cssi/SciSciGPT-SciSciNet huggingface dataset:
Tear miRNAs identified in a murine model of Sjögren’s Syndrome as potential diagnostic biomarkers and indicators of disease mechanism

ABSTRACT Objective The tear miRNAome of the male NOD mouse, a model of ocular symptoms of Sjogren’s syndrome (SS), was analyzed to identify possible tear biomarkers of the disease. Methods Male NOD mice, aged 12-14 weeks, were used to identify tear miRNAs associated with development of autoimmune dacryoadenitis. Age-matched female NOD mice that do not develop the autoimmune dacryoadenitis characteristic of SS were used as negative controls while age- and sex-matched male BALB/c mice served as healthy controls. Total RNA was isolated from stimulated tears pooled from 5 mice per sample and tear miRNAs were sequenced and analyzed. Putative miRNA hits were validated using RT-qPCR in a separate mouse cohort, and the pathways influenced by the validated hits were identified using Ingenuity Pathway Analysis. Results In comparison to tears from both healthy (male BALB/c) and negative control (female NOD) mice, initial analysis identified 7 upregulated and 7 downregulated miRNAs in male NOD mouse tears. Of these, 8 were subsequently validated by RT-qPCR in tears from additional mouse cohorts. miRNAs previously implicated in SS pathology included mmu-miR-146a/b-5p, which were significantly downregulated in the male NOD mouse tears, as well as mmu-miR-150-5p and mmu-miR-181a-5p, which were upregulated in the male NOD mouse tears. All other validated hits including the upregulated miR-181b-5p and mmu-miR-203-3p, as well as the downregulated mmu-miR-322-5p and mmu-miR-503-5p, represent novel putative indicators of autoimmune dacryoadenitis in SS. Conclusions A panel of differentially expressed miRNAs were identified in tears of SS model male NOD mice, including some never previously linked to SS. These may have potential utility as diagnostic biomarkers for ocular symptoms of SS; evaluation of the pathways influenced by these dysregulated miRNAs may also provide further insights into SS pathogenesis.
The Educateur: An Atypical Childcare Worker.

A brief historical account is given of the origins of the educateur in France, Canada, and the United States. The role of the educateur in the reeducation process of behaviorally disordered youth i...
The "Culture OSCE"--introducing a formative assessment into a postgraduate program.

Background: There is a growing need for appropriate training models in the area of cultural competence. An Objective Structured Clinical Exam (OSCE) format is ideal for this endeavor, since it allows for skills practice and feedback. As a result, we designed the first formative Culture OSCE at Maimonides Medical Center and have been implementing it since 1999. Program Development: An interdisciplinary committee developed the OSCE as a formative assessment. Stations were designed based on a review of the literature and real situations experienced in the hospital. A two-hour workshop introducing the concept of cultural competence precedes the OSCE. The emphasis is on skills that are generalizable to encounters with any culture. Standardized patients are recruited from the relevant cultural groups or are trained to understand specific cultural issues. Costumes and props are utilized to enhance the authenticity of the encounter. Faculty, recruited and trained to observe encounters, gives constructive feedback, thus enhancing faculty development in this area as well. A rating scale was developed which incorporates communication and cultural skills as two separate dimensions of the encounter. Program Evaluation: Written feedback is obtained from residents, the trained faculty observers and the standardized patients. Resident feedback has demonstrated good face validity. A post-OSCE debriefing session allows residents an opportunity to consolidate learning and give oral feedback. Conclusion: The Maimonides Medical Center Pediatrics Department designed the first Culture OSCE. This is deemed to be a valuable training tool, and serves to highlight the importance of cultural competence within the Department.
Are Online Business Transactions Executed by Electronic Signatures Legally Binding

Most of us believe that we make contracts over the Internet all the time. We buy books and computers, arrange for hotels and planes, trade stocks, and apply for mortgages. But as recently as seven months ago that transaction was most likely not legally binding. This uncertainty led many practitioners, businesspeople, and consumers to question the efficacy of contracts executed by electronic signatures. Without a uniform standard, many jurisdictions ruled inconsistently, while other jurisdictions did not consider the issue. This disparate treatment threatened the legitimacy of online agreements and deprived both consumers and businesses of the certainty and predictability expected from well-developed markets. The law's formalities evolved outside of the digital world, and the process of adapting them to it has proven to be more difficult than expected. In June of 2000, Congress attempted to solve this problem with the Electronic Signatures in Global and National Commerce Act (E-Sign).
Waveguide with Statistically Rough Boundary in Noncorrelated Successive Reflections Approximation

The present chapter deals with wave propagation in the stratified medium bounded by a rough surface when refraction returns radiation scattered from roughness back to the boundary.
Understanding Links between Children's Health and Education

