cssi/SciSciGPT-SciSciNet huggingface dataset:
Synthesis of metal nanoclusters within microphase-separated diblock copolymers: ICP-AES analysis of metal ion uptake

Abstract The rate and extent of aqueous metal ion transport (Ag+, Au+3, Cu+2, Eu+2, Eu+3, Fe+2, Fe+3, Gd+3, Ni+2, Pd+2, Pt+2, and Pt+4) into microphase-separated block copolymers of methyl-tetracyclododecene (MTD) and 2-norbornene-5,6,-dicar☐ylic acid (NORCOOH) was monitored using inductively coupled plasma atomic emission spectroscopy. Continuous interconnected polyNORCOOH domains were found to be necessary for metal ion uptake. The metal-bound car☐ylate ions in the polyNORCOOH domains can be re-protonated by hydrogen reduction, rendering them active for further participation in metal binding. Following reduction, metal nanocluster-containing films were characterized using wide-angle X-ray scattering, infrared spectroscopy, and ultraviolet-visible spectroscopy.
A spot price based control mechanism for electric utility systems with small power producing facilities

A spot price determination procedure is presented in the context of a small power producing facility (SPPF) control mechanism for utilities under the provisions of the Public Utility Regulatory Policies Act (PURPA). Under the stipulations of PURPA, local utilities must offer to purchase all available excess electric energy at fair market prices from SPPFs which meet the legislative requirements. For a given set of spot prices, and SPPF may optimize its operational schedule in order to minimize its operational costs. Conversely, the utility may establish spot prices which will induce SPPF schedules that reduce its own generation costs. In particular, the utility may offer incentive purchasing spot prices that encourage additional SPPF generation during specific time intervals while respecting regulatory and contractual requirements. The proposed spot price determination procedure utilizes an SPPF comprehensive model, which includes the major electrical and thermal operations of a cogeneration facility. >
Region-based supine-prone correspondence for the reduction of false-positive CAD polyp candidates in CT colonography.

Region-based supine-prone correspondence for the reduction of false-positive CAD polyp candidates in CT colonography
Texture Laciness: The Texture Equivalent of Transparency?

Displays with overlapping squares of different textures were produced. In some texture combinations, the overlapping area appears to be a new texture. In other combinations, however, one texture is seen through the other as if it were inscribed on a transparent sheet and held in front of the other. This phenomenon can be called texture laciness. It is claimed that texture laciness is important because in the natural world we frequently encounter overlapping textures that we perceive as separate. In examining the conditions that lead to texture laciness, it was found that (1) laciness occurs more strongly with decreasing similarity between elements of two textures, (2) when the elements of the two textures are the same, the overlapped area tends to appear as a new texture, and (3) the physical overlapping of the individual elements of two textures hinders texture decomposition, irrespective of relative positioning. It is suggested that the textures inducing laciness may be processed as surfaces rather than...
Pressure Measurements for Translating Hydrostatic Thrust Bearings

AbstractThe objective of this study is to take insitu measurement of the pressure profile that exists between a sliding thrust bearing and a stationary thrust surface. Using a two-dimensional model of the bearing and the classical one-dimensional Reynolds equation, the experimental results are explained and the minimum fluid film thickness and the tilt angle of the bearing are numerically determined. In this work, it is shown that the bearings tilt into the leading edge of the bearing and that the minimum fluid-film thickness at the leading edge of the bearing is on the order of the surface roughness. This work provides fundamental insight into the problem of metal-to-metal contact for thrust bearings.
A Model for Studying R&D–Marketing Interface in the Product Innovation Process:

It is proposed that a firm's strategy and how it perceives environmental uncertainty can influence the need for R&D–marketing integration. Factors related to organizational design and senior manage...
Short-term speculators and the puzzling behaviour of exchange rates

Abstract This paper shows that rational short-term speculative activity transforms exchange rates' response to shocks. Transitory shocks will have a permanent impact on exchange rates when such speculators are active, and the impact of shocks will be smoothed. The model may help explain the observed extended response of exchange rates to sterilized intervention. Further, the model suggests that exchange rate fundamentals may be properly identified even when those variables fail to forecast better than a random walk. Finally, the model could help explain why exchange rates closely resemble a random walk while most fundamentals do not follow such a process.
Benzodiazepine associated reversal of the effects of experimental sleep fragmentation

Thirty-six healthy young men and women (age 21–35) received 0.00, 0.25, or 0.50 mg triazolam (n = 12 per group) while undergoing experimental sleep fragmentation in which sleep was disrupted by presenting tones to produce brief EEG arousals (without shortening sleep time). The following day subjects' daytime function was assessed using the Multiple Sleep Latency Test and a divided attention performance task. The fragmentation of sleep produced significant disruption of nocturnal sleep and it reduced daytime alertness. Both active drug doses, relative to placebo, reversed the experimentally produced sleep disturbance and they restored daytime alertness.
A novel platform for in situ investigation of cells and tissues under mechanical strain

