cssi/SciSciGPT-SciSciNet huggingface dataset:
Abstract 1350: Regulation of pH by growth factors is dependent on the expression of the calcineurin homologous protein-2 in human bone sarcoma cells

Bone sarcoma is a malignant tumor that includes multiple subtypes. The osteosarcoma is the sixth most common malignancy in adolescents, while chondrosarcoma is primarily a disease of adults. Current treatments for both osteosarcoma and chondrosarcoma have not demonstrated improvement in patients9 survival over the past three decades. Extracellular acidosis affects osteoblast and chondrocyte function by reducing bone mineralization and increasing production of cartilage matrix, respectively. Thereby, it weakens bone matrix and expands cartilage matrix, and may play a role in the development of bone characteristics seen in patients with osteosarcoma or chondrosarcoma. Development of extracellular acidosis in cancer is due to dysregulation of pH dynamics mediated by constitutive activation of Na+/H+ exchanger-1 (NHE1) activity, the main transporter responsible for pH regulation. Current therapeutic agents that target inhibition of NHE1 activity are ineffective due to broad inhibitory effects. The calcineurin homologous protein (CHP) family binds to and regulates NHE1 activity. CHP isoform 1 (CHP1) is expressed in non-cancerous cells and forms a dynamic complex with NHE1. On the other hand, CHP isoform 2 (CHP2) is expressed primarily in cancerous cells and has a stronger binding affinity to NHE1 compared with CHP1. We hypothesize that CHP2 binding to NHE1 in cancer cells induces the over-activity of NHE1, making the extracellular pH of cancer cells more acidic than non-cancerous cells. We measured CHP1 or CHP2 protein expression levels in human osteoblast (hFOB), osteosarcoma (143B), and chondrosarcoma (SW1353) cells and studied whether the levels of CHP2 protein expression affected NHE activity in these cell lines. We determined that: 1. hFOB, 143B, and SW1353 cells expressed mainly NHE1; NHE activity measured using spectrofluorometry was completely blocked by a highly selective NHE1 inhibitor (zoniporide, 10-8 M); 2. NHE1 activity was increased by serum-nutrient deprivation, used to mimic a cancerous microenvironment and NHE1 over-activity was associated with increased levels of CHP2 protein expression; 3. silencing of CHP2 by shRNA inhibited NHE1 activity in response to serum-nutrient deprivation in 143B or SW1353 cells and restored the NHE1 response inducted by serum-deprivation in non-cancerous cells. Regulation of NHE1 through CHP2 is proposed as a promising novel target in sarcoma treatment and to overcome the wide range of side effects induced by inhibitors of NHE1 activity. Citation Format: Tiffany Chang, Serena S. Luong, Adam P. Zobel, Elitsa Ananieva, Victor Babich, Francesca Di Sole. Regulation of pH by growth factors is dependent on the expression of the calcineurin homologous protein-2 in human bone sarcoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1350.
The Association of "GOOP" on Gross Examination of Fine Needle Aspiration Samples and On-Site Adequacy.

BACKGROUND Rapid on-site cytologic evaluation (ROSE) is not always available for fine needle aspiration (FNA) specimens. We have examined the relationships between the presence of "GOOP" (defined as gooey white material) on FNA aspirates, on-site adequacy (OSA), and diagnosis. METHODS Consecutive FNA samples obtained over the study interval were included. Samples were assessed macroscopically for the presence or absence of GOOP (GOOP+ or GOOP-). GOOP+ samples were further characterized as shiny (G+S) or cheesy (G+C). Gross descriptors were correlated with OSA and final diagnoses. RESULTS Of the 204 sites biopsied, 102 were malignant, 94 benign, and 8 nondiagnostic. The presence of GOOP was highly predictive for adequacy (positive predictive value 98%). While these correlations for GOOP positivity were significant, the absence of GOOP did not rule out adequacy or malignancy. The presence of GOOP was also significantly correlated with a malignant diagnosis. CONCLUSIONS We have prospectively demonstrated that the presence of GOOP correlates strongly with adequacy. This may be of value for those for whom ROSE is not available and, when available, may help prioritize specimens for on-site review.
Dynamic economic game theory and Asian free trade agreements

The purpose of this paper is to use fairly standard game theory elements and apply them to free trade agreements (FTA) made within ASEAN countries and between ASEAN countries and outside countries and the rest of the world (ROW). The applications use some mathematics, but it is not my intent to burden unnecessarily the reader with the mathematics. My intent is to make the applications appeal to the practitioners who are directly or at least indirectly engaged in the process of making FTAi?½s and who are interested in a theoretical basis for FTAi?½s. The intent then could be described as being largely pedagogical. The main contribution of the paper is to show the structure and behavior of the backward solution method used in dynamic game theory.
Digital library educational module development strategies and sustainable enhancement by the community