This paper has two goals. First, I evaluate the role of several mechanisms that may mediate the connection between children’s health and their educational attainment. Researchers have begun to pay more attention to the possibility that the relationship between health and socioeconomic status is bidirectional. While poor health has often been studied as a consequence of childhood and/or family socioeconomic conditions, it is also clear that illness and poor health during childhood have lasting socioeconomic effects. What is less clear is why poor health during childhood may influence educational outcomes in late childhood/young adulthood. Do children with a health disadvantage graduate from high school at lower rates, for example, because they are less school-ready than other children, or because they develop less productive social relationships and reduced expectations for their future? Secondly, I consider the extent to which health disparities among children account for racial disparities in children’s educational achievement. While childhood health disparities may contribute to socioeconomic disparities among the general population, they may also play a role in creating and maintaining the racial achievement gap that is so persistent in American society. Using data from the National Longitudinal Survey of Youth (NLSY) 97 and Child and Young Adult files, I examine these questions. Understanding the role of childhood health in creating and maintaining educational disparities among older children and young adults, as well as the role of race in this process, will facilitate the development of effective intervention strategies.
Structural Analysis Enhancements for Natural Products

The sections in this article are 1 Introduction 2 Traditional Routes to Structure 3 Inadequate Structural Determinations 4 Conformational Analysis Using Solid-State NMR 5 Stereochemical Determination Using Solid-State NMR 6 Conclusions 7 Biographical Sketch Related Articles
Fourier-transform method for accurate analysis of Mössbauer spectra.

We report a simple analytic form for the convolution integral in transmission Moessbauer spectroscopy allowing accurate representation of the line shape even for very thick absorbers (t = 10), and permitting easy fitting to the true line-shape function. This representation permits the accurate determination of all Moessbauer-effect (ME) parameters, including position, width, cross section, and interference. This analytic method can be applied to deconvolute accurately information contained in either source or absorber, and an explicit analytic form for the emission and absorption Fourier transforms is given. We show that from the asymptotics of the line shape, it is possible to determine all line-shape parameters, and that line-shape asymptotics can circumvent short-ranged hyperfine or instrumental broadening contributions to the observed spectrum. A formula for the correction to the line shape caused by source self-absorption is given, and it is shown that when there is significant source resonance self-absorption a ''good'' fit to data, judged by a chi-squared analysis, can yield completely wrong ME line-shape parameters. We find an equation for the dependence of the area under the absorption curve and the resonance peak height, and give its explicit dependence on the interference parameter and source broadening parameters. Although these effects havemore » been neglected in earlier work, their contribution may be of order 10% in many cases of interest.« less
Design, Analysis, and Simulation of Engineering Systems Over the World Wide Web for Educational Use

This paper presents the use of developed software tools for engineering education accessible via a web browser over the World Wide Web. The primary purpose of this work aims at improving the understanding of engineering fundamentals through interactive real-time simulation. The environment consists of modules for interactive real-time simulation of linear time invariant dynamic systems, and for the synthesis and analysis of planar mechanisms. The user interface enables easy understanding of the required inputs from the user. The outputs are presented in pictorial, graphical and textual forms. In addition to these forms, for the mechanism modules the user has the option to view an animation of the synthesized mechanism. This work demonstrates the ease of implementation, advantages of using this technology to aid in classroom instruction and provides valuable analysis tools to engineering professionals. Examples demonstrating features of the developed tools are presented. Users with Internet access can use the developed modules at http://zodhia.uta.edu/development .Copyright © 2002 by ASME
EEG spectra in twins: Evidence for a neglected mechanism of genetic determination

Electroencephalographic (EEG) spectra obtained from monozygotic (MZ) twins show striking within-pair similarity, while spectra of dizygotic (DZ) twins are no more similar than those ob­ tained from pairs of unrelated persons. At least one parameter of the EEG spectrum, the mid­ frequency of the alpha rhythm, is strongly correlated (.8) within pairs of MZ twins and yet its correlation within pairs of DZ twins is about zero. The frequency composition of the resting EEG may be an example of "emergenesis," in which the phenotypic character is determined by the interaction of independently heritable traits and is substantially altered if any genotypic component is changed. Such emergenic traits would not reveal their genetic origin in the usual analysis of pedigrees. An electroencephalographic (EEG) spectrum is a graph of EEG voltage with respect to frequency. In our work, each spectrum consists of 200 ordinates which estimate the relative voltage at .1-Hz intervals, from .1 to 20.0 Hz, contained in a 3-min sample of resting EEG, eyes closed. We have reported previ­ ously that EEG spectra of monozygotic (MZ) twins are remarkably similar when obtained at the same time and under similar conditions (Lykken, Tellegen, & Thorkelson, 1974). This similarity, illustrated in Figure I, can be measured by the spectrum difference ratio (SDR): where, as shown in Figure 2, At is the spectrum ob­ tained from Twin A (the first-born) at the start of the session, Bl is Twin B's spectrum at the end of the ses­ sion, etc., and D is the root-mean-squared difference between the two spectra specified within the paren­ theses. When SDR ~ 1.0, one could say that, with respect to their EEG spectra, the twins resemble each other as much as they resemble themselves. SDRs for the 39 pairs of MZ twins previously reported are plotted in Figure 3A against a distribution of SDRs for pairs of unrelated persons (obtained by pairing each indi­ vidual twin with all persons other than his/her co­ twin); 33% of the MZ ratios are ~ 1.0, and the mean difference between the MZ and unrelated pairs dis­ tributions is highly significant (p ~ .(01). We con­ clude that persons with identical genomes will usually
Adsorption of bacteria on soils: Experiments, thermodynamic rationale, and application

