful in other VLSI CAD problems that operate with restricted orientation geometries.
Polymer chemistry in flow: New polymers, beads, capsules, and fibers

The union between polymer science and microfluidics is reviewed. Fluids in microreactors allow the synthesis of a wide range of polymeric materials with unique properties. We begin by discussing the important fluid dynamics that dominate the behavior of fluids on the micrometer scale. We then progress through a comprehensive analysis of the polymeric materials synthesized to date. This highlight concludes with an overview of the methods used to make microreactors. We enthusiastically endorse microreactors as a powerful approach to making materials with controlled properties, although we have tried to provide a critical eye to help the nonexpert enter the field. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6505–6533, 2006
Ammonium uptake by field-grown Eriophorum vaginatum roots under laboratory and simulated field conditions

Nitrogen (N) deficiencies in tundra ecosystems could be caused, in part, by the kinetics of root N uptake. The objectives of this study were to quantify NH4 uptake by field-grown excised roots of Eriophorum vaginatum I. under controlled NH4 concentrations (0-250 μmol I-1) and temperatures (5-20°C) and to evaluate this laboratory derived model as a means of estimating field NH4 uptake. There was no consistent temperature effect on root NH4 uptake which suggests a relative in-sensitivity of E. vaginatum roots to short-term temperature fluctuations. The Michaelis-Menten equation parameters for NH4 uptake were Vmax= 22.1 μmol h-1 g-1 and Km= 191 μmol I-1. Using field NH4 concentrations, field E. vaginatum root biomass data, and the Michaelis-Menten equation, an estimate was made of NH4 uptake over a 42 day period; this estimate of NH4 uptake accounted for 28% of the net incorporation of N into leaves and roots which is a reasonable estimate for E. vaginatum which relies primarily on N retranslocation for supplying new leaves and roots. Major uncertainties in field N uptake rates, model parameterization, and site characterization preclude an accurate model validation and indicate research areas most in need of future study.
Promoting the Educational Attainment of Adults The Potential Role of Youth-Oriented Precollege Outreach Programs

This study draws on data collected from case studies of four precollege outreach programs and a survey of program administrators to explore the ways that youth-oriented precollege outreach programs may promote the educational attainment of the parents of participating students. The results suggest that precollege outreach programs may expand the “worldview” of participating students’ parents to include enrollment in an educational program as a realistic option and provide parents with information required for this enrollment. The results also suggest that, despite the potential role of precollege outreach programs in promoting the educational attainment of participating students’ parents, low current educational attainment and insufficient financial resources are substantial deterrents to enrollment.
The relation among hearing loss, sensory cell loss and tuning characteristics in the chinchilla

Abstract Evoked-potential tuning curves were obtained on over 150 chinchillas before and after acoustic overstimulation in order to relate the effects of changes in frequency selectivity to sensory cell loss over a wide range of hearing loss. Pre- and post-exposure measures of auditory thresholds and masked thresholds (simultaneous tone-on-tone paradigm) were obtained in each animal at 0.5, 1.0, 2.0, 4.0, 8.0 and 11.2 kHz, using the auditory evoked potential recorded from the inferior colliculus. Three tuning curve variables ( Q 10 dB , low-frequency slope and high-frequency slope) were compared to the amount of noise-induced permanent threshold shift and to the percent sensory cell loss produced by a variety of noise exposures. Based upon large sample averages, frequencies showing permanent threshold shifts in excess of 10 dB also showed statistically significant differences between pre- and post-exposure measures of all three tuning curve variables. Shifts of less than 10 dB were not accompanied by statistically significant changes in the tuning curve variables. The percentage of outer hair cell loss, and percentage change in tuning curve characteristics showed systematic and parallel increases as threshold shifts increased at all probe tone frequencies except 8.0 and 11.2 kHz. In general, the results were consistent in showing that there is a systematic change in the variables which define the quality of tuning as hearing loss progressively increases and that these changes are clearly related to outer hair cell losses.
Comparative Study of Cardiovascular Function and Ventricular Premature Complexes in Smokers and Nonsmokers During Maximal Treadmill Exercise