The Digital Library Curriculum Development Project (http://curric.dlib.vt.edu) team has been developing educational modules and conducting field-tests internationally since January 2006. There had been three approaches for module development in the past. The first approach was that the project team members created draft modules (total of 9) and then those modules were reviewed by the experts in the field as well as by other members of the team. The second approach was that graduate student teams developed modules under the supervision of an instructor and the project team. Four members in each team collaborated for a single module. In total four modules were produced in this way. The last approach was that five graduate students developed a total of five modules, each module reviewed by two students. The completed modules were posted in Wikiversity.org for wider distribution and collaborative improvements by the community. The entire list of modules in the Digital Library Educational Framework also can be found in that location.
Kinetics – Chemical Kinetics

Throughout much of this book we have emphasized the description of a system in terms of an equilibrium state. This approach is invaluable when we are beginning study and are not sure exactly what are the elements and the linkages that comprise the rules of the system under study. Still it seems to be a compulsive pulse taking that is stodgy. We really want to get to the visceral issue of our curiosity; what are the details of how it works: what are the wheels and gears of the system? That question is not always easily answered and as we will see in the following section is often approached using the thermodynamic tools we have already discussed. After all, knowing how the wheels and gears are arranged is invaluable when trying to understand how a machine works.
The Development and Application of Massively Parallel Solid Mechanics Codes

Computational physicists at Sandia National Laboratories have moved the Eulerian CTH code, and the arbitrary-Lagrangian-Eulerian ALEGRA code to distributed memory parallel computers. CTH is a three-dimensional solid mechanics code used for large-deformation, shock wave analysis. ALEGRA is a three-dimensional arbitrary Lagrangian-Eulerian solid-mechanics code used for coupled large-deformation, shock and structural mechanics problems. This paper discusses our experiences moving the codes to parallel computers, the algorithms we used and our experiences running the codes.
A Secure Wireless Protocol for Intersection Collision Warning Systems

Radar and infrared technologies can detect impending rear-end and lane-change collisions. However, these technologies cannot detect impending intersection collisions because they require line-of-sight communications. Wireless communication technology will be a viable technology for detecting intersection collisions. In this paper, we assumed that every vehicle is equipped with a wireless communication unit and every intersection has a wireless unit called the Intersection Traffic Controller (ITC). All vehicles near an intersection communicate with the corresponding ITC to send their dynamic information such as speed, acceleration, lane number, road number, and distance from the intersection. Though the wireless technology will be a viable technology for developing intersection collision warning systems, it is subject to various types of security attacks unless the system is properly designed. This paper presents a secure wireless protocol for intersection collision warning systems with a detailed bit level description of the protocol. The security is maintained using a chain of digital certificates issued by various federal and state organizations. The vehicles validate the certificate of the ITC using the public key issued by a federal organization, such as the US Department of Transportation. This paper also presents the performance analysis of the intersection collision warning system.
VALUING A TIMBER HARVEST CONTRACT AS A HIGH‐DIMENSIONAL AMERICAN CALL OPTION VIA LEAST‐SQUARES MONTE CARLO SIMULATION

Industrial timberland ownership in the United States has shifted substantially in the last 20 years. Having sold their fee-owned timberlands, forest products companies relied heavily on the open market for raw timber. To reduce their exposure to market risks, however, forest products companies have been using a number of supply chain instruments, such as timber harvest contracts. As these vehicles become increasingly important to the forest industry, it is necessary and important to determine their economic values. In this study, we treated a 3-year timber harvest contract on a 30-year-old loblolly pine plantation as a high-dimensional American call option and calculated its value by the least-squares Monte Carlo simulation technique. The estimated values of such a contract ranged from $1,693/ac to $1,984/ac under two timber price assumptions. With reasonable starting timber prices and strike price in the simulation, random timber prices led to higher contract values. Results from this study can help private landowners, timber brokers, and forest products companies better manage their business risks.
Drivers of Vegetation Species Diversity and Composition in Urban Ecosystems

In terrestrial systems, plants are the base of the food web, and their population growth is generally limited by resource availability rather than by higher trophic levels. Plants are also important components of the biogeochemical cycles that drive the movement of energy and resources. As primary producers, plants make energy available to higher trophic levels by converting sunlight, via photosynthesis, into biomass. Plants also create highly textured and structured habitat that provides food and cover for wildlife. Patterns of vegetation are shaped by variation in climate, soils, and disturbances, and provide the environmental template that drives patterns of species interactions throughout food webs. Where in this picture do urban areas fit?
MODELING DISSOLVED OZONE AND BROMATE ION FORMATION IN OZONE CONTACTORS

Many drinking water utilities that use source waters with significant bromide ion levels are currently seeking disinfection regimes that will minimize the formation of brominated disinfection byproducts while providing adequate disinfection. While ozonation appears to be a promising option for achieving these goals, the uncertainty of future drinking water regulations has developed a need for predicting actual disinfection byproduct formation prior to the costly investment for upgrading existing treatment facilities. The models developed in this paper provide comparisons of ozonation application methods, providing a basis for minimizing bromate and aiding in future design considerations. Theoretical and empirical models for the determination of ozone transferred, dissolved ozone concentrations, and bromate formation have been derived and compared with pilot-scale and full-scale data; a good agreement has been observed between the actual data and the predicted data, showing the validity of these models. True-batch bromate formation more closely simulated pilot-scale and full-scale data. Bromate formation in one stage vs two stage ozone contactors and different reactor configurations have been compared. Ozone gas phase concentration appears to have an effect on bromate formation as well.
Gender in Context: Considering Variability in Wood and Eagly’s Traditions of Gender Identity