A model for the adsorption of bacteria to soil particles is described using the physical-chemical Langmuir isotherm and the van't Hoff equation. An example of the use of the model for assessing bacterial movement through soil is provided.Staphylococcus aureus was the sorbate with sorbents of activated charcoal, kaolinite clay, Mendon silt loam, and silica sand. Competitive agents sodium lauryl sulfate, sodium chloride, and peptone were also studied. Peptone was the most successful competitor with the bacteria for sites on the sorbent.
Military trauma training performed in a civilian trauma center.

Abstract Background. In 1996, Congress passed legislation requiring the Department of Defense to conduct trauma training in civilian hospitals. In September of 1998 an Army team composed of surgeons, nurses, emergency medical technicians (EMTs), and operating room technicians (OR techs) trained in a civilian level 1 trauma center. This study analyzes the quality of the training. Methods. The training period was 30 days. Before and after training all members completed a questionnaire of their individual and team ability to perform at their home station, at the civilian hospital, and in the combat setting. Surgeons maintained an operative log, which was compared with their prior year's experience. Primary trauma cases (PTCs) met Residency Review Committee criteria as defined category cases and were done acutely. Other personnel tracked the percentage of supporting soldier tasks (SSTs) they performed or were exposed to during the training period. Results. Review of the questionnaires revealed a significant increase in confidence levels in all areas tested (P Conclusions. A 1-month training experience at a civilian trauma center provided military general surgeons with a greater trauma experience than they receive in 1 year at their home station. Other personnel on the team benefited by performing or being exposed to their SSTs. Further training of military teams in civilian trauma centers should be investigated.
Cram's rule for radicals: Stereoselective hydrogen abstraction reactions of NH substituted radicals

Abstract Radical reductions of chiral thiazolidines with (TMS) 3 SiH reveal stereochemical parallels between ionic reactions of ketones/imines and radical reactions of aminoalkyl radicals bearing NHR substituents.
Relationship between oxygen consumption and sediment‐water fluxes of heavy metals in coastal marine sediments

The relationship between benthic oxygen demand and the sediment–water flux of six heavy metals (cobolt [Co], nickel [Ni], copper [Cu], zinc [Zn], cadmium [Cd], and lead [Pb]) was examined at two locations: New Bedford Harbor and Buzzards Bay, Massachusetts, USA. Dissolved metal fluxes were measured in laboratory microcosms incubated in the dark at in situ temperatures, and microcosms were collected over different seasons to examine temporal and spatial variability in the fluxes. The net flux of all metals was generally out of the sediments. However, at low rates of benthic oxygen demand, net flux of Pb and Co was into the sediments. When data from the two sites are combined, regression of metal fluxes (normalized to sediment metal content) against benthic oxygen demand was significant for all metals (r2 = 0.58-0.85), with all slopes significantly different from zero. The flux values (normalized to sediment metal content) ranged from -1.4 (mmole/m2/d)/(mole/mole C)sediment for Zn during winter to 42 (mmole/m2/d)/(mole/mole C)sediment for Cd during summer months. The magnitude of the fluxes generally showed the following relationship: Cd < Zn < Co, Ni, Cu < Pb, indicating higher relative mobility for Cd and lower mobility for Pb. The estimated annual fluxes of metals to New Bedford Harbor and Buzzards Bay amount to ˜0.06% (Pb) to 25% (Cd) of the inventory of metals in the top 2 cm of sediments and can equal the inventory of metals in the water column on a time scale as short as 7 d for Zn.
Música colonial: 18th century music score meets 21st century digitalization technology

The Musica Colonial project is an initiative to preserve, digitize, and provide online access to the sole copy of a handwritten Colonial times cathedral music scores with Spanish lyrics collection in microfilm format archived at the Mesoamerican Center for Regional Research (CIRMA) located in Antigua, Guatemala. Various fields and methodologies of research can be done on this collection because of its multi-faceted and culturally rich content. This poster mainly focuses on the music aspect of the collection and illustrates the different stages of making the musical content of the collection accessible to the public. Digitization is the most affective and promising way to display this special collection to the rest of the world.
Effect of ACE Inhibitors on Endothelial Dysfunction: Unanswered Questions and Implications for Further Investigation and Therapy