Maximal treadmill exercise tests were performed by 586 male members of the Indiana State Polic Force who were free of clinical evidence of cardiovascular disease. The study population was categorized into groups according to cigarette smoking experience and subgroups according to age and number of pack-years of exposure. There were 176 nonsmokers (30 percent), 268 current smokers (46 percent) and 142 former smokers who had abstained for at least 1 year (24 percent). No statistically significant differences were found in the prevalence of exercise-induced ventricular premature complexes when current smokers were compared with nonsmokers or former smokers either as a group or as subgroups classified by age. The duration of maximal exercise and the peak heart rate and systolic blood pressure during maximal exercise were compared for each group. The duration of maximal exercise was significantly shorter in smokers (P less than 0.001) and former smokers (P less than 0.005) than in nonsmokers. Maximal systolic blood pressure during exercise was greater in smokers than in nonsmokers (P less than 0.01) but did not differ significantly between nonsmokers and former smokers. Maximal heart rate during exercise was significantly lower in smokers (P less than 0.01) and former smokers (P less than 0.01) than in nonsmokers. In conclusion, there was a statistically significant difference in the duration of exercise and the maximal heart rate and systolic blood pressure attained during exercise between men who smoked and nonsmokers, but the prevalence of the exercise-induced ventricular premature complexes did not appear to be influenced by smoking habits.
Spectrum sensing techniques for nonlinear radar

In this paper, spectrum sensing techniques are explored for nonlinear radar. These techniques use energy detection to identify an unoccupied receive frequency for nonlinear radar. A frequency is considered unoccupied if it satisfies the following criteria: 1) for a given frequency of interest, its energy must be below a predetermined threshold; 2) the surrounding energy of this frequency must also be below a predetermined threshold. Two energy detection techniques are used to select an unoccupied frequency. The first technique requires the fast Fourier transform and a weighting function to test the energy in neighboring frequency bins; both of these procedures may require a high degree of computational resources. The second technique uses multirate digital signal processing and the fast binary search techniques to lower the overall computational complexity while satisfying the requirements for an unoccupied frequency.
Analgesia, antianalgesia, and hyperalgesia: What role might neurons of the rostral ventromedial medulla play?

T he ability of a conditioned safety signal to block morphine analgesia as described in the focus article by Maier et al. is both startling and exciting. Peripheral’ and spinall mechanisms of hyperalgesia have been well-documented, yet the concept of central mechanisms that enhance nociception has only recently begun to attract attention.2 Maier et al. now propose distinct “antianalgesia” and “hyperalgesia” systems that modulate nociception at the level of the spinal cord. According to their proposal, the antianalgesia system has no effect on basal nociceptive responsiveness, and it is activated in concert with “analgesia systems.” The relative activity in analgesia and antianalgesia systems must, therefore, determine the net effect on nociceptive transmission. The interaction between analgesia and antianalgesia systems appears to be mediated, at least in part, by release of cholecystokinin (CCK) at the level of the spinal cord. Administration of CCK antagonists potentiates conditioned antinociception, indicating that those contextual stimuli that activate the endogeneous analgesia system also recruit the antianalgesia system. According to Maier et al.‘s model, the antianalgesia system can be differentiated from descending hyperalgesia systems, which produce a decrease in nociceptive threshold. Although the authors’ evidence for these systems is compelling, relatively little is known about the central mechanisms involved. However, the physiologi-
Hybrid ceramic matrix composites

A model hybrid glass-matrix composite has been studied. The system investigated was Corning Code 1723 glass matrix (an alkaline earth aluminosilicate glass) with silicon carbide whiskers and Nicalon® fibres. It was found that a 10 wt % whisker loading of the matrix gave optimum composite properties. The optimized hybrid composite, when compared to an optimized non-hybrid composite, showed increases in microcrack yield stress from 330 to 650 MPa, interlaminar shear strength from 47 to 130 MPa, and transverse strength from 12 to 50 MPa, while the ultimate strength decreased from 965 to 900 MPa.
Regulation of Non-Infectious Lung Injury, Inflammation, and Repair by the Extracellular Matrix Glycosaminoglycan Hyaluronan

An important hallmark of tissue remodeling is the dynamic turnover of extracellular matrix (ECM). ECM performs a variety of functions in tissue repair including scaffold formation, modulation of fluid dynamics, and regulating cell behavior. During non-infectious tissue injury ECM degradation products are generated that acquire signaling functions not attributable to the native precursor molecules. Hyaluronan (HA) is a non-sulfated glycosaminoglycan which is produced in great abundance following tissue injury. It exists both in a soluble form and as side chains on proteoglycans. HA has critical roles in development as well as a variety of biological processes including wound healing, tumor growth and metastasis, and inflammation. HA fragments share structural similarities with pathogens and following tissue injury can be recognized by innate immune receptors. Elucidating the protean roles of HA in tissue injury, inflammation, and repair will generate new insights into mechanisms of diseases characterized by chronic inflammation and tissue remodeling.
Suspicion, growth and co-management in the commercial fishing industry: the financial settlers of New Bedford