This paper was written in response to Wood and Eagly’s (2015) feminist forum paper that proposes two traditions for gender identity research, a tradition based on gender-typed attributes and a tradition based on gender self-conceptualization. The present paper expands on Wood and Eagly’s (2015) framework by proposing, in line with social constructivist models, that both traditions of gender identity may be variable and context dependent. Specifically, the present paper reviews research conducted in the U.S.A. that suggests that gender-typed attributes and components of gender self-conceptualization may change based on contextual factors such as the gender of people in a person’s immediate context and the salience of gender in a given situation. The paper also reviews ways in which variation in gender-typed attributes and components of gender self-conceptualization has been measured previously, and suggests the use of experience sampling methodology for future research. Finally, the paper encourages researchers to consider Wood and Eagly’s (2015) suggestion of using the principle of compatibility when selecting trait or state measures of gender identity, and proposes that beliefs in gender essentialism (that gender differences are due to innate traits) may be reduced by understanding how contextual factors influence gender identity.
The Effect of Matching Contribution Offers and Legitimization of Paltry Contributions On Compliance

The use of a matching contribution offer in conjunction with legitimization of paltry contributions is examined in a door-to-door charitable solicitation context. Three hundred and twenty households were exposed to charitable contribution requests employing either legitimization of paltry contributions, a matching contribution offer, both, or a control. It was predicted that the matching funds offer, paired with legitimization of paltry donations, would increase both compliance rates and donation sizes and generate greater revenues than either tactic used singly. The results of a field experiment support this prediction.
Fire in the Northeast: Learning from the Past, Planning for the Future

Fire is an important disturbance process that regulates forest stand structure and species diversity in many ecosystems across the northeastern United States. Fires have promoted the growth and regeneration of shade intolerant genera throughout the Holocene, during which time humans have had a dominant influence on northeastern fire regimes. Humans have used fire for many applications including wildlife management, land clearing, and vegetation maintenance. Fire frequency increased during the periods of Native American occupation and early European colonization, but it has decreased since Native American displacement, colonist farm abandonment, and direct fire suppression, causing shifts in plant community composition toward shade-tolerant, pyrophobic species. Managers need appropriate benchmarks for using prescribed fire for restoration, especially in the face of climatic change. Salient lessons from history are: (a) fire is natural, (b) fire is cultural, (c) fire is economic, and (d) human decisions reg...
Velocity Field-Based Maneuver Regulation of Autonomous Motorcycles

Abstract Single-track vehicles such as motorcycles or bicycles provide an agile mobile platform. Control of motorcycles is challenging due to its underactuation and non-minimum phase dynamics properties. In this paper, we present a maneuver regulation control design for autonomous motorcycles. The maneuver regulation control guides the vehicle to follow a desired path and automatically tunes the desired velocity. We extend the motorcycle dynamics by including the coupled longitudinal/lateral tire/road interaction. We then design a velocity field for regulating vehicle maneuvers. The velocity field-based maneuver regulation design is integrated with the previously established trajectory tracking controller for motorcycle systems. Simulation results are presented to illustrate the maneuver regulation design.
Effect of migration inhibitory factor (MIF) on cyclic AMP levels of guinea pig macrophages

Abstract The effect of migration inhibitory factor (MIF)-rich Sephadex fraction IV (55,000–25,000 daltons) on the level of macrophage cyclic AMP has been investigated. Macrophage monolayers were incubated with MIF for times ranging from 1 min to 24 hr. During this period no significant difference was found in the level of cyclic AMP in monolayers incubated with MIF or control fractions. It is concluded from these results that the inhibition of macrophage migration by MIF is not due to a direct alteration of macrophage cyclic AMP levels by MIF.
Modeling of Nitrate Adsorption and Reduction in Fe0-Packed Columns through Impulse Loading Tests

A conventional tracer study using Li+ and Cl− was conducted on four Fe0 -packed column reactors for nitrate removal. Both Li+ and Cl− showed strong adsorption onto iron media and thus were not ideal tracers for the study. Tests using an impulse loading of nitrate were then innovated to investigate the transport and reduction of nitrate in the reactors. The impulse loading was superposed on a continuous constant feeding of nitrate which generated a steady effluent baseline. A multivariable model incorporating hydraulic dispersion, adsorption/desorption, and reduction of nitrate was developed and numerically solved. Both Langmuir adsorption and linear adsorption isotherms were separately applied to describe nitrate adsorption on the reactive surface. The parameters of the model were estimated by fitting the model with the response curves from the impulse loading tests. These estimated parameters were consistent with previous studies. Specifically, the modeling results suggest a significant adsorption of nit...
Rethinking geopolitics in an era of climate change