Experimental studies have suggested that angiotensin-converting enzyme (ACE) inhibitors may have an important role in blocking the progression of and/or reversing endothelial dysfunction. The extrapolation of these experimental studies to the clinical situation has, however, been disappointing. Studies of forearm-mediated endothelial vasodilatation in patients with hypertension with captopril, enalapril, and cilazapril have been negative. The finding of the Trial in Reversing Endothelial Dysfunction (TREND) that the administration of quinapril to normotensive patients with coronary artery disease in part restores endothelial-mediated coronary vasodilation, as assessed by intracoronary administration of acetylcholine, has important implications for future therapy and raises several important questions. The differences in the TREND and previous studies of ACE inhibitors on endothelial dysfunction may be due to mechanistic differences in endothelial dysfunction in patients with coronary artery disease and hypertension. Although in general there has been a good correlation between endothelial dysfunction as assessed by forearm flow and coronary endothelial dysfunction as assessed by acetylcholine, these vascular beds may be affected differently by therapeutic interventions, especially with an ACE inhibitor, which may affect sheart stress and angiotensin II formation in different vascular beds differently. Third, one needs to question whether the effect of quinapril on coronary endothelial dysfunction is a class effect or unique to quinapril. It will be necessary to test the effectiveness of other ACE inhibitors on coronary endothelial dysfunction in humans before concluding that the beneficial effects of quinapril are due to a class effect.
Transportation Capstone Design Project: Review and Future Directions

The main technical and pedagogical aspects of a capstone design course presented at Northeastern University's Department of Civil Engineering for the undergraduate transportation concentration are described. An outline of the design problem, specifications, parameters, and major physical and operational features provides the basic scope of the work to be done. Comments are then made about the way the course is structured and how students, instructor and invited guest practitioners interact to provide a real‐life design situation, covering the definition of the demand for the facilities to layout, engineering specifications, a presentation typically needed for public information meetings, and a final report that also addresses the comments of those who attended the presentation. The approach adopted, the opportunities and constraints inherent in the presentation of the course, the perceived successes, the problems and difficulties encountered, and students' evaluation of the course are described. Compariso...
Photophysical Behavior of Variously Sized Colloidal Gold Clusters Capped with Monolayers of an Alkylstilbenethiolate

trans-4-(Mercaptoheptoxy)stilbene (S7-SH) was capped as a monolayer on colloidal gold clusters of diameters ranging from 1.4 to 5.2 nm. The resulting shell−core nanostructured composite showed emission from the metal and the appended arene. Differential surface area, rather than gold cluster size per se, accounted for the observed decreases in fluorescence intensity of the excited stilbene moiety upon shrinking the metal core size. Tight packing by an organic monolayer bound to the surface of the Au core was achieved most easily on large composite particles, whereas thiolatestilbene S7-SH groups bound to the surface of the smallest metal clusters were found to be conformationally more labile.
Understanding and Controlling the Reactivity of the Calcium Silicate phases from First Principles

First principles calculations are employed to provide a fundamental understanding of the relationship between the reactivity of synthetic calcium silicate phases and their electronic structure. Our aim is to shed light on the wide range of hydration kinetics observed in different phases of calcium silicate. For example, while the dicalcium silicate (Ca2SiO4) phase slowly reacts with water, the tricalcium silicate (Ca3SiO5) shows much faster hydration kinetics. We show that the high reactivity of Ca3SiO5 is mainly related to the reactive sites around its more ionic oxygen atoms. Ca2SiO4 does not contain these types of oxygen atoms, although experiments suggest that impurities may play a role in changing the reactivity of these materials. We analyze the electronic structure of a wide range of possible substitutions in both Ca3SiO5 and Ca2SiO4 and show that while the influence of different types of impurities on structural properties is similar, their effect on reactivity is very different. Our calculations ...
Hydrology and species‐specific effects of Bacopa monnieri and Leersia oryzoides on soil and water chemistry

In an 8-week greenhouse experiment, Bacopa monnieri (water hyssop) and Leersia oryzoides (rice cutgrass) were compared for nutrient assimilation as well as soil and water chemistry under variable flooding regimes using a nutrient solution rich in nitrogen (N) and phosphorus (P). Soil redox potential decreased in flooded treatments; however, mesocosms containing B. monnieri remained aerobic for much of the study, while flooded mesocosms containing L. oryzoides became moderately reduced. Soils containing L. oryzoides were higher in nitrogen. Generally, effluent concentrations of PO 4 3- were higher in B. monnieri mesocosms. B. monnieri immobilization of N and P was significantly less in below-ground tissues than L. oryzoides. P immobilization in L. oryzoides generally increased in response to flooding, while B. monnieri showed no detectable response. Results indicated that species-specific flood responses in plant nutrient status are due to differing interactions of B. monnieri and L. oryzoides with the soil environment. Additionally, L. oryzoides demonstrated greater P uptake than B. monnieri across treatments, resulting in decreased concentrations of PO 4 -3 in effluent. Although N was also affected by flooding and species, generalizations on N allocation within the system are difficult to describe due to the changes in species of N in response to oxidation-reduction gradients and biotic assimilation.
A polarographic study of the iron-2-hydroxymethyl-6-(2′-hydroxymethyl-5′-hydroxy-4′-pyrone-6′)-pyranyl-3,2[b]pyran-4,8-dione complex