The mechanical micro-environment influences cellular responses such as migration, proliferation, differentiation and apoptosis. Cells are subjected to mechanical stretching in vivo, e.g., epithelial cells during embryogenesis. Current methodologies do not allow high-resolution in situ observation of cells and tissues under applied strain, which may reveal intracellular dynamics and the origin of cell mechanosensitivity. A novel polydimethylsiloxane substrate was developed, capable of applying tensile and compressive strain (up to 45%) to cells and tissues while allowing in situ observation with high-resolution optics. The strain field of the substrate was characterized experimentally using digital image correlation, and the deformation was modeled by the finite element method, using a Mooney-Rivlin hyperelastic constitutive relation. The substrate strain was found to be uniform for >95% of the substrate area. As a demonstration of the system, mechanical strain was applied to single fibroblasts transfected with GFP-actin and whole transgenic Drosophila embryos expressing GFP in all neurons during live imaging. Three observations of biological responses due to applied strain are reported: (1) dynamic rotation of intact actin stress fibers in fibroblasts; (2) lamellipodia activity and actin polymerization in fibroblasts; (3) active axonal contraction in Drosophila embryo motor neurons. The novel platform may serve as an important tool in studying the mechanoresponse of cells and tissues, including whole embryos.
Note on restoring manifest rotational symmetry in hyperfine and fine structure in light-front QED.

We study the part of the renormalized, cutoff QED light-front Hamiltonian that does not change particle number. The Hamiltonian contains interactions that must be treated in second-order bound-state perturbation theory to obtain hyperfine structure. We show that a simple unitary transformation leads directly to the familiar Breit-Fermi spin-spin and tensor interactions, which can be treated in degenerate first-order bound-state perturbation theory, thus simplifying analytic light-front QED calculations. To the order in momenta we need to consider, this transformation is equivalent to a Melosh rotation. We also study how the similarity transformation affects spin-orbit interactions. {copyright} {ital 1996 The American Physical Society.}
Work distribution of an expanding gas and transverse energy production in relativistic heavy ion collisions

Abstract The work distribution of an expanding extreme relativistic gas is shown to be a gamma distribution with a different shape parameter as compared with its non-relativistic counterpart. This implies that the shape of the transverse energy distribution in relativistic heavy ion collisions depends on the particle contents during the evolution of the hot and dense matter. Therefore, transverse energy fluctuations provide additional insights into the Quark–Gluon Plasma produced in these collisions.
Safety of viral DNA in biological products.

Abstract Data from studies of the infectivity of dNA injected directly into laboratory animals are used to estimate the potential infectivity risk of residual DNA in biological products. The potential for some novel products to contain infectious quantities of residual cellular DNA is discussed, and further study of this subject is suggested.
Single base pair change in the long‐range Sonic hedgehog limb‐specific enhancer is a genetic basis for preaxial polydactyly

In most instances of preaxial polydactyly (PPD), Sonic Hedgehog (Shh), an essential limb patterning signal, is ectopically expressed in an anterior region of the developing limb in addition to the normal posterior domain. It is thought that this anterior Shh expression leads directly to the development of the extra digits. Recent reports have identified a conserved limb-specific Shh enhancer ∼1 megabase upstream of the Shh transcription initiation site, and individual base pair changes within this region are associated with PPD. We report here that a single base pair change within this enhancer is sufficient to drive β-galactosidase expression in both anterior and posterior limb domains, similar to Shh expression in animal PPD models, whereas a wild-type construct is expressed only in the posterior limb, similar to Shh expression in normal embryos. These findings provide the first direct evidence that a single base pair change within the limb-specific Shh enhancer acts as a genetic basis for PPD. Developmental Dynamics 232:345–348, 2005. © 2005 Wiley-Liss, Inc.
Diamond-nickel interfaces: calculation of the electronic and atomic structure and Schottky barriers

Abstract We report the results of first-principles local-density functional calculations of abrupt diamond-nickel interfaces of four types: for both (001) and (111) interfaces we considered atomic geometries with the first nickel layer either in (i) a “tetrahedral” orientation providing a semiconductor-like coordination of the carbon atom at the interface, or (ii) an “in-hollow” orientation providing a more metallic-like coordination. The interlayer distances were optimized in each case. We find that the in-hollow geometries lead to a (hole) Schottky barrier height of 0.9 eV while the tetrahedral arrangements lead to ohmic interfaces (barrier height less than 0.1 eV). The tetrahedral arrangements are favored energetically; analysis of the electronic structure suggests that both the barrier heights and the stabilization energy are related to interface states which retain some diamond dangling-bond character.
Comparison of finite difference‐ and pseudospectral methods for convective flow over a sphere

For modeling convective flows over a sphere or within a spherical shell, pseudospectral (PS) methods are in general far more cost-effective than finite difference- (or finite element) methods. This study confirms this, and proceeds by comparing a Fourier-PS implementation (based on a longitude-latitude grid) with one using spherical harmonics. For similar resolutions, these are found to be of similar accuracy. However, the former is computationally about ten times faster.
Responding to calls for change in high school mathematics: Implications for collegiate mathematics