This article examines the disconnect between predictions about climate change and dominant geopolitical framings of the future. To begin, we introduce four popular geopolitical models of the world. We then show how climate change is a critical variable when considering the future of international politics. Focusing on the specific issues of water availability, agricultural productivity, coastal impacts, and shipping routes, we discuss the implications of predicted changes in the wake of climate change for the assumptions on which these scenarios are built. We show that work linking climate change and geopolitics has clear implications for the ways in which the future geopolitical (dis)order is conceptualized, and we argue that the failure to incorporate this work into geopolitical scenario-planning represents a significant limitation to their utility. We offer some direction for a re-conceptualization of the future based on a more dynamic and flexible approach to geopolitics that recognizes the disruptions posed by climatic and other environmental changes.
Signal-to-noise enhancement techniques for quantum cascade absorption spectrometers employing optimal filtering and other approaches

Optical feedback to the laser source in tunable diode laser spectroscopy (TDLS) is known to create intensity modulation noise due to elatoning and optical feedback (i.e. multiplicative technical noise) that usually limits spectral signal-to-noise (S/N). The large technical noise often limits absorption spectroscopy to noise floors 100-fold greater than the Poisson shot noise limit due to fluctuations in the laser intensity. The high output powers generated from quantum cascade (QC) lasers, along with their high gain, makes these injection laser systems especially susceptible to technical noise. In this article we discuss a method of using optimal filtering to reduce technical noise. We have observed S/N enhancements ranging from ∼20% to a factor of ∼50. The degree to which optimal filtering enhances S/N depends on the similarity between the Fourier components of the technical noise and those of the signal, with lower S/N enhancements observed for more similar Fourier decompositions of the signal and technical noise. We also examine the linearity of optimal filtered spectra in both time and intensity. This was accomplished by creating a synthetic spectrum for the species being studied (CH4, N2O, CO2 and H2O in ambient air) utilizing line positions and linewidths with an assumed Voigt profile from a commercial database (HITRAN). Agreement better than 0.036% in wavenumber and 1.64% in intensity (up to a 260-fold intensity ratio employed) was observed. Our results suggest that rapid ex post facto digital optimal filtering can be used to enhance S/N for routine trace gas detection.
Superthermal electron processes in the upper atmosphere of Uranus: Aurora and electroglow

Strong ultraviolet emissions from the upper atmosphere of Uranus suggest that both auroral and electroglow phenomena are of significant aeronomical consequences in the structure of the upper atmosphere. Combined modeling and data analysis were performed to determine the effect of electroglow and auroral phenomena on the global heat and atomic hydrogen budgets in the Uranus upper atmosphere. The results indicate that the auroral and electroglow heat sources are not adequate to explain the high exospheric temperature observed at Uranus, but that the atomic hydrogen supplied by these processes is more than sufficient to explain the observations. The various superthermal electron distributions modeled have significantly different efficiencies for the various processes such as UV emission, heating, ionization, and atomic hydrogen production, and produce quite different H2 band spectra. However, additional information on the UV spectra and global parameters is needed before modeling can be used to distinguish between the possible mechanisms for electroglow.
Who's in the house?

(1986). Who's in the house? Women & Performance: a journal of feminist theory: Vol. 3, No. 1, pp. 28-34.
Causal Models and Space-Time Geometries

There are many points of view from which one finds it appropriate to look at the notion of causality. These include what I call the logical (linguistic), probabilistic (stochastic), analytic (physical, system-theoretic), and geometric (relativity-theoretic) viewpoints. In all of them, throughout the rather long and confusing intellectual history of the subject, the main intention has been to explicate and then to answer in the best possible way the following two basic questions: Q1 What curious entities, usually called causes and effects, are supposed to be in a causal relationship? Q2 What kind of relation, operator, or perhaps something else, called causal relation or causal operator, is associated with or attributed to the causal entities?
Student perceptions of cheating in online and traditional classes

With classroom instruction undergoing a massive transformation to incorporate online learning techniques at unprecedented levels, technological advances have facilitated a range of mechanisms that improve teaching and learning. At the same time, these technological advances have also facilitated different forms of cheating in classes.
The uptake of the apoprotein and cholesteryl ester of high-density lipoproteins by the perfused rat liver