Abstract A polarographic study has been carried out on the colored product formed in the interaction of iron(III) with 2-hydroxymethyl-6-(2′-hydroxymethyl-5′-hydroxy-4′-pyrone-6′)-pyranyl-3,2[ b ]pyran-4,8-dione. Measurements using the differential pulse method show that iron(III) exhibits a coordination number of 2 and a reproducible formation constant that varies somewhat depending upon the supporting electrolyte employed.
On Y M2 measures and area-preserving diffeomorphisms

Abstract For a given gauge group and compact Riemannian two-manifold, it is known that the associated Yang-Mills measure can be defined directly as a finitely additive measure on the space of connections, and this finitely additive measure is invariant with respect to SDiff, the group of all area-preserving diffeomorphisms of the surface. The first question we address is whether this symmetry essentially characterizes the projection of the Yang-Mills measure to the space of gauge equivalence classes. The proper formulation of this question entails the construction of an SDiff-equivariant equivariant completion of the space of continuous connections, such that the projection of the Yang-Mills measure to the space of gauge equivalence classes has a countably additive extension. We also consider the coupling of the Yang-Mills measure to determinants of Dirac operators. The basic problems are to prove that the coupled measure is absolutely continuous with respect to the background Yang-Mills measure, to find a reasonable formula for the Radon-Nikodym derivative, and to analyze the action of SDiff.
Water Waves and Circular Damping Regions

An analytical formulation is presented for the calculation of the water wave field in and around a circular region of wave damping, such as might occur over a kelp bed. Figures show the instantaneous wave field and wave amplitude along several transects across the circular damping region.
A Report on the Chinese Commune

Among the many remarkable achievements in the People's Republic of China, one of the most significant has been the development of the commune system. Since 80 percent of the Chinese people live on the farms, the development of a stable agricultural sector is essential to the overall stability and development of the Chinese society.
Isolation and characterization of newborn rabbit brain-derived microglia

We isolated brain microglia from newborn rabbits and maintained these cells in in vitro culture. Enriched populations of rabbit microglia share several characteristics of mononuclear phagocytes including intracellular staining for nonspecific esterase and acid phosphatase. Microglia express Fc receptors, generate superoxide anion, and stain positive with the lectin Ricinus communis. Rabbit brain microglia develop multinucleated giant cells and small colonies in in vitro culture. The cells are highly phagocytic in culture. Other investigators have recently demonstrated that rabbits can be infected with HIV-1 in vivo and that neurological symptoms occur only when HIV-1 infection was carried out in HTLV-1-infected rabbits. Brain microglia most likely play a central role in HIV-1 encephalopathy. The availability of rabbit brain microglia in in vitro culture, offers a valuable potential cell model to study HIV-1 infection in the central nervous system.
Structure-activity relationship of a series of diaminoalkyl substituted benzimidazole as neuropeptide Y Y1 receptor antagonists.

A series of benzimidazoles (4) was synthesized and evaluated in vitro as potent and selective NPY Y1 receptor antagonists. Substitution of the piperidine nitrogen of 4 with appropriate R groups resulted in compounds with more than 80-fold higher affinity at the Y1 receptor compared to the parent compound 5 (R = 11). The most potent benzimidazole in this series was 21 (Ki = 0.052 nM).
Mantle rheology and the scaling of bending dissipation in plate tectonics

[1] Plate tectonics on Earth involves the bending deformation of plates at subduction zones, and because plates are generally considered to be stiff owning to the rheology of mantle minerals, the role of energy dissipation by plate bending in the global energy balance has been frequently debated in the recent literature. Here we consider how bending dissipation should scale with slab parameters such as dip angle, plate age, the radius of curvature, and plate velocity by systematically exploring the parameter space with instantaneous Stokes flow calculations. We derive the scaling of bending dissipation for a range of mantle viscosity functions, including pseudoplastic rheology with olivine flow laws. Our results indicate that, as we move away from the isoviscous case, the scaling gradually deviates from what has commonly been assumed in previous studies, most notably for the radius exponent, which exhibits more than threefold reduction and even a sign reversal in some cases. These modifications in scaling exponents originate in the complication of the deformation field caused by viscosity variations within the bending plate. Approximating the lithospheric rheology by a single effective viscosity in the dynamical models of subduction has been a common practice, but we suggest that such approximation may limit the geological relevance of modeling studies, in particular when estimating the significance of bending dissipation.
Primitive lead in deep crustal xenoliths from the Snake River Plain, Idaho

The petrology and geochemistry of deep crustal rocks are poorly understood due to the inaccessibility of such materials. Most inferences of the lower crust are based on studies of ancient high-grade metamorphic terranes now exposed after a history of deep burial. However, direct sampling of deep crustal rocks is feasible when they are carried to the surface as accidental fragments (or xenoliths) in lava flows. Ferro-basalt to ferrolatite lavas from Craters of the Moon lava field (COM) in the Snake River Plain, southern Idaho are characterised by variable and high 87Sr/86Sr ratios (0.708–0.712) interpreted as reflecting variable degrees of crustal contamination1,2. Some of these lavas contain xenoliths of crustal derivation (silicic charnockites and pyroxene granulites) that are found nowhere in the vicinity in surface outcrops. I present here initial isotopic and trace element results for a suite of these crustal xenoliths. As part of a detailed Pb isotopic study of the lavas (in preparation), three granulites were analysed to test the contamination hypothesis. The results indicate an affinity between the xenoliths and many exposed granulite-facies metamorphic terranes, and the unusually primitive lead isotopic ratios recorded establish the presence of early Archean crust beneath south-central Idaho.
An Evaluation of the Resistance to Electrolysis of Metals for Use in Biostimulation Microprobes