This article briefly discusses the recent history of mathematics reform in high school, and then reports on research evidence for one of the new NSF-funded curriculum projects, the Core-Plus Mathematics Project (CPMP). Implications for collegiate mathematics are also discussed. A summary of the results of several studies using a range of achievement measures comparing CPMP students to comparable students in more conventional high school mathematics curricula is given on page 114: “Thus, research to date indicates that CPMP students perform particularly well [and better than the comparison students] on measures of conceptual understanding, interpretation of mathematical representations and calculations, and problem solving in applied contexts. Their performance is also relatively strong in content areas like statistics and probability that are emphasized in the curriculum. On measures of algebraic manipulative skills, CPMP students usually, but not always, score as well as students in more conventional curricula.” A study of student performance on a mathematics placement test used at a major university is summarized on page 116: “On the algebra subtest, the means of the [conventional] precalculus students and the CPMP Course 4 students were virtually identical. On the intermediate algebra subtest, the mean of the precalculus group was greater than that of the Course 4 group. The only statistically significant difference in means was on the calculus readiness subtest (t = 4.93, p < 0.01). That difference favored the CPMP students.” Responding to Calls for Change in High School Mathematics: Implications for Collegiate Mathematics Harold L. Schoen and Christian R. Hirsch
Mercury crater statistics from MESSENGER flybys: Implications for stratigraphy and resurfacing history

Abstract The primary crater population on Mercury has been modified by volcanism and secondary craters. Two phases of volcanism are recognized. One volcanic episode that produced widespread intercrater plains occurred during the period of the Late Heavy Bombardment and markedly altered the surface in many areas. The second episode is typified by the smooth plains interior and exterior to the Caloris basin, both of which have a different crater size-frequency distribution than the intercrater plains, consistent with a cratering record dominated by a younger population of impactors. These two phases may have overlapped as parts of a continuous period of volcanism during which the volcanic flux tended to decrease with time. The youngest age of smooth plains volcanism cannot yet be determined, but at least small expanses of plains are substantially younger than the plains associated with the Caloris basin. The spatial and temporal variations of volcanic resurfacing events can be used to reconstruct Mercury's geologic history from images and compositional and topographic data to be acquired during the orbital phase of the MESSENGER mission.
Symbol versus substance in legislative activity: The case of illegal immigration

Although much research indicates that the United States benefits from illegal immigration, public opinion polls indicate the public wants immigration law enforced.1 If there are parties who are adversely affected by the restriction of illegals, and those effects are sufficiently concentrated that it pays the parties to organize and lobby, the results of this paper should be expected. Politicians have incentives to demonstrate a restrictive stance on illegal immigration to appease general public opinion. That is why bills have been repeatedly proposed in spite of the long history of legislative failure of such attempts. Coincident with proposed restrictions, the growth of the funding for the enforcement agency declines. Such de jure concern but de facto neglect is the way a politician could rationally deal with such conflicting demands. One would expect such behavior to be manifest in political realms other than that of illegal immigration. Prostitution and drinking laws are obvious examples.
Effect of cromakalim on micturition function in rats.

Although many studies investigating the effect of cromakalim on bladder contractility exist, thus far, there are no published studies investigating its effect on micturition function in conscious rats. We measured the effect of cromakalim i.v. on urine output, frequency, volume of each micturition, and blood pressure in saline-diuresed and non-diuresed rats. In saline-diuresed rats cromakalim produced significant decreases in urine output (0.1 mg/kg, 32%; 0.3 mg/kg, 46%; 1.0 mg/kg, 68%) and average frequency (0.1 mg/kg, 36%; 0.3 mg/kg, 51%; 1.0 mg/kg, 70%) in the first 3 hours. At 3–6 hours after administration of cromakalim there were rebound increases in both urine output (0.1 mg/kg, 290%; 0.3 mg/kg, 373%; 1.0 mg/kg, 538%), and frequency (0.1 mg/kg, 147%; 0.3 mg/kg, 181%; 1.0 mg/kg, 314%) and by 6–12 hours the effects of cromakalim on micturition function were gone. Mean arterial pressure dropped to 50% of control immediately after cromakalim administration in saline-diuresed rats and began to return to control levels after 3 hours. Cromakalim produced similar results in non-diuresed rats. The decrease in urine output 0–3 hours after cromakalim administration may have been a consequence of cromakalim's profound decrease in blood pressure that occurred during that time. © 1993 Wiley-Liss, Inc.
Inner shell satellite lines in CO(2) laser-produced plasmas.