Abstract Origins and organization of New Bedford financial settlement houses are examined. Settlement houses are an important part of the extensive fishing community and have made significant historic contributions. Economic, political and social factors leading to the development of formal settlement houses in New Bedford are traced and the contemporary organization and responsibilities of settlement houses are investigated. Settlement houses and fishing routines were observed from 1986 to 1998. Interviews of the settler/owners of the five largest settlement houses in New Bedford and early settlers and fishermen from the 1930s and 1940s were conducted. Financial settlers helped bring order and increased trust to financial settlements that, prior to the 1930s, had largely been conducted in cash and based on unwritten agreements. Most contemporary and many of the earliest settlers are female and women’s contributions to the fishing industry are discussed. Emphasis is also placed on the fisher-based solution that settlement houses represent; implications for use in co-management strategies and the need to reduce the adversarial atmosphere in fisheries governance are discussed.
Predicted, actual and optimal precompetition anxiety in adolescent track and field athletes

Anxiety was assessed in younger and older adolescent athletes in an attempt to test aspects of Hanin's zone of optimal function theory. Sixty-five participants in a track and field camp completed anxiety inventories at baseline and were instructed: 1) to recall how anxious they felt prior to their best performance and 2) to predict how anxious they would feel prior to an informal meet to be held 4 days later. Actual precompetition anxiety was assessed 1 h prior to the meet. Predicted precompetition anxiety was significantly higher than baseline and actual precompetition anxiety. Mean actual precompetition anxiety was not elevated above baseline. However, 34% (22/65) of the sample experienced high levels of precompetition anxiety, and the majority of these (17/22) reported performing optimally with high anxiety. Significant correlations between predicted and actual precompetition anxiety occurred for boys, but not for girls. The differences between predicted and actual precompetition values tended to be smaller in boys than in girls. Based on this sample, it is concluded that: 1) in accordance with the zone of optimal function theory, young athletes display considerable diversity in actual and optimal precompetition anxiety values; and 2) young athletes tend to overestimate the level of anxiety they will experience prior to an easy competition.
MATHEMATICAL ANALYSIS AND CHALLENGES ARISING FROM MODELS OF TUMOR GROWTH

In the last four decades, various cancer models have been developed in which the evolution of the densities of cells (abnormal, normal, or dead) and the concentrations of biochemical species are described in terms of differential equations. In this paper, we deal with tumor models in which the tumor occupies a well-defined region in space; the boundary of this region is held together by the forces of cell-to-cell adhesion. We shall refer to such tumors as "solid" tumors, although they may sometimes consist of fluid-like tissue, such as in the case of brain tumors (e.g. gliomas) and breast tumors. The most common class of solid tumors is carcinoma: a cancer originating from epithelial cells, that is, from the closely packed cells which align the internal cavities of the body. Models of solid tumors must take spatial effects into account, and are therefore described in terms of partial differential equations (PDEs). They also need to take into account the fact that the tumor region is changing in time; in fact, the tumor region, say Ω(t), and its boundary Γ(t), are unknown in advance. Thus one needs to determine both the unknown "free boundary" Γ(t) together with the solution of the PDEs in Ω(t). These types of problems are called free boundary problems. The models described in this paper are free boundary problems, and our primary interest is the spatial/geometric features of the free boundary. Some of the basic questions we shall address are: What is the shape of the free boundary? How does the free boundary behave as t → ∞? Does the tumor volume increase or shrink as t → ∞? Under what conditions does the tumor eventually become dormant? Finally, we shall explore the dependence of the free boundary on some biological parameters, and this will give rise to interesting bifurcation phenomena. The structure of the paper is as follows. In Secs. 1 and 2 we consider models in which all the cells are of one type, they are all proliferating cells. The tissue is modeled either as a porous medium (in Sec. 1) or as a fluid medium (in Sec. 2). The models are extended in Secs. 3 and 4 to include three types of cells: proliferating, quiescent, and dead. Finally, in Sec. 5 we outline a general multiphase model that includes gene mutations.
Malondialdehyde–acetaldehyde-adducted bovine serum albumin activates protein kinase C and stimulates interleukin-8 release in bovine bronchial epithelial cells