The uptake of the 125I-labeled apolipoprotein and 3H-labeled cholesteryl ester components of rat apolipoprotein E-deficient HDL by the perfused liver was studied. The uptake of the cholesteryl ester moiety was 4-fold higher than that of apolipoprotein. The concentration-dependent uptake of labeled protein was saturable and competed for by an excess of unlabeled HDL. The uptake of cholesteryl ester was not saturable over the concentration range studied. In the presence of a 50-fold excess of unlabeled HDL, the uptake of both radiolabeled components was decreased by over 75%, indicating that three-quarters of the hepatic uptake of HDL is by a receptor-mediated process. After 15 min of perfusion, 37% of the apolipoprotein radioactivity that was initially bound at 5 min was released into the perfusate as a more dense particle. After 5, 15, 30 and 60 min of perfusion the subcellular distribution of the apolipoprotein and cholesteryl ester components was analyzed by Percoll density gradient centrifugation. Over the 60 min period, there appeared to be transfer of radioactivity from the plasma membrane fraction to the lysosomal fraction. However, the internalization and degradation of cholesteryl ester was more rapid than that of the apolipoprotein. Our findings indicate that there is preferential uptake of HDL cholesteryl ester relative to protein by the liver and that the internalization of these components may occur independently.
Thermodynamics of ordering alloys, II. The gold-copper system

Abstract The solid solutions of the gold-copper system have been investigated by the galvanic e.m.f. technique. The results at temperatures higher than the critical temperatures of ordering agree with those of previous workers in showing negative deviations from Raoult's law, and a negative heat of solution. A minimum in the curve for the entropy of mixing of the disordered phase is found and is indicative of short-range order. The degrees of short-range order computed from the thermodynamic data and the quasi-chemical theory of ordering agree well with those found by X-ray diffraction. At lower temperature two-phase regions are found separating one superlattice phase from another, or from the disordered solid solution. The orthorhombic CuAuII is characterized by a relatively unsharp cusp in the curve of entropy of solution, which shows the presence of many imperfections in the superlattice.
Electromigration failure modes in aluminum metallization for semiconductor devices

Two wear-out type failure modes involving aluminum metallization for semiconductor devices are described. Both modes involve mass transport by momentum exchange between conducting electrons and metal ions. The first failure mode is the formation of an electrically open circuit due to the condensation of vacancies in the aluminum to form voids. The second is the formation of etch pits into silicon by the dissolution of silicon into aluminum, and the transport of the solute ions down the aluminum conductor away from the silicon-aluminum interface by electron wind forces. The process continues until an etch pit grows into the silicon to a depth sufficient to short out an underlying junction.
A near-tight approximation lower bound and algorithm for the kidnapped robot problem

Localization is a fundamental problem in robotics. The 'kidnapped robot' possesses a compass and map of its environment; it must determine its location at a minimum cost of travel distance. The problem is NP-hard [6] even to minimize within factor c log n[21], where n is the number of vertices. No approximation algorithm has been known. We give a O(log3n)-factor algorithm. The key idea is to plan travel in a 'majority-rule' map, which eliminates uncertainty and permits a link to the 1/2-Group Steiner (not Group Steiner) problem. The approximation factor is not far from optimal: we prove a c log2-en lower bound, assuming NP n ZTIME(npolylog(n)), for the grid graphs commonly used in practice. We also introduce a new hypothesis equivalence decomposition of the plane, built from pairs of aspect graph duals, in order to extend the algorithm to polygonal maps.
HipMer: an extreme-scale de novo genome assembler

De novo whole genome assembly reconstructs genomic sequences from short, overlapping, and potentially erroneous DNA segments and is one of the most important computations in modern genomics. This work presents HipMer, the first high-quality end-to-end de novo assembler designed for extreme scale analysis, via efficient parallelization of the Meraculous code. First, we significantly improve scalability of parallel k-mer analysis for complex repetitive genomes that exhibit skewed frequency distributions. Next, we optimize the traversal of the de Bruijn graph of k-mers by employing a novel communication-avoiding parallel algorithm in a variety of use-case scenarios. Finally, we parallelize the Meraculous scaffolding modules by leveraging the one-sided communication capabilities of the Unified Parallel C while effectively mitigating load imbalance. Large-scale results on a Cray XC30 using grand-challenge genomes demonstrate efficient performance and scalability on thousands of cores. Overall, our pipeline accelerates Meraculous performance by orders of magnitude, enabling the complete assembly of the human genome in just 8.4 minutes on 15K cores of the Cray XC30, and creating unprecedented capability for extreme-scale genomic analysis.
A geometric computing method for nonlinear optimal regulator problems with singular arcs

A computing algorithm, based on the geometry of certain reachable sets, is presented for fixed terminal time optimal regular problems having differential equations $$\dot x = f(x ,u , t)$$ . Admissible controls must be measurable and have values in a setU, which must be compact, but need not be convex. Functionsf(x, u, t) andf x (x, u, t) must be continuous and Lipschitz inx andu, but existence off u (x, u, t) or second derivatives is not required. The algorithm is based on taking a sequence of nonlinear steps, each of which linearizes $$\dot x = f(x ,u , t)$$ in state only, about a current nominal control and trajectory. Small perturbations are assured by keeping the perturbed controlclose to the nominal control. In each nonlinear step, a regulator problem,linear in state, is solved by a convexity method of Barr and Gilbert (Refs. 1---2), which is undeterred by the possibility of singular arcs. The resulting control function is substituted into the original nonlinear differential equations, producing an improved trajectory. Convergence of the algorithm is not proved, but demonstrated by a computing example, known to be singular. In addition, procedures are described for choosing parameters in the algorithm and for testing for theplausibility of convergence.
“Lower insular rise hills” shaped by a bottom boundary current in the mid-Pacific