Irradiation of titanium slabs with 250 J CO/sub 2/ laser 1-nsec pulses gives K/sub ..cap alpha../ satellites shifted by ionization of different degrees from different spatial regions. (AIP)
Comparative optical observations of prebreakdown events in n-Hexane

Abstract An optical study has been made of electrically induced disturbances in n-hexane. A high speed image converter camera was used that provided both sub-microsecond temporal resolution and a complete record of the events that terminate breakdown. In order to generate a benchmark for this comparative study, the high speed camera was first used with conventional shadowgraph optics. The time resolved records were seen to support earlier findings. Such findings, however, are subject to the uncertainties that are rooted in the sensitivity of the shadowgraph technique. Images are generated by an integration of all perturbations over the optical path. The net deflection that generates the recorded image may thus be produced by a range of events. Scattered light photography was used to augment and clarify the information gathered from the shadowgraph images, it being particularly sensitive to localized interfacial phenomena associated with phase changes in the test fluid. To furnish the experimental data, the electrode gap was illuminated off axis such that the high speed camera could record the light that was scattered by prebreakdown streamers. On comparison with the shadowgraph recordings, a strong image correlation was apparent for either positive or negative point polarity.
The pressure field around a two-dimensional gas bubble in a fluidized bed

Abstract Measurements of the entire pressure field around a two-dimensional bubble rising in an incipiently fluidized bed are reported. Above the center of pressure line, the field is Laplacian and reasonably well described by Davidson's theory. The pressure wake is closed. It extends for 12 bubble radii below the stagnation point and four radii on either side of the vertical axis of symmetry.
Thin Shell, Segmented X-Ray Mirrors

Thin foil mirrors were introduced as a means of achieving high throughput in an X-ray astronomical imaging system in applications for which high angular resolution were not necessary. Since their introduction, their high filling factor, modest mass, relative ease of construction, and modest cost have led to their use in numerous X-ray observatories, including the Broad Band X-ray Telescope, ASCA, and Suzaku. The introduction of key innovations, including epoxy replicated surfaces, multilayer coatings, and glass mirror substrates, has led to performance improvements, and in their becoming widely used for X-ray astronomical imaging at energies above 10 keV. The use of glass substrates has also led to substantial improvement in angular resolution, and thus their incorporation into the NASA concept for the International X-ray Observatory with a planned 3 in diameter aperture. This paper traces the development of foil mirrors from their inception in the 1970's through their current and anticipated future applications.
'Bridging hydroxide effect' on μ-carboxylato coordination and electrochemical potentials of bimetallic centers: Mn2(II,II) and Mn2(III,III) complexes as functional models of dimanganese catalases

Synthesis, solution structures, and electrochemistry of several dinuclear Mn2(II,II) complexes (1-4) and Mn2(III,III) complexes (6 and 8), derived from a functional catalase mimic [(L1,2)Mn2(II,II)(mu 13-O2CCH3)]2+ (1) are described that enable testing of the role of intramolecular hydroxide ligands on the redox properties. Addition of 1 equiv of hydroxide to 1 or 3 forms [(L1,2)Mn2(II,II)(mu 13-O2CCH3)(mu- OH)]+ (7A or 7B, respectively), possessing two six-coordinate Mn(II) ions bridged by hydroxide and acetato ligands. Two-electron oxidation of 7 with O2 occurs by forming [(L1,2)Mn2(III,III)(mu 1,3-O2CCH3)(mu-OH)]3+ (8) and H2O2 with no ligand rearrangements in methanol. Reaction of 8 with 2-3 equiv hydroxide forms [(L1,2)Mn2(III,III)(mu-O)(OH)(O2CCH3)]+ in which deprotonation of mu-OH- to yield mu-O2- favors subsequent addition of a terminal hydroxide ligand, accommodated by a bridging-to-terminal "carboxylate-shift". Preservation of six-coordinate Mn(II) ions throughout all hydroxide-induced transformations is observed, including oxidation by O2. Cyclic voltammetry reveals that addition of mu-OH- converts the two-electron redox couple II,II/III,III for complexes 1-4 to sequential one-electron couples at lower reduction potentials, yielding substantial stabilization of the II,III and III,III oxidation states by delta E = 440 and 730 mV, respectively. Binding of a second OH- to 7A or 7B forms (L1,2)Mn2(II,II)(mu 13-O2CCH3)(OH)2, containing two six-coordinate Mn(II) ions with two terminal hydroxides and a mu 1,3-bridging acetato. Electrochemistry reveals that displacement of the bridging hydroxide to a terminal site upon addition of the second OH- restores a two-electron redox couple II,II/III,III but now at a higher reduction potential with considerable loss of the electrochemical stabilization energy provided by the mu-OH- (delta E = 250 and 350 mV loss for Mn2(II,II) and Mn2(III,III), (respectively). These results indicate a considerably stronger influence of bridging vs terminal hydroxide ligands in stabilizing the higher oxidation states and separating the one-electron redox potentials of bimetallic centers. By contrast, in the absence of mu-OH- bridges the longer separation with the mu 1,3-carboxylato bridge in dimanganese(II,II) complexes leads to nearly complete uncoupling of the Mn(II) oxidation potentials, thus yielding a two-electron redox transition to (III,III). We hypothesize that this "bridging hydroxide effect" may be due to both greater screening of the repulsive intermetallic electric potential energy and increased resonance stabilization of the mixed-valence (II,III) oxidation state by charge delocalization . These data provide a physicochemical basis for interpretation of the catalase activity of these complexes and of dimanganese catalase enzymes (see the following manuscript).
Isolation of a fragment (C3a) of the third component of human complement containing anaphylatoxin and chemotactic activity and description of an anaphylatoxin inactivator of human serum.