Electrolysis measurements have been made on electrodes of platinum, stainless steel, tungsten, iridium, palladium, rhodium, rhenium, gold, tantalum, titanium, zirconium, and some conducting oxides of the tungsten bronze family. Electrodes were immersed in physiologic saline solution and subjected to biphasic rectangular current pulses of various current densities at 50 pps, 24 hours per day for periods up to nine months. Weight loss was recorded at intervals during this time. We conclude that iridium,rhodium, platinum and palladium are extremely resistant to electrolysis under these conditions and electrolysis under 5? thick, made of such materials should have lifetimes on the order of decades. Gold is somewhat poorer but probably acceptable; all the other materials tested, including tungsten and stainless steel, are unacceptable as chronic microelectrode materials.
In situ comparison of water content and dynamics in parallel, single-serpentine, and interdigitated flow fields of polymer electrolyte membrane fuel cells

Abstract Water content and dynamics were characterized and compared in situ by simultaneous neutron and optical imaging for three PEM fuel cell flow fields: parallel, serpentine, and interdigitated. Two independent sets of images were obtained simultaneously: liquid water dynamics in the flow field (channels and manifolds) were recorded by a digital camera through an optical window, while the through-thickness integrated water content was measured across the cell area by neutron imaging. Complementary data from the concurrent images allowed distinguishing between the water dynamics on the cathode and the anode side. The transient water content within the cell measured using neutron imaging is correlated with optical data as well as with temporal variations in the cell output and pressure differentials across the flow fields. Water dynamics on both the cathode and anode side were visualized and discussed. The serpentine cell showed stable output across the current range and the highest limiting current. Parallel and interdigitated cells exhibited substantially higher water contents and lower pressure differentials than the serpentine. Anode flooding significantly impeded their performance at high current. At moderate current, cell output correlated with the changes in water distribution in the cathode flow field rather than with the variations in the overall water content. Performance of the interdigitated cell was similar to the serpentine one in spite of the vastly different water contents. The cell's water-content response to a step-change in current revealed three distinct stages of water accumulation. Flow field configuration greatly affected both the amount of water accumulated in the cell and the duration of each stage.
Muscarinic modulation of a transient K+ conductance in rat neostriatal neurons.

NEURONS of the neostriatum are richly innervated by cholinergic neurons of intrinsic origin1–3. Both pre- and post-synaptic muscarinic receptors mediate the effects of acetylcholine (ACh) 4–6. Activation of these receptors is functionally significant, particularly in Parkinson's disease7. Current-clamp studies indicate that muscarinic receptors serve to decrease the responsiveness of neostriatal neurons to excitatory inputs8–10. Here we present evidence that this effect is caused, in part, by the muscarinic modulation of the A-current, a transient outward potassium current. The voltage dependence of this current suggets that normally it enhances spike repolarization and slows discharge rate, but does not affect 'synaptic integration'. We find that under the influence of muscarinic agonists, the voltage dependence of A-current activation and inactivation is shifted towards more negative membrane potentials and the peak conductance is increased. Therefore, at relatively hyperpolarized resting potentials, ACh transiently alters the functional role of the A-current, allowing it to suppress excitatory inputs and further slow the discharge rate. But at relatively depolarized resting potentials, ACh increases excitability by removing the A-current through inactivation.
A Global Survey of Possible Subduction Sites on Venus

Abstract About 10,000 km of trenches in chasmata and coronae have been identified as possible sites of retrograde subduction on Venus. All the sites have narrow deep trenches elongate along strike with arcuate planforms, ridge-trench-outer rise topographic profiles typical of terrestrial subduction zones, large outer rise curvatures >10 -7 m -1 , fractures parallel to the strike of the trench on the outer trench wall and outer rise, and no cross-strike fractures across the trench. Both the northern and southern margins of Latona Corona are possible subduction sites. Identification of a major graben between the two principal outer ridges in southern Latona Corona is evidence of back-arc extension in the corona; the amount of extension is estimated to be more than 2-11 km. The moment exerted by the ridges of southern Latona Corona is insufficient to bend the lithosphere into the observed outer rise shape; a negatively buoyant subducted or underthrust slab is needed. Depending on the unknown trench migration rate, lithospheric subduction can make a significant contribution to mantle cooling on Venus. Venusian chasmata could have a dual character. They may be propagating rifts near major volcanic rises, and subduction trenches far from the rises in the lowlands. Subduction and rifting may occur in close proximity on Venus, unlike on Earth. Rifting induced by hotspots on Venus may be necessary to break the lithosphere and allow subduction to occur. Such a process could result in gradual lithospheric subduction or global, episodic overturn of the lithosphere.
Amplitude and phase apodization caused by focusing light through an evanescent gap in SIL recorders