Abstract Large upslope-migrating sediment waves occur at depths of 5000–5250 m along the apron on the east side of the Marshall-Gilberts archipelago. They are similar in scale and structure to the “lower continental rise hills” beneath the Western Boundary Undercurrent on the North American continental rise. The mid-Pacific bedforms are believed to be created by the current of Pacific Bottom Water that flows along the western boundary of the Central Basin, between the Samoan and Wake Island Passages.
Scanning Soft X-Ray Microscopy With A Fresnel Zoneplate At The National Synchrotron Light Source

We have built a scanning transmission soft X-ray microscope located at the National Synchrotron Light Source (NSLS). Images of biological specimens have been formed with submicron resolution. A Fresnel zoneplate serves as the focusing element.© (1984) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Specific Adhesion of Micron-Sized Colloids to Surfaces Mediated by Hybridizing DNA Chains

The hybridization of complementary DNA chains can be used to identify unknown strands. Substantial work has been done to link nanoparticles in solution or on surfaces via DNA hybridization. However, few studies have been done on micron-sized particles that can be visually identified using optical microscopy. In this paper, we used 9.95 μm oligonucleotide coated polystyrene microspheres as probes to identify complementary oligonucleotide sequences immobilized on polystyrene substrate surfaces. We showed that particle adhesion is specific and only seen when beads and surfaces are complementary; nonspecific binding was negligible. Using a flow chamber, we studied the effects of shear rate on microsphere detachment as a function of oligonucleotide site density on the substrate. We show that the critical shear rate at which the beads are detached is an increasing function of oligonucleotide substrate site density. Analysis of the microspheres detached from the slide by flow cytometry demonstrated that the bond...
Geopolitics and the dollar

Abstract In this paper, coefficients relating the real dollar exchange rates of 11 industrialized democracies to US defense expenditures are found to be a function of geopolitical national security variables. These findings support the hypothesis that ‘safe haven’ investment decisions have affected real dollar exchange rates over the 1973–86 period.
Maximum weight clique algorithms for circular-arc graphs and circle graphs

Circle graphs and circular-arc graphs are the intersection graphs of chords and arcs in a circle. In this paper we present algorithms for finding maximum weight cliques in these graphs. The running times of the algorithms are $O(n^2 + m\log \log n)$ for circle graphs and $O(mn)$ for circular-arc graphs. Our algorithms are based on the scanning of appropriate endpoint sequences and efficient bookkeeping of results for subproblems.
Combustion Instability and Flame Structure of Turbulent Swirl-Stabilized Liquid-Fueled Combustion

The present paper reports flame structure and combustion instability characteristics in a turbulent liquid-fueled swirl-stabilized lean direct fuel injection combustor. Because of the complexities in droplet size and distribution, evaporation, droplets–vapor–air entrainment and mixing, and droplets–flame–turbulence interactions, the flame structure is remarkably different from lean premixed gas-fueled combustion. With the preheat temperature above 423K, heat release is completed within a compact doughnut ring, about 12mmdownstream of the dump plane; with decreasing equivalence ratios at the approach of lean blowout, the doughnut ring shrinks in diameter and gradually converges to the axis; after that, the heat release zone becomes elongated and tilted off the axis. Chemiluminescence only provides qualitative information of the heat release rate, suggesting the limitations of global chemiluminescence measurements for spray combustion. Phase-locked intensified charge coupled device imaging of CH chemiluminescence shows that during combustion instability there aremainly variations in the chemiluminescence intensity rather than in the spatial distribution of heat release. Depending on the working conditions, the one-wave mode, the half-wave mode, or both of the combustion chambers can be excited. Although the combustion chamber is highly blocked at both ends, no pressure antinodes are found at the chamber exit and the chamber inlet. Simultaneous excitation of the one-wave mode and the half-wave mode is intrinsically unsteady and unstable, which can be attributed to the nonlinear response of the reacting swirling shear layer to acoustic oscillations. Both the amplitude and the frequency of thermoacoustic oscillations are constantly time-varying. With decreasing oscillation intensity, the limit-cycle oscillator becomes increasingly vulnerable to external disturbances, as indicated by a larger neighborhood of the state trajectory.
Adiabatic Charge Pumping in Almost Open Dots

We consider adiabatic charge transport through an almost open quantum dot. We show that the charge transmitted in one cycle is quantized in the limit of vanishing temperature and one-electron mean level spacing in the dot. The explicit analytic expression for the pumped charge at finite temperature is obtained for spinless electrons. The pumped charge is produced by both nondissipative and dissipative currents. The former give a quantized contribution to the transferred charge, whereas the latter are responsible for the corrections to charge quantization which are expressed through the conductance of the system.
Meta-Analysis of Effectiveness of Interventions to Increase Influenza Immunization Rates among High-Risk Population Groups