A small fragment of C3, called C3a, which has smooth muscle contracting activity, was isolated by three different methods. At pH 8.6, C3a behaved as cation, and using the Archibald method, its mol wt was determined to be 7000. A specific antiserum to C3a showed the fragment to be antigenically distinct from the rest of the C3 molecule, i.e., the C3b portion. The same antiserum and an anti-whole C3 were able to inhibit the biologic activity of C3a. In addition to anaphylatoxin activity, leukocyte chemotactic activity was shown to reside in C3a. Treatment with trypsin caused the cationic fragment to become anionic and abolished the anaphylatoxin but not the chemotactic activity. C3a fragments with identical biologic activity and comparable cationic properties, as determined by acid disc electrophoresis, were obtained by treatment of C3 with C3 convertase, C3 inactivator complex, trypsin, and plasmin. Thrombin produced a similar C3 fragment which was inactive. It was concluded that C3a corresponds to an unusually basic portion of C3 which may be liberated by attack of a variety of enzymes on a highly susceptible region of the native C3 molecule. C3b was cleaved by trypsin and less efficiently by thrombin or plasmin into two antigenically distinct pieces: the larger C3c fragment corresponding to beta(1A) and the smaller C3d fragment to alpha(2D) of aged serum. The c- and the d-fragments were separated and characterized. Isolated C3a rapidly lost its anaphylatoxin activity when treated with small amounts of a partially purified, thermolabile 10S alpha-pseudoglobulin of human serum. The conditions of inactivation suggested an enzymatic reaction. The anaphylatoxin inactivator also destroyed the activity of C5-derived anaphylatoxin and of lysyl bradykinin.
A Note on Lagrange's Theorem.

(1983). A Note on Lagrange's Theorem. The American Mathematical Monthly: Vol. 90, No. 2, pp. 132-133.
Eclipse vs. Mozilla: A Comparison of Two Large-Scale Open Source Problem Report Repositories

Bug tracking systems play an important role in the development and maintenance of large-scale software systems. Having access to open source bug tracking systems has allowed researchers to take advantage of rich datasets and propose solutions to manage duplicate report classification, developer assignment and quality assessment. In spite of research advances, our understanding of the content of these repositories remains limited, primarily because of their size. In many cases, researchers analyze small portions of datasets thus limiting the understanding of the dynamics of problem reporting. The objective of this study is to explore the properties of two large-scale open source problem report repositories. The Eclipse dataset, at the time of download, consisted of 363; 770 reports spanning 11+ years, whereas Mozilla contained 699; 085 reports spanning 14+ years.Our research examines the evolution of datasets over time by analyzing the changes in the repository and the profiles of users who submit problem reports. We provide quantitative evidence on how submitter's maturity reduces the propensity to submit poor quality, insignificant or duplicate reports. We show that a diverse user base, characteristic of Mozilla, creates challenges for the development team as they spend more time triaging, rather than fixing, issues. Finally, we provide the research community with a series of observations and suggestions on how to study large-scale problem repositories.
Phase-locking of artificial neural oscillators can perform dynamic role binding and inferencing

Summary form only given, as follows. Previously, the authors have described a localist spreading-activation model, ROBIN (role binding and inferencing network), which uses stable, uniquely-identifying activation patterns, called signatures, to represent the dynamic role bindings critical for high-level natural language understanding tasks. A unique signature activation on a node represents a role binding, which can be propagated as activation across long paths of nodes to allow inferencing. The authors illustrate that metastable artificial neural oscillators can be used to implement signature activations. In this novel model, groups of relaxation oscillators with unique patterns of natural oscillation frequencies serve as signatures. Phase-locking of gated, interacting oscillators allows the signatures to be propagated dynamically across the network for inferencing. Paths of synchronized oscillators form a chain of role bindings representing the model's plan/goal analysis of its natural language input. >
Two interacting magnetic impurities in a metal: Renormalization-group treatment of a simple model.

The single-impurity Kondo problem can be mapped onto a resonant level of spinless fermions with an attractive interaction between the localized and extended states. We consider two such impurities at sites {bold R}{sub 1} and {bold R}{sub 2} interacting with each other via a hopping matrix element {ital t} and an interaction {ital G} between the localized fermions. The interactions {ital t} and {ital G} resemble the Ruderman-Kittel-Kasuya-Yosida interaction between the impurities. The physics of the model is most conveniently discussed in terms of even- and odd-parity states with respect to the point 1/2({bold R}{sub 1}+{bold R}{sub 2}). We obtain the {ital k}-space renormalization-group equations for the model, which are integrated and discussed in terms of Ward cancellations. Finally, approximate expressions for the static and dynamical susceptibilities for the response to a homogeneous and staggered field are obtained. No dramatic anomalies are found, probably as a consequence of the broken spin-rotational invariance of the model.
Perceptions of Price Unfairness: Antecedents and Consequences:

Using two studies, the author examines the influence of the inferred motive for a firm's price increase on perceptions of price unfairness. Prior to the research presented here, the only establishe...
Identification and characterization of c-erbB-2 proteins in serum, breast tumor tissue, and SK-BR-3 cell line.