Abstract Previous study results have demonstrated that cigarette smoke or acetaldehyde rapidly stimulates protein kinase C (PKC)–mediated release of interleukin-8 (IL-8) in bovine bronchial epithelial cells (BECs). Low concentrations of acetaldehyde combine synergistically with malondialdehyde to increase significantly maximal BEC PKC activity at 48 to 96 h stimulation. Because more than 95% of alcoholics are cigarette smokers, we hypothesized that malondialdehyde, an inflammation product of lipid peroxidation, and acetaldehyde, both a product of ethanol metabolism and a component of cigarette smoke, might stimulate PKC-mediated IL-8 release in BECs by malondialdehyde–acetaldehyde (MAA) adduct formation, rather than as free aldehydes. Protein kinase C activity is maximally elevated in BECs treated with 50 μg/ml of BSA–MAA from approximately 1 to 3 h. This activity subsequently begins to decrease by 4 to 6 h, with a return to baseline unstimulated kinase activity levels by 24 h. No activation of cyclic AMP–dependent protein kinase (PKA) or cyclic GMP–dependent protein kinase (PKG) was observed in BSA–MAA-treated BECs. The MAA adduct activation of PKC was followed by a fourfold to tenfold greater release of IL-8 over that observed for both BECs exposed to media only and BSA control–treated BECs. Protein kinase C activation and IL-8 release were blocked by pretreating BECs with 1 μM calphostin C or 100 nM of the PKC alpha–specific inhibitor, Go 6976. Isoform-specific inhibitors to PKC beta, PKC delta, and PKC zeta failed to inhibit completely MAA adduct–stimulated PKC or IL-8 release. Results of these studies indicate that metabolites derived from ethanol and cigarette smoke, such as acetaldehyde and malondialdehyde, form adducts that stimulate airway epithelial cell PKC alpha–mediated release of promigratory cytokines.
Locomotion in land crabs: Respiratory and cardiac response of Gecarcinus lateralis

Abstract 1. 1. Land crabs with a respiratory mask were run on a miniature treadmill at controlled speeds. O 2 consumption ( dot V O 2 ) and CO 2 production measurements showed that the aerobic response to exercise was slow. 2. 2. Steady-state O 2 consumption was not attained during 10 min runs nor when they ran freely for 20 min in a treadmill respirometer. Recovery from exercise was prolonged in both cases. 3. 3. This indicates that this species, like another land crab, Cardisoma guanhumi , relies heavily upon anaerobic fermentation, phosphagen and O 2 stores to support its energetic demands during running. 4. 4. Aerobic compensatory devices were evident also. Peak O 2 consumption values did tend to rise with increased velocity of running as did the area under the dot V O 2 curve during running and recovery. 5. 5. Both ventilation volume and Oz extraction also rose during running; the latter seemed to be the most important of the two respiratory compensatory mechanisms. 6. 6. Circulatory adjustments were evident. Heart rate showed a rapid rise with exercise and the O 2 pulse (the amount of O 2 delivered per heart beat) increased directly with O 2 consumption as well. 7. 7. Energetic considerations suggest that running with a mask may be slightly more demanding than free running. 8. 8. Estimation of an energetic cost of transport for this 53 g crab suggests it is comparable to that of quadrupedal and bipedal vertebrates of a similar size.
Characteristics of magnetic media models

Full characterization of particulate recording media requires the modeling of both the reversible and the irreversible components of the magnetization. Experiments show that the height of minor loops originating from negative saturation is not an even function of the magnetization. A moving Preisach-type model with reversible magnetization that is capable of calculating these results is introduced. The properties of the model are discussed. It is shown that previous models are special cases of this model. >
Swing voting and fast-track authority

Following the passage of the North American Free Trade Agreement (NAFTA) in 1993 and the Uruguay Round Agreement in 1994, the United States appeared to be on the verge of an era of unprecedented trade liberalization. Since that time, however, the United States has struggled to pass almost every important trade liberalization bill. Results indicate that the factor most likely responsible for the difficulty in achieving trade liberalization over the last 15 years is shifting pressures within the U.S. House of Representatives related to partisanship and constituency.