Public health interventions have been developed to increase influenza immunization rates among the high-risk elders and patients suffering from cardiopulmonary, metabolic, and other chronic conditions. The relative effectiveness of alternative intervention strategies is not yet well understood. Determination of the most effective strategy should consider characteristics ofthe target population and the health care delivery system. This meta-analysis of intervention evaluation studies highlights the importance of considering the baseline immunization rate of the target population in selecting the most effective strategy. While the analysis confirms the feasibility of achieving the 60 percent target coverage established in Healthy People 2000, the results also suggest that as coverage levels increase, single-faceted patient-focused interventions may need to be strengthened by the addition of complementary changes in provider behaviors and/or the delivery system. Further research is needed to identify the most cost-effective combination of intervention strategies, particularly in populations with higher immunization coverage.
The BCR gene encodes a novel serine/threonine kinase activity within a single exon

Abstract Sequences encoded by the first exon of BCR that bind to the ABL SH2 domain are essential for the activation of the ABL tyrosine kinase and transforming potential of the chimeric BCR-ABL oncogene. The normal cellular BCR gene encodes a 160,000 dalton phosphoprotein associated with a serine/threonine kinase activity, but it shows only weak dispersed homologies to protein kinases. p160 c-BCR was purified to apparent homogeneity as an oligomer of >600,000 daltons that contains autophosphorylation activity and transphosphorylation activity for several protein substrates. A region containing paired cysteine residues within the 426 amino acids encoded by the first exon of BCR is essential for its novel phosphotransferase activity, which overlaps with the strong SH2-binding regions. The recent demonstration of a GTPase-activating function within the C-terminal portion of BCR suggests that the protein kinase and SH2-binding domains may work in concert with other regions of the molecule in intracellular signaling processes.
EQUILIBRIUM PARTITIONING OF A DIMERIZING FLUID THROUGH A MICROPOROUS SOLID: A MONTE CARLO STUDY OF THE DENSITY DISTRIBUTIONS AND ADSORPTION ISOTHERMS

We have considered a simple, hard-core-type model for an inhomogeneous system consisting of a dimerizing fluid and a microporous solid membrane with a slit shape. The system is confined to a wide slitlike pore. The bulk and porous regions are in thermodynamic equilibrium. Monte Carlo canonical simulation results are presented for the density distributions of the particles in the bulk fluid region, in layers close to the outer surfaces of the porous solid and inside the crystalline membrane. We have observed that dimers prefer to be located in the interstices of the membrane channels rather than in the membrane cavities. The pressure is obtained from the density profiles on the walls of a wide pore. We show that the adsorption isotherms and the partition coefficients are sensitive to the association energy between fluid particles. For almost all densities, the partition coefficient of the monomers is found to be higher than for those particles that belong to dimers. This reflects the shape selectivity of t...
Metabolism of alternative substrates and the bioenergetic status of EMT6 tumor cell spheroids

In order to evaluate the ability of EMT6/Ro multicellular spheroids to utilize various pathways of energy production, 13C and 31P MRS have been employed to monitor the metabolism of glucose, glutamine, acetate and propionate. EMT6/Ro spheroids perfused with culture medium containing 5.5 mM glucose maintain stable levels of nucleotide triphosphates (NTP) and phosphocreatine (PCr) for up to 48 h, even in the absence of glutamine. The metabolism of 1-13C-glucose was almost entirely to 3-13C-lactate (88 ± 12%, n = 7), even though the perfusion medium was equilibrated with 95% O2. Labeling was also observed in other glycolytic metabolites, primarily alanine and α-glycerolphosphate. A low level of 13C labeling in glutamate, indicative of mitochondrial oxidative metabolism (TCA cycle), was consistently detected when spheroids were perfused with 1-13C-glucose, almost exclusively in the C4 position of glutamate. Labeling of glutamate C2 and C3 was always less than 20% of the labeling in C4 and was usually undetectable. No evidence of adjacent carbon labeling in individual glutamate molecules (indicative of multiple cycles of label incorporation) was found, even in high-resolution 13C NMR spectra of extracts from cells or spheroids. Despite the predominantly glycolytic metabolism of glucose, the mitochondrial substrate glutamine (2 mM, in the presence of ≤0.5 mM glucose from fetal bovine serum), supported stable levels of NTP and PCr in the tumor cells for up to 12 h. In the presence of 2.5 mM acetate, the bioenergetic status of cells in EMT6 spheroids declined slowly but measurably, and no incorporation of label from 2-13C-acetate into other metabolites was detected either in intact perfused spheroids or in high-resolution spectra of extracts. In contrast, when the anaplerotic TCA cycle substrate 3-13C-propionate replaced acetate, the high-energy phosphate levels in EMT6/Ro spheroids were somewhat reduced, but stabilized at a new lower level. Incubation of spheroids with 3-13C-propionate (with natural abundance glucose and glutamine) resulted in label detectable in the C2 and C3 of glutamate, but the primary labeled compound was methylmalonate, an intermediate in propionate metabolism. Addition of vitamin B12, a cofactor for methylmalonyl CoA reductase, to the growth medium 24 h prior to perfusion with propionate resulted in the elimination of the methylmalonate resonance. A variety of 2- and 3-labeled metabolites were detected, including succinate, malate and glutamate. Labeling of C2 and C3 of lactate implicated cytoplasmic malic enzyme activity. Copyright © 2000 John Wiley & Sons, Ltd. Abbreviations used: EMEM Eagle's minimum essential medium HBSS Harte's buffered salt solution NOE nuclear over hauser effect NTP nucleotide triphosphates PCr phosphocreative PE phosphoethanolamine TFA trifluoroacetate TMP trimetaphosphate UDPG uridine diphosphogluccose.
Cuticular hydrocarbons of eight species of north american cone beetles,Conophthorus hopkins.