We have identified and characterized c-erbB-2 protein molecules in sera from patients with carcinomas, in both cytosol and cell membrane extract from breast tumor tissue and in both the culture medium and cell extract of the SK-BR-3 cell line. These proteins were characterized by various chromatographic techniques and identified by the use of two immunoassays; one measures both the c-erbB-2 oncoprotein (p 185) and its ectodomain (p 120), and the other in-house assay reacts specifically for p 185. We found that the majority of the immunoreactivity detected in the serum, tumor tissue cytosol, and conditioned cell medium was derived from the ectodomain molecule (p 120) of the c-erbB-2 oncoprotein (p 185), whereas only p185 was detected in the extracts from cell membrane of both tumor tissue and the SK-BR-3 cell line. The ectodomain molecules (p 120) found in the serum, cytosol, and cell medium were very similar in terms of molecular size and charge property. The molecular weight was determined to be 120 kDa by the size exclusion HPLC method. Both p 120 and p 185 are glycoproteins and were retained by the ConA Sepharose column. Both molecules are also heterogeneous in charge and multiple peaks could be identified in the elution profiles of anion exchange HPLC and chromatofocusing. This information should not only facilitate the isolation of these molecules, but also improve preparation of specific antibodies, preparation of calibrators, and development of improved assays for these proteins.©1995 wiley-Liss, inc.
Evolution Can Favor Antagonistic Epistasis

The accumulation of deleterious mutations plays a major role in evolution, and key to this are the interactions between their fitness effects, known as epistasis. Whether mutations tend to interact synergistically (with multiple mutations being more deleterious than would be expected from their individual fitness effects) or antagonistically is important for a variety of evolutionary questions, particularly the evolution of sex. Unfortunately, the experimental evidence on the prevalence and strength of epistasis is mixed and inconclusive. Here we study theoretically whether synergistic or antagonistic epistasis is likely to be favored by evolution and by how much. We find that in the presence of recombination, evolution favors less synergistic or more antagonistic epistasis whenever mutations that change the epistasis in this direction are possible. This is because evolution favors increased buffering against the effects of deleterious mutations. This suggests that we should not expect synergistic epistasis to be widespread in nature and hence that the mutational deterministic hypothesis for the advantage of sex may not apply widely.
Principal component filter banks for optimal multiresolution analysis

An important issue in multiresolution analysis is that of optimal basis selection. An optimal P-band perfect reconstruction filter bank (PRFB) is derived in this paper, which minimizes the approximation error (in the mean-square sense) between the original signal and its low-resolution version. The resulting PRFB decomposes the input signal into uncorrelated, low-resolution principal components with decreasing variance. Optimality issues are further analyzed in the special case of stationary and cyclostationary processes. By exploiting the connection between discrete-time filter banks and continuous wavelets, an optimal multiresolution decomposition of L/sub 2/(R) is obtained. Analogous results are also derived for deterministic signals. Some illustrative examples and simulations are presented. >
New steroids for IBD: progress report

Corticosteroids remain the benchmark therapy for moderate to severe ulcerative colitis and Crohn's disease but are problematic due to unacceptable side effects and lack of maintenance benefits. Developments in corticosteroid chemistry have led to a series of anti-inflammatory glucocorticoids with enhanced topical (mucosal) potency and less systemic activity1–4 such as prednisolone-metasulphobenzoate, beclomethasone diproprionate, tixocortol pivalate, fluticasone, and budesonide. To date, budesonide has been the primary alternative compound to hydrocortisone and prednisolone marketed in many parts of the globe and, most recently, has been introduced in an ileal release formulation in the USA.3,5 For many years, topical (rectal) steroids have had a primary role in the treatment of distal ulcerative colitis6,7 and have been incorporated as an adjunctive treatment to parenteral steroids for treatment of severe colitis.8,9 The relative potency of rectally applied steroids is increased compared with a similar systemic exposure, providing evidence that the mucosal …
Mathematical theory of partial correctness

In this work we show that it is possible to express most properties regularly observed in algorithms in terms of 'partial correctness' (i.e., the property that the final results of the algorithm, if any, satisfy some given input-output relation). This result is of special interest since 'partial correctness' has already been formulated in predicate calculus and in partial function logic for many classes of algorithms.
Gastric Tonometry: A New Monitoring Modality in the Intensive Care Unit