High numerical aperture vector diffraction theory is used to analyze a near field optical system using a solid immersion lens. The amplitude and phase of the transmitted light through the system changes as a function of the air gap height as well as indices of refraction, incident angle, etc. We call these `amplitude apodization' and `phase apodization'. The characteristics of those are done using supergaussian form. The effects of amplitude and phase apodization on irradiance are investigated for various index of refraction and air gap height.
Functional Proteomics Identifies Targets of Phosphorylation by B-Raf Signaling in Melanoma

Summary Melanoma and other cancers harbor oncogenic mutations in the protein kinase B-Raf, which leads to constitutive activation and dysregulation of MAP kinase signaling. In order to elucidate molecular determinants responsible for B-Raf control of cancer phenotypes, we present a method for phosphoprotein profiling, using negative ionization mass spectrometry to detect phosphopeptides based on their fragment ion signature caused by release of PO 3 − . The method provides an alternative strategy for phosphoproteomics, circumventing affinity enrichment of phosphopeptides and isotopic labeling of samples. Ninety phosphorylation events were regulated by oncogenic B-Raf signaling, based on their responses to treating melanoma cells with MKK1/2 inhibitor. Regulated phosphoproteins included known signaling effectors and cytoskeletal regulators. We investigated MINERVA/FAM129B, a target belonging to a protein family with unknown category and function, and established the importance of this protein and its MAP kinase-dependent phosphorylation in controlling melanoma cell invasion into three-dimensional collagen matrix.
Towards overcoming the transitive-closure bottleneck: efficient parallel algorithms for planar digraphs

Abstract There are linear-time sequential algorithms for many fundamental problems related to digraph reachability. In contrast, the best parallel algorithms known for these problems, although fast, require a great many processors and, hence, require much more computation overall than the sequential algorithms. This contrast reflects a seemingly unavoidable reliance on transitive closure techniques in parallel algorithms for digraph reachability. To further understanding of the nature of the bottleneck, we present a collection of polylog-time reductions among reachability problems. These reductions use only linear processors and work for general graphs. Futhermore, for planar digraphs, we give polylog-time algorithms for the following problems: (1) directed ear decomposition, (2) topological ordering, (3) digraph reachability, (4) descendant counting, and (5) depth-first search. Our new algorithms use only a linear number of processors, and, hence, are the first to be within a polylog factor of optimal in their use of parallelism.
Deposition of Aerosol Particles in Contraction Fittings

ABSTRACT Particle deposition was measured in contraction fittings with half-angles of 12°, 45°, and 90°. It was found that for a given contraction half angle, the losses in a contraction fitting correlate well with the parameter Stk(1-Ao Ai ) where: Stk is a Pich-type Stokes number based on inlet velocity and outlet diameter, Ao is the outlet area, and Ai is the inlet area. A correlation developed from the experimental results allows prediction of the particle losses in contraction fittings as a function of Stokes number, area ratio, and contraction half-angle. Test conditions on which the correlation was based include a range of 0.001 ≤ Stk(1-Ao/Ai ) ≤ 100. Area ratios Ao/Ai used in the tests were 0.062, 0.215, and 0.571, and the test conditions encompassed Reynolds numbers based on downstream port diameter of 1120 to 58,500. The aerosol particle deposition in the contraction fitting was also modeled numerically and the numerical results show good agreement with the experimental data. Flow turbulence was...
SEM/XPS analysis of fractured adhesively bonded graphite fibre surface resin-rich/graphite fibre composites

Samples of graphite fiber-reinforced polyimide were fabricated allowing the resin to accumulate at the composite surface. These surface resin-rich composites were then bonded together and tested for lap shear strength both before and after thermal aging. Lap shear strength did not appear to show a significant improvement over that previously recorded for resin-poor samples and was shown to decrease with increasing aging time and temperature.
Mastery Quizzes as a Teaching Tool in the Mechanics Series

Ohio Northern University (ONU) is a 2800 student, United Methodist Church related, undergraduate institution. In the Fall quarter of the 1988-89 academic year, the Engineering College began using mastery quizzes in the “Mechanics Series” courses of Statics, Dynamics, and Mechanics of Materials 1. These three courses are typically taken during the sophomore year. Mastery quizzes are used as a reinforcing tool. Three or four areas in each of these mechanics courses were identified as critical to the success of a student in future courses. A set of mastery quizzes has been made for each of these critical areas. A student must complete one of the quizzes in each set with a perfect score to pass the course. The first quiz in each critical area is taken in class for a score, and if not completed perfectly, must be retaken outside class on a pass-fail basis. This analysis looked at the percent answered correctly by Ohio Northern students in the specific areas of statics, dynamics, and mechanics of materials on the Fundamentals Exam (F.E.) to determine whether the use of mastery quizzes improved scores in these three areas. Statistical analysis (Analysis of Variance-ANOVA) was performed on the two sets of data. The three years from 1988-90 were used to represent the F.E. pass rates without the use of mastery quizzes and 1991-93 were used to represent the scores with the use of mastery quizzes. Mixed results were obtained from this analysis. It indicated that mastery quizzes improved the scores in the dynamics and mechanics areas, which seem to be the most difficult courses of the three for ONU students. There seems to be no improvement in the statics area. It is felt that the reinforcing of concepts and problem solving by the repetitive taking of mastery quizzes is a help in the more difficult courses such as Dynamics and Mechanics of Materials.
Understanding the use and utility of anthropomorphic interface agents