A study to determine the degree of similarity and/or diversity among eight of the 15 described species ofConophthorus is reported. Cuticular hydrocarbons were evaluated forC. conicolens, C. ponderosae, C. cembroides, C. edulis, C. radiatae, C. coniperda, C. resinosae, andC. banksianae. Seventy-eight individual and isomeric mixtures of hydrocarbons were identified by gas chromatography-mass spectrometry, includingn-alkanes, alkenes, alkadienes, 2- or 4-methylalkanes, 3-methylalkanes, and single-component and isomeric mixtures of internally branched mono-, di-, and trimethylalkanes. Differences in alkenes and mono-, di-, and trimethylalkanes can be used easily to separate the eight species.Conophthorus conicolens andC. ponderosae contain the most complex blends. Hydrocarbon patterns in three geographically separated populations ofC. ponderosae, each from a different host, are qualitatively identical with the exception of a homologous series of 3,7-dimethylalkanes from adults collected fromPinus lambertiana cones. The latter could comprise a sibling species. Hydrocarbon mixtures of two eastern species,C. resinosae andC. banksianae, are qualitatively identical, supporting the suspicion thatC. banksianae may not be a valid species. Closely relatedC. cembroides andC. edulis have similar combinations of hydrocarbons except for a unique and abundant alkene (C27∶1) inC. edulis and two dimethyhexacosanes inC. cembriodes.
Correction of ground-water chemistry and carbon isotopic composition for effects of CO2 outgassing

Abstract Direct P co 2 measurements on water samples from several CO2-charged warm springs are significantly higher than P co 2 values calculated from field pH and alkalinity (and other constituents). In addition, calcite saturation indices calculated from field pH and solution composition indicated supersaturation in samples which, on the basis of hydrogeologic concepts, should be near saturation or undersaturated. We attribute these discrepancies to uncertainties in field pH, resulting from CO2 outgassing during pH measurement. Because samples for direct P co 2 measurement can be taken with minimal disturbance to the water chemistry, we have used the measured P co 2 to back calculate an estimate of the field pH and the carbon isotopic composition of the water before outgassing. By reconstructing water chemistry in this way, we find generally consistent grouping of δ 13 C , pH, and degree of calcite saturation in samples taken from the same source at different times, an observation which we expect based on our understanding of the hydrogeology and geochemistry of the ground-water systems. This suggests that for very careful geochemical work, particularly on ground-waters much above ambient temperature, P co 2 measurements may provide more information on the system and a better estimate of its state of saturation with respect to carbonate minerals than can field measurements of pH.
A CARBON BUDGET FOR THE AUTOTROPHIC CILIATE MESODINIUM RUBRUM1

Extensive blooms of the autotrophic ciliate Mesodinium rubrum (Lohmann) occurred in the Peru coastal upwelling region at 15°S latitude in March through May 1977 and contributed significantly to the organic productivity of the region. From observations made during the JOINT-II oceanographic expedition, a budget of the carbon flux of these unusual photosynthetic organisms can be constructed. The light dependent C fixation was determined with short (1 h) incubations because of the organisms' sensitivity to confinement and rapid nutrient exhaustion. Maximum photosynthesis occurred at 50% of incident light with a maximum rate of particulate C synthesis of 2187 mg C · m−3· h−1. The specific carbon uptake rates were also high with a maximum light saturated value of 16.8 mg C ·(mg chl a)−1· h−1. The rate of excretion of dissolved organic C at the productivity maximum ranged from 16.1 to 181.1 mg C · m−3· h−1. The range of percent excretion was 1.8–12.5% the total C fixed, similar to the range found in both motile and nonmotile phytoplankton assemblages. Respiration, determined by the decrease in particulate C in the dark, averaged 4.6% of the previously fixed photosynthetic C · h−1. M. rubrum actively took up amino acids and naturally occurring dissolved organic carbon. The C budget for this ciliate indicates that the daily contribution to the particulate food chain is large, although not as great as is indicated by short incubations. The contribution of M. rubrum to the productivity and elemental fluxes of upwelling and coastal ecosystems has been seriously underestimated.