In many critically ill patients, systemic measures of hemodynamic and O2 transport variables may not be sufficiently sensitive to portray the complex interaction between energy requirements and energy supply in all tissues. Gastric or intestinal tonometry has been proposed as a relative noninvasive index of the adequacy of aerobic metabolism in the gut mucosa, a tissue that is particularly vulnerable to alterations in perfusion and oxygenation. The gut mucosa lacks some of the microvascular control mechanisms that allow other tissues, such as the heart, skeletal muscle, and the brain, to increase tissue perfusion during times of stress, and, just like the canary, it will display metabolic changes indicative of dysoxia earlier than those more "vital" tissues. The tonometric measurement of mucosal PCO2 rests on the premise that equilibrium exists between mucosal and luminal PCO2. Increases in mucosal PCO2, or conversely, decreases in mucosal pH (pHi), are associated with the development of intestinal mucosa ischemia. The clinical utility of pHi to detect intestinal mucosal ischemia has been demonstrated in patients undergoing abdominal aortic surgery. Further, a low gastric mucosal pHi on admission to the ICU appears to be predictive of mortality and pHi-guided resuscitation may improve outcome in a subpopulation of patients admitted to the ICU with normal pHi, perhaps by preventing splanchnic ischemia and the development of a systemic oxygen deficit.
The effects of geometry and stability of solid-state nanopores on detecting single DNA molecules

In this work we use a combination of 3D-TEM tomography, energy filtered TEM, single molecule DNA translocation experiments, and numerical modeling to show a more precise relationship between nanopore shape and ionic conductance and show that changes in geometry while in solution can account for most deviations between predicted and measured conductance. We compare the structural stability of ion beam sculpted (IBS), IBS-annealed, and TEM drilled nanopores. We demonstrate that annealing can significantly improve the stability of IBS made pores. Furthermore, the methods developed in this work can be used to predict pore conductance and current drop amplitudes of DNA translocation events for a wide variety of pore geometries. We discuss that chemical dissolution is one mechanism of the geometry change for SiNx nanopores and show that small modification in fabrication procedure can significantly increase the stability of IBS nanopores.
Small molecule interactions were central to the origin of life.

ABSTRACT Many scientists believe life began with the spontaneous formation of a replicator. This idea has been supported by “prebiotic” syntheses carried out by chemists using modern apparatus and purified reagents. The probability that such reactions would take place spontaneously on the early Earth is minute. These points are illustrated here by considering the often cited oligomerization of activated RNA components by clay minerals. A more likely alternative for the origin of life is one in which a collection of small organic molecules multiply their numbers through catalyzed reaction cycles, driven by a flow of available free energy. Although a number of possible systems of this type have been discussed, no experimental demonstration has been made. The inclusion of a “driver” reaction, directly coupled to the energy source, may lead to a solution.
Murder and Medicine: The Lethality of Criminal Assault 1960-1999

Despite the proliferation of increasingly dangerous weapons and the very large increase in rates of serious criminal assault, since 1960, the lethality of such assault in the United States has drop...
Infectious and Pathogenic Forms of PrP

Prion diseases are transmitted by unconventional infectious agents (prions) generated by the conformational conversion of PrPC, a normal, cell-surface glycoprotein, into PrPSc, a misfolded isoform that propagates itself by a self-templating mechanism. Although PrPSc has commonly been considered the primary neurotoxic species in prion diseases, strong experimental evidence now challenges this dogma and suggests that alternative pathogenic forms of PrP may operate by altering the normal physiological function of PrPC. In the past 15 years, we and others have generated cellular and animal models for studying prion diseases that shed light on important aspects of PrP infectivity, aggregation, and toxicity. In this chapter, we review some of these results and discuss our current understanding of the molecular processes responsible for the formation of aberrant forms of PrP and their acquisition of infectious and toxic properties.
Decision making involving imperfect knowledge

The human capability of making complex decisions is one of the most fascinating facets of human intelligence, especially if vague, judgemental, default, or uncertain knowledge is involved. This paper focuses on the automation of this capability. It advocates treating rule-based decision making as a problem of evidence combination: Rules are considered to provide evidence for or against a certain decision; after the rules have been processed, the evidence associated with the individual decisions is combined and the best decision is selected. Advantages and problems of this approach are discussed and experiences the authors had in applying this approach in a Computer Bridge project are surveyed. Finally, a language construct, called a decision block, that facilitates the automation of rule-based decision making involving imperfect knowledge is introduced. The benefits of decision blocks for writing complex decision support systems are evaluated, and their integration with a rule-based forward chaining language is discussed. >
Developing a Combustor Simulator for Investigating High Pressure Turbine Aerodynamics and Heat Transfer