We are exploring the use of anthropomorphic agents in user interfaces in order to understand their potential and utility. Initially, we are conducting a series of Wizard of Oz experiments in order to factor out competence as an issue, and to vary particular aspects of an anthropomorphic agent's presentation.
Radar tracking of multitarget complexes using Hough transforms

An important function for a fire control radar consists of the simultaneous tracking of multiple objects in a missile complex. A challenging tracking scenario is encountered when dense clusters of targets are viewed at large stand-off ranges. In this case, multiple target detections are found within a single radar beam. Because such highly populated complexes are not resolved in angle (azimuth, elevation), separation of the individual objects must rely on the use of wideband waveforms with good range resolution. A multi-object tracking algorithm suitable for real-time implementation has been designed to exploit range-only correlations. Good track initiation efficiency is achieved through the use of short radar observation times combined with applications of Hough transforms. Tracking filters are subsequently used to update all existing tracks with metrics and signature histories. A brief description of the algorithm is presented with focus on the specific tracking techniques appropriate for dense clusters of slowly separating objects on ballistic trajectories. The performance of the tracking algorithm has been evaluated and results are presented for several tracking strategies and different radar sampling rates.
Amelioration of aluminum toxicity to sorghum seedlings by chelating agents

Abstract At the pH levels found in acid soils (4.5 to 5.5), theoretical equilibrium models predict that Al will be complexed on a nearly one to one molar basis by NTA, EGTA. oxalate (OX) and citrate (CIT). Growth chamber experiments were initiated using solutions containing Al (0, 2, or 10 μM), Ca (400 μ.M). and a chelate (0 or 10 μM) growing sorghum [Sorghum bicolor (L.) Moench cv. AT×399 × RT×430] for four days following germination to test the equilibrium models. The pH and concentration of Al in the solutions were measured before and after each experiment. Plant root length and weight, and shoot weights were used as a bioassay for the uncomplexed, toxic Al. Root length showed the greatest response to aluminum and chelate treatments, although root weight and shoot weight gave the same general results. Chelate effectiveness in reducing Al toxicity was NTA > OX = CIT > EGTA. The pH values were altered very little by NTA or EGTA and averaged 5.2 to 5.3; however, the pH was raised 0.2 to 0.9 units by OX an...
Doppler-limited spectrum and analysis of the 2ν1 + ν3 band of SF6

Abstract The Doppler-limited spectrum of the 2ν1 + ν3 band of SF6 was recorded at 160 and 295 K using a tunable laser difference-frequency spectrometer. The lower temperature eliminates complications from hot bands and reduces the Doppler width, thereby enhancing the resolution and ground-state intensities. An analysis of the band based on an isolated l = 1 F1u mode yields rotational constants in good agreement with those predicted from the ν1 and ν3 fundamentals. Small perturbations are observed indicating resonant crossings with nearby vibrations. The X11 anharmonic constant is obtained from the band center and previous measurements of ν1, ν3 and ν1 + ν3; this is the final parameter needed to calculate the entire mν1 + nν3 combination ladder.
A comparison of microcode, assembly code, and high-level languages on the VAX-11 and RISC I

This paper compares the performance of three implementations of simplified pattern matching instruction. The fastest version was microprogrammed on a VAX-11/750, the next fastest was written for a Reduced Instruction Set. Computer (RISC I) developed at Berkeley, and the slowest was pro grammed on the VAX. The paper presents execution times for the microcode and for high-level language and machine language versions of the instruction.
Presidential Popularity and Presidential Elections: An Update and Extension

THIS paper updates and extends findings reported by Sigelman (1979), who discovered, contrary to earlier indications (Mueller, 1973), that the outcomes of presidential elections can be predicted with some accuracy on the basis of the president's rating in the final preelection popularity poll. The 1980 election provides an additional case to work with-the eighth time an incumbent president has sought reelection since 1938, when the Gallup presidential popularity question was first asked-and it is of obvious interest to see how closely this most recent case fits into the pattern established earlier. We also bring three previously ignored cases (the 1952, 1960, and 1968 elections) into the analysis by shifting the dependent variable from votes for the incumbent president to votes for the candidate of the incumbent president's party. This substitution is based on indications that presidential popularity has a powerful carryover effect on the outcome of midterm congressional elections (Tufte, 1975). If congressmen of the president's party are held responsible for the incumbent's performance, can we afford to overlook the possibility that the presidential candidate of the president's party is also judged accordingly?