Within a gas turbine engine, the high pressure turbine vanes are subjected to very harsh conditions from the highly turbulent and hot gases exiting the combustor. The temperature and pressure fields exiting the combustor dictate the heat transfer and aero losses that occur in the turbine passages. To better understand these effects, the goal of this work is to develop an adjustable combustor exit profile simulator for the Turbine Research Facility (TRF) at the Air Force Research Laboratory (AFRL). The TRF is a high temperature, high pressure, short duration blow-down test facility that is capable of matching several aerodynamic and thermal non-dimensional engine parameters including Reynolds number, Mach number, pressure ratio, corrected mass flow, gas-to-metal temperature ratio, and corrected speed. The research objective was to design, install, and verify a non-reacting simulator device that provides representative combustor exit total pressure and temperature profiles to the inlet of the TRF turbine test section. This required the upstream section of the facility to be redesigned into multiple concentric annuli that serve the purpose of injecting high momentum dilution jets and low momentum film cooling jets into a central annular chamber, similar to a turbine engine combustor. The design of the simulator allows for variations in injection levels to generate turbulence and pressure profiles. It also can vary the dilution and film cooling temperatures to create a variety of temperature profiles consistent with real combustors. To date, the design and construction of the simulator device has been completed. All of the hardware has been trial fitted and the flow control shutter systems have been successfully installed and tested. Currently, verification testing is being performed to investigate the impact of the generated temperature, pressure, and turbulence profiles on turbine heat transfer and secondary flow development. NOMENCLATURE A flow area or surface area cp specific heat D hole diameter G mass flow velocity, ff A m G &
Active vision for sociable robots

Ballard (1991) described the implications of having a visual system that could actively position the camera coordinates in response to physical stimuli. In humanoid robotic systems, or in any animate vision system that interacts with people, social dynamics provide additional levels of constraint and additional opportunities for processing economy. In this paper, we describe an integrated visual-motor system that was implemented on a humanoid robot to negotiate the robot's physical constraints, the perceptual needs of the robot's behavioral and motivational systems, and the social implications of the motor acts.
Conceptual model for predicting mudstone dimensions in sandy braided-river reservoirs

Sandy braided-river deposits with high net-to-gross sand ratios are commonly attractive reservoirs, yet internal lithologic heterogeneities, particularly the presence of low-permeability mudstone deposits, significantly complicate the development of such units. Previous work has focused on measuring the scale and distribution of mudstone deposits in outcrop analogs; however, because of extreme differences in scale, discharge, sediment load, and geologic history, the results of these studies are difficult to apply with confidence to a wide range of sandy braided-river reservoirs. Based on work in modern braided rivers (Niobrara and North Loup rivers, Nebraska) and ancient braided-river deposits (Kayenta Formation, Jurassic and lower Castlegate Sandstone, Cretaceous, Colorado and Utah), we propose a process-based conceptual model for understanding and predicting the distribution and geometries of fine-grained (mudstone) intervals in sandy braided-river deposits. This model is an idealized channel-fill unit composed of five fine-grained lithofacies (mud plugs, channel-lining muds, interbar muds, inclined heterolithic strata, and flood-plain and overbank material) that scale proportional to channel-thread dimensions, including depth, cross-stream width, and downstream length. Each lithofacies is found in a different region in an individual channel fill, and lithofacies found low in a fill may be preferentially preserved. Within braided-river deposits, extrinsic depositional factors, such as aggradation rate, available accommodation, and avulsion-return time, produce different channel-fill stacking arrangements, preserving fine-grained lithofacies in different, relative proportions. This conceptual model provides an approach to reservoir characterization that deductively constrains the dimensions and distribution of fine-grained barriers to flow and may help account for the inherent variability in sandy braided-river deposits.
Locating and bypassing routing holes in sensor networks

Many algorithms for routing in sensor networks exploit greedy forwarding strategies to get packets to their destinations. We study a fundamental difficulty such strategies face: the "local minimum phenomena" that can cause packets to get stuck. We give a definition of stuck nodes where packets may get stuck in greedy multi-hop forwarding, and develop a local rule, the TENT rule, for each node in the network to test whether a packet can get stuck at that node. To help the packets get out of stuck nodes, we describe a distributed algorithm, BOUNDHOLE, to build routes around holes, which are connected regions of the network with boundaries consisting of all the stuck nodes. We show that these hole-surrounding routes can be used in many applications such as geographic routing, path migration, information storage mechanisms and identification of regions of interest.
Burst Mode Two-Way Ranging with Cramer-Rao Bound Noise Performance

This paper addresses estimating the distance between wireless nodes using a two-way ranging technique that approaches the Cramer-Rao Lower Bound (CRB) on ranging accuracy in a white noise environment. Standard two-way ranging methods do not achieve this bound because sampling artifacts limit resolution through range binning, so multiple measurements are combined to improve performance. Code modulus synchronization is presented as an alternative that approaches the CRB. The analytical results presented in this article are confirmed by implementing the technique on a prototype wireless system and measuring the performance in the presence of noise.
PPADS does not block contraction-induced prostaglandin E2 synthesis in cat skeletal muscle.

Pyridoxal-phosphate-6-azophenyl-2′-4-disulfonate (PPADS), a purinergic 2 (P2) receptor antagonist, has been shown to attenuate the exercise pressor reflex in cats. In vitro, however, PPADS